diff --git "a/leetcode_free.json" "b/leetcode_free.json" deleted file mode 100644--- "a/leetcode_free.json" +++ /dev/null @@ -1,11567 +0,0 @@ -[ - { - "number": 1, - "question": "class Solution:\n def twoSum(self, nums: List[int], target: int) -> List[int]:\n\t\t\"\"\"\n\t\tGiven an array of integers nums and an integer target, return indices of the two numbers such that they add up to target.\n\t\tYou may assume that each input would have exactly one solution, and you may not use the same element twice.\n\t\tYou can return the answer in any order.\n\t\tExample 1:\n\t\tInput: nums = [2,7,11,15], target = 9\n\t\tOutput: [0,1]\n\t\tExplanation: Because nums[0] + nums[1] == 9, we return [0, 1].\n\t\tExample 2:\n\t\tInput: nums = [3,2,4], target = 6\n\t\tOutput: [1,2]\n\t\tExample 3:\n\t\tInput: nums = [3,3], target = 6\n\t\tOutput: [0,1]\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 2, - "question": "class Solution:\n def addTwoNumbers(self, l1: Optional[ListNode], l2: Optional[ListNode]) -> Optional[ListNode]:\n\t\t\"\"\"\n\t\tYou are given two non-empty linked lists representing two non-negative integers. The digits are stored in reverse order, and each of their nodes contains a single digit. Add the two numbers and return the sum as a linked list.\n\t\tYou may assume the two numbers do not contain any leading zero, except the number 0 itself.\n\t\tExample 1:\n\t\tInput: l1 = [2,4,3], l2 = [5,6,4]\n\t\tOutput: [7,0,8]\n\t\tExplanation: 342 + 465 = 807.\n\t\tExample 2:\n\t\tInput: l1 = [0], l2 = [0]\n\t\tOutput: [0]\n\t\tExample 3:\n\t\tInput: l1 = [9,9,9,9,9,9,9], l2 = [9,9,9,9]\n\t\tOutput: [8,9,9,9,0,0,0,1]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 3, - "question": "class Solution:\n def lengthOfLongestSubstring(self, s: str) -> int:\n\t\t\"\"\"\n\t\tGiven a string s, find the length of the longest substring without repeating characters.\n\t\tExample 1:\n\t\tInput: s = \"abcabcbb\"\n\t\tOutput: 3\n\t\tExplanation: The answer is \"abc\", with the length of 3.\n\t\tExample 2:\n\t\tInput: s = \"bbbbb\"\n\t\tOutput: 1\n\t\tExplanation: The answer is \"b\", with the length of 1.\n\t\tExample 3:\n\t\tInput: s = \"pwwkew\"\n\t\tOutput: 3\n\t\tExplanation: The answer is \"wke\", with the length of 3.\n\t\tNotice that the answer must be a substring, \"pwke\" is a subsequence and not a substring.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 4, - "question": "class Solution:\n def findMedianSortedArrays(self, nums1: List[int], nums2: List[int]) -> float:\n\t\t\"\"\"\n\t\tGiven two sorted arrays nums1 and nums2 of size m and n respectively, return the median of the two sorted arrays.\n\t\tThe overall run time complexity should be O(log (m+n)).\n\t\tExample 1:\n\t\tInput: nums1 = [1,3], nums2 = [2]\n\t\tOutput: 2.00000\n\t\tExplanation: merged array = [1,2,3] and median is 2.\n\t\tExample 2:\n\t\tInput: nums1 = [1,2], nums2 = [3,4]\n\t\tOutput: 2.50000\n\t\tExplanation: merged array = [1,2,3,4] and median is (2 + 3) / 2 = 2.5.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 5, - "question": "class Solution:\n def longestPalindrome(self, s: str) -> str:\n\t\t\"\"\"\n\t\tGiven a string s, return the longest palindromic substring in s.\n\t\tExample 1:\n\t\tInput: s = \"babad\"\n\t\tOutput: \"bab\"\n\t\tExplanation: \"aba\" is also a valid answer.\n\t\tExample 2:\n\t\tInput: s = \"cbbd\"\n\t\tOutput: \"bb\"\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 6, - "question": "class Solution:\n def convert(self, s: str, numRows: int) -> str:\n\t\t\"\"\"\n\t\tThe string \"PAYPALISHIRING\" is written in a zigzag pattern on a given number of rows like this: (you may want to display this pattern in a fixed font for better legibility)\n\t\tP A H N\n\t\tA P L S I I G\n\t\tY I R\n\t\tAnd then read line by line: \"PAHNAPLSIIGYIR\"\n\t\tWrite the code that will take a string and make this conversion given a number of rows:\n\t\tstring convert(string s, int numRows);\n\t\tExample 1:\n\t\tInput: s = \"PAYPALISHIRING\", numRows = 3\n\t\tOutput: \"PAHNAPLSIIGYIR\"\n\t\tExample 2:\n\t\tInput: s = \"PAYPALISHIRING\", numRows = 4\n\t\tOutput: \"PINALSIGYAHRPI\"\n\t\tExplanation:\n\t\tP I N\n\t\tA L S I G\n\t\tY A H R\n\t\tP I\n\t\tExample 3:\n\t\tInput: s = \"A\", numRows = 1\n\t\tOutput: \"A\"\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 7, - "question": "class Solution:\n def reverse(self, x: int) -> int:\n\t\t\"\"\"\n\t\tGiven a signed 32-bit integer x, return x with its digits reversed. If reversing x causes the value to go outside the signed 32-bit integer range [-231, 231 - 1], then return 0.\n\t\tAssume the environment does not allow you to store 64-bit integers (signed or unsigned).\n\t\tExample 1:\n\t\tInput: x = 123\n\t\tOutput: 321\n\t\tExample 2:\n\t\tInput: x = -123\n\t\tOutput: -321\n\t\tExample 3:\n\t\tInput: x = 120\n\t\tOutput: 21\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 8, - "question": "class Solution:\n def myAtoi(self, s: str) -> int:\n\t\t\"\"\"\n\t\tImplement the myAtoi(string s) function, which converts a string to a 32-bit signed integer (similar to C/C++'s atoi function).\n\t\tThe algorithm for myAtoi(string s) is as follows:\n\t\t\tRead in and ignore any leading whitespace.\n\t\t\tCheck if the next character (if not already at the end of the string) is '-' or '+'. Read this character in if it is either. This determines if the final result is negative or positive respectively. Assume the result is positive if neither is present.\n\t\t\tRead in next the characters until the next non-digit character or the end of the input is reached. The rest of the string is ignored.\n\t\t\tConvert these digits into an integer (i.e. \"123\" -> 123, \"0032\" -> 32). If no digits were read, then the integer is 0. Change the sign as necessary (from step 2).\n\t\t\tIf the integer is out of the 32-bit signed integer range [-231, 231 - 1], then clamp the integer so that it remains in the range. Specifically, integers less than -231 should be clamped to -231, and integers greater than 231 - 1 should be clamped to 231 - 1.\n\t\t\tReturn the integer as the final result.\n\t\tNote:\n\t\t\tOnly the space character ' ' is considered a whitespace character.\n\t\t\tDo not ignore any characters other than the leading whitespace or the rest of the string after the digits.\n\t\tExample 1:\n\t\tInput: s = \"42\"\n\t\tOutput: 42\n\t\tExplanation: The underlined characters are what is read in, the caret is the current reader position.\n\t\tStep 1: \"42\" (no characters read because there is no leading whitespace)\n\t\t ^\n\t\tStep 2: \"42\" (no characters read because there is neither a '-' nor '+')\n\t\t ^\n\t\tStep 3: \"42\" (\"42\" is read in)\n\t\t ^\n\t\tThe parsed integer is 42.\n\t\tSince 42 is in the range [-231, 231 - 1], the final result is 42.\n\t\tExample 2:\n\t\tInput: s = \" -42\"\n\t\tOutput: -42\n\t\tExplanation:\n\t\tStep 1: \" -42\" (leading whitespace is read and ignored)\n\t\t ^\n\t\tStep 2: \" -42\" ('-' is read, so the result should be negative)\n\t\t ^\n\t\tStep 3: \" -42\" (\"42\" is read in)\n\t\t ^\n\t\tThe parsed integer is -42.\n\t\tSince -42 is in the range [-231, 231 - 1], the final result is -42.\n\t\tExample 3:\n\t\tInput: s = \"4193 with words\"\n\t\tOutput: 4193\n\t\tExplanation:\n\t\tStep 1: \"4193 with words\" (no characters read because there is no leading whitespace)\n\t\t ^\n\t\tStep 2: \"4193 with words\" (no characters read because there is neither a '-' nor '+')\n\t\t ^\n\t\tStep 3: \"4193 with words\" (\"4193\" is read in; reading stops because the next character is a non-digit)\n\t\t ^\n\t\tThe parsed integer is 4193.\n\t\tSince 4193 is in the range [-231, 231 - 1], the final result is 4193.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 9, - "question": "class Solution:\n def isPalindrome(self, x: int) -> bool:\n\t\t\"\"\"\n\t\tGiven an integer x, return true if x is a palindrome, and false otherwise.\n\t\tExample 1:\n\t\tInput: x = 121\n\t\tOutput: true\n\t\tExplanation: 121 reads as 121 from left to right and from right to left.\n\t\tExample 2:\n\t\tInput: x = -121\n\t\tOutput: false\n\t\tExplanation: From left to right, it reads -121. From right to left, it becomes 121-. Therefore it is not a palindrome.\n\t\tExample 3:\n\t\tInput: x = 10\n\t\tOutput: false\n\t\tExplanation: Reads 01 from right to left. Therefore it is not a palindrome.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 10, - "question": "class Solution:\n def isMatch(self, s: str, p: str) -> bool:\n\t\t\"\"\"\n\t\tGiven an input string s and a pattern p, implement regular expression matching with support for '.' and '*' where:\n\t\t\t'.' Matches any single character.\u200b\u200b\u200b\u200b\n\t\t\t'*' Matches zero or more of the preceding element.\n\t\tThe matching should cover the entire input string (not partial).\n\t\tExample 1:\n\t\tInput: s = \"aa\", p = \"a\"\n\t\tOutput: false\n\t\tExplanation: \"a\" does not match the entire string \"aa\".\n\t\tExample 2:\n\t\tInput: s = \"aa\", p = \"a*\"\n\t\tOutput: true\n\t\tExplanation: '*' means zero or more of the preceding element, 'a'. Therefore, by repeating 'a' once, it becomes \"aa\".\n\t\tExample 3:\n\t\tInput: s = \"ab\", p = \".*\"\n\t\tOutput: true\n\t\tExplanation: \".*\" means \"zero or more (*) of any character (.)\".\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 11, - "question": "class Solution:\n def maxArea(self, height: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou are given an integer array height of length n. There are n vertical lines drawn such that the two endpoints of the ith line are (i, 0) and (i, height[i]).\n\t\tFind two lines that together with the x-axis form a container, such that the container contains the most water.\n\t\tReturn the maximum amount of water a container can store.\n\t\tNotice that you may not slant the container.\n\t\tExample 1:\n\t\tInput: height = [1,8,6,2,5,4,8,3,7]\n\t\tOutput: 49\n\t\tExplanation: The above vertical lines are represented by array [1,8,6,2,5,4,8,3,7]. In this case, the max area of water (blue section) the container can contain is 49.\n\t\tExample 2:\n\t\tInput: height = [1,1]\n\t\tOutput: 1\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 12, - "question": "class Solution:\n def intToRoman(self, num: int) -> str:\n\t\t\"\"\"\n\t\tRoman numerals are represented by seven different symbols: I, V, X, L, C, D and M.\n\t\tSymbol Value\n\t\tI 1\n\t\tV 5\n\t\tX 10\n\t\tL 50\n\t\tC 100\n\t\tD 500\n\t\tM 1000\n\t\tFor example, 2 is written as II in Roman numeral, just two one's added together. 12 is written as XII, which is simply X + II. The number 27 is written as XXVII, which is XX + V + II.\n\t\tRoman numerals are usually written largest to smallest from left to right. However, the numeral for four is not IIII. Instead, the number four is written as IV. Because the one is before the five we subtract it making four. The same principle applies to the number nine, which is written as IX. There are six instances where subtraction is used:\n\t\t\tI can be placed before V (5) and X (10) to make 4 and 9. \n\t\t\tX can be placed before L (50) and C (100) to make 40 and 90. \n\t\t\tC can be placed before D (500) and M (1000) to make 400 and 900.\n\t\tGiven an integer, convert it to a roman numeral.\n\t\tExample 1:\n\t\tInput: num = 3\n\t\tOutput: \"III\"\n\t\tExplanation: 3 is represented as 3 ones.\n\t\tExample 2:\n\t\tInput: num = 58\n\t\tOutput: \"LVIII\"\n\t\tExplanation: L = 50, V = 5, III = 3.\n\t\tExample 3:\n\t\tInput: num = 1994\n\t\tOutput: \"MCMXCIV\"\n\t\tExplanation: M = 1000, CM = 900, XC = 90 and IV = 4.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 13, - "question": "class Solution:\n def romanToInt(self, s: str) -> int:\n\t\t\"\"\"\n\t\tRoman numerals are represented by seven different symbols: I, V, X, L, C, D and M.\n\t\tSymbol Value\n\t\tI 1\n\t\tV 5\n\t\tX 10\n\t\tL 50\n\t\tC 100\n\t\tD 500\n\t\tM 1000\n\t\tFor example, 2 is written as II in Roman numeral, just two ones added together. 12 is written as XII, which is simply X + II. The number 27 is written as XXVII, which is XX + V + II.\n\t\tRoman numerals are usually written largest to smallest from left to right. However, the numeral for four is not IIII. Instead, the number four is written as IV. Because the one is before the five we subtract it making four. The same principle applies to the number nine, which is written as IX. There are six instances where subtraction is used:\n\t\t\tI can be placed before V (5) and X (10) to make 4 and 9. \n\t\t\tX can be placed before L (50) and C (100) to make 40 and 90. \n\t\t\tC can be placed before D (500) and M (1000) to make 400 and 900.\n\t\tGiven a roman numeral, convert it to an integer.\n\t\tExample 1:\n\t\tInput: s = \"III\"\n\t\tOutput: 3\n\t\tExplanation: III = 3.\n\t\tExample 2:\n\t\tInput: s = \"LVIII\"\n\t\tOutput: 58\n\t\tExplanation: L = 50, V= 5, III = 3.\n\t\tExample 3:\n\t\tInput: s = \"MCMXCIV\"\n\t\tOutput: 1994\n\t\tExplanation: M = 1000, CM = 900, XC = 90 and IV = 4.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 14, - "question": "class Solution:\n def longestCommonPrefix(self, strs: List[str]) -> str:\n\t\t\"\"\"\n\t\tWrite a function to find the longest common prefix string amongst an array of strings.\n\t\tIf there is no common prefix, return an empty string \"\".\n\t\tExample 1:\n\t\tInput: strs = [\"flower\",\"flow\",\"flight\"]\n\t\tOutput: \"fl\"\n\t\tExample 2:\n\t\tInput: strs = [\"dog\",\"racecar\",\"car\"]\n\t\tOutput: \"\"\n\t\tExplanation: There is no common prefix among the input strings.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 15, - "question": "class Solution:\n def threeSum(self, nums: List[int]) -> List[List[int]]:\n\t\t\"\"\"\n\t\tGiven an integer array nums, return all the triplets [nums[i], nums[j], nums[k]] such that i != j, i != k, and j != k, and nums[i] + nums[j] + nums[k] == 0.\n\t\tNotice that the solution set must not contain duplicate triplets.\n\t\tExample 1:\n\t\tInput: nums = [-1,0,1,2,-1,-4]\n\t\tOutput: [[-1,-1,2],[-1,0,1]]\n\t\tExplanation: \n\t\tnums[0] + nums[1] + nums[2] = (-1) + 0 + 1 = 0.\n\t\tnums[1] + nums[2] + nums[4] = 0 + 1 + (-1) = 0.\n\t\tnums[0] + nums[3] + nums[4] = (-1) + 2 + (-1) = 0.\n\t\tThe distinct triplets are [-1,0,1] and [-1,-1,2].\n\t\tNotice that the order of the output and the order of the triplets does not matter.\n\t\tExample 2:\n\t\tInput: nums = [0,1,1]\n\t\tOutput: []\n\t\tExplanation: The only possible triplet does not sum up to 0.\n\t\tExample 3:\n\t\tInput: nums = [0,0,0]\n\t\tOutput: [[0,0,0]]\n\t\tExplanation: The only possible triplet sums up to 0.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 16, - "question": "class Solution:\n def threeSumClosest(self, nums: List[int], target: int) -> int:\n\t\t\"\"\"\n\t\tGiven an integer array nums of length n and an integer target, find three integers in nums such that the sum is closest to target.\n\t\tReturn the sum of the three integers.\n\t\tYou may assume that each input would have exactly one solution.\n\t\tExample 1:\n\t\tInput: nums = [-1,2,1,-4], target = 1\n\t\tOutput: 2\n\t\tExplanation: The sum that is closest to the target is 2. (-1 + 2 + 1 = 2).\n\t\tExample 2:\n\t\tInput: nums = [0,0,0], target = 1\n\t\tOutput: 0\n\t\tExplanation: The sum that is closest to the target is 0. (0 + 0 + 0 = 0).\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 17, - "question": "class Solution:\n def letterCombinations(self, digits: str) -> List[str]:\n\t\t\"\"\"\n\t\tGiven a string containing digits from 2-9 inclusive, return all possible letter combinations that the number could represent. Return the answer in any order.\n\t\tA mapping of digits to letters (just like on the telephone buttons) is given below. Note that 1 does not map to any letters.\n\t\tExample 1:\n\t\tInput: digits = \"23\"\n\t\tOutput: [\"ad\",\"ae\",\"af\",\"bd\",\"be\",\"bf\",\"cd\",\"ce\",\"cf\"]\n\t\tExample 2:\n\t\tInput: digits = \"\"\n\t\tOutput: []\n\t\tExample 3:\n\t\tInput: digits = \"2\"\n\t\tOutput: [\"a\",\"b\",\"c\"]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 18, - "question": "class Solution:\n def fourSum(self, nums: List[int], target: int) -> List[List[int]]:\n\t\t\"\"\"\n\t\tGiven an array nums of n integers, return an array of all the unique quadruplets [nums[a], nums[b], nums[c], nums[d]] such that:\n\t\t\t0 <= a, b, c, d < n\n\t\t\ta, b, c, and d are distinct.\n\t\t\tnums[a] + nums[b] + nums[c] + nums[d] == target\n\t\tYou may return the answer in any order.\n\t\tExample 1:\n\t\tInput: nums = [1,0,-1,0,-2,2], target = 0\n\t\tOutput: [[-2,-1,1,2],[-2,0,0,2],[-1,0,0,1]]\n\t\tExample 2:\n\t\tInput: nums = [2,2,2,2,2], target = 8\n\t\tOutput: [[2,2,2,2]]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 19, - "question": "class Solution:\n def removeNthFromEnd(self, head: Optional[ListNode], n: int) -> Optional[ListNode]:\n\t\t\"\"\"\n\t\tGiven the head of a linked list, remove the nth node from the end of the list and return its head.\n\t\tExample 1:\n\t\tInput: head = [1,2,3,4,5], n = 2\n\t\tOutput: [1,2,3,5]\n\t\tExample 2:\n\t\tInput: head = [1], n = 1\n\t\tOutput: []\n\t\tExample 3:\n\t\tInput: head = [1,2], n = 1\n\t\tOutput: [1]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 20, - "question": "class Solution:\n def isValid(self, s: str) -> bool:\n\t\t\"\"\"\n\t\tGiven a string s containing just the characters '(', ')', '{', '}', '[' and ']', determine if the input string is valid.\n\t\tAn input string is valid if:\n\t\t\tOpen brackets must be closed by the same type of brackets.\n\t\t\tOpen brackets must be closed in the correct order.\n\t\t\tEvery close bracket has a corresponding open bracket of the same type.\n\t\tExample 1:\n\t\tInput: s = \"()\"\n\t\tOutput: true\n\t\tExample 2:\n\t\tInput: s = \"()[]{}\"\n\t\tOutput: true\n\t\tExample 3:\n\t\tInput: s = \"(]\"\n\t\tOutput: false\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 21, - "question": "class Solution:\n def mergeTwoLists(self, list1: Optional[ListNode], list2: Optional[ListNode]) -> Optional[ListNode]:\n\t\t\"\"\"\n\t\tYou are given the heads of two sorted linked lists list1 and list2.\n\t\tMerge the two lists in a one sorted list. The list should be made by splicing together the nodes of the first two lists.\n\t\tReturn the head of the merged linked list.\n\t\tExample 1:\n\t\tInput: list1 = [1,2,4], list2 = [1,3,4]\n\t\tOutput: [1,1,2,3,4,4]\n\t\tExample 2:\n\t\tInput: list1 = [], list2 = []\n\t\tOutput: []\n\t\tExample 3:\n\t\tInput: list1 = [], list2 = [0]\n\t\tOutput: [0]\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 22, - "question": "class Solution:\n def generateParenthesis(self, n: int) -> List[str]:\n\t\t\"\"\"\n\t\tGiven n pairs of parentheses, write a function to generate all combinations of well-formed parentheses.\n\t\tExample 1:\n\t\tInput: n = 3\n\t\tOutput: [\"((()))\",\"(()())\",\"(())()\",\"()(())\",\"()()()\"]\n\t\tExample 2:\n\t\tInput: n = 1\n\t\tOutput: [\"()\"]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 23, - "question": "class Solution:\n def mergeKLists(self, lists: List[Optional[ListNode]]) -> Optional[ListNode]:\n\t\t\"\"\"\n\t\tYou are given an array of k linked-lists lists, each linked-list is sorted in ascending order.\n\t\tMerge all the linked-lists into one sorted linked-list and return it.\n\t\tExample 1:\n\t\tInput: lists = [[1,4,5],[1,3,4],[2,6]]\n\t\tOutput: [1,1,2,3,4,4,5,6]\n\t\tExplanation: The linked-lists are:\n\t\t[\n\t\t 1->4->5,\n\t\t 1->3->4,\n\t\t 2->6\n\t\t]\n\t\tmerging them into one sorted list:\n\t\t1->1->2->3->4->4->5->6\n\t\tExample 2:\n\t\tInput: lists = []\n\t\tOutput: []\n\t\tExample 3:\n\t\tInput: lists = [[]]\n\t\tOutput: []\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 24, - "question": "class Solution:\n def swapPairs(self, head: Optional[ListNode]) -> Optional[ListNode]:\n\t\t\"\"\"\n\t\tGiven a linked list, swap every two adjacent nodes and return its head. You must solve the problem without modifying the values in the list's nodes (i.e., only nodes themselves may be changed.)\n\t\tExample 1:\n\t\tInput: head = [1,2,3,4]\n\t\tOutput: [2,1,4,3]\n\t\tExample 2:\n\t\tInput: head = []\n\t\tOutput: []\n\t\tExample 3:\n\t\tInput: head = [1]\n\t\tOutput: [1]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 25, - "question": "class Solution:\n def reverseKGroup(self, head: Optional[ListNode], k: int) -> Optional[ListNode]:\n\t\t\"\"\"\n\t\tGiven the head of a linked list, reverse the nodes of the list k at a time, and return the modified list.\n\t\tk is a positive integer and is less than or equal to the length of the linked list. If the number of nodes is not a multiple of k then left-out nodes, in the end, should remain as it is.\n\t\tYou may not alter the values in the list's nodes, only nodes themselves may be changed.\n\t\tExample 1:\n\t\tInput: head = [1,2,3,4,5], k = 2\n\t\tOutput: [2,1,4,3,5]\n\t\tExample 2:\n\t\tInput: head = [1,2,3,4,5], k = 3\n\t\tOutput: [3,2,1,4,5]\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 26, - "question": "class Solution:\n def removeDuplicates(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tGiven an integer array nums sorted in non-decreasing order, remove the duplicates in-place such that each unique element appears only once. The relative order of the elements should be kept the same.\n\t\tSince it is impossible to change the length of the array in some languages, you must instead have the result be placed in the first part of the array nums. More formally, if there are k elements after removing the duplicates, then the first k elements of nums should hold the final result. It does not matter what you leave beyond the first k elements.\n\t\tReturn k after placing the final result in the first k slots of nums.\n\t\tDo not allocate extra space for another array. You must do this by modifying the input array in-place with O(1) extra memory.\n\t\tCustom Judge:\n\t\tThe judge will test your solution with the following code:\n\t\tint[] nums = [...]; // Input array\n\t\tint[] expectedNums = [...]; // The expected answer with correct length\n\t\tint k = removeDuplicates(nums); // Calls your implementation\n\t\tassert k == expectedNums.length;\n\t\tfor (int i = 0; i < k; i++) {\n\t\t assert nums[i] == expectedNums[i];\n\t\t}\n\t\tIf all assertions pass, then your solution will be accepted.\n\t\tExample 1:\n\t\tInput: nums = [1,1,2]\n\t\tOutput: 2, nums = [1,2,_]\n\t\tExplanation: Your function should return k = 2, with the first two elements of nums being 1 and 2 respectively.\n\t\tIt does not matter what you leave beyond the returned k (hence they are underscores).\n\t\tExample 2:\n\t\tInput: nums = [0,0,1,1,1,2,2,3,3,4]\n\t\tOutput: 5, nums = [0,1,2,3,4,_,_,_,_,_]\n\t\tExplanation: Your function should return k = 5, with the first five elements of nums being 0, 1, 2, 3, and 4 respectively.\n\t\tIt does not matter what you leave beyond the returned k (hence they are underscores).\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 27, - "question": "class Solution:\n def removeElement(self, nums: List[int], val: int) -> int:\n\t\t\"\"\"\n\t\tGiven an integer array nums and an integer val, remove all occurrences of val in nums in-place. The relative order of the elements may be changed.\n\t\tSince it is impossible to change the length of the array in some languages, you must instead have the result be placed in the first part of the array nums. More formally, if there are k elements after removing the duplicates, then the first k elements of nums should hold the final result. It does not matter what you leave beyond the first k elements.\n\t\tReturn k after placing the final result in the first k slots of nums.\n\t\tDo not allocate extra space for another array. You must do this by modifying the input array in-place with O(1) extra memory.\n\t\tCustom Judge:\n\t\tThe judge will test your solution with the following code:\n\t\tint[] nums = [...]; // Input array\n\t\tint val = ...; // Value to remove\n\t\tint[] expectedNums = [...]; // The expected answer with correct length.\n\t\t // It is sorted with no values equaling val.\n\t\tint k = removeElement(nums, val); // Calls your implementation\n\t\tassert k == expectedNums.length;\n\t\tsort(nums, 0, k); // Sort the first k elements of nums\n\t\tfor (int i = 0; i < actualLength; i++) {\n\t\t assert nums[i] == expectedNums[i];\n\t\t}\n\t\tIf all assertions pass, then your solution will be accepted.\n\t\tExample 1:\n\t\tInput: nums = [3,2,2,3], val = 3\n\t\tOutput: 2, nums = [2,2,_,_]\n\t\tExplanation: Your function should return k = 2, with the first two elements of nums being 2.\n\t\tIt does not matter what you leave beyond the returned k (hence they are underscores).\n\t\tExample 2:\n\t\tInput: nums = [0,1,2,2,3,0,4,2], val = 2\n\t\tOutput: 5, nums = [0,1,4,0,3,_,_,_]\n\t\tExplanation: Your function should return k = 5, with the first five elements of nums containing 0, 0, 1, 3, and 4.\n\t\tNote that the five elements can be returned in any order.\n\t\tIt does not matter what you leave beyond the returned k (hence they are underscores).\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 28, - "question": "class Solution:\n def strStr(self, haystack: str, needle: str) -> int:\n\t\t\"\"\"\n\t\tGiven two strings needle and haystack, return the index of the first occurrence of needle in haystack, or -1 if needle is not part of haystack.\n\t\tExample 1:\n\t\tInput: haystack = \"sadbutsad\", needle = \"sad\"\n\t\tOutput: 0\n\t\tExplanation: \"sad\" occurs at index 0 and 6.\n\t\tThe first occurrence is at index 0, so we return 0.\n\t\tExample 2:\n\t\tInput: haystack = \"leetcode\", needle = \"leeto\"\n\t\tOutput: -1\n\t\tExplanation: \"leeto\" did not occur in \"leetcode\", so we return -1.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 29, - "question": "class Solution:\n def divide(self, dividend: int, divisor: int) -> int:\n\t\t\"\"\"\n\t\tGiven two integers dividend and divisor, divide two integers without using multiplication, division, and mod operator.\n\t\tThe integer division should truncate toward zero, which means losing its fractional part. For example, 8.345 would be truncated to 8, and -2.7335 would be truncated to -2.\n\t\tReturn the quotient after dividing dividend by divisor.\n\t\tNote: Assume we are dealing with an environment that could only store integers within the 32-bit signed integer range: [\u2212231, 231 \u2212 1]. For this problem, if the quotient is strictly greater than 231 - 1, then return 231 - 1, and if the quotient is strictly less than -231, then return -231.\n\t\tExample 1:\n\t\tInput: dividend = 10, divisor = 3\n\t\tOutput: 3\n\t\tExplanation: 10/3 = 3.33333.. which is truncated to 3.\n\t\tExample 2:\n\t\tInput: dividend = 7, divisor = -3\n\t\tOutput: -2\n\t\tExplanation: 7/-3 = -2.33333.. which is truncated to -2.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 30, - "question": "class Solution:\n def findSubstring(self, s: str, words: List[str]) -> List[int]:\n\t\t\"\"\"\n\t\tYou are given a string s and an array of strings words. All the strings of words are of the same length.\n\t\tA concatenated substring in s is a substring that contains all the strings of any permutation of words concatenated.\n\t\t\tFor example, if words = [\"ab\",\"cd\",\"ef\"], then \"abcdef\", \"abefcd\", \"cdabef\", \"cdefab\", \"efabcd\", and \"efcdab\" are all concatenated strings. \"acdbef\" is not a concatenated substring because it is not the concatenation of any permutation of words.\n\t\tReturn the starting indices of all the concatenated substrings in s. You can return the answer in any order.\n\t\tExample 1:\n\t\tInput: s = \"barfoothefoobarman\", words = [\"foo\",\"bar\"]\n\t\tOutput: [0,9]\n\t\tExplanation: Since words.length == 2 and words[i].length == 3, the concatenated substring has to be of length 6.\n\t\tThe substring starting at 0 is \"barfoo\". It is the concatenation of [\"bar\",\"foo\"] which is a permutation of words.\n\t\tThe substring starting at 9 is \"foobar\". It is the concatenation of [\"foo\",\"bar\"] which is a permutation of words.\n\t\tThe output order does not matter. Returning [9,0] is fine too.\n\t\tExample 2:\n\t\tInput: s = \"wordgoodgoodgoodbestword\", words = [\"word\",\"good\",\"best\",\"word\"]\n\t\tOutput: []\n\t\tExplanation: Since words.length == 4 and words[i].length == 4, the concatenated substring has to be of length 16.\n\t\tThere is no substring of length 16 is s that is equal to the concatenation of any permutation of words.\n\t\tWe return an empty array.\n\t\tExample 3:\n\t\tInput: s = \"barfoofoobarthefoobarman\", words = [\"bar\",\"foo\",\"the\"]\n\t\tOutput: [6,9,12]\n\t\tExplanation: Since words.length == 3 and words[i].length == 3, the concatenated substring has to be of length 9.\n\t\tThe substring starting at 6 is \"foobarthe\". It is the concatenation of [\"foo\",\"bar\",\"the\"] which is a permutation of words.\n\t\tThe substring starting at 9 is \"barthefoo\". It is the concatenation of [\"bar\",\"the\",\"foo\"] which is a permutation of words.\n\t\tThe substring starting at 12 is \"thefoobar\". It is the concatenation of [\"the\",\"foo\",\"bar\"] which is a permutation of words.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 31, - "question": "class Solution:\n def nextPermutation(self, nums: List[int]) -> None:\n\t\t\"\"\"\n Do not return anything, modify nums in-place instead.\n\t\tA permutation of an array of integers is an arrangement of its members into a sequence or linear order.\n\t\t\tFor example, for arr = [1,2,3], the following are all the permutations of arr: [1,2,3], [1,3,2], [2, 1, 3], [2, 3, 1], [3,1,2], [3,2,1].\n\t\tThe next permutation of an array of integers is the next lexicographically greater permutation of its integer. More formally, if all the permutations of the array are sorted in one container according to their lexicographical order, then the next permutation of that array is the permutation that follows it in the sorted container. If such arrangement is not possible, the array must be rearranged as the lowest possible order (i.e., sorted in ascending order).\n\t\t\tFor example, the next permutation of arr = [1,2,3] is [1,3,2].\n\t\t\tSimilarly, the next permutation of arr = [2,3,1] is [3,1,2].\n\t\t\tWhile the next permutation of arr = [3,2,1] is [1,2,3] because [3,2,1] does not have a lexicographical larger rearrangement.\n\t\tGiven an array of integers nums, find the next permutation of nums.\n\t\tThe replacement must be in place and use only constant extra memory.\n\t\tExample 1:\n\t\tInput: nums = [1,2,3]\n\t\tOutput: [1,3,2]\n\t\tExample 2:\n\t\tInput: nums = [3,2,1]\n\t\tOutput: [1,2,3]\n\t\tExample 3:\n\t\tInput: nums = [1,1,5]\n\t\tOutput: [1,5,1]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 32, - "question": "class Solution:\n def longestValidParentheses(self, s: str) -> int:\n\t\t\"\"\"\n\t\tGiven a string containing just the characters '(' and ')', return the length of the longest valid (well-formed) parentheses substring.\n\t\tExample 1:\n\t\tInput: s = \"(()\"\n\t\tOutput: 2\n\t\tExplanation: The longest valid parentheses substring is \"()\".\n\t\tExample 2:\n\t\tInput: s = \")()())\"\n\t\tOutput: 4\n\t\tExplanation: The longest valid parentheses substring is \"()()\".\n\t\tExample 3:\n\t\tInput: s = \"\"\n\t\tOutput: 0\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 33, - "question": "class Solution:\n def search(self, nums: List[int], target: int) -> int:\n\t\t\"\"\"\n\t\tThere is an integer array nums sorted in ascending order (with distinct values).\n\t\tPrior to being passed to your function, nums is possibly rotated at an unknown pivot index k (1 <= k < nums.length) such that the resulting array is [nums[k], nums[k+1], ..., nums[n-1], nums[0], nums[1], ..., nums[k-1]] (0-indexed). For example, [0,1,2,4,5,6,7] might be rotated at pivot index 3 and become [4,5,6,7,0,1,2].\n\t\tGiven the array nums after the possible rotation and an integer target, return the index of target if it is in nums, or -1 if it is not in nums.\n\t\tYou must write an algorithm with O(log n) runtime complexity.\n\t\tExample 1:\n\t\tInput: nums = [4,5,6,7,0,1,2], target = 0\n\t\tOutput: 4\n\t\tExample 2:\n\t\tInput: nums = [4,5,6,7,0,1,2], target = 3\n\t\tOutput: -1\n\t\tExample 3:\n\t\tInput: nums = [1], target = 0\n\t\tOutput: -1\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 34, - "question": "class Solution:\n def searchRange(self, nums: List[int], target: int) -> List[int]:\n\t\t\"\"\"\n\t\tGiven an array of integers nums sorted in non-decreasing order, find the starting and ending position of a given target value.\n\t\tIf target is not found in the array, return [-1, -1].\n\t\tYou must write an algorithm with O(log n) runtime complexity.\n\t\tExample 1:\n\t\tInput: nums = [5,7,7,8,8,10], target = 8\n\t\tOutput: [3,4]\n\t\tExample 2:\n\t\tInput: nums = [5,7,7,8,8,10], target = 6\n\t\tOutput: [-1,-1]\n\t\tExample 3:\n\t\tInput: nums = [], target = 0\n\t\tOutput: [-1,-1]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 35, - "question": "class Solution:\n def searchInsert(self, nums: List[int], target: int) -> int:\n\t\t\"\"\"\n\t\tGiven a sorted array of distinct integers and a target value, return the index if the target is found. If not, return the index where it would be if it were inserted in order.\n\t\tYou must write an algorithm with O(log n) runtime complexity.\n\t\tExample 1:\n\t\tInput: nums = [1,3,5,6], target = 5\n\t\tOutput: 2\n\t\tExample 2:\n\t\tInput: nums = [1,3,5,6], target = 2\n\t\tOutput: 1\n\t\tExample 3:\n\t\tInput: nums = [1,3,5,6], target = 7\n\t\tOutput: 4\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 36, - "question": "class Solution:\n def isValidSudoku(self, board: List[List[str]]) -> bool:\n\t\t\"\"\"\n\t\tDetermine if a 9 x 9 Sudoku board is valid. Only the filled cells need to be validated according to the following rules:\n\t\t\tEach row must contain the digits 1-9 without repetition.\n\t\t\tEach column must contain the digits 1-9 without repetition.\n\t\t\tEach of the nine 3 x 3 sub-boxes of the grid must contain the digits 1-9 without repetition.\n\t\tNote:\n\t\t\tA Sudoku board (partially filled) could be valid but is not necessarily solvable.\n\t\t\tOnly the filled cells need to be validated according to the mentioned rules.\n\t\tExample 1:\n\t\tInput: board = \n\t\t[[\"5\",\"3\",\".\",\".\",\"7\",\".\",\".\",\".\",\".\"]\n\t\t,[\"6\",\".\",\".\",\"1\",\"9\",\"5\",\".\",\".\",\".\"]\n\t\t,[\".\",\"9\",\"8\",\".\",\".\",\".\",\".\",\"6\",\".\"]\n\t\t,[\"8\",\".\",\".\",\".\",\"6\",\".\",\".\",\".\",\"3\"]\n\t\t,[\"4\",\".\",\".\",\"8\",\".\",\"3\",\".\",\".\",\"1\"]\n\t\t,[\"7\",\".\",\".\",\".\",\"2\",\".\",\".\",\".\",\"6\"]\n\t\t,[\".\",\"6\",\".\",\".\",\".\",\".\",\"2\",\"8\",\".\"]\n\t\t,[\".\",\".\",\".\",\"4\",\"1\",\"9\",\".\",\".\",\"5\"]\n\t\t,[\".\",\".\",\".\",\".\",\"8\",\".\",\".\",\"7\",\"9\"]]\n\t\tOutput: true\n\t\tExample 2:\n\t\tInput: board = \n\t\t[[\"8\",\"3\",\".\",\".\",\"7\",\".\",\".\",\".\",\".\"]\n\t\t,[\"6\",\".\",\".\",\"1\",\"9\",\"5\",\".\",\".\",\".\"]\n\t\t,[\".\",\"9\",\"8\",\".\",\".\",\".\",\".\",\"6\",\".\"]\n\t\t,[\"8\",\".\",\".\",\".\",\"6\",\".\",\".\",\".\",\"3\"]\n\t\t,[\"4\",\".\",\".\",\"8\",\".\",\"3\",\".\",\".\",\"1\"]\n\t\t,[\"7\",\".\",\".\",\".\",\"2\",\".\",\".\",\".\",\"6\"]\n\t\t,[\".\",\"6\",\".\",\".\",\".\",\".\",\"2\",\"8\",\".\"]\n\t\t,[\".\",\".\",\".\",\"4\",\"1\",\"9\",\".\",\".\",\"5\"]\n\t\t,[\".\",\".\",\".\",\".\",\"8\",\".\",\".\",\"7\",\"9\"]]\n\t\tOutput: false\n\t\tExplanation: Same as Example 1, except with the 5 in the top left corner being modified to 8. Since there are two 8's in the top left 3x3 sub-box, it is invalid.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 37, - "question": "class Solution:\n def solveSudoku(self, board: List[List[str]]) -> None:\n\t\t\"\"\"\n Do not return anything, modify board in-place instead.\n\t\tWrite a program to solve a Sudoku puzzle by filling the empty cells.\n\t\tA sudoku solution must satisfy all of the following rules:\n\t\t\tEach of the digits 1-9 must occur exactly once in each row.\n\t\t\tEach of the digits 1-9 must occur exactly once in each column.\n\t\t\tEach of the digits 1-9 must occur exactly once in each of the 9 3x3 sub-boxes of the grid.\n\t\tThe '.' character indicates empty cells.\n\t\tExample 1:\n\t\tInput: board = [[\"5\",\"3\",\".\",\".\",\"7\",\".\",\".\",\".\",\".\"],[\"6\",\".\",\".\",\"1\",\"9\",\"5\",\".\",\".\",\".\"],[\".\",\"9\",\"8\",\".\",\".\",\".\",\".\",\"6\",\".\"],[\"8\",\".\",\".\",\".\",\"6\",\".\",\".\",\".\",\"3\"],[\"4\",\".\",\".\",\"8\",\".\",\"3\",\".\",\".\",\"1\"],[\"7\",\".\",\".\",\".\",\"2\",\".\",\".\",\".\",\"6\"],[\".\",\"6\",\".\",\".\",\".\",\".\",\"2\",\"8\",\".\"],[\".\",\".\",\".\",\"4\",\"1\",\"9\",\".\",\".\",\"5\"],[\".\",\".\",\".\",\".\",\"8\",\".\",\".\",\"7\",\"9\"]]\n\t\tOutput: [[\"5\",\"3\",\"4\",\"6\",\"7\",\"8\",\"9\",\"1\",\"2\"],[\"6\",\"7\",\"2\",\"1\",\"9\",\"5\",\"3\",\"4\",\"8\"],[\"1\",\"9\",\"8\",\"3\",\"4\",\"2\",\"5\",\"6\",\"7\"],[\"8\",\"5\",\"9\",\"7\",\"6\",\"1\",\"4\",\"2\",\"3\"],[\"4\",\"2\",\"6\",\"8\",\"5\",\"3\",\"7\",\"9\",\"1\"],[\"7\",\"1\",\"3\",\"9\",\"2\",\"4\",\"8\",\"5\",\"6\"],[\"9\",\"6\",\"1\",\"5\",\"3\",\"7\",\"2\",\"8\",\"4\"],[\"2\",\"8\",\"7\",\"4\",\"1\",\"9\",\"6\",\"3\",\"5\"],[\"3\",\"4\",\"5\",\"2\",\"8\",\"6\",\"1\",\"7\",\"9\"]]\n\t\tExplanation: The input board is shown above and the only valid solution is shown below:\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 38, - "question": "class Solution:\n def countAndSay(self, n: int) -> str:\n\t\t\"\"\"\n\t\tThe count-and-say sequence is a sequence of digit strings defined by the recursive formula:\n\t\t\tcountAndSay(1) = \"1\"\n\t\t\tcountAndSay(n) is the way you would \"say\" the digit string from countAndSay(n-1), which is then converted into a different digit string.\n\t\tTo determine how you \"say\" a digit string, split it into the minimal number of substrings such that each substring contains exactly one unique digit. Then for each substring, say the number of digits, then say the digit. Finally, concatenate every said digit.\n\t\tFor example, the saying and conversion for digit string \"3322251\":\n\t\tGiven a positive integer n, return the nth term of the count-and-say sequence.\n\t\tExample 1:\n\t\tInput: n = 1\n\t\tOutput: \"1\"\n\t\tExplanation: This is the base case.\n\t\tExample 2:\n\t\tInput: n = 4\n\t\tOutput: \"1211\"\n\t\tExplanation:\n\t\tcountAndSay(1) = \"1\"\n\t\tcountAndSay(2) = say \"1\" = one 1 = \"11\"\n\t\tcountAndSay(3) = say \"11\" = two 1's = \"21\"\n\t\tcountAndSay(4) = say \"21\" = one 2 + one 1 = \"12\" + \"11\" = \"1211\"\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 39, - "question": "class Solution:\n def combinationSum(self, candidates: List[int], target: int) -> List[List[int]]:\n\t\t\"\"\"\n\t\tGiven an array of distinct integers candidates and a target integer target, return a list of all unique combinations of candidates where the chosen numbers sum to target. You may return the combinations in any order.\n\t\tThe same number may be chosen from candidates an unlimited number of times. Two combinations are unique if the frequency of at least one of the chosen numbers is different.\n\t\tThe test cases are generated such that the number of unique combinations that sum up to target is less than 150 combinations for the given input.\n\t\tExample 1:\n\t\tInput: candidates = [2,3,6,7], target = 7\n\t\tOutput: [[2,2,3],[7]]\n\t\tExplanation:\n\t\t2 and 3 are candidates, and 2 + 2 + 3 = 7. Note that 2 can be used multiple times.\n\t\t7 is a candidate, and 7 = 7.\n\t\tThese are the only two combinations.\n\t\tExample 2:\n\t\tInput: candidates = [2,3,5], target = 8\n\t\tOutput: [[2,2,2,2],[2,3,3],[3,5]]\n\t\tExample 3:\n\t\tInput: candidates = [2], target = 1\n\t\tOutput: []\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 40, - "question": "class Solution:\n def combinationSum2(self, candidates: List[int], target: int) -> List[List[int]]:\n\t\t\"\"\"\n\t\tGiven a collection of candidate numbers (candidates) and a target number (target), find all unique combinations in candidates where the candidate numbers sum to target.\n\t\tEach number in candidates may only be used once in the combination.\n\t\tNote: The solution set must not contain duplicate combinations.\n\t\tExample 1:\n\t\tInput: candidates = [10,1,2,7,6,1,5], target = 8\n\t\tOutput: \n\t\t[\n\t\t[1,1,6],\n\t\t[1,2,5],\n\t\t[1,7],\n\t\t[2,6]\n\t\t]\n\t\tExample 2:\n\t\tInput: candidates = [2,5,2,1,2], target = 5\n\t\tOutput: \n\t\t[\n\t\t[1,2,2],\n\t\t[5]\n\t\t]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 41, - "question": "class Solution:\n def firstMissingPositive(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tGiven an unsorted integer array nums, return the smallest missing positive integer.\n\t\tYou must implement an algorithm that runs in O(n) time and uses constant extra space.\n\t\tExample 1:\n\t\tInput: nums = [1,2,0]\n\t\tOutput: 3\n\t\tExplanation: The numbers in the range [1,2] are all in the array.\n\t\tExample 2:\n\t\tInput: nums = [3,4,-1,1]\n\t\tOutput: 2\n\t\tExplanation: 1 is in the array but 2 is missing.\n\t\tExample 3:\n\t\tInput: nums = [7,8,9,11,12]\n\t\tOutput: 1\n\t\tExplanation: The smallest positive integer 1 is missing.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 42, - "question": "class Solution:\n def trap(self, height: List[int]) -> int:\n\t\t\"\"\"\n\t\tGiven n non-negative integers representing an elevation map where the width of each bar is 1, compute how much water it can trap after raining.\n\t\tExample 1:\n\t\tInput: height = [0,1,0,2,1,0,1,3,2,1,2,1]\n\t\tOutput: 6\n\t\tExplanation: The above elevation map (black section) is represented by array [0,1,0,2,1,0,1,3,2,1,2,1]. In this case, 6 units of rain water (blue section) are being trapped.\n\t\tExample 2:\n\t\tInput: height = [4,2,0,3,2,5]\n\t\tOutput: 9\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 43, - "question": "class Solution:\n def multiply(self, num1: str, num2: str) -> str:\n\t\t\"\"\"\n\t\tGiven two non-negative integers num1 and num2 represented as strings, return the product of num1 and num2, also represented as a string.\n\t\tNote: You must not use any built-in BigInteger library or convert the inputs to integer directly.\n\t\tExample 1:\n\t\tInput: num1 = \"2\", num2 = \"3\"\n\t\tOutput: \"6\"\n\t\tExample 2:\n\t\tInput: num1 = \"123\", num2 = \"456\"\n\t\tOutput: \"56088\"\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 44, - "question": "class Solution:\n def isMatch(self, s: str, p: str) -> bool:\n\t\t\"\"\"\n\t\tGiven an input string (s) and a pattern (p), implement wildcard pattern matching with support for '?' and '*' where:\n\t\t\t'?' Matches any single character.\n\t\t\t'*' Matches any sequence of characters (including the empty sequence).\n\t\tThe matching should cover the entire input string (not partial).\n\t\tExample 1:\n\t\tInput: s = \"aa\", p = \"a\"\n\t\tOutput: false\n\t\tExplanation: \"a\" does not match the entire string \"aa\".\n\t\tExample 2:\n\t\tInput: s = \"aa\", p = \"*\"\n\t\tOutput: true\n\t\tExplanation: '*' matches any sequence.\n\t\tExample 3:\n\t\tInput: s = \"cb\", p = \"?a\"\n\t\tOutput: false\n\t\tExplanation: '?' matches 'c', but the second letter is 'a', which does not match 'b'.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 45, - "question": "class Solution:\n def jump(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou are given a 0-indexed array of integers nums of length n. You are initially positioned at nums[0].\n\t\tEach element nums[i] represents the maximum length of a forward jump from index i. In other words, if you are at nums[i], you can jump to any nums[i + j] where:\n\t\t\t0 <= j <= nums[i] and\n\t\t\ti + j < n\n\t\tReturn the minimum number of jumps to reach nums[n - 1]. The test cases are generated such that you can reach nums[n - 1].\n\t\tExample 1:\n\t\tInput: nums = [2,3,1,1,4]\n\t\tOutput: 2\n\t\tExplanation: The minimum number of jumps to reach the last index is 2. Jump 1 step from index 0 to 1, then 3 steps to the last index.\n\t\tExample 2:\n\t\tInput: nums = [2,3,0,1,4]\n\t\tOutput: 2\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 46, - "question": "class Solution:\n def permute(self, nums: List[int]) -> List[List[int]]:\n\t\t\"\"\"\n\t\tGiven an array nums of distinct integers, return all the possible permutations. You can return the answer in any order.\n\t\tExample 1:\n\t\tInput: nums = [1,2,3]\n\t\tOutput: [[1,2,3],[1,3,2],[2,1,3],[2,3,1],[3,1,2],[3,2,1]]\n\t\tExample 2:\n\t\tInput: nums = [0,1]\n\t\tOutput: [[0,1],[1,0]]\n\t\tExample 3:\n\t\tInput: nums = [1]\n\t\tOutput: [[1]]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 47, - "question": "class Solution:\n def permuteUnique(self, nums: List[int]) -> List[List[int]]:\n\t\t\"\"\"\n\t\tGiven a collection of numbers, nums, that might contain duplicates, return all possible unique permutations in any order.\n\t\tExample 1:\n\t\tInput: nums = [1,1,2]\n\t\tOutput:\n\t\t[[1,1,2],\n\t\t [1,2,1],\n\t\t [2,1,1]]\n\t\tExample 2:\n\t\tInput: nums = [1,2,3]\n\t\tOutput: [[1,2,3],[1,3,2],[2,1,3],[2,3,1],[3,1,2],[3,2,1]]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 48, - "question": "class Solution:\n def rotate(self, matrix: List[List[int]]) -> None:\n\t\t\"\"\"\n Do not return anything, modify matrix in-place instead.\n\t\tYou are given an n x n 2D matrix representing an image, rotate the image by 90 degrees (clockwise).\n\t\tYou have to rotate the image in-place, which means you have to modify the input 2D matrix directly. DO NOT allocate another 2D matrix and do the rotation.\n\t\tExample 1:\n\t\tInput: matrix = [[1,2,3],[4,5,6],[7,8,9]]\n\t\tOutput: [[7,4,1],[8,5,2],[9,6,3]]\n\t\tExample 2:\n\t\tInput: matrix = [[5,1,9,11],[2,4,8,10],[13,3,6,7],[15,14,12,16]]\n\t\tOutput: [[15,13,2,5],[14,3,4,1],[12,6,8,9],[16,7,10,11]]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 49, - "question": "class Solution:\n def groupAnagrams(self, strs: List[str]) -> List[List[str]]:\n\t\t\"\"\"\n\t\tGiven an array of strings strs, group the anagrams together. You can return the answer in any order.\n\t\tAn Anagram is a word or phrase formed by rearranging the letters of a different word or phrase, typically using all the original letters exactly once.\n\t\tExample 1:\n\t\tInput: strs = [\"eat\",\"tea\",\"tan\",\"ate\",\"nat\",\"bat\"]\n\t\tOutput: [[\"bat\"],[\"nat\",\"tan\"],[\"ate\",\"eat\",\"tea\"]]\n\t\tExample 2:\n\t\tInput: strs = [\"\"]\n\t\tOutput: [[\"\"]]\n\t\tExample 3:\n\t\tInput: strs = [\"a\"]\n\t\tOutput: [[\"a\"]]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 50, - "question": "class Solution:\n def myPow(self, x: float, n: int) -> float:\n\t\t\"\"\"\n\t\tImplement pow(x, n), which calculates x raised to the power n (i.e., xn).\n\t\tExample 1:\n\t\tInput: x = 2.00000, n = 10\n\t\tOutput: 1024.00000\n\t\tExample 2:\n\t\tInput: x = 2.10000, n = 3\n\t\tOutput: 9.26100\n\t\tExample 3:\n\t\tInput: x = 2.00000, n = -2\n\t\tOutput: 0.25000\n\t\tExplanation: 2-2 = 1/22 = 1/4 = 0.25\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 51, - "question": "class Solution:\n def solveNQueens(self, n: int) -> List[List[str]]:\n\t\t\"\"\"\n\t\tThe n-queens puzzle is the problem of placing n queens on an n x n chessboard such that no two queens attack each other.\n\t\tGiven an integer n, return all distinct solutions to the n-queens puzzle. You may return the answer in any order.\n\t\tEach solution contains a distinct board configuration of the n-queens' placement, where 'Q' and '.' both indicate a queen and an empty space, respectively.\n\t\tExample 1:\n\t\tInput: n = 4\n\t\tOutput: [[\".Q..\",\"...Q\",\"Q...\",\"..Q.\"],[\"..Q.\",\"Q...\",\"...Q\",\".Q..\"]]\n\t\tExplanation: There exist two distinct solutions to the 4-queens puzzle as shown above\n\t\tExample 2:\n\t\tInput: n = 1\n\t\tOutput: [[\"Q\"]]\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 52, - "question": "class Solution:\n def totalNQueens(self, n: int) -> int:\n\t\t\"\"\"\n\t\tThe n-queens puzzle is the problem of placing n queens on an n x n chessboard such that no two queens attack each other.\n\t\tGiven an integer n, return the number of distinct solutions to the n-queens puzzle.\n\t\tExample 1:\n\t\tInput: n = 4\n\t\tOutput: 2\n\t\tExplanation: There are two distinct solutions to the 4-queens puzzle as shown.\n\t\tExample 2:\n\t\tInput: n = 1\n\t\tOutput: 1\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 53, - "question": "class Solution:\n def maxSubArray(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tGiven an integer array nums, find the subarray with the largest sum, and return its sum.\n\t\tExample 1:\n\t\tInput: nums = [-2,1,-3,4,-1,2,1,-5,4]\n\t\tOutput: 6\n\t\tExplanation: The subarray [4,-1,2,1] has the largest sum 6.\n\t\tExample 2:\n\t\tInput: nums = [1]\n\t\tOutput: 1\n\t\tExplanation: The subarray [1] has the largest sum 1.\n\t\tExample 3:\n\t\tInput: nums = [5,4,-1,7,8]\n\t\tOutput: 23\n\t\tExplanation: The subarray [5,4,-1,7,8] has the largest sum 23.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 54, - "question": "class Solution:\n def spiralOrder(self, matrix: List[List[int]]) -> List[int]:\n\t\t\"\"\"\n\t\tGiven an m x n matrix, return all elements of the matrix in spiral order.\n\t\tExample 1:\n\t\tInput: matrix = [[1,2,3],[4,5,6],[7,8,9]]\n\t\tOutput: [1,2,3,6,9,8,7,4,5]\n\t\tExample 2:\n\t\tInput: matrix = [[1,2,3,4],[5,6,7,8],[9,10,11,12]]\n\t\tOutput: [1,2,3,4,8,12,11,10,9,5,6,7]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 55, - "question": "class Solution:\n def canJump(self, nums: List[int]) -> bool:\n\t\t\"\"\"\n\t\tYou are given an integer array nums. You are initially positioned at the array's first index, and each element in the array represents your maximum jump length at that position.\n\t\tReturn true if you can reach the last index, or false otherwise.\n\t\tExample 1:\n\t\tInput: nums = [2,3,1,1,4]\n\t\tOutput: true\n\t\tExplanation: Jump 1 step from index 0 to 1, then 3 steps to the last index.\n\t\tExample 2:\n\t\tInput: nums = [3,2,1,0,4]\n\t\tOutput: false\n\t\tExplanation: You will always arrive at index 3 no matter what. Its maximum jump length is 0, which makes it impossible to reach the last index.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 56, - "question": "class Solution:\n def merge(self, intervals: List[List[int]]) -> List[List[int]]:\n\t\t\"\"\"\n\t\tGiven an array of intervals where intervals[i] = [starti, endi], merge all overlapping intervals, and return an array of the non-overlapping intervals that cover all the intervals in the input.\n\t\tExample 1:\n\t\tInput: intervals = [[1,3],[2,6],[8,10],[15,18]]\n\t\tOutput: [[1,6],[8,10],[15,18]]\n\t\tExplanation: Since intervals [1,3] and [2,6] overlap, merge them into [1,6].\n\t\tExample 2:\n\t\tInput: intervals = [[1,4],[4,5]]\n\t\tOutput: [[1,5]]\n\t\tExplanation: Intervals [1,4] and [4,5] are considered overlapping.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 57, - "question": "class Solution:\n def insert(self, intervals: List[List[int]], newInterval: List[int]) -> List[List[int]]:\n\t\t\"\"\"\n\t\tYou are given an array of non-overlapping intervals intervals where intervals[i] = [starti, endi] represent the start and the end of the ith interval and intervals is sorted in ascending order by starti. You are also given an interval newInterval = [start, end] that represents the start and end of another interval.\n\t\tInsert newInterval into intervals such that intervals is still sorted in ascending order by starti and intervals still does not have any overlapping intervals (merge overlapping intervals if necessary).\n\t\tReturn intervals after the insertion.\n\t\tExample 1:\n\t\tInput: intervals = [[1,3],[6,9]], newInterval = [2,5]\n\t\tOutput: [[1,5],[6,9]]\n\t\tExample 2:\n\t\tInput: intervals = [[1,2],[3,5],[6,7],[8,10],[12,16]], newInterval = [4,8]\n\t\tOutput: [[1,2],[3,10],[12,16]]\n\t\tExplanation: Because the new interval [4,8] overlaps with [3,5],[6,7],[8,10].\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 58, - "question": "class Solution:\n def lengthOfLastWord(self, s: str) -> int:\n\t\t\"\"\"\n\t\tGiven a string s consisting of words and spaces, return the length of the last word in the string.\n\t\tA word is a maximal substring consisting of non-space characters only.\n\t\tExample 1:\n\t\tInput: s = \"Hello World\"\n\t\tOutput: 5\n\t\tExplanation: The last word is \"World\" with length 5.\n\t\tExample 2:\n\t\tInput: s = \" fly me to the moon \"\n\t\tOutput: 4\n\t\tExplanation: The last word is \"moon\" with length 4.\n\t\tExample 3:\n\t\tInput: s = \"luffy is still joyboy\"\n\t\tOutput: 6\n\t\tExplanation: The last word is \"joyboy\" with length 6.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 59, - "question": "class Solution:\n def generateMatrix(self, n: int) -> List[List[int]]:\n\t\t\"\"\"\n\t\tGiven a positive integer n, generate an n x n matrix filled with elements from 1 to n2 in spiral order.\n\t\tExample 1:\n\t\tInput: n = 3\n\t\tOutput: [[1,2,3],[8,9,4],[7,6,5]]\n\t\tExample 2:\n\t\tInput: n = 1\n\t\tOutput: [[1]]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 60, - "question": "class Solution:\n def getPermutation(self, n: int, k: int) -> str:\n\t\t\"\"\"\n\t\tThe set [1, 2, 3, ..., n] contains a total of n! unique permutations.\n\t\tBy listing and labeling all of the permutations in order, we get the following sequence for n = 3:\n\t\t\t\"123\"\n\t\t\t\"132\"\n\t\t\t\"213\"\n\t\t\t\"231\"\n\t\t\t\"312\"\n\t\t\t\"321\"\n\t\tGiven n and k, return the kth permutation sequence.\n\t\tExample 1:\n\t\tInput: n = 3, k = 3\n\t\tOutput: \"213\"\n\t\tExample 2:\n\t\tInput: n = 4, k = 9\n\t\tOutput: \"2314\"\n\t\tExample 3:\n\t\tInput: n = 3, k = 1\n\t\tOutput: \"123\"\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 61, - "question": "class Solution:\n def rotateRight(self, head: Optional[ListNode], k: int) -> Optional[ListNode]:\n\t\t\"\"\"\n\t\tGiven the head of a linked list, rotate the list to the right by k places.\n\t\tExample 1:\n\t\tInput: head = [1,2,3,4,5], k = 2\n\t\tOutput: [4,5,1,2,3]\n\t\tExample 2:\n\t\tInput: head = [0,1,2], k = 4\n\t\tOutput: [2,0,1]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 62, - "question": "class Solution:\n def uniquePaths(self, m: int, n: int) -> int:\n\t\t\"\"\"\n\t\tThere is a robot on an m x n grid. The robot is initially located at the top-left corner (i.e., grid[0][0]). The robot tries to move to the bottom-right corner (i.e., grid[m - 1][n - 1]). The robot can only move either down or right at any point in time.\n\t\tGiven the two integers m and n, return the number of possible unique paths that the robot can take to reach the bottom-right corner.\n\t\tThe test cases are generated so that the answer will be less than or equal to 2 * 109.\n\t\tExample 1:\n\t\tInput: m = 3, n = 7\n\t\tOutput: 28\n\t\tExample 2:\n\t\tInput: m = 3, n = 2\n\t\tOutput: 3\n\t\tExplanation: From the top-left corner, there are a total of 3 ways to reach the bottom-right corner:\n\t\t1. Right -> Down -> Down\n\t\t2. Down -> Down -> Right\n\t\t3. Down -> Right -> Down\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 63, - "question": "class Solution:\n def uniquePathsWithObstacles(self, obstacleGrid: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tYou are given an m x n integer array grid. There is a robot initially located at the top-left corner (i.e., grid[0][0]). The robot tries to move to the bottom-right corner (i.e., grid[m - 1][n - 1]). The robot can only move either down or right at any point in time.\n\t\tAn obstacle and space are marked as 1 or 0 respectively in grid. A path that the robot takes cannot include any square that is an obstacle.\n\t\tReturn the number of possible unique paths that the robot can take to reach the bottom-right corner.\n\t\tThe testcases are generated so that the answer will be less than or equal to 2 * 109.\n\t\tExample 1:\n\t\tInput: obstacleGrid = [[0,0,0],[0,1,0],[0,0,0]]\n\t\tOutput: 2\n\t\tExplanation: There is one obstacle in the middle of the 3x3 grid above.\n\t\tThere are two ways to reach the bottom-right corner:\n\t\t1. Right -> Right -> Down -> Down\n\t\t2. Down -> Down -> Right -> Right\n\t\tExample 2:\n\t\tInput: obstacleGrid = [[0,1],[0,0]]\n\t\tOutput: 1\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 64, - "question": "class Solution:\n def minPathSum(self, grid: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tGiven a m x n grid filled with non-negative numbers, find a path from top left to bottom right, which minimizes the sum of all numbers along its path.\n\t\tNote: You can only move either down or right at any point in time.\n\t\tExample 1:\n\t\tInput: grid = [[1,3,1],[1,5,1],[4,2,1]]\n\t\tOutput: 7\n\t\tExplanation: Because the path 1 \u2192 3 \u2192 1 \u2192 1 \u2192 1 minimizes the sum.\n\t\tExample 2:\n\t\tInput: grid = [[1,2,3],[4,5,6]]\n\t\tOutput: 12\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 65, - "question": "class Solution:\n def isNumber(self, s: str) -> bool:\n\t\t\"\"\"\n\t\tA valid number can be split up into these components (in order):\n\t\t\tA decimal number or an integer.\n\t\t\t(Optional) An 'e' or 'E', followed by an integer.\n\t\tA decimal number can be split up into these components (in order):\n\t\t\t(Optional) A sign character (either '+' or '-').\n\t\t\tOne of the following formats:\n\t\t\t\tOne or more digits, followed by a dot '.'.\n\t\t\t\tOne or more digits, followed by a dot '.', followed by one or more digits.\n\t\t\t\tA dot '.', followed by one or more digits.\n\t\tAn integer can be split up into these components (in order):\n\t\t\t(Optional) A sign character (either '+' or '-').\n\t\t\tOne or more digits.\n\t\tFor example, all the following are valid numbers: [\"2\", \"0089\", \"-0.1\", \"+3.14\", \"4.\", \"-.9\", \"2e10\", \"-90E3\", \"3e+7\", \"+6e-1\", \"53.5e93\", \"-123.456e789\"], while the following are not valid numbers: [\"abc\", \"1a\", \"1e\", \"e3\", \"99e2.5\", \"--6\", \"-+3\", \"95a54e53\"].\n\t\tGiven a string s, return true if s is a valid number.\n\t\tExample 1:\n\t\tInput: s = \"0\"\n\t\tOutput: true\n\t\tExample 2:\n\t\tInput: s = \"e\"\n\t\tOutput: false\n\t\tExample 3:\n\t\tInput: s = \".\"\n\t\tOutput: false\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 66, - "question": "class Solution:\n def plusOne(self, digits: List[int]) -> List[int]:\n\t\t\"\"\"\n\t\tYou are given a large integer represented as an integer array digits, where each digits[i] is the ith digit of the integer. The digits are ordered from most significant to least significant in left-to-right order. The large integer does not contain any leading 0's.\n\t\tIncrement the large integer by one and return the resulting array of digits.\n\t\tExample 1:\n\t\tInput: digits = [1,2,3]\n\t\tOutput: [1,2,4]\n\t\tExplanation: The array represents the integer 123.\n\t\tIncrementing by one gives 123 + 1 = 124.\n\t\tThus, the result should be [1,2,4].\n\t\tExample 2:\n\t\tInput: digits = [4,3,2,1]\n\t\tOutput: [4,3,2,2]\n\t\tExplanation: The array represents the integer 4321.\n\t\tIncrementing by one gives 4321 + 1 = 4322.\n\t\tThus, the result should be [4,3,2,2].\n\t\tExample 3:\n\t\tInput: digits = [9]\n\t\tOutput: [1,0]\n\t\tExplanation: The array represents the integer 9.\n\t\tIncrementing by one gives 9 + 1 = 10.\n\t\tThus, the result should be [1,0].\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 67, - "question": "class Solution:\n def addBinary(self, a: str, b: str) -> str:\n\t\t\"\"\"\n\t\tGiven two binary strings a and b, return their sum as a binary string.\n\t\tExample 1:\n\t\tInput: a = \"11\", b = \"1\"\n\t\tOutput: \"100\"\n\t\tExample 2:\n\t\tInput: a = \"1010\", b = \"1011\"\n\t\tOutput: \"10101\"\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 68, - "question": "class Solution:\n def fullJustify(self, words: List[str], maxWidth: int) -> List[str]:\n\t\t\"\"\"\n\t\tGiven an array of strings words and a width maxWidth, format the text such that each line has exactly maxWidth characters and is fully (left and right) justified.\n\t\tYou should pack your words in a greedy approach; that is, pack as many words as you can in each line. Pad extra spaces ' ' when necessary so that each line has exactly maxWidth characters.\n\t\tExtra spaces between words should be distributed as evenly as possible. If the number of spaces on a line does not divide evenly between words, the empty slots on the left will be assigned more spaces than the slots on the right.\n\t\tFor the last line of text, it should be left-justified, and no extra space is inserted between words.\n\t\tNote:\n\t\t\tA word is defined as a character sequence consisting of non-space characters only.\n\t\t\tEach word's length is guaranteed to be greater than 0 and not exceed maxWidth.\n\t\t\tThe input array words contains at least one word.\n\t\tExample 1:\n\t\tInput: words = [\"This\", \"is\", \"an\", \"example\", \"of\", \"text\", \"justification.\"], maxWidth = 16\n\t\tOutput:\n\t\t[\n\t\t \"This is an\",\n\t\t \"example of text\",\n\t\t \"justification. \"\n\t\t]\n\t\tExample 2:\n\t\tInput: words = [\"What\",\"must\",\"be\",\"acknowledgment\",\"shall\",\"be\"], maxWidth = 16\n\t\tOutput:\n\t\t[\n\t\t \"What must be\",\n\t\t \"acknowledgment \",\n\t\t \"shall be \"\n\t\t]\n\t\tExplanation: Note that the last line is \"shall be \" instead of \"shall be\", because the last line must be left-justified instead of fully-justified.\n\t\tNote that the second line is also left-justified because it contains only one word.\n\t\tExample 3:\n\t\tInput: words = [\"Science\",\"is\",\"what\",\"we\",\"understand\",\"well\",\"enough\",\"to\",\"explain\",\"to\",\"a\",\"computer.\",\"Art\",\"is\",\"everything\",\"else\",\"we\",\"do\"], maxWidth = 20\n\t\tOutput:\n\t\t[\n\t\t \"Science is what we\",\n\t\t \"understand well\",\n\t\t \"enough to explain to\",\n\t\t \"a computer. Art is\",\n\t\t \"everything else we\",\n\t\t \"do \"\n\t\t]\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 69, - "question": "class Solution:\n def mySqrt(self, x: int) -> int:\n\t\t\"\"\"\n\t\tGiven a non-negative integer x, return the square root of x rounded down to the nearest integer. The returned integer should be non-negative as well.\n\t\tYou must not use any built-in exponent function or operator.\n\t\t\tFor example, do not use pow(x, 0.5) in c++ or x ** 0.5 in python.\n\t\tExample 1:\n\t\tInput: x = 4\n\t\tOutput: 2\n\t\tExplanation: The square root of 4 is 2, so we return 2.\n\t\tExample 2:\n\t\tInput: x = 8\n\t\tOutput: 2\n\t\tExplanation: The square root of 8 is 2.82842..., and since we round it down to the nearest integer, 2 is returned.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 70, - "question": "class Solution:\n def climbStairs(self, n: int) -> int:\n\t\t\"\"\"\n\t\tYou are climbing a staircase. It takes n steps to reach the top.\n\t\tEach time you can either climb 1 or 2 steps. In how many distinct ways can you climb to the top?\n\t\tExample 1:\n\t\tInput: n = 2\n\t\tOutput: 2\n\t\tExplanation: There are two ways to climb to the top.\n\t\t1. 1 step + 1 step\n\t\t2. 2 steps\n\t\tExample 2:\n\t\tInput: n = 3\n\t\tOutput: 3\n\t\tExplanation: There are three ways to climb to the top.\n\t\t1. 1 step + 1 step + 1 step\n\t\t2. 1 step + 2 steps\n\t\t3. 2 steps + 1 step\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 71, - "question": "class Solution:\n def simplifyPath(self, path: str) -> str:\n\t\t\"\"\"\n\t\tGiven a string path, which is an absolute path (starting with a slash '/') to a file or directory in a Unix-style file system, convert it to the simplified canonical path.\n\t\tIn a Unix-style file system, a period '.' refers to the current directory, a double period '..' refers to the directory up a level, and any multiple consecutive slashes (i.e. '//') are treated as a single slash '/'. For this problem, any other format of periods such as '...' are treated as file/directory names.\n\t\tThe canonical path should have the following format:\n\t\t\tThe path starts with a single slash '/'.\n\t\t\tAny two directories are separated by a single slash '/'.\n\t\t\tThe path does not end with a trailing '/'.\n\t\t\tThe path only contains the directories on the path from the root directory to the target file or directory (i.e., no period '.' or double period '..')\n\t\tReturn the simplified canonical path.\n\t\tExample 1:\n\t\tInput: path = \"/home/\"\n\t\tOutput: \"/home\"\n\t\tExplanation: Note that there is no trailing slash after the last directory name.\n\t\tExample 2:\n\t\tInput: path = \"/../\"\n\t\tOutput: \"/\"\n\t\tExplanation: Going one level up from the root directory is a no-op, as the root level is the highest level you can go.\n\t\tExample 3:\n\t\tInput: path = \"/home//foo/\"\n\t\tOutput: \"/home/foo\"\n\t\tExplanation: In the canonical path, multiple consecutive slashes are replaced by a single one.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 72, - "question": "class Solution:\n def minDistance(self, word1: str, word2: str) -> int:\n\t\t\"\"\"\n\t\tGiven two strings word1 and word2, return the minimum number of operations required to convert word1 to word2.\n\t\tYou have the following three operations permitted on a word:\n\t\t\tInsert a character\n\t\t\tDelete a character\n\t\t\tReplace a character\n\t\tExample 1:\n\t\tInput: word1 = \"horse\", word2 = \"ros\"\n\t\tOutput: 3\n\t\tExplanation: \n\t\thorse -> rorse (replace 'h' with 'r')\n\t\trorse -> rose (remove 'r')\n\t\trose -> ros (remove 'e')\n\t\tExample 2:\n\t\tInput: word1 = \"intention\", word2 = \"execution\"\n\t\tOutput: 5\n\t\tExplanation: \n\t\tintention -> inention (remove 't')\n\t\tinention -> enention (replace 'i' with 'e')\n\t\tenention -> exention (replace 'n' with 'x')\n\t\texention -> exection (replace 'n' with 'c')\n\t\texection -> execution (insert 'u')\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 73, - "question": "class Solution:\n def setZeroes(self, matrix: List[List[int]]) -> None:\n\t\t\"\"\"\n Do not return anything, modify matrix in-place instead.\n\t\tGiven an m x n integer matrix matrix, if an element is 0, set its entire row and column to 0's.\n\t\tYou must do it in place.\n\t\tExample 1:\n\t\tInput: matrix = [[1,1,1],[1,0,1],[1,1,1]]\n\t\tOutput: [[1,0,1],[0,0,0],[1,0,1]]\n\t\tExample 2:\n\t\tInput: matrix = [[0,1,2,0],[3,4,5,2],[1,3,1,5]]\n\t\tOutput: [[0,0,0,0],[0,4,5,0],[0,3,1,0]]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 74, - "question": "class Solution:\n def searchMatrix(self, matrix: List[List[int]], target: int) -> bool:\n\t\t\"\"\"\n\t\tYou are given an m x n integer matrix matrix with the following two properties:\n\t\t\tEach row is sorted in non-decreasing order.\n\t\t\tThe first integer of each row is greater than the last integer of the previous row.\n\t\tGiven an integer target, return true if target is in matrix or false otherwise.\n\t\tYou must write a solution in O(log(m * n)) time complexity.\n\t\tExample 1:\n\t\tInput: matrix = [[1,3,5,7],[10,11,16,20],[23,30,34,60]], target = 3\n\t\tOutput: true\n\t\tExample 2:\n\t\tInput: matrix = [[1,3,5,7],[10,11,16,20],[23,30,34,60]], target = 13\n\t\tOutput: false\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 75, - "question": "class Solution:\n def sortColors(self, nums: List[int]) -> None:\n\t\t\"\"\"\n Do not return anything, modify nums in-place instead.\n\t\tGiven an array nums with n objects colored red, white, or blue, sort them in-place so that objects of the same color are adjacent, with the colors in the order red, white, and blue.\n\t\tWe will use the integers 0, 1, and 2 to represent the color red, white, and blue, respectively.\n\t\tYou must solve this problem without using the library's sort function.\n\t\tExample 1:\n\t\tInput: nums = [2,0,2,1,1,0]\n\t\tOutput: [0,0,1,1,2,2]\n\t\tExample 2:\n\t\tInput: nums = [2,0,1]\n\t\tOutput: [0,1,2]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 76, - "question": "class Solution:\n def minWindow(self, s: str, t: str) -> str:\n\t\t\"\"\"\n\t\tGiven two strings s and t of lengths m and n respectively, return the minimum window substring of s such that every character in t (including duplicates) is included in the window. If there is no such substring, return the empty string \"\".\n\t\tThe testcases will be generated such that the answer is unique.\n\t\tExample 1:\n\t\tInput: s = \"ADOBECODEBANC\", t = \"ABC\"\n\t\tOutput: \"BANC\"\n\t\tExplanation: The minimum window substring \"BANC\" includes 'A', 'B', and 'C' from string t.\n\t\tExample 2:\n\t\tInput: s = \"a\", t = \"a\"\n\t\tOutput: \"a\"\n\t\tExplanation: The entire string s is the minimum window.\n\t\tExample 3:\n\t\tInput: s = \"a\", t = \"aa\"\n\t\tOutput: \"\"\n\t\tExplanation: Both 'a's from t must be included in the window.\n\t\tSince the largest window of s only has one 'a', return empty string.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 77, - "question": "class Solution:\n def combine(self, n: int, k: int) -> List[List[int]]:\n\t\t\"\"\"\n\t\tGiven two integers n and k, return all possible combinations of k numbers chosen from the range [1, n].\n\t\tYou may return the answer in any order.\n\t\tExample 1:\n\t\tInput: n = 4, k = 2\n\t\tOutput: [[1,2],[1,3],[1,4],[2,3],[2,4],[3,4]]\n\t\tExplanation: There are 4 choose 2 = 6 total combinations.\n\t\tNote that combinations are unordered, i.e., [1,2] and [2,1] are considered to be the same combination.\n\t\tExample 2:\n\t\tInput: n = 1, k = 1\n\t\tOutput: [[1]]\n\t\tExplanation: There is 1 choose 1 = 1 total combination.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 78, - "question": "class Solution:\n def subsets(self, nums: List[int]) -> List[List[int]]:\n\t\t\"\"\"\n\t\tGiven an integer array nums of unique elements, return all possible subsets (the power set).\n\t\tThe solution set must not contain duplicate subsets. Return the solution in any order.\n\t\tExample 1:\n\t\tInput: nums = [1,2,3]\n\t\tOutput: [[],[1],[2],[1,2],[3],[1,3],[2,3],[1,2,3]]\n\t\tExample 2:\n\t\tInput: nums = [0]\n\t\tOutput: [[],[0]]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 79, - "question": "class Solution:\n def exist(self, board: List[List[str]], word: str) -> bool:\n\t\t\"\"\"\n\t\tGiven an m x n grid of characters board and a string word, return true if word exists in the grid.\n\t\tThe word can be constructed from letters of sequentially adjacent cells, where adjacent cells are horizontally or vertically neighboring. The same letter cell may not be used more than once.\n\t\tExample 1:\n\t\tInput: board = [[\"A\",\"B\",\"C\",\"E\"],[\"S\",\"F\",\"C\",\"S\"],[\"A\",\"D\",\"E\",\"E\"]], word = \"ABCCED\"\n\t\tOutput: true\n\t\tExample 2:\n\t\tInput: board = [[\"A\",\"B\",\"C\",\"E\"],[\"S\",\"F\",\"C\",\"S\"],[\"A\",\"D\",\"E\",\"E\"]], word = \"SEE\"\n\t\tOutput: true\n\t\tExample 3:\n\t\tInput: board = [[\"A\",\"B\",\"C\",\"E\"],[\"S\",\"F\",\"C\",\"S\"],[\"A\",\"D\",\"E\",\"E\"]], word = \"ABCB\"\n\t\tOutput: false\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 80, - "question": "class Solution:\n def removeDuplicates(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tGiven an integer array nums sorted in non-decreasing order, remove some duplicates in-place such that each unique element appears at most twice. The relative order of the elements should be kept the same.\n\t\tSince it is impossible to change the length of the array in some languages, you must instead have the result be placed in the first part of the array nums. More formally, if there are k elements after removing the duplicates, then the first k elements of nums should hold the final result. It does not matter what you leave beyond the first k elements.\n\t\tReturn k after placing the final result in the first k slots of nums.\n\t\tDo not allocate extra space for another array. You must do this by modifying the input array in-place with O(1) extra memory.\n\t\tCustom Judge:\n\t\tThe judge will test your solution with the following code:\n\t\tint[] nums = [...]; // Input array\n\t\tint[] expectedNums = [...]; // The expected answer with correct length\n\t\tint k = removeDuplicates(nums); // Calls your implementation\n\t\tassert k == expectedNums.length;\n\t\tfor (int i = 0; i < k; i++) {\n\t\t assert nums[i] == expectedNums[i];\n\t\t}\n\t\tIf all assertions pass, then your solution will be accepted.\n\t\tExample 1:\n\t\tInput: nums = [1,1,1,2,2,3]\n\t\tOutput: 5, nums = [1,1,2,2,3,_]\n\t\tExplanation: Your function should return k = 5, with the first five elements of nums being 1, 1, 2, 2 and 3 respectively.\n\t\tIt does not matter what you leave beyond the returned k (hence they are underscores).\n\t\tExample 2:\n\t\tInput: nums = [0,0,1,1,1,1,2,3,3]\n\t\tOutput: 7, nums = [0,0,1,1,2,3,3,_,_]\n\t\tExplanation: Your function should return k = 7, with the first seven elements of nums being 0, 0, 1, 1, 2, 3 and 3 respectively.\n\t\tIt does not matter what you leave beyond the returned k (hence they are underscores).\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 81, - "question": "class Solution:\n def search(self, nums: List[int], target: int) -> bool:\n\t\t\"\"\"\n\t\tThere is an integer array nums sorted in non-decreasing order (not necessarily with distinct values).\n\t\tBefore being passed to your function, nums is rotated at an unknown pivot index k (0 <= k < nums.length) such that the resulting array is [nums[k], nums[k+1], ..., nums[n-1], nums[0], nums[1], ..., nums[k-1]] (0-indexed). For example, [0,1,2,4,4,4,5,6,6,7] might be rotated at pivot index 5 and become [4,5,6,6,7,0,1,2,4,4].\n\t\tGiven the array nums after the rotation and an integer target, return true if target is in nums, or false if it is not in nums.\n\t\tYou must decrease the overall operation steps as much as possible.\n\t\tExample 1:\n\t\tInput: nums = [2,5,6,0,0,1,2], target = 0\n\t\tOutput: true\n\t\tExample 2:\n\t\tInput: nums = [2,5,6,0,0,1,2], target = 3\n\t\tOutput: false\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 82, - "question": "class Solution:\n def deleteDuplicates(self, head: Optional[ListNode]) -> Optional[ListNode]:\n\t\t\"\"\"\n\t\tGiven the head of a sorted linked list, delete all nodes that have duplicate numbers, leaving only distinct numbers from the original list. Return the linked list sorted as well.\n\t\tExample 1:\n\t\tInput: head = [1,2,3,3,4,4,5]\n\t\tOutput: [1,2,5]\n\t\tExample 2:\n\t\tInput: head = [1,1,1,2,3]\n\t\tOutput: [2,3]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 83, - "question": "class Solution:\n def deleteDuplicates(self, head: Optional[ListNode]) -> Optional[ListNode]:\n\t\t\"\"\"\n\t\tGiven the head of a sorted linked list, delete all duplicates such that each element appears only once. Return the linked list sorted as well.\n\t\tExample 1:\n\t\tInput: head = [1,1,2]\n\t\tOutput: [1,2]\n\t\tExample 2:\n\t\tInput: head = [1,1,2,3,3]\n\t\tOutput: [1,2,3]\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 84, - "question": "class Solution:\n def largestRectangleArea(self, heights: List[int]) -> int:\n\t\t\"\"\"\n\t\tGiven an array of integers heights representing the histogram's bar height where the width of each bar is 1, return the area of the largest rectangle in the histogram.\n\t\tExample 1:\n\t\tInput: heights = [2,1,5,6,2,3]\n\t\tOutput: 10\n\t\tExplanation: The above is a histogram where width of each bar is 1.\n\t\tThe largest rectangle is shown in the red area, which has an area = 10 units.\n\t\tExample 2:\n\t\tInput: heights = [2,4]\n\t\tOutput: 4\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 85, - "question": "class Solution:\n def maximalRectangle(self, matrix: List[List[str]]) -> int:\n\t\t\"\"\"\n\t\tGiven a rows x cols binary matrix filled with 0's and 1's, find the largest rectangle containing only 1's and return its area.\n\t\tExample 1:\n\t\tInput: matrix = [[\"1\",\"0\",\"1\",\"0\",\"0\"],[\"1\",\"0\",\"1\",\"1\",\"1\"],[\"1\",\"1\",\"1\",\"1\",\"1\"],[\"1\",\"0\",\"0\",\"1\",\"0\"]]\n\t\tOutput: 6\n\t\tExplanation: The maximal rectangle is shown in the above picture.\n\t\tExample 2:\n\t\tInput: matrix = [[\"0\"]]\n\t\tOutput: 0\n\t\tExample 3:\n\t\tInput: matrix = [[\"1\"]]\n\t\tOutput: 1\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 86, - "question": "class Solution:\n def partition(self, head: Optional[ListNode], x: int) -> Optional[ListNode]:\n\t\t\"\"\"\n\t\tGiven the head of a linked list and a value x, partition it such that all nodes less than x come before nodes greater than or equal to x.\n\t\tYou should preserve the original relative order of the nodes in each of the two partitions.\n\t\tExample 1:\n\t\tInput: head = [1,4,3,2,5,2], x = 3\n\t\tOutput: [1,2,2,4,3,5]\n\t\tExample 2:\n\t\tInput: head = [2,1], x = 2\n\t\tOutput: [1,2]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 87, - "question": "class Solution:\n def isScramble(self, s1: str, s2: str) -> bool:\n\t\t\"\"\"\n\t\tWe can scramble a string s to get a string t using the following algorithm:\n\t\t\tIf the length of the string is 1, stop.\n\t\t\tIf the length of the string is > 1, do the following:\n\t\t\t\tSplit the string into two non-empty substrings at a random index, i.e., if the string is s, divide it to x and y where s = x + y.\n\t\t\t\tRandomly decide to swap the two substrings or to keep them in the same order. i.e., after this step, s may become s = x + y or s = y + x.\n\t\t\t\tApply step 1 recursively on each of the two substrings x and y.\n\t\tGiven two strings s1 and s2 of the same length, return true if s2 is a scrambled string of s1, otherwise, return false.\n\t\tExample 1:\n\t\tInput: s1 = \"great\", s2 = \"rgeat\"\n\t\tOutput: true\n\t\tExplanation: One possible scenario applied on s1 is:\n\t\t\"great\" --> \"gr/eat\" // divide at random index.\n\t\t\"gr/eat\" --> \"gr/eat\" // random decision is not to swap the two substrings and keep them in order.\n\t\t\"gr/eat\" --> \"g/r / e/at\" // apply the same algorithm recursively on both substrings. divide at random index each of them.\n\t\t\"g/r / e/at\" --> \"r/g / e/at\" // random decision was to swap the first substring and to keep the second substring in the same order.\n\t\t\"r/g / e/at\" --> \"r/g / e/ a/t\" // again apply the algorithm recursively, divide \"at\" to \"a/t\".\n\t\t\"r/g / e/ a/t\" --> \"r/g / e/ a/t\" // random decision is to keep both substrings in the same order.\n\t\tThe algorithm stops now, and the result string is \"rgeat\" which is s2.\n\t\tAs one possible scenario led s1 to be scrambled to s2, we return true.\n\t\tExample 2:\n\t\tInput: s1 = \"abcde\", s2 = \"caebd\"\n\t\tOutput: false\n\t\tExample 3:\n\t\tInput: s1 = \"a\", s2 = \"a\"\n\t\tOutput: true\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 88, - "question": "class Solution:\n def merge(self, nums1: List[int], m: int, nums2: List[int], n: int) -> None:\n\t\t\"\"\"\n Do not return anything, modify nums1 in-place instead.\n\t\tYou are given two integer arrays nums1 and nums2, sorted in non-decreasing order, and two integers m and n, representing the number of elements in nums1 and nums2 respectively.\n\t\tMerge nums1 and nums2 into a single array sorted in non-decreasing order.\n\t\tThe final sorted array should not be returned by the function, but instead be stored inside the array nums1. To accommodate this, nums1 has a length of m + n, where the first m elements denote the elements that should be merged, and the last n elements are set to 0 and should be ignored. nums2 has a length of n.\n\t\tExample 1:\n\t\tInput: nums1 = [1,2,3,0,0,0], m = 3, nums2 = [2,5,6], n = 3\n\t\tOutput: [1,2,2,3,5,6]\n\t\tExplanation: The arrays we are merging are [1,2,3] and [2,5,6].\n\t\tThe result of the merge is [1,2,2,3,5,6] with the underlined elements coming from nums1.\n\t\tExample 2:\n\t\tInput: nums1 = [1], m = 1, nums2 = [], n = 0\n\t\tOutput: [1]\n\t\tExplanation: The arrays we are merging are [1] and [].\n\t\tThe result of the merge is [1].\n\t\tExample 3:\n\t\tInput: nums1 = [0], m = 0, nums2 = [1], n = 1\n\t\tOutput: [1]\n\t\tExplanation: The arrays we are merging are [] and [1].\n\t\tThe result of the merge is [1].\n\t\tNote that because m = 0, there are no elements in nums1. The 0 is only there to ensure the merge result can fit in nums1.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 89, - "question": "class Solution:\n def grayCode(self, n: int) -> List[int]:\n\t\t\"\"\"\n\t\tAn n-bit gray code sequence is a sequence of 2n integers where:\n\t\t\tEvery integer is in the inclusive range [0, 2n - 1],\n\t\t\tThe first integer is 0,\n\t\t\tAn integer appears no more than once in the sequence,\n\t\t\tThe binary representation of every pair of adjacent integers differs by exactly one bit, and\n\t\t\tThe binary representation of the first and last integers differs by exactly one bit.\n\t\tGiven an integer n, return any valid n-bit gray code sequence.\n\t\tExample 1:\n\t\tInput: n = 2\n\t\tOutput: [0,1,3,2]\n\t\tExplanation:\n\t\tThe binary representation of [0,1,3,2] is [00,01,11,10].\n\t\t- 00 and 01 differ by one bit\n\t\t- 01 and 11 differ by one bit\n\t\t- 11 and 10 differ by one bit\n\t\t- 10 and 00 differ by one bit\n\t\t[0,2,3,1] is also a valid gray code sequence, whose binary representation is [00,10,11,01].\n\t\t- 00 and 10 differ by one bit\n\t\t- 10 and 11 differ by one bit\n\t\t- 11 and 01 differ by one bit\n\t\t- 01 and 00 differ by one bit\n\t\tExample 2:\n\t\tInput: n = 1\n\t\tOutput: [0,1]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 90, - "question": "class Solution:\n def subsetsWithDup(self, nums: List[int]) -> List[List[int]]:\n\t\t\"\"\"\n\t\tGiven an integer array nums that may contain duplicates, return all possible subsets (the power set).\n\t\tThe solution set must not contain duplicate subsets. Return the solution in any order.\n\t\tExample 1:\n\t\tInput: nums = [1,2,2]\n\t\tOutput: [[],[1],[1,2],[1,2,2],[2],[2,2]]\n\t\tExample 2:\n\t\tInput: nums = [0]\n\t\tOutput: [[],[0]]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 91, - "question": "class Solution:\n def numDecodings(self, s: str) -> int:\n\t\t\"\"\"\n\t\tA message containing letters from A-Z can be encoded into numbers using the following mapping:\n\t\t'A' -> \"1\"\n\t\t'B' -> \"2\"\n\t\t...\n\t\t'Z' -> \"26\"\n\t\tTo decode an encoded message, all the digits must be grouped then mapped back into letters using the reverse of the mapping above (there may be multiple ways). For example, \"11106\" can be mapped into:\n\t\t\t\"AAJF\" with the grouping (1 1 10 6)\n\t\t\t\"KJF\" with the grouping (11 10 6)\n\t\tNote that the grouping (1 11 06) is invalid because \"06\" cannot be mapped into 'F' since \"6\" is different from \"06\".\n\t\tGiven a string s containing only digits, return the number of ways to decode it.\n\t\tThe test cases are generated so that the answer fits in a 32-bit integer.\n\t\tExample 1:\n\t\tInput: s = \"12\"\n\t\tOutput: 2\n\t\tExplanation: \"12\" could be decoded as \"AB\" (1 2) or \"L\" (12).\n\t\tExample 2:\n\t\tInput: s = \"226\"\n\t\tOutput: 3\n\t\tExplanation: \"226\" could be decoded as \"BZ\" (2 26), \"VF\" (22 6), or \"BBF\" (2 2 6).\n\t\tExample 3:\n\t\tInput: s = \"06\"\n\t\tOutput: 0\n\t\tExplanation: \"06\" cannot be mapped to \"F\" because of the leading zero (\"6\" is different from \"06\").\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 92, - "question": "class Solution:\n def reverseBetween(self, head: Optional[ListNode], left: int, right: int) -> Optional[ListNode]:\n\t\t\"\"\"\n\t\tGiven the head of a singly linked list and two integers left and right where left <= right, reverse the nodes of the list from position left to position right, and return the reversed list.\n\t\tExample 1:\n\t\tInput: head = [1,2,3,4,5], left = 2, right = 4\n\t\tOutput: [1,4,3,2,5]\n\t\tExample 2:\n\t\tInput: head = [5], left = 1, right = 1\n\t\tOutput: [5]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 93, - "question": "class Solution:\n def restoreIpAddresses(self, s: str) -> List[str]:\n\t\t\"\"\"\n\t\tA valid IP address consists of exactly four integers separated by single dots. Each integer is between 0 and 255 (inclusive) and cannot have leading zeros.\n\t\t\tFor example, \"0.1.2.201\" and \"192.168.1.1\" are valid IP addresses, but \"0.011.255.245\", \"192.168.1.312\" and \"192.168@1.1\" are invalid IP addresses.\n\t\tGiven a string s containing only digits, return all possible valid IP addresses that can be formed by inserting dots into s. You are not allowed to reorder or remove any digits in s. You may return the valid IP addresses in any order.\n\t\tExample 1:\n\t\tInput: s = \"25525511135\"\n\t\tOutput: [\"255.255.11.135\",\"255.255.111.35\"]\n\t\tExample 2:\n\t\tInput: s = \"0000\"\n\t\tOutput: [\"0.0.0.0\"]\n\t\tExample 3:\n\t\tInput: s = \"101023\"\n\t\tOutput: [\"1.0.10.23\",\"1.0.102.3\",\"10.1.0.23\",\"10.10.2.3\",\"101.0.2.3\"]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 94, - "question": "class Solution:\n def inorderTraversal(self, root: Optional[TreeNode]) -> List[int]:\n\t\t\"\"\"\n\t\tGiven the root of a binary tree, return the inorder traversal of its nodes' values.\n\t\tExample 1:\n\t\tInput: root = [1,null,2,3]\n\t\tOutput: [1,3,2]\n\t\tExample 2:\n\t\tInput: root = []\n\t\tOutput: []\n\t\tExample 3:\n\t\tInput: root = [1]\n\t\tOutput: [1]\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 95, - "question": "class Solution:\n def generateTrees(self, n: int) -> List[Optional[TreeNode]]:\n\t\t\"\"\"\n\t\tGiven an integer n, return all the structurally unique BST's (binary search trees), which has exactly n nodes of unique values from 1 to n. Return the answer in any order.\n\t\tExample 1:\n\t\tInput: n = 3\n\t\tOutput: [[1,null,2,null,3],[1,null,3,2],[2,1,3],[3,1,null,null,2],[3,2,null,1]]\n\t\tExample 2:\n\t\tInput: n = 1\n\t\tOutput: [[1]]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 96, - "question": "class Solution:\n def numTrees(self, n: int) -> int:\n\t\t\"\"\"\n\t\tGiven an integer n, return the number of structurally unique BST's (binary search trees) which has exactly n nodes of unique values from 1 to n.\n\t\tExample 1:\n\t\tInput: n = 3\n\t\tOutput: 5\n\t\tExample 2:\n\t\tInput: n = 1\n\t\tOutput: 1\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 97, - "question": "class Solution:\n def isInterleave(self, s1: str, s2: str, s3: str) -> bool:\n\t\t\"\"\"\n\t\tGiven strings s1, s2, and s3, find whether s3 is formed by an interleaving of s1 and s2.\n\t\tAn interleaving of two strings s and t is a configuration where s and t are divided into n and m substrings respectively, such that:\n\t\t\ts = s1 + s2 + ... + sn\n\t\t\tt = t1 + t2 + ... + tm\n\t\t\t|n - m| <= 1\n\t\t\tThe interleaving is s1 + t1 + s2 + t2 + s3 + t3 + ... or t1 + s1 + t2 + s2 + t3 + s3 + ...\n\t\tNote: a + b is the concatenation of strings a and b.\n\t\tExample 1:\n\t\tInput: s1 = \"aabcc\", s2 = \"dbbca\", s3 = \"aadbbcbcac\"\n\t\tOutput: true\n\t\tExplanation: One way to obtain s3 is:\n\t\tSplit s1 into s1 = \"aa\" + \"bc\" + \"c\", and s2 into s2 = \"dbbc\" + \"a\".\n\t\tInterleaving the two splits, we get \"aa\" + \"dbbc\" + \"bc\" + \"a\" + \"c\" = \"aadbbcbcac\".\n\t\tSince s3 can be obtained by interleaving s1 and s2, we return true.\n\t\tExample 2:\n\t\tInput: s1 = \"aabcc\", s2 = \"dbbca\", s3 = \"aadbbbaccc\"\n\t\tOutput: false\n\t\tExplanation: Notice how it is impossible to interleave s2 with any other string to obtain s3.\n\t\tExample 3:\n\t\tInput: s1 = \"\", s2 = \"\", s3 = \"\"\n\t\tOutput: true\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 98, - "question": "class Solution:\n def isValidBST(self, root: Optional[TreeNode]) -> bool:\n\t\t\"\"\"\n\t\tGiven the root of a binary tree, determine if it is a valid binary search tree (BST).\n\t\tA valid BST is defined as follows:\n\t\t\tThe left subtree of a node contains only nodes with keys less than the node's key.\n\t\t\tThe right subtree of a node contains only nodes with keys greater than the node's key.\n\t\t\tBoth the left and right subtrees must also be binary search trees.\n\t\tExample 1:\n\t\tInput: root = [2,1,3]\n\t\tOutput: true\n\t\tExample 2:\n\t\tInput: root = [5,1,4,null,null,3,6]\n\t\tOutput: false\n\t\tExplanation: The root node's value is 5 but its right child's value is 4.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 99, - "question": "class Solution:\n def recoverTree(self, root: Optional[TreeNode]) -> None:\n\t\t\"\"\"\n Do not return anything, modify root in-place instead.\n\t\tYou are given the root of a binary search tree (BST), where the values of exactly two nodes of the tree were swapped by mistake. Recover the tree without changing its structure.\n\t\tExample 1:\n\t\tInput: root = [1,3,null,null,2]\n\t\tOutput: [3,1,null,null,2]\n\t\tExplanation: 3 cannot be a left child of 1 because 3 > 1. Swapping 1 and 3 makes the BST valid.\n\t\tExample 2:\n\t\tInput: root = [3,1,4,null,null,2]\n\t\tOutput: [2,1,4,null,null,3]\n\t\tExplanation: 2 cannot be in the right subtree of 3 because 2 < 3. Swapping 2 and 3 makes the BST valid.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 100, - "question": "class Solution:\n def isSameTree(self, p: Optional[TreeNode], q: Optional[TreeNode]) -> bool:\n\t\t\"\"\"\n\t\tGiven the roots of two binary trees p and q, write a function to check if they are the same or not.\n\t\tTwo binary trees are considered the same if they are structurally identical, and the nodes have the same value.\n\t\tExample 1:\n\t\tInput: p = [1,2,3], q = [1,2,3]\n\t\tOutput: true\n\t\tExample 2:\n\t\tInput: p = [1,2], q = [1,null,2]\n\t\tOutput: false\n\t\tExample 3:\n\t\tInput: p = [1,2,1], q = [1,1,2]\n\t\tOutput: false\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 101, - "question": "class Solution:\n def isSymmetric(self, root: Optional[TreeNode]) -> bool:\n\t\t\"\"\"\n\t\tGiven the root of a binary tree, check whether it is a mirror of itself (i.e., symmetric around its center).\n\t\tExample 1:\n\t\tInput: root = [1,2,2,3,4,4,3]\n\t\tOutput: true\n\t\tExample 2:\n\t\tInput: root = [1,2,2,null,3,null,3]\n\t\tOutput: false\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 102, - "question": "class Solution:\n def levelOrder(self, root: Optional[TreeNode]) -> List[List[int]]:\n\t\t\"\"\"\n\t\tGiven the root of a binary tree, return the level order traversal of its nodes' values. (i.e., from left to right, level by level).\n\t\tExample 1:\n\t\tInput: root = [3,9,20,null,null,15,7]\n\t\tOutput: [[3],[9,20],[15,7]]\n\t\tExample 2:\n\t\tInput: root = [1]\n\t\tOutput: [[1]]\n\t\tExample 3:\n\t\tInput: root = []\n\t\tOutput: []\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 103, - "question": "class Solution:\n def zigzagLevelOrder(self, root: Optional[TreeNode]) -> List[List[int]]:\n\t\t\"\"\"\n\t\tGiven the root of a binary tree, return the zigzag level order traversal of its nodes' values. (i.e., from left to right, then right to left for the next level and alternate between).\n\t\tExample 1:\n\t\tInput: root = [3,9,20,null,null,15,7]\n\t\tOutput: [[3],[20,9],[15,7]]\n\t\tExample 2:\n\t\tInput: root = [1]\n\t\tOutput: [[1]]\n\t\tExample 3:\n\t\tInput: root = []\n\t\tOutput: []\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 104, - "question": "class Solution:\n def maxDepth(self, root: Optional[TreeNode]) -> int:\n\t\t\"\"\"\n\t\tGiven the root of a binary tree, return its maximum depth.\n\t\tA binary tree's maximum depth is the number of nodes along the longest path from the root node down to the farthest leaf node.\n\t\tExample 1:\n\t\tInput: root = [3,9,20,null,null,15,7]\n\t\tOutput: 3\n\t\tExample 2:\n\t\tInput: root = [1,null,2]\n\t\tOutput: 2\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 105, - "question": "class Solution:\n def buildTree(self, preorder: List[int], inorder: List[int]) -> Optional[TreeNode]:\n\t\t\"\"\"\n\t\tGiven two integer arrays preorder and inorder where preorder is the preorder traversal of a binary tree and inorder is the inorder traversal of the same tree, construct and return the binary tree.\n\t\tExample 1:\n\t\tInput: preorder = [3,9,20,15,7], inorder = [9,3,15,20,7]\n\t\tOutput: [3,9,20,null,null,15,7]\n\t\tExample 2:\n\t\tInput: preorder = [-1], inorder = [-1]\n\t\tOutput: [-1]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 106, - "question": "class Solution:\n def buildTree(self, inorder: List[int], postorder: List[int]) -> Optional[TreeNode]:\n\t\t\"\"\"\n\t\tGiven two integer arrays inorder and postorder where inorder is the inorder traversal of a binary tree and postorder is the postorder traversal of the same tree, construct and return the binary tree.\n\t\tExample 1:\n\t\tInput: inorder = [9,3,15,20,7], postorder = [9,15,7,20,3]\n\t\tOutput: [3,9,20,null,null,15,7]\n\t\tExample 2:\n\t\tInput: inorder = [-1], postorder = [-1]\n\t\tOutput: [-1]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 107, - "question": "class Solution:\n def levelOrderBottom(self, root: Optional[TreeNode]) -> List[List[int]]:\n\t\t\"\"\"\n\t\tGiven the root of a binary tree, return the bottom-up level order traversal of its nodes' values. (i.e., from left to right, level by level from leaf to root).\n\t\tExample 1:\n\t\tInput: root = [3,9,20,null,null,15,7]\n\t\tOutput: [[15,7],[9,20],[3]]\n\t\tExample 2:\n\t\tInput: root = [1]\n\t\tOutput: [[1]]\n\t\tExample 3:\n\t\tInput: root = []\n\t\tOutput: []\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 108, - "question": "class Solution:\n def sortedArrayToBST(self, nums: List[int]) -> Optional[TreeNode]:\n\t\t\"\"\"\n\t\tGiven an integer array nums where the elements are sorted in ascending order, convert it to a height-balanced binary search tree.\n\t\tExample 1:\n\t\tInput: nums = [-10,-3,0,5,9]\n\t\tOutput: [0,-3,9,-10,null,5]\n\t\tExplanation: [0,-10,5,null,-3,null,9] is also accepted:\n\t\tExample 2:\n\t\tInput: nums = [1,3]\n\t\tOutput: [3,1]\n\t\tExplanation: [1,null,3] and [3,1] are both height-balanced BSTs.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 109, - "question": "class Solution:\n def sortedListToBST(self, head: Optional[ListNode]) -> Optional[TreeNode]:\n\t\t\"\"\"\n\t\tGiven the head of a singly linked list where elements are sorted in ascending order, convert it to a height-balanced binary search tree.\n\t\tExample 1:\n\t\tInput: head = [-10,-3,0,5,9]\n\t\tOutput: [0,-3,9,-10,null,5]\n\t\tExplanation: One possible answer is [0,-3,9,-10,null,5], which represents the shown height balanced BST.\n\t\tExample 2:\n\t\tInput: head = []\n\t\tOutput: []\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 110, - "question": "class Solution:\n def isBalanced(self, root: Optional[TreeNode]) -> bool:\n\t\t\"\"\"\n\t\tGiven a binary tree, determine if it is height-balanced.\n\t\tExample 1:\n\t\tInput: root = [3,9,20,null,null,15,7]\n\t\tOutput: true\n\t\tExample 2:\n\t\tInput: root = [1,2,2,3,3,null,null,4,4]\n\t\tOutput: false\n\t\tExample 3:\n\t\tInput: root = []\n\t\tOutput: true\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 111, - "question": "class Solution:\n def minDepth(self, root: Optional[TreeNode]) -> int:\n\t\t\"\"\"\n\t\tGiven a binary tree, find its minimum depth.\n\t\tThe minimum depth is the number of nodes along the shortest path from the root node down to the nearest leaf node.\n\t\tNote: A leaf is a node with no children.\n\t\tExample 1:\n\t\tInput: root = [3,9,20,null,null,15,7]\n\t\tOutput: 2\n\t\tExample 2:\n\t\tInput: root = [2,null,3,null,4,null,5,null,6]\n\t\tOutput: 5\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 112, - "question": "class Solution:\n def hasPathSum(self, root: Optional[TreeNode], targetSum: int) -> bool:\n\t\t\"\"\"\n\t\tGiven the root of a binary tree and an integer targetSum, return true if the tree has a root-to-leaf path such that adding up all the values along the path equals targetSum.\n\t\tA leaf is a node with no children.\n\t\tExample 1:\n\t\tInput: root = [5,4,8,11,null,13,4,7,2,null,null,null,1], targetSum = 22\n\t\tOutput: true\n\t\tExplanation: The root-to-leaf path with the target sum is shown.\n\t\tExample 2:\n\t\tInput: root = [1,2,3], targetSum = 5\n\t\tOutput: false\n\t\tExplanation: There two root-to-leaf paths in the tree:\n\t\t(1 --> 2): The sum is 3.\n\t\t(1 --> 3): The sum is 4.\n\t\tThere is no root-to-leaf path with sum = 5.\n\t\tExample 3:\n\t\tInput: root = [], targetSum = 0\n\t\tOutput: false\n\t\tExplanation: Since the tree is empty, there are no root-to-leaf paths.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 113, - "question": "class Solution:\n def pathSum(self, root: Optional[TreeNode], targetSum: int) -> List[List[int]]:\n\t\t\"\"\"\n\t\tGiven the root of a binary tree and an integer targetSum, return all root-to-leaf paths where the sum of the node values in the path equals targetSum. Each path should be returned as a list of the node values, not node references.\n\t\tA root-to-leaf path is a path starting from the root and ending at any leaf node. A leaf is a node with no children.\n\t\tExample 1:\n\t\tInput: root = [5,4,8,11,null,13,4,7,2,null,null,5,1], targetSum = 22\n\t\tOutput: [[5,4,11,2],[5,8,4,5]]\n\t\tExplanation: There are two paths whose sum equals targetSum:\n\t\t5 + 4 + 11 + 2 = 22\n\t\t5 + 8 + 4 + 5 = 22\n\t\tExample 2:\n\t\tInput: root = [1,2,3], targetSum = 5\n\t\tOutput: []\n\t\tExample 3:\n\t\tInput: root = [1,2], targetSum = 0\n\t\tOutput: []\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 114, - "question": "class Solution:\n def flatten(self, root: Optional[TreeNode]) -> None:\n\t\t\"\"\"\n Do not return anything, modify root in-place instead.\n\t\tGiven the root of a binary tree, flatten the tree into a \"linked list\":\n\t\t\tThe \"linked list\" should use the same TreeNode class where the right child pointer points to the next node in the list and the left child pointer is always null.\n\t\t\tThe \"linked list\" should be in the same order as a pre-order traversal of the binary tree.\n\t\tExample 1:\n\t\tInput: root = [1,2,5,3,4,null,6]\n\t\tOutput: [1,null,2,null,3,null,4,null,5,null,6]\n\t\tExample 2:\n\t\tInput: root = []\n\t\tOutput: []\n\t\tExample 3:\n\t\tInput: root = [0]\n\t\tOutput: [0]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 115, - "question": "class Solution:\n def numDistinct(self, s: str, t: str) -> int:\n\t\t\"\"\"\n\t\tGiven two strings s and t, return the number of distinct subsequences of s which equals t.\n\t\tThe test cases are generated so that the answer fits on a 32-bit signed integer.\n\t\tExample 1:\n\t\tInput: s = \"rabbbit\", t = \"rabbit\"\n\t\tOutput: 3\n\t\tExplanation:\n\t\tAs shown below, there are 3 ways you can generate \"rabbit\" from s.\n\t\trabbbit\n\t\trabbbit\n\t\trabbbit\n\t\tExample 2:\n\t\tInput: s = \"babgbag\", t = \"bag\"\n\t\tOutput: 5\n\t\tExplanation:\n\t\tAs shown below, there are 5 ways you can generate \"bag\" from s.\n\t\tbabgbag\n\t\tbabgbag\n\t\tbabgbag\n\t\tbabgbag\n\t\tbabgbag\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 116, - "question": "\n\t\t\"\"\"\nclass Node:\n def __init__(self, val: int = 0, left: 'Node' = None, right: 'Node' = None, next: 'Node' = None):\n self.val = val\n self.left = left\n self.right = right\n self.next = next\n\t\tYou are given a perfect binary tree where all leaves are on the same level, and every parent has two children. The binary tree has the following definition:\n\t\tstruct Node {\n\t\t int val;\n\t\t Node *left;\n\t\t Node *right;\n\t\t Node *next;\n\t\t}\n\t\tPopulate each next pointer to point to its next right node. If there is no next right node, the next pointer should be set to NULL.\n\t\tInitially, all next pointers are set to NULL.\n\t\tExample 1:\n\t\tInput: root = [1,2,3,4,5,6,7]\n\t\tOutput: [1,#,2,3,#,4,5,6,7,#]\n\t\tExplanation: Given the above perfect binary tree (Figure A), your function should populate each next pointer to point to its next right node, just like in Figure B. The serialized output is in level order as connected by the next pointers, with '#' signifying the end of each level.\n\t\tExample 2:\n\t\tInput: root = []\n\t\tOutput: []\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 117, - "question": "\n\t\t\"\"\"\nclass Node:\n def __init__(self, val: int = 0, left: 'Node' = None, right: 'Node' = None, next: 'Node' = None):\n self.val = val\n self.left = left\n self.right = right\n self.next = next\n\t\tGiven a binary tree\n\t\tstruct Node {\n\t\t int val;\n\t\t Node *left;\n\t\t Node *right;\n\t\t Node *next;\n\t\t}\n\t\tPopulate each next pointer to point to its next right node. If there is no next right node, the next pointer should be set to NULL.\n\t\tInitially, all next pointers are set to NULL.\n\t\tExample 1:\n\t\tInput: root = [1,2,3,4,5,null,7]\n\t\tOutput: [1,#,2,3,#,4,5,7,#]\n\t\tExplanation: Given the above binary tree (Figure A), your function should populate each next pointer to point to its next right node, just like in Figure B. The serialized output is in level order as connected by the next pointers, with '#' signifying the end of each level.\n\t\tExample 2:\n\t\tInput: root = []\n\t\tOutput: []\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 118, - "question": "class Solution:\n def generate(self, numRows: int) -> List[List[int]]:\n\t\t\"\"\"\n\t\tGiven an integer numRows, return the first numRows of Pascal's triangle.\n\t\tIn Pascal's triangle, each number is the sum of the two numbers directly above it as shown:\n\t\tExample 1:\n\t\tInput: numRows = 5\n\t\tOutput: [[1],[1,1],[1,2,1],[1,3,3,1],[1,4,6,4,1]]\n\t\tExample 2:\n\t\tInput: numRows = 1\n\t\tOutput: [[1]]\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 119, - "question": "class Solution:\n def getRow(self, rowIndex: int) -> List[int]:\n\t\t\"\"\"\n\t\tGiven an integer rowIndex, return the rowIndexth (0-indexed) row of the Pascal's triangle.\n\t\tIn Pascal's triangle, each number is the sum of the two numbers directly above it as shown:\n\t\tExample 1:\n\t\tInput: rowIndex = 3\n\t\tOutput: [1,3,3,1]\n\t\tExample 2:\n\t\tInput: rowIndex = 0\n\t\tOutput: [1]\n\t\tExample 3:\n\t\tInput: rowIndex = 1\n\t\tOutput: [1,1]\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 120, - "question": "class Solution:\n def minimumTotal(self, triangle: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tGiven a triangle array, return the minimum path sum from top to bottom.\n\t\tFor each step, you may move to an adjacent number of the row below. More formally, if you are on index i on the current row, you may move to either index i or index i + 1 on the next row.\n\t\tExample 1:\n\t\tInput: triangle = [[2],[3,4],[6,5,7],[4,1,8,3]]\n\t\tOutput: 11\n\t\tExplanation: The triangle looks like:\n\t\t 2\n\t\t 3 4\n\t\t 6 5 7\n\t\t4 1 8 3\n\t\tThe minimum path sum from top to bottom is 2 + 3 + 5 + 1 = 11 (underlined above).\n\t\tExample 2:\n\t\tInput: triangle = [[-10]]\n\t\tOutput: -10\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 121, - "question": "class Solution:\n def maxProfit(self, prices: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou are given an array prices where prices[i] is the price of a given stock on the ith day.\n\t\tYou want to maximize your profit by choosing a single day to buy one stock and choosing a different day in the future to sell that stock.\n\t\tReturn the maximum profit you can achieve from this transaction. If you cannot achieve any profit, return 0.\n\t\tExample 1:\n\t\tInput: prices = [7,1,5,3,6,4]\n\t\tOutput: 5\n\t\tExplanation: Buy on day 2 (price = 1) and sell on day 5 (price = 6), profit = 6-1 = 5.\n\t\tNote that buying on day 2 and selling on day 1 is not allowed because you must buy before you sell.\n\t\tExample 2:\n\t\tInput: prices = [7,6,4,3,1]\n\t\tOutput: 0\n\t\tExplanation: In this case, no transactions are done and the max profit = 0.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 122, - "question": "class Solution:\n def maxProfit(self, prices: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou are given an integer array prices where prices[i] is the price of a given stock on the ith day.\n\t\tOn each day, you may decide to buy and/or sell the stock. You can only hold at most one share of the stock at any time. However, you can buy it then immediately sell it on the same day.\n\t\tFind and return the maximum profit you can achieve.\n\t\tExample 1:\n\t\tInput: prices = [7,1,5,3,6,4]\n\t\tOutput: 7\n\t\tExplanation: Buy on day 2 (price = 1) and sell on day 3 (price = 5), profit = 5-1 = 4.\n\t\tThen buy on day 4 (price = 3) and sell on day 5 (price = 6), profit = 6-3 = 3.\n\t\tTotal profit is 4 + 3 = 7.\n\t\tExample 2:\n\t\tInput: prices = [1,2,3,4,5]\n\t\tOutput: 4\n\t\tExplanation: Buy on day 1 (price = 1) and sell on day 5 (price = 5), profit = 5-1 = 4.\n\t\tTotal profit is 4.\n\t\tExample 3:\n\t\tInput: prices = [7,6,4,3,1]\n\t\tOutput: 0\n\t\tExplanation: There is no way to make a positive profit, so we never buy the stock to achieve the maximum profit of 0.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 123, - "question": "class Solution:\n def maxProfit(self, prices: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou are given an array prices where prices[i] is the price of a given stock on the ith day.\n\t\tFind the maximum profit you can achieve. You may complete at most two transactions.\n\t\tNote: You may not engage in multiple transactions simultaneously (i.e., you must sell the stock before you buy again).\n\t\tExample 1:\n\t\tInput: prices = [3,3,5,0,0,3,1,4]\n\t\tOutput: 6\n\t\tExplanation: Buy on day 4 (price = 0) and sell on day 6 (price = 3), profit = 3-0 = 3.\n\t\tThen buy on day 7 (price = 1) and sell on day 8 (price = 4), profit = 4-1 = 3.\n\t\tExample 2:\n\t\tInput: prices = [1,2,3,4,5]\n\t\tOutput: 4\n\t\tExplanation: Buy on day 1 (price = 1) and sell on day 5 (price = 5), profit = 5-1 = 4.\n\t\tNote that you cannot buy on day 1, buy on day 2 and sell them later, as you are engaging multiple transactions at the same time. You must sell before buying again.\n\t\tExample 3:\n\t\tInput: prices = [7,6,4,3,1]\n\t\tOutput: 0\n\t\tExplanation: In this case, no transaction is done, i.e. max profit = 0.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 124, - "question": "class Solution:\n def maxPathSum(self, root: Optional[TreeNode]) -> int:\n\t\t\"\"\"\n\t\tA path in a binary tree is a sequence of nodes where each pair of adjacent nodes in the sequence has an edge connecting them. A node can only appear in the sequence at most once. Note that the path does not need to pass through the root.\n\t\tThe path sum of a path is the sum of the node's values in the path.\n\t\tGiven the root of a binary tree, return the maximum path sum of any non-empty path.\n\t\tExample 1:\n\t\tInput: root = [1,2,3]\n\t\tOutput: 6\n\t\tExplanation: The optimal path is 2 -> 1 -> 3 with a path sum of 2 + 1 + 3 = 6.\n\t\tExample 2:\n\t\tInput: root = [-10,9,20,null,null,15,7]\n\t\tOutput: 42\n\t\tExplanation: The optimal path is 15 -> 20 -> 7 with a path sum of 15 + 20 + 7 = 42.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 125, - "question": "class Solution:\n def isPalindrome(self, s: str) -> bool:\n\t\t\"\"\"\n\t\tA phrase is a palindrome if, after converting all uppercase letters into lowercase letters and removing all non-alphanumeric characters, it reads the same forward and backward. Alphanumeric characters include letters and numbers.\n\t\tGiven a string s, return true if it is a palindrome, or false otherwise.\n\t\tExample 1:\n\t\tInput: s = \"A man, a plan, a canal: Panama\"\n\t\tOutput: true\n\t\tExplanation: \"amanaplanacanalpanama\" is a palindrome.\n\t\tExample 2:\n\t\tInput: s = \"race a car\"\n\t\tOutput: false\n\t\tExplanation: \"raceacar\" is not a palindrome.\n\t\tExample 3:\n\t\tInput: s = \" \"\n\t\tOutput: true\n\t\tExplanation: s is an empty string \"\" after removing non-alphanumeric characters.\n\t\tSince an empty string reads the same forward and backward, it is a palindrome.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 126, - "question": "class Solution:\n def findLadders(self, beginWord: str, endWord: str, wordList: List[str]) -> List[List[str]]:\n\t\t\"\"\"\n\t\tA transformation sequence from word beginWord to word endWord using a dictionary wordList is a sequence of words beginWord -> s1 -> s2 -> ... -> sk such that:\n\t\t\tEvery adjacent pair of words differs by a single letter.\n\t\t\tEvery si for 1 <= i <= k is in wordList. Note that beginWord does not need to be in wordList.\n\t\t\tsk == endWord\n\t\tGiven two words, beginWord and endWord, and a dictionary wordList, return all the shortest transformation sequences from beginWord to endWord, or an empty list if no such sequence exists. Each sequence should be returned as a list of the words [beginWord, s1, s2, ..., sk].\n\t\tExample 1:\n\t\tInput: beginWord = \"hit\", endWord = \"cog\", wordList = [\"hot\",\"dot\",\"dog\",\"lot\",\"log\",\"cog\"]\n\t\tOutput: [[\"hit\",\"hot\",\"dot\",\"dog\",\"cog\"],[\"hit\",\"hot\",\"lot\",\"log\",\"cog\"]]\n\t\tExplanation: There are 2 shortest transformation sequences:\n\t\t\"hit\" -> \"hot\" -> \"dot\" -> \"dog\" -> \"cog\"\n\t\t\"hit\" -> \"hot\" -> \"lot\" -> \"log\" -> \"cog\"\n\t\tExample 2:\n\t\tInput: beginWord = \"hit\", endWord = \"cog\", wordList = [\"hot\",\"dot\",\"dog\",\"lot\",\"log\"]\n\t\tOutput: []\n\t\tExplanation: The endWord \"cog\" is not in wordList, therefore there is no valid transformation sequence.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 127, - "question": "class Solution:\n def ladderLength(self, beginWord: str, endWord: str, wordList: List[str]) -> int:\n\t\t\"\"\"\n\t\tA transformation sequence from word beginWord to word endWord using a dictionary wordList is a sequence of words beginWord -> s1 -> s2 -> ... -> sk such that:\n\t\t\tEvery adjacent pair of words differs by a single letter.\n\t\t\tEvery si for 1 <= i <= k is in wordList. Note that beginWord does not need to be in wordList.\n\t\t\tsk == endWord\n\t\tGiven two words, beginWord and endWord, and a dictionary wordList, return the number of words in the shortest transformation sequence from beginWord to endWord, or 0 if no such sequence exists.\n\t\tExample 1:\n\t\tInput: beginWord = \"hit\", endWord = \"cog\", wordList = [\"hot\",\"dot\",\"dog\",\"lot\",\"log\",\"cog\"]\n\t\tOutput: 5\n\t\tExplanation: One shortest transformation sequence is \"hit\" -> \"hot\" -> \"dot\" -> \"dog\" -> cog\", which is 5 words long.\n\t\tExample 2:\n\t\tInput: beginWord = \"hit\", endWord = \"cog\", wordList = [\"hot\",\"dot\",\"dog\",\"lot\",\"log\"]\n\t\tOutput: 0\n\t\tExplanation: The endWord \"cog\" is not in wordList, therefore there is no valid transformation sequence.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 128, - "question": "class Solution:\n def longestConsecutive(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tGiven an unsorted array of integers nums, return the length of the longest consecutive elements sequence.\n\t\tYou must write an algorithm that runs in O(n) time.\n\t\tExample 1:\n\t\tInput: nums = [100,4,200,1,3,2]\n\t\tOutput: 4\n\t\tExplanation: The longest consecutive elements sequence is [1, 2, 3, 4]. Therefore its length is 4.\n\t\tExample 2:\n\t\tInput: nums = [0,3,7,2,5,8,4,6,0,1]\n\t\tOutput: 9\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 129, - "question": "class Solution:\n def sumNumbers(self, root: Optional[TreeNode]) -> int:\n\t\t\"\"\"\n\t\tYou are given the root of a binary tree containing digits from 0 to 9 only.\n\t\tEach root-to-leaf path in the tree represents a number.\n\t\t\tFor example, the root-to-leaf path 1 -> 2 -> 3 represents the number 123.\n\t\tReturn the total sum of all root-to-leaf numbers. Test cases are generated so that the answer will fit in a 32-bit integer.\n\t\tA leaf node is a node with no children.\n\t\tExample 1:\n\t\tInput: root = [1,2,3]\n\t\tOutput: 25\n\t\tExplanation:\n\t\tThe root-to-leaf path 1->2 represents the number 12.\n\t\tThe root-to-leaf path 1->3 represents the number 13.\n\t\tTherefore, sum = 12 + 13 = 25.\n\t\tExample 2:\n\t\tInput: root = [4,9,0,5,1]\n\t\tOutput: 1026\n\t\tExplanation:\n\t\tThe root-to-leaf path 4->9->5 represents the number 495.\n\t\tThe root-to-leaf path 4->9->1 represents the number 491.\n\t\tThe root-to-leaf path 4->0 represents the number 40.\n\t\tTherefore, sum = 495 + 491 + 40 = 1026.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 130, - "question": "class Solution:\n def solve(self, board: List[List[str]]) -> None:\n\t\t\"\"\"\n Do not return anything, modify board in-place instead.\n\t\tGiven an m x n matrix board containing 'X' and 'O', capture all regions that are 4-directionally surrounded by 'X'.\n\t\tA region is captured by flipping all 'O's into 'X's in that surrounded region.\n\t\tExample 1:\n\t\tInput: board = [[\"X\",\"X\",\"X\",\"X\"],[\"X\",\"O\",\"O\",\"X\"],[\"X\",\"X\",\"O\",\"X\"],[\"X\",\"O\",\"X\",\"X\"]]\n\t\tOutput: [[\"X\",\"X\",\"X\",\"X\"],[\"X\",\"X\",\"X\",\"X\"],[\"X\",\"X\",\"X\",\"X\"],[\"X\",\"O\",\"X\",\"X\"]]\n\t\tExplanation: Notice that an 'O' should not be flipped if:\n\t\t- It is on the border, or\n\t\t- It is adjacent to an 'O' that should not be flipped.\n\t\tThe bottom 'O' is on the border, so it is not flipped.\n\t\tThe other three 'O' form a surrounded region, so they are flipped.\n\t\tExample 2:\n\t\tInput: board = [[\"X\"]]\n\t\tOutput: [[\"X\"]]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 131, - "question": "class Solution:\n def partition(self, s: str) -> List[List[str]]:\n\t\t\"\"\"\n\t\tGiven a string s, partition s such that every substring of the partition is a palindrome. Return all possible palindrome partitioning of s.\n\t\tExample 1:\n\t\tInput: s = \"aab\"\n\t\tOutput: [[\"a\",\"a\",\"b\"],[\"aa\",\"b\"]]\n\t\tExample 2:\n\t\tInput: s = \"a\"\n\t\tOutput: [[\"a\"]]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 132, - "question": "class Solution:\n def minCut(self, s: str) -> int:\n\t\t\"\"\"\n\t\tGiven a string s, partition s such that every substring of the partition is a palindrome.\n\t\tReturn the minimum cuts needed for a palindrome partitioning of s.\n\t\tExample 1:\n\t\tInput: s = \"aab\"\n\t\tOutput: 1\n\t\tExplanation: The palindrome partitioning [\"aa\",\"b\"] could be produced using 1 cut.\n\t\tExample 2:\n\t\tInput: s = \"a\"\n\t\tOutput: 0\n\t\tExample 3:\n\t\tInput: s = \"ab\"\n\t\tOutput: 1\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 133, - "question": "\n\t\t\"\"\"\nclass Node:\n def __init__(self, val = 0, neighbors = None):\n self.val = val\n self.neighbors = neighbors if neighbors is not None else []\n\t\tGiven a reference of a node in a connected undirected graph.\n\t\tReturn a deep copy (clone) of the graph.\n\t\tEach node in the graph contains a value (int) and a list (List[Node]) of its neighbors.\n\t\tclass Node {\n\t\t public int val;\n\t\t public List neighbors;\n\t\t}\n\t\tTest case format:\n\t\tFor simplicity, each node's value is the same as the node's index (1-indexed). For example, the first node with val == 1, the second node with val == 2, and so on. The graph is represented in the test case using an adjacency list.\n\t\tAn adjacency list is a collection of unordered lists used to represent a finite graph. Each list describes the set of neighbors of a node in the graph.\n\t\tThe given node will always be the first node with val = 1. You must return the copy of the given node as a reference to the cloned graph.\n\t\tExample 1:\n\t\tInput: adjList = [[2,4],[1,3],[2,4],[1,3]]\n\t\tOutput: [[2,4],[1,3],[2,4],[1,3]]\n\t\tExplanation: There are 4 nodes in the graph.\n\t\t1st node (val = 1)'s neighbors are 2nd node (val = 2) and 4th node (val = 4).\n\t\t2nd node (val = 2)'s neighbors are 1st node (val = 1) and 3rd node (val = 3).\n\t\t3rd node (val = 3)'s neighbors are 2nd node (val = 2) and 4th node (val = 4).\n\t\t4th node (val = 4)'s neighbors are 1st node (val = 1) and 3rd node (val = 3).\n\t\tExample 2:\n\t\tInput: adjList = [[]]\n\t\tOutput: [[]]\n\t\tExplanation: Note that the input contains one empty list. The graph consists of only one node with val = 1 and it does not have any neighbors.\n\t\tExample 3:\n\t\tInput: adjList = []\n\t\tOutput: []\n\t\tExplanation: This an empty graph, it does not have any nodes.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 134, - "question": "class Solution:\n def canCompleteCircuit(self, gas: List[int], cost: List[int]) -> int:\n\t\t\"\"\"\n\t\tThere are n gas stations along a circular route, where the amount of gas at the ith station is gas[i].\n\t\tYou have a car with an unlimited gas tank and it costs cost[i] of gas to travel from the ith station to its next (i + 1)th station. You begin the journey with an empty tank at one of the gas stations.\n\t\tGiven two integer arrays gas and cost, return the starting gas station's index if you can travel around the circuit once in the clockwise direction, otherwise return -1. If there exists a solution, it is guaranteed to be unique\n\t\tExample 1:\n\t\tInput: gas = [1,2,3,4,5], cost = [3,4,5,1,2]\n\t\tOutput: 3\n\t\tExplanation:\n\t\tStart at station 3 (index 3) and fill up with 4 unit of gas. Your tank = 0 + 4 = 4\n\t\tTravel to station 4. Your tank = 4 - 1 + 5 = 8\n\t\tTravel to station 0. Your tank = 8 - 2 + 1 = 7\n\t\tTravel to station 1. Your tank = 7 - 3 + 2 = 6\n\t\tTravel to station 2. Your tank = 6 - 4 + 3 = 5\n\t\tTravel to station 3. The cost is 5. Your gas is just enough to travel back to station 3.\n\t\tTherefore, return 3 as the starting index.\n\t\tExample 2:\n\t\tInput: gas = [2,3,4], cost = [3,4,3]\n\t\tOutput: -1\n\t\tExplanation:\n\t\tYou can't start at station 0 or 1, as there is not enough gas to travel to the next station.\n\t\tLet's start at station 2 and fill up with 4 unit of gas. Your tank = 0 + 4 = 4\n\t\tTravel to station 0. Your tank = 4 - 3 + 2 = 3\n\t\tTravel to station 1. Your tank = 3 - 3 + 3 = 3\n\t\tYou cannot travel back to station 2, as it requires 4 unit of gas but you only have 3.\n\t\tTherefore, you can't travel around the circuit once no matter where you start.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 135, - "question": "class Solution:\n def candy(self, ratings: List[int]) -> int:\n\t\t\"\"\"\n\t\tThere are n children standing in a line. Each child is assigned a rating value given in the integer array ratings.\n\t\tYou are giving candies to these children subjected to the following requirements:\n\t\t\tEach child must have at least one candy.\n\t\t\tChildren with a higher rating get more candies than their neighbors.\n\t\tReturn the minimum number of candies you need to have to distribute the candies to the children.\n\t\tExample 1:\n\t\tInput: ratings = [1,0,2]\n\t\tOutput: 5\n\t\tExplanation: You can allocate to the first, second and third child with 2, 1, 2 candies respectively.\n\t\tExample 2:\n\t\tInput: ratings = [1,2,2]\n\t\tOutput: 4\n\t\tExplanation: You can allocate to the first, second and third child with 1, 2, 1 candies respectively.\n\t\tThe third child gets 1 candy because it satisfies the above two conditions.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 136, - "question": "class Solution:\n def singleNumber(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tGiven a non-empty array of integers nums, every element appears twice except for one. Find that single one.\n\t\tYou must implement a solution with a linear runtime complexity and use only constant extra space.\n\t\tExample 1:\n\t\tInput: nums = [2,2,1]\n\t\tOutput: 1\n\t\tExample 2:\n\t\tInput: nums = [4,1,2,1,2]\n\t\tOutput: 4\n\t\tExample 3:\n\t\tInput: nums = [1]\n\t\tOutput: 1\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 137, - "question": "class Solution:\n def singleNumber(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tGiven an integer array nums where every element appears three times except for one, which appears exactly once. Find the single element and return it.\n\t\tYou must implement a solution with a linear runtime complexity and use only constant extra space.\n\t\tExample 1:\n\t\tInput: nums = [2,2,3,2]\n\t\tOutput: 3\n\t\tExample 2:\n\t\tInput: nums = [0,1,0,1,0,1,99]\n\t\tOutput: 99\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 138, - "question": "\n\t\t\"\"\"\nclass Node:\n def __init__(self, x: int, next: 'Node' = None, random: 'Node' = None):\n self.val = int(x)\n self.next = next\n self.random = random\n\t\tA linked list of length n is given such that each node contains an additional random pointer, which could point to any node in the list, or null.\n\t\tConstruct a deep copy of the list. The deep copy should consist of exactly n brand new nodes, where each new node has its value set to the value of its corresponding original node. Both the next and random pointer of the new nodes should point to new nodes in the copied list such that the pointers in the original list and copied list represent the same list state. None of the pointers in the new list should point to nodes in the original list.\n\t\tFor example, if there are two nodes X and Y in the original list, where X.random --> Y, then for the corresponding two nodes x and y in the copied list, x.random --> y.\n\t\tReturn the head of the copied linked list.\n\t\tThe linked list is represented in the input/output as a list of n nodes. Each node is represented as a pair of [val, random_index] where:\n\t\t\tval: an integer representing Node.val\n\t\t\trandom_index: the index of the node (range from 0 to n-1) that the random pointer points to, or null if it does not point to any node.\n\t\tYour code will only be given the head of the original linked list.\n\t\tExample 1:\n\t\tInput: head = [[7,null],[13,0],[11,4],[10,2],[1,0]]\n\t\tOutput: [[7,null],[13,0],[11,4],[10,2],[1,0]]\n\t\tExample 2:\n\t\tInput: head = [[1,1],[2,1]]\n\t\tOutput: [[1,1],[2,1]]\n\t\tExample 3:\n\t\tInput: head = [[3,null],[3,0],[3,null]]\n\t\tOutput: [[3,null],[3,0],[3,null]]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 139, - "question": "class Solution:\n def wordBreak(self, s: str, wordDict: List[str]) -> bool:\n\t\t\"\"\"\n\t\tGiven a string s and a dictionary of strings wordDict, return true if s can be segmented into a space-separated sequence of one or more dictionary words.\n\t\tNote that the same word in the dictionary may be reused multiple times in the segmentation.\n\t\tExample 1:\n\t\tInput: s = \"leetcode\", wordDict = [\"leet\",\"code\"]\n\t\tOutput: true\n\t\tExplanation: Return true because \"leetcode\" can be segmented as \"leet code\".\n\t\tExample 2:\n\t\tInput: s = \"applepenapple\", wordDict = [\"apple\",\"pen\"]\n\t\tOutput: true\n\t\tExplanation: Return true because \"applepenapple\" can be segmented as \"apple pen apple\".\n\t\tNote that you are allowed to reuse a dictionary word.\n\t\tExample 3:\n\t\tInput: s = \"catsandog\", wordDict = [\"cats\",\"dog\",\"sand\",\"and\",\"cat\"]\n\t\tOutput: false\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 140, - "question": "class Solution:\n def wordBreak(self, s: str, wordDict: List[str]) -> List[str]:\n\t\t\"\"\"\n\t\tGiven a string s and a dictionary of strings wordDict, add spaces in s to construct a sentence where each word is a valid dictionary word. Return all such possible sentences in any order.\n\t\tNote that the same word in the dictionary may be reused multiple times in the segmentation.\n\t\tExample 1:\n\t\tInput: s = \"catsanddog\", wordDict = [\"cat\",\"cats\",\"and\",\"sand\",\"dog\"]\n\t\tOutput: [\"cats and dog\",\"cat sand dog\"]\n\t\tExample 2:\n\t\tInput: s = \"pineapplepenapple\", wordDict = [\"apple\",\"pen\",\"applepen\",\"pine\",\"pineapple\"]\n\t\tOutput: [\"pine apple pen apple\",\"pineapple pen apple\",\"pine applepen apple\"]\n\t\tExplanation: Note that you are allowed to reuse a dictionary word.\n\t\tExample 3:\n\t\tInput: s = \"catsandog\", wordDict = [\"cats\",\"dog\",\"sand\",\"and\",\"cat\"]\n\t\tOutput: []\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 141, - "question": "class Solution:\n def hasCycle(self, head: Optional[ListNode]) -> bool:\n\t\t\"\"\"\n\t\tGiven head, the head of a linked list, determine if the linked list has a cycle in it.\n\t\tThere is a cycle in a linked list if there is some node in the list that can be reached again by continuously following the next pointer. Internally, pos is used to denote the index of the node that tail's next pointer is connected to. Note that pos is not passed as a parameter.\n\t\tReturn true if there is a cycle in the linked list. Otherwise, return false.\n\t\tExample 1:\n\t\tInput: head = [3,2,0,-4], pos = 1\n\t\tOutput: true\n\t\tExplanation: There is a cycle in the linked list, where the tail connects to the 1st node (0-indexed).\n\t\tExample 2:\n\t\tInput: head = [1,2], pos = 0\n\t\tOutput: true\n\t\tExplanation: There is a cycle in the linked list, where the tail connects to the 0th node.\n\t\tExample 3:\n\t\tInput: head = [1], pos = -1\n\t\tOutput: false\n\t\tExplanation: There is no cycle in the linked list.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 142, - "question": "class Solution:\n def detectCycle(self, head: Optional[ListNode]) -> Optional[ListNode]:\n\t\t\"\"\"\n\t\tGiven the head of a linked list, return the node where the cycle begins. If there is no cycle, return null.\n\t\tThere is a cycle in a linked list if there is some node in the list that can be reached again by continuously following the next pointer. Internally, pos is used to denote the index of the node that tail's next pointer is connected to (0-indexed). It is -1 if there is no cycle. Note that pos is not passed as a parameter.\n\t\tDo not modify the linked list.\n\t\tExample 1:\n\t\tInput: head = [3,2,0,-4], pos = 1\n\t\tOutput: tail connects to node index 1\n\t\tExplanation: There is a cycle in the linked list, where tail connects to the second node.\n\t\tExample 2:\n\t\tInput: head = [1,2], pos = 0\n\t\tOutput: tail connects to node index 0\n\t\tExplanation: There is a cycle in the linked list, where tail connects to the first node.\n\t\tExample 3:\n\t\tInput: head = [1], pos = -1\n\t\tOutput: no cycle\n\t\tExplanation: There is no cycle in the linked list.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 143, - "question": "class Solution:\n def reorderList(self, head: Optional[ListNode]) -> None:\n\t\t\"\"\"\n Do not return anything, modify head in-place instead.\n\t\tYou are given the head of a singly linked-list. The list can be represented as:\n\t\tL0 \u2192 L1 \u2192 \u2026 \u2192 Ln - 1 \u2192 Ln\n\t\tReorder the list to be on the following form:\n\t\tL0 \u2192 Ln \u2192 L1 \u2192 Ln - 1 \u2192 L2 \u2192 Ln - 2 \u2192 \u2026\n\t\tYou may not modify the values in the list's nodes. Only nodes themselves may be changed.\n\t\tExample 1:\n\t\tInput: head = [1,2,3,4]\n\t\tOutput: [1,4,2,3]\n\t\tExample 2:\n\t\tInput: head = [1,2,3,4,5]\n\t\tOutput: [1,5,2,4,3]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 144, - "question": "class Solution:\n def preorderTraversal(self, root: Optional[TreeNode]) -> List[int]:\n\t\t\"\"\"\n\t\tGiven the root of a binary tree, return the preorder traversal of its nodes' values.\n\t\tExample 1:\n\t\tInput: root = [1,null,2,3]\n\t\tOutput: [1,2,3]\n\t\tExample 2:\n\t\tInput: root = []\n\t\tOutput: []\n\t\tExample 3:\n\t\tInput: root = [1]\n\t\tOutput: [1]\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 145, - "question": "class Solution:\n def postorderTraversal(self, root: Optional[TreeNode]) -> List[int]:\n\t\t\"\"\"\n\t\tGiven the root of a binary tree, return the postorder traversal of its nodes' values.\n\t\tExample 1:\n\t\tInput: root = [1,null,2,3]\n\t\tOutput: [3,2,1]\n\t\tExample 2:\n\t\tInput: root = []\n\t\tOutput: []\n\t\tExample 3:\n\t\tInput: root = [1]\n\t\tOutput: [1]\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 146, - "question": "class LRUCache:\n def __init__(self, capacity: int):\n def get(self, key: int) -> int:\n def put(self, key: int, value: int) -> None:\n\t\t\"\"\"\n\t\tDesign a data structure that follows the constraints of a Least Recently Used (LRU) cache.\n\t\tImplement the LRUCache class:\n\t\t\tLRUCache(int capacity) Initialize the LRU cache with positive size capacity.\n\t\t\tint get(int key) Return the value of the key if the key exists, otherwise return -1.\n\t\t\tvoid put(int key, int value) Update the value of the key if the key exists. Otherwise, add the key-value pair to the cache. If the number of keys exceeds the capacity from this operation, evict the least recently used key.\n\t\tThe functions get and put must each run in O(1) average time complexity.\n\t\tExample 1:\n\t\tInput\n\t\t[\"LRUCache\", \"put\", \"put\", \"get\", \"put\", \"get\", \"put\", \"get\", \"get\", \"get\"]\n\t\t[[2], [1, 1], [2, 2], [1], [3, 3], [2], [4, 4], [1], [3], [4]]\n\t\tOutput\n\t\t[null, null, null, 1, null, -1, null, -1, 3, 4]\n\t\tExplanation\n\t\tLRUCache lRUCache = new LRUCache(2);\n\t\tlRUCache.put(1, 1); // cache is {1=1}\n\t\tlRUCache.put(2, 2); // cache is {1=1, 2=2}\n\t\tlRUCache.get(1); // return 1\n\t\tlRUCache.put(3, 3); // LRU key was 2, evicts key 2, cache is {1=1, 3=3}\n\t\tlRUCache.get(2); // returns -1 (not found)\n\t\tlRUCache.put(4, 4); // LRU key was 1, evicts key 1, cache is {4=4, 3=3}\n\t\tlRUCache.get(1); // return -1 (not found)\n\t\tlRUCache.get(3); // return 3\n\t\tlRUCache.get(4); // return 4\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 147, - "question": "class Solution:\n def insertionSortList(self, head: Optional[ListNode]) -> Optional[ListNode]:\n\t\t\"\"\"\n\t\tGiven the head of a singly linked list, sort the list using insertion sort, and return the sorted list's head.\n\t\tThe steps of the insertion sort algorithm:\n\t\t\tInsertion sort iterates, consuming one input element each repetition and growing a sorted output list.\n\t\t\tAt each iteration, insertion sort removes one element from the input data, finds the location it belongs within the sorted list and inserts it there.\n\t\t\tIt repeats until no input elements remain.\n\t\tThe following is a graphical example of the insertion sort algorithm. The partially sorted list (black) initially contains only the first element in the list. One element (red) is removed from the input data and inserted in-place into the sorted list with each iteration.\n\t\tExample 1:\n\t\tInput: head = [4,2,1,3]\n\t\tOutput: [1,2,3,4]\n\t\tExample 2:\n\t\tInput: head = [-1,5,3,4,0]\n\t\tOutput: [-1,0,3,4,5]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 148, - "question": "class Solution:\n def sortList(self, head: Optional[ListNode]) -> Optional[ListNode]:\n\t\t\"\"\"\n\t\tGiven the head of a linked list, return the list after sorting it in ascending order.\n\t\tExample 1:\n\t\tInput: head = [4,2,1,3]\n\t\tOutput: [1,2,3,4]\n\t\tExample 2:\n\t\tInput: head = [-1,5,3,4,0]\n\t\tOutput: [-1,0,3,4,5]\n\t\tExample 3:\n\t\tInput: head = []\n\t\tOutput: []\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 149, - "question": "class Solution:\n def maxPoints(self, points: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tGiven an array of points where points[i] = [xi, yi] represents a point on the X-Y plane, return the maximum number of points that lie on the same straight line.\n\t\tExample 1:\n\t\tInput: points = [[1,1],[2,2],[3,3]]\n\t\tOutput: 3\n\t\tExample 2:\n\t\tInput: points = [[1,1],[3,2],[5,3],[4,1],[2,3],[1,4]]\n\t\tOutput: 4\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 150, - "question": "class Solution:\n def evalRPN(self, tokens: List[str]) -> int:\n\t\t\"\"\"\n\t\tYou are given an array of strings tokens that represents an arithmetic expression in a Reverse Polish Notation.\n\t\tEvaluate the expression. Return an integer that represents the value of the expression.\n\t\tNote that:\n\t\t\tThe valid operators are '+', '-', '*', and '/'.\n\t\t\tEach operand may be an integer or another expression.\n\t\t\tThe division between two integers always truncates toward zero.\n\t\t\tThere will not be any division by zero.\n\t\t\tThe input represents a valid arithmetic expression in a reverse polish notation.\n\t\t\tThe answer and all the intermediate calculations can be represented in a 32-bit integer.\n\t\tExample 1:\n\t\tInput: tokens = [\"2\",\"1\",\"+\",\"3\",\"*\"]\n\t\tOutput: 9\n\t\tExplanation: ((2 + 1) * 3) = 9\n\t\tExample 2:\n\t\tInput: tokens = [\"4\",\"13\",\"5\",\"/\",\"+\"]\n\t\tOutput: 6\n\t\tExplanation: (4 + (13 / 5)) = 6\n\t\tExample 3:\n\t\tInput: tokens = [\"10\",\"6\",\"9\",\"3\",\"+\",\"-11\",\"*\",\"/\",\"*\",\"17\",\"+\",\"5\",\"+\"]\n\t\tOutput: 22\n\t\tExplanation: ((10 * (6 / ((9 + 3) * -11))) + 17) + 5\n\t\t= ((10 * (6 / (12 * -11))) + 17) + 5\n\t\t= ((10 * (6 / -132)) + 17) + 5\n\t\t= ((10 * 0) + 17) + 5\n\t\t= (0 + 17) + 5\n\t\t= 17 + 5\n\t\t= 22\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 151, - "question": "class Solution:\n def reverseWords(self, s: str) -> str:\n\t\t\"\"\"\n\t\tGiven an input string s, reverse the order of the words.\n\t\tA word is defined as a sequence of non-space characters. The words in s will be separated by at least one space.\n\t\tReturn a string of the words in reverse order concatenated by a single space.\n\t\tNote that s may contain leading or trailing spaces or multiple spaces between two words. The returned string should only have a single space separating the words. Do not include any extra spaces.\n\t\tExample 1:\n\t\tInput: s = \"the sky is blue\"\n\t\tOutput: \"blue is sky the\"\n\t\tExample 2:\n\t\tInput: s = \" hello world \"\n\t\tOutput: \"world hello\"\n\t\tExplanation: Your reversed string should not contain leading or trailing spaces.\n\t\tExample 3:\n\t\tInput: s = \"a good example\"\n\t\tOutput: \"example good a\"\n\t\tExplanation: You need to reduce multiple spaces between two words to a single space in the reversed string.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 152, - "question": "class Solution:\n def maxProduct(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tGiven an integer array nums, find a subarray that has the largest product, and return the product.\n\t\tThe test cases are generated so that the answer will fit in a 32-bit integer.\n\t\tExample 1:\n\t\tInput: nums = [2,3,-2,4]\n\t\tOutput: 6\n\t\tExplanation: [2,3] has the largest product 6.\n\t\tExample 2:\n\t\tInput: nums = [-2,0,-1]\n\t\tOutput: 0\n\t\tExplanation: The result cannot be 2, because [-2,-1] is not a subarray.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 153, - "question": "class Solution:\n def findMin(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tSuppose an array of length n sorted in ascending order is rotated between 1 and n times. For example, the array nums = [0,1,2,4,5,6,7] might become:\n\t\t\t[4,5,6,7,0,1,2] if it was rotated 4 times.\n\t\t\t[0,1,2,4,5,6,7] if it was rotated 7 times.\n\t\tNotice that rotating an array [a[0], a[1], a[2], ..., a[n-1]] 1 time results in the array [a[n-1], a[0], a[1], a[2], ..., a[n-2]].\n\t\tGiven the sorted rotated array nums of unique elements, return the minimum element of this array.\n\t\tYou must write an algorithm that runs in O(log n) time.\n\t\tExample 1:\n\t\tInput: nums = [3,4,5,1,2]\n\t\tOutput: 1\n\t\tExplanation: The original array was [1,2,3,4,5] rotated 3 times.\n\t\tExample 2:\n\t\tInput: nums = [4,5,6,7,0,1,2]\n\t\tOutput: 0\n\t\tExplanation: The original array was [0,1,2,4,5,6,7] and it was rotated 4 times.\n\t\tExample 3:\n\t\tInput: nums = [11,13,15,17]\n\t\tOutput: 11\n\t\tExplanation: The original array was [11,13,15,17] and it was rotated 4 times. \n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 154, - "question": "class Solution:\n def findMin(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tSuppose an array of length n sorted in ascending order is rotated between 1 and n times. For example, the array nums = [0,1,4,4,5,6,7] might become:\n\t\t\t[4,5,6,7,0,1,4] if it was rotated 4 times.\n\t\t\t[0,1,4,4,5,6,7] if it was rotated 7 times.\n\t\tNotice that rotating an array [a[0], a[1], a[2], ..., a[n-1]] 1 time results in the array [a[n-1], a[0], a[1], a[2], ..., a[n-2]].\n\t\tGiven the sorted rotated array nums that may contain duplicates, return the minimum element of this array.\n\t\tYou must decrease the overall operation steps as much as possible.\n\t\tExample 1:\n\t\tInput: nums = [1,3,5]\n\t\tOutput: 1\n\t\tExample 2:\n\t\tInput: nums = [2,2,2,0,1]\n\t\tOutput: 0\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 155, - "question": "class MinStack:\n def __init__(self):\n def push(self, val: int) -> None:\n def pop(self) -> None:\n def top(self) -> int:\n def getMin(self) -> int:\n\t\t\"\"\"\n\t\tDesign a stack that supports push, pop, top, and retrieving the minimum element in constant time.\n\t\tImplement the MinStack class:\n\t\t\tMinStack() initializes the stack object.\n\t\t\tvoid push(int val) pushes the element val onto the stack.\n\t\t\tvoid pop() removes the element on the top of the stack.\n\t\t\tint top() gets the top element of the stack.\n\t\t\tint getMin() retrieves the minimum element in the stack.\n\t\tYou must implement a solution with O(1) time complexity for each function.\n\t\tExample 1:\n\t\tInput\n\t\t[\"MinStack\",\"push\",\"push\",\"push\",\"getMin\",\"pop\",\"top\",\"getMin\"]\n\t\t[[],[-2],[0],[-3],[],[],[],[]]\n\t\tOutput\n\t\t[null,null,null,null,-3,null,0,-2]\n\t\tExplanation\n\t\tMinStack minStack = new MinStack();\n\t\tminStack.push(-2);\n\t\tminStack.push(0);\n\t\tminStack.push(-3);\n\t\tminStack.getMin(); // return -3\n\t\tminStack.pop();\n\t\tminStack.top(); // return 0\n\t\tminStack.getMin(); // return -2\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 160, - "question": "class Solution:\n def getIntersectionNode(self, headA: ListNode, headB: ListNode) -> Optional[ListNode]:\n\t\t\"\"\"\n\t\tGiven the heads of two singly linked-lists headA and headB, return the node at which the two lists intersect. If the two linked lists have no intersection at all, return null.\n\t\tFor example, the following two linked lists begin to intersect at node c1:\n\t\tThe test cases are generated such that there are no cycles anywhere in the entire linked structure.\n\t\tNote that the linked lists must retain their original structure after the function returns.\n\t\tCustom Judge:\n\t\tThe inputs to the judge are given as follows (your program is not given these inputs):\n\t\t\tintersectVal - The value of the node where the intersection occurs. This is 0 if there is no intersected node.\n\t\t\tlistA - The first linked list.\n\t\t\tlistB - The second linked list.\n\t\t\tskipA - The number of nodes to skip ahead in listA (starting from the head) to get to the intersected node.\n\t\t\tskipB - The number of nodes to skip ahead in listB (starting from the head) to get to the intersected node.\n\t\tThe judge will then create the linked structure based on these inputs and pass the two heads, headA and headB to your program. If you correctly return the intersected node, then your solution will be accepted.\n\t\tExample 1:\n\t\tInput: intersectVal = 8, listA = [4,1,8,4,5], listB = [5,6,1,8,4,5], skipA = 2, skipB = 3\n\t\tOutput: Intersected at '8'\n\t\tExplanation: The intersected node's value is 8 (note that this must not be 0 if the two lists intersect).\n\t\tFrom the head of A, it reads as [4,1,8,4,5]. From the head of B, it reads as [5,6,1,8,4,5]. There are 2 nodes before the intersected node in A; There are 3 nodes before the intersected node in B.\n\t\t- Note that the intersected node's value is not 1 because the nodes with value 1 in A and B (2nd node in A and 3rd node in B) are different node references. In other words, they point to two different locations in memory, while the nodes with value 8 in A and B (3rd node in A and 4th node in B) point to the same location in memory.\n\t\tExample 2:\n\t\tInput: intersectVal = 2, listA = [1,9,1,2,4], listB = [3,2,4], skipA = 3, skipB = 1\n\t\tOutput: Intersected at '2'\n\t\tExplanation: The intersected node's value is 2 (note that this must not be 0 if the two lists intersect).\n\t\tFrom the head of A, it reads as [1,9,1,2,4]. From the head of B, it reads as [3,2,4]. There are 3 nodes before the intersected node in A; There are 1 node before the intersected node in B.\n\t\tExample 3:\n\t\tInput: intersectVal = 0, listA = [2,6,4], listB = [1,5], skipA = 3, skipB = 2\n\t\tOutput: No intersection\n\t\tExplanation: From the head of A, it reads as [2,6,4]. From the head of B, it reads as [1,5]. Since the two lists do not intersect, intersectVal must be 0, while skipA and skipB can be arbitrary values.\n\t\tExplanation: The two lists do not intersect, so return null.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 162, - "question": "class Solution:\n def findPeakElement(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tA peak element is an element that is strictly greater than its neighbors.\n\t\tGiven a 0-indexed integer array nums, find a peak element, and return its index. If the array contains multiple peaks, return the index to any of the peaks.\n\t\tYou may imagine that nums[-1] = nums[n] = -\u221e. In other words, an element is always considered to be strictly greater than a neighbor that is outside the array.\n\t\tYou must write an algorithm that runs in O(log n) time.\n\t\tExample 1:\n\t\tInput: nums = [1,2,3,1]\n\t\tOutput: 2\n\t\tExplanation: 3 is a peak element and your function should return the index number 2.\n\t\tExample 2:\n\t\tInput: nums = [1,2,1,3,5,6,4]\n\t\tOutput: 5\n\t\tExplanation: Your function can return either index number 1 where the peak element is 2, or index number 5 where the peak element is 6.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 164, - "question": "class Solution:\n def maximumGap(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tGiven an integer array nums, return the maximum difference between two successive elements in its sorted form. If the array contains less than two elements, return 0.\n\t\tYou must write an algorithm that runs in linear time and uses linear extra space.\n\t\tExample 1:\n\t\tInput: nums = [3,6,9,1]\n\t\tOutput: 3\n\t\tExplanation: The sorted form of the array is [1,3,6,9], either (3,6) or (6,9) has the maximum difference 3.\n\t\tExample 2:\n\t\tInput: nums = [10]\n\t\tOutput: 0\n\t\tExplanation: The array contains less than 2 elements, therefore return 0.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 165, - "question": "class Solution:\n def compareVersion(self, version1: str, version2: str) -> int:\n\t\t\"\"\"\n\t\tGiven two version numbers, version1 and version2, compare them.\n\t\tVersion numbers consist of one or more revisions joined by a dot '.'. Each revision consists of digits and may contain leading zeros. Every revision contains at least one character. Revisions are 0-indexed from left to right, with the leftmost revision being revision 0, the next revision being revision 1, and so on. For example 2.5.33 and 0.1 are valid version numbers.\n\t\tTo compare version numbers, compare their revisions in left-to-right order. Revisions are compared using their integer value ignoring any leading zeros. This means that revisions 1 and 001 are considered equal. If a version number does not specify a revision at an index, then treat the revision as 0. For example, version 1.0 is less than version 1.1 because their revision 0s are the same, but their revision 1s are 0 and 1 respectively, and 0 < 1.\n\t\tReturn the following:\n\t\t\tIf version1 < version2, return -1.\n\t\t\tIf version1 > version2, return 1.\n\t\t\tOtherwise, return 0.\n\t\tExample 1:\n\t\tInput: version1 = \"1.01\", version2 = \"1.001\"\n\t\tOutput: 0\n\t\tExplanation: Ignoring leading zeroes, both \"01\" and \"001\" represent the same integer \"1\".\n\t\tExample 2:\n\t\tInput: version1 = \"1.0\", version2 = \"1.0.0\"\n\t\tOutput: 0\n\t\tExplanation: version1 does not specify revision 2, which means it is treated as \"0\".\n\t\tExample 3:\n\t\tInput: version1 = \"0.1\", version2 = \"1.1\"\n\t\tOutput: -1\n\t\tExplanation: version1's revision 0 is \"0\", while version2's revision 0 is \"1\". 0 < 1, so version1 < version2.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 166, - "question": "class Solution:\n def fractionToDecimal(self, numerator: int, denominator: int) -> str:\n\t\t\"\"\"\n\t\tGiven two integers representing the numerator and denominator of a fraction, return the fraction in string format.\n\t\tIf the fractional part is repeating, enclose the repeating part in parentheses.\n\t\tIf multiple answers are possible, return any of them.\n\t\tIt is guaranteed that the length of the answer string is less than 104 for all the given inputs.\n\t\tExample 1:\n\t\tInput: numerator = 1, denominator = 2\n\t\tOutput: \"0.5\"\n\t\tExample 2:\n\t\tInput: numerator = 2, denominator = 1\n\t\tOutput: \"2\"\n\t\tExample 3:\n\t\tInput: numerator = 4, denominator = 333\n\t\tOutput: \"0.(012)\"\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 167, - "question": "class Solution:\n def twoSum(self, numbers: List[int], target: int) -> List[int]:\n\t\t\"\"\"\n\t\tGiven a 1-indexed array of integers numbers that is already sorted in non-decreasing order, find two numbers such that they add up to a specific target number. Let these two numbers be numbers[index1] and numbers[index2] where 1 <= index1 < index2 <= numbers.length.\n\t\tReturn the indices of the two numbers, index1 and index2, added by one as an integer array [index1, index2] of length 2.\n\t\tThe tests are generated such that there is exactly one solution. You may not use the same element twice.\n\t\tYour solution must use only constant extra space.\n\t\tExample 1:\n\t\tInput: numbers = [2,7,11,15], target = 9\n\t\tOutput: [1,2]\n\t\tExplanation: The sum of 2 and 7 is 9. Therefore, index1 = 1, index2 = 2. We return [1, 2].\n\t\tExample 2:\n\t\tInput: numbers = [2,3,4], target = 6\n\t\tOutput: [1,3]\n\t\tExplanation: The sum of 2 and 4 is 6. Therefore index1 = 1, index2 = 3. We return [1, 3].\n\t\tExample 3:\n\t\tInput: numbers = [-1,0], target = -1\n\t\tOutput: [1,2]\n\t\tExplanation: The sum of -1 and 0 is -1. Therefore index1 = 1, index2 = 2. We return [1, 2].\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 168, - "question": "class Solution:\n def convertToTitle(self, columnNumber: int) -> str:\n\t\t\"\"\"\n\t\tGiven an integer columnNumber, return its corresponding column title as it appears in an Excel sheet.\n\t\tFor example:\n\t\tA -> 1\n\t\tB -> 2\n\t\tC -> 3\n\t\t...\n\t\tZ -> 26\n\t\tAA -> 27\n\t\tAB -> 28 \n\t\t...\n\t\tExample 1:\n\t\tInput: columnNumber = 1\n\t\tOutput: \"A\"\n\t\tExample 2:\n\t\tInput: columnNumber = 28\n\t\tOutput: \"AB\"\n\t\tExample 3:\n\t\tInput: columnNumber = 701\n\t\tOutput: \"ZY\"\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 169, - "question": "class Solution:\n def majorityElement(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tGiven an array nums of size n, return the majority element.\n\t\tThe majority element is the element that appears more than \u230an / 2\u230b times. You may assume that the majority element always exists in the array.\n\t\tExample 1:\n\t\tInput: nums = [3,2,3]\n\t\tOutput: 3\n\t\tExample 2:\n\t\tInput: nums = [2,2,1,1,1,2,2]\n\t\tOutput: 2\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 171, - "question": "class Solution:\n def titleToNumber(self, columnTitle: str) -> int:\n\t\t\"\"\"\n\t\tGiven a string columnTitle that represents the column title as appears in an Excel sheet, return its corresponding column number.\n\t\tFor example:\n\t\tA -> 1\n\t\tB -> 2\n\t\tC -> 3\n\t\t...\n\t\tZ -> 26\n\t\tAA -> 27\n\t\tAB -> 28 \n\t\t...\n\t\tExample 1:\n\t\tInput: columnTitle = \"A\"\n\t\tOutput: 1\n\t\tExample 2:\n\t\tInput: columnTitle = \"AB\"\n\t\tOutput: 28\n\t\tExample 3:\n\t\tInput: columnTitle = \"ZY\"\n\t\tOutput: 701\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 172, - "question": "class Solution:\n def trailingZeroes(self, n: int) -> int:\n\t\t\"\"\"\n\t\tGiven an integer n, return the number of trailing zeroes in n!.\n\t\tNote that n! = n * (n - 1) * (n - 2) * ... * 3 * 2 * 1.\n\t\tExample 1:\n\t\tInput: n = 3\n\t\tOutput: 0\n\t\tExplanation: 3! = 6, no trailing zero.\n\t\tExample 2:\n\t\tInput: n = 5\n\t\tOutput: 1\n\t\tExplanation: 5! = 120, one trailing zero.\n\t\tExample 3:\n\t\tInput: n = 0\n\t\tOutput: 0\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 173, - "question": "class BSTIterator:\n def __init__(self, root: Optional[TreeNode]):\n def next(self) -> int:\n def hasNext(self) -> bool:\n\t\t\"\"\"\n\t\tImplement the BSTIterator class that represents an iterator over the in-order traversal of a binary search tree (BST):\n\t\t\tBSTIterator(TreeNode root) Initializes an object of the BSTIterator class. The root of the BST is given as part of the constructor. The pointer should be initialized to a non-existent number smaller than any element in the BST.\n\t\t\tboolean hasNext() Returns true if there exists a number in the traversal to the right of the pointer, otherwise returns false.\n\t\t\tint next() Moves the pointer to the right, then returns the number at the pointer.\n\t\tNotice that by initializing the pointer to a non-existent smallest number, the first call to next() will return the smallest element in the BST.\n\t\tYou may assume that next() calls will always be valid. That is, there will be at least a next number in the in-order traversal when next() is called.\n\t\tExample 1:\n\t\tInput\n\t\t[\"BSTIterator\", \"next\", \"next\", \"hasNext\", \"next\", \"hasNext\", \"next\", \"hasNext\", \"next\", \"hasNext\"]\n\t\t[[[7, 3, 15, null, null, 9, 20]], [], [], [], [], [], [], [], [], []]\n\t\tOutput\n\t\t[null, 3, 7, true, 9, true, 15, true, 20, false]\n\t\tExplanation\n\t\tBSTIterator bSTIterator = new BSTIterator([7, 3, 15, null, null, 9, 20]);\n\t\tbSTIterator.next(); // return 3\n\t\tbSTIterator.next(); // return 7\n\t\tbSTIterator.hasNext(); // return True\n\t\tbSTIterator.next(); // return 9\n\t\tbSTIterator.hasNext(); // return True\n\t\tbSTIterator.next(); // return 15\n\t\tbSTIterator.hasNext(); // return True\n\t\tbSTIterator.next(); // return 20\n\t\tbSTIterator.hasNext(); // return False\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 174, - "question": "class Solution:\n def calculateMinimumHP(self, dungeon: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tThe demons had captured the princess and imprisoned her in the bottom-right corner of a dungeon. The dungeon consists of m x n rooms laid out in a 2D grid. Our valiant knight was initially positioned in the top-left room and must fight his way through dungeon to rescue the princess.\n\t\tThe knight has an initial health point represented by a positive integer. If at any point his health point drops to 0 or below, he dies immediately.\n\t\tSome of the rooms are guarded by demons (represented by negative integers), so the knight loses health upon entering these rooms; other rooms are either empty (represented as 0) or contain magic orbs that increase the knight's health (represented by positive integers).\n\t\tTo reach the princess as quickly as possible, the knight decides to move only rightward or downward in each step.\n\t\tReturn the knight's minimum initial health so that he can rescue the princess.\n\t\tNote that any room can contain threats or power-ups, even the first room the knight enters and the bottom-right room where the princess is imprisoned.\n\t\tExample 1:\n\t\tInput: dungeon = [[-2,-3,3],[-5,-10,1],[10,30,-5]]\n\t\tOutput: 7\n\t\tExplanation: The initial health of the knight must be at least 7 if he follows the optimal path: RIGHT-> RIGHT -> DOWN -> DOWN.\n\t\tExample 2:\n\t\tInput: dungeon = [[0]]\n\t\tOutput: 1\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 179, - "question": "class Solution:\n def largestNumber(self, nums: List[int]) -> str:\n\t\t\"\"\"\n\t\tGiven a list of non-negative integers nums, arrange them such that they form the largest number and return it.\n\t\tSince the result may be very large, so you need to return a string instead of an integer.\n\t\tExample 1:\n\t\tInput: nums = [10,2]\n\t\tOutput: \"210\"\n\t\tExample 2:\n\t\tInput: nums = [3,30,34,5,9]\n\t\tOutput: \"9534330\"\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 187, - "question": "class Solution:\n def findRepeatedDnaSequences(self, s: str) -> List[str]:\n\t\t\"\"\"\n\t\tThe DNA sequence is composed of a series of nucleotides abbreviated as 'A', 'C', 'G', and 'T'.\n\t\t\tFor example, \"ACGAATTCCG\" is a DNA sequence.\n\t\tWhen studying DNA, it is useful to identify repeated sequences within the DNA.\n\t\tGiven a string s that represents a DNA sequence, return all the 10-letter-long sequences (substrings) that occur more than once in a DNA molecule. You may return the answer in any order.\n\t\tExample 1:\n\t\tInput: s = \"AAAAACCCCCAAAAACCCCCCAAAAAGGGTTT\"\n\t\tOutput: [\"AAAAACCCCC\",\"CCCCCAAAAA\"]\n\t\tExample 2:\n\t\tInput: s = \"AAAAAAAAAAAAA\"\n\t\tOutput: [\"AAAAAAAAAA\"]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 188, - "question": "class Solution:\n def maxProfit(self, k: int, prices: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou are given an integer array prices where prices[i] is the price of a given stock on the ith day, and an integer k.\n\t\tFind the maximum profit you can achieve. You may complete at most k transactions.\n\t\tNote: You may not engage in multiple transactions simultaneously (i.e., you must sell the stock before you buy again).\n\t\tExample 1:\n\t\tInput: k = 2, prices = [2,4,1]\n\t\tOutput: 2\n\t\tExplanation: Buy on day 1 (price = 2) and sell on day 2 (price = 4), profit = 4-2 = 2.\n\t\tExample 2:\n\t\tInput: k = 2, prices = [3,2,6,5,0,3]\n\t\tOutput: 7\n\t\tExplanation: Buy on day 2 (price = 2) and sell on day 3 (price = 6), profit = 6-2 = 4. Then buy on day 5 (price = 0) and sell on day 6 (price = 3), profit = 3-0 = 3.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 189, - "question": "class Solution:\n def rotate(self, nums: List[int], k: int) -> None:\n\t\t\"\"\"\n Do not return anything, modify nums in-place instead.\n\t\tGiven an integer array nums, rotate the array to the right by k steps, where k is non-negative.\n\t\tExample 1:\n\t\tInput: nums = [1,2,3,4,5,6,7], k = 3\n\t\tOutput: [5,6,7,1,2,3,4]\n\t\tExplanation:\n\t\trotate 1 steps to the right: [7,1,2,3,4,5,6]\n\t\trotate 2 steps to the right: [6,7,1,2,3,4,5]\n\t\trotate 3 steps to the right: [5,6,7,1,2,3,4]\n\t\tExample 2:\n\t\tInput: nums = [-1,-100,3,99], k = 2\n\t\tOutput: [3,99,-1,-100]\n\t\tExplanation: \n\t\trotate 1 steps to the right: [99,-1,-100,3]\n\t\trotate 2 steps to the right: [3,99,-1,-100]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 190, - "question": "class Solution:\n def reverseBits(self, n: int) -> int:\n\t\t\"\"\"\n\t\tReverse bits of a given 32 bits unsigned integer.\n\t\tNote:\n\t\t\tNote that in some languages, such as Java, there is no unsigned integer type. In this case, both input and output will be given as a signed integer type. They should not affect your implementation, as the integer's internal binary representation is the same, whether it is signed or unsigned.\n\t\t\tIn Java, the compiler represents the signed integers using 2's complement notation. Therefore, in Example 2 above, the input represents the signed integer -3 and the output represents the signed integer -1073741825.\n\t\tExample 1:\n\t\tInput: n = 00000010100101000001111010011100\n\t\tOutput: 964176192 (00111001011110000010100101000000)\n\t\tExplanation: The input binary string 00000010100101000001111010011100 represents the unsigned integer 43261596, so return 964176192 which its binary representation is 00111001011110000010100101000000.\n\t\tExample 2:\n\t\tInput: n = 11111111111111111111111111111101\n\t\tOutput: 3221225471 (10111111111111111111111111111111)\n\t\tExplanation: The input binary string 11111111111111111111111111111101 represents the unsigned integer 4294967293, so return 3221225471 which its binary representation is 10111111111111111111111111111111.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 191, - "question": "class Solution:\n def hammingWeight(self, n: int) -> int:\n\t\t\"\"\"\n\t\tWrite a function that takes the binary representation of an unsigned integer and returns the number of '1' bits it has (also known as the Hamming weight).\n\t\tNote:\n\t\t\tNote that in some languages, such as Java, there is no unsigned integer type. In this case, the input will be given as a signed integer type. It should not affect your implementation, as the integer's internal binary representation is the same, whether it is signed or unsigned.\n\t\t\tIn Java, the compiler represents the signed integers using 2's complement notation. Therefore, in Example 3, the input represents the signed integer. -3.\n\t\tExample 1:\n\t\tInput: n = 00000000000000000000000000001011\n\t\tOutput: 3\n\t\tExplanation: The input binary string 00000000000000000000000000001011 has a total of three '1' bits.\n\t\tExample 2:\n\t\tInput: n = 00000000000000000000000010000000\n\t\tOutput: 1\n\t\tExplanation: The input binary string 00000000000000000000000010000000 has a total of one '1' bit.\n\t\tExample 3:\n\t\tInput: n = 11111111111111111111111111111101\n\t\tOutput: 31\n\t\tExplanation: The input binary string 11111111111111111111111111111101 has a total of thirty one '1' bits.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 198, - "question": "class Solution:\n def rob(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou are a professional robber planning to rob houses along a street. Each house has a certain amount of money stashed, the only constraint stopping you from robbing each of them is that adjacent houses have security systems connected and it will automatically contact the police if two adjacent houses were broken into on the same night.\n\t\tGiven an integer array nums representing the amount of money of each house, return the maximum amount of money you can rob tonight without alerting the police.\n\t\tExample 1:\n\t\tInput: nums = [1,2,3,1]\n\t\tOutput: 4\n\t\tExplanation: Rob house 1 (money = 1) and then rob house 3 (money = 3).\n\t\tTotal amount you can rob = 1 + 3 = 4.\n\t\tExample 2:\n\t\tInput: nums = [2,7,9,3,1]\n\t\tOutput: 12\n\t\tExplanation: Rob house 1 (money = 2), rob house 3 (money = 9) and rob house 5 (money = 1).\n\t\tTotal amount you can rob = 2 + 9 + 1 = 12.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 199, - "question": "class Solution:\n def rightSideView(self, root: Optional[TreeNode]) -> List[int]:\n\t\t\"\"\"\n\t\tGiven the root of a binary tree, imagine yourself standing on the right side of it, return the values of the nodes you can see ordered from top to bottom.\n\t\tExample 1:\n\t\tInput: root = [1,2,3,null,5,null,4]\n\t\tOutput: [1,3,4]\n\t\tExample 2:\n\t\tInput: root = [1,null,3]\n\t\tOutput: [1,3]\n\t\tExample 3:\n\t\tInput: root = []\n\t\tOutput: []\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 200, - "question": "class Solution:\n def numIslands(self, grid: List[List[str]]) -> int:\n\t\t\"\"\"\n\t\tGiven an m x n 2D binary grid grid which represents a map of '1's (land) and '0's (water), return the number of islands.\n\t\tAn island is surrounded by water and is formed by connecting adjacent lands horizontally or vertically. You may assume all four edges of the grid are all surrounded by water.\n\t\tExample 1:\n\t\tInput: grid = [\n\t\t [\"1\",\"1\",\"1\",\"1\",\"0\"],\n\t\t [\"1\",\"1\",\"0\",\"1\",\"0\"],\n\t\t [\"1\",\"1\",\"0\",\"0\",\"0\"],\n\t\t [\"0\",\"0\",\"0\",\"0\",\"0\"]\n\t\t]\n\t\tOutput: 1\n\t\tExample 2:\n\t\tInput: grid = [\n\t\t [\"1\",\"1\",\"0\",\"0\",\"0\"],\n\t\t [\"1\",\"1\",\"0\",\"0\",\"0\"],\n\t\t [\"0\",\"0\",\"1\",\"0\",\"0\"],\n\t\t [\"0\",\"0\",\"0\",\"1\",\"1\"]\n\t\t]\n\t\tOutput: 3\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 201, - "question": "class Solution:\n def rangeBitwiseAnd(self, left: int, right: int) -> int:\n\t\t\"\"\"\n\t\tGiven two integers left and right that represent the range [left, right], return the bitwise AND of all numbers in this range, inclusive.\n\t\tExample 1:\n\t\tInput: left = 5, right = 7\n\t\tOutput: 4\n\t\tExample 2:\n\t\tInput: left = 0, right = 0\n\t\tOutput: 0\n\t\tExample 3:\n\t\tInput: left = 1, right = 2147483647\n\t\tOutput: 0\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 202, - "question": "class Solution:\n def isHappy(self, n: int) -> bool:\n\t\t\"\"\"\n\t\tWrite an algorithm to determine if a number n is happy.\n\t\tA happy number is a number defined by the following process:\n\t\t\tStarting with any positive integer, replace the number by the sum of the squares of its digits.\n\t\t\tRepeat the process until the number equals 1 (where it will stay), or it loops endlessly in a cycle which does not include 1.\n\t\t\tThose numbers for which this process ends in 1 are happy.\n\t\tReturn true if n is a happy number, and false if not.\n\t\tExample 1:\n\t\tInput: n = 19\n\t\tOutput: true\n\t\tExplanation:\n\t\t12 + 92 = 82\n\t\t82 + 22 = 68\n\t\t62 + 82 = 100\n\t\t12 + 02 + 02 = 1\n\t\tExample 2:\n\t\tInput: n = 2\n\t\tOutput: false\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 203, - "question": "class Solution:\n def removeElements(self, head: Optional[ListNode], val: int) -> Optional[ListNode]:\n\t\t\"\"\"\n\t\tGiven the head of a linked list and an integer val, remove all the nodes of the linked list that has Node.val == val, and return the new head.\n\t\tExample 1:\n\t\tInput: head = [1,2,6,3,4,5,6], val = 6\n\t\tOutput: [1,2,3,4,5]\n\t\tExample 2:\n\t\tInput: head = [], val = 1\n\t\tOutput: []\n\t\tExample 3:\n\t\tInput: head = [7,7,7,7], val = 7\n\t\tOutput: []\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 204, - "question": "class Solution:\n def countPrimes(self, n: int) -> int:\n\t\t\"\"\"\n\t\tGiven an integer n, return the number of prime numbers that are strictly less than n.\n\t\tExample 1:\n\t\tInput: n = 10\n\t\tOutput: 4\n\t\tExplanation: There are 4 prime numbers less than 10, they are 2, 3, 5, 7.\n\t\tExample 2:\n\t\tInput: n = 0\n\t\tOutput: 0\n\t\tExample 3:\n\t\tInput: n = 1\n\t\tOutput: 0\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 205, - "question": "class Solution:\n def isIsomorphic(self, s: str, t: str) -> bool:\n\t\t\"\"\"\n\t\tGiven two strings s and t, determine if they are isomorphic.\n\t\tTwo strings s and t are isomorphic if the characters in s can be replaced to get t.\n\t\tAll occurrences of a character must be replaced with another character while preserving the order of characters. No two characters may map to the same character, but a character may map to itself.\n\t\tExample 1:\n\t\tInput: s = \"egg\", t = \"add\"\n\t\tOutput: true\n\t\tExample 2:\n\t\tInput: s = \"foo\", t = \"bar\"\n\t\tOutput: false\n\t\tExample 3:\n\t\tInput: s = \"paper\", t = \"title\"\n\t\tOutput: true\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 206, - "question": "class Solution:\n def reverseList(self, head: Optional[ListNode]) -> Optional[ListNode]:\n\t\t\"\"\"\n\t\tGiven the head of a singly linked list, reverse the list, and return the reversed list.\n\t\tExample 1:\n\t\tInput: head = [1,2,3,4,5]\n\t\tOutput: [5,4,3,2,1]\n\t\tExample 2:\n\t\tInput: head = [1,2]\n\t\tOutput: [2,1]\n\t\tExample 3:\n\t\tInput: head = []\n\t\tOutput: []\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 207, - "question": "class Solution:\n def canFinish(self, numCourses: int, prerequisites: List[List[int]]) -> bool:\n\t\t\"\"\"\n\t\tThere are a total of numCourses courses you have to take, labeled from 0 to numCourses - 1. You are given an array prerequisites where prerequisites[i] = [ai, bi] indicates that you must take course bi first if you want to take course ai.\n\t\t\tFor example, the pair [0, 1], indicates that to take course 0 you have to first take course 1.\n\t\tReturn true if you can finish all courses. Otherwise, return false.\n\t\tExample 1:\n\t\tInput: numCourses = 2, prerequisites = [[1,0]]\n\t\tOutput: true\n\t\tExplanation: There are a total of 2 courses to take. \n\t\tTo take course 1 you should have finished course 0. So it is possible.\n\t\tExample 2:\n\t\tInput: numCourses = 2, prerequisites = [[1,0],[0,1]]\n\t\tOutput: false\n\t\tExplanation: There are a total of 2 courses to take. \n\t\tTo take course 1 you should have finished course 0, and to take course 0 you should also have finished course 1. So it is impossible.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 208, - "question": "class Trie:\n def __init__(self):\n def insert(self, word: str) -> None:\n def search(self, word: str) -> bool:\n def startsWith(self, prefix: str) -> bool:\n\t\t\"\"\"\n\t\tA trie (pronounced as \"try\") or prefix tree is a tree data structure used to efficiently store and retrieve keys in a dataset of strings. There are various applications of this data structure, such as autocomplete and spellchecker.\n\t\tImplement the Trie class:\n\t\t\tTrie() Initializes the trie object.\n\t\t\tvoid insert(String word) Inserts the string word into the trie.\n\t\t\tboolean search(String word) Returns true if the string word is in the trie (i.e., was inserted before), and false otherwise.\n\t\t\tboolean startsWith(String prefix) Returns true if there is a previously inserted string word that has the prefix prefix, and false otherwise.\n\t\tExample 1:\n\t\tInput\n\t\t[\"Trie\", \"insert\", \"search\", \"search\", \"startsWith\", \"insert\", \"search\"]\n\t\t[[], [\"apple\"], [\"apple\"], [\"app\"], [\"app\"], [\"app\"], [\"app\"]]\n\t\tOutput\n\t\t[null, null, true, false, true, null, true]\n\t\tExplanation\n\t\tTrie trie = new Trie();\n\t\ttrie.insert(\"apple\");\n\t\ttrie.search(\"apple\"); // return True\n\t\ttrie.search(\"app\"); // return False\n\t\ttrie.startsWith(\"app\"); // return True\n\t\ttrie.insert(\"app\");\n\t\ttrie.search(\"app\"); // return True\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 209, - "question": "class Solution:\n def minSubArrayLen(self, target: int, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tGiven an array of positive integers nums and a positive integer target, return the minimal length of a subarray whose sum is greater than or equal to target. If there is no such subarray, return 0 instead.\n\t\tExample 1:\n\t\tInput: target = 7, nums = [2,3,1,2,4,3]\n\t\tOutput: 2\n\t\tExplanation: The subarray [4,3] has the minimal length under the problem constraint.\n\t\tExample 2:\n\t\tInput: target = 4, nums = [1,4,4]\n\t\tOutput: 1\n\t\tExample 3:\n\t\tInput: target = 11, nums = [1,1,1,1,1,1,1,1]\n\t\tOutput: 0\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 210, - "question": "class Solution:\n def findOrder(self, numCourses: int, prerequisites: List[List[int]]) -> List[int]:\n\t\t\"\"\"\n\t\tThere are a total of numCourses courses you have to take, labeled from 0 to numCourses - 1. You are given an array prerequisites where prerequisites[i] = [ai, bi] indicates that you must take course bi first if you want to take course ai.\n\t\t\tFor example, the pair [0, 1], indicates that to take course 0 you have to first take course 1.\n\t\tReturn the ordering of courses you should take to finish all courses. If there are many valid answers, return any of them. If it is impossible to finish all courses, return an empty array.\n\t\tExample 1:\n\t\tInput: numCourses = 2, prerequisites = [[1,0]]\n\t\tOutput: [0,1]\n\t\tExplanation: There are a total of 2 courses to take. To take course 1 you should have finished course 0. So the correct course order is [0,1].\n\t\tExample 2:\n\t\tInput: numCourses = 4, prerequisites = [[1,0],[2,0],[3,1],[3,2]]\n\t\tOutput: [0,2,1,3]\n\t\tExplanation: There are a total of 4 courses to take. To take course 3 you should have finished both courses 1 and 2. Both courses 1 and 2 should be taken after you finished course 0.\n\t\tSo one correct course order is [0,1,2,3]. Another correct ordering is [0,2,1,3].\n\t\tExample 3:\n\t\tInput: numCourses = 1, prerequisites = []\n\t\tOutput: [0]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 211, - "question": "class WordDictionary:\n def __init__(self):\n def addWord(self, word: str) -> None:\n def search(self, word: str) -> bool:\n\t\t\"\"\"\n\t\tDesign a data structure that supports adding new words and finding if a string matches any previously added string.\n\t\tImplement the WordDictionary class:\n\t\t\tWordDictionary() Initializes the object.\n\t\t\tvoid addWord(word) Adds word to the data structure, it can be matched later.\n\t\t\tbool search(word) Returns true if there is any string in the data structure that matches word or false otherwise. word may contain dots '.' where dots can be matched with any letter.\n\t\tExample:\n\t\tInput\n\t\t[\"WordDictionary\",\"addWord\",\"addWord\",\"addWord\",\"search\",\"search\",\"search\",\"search\"]\n\t\t[[],[\"bad\"],[\"dad\"],[\"mad\"],[\"pad\"],[\"bad\"],[\".ad\"],[\"b..\"]]\n\t\tOutput\n\t\t[null,null,null,null,false,true,true,true]\n\t\tExplanation\n\t\tWordDictionary wordDictionary = new WordDictionary();\n\t\twordDictionary.addWord(\"bad\");\n\t\twordDictionary.addWord(\"dad\");\n\t\twordDictionary.addWord(\"mad\");\n\t\twordDictionary.search(\"pad\"); // return False\n\t\twordDictionary.search(\"bad\"); // return True\n\t\twordDictionary.search(\".ad\"); // return True\n\t\twordDictionary.search(\"b..\"); // return True\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 212, - "question": "class Solution:\n def findWords(self, board: List[List[str]], words: List[str]) -> List[str]:\n\t\t\"\"\"\n\t\tGiven an m x n board of characters and a list of strings words, return all words on the board.\n\t\tEach word must be constructed from letters of sequentially adjacent cells, where adjacent cells are horizontally or vertically neighboring. The same letter cell may not be used more than once in a word.\n\t\tExample 1:\n\t\tInput: board = [[\"o\",\"a\",\"a\",\"n\"],[\"e\",\"t\",\"a\",\"e\"],[\"i\",\"h\",\"k\",\"r\"],[\"i\",\"f\",\"l\",\"v\"]], words = [\"oath\",\"pea\",\"eat\",\"rain\"]\n\t\tOutput: [\"eat\",\"oath\"]\n\t\tExample 2:\n\t\tInput: board = [[\"a\",\"b\"],[\"c\",\"d\"]], words = [\"abcb\"]\n\t\tOutput: []\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 213, - "question": "class Solution:\n def rob(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou are a professional robber planning to rob houses along a street. Each house has a certain amount of money stashed. All houses at this place are arranged in a circle. That means the first house is the neighbor of the last one. Meanwhile, adjacent houses have a security system connected, and it will automatically contact the police if two adjacent houses were broken into on the same night.\n\t\tGiven an integer array nums representing the amount of money of each house, return the maximum amount of money you can rob tonight without alerting the police.\n\t\tExample 1:\n\t\tInput: nums = [2,3,2]\n\t\tOutput: 3\n\t\tExplanation: You cannot rob house 1 (money = 2) and then rob house 3 (money = 2), because they are adjacent houses.\n\t\tExample 2:\n\t\tInput: nums = [1,2,3,1]\n\t\tOutput: 4\n\t\tExplanation: Rob house 1 (money = 1) and then rob house 3 (money = 3).\n\t\tTotal amount you can rob = 1 + 3 = 4.\n\t\tExample 3:\n\t\tInput: nums = [1,2,3]\n\t\tOutput: 3\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 214, - "question": "class Solution:\n def shortestPalindrome(self, s: str) -> str:\n\t\t\"\"\"\n\t\tYou are given a string s. You can convert s to a palindrome by adding characters in front of it.\n\t\tReturn the shortest palindrome you can find by performing this transformation.\n\t\tExample 1:\n\t\tInput: s = \"aacecaaa\"\n\t\tOutput: \"aaacecaaa\"\n\t\tExample 2:\n\t\tInput: s = \"abcd\"\n\t\tOutput: \"dcbabcd\"\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 215, - "question": "class Solution:\n def findKthLargest(self, nums: List[int], k: int) -> int:\n\t\t\"\"\"\n\t\tGiven an integer array nums and an integer k, return the kth largest element in the array.\n\t\tNote that it is the kth largest element in the sorted order, not the kth distinct element.\n\t\tYou must solve it in O(n) time complexity.\n\t\tExample 1:\n\t\tInput: nums = [3,2,1,5,6,4], k = 2\n\t\tOutput: 5\n\t\tExample 2:\n\t\tInput: nums = [3,2,3,1,2,4,5,5,6], k = 4\n\t\tOutput: 4\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 216, - "question": "class Solution:\n def combinationSum3(self, k: int, n: int) -> List[List[int]]:\n\t\t\"\"\"\n\t\tFind all valid combinations of k numbers that sum up to n such that the following conditions are true:\n\t\t\tOnly numbers 1 through 9 are used.\n\t\t\tEach number is used at most once.\n\t\tReturn a list of all possible valid combinations. The list must not contain the same combination twice, and the combinations may be returned in any order.\n\t\tExample 1:\n\t\tInput: k = 3, n = 7\n\t\tOutput: [[1,2,4]]\n\t\tExplanation:\n\t\t1 + 2 + 4 = 7\n\t\tThere are no other valid combinations.\n\t\tExample 2:\n\t\tInput: k = 3, n = 9\n\t\tOutput: [[1,2,6],[1,3,5],[2,3,4]]\n\t\tExplanation:\n\t\t1 + 2 + 6 = 9\n\t\t1 + 3 + 5 = 9\n\t\t2 + 3 + 4 = 9\n\t\tThere are no other valid combinations.\n\t\tExample 3:\n\t\tInput: k = 4, n = 1\n\t\tOutput: []\n\t\tExplanation: There are no valid combinations.\n\t\tUsing 4 different numbers in the range [1,9], the smallest sum we can get is 1+2+3+4 = 10 and since 10 > 1, there are no valid combination.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 217, - "question": "class Solution:\n def containsDuplicate(self, nums: List[int]) -> bool:\n\t\t\"\"\"\n\t\tGiven an integer array nums, return true if any value appears at least twice in the array, and return false if every element is distinct.\n\t\tExample 1:\n\t\tInput: nums = [1,2,3,1]\n\t\tOutput: true\n\t\tExample 2:\n\t\tInput: nums = [1,2,3,4]\n\t\tOutput: false\n\t\tExample 3:\n\t\tInput: nums = [1,1,1,3,3,4,3,2,4,2]\n\t\tOutput: true\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 218, - "question": "class Solution:\n def getSkyline(self, buildings: List[List[int]]) -> List[List[int]]:\n\t\t\"\"\"\n\t\tA city's skyline is the outer contour of the silhouette formed by all the buildings in that city when viewed from a distance. Given the locations and heights of all the buildings, return the skyline formed by these buildings collectively.\n\t\tThe geometric information of each building is given in the array buildings where buildings[i] = [lefti, righti, heighti]:\n\t\t\tlefti is the x coordinate of the left edge of the ith building.\n\t\t\trighti is the x coordinate of the right edge of the ith building.\n\t\t\theighti is the height of the ith building.\n\t\tYou may assume all buildings are perfect rectangles grounded on an absolutely flat surface at height 0.\n\t\tThe skyline should be represented as a list of \"key points\" sorted by their x-coordinate in the form [[x1,y1],[x2,y2],...]. Each key point is the left endpoint of some horizontal segment in the skyline except the last point in the list, which always has a y-coordinate 0 and is used to mark the skyline's termination where the rightmost building ends. Any ground between the leftmost and rightmost buildings should be part of the skyline's contour.\n\t\tNote: There must be no consecutive horizontal lines of equal height in the output skyline. For instance, [...,[2 3],[4 5],[7 5],[11 5],[12 7],...] is not acceptable; the three lines of height 5 should be merged into one in the final output as such: [...,[2 3],[4 5],[12 7],...]\n\t\tExample 1:\n\t\tInput: buildings = [[2,9,10],[3,7,15],[5,12,12],[15,20,10],[19,24,8]]\n\t\tOutput: [[2,10],[3,15],[7,12],[12,0],[15,10],[20,8],[24,0]]\n\t\tExplanation:\n\t\tFigure A shows the buildings of the input.\n\t\tFigure B shows the skyline formed by those buildings. The red points in figure B represent the key points in the output list.\n\t\tExample 2:\n\t\tInput: buildings = [[0,2,3],[2,5,3]]\n\t\tOutput: [[0,3],[5,0]]\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 219, - "question": "class Solution:\n def containsNearbyDuplicate(self, nums: List[int], k: int) -> bool:\n\t\t\"\"\"\n\t\tGiven an integer array nums and an integer k, return true if there are two distinct indices i and j in the array such that nums[i] == nums[j] and abs(i - j) <= k.\n\t\tExample 1:\n\t\tInput: nums = [1,2,3,1], k = 3\n\t\tOutput: true\n\t\tExample 2:\n\t\tInput: nums = [1,0,1,1], k = 1\n\t\tOutput: true\n\t\tExample 3:\n\t\tInput: nums = [1,2,3,1,2,3], k = 2\n\t\tOutput: false\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 220, - "question": "class Solution:\n def containsNearbyAlmostDuplicate(self, nums: List[int], indexDiff: int, valueDiff: int) -> bool:\n\t\t\"\"\"\n\t\tYou are given an integer array nums and two integers indexDiff and valueDiff.\n\t\tFind a pair of indices (i, j) such that:\n\t\t\ti != j,\n\t\t\tabs(i - j) <= indexDiff.\n\t\t\tabs(nums[i] - nums[j]) <= valueDiff, and\n\t\tReturn true if such pair exists or false otherwise.\n\t\tExample 1:\n\t\tInput: nums = [1,2,3,1], indexDiff = 3, valueDiff = 0\n\t\tOutput: true\n\t\tExplanation: We can choose (i, j) = (0, 3).\n\t\tWe satisfy the three conditions:\n\t\ti != j --> 0 != 3\n\t\tabs(i - j) <= indexDiff --> abs(0 - 3) <= 3\n\t\tabs(nums[i] - nums[j]) <= valueDiff --> abs(1 - 1) <= 0\n\t\tExample 2:\n\t\tInput: nums = [1,5,9,1,5,9], indexDiff = 2, valueDiff = 3\n\t\tOutput: false\n\t\tExplanation: After trying all the possible pairs (i, j), we cannot satisfy the three conditions, so we return false.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 221, - "question": "class Solution:\n def maximalSquare(self, matrix: List[List[str]]) -> int:\n\t\t\"\"\"\n\t\tGiven an m x n binary matrix filled with 0's and 1's, find the largest square containing only 1's and return its area.\n\t\tExample 1:\n\t\tInput: matrix = [[\"1\",\"0\",\"1\",\"0\",\"0\"],[\"1\",\"0\",\"1\",\"1\",\"1\"],[\"1\",\"1\",\"1\",\"1\",\"1\"],[\"1\",\"0\",\"0\",\"1\",\"0\"]]\n\t\tOutput: 4\n\t\tExample 2:\n\t\tInput: matrix = [[\"0\",\"1\"],[\"1\",\"0\"]]\n\t\tOutput: 1\n\t\tExample 3:\n\t\tInput: matrix = [[\"0\"]]\n\t\tOutput: 0\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 222, - "question": "class Solution:\n def countNodes(self, root: Optional[TreeNode]) -> int:\n\t\t\"\"\"\n\t\tGiven the root of a complete binary tree, return the number of the nodes in the tree.\n\t\tAccording to Wikipedia, every level, except possibly the last, is completely filled in a complete binary tree, and all nodes in the last level are as far left as possible. It can have between 1 and 2h nodes inclusive at the last level h.\n\t\tDesign an algorithm that runs in less than O(n) time complexity.\n\t\tExample 1:\n\t\tInput: root = [1,2,3,4,5,6]\n\t\tOutput: 6\n\t\tExample 2:\n\t\tInput: root = []\n\t\tOutput: 0\n\t\tExample 3:\n\t\tInput: root = [1]\n\t\tOutput: 1\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 223, - "question": "class Solution:\n def computeArea(self, ax1: int, ay1: int, ax2: int, ay2: int, bx1: int, by1: int, bx2: int, by2: int) -> int:\n\t\t\"\"\"\n\t\tGiven the coordinates of two rectilinear rectangles in a 2D plane, return the total area covered by the two rectangles.\n\t\tThe first rectangle is defined by its bottom-left corner (ax1, ay1) and its top-right corner (ax2, ay2).\n\t\tThe second rectangle is defined by its bottom-left corner (bx1, by1) and its top-right corner (bx2, by2).\n\t\tExample 1:\n\t\tInput: ax1 = -3, ay1 = 0, ax2 = 3, ay2 = 4, bx1 = 0, by1 = -1, bx2 = 9, by2 = 2\n\t\tOutput: 45\n\t\tExample 2:\n\t\tInput: ax1 = -2, ay1 = -2, ax2 = 2, ay2 = 2, bx1 = -2, by1 = -2, bx2 = 2, by2 = 2\n\t\tOutput: 16\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 224, - "question": "class Solution:\n def calculate(self, s: str) -> int:\n\t\t\"\"\"\n\t\tGiven a string s representing a valid expression, implement a basic calculator to evaluate it, and return the result of the evaluation.\n\t\tNote: You are not allowed to use any built-in function which evaluates strings as mathematical expressions, such as eval().\n\t\tExample 1:\n\t\tInput: s = \"1 + 1\"\n\t\tOutput: 2\n\t\tExample 2:\n\t\tInput: s = \" 2-1 + 2 \"\n\t\tOutput: 3\n\t\tExample 3:\n\t\tInput: s = \"(1+(4+5+2)-3)+(6+8)\"\n\t\tOutput: 23\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 225, - "question": "class MyStack:\n def __init__(self):\n def push(self, x: int) -> None:\n def pop(self) -> int:\n def top(self) -> int:\n def empty(self) -> bool:\n\t\t\"\"\"\n\t\tImplement a last-in-first-out (LIFO) stack using only two queues. The implemented stack should support all the functions of a normal stack (push, top, pop, and empty).\n\t\tImplement the MyStack class:\n\t\t\tvoid push(int x) Pushes element x to the top of the stack.\n\t\t\tint pop() Removes the element on the top of the stack and returns it.\n\t\t\tint top() Returns the element on the top of the stack.\n\t\t\tboolean empty() Returns true if the stack is empty, false otherwise.\n\t\tNotes:\n\t\t\tYou must use only standard operations of a queue, which means that only push to back, peek/pop from front, size and is empty operations are valid.\n\t\t\tDepending on your language, the queue may not be supported natively. You may simulate a queue using a list or deque (double-ended queue) as long as you use only a queue's standard operations.\n\t\tExample 1:\n\t\tInput\n\t\t[\"MyStack\", \"push\", \"push\", \"top\", \"pop\", \"empty\"]\n\t\t[[], [1], [2], [], [], []]\n\t\tOutput\n\t\t[null, null, null, 2, 2, false]\n\t\tExplanation\n\t\tMyStack myStack = new MyStack();\n\t\tmyStack.push(1);\n\t\tmyStack.push(2);\n\t\tmyStack.top(); // return 2\n\t\tmyStack.pop(); // return 2\n\t\tmyStack.empty(); // return False\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 226, - "question": "class Solution:\n def invertTree(self, root: Optional[TreeNode]) -> Optional[TreeNode]:\n\t\t\"\"\"\n\t\tGiven the root of a binary tree, invert the tree, and return its root.\n\t\tExample 1:\n\t\tInput: root = [4,2,7,1,3,6,9]\n\t\tOutput: [4,7,2,9,6,3,1]\n\t\tExample 2:\n\t\tInput: root = [2,1,3]\n\t\tOutput: [2,3,1]\n\t\tExample 3:\n\t\tInput: root = []\n\t\tOutput: []\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 227, - "question": "class Solution:\n def calculate(self, s: str) -> int:\n\t\t\"\"\"\n\t\tGiven a string s which represents an expression, evaluate this expression and return its value. \n\t\tThe integer division should truncate toward zero.\n\t\tYou may assume that the given expression is always valid. All intermediate results will be in the range of [-231, 231 - 1].\n\t\tNote: You are not allowed to use any built-in function which evaluates strings as mathematical expressions, such as eval().\n\t\tExample 1:\n\t\tInput: s = \"3+2*2\"\n\t\tOutput: 7\n\t\tExample 2:\n\t\tInput: s = \" 3/2 \"\n\t\tOutput: 1\n\t\tExample 3:\n\t\tInput: s = \" 3+5 / 2 \"\n\t\tOutput: 5\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 228, - "question": "class Solution:\n def summaryRanges(self, nums: List[int]) -> List[str]:\n\t\t\"\"\"\n\t\tYou are given a sorted unique integer array nums.\n\t\tA range [a,b] is the set of all integers from a to b (inclusive).\n\t\tReturn the smallest sorted list of ranges that cover all the numbers in the array exactly. That is, each element of nums is covered by exactly one of the ranges, and there is no integer x such that x is in one of the ranges but not in nums.\n\t\tEach range [a,b] in the list should be output as:\n\t\t\t\"a->b\" if a != b\n\t\t\t\"a\" if a == b\n\t\tExample 1:\n\t\tInput: nums = [0,1,2,4,5,7]\n\t\tOutput: [\"0->2\",\"4->5\",\"7\"]\n\t\tExplanation: The ranges are:\n\t\t[0,2] --> \"0->2\"\n\t\t[4,5] --> \"4->5\"\n\t\t[7,7] --> \"7\"\n\t\tExample 2:\n\t\tInput: nums = [0,2,3,4,6,8,9]\n\t\tOutput: [\"0\",\"2->4\",\"6\",\"8->9\"]\n\t\tExplanation: The ranges are:\n\t\t[0,0] --> \"0\"\n\t\t[2,4] --> \"2->4\"\n\t\t[6,6] --> \"6\"\n\t\t[8,9] --> \"8->9\"\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 229, - "question": "class Solution:\n def majorityElement(self, nums: List[int]) -> List[int]:\n\t\t\"\"\"\n\t\tGiven an integer array of size n, find all elements that appear more than \u230a n/3 \u230b times.\n\t\tExample 1:\n\t\tInput: nums = [3,2,3]\n\t\tOutput: [3]\n\t\tExample 2:\n\t\tInput: nums = [1]\n\t\tOutput: [1]\n\t\tExample 3:\n\t\tInput: nums = [1,2]\n\t\tOutput: [1,2]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 230, - "question": "class Solution:\n def kthSmallest(self, root: Optional[TreeNode], k: int) -> int:\n\t\t\"\"\"\n\t\tGiven the root of a binary search tree, and an integer k, return the kth smallest value (1-indexed) of all the values of the nodes in the tree.\n\t\tExample 1:\n\t\tInput: root = [3,1,4,null,2], k = 1\n\t\tOutput: 1\n\t\tExample 2:\n\t\tInput: root = [5,3,6,2,4,null,null,1], k = 3\n\t\tOutput: 3\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 231, - "question": "class Solution:\n def isPowerOfTwo(self, n: int) -> bool:\n\t\t\"\"\"\n\t\tGiven an integer n, return true if it is a power of two. Otherwise, return false.\n\t\tAn integer n is a power of two, if there exists an integer x such that n == 2x.\n\t\tExample 1:\n\t\tInput: n = 1\n\t\tOutput: true\n\t\tExplanation: 20 = 1\n\t\tExample 2:\n\t\tInput: n = 16\n\t\tOutput: true\n\t\tExplanation: 24 = 16\n\t\tExample 3:\n\t\tInput: n = 3\n\t\tOutput: false\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 232, - "question": "class MyQueue:\n def __init__(self):\n def push(self, x: int) -> None:\n def pop(self) -> int:\n def peek(self) -> int:\n def empty(self) -> bool:\n\t\t\"\"\"\n\t\tImplement a first in first out (FIFO) queue using only two stacks. The implemented queue should support all the functions of a normal queue (push, peek, pop, and empty).\n\t\tImplement the MyQueue class:\n\t\t\tvoid push(int x) Pushes element x to the back of the queue.\n\t\t\tint pop() Removes the element from the front of the queue and returns it.\n\t\t\tint peek() Returns the element at the front of the queue.\n\t\t\tboolean empty() Returns true if the queue is empty, false otherwise.\n\t\tNotes:\n\t\t\tYou must use only standard operations of a stack, which means only push to top, peek/pop from top, size, and is empty operations are valid.\n\t\t\tDepending on your language, the stack may not be supported natively. You may simulate a stack using a list or deque (double-ended queue) as long as you use only a stack's standard operations.\n\t\tExample 1:\n\t\tInput\n\t\t[\"MyQueue\", \"push\", \"push\", \"peek\", \"pop\", \"empty\"]\n\t\t[[], [1], [2], [], [], []]\n\t\tOutput\n\t\t[null, null, null, 1, 1, false]\n\t\tExplanation\n\t\tMyQueue myQueue = new MyQueue();\n\t\tmyQueue.push(1); // queue is: [1]\n\t\tmyQueue.push(2); // queue is: [1, 2] (leftmost is front of the queue)\n\t\tmyQueue.peek(); // return 1\n\t\tmyQueue.pop(); // return 1, queue is [2]\n\t\tmyQueue.empty(); // return false\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 233, - "question": "class Solution:\n def countDigitOne(self, n: int) -> int:\n\t\t\"\"\"\n\t\tGiven an integer n, count the total number of digit 1 appearing in all non-negative integers less than or equal to n.\n\t\tExample 1:\n\t\tInput: n = 13\n\t\tOutput: 6\n\t\tExample 2:\n\t\tInput: n = 0\n\t\tOutput: 0\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 234, - "question": "class Solution:\n def isPalindrome(self, head: Optional[ListNode]) -> bool:\n\t\t\"\"\"\n\t\tGiven the head of a singly linked list, return true if it is a palindrome or false otherwise.\n\t\tExample 1:\n\t\tInput: head = [1,2,2,1]\n\t\tOutput: true\n\t\tExample 2:\n\t\tInput: head = [1,2]\n\t\tOutput: false\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 235, - "question": "class Solution:\n def lowestCommonAncestor(self, root: 'TreeNode', p: 'TreeNode', q: 'TreeNode') -> 'TreeNode':\n\t\t\"\"\"\n\t\tGiven a binary search tree (BST), find the lowest common ancestor (LCA) node of two given nodes in the BST.\n\t\tAccording to the definition of LCA on Wikipedia: \u201cThe lowest common ancestor is defined between two nodes p and q as the lowest node in T that has both p and q as descendants (where we allow a node to be a descendant of itself).\u201d\n\t\tExample 1:\n\t\tInput: root = [6,2,8,0,4,7,9,null,null,3,5], p = 2, q = 8\n\t\tOutput: 6\n\t\tExplanation: The LCA of nodes 2 and 8 is 6.\n\t\tExample 2:\n\t\tInput: root = [6,2,8,0,4,7,9,null,null,3,5], p = 2, q = 4\n\t\tOutput: 2\n\t\tExplanation: The LCA of nodes 2 and 4 is 2, since a node can be a descendant of itself according to the LCA definition.\n\t\tExample 3:\n\t\tInput: root = [2,1], p = 2, q = 1\n\t\tOutput: 2\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 236, - "question": "class Solution:\n def lowestCommonAncestor(self, root: 'TreeNode', p: 'TreeNode', q: 'TreeNode') -> 'TreeNode':\n\t\t\"\"\"\n\t\tGiven a binary tree, find the lowest common ancestor (LCA) of two given nodes in the tree.\n\t\tAccording to the definition of LCA on Wikipedia: \u201cThe lowest common ancestor is defined between two nodes p and q as the lowest node in T that has both p and q as descendants (where we allow a node to be a descendant of itself).\u201d\n\t\tExample 1:\n\t\tInput: root = [3,5,1,6,2,0,8,null,null,7,4], p = 5, q = 1\n\t\tOutput: 3\n\t\tExplanation: The LCA of nodes 5 and 1 is 3.\n\t\tExample 2:\n\t\tInput: root = [3,5,1,6,2,0,8,null,null,7,4], p = 5, q = 4\n\t\tOutput: 5\n\t\tExplanation: The LCA of nodes 5 and 4 is 5, since a node can be a descendant of itself according to the LCA definition.\n\t\tExample 3:\n\t\tInput: root = [1,2], p = 1, q = 2\n\t\tOutput: 1\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 237, - "question": "class Solution:\n def deleteNode(self, node):\n\t\t\"\"\"\n :type node: ListNode\n :rtype: void Do not return anything, modify node in-place instead.\n\t\tThere is a singly-linked list head and we want to delete a node node in it.\n\t\tYou are given the node to be deleted node. You will not be given access to the first node of head.\n\t\tAll the values of the linked list are unique, and it is guaranteed that the given node node is not the last node in the linked list.\n\t\tDelete the given node. Note that by deleting the node, we do not mean removing it from memory. We mean:\n\t\t\tThe value of the given node should not exist in the linked list.\n\t\t\tThe number of nodes in the linked list should decrease by one.\n\t\t\tAll the values before node should be in the same order.\n\t\t\tAll the values after node should be in the same order.\n\t\tCustom testing:\n\t\t\tFor the input, you should provide the entire linked list head and the node to be given node. node should not be the last node of the list and should be an actual node in the list.\n\t\t\tWe will build the linked list and pass the node to your function.\n\t\t\tThe output will be the entire list after calling your function.\n\t\tExample 1:\n\t\tInput: head = [4,5,1,9], node = 5\n\t\tOutput: [4,1,9]\n\t\tExplanation: You are given the second node with value 5, the linked list should become 4 -> 1 -> 9 after calling your function.\n\t\tExample 2:\n\t\tInput: head = [4,5,1,9], node = 1\n\t\tOutput: [4,5,9]\n\t\tExplanation: You are given the third node with value 1, the linked list should become 4 -> 5 -> 9 after calling your function.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 238, - "question": "class Solution:\n def productExceptSelf(self, nums: List[int]) -> List[int]:\n\t\t\"\"\"\n\t\tGiven an integer array nums, return an array answer such that answer[i] is equal to the product of all the elements of nums except nums[i].\n\t\tThe product of any prefix or suffix of nums is guaranteed to fit in a 32-bit integer.\n\t\tYou must write an algorithm that runs in O(n) time and without using the division operation.\n\t\tExample 1:\n\t\tInput: nums = [1,2,3,4]\n\t\tOutput: [24,12,8,6]\n\t\tExample 2:\n\t\tInput: nums = [-1,1,0,-3,3]\n\t\tOutput: [0,0,9,0,0]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 239, - "question": "class Solution:\n def maxSlidingWindow(self, nums: List[int], k: int) -> List[int]:\n\t\t\"\"\"\n\t\tYou are given an array of integers nums, there is a sliding window of size k which is moving from the very left of the array to the very right. You can only see the k numbers in the window. Each time the sliding window moves right by one position.\n\t\tReturn the max sliding window.\n\t\tExample 1:\n\t\tInput: nums = [1,3,-1,-3,5,3,6,7], k = 3\n\t\tOutput: [3,3,5,5,6,7]\n\t\tExplanation: \n\t\tWindow position Max\n\t\t--------------- -----\n\t\t[1 3 -1] -3 5 3 6 7 3\n\t\t 1 [3 -1 -3] 5 3 6 7 3\n\t\t 1 3 [-1 -3 5] 3 6 7 5\n\t\t 1 3 -1 [-3 5 3] 6 7 5\n\t\t 1 3 -1 -3 [5 3 6] 7 6\n\t\t 1 3 -1 -3 5 [3 6 7] 7\n\t\tExample 2:\n\t\tInput: nums = [1], k = 1\n\t\tOutput: [1]\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 240, - "question": "class Solution:\n def searchMatrix(self, matrix: List[List[int]], target: int) -> bool:\n\t\t\"\"\"\n\t\tWrite an efficient algorithm that searches for a value target in an m x n integer matrix matrix. This matrix has the following properties:\n\t\t\tIntegers in each row are sorted in ascending from left to right.\n\t\t\tIntegers in each column are sorted in ascending from top to bottom.\n\t\tExample 1:\n\t\tInput: matrix = [[1,4,7,11,15],[2,5,8,12,19],[3,6,9,16,22],[10,13,14,17,24],[18,21,23,26,30]], target = 5\n\t\tOutput: true\n\t\tExample 2:\n\t\tInput: matrix = [[1,4,7,11,15],[2,5,8,12,19],[3,6,9,16,22],[10,13,14,17,24],[18,21,23,26,30]], target = 20\n\t\tOutput: false\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 241, - "question": "class Solution:\n def diffWaysToCompute(self, expression: str) -> List[int]:\n\t\t\"\"\"\n\t\tGiven a string expression of numbers and operators, return all possible results from computing all the different possible ways to group numbers and operators. You may return the answer in any order.\n\t\tThe test cases are generated such that the output values fit in a 32-bit integer and the number of different results does not exceed 104.\n\t\tExample 1:\n\t\tInput: expression = \"2-1-1\"\n\t\tOutput: [0,2]\n\t\tExplanation:\n\t\t((2-1)-1) = 0 \n\t\t(2-(1-1)) = 2\n\t\tExample 2:\n\t\tInput: expression = \"2*3-4*5\"\n\t\tOutput: [-34,-14,-10,-10,10]\n\t\tExplanation:\n\t\t(2*(3-(4*5))) = -34 \n\t\t((2*3)-(4*5)) = -14 \n\t\t((2*(3-4))*5) = -10 \n\t\t(2*((3-4)*5)) = -10 \n\t\t(((2*3)-4)*5) = 10\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 242, - "question": "class Solution:\n def isAnagram(self, s: str, t: str) -> bool:\n\t\t\"\"\"\n\t\tGiven two strings s and t, return true if t is an anagram of s, and false otherwise.\n\t\tAn Anagram is a word or phrase formed by rearranging the letters of a different word or phrase, typically using all the original letters exactly once.\n\t\tExample 1:\n\t\tInput: s = \"anagram\", t = \"nagaram\"\n\t\tOutput: true\n\t\tExample 2:\n\t\tInput: s = \"rat\", t = \"car\"\n\t\tOutput: false\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 257, - "question": "class Solution:\n def binaryTreePaths(self, root: Optional[TreeNode]) -> List[str]:\n\t\t\"\"\"\n\t\tGiven the root of a binary tree, return all root-to-leaf paths in any order.\n\t\tA leaf is a node with no children.\n\t\tExample 1:\n\t\tInput: root = [1,2,3,null,5]\n\t\tOutput: [\"1->2->5\",\"1->3\"]\n\t\tExample 2:\n\t\tInput: root = [1]\n\t\tOutput: [\"1\"]\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 258, - "question": "class Solution:\n def addDigits(self, num: int) -> int:\n\t\t\"\"\"\n\t\tGiven an integer num, repeatedly add all its digits until the result has only one digit, and return it.\n\t\tExample 1:\n\t\tInput: num = 38\n\t\tOutput: 2\n\t\tExplanation: The process is\n\t\t38 --> 3 + 8 --> 11\n\t\t11 --> 1 + 1 --> 2 \n\t\tSince 2 has only one digit, return it.\n\t\tExample 2:\n\t\tInput: num = 0\n\t\tOutput: 0\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 260, - "question": "class Solution:\n def singleNumber(self, nums: List[int]) -> List[int]:\n\t\t\"\"\"\n\t\tGiven an integer array nums, in which exactly two elements appear only once and all the other elements appear exactly twice. Find the two elements that appear only once. You can return the answer in any order.\n\t\tYou must write an algorithm that runs in linear runtime complexity and uses only constant extra space.\n\t\tExample 1:\n\t\tInput: nums = [1,2,1,3,2,5]\n\t\tOutput: [3,5]\n\t\tExplanation: [5, 3] is also a valid answer.\n\t\tExample 2:\n\t\tInput: nums = [-1,0]\n\t\tOutput: [-1,0]\n\t\tExample 3:\n\t\tInput: nums = [0,1]\n\t\tOutput: [1,0]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 263, - "question": "class Solution:\n def isUgly(self, n: int) -> bool:\n\t\t\"\"\"\n\t\tAn ugly number is a positive integer whose prime factors are limited to 2, 3, and 5.\n\t\tGiven an integer n, return true if n is an ugly number.\n\t\tExample 1:\n\t\tInput: n = 6\n\t\tOutput: true\n\t\tExplanation: 6 = 2 \u00d7 3\n\t\tExample 2:\n\t\tInput: n = 1\n\t\tOutput: true\n\t\tExplanation: 1 has no prime factors, therefore all of its prime factors are limited to 2, 3, and 5.\n\t\tExample 3:\n\t\tInput: n = 14\n\t\tOutput: false\n\t\tExplanation: 14 is not ugly since it includes the prime factor 7.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 264, - "question": "class Solution:\n def nthUglyNumber(self, n: int) -> int:\n\t\t\"\"\"\n\t\tAn ugly number is a positive integer whose prime factors are limited to 2, 3, and 5.\n\t\tGiven an integer n, return the nth ugly number.\n\t\tExample 1:\n\t\tInput: n = 10\n\t\tOutput: 12\n\t\tExplanation: [1, 2, 3, 4, 5, 6, 8, 9, 10, 12] is the sequence of the first 10 ugly numbers.\n\t\tExample 2:\n\t\tInput: n = 1\n\t\tOutput: 1\n\t\tExplanation: 1 has no prime factors, therefore all of its prime factors are limited to 2, 3, and 5.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 268, - "question": "class Solution:\n def missingNumber(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tGiven an array nums containing n distinct numbers in the range [0, n], return the only number in the range that is missing from the array.\n\t\tExample 1:\n\t\tInput: nums = [3,0,1]\n\t\tOutput: 2\n\t\tExplanation: n = 3 since there are 3 numbers, so all numbers are in the range [0,3]. 2 is the missing number in the range since it does not appear in nums.\n\t\tExample 2:\n\t\tInput: nums = [0,1]\n\t\tOutput: 2\n\t\tExplanation: n = 2 since there are 2 numbers, so all numbers are in the range [0,2]. 2 is the missing number in the range since it does not appear in nums.\n\t\tExample 3:\n\t\tInput: nums = [9,6,4,2,3,5,7,0,1]\n\t\tOutput: 8\n\t\tExplanation: n = 9 since there are 9 numbers, so all numbers are in the range [0,9]. 8 is the missing number in the range since it does not appear in nums.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 273, - "question": "class Solution:\n def numberToWords(self, num: int) -> str:\n\t\t\"\"\"\n\t\tConvert a non-negative integer num to its English words representation.\n\t\tExample 1:\n\t\tInput: num = 123\n\t\tOutput: \"One Hundred Twenty Three\"\n\t\tExample 2:\n\t\tInput: num = 12345\n\t\tOutput: \"Twelve Thousand Three Hundred Forty Five\"\n\t\tExample 3:\n\t\tInput: num = 1234567\n\t\tOutput: \"One Million Two Hundred Thirty Four Thousand Five Hundred Sixty Seven\"\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 274, - "question": "class Solution:\n def hIndex(self, citations: List[int]) -> int:\n\t\t\"\"\"\n\t\tGiven an array of integers citations where citations[i] is the number of citations a researcher received for their ith paper, return compute the researcher's h-index.\n\t\tAccording to the definition of h-index on Wikipedia: A scientist has an index h if h of their n papers have at least h citations each, and the other n \u2212 h papers have no more than h citations each.\n\t\tIf there are several possible values for h, the maximum one is taken as the h-index.\n\t\tExample 1:\n\t\tInput: citations = [3,0,6,1,5]\n\t\tOutput: 3\n\t\tExplanation: [3,0,6,1,5] means the researcher has 5 papers in total and each of them had received 3, 0, 6, 1, 5 citations respectively.\n\t\tSince the researcher has 3 papers with at least 3 citations each and the remaining two with no more than 3 citations each, their h-index is 3.\n\t\tExample 2:\n\t\tInput: citations = [1,3,1]\n\t\tOutput: 1\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 275, - "question": "class Solution:\n def hIndex(self, citations: List[int]) -> int:\n\t\t\"\"\"\n\t\tGiven an array of integers citations where citations[i] is the number of citations a researcher received for their ith paper and citations is sorted in an ascending order, return compute the researcher's h-index.\n\t\tAccording to the definition of h-index on Wikipedia: A scientist has an index h if h of their n papers have at least h citations each, and the other n \u2212 h papers have no more than h citations each.\n\t\tIf there are several possible values for h, the maximum one is taken as the h-index.\n\t\tYou must write an algorithm that runs in logarithmic time.\n\t\tExample 1:\n\t\tInput: citations = [0,1,3,5,6]\n\t\tOutput: 3\n\t\tExplanation: [0,1,3,5,6] means the researcher has 5 papers in total and each of them had received 0, 1, 3, 5, 6 citations respectively.\n\t\tSince the researcher has 3 papers with at least 3 citations each and the remaining two with no more than 3 citations each, their h-index is 3.\n\t\tExample 2:\n\t\tInput: citations = [1,2,100]\n\t\tOutput: 2\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 278, - "question": "class Solution:\n def firstBadVersion(self, n: int) -> int:\n\t\t\"\"\"\n\t\tYou are a product manager and currently leading a team to develop a new product. Unfortunately, the latest version of your product fails the quality check. Since each version is developed based on the previous version, all the versions after a bad version are also bad.\n\t\tSuppose you have n versions [1, 2, ..., n] and you want to find out the first bad one, which causes all the following ones to be bad.\n\t\tYou are given an API bool isBadVersion(version) which returns whether version is bad. Implement a function to find the first bad version. You should minimize the number of calls to the API.\n\t\tExample 1:\n\t\tInput: n = 5, bad = 4\n\t\tOutput: 4\n\t\tExplanation:\n\t\tcall isBadVersion(3) -> false\n\t\tcall isBadVersion(5) -> true\n\t\tcall isBadVersion(4) -> true\n\t\tThen 4 is the first bad version.\n\t\tExample 2:\n\t\tInput: n = 1, bad = 1\n\t\tOutput: 1\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 279, - "question": "class Solution:\n def numSquares(self, n: int) -> int:\n\t\t\"\"\"\n\t\tGiven an integer n, return the least number of perfect square numbers that sum to n.\n\t\tA perfect square is an integer that is the square of an integer; in other words, it is the product of some integer with itself. For example, 1, 4, 9, and 16 are perfect squares while 3 and 11 are not.\n\t\tExample 1:\n\t\tInput: n = 12\n\t\tOutput: 3\n\t\tExplanation: 12 = 4 + 4 + 4.\n\t\tExample 2:\n\t\tInput: n = 13\n\t\tOutput: 2\n\t\tExplanation: 13 = 4 + 9.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 282, - "question": "class Solution:\n def addOperators(self, num: str, target: int) -> List[str]:\n\t\t\"\"\"\n\t\tGiven a string num that contains only digits and an integer target, return all possibilities to insert the binary operators '+', '-', and/or '*' between the digits of num so that the resultant expression evaluates to the target value.\n\t\tNote that operands in the returned expressions should not contain leading zeros.\n\t\tExample 1:\n\t\tInput: num = \"123\", target = 6\n\t\tOutput: [\"1*2*3\",\"1+2+3\"]\n\t\tExplanation: Both \"1*2*3\" and \"1+2+3\" evaluate to 6.\n\t\tExample 2:\n\t\tInput: num = \"232\", target = 8\n\t\tOutput: [\"2*3+2\",\"2+3*2\"]\n\t\tExplanation: Both \"2*3+2\" and \"2+3*2\" evaluate to 8.\n\t\tExample 3:\n\t\tInput: num = \"3456237490\", target = 9191\n\t\tOutput: []\n\t\tExplanation: There are no expressions that can be created from \"3456237490\" to evaluate to 9191.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 283, - "question": "class Solution:\n def moveZeroes(self, nums: List[int]) -> None:\n\t\t\"\"\"\n Do not return anything, modify nums in-place instead.\n\t\tGiven an integer array nums, move all 0's to the end of it while maintaining the relative order of the non-zero elements.\n\t\tNote that you must do this in-place without making a copy of the array.\n\t\tExample 1:\n\t\tInput: nums = [0,1,0,3,12]\n\t\tOutput: [1,3,12,0,0]\n\t\tExample 2:\n\t\tInput: nums = [0]\n\t\tOutput: [0]\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 284, - "question": "\t\t\"\"\"\n\t\tDesign an iterator that supports the peek operation on an existing iterator in addition to the hasNext and the next operations.\n\t\tImplement the PeekingIterator class:\n\t\t\tPeekingIterator(Iterator nums) Initializes the object with the given integer iterator iterator.\n\t\t\tint next() Returns the next element in the array and moves the pointer to the next element.\n\t\t\tboolean hasNext() Returns true if there are still elements in the array.\n\t\t\tint peek() Returns the next element in the array without moving the pointer.\n\t\tNote: Each language may have a different implementation of the constructor and Iterator, but they all support the int next() and boolean hasNext() functions.\n\t\tExample 1:\n\t\tInput\n\t\t[\"PeekingIterator\", \"next\", \"peek\", \"next\", \"next\", \"hasNext\"]\n\t\t[[[1, 2, 3]], [], [], [], [], []]\n\t\tOutput\n\t\t[null, 1, 2, 2, 3, false]\n\t\tExplanation\n\t\tPeekingIterator peekingIterator = new PeekingIterator([1, 2, 3]); // [1,2,3]\n\t\tpeekingIterator.next(); // return 1, the pointer moves to the next element [1,2,3].\n\t\tpeekingIterator.peek(); // return 2, the pointer does not move [1,2,3].\n\t\tpeekingIterator.next(); // return 2, the pointer moves to the next element [1,2,3]\n\t\tpeekingIterator.next(); // return 3, the pointer moves to the next element [1,2,3]\n\t\tpeekingIterator.hasNext(); // return False\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 287, - "question": "class Solution:\n def findDuplicate(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tGiven an array of integers nums containing n + 1 integers where each integer is in the range [1, n] inclusive.\n\t\tThere is only one repeated number in nums, return this repeated number.\n\t\tYou must solve the problem without modifying the array nums and uses only constant extra space.\n\t\tExample 1:\n\t\tInput: nums = [1,3,4,2,2]\n\t\tOutput: 2\n\t\tExample 2:\n\t\tInput: nums = [3,1,3,4,2]\n\t\tOutput: 3\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 289, - "question": "class Solution:\n def gameOfLife(self, board: List[List[int]]) -> None:\n\t\t\"\"\"\n Do not return anything, modify board in-place instead.\n\t\tAccording to Wikipedia's article: \"The Game of Life, also known simply as Life, is a cellular automaton devised by the British mathematician John Horton Conway in 1970.\"\n\t\tThe board is made up of an m x n grid of cells, where each cell has an initial state: live (represented by a 1) or dead (represented by a 0). Each cell interacts with its eight neighbors (horizontal, vertical, diagonal) using the following four rules (taken from the above Wikipedia article):\n\t\t\tAny live cell with fewer than two live neighbors dies as if caused by under-population.\n\t\t\tAny live cell with two or three live neighbors lives on to the next generation.\n\t\t\tAny live cell with more than three live neighbors dies, as if by over-population.\n\t\t\tAny dead cell with exactly three live neighbors becomes a live cell, as if by reproduction.\n\t\tThe next state is created by applying the above rules simultaneously to every cell in the current state, where births and deaths occur simultaneously. Given the current state of the m x n grid board, return the next state.\n\t\tExample 1:\n\t\tInput: board = [[0,1,0],[0,0,1],[1,1,1],[0,0,0]]\n\t\tOutput: [[0,0,0],[1,0,1],[0,1,1],[0,1,0]]\n\t\tExample 2:\n\t\tInput: board = [[1,1],[1,0]]\n\t\tOutput: [[1,1],[1,1]]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 290, - "question": "class Solution:\n def wordPattern(self, pattern: str, s: str) -> bool:\n\t\t\"\"\"\n\t\tGiven a pattern and a string s, find if s follows the same pattern.\n\t\tHere follow means a full match, such that there is a bijection between a letter in pattern and a non-empty word in s.\n\t\tExample 1:\n\t\tInput: pattern = \"abba\", s = \"dog cat cat dog\"\n\t\tOutput: true\n\t\tExample 2:\n\t\tInput: pattern = \"abba\", s = \"dog cat cat fish\"\n\t\tOutput: false\n\t\tExample 3:\n\t\tInput: pattern = \"aaaa\", s = \"dog cat cat dog\"\n\t\tOutput: false\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 292, - "question": "class Solution:\n def canWinNim(self, n: int) -> bool:\n\t\t\"\"\"\n\t\tYou are playing the following Nim Game with your friend:\n\t\t\tInitially, there is a heap of stones on the table.\n\t\t\tYou and your friend will alternate taking turns, and you go first.\n\t\t\tOn each turn, the person whose turn it is will remove 1 to 3 stones from the heap.\n\t\t\tThe one who removes the last stone is the winner.\n\t\tGiven n, the number of stones in the heap, return true if you can win the game assuming both you and your friend play optimally, otherwise return false.\n\t\tExample 1:\n\t\tInput: n = 4\n\t\tOutput: false\n\t\tExplanation: These are the possible outcomes:\n\t\t1. You remove 1 stone. Your friend removes 3 stones, including the last stone. Your friend wins.\n\t\t2. You remove 2 stones. Your friend removes 2 stones, including the last stone. Your friend wins.\n\t\t3. You remove 3 stones. Your friend removes the last stone. Your friend wins.\n\t\tIn all outcomes, your friend wins.\n\t\tExample 2:\n\t\tInput: n = 1\n\t\tOutput: true\n\t\tExample 3:\n\t\tInput: n = 2\n\t\tOutput: true\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 295, - "question": "class MedianFinder:\n def __init__(self):\n def addNum(self, num: int) -> None:\n def findMedian(self) -> float:\n\t\t\"\"\"\n\t\tThe median is the middle value in an ordered integer list. If the size of the list is even, there is no middle value, and the median is the mean of the two middle values.\n\t\t\tFor example, for arr = [2,3,4], the median is 3.\n\t\t\tFor example, for arr = [2,3], the median is (2 + 3) / 2 = 2.5.\n\t\tImplement the MedianFinder class:\n\t\t\tMedianFinder() initializes the MedianFinder object.\n\t\t\tvoid addNum(int num) adds the integer num from the data stream to the data structure.\n\t\t\tdouble findMedian() returns the median of all elements so far. Answers within 10-5 of the actual answer will be accepted.\n\t\tExample 1:\n\t\tInput\n\t\t[\"MedianFinder\", \"addNum\", \"addNum\", \"findMedian\", \"addNum\", \"findMedian\"]\n\t\t[[], [1], [2], [], [3], []]\n\t\tOutput\n\t\t[null, null, null, 1.5, null, 2.0]\n\t\tExplanation\n\t\tMedianFinder medianFinder = new MedianFinder();\n\t\tmedianFinder.addNum(1); // arr = [1]\n\t\tmedianFinder.addNum(2); // arr = [1, 2]\n\t\tmedianFinder.findMedian(); // return 1.5 (i.e., (1 + 2) / 2)\n\t\tmedianFinder.addNum(3); // arr[1, 2, 3]\n\t\tmedianFinder.findMedian(); // return 2.0\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 297, - "question": "class Codec:\n def serialize(self, root):\n\t\t\"\"\"Encodes a tree to a single string.\n :type root: TreeNode\n :rtype: str\n\t\tSerialization is the process of converting a data structure or object into a sequence of bits so that it can be stored in a file or memory buffer, or transmitted across a network connection link to be reconstructed later in the same or another computer environment.\n\t\tDesign an algorithm to serialize and deserialize a binary tree. There is no restriction on how your serialization/deserialization algorithm should work. You just need to ensure that a binary tree can be serialized to a string and this string can be deserialized to the original tree structure.\n\t\tClarification: The input/output format is the same as how LeetCode serializes a binary tree. You do not necessarily need to follow this format, so please be creative and come up with different approaches yourself.\n\t\tExample 1:\n\t\tInput: root = [1,2,3,null,null,4,5]\n\t\tOutput: [1,2,3,null,null,4,5]\n\t\tExample 2:\n\t\tInput: root = []\n\t\tOutput: []\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 299, - "question": "class Solution:\n def getHint(self, secret: str, guess: str) -> str:\n\t\t\"\"\"\n\t\tYou are playing the Bulls and Cows game with your friend.\n\t\tYou write down a secret number and ask your friend to guess what the number is. When your friend makes a guess, you provide a hint with the following info:\n\t\t\tThe number of \"bulls\", which are digits in the guess that are in the correct position.\n\t\t\tThe number of \"cows\", which are digits in the guess that are in your secret number but are located in the wrong position. Specifically, the non-bull digits in the guess that could be rearranged such that they become bulls.\n\t\tGiven the secret number secret and your friend's guess guess, return the hint for your friend's guess.\n\t\tThe hint should be formatted as \"xAyB\", where x is the number of bulls and y is the number of cows. Note that both secret and guess may contain duplicate digits.\n\t\tExample 1:\n\t\tInput: secret = \"1807\", guess = \"7810\"\n\t\tOutput: \"1A3B\"\n\t\tExplanation: Bulls are connected with a '|' and cows are underlined:\n\t\t\"1807\"\n\t\t |\n\t\t\"7810\"\n\t\tExample 2:\n\t\tInput: secret = \"1123\", guess = \"0111\"\n\t\tOutput: \"1A1B\"\n\t\tExplanation: Bulls are connected with a '|' and cows are underlined:\n\t\t\"1123\" \"1123\"\n\t\t | or |\n\t\t\"0111\" \"0111\"\n\t\tNote that only one of the two unmatched 1s is counted as a cow since the non-bull digits can only be rearranged to allow one 1 to be a bull.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 300, - "question": "class Solution:\n def lengthOfLIS(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tGiven an integer array nums, return the length of the longest strictly increasing subsequence.\n\t\tExample 1:\n\t\tInput: nums = [10,9,2,5,3,7,101,18]\n\t\tOutput: 4\n\t\tExplanation: The longest increasing subsequence is [2,3,7,101], therefore the length is 4.\n\t\tExample 2:\n\t\tInput: nums = [0,1,0,3,2,3]\n\t\tOutput: 4\n\t\tExample 3:\n\t\tInput: nums = [7,7,7,7,7,7,7]\n\t\tOutput: 1\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 301, - "question": "class Solution:\n def removeInvalidParentheses(self, s: str) -> List[str]:\n\t\t\"\"\"\n\t\tGiven a string s that contains parentheses and letters, remove the minimum number of invalid parentheses to make the input string valid.\n\t\tReturn a list of unique strings that are valid with the minimum number of removals. You may return the answer in any order.\n\t\tExample 1:\n\t\tInput: s = \"()())()\"\n\t\tOutput: [\"(())()\",\"()()()\"]\n\t\tExample 2:\n\t\tInput: s = \"(a)())()\"\n\t\tOutput: [\"(a())()\",\"(a)()()\"]\n\t\tExample 3:\n\t\tInput: s = \")(\"\n\t\tOutput: [\"\"]\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 303, - "question": "class NumArray:\n def __init__(self, nums: List[int]):\n def sumRange(self, left: int, right: int) -> int:\n\t\t\"\"\"\n\t\tGiven an integer array nums, handle multiple queries of the following type:\n\t\t\tCalculate the sum of the elements of nums between indices left and right inclusive where left <= right.\n\t\tImplement the NumArray class:\n\t\t\tNumArray(int[] nums) Initializes the object with the integer array nums.\n\t\t\tint sumRange(int left, int right) Returns the sum of the elements of nums between indices left and right inclusive (i.e. nums[left] + nums[left + 1] + ... + nums[right]).\n\t\tExample 1:\n\t\tInput\n\t\t[\"NumArray\", \"sumRange\", \"sumRange\", \"sumRange\"]\n\t\t[[[-2, 0, 3, -5, 2, -1]], [0, 2], [2, 5], [0, 5]]\n\t\tOutput\n\t\t[null, 1, -1, -3]\n\t\tExplanation\n\t\tNumArray numArray = new NumArray([-2, 0, 3, -5, 2, -1]);\n\t\tnumArray.sumRange(0, 2); // return (-2) + 0 + 3 = 1\n\t\tnumArray.sumRange(2, 5); // return 3 + (-5) + 2 + (-1) = -1\n\t\tnumArray.sumRange(0, 5); // return (-2) + 0 + 3 + (-5) + 2 + (-1) = -3\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 304, - "question": "class NumMatrix:\n def __init__(self, matrix: List[List[int]]):\n def sumRegion(self, row1: int, col1: int, row2: int, col2: int) -> int:\n\t\t\"\"\"\n\t\tGiven a 2D matrix matrix, handle multiple queries of the following type:\n\t\t\tCalculate the sum of the elements of matrix inside the rectangle defined by its upper left corner (row1, col1) and lower right corner (row2, col2).\n\t\tImplement the NumMatrix class:\n\t\t\tNumMatrix(int[][] matrix) Initializes the object with the integer matrix matrix.\n\t\t\tint sumRegion(int row1, int col1, int row2, int col2) Returns the sum of the elements of matrix inside the rectangle defined by its upper left corner (row1, col1) and lower right corner (row2, col2).\n\t\tYou must design an algorithm where sumRegion works on O(1) time complexity.\n\t\tExample 1:\n\t\tInput\n\t\t[\"NumMatrix\", \"sumRegion\", \"sumRegion\", \"sumRegion\"]\n\t\t[[[[3, 0, 1, 4, 2], [5, 6, 3, 2, 1], [1, 2, 0, 1, 5], [4, 1, 0, 1, 7], [1, 0, 3, 0, 5]]], [2, 1, 4, 3], [1, 1, 2, 2], [1, 2, 2, 4]]\n\t\tOutput\n\t\t[null, 8, 11, 12]\n\t\tExplanation\n\t\tNumMatrix numMatrix = new NumMatrix([[3, 0, 1, 4, 2], [5, 6, 3, 2, 1], [1, 2, 0, 1, 5], [4, 1, 0, 1, 7], [1, 0, 3, 0, 5]]);\n\t\tnumMatrix.sumRegion(2, 1, 4, 3); // return 8 (i.e sum of the red rectangle)\n\t\tnumMatrix.sumRegion(1, 1, 2, 2); // return 11 (i.e sum of the green rectangle)\n\t\tnumMatrix.sumRegion(1, 2, 2, 4); // return 12 (i.e sum of the blue rectangle)\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 306, - "question": "class Solution:\n def isAdditiveNumber(self, num: str) -> bool:\n\t\t\"\"\"\n\t\tAn additive number is a string whose digits can form an additive sequence.\n\t\tA valid additive sequence should contain at least three numbers. Except for the first two numbers, each subsequent number in the sequence must be the sum of the preceding two.\n\t\tGiven a string containing only digits, return true if it is an additive number or false otherwise.\n\t\tNote: Numbers in the additive sequence cannot have leading zeros, so sequence 1, 2, 03 or 1, 02, 3 is invalid.\n\t\tExample 1:\n\t\tInput: \"112358\"\n\t\tOutput: true\n\t\tExplanation: \n\t\tThe digits can form an additive sequence: 1, 1, 2, 3, 5, 8. \n\t\t1 + 1 = 2, 1 + 2 = 3, 2 + 3 = 5, 3 + 5 = 8\n\t\tExample 2:\n\t\tInput: \"199100199\"\n\t\tOutput: true\n\t\tExplanation: \n\t\tThe additive sequence is: 1, 99, 100, 199. \n\t\t1 + 99 = 100, 99 + 100 = 199\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 307, - "question": "class NumArray:\n def __init__(self, nums: List[int]):\n def update(self, index: int, val: int) -> None:\n def sumRange(self, left: int, right: int) -> int:\n\t\t\"\"\"\n\t\tGiven an integer array nums, handle multiple queries of the following types:\n\t\t\tUpdate the value of an element in nums.\n\t\t\tCalculate the sum of the elements of nums between indices left and right inclusive where left <= right.\n\t\tImplement the NumArray class:\n\t\t\tNumArray(int[] nums) Initializes the object with the integer array nums.\n\t\t\tvoid update(int index, int val) Updates the value of nums[index] to be val.\n\t\t\tint sumRange(int left, int right) Returns the sum of the elements of nums between indices left and right inclusive (i.e. nums[left] + nums[left + 1] + ... + nums[right]).\n\t\tExample 1:\n\t\tInput\n\t\t[\"NumArray\", \"sumRange\", \"update\", \"sumRange\"]\n\t\t[[[1, 3, 5]], [0, 2], [1, 2], [0, 2]]\n\t\tOutput\n\t\t[null, 9, null, 8]\n\t\tExplanation\n\t\tNumArray numArray = new NumArray([1, 3, 5]);\n\t\tnumArray.sumRange(0, 2); // return 1 + 3 + 5 = 9\n\t\tnumArray.update(1, 2); // nums = [1, 2, 5]\n\t\tnumArray.sumRange(0, 2); // return 1 + 2 + 5 = 8\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 309, - "question": "class Solution:\n def maxProfit(self, prices: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou are given an array prices where prices[i] is the price of a given stock on the ith day.\n\t\tFind the maximum profit you can achieve. You may complete as many transactions as you like (i.e., buy one and sell one share of the stock multiple times) with the following restrictions:\n\t\t\tAfter you sell your stock, you cannot buy stock on the next day (i.e., cooldown one day).\n\t\tNote: You may not engage in multiple transactions simultaneously (i.e., you must sell the stock before you buy again).\n\t\tExample 1:\n\t\tInput: prices = [1,2,3,0,2]\n\t\tOutput: 3\n\t\tExplanation: transactions = [buy, sell, cooldown, buy, sell]\n\t\tExample 2:\n\t\tInput: prices = [1]\n\t\tOutput: 0\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 310, - "question": "class Solution:\n def findMinHeightTrees(self, n: int, edges: List[List[int]]) -> List[int]:\n\t\t\"\"\"\n\t\tA tree is an undirected graph in which any two vertices are connected by exactly one path. In other words, any connected graph without simple cycles is a tree.\n\t\tGiven a tree of n nodes labelled from 0 to n - 1, and an array of n - 1 edges where edges[i] = [ai, bi] indicates that there is an undirected edge between the two nodes ai and bi in the tree, you can choose any node of the tree as the root. When you select a node x as the root, the result tree has height h. Among all possible rooted trees, those with minimum height (i.e. min(h)) are called minimum height trees (MHTs).\n\t\tReturn a list of all MHTs' root labels. You can return the answer in any order.\n\t\tThe height of a rooted tree is the number of edges on the longest downward path between the root and a leaf.\n\t\tExample 1:\n\t\tInput: n = 4, edges = [[1,0],[1,2],[1,3]]\n\t\tOutput: [1]\n\t\tExplanation: As shown, the height of the tree is 1 when the root is the node with label 1 which is the only MHT.\n\t\tExample 2:\n\t\tInput: n = 6, edges = [[3,0],[3,1],[3,2],[3,4],[5,4]]\n\t\tOutput: [3,4]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 312, - "question": "class Solution:\n def maxCoins(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou are given n balloons, indexed from 0 to n - 1. Each balloon is painted with a number on it represented by an array nums. You are asked to burst all the balloons.\n\t\tIf you burst the ith balloon, you will get nums[i - 1] * nums[i] * nums[i + 1] coins. If i - 1 or i + 1 goes out of bounds of the array, then treat it as if there is a balloon with a 1 painted on it.\n\t\tReturn the maximum coins you can collect by bursting the balloons wisely.\n\t\tExample 1:\n\t\tInput: nums = [3,1,5,8]\n\t\tOutput: 167\n\t\tExplanation:\n\t\tnums = [3,1,5,8] --> [3,5,8] --> [3,8] --> [8] --> []\n\t\tcoins = 3*1*5 + 3*5*8 + 1*3*8 + 1*8*1 = 167\n\t\tExample 2:\n\t\tInput: nums = [1,5]\n\t\tOutput: 10\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 313, - "question": "class Solution:\n def nthSuperUglyNumber(self, n: int, primes: List[int]) -> int:\n\t\t\"\"\"\n\t\tA super ugly number is a positive integer whose prime factors are in the array primes.\n\t\tGiven an integer n and an array of integers primes, return the nth super ugly number.\n\t\tThe nth super ugly number is guaranteed to fit in a 32-bit signed integer.\n\t\tExample 1:\n\t\tInput: n = 12, primes = [2,7,13,19]\n\t\tOutput: 32\n\t\tExplanation: [1,2,4,7,8,13,14,16,19,26,28,32] is the sequence of the first 12 super ugly numbers given primes = [2,7,13,19].\n\t\tExample 2:\n\t\tInput: n = 1, primes = [2,3,5]\n\t\tOutput: 1\n\t\tExplanation: 1 has no prime factors, therefore all of its prime factors are in the array primes = [2,3,5].\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 315, - "question": "class Solution:\n def countSmaller(self, nums: List[int]) -> List[int]:\n\t\t\"\"\"\n\t\tGiven an integer array nums, return an integer array counts where counts[i] is the number of smaller elements to the right of nums[i].\n\t\tExample 1:\n\t\tInput: nums = [5,2,6,1]\n\t\tOutput: [2,1,1,0]\n\t\tExplanation:\n\t\tTo the right of 5 there are 2 smaller elements (2 and 1).\n\t\tTo the right of 2 there is only 1 smaller element (1).\n\t\tTo the right of 6 there is 1 smaller element (1).\n\t\tTo the right of 1 there is 0 smaller element.\n\t\tExample 2:\n\t\tInput: nums = [-1]\n\t\tOutput: [0]\n\t\tExample 3:\n\t\tInput: nums = [-1,-1]\n\t\tOutput: [0,0]\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 316, - "question": "class Solution:\n def removeDuplicateLetters(self, s: str) -> str:\n\t\t\"\"\"\n\t\tGiven a string s, remove duplicate letters so that every letter appears once and only once. You must make sure your result is the smallest in lexicographical order among all possible results.\n\t\tExample 1:\n\t\tInput: s = \"bcabc\"\n\t\tOutput: \"abc\"\n\t\tExample 2:\n\t\tInput: s = \"cbacdcbc\"\n\t\tOutput: \"acdb\"\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 318, - "question": "class Solution:\n def maxProduct(self, words: List[str]) -> int:\n\t\t\"\"\"\n\t\tGiven a string array words, return the maximum value of length(word[i]) * length(word[j]) where the two words do not share common letters. If no such two words exist, return 0.\n\t\tExample 1:\n\t\tInput: words = [\"abcw\",\"baz\",\"foo\",\"bar\",\"xtfn\",\"abcdef\"]\n\t\tOutput: 16\n\t\tExplanation: The two words can be \"abcw\", \"xtfn\".\n\t\tExample 2:\n\t\tInput: words = [\"a\",\"ab\",\"abc\",\"d\",\"cd\",\"bcd\",\"abcd\"]\n\t\tOutput: 4\n\t\tExplanation: The two words can be \"ab\", \"cd\".\n\t\tExample 3:\n\t\tInput: words = [\"a\",\"aa\",\"aaa\",\"aaaa\"]\n\t\tOutput: 0\n\t\tExplanation: No such pair of words.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 319, - "question": "class Solution:\n def bulbSwitch(self, n: int) -> int:\n\t\t\"\"\"\n\t\tThere are n bulbs that are initially off. You first turn on all the bulbs, then you turn off every second bulb.\n\t\tOn the third round, you toggle every third bulb (turning on if it's off or turning off if it's on). For the ith round, you toggle every i bulb. For the nth round, you only toggle the last bulb.\n\t\tReturn the number of bulbs that are on after n rounds.\n\t\tExample 1:\n\t\tInput: n = 3\n\t\tOutput: 1\n\t\tExplanation: At first, the three bulbs are [off, off, off].\n\t\tAfter the first round, the three bulbs are [on, on, on].\n\t\tAfter the second round, the three bulbs are [on, off, on].\n\t\tAfter the third round, the three bulbs are [on, off, off]. \n\t\tSo you should return 1 because there is only one bulb is on.\n\t\tExample 2:\n\t\tInput: n = 0\n\t\tOutput: 0\n\t\tExample 3:\n\t\tInput: n = 1\n\t\tOutput: 1\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 321, - "question": "class Solution:\n def maxNumber(self, nums1: List[int], nums2: List[int], k: int) -> List[int]:\n\t\t\"\"\"\n\t\tYou are given two integer arrays nums1 and nums2 of lengths m and n respectively. nums1 and nums2 represent the digits of two numbers. You are also given an integer k.\n\t\tCreate the maximum number of length k <= m + n from digits of the two numbers. The relative order of the digits from the same array must be preserved.\n\t\tReturn an array of the k digits representing the answer.\n\t\tExample 1:\n\t\tInput: nums1 = [3,4,6,5], nums2 = [9,1,2,5,8,3], k = 5\n\t\tOutput: [9,8,6,5,3]\n\t\tExample 2:\n\t\tInput: nums1 = [6,7], nums2 = [6,0,4], k = 5\n\t\tOutput: [6,7,6,0,4]\n\t\tExample 3:\n\t\tInput: nums1 = [3,9], nums2 = [8,9], k = 3\n\t\tOutput: [9,8,9]\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 322, - "question": "class Solution:\n def coinChange(self, coins: List[int], amount: int) -> int:\n\t\t\"\"\"\n\t\tYou are given an integer array coins representing coins of different denominations and an integer amount representing a total amount of money.\n\t\tReturn the fewest number of coins that you need to make up that amount. If that amount of money cannot be made up by any combination of the coins, return -1.\n\t\tYou may assume that you have an infinite number of each kind of coin.\n\t\tExample 1:\n\t\tInput: coins = [1,2,5], amount = 11\n\t\tOutput: 3\n\t\tExplanation: 11 = 5 + 5 + 1\n\t\tExample 2:\n\t\tInput: coins = [2], amount = 3\n\t\tOutput: -1\n\t\tExample 3:\n\t\tInput: coins = [1], amount = 0\n\t\tOutput: 0\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 324, - "question": "class Solution:\n def wiggleSort(self, nums: List[int]) -> None:\n\t\t\"\"\"\n Do not return anything, modify nums in-place instead.\n\t\tGiven an integer array nums, reorder it such that nums[0] < nums[1] > nums[2] < nums[3]....\n\t\tYou may assume the input array always has a valid answer.\n\t\tExample 1:\n\t\tInput: nums = [1,5,1,1,6,4]\n\t\tOutput: [1,6,1,5,1,4]\n\t\tExplanation: [1,4,1,5,1,6] is also accepted.\n\t\tExample 2:\n\t\tInput: nums = [1,3,2,2,3,1]\n\t\tOutput: [2,3,1,3,1,2]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 326, - "question": "class Solution:\n def isPowerOfThree(self, n: int) -> bool:\n\t\t\"\"\"\n\t\tGiven an integer n, return true if it is a power of three. Otherwise, return false.\n\t\tAn integer n is a power of three, if there exists an integer x such that n == 3x.\n\t\tExample 1:\n\t\tInput: n = 27\n\t\tOutput: true\n\t\tExplanation: 27 = 33\n\t\tExample 2:\n\t\tInput: n = 0\n\t\tOutput: false\n\t\tExplanation: There is no x where 3x = 0.\n\t\tExample 3:\n\t\tInput: n = -1\n\t\tOutput: false\n\t\tExplanation: There is no x where 3x = (-1).\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 327, - "question": "class Solution:\n def countRangeSum(self, nums: List[int], lower: int, upper: int) -> int:\n\t\t\"\"\"\n\t\tGiven an integer array nums and two integers lower and upper, return the number of range sums that lie in [lower, upper] inclusive.\n\t\tRange sum S(i, j) is defined as the sum of the elements in nums between indices i and j inclusive, where i <= j.\n\t\tExample 1:\n\t\tInput: nums = [-2,5,-1], lower = -2, upper = 2\n\t\tOutput: 3\n\t\tExplanation: The three ranges are: [0,0], [2,2], and [0,2] and their respective sums are: -2, -1, 2.\n\t\tExample 2:\n\t\tInput: nums = [0], lower = 0, upper = 0\n\t\tOutput: 1\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 328, - "question": "class Solution:\n def oddEvenList(self, head: Optional[ListNode]) -> Optional[ListNode]:\n\t\t\"\"\"\n\t\tGiven the head of a singly linked list, group all the nodes with odd indices together followed by the nodes with even indices, and return the reordered list.\n\t\tThe first node is considered odd, and the second node is even, and so on.\n\t\tNote that the relative order inside both the even and odd groups should remain as it was in the input.\n\t\tYou must solve the problem in O(1) extra space complexity and O(n) time complexity.\n\t\tExample 1:\n\t\tInput: head = [1,2,3,4,5]\n\t\tOutput: [1,3,5,2,4]\n\t\tExample 2:\n\t\tInput: head = [2,1,3,5,6,4,7]\n\t\tOutput: [2,3,6,7,1,5,4]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 329, - "question": "class Solution:\n def longestIncreasingPath(self, matrix: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tGiven an m x n integers matrix, return the length of the longest increasing path in matrix.\n\t\tFrom each cell, you can either move in four directions: left, right, up, or down. You may not move diagonally or move outside the boundary (i.e., wrap-around is not allowed).\n\t\tExample 1:\n\t\tInput: matrix = [[9,9,4],[6,6,8],[2,1,1]]\n\t\tOutput: 4\n\t\tExplanation: The longest increasing path is [1, 2, 6, 9].\n\t\tExample 2:\n\t\tInput: matrix = [[3,4,5],[3,2,6],[2,2,1]]\n\t\tOutput: 4\n\t\tExplanation: The longest increasing path is [3, 4, 5, 6]. Moving diagonally is not allowed.\n\t\tExample 3:\n\t\tInput: matrix = [[1]]\n\t\tOutput: 1\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 330, - "question": "class Solution:\n def minPatches(self, nums: List[int], n: int) -> int:\n\t\t\"\"\"\n\t\tGiven a sorted integer array nums and an integer n, add/patch elements to the array such that any number in the range [1, n] inclusive can be formed by the sum of some elements in the array.\n\t\tReturn the minimum number of patches required.\n\t\tExample 1:\n\t\tInput: nums = [1,3], n = 6\n\t\tOutput: 1\n\t\tExplanation:\n\t\tCombinations of nums are [1], [3], [1,3], which form possible sums of: 1, 3, 4.\n\t\tNow if we add/patch 2 to nums, the combinations are: [1], [2], [3], [1,3], [2,3], [1,2,3].\n\t\tPossible sums are 1, 2, 3, 4, 5, 6, which now covers the range [1, 6].\n\t\tSo we only need 1 patch.\n\t\tExample 2:\n\t\tInput: nums = [1,5,10], n = 20\n\t\tOutput: 2\n\t\tExplanation: The two patches can be [2, 4].\n\t\tExample 3:\n\t\tInput: nums = [1,2,2], n = 5\n\t\tOutput: 0\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 331, - "question": "class Solution:\n def isValidSerialization(self, preorder: str) -> bool:\n\t\t\"\"\"\n\t\tOne way to serialize a binary tree is to use preorder traversal. When we encounter a non-null node, we record the node's value. If it is a null node, we record using a sentinel value such as '#'.\n\t\tFor example, the above binary tree can be serialized to the string \"9,3,4,#,#,1,#,#,2,#,6,#,#\", where '#' represents a null node.\n\t\tGiven a string of comma-separated values preorder, return true if it is a correct preorder traversal serialization of a binary tree.\n\t\tIt is guaranteed that each comma-separated value in the string must be either an integer or a character '#' representing null pointer.\n\t\tYou may assume that the input format is always valid.\n\t\t\tFor example, it could never contain two consecutive commas, such as \"1,,3\".\n\t\tNote: You are not allowed to reconstruct the tree.\n\t\tExample 1:\n\t\tInput: preorder = \"9,3,4,#,#,1,#,#,2,#,6,#,#\"\n\t\tOutput: true\n\t\tExample 2:\n\t\tInput: preorder = \"1,#\"\n\t\tOutput: false\n\t\tExample 3:\n\t\tInput: preorder = \"9,#,#,1\"\n\t\tOutput: false\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 332, - "question": "class Solution:\n def findItinerary(self, tickets: List[List[str]]) -> List[str]:\n\t\t\"\"\"\n\t\tYou are given a list of airline tickets where tickets[i] = [fromi, toi] represent the departure and the arrival airports of one flight. Reconstruct the itinerary in order and return it.\n\t\tAll of the tickets belong to a man who departs from \"JFK\", thus, the itinerary must begin with \"JFK\". If there are multiple valid itineraries, you should return the itinerary that has the smallest lexical order when read as a single string.\n\t\t\tFor example, the itinerary [\"JFK\", \"LGA\"] has a smaller lexical order than [\"JFK\", \"LGB\"].\n\t\tYou may assume all tickets form at least one valid itinerary. You must use all the tickets once and only once.\n\t\tExample 1:\n\t\tInput: tickets = [[\"MUC\",\"LHR\"],[\"JFK\",\"MUC\"],[\"SFO\",\"SJC\"],[\"LHR\",\"SFO\"]]\n\t\tOutput: [\"JFK\",\"MUC\",\"LHR\",\"SFO\",\"SJC\"]\n\t\tExample 2:\n\t\tInput: tickets = [[\"JFK\",\"SFO\"],[\"JFK\",\"ATL\"],[\"SFO\",\"ATL\"],[\"ATL\",\"JFK\"],[\"ATL\",\"SFO\"]]\n\t\tOutput: [\"JFK\",\"ATL\",\"JFK\",\"SFO\",\"ATL\",\"SFO\"]\n\t\tExplanation: Another possible reconstruction is [\"JFK\",\"SFO\",\"ATL\",\"JFK\",\"ATL\",\"SFO\"] but it is larger in lexical order.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 334, - "question": "class Solution:\n def increasingTriplet(self, nums: List[int]) -> bool:\n\t\t\"\"\"\n\t\tGiven an integer array nums, return true if there exists a triple of indices (i, j, k) such that i < j < k and nums[i] < nums[j] < nums[k]. If no such indices exists, return false.\n\t\tExample 1:\n\t\tInput: nums = [1,2,3,4,5]\n\t\tOutput: true\n\t\tExplanation: Any triplet where i < j < k is valid.\n\t\tExample 2:\n\t\tInput: nums = [5,4,3,2,1]\n\t\tOutput: false\n\t\tExplanation: No triplet exists.\n\t\tExample 3:\n\t\tInput: nums = [2,1,5,0,4,6]\n\t\tOutput: true\n\t\tExplanation: The triplet (3, 4, 5) is valid because nums[3] == 0 < nums[4] == 4 < nums[5] == 6.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 335, - "question": "class Solution:\n def isSelfCrossing(self, distance: List[int]) -> bool:\n\t\t\"\"\"\n\t\tYou are given an array of integers distance.\n\t\tYou start at the point (0, 0) on an X-Y plane, and you move distance[0] meters to the north, then distance[1] meters to the west, distance[2] meters to the south, distance[3] meters to the east, and so on. In other words, after each move, your direction changes counter-clockwise.\n\t\tReturn true if your path crosses itself or false if it does not.\n\t\tExample 1:\n\t\tInput: distance = [2,1,1,2]\n\t\tOutput: true\n\t\tExplanation: The path crosses itself at the point (0, 1).\n\t\tExample 2:\n\t\tInput: distance = [1,2,3,4]\n\t\tOutput: false\n\t\tExplanation: The path does not cross itself at any point.\n\t\tExample 3:\n\t\tInput: distance = [1,1,1,2,1]\n\t\tOutput: true\n\t\tExplanation: The path crosses itself at the point (0, 0).\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 336, - "question": "class Solution:\n def palindromePairs(self, words: List[str]) -> List[List[int]]:\n\t\t\"\"\"\n\t\tYou are given a 0-indexed array of unique strings words.\n\t\tA palindrome pair is a pair of integers (i, j) such that:\n\t\t\t0 <= i, j < words.length,\n\t\t\ti != j, and\n\t\t\twords[i] + words[j] (the concatenation of the two strings) is a palindrome.\n\t\tReturn an array of all the palindrome pairs of words.\n\t\tExample 1:\n\t\tInput: words = [\"abcd\",\"dcba\",\"lls\",\"s\",\"sssll\"]\n\t\tOutput: [[0,1],[1,0],[3,2],[2,4]]\n\t\tExplanation: The palindromes are [\"abcddcba\",\"dcbaabcd\",\"slls\",\"llssssll\"]\n\t\tExample 2:\n\t\tInput: words = [\"bat\",\"tab\",\"cat\"]\n\t\tOutput: [[0,1],[1,0]]\n\t\tExplanation: The palindromes are [\"battab\",\"tabbat\"]\n\t\tExample 3:\n\t\tInput: words = [\"a\",\"\"]\n\t\tOutput: [[0,1],[1,0]]\n\t\tExplanation: The palindromes are [\"a\",\"a\"]\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 337, - "question": "class Solution:\n def rob(self, root: Optional[TreeNode]) -> int:\n\t\t\"\"\"\n\t\tThe thief has found himself a new place for his thievery again. There is only one entrance to this area, called root.\n\t\tBesides the root, each house has one and only one parent house. After a tour, the smart thief realized that all houses in this place form a binary tree. It will automatically contact the police if two directly-linked houses were broken into on the same night.\n\t\tGiven the root of the binary tree, return the maximum amount of money the thief can rob without alerting the police.\n\t\tExample 1:\n\t\tInput: root = [3,2,3,null,3,null,1]\n\t\tOutput: 7\n\t\tExplanation: Maximum amount of money the thief can rob = 3 + 3 + 1 = 7.\n\t\tExample 2:\n\t\tInput: root = [3,4,5,1,3,null,1]\n\t\tOutput: 9\n\t\tExplanation: Maximum amount of money the thief can rob = 4 + 5 = 9.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 338, - "question": "class Solution:\n def countBits(self, n: int) -> List[int]:\n\t\t\"\"\"\n\t\tGiven an integer n, return an array ans of length n + 1 such that for each i (0 <= i <= n), ans[i] is the number of 1's in the binary representation of i.\n\t\tExample 1:\n\t\tInput: n = 2\n\t\tOutput: [0,1,1]\n\t\tExplanation:\n\t\t0 --> 0\n\t\t1 --> 1\n\t\t2 --> 10\n\t\tExample 2:\n\t\tInput: n = 5\n\t\tOutput: [0,1,1,2,1,2]\n\t\tExplanation:\n\t\t0 --> 0\n\t\t1 --> 1\n\t\t2 --> 10\n\t\t3 --> 11\n\t\t4 --> 100\n\t\t5 --> 101\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 341, - "question": "\t\t\"\"\"\n\t\tYou are given a nested list of integers nestedList. Each element is either an integer or a list whose elements may also be integers or other lists. Implement an iterator to flatten it.\n\t\tImplement the NestedIterator class:\n\t\t\tNestedIterator(List nestedList) Initializes the iterator with the nested list nestedList.\n\t\t\tint next() Returns the next integer in the nested list.\n\t\t\tboolean hasNext() Returns true if there are still some integers in the nested list and false otherwise.\n\t\tYour code will be tested with the following pseudocode:\n\t\tinitialize iterator with nestedList\n\t\tres = []\n\t\twhile iterator.hasNext()\n\t\t append iterator.next() to the end of res\n\t\treturn res\n\t\tIf res matches the expected flattened list, then your code will be judged as correct.\n\t\tExample 1:\n\t\tInput: nestedList = [[1,1],2,[1,1]]\n\t\tOutput: [1,1,2,1,1]\n\t\tExplanation: By calling next repeatedly until hasNext returns false, the order of elements returned by next should be: [1,1,2,1,1].\n\t\tExample 2:\n\t\tInput: nestedList = [1,[4,[6]]]\n\t\tOutput: [1,4,6]\n\t\tExplanation: By calling next repeatedly until hasNext returns false, the order of elements returned by next should be: [1,4,6].\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 342, - "question": "class Solution:\n def isPowerOfFour(self, n: int) -> bool:\n\t\t\"\"\"\n\t\tGiven an integer n, return true if it is a power of four. Otherwise, return false.\n\t\tAn integer n is a power of four, if there exists an integer x such that n == 4x.\n\t\tExample 1:\n\t\tInput: n = 16\n\t\tOutput: true\n\t\tExample 2:\n\t\tInput: n = 5\n\t\tOutput: false\n\t\tExample 3:\n\t\tInput: n = 1\n\t\tOutput: true\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 343, - "question": "class Solution:\n def integerBreak(self, n: int) -> int:\n\t\t\"\"\"\n\t\tGiven an integer n, break it into the sum of k positive integers, where k >= 2, and maximize the product of those integers.\n\t\tReturn the maximum product you can get.\n\t\tExample 1:\n\t\tInput: n = 2\n\t\tOutput: 1\n\t\tExplanation: 2 = 1 + 1, 1 \u00d7 1 = 1.\n\t\tExample 2:\n\t\tInput: n = 10\n\t\tOutput: 36\n\t\tExplanation: 10 = 3 + 3 + 4, 3 \u00d7 3 \u00d7 4 = 36.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 344, - "question": "class Solution:\n def reverseString(self, s: List[str]) -> None:\n\t\t\"\"\"\n Do not return anything, modify s in-place instead.\n\t\tWrite a function that reverses a string. The input string is given as an array of characters s.\n\t\tYou must do this by modifying the input array in-place with O(1) extra memory.\n\t\tExample 1:\n\t\tInput: s = [\"h\",\"e\",\"l\",\"l\",\"o\"]\n\t\tOutput: [\"o\",\"l\",\"l\",\"e\",\"h\"]\n\t\tExample 2:\n\t\tInput: s = [\"H\",\"a\",\"n\",\"n\",\"a\",\"h\"]\n\t\tOutput: [\"h\",\"a\",\"n\",\"n\",\"a\",\"H\"]\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 345, - "question": "class Solution:\n def reverseVowels(self, s: str) -> str:\n\t\t\"\"\"\n\t\tGiven a string s, reverse only all the vowels in the string and return it.\n\t\tThe vowels are 'a', 'e', 'i', 'o', and 'u', and they can appear in both lower and upper cases, more than once.\n\t\tExample 1:\n\t\tInput: s = \"hello\"\n\t\tOutput: \"holle\"\n\t\tExample 2:\n\t\tInput: s = \"leetcode\"\n\t\tOutput: \"leotcede\"\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 347, - "question": "class Solution:\n def topKFrequent(self, nums: List[int], k: int) -> List[int]:\n\t\t\"\"\"\n\t\tGiven an integer array nums and an integer k, return the k most frequent elements. You may return the answer in any order.\n\t\tExample 1:\n\t\tInput: nums = [1,1,1,2,2,3], k = 2\n\t\tOutput: [1,2]\n\t\tExample 2:\n\t\tInput: nums = [1], k = 1\n\t\tOutput: [1]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 349, - "question": "class Solution:\n def intersection(self, nums1: List[int], nums2: List[int]) -> List[int]:\n\t\t\"\"\"\n\t\tGiven two integer arrays nums1 and nums2, return an array of their intersection. Each element in the result must be unique and you may return the result in any order.\n\t\tExample 1:\n\t\tInput: nums1 = [1,2,2,1], nums2 = [2,2]\n\t\tOutput: [2]\n\t\tExample 2:\n\t\tInput: nums1 = [4,9,5], nums2 = [9,4,9,8,4]\n\t\tOutput: [9,4]\n\t\tExplanation: [4,9] is also accepted.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 350, - "question": "class Solution:\n def intersect(self, nums1: List[int], nums2: List[int]) -> List[int]:\n\t\t\"\"\"\n\t\tGiven two integer arrays nums1 and nums2, return an array of their intersection. Each element in the result must appear as many times as it shows in both arrays and you may return the result in any order.\n\t\tExample 1:\n\t\tInput: nums1 = [1,2,2,1], nums2 = [2,2]\n\t\tOutput: [2,2]\n\t\tExample 2:\n\t\tInput: nums1 = [4,9,5], nums2 = [9,4,9,8,4]\n\t\tOutput: [4,9]\n\t\tExplanation: [9,4] is also accepted.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 352, - "question": "class SummaryRanges:\n def __init__(self):\n def addNum(self, value: int) -> None:\n def getIntervals(self) -> List[List[int]]:\n\t\t\"\"\"\n\t\tGiven a data stream input of non-negative integers a1, a2, ..., an, summarize the numbers seen so far as a list of disjoint intervals.\n\t\tImplement the SummaryRanges class:\n\t\t\tSummaryRanges() Initializes the object with an empty stream.\n\t\t\tvoid addNum(int value) Adds the integer value to the stream.\n\t\t\tint[][] getIntervals() Returns a summary of the integers in the stream currently as a list of disjoint intervals [starti, endi]. The answer should be sorted by starti.\n\t\tExample 1:\n\t\tInput\n\t\t[\"SummaryRanges\", \"addNum\", \"getIntervals\", \"addNum\", \"getIntervals\", \"addNum\", \"getIntervals\", \"addNum\", \"getIntervals\", \"addNum\", \"getIntervals\"]\n\t\t[[], [1], [], [3], [], [7], [], [2], [], [6], []]\n\t\tOutput\n\t\t[null, null, [[1, 1]], null, [[1, 1], [3, 3]], null, [[1, 1], [3, 3], [7, 7]], null, [[1, 3], [7, 7]], null, [[1, 3], [6, 7]]]\n\t\tExplanation\n\t\tSummaryRanges summaryRanges = new SummaryRanges();\n\t\tsummaryRanges.addNum(1); // arr = [1]\n\t\tsummaryRanges.getIntervals(); // return [[1, 1]]\n\t\tsummaryRanges.addNum(3); // arr = [1, 3]\n\t\tsummaryRanges.getIntervals(); // return [[1, 1], [3, 3]]\n\t\tsummaryRanges.addNum(7); // arr = [1, 3, 7]\n\t\tsummaryRanges.getIntervals(); // return [[1, 1], [3, 3], [7, 7]]\n\t\tsummaryRanges.addNum(2); // arr = [1, 2, 3, 7]\n\t\tsummaryRanges.getIntervals(); // return [[1, 3], [7, 7]]\n\t\tsummaryRanges.addNum(6); // arr = [1, 2, 3, 6, 7]\n\t\tsummaryRanges.getIntervals(); // return [[1, 3], [6, 7]]\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 354, - "question": "class Solution:\n def maxEnvelopes(self, envelopes: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tYou are given a 2D array of integers envelopes where envelopes[i] = [wi, hi] represents the width and the height of an envelope.\n\t\tOne envelope can fit into another if and only if both the width and height of one envelope are greater than the other envelope's width and height.\n\t\tReturn the maximum number of envelopes you can Russian doll (i.e., put one inside the other).\n\t\tNote: You cannot rotate an envelope.\n\t\tExample 1:\n\t\tInput: envelopes = [[5,4],[6,4],[6,7],[2,3]]\n\t\tOutput: 3\n\t\tExplanation: The maximum number of envelopes you can Russian doll is 3 ([2,3] => [5,4] => [6,7]).\n\t\tExample 2:\n\t\tInput: envelopes = [[1,1],[1,1],[1,1]]\n\t\tOutput: 1\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 355, - "question": "class Twitter:\n def __init__(self):\n def postTweet(self, userId: int, tweetId: int) -> None:\n def getNewsFeed(self, userId: int) -> List[int]:\n def follow(self, followerId: int, followeeId: int) -> None:\n def unfollow(self, followerId: int, followeeId: int) -> None:\n\t\t\"\"\"\n\t\tDesign a simplified version of Twitter where users can post tweets, follow/unfollow another user, and is able to see the 10 most recent tweets in the user's news feed.\n\t\tImplement the Twitter class:\n\t\t\tTwitter() Initializes your twitter object.\n\t\t\tvoid postTweet(int userId, int tweetId) Composes a new tweet with ID tweetId by the user userId. Each call to this function will be made with a unique tweetId.\n\t\t\tList getNewsFeed(int userId) Retrieves the 10 most recent tweet IDs in the user's news feed. Each item in the news feed must be posted by users who the user followed or by the user themself. Tweets must be ordered from most recent to least recent.\n\t\t\tvoid follow(int followerId, int followeeId) The user with ID followerId started following the user with ID followeeId.\n\t\t\tvoid unfollow(int followerId, int followeeId) The user with ID followerId started unfollowing the user with ID followeeId.\n\t\tExample 1:\n\t\tInput\n\t\t[\"Twitter\", \"postTweet\", \"getNewsFeed\", \"follow\", \"postTweet\", \"getNewsFeed\", \"unfollow\", \"getNewsFeed\"]\n\t\t[[], [1, 5], [1], [1, 2], [2, 6], [1], [1, 2], [1]]\n\t\tOutput\n\t\t[null, null, [5], null, null, [6, 5], null, [5]]\n\t\tExplanation\n\t\tTwitter twitter = new Twitter();\n\t\ttwitter.postTweet(1, 5); // User 1 posts a new tweet (id = 5).\n\t\ttwitter.getNewsFeed(1); // User 1's news feed should return a list with 1 tweet id -> [5]. return [5]\n\t\ttwitter.follow(1, 2); // User 1 follows user 2.\n\t\ttwitter.postTweet(2, 6); // User 2 posts a new tweet (id = 6).\n\t\ttwitter.getNewsFeed(1); // User 1's news feed should return a list with 2 tweet ids -> [6, 5]. Tweet id 6 should precede tweet id 5 because it is posted after tweet id 5.\n\t\ttwitter.unfollow(1, 2); // User 1 unfollows user 2.\n\t\ttwitter.getNewsFeed(1); // User 1's news feed should return a list with 1 tweet id -> [5], since user 1 is no longer following user 2.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 357, - "question": "class Solution:\n def countNumbersWithUniqueDigits(self, n: int) -> int:\n\t\t\"\"\"\n\t\tGiven an integer n, return the count of all numbers with unique digits, x, where 0 <= x < 10n.\n\t\tExample 1:\n\t\tInput: n = 2\n\t\tOutput: 91\n\t\tExplanation: The answer should be the total numbers in the range of 0 \u2264 x < 100, excluding 11,22,33,44,55,66,77,88,99\n\t\tExample 2:\n\t\tInput: n = 0\n\t\tOutput: 1\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 363, - "question": "class Solution:\n def maxSumSubmatrix(self, matrix: List[List[int]], k: int) -> int:\n\t\t\"\"\"\n\t\tGiven an m x n matrix matrix and an integer k, return the max sum of a rectangle in the matrix such that its sum is no larger than k.\n\t\tIt is guaranteed that there will be a rectangle with a sum no larger than k.\n\t\tExample 1:\n\t\tInput: matrix = [[1,0,1],[0,-2,3]], k = 2\n\t\tOutput: 2\n\t\tExplanation: Because the sum of the blue rectangle [[0, 1], [-2, 3]] is 2, and 2 is the max number no larger than k (k = 2).\n\t\tExample 2:\n\t\tInput: matrix = [[2,2,-1]], k = 3\n\t\tOutput: 3\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 365, - "question": "class Solution:\n def canMeasureWater(self, jug1Capacity: int, jug2Capacity: int, targetCapacity: int) -> bool:\n\t\t\"\"\"\n\t\tYou are given two jugs with capacities jug1Capacity and jug2Capacity liters. There is an infinite amount of water supply available. Determine whether it is possible to measure exactly targetCapacity liters using these two jugs.\n\t\tIf targetCapacity liters of water are measurable, you must have targetCapacity liters of water contained within one or both buckets by the end.\n\t\tOperations allowed:\n\t\t\tFill any of the jugs with water.\n\t\t\tEmpty any of the jugs.\n\t\t\tPour water from one jug into another till the other jug is completely full, or the first jug itself is empty.\n\t\tExample 1:\n\t\tInput: jug1Capacity = 3, jug2Capacity = 5, targetCapacity = 4\n\t\tOutput: true\n\t\tExplanation: The famous Die Hard example \n\t\tExample 2:\n\t\tInput: jug1Capacity = 2, jug2Capacity = 6, targetCapacity = 5\n\t\tOutput: false\n\t\tExample 3:\n\t\tInput: jug1Capacity = 1, jug2Capacity = 2, targetCapacity = 3\n\t\tOutput: true\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 367, - "question": "class Solution:\n def isPerfectSquare(self, num: int) -> bool:\n\t\t\"\"\"\n\t\tGiven a positive integer num, return true if num is a perfect square or false otherwise.\n\t\tA perfect square is an integer that is the square of an integer. In other words, it is the product of some integer with itself.\n\t\tYou must not use any built-in library function, such as sqrt.\n\t\tExample 1:\n\t\tInput: num = 16\n\t\tOutput: true\n\t\tExplanation: We return true because 4 * 4 = 16 and 4 is an integer.\n\t\tExample 2:\n\t\tInput: num = 14\n\t\tOutput: false\n\t\tExplanation: We return false because 3.742 * 3.742 = 14 and 3.742 is not an integer.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 368, - "question": "class Solution:\n def largestDivisibleSubset(self, nums: List[int]) -> List[int]:\n\t\t\"\"\"\n\t\tGiven a set of distinct positive integers nums, return the largest subset answer such that every pair (answer[i], answer[j]) of elements in this subset satisfies:\n\t\t\tanswer[i] % answer[j] == 0, or\n\t\t\tanswer[j] % answer[i] == 0\n\t\tIf there are multiple solutions, return any of them.\n\t\tExample 1:\n\t\tInput: nums = [1,2,3]\n\t\tOutput: [1,2]\n\t\tExplanation: [1,3] is also accepted.\n\t\tExample 2:\n\t\tInput: nums = [1,2,4,8]\n\t\tOutput: [1,2,4,8]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 371, - "question": "class Solution:\n def getSum(self, a: int, b: int) -> int:\n\t\t\"\"\"\n\t\tGiven two integers a and b, return the sum of the two integers without using the operators + and -.\n\t\tExample 1:\n\t\tInput: a = 1, b = 2\n\t\tOutput: 3\n\t\tExample 2:\n\t\tInput: a = 2, b = 3\n\t\tOutput: 5\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 372, - "question": "class Solution:\n def superPow(self, a: int, b: List[int]) -> int:\n\t\t\"\"\"\n\t\tYour task is to calculate ab mod 1337 where a is a positive integer and b is an extremely large positive integer given in the form of an array.\n\t\tExample 1:\n\t\tInput: a = 2, b = [3]\n\t\tOutput: 8\n\t\tExample 2:\n\t\tInput: a = 2, b = [1,0]\n\t\tOutput: 1024\n\t\tExample 3:\n\t\tInput: a = 1, b = [4,3,3,8,5,2]\n\t\tOutput: 1\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 373, - "question": "class Solution:\n def kSmallestPairs(self, nums1: List[int], nums2: List[int], k: int) -> List[List[int]]:\n\t\t\"\"\"\n\t\tYou are given two integer arrays nums1 and nums2 sorted in ascending order and an integer k.\n\t\tDefine a pair (u, v) which consists of one element from the first array and one element from the second array.\n\t\tReturn the k pairs (u1, v1), (u2, v2), ..., (uk, vk) with the smallest sums.\n\t\tExample 1:\n\t\tInput: nums1 = [1,7,11], nums2 = [2,4,6], k = 3\n\t\tOutput: [[1,2],[1,4],[1,6]]\n\t\tExplanation: The first 3 pairs are returned from the sequence: [1,2],[1,4],[1,6],[7,2],[7,4],[11,2],[7,6],[11,4],[11,6]\n\t\tExample 2:\n\t\tInput: nums1 = [1,1,2], nums2 = [1,2,3], k = 2\n\t\tOutput: [[1,1],[1,1]]\n\t\tExplanation: The first 2 pairs are returned from the sequence: [1,1],[1,1],[1,2],[2,1],[1,2],[2,2],[1,3],[1,3],[2,3]\n\t\tExample 3:\n\t\tInput: nums1 = [1,2], nums2 = [3], k = 3\n\t\tOutput: [[1,3],[2,3]]\n\t\tExplanation: All possible pairs are returned from the sequence: [1,3],[2,3]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 374, - "question": "class Solution:\n def guessNumber(self, n: int) -> int:\n\t\t\"\"\"\n\t\tWe are playing the Guess Game. The game is as follows:\n\t\tI pick a number from 1 to n. You have to guess which number I picked.\n\t\tEvery time you guess wrong, I will tell you whether the number I picked is higher or lower than your guess.\n\t\tYou call a pre-defined API int guess(int num), which returns three possible results:\n\t\t\t-1: Your guess is higher than the number I picked (i.e. num > pick).\n\t\t\t1: Your guess is lower than the number I picked (i.e. num < pick).\n\t\t\t0: your guess is equal to the number I picked (i.e. num == pick).\n\t\tReturn the number that I picked.\n\t\tExample 1:\n\t\tInput: n = 10, pick = 6\n\t\tOutput: 6\n\t\tExample 2:\n\t\tInput: n = 1, pick = 1\n\t\tOutput: 1\n\t\tExample 3:\n\t\tInput: n = 2, pick = 1\n\t\tOutput: 1\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 375, - "question": "class Solution:\n def getMoneyAmount(self, n: int) -> int:\n\t\t\"\"\"\n\t\tWe are playing the Guessing Game. The game will work as follows:\n\t\t\tI pick a number between 1 and n.\n\t\t\tYou guess a number.\n\t\t\tIf you guess the right number, you win the game.\n\t\t\tIf you guess the wrong number, then I will tell you whether the number I picked is higher or lower, and you will continue guessing.\n\t\t\tEvery time you guess a wrong number x, you will pay x dollars. If you run out of money, you lose the game.\n\t\tGiven a particular n, return the minimum amount of money you need to guarantee a win regardless of what number I pick.\n\t\tExample 1:\n\t\tInput: n = 10\n\t\tOutput: 16\n\t\tExplanation: The winning strategy is as follows:\n\t\t- The range is [1,10]. Guess 7.\n\t\t - If this is my number, your total is $0. Otherwise, you pay $7.\n\t\t - If my number is higher, the range is [8,10]. Guess 9.\n\t\t - If this is my number, your total is $7. Otherwise, you pay $9.\n\t\t - If my number is higher, it must be 10. Guess 10. Your total is $7 + $9 = $16.\n\t\t - If my number is lower, it must be 8. Guess 8. Your total is $7 + $9 = $16.\n\t\t - If my number is lower, the range is [1,6]. Guess 3.\n\t\t - If this is my number, your total is $7. Otherwise, you pay $3.\n\t\t - If my number is higher, the range is [4,6]. Guess 5.\n\t\t - If this is my number, your total is $7 + $3 = $10. Otherwise, you pay $5.\n\t\t - If my number is higher, it must be 6. Guess 6. Your total is $7 + $3 + $5 = $15.\n\t\t - If my number is lower, it must be 4. Guess 4. Your total is $7 + $3 + $5 = $15.\n\t\t - If my number is lower, the range is [1,2]. Guess 1.\n\t\t - If this is my number, your total is $7 + $3 = $10. Otherwise, you pay $1.\n\t\t - If my number is higher, it must be 2. Guess 2. Your total is $7 + $3 + $1 = $11.\n\t\tThe worst case in all these scenarios is that you pay $16. Hence, you only need $16 to guarantee a win.\n\t\tExample 2:\n\t\tInput: n = 1\n\t\tOutput: 0\n\t\tExplanation: There is only one possible number, so you can guess 1 and not have to pay anything.\n\t\tExample 3:\n\t\tInput: n = 2\n\t\tOutput: 1\n\t\tExplanation: There are two possible numbers, 1 and 2.\n\t\t- Guess 1.\n\t\t - If this is my number, your total is $0. Otherwise, you pay $1.\n\t\t - If my number is higher, it must be 2. Guess 2. Your total is $1.\n\t\tThe worst case is that you pay $1.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 376, - "question": "class Solution:\n def wiggleMaxLength(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tA wiggle sequence is a sequence where the differences between successive numbers strictly alternate between positive and negative. The first difference (if one exists) may be either positive or negative. A sequence with one element and a sequence with two non-equal elements are trivially wiggle sequences.\n\t\t\tFor example, [1, 7, 4, 9, 2, 5] is a wiggle sequence because the differences (6, -3, 5, -7, 3) alternate between positive and negative.\n\t\t\tIn contrast, [1, 4, 7, 2, 5] and [1, 7, 4, 5, 5] are not wiggle sequences. The first is not because its first two differences are positive, and the second is not because its last difference is zero.\n\t\tA subsequence is obtained by deleting some elements (possibly zero) from the original sequence, leaving the remaining elements in their original order.\n\t\tGiven an integer array nums, return the length of the longest wiggle subsequence of nums.\n\t\tExample 1:\n\t\tInput: nums = [1,7,4,9,2,5]\n\t\tOutput: 6\n\t\tExplanation: The entire sequence is a wiggle sequence with differences (6, -3, 5, -7, 3).\n\t\tExample 2:\n\t\tInput: nums = [1,17,5,10,13,15,10,5,16,8]\n\t\tOutput: 7\n\t\tExplanation: There are several subsequences that achieve this length.\n\t\tOne is [1, 17, 10, 13, 10, 16, 8] with differences (16, -7, 3, -3, 6, -8).\n\t\tExample 3:\n\t\tInput: nums = [1,2,3,4,5,6,7,8,9]\n\t\tOutput: 2\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 377, - "question": "class Solution:\n def combinationSum4(self, nums: List[int], target: int) -> int:\n\t\t\"\"\"\n\t\tGiven an array of distinct integers nums and a target integer target, return the number of possible combinations that add up to target.\n\t\tThe test cases are generated so that the answer can fit in a 32-bit integer.\n\t\tExample 1:\n\t\tInput: nums = [1,2,3], target = 4\n\t\tOutput: 7\n\t\tExplanation:\n\t\tThe possible combination ways are:\n\t\t(1, 1, 1, 1)\n\t\t(1, 1, 2)\n\t\t(1, 2, 1)\n\t\t(1, 3)\n\t\t(2, 1, 1)\n\t\t(2, 2)\n\t\t(3, 1)\n\t\tNote that different sequences are counted as different combinations.\n\t\tExample 2:\n\t\tInput: nums = [9], target = 3\n\t\tOutput: 0\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 378, - "question": "class Solution:\n def kthSmallest(self, matrix: List[List[int]], k: int) -> int:\n\t\t\"\"\"\n\t\tGiven an n x n matrix where each of the rows and columns is sorted in ascending order, return the kth smallest element in the matrix.\n\t\tNote that it is the kth smallest element in the sorted order, not the kth distinct element.\n\t\tYou must find a solution with a memory complexity better than O(n2).\n\t\tExample 1:\n\t\tInput: matrix = [[1,5,9],[10,11,13],[12,13,15]], k = 8\n\t\tOutput: 13\n\t\tExplanation: The elements in the matrix are [1,5,9,10,11,12,13,13,15], and the 8th smallest number is 13\n\t\tExample 2:\n\t\tInput: matrix = [[-5]], k = 1\n\t\tOutput: -5\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 380, - "question": "class RandomizedSet:\n def __init__(self):\n def insert(self, val: int) -> bool:\n def remove(self, val: int) -> bool:\n def getRandom(self) -> int:\n\t\t\"\"\"\n\t\tImplement the RandomizedSet class:\n\t\t\tRandomizedSet() Initializes the RandomizedSet object.\n\t\t\tbool insert(int val) Inserts an item val into the set if not present. Returns true if the item was not present, false otherwise.\n\t\t\tbool remove(int val) Removes an item val from the set if present. Returns true if the item was present, false otherwise.\n\t\t\tint getRandom() Returns a random element from the current set of elements (it's guaranteed that at least one element exists when this method is called). Each element must have the same probability of being returned.\n\t\tYou must implement the functions of the class such that each function works in average O(1) time complexity.\n\t\tExample 1:\n\t\tInput\n\t\t[\"RandomizedSet\", \"insert\", \"remove\", \"insert\", \"getRandom\", \"remove\", \"insert\", \"getRandom\"]\n\t\t[[], [1], [2], [2], [], [1], [2], []]\n\t\tOutput\n\t\t[null, true, false, true, 2, true, false, 2]\n\t\tExplanation\n\t\tRandomizedSet randomizedSet = new RandomizedSet();\n\t\trandomizedSet.insert(1); // Inserts 1 to the set. Returns true as 1 was inserted successfully.\n\t\trandomizedSet.remove(2); // Returns false as 2 does not exist in the set.\n\t\trandomizedSet.insert(2); // Inserts 2 to the set, returns true. Set now contains [1,2].\n\t\trandomizedSet.getRandom(); // getRandom() should return either 1 or 2 randomly.\n\t\trandomizedSet.remove(1); // Removes 1 from the set, returns true. Set now contains [2].\n\t\trandomizedSet.insert(2); // 2 was already in the set, so return false.\n\t\trandomizedSet.getRandom(); // Since 2 is the only number in the set, getRandom() will always return 2.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 381, - "question": "class RandomizedCollection:\n def __init__(self):\n def insert(self, val: int) -> bool:\n def remove(self, val: int) -> bool:\n def getRandom(self) -> int:\n\t\t\"\"\"\n\t\tRandomizedCollection is a data structure that contains a collection of numbers, possibly duplicates (i.e., a multiset). It should support inserting and removing specific elements and also reporting a random element.\n\t\tImplement the RandomizedCollection class:\n\t\t\tRandomizedCollection() Initializes the empty RandomizedCollection object.\n\t\t\tbool insert(int val) Inserts an item val into the multiset, even if the item is already present. Returns true if the item is not present, false otherwise.\n\t\t\tbool remove(int val) Removes an item val from the multiset if present. Returns true if the item is present, false otherwise. Note that if val has multiple occurrences in the multiset, we only remove one of them.\n\t\t\tint getRandom() Returns a random element from the current multiset of elements. The probability of each element being returned is linearly related to the number of the same values the multiset contains.\n\t\tYou must implement the functions of the class such that each function works on average O(1) time complexity.\n\t\tNote: The test cases are generated such that getRandom will only be called if there is at least one item in the RandomizedCollection.\n\t\tExample 1:\n\t\tInput\n\t\t[\"RandomizedCollection\", \"insert\", \"insert\", \"insert\", \"getRandom\", \"remove\", \"getRandom\"]\n\t\t[[], [1], [1], [2], [], [1], []]\n\t\tOutput\n\t\t[null, true, false, true, 2, true, 1]\n\t\tExplanation\n\t\tRandomizedCollection randomizedCollection = new RandomizedCollection();\n\t\trandomizedCollection.insert(1); // return true since the collection does not contain 1.\n\t\t // Inserts 1 into the collection.\n\t\trandomizedCollection.insert(1); // return false since the collection contains 1.\n\t\t // Inserts another 1 into the collection. Collection now contains [1,1].\n\t\trandomizedCollection.insert(2); // return true since the collection does not contain 2.\n\t\t // Inserts 2 into the collection. Collection now contains [1,1,2].\n\t\trandomizedCollection.getRandom(); // getRandom should:\n\t\t // - return 1 with probability 2/3, or\n\t\t // - return 2 with probability 1/3.\n\t\trandomizedCollection.remove(1); // return true since the collection contains 1.\n\t\t // Removes 1 from the collection. Collection now contains [1,2].\n\t\trandomizedCollection.getRandom(); // getRandom should return 1 or 2, both equally likely.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 382, - "question": "class Solution:\n def __init__(self, head: Optional[ListNode]):\n def getRandom(self) -> int:\n\t\t\"\"\"\n\t\tGiven a singly linked list, return a random node's value from the linked list. Each node must have the same probability of being chosen.\n\t\tImplement the Solution class:\n\t\t\tSolution(ListNode head) Initializes the object with the head of the singly-linked list head.\n\t\t\tint getRandom() Chooses a node randomly from the list and returns its value. All the nodes of the list should be equally likely to be chosen.\n\t\tExample 1:\n\t\tInput\n\t\t[\"Solution\", \"getRandom\", \"getRandom\", \"getRandom\", \"getRandom\", \"getRandom\"]\n\t\t[[[1, 2, 3]], [], [], [], [], []]\n\t\tOutput\n\t\t[null, 1, 3, 2, 2, 3]\n\t\tExplanation\n\t\tSolution solution = new Solution([1, 2, 3]);\n\t\tsolution.getRandom(); // return 1\n\t\tsolution.getRandom(); // return 3\n\t\tsolution.getRandom(); // return 2\n\t\tsolution.getRandom(); // return 2\n\t\tsolution.getRandom(); // return 3\n\t\t// getRandom() should return either 1, 2, or 3 randomly. Each element should have equal probability of returning.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 383, - "question": "class Solution:\n def canConstruct(self, ransomNote: str, magazine: str) -> bool:\n\t\t\"\"\"\n\t\tGiven two strings ransomNote and magazine, return true if ransomNote can be constructed by using the letters from magazine and false otherwise.\n\t\tEach letter in magazine can only be used once in ransomNote.\n\t\tExample 1:\n\t\tInput: ransomNote = \"a\", magazine = \"b\"\n\t\tOutput: false\n\t\tExample 2:\n\t\tInput: ransomNote = \"aa\", magazine = \"ab\"\n\t\tOutput: false\n\t\tExample 3:\n\t\tInput: ransomNote = \"aa\", magazine = \"aab\"\n\t\tOutput: true\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 384, - "question": "class Solution:\n def __init__(self, nums: List[int]):\n def reset(self) -> List[int]:\n def shuffle(self) -> List[int]:\n\t\t\"\"\"\n\t\tGiven an integer array nums, design an algorithm to randomly shuffle the array. All permutations of the array should be equally likely as a result of the shuffling.\n\t\tImplement the Solution class:\n\t\t\tSolution(int[] nums) Initializes the object with the integer array nums.\n\t\t\tint[] reset() Resets the array to its original configuration and returns it.\n\t\t\tint[] shuffle() Returns a random shuffling of the array.\n\t\tExample 1:\n\t\tInput\n\t\t[\"Solution\", \"shuffle\", \"reset\", \"shuffle\"]\n\t\t[[[1, 2, 3]], [], [], []]\n\t\tOutput\n\t\t[null, [3, 1, 2], [1, 2, 3], [1, 3, 2]]\n\t\tExplanation\n\t\tSolution solution = new Solution([1, 2, 3]);\n\t\tsolution.shuffle(); // Shuffle the array [1,2,3] and return its result.\n\t\t // Any permutation of [1,2,3] must be equally likely to be returned.\n\t\t // Example: return [3, 1, 2]\n\t\tsolution.reset(); // Resets the array back to its original configuration [1,2,3]. Return [1, 2, 3]\n\t\tsolution.shuffle(); // Returns the random shuffling of array [1,2,3]. Example: return [1, 3, 2]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 385, - "question": "\t\t\"\"\"\n\t\tGiven a string s represents the serialization of a nested list, implement a parser to deserialize it and return the deserialized NestedInteger.\n\t\tEach element is either an integer or a list whose elements may also be integers or other lists.\n\t\tExample 1:\n\t\tInput: s = \"324\"\n\t\tOutput: 324\n\t\tExplanation: You should return a NestedInteger object which contains a single integer 324.\n\t\tExample 2:\n\t\tInput: s = \"[123,[456,[789]]]\"\n\t\tOutput: [123,[456,[789]]]\n\t\tExplanation: Return a NestedInteger object containing a nested list with 2 elements:\n\t\t1. An integer containing value 123.\n\t\t2. A nested list containing two elements:\n\t\t i. An integer containing value 456.\n\t\t ii. A nested list with one element:\n\t\t a. An integer containing value 789\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 386, - "question": "class Solution:\n def lexicalOrder(self, n: int) -> List[int]:\n\t\t\"\"\"\n\t\tGiven an integer n, return all the numbers in the range [1, n] sorted in lexicographical order.\n\t\tYou must write an algorithm that runs in O(n) time and uses O(1) extra space. \n\t\tExample 1:\n\t\tInput: n = 13\n\t\tOutput: [1,10,11,12,13,2,3,4,5,6,7,8,9]\n\t\tExample 2:\n\t\tInput: n = 2\n\t\tOutput: [1,2]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 387, - "question": "class Solution:\n def firstUniqChar(self, s: str) -> int:\n\t\t\"\"\"\n\t\tGiven a string s, find the first non-repeating character in it and return its index. If it does not exist, return -1.\n\t\tExample 1:\n\t\tInput: s = \"leetcode\"\n\t\tOutput: 0\n\t\tExample 2:\n\t\tInput: s = \"loveleetcode\"\n\t\tOutput: 2\n\t\tExample 3:\n\t\tInput: s = \"aabb\"\n\t\tOutput: -1\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 388, - "question": "class Solution:\n def lengthLongestPath(self, input: str) -> int:\n\t\t\"\"\"\n\t\tSuppose we have a file system that stores both files and directories. An example of one system is represented in the following picture:\n\t\tHere, we have dir as the only directory in the root. dir contains two subdirectories, subdir1 and subdir2. subdir1 contains a file file1.ext and subdirectory subsubdir1. subdir2 contains a subdirectory subsubdir2, which contains a file file2.ext.\n\t\tIn text form, it looks like this (with \u27f6 representing the tab character):\n\t\tdir\n\t\t\u27f6 subdir1\n\t\t\u27f6 \u27f6 file1.ext\n\t\t\u27f6 \u27f6 subsubdir1\n\t\t\u27f6 subdir2\n\t\t\u27f6 \u27f6 subsubdir2\n\t\t\u27f6 \u27f6 \u27f6 file2.ext\n\t\tIf we were to write this representation in code, it will look like this: \"dir\\n\\tsubdir1\\n\\t\\tfile1.ext\\n\\t\\tsubsubdir1\\n\\tsubdir2\\n\\t\\tsubsubdir2\\n\\t\\t\\tfile2.ext\". Note that the '\\n' and '\\t' are the new-line and tab characters.\n\t\tEvery file and directory has a unique absolute path in the file system, which is the order of directories that must be opened to reach the file/directory itself, all concatenated by '/'s. Using the above example, the absolute path to file2.ext is \"dir/subdir2/subsubdir2/file2.ext\". Each directory name consists of letters, digits, and/or spaces. Each file name is of the form name.extension, where name and extension consist of letters, digits, and/or spaces.\n\t\tGiven a string input representing the file system in the explained format, return the length of the longest absolute path to a file in the abstracted file system. If there is no file in the system, return 0.\n\t\tNote that the testcases are generated such that the file system is valid and no file or directory name has length 0.\n\t\tExample 1:\n\t\tInput: input = \"dir\\n\\tsubdir1\\n\\tsubdir2\\n\\t\\tfile.ext\"\n\t\tOutput: 20\n\t\tExplanation: We have only one file, and the absolute path is \"dir/subdir2/file.ext\" of length 20.\n\t\tExample 2:\n\t\tInput: input = \"dir\\n\\tsubdir1\\n\\t\\tfile1.ext\\n\\t\\tsubsubdir1\\n\\tsubdir2\\n\\t\\tsubsubdir2\\n\\t\\t\\tfile2.ext\"\n\t\tOutput: 32\n\t\tExplanation: We have two files:\n\t\t\"dir/subdir1/file1.ext\" of length 21\n\t\t\"dir/subdir2/subsubdir2/file2.ext\" of length 32.\n\t\tWe return 32 since it is the longest absolute path to a file.\n\t\tExample 3:\n\t\tInput: input = \"a\"\n\t\tOutput: 0\n\t\tExplanation: We do not have any files, just a single directory named \"a\".\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 389, - "question": "class Solution:\n def findTheDifference(self, s: str, t: str) -> str:\n\t\t\"\"\"\n\t\tYou are given two strings s and t.\n\t\tString t is generated by random shuffling string s and then add one more letter at a random position.\n\t\tReturn the letter that was added to t.\n\t\tExample 1:\n\t\tInput: s = \"abcd\", t = \"abcde\"\n\t\tOutput: \"e\"\n\t\tExplanation: 'e' is the letter that was added.\n\t\tExample 2:\n\t\tInput: s = \"\", t = \"y\"\n\t\tOutput: \"y\"\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 390, - "question": "class Solution:\n def lastRemaining(self, n: int) -> int:\n\t\t\"\"\"\n\t\tYou have a list arr of all integers in the range [1, n] sorted in a strictly increasing order. Apply the following algorithm on arr:\n\t\t\tStarting from left to right, remove the first number and every other number afterward until you reach the end of the list.\n\t\t\tRepeat the previous step again, but this time from right to left, remove the rightmost number and every other number from the remaining numbers.\n\t\t\tKeep repeating the steps again, alternating left to right and right to left, until a single number remains.\n\t\tGiven the integer n, return the last number that remains in arr.\n\t\tExample 1:\n\t\tInput: n = 9\n\t\tOutput: 6\n\t\tExplanation:\n\t\tarr = [1, 2, 3, 4, 5, 6, 7, 8, 9]\n\t\tarr = [2, 4, 6, 8]\n\t\tarr = [2, 6]\n\t\tarr = [6]\n\t\tExample 2:\n\t\tInput: n = 1\n\t\tOutput: 1\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 391, - "question": "class Solution:\n def isRectangleCover(self, rectangles: List[List[int]]) -> bool:\n\t\t\"\"\"\n\t\tGiven an array rectangles where rectangles[i] = [xi, yi, ai, bi] represents an axis-aligned rectangle. The bottom-left point of the rectangle is (xi, yi) and the top-right point of it is (ai, bi).\n\t\tReturn true if all the rectangles together form an exact cover of a rectangular region.\n\t\tExample 1:\n\t\tInput: rectangles = [[1,1,3,3],[3,1,4,2],[3,2,4,4],[1,3,2,4],[2,3,3,4]]\n\t\tOutput: true\n\t\tExplanation: All 5 rectangles together form an exact cover of a rectangular region.\n\t\tExample 2:\n\t\tInput: rectangles = [[1,1,2,3],[1,3,2,4],[3,1,4,2],[3,2,4,4]]\n\t\tOutput: false\n\t\tExplanation: Because there is a gap between the two rectangular regions.\n\t\tExample 3:\n\t\tInput: rectangles = [[1,1,3,3],[3,1,4,2],[1,3,2,4],[2,2,4,4]]\n\t\tOutput: false\n\t\tExplanation: Because two of the rectangles overlap with each other.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 392, - "question": "class Solution:\n def isSubsequence(self, s: str, t: str) -> bool:\n\t\t\"\"\"\n\t\tGiven two strings s and t, return true if s is a subsequence of t, or false otherwise.\n\t\tA subsequence of a string is a new string that is formed from the original string by deleting some (can be none) of the characters without disturbing the relative positions of the remaining characters. (i.e., \"ace\" is a subsequence of \"abcde\" while \"aec\" is not).\n\t\tExample 1:\n\t\tInput: s = \"abc\", t = \"ahbgdc\"\n\t\tOutput: true\n\t\tExample 2:\n\t\tInput: s = \"axc\", t = \"ahbgdc\"\n\t\tOutput: false\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 393, - "question": "class Solution:\n def validUtf8(self, data: List[int]) -> bool:\n\t\t\"\"\"\n\t\tGiven an integer array data representing the data, return whether it is a valid UTF-8 encoding (i.e. it translates to a sequence of valid UTF-8 encoded characters).\n\t\tA character in UTF8 can be from 1 to 4 bytes long, subjected to the following rules:\n\t\t\tFor a 1-byte character, the first bit is a 0, followed by its Unicode code.\n\t\t\tFor an n-bytes character, the first n bits are all one's, the n + 1 bit is 0, followed by n - 1 bytes with the most significant 2 bits being 10.\n\t\tThis is how the UTF-8 encoding would work:\n\t\t Number of Bytes | UTF-8 Octet Sequence\n\t\t | (binary)\n\t\t --------------------+-----------------------------------------\n\t\t 1 | 0xxxxxxx\n\t\t 2 | 110xxxxx 10xxxxxx\n\t\t 3 | 1110xxxx 10xxxxxx 10xxxxxx\n\t\t 4 | 11110xxx 10xxxxxx 10xxxxxx 10xxxxxx\n\t\tx denotes a bit in the binary form of a byte that may be either 0 or 1.\n\t\tNote: The input is an array of integers. Only the least significant 8 bits of each integer is used to store the data. This means each integer represents only 1 byte of data.\n\t\tExample 1:\n\t\tInput: data = [197,130,1]\n\t\tOutput: true\n\t\tExplanation: data represents the octet sequence: 11000101 10000010 00000001.\n\t\tIt is a valid utf-8 encoding for a 2-bytes character followed by a 1-byte character.\n\t\tExample 2:\n\t\tInput: data = [235,140,4]\n\t\tOutput: false\n\t\tExplanation: data represented the octet sequence: 11101011 10001100 00000100.\n\t\tThe first 3 bits are all one's and the 4th bit is 0 means it is a 3-bytes character.\n\t\tThe next byte is a continuation byte which starts with 10 and that's correct.\n\t\tBut the second continuation byte does not start with 10, so it is invalid.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 394, - "question": "class Solution:\n def decodeString(self, s: str) -> str:\n\t\t\"\"\"\n\t\tGiven an encoded string, return its decoded string.\n\t\tThe encoding rule is: k[encoded_string], where the encoded_string inside the square brackets is being repeated exactly k times. Note that k is guaranteed to be a positive integer.\n\t\tYou may assume that the input string is always valid; there are no extra white spaces, square brackets are well-formed, etc. Furthermore, you may assume that the original data does not contain any digits and that digits are only for those repeat numbers, k. For example, there will not be input like 3a or 2[4].\n\t\tThe test cases are generated so that the length of the output will never exceed 105.\n\t\tExample 1:\n\t\tInput: s = \"3[a]2[bc]\"\n\t\tOutput: \"aaabcbc\"\n\t\tExample 2:\n\t\tInput: s = \"3[a2[c]]\"\n\t\tOutput: \"accaccacc\"\n\t\tExample 3:\n\t\tInput: s = \"2[abc]3[cd]ef\"\n\t\tOutput: \"abcabccdcdcdef\"\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 395, - "question": "class Solution:\n def longestSubstring(self, s: str, k: int) -> int:\n\t\t\"\"\"\n\t\tGiven a string s and an integer k, return the length of the longest substring of s such that the frequency of each character in this substring is greater than or equal to k.\n\t\tExample 1:\n\t\tInput: s = \"aaabb\", k = 3\n\t\tOutput: 3\n\t\tExplanation: The longest substring is \"aaa\", as 'a' is repeated 3 times.\n\t\tExample 2:\n\t\tInput: s = \"ababbc\", k = 2\n\t\tOutput: 5\n\t\tExplanation: The longest substring is \"ababb\", as 'a' is repeated 2 times and 'b' is repeated 3 times.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 396, - "question": "class Solution:\n def maxRotateFunction(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou are given an integer array nums of length n.\n\t\tAssume arrk to be an array obtained by rotating nums by k positions clock-wise. We define the rotation function F on nums as follow:\n\t\t\tF(k) = 0 * arrk[0] + 1 * arrk[1] + ... + (n - 1) * arrk[n - 1].\n\t\tReturn the maximum value of F(0), F(1), ..., F(n-1).\n\t\tThe test cases are generated so that the answer fits in a 32-bit integer.\n\t\tExample 1:\n\t\tInput: nums = [4,3,2,6]\n\t\tOutput: 26\n\t\tExplanation:\n\t\tF(0) = (0 * 4) + (1 * 3) + (2 * 2) + (3 * 6) = 0 + 3 + 4 + 18 = 25\n\t\tF(1) = (0 * 6) + (1 * 4) + (2 * 3) + (3 * 2) = 0 + 4 + 6 + 6 = 16\n\t\tF(2) = (0 * 2) + (1 * 6) + (2 * 4) + (3 * 3) = 0 + 6 + 8 + 9 = 23\n\t\tF(3) = (0 * 3) + (1 * 2) + (2 * 6) + (3 * 4) = 0 + 2 + 12 + 12 = 26\n\t\tSo the maximum value of F(0), F(1), F(2), F(3) is F(3) = 26.\n\t\tExample 2:\n\t\tInput: nums = [100]\n\t\tOutput: 0\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 397, - "question": "class Solution:\n def integerReplacement(self, n: int) -> int:\n\t\t\"\"\"\n\t\tGiven a positive integer n, you can apply one of the following operations:\n\t\t\tIf n is even, replace n with n / 2.\n\t\t\tIf n is odd, replace n with either n + 1 or n - 1.\n\t\tReturn the minimum number of operations needed for n to become 1.\n\t\tExample 1:\n\t\tInput: n = 8\n\t\tOutput: 3\n\t\tExplanation: 8 -> 4 -> 2 -> 1\n\t\tExample 2:\n\t\tInput: n = 7\n\t\tOutput: 4\n\t\tExplanation: 7 -> 8 -> 4 -> 2 -> 1\n\t\tor 7 -> 6 -> 3 -> 2 -> 1\n\t\tExample 3:\n\t\tInput: n = 4\n\t\tOutput: 2\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 398, - "question": "class Solution:\n def __init__(self, nums: List[int]):\n def pick(self, target: int) -> int:\n\t\t\"\"\"\n\t\tGiven an integer array nums with possible duplicates, randomly output the index of a given target number. You can assume that the given target number must exist in the array.\n\t\tImplement the Solution class:\n\t\t\tSolution(int[] nums) Initializes the object with the array nums.\n\t\t\tint pick(int target) Picks a random index i from nums where nums[i] == target. If there are multiple valid i's, then each index should have an equal probability of returning.\n\t\tExample 1:\n\t\tInput\n\t\t[\"Solution\", \"pick\", \"pick\", \"pick\"]\n\t\t[[[1, 2, 3, 3, 3]], [3], [1], [3]]\n\t\tOutput\n\t\t[null, 4, 0, 2]\n\t\tExplanation\n\t\tSolution solution = new Solution([1, 2, 3, 3, 3]);\n\t\tsolution.pick(3); // It should return either index 2, 3, or 4 randomly. Each index should have equal probability of returning.\n\t\tsolution.pick(1); // It should return 0. Since in the array only nums[0] is equal to 1.\n\t\tsolution.pick(3); // It should return either index 2, 3, or 4 randomly. Each index should have equal probability of returning.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 399, - "question": "class Solution:\n def calcEquation(self, equations: List[List[str]], values: List[float], queries: List[List[str]]) -> List[float]:\n\t\t\"\"\"\n\t\tYou are given an array of variable pairs equations and an array of real numbers values, where equations[i] = [Ai, Bi] and values[i] represent the equation Ai / Bi = values[i]. Each Ai or Bi is a string that represents a single variable.\n\t\tYou are also given some queries, where queries[j] = [Cj, Dj] represents the jth query where you must find the answer for Cj / Dj = ?.\n\t\tReturn the answers to all queries. If a single answer cannot be determined, return -1.0.\n\t\tNote: The input is always valid. You may assume that evaluating the queries will not result in division by zero and that there is no contradiction.\n\t\tExample 1:\n\t\tInput: equations = [[\"a\",\"b\"],[\"b\",\"c\"]], values = [2.0,3.0], queries = [[\"a\",\"c\"],[\"b\",\"a\"],[\"a\",\"e\"],[\"a\",\"a\"],[\"x\",\"x\"]]\n\t\tOutput: [6.00000,0.50000,-1.00000,1.00000,-1.00000]\n\t\tExplanation: \n\t\tGiven: a / b = 2.0, b / c = 3.0\n\t\tqueries are: a / c = ?, b / a = ?, a / e = ?, a / a = ?, x / x = ?\n\t\treturn: [6.0, 0.5, -1.0, 1.0, -1.0 ]\n\t\tExample 2:\n\t\tInput: equations = [[\"a\",\"b\"],[\"b\",\"c\"],[\"bc\",\"cd\"]], values = [1.5,2.5,5.0], queries = [[\"a\",\"c\"],[\"c\",\"b\"],[\"bc\",\"cd\"],[\"cd\",\"bc\"]]\n\t\tOutput: [3.75000,0.40000,5.00000,0.20000]\n\t\tExample 3:\n\t\tInput: equations = [[\"a\",\"b\"]], values = [0.5], queries = [[\"a\",\"b\"],[\"b\",\"a\"],[\"a\",\"c\"],[\"x\",\"y\"]]\n\t\tOutput: [0.50000,2.00000,-1.00000,-1.00000]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 400, - "question": "class Solution:\n def findNthDigit(self, n: int) -> int:\n\t\t\"\"\"\n\t\tGiven an integer n, return the nth digit of the infinite integer sequence [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, ...].\n\t\tExample 1:\n\t\tInput: n = 3\n\t\tOutput: 3\n\t\tExample 2:\n\t\tInput: n = 11\n\t\tOutput: 0\n\t\tExplanation: The 11th digit of the sequence 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, ... is a 0, which is part of the number 10.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 401, - "question": "class Solution:\n def readBinaryWatch(self, turnedOn: int) -> List[str]:\n\t\t\"\"\"\n\t\tA binary watch has 4 LEDs on the top to represent the hours (0-11), and 6 LEDs on the bottom to represent the minutes (0-59). Each LED represents a zero or one, with the least significant bit on the right.\n\t\t\tFor example, the below binary watch reads \"4:51\".\n\t\tGiven an integer turnedOn which represents the number of LEDs that are currently on (ignoring the PM), return all possible times the watch could represent. You may return the answer in any order.\n\t\tThe hour must not contain a leading zero.\n\t\t\tFor example, \"01:00\" is not valid. It should be \"1:00\".\n\t\tThe minute must be consist of two digits and may contain a leading zero.\n\t\t\tFor example, \"10:2\" is not valid. It should be \"10:02\".\n\t\tExample 1:\n\t\tInput: turnedOn = 1\n\t\tOutput: [\"0:01\",\"0:02\",\"0:04\",\"0:08\",\"0:16\",\"0:32\",\"1:00\",\"2:00\",\"4:00\",\"8:00\"]\n\t\tExample 2:\n\t\tInput: turnedOn = 9\n\t\tOutput: []\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 402, - "question": "class Solution:\n def removeKdigits(self, num: str, k: int) -> str:\n\t\t\"\"\"\n\t\tGiven string num representing a non-negative integer num, and an integer k, return the smallest possible integer after removing k digits from num.\n\t\tExample 1:\n\t\tInput: num = \"1432219\", k = 3\n\t\tOutput: \"1219\"\n\t\tExplanation: Remove the three digits 4, 3, and 2 to form the new number 1219 which is the smallest.\n\t\tExample 2:\n\t\tInput: num = \"10200\", k = 1\n\t\tOutput: \"200\"\n\t\tExplanation: Remove the leading 1 and the number is 200. Note that the output must not contain leading zeroes.\n\t\tExample 3:\n\t\tInput: num = \"10\", k = 2\n\t\tOutput: \"0\"\n\t\tExplanation: Remove all the digits from the number and it is left with nothing which is 0.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 403, - "question": "class Solution:\n def canCross(self, stones: List[int]) -> bool:\n\t\t\"\"\"\n\t\tA frog is crossing a river. The river is divided into some number of units, and at each unit, there may or may not exist a stone. The frog can jump on a stone, but it must not jump into the water.\n\t\tGiven a list of stones' positions (in units) in sorted ascending order, determine if the frog can cross the river by landing on the last stone. Initially, the frog is on the first stone and assumes the first jump must be 1 unit.\n\t\tIf the frog's last jump was k units, its next jump must be either k - 1, k, or k + 1 units. The frog can only jump in the forward direction.\n\t\tExample 1:\n\t\tInput: stones = [0,1,3,5,6,8,12,17]\n\t\tOutput: true\n\t\tExplanation: The frog can jump to the last stone by jumping 1 unit to the 2nd stone, then 2 units to the 3rd stone, then 2 units to the 4th stone, then 3 units to the 6th stone, 4 units to the 7th stone, and 5 units to the 8th stone.\n\t\tExample 2:\n\t\tInput: stones = [0,1,2,3,4,8,9,11]\n\t\tOutput: false\n\t\tExplanation: There is no way to jump to the last stone as the gap between the 5th and 6th stone is too large.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 404, - "question": "class Solution:\n def sumOfLeftLeaves(self, root: Optional[TreeNode]) -> int:\n\t\t\"\"\"\n\t\tGiven the root of a binary tree, return the sum of all left leaves.\n\t\tA leaf is a node with no children. A left leaf is a leaf that is the left child of another node.\n\t\tExample 1:\n\t\tInput: root = [3,9,20,null,null,15,7]\n\t\tOutput: 24\n\t\tExplanation: There are two left leaves in the binary tree, with values 9 and 15 respectively.\n\t\tExample 2:\n\t\tInput: root = [1]\n\t\tOutput: 0\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 405, - "question": "class Solution:\n def toHex(self, num: int) -> str:\n\t\t\"\"\"\n\t\tGiven an integer num, return a string representing its hexadecimal representation. For negative integers, two\u2019s complement method is used.\n\t\tAll the letters in the answer string should be lowercase characters, and there should not be any leading zeros in the answer except for the zero itself.\n\t\tNote: You are not allowed to use any built-in library method to directly solve this problem.\n\t\tExample 1:\n\t\tInput: num = 26\n\t\tOutput: \"1a\"\n\t\tExample 2:\n\t\tInput: num = -1\n\t\tOutput: \"ffffffff\"\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 406, - "question": "class Solution:\n def reconstructQueue(self, people: List[List[int]]) -> List[List[int]]:\n\t\t\"\"\"\n\t\tYou are given an array of people, people, which are the attributes of some people in a queue (not necessarily in order). Each people[i] = [hi, ki] represents the ith person of height hi with exactly ki other people in front who have a height greater than or equal to hi.\n\t\tReconstruct and return the queue that is represented by the input array people. The returned queue should be formatted as an array queue, where queue[j] = [hj, kj] is the attributes of the jth person in the queue (queue[0] is the person at the front of the queue).\n\t\tExample 1:\n\t\tInput: people = [[7,0],[4,4],[7,1],[5,0],[6,1],[5,2]]\n\t\tOutput: [[5,0],[7,0],[5,2],[6,1],[4,4],[7,1]]\n\t\tExplanation:\n\t\tPerson 0 has height 5 with no other people taller or the same height in front.\n\t\tPerson 1 has height 7 with no other people taller or the same height in front.\n\t\tPerson 2 has height 5 with two persons taller or the same height in front, which is person 0 and 1.\n\t\tPerson 3 has height 6 with one person taller or the same height in front, which is person 1.\n\t\tPerson 4 has height 4 with four people taller or the same height in front, which are people 0, 1, 2, and 3.\n\t\tPerson 5 has height 7 with one person taller or the same height in front, which is person 1.\n\t\tHence [[5,0],[7,0],[5,2],[6,1],[4,4],[7,1]] is the reconstructed queue.\n\t\tExample 2:\n\t\tInput: people = [[6,0],[5,0],[4,0],[3,2],[2,2],[1,4]]\n\t\tOutput: [[4,0],[5,0],[2,2],[3,2],[1,4],[6,0]]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 407, - "question": "class Solution:\n def trapRainWater(self, heightMap: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tGiven an m x n integer matrix heightMap representing the height of each unit cell in a 2D elevation map, return the volume of water it can trap after raining.\n\t\tExample 1:\n\t\tInput: heightMap = [[1,4,3,1,3,2],[3,2,1,3,2,4],[2,3,3,2,3,1]]\n\t\tOutput: 4\n\t\tExplanation: After the rain, water is trapped between the blocks.\n\t\tWe have two small ponds 1 and 3 units trapped.\n\t\tThe total volume of water trapped is 4.\n\t\tExample 2:\n\t\tInput: heightMap = [[3,3,3,3,3],[3,2,2,2,3],[3,2,1,2,3],[3,2,2,2,3],[3,3,3,3,3]]\n\t\tOutput: 10\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 409, - "question": "class Solution:\n def longestPalindrome(self, s: str) -> int:\n\t\t\"\"\"\n\t\tGiven a string s which consists of lowercase or uppercase letters, return the length of the longest palindrome that can be built with those letters.\n\t\tLetters are case sensitive, for example, \"Aa\" is not considered a palindrome here.\n\t\tExample 1:\n\t\tInput: s = \"abccccdd\"\n\t\tOutput: 7\n\t\tExplanation: One longest palindrome that can be built is \"dccaccd\", whose length is 7.\n\t\tExample 2:\n\t\tInput: s = \"a\"\n\t\tOutput: 1\n\t\tExplanation: The longest palindrome that can be built is \"a\", whose length is 1.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 410, - "question": "class Solution:\n def splitArray(self, nums: List[int], k: int) -> int:\n\t\t\"\"\"\n\t\tGiven an integer array nums and an integer k, split nums into k non-empty subarrays such that the largest sum of any subarray is minimized.\n\t\tReturn the minimized largest sum of the split.\n\t\tA subarray is a contiguous part of the array.\n\t\tExample 1:\n\t\tInput: nums = [7,2,5,10,8], k = 2\n\t\tOutput: 18\n\t\tExplanation: There are four ways to split nums into two subarrays.\n\t\tThe best way is to split it into [7,2,5] and [10,8], where the largest sum among the two subarrays is only 18.\n\t\tExample 2:\n\t\tInput: nums = [1,2,3,4,5], k = 2\n\t\tOutput: 9\n\t\tExplanation: There are four ways to split nums into two subarrays.\n\t\tThe best way is to split it into [1,2,3] and [4,5], where the largest sum among the two subarrays is only 9.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 412, - "question": "class Solution:\n def fizzBuzz(self, n: int) -> List[str]:\n\t\t\"\"\"\n\t\tGiven an integer n, return a string array answer (1-indexed) where:\n\t\t\tanswer[i] == \"FizzBuzz\" if i is divisible by 3 and 5.\n\t\t\tanswer[i] == \"Fizz\" if i is divisible by 3.\n\t\t\tanswer[i] == \"Buzz\" if i is divisible by 5.\n\t\t\tanswer[i] == i (as a string) if none of the above conditions are true.\n\t\tExample 1:\n\t\tInput: n = 3\n\t\tOutput: [\"1\",\"2\",\"Fizz\"]\n\t\tExample 2:\n\t\tInput: n = 5\n\t\tOutput: [\"1\",\"2\",\"Fizz\",\"4\",\"Buzz\"]\n\t\tExample 3:\n\t\tInput: n = 15\n\t\tOutput: [\"1\",\"2\",\"Fizz\",\"4\",\"Buzz\",\"Fizz\",\"7\",\"8\",\"Fizz\",\"Buzz\",\"11\",\"Fizz\",\"13\",\"14\",\"FizzBuzz\"]\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 413, - "question": "class Solution:\n def numberOfArithmeticSlices(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tAn integer array is called arithmetic if it consists of at least three elements and if the difference between any two consecutive elements is the same.\n\t\t\tFor example, [1,3,5,7,9], [7,7,7,7], and [3,-1,-5,-9] are arithmetic sequences.\n\t\tGiven an integer array nums, return the number of arithmetic subarrays of nums.\n\t\tA subarray is a contiguous subsequence of the array.\n\t\tExample 1:\n\t\tInput: nums = [1,2,3,4]\n\t\tOutput: 3\n\t\tExplanation: We have 3 arithmetic slices in nums: [1, 2, 3], [2, 3, 4] and [1,2,3,4] itself.\n\t\tExample 2:\n\t\tInput: nums = [1]\n\t\tOutput: 0\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 414, - "question": "class Solution:\n def thirdMax(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tGiven an integer array nums, return the third distinct maximum number in this array. If the third maximum does not exist, return the maximum number.\n\t\tExample 1:\n\t\tInput: nums = [3,2,1]\n\t\tOutput: 1\n\t\tExplanation:\n\t\tThe first distinct maximum is 3.\n\t\tThe second distinct maximum is 2.\n\t\tThe third distinct maximum is 1.\n\t\tExample 2:\n\t\tInput: nums = [1,2]\n\t\tOutput: 2\n\t\tExplanation:\n\t\tThe first distinct maximum is 2.\n\t\tThe second distinct maximum is 1.\n\t\tThe third distinct maximum does not exist, so the maximum (2) is returned instead.\n\t\tExample 3:\n\t\tInput: nums = [2,2,3,1]\n\t\tOutput: 1\n\t\tExplanation:\n\t\tThe first distinct maximum is 3.\n\t\tThe second distinct maximum is 2 (both 2's are counted together since they have the same value).\n\t\tThe third distinct maximum is 1.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 415, - "question": "class Solution:\n def addStrings(self, num1: str, num2: str) -> str:\n\t\t\"\"\"\n\t\tGiven two non-negative integers, num1 and num2 represented as string, return the sum of num1 and num2 as a string.\n\t\tYou must solve the problem without using any built-in library for handling large integers (such as BigInteger). You must also not convert the inputs to integers directly.\n\t\tExample 1:\n\t\tInput: num1 = \"11\", num2 = \"123\"\n\t\tOutput: \"134\"\n\t\tExample 2:\n\t\tInput: num1 = \"456\", num2 = \"77\"\n\t\tOutput: \"533\"\n\t\tExample 3:\n\t\tInput: num1 = \"0\", num2 = \"0\"\n\t\tOutput: \"0\"\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 416, - "question": "class Solution:\n def canPartition(self, nums: List[int]) -> bool:\n\t\t\"\"\"\n\t\tGiven an integer array nums, return true if you can partition the array into two subsets such that the sum of the elements in both subsets is equal or false otherwise.\n\t\tExample 1:\n\t\tInput: nums = [1,5,11,5]\n\t\tOutput: true\n\t\tExplanation: The array can be partitioned as [1, 5, 5] and [11].\n\t\tExample 2:\n\t\tInput: nums = [1,2,3,5]\n\t\tOutput: false\n\t\tExplanation: The array cannot be partitioned into equal sum subsets.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 417, - "question": "class Solution:\n def pacificAtlantic(self, heights: List[List[int]]) -> List[List[int]]:\n\t\t\"\"\"\n\t\tThere is an m x n rectangular island that borders both the Pacific Ocean and Atlantic Ocean. The Pacific Ocean touches the island's left and top edges, and the Atlantic Ocean touches the island's right and bottom edges.\n\t\tThe island is partitioned into a grid of square cells. You are given an m x n integer matrix heights where heights[r][c] represents the height above sea level of the cell at coordinate (r, c).\n\t\tThe island receives a lot of rain, and the rain water can flow to neighboring cells directly north, south, east, and west if the neighboring cell's height is less than or equal to the current cell's height. Water can flow from any cell adjacent to an ocean into the ocean.\n\t\tReturn a 2D list of grid coordinates result where result[i] = [ri, ci] denotes that rain water can flow from cell (ri, ci) to both the Pacific and Atlantic oceans.\n\t\tExample 1:\n\t\tInput: heights = [[1,2,2,3,5],[3,2,3,4,4],[2,4,5,3,1],[6,7,1,4,5],[5,1,1,2,4]]\n\t\tOutput: [[0,4],[1,3],[1,4],[2,2],[3,0],[3,1],[4,0]]\n\t\tExplanation: The following cells can flow to the Pacific and Atlantic oceans, as shown below:\n\t\t[0,4]: [0,4] -> Pacific Ocean \n\t\t [0,4] -> Atlantic Ocean\n\t\t[1,3]: [1,3] -> [0,3] -> Pacific Ocean \n\t\t [1,3] -> [1,4] -> Atlantic Ocean\n\t\t[1,4]: [1,4] -> [1,3] -> [0,3] -> Pacific Ocean \n\t\t [1,4] -> Atlantic Ocean\n\t\t[2,2]: [2,2] -> [1,2] -> [0,2] -> Pacific Ocean \n\t\t [2,2] -> [2,3] -> [2,4] -> Atlantic Ocean\n\t\t[3,0]: [3,0] -> Pacific Ocean \n\t\t [3,0] -> [4,0] -> Atlantic Ocean\n\t\t[3,1]: [3,1] -> [3,0] -> Pacific Ocean \n\t\t [3,1] -> [4,1] -> Atlantic Ocean\n\t\t[4,0]: [4,0] -> Pacific Ocean \n\t\t [4,0] -> Atlantic Ocean\n\t\tNote that there are other possible paths for these cells to flow to the Pacific and Atlantic oceans.\n\t\tExample 2:\n\t\tInput: heights = [[1]]\n\t\tOutput: [[0,0]]\n\t\tExplanation: The water can flow from the only cell to the Pacific and Atlantic oceans.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 419, - "question": "class Solution:\n def countBattleships(self, board: List[List[str]]) -> int:\n\t\t\"\"\"\n\t\tGiven an m x n matrix board where each cell is a battleship 'X' or empty '.', return the number of the battleships on board.\n\t\tBattleships can only be placed horizontally or vertically on board. In other words, they can only be made of the shape 1 x k (1 row, k columns) or k x 1 (k rows, 1 column), where k can be of any size. At least one horizontal or vertical cell separates between two battleships (i.e., there are no adjacent battleships).\n\t\tExample 1:\n\t\tInput: board = [[\"X\",\".\",\".\",\"X\"],[\".\",\".\",\".\",\"X\"],[\".\",\".\",\".\",\"X\"]]\n\t\tOutput: 2\n\t\tExample 2:\n\t\tInput: board = [[\".\"]]\n\t\tOutput: 0\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 420, - "question": "class Solution:\n def strongPasswordChecker(self, password: str) -> int:\n\t\t\"\"\"\n\t\tA password is considered strong if the below conditions are all met:\n\t\t\tIt has at least 6 characters and at most 20 characters.\n\t\t\tIt contains at least one lowercase letter, at least one uppercase letter, and at least one digit.\n\t\t\tIt does not contain three repeating characters in a row (i.e., \"Baaabb0\" is weak, but \"Baaba0\" is strong).\n\t\tGiven a string password, return the minimum number of steps required to make password strong. if password is already strong, return 0.\n\t\tIn one step, you can:\n\t\t\tInsert one character to password,\n\t\t\tDelete one character from password, or\n\t\t\tReplace one character of password with another character.\n\t\tExample 1:\n\t\tInput: password = \"a\"\n\t\tOutput: 5\n\t\tExample 2:\n\t\tInput: password = \"aA1\"\n\t\tOutput: 3\n\t\tExample 3:\n\t\tInput: password = \"1337C0d3\"\n\t\tOutput: 0\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 421, - "question": "class Solution:\n def findMaximumXOR(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tGiven an integer array nums, return the maximum result of nums[i] XOR nums[j], where 0 <= i <= j < n.\n\t\tExample 1:\n\t\tInput: nums = [3,10,5,25,2,8]\n\t\tOutput: 28\n\t\tExplanation: The maximum result is 5 XOR 25 = 28.\n\t\tExample 2:\n\t\tInput: nums = [14,70,53,83,49,91,36,80,92,51,66,70]\n\t\tOutput: 127\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 423, - "question": "class Solution:\n def originalDigits(self, s: str) -> str:\n\t\t\"\"\"\n\t\tGiven a string s containing an out-of-order English representation of digits 0-9, return the digits in ascending order.\n\t\tExample 1:\n\t\tInput: s = \"owoztneoer\"\n\t\tOutput: \"012\"\n\t\tExample 2:\n\t\tInput: s = \"fviefuro\"\n\t\tOutput: \"45\"\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 424, - "question": "class Solution:\n def characterReplacement(self, s: str, k: int) -> int:\n\t\t\"\"\"\n\t\tYou are given a string s and an integer k. You can choose any character of the string and change it to any other uppercase English character. You can perform this operation at most k times.\n\t\tReturn the length of the longest substring containing the same letter you can get after performing the above operations.\n\t\tExample 1:\n\t\tInput: s = \"ABAB\", k = 2\n\t\tOutput: 4\n\t\tExplanation: Replace the two 'A's with two 'B's or vice versa.\n\t\tExample 2:\n\t\tInput: s = \"AABABBA\", k = 1\n\t\tOutput: 4\n\t\tExplanation: Replace the one 'A' in the middle with 'B' and form \"AABBBBA\".\n\t\tThe substring \"BBBB\" has the longest repeating letters, which is 4.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 432, - "question": "class AllOne:\n def __init__(self):\n def inc(self, key: str) -> None:\n def dec(self, key: str) -> None:\n def getMaxKey(self) -> str:\n def getMinKey(self) -> str:\n\t\t\"\"\"\n\t\tDesign a data structure to store the strings' count with the ability to return the strings with minimum and maximum counts.\n\t\tImplement the AllOne class:\n\t\t\tAllOne() Initializes the object of the data structure.\n\t\t\tinc(String key) Increments the count of the string key by 1. If key does not exist in the data structure, insert it with count 1.\n\t\t\tdec(String key) Decrements the count of the string key by 1. If the count of key is 0 after the decrement, remove it from the data structure. It is guaranteed that key exists in the data structure before the decrement.\n\t\t\tgetMaxKey() Returns one of the keys with the maximal count. If no element exists, return an empty string \"\".\n\t\t\tgetMinKey() Returns one of the keys with the minimum count. If no element exists, return an empty string \"\".\n\t\tNote that each function must run in O(1) average time complexity.\n\t\tExample 1:\n\t\tInput\n\t\t[\"AllOne\", \"inc\", \"inc\", \"getMaxKey\", \"getMinKey\", \"inc\", \"getMaxKey\", \"getMinKey\"]\n\t\t[[], [\"hello\"], [\"hello\"], [], [], [\"leet\"], [], []]\n\t\tOutput\n\t\t[null, null, null, \"hello\", \"hello\", null, \"hello\", \"leet\"]\n\t\tExplanation\n\t\tAllOne allOne = new AllOne();\n\t\tallOne.inc(\"hello\");\n\t\tallOne.inc(\"hello\");\n\t\tallOne.getMaxKey(); // return \"hello\"\n\t\tallOne.getMinKey(); // return \"hello\"\n\t\tallOne.inc(\"leet\");\n\t\tallOne.getMaxKey(); // return \"hello\"\n\t\tallOne.getMinKey(); // return \"leet\"\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 433, - "question": "class Solution:\n def minMutation(self, startGene: str, endGene: str, bank: List[str]) -> int:\n\t\t\"\"\"\n\t\tA gene string can be represented by an 8-character long string, with choices from 'A', 'C', 'G', and 'T'.\n\t\tSuppose we need to investigate a mutation from a gene string startGene to a gene string endGene where one mutation is defined as one single character changed in the gene string.\n\t\t\tFor example, \"AACCGGTT\" --> \"AACCGGTA\" is one mutation.\n\t\tThere is also a gene bank bank that records all the valid gene mutations. A gene must be in bank to make it a valid gene string.\n\t\tGiven the two gene strings startGene and endGene and the gene bank bank, return the minimum number of mutations needed to mutate from startGene to endGene. If there is no such a mutation, return -1.\n\t\tNote that the starting point is assumed to be valid, so it might not be included in the bank.\n\t\tExample 1:\n\t\tInput: startGene = \"AACCGGTT\", endGene = \"AACCGGTA\", bank = [\"AACCGGTA\"]\n\t\tOutput: 1\n\t\tExample 2:\n\t\tInput: startGene = \"AACCGGTT\", endGene = \"AAACGGTA\", bank = [\"AACCGGTA\",\"AACCGCTA\",\"AAACGGTA\"]\n\t\tOutput: 2\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 434, - "question": "class Solution:\n def countSegments(self, s: str) -> int:\n\t\t\"\"\"\n\t\tGiven a string s, return the number of segments in the string.\n\t\tA segment is defined to be a contiguous sequence of non-space characters.\n\t\tExample 1:\n\t\tInput: s = \"Hello, my name is John\"\n\t\tOutput: 5\n\t\tExplanation: The five segments are [\"Hello,\", \"my\", \"name\", \"is\", \"John\"]\n\t\tExample 2:\n\t\tInput: s = \"Hello\"\n\t\tOutput: 1\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 435, - "question": "class Solution:\n def eraseOverlapIntervals(self, intervals: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tGiven an array of intervals intervals where intervals[i] = [starti, endi], return the minimum number of intervals you need to remove to make the rest of the intervals non-overlapping.\n\t\tExample 1:\n\t\tInput: intervals = [[1,2],[2,3],[3,4],[1,3]]\n\t\tOutput: 1\n\t\tExplanation: [1,3] can be removed and the rest of the intervals are non-overlapping.\n\t\tExample 2:\n\t\tInput: intervals = [[1,2],[1,2],[1,2]]\n\t\tOutput: 2\n\t\tExplanation: You need to remove two [1,2] to make the rest of the intervals non-overlapping.\n\t\tExample 3:\n\t\tInput: intervals = [[1,2],[2,3]]\n\t\tOutput: 0\n\t\tExplanation: You don't need to remove any of the intervals since they're already non-overlapping.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 436, - "question": "class Solution:\n def findRightInterval(self, intervals: List[List[int]]) -> List[int]:\n\t\t\"\"\"\n\t\tYou are given an array of intervals, where intervals[i] = [starti, endi] and each starti is unique.\n\t\tThe right interval for an interval i is an interval j such that startj >= endi and startj is minimized. Note that i may equal j.\n\t\tReturn an array of right interval indices for each interval i. If no right interval exists for interval i, then put -1 at index i.\n\t\tExample 1:\n\t\tInput: intervals = [[1,2]]\n\t\tOutput: [-1]\n\t\tExplanation: There is only one interval in the collection, so it outputs -1.\n\t\tExample 2:\n\t\tInput: intervals = [[3,4],[2,3],[1,2]]\n\t\tOutput: [-1,0,1]\n\t\tExplanation: There is no right interval for [3,4].\n\t\tThe right interval for [2,3] is [3,4] since start0 = 3 is the smallest start that is >= end1 = 3.\n\t\tThe right interval for [1,2] is [2,3] since start1 = 2 is the smallest start that is >= end2 = 2.\n\t\tExample 3:\n\t\tInput: intervals = [[1,4],[2,3],[3,4]]\n\t\tOutput: [-1,2,-1]\n\t\tExplanation: There is no right interval for [1,4] and [3,4].\n\t\tThe right interval for [2,3] is [3,4] since start2 = 3 is the smallest start that is >= end1 = 3.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 437, - "question": "class Solution:\n def pathSum(self, root: Optional[TreeNode], targetSum: int) -> int:\n\t\t\"\"\"\n\t\tGiven the root of a binary tree and an integer targetSum, return the number of paths where the sum of the values along the path equals targetSum.\n\t\tThe path does not need to start or end at the root or a leaf, but it must go downwards (i.e., traveling only from parent nodes to child nodes).\n\t\tExample 1:\n\t\tInput: root = [10,5,-3,3,2,null,11,3,-2,null,1], targetSum = 8\n\t\tOutput: 3\n\t\tExplanation: The paths that sum to 8 are shown.\n\t\tExample 2:\n\t\tInput: root = [5,4,8,11,null,13,4,7,2,null,null,5,1], targetSum = 22\n\t\tOutput: 3\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 438, - "question": "class Solution:\n def findAnagrams(self, s: str, p: str) -> List[int]:\n\t\t\"\"\"\n\t\tGiven two strings s and p, return an array of all the start indices of p's anagrams in s. You may return the answer in any order.\n\t\tAn Anagram is a word or phrase formed by rearranging the letters of a different word or phrase, typically using all the original letters exactly once.\n\t\tExample 1:\n\t\tInput: s = \"cbaebabacd\", p = \"abc\"\n\t\tOutput: [0,6]\n\t\tExplanation:\n\t\tThe substring with start index = 0 is \"cba\", which is an anagram of \"abc\".\n\t\tThe substring with start index = 6 is \"bac\", which is an anagram of \"abc\".\n\t\tExample 2:\n\t\tInput: s = \"abab\", p = \"ab\"\n\t\tOutput: [0,1,2]\n\t\tExplanation:\n\t\tThe substring with start index = 0 is \"ab\", which is an anagram of \"ab\".\n\t\tThe substring with start index = 1 is \"ba\", which is an anagram of \"ab\".\n\t\tThe substring with start index = 2 is \"ab\", which is an anagram of \"ab\".\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 440, - "question": "class Solution:\n def findKthNumber(self, n: int, k: int) -> int:\n\t\t\"\"\"\n\t\tGiven two integers n and k, return the kth lexicographically smallest integer in the range [1, n].\n\t\tExample 1:\n\t\tInput: n = 13, k = 2\n\t\tOutput: 10\n\t\tExplanation: The lexicographical order is [1, 10, 11, 12, 13, 2, 3, 4, 5, 6, 7, 8, 9], so the second smallest number is 10.\n\t\tExample 2:\n\t\tInput: n = 1, k = 1\n\t\tOutput: 1\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 441, - "question": "class Solution:\n def arrangeCoins(self, n: int) -> int:\n\t\t\"\"\"\n\t\tYou have n coins and you want to build a staircase with these coins. The staircase consists of k rows where the ith row has exactly i coins. The last row of the staircase may be incomplete.\n\t\tGiven the integer n, return the number of complete rows of the staircase you will build.\n\t\tExample 1:\n\t\tInput: n = 5\n\t\tOutput: 2\n\t\tExplanation: Because the 3rd row is incomplete, we return 2.\n\t\tExample 2:\n\t\tInput: n = 8\n\t\tOutput: 3\n\t\tExplanation: Because the 4th row is incomplete, we return 3.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 442, - "question": "class Solution:\n def findDuplicates(self, nums: List[int]) -> List[int]:\n\t\t\"\"\"\n\t\tGiven an integer array nums of length n where all the integers of nums are in the range [1, n] and each integer appears once or twice, return an array of all the integers that appears twice.\n\t\tYou must write an algorithm that runs in O(n) time and uses only constant extra space.\n\t\tExample 1:\n\t\tInput: nums = [4,3,2,7,8,2,3,1]\n\t\tOutput: [2,3]\n\t\tExample 2:\n\t\tInput: nums = [1,1,2]\n\t\tOutput: [1]\n\t\tExample 3:\n\t\tInput: nums = [1]\n\t\tOutput: []\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 443, - "question": "class Solution:\n def compress(self, chars: List[str]) -> int:\n\t\t\"\"\"\n\t\tGiven an array of characters chars, compress it using the following algorithm:\n\t\tBegin with an empty string s. For each group of consecutive repeating characters in chars:\n\t\t\tIf the group's length is 1, append the character to s.\n\t\t\tOtherwise, append the character followed by the group's length.\n\t\tThe compressed string s should not be returned separately, but instead, be stored in the input character array chars. Note that group lengths that are 10 or longer will be split into multiple characters in chars.\n\t\tAfter you are done modifying the input array, return the new length of the array.\n\t\tYou must write an algorithm that uses only constant extra space.\n\t\tExample 1:\n\t\tInput: chars = [\"a\",\"a\",\"b\",\"b\",\"c\",\"c\",\"c\"]\n\t\tOutput: Return 6, and the first 6 characters of the input array should be: [\"a\",\"2\",\"b\",\"2\",\"c\",\"3\"]\n\t\tExplanation: The groups are \"aa\", \"bb\", and \"ccc\". This compresses to \"a2b2c3\".\n\t\tExample 2:\n\t\tInput: chars = [\"a\"]\n\t\tOutput: Return 1, and the first character of the input array should be: [\"a\"]\n\t\tExplanation: The only group is \"a\", which remains uncompressed since it's a single character.\n\t\tExample 3:\n\t\tInput: chars = [\"a\",\"b\",\"b\",\"b\",\"b\",\"b\",\"b\",\"b\",\"b\",\"b\",\"b\",\"b\",\"b\"]\n\t\tOutput: Return 4, and the first 4 characters of the input array should be: [\"a\",\"b\",\"1\",\"2\"].\n\t\tExplanation: The groups are \"a\" and \"bbbbbbbbbbbb\". This compresses to \"ab12\".\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 445, - "question": "class Solution:\n def addTwoNumbers(self, l1: Optional[ListNode], l2: Optional[ListNode]) -> Optional[ListNode]:\n\t\t\"\"\"\n\t\tYou are given two non-empty linked lists representing two non-negative integers. The most significant digit comes first and each of their nodes contains a single digit. Add the two numbers and return the sum as a linked list.\n\t\tYou may assume the two numbers do not contain any leading zero, except the number 0 itself.\n\t\tExample 1:\n\t\tInput: l1 = [7,2,4,3], l2 = [5,6,4]\n\t\tOutput: [7,8,0,7]\n\t\tExample 2:\n\t\tInput: l1 = [2,4,3], l2 = [5,6,4]\n\t\tOutput: [8,0,7]\n\t\tExample 3:\n\t\tInput: l1 = [0], l2 = [0]\n\t\tOutput: [0]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 446, - "question": "class Solution:\n def numberOfArithmeticSlices(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tGiven an integer array nums, return the number of all the arithmetic subsequences of nums.\n\t\tA sequence of numbers is called arithmetic if it consists of at least three elements and if the difference between any two consecutive elements is the same.\n\t\t\tFor example, [1, 3, 5, 7, 9], [7, 7, 7, 7], and [3, -1, -5, -9] are arithmetic sequences.\n\t\t\tFor example, [1, 1, 2, 5, 7] is not an arithmetic sequence.\n\t\tA subsequence of an array is a sequence that can be formed by removing some elements (possibly none) of the array.\n\t\t\tFor example, [2,5,10] is a subsequence of [1,2,1,2,4,1,5,10].\n\t\tThe test cases are generated so that the answer fits in 32-bit integer.\n\t\tExample 1:\n\t\tInput: nums = [2,4,6,8,10]\n\t\tOutput: 7\n\t\tExplanation: All arithmetic subsequence slices are:\n\t\t[2,4,6]\n\t\t[4,6,8]\n\t\t[6,8,10]\n\t\t[2,4,6,8]\n\t\t[4,6,8,10]\n\t\t[2,4,6,8,10]\n\t\t[2,6,10]\n\t\tExample 2:\n\t\tInput: nums = [7,7,7,7,7]\n\t\tOutput: 16\n\t\tExplanation: Any subsequence of this array is arithmetic.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 447, - "question": "class Solution:\n def numberOfBoomerangs(self, points: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tYou are given n points in the plane that are all distinct, where points[i] = [xi, yi]. A boomerang is a tuple of points (i, j, k) such that the distance between i and j equals the distance between i and k (the order of the tuple matters).\n\t\tReturn the number of boomerangs.\n\t\tExample 1:\n\t\tInput: points = [[0,0],[1,0],[2,0]]\n\t\tOutput: 2\n\t\tExplanation: The two boomerangs are [[1,0],[0,0],[2,0]] and [[1,0],[2,0],[0,0]].\n\t\tExample 2:\n\t\tInput: points = [[1,1],[2,2],[3,3]]\n\t\tOutput: 2\n\t\tExample 3:\n\t\tInput: points = [[1,1]]\n\t\tOutput: 0\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 448, - "question": "class Solution:\n def findDisappearedNumbers(self, nums: List[int]) -> List[int]:\n\t\t\"\"\"\n\t\tGiven an array nums of n integers where nums[i] is in the range [1, n], return an array of all the integers in the range [1, n] that do not appear in nums.\n\t\tExample 1:\n\t\tInput: nums = [4,3,2,7,8,2,3,1]\n\t\tOutput: [5,6]\n\t\tExample 2:\n\t\tInput: nums = [1,1]\n\t\tOutput: [2]\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 449, - "question": "class Codec:\n def serialize(self, root: Optional[TreeNode]) -> str:\n\t\t\"\"\"Encodes a tree to a single string.\n\t\tSerialization is converting a data structure or object into a sequence of bits so that it can be stored in a file or memory buffer, or transmitted across a network connection link to be reconstructed later in the same or another computer environment.\n\t\tDesign an algorithm to serialize and deserialize a binary search tree. There is no restriction on how your serialization/deserialization algorithm should work. You need to ensure that a binary search tree can be serialized to a string, and this string can be deserialized to the original tree structure.\n\t\tThe encoded string should be as compact as possible.\n\t\tExample 1:\n\t\tInput: root = [2,1,3]\n\t\tOutput: [2,1,3]\n\t\tExample 2:\n\t\tInput: root = []\n\t\tOutput: []\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 450, - "question": "class Solution:\n def deleteNode(self, root: Optional[TreeNode], key: int) -> Optional[TreeNode]:\n\t\t\"\"\"\n\t\tGiven a root node reference of a BST and a key, delete the node with the given key in the BST. Return the root node reference (possibly updated) of the BST.\n\t\tBasically, the deletion can be divided into two stages:\n\t\t\tSearch for a node to remove.\n\t\t\tIf the node is found, delete the node.\n\t\tExample 1:\n\t\tInput: root = [5,3,6,2,4,null,7], key = 3\n\t\tOutput: [5,4,6,2,null,null,7]\n\t\tExplanation: Given key to delete is 3. So we find the node with value 3 and delete it.\n\t\tOne valid answer is [5,4,6,2,null,null,7], shown in the above BST.\n\t\tPlease notice that another valid answer is [5,2,6,null,4,null,7] and it's also accepted.\n\t\tExample 2:\n\t\tInput: root = [5,3,6,2,4,null,7], key = 0\n\t\tOutput: [5,3,6,2,4,null,7]\n\t\tExplanation: The tree does not contain a node with value = 0.\n\t\tExample 3:\n\t\tInput: root = [], key = 0\n\t\tOutput: []\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 451, - "question": "class Solution:\n def frequencySort(self, s: str) -> str:\n\t\t\"\"\"\n\t\tGiven a string s, sort it in decreasing order based on the frequency of the characters. The frequency of a character is the number of times it appears in the string.\n\t\tReturn the sorted string. If there are multiple answers, return any of them.\n\t\tExample 1:\n\t\tInput: s = \"tree\"\n\t\tOutput: \"eert\"\n\t\tExplanation: 'e' appears twice while 'r' and 't' both appear once.\n\t\tSo 'e' must appear before both 'r' and 't'. Therefore \"eetr\" is also a valid answer.\n\t\tExample 2:\n\t\tInput: s = \"cccaaa\"\n\t\tOutput: \"aaaccc\"\n\t\tExplanation: Both 'c' and 'a' appear three times, so both \"cccaaa\" and \"aaaccc\" are valid answers.\n\t\tNote that \"cacaca\" is incorrect, as the same characters must be together.\n\t\tExample 3:\n\t\tInput: s = \"Aabb\"\n\t\tOutput: \"bbAa\"\n\t\tExplanation: \"bbaA\" is also a valid answer, but \"Aabb\" is incorrect.\n\t\tNote that 'A' and 'a' are treated as two different characters.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 452, - "question": "class Solution:\n def findMinArrowShots(self, points: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tThere are some spherical balloons taped onto a flat wall that represents the XY-plane. The balloons are represented as a 2D integer array points where points[i] = [xstart, xend] denotes a balloon whose horizontal diameter stretches between xstart and xend. You do not know the exact y-coordinates of the balloons.\n\t\tArrows can be shot up directly vertically (in the positive y-direction) from different points along the x-axis. A balloon with xstart and xend is burst by an arrow shot at x if xstart <= x <= xend. There is no limit to the number of arrows that can be shot. A shot arrow keeps traveling up infinitely, bursting any balloons in its path.\n\t\tGiven the array points, return the minimum number of arrows that must be shot to burst all balloons.\n\t\tExample 1:\n\t\tInput: points = [[10,16],[2,8],[1,6],[7,12]]\n\t\tOutput: 2\n\t\tExplanation: The balloons can be burst by 2 arrows:\n\t\t- Shoot an arrow at x = 6, bursting the balloons [2,8] and [1,6].\n\t\t- Shoot an arrow at x = 11, bursting the balloons [10,16] and [7,12].\n\t\tExample 2:\n\t\tInput: points = [[1,2],[3,4],[5,6],[7,8]]\n\t\tOutput: 4\n\t\tExplanation: One arrow needs to be shot for each balloon for a total of 4 arrows.\n\t\tExample 3:\n\t\tInput: points = [[1,2],[2,3],[3,4],[4,5]]\n\t\tOutput: 2\n\t\tExplanation: The balloons can be burst by 2 arrows:\n\t\t- Shoot an arrow at x = 2, bursting the balloons [1,2] and [2,3].\n\t\t- Shoot an arrow at x = 4, bursting the balloons [3,4] and [4,5].\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 453, - "question": "class Solution:\n def minMoves(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tGiven an integer array nums of size n, return the minimum number of moves required to make all array elements equal.\n\t\tIn one move, you can increment n - 1 elements of the array by 1.\n\t\tExample 1:\n\t\tInput: nums = [1,2,3]\n\t\tOutput: 3\n\t\tExplanation: Only three moves are needed (remember each move increments two elements):\n\t\t[1,2,3] => [2,3,3] => [3,4,3] => [4,4,4]\n\t\tExample 2:\n\t\tInput: nums = [1,1,1]\n\t\tOutput: 0\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 454, - "question": "class Solution:\n def fourSumCount(self, nums1: List[int], nums2: List[int], nums3: List[int], nums4: List[int]) -> int:\n\t\t\"\"\"\n\t\tGiven four integer arrays nums1, nums2, nums3, and nums4 all of length n, return the number of tuples (i, j, k, l) such that:\n\t\t\t0 <= i, j, k, l < n\n\t\t\tnums1[i] + nums2[j] + nums3[k] + nums4[l] == 0\n\t\tExample 1:\n\t\tInput: nums1 = [1,2], nums2 = [-2,-1], nums3 = [-1,2], nums4 = [0,2]\n\t\tOutput: 2\n\t\tExplanation:\n\t\tThe two tuples are:\n\t\t1. (0, 0, 0, 1) -> nums1[0] + nums2[0] + nums3[0] + nums4[1] = 1 + (-2) + (-1) + 2 = 0\n\t\t2. (1, 1, 0, 0) -> nums1[1] + nums2[1] + nums3[0] + nums4[0] = 2 + (-1) + (-1) + 0 = 0\n\t\tExample 2:\n\t\tInput: nums1 = [0], nums2 = [0], nums3 = [0], nums4 = [0]\n\t\tOutput: 1\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 455, - "question": "class Solution:\n def findContentChildren(self, g: List[int], s: List[int]) -> int:\n\t\t\"\"\"\n\t\tAssume you are an awesome parent and want to give your children some cookies. But, you should give each child at most one cookie.\n\t\tEach child i has a greed factor g[i], which is the minimum size of a cookie that the child will be content with; and each cookie j has a size s[j]. If s[j] >= g[i], we can assign the cookie j to the child i, and the child i will be content. Your goal is to maximize the number of your content children and output the maximum number.\n\t\tExample 1:\n\t\tInput: g = [1,2,3], s = [1,1]\n\t\tOutput: 1\n\t\tExplanation: You have 3 children and 2 cookies. The greed factors of 3 children are 1, 2, 3. \n\t\tAnd even though you have 2 cookies, since their size is both 1, you could only make the child whose greed factor is 1 content.\n\t\tYou need to output 1.\n\t\tExample 2:\n\t\tInput: g = [1,2], s = [1,2,3]\n\t\tOutput: 2\n\t\tExplanation: You have 2 children and 3 cookies. The greed factors of 2 children are 1, 2. \n\t\tYou have 3 cookies and their sizes are big enough to gratify all of the children, \n\t\tYou need to output 2.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 456, - "question": "class Solution:\n def find132pattern(self, nums: List[int]) -> bool:\n\t\t\"\"\"\n\t\tGiven an array of n integers nums, a 132 pattern is a subsequence of three integers nums[i], nums[j] and nums[k] such that i < j < k and nums[i] < nums[k] < nums[j].\n\t\tReturn true if there is a 132 pattern in nums, otherwise, return false.\n\t\tExample 1:\n\t\tInput: nums = [1,2,3,4]\n\t\tOutput: false\n\t\tExplanation: There is no 132 pattern in the sequence.\n\t\tExample 2:\n\t\tInput: nums = [3,1,4,2]\n\t\tOutput: true\n\t\tExplanation: There is a 132 pattern in the sequence: [1, 4, 2].\n\t\tExample 3:\n\t\tInput: nums = [-1,3,2,0]\n\t\tOutput: true\n\t\tExplanation: There are three 132 patterns in the sequence: [-1, 3, 2], [-1, 3, 0] and [-1, 2, 0].\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 457, - "question": "class Solution:\n def circularArrayLoop(self, nums: List[int]) -> bool:\n\t\t\"\"\"\n\t\tYou are playing a game involving a circular array of non-zero integers nums. Each nums[i] denotes the number of indices forward/backward you must move if you are located at index i:\n\t\t\tIf nums[i] is positive, move nums[i] steps forward, and\n\t\t\tIf nums[i] is negative, move nums[i] steps backward.\n\t\tSince the array is circular, you may assume that moving forward from the last element puts you on the first element, and moving backwards from the first element puts you on the last element.\n\t\tA cycle in the array consists of a sequence of indices seq of length k where:\n\t\t\tFollowing the movement rules above results in the repeating index sequence seq[0] -> seq[1] -> ... -> seq[k - 1] -> seq[0] -> ...\n\t\t\tEvery nums[seq[j]] is either all positive or all negative.\n\t\t\tk > 1\n\t\tReturn true if there is a cycle in nums, or false otherwise.\n\t\tExample 1:\n\t\tInput: nums = [2,-1,1,2,2]\n\t\tOutput: true\n\t\tExplanation: The graph shows how the indices are connected. White nodes are jumping forward, while red is jumping backward.\n\t\tWe can see the cycle 0 --> 2 --> 3 --> 0 --> ..., and all of its nodes are white (jumping in the same direction).\n\t\tExample 2:\n\t\tInput: nums = [-1,-2,-3,-4,-5,6]\n\t\tOutput: false\n\t\tExplanation: The graph shows how the indices are connected. White nodes are jumping forward, while red is jumping backward.\n\t\tThe only cycle is of size 1, so we return false.\n\t\tExample 3:\n\t\tInput: nums = [1,-1,5,1,4]\n\t\tOutput: true\n\t\tExplanation: The graph shows how the indices are connected. White nodes are jumping forward, while red is jumping backward.\n\t\tWe can see the cycle 0 --> 1 --> 0 --> ..., and while it is of size > 1, it has a node jumping forward and a node jumping backward, so it is not a cycle.\n\t\tWe can see the cycle 3 --> 4 --> 3 --> ..., and all of its nodes are white (jumping in the same direction).\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 458, - "question": "class Solution:\n def poorPigs(self, buckets: int, minutesToDie: int, minutesToTest: int) -> int:\n\t\t\"\"\"\n\t\tThere are buckets buckets of liquid, where exactly one of the buckets is poisonous. To figure out which one is poisonous, you feed some number of (poor) pigs the liquid to see whether they will die or not. Unfortunately, you only have minutesToTest minutes to determine which bucket is poisonous.\n\t\tYou can feed the pigs according to these steps:\n\t\t\tChoose some live pigs to feed.\n\t\t\tFor each pig, choose which buckets to feed it. The pig will consume all the chosen buckets simultaneously and will take no time. Each pig can feed from any number of buckets, and each bucket can be fed from by any number of pigs.\n\t\t\tWait for minutesToDie minutes. You may not feed any other pigs during this time.\n\t\t\tAfter minutesToDie minutes have passed, any pigs that have been fed the poisonous bucket will die, and all others will survive.\n\t\t\tRepeat this process until you run out of time.\n\t\tGiven buckets, minutesToDie, and minutesToTest, return the minimum number of pigs needed to figure out which bucket is poisonous within the allotted time.\n\t\tExample 1:\n\t\tInput: buckets = 4, minutesToDie = 15, minutesToTest = 15\n\t\tOutput: 2\n\t\tExplanation: We can determine the poisonous bucket as follows:\n\t\tAt time 0, feed the first pig buckets 1 and 2, and feed the second pig buckets 2 and 3.\n\t\tAt time 15, there are 4 possible outcomes:\n\t\t- If only the first pig dies, then bucket 1 must be poisonous.\n\t\t- If only the second pig dies, then bucket 3 must be poisonous.\n\t\t- If both pigs die, then bucket 2 must be poisonous.\n\t\t- If neither pig dies, then bucket 4 must be poisonous.\n\t\tExample 2:\n\t\tInput: buckets = 4, minutesToDie = 15, minutesToTest = 30\n\t\tOutput: 2\n\t\tExplanation: We can determine the poisonous bucket as follows:\n\t\tAt time 0, feed the first pig bucket 1, and feed the second pig bucket 2.\n\t\tAt time 15, there are 2 possible outcomes:\n\t\t- If either pig dies, then the poisonous bucket is the one it was fed.\n\t\t- If neither pig dies, then feed the first pig bucket 3, and feed the second pig bucket 4.\n\t\tAt time 30, one of the two pigs must die, and the poisonous bucket is the one it was fed.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 459, - "question": "class Solution:\n def repeatedSubstringPattern(self, s: str) -> bool:\n\t\t\"\"\"\n\t\tGiven a string s, check if it can be constructed by taking a substring of it and appending multiple copies of the substring together.\n\t\tExample 1:\n\t\tInput: s = \"abab\"\n\t\tOutput: true\n\t\tExplanation: It is the substring \"ab\" twice.\n\t\tExample 2:\n\t\tInput: s = \"aba\"\n\t\tOutput: false\n\t\tExample 3:\n\t\tInput: s = \"abcabcabcabc\"\n\t\tOutput: true\n\t\tExplanation: It is the substring \"abc\" four times or the substring \"abcabc\" twice.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 460, - "question": "class LFUCache:\n def __init__(self, capacity: int):\n def get(self, key: int) -> int:\n def put(self, key: int, value: int) -> None:\n\t\t\"\"\"\n\t\tDesign and implement a data structure for a Least Frequently Used (LFU) cache.\n\t\tImplement the LFUCache class:\n\t\t\tLFUCache(int capacity) Initializes the object with the capacity of the data structure.\n\t\t\tint get(int key) Gets the value of the key if the key exists in the cache. Otherwise, returns -1.\n\t\t\tvoid put(int key, int value) Update the value of the key if present, or inserts the key if not already present. When the cache reaches its capacity, it should invalidate and remove the least frequently used key before inserting a new item. For this problem, when there is a tie (i.e., two or more keys with the same frequency), the least recently used key would be invalidated.\n\t\tTo determine the least frequently used key, a use counter is maintained for each key in the cache. The key with the smallest use counter is the least frequently used key.\n\t\tWhen a key is first inserted into the cache, its use counter is set to 1 (due to the put operation). The use counter for a key in the cache is incremented either a get or put operation is called on it.\n\t\tThe functions get and put must each run in O(1) average time complexity.\n\t\tExample 1:\n\t\tInput\n\t\t[\"LFUCache\", \"put\", \"put\", \"get\", \"put\", \"get\", \"get\", \"put\", \"get\", \"get\", \"get\"]\n\t\t[[2], [1, 1], [2, 2], [1], [3, 3], [2], [3], [4, 4], [1], [3], [4]]\n\t\tOutput\n\t\t[null, null, null, 1, null, -1, 3, null, -1, 3, 4]\n\t\tExplanation\n\t\t// cnt(x) = the use counter for key x\n\t\t// cache=[] will show the last used order for tiebreakers (leftmost element is most recent)\n\t\tLFUCache lfu = new LFUCache(2);\n\t\tlfu.put(1, 1); // cache=[1,_], cnt(1)=1\n\t\tlfu.put(2, 2); // cache=[2,1], cnt(2)=1, cnt(1)=1\n\t\tlfu.get(1); // return 1\n\t\t // cache=[1,2], cnt(2)=1, cnt(1)=2\n\t\tlfu.put(3, 3); // 2 is the LFU key because cnt(2)=1 is the smallest, invalidate 2.\n\t\t // cache=[3,1], cnt(3)=1, cnt(1)=2\n\t\tlfu.get(2); // return -1 (not found)\n\t\tlfu.get(3); // return 3\n\t\t // cache=[3,1], cnt(3)=2, cnt(1)=2\n\t\tlfu.put(4, 4); // Both 1 and 3 have the same cnt, but 1 is LRU, invalidate 1.\n\t\t // cache=[4,3], cnt(4)=1, cnt(3)=2\n\t\tlfu.get(1); // return -1 (not found)\n\t\tlfu.get(3); // return 3\n\t\t // cache=[3,4], cnt(4)=1, cnt(3)=3\n\t\tlfu.get(4); // return 4\n\t\t // cache=[4,3], cnt(4)=2, cnt(3)=3\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 461, - "question": "class Solution:\n def hammingDistance(self, x: int, y: int) -> int:\n\t\t\"\"\"\n\t\tThe Hamming distance between two integers is the number of positions at which the corresponding bits are different.\n\t\tGiven two integers x and y, return the Hamming distance between them.\n\t\tExample 1:\n\t\tInput: x = 1, y = 4\n\t\tOutput: 2\n\t\tExplanation:\n\t\t1 (0 0 0 1)\n\t\t4 (0 1 0 0)\n\t\t \u2191 \u2191\n\t\tThe above arrows point to positions where the corresponding bits are different.\n\t\tExample 2:\n\t\tInput: x = 3, y = 1\n\t\tOutput: 1\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 462, - "question": "class Solution:\n def minMoves2(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tGiven an integer array nums of size n, return the minimum number of moves required to make all array elements equal.\n\t\tIn one move, you can increment or decrement an element of the array by 1.\n\t\tTest cases are designed so that the answer will fit in a 32-bit integer.\n\t\tExample 1:\n\t\tInput: nums = [1,2,3]\n\t\tOutput: 2\n\t\tExplanation:\n\t\tOnly two moves are needed (remember each move increments or decrements one element):\n\t\t[1,2,3] => [2,2,3] => [2,2,2]\n\t\tExample 2:\n\t\tInput: nums = [1,10,2,9]\n\t\tOutput: 16\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 463, - "question": "class Solution:\n def islandPerimeter(self, grid: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tYou are given row x col grid representing a map where grid[i][j] = 1 represents land and grid[i][j] = 0 represents water.\n\t\tGrid cells are connected horizontally/vertically (not diagonally). The grid is completely surrounded by water, and there is exactly one island (i.e., one or more connected land cells).\n\t\tThe island doesn't have \"lakes\", meaning the water inside isn't connected to the water around the island. One cell is a square with side length 1. The grid is rectangular, width and height don't exceed 100. Determine the perimeter of the island.\n\t\tExample 1:\n\t\tInput: grid = [[0,1,0,0],[1,1,1,0],[0,1,0,0],[1,1,0,0]]\n\t\tOutput: 16\n\t\tExplanation: The perimeter is the 16 yellow stripes in the image above.\n\t\tExample 2:\n\t\tInput: grid = [[1]]\n\t\tOutput: 4\n\t\tExample 3:\n\t\tInput: grid = [[1,0]]\n\t\tOutput: 4\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 464, - "question": "class Solution:\n def canIWin(self, maxChoosableInteger: int, desiredTotal: int) -> bool:\n\t\t\"\"\"\n\t\tIn the \"100 game\" two players take turns adding, to a running total, any integer from 1 to 10. The player who first causes the running total to reach or exceed 100 wins.\n\t\tWhat if we change the game so that players cannot re-use integers?\n\t\tFor example, two players might take turns drawing from a common pool of numbers from 1 to 15 without replacement until they reach a total >= 100.\n\t\tGiven two integers maxChoosableInteger and desiredTotal, return true if the first player to move can force a win, otherwise, return false. Assume both players play optimally.\n\t\tExample 1:\n\t\tInput: maxChoosableInteger = 10, desiredTotal = 11\n\t\tOutput: false\n\t\tExplanation:\n\t\tNo matter which integer the first player choose, the first player will lose.\n\t\tThe first player can choose an integer from 1 up to 10.\n\t\tIf the first player choose 1, the second player can only choose integers from 2 up to 10.\n\t\tThe second player will win by choosing 10 and get a total = 11, which is >= desiredTotal.\n\t\tSame with other integers chosen by the first player, the second player will always win.\n\t\tExample 2:\n\t\tInput: maxChoosableInteger = 10, desiredTotal = 0\n\t\tOutput: true\n\t\tExample 3:\n\t\tInput: maxChoosableInteger = 10, desiredTotal = 1\n\t\tOutput: true\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 466, - "question": "class Solution:\n def getMaxRepetitions(self, s1: str, n1: int, s2: str, n2: int) -> int:\n\t\t\"\"\"\n\t\tWe define str = [s, n] as the string str which consists of the string s concatenated n times.\n\t\t\tFor example, str == [\"abc\", 3] ==\"abcabcabc\".\n\t\tWe define that string s1 can be obtained from string s2 if we can remove some characters from s2 such that it becomes s1.\n\t\t\tFor example, s1 = \"abc\" can be obtained from s2 = \"abdbec\" based on our definition by removing the bolded underlined characters.\n\t\tYou are given two strings s1 and s2 and two integers n1 and n2. You have the two strings str1 = [s1, n1] and str2 = [s2, n2].\n\t\tReturn the maximum integer m such that str = [str2, m] can be obtained from str1.\n\t\tExample 1:\n\t\tInput: s1 = \"acb\", n1 = 4, s2 = \"ab\", n2 = 2\n\t\tOutput: 2\n\t\tExample 2:\n\t\tInput: s1 = \"acb\", n1 = 1, s2 = \"acb\", n2 = 1\n\t\tOutput: 1\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 467, - "question": "class Solution:\n def findSubstringInWraproundString(self, s: str) -> int:\n\t\t\"\"\"\n\t\tWe define the string base to be the infinite wraparound string of \"abcdefghijklmnopqrstuvwxyz\", so base will look like this:\n\t\t\t\"...zabcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyzabcd....\".\n\t\tGiven a string s, return the number of unique non-empty substrings of s are present in base.\n\t\tExample 1:\n\t\tInput: s = \"a\"\n\t\tOutput: 1\n\t\tExplanation: Only the substring \"a\" of s is in base.\n\t\tExample 2:\n\t\tInput: s = \"cac\"\n\t\tOutput: 2\n\t\tExplanation: There are two substrings (\"a\", \"c\") of s in base.\n\t\tExample 3:\n\t\tInput: s = \"zab\"\n\t\tOutput: 6\n\t\tExplanation: There are six substrings (\"z\", \"a\", \"b\", \"za\", \"ab\", and \"zab\") of s in base.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 468, - "question": "class Solution:\n def validIPAddress(self, queryIP: str) -> str:\n\t\t\"\"\"\n\t\tGiven a string queryIP, return \"IPv4\" if IP is a valid IPv4 address, \"IPv6\" if IP is a valid IPv6 address or \"Neither\" if IP is not a correct IP of any type.\n\t\tA valid IPv4 address is an IP in the form \"x1.x2.x3.x4\" where 0 <= xi <= 255 and xi cannot contain leading zeros. For example, \"192.168.1.1\" and \"192.168.1.0\" are valid IPv4 addresses while \"192.168.01.1\", \"192.168.1.00\", and \"192.168@1.1\" are invalid IPv4 addresses.\n\t\tA valid IPv6 address is an IP in the form \"x1:x2:x3:x4:x5:x6:x7:x8\" where:\n\t\t\t1 <= xi.length <= 4\n\t\t\txi is a hexadecimal string which may contain digits, lowercase English letter ('a' to 'f') and upper-case English letters ('A' to 'F').\n\t\t\tLeading zeros are allowed in xi.\n\t\tFor example, \"2001:0db8:85a3:0000:0000:8a2e:0370:7334\" and \"2001:db8:85a3:0:0:8A2E:0370:7334\" are valid IPv6 addresses, while \"2001:0db8:85a3::8A2E:037j:7334\" and \"02001:0db8:85a3:0000:0000:8a2e:0370:7334\" are invalid IPv6 addresses.\n\t\tExample 1:\n\t\tInput: queryIP = \"172.16.254.1\"\n\t\tOutput: \"IPv4\"\n\t\tExplanation: This is a valid IPv4 address, return \"IPv4\".\n\t\tExample 2:\n\t\tInput: queryIP = \"2001:0db8:85a3:0:0:8A2E:0370:7334\"\n\t\tOutput: \"IPv6\"\n\t\tExplanation: This is a valid IPv6 address, return \"IPv6\".\n\t\tExample 3:\n\t\tInput: queryIP = \"256.256.256.256\"\n\t\tOutput: \"Neither\"\n\t\tExplanation: This is neither a IPv4 address nor a IPv6 address.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 472, - "question": "class Solution:\n def findAllConcatenatedWordsInADict(self, words: List[str]) -> List[str]:\n\t\t\"\"\"\n\t\tGiven an array of strings words (without duplicates), return all the concatenated words in the given list of words.\n\t\tA concatenated word is defined as a string that is comprised entirely of at least two shorter words (not necesssarily distinct) in the given array.\n\t\tExample 1:\n\t\tInput: words = [\"cat\",\"cats\",\"catsdogcats\",\"dog\",\"dogcatsdog\",\"hippopotamuses\",\"rat\",\"ratcatdogcat\"]\n\t\tOutput: [\"catsdogcats\",\"dogcatsdog\",\"ratcatdogcat\"]\n\t\tExplanation: \"catsdogcats\" can be concatenated by \"cats\", \"dog\" and \"cats\"; \n\t\t\"dogcatsdog\" can be concatenated by \"dog\", \"cats\" and \"dog\"; \n\t\t\"ratcatdogcat\" can be concatenated by \"rat\", \"cat\", \"dog\" and \"cat\".\n\t\tExample 2:\n\t\tInput: words = [\"cat\",\"dog\",\"catdog\"]\n\t\tOutput: [\"catdog\"]\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 473, - "question": "class Solution:\n def makesquare(self, matchsticks: List[int]) -> bool:\n\t\t\"\"\"\n\t\tYou are given an integer array matchsticks where matchsticks[i] is the length of the ith matchstick. You want to use all the matchsticks to make one square. You should not break any stick, but you can link them up, and each matchstick must be used exactly one time.\n\t\tReturn true if you can make this square and false otherwise.\n\t\tExample 1:\n\t\tInput: matchsticks = [1,1,2,2,2]\n\t\tOutput: true\n\t\tExplanation: You can form a square with length 2, one side of the square came two sticks with length 1.\n\t\tExample 2:\n\t\tInput: matchsticks = [3,3,3,3,4]\n\t\tOutput: false\n\t\tExplanation: You cannot find a way to form a square with all the matchsticks.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 474, - "question": "class Solution:\n def findMaxForm(self, strs: List[str], m: int, n: int) -> int:\n\t\t\"\"\"\n\t\tYou are given an array of binary strings strs and two integers m and n.\n\t\tReturn the size of the largest subset of strs such that there are at most m 0's and n 1's in the subset.\n\t\tA set x is a subset of a set y if all elements of x are also elements of y.\n\t\tExample 1:\n\t\tInput: strs = [\"10\",\"0001\",\"111001\",\"1\",\"0\"], m = 5, n = 3\n\t\tOutput: 4\n\t\tExplanation: The largest subset with at most 5 0's and 3 1's is {\"10\", \"0001\", \"1\", \"0\"}, so the answer is 4.\n\t\tOther valid but smaller subsets include {\"0001\", \"1\"} and {\"10\", \"1\", \"0\"}.\n\t\t{\"111001\"} is an invalid subset because it contains 4 1's, greater than the maximum of 3.\n\t\tExample 2:\n\t\tInput: strs = [\"10\",\"0\",\"1\"], m = 1, n = 1\n\t\tOutput: 2\n\t\tExplanation: The largest subset is {\"0\", \"1\"}, so the answer is 2.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 475, - "question": "class Solution:\n def findRadius(self, houses: List[int], heaters: List[int]) -> int:\n\t\t\"\"\"\n\t\tWinter is coming! During the contest, your first job is to design a standard heater with a fixed warm radius to warm all the houses.\n\t\tEvery house can be warmed, as long as the house is within the heater's warm radius range. \n\t\tGiven the positions of houses and heaters on a horizontal line, return the minimum radius standard of heaters so that those heaters could cover all houses.\n\t\tNotice that all the heaters follow your radius standard, and the warm radius will the same.\n\t\tExample 1:\n\t\tInput: houses = [1,2,3], heaters = [2]\n\t\tOutput: 1\n\t\tExplanation: The only heater was placed in the position 2, and if we use the radius 1 standard, then all the houses can be warmed.\n\t\tExample 2:\n\t\tInput: houses = [1,2,3,4], heaters = [1,4]\n\t\tOutput: 1\n\t\tExplanation: The two heater was placed in the position 1 and 4. We need to use radius 1 standard, then all the houses can be warmed.\n\t\tExample 3:\n\t\tInput: houses = [1,5], heaters = [2]\n\t\tOutput: 3\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 476, - "question": "class Solution:\n def findComplement(self, num: int) -> int:\n\t\t\"\"\"\n\t\tThe complement of an integer is the integer you get when you flip all the 0's to 1's and all the 1's to 0's in its binary representation.\n\t\t\tFor example, The integer 5 is \"101\" in binary and its complement is \"010\" which is the integer 2.\n\t\tGiven an integer num, return its complement.\n\t\tExample 1:\n\t\tInput: num = 5\n\t\tOutput: 2\n\t\tExplanation: The binary representation of 5 is 101 (no leading zero bits), and its complement is 010. So you need to output 2.\n\t\tExample 2:\n\t\tInput: num = 1\n\t\tOutput: 0\n\t\tExplanation: The binary representation of 1 is 1 (no leading zero bits), and its complement is 0. So you need to output 0.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 477, - "question": "class Solution:\n def totalHammingDistance(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tThe Hamming distance between two integers is the number of positions at which the corresponding bits are different.\n\t\tGiven an integer array nums, return the sum of Hamming distances between all the pairs of the integers in nums.\n\t\tExample 1:\n\t\tInput: nums = [4,14,2]\n\t\tOutput: 6\n\t\tExplanation: In binary representation, the 4 is 0100, 14 is 1110, and 2 is 0010 (just\n\t\tshowing the four bits relevant in this case).\n\t\tThe answer will be:\n\t\tHammingDistance(4, 14) + HammingDistance(4, 2) + HammingDistance(14, 2) = 2 + 2 + 2 = 6.\n\t\tExample 2:\n\t\tInput: nums = [4,14,4]\n\t\tOutput: 4\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 479, - "question": "class Solution:\n def largestPalindrome(self, n: int) -> int:\n\t\t\"\"\"\n\t\tGiven an integer n, return the largest palindromic integer that can be represented as the product of two n-digits integers. Since the answer can be very large, return it modulo 1337.\n\t\tExample 1:\n\t\tInput: n = 2\n\t\tOutput: 987\n\t\tExplanation: 99 x 91 = 9009, 9009 % 1337 = 987\n\t\tExample 2:\n\t\tInput: n = 1\n\t\tOutput: 9\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 480, - "question": "class Solution:\n def medianSlidingWindow(self, nums: List[int], k: int) -> List[float]:\n\t\t\"\"\"\n\t\tThe median is the middle value in an ordered integer list. If the size of the list is even, there is no middle value. So the median is the mean of the two middle values.\n\t\t\tFor examples, if arr = [2,3,4], the median is 3.\n\t\t\tFor examples, if arr = [1,2,3,4], the median is (2 + 3) / 2 = 2.5.\n\t\tYou are given an integer array nums and an integer k. There is a sliding window of size k which is moving from the very left of the array to the very right. You can only see the k numbers in the window. Each time the sliding window moves right by one position.\n\t\tReturn the median array for each window in the original array. Answers within 10-5 of the actual value will be accepted.\n\t\tExample 1:\n\t\tInput: nums = [1,3,-1,-3,5,3,6,7], k = 3\n\t\tOutput: [1.00000,-1.00000,-1.00000,3.00000,5.00000,6.00000]\n\t\tExplanation: \n\t\tWindow position Median\n\t\t--------------- -----\n\t\t[1 3 -1] -3 5 3 6 7 1\n\t\t 1 [3 -1 -3] 5 3 6 7 -1\n\t\t 1 3 [-1 -3 5] 3 6 7 -1\n\t\t 1 3 -1 [-3 5 3] 6 7 3\n\t\t 1 3 -1 -3 [5 3 6] 7 5\n\t\t 1 3 -1 -3 5 [3 6 7] 6\n\t\tExample 2:\n\t\tInput: nums = [1,2,3,4,2,3,1,4,2], k = 3\n\t\tOutput: [2.00000,3.00000,3.00000,3.00000,2.00000,3.00000,2.00000]\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 481, - "question": "class Solution:\n def magicalString(self, n: int) -> int:\n\t\t\"\"\"\n\t\tA magical string s consists of only '1' and '2' and obeys the following rules:\n\t\t\tThe string s is magical because concatenating the number of contiguous occurrences of characters '1' and '2' generates the string s itself.\n\t\tThe first few elements of s is s = \"1221121221221121122\u2026\u2026\". If we group the consecutive 1's and 2's in s, it will be \"1 22 11 2 1 22 1 22 11 2 11 22 ......\" and the occurrences of 1's or 2's in each group are \"1 2 2 1 1 2 1 2 2 1 2 2 ......\". You can see that the occurrence sequence is s itself.\n\t\tGiven an integer n, return the number of 1's in the first n number in the magical string s.\n\t\tExample 1:\n\t\tInput: n = 6\n\t\tOutput: 3\n\t\tExplanation: The first 6 elements of magical string s is \"122112\" and it contains three 1's, so return 3.\n\t\tExample 2:\n\t\tInput: n = 1\n\t\tOutput: 1\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 482, - "question": "class Solution:\n def licenseKeyFormatting(self, s: str, k: int) -> str:\n\t\t\"\"\"\n\t\tYou are given a license key represented as a string s that consists of only alphanumeric characters and dashes. The string is separated into n + 1 groups by n dashes. You are also given an integer k.\n\t\tWe want to reformat the string s such that each group contains exactly k characters, except for the first group, which could be shorter than k but still must contain at least one character. Furthermore, there must be a dash inserted between two groups, and you should convert all lowercase letters to uppercase.\n\t\tReturn the reformatted license key.\n\t\tExample 1:\n\t\tInput: s = \"5F3Z-2e-9-w\", k = 4\n\t\tOutput: \"5F3Z-2E9W\"\n\t\tExplanation: The string s has been split into two parts, each part has 4 characters.\n\t\tNote that the two extra dashes are not needed and can be removed.\n\t\tExample 2:\n\t\tInput: s = \"2-5g-3-J\", k = 2\n\t\tOutput: \"2-5G-3J\"\n\t\tExplanation: The string s has been split into three parts, each part has 2 characters except the first part as it could be shorter as mentioned above.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 483, - "question": "class Solution:\n def smallestGoodBase(self, n: str) -> str:\n\t\t\"\"\"\n\t\tGiven an integer n represented as a string, return the smallest good base of n.\n\t\tWe call k >= 2 a good base of n, if all digits of n base k are 1's.\n\t\tExample 1:\n\t\tInput: n = \"13\"\n\t\tOutput: \"3\"\n\t\tExplanation: 13 base 3 is 111.\n\t\tExample 2:\n\t\tInput: n = \"4681\"\n\t\tOutput: \"8\"\n\t\tExplanation: 4681 base 8 is 11111.\n\t\tExample 3:\n\t\tInput: n = \"1000000000000000000\"\n\t\tOutput: \"999999999999999999\"\n\t\tExplanation: 1000000000000000000 base 999999999999999999 is 11.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 485, - "question": "class Solution:\n def findMaxConsecutiveOnes(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tGiven a binary array nums, return the maximum number of consecutive 1's in the array.\n\t\tExample 1:\n\t\tInput: nums = [1,1,0,1,1,1]\n\t\tOutput: 3\n\t\tExplanation: The first two digits or the last three digits are consecutive 1s. The maximum number of consecutive 1s is 3.\n\t\tExample 2:\n\t\tInput: nums = [1,0,1,1,0,1]\n\t\tOutput: 2\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 486, - "question": "class Solution:\n def PredictTheWinner(self, nums: List[int]) -> bool:\n\t\t\"\"\"\n\t\tYou are given an integer array nums. Two players are playing a game with this array: player 1 and player 2.\n\t\tPlayer 1 and player 2 take turns, with player 1 starting first. Both players start the game with a score of 0. At each turn, the player takes one of the numbers from either end of the array (i.e., nums[0] or nums[nums.length - 1]) which reduces the size of the array by 1. The player adds the chosen number to their score. The game ends when there are no more elements in the array.\n\t\tReturn true if Player 1 can win the game. If the scores of both players are equal, then player 1 is still the winner, and you should also return true. You may assume that both players are playing optimally.\n\t\tExample 1:\n\t\tInput: nums = [1,5,2]\n\t\tOutput: false\n\t\tExplanation: Initially, player 1 can choose between 1 and 2. \n\t\tIf he chooses 2 (or 1), then player 2 can choose from 1 (or 2) and 5. If player 2 chooses 5, then player 1 will be left with 1 (or 2). \n\t\tSo, final score of player 1 is 1 + 2 = 3, and player 2 is 5. \n\t\tHence, player 1 will never be the winner and you need to return false.\n\t\tExample 2:\n\t\tInput: nums = [1,5,233,7]\n\t\tOutput: true\n\t\tExplanation: Player 1 first chooses 1. Then player 2 has to choose between 5 and 7. No matter which number player 2 choose, player 1 can choose 233.\n\t\tFinally, player 1 has more score (234) than player 2 (12), so you need to return True representing player1 can win.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 488, - "question": "class Solution:\n def findMinStep(self, board: str, hand: str) -> int:\n\t\t\"\"\"\n\t\tYou are playing a variation of the game Zuma.\n\t\tIn this variation of Zuma, there is a single row of colored balls on a board, where each ball can be colored red 'R', yellow 'Y', blue 'B', green 'G', or white 'W'. You also have several colored balls in your hand.\n\t\tYour goal is to clear all of the balls from the board. On each turn:\n\t\t\tPick any ball from your hand and insert it in between two balls in the row or on either end of the row.\n\t\t\tIf there is a group of three or more consecutive balls of the same color, remove the group of balls from the board.\n\t\t\t\tIf this removal causes more groups of three or more of the same color to form, then continue removing each group until there are none left.\n\t\t\tIf there are no more balls on the board, then you win the game.\n\t\t\tRepeat this process until you either win or do not have any more balls in your hand.\n\t\tGiven a string board, representing the row of balls on the board, and a string hand, representing the balls in your hand, return the minimum number of balls you have to insert to clear all the balls from the board. If you cannot clear all the balls from the board using the balls in your hand, return -1.\n\t\tExample 1:\n\t\tInput: board = \"WRRBBW\", hand = \"RB\"\n\t\tOutput: -1\n\t\tExplanation: It is impossible to clear all the balls. The best you can do is:\n\t\t- Insert 'R' so the board becomes WRRRBBW. WRRRBBW -> WBBW.\n\t\t- Insert 'B' so the board becomes WBBBW. WBBBW -> WW.\n\t\tThere are still balls remaining on the board, and you are out of balls to insert.\n\t\tExample 2:\n\t\tInput: board = \"WWRRBBWW\", hand = \"WRBRW\"\n\t\tOutput: 2\n\t\tExplanation: To make the board empty:\n\t\t- Insert 'R' so the board becomes WWRRRBBWW. WWRRRBBWW -> WWBBWW.\n\t\t- Insert 'B' so the board becomes WWBBBWW. WWBBBWW -> WWWW -> empty.\n\t\t2 balls from your hand were needed to clear the board.\n\t\tExample 3:\n\t\tInput: board = \"G\", hand = \"GGGGG\"\n\t\tOutput: 2\n\t\tExplanation: To make the board empty:\n\t\t- Insert 'G' so the board becomes GG.\n\t\t- Insert 'G' so the board becomes GGG. GGG -> empty.\n\t\t2 balls from your hand were needed to clear the board.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 489, - "question": "class Solution:\n def kthSmallestPath(self, destination: List[int], k: int) -> str:\n\t\t\"\"\"\n\t\tBob is standing at cell (0, 0), and he wants to reach destination: (row, column). He can only travel right and down. You are going to help Bob by providing instructions for him to reach destination.\n\t\tThe instructions are represented as a string, where each character is either:\n\t\t\t'H', meaning move horizontally (go right), or\n\t\t\t'V', meaning move vertically (go down).\n\t\tMultiple instructions will lead Bob to destination. For example, if destination is (2, 3), both \"HHHVV\" and \"HVHVH\" are valid instructions.\n\t\tHowever, Bob is very picky. Bob has a lucky number k, and he wants the kth lexicographically smallest instructions that will lead him to destination. k is 1-indexed.\n\t\tGiven an integer array destination and an integer k, return the kth lexicographically smallest instructions that will take Bob to destination.\n\t\tExample 1:\n\t\tInput: destination = [2,3], k = 1\n\t\tOutput: \"HHHVV\"\n\t\tExplanation: All the instructions that reach (2, 3) in lexicographic order are as follows:\n\t\t[\"HHHVV\", \"HHVHV\", \"HHVVH\", \"HVHHV\", \"HVHVH\", \"HVVHH\", \"VHHHV\", \"VHHVH\", \"VHVHH\", \"VVHHH\"].\n\t\tExample 2:\n\t\tInput: destination = [2,3], k = 2\n\t\tOutput: \"HHVHV\"\n\t\tExample 3:\n\t\tInput: destination = [2,3], k = 3\n\t\tOutput: \"HHVVH\"\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 491, - "question": "class Solution:\n def findSubsequences(self, nums: List[int]) -> List[List[int]]:\n\t\t\"\"\"\n\t\tGiven an integer array nums, return all the different possible non-decreasing subsequences of the given array with at least two elements. You may return the answer in any order.\n\t\tExample 1:\n\t\tInput: nums = [4,6,7,7]\n\t\tOutput: [[4,6],[4,6,7],[4,6,7,7],[4,7],[4,7,7],[6,7],[6,7,7],[7,7]]\n\t\tExample 2:\n\t\tInput: nums = [4,4,3,2,1]\n\t\tOutput: [[4,4]]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 492, - "question": "class Solution:\n def constructRectangle(self, area: int) -> List[int]:\n\t\t\"\"\"\n\t\tA web developer needs to know how to design a web page's size. So, given a specific rectangular web page\u2019s area, your job by now is to design a rectangular web page, whose length L and width W satisfy the following requirements:\n\t\t\tThe area of the rectangular web page you designed must equal to the given target area.\n\t\t\tThe width W should not be larger than the length L, which means L >= W.\n\t\t\tThe difference between length L and width W should be as small as possible.\n\t\tReturn an array [L, W] where L and W are the length and width of the web page you designed in sequence.\n\t\tExample 1:\n\t\tInput: area = 4\n\t\tOutput: [2,2]\n\t\tExplanation: The target area is 4, and all the possible ways to construct it are [1,4], [2,2], [4,1]. \n\t\tBut according to requirement 2, [1,4] is illegal; according to requirement 3, [4,1] is not optimal compared to [2,2]. So the length L is 2, and the width W is 2.\n\t\tExample 2:\n\t\tInput: area = 37\n\t\tOutput: [37,1]\n\t\tExample 3:\n\t\tInput: area = 122122\n\t\tOutput: [427,286]\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 493, - "question": "class Solution:\n def reversePairs(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tGiven an integer array nums, return the number of reverse pairs in the array.\n\t\tA reverse pair is a pair (i, j) where:\n\t\t\t0 <= i < j < nums.length and\n\t\t\tnums[i] > 2 * nums[j].\n\t\tExample 1:\n\t\tInput: nums = [1,3,2,3,1]\n\t\tOutput: 2\n\t\tExplanation: The reverse pairs are:\n\t\t(1, 4) --> nums[1] = 3, nums[4] = 1, 3 > 2 * 1\n\t\t(3, 4) --> nums[3] = 3, nums[4] = 1, 3 > 2 * 1\n\t\tExample 2:\n\t\tInput: nums = [2,4,3,5,1]\n\t\tOutput: 3\n\t\tExplanation: The reverse pairs are:\n\t\t(1, 4) --> nums[1] = 4, nums[4] = 1, 4 > 2 * 1\n\t\t(2, 4) --> nums[2] = 3, nums[4] = 1, 3 > 2 * 1\n\t\t(3, 4) --> nums[3] = 5, nums[4] = 1, 5 > 2 * 1\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 494, - "question": "class Solution:\n def findTargetSumWays(self, nums: List[int], target: int) -> int:\n\t\t\"\"\"\n\t\tYou are given an integer array nums and an integer target.\n\t\tYou want to build an expression out of nums by adding one of the symbols '+' and '-' before each integer in nums and then concatenate all the integers.\n\t\t\tFor example, if nums = [2, 1], you can add a '+' before 2 and a '-' before 1 and concatenate them to build the expression \"+2-1\".\n\t\tReturn the number of different expressions that you can build, which evaluates to target.\n\t\tExample 1:\n\t\tInput: nums = [1,1,1,1,1], target = 3\n\t\tOutput: 5\n\t\tExplanation: There are 5 ways to assign symbols to make the sum of nums be target 3.\n\t\t-1 + 1 + 1 + 1 + 1 = 3\n\t\t+1 - 1 + 1 + 1 + 1 = 3\n\t\t+1 + 1 - 1 + 1 + 1 = 3\n\t\t+1 + 1 + 1 - 1 + 1 = 3\n\t\t+1 + 1 + 1 + 1 - 1 = 3\n\t\tExample 2:\n\t\tInput: nums = [1], target = 1\n\t\tOutput: 1\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 495, - "question": "class Solution:\n def findPoisonedDuration(self, timeSeries: List[int], duration: int) -> int:\n\t\t\"\"\"\n\t\tOur hero Teemo is attacking an enemy Ashe with poison attacks! When Teemo attacks Ashe, Ashe gets poisoned for a exactly duration seconds. More formally, an attack at second t will mean Ashe is poisoned during the inclusive time interval [t, t + duration - 1]. If Teemo attacks again before the poison effect ends, the timer for it is reset, and the poison effect will end duration seconds after the new attack.\n\t\tYou are given a non-decreasing integer array timeSeries, where timeSeries[i] denotes that Teemo attacks Ashe at second timeSeries[i], and an integer duration.\n\t\tReturn the total number of seconds that Ashe is poisoned.\n\t\tExample 1:\n\t\tInput: timeSeries = [1,4], duration = 2\n\t\tOutput: 4\n\t\tExplanation: Teemo's attacks on Ashe go as follows:\n\t\t- At second 1, Teemo attacks, and Ashe is poisoned for seconds 1 and 2.\n\t\t- At second 4, Teemo attacks, and Ashe is poisoned for seconds 4 and 5.\n\t\tAshe is poisoned for seconds 1, 2, 4, and 5, which is 4 seconds in total.\n\t\tExample 2:\n\t\tInput: timeSeries = [1,2], duration = 2\n\t\tOutput: 3\n\t\tExplanation: Teemo's attacks on Ashe go as follows:\n\t\t- At second 1, Teemo attacks, and Ashe is poisoned for seconds 1 and 2.\n\t\t- At second 2 however, Teemo attacks again and resets the poison timer. Ashe is poisoned for seconds 2 and 3.\n\t\tAshe is poisoned for seconds 1, 2, and 3, which is 3 seconds in total.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 496, - "question": "class Solution:\n def nextGreaterElement(self, nums1: List[int], nums2: List[int]) -> List[int]:\n\t\t\"\"\"\n\t\tThe next greater element of some element x in an array is the first greater element that is to the right of x in the same array.\n\t\tYou are given two distinct 0-indexed integer arrays nums1 and nums2, where nums1 is a subset of nums2.\n\t\tFor each 0 <= i < nums1.length, find the index j such that nums1[i] == nums2[j] and determine the next greater element of nums2[j] in nums2. If there is no next greater element, then the answer for this query is -1.\n\t\tReturn an array ans of length nums1.length such that ans[i] is the next greater element as described above.\n\t\tExample 1:\n\t\tInput: nums1 = [4,1,2], nums2 = [1,3,4,2]\n\t\tOutput: [-1,3,-1]\n\t\tExplanation: The next greater element for each value of nums1 is as follows:\n\t\t- 4 is underlined in nums2 = [1,3,4,2]. There is no next greater element, so the answer is -1.\n\t\t- 1 is underlined in nums2 = [1,3,4,2]. The next greater element is 3.\n\t\t- 2 is underlined in nums2 = [1,3,4,2]. There is no next greater element, so the answer is -1.\n\t\tExample 2:\n\t\tInput: nums1 = [2,4], nums2 = [1,2,3,4]\n\t\tOutput: [3,-1]\n\t\tExplanation: The next greater element for each value of nums1 is as follows:\n\t\t- 2 is underlined in nums2 = [1,2,3,4]. The next greater element is 3.\n\t\t- 4 is underlined in nums2 = [1,2,3,4]. There is no next greater element, so the answer is -1.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 498, - "question": "class Solution:\n def findDiagonalOrder(self, mat: List[List[int]]) -> List[int]:\n\t\t\"\"\"\n\t\tGiven an m x n matrix mat, return an array of all the elements of the array in a diagonal order.\n\t\tExample 1:\n\t\tInput: mat = [[1,2,3],[4,5,6],[7,8,9]]\n\t\tOutput: [1,2,4,7,5,3,6,8,9]\n\t\tExample 2:\n\t\tInput: mat = [[1,2],[3,4]]\n\t\tOutput: [1,2,3,4]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 500, - "question": "class Solution:\n def findWords(self, words: List[str]) -> List[str]:\n\t\t\"\"\"\n\t\tGiven an array of strings words, return the words that can be typed using letters of the alphabet on only one row of American keyboard like the image below.\n\t\tIn the American keyboard:\n\t\t\tthe first row consists of the characters \"qwertyuiop\",\n\t\t\tthe second row consists of the characters \"asdfghjkl\", and\n\t\t\tthe third row consists of the characters \"zxcvbnm\".\n\t\tExample 1:\n\t\tInput: words = [\"Hello\",\"Alaska\",\"Dad\",\"Peace\"]\n\t\tOutput: [\"Alaska\",\"Dad\"]\n\t\tExample 2:\n\t\tInput: words = [\"omk\"]\n\t\tOutput: []\n\t\tExample 3:\n\t\tInput: words = [\"adsdf\",\"sfd\"]\n\t\tOutput: [\"adsdf\",\"sfd\"]\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 501, - "question": "class Solution:\n def findMode(self, root: Optional[TreeNode]) -> List[int]:\n\t\t\"\"\"\n\t\tGiven the root of a binary search tree (BST) with duplicates, return all the mode(s) (i.e., the most frequently occurred element) in it.\n\t\tIf the tree has more than one mode, return them in any order.\n\t\tAssume a BST is defined as follows:\n\t\t\tThe left subtree of a node contains only nodes with keys less than or equal to the node's key.\n\t\t\tThe right subtree of a node contains only nodes with keys greater than or equal to the node's key.\n\t\t\tBoth the left and right subtrees must also be binary search trees.\n\t\tExample 1:\n\t\tInput: root = [1,null,2,2]\n\t\tOutput: [2]\n\t\tExample 2:\n\t\tInput: root = [0]\n\t\tOutput: [0]\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 502, - "question": "class Solution:\n def findMaximizedCapital(self, k: int, w: int, profits: List[int], capital: List[int]) -> int:\n\t\t\"\"\"\n\t\tSuppose LeetCode will start its IPO soon. In order to sell a good price of its shares to Venture Capital, LeetCode would like to work on some projects to increase its capital before the IPO. Since it has limited resources, it can only finish at most k distinct projects before the IPO. Help LeetCode design the best way to maximize its total capital after finishing at most k distinct projects.\n\t\tYou are given n projects where the ith project has a pure profit profits[i] and a minimum capital of capital[i] is needed to start it.\n\t\tInitially, you have w capital. When you finish a project, you will obtain its pure profit and the profit will be added to your total capital.\n\t\tPick a list of at most k distinct projects from given projects to maximize your final capital, and return the final maximized capital.\n\t\tThe answer is guaranteed to fit in a 32-bit signed integer.\n\t\tExample 1:\n\t\tInput: k = 2, w = 0, profits = [1,2,3], capital = [0,1,1]\n\t\tOutput: 4\n\t\tExplanation: Since your initial capital is 0, you can only start the project indexed 0.\n\t\tAfter finishing it you will obtain profit 1 and your capital becomes 1.\n\t\tWith capital 1, you can either start the project indexed 1 or the project indexed 2.\n\t\tSince you can choose at most 2 projects, you need to finish the project indexed 2 to get the maximum capital.\n\t\tTherefore, output the final maximized capital, which is 0 + 1 + 3 = 4.\n\t\tExample 2:\n\t\tInput: k = 3, w = 0, profits = [1,2,3], capital = [0,1,2]\n\t\tOutput: 6\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 503, - "question": "class Solution:\n def nextGreaterElements(self, nums: List[int]) -> List[int]:\n\t\t\"\"\"\n\t\tGiven a circular integer array nums (i.e., the next element of nums[nums.length - 1] is nums[0]), return the next greater number for every element in nums.\n\t\tThe next greater number of a number x is the first greater number to its traversing-order next in the array, which means you could search circularly to find its next greater number. If it doesn't exist, return -1 for this number.\n\t\tExample 1:\n\t\tInput: nums = [1,2,1]\n\t\tOutput: [2,-1,2]\n\t\tExplanation: The first 1's next greater number is 2; \n\t\tThe number 2 can't find next greater number. \n\t\tThe second 1's next greater number needs to search circularly, which is also 2.\n\t\tExample 2:\n\t\tInput: nums = [1,2,3,4,3]\n\t\tOutput: [2,3,4,-1,4]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 504, - "question": "class Solution:\n def convertToBase7(self, num: int) -> str:\n\t\t\"\"\"\n\t\tGiven an integer num, return a string of its base 7 representation.\n\t\tExample 1:\n\t\tInput: num = 100\n\t\tOutput: \"202\"\n\t\tExample 2:\n\t\tInput: num = -7\n\t\tOutput: \"-10\"\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 506, - "question": "class Solution:\n def findRelativeRanks(self, score: List[int]) -> List[str]:\n\t\t\"\"\"\n\t\tYou are given an integer array score of size n, where score[i] is the score of the ith athlete in a competition. All the scores are guaranteed to be unique.\n\t\tThe athletes are placed based on their scores, where the 1st place athlete has the highest score, the 2nd place athlete has the 2nd highest score, and so on. The placement of each athlete determines their rank:\n\t\t\tThe 1st place athlete's rank is \"Gold Medal\".\n\t\t\tThe 2nd place athlete's rank is \"Silver Medal\".\n\t\t\tThe 3rd place athlete's rank is \"Bronze Medal\".\n\t\t\tFor the 4th place to the nth place athlete, their rank is their placement number (i.e., the xth place athlete's rank is \"x\").\n\t\tReturn an array answer of size n where answer[i] is the rank of the ith athlete.\n\t\tExample 1:\n\t\tInput: score = [5,4,3,2,1]\n\t\tOutput: [\"Gold Medal\",\"Silver Medal\",\"Bronze Medal\",\"4\",\"5\"]\n\t\tExplanation: The placements are [1st, 2nd, 3rd, 4th, 5th].\n\t\tExample 2:\n\t\tInput: score = [10,3,8,9,4]\n\t\tOutput: [\"Gold Medal\",\"5\",\"Bronze Medal\",\"Silver Medal\",\"4\"]\n\t\tExplanation: The placements are [1st, 5th, 3rd, 2nd, 4th].\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 507, - "question": "class Solution:\n def checkPerfectNumber(self, num: int) -> bool:\n\t\t\"\"\"\n\t\tA perfect number is a positive integer that is equal to the sum of its positive divisors, excluding the number itself. A divisor of an integer x is an integer that can divide x evenly.\n\t\tGiven an integer n, return true if n is a perfect number, otherwise return false.\n\t\tExample 1:\n\t\tInput: num = 28\n\t\tOutput: true\n\t\tExplanation: 28 = 1 + 2 + 4 + 7 + 14\n\t\t1, 2, 4, 7, and 14 are all divisors of 28.\n\t\tExample 2:\n\t\tInput: num = 7\n\t\tOutput: false\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 508, - "question": "class Solution:\n def findFrequentTreeSum(self, root: Optional[TreeNode]) -> List[int]:\n\t\t\"\"\"\n\t\tGiven the root of a binary tree, return the most frequent subtree sum. If there is a tie, return all the values with the highest frequency in any order.\n\t\tThe subtree sum of a node is defined as the sum of all the node values formed by the subtree rooted at that node (including the node itself).\n\t\tExample 1:\n\t\tInput: root = [5,2,-3]\n\t\tOutput: [2,-3,4]\n\t\tExample 2:\n\t\tInput: root = [5,2,-5]\n\t\tOutput: [2]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 513, - "question": "class Solution:\n def findBottomLeftValue(self, root: Optional[TreeNode]) -> int:\n\t\t\"\"\"\n\t\tGiven the root of a binary tree, return the leftmost value in the last row of the tree.\n\t\tExample 1:\n\t\tInput: root = [2,1,3]\n\t\tOutput: 1\n\t\tExample 2:\n\t\tInput: root = [1,2,3,4,null,5,6,null,null,7]\n\t\tOutput: 7\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 514, - "question": "class Solution:\n def findRotateSteps(self, ring: str, key: str) -> int:\n\t\t\"\"\"\n\t\tIn the video game Fallout 4, the quest \"Road to Freedom\" requires players to reach a metal dial called the \"Freedom Trail Ring\" and use the dial to spell a specific keyword to open the door.\n\t\tGiven a string ring that represents the code engraved on the outer ring and another string key that represents the keyword that needs to be spelled, return the minimum number of steps to spell all the characters in the keyword.\n\t\tInitially, the first character of the ring is aligned at the \"12:00\" direction. You should spell all the characters in key one by one by rotating ring clockwise or anticlockwise to make each character of the string key aligned at the \"12:00\" direction and then by pressing the center button.\n\t\tAt the stage of rotating the ring to spell the key character key[i]:\n\t\t\tYou can rotate the ring clockwise or anticlockwise by one place, which counts as one step. The final purpose of the rotation is to align one of ring's characters at the \"12:00\" direction, where this character must equal key[i].\n\t\t\tIf the character key[i] has been aligned at the \"12:00\" direction, press the center button to spell, which also counts as one step. After the pressing, you could begin to spell the next character in the key (next stage). Otherwise, you have finished all the spelling.\n\t\tExample 1:\n\t\tInput: ring = \"godding\", key = \"gd\"\n\t\tOutput: 4\n\t\tExplanation:\n\t\tFor the first key character 'g', since it is already in place, we just need 1 step to spell this character. \n\t\tFor the second key character 'd', we need to rotate the ring \"godding\" anticlockwise by two steps to make it become \"ddinggo\".\n\t\tAlso, we need 1 more step for spelling.\n\t\tSo the final output is 4.\n\t\tExample 2:\n\t\tInput: ring = \"godding\", key = \"godding\"\n\t\tOutput: 13\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 515, - "question": "class Solution:\n def largestValues(self, root: Optional[TreeNode]) -> List[int]:\n\t\t\"\"\"\n\t\tGiven the root of a binary tree, return an array of the largest value in each row of the tree (0-indexed).\n\t\tExample 1:\n\t\tInput: root = [1,3,2,5,3,null,9]\n\t\tOutput: [1,3,9]\n\t\tExample 2:\n\t\tInput: root = [1,2,3]\n\t\tOutput: [1,3]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 516, - "question": "class Solution:\n def longestPalindromeSubseq(self, s: str) -> int:\n\t\t\"\"\"\n\t\tGiven a string s, find the longest palindromic subsequence's length in s.\n\t\tA subsequence is a sequence that can be derived from another sequence by deleting some or no elements without changing the order of the remaining elements.\n\t\tExample 1:\n\t\tInput: s = \"bbbab\"\n\t\tOutput: 4\n\t\tExplanation: One possible longest palindromic subsequence is \"bbbb\".\n\t\tExample 2:\n\t\tInput: s = \"cbbd\"\n\t\tOutput: 2\n\t\tExplanation: One possible longest palindromic subsequence is \"bb\".\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 517, - "question": "class Solution:\n def findMinMoves(self, machines: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou have n super washing machines on a line. Initially, each washing machine has some dresses or is empty.\n\t\tFor each move, you could choose any m (1 <= m <= n) washing machines, and pass one dress of each washing machine to one of its adjacent washing machines at the same time.\n\t\tGiven an integer array machines representing the number of dresses in each washing machine from left to right on the line, return the minimum number of moves to make all the washing machines have the same number of dresses. If it is not possible to do it, return -1.\n\t\tExample 1:\n\t\tInput: machines = [1,0,5]\n\t\tOutput: 3\n\t\tExplanation:\n\t\t1st move: 1 0 <-- 5 => 1 1 4\n\t\t2nd move: 1 <-- 1 <-- 4 => 2 1 3\n\t\t3rd move: 2 1 <-- 3 => 2 2 2\n\t\tExample 2:\n\t\tInput: machines = [0,3,0]\n\t\tOutput: 2\n\t\tExplanation:\n\t\t1st move: 0 <-- 3 0 => 1 2 0\n\t\t2nd move: 1 2 --> 0 => 1 1 1\n\t\tExample 3:\n\t\tInput: machines = [0,2,0]\n\t\tOutput: -1\n\t\tExplanation:\n\t\tIt's impossible to make all three washing machines have the same number of dresses.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 518, - "question": "class Solution:\n def change(self, amount: int, coins: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou are given an integer array coins representing coins of different denominations and an integer amount representing a total amount of money.\n\t\tReturn the number of combinations that make up that amount. If that amount of money cannot be made up by any combination of the coins, return 0.\n\t\tYou may assume that you have an infinite number of each kind of coin.\n\t\tThe answer is guaranteed to fit into a signed 32-bit integer.\n\t\tExample 1:\n\t\tInput: amount = 5, coins = [1,2,5]\n\t\tOutput: 4\n\t\tExplanation: there are four ways to make up the amount:\n\t\t5=5\n\t\t5=2+2+1\n\t\t5=2+1+1+1\n\t\t5=1+1+1+1+1\n\t\tExample 2:\n\t\tInput: amount = 3, coins = [2]\n\t\tOutput: 0\n\t\tExplanation: the amount of 3 cannot be made up just with coins of 2.\n\t\tExample 3:\n\t\tInput: amount = 10, coins = [10]\n\t\tOutput: 1\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 520, - "question": "class Solution:\n def detectCapitalUse(self, word: str) -> bool:\n\t\t\"\"\"\n\t\tWe define the usage of capitals in a word to be right when one of the following cases holds:\n\t\t\tAll letters in this word are capitals, like \"USA\".\n\t\t\tAll letters in this word are not capitals, like \"leetcode\".\n\t\t\tOnly the first letter in this word is capital, like \"Google\".\n\t\tGiven a string word, return true if the usage of capitals in it is right.\n\t\tExample 1:\n\t\tInput: word = \"USA\"\n\t\tOutput: true\n\t\tExample 2:\n\t\tInput: word = \"FlaG\"\n\t\tOutput: false\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 521, - "question": "class Solution:\n def findLUSlength(self, a: str, b: str) -> int:\n\t\t\"\"\"\n\t\tGiven two strings a and b, return the length of the longest uncommon subsequence between a and b. If the longest uncommon subsequence does not exist, return -1.\n\t\tAn uncommon subsequence between two strings is a string that is a subsequence of one but not the other.\n\t\tA subsequence of a string s is a string that can be obtained after deleting any number of characters from s.\n\t\t\tFor example, \"abc\" is a subsequence of \"aebdc\" because you can delete the underlined characters in \"aebdc\" to get \"abc\". Other subsequences of \"aebdc\" include \"aebdc\", \"aeb\", and \"\" (empty string).\n\t\tExample 1:\n\t\tInput: a = \"aba\", b = \"cdc\"\n\t\tOutput: 3\n\t\tExplanation: One longest uncommon subsequence is \"aba\" because \"aba\" is a subsequence of \"aba\" but not \"cdc\".\n\t\tNote that \"cdc\" is also a longest uncommon subsequence.\n\t\tExample 2:\n\t\tInput: a = \"aaa\", b = \"bbb\"\n\t\tOutput: 3\n\t\tExplanation: The longest uncommon subsequences are \"aaa\" and \"bbb\".\n\t\tExample 3:\n\t\tInput: a = \"aaa\", b = \"aaa\"\n\t\tOutput: -1\n\t\tExplanation: Every subsequence of string a is also a subsequence of string b. Similarly, every subsequence of string b is also a subsequence of string a.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 522, - "question": "class Solution:\n def findLUSlength(self, strs: List[str]) -> int:\n\t\t\"\"\"\n\t\tGiven an array of strings strs, return the length of the longest uncommon subsequence between them. If the longest uncommon subsequence does not exist, return -1.\n\t\tAn uncommon subsequence between an array of strings is a string that is a subsequence of one string but not the others.\n\t\tA subsequence of a string s is a string that can be obtained after deleting any number of characters from s.\n\t\t\tFor example, \"abc\" is a subsequence of \"aebdc\" because you can delete the underlined characters in \"aebdc\" to get \"abc\". Other subsequences of \"aebdc\" include \"aebdc\", \"aeb\", and \"\" (empty string).\n\t\tExample 1:\n\t\tInput: strs = [\"aba\",\"cdc\",\"eae\"]\n\t\tOutput: 3\n\t\tExample 2:\n\t\tInput: strs = [\"aaa\",\"aaa\",\"aa\"]\n\t\tOutput: -1\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 523, - "question": "class Solution:\n def checkSubarraySum(self, nums: List[int], k: int) -> bool:\n\t\t\"\"\"\n\t\tGiven an integer array nums and an integer k, return true if nums has a good subarray or false otherwise.\n\t\tA good subarray is a subarray where:\n\t\t\tits length is at least two, and\n\t\t\tthe sum of the elements of the subarray is a multiple of k.\n\t\tNote that:\n\t\t\tA subarray is a contiguous part of the array.\n\t\t\tAn integer x is a multiple of k if there exists an integer n such that x = n * k. 0 is always a multiple of k.\n\t\tExample 1:\n\t\tInput: nums = [23,2,4,6,7], k = 6\n\t\tOutput: true\n\t\tExplanation: [2, 4] is a continuous subarray of size 2 whose elements sum up to 6.\n\t\tExample 2:\n\t\tInput: nums = [23,2,6,4,7], k = 6\n\t\tOutput: true\n\t\tExplanation: [23, 2, 6, 4, 7] is an continuous subarray of size 5 whose elements sum up to 42.\n\t\t42 is a multiple of 6 because 42 = 7 * 6 and 7 is an integer.\n\t\tExample 3:\n\t\tInput: nums = [23,2,6,4,7], k = 13\n\t\tOutput: false\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 524, - "question": "class Solution:\n def findLongestWord(self, s: str, dictionary: List[str]) -> str:\n\t\t\"\"\"\n\t\tGiven a string s and a string array dictionary, return the longest string in the dictionary that can be formed by deleting some of the given string characters. If there is more than one possible result, return the longest word with the smallest lexicographical order. If there is no possible result, return the empty string.\n\t\tExample 1:\n\t\tInput: s = \"abpcplea\", dictionary = [\"ale\",\"apple\",\"monkey\",\"plea\"]\n\t\tOutput: \"apple\"\n\t\tExample 2:\n\t\tInput: s = \"abpcplea\", dictionary = [\"a\",\"b\",\"c\"]\n\t\tOutput: \"a\"\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 525, - "question": "class Solution:\n def findMaxLength(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tGiven a binary array nums, return the maximum length of a contiguous subarray with an equal number of 0 and 1.\n\t\tExample 1:\n\t\tInput: nums = [0,1]\n\t\tOutput: 2\n\t\tExplanation: [0, 1] is the longest contiguous subarray with an equal number of 0 and 1.\n\t\tExample 2:\n\t\tInput: nums = [0,1,0]\n\t\tOutput: 2\n\t\tExplanation: [0, 1] (or [1, 0]) is a longest contiguous subarray with equal number of 0 and 1.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 526, - "question": "class Solution:\n def countArrangement(self, n: int) -> int:\n\t\t\"\"\"\n\t\tSuppose you have n integers labeled 1 through n. A permutation of those n integers perm (1-indexed) is considered a beautiful arrangement if for every i (1 <= i <= n), either of the following is true:\n\t\t\tperm[i] is divisible by i.\n\t\t\ti is divisible by perm[i].\n\t\tGiven an integer n, return the number of the beautiful arrangements that you can construct.\n\t\tExample 1:\n\t\tInput: n = 2\n\t\tOutput: 2\n\t\tExplanation: \n\t\tThe first beautiful arrangement is [1,2]:\n\t\t - perm[1] = 1 is divisible by i = 1\n\t\t - perm[2] = 2 is divisible by i = 2\n\t\tThe second beautiful arrangement is [2,1]:\n\t\t - perm[1] = 2 is divisible by i = 1\n\t\t - i = 2 is divisible by perm[2] = 1\n\t\tExample 2:\n\t\tInput: n = 1\n\t\tOutput: 1\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 528, - "question": "class Solution:\n def swapNodes(self, head: Optional[ListNode], k: int) -> Optional[ListNode]:\n\t\t\"\"\"\n\t\tYou are given the head of a linked list, and an integer k.\n\t\tReturn the head of the linked list after swapping the values of the kth node from the beginning and the kth node from the end (the list is 1-indexed).\n\t\tExample 1:\n\t\tInput: head = [1,2,3,4,5], k = 2\n\t\tOutput: [1,4,3,2,5]\n\t\tExample 2:\n\t\tInput: head = [7,9,6,6,7,8,3,0,9,5], k = 5\n\t\tOutput: [7,9,6,6,8,7,3,0,9,5]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 529, - "question": "class Solution:\n def updateBoard(self, board: List[List[str]], click: List[int]) -> List[List[str]]:\n\t\t\"\"\"\n\t\tLet's play the minesweeper game (Wikipedia, online game)!\n\t\tYou are given an m x n char matrix board representing the game board where:\n\t\t\t'M' represents an unrevealed mine,\n\t\t\t'E' represents an unrevealed empty square,\n\t\t\t'B' represents a revealed blank square that has no adjacent mines (i.e., above, below, left, right, and all 4 diagonals),\n\t\t\tdigit ('1' to '8') represents how many mines are adjacent to this revealed square, and\n\t\t\t'X' represents a revealed mine.\n\t\tYou are also given an integer array click where click = [clickr, clickc] represents the next click position among all the unrevealed squares ('M' or 'E').\n\t\tReturn the board after revealing this position according to the following rules:\n\t\t\tIf a mine 'M' is revealed, then the game is over. You should change it to 'X'.\n\t\t\tIf an empty square 'E' with no adjacent mines is revealed, then change it to a revealed blank 'B' and all of its adjacent unrevealed squares should be revealed recursively.\n\t\t\tIf an empty square 'E' with at least one adjacent mine is revealed, then change it to a digit ('1' to '8') representing the number of adjacent mines.\n\t\t\tReturn the board when no more squares will be revealed.\n\t\tExample 1:\n\t\tInput: board = [[\"E\",\"E\",\"E\",\"E\",\"E\"],[\"E\",\"E\",\"M\",\"E\",\"E\"],[\"E\",\"E\",\"E\",\"E\",\"E\"],[\"E\",\"E\",\"E\",\"E\",\"E\"]], click = [3,0]\n\t\tOutput: [[\"B\",\"1\",\"E\",\"1\",\"B\"],[\"B\",\"1\",\"M\",\"1\",\"B\"],[\"B\",\"1\",\"1\",\"1\",\"B\"],[\"B\",\"B\",\"B\",\"B\",\"B\"]]\n\t\tExample 2:\n\t\tInput: board = [[\"B\",\"1\",\"E\",\"1\",\"B\"],[\"B\",\"1\",\"M\",\"1\",\"B\"],[\"B\",\"1\",\"1\",\"1\",\"B\"],[\"B\",\"B\",\"B\",\"B\",\"B\"]], click = [1,2]\n\t\tOutput: [[\"B\",\"1\",\"E\",\"1\",\"B\"],[\"B\",\"1\",\"X\",\"1\",\"B\"],[\"B\",\"1\",\"1\",\"1\",\"B\"],[\"B\",\"B\",\"B\",\"B\",\"B\"]]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 530, - "question": "class Solution:\n def getMinimumDifference(self, root: Optional[TreeNode]) -> int:\n\t\t\"\"\"\n\t\tGiven the root of a Binary Search Tree (BST), return the minimum absolute difference between the values of any two different nodes in the tree.\n\t\tExample 1:\n\t\tInput: root = [4,2,6,1,3]\n\t\tOutput: 1\n\t\tExample 2:\n\t\tInput: root = [1,0,48,null,null,12,49]\n\t\tOutput: 1\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 532, - "question": "class Solution:\n def findPairs(self, nums: List[int], k: int) -> int:\n\t\t\"\"\"\n\t\tGiven an array of integers nums and an integer k, return the number of unique k-diff pairs in the array.\n\t\tA k-diff pair is an integer pair (nums[i], nums[j]), where the following are true:\n\t\t\t0 <= i, j < nums.length\n\t\t\ti != j\n\t\t\tnums[i] - nums[j] == k\n\t\tNotice that |val| denotes the absolute value of val.\n\t\tExample 1:\n\t\tInput: nums = [3,1,4,1,5], k = 2\n\t\tOutput: 2\n\t\tExplanation: There are two 2-diff pairs in the array, (1, 3) and (3, 5).\n\t\tAlthough we have two 1s in the input, we should only return the number of unique pairs.\n\t\tExample 2:\n\t\tInput: nums = [1,2,3,4,5], k = 1\n\t\tOutput: 4\n\t\tExplanation: There are four 1-diff pairs in the array, (1, 2), (2, 3), (3, 4) and (4, 5).\n\t\tExample 3:\n\t\tInput: nums = [1,3,1,5,4], k = 0\n\t\tOutput: 1\n\t\tExplanation: There is one 0-diff pair in the array, (1, 1).\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 535, - "question": "class Codec:\n def encode(self, longUrl: str) -> str:\n\t\t\"\"\"Encodes a URL to a shortened URL.\n\t\tNote: This is a companion problem to the System Design problem: Design TinyURL.\n\t\tTinyURL is a URL shortening service where you enter a URL such as https://leetcode.com/problems/design-tinyurl and it returns a short URL such as http://tinyurl.com/4e9iAk. Design a class to encode a URL and decode a tiny URL.\n\t\tThere is no restriction on how your encode/decode algorithm should work. You just need to ensure that a URL can be encoded to a tiny URL and the tiny URL can be decoded to the original URL.\n\t\tImplement the Solution class:\n\t\t\tSolution() Initializes the object of the system.\n\t\t\tString encode(String longUrl) Returns a tiny URL for the given longUrl.\n\t\t\tString decode(String shortUrl) Returns the original long URL for the given shortUrl. It is guaranteed that the given shortUrl was encoded by the same object.\n\t\tExample 1:\n\t\tInput: url = \"https://leetcode.com/problems/design-tinyurl\"\n\t\tOutput: \"https://leetcode.com/problems/design-tinyurl\"\n\t\tExplanation:\n\t\tSolution obj = new Solution();\n\t\tstring tiny = obj.encode(url); // returns the encoded tiny url.\n\t\tstring ans = obj.decode(tiny); // returns the original url after deconding it.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 537, - "question": "class Solution:\n def complexNumberMultiply(self, num1: str, num2: str) -> str:\n\t\t\"\"\"\n\t\tA complex number can be represented as a string on the form \"real+imaginaryi\" where:\n\t\t\treal is the real part and is an integer in the range [-100, 100].\n\t\t\timaginary is the imaginary part and is an integer in the range [-100, 100].\n\t\t\ti2 == -1.\n\t\tGiven two complex numbers num1 and num2 as strings, return a string of the complex number that represents their multiplications.\n\t\tExample 1:\n\t\tInput: num1 = \"1+1i\", num2 = \"1+1i\"\n\t\tOutput: \"0+2i\"\n\t\tExplanation: (1 + i) * (1 + i) = 1 + i2 + 2 * i = 2i, and you need convert it to the form of 0+2i.\n\t\tExample 2:\n\t\tInput: num1 = \"1+-1i\", num2 = \"1+-1i\"\n\t\tOutput: \"0+-2i\"\n\t\tExplanation: (1 - i) * (1 - i) = 1 + i2 - 2 * i = -2i, and you need convert it to the form of 0+-2i.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 538, - "question": "class Solution:\n def convertBST(self, root: Optional[TreeNode]) -> Optional[TreeNode]:\n\t\t\"\"\"\n\t\tGiven the root of a Binary Search Tree (BST), convert it to a Greater Tree such that every key of the original BST is changed to the original key plus the sum of all keys greater than the original key in BST.\n\t\tAs a reminder, a binary search tree is a tree that satisfies these constraints:\n\t\t\tThe left subtree of a node contains only nodes with keys less than the node's key.\n\t\t\tThe right subtree of a node contains only nodes with keys greater than the node's key.\n\t\t\tBoth the left and right subtrees must also be binary search trees.\n\t\tExample 1:\n\t\tInput: root = [4,1,6,0,2,5,7,null,null,null,3,null,null,null,8]\n\t\tOutput: [30,36,21,36,35,26,15,null,null,null,33,null,null,null,8]\n\t\tExample 2:\n\t\tInput: root = [0,null,1]\n\t\tOutput: [1,null,1]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 539, - "question": "class Solution:\n def findMinDifference(self, timePoints: List[str]) -> int:\n\t\t\"\"\"\n\t\tGiven a list of 24-hour clock time points in \"HH:MM\" format, return the minimum minutes difference between any two time-points in the list.\n\t\tExample 1:\n\t\tInput: timePoints = [\"23:59\",\"00:00\"]\n\t\tOutput: 1\n\t\tExample 2:\n\t\tInput: timePoints = [\"00:00\",\"23:59\",\"00:00\"]\n\t\tOutput: 0\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 540, - "question": "class Solution:\n def singleNonDuplicate(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou are given a sorted array consisting of only integers where every element appears exactly twice, except for one element which appears exactly once.\n\t\tReturn the single element that appears only once.\n\t\tYour solution must run in O(log n) time and O(1) space.\n\t\tExample 1:\n\t\tInput: nums = [1,1,2,3,3,4,4,8,8]\n\t\tOutput: 2\n\t\tExample 2:\n\t\tInput: nums = [3,3,7,7,10,11,11]\n\t\tOutput: 10\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 541, - "question": "class Solution:\n def reverseStr(self, s: str, k: int) -> str:\n\t\t\"\"\"\n\t\tGiven a string s and an integer k, reverse the first k characters for every 2k characters counting from the start of the string.\n\t\tIf there are fewer than k characters left, reverse all of them. If there are less than 2k but greater than or equal to k characters, then reverse the first k characters and leave the other as original.\n\t\tExample 1:\n\t\tInput: s = \"abcdefg\", k = 2\n\t\tOutput: \"bacdfeg\"\n\t\tExample 2:\n\t\tInput: s = \"abcd\", k = 2\n\t\tOutput: \"bacd\"\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 542, - "question": "class Solution:\n def updateMatrix(self, mat: List[List[int]]) -> List[List[int]]:\n\t\t\"\"\"\n\t\tGiven an m x n binary matrix mat, return the distance of the nearest 0 for each cell.\n\t\tThe distance between two adjacent cells is 1.\n\t\tExample 1:\n\t\tInput: mat = [[0,0,0],[0,1,0],[0,0,0]]\n\t\tOutput: [[0,0,0],[0,1,0],[0,0,0]]\n\t\tExample 2:\n\t\tInput: mat = [[0,0,0],[0,1,0],[1,1,1]]\n\t\tOutput: [[0,0,0],[0,1,0],[1,2,1]]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 543, - "question": "class Solution:\n def diameterOfBinaryTree(self, root: Optional[TreeNode]) -> int:\n\t\t\"\"\"\n\t\tGiven the root of a binary tree, return the length of the diameter of the tree.\n\t\tThe diameter of a binary tree is the length of the longest path between any two nodes in a tree. This path may or may not pass through the root.\n\t\tThe length of a path between two nodes is represented by the number of edges between them.\n\t\tExample 1:\n\t\tInput: root = [1,2,3,4,5]\n\t\tOutput: 3\n\t\tExplanation: 3 is the length of the path [4,2,1,3] or [5,2,1,3].\n\t\tExample 2:\n\t\tInput: root = [1,2]\n\t\tOutput: 1\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 546, - "question": "class Solution:\n def removeBoxes(self, boxes: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou are given several boxes with different colors represented by different positive numbers.\n\t\tYou may experience several rounds to remove boxes until there is no box left. Each time you can choose some continuous boxes with the same color (i.e., composed of k boxes, k >= 1), remove them and get k * k points.\n\t\tReturn the maximum points you can get.\n\t\tExample 1:\n\t\tInput: boxes = [1,3,2,2,2,3,4,3,1]\n\t\tOutput: 23\n\t\tExplanation:\n\t\t[1, 3, 2, 2, 2, 3, 4, 3, 1] \n\t\t----> [1, 3, 3, 4, 3, 1] (3*3=9 points) \n\t\t----> [1, 3, 3, 3, 1] (1*1=1 points) \n\t\t----> [1, 1] (3*3=9 points) \n\t\t----> [] (2*2=4 points)\n\t\tExample 2:\n\t\tInput: boxes = [1,1,1]\n\t\tOutput: 9\n\t\tExample 3:\n\t\tInput: boxes = [1]\n\t\tOutput: 1\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 547, - "question": "class Solution:\n def findCircleNum(self, isConnected: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tThere are n cities. Some of them are connected, while some are not. If city a is connected directly with city b, and city b is connected directly with city c, then city a is connected indirectly with city c.\n\t\tA province is a group of directly or indirectly connected cities and no other cities outside of the group.\n\t\tYou are given an n x n matrix isConnected where isConnected[i][j] = 1 if the ith city and the jth city are directly connected, and isConnected[i][j] = 0 otherwise.\n\t\tReturn the total number of provinces.\n\t\tExample 1:\n\t\tInput: isConnected = [[1,1,0],[1,1,0],[0,0,1]]\n\t\tOutput: 2\n\t\tExample 2:\n\t\tInput: isConnected = [[1,0,0],[0,1,0],[0,0,1]]\n\t\tOutput: 3\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 551, - "question": "class Solution:\n def checkRecord(self, s: str) -> bool:\n\t\t\"\"\"\n\t\tYou are given a string s representing an attendance record for a student where each character signifies whether the student was absent, late, or present on that day. The record only contains the following three characters:\n\t\t\t'A': Absent.\n\t\t\t'L': Late.\n\t\t\t'P': Present.\n\t\tThe student is eligible for an attendance award if they meet both of the following criteria:\n\t\t\tThe student was absent ('A') for strictly fewer than 2 days total.\n\t\t\tThe student was never late ('L') for 3 or more consecutive days.\n\t\tReturn true if the student is eligible for an attendance award, or false otherwise.\n\t\tExample 1:\n\t\tInput: s = \"PPALLP\"\n\t\tOutput: true\n\t\tExplanation: The student has fewer than 2 absences and was never late 3 or more consecutive days.\n\t\tExample 2:\n\t\tInput: s = \"PPALLL\"\n\t\tOutput: false\n\t\tExplanation: The student was late 3 consecutive days in the last 3 days, so is not eligible for the award.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 552, - "question": "class Solution:\n def checkRecord(self, n: int) -> int:\n\t\t\"\"\"\n\t\tAn attendance record for a student can be represented as a string where each character signifies whether the student was absent, late, or present on that day. The record only contains the following three characters:\n\t\t\t'A': Absent.\n\t\t\t'L': Late.\n\t\t\t'P': Present.\n\t\tAny student is eligible for an attendance award if they meet both of the following criteria:\n\t\t\tThe student was absent ('A') for strictly fewer than 2 days total.\n\t\t\tThe student was never late ('L') for 3 or more consecutive days.\n\t\tGiven an integer n, return the number of possible attendance records of length n that make a student eligible for an attendance award. The answer may be very large, so return it modulo 109 + 7.\n\t\tExample 1:\n\t\tInput: n = 2\n\t\tOutput: 8\n\t\tExplanation: There are 8 records with length 2 that are eligible for an award:\n\t\t\"PP\", \"AP\", \"PA\", \"LP\", \"PL\", \"AL\", \"LA\", \"LL\"\n\t\tOnly \"AA\" is not eligible because there are 2 absences (there need to be fewer than 2).\n\t\tExample 2:\n\t\tInput: n = 1\n\t\tOutput: 3\n\t\tExample 3:\n\t\tInput: n = 10101\n\t\tOutput: 183236316\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 553, - "question": "class Solution:\n def optimalDivision(self, nums: List[int]) -> str:\n\t\t\"\"\"\n\t\tYou are given an integer array nums. The adjacent integers in nums will perform the float division.\n\t\t\tFor example, for nums = [2,3,4], we will evaluate the expression \"2/3/4\".\n\t\tHowever, you can add any number of parenthesis at any position to change the priority of operations. You want to add these parentheses such the value of the expression after the evaluation is maximum.\n\t\tReturn the corresponding expression that has the maximum value in string format.\n\t\tNote: your expression should not contain redundant parenthesis.\n\t\tExample 1:\n\t\tInput: nums = [1000,100,10,2]\n\t\tOutput: \"1000/(100/10/2)\"\n\t\tExplanation: 1000/(100/10/2) = 1000/((100/10)/2) = 200\n\t\tHowever, the bold parenthesis in \"1000/((100/10)/2)\" are redundant since they do not influence the operation priority.\n\t\tSo you should return \"1000/(100/10/2)\".\n\t\tOther cases:\n\t\t1000/(100/10)/2 = 50\n\t\t1000/(100/(10/2)) = 50\n\t\t1000/100/10/2 = 0.5\n\t\t1000/100/(10/2) = 2\n\t\tExample 2:\n\t\tInput: nums = [2,3,4]\n\t\tOutput: \"2/(3/4)\"\n\t\tExplanation: (2/(3/4)) = 8/3 = 2.667\n\t\tIt can be shown that after trying all possibilities, we cannot get an expression with evaluation greater than 2.667\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 554, - "question": "class Solution:\n def leastBricks(self, wall: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tThere is a rectangular brick wall in front of you with n rows of bricks. The ith row has some number of bricks each of the same height (i.e., one unit) but they can be of different widths. The total width of each row is the same.\n\t\tDraw a vertical line from the top to the bottom and cross the least bricks. If your line goes through the edge of a brick, then the brick is not considered as crossed. You cannot draw a line just along one of the two vertical edges of the wall, in which case the line will obviously cross no bricks.\n\t\tGiven the 2D array wall that contains the information about the wall, return the minimum number of crossed bricks after drawing such a vertical line.\n\t\tExample 1:\n\t\tInput: wall = [[1,2,2,1],[3,1,2],[1,3,2],[2,4],[3,1,2],[1,3,1,1]]\n\t\tOutput: 2\n\t\tExample 2:\n\t\tInput: wall = [[1],[1],[1]]\n\t\tOutput: 3\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 556, - "question": "class Solution:\n def nextGreaterElement(self, n: int) -> int:\n\t\t\"\"\"\n\t\tGiven a positive integer n, find the smallest integer which has exactly the same digits existing in the integer n and is greater in value than n. If no such positive integer exists, return -1.\n\t\tNote that the returned integer should fit in 32-bit integer, if there is a valid answer but it does not fit in 32-bit integer, return -1.\n\t\tExample 1:\n\t\tInput: n = 12\n\t\tOutput: 21\n\t\tExample 2:\n\t\tInput: n = 21\n\t\tOutput: -1\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 557, - "question": "class Solution:\n def reverseWords(self, s: str) -> str:\n\t\t\"\"\"\n\t\tGiven a string s, reverse the order of characters in each word within a sentence while still preserving whitespace and initial word order.\n\t\tExample 1:\n\t\tInput: s = \"Let's take LeetCode contest\"\n\t\tOutput: \"s'teL ekat edoCteeL tsetnoc\"\n\t\tExample 2:\n\t\tInput: s = \"God Ding\"\n\t\tOutput: \"doG gniD\"\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 560, - "question": "class Solution:\n def subarraySum(self, nums: List[int], k: int) -> int:\n\t\t\"\"\"\n\t\tGiven an array of integers nums and an integer k, return the total number of subarrays whose sum equals to k.\n\t\tA subarray is a contiguous non-empty sequence of elements within an array.\n\t\tExample 1:\n\t\tInput: nums = [1,1,1], k = 2\n\t\tOutput: 2\n\t\tExample 2:\n\t\tInput: nums = [1,2,3], k = 3\n\t\tOutput: 2\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 561, - "question": "class Solution:\n def arrayPairSum(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tGiven an integer array nums of 2n integers, group these integers into n pairs (a1, b1), (a2, b2), ..., (an, bn) such that the sum of min(ai, bi) for all i is maximized. Return the maximized sum.\n\t\tExample 1:\n\t\tInput: nums = [1,4,3,2]\n\t\tOutput: 4\n\t\tExplanation: All possible pairings (ignoring the ordering of elements) are:\n\t\t1. (1, 4), (2, 3) -> min(1, 4) + min(2, 3) = 1 + 2 = 3\n\t\t2. (1, 3), (2, 4) -> min(1, 3) + min(2, 4) = 1 + 2 = 3\n\t\t3. (1, 2), (3, 4) -> min(1, 2) + min(3, 4) = 1 + 3 = 4\n\t\tSo the maximum possible sum is 4.\n\t\tExample 2:\n\t\tInput: nums = [6,2,6,5,1,2]\n\t\tOutput: 9\n\t\tExplanation: The optimal pairing is (2, 1), (2, 5), (6, 6). min(2, 1) + min(2, 5) + min(6, 6) = 1 + 2 + 6 = 9.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 563, - "question": "class Solution:\n def findTilt(self, root: Optional[TreeNode]) -> int:\n\t\t\"\"\"\n\t\tGiven the root of a binary tree, return the sum of every tree node's tilt.\n\t\tThe tilt of a tree node is the absolute difference between the sum of all left subtree node values and all right subtree node values. If a node does not have a left child, then the sum of the left subtree node values is treated as 0. The rule is similar if the node does not have a right child.\n\t\tExample 1:\n\t\tInput: root = [1,2,3]\n\t\tOutput: 1\n\t\tExplanation: \n\t\tTilt of node 2 : |0-0| = 0 (no children)\n\t\tTilt of node 3 : |0-0| = 0 (no children)\n\t\tTilt of node 1 : |2-3| = 1 (left subtree is just left child, so sum is 2; right subtree is just right child, so sum is 3)\n\t\tSum of every tilt : 0 + 0 + 1 = 1\n\t\tExample 2:\n\t\tInput: root = [4,2,9,3,5,null,7]\n\t\tOutput: 15\n\t\tExplanation: \n\t\tTilt of node 3 : |0-0| = 0 (no children)\n\t\tTilt of node 5 : |0-0| = 0 (no children)\n\t\tTilt of node 7 : |0-0| = 0 (no children)\n\t\tTilt of node 2 : |3-5| = 2 (left subtree is just left child, so sum is 3; right subtree is just right child, so sum is 5)\n\t\tTilt of node 9 : |0-7| = 7 (no left child, so sum is 0; right subtree is just right child, so sum is 7)\n\t\tTilt of node 4 : |(3+5+2)-(9+7)| = |10-16| = 6 (left subtree values are 3, 5, and 2, which sums to 10; right subtree values are 9 and 7, which sums to 16)\n\t\tSum of every tilt : 0 + 0 + 0 + 2 + 7 + 6 = 15\n\t\tExample 3:\n\t\tInput: root = [21,7,14,1,1,2,2,3,3]\n\t\tOutput: 9\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 564, - "question": "class Solution:\n def nearestPalindromic(self, n: str) -> str:\n\t\t\"\"\"\n\t\tGiven a string n representing an integer, return the closest integer (not including itself), which is a palindrome. If there is a tie, return the smaller one.\n\t\tThe closest is defined as the absolute difference minimized between two integers.\n\t\tExample 1:\n\t\tInput: n = \"123\"\n\t\tOutput: \"121\"\n\t\tExample 2:\n\t\tInput: n = \"1\"\n\t\tOutput: \"0\"\n\t\tExplanation: 0 and 2 are the closest palindromes but we return the smallest which is 0.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 565, - "question": "class Solution:\n def arrayNesting(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou are given an integer array nums of length n where nums is a permutation of the numbers in the range [0, n - 1].\n\t\tYou should build a set s[k] = {nums[k], nums[nums[k]], nums[nums[nums[k]]], ... } subjected to the following rule:\n\t\t\tThe first element in s[k] starts with the selection of the element nums[k] of index = k.\n\t\t\tThe next element in s[k] should be nums[nums[k]], and then nums[nums[nums[k]]], and so on.\n\t\t\tWe stop adding right before a duplicate element occurs in s[k].\n\t\tReturn the longest length of a set s[k].\n\t\tExample 1:\n\t\tInput: nums = [5,4,0,3,1,6,2]\n\t\tOutput: 4\n\t\tExplanation: \n\t\tnums[0] = 5, nums[1] = 4, nums[2] = 0, nums[3] = 3, nums[4] = 1, nums[5] = 6, nums[6] = 2.\n\t\tOne of the longest sets s[k]:\n\t\ts[0] = {nums[0], nums[5], nums[6], nums[2]} = {5, 6, 2, 0}\n\t\tExample 2:\n\t\tInput: nums = [0,1,2]\n\t\tOutput: 1\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 566, - "question": "class Solution:\n def matrixReshape(self, mat: List[List[int]], r: int, c: int) -> List[List[int]]:\n\t\t\"\"\"\n\t\tIn MATLAB, there is a handy function called reshape which can reshape an m x n matrix into a new one with a different size r x c keeping its original data.\n\t\tYou are given an m x n matrix mat and two integers r and c representing the number of rows and the number of columns of the wanted reshaped matrix.\n\t\tThe reshaped matrix should be filled with all the elements of the original matrix in the same row-traversing order as they were.\n\t\tIf the reshape operation with given parameters is possible and legal, output the new reshaped matrix; Otherwise, output the original matrix.\n\t\tExample 1:\n\t\tInput: mat = [[1,2],[3,4]], r = 1, c = 4\n\t\tOutput: [[1,2,3,4]]\n\t\tExample 2:\n\t\tInput: mat = [[1,2],[3,4]], r = 2, c = 4\n\t\tOutput: [[1,2],[3,4]]\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 567, - "question": "class Solution:\n def checkInclusion(self, s1: str, s2: str) -> bool:\n\t\t\"\"\"\n\t\tGiven two strings s1 and s2, return true if s2 contains a permutation of s1, or false otherwise.\n\t\tIn other words, return true if one of s1's permutations is the substring of s2.\n\t\tExample 1:\n\t\tInput: s1 = \"ab\", s2 = \"eidbaooo\"\n\t\tOutput: true\n\t\tExplanation: s2 contains one permutation of s1 (\"ba\").\n\t\tExample 2:\n\t\tInput: s1 = \"ab\", s2 = \"eidboaoo\"\n\t\tOutput: false\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 572, - "question": "class Solution:\n def isSubtree(self, root: Optional[TreeNode], subRoot: Optional[TreeNode]) -> bool:\n\t\t\"\"\"\n\t\tGiven the roots of two binary trees root and subRoot, return true if there is a subtree of root with the same structure and node values of subRoot and false otherwise.\n\t\tA subtree of a binary tree tree is a tree that consists of a node in tree and all of this node's descendants. The tree tree could also be considered as a subtree of itself.\n\t\tExample 1:\n\t\tInput: root = [3,4,5,1,2], subRoot = [4,1,2]\n\t\tOutput: true\n\t\tExample 2:\n\t\tInput: root = [3,4,5,1,2,null,null,null,null,0], subRoot = [4,1,2]\n\t\tOutput: false\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 575, - "question": "class Solution:\n def distributeCandies(self, candyType: List[int]) -> int:\n\t\t\"\"\"\n\t\tAlice has n candies, where the ith candy is of type candyType[i]. Alice noticed that she started to gain weight, so she visited a doctor.\n\t\tThe doctor advised Alice to only eat n / 2 of the candies she has (n is always even). Alice likes her candies very much, and she wants to eat the maximum number of different types of candies while still following the doctor's advice.\n\t\tGiven the integer array candyType of length n, return the maximum number of different types of candies she can eat if she only eats n / 2 of them.\n\t\tExample 1:\n\t\tInput: candyType = [1,1,2,2,3,3]\n\t\tOutput: 3\n\t\tExplanation: Alice can only eat 6 / 2 = 3 candies. Since there are only 3 types, she can eat one of each type.\n\t\tExample 2:\n\t\tInput: candyType = [1,1,2,3]\n\t\tOutput: 2\n\t\tExplanation: Alice can only eat 4 / 2 = 2 candies. Whether she eats types [1,2], [1,3], or [2,3], she still can only eat 2 different types.\n\t\tExample 3:\n\t\tInput: candyType = [6,6,6,6]\n\t\tOutput: 1\n\t\tExplanation: Alice can only eat 4 / 2 = 2 candies. Even though she can eat 2 candies, she only has 1 type.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 576, - "question": "class Solution:\n def findPaths(self, m: int, n: int, maxMove: int, startRow: int, startColumn: int) -> int:\n\t\t\"\"\"\n\t\tThere is an m x n grid with a ball. The ball is initially at the position [startRow, startColumn]. You are allowed to move the ball to one of the four adjacent cells in the grid (possibly out of the grid crossing the grid boundary). You can apply at most maxMove moves to the ball.\n\t\tGiven the five integers m, n, maxMove, startRow, startColumn, return the number of paths to move the ball out of the grid boundary. Since the answer can be very large, return it modulo 109 + 7.\n\t\tExample 1:\n\t\tInput: m = 2, n = 2, maxMove = 2, startRow = 0, startColumn = 0\n\t\tOutput: 6\n\t\tExample 2:\n\t\tInput: m = 1, n = 3, maxMove = 3, startRow = 0, startColumn = 1\n\t\tOutput: 12\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 581, - "question": "class Solution:\n def findUnsortedSubarray(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tGiven an integer array nums, you need to find one continuous subarray that if you only sort this subarray in ascending order, then the whole array will be sorted in ascending order.\n\t\tReturn the shortest such subarray and output its length.\n\t\tExample 1:\n\t\tInput: nums = [2,6,4,8,10,9,15]\n\t\tOutput: 5\n\t\tExplanation: You need to sort [6, 4, 8, 10, 9] in ascending order to make the whole array sorted in ascending order.\n\t\tExample 2:\n\t\tInput: nums = [1,2,3,4]\n\t\tOutput: 0\n\t\tExample 3:\n\t\tInput: nums = [1]\n\t\tOutput: 0\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 583, - "question": "class Solution:\n def minDistance(self, word1: str, word2: str) -> int:\n\t\t\"\"\"\n\t\tGiven two strings word1 and word2, return the minimum number of steps required to make word1 and word2 the same.\n\t\tIn one step, you can delete exactly one character in either string.\n\t\tExample 1:\n\t\tInput: word1 = \"sea\", word2 = \"eat\"\n\t\tOutput: 2\n\t\tExplanation: You need one step to make \"sea\" to \"ea\" and another step to make \"eat\" to \"ea\".\n\t\tExample 2:\n\t\tInput: word1 = \"leetcode\", word2 = \"etco\"\n\t\tOutput: 4\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 587, - "question": "class Solution:\n def outerTrees(self, trees: List[List[int]]) -> List[List[int]]:\n\t\t\"\"\"\n\t\tYou are given an array trees where trees[i] = [xi, yi] represents the location of a tree in the garden.\n\t\tFence the entire garden using the minimum length of rope, as it is expensive. The garden is well-fenced only if all the trees are enclosed.\n\t\tReturn the coordinates of trees that are exactly located on the fence perimeter. You may return the answer in any order.\n\t\tExample 1:\n\t\tInput: trees = [[1,1],[2,2],[2,0],[2,4],[3,3],[4,2]]\n\t\tOutput: [[1,1],[2,0],[4,2],[3,3],[2,4]]\n\t\tExplanation: All the trees will be on the perimeter of the fence except the tree at [2, 2], which will be inside the fence.\n\t\tExample 2:\n\t\tInput: trees = [[1,2],[2,2],[4,2]]\n\t\tOutput: [[4,2],[2,2],[1,2]]\n\t\tExplanation: The fence forms a line that passes through all the trees.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 591, - "question": "class Solution:\n def isValid(self, code: str) -> bool:\n\t\t\"\"\"\n\t\tGiven a string representing a code snippet, implement a tag validator to parse the code and return whether it is valid.\n\t\tA code snippet is valid if all the following rules hold:\n\t\t\tThe code must be wrapped in a valid closed tag. Otherwise, the code is invalid.\n\t\t\tA closed tag (not necessarily valid) has exactly the following format : TAG_CONTENT. Among them, is the start tag, and is the end tag. The TAG_NAME in start and end tags should be the same. A closed tag is valid if and only if the TAG_NAME and TAG_CONTENT are valid.\n\t\t\tA valid TAG_NAME only contain upper-case letters, and has length in range [1,9]. Otherwise, the TAG_NAME is invalid.\n\t\t\tA valid TAG_CONTENT may contain other valid closed tags, cdata and any characters (see note1) EXCEPT unmatched <, unmatched start and end tag, and unmatched or closed tags with invalid TAG_NAME. Otherwise, the TAG_CONTENT is invalid.\n\t\t\tA start tag is unmatched if no end tag exists with the same TAG_NAME, and vice versa. However, you also need to consider the issue of unbalanced when tags are nested.\n\t\t\tA < is unmatched if you cannot find a subsequent >. And when you find a < or should be parsed as TAG_NAME (not necessarily valid).\n\t\t\tThe cdata has the following format : . The range of CDATA_CONTENT is defined as the characters between .\n\t\t\tCDATA_CONTENT may contain any characters. The function of cdata is to forbid the validator to parse CDATA_CONTENT, so even it has some characters that can be parsed as tag (no matter valid or invalid), you should treat it as regular characters.\n\t\tExample 1:\n\t\tInput: code = \"
This is the first line ]]>
\"\n\t\tOutput: true\n\t\tExplanation: \n\t\tThe code is wrapped in a closed tag :
and
. \n\t\tThe TAG_NAME is valid, the TAG_CONTENT consists of some characters and cdata. \n\t\tAlthough CDATA_CONTENT has an unmatched start tag with invalid TAG_NAME, it should be considered as plain text, not parsed as a tag.\n\t\tSo TAG_CONTENT is valid, and then the code is valid. Thus return true.\n\t\tExample 2:\n\t\tInput: code = \"
>> ![cdata[]] ]>]]>]]>>]
\"\n\t\tOutput: true\n\t\tExplanation:\n\t\tWe first separate the code into : start_tag|tag_content|end_tag.\n\t\tstart_tag -> \"
\"\n\t\tend_tag -> \"
\"\n\t\ttag_content could also be separated into : text1|cdata|text2.\n\t\ttext1 -> \">> ![cdata[]] \"\n\t\tcdata -> \"]>]]>\", where the CDATA_CONTENT is \"
]>\"\n\t\ttext2 -> \"]]>>]\"\n\t\tThe reason why start_tag is NOT \"
>>\" is because of the rule 6.\n\t\tThe reason why cdata is NOT \"]>]]>]]>\" is because of the rule 7.\n\t\tExample 3:\n\t\tInput: code = \" \"\n\t\tOutput: false\n\t\tExplanation: Unbalanced. If \"\" is closed, then \"\" must be unmatched, and vice versa.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 592, - "question": "class Solution:\n def fractionAddition(self, expression: str) -> str:\n\t\t\"\"\"\n\t\tGiven a string expression representing an expression of fraction addition and subtraction, return the calculation result in string format.\n\t\tThe final result should be an irreducible fraction. If your final result is an integer, change it to the format of a fraction that has a denominator 1. So in this case, 2 should be converted to 2/1.\n\t\tExample 1:\n\t\tInput: expression = \"-1/2+1/2\"\n\t\tOutput: \"0/1\"\n\t\tExample 2:\n\t\tInput: expression = \"-1/2+1/2+1/3\"\n\t\tOutput: \"1/3\"\n\t\tExample 3:\n\t\tInput: expression = \"1/3-1/2\"\n\t\tOutput: \"-1/6\"\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 593, - "question": "class Solution:\n def validSquare(self, p1: List[int], p2: List[int], p3: List[int], p4: List[int]) -> bool:\n\t\t\"\"\"\n\t\tGiven the coordinates of four points in 2D space p1, p2, p3 and p4, return true if the four points construct a square.\n\t\tThe coordinate of a point pi is represented as [xi, yi]. The input is not given in any order.\n\t\tA valid square has four equal sides with positive length and four equal angles (90-degree angles).\n\t\tExample 1:\n\t\tInput: p1 = [0,0], p2 = [1,1], p3 = [1,0], p4 = [0,1]\n\t\tOutput: true\n\t\tExample 2:\n\t\tInput: p1 = [0,0], p2 = [1,1], p3 = [1,0], p4 = [0,12]\n\t\tOutput: false\n\t\tExample 3:\n\t\tInput: p1 = [1,0], p2 = [-1,0], p3 = [0,1], p4 = [0,-1]\n\t\tOutput: true\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 594, - "question": "class Solution:\n def findLHS(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tWe define a harmonious array as an array where the difference between its maximum value and its minimum value is exactly 1.\r\n\t\tGiven an integer array nums, return the length of its longest harmonious subsequence among all its possible subsequences.\r\n\t\tA subsequence of array is a sequence that can be derived from the array by deleting some or no elements without changing the order of the remaining elements.\r\n\t\tExample 1:\r\n\t\tInput: nums = [1,3,2,2,5,2,3,7]\r\n\t\tOutput: 5\r\n\t\tExplanation: The longest harmonious subsequence is [3,2,2,2,3].\r\n\t\tExample 2:\r\n\t\tInput: nums = [1,2,3,4]\r\n\t\tOutput: 2\r\n\t\tExample 3:\r\n\t\tInput: nums = [1,1,1,1]\r\n\t\tOutput: 0\r\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 598, - "question": "class Solution:\n def maxCount(self, m: int, n: int, ops: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tYou are given an m x n matrix M initialized with all 0's and an array of operations ops, where ops[i] = [ai, bi] means M[x][y] should be incremented by one for all 0 <= x < ai and 0 <= y < bi.\n\t\tCount and return the number of maximum integers in the matrix after performing all the operations.\n\t\tExample 1:\n\t\tInput: m = 3, n = 3, ops = [[2,2],[3,3]]\n\t\tOutput: 4\n\t\tExplanation: The maximum integer in M is 2, and there are four of it in M. So return 4.\n\t\tExample 2:\n\t\tInput: m = 3, n = 3, ops = [[2,2],[3,3],[3,3],[3,3],[2,2],[3,3],[3,3],[3,3],[2,2],[3,3],[3,3],[3,3]]\n\t\tOutput: 4\n\t\tExample 3:\n\t\tInput: m = 3, n = 3, ops = []\n\t\tOutput: 9\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 599, - "question": "class Solution:\n def findRestaurant(self, list1: List[str], list2: List[str]) -> List[str]:\n\t\t\"\"\"\n\t\tGiven two arrays of strings list1 and list2, find the common strings with the least index sum.\n\t\tA common string is a string that appeared in both list1 and list2.\n\t\tA common string with the least index sum is a common string such that if it appeared at list1[i] and list2[j] then i + j should be the minimum value among all the other common strings.\n\t\tReturn all the common strings with the least index sum. Return the answer in any order.\n\t\tExample 1:\n\t\tInput: list1 = [\"Shogun\",\"Tapioca Express\",\"Burger King\",\"KFC\"], list2 = [\"Piatti\",\"The Grill at Torrey Pines\",\"Hungry Hunter Steakhouse\",\"Shogun\"]\n\t\tOutput: [\"Shogun\"]\n\t\tExplanation: The only common string is \"Shogun\".\n\t\tExample 2:\n\t\tInput: list1 = [\"Shogun\",\"Tapioca Express\",\"Burger King\",\"KFC\"], list2 = [\"KFC\",\"Shogun\",\"Burger King\"]\n\t\tOutput: [\"Shogun\"]\n\t\tExplanation: The common string with the least index sum is \"Shogun\" with index sum = (0 + 1) = 1.\n\t\tExample 3:\n\t\tInput: list1 = [\"happy\",\"sad\",\"good\"], list2 = [\"sad\",\"happy\",\"good\"]\n\t\tOutput: [\"sad\",\"happy\"]\n\t\tExplanation: There are three common strings:\n\t\t\"happy\" with index sum = (0 + 1) = 1.\n\t\t\"sad\" with index sum = (1 + 0) = 1.\n\t\t\"good\" with index sum = (2 + 2) = 4.\n\t\tThe strings with the least index sum are \"sad\" and \"happy\".\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 600, - "question": "class Solution:\n def findIntegers(self, n: int) -> int:\n\t\t\"\"\"\n\t\tGiven a positive integer n, return the number of the integers in the range [0, n] whose binary representations do not contain consecutive ones.\n\t\tExample 1:\n\t\tInput: n = 5\n\t\tOutput: 5\n\t\tExplanation:\n\t\tHere are the non-negative integers <= 5 with their corresponding binary representations:\n\t\t0 : 0\n\t\t1 : 1\n\t\t2 : 10\n\t\t3 : 11\n\t\t4 : 100\n\t\t5 : 101\n\t\tAmong them, only integer 3 disobeys the rule (two consecutive ones) and the other 5 satisfy the rule. \n\t\tExample 2:\n\t\tInput: n = 1\n\t\tOutput: 2\n\t\tExample 3:\n\t\tInput: n = 2\n\t\tOutput: 3\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 605, - "question": "class Solution:\n def canPlaceFlowers(self, flowerbed: List[int], n: int) -> bool:\n\t\t\"\"\"\n\t\tYou have a long flowerbed in which some of the plots are planted, and some are not. However, flowers cannot be planted in adjacent plots.\n\t\tGiven an integer array flowerbed containing 0's and 1's, where 0 means empty and 1 means not empty, and an integer n, return if n new flowers can be planted in the flowerbed without violating the no-adjacent-flowers rule.\n\t\tExample 1:\n\t\tInput: flowerbed = [1,0,0,0,1], n = 1\n\t\tOutput: true\n\t\tExample 2:\n\t\tInput: flowerbed = [1,0,0,0,1], n = 2\n\t\tOutput: false\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 606, - "question": "class Solution:\n def tree2str(self, root: Optional[TreeNode]) -> str:\n\t\t\"\"\"\n\t\tGiven the root of a binary tree, construct a string consisting of parenthesis and integers from a binary tree with the preorder traversal way, and return it.\n\t\tOmit all the empty parenthesis pairs that do not affect the one-to-one mapping relationship between the string and the original binary tree.\n\t\tExample 1:\n\t\tInput: root = [1,2,3,4]\n\t\tOutput: \"1(2(4))(3)\"\n\t\tExplanation: Originally, it needs to be \"1(2(4)())(3()())\", but you need to omit all the unnecessary empty parenthesis pairs. And it will be \"1(2(4))(3)\"\n\t\tExample 2:\n\t\tInput: root = [1,2,3,null,4]\n\t\tOutput: \"1(2()(4))(3)\"\n\t\tExplanation: Almost the same as the first example, except we cannot omit the first parenthesis pair to break the one-to-one mapping relationship between the input and the output.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 609, - "question": "class Solution:\n def findDuplicate(self, paths: List[str]) -> List[List[str]]:\n\t\t\"\"\"\n\t\tGiven a list paths of directory info, including the directory path, and all the files with contents in this directory, return all the duplicate files in the file system in terms of their paths. You may return the answer in any order.\n\t\tA group of duplicate files consists of at least two files that have the same content.\n\t\tA single directory info string in the input list has the following format:\n\t\t\t\"root/d1/d2/.../dm f1.txt(f1_content) f2.txt(f2_content) ... fn.txt(fn_content)\"\n\t\tIt means there are n files (f1.txt, f2.txt ... fn.txt) with content (f1_content, f2_content ... fn_content) respectively in the directory \"root/d1/d2/.../dm\". Note that n >= 1 and m >= 0. If m = 0, it means the directory is just the root directory.\n\t\tThe output is a list of groups of duplicate file paths. For each group, it contains all the file paths of the files that have the same content. A file path is a string that has the following format:\n\t\t\t\"directory_path/file_name.txt\"\n\t\tExample 1:\n\t\tInput: paths = [\"root/a 1.txt(abcd) 2.txt(efgh)\",\"root/c 3.txt(abcd)\",\"root/c/d 4.txt(efgh)\",\"root 4.txt(efgh)\"]\n\t\tOutput: [[\"root/a/2.txt\",\"root/c/d/4.txt\",\"root/4.txt\"],[\"root/a/1.txt\",\"root/c/3.txt\"]]\n\t\tExample 2:\n\t\tInput: paths = [\"root/a 1.txt(abcd) 2.txt(efgh)\",\"root/c 3.txt(abcd)\",\"root/c/d 4.txt(efgh)\"]\n\t\tOutput: [[\"root/a/2.txt\",\"root/c/d/4.txt\"],[\"root/a/1.txt\",\"root/c/3.txt\"]]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 611, - "question": "class Solution:\n def triangleNumber(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tGiven an integer array nums, return the number of triplets chosen from the array that can make triangles if we take them as side lengths of a triangle.\n\t\tExample 1:\n\t\tInput: nums = [2,2,3,4]\n\t\tOutput: 3\n\t\tExplanation: Valid combinations are: \n\t\t2,3,4 (using the first 2)\n\t\t2,3,4 (using the second 2)\n\t\t2,2,3\n\t\tExample 2:\n\t\tInput: nums = [4,2,3,4]\n\t\tOutput: 4\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 617, - "question": "class Solution:\n def mergeTrees(self, root1: Optional[TreeNode], root2: Optional[TreeNode]) -> Optional[TreeNode]:\n\t\t\"\"\"\n\t\tYou are given two binary trees root1 and root2.\n\t\tImagine that when you put one of them to cover the other, some nodes of the two trees are overlapped while the others are not. You need to merge the two trees into a new binary tree. The merge rule is that if two nodes overlap, then sum node values up as the new value of the merged node. Otherwise, the NOT null node will be used as the node of the new tree.\n\t\tReturn the merged tree.\n\t\tNote: The merging process must start from the root nodes of both trees.\n\t\tExample 1:\n\t\tInput: root1 = [1,3,2,5], root2 = [2,1,3,null,4,null,7]\n\t\tOutput: [3,4,5,5,4,null,7]\n\t\tExample 2:\n\t\tInput: root1 = [1], root2 = [1,2]\n\t\tOutput: [2,2]\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 621, - "question": "class Solution:\n def leastInterval(self, tasks: List[str], n: int) -> int:\n\t\t\"\"\"\n\t\tGiven a characters array tasks, representing the tasks a CPU needs to do, where each letter represents a different task. Tasks could be done in any order. Each task is done in one unit of time. For each unit of time, the CPU could complete either one task or just be idle.\n\t\tHowever, there is a non-negative integer n that represents the cooldown period between two same tasks (the same letter in the array), that is that there must be at least n units of time between any two same tasks.\n\t\tReturn the least number of units of times that the CPU will take to finish all the given tasks.\n\t\tExample 1:\n\t\tInput: tasks = [\"A\",\"A\",\"A\",\"B\",\"B\",\"B\"], n = 2\n\t\tOutput: 8\n\t\tExplanation: \n\t\tA -> B -> idle -> A -> B -> idle -> A -> B\n\t\tThere is at least 2 units of time between any two same tasks.\n\t\tExample 2:\n\t\tInput: tasks = [\"A\",\"A\",\"A\",\"B\",\"B\",\"B\"], n = 0\n\t\tOutput: 6\n\t\tExplanation: On this case any permutation of size 6 would work since n = 0.\n\t\t[\"A\",\"A\",\"A\",\"B\",\"B\",\"B\"]\n\t\t[\"A\",\"B\",\"A\",\"B\",\"A\",\"B\"]\n\t\t[\"B\",\"B\",\"B\",\"A\",\"A\",\"A\"]\n\t\t...\n\t\tAnd so on.\n\t\tExample 3:\n\t\tInput: tasks = [\"A\",\"A\",\"A\",\"A\",\"A\",\"A\",\"B\",\"C\",\"D\",\"E\",\"F\",\"G\"], n = 2\n\t\tOutput: 16\n\t\tExplanation: \n\t\tOne possible solution is\n\t\tA -> B -> C -> A -> D -> E -> A -> F -> G -> A -> idle -> idle -> A -> idle -> idle -> A\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 623, - "question": "class Solution:\n def addOneRow(self, root: Optional[TreeNode], val: int, depth: int) -> Optional[TreeNode]:\n\t\t\"\"\"\n\t\tGiven the root of a binary tree and two integers val and depth, add a row of nodes with value val at the given depth depth.\n\t\tNote that the root node is at depth 1.\n\t\tThe adding rule is:\n\t\t\tGiven the integer depth, for each not null tree node cur at the depth depth - 1, create two tree nodes with value val as cur's left subtree root and right subtree root.\n\t\t\tcur's original left subtree should be the left subtree of the new left subtree root.\n\t\t\tcur's original right subtree should be the right subtree of the new right subtree root.\n\t\t\tIf depth == 1 that means there is no depth depth - 1 at all, then create a tree node with value val as the new root of the whole original tree, and the original tree is the new root's left subtree.\n\t\tExample 1:\n\t\tInput: root = [4,2,6,3,1,5], val = 1, depth = 2\n\t\tOutput: [4,1,1,2,null,null,6,3,1,5]\n\t\tExample 2:\n\t\tInput: root = [4,2,null,3,1], val = 1, depth = 3\n\t\tOutput: [4,2,null,1,1,3,null,null,1]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 628, - "question": "class Solution:\n def maximumProduct(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tGiven an integer array nums, find three numbers whose product is maximum and return the maximum product.\n\t\tExample 1:\n\t\tInput: nums = [1,2,3]\n\t\tOutput: 6\n\t\tExample 2:\n\t\tInput: nums = [1,2,3,4]\n\t\tOutput: 24\n\t\tExample 3:\n\t\tInput: nums = [-1,-2,-3]\n\t\tOutput: -6\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 629, - "question": "class Solution:\n def kInversePairs(self, n: int, k: int) -> int:\n\t\t\"\"\"\n\t\tFor an integer array nums, an inverse pair is a pair of integers [i, j] where 0 <= i < j < nums.length and nums[i] > nums[j].\n\t\tGiven two integers n and k, return the number of different arrays consist of numbers from 1 to n such that there are exactly k inverse pairs. Since the answer can be huge, return it modulo 109 + 7.\n\t\tExample 1:\n\t\tInput: n = 3, k = 0\n\t\tOutput: 1\n\t\tExplanation: Only the array [1,2,3] which consists of numbers from 1 to 3 has exactly 0 inverse pairs.\n\t\tExample 2:\n\t\tInput: n = 3, k = 1\n\t\tOutput: 2\n\t\tExplanation: The array [1,3,2] and [2,1,3] have exactly 1 inverse pair.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 630, - "question": "class Solution:\n def scheduleCourse(self, courses: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tThere are n different online courses numbered from 1 to n. You are given an array courses where courses[i] = [durationi, lastDayi] indicate that the ith course should be taken continuously for durationi days and must be finished before or on lastDayi.\n\t\tYou will start on the 1st day and you cannot take two or more courses simultaneously.\n\t\tReturn the maximum number of courses that you can take.\n\t\tExample 1:\n\t\tInput: courses = [[100,200],[200,1300],[1000,1250],[2000,3200]]\n\t\tOutput: 3\n\t\tExplanation: \n\t\tThere are totally 4 courses, but you can take 3 courses at most:\n\t\tFirst, take the 1st course, it costs 100 days so you will finish it on the 100th day, and ready to take the next course on the 101st day.\n\t\tSecond, take the 3rd course, it costs 1000 days so you will finish it on the 1100th day, and ready to take the next course on the 1101st day. \n\t\tThird, take the 2nd course, it costs 200 days so you will finish it on the 1300th day. \n\t\tThe 4th course cannot be taken now, since you will finish it on the 3300th day, which exceeds the closed date.\n\t\tExample 2:\n\t\tInput: courses = [[1,2]]\n\t\tOutput: 1\n\t\tExample 3:\n\t\tInput: courses = [[3,2],[4,3]]\n\t\tOutput: 0\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 632, - "question": "class Solution:\n def smallestRange(self, nums: List[List[int]]) -> List[int]:\n\t\t\"\"\"\n\t\tYou have k lists of sorted integers in non-decreasing order. Find the smallest range that includes at least one number from each of the k lists.\n\t\tWe define the range [a, b] is smaller than range [c, d] if b - a < d - c or a < c if b - a == d - c.\n\t\tExample 1:\n\t\tInput: nums = [[4,10,15,24,26],[0,9,12,20],[5,18,22,30]]\n\t\tOutput: [20,24]\n\t\tExplanation: \n\t\tList 1: [4, 10, 15, 24,26], 24 is in range [20,24].\n\t\tList 2: [0, 9, 12, 20], 20 is in range [20,24].\n\t\tList 3: [5, 18, 22, 30], 22 is in range [20,24].\n\t\tExample 2:\n\t\tInput: nums = [[1,2,3],[1,2,3],[1,2,3]]\n\t\tOutput: [1,1]\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 633, - "question": "class Solution:\n def judgeSquareSum(self, c: int) -> bool:\n\t\t\"\"\"\n\t\tGiven a non-negative integer c, decide whether there're two integers a and b such that a2 + b2 = c.\n\t\tExample 1:\n\t\tInput: c = 5\n\t\tOutput: true\n\t\tExplanation: 1 * 1 + 2 * 2 = 5\n\t\tExample 2:\n\t\tInput: c = 3\n\t\tOutput: false\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 636, - "question": "class Solution:\n def exclusiveTime(self, n: int, logs: List[str]) -> List[int]:\n\t\t\"\"\"\n\t\tOn a single-threaded CPU, we execute a program containing n functions. Each function has a unique ID between 0 and n-1.\n\t\tFunction calls are stored in a call stack: when a function call starts, its ID is pushed onto the stack, and when a function call ends, its ID is popped off the stack. The function whose ID is at the top of the stack is the current function being executed. Each time a function starts or ends, we write a log with the ID, whether it started or ended, and the timestamp.\n\t\tYou are given a list logs, where logs[i] represents the ith log message formatted as a string \"{function_id}:{\"start\" | \"end\"}:{timestamp}\". For example, \"0:start:3\" means a function call with function ID 0 started at the beginning of timestamp 3, and \"1:end:2\" means a function call with function ID 1 ended at the end of timestamp 2. Note that a function can be called multiple times, possibly recursively.\n\t\tA function's exclusive time is the sum of execution times for all function calls in the program. For example, if a function is called twice, one call executing for 2 time units and another call executing for 1 time unit, the exclusive time is 2 + 1 = 3.\n\t\tReturn the exclusive time of each function in an array, where the value at the ith index represents the exclusive time for the function with ID i.\n\t\tExample 1:\n\t\tInput: n = 2, logs = [\"0:start:0\",\"1:start:2\",\"1:end:5\",\"0:end:6\"]\n\t\tOutput: [3,4]\n\t\tExplanation:\n\t\tFunction 0 starts at the beginning of time 0, then it executes 2 for units of time and reaches the end of time 1.\n\t\tFunction 1 starts at the beginning of time 2, executes for 4 units of time, and ends at the end of time 5.\n\t\tFunction 0 resumes execution at the beginning of time 6 and executes for 1 unit of time.\n\t\tSo function 0 spends 2 + 1 = 3 units of total time executing, and function 1 spends 4 units of total time executing.\n\t\tExample 2:\n\t\tInput: n = 1, logs = [\"0:start:0\",\"0:start:2\",\"0:end:5\",\"0:start:6\",\"0:end:6\",\"0:end:7\"]\n\t\tOutput: [8]\n\t\tExplanation:\n\t\tFunction 0 starts at the beginning of time 0, executes for 2 units of time, and recursively calls itself.\n\t\tFunction 0 (recursive call) starts at the beginning of time 2 and executes for 4 units of time.\n\t\tFunction 0 (initial call) resumes execution then immediately calls itself again.\n\t\tFunction 0 (2nd recursive call) starts at the beginning of time 6 and executes for 1 unit of time.\n\t\tFunction 0 (initial call) resumes execution at the beginning of time 7 and executes for 1 unit of time.\n\t\tSo function 0 spends 2 + 4 + 1 + 1 = 8 units of total time executing.\n\t\tExample 3:\n\t\tInput: n = 2, logs = [\"0:start:0\",\"0:start:2\",\"0:end:5\",\"1:start:6\",\"1:end:6\",\"0:end:7\"]\n\t\tOutput: [7,1]\n\t\tExplanation:\n\t\tFunction 0 starts at the beginning of time 0, executes for 2 units of time, and recursively calls itself.\n\t\tFunction 0 (recursive call) starts at the beginning of time 2 and executes for 4 units of time.\n\t\tFunction 0 (initial call) resumes execution then immediately calls function 1.\n\t\tFunction 1 starts at the beginning of time 6, executes 1 unit of time, and ends at the end of time 6.\n\t\tFunction 0 resumes execution at the beginning of time 6 and executes for 2 units of time.\n\t\tSo function 0 spends 2 + 4 + 1 = 7 units of total time executing, and function 1 spends 1 unit of total time executing.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 637, - "question": "class Solution:\n def averageOfLevels(self, root: Optional[TreeNode]) -> List[float]:\n\t\t\"\"\"\n\t\tGiven the root of a binary tree, return the average value of the nodes on each level in the form of an array. Answers within 10-5 of the actual answer will be accepted.\n\t\tExample 1:\n\t\tInput: root = [3,9,20,null,null,15,7]\n\t\tOutput: [3.00000,14.50000,11.00000]\n\t\tExplanation: The average value of nodes on level 0 is 3, on level 1 is 14.5, and on level 2 is 11.\n\t\tHence return [3, 14.5, 11].\n\t\tExample 2:\n\t\tInput: root = [3,9,20,15,7]\n\t\tOutput: [3.00000,14.50000,11.00000]\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 638, - "question": "class Solution:\n def shoppingOffers(self, price: List[int], special: List[List[int]], needs: List[int]) -> int:\n\t\t\"\"\"\n\t\tIn LeetCode Store, there are n items to sell. Each item has a price. However, there are some special offers, and a special offer consists of one or more different kinds of items with a sale price.\n\t\tYou are given an integer array price where price[i] is the price of the ith item, and an integer array needs where needs[i] is the number of pieces of the ith item you want to buy.\n\t\tYou are also given an array special where special[i] is of size n + 1 where special[i][j] is the number of pieces of the jth item in the ith offer and special[i][n] (i.e., the last integer in the array) is the price of the ith offer.\n\t\tReturn the lowest price you have to pay for exactly certain items as given, where you could make optimal use of the special offers. You are not allowed to buy more items than you want, even if that would lower the overall price. You could use any of the special offers as many times as you want.\n\t\tExample 1:\n\t\tInput: price = [2,5], special = [[3,0,5],[1,2,10]], needs = [3,2]\n\t\tOutput: 14\n\t\tExplanation: There are two kinds of items, A and B. Their prices are $2 and $5 respectively. \n\t\tIn special offer 1, you can pay $5 for 3A and 0B\n\t\tIn special offer 2, you can pay $10 for 1A and 2B. \n\t\tYou need to buy 3A and 2B, so you may pay $10 for 1A and 2B (special offer #2), and $4 for 2A.\n\t\tExample 2:\n\t\tInput: price = [2,3,4], special = [[1,1,0,4],[2,2,1,9]], needs = [1,2,1]\n\t\tOutput: 11\n\t\tExplanation: The price of A is $2, and $3 for B, $4 for C. \n\t\tYou may pay $4 for 1A and 1B, and $9 for 2A ,2B and 1C. \n\t\tYou need to buy 1A ,2B and 1C, so you may pay $4 for 1A and 1B (special offer #1), and $3 for 1B, $4 for 1C. \n\t\tYou cannot add more items, though only $9 for 2A ,2B and 1C.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 639, - "question": "class Solution:\n def numDecodings(self, s: str) -> int:\n\t\t\"\"\"\n\t\tA message containing letters from A-Z can be encoded into numbers using the following mapping:\n\t\t'A' -> \"1\"\n\t\t'B' -> \"2\"\n\t\t...\n\t\t'Z' -> \"26\"\n\t\tTo decode an encoded message, all the digits must be grouped then mapped back into letters using the reverse of the mapping above (there may be multiple ways). For example, \"11106\" can be mapped into:\n\t\t\t\"AAJF\" with the grouping (1 1 10 6)\n\t\t\t\"KJF\" with the grouping (11 10 6)\n\t\tNote that the grouping (1 11 06) is invalid because \"06\" cannot be mapped into 'F' since \"6\" is different from \"06\".\n\t\tIn addition to the mapping above, an encoded message may contain the '*' character, which can represent any digit from '1' to '9' ('0' is excluded). For example, the encoded message \"1*\" may represent any of the encoded messages \"11\", \"12\", \"13\", \"14\", \"15\", \"16\", \"17\", \"18\", or \"19\". Decoding \"1*\" is equivalent to decoding any of the encoded messages it can represent.\n\t\tGiven a string s consisting of digits and '*' characters, return the number of ways to decode it.\n\t\tSince the answer may be very large, return it modulo 109 + 7.\n\t\tExample 1:\n\t\tInput: s = \"*\"\n\t\tOutput: 9\n\t\tExplanation: The encoded message can represent any of the encoded messages \"1\", \"2\", \"3\", \"4\", \"5\", \"6\", \"7\", \"8\", or \"9\".\n\t\tEach of these can be decoded to the strings \"A\", \"B\", \"C\", \"D\", \"E\", \"F\", \"G\", \"H\", and \"I\" respectively.\n\t\tHence, there are a total of 9 ways to decode \"*\".\n\t\tExample 2:\n\t\tInput: s = \"1*\"\n\t\tOutput: 18\n\t\tExplanation: The encoded message can represent any of the encoded messages \"11\", \"12\", \"13\", \"14\", \"15\", \"16\", \"17\", \"18\", or \"19\".\n\t\tEach of these encoded messages have 2 ways to be decoded (e.g. \"11\" can be decoded to \"AA\" or \"K\").\n\t\tHence, there are a total of 9 * 2 = 18 ways to decode \"1*\".\n\t\tExample 3:\n\t\tInput: s = \"2*\"\n\t\tOutput: 15\n\t\tExplanation: The encoded message can represent any of the encoded messages \"21\", \"22\", \"23\", \"24\", \"25\", \"26\", \"27\", \"28\", or \"29\".\n\t\t\"21\", \"22\", \"23\", \"24\", \"25\", and \"26\" have 2 ways of being decoded, but \"27\", \"28\", and \"29\" only have 1 way.\n\t\tHence, there are a total of (6 * 2) + (3 * 1) = 12 + 3 = 15 ways to decode \"2*\".\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 640, - "question": "class Solution:\n def solveEquation(self, equation: str) -> str:\n\t\t\"\"\"\n\t\tSolve a given equation and return the value of 'x' in the form of a string \"x=#value\". The equation contains only '+', '-' operation, the variable 'x' and its coefficient. You should return \"No solution\" if there is no solution for the equation, or \"Infinite solutions\" if there are infinite solutions for the equation.\n\t\tIf there is exactly one solution for the equation, we ensure that the value of 'x' is an integer.\n\t\tExample 1:\n\t\tInput: equation = \"x+5-3+x=6+x-2\"\n\t\tOutput: \"x=2\"\n\t\tExample 2:\n\t\tInput: equation = \"x=x\"\n\t\tOutput: \"Infinite solutions\"\n\t\tExample 3:\n\t\tInput: equation = \"2x=x\"\n\t\tOutput: \"x=0\"\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 643, - "question": "class Solution:\n def findMaxAverage(self, nums: List[int], k: int) -> float:\n\t\t\"\"\"\n\t\tYou are given an integer array nums consisting of n elements, and an integer k.\n\t\tFind a contiguous subarray whose length is equal to k that has the maximum average value and return this value. Any answer with a calculation error less than 10-5 will be accepted.\n\t\tExample 1:\n\t\tInput: nums = [1,12,-5,-6,50,3], k = 4\n\t\tOutput: 12.75000\n\t\tExplanation: Maximum average is (12 - 5 - 6 + 50) / 4 = 51 / 4 = 12.75\n\t\tExample 2:\n\t\tInput: nums = [5], k = 1\n\t\tOutput: 5.00000\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 645, - "question": "class Solution:\n def findErrorNums(self, nums: List[int]) -> List[int]:\n\t\t\"\"\"\n\t\tYou have a set of integers s, which originally contains all the numbers from 1 to n. Unfortunately, due to some error, one of the numbers in s got duplicated to another number in the set, which results in repetition of one number and loss of another number.\n\t\tYou are given an integer array nums representing the data status of this set after the error.\n\t\tFind the number that occurs twice and the number that is missing and return them in the form of an array.\n\t\tExample 1:\n\t\tInput: nums = [1,2,2,4]\n\t\tOutput: [2,3]\n\t\tExample 2:\n\t\tInput: nums = [1,1]\n\t\tOutput: [1,2]\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 646, - "question": "class Solution:\n def findLongestChain(self, pairs: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tYou are given an array of n pairs pairs where pairs[i] = [lefti, righti] and lefti < righti.\n\t\tA pair p2 = [c, d] follows a pair p1 = [a, b] if b < c. A chain of pairs can be formed in this fashion.\n\t\tReturn the length longest chain which can be formed.\n\t\tYou do not need to use up all the given intervals. You can select pairs in any order.\n\t\tExample 1:\n\t\tInput: pairs = [[1,2],[2,3],[3,4]]\n\t\tOutput: 2\n\t\tExplanation: The longest chain is [1,2] -> [3,4].\n\t\tExample 2:\n\t\tInput: pairs = [[1,2],[7,8],[4,5]]\n\t\tOutput: 3\n\t\tExplanation: The longest chain is [1,2] -> [4,5] -> [7,8].\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 647, - "question": "class Solution:\n def countSubstrings(self, s: str) -> int:\n\t\t\"\"\"\n\t\tGiven a string s, return the number of palindromic substrings in it.\n\t\tA string is a palindrome when it reads the same backward as forward.\n\t\tA substring is a contiguous sequence of characters within the string.\n\t\tExample 1:\n\t\tInput: s = \"abc\"\n\t\tOutput: 3\n\t\tExplanation: Three palindromic strings: \"a\", \"b\", \"c\".\n\t\tExample 2:\n\t\tInput: s = \"aaa\"\n\t\tOutput: 6\n\t\tExplanation: Six palindromic strings: \"a\", \"a\", \"a\", \"aa\", \"aa\", \"aaa\".\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 648, - "question": "class Solution:\n def replaceWords(self, dictionary: List[str], sentence: str) -> str:\n\t\t\"\"\"\n\t\tIn English, we have a concept called root, which can be followed by some other word to form another longer word - let's call this word successor. For example, when the root \"an\" is followed by the successor word \"other\", we can form a new word \"another\".\n\t\tGiven a dictionary consisting of many roots and a sentence consisting of words separated by spaces, replace all the successors in the sentence with the root forming it. If a successor can be replaced by more than one root, replace it with the root that has the shortest length.\n\t\tReturn the sentence after the replacement.\n\t\tExample 1:\n\t\tInput: dictionary = [\"cat\",\"bat\",\"rat\"], sentence = \"the cattle was rattled by the battery\"\n\t\tOutput: \"the cat was rat by the bat\"\n\t\tExample 2:\n\t\tInput: dictionary = [\"a\",\"b\",\"c\"], sentence = \"aadsfasf absbs bbab cadsfafs\"\n\t\tOutput: \"a a b c\"\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 649, - "question": "class Solution:\n def predictPartyVictory(self, senate: str) -> str:\n\t\t\"\"\"\n\t\tIn the world of Dota2, there are two parties: the Radiant and the Dire.\n\t\tThe Dota2 senate consists of senators coming from two parties. Now the Senate wants to decide on a change in the Dota2 game. The voting for this change is a round-based procedure. In each round, each senator can exercise one of the two rights:\n\t\t\tBan one senator's right: A senator can make another senator lose all his rights in this and all the following rounds.\n\t\t\tAnnounce the victory: If this senator found the senators who still have rights to vote are all from the same party, he can announce the victory and decide on the change in the game.\n\t\tGiven a string senate representing each senator's party belonging. The character 'R' and 'D' represent the Radiant party and the Dire party. Then if there are n senators, the size of the given string will be n.\n\t\tThe round-based procedure starts from the first senator to the last senator in the given order. This procedure will last until the end of voting. All the senators who have lost their rights will be skipped during the procedure.\n\t\tSuppose every senator is smart enough and will play the best strategy for his own party. Predict which party will finally announce the victory and change the Dota2 game. The output should be \"Radiant\" or \"Dire\".\n\t\tExample 1:\n\t\tInput: senate = \"RD\"\n\t\tOutput: \"Radiant\"\n\t\tExplanation: \n\t\tThe first senator comes from Radiant and he can just ban the next senator's right in round 1. \n\t\tAnd the second senator can't exercise any rights anymore since his right has been banned. \n\t\tAnd in round 2, the first senator can just announce the victory since he is the only guy in the senate who can vote.\n\t\tExample 2:\n\t\tInput: senate = \"RDD\"\n\t\tOutput: \"Dire\"\n\t\tExplanation: \n\t\tThe first senator comes from Radiant and he can just ban the next senator's right in round 1. \n\t\tAnd the second senator can't exercise any rights anymore since his right has been banned. \n\t\tAnd the third senator comes from Dire and he can ban the first senator's right in round 1. \n\t\tAnd in round 2, the third senator can just announce the victory since he is the only guy in the senate who can vote.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 650, - "question": "class Solution:\n def minSteps(self, n: int) -> int:\n\t\t\"\"\"\n\t\tThere is only one character 'A' on the screen of a notepad. You can perform one of two operations on this notepad for each step:\n\t\t\tCopy All: You can copy all the characters present on the screen (a partial copy is not allowed).\n\t\t\tPaste: You can paste the characters which are copied last time.\n\t\tGiven an integer n, return the minimum number of operations to get the character 'A' exactly n times on the screen.\n\t\tExample 1:\n\t\tInput: n = 3\n\t\tOutput: 3\n\t\tExplanation: Initially, we have one character 'A'.\n\t\tIn step 1, we use Copy All operation.\n\t\tIn step 2, we use Paste operation to get 'AA'.\n\t\tIn step 3, we use Paste operation to get 'AAA'.\n\t\tExample 2:\n\t\tInput: n = 1\n\t\tOutput: 0\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 652, - "question": "class Solution:\n def findDuplicateSubtrees(self, root: Optional[TreeNode]) -> List[Optional[TreeNode]]:\n\t\t\"\"\"\n\t\tGiven the root of a binary tree, return all duplicate subtrees.\n\t\tFor each kind of duplicate subtrees, you only need to return the root node of any one of them.\n\t\tTwo trees are duplicate if they have the same structure with the same node values.\n\t\tExample 1:\n\t\tInput: root = [1,2,3,4,null,2,4,null,null,4]\n\t\tOutput: [[2,4],[4]]\n\t\tExample 2:\n\t\tInput: root = [2,1,1]\n\t\tOutput: [[1]]\n\t\tExample 3:\n\t\tInput: root = [2,2,2,3,null,3,null]\n\t\tOutput: [[2,3],[3]]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 653, - "question": "class Solution:\n def findTarget(self, root: Optional[TreeNode], k: int) -> bool:\n\t\t\"\"\"\n\t\tGiven the root of a binary search tree and an integer k, return true if there exist two elements in the BST such that their sum is equal to k, or false otherwise.\n\t\tExample 1:\n\t\tInput: root = [5,3,6,2,4,null,7], k = 9\n\t\tOutput: true\n\t\tExample 2:\n\t\tInput: root = [5,3,6,2,4,null,7], k = 28\n\t\tOutput: false\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 654, - "question": "class Solution:\n def constructMaximumBinaryTree(self, nums: List[int]) -> Optional[TreeNode]:\n\t\t\"\"\"\n\t\tYou are given an integer array nums with no duplicates. A maximum binary tree can be built recursively from nums using the following algorithm:\n\t\t\tCreate a root node whose value is the maximum value in nums.\n\t\t\tRecursively build the left subtree on the subarray prefix to the left of the maximum value.\n\t\t\tRecursively build the right subtree on the subarray suffix to the right of the maximum value.\n\t\tReturn the maximum binary tree built from nums.\n\t\tExample 1:\n\t\tInput: nums = [3,2,1,6,0,5]\n\t\tOutput: [6,3,5,null,2,0,null,null,1]\n\t\tExplanation: The recursive calls are as follow:\n\t\t- The largest value in [3,2,1,6,0,5] is 6. Left prefix is [3,2,1] and right suffix is [0,5].\n\t\t - The largest value in [3,2,1] is 3. Left prefix is [] and right suffix is [2,1].\n\t\t - Empty array, so no child.\n\t\t - The largest value in [2,1] is 2. Left prefix is [] and right suffix is [1].\n\t\t - Empty array, so no child.\n\t\t - Only one element, so child is a node with value 1.\n\t\t - The largest value in [0,5] is 5. Left prefix is [0] and right suffix is [].\n\t\t - Only one element, so child is a node with value 0.\n\t\t - Empty array, so no child.\n\t\tExample 2:\n\t\tInput: nums = [3,2,1]\n\t\tOutput: [3,null,2,null,1]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 655, - "question": "class Solution:\n def printTree(self, root: Optional[TreeNode]) -> List[List[str]]:\n\t\t\"\"\"\n\t\tGiven the root of a binary tree, construct a 0-indexed m x n string matrix res that represents a formatted layout of the tree. The formatted layout matrix should be constructed using the following rules:\n\t\t\tThe height of the tree is height and the number of rows m should be equal to height + 1.\n\t\t\tThe number of columns n should be equal to 2height+1 - 1.\n\t\t\tPlace the root node in the middle of the top row (more formally, at location res[0][(n-1)/2]).\n\t\t\tFor each node that has been placed in the matrix at position res[r][c], place its left child at res[r+1][c-2height-r-1] and its right child at res[r+1][c+2height-r-1].\n\t\t\tContinue this process until all the nodes in the tree have been placed.\n\t\t\tAny empty cells should contain the empty string \"\".\n\t\tReturn the constructed matrix res.\n\t\tExample 1:\n\t\tInput: root = [1,2]\n\t\tOutput: \n\t\t[[\"\",\"1\",\"\"],\n\t\t [\"2\",\"\",\"\"]]\n\t\tExample 2:\n\t\tInput: root = [1,2,3,null,4]\n\t\tOutput: \n\t\t[[\"\",\"\",\"\",\"1\",\"\",\"\",\"\"],\n\t\t [\"\",\"2\",\"\",\"\",\"\",\"3\",\"\"],\n\t\t [\"\",\"\",\"4\",\"\",\"\",\"\",\"\"]]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 657, - "question": "class Solution:\n def judgeCircle(self, moves: str) -> bool:\n\t\t\"\"\"\n\t\tThere is a robot starting at the position (0, 0), the origin, on a 2D plane. Given a sequence of its moves, judge if this robot ends up at (0, 0) after it completes its moves.\n\t\tYou are given a string moves that represents the move sequence of the robot where moves[i] represents its ith move. Valid moves are 'R' (right), 'L' (left), 'U' (up), and 'D' (down).\n\t\tReturn true if the robot returns to the origin after it finishes all of its moves, or false otherwise.\n\t\tNote: The way that the robot is \"facing\" is irrelevant. 'R' will always make the robot move to the right once, 'L' will always make it move left, etc. Also, assume that the magnitude of the robot's movement is the same for each move.\n\t\tExample 1:\n\t\tInput: moves = \"UD\"\n\t\tOutput: true\n\t\tExplanation: The robot moves up once, and then down once. All moves have the same magnitude, so it ended up at the origin where it started. Therefore, we return true.\n\t\tExample 2:\n\t\tInput: moves = \"LL\"\n\t\tOutput: false\n\t\tExplanation: The robot moves left twice. It ends up two \"moves\" to the left of the origin. We return false because it is not at the origin at the end of its moves.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 658, - "question": "class Solution:\n def findClosestElements(self, arr: List[int], k: int, x: int) -> List[int]:\n\t\t\"\"\"\n\t\tGiven a sorted integer array arr, two integers k and x, return the k closest integers to x in the array. The result should also be sorted in ascending order.\n\t\tAn integer a is closer to x than an integer b if:\n\t\t\t|a - x| < |b - x|, or\n\t\t\t|a - x| == |b - x| and a < b\n\t\tExample 1:\n\t\tInput: arr = [1,2,3,4,5], k = 4, x = 3\n\t\tOutput: [1,2,3,4]\n\t\tExample 2:\n\t\tInput: arr = [1,2,3,4,5], k = 4, x = -1\n\t\tOutput: [1,2,3,4]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 659, - "question": "class Solution:\n def isPossible(self, nums: List[int]) -> bool:\n\t\t\"\"\"\n\t\tYou are given an integer array nums that is sorted in non-decreasing order.\n\t\tDetermine if it is possible to split nums into one or more subsequences such that both of the following conditions are true:\n\t\t\tEach subsequence is a consecutive increasing sequence (i.e. each integer is exactly one more than the previous integer).\n\t\t\tAll subsequences have a length of 3 or more.\n\t\tReturn true if you can split nums according to the above conditions, or false otherwise.\n\t\tA subsequence of an array is a new array that is formed from the original array by deleting some (can be none) of the elements without disturbing the relative positions of the remaining elements. (i.e., [1,3,5] is a subsequence of [1,2,3,4,5] while [1,3,2] is not).\n\t\tExample 1:\n\t\tInput: nums = [1,2,3,3,4,5]\n\t\tOutput: true\n\t\tExplanation: nums can be split into the following subsequences:\n\t\t[1,2,3,3,4,5] --> 1, 2, 3\n\t\t[1,2,3,3,4,5] --> 3, 4, 5\n\t\tExample 2:\n\t\tInput: nums = [1,2,3,3,4,4,5,5]\n\t\tOutput: true\n\t\tExplanation: nums can be split into the following subsequences:\n\t\t[1,2,3,3,4,4,5,5] --> 1, 2, 3, 4, 5\n\t\t[1,2,3,3,4,4,5,5] --> 3, 4, 5\n\t\tExample 3:\n\t\tInput: nums = [1,2,3,4,4,5]\n\t\tOutput: false\n\t\tExplanation: It is impossible to split nums into consecutive increasing subsequences of length 3 or more.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 661, - "question": "class Solution:\n def imageSmoother(self, img: List[List[int]]) -> List[List[int]]:\n\t\t\"\"\"\n\t\tAn image smoother is a filter of the size 3 x 3 that can be applied to each cell of an image by rounding down the average of the cell and the eight surrounding cells (i.e., the average of the nine cells in the blue smoother). If one or more of the surrounding cells of a cell is not present, we do not consider it in the average (i.e., the average of the four cells in the red smoother).\n\t\tGiven an m x n integer matrix img representing the grayscale of an image, return the image after applying the smoother on each cell of it.\n\t\tExample 1:\n\t\tInput: img = [[1,1,1],[1,0,1],[1,1,1]]\n\t\tOutput: [[0,0,0],[0,0,0],[0,0,0]]\n\t\tExplanation:\n\t\tFor the points (0,0), (0,2), (2,0), (2,2): floor(3/4) = floor(0.75) = 0\n\t\tFor the points (0,1), (1,0), (1,2), (2,1): floor(5/6) = floor(0.83333333) = 0\n\t\tFor the point (1,1): floor(8/9) = floor(0.88888889) = 0\n\t\tExample 2:\n\t\tInput: img = [[100,200,100],[200,50,200],[100,200,100]]\n\t\tOutput: [[137,141,137],[141,138,141],[137,141,137]]\n\t\tExplanation:\n\t\tFor the points (0,0), (0,2), (2,0), (2,2): floor((100+200+200+50)/4) = floor(137.5) = 137\n\t\tFor the points (0,1), (1,0), (1,2), (2,1): floor((200+200+50+200+100+100)/6) = floor(141.666667) = 141\n\t\tFor the point (1,1): floor((50+200+200+200+200+100+100+100+100)/9) = floor(138.888889) = 138\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 662, - "question": "class Solution:\n def widthOfBinaryTree(self, root: Optional[TreeNode]) -> int:\n\t\t\"\"\"\n\t\tGiven the root of a binary tree, return the maximum width of the given tree.\n\t\tThe maximum width of a tree is the maximum width among all levels.\n\t\tThe width of one level is defined as the length between the end-nodes (the leftmost and rightmost non-null nodes), where the null nodes between the end-nodes that would be present in a complete binary tree extending down to that level are also counted into the length calculation.\n\t\tIt is guaranteed that the answer will in the range of a 32-bit signed integer.\n\t\tExample 1:\n\t\tInput: root = [1,3,2,5,3,null,9]\n\t\tOutput: 4\n\t\tExplanation: The maximum width exists in the third level with length 4 (5,3,null,9).\n\t\tExample 2:\n\t\tInput: root = [1,3,2,5,null,null,9,6,null,7]\n\t\tOutput: 7\n\t\tExplanation: The maximum width exists in the fourth level with length 7 (6,null,null,null,null,null,7).\n\t\tExample 3:\n\t\tInput: root = [1,3,2,5]\n\t\tOutput: 2\n\t\tExplanation: The maximum width exists in the second level with length 2 (3,2).\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 664, - "question": "class Solution:\n def strangePrinter(self, s: str) -> int:\n\t\t\"\"\"\n\t\tThere is a strange printer with the following two special properties:\n\t\t\tThe printer can only print a sequence of the same character each time.\n\t\t\tAt each turn, the printer can print new characters starting from and ending at any place and will cover the original existing characters.\n\t\tGiven a string s, return the minimum number of turns the printer needed to print it.\n\t\tExample 1:\n\t\tInput: s = \"aaabbb\"\n\t\tOutput: 2\n\t\tExplanation: Print \"aaa\" first and then print \"bbb\".\n\t\tExample 2:\n\t\tInput: s = \"aba\"\n\t\tOutput: 2\n\t\tExplanation: Print \"aaa\" first and then print \"b\" from the second place of the string, which will cover the existing character 'a'.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 665, - "question": "class Solution:\n def checkPossibility(self, nums: List[int]) -> bool:\n\t\t\"\"\"\n\t\tGiven an array nums with n integers, your task is to check if it could become non-decreasing by modifying at most one element.\n\t\tWe define an array is non-decreasing if nums[i] <= nums[i + 1] holds for every i (0-based) such that (0 <= i <= n - 2).\n\t\tExample 1:\n\t\tInput: nums = [4,2,3]\n\t\tOutput: true\n\t\tExplanation: You could modify the first 4 to 1 to get a non-decreasing array.\n\t\tExample 2:\n\t\tInput: nums = [4,2,1]\n\t\tOutput: false\n\t\tExplanation: You cannot get a non-decreasing array by modifying at most one element.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 667, - "question": "class Solution:\n def constructArray(self, n: int, k: int) -> List[int]:\n\t\t\"\"\"\n\t\tGiven two integers n and k, construct a list answer that contains n different positive integers ranging from 1 to n and obeys the following requirement:\n\t\t\tSuppose this list is answer = [a1, a2, a3, ... , an], then the list [|a1 - a2|, |a2 - a3|, |a3 - a4|, ... , |an-1 - an|] has exactly k distinct integers.\n\t\tReturn the list answer. If there multiple valid answers, return any of them.\n\t\tExample 1:\n\t\tInput: n = 3, k = 1\n\t\tOutput: [1,2,3]\n\t\tExplanation: The [1,2,3] has three different positive integers ranging from 1 to 3, and the [1,1] has exactly 1 distinct integer: 1\n\t\tExample 2:\n\t\tInput: n = 3, k = 2\n\t\tOutput: [1,3,2]\n\t\tExplanation: The [1,3,2] has three different positive integers ranging from 1 to 3, and the [2,1] has exactly 2 distinct integers: 1 and 2.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 668, - "question": "class Solution:\n def findKthNumber(self, m: int, n: int, k: int) -> int:\n\t\t\"\"\"\n\t\tNearly everyone has used the Multiplication Table. The multiplication table of size m x n is an integer matrix mat where mat[i][j] == i * j (1-indexed).\n\t\tGiven three integers m, n, and k, return the kth smallest element in the m x n multiplication table.\n\t\tExample 1:\n\t\tInput: m = 3, n = 3, k = 5\n\t\tOutput: 3\n\t\tExplanation: The 5th smallest number is 3.\n\t\tExample 2:\n\t\tInput: m = 2, n = 3, k = 6\n\t\tOutput: 6\n\t\tExplanation: The 6th smallest number is 6.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 669, - "question": "class Solution:\n def trimBST(self, root: Optional[TreeNode], low: int, high: int) -> Optional[TreeNode]:\n\t\t\"\"\"\n\t\tGiven the root of a binary search tree and the lowest and highest boundaries as low and high, trim the tree so that all its elements lies in [low, high]. Trimming the tree should not change the relative structure of the elements that will remain in the tree (i.e., any node's descendant should remain a descendant). It can be proven that there is a unique answer.\n\t\tReturn the root of the trimmed binary search tree. Note that the root may change depending on the given bounds.\n\t\tExample 1:\n\t\tInput: root = [1,0,2], low = 1, high = 2\n\t\tOutput: [1,null,2]\n\t\tExample 2:\n\t\tInput: root = [3,0,4,null,2,null,null,1], low = 1, high = 3\n\t\tOutput: [3,2,null,1]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 670, - "question": "class Solution:\n def maximumSwap(self, num: int) -> int:\n\t\t\"\"\"\n\t\tYou are given an integer num. You can swap two digits at most once to get the maximum valued number.\n\t\tReturn the maximum valued number you can get.\n\t\tExample 1:\n\t\tInput: num = 2736\n\t\tOutput: 7236\n\t\tExplanation: Swap the number 2 and the number 7.\n\t\tExample 2:\n\t\tInput: num = 9973\n\t\tOutput: 9973\n\t\tExplanation: No swap.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 671, - "question": "class Solution:\n def findSecondMinimumValue(self, root: Optional[TreeNode]) -> int:\n\t\t\"\"\"\n\t\tGiven a non-empty special binary tree consisting of nodes with the non-negative value, where each node in this tree has exactly two or zero sub-node. If the node has two sub-nodes, then this node's value is the smaller value among its two sub-nodes. More formally, the property root.val = min(root.left.val, root.right.val) always holds.\n\t\tGiven such a binary tree, you need to output the second minimum value in the set made of all the nodes' value in the whole tree.\n\t\tIf no such second minimum value exists, output -1 instead.\n\t\tExample 1:\n\t\tInput: root = [2,2,5,null,null,5,7]\n\t\tOutput: 5\n\t\tExplanation: The smallest value is 2, the second smallest value is 5.\n\t\tExample 2:\n\t\tInput: root = [2,2,2]\n\t\tOutput: -1\n\t\tExplanation: The smallest value is 2, but there isn't any second smallest value.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 672, - "question": "class Solution:\n def flipLights(self, n: int, presses: int) -> int:\n\t\t\"\"\"\n\t\tThere is a room with n bulbs labeled from 1 to n that all are turned on initially, and four buttons on the wall. Each of the four buttons has a different functionality where:\n\t\t\tButton 1: Flips the status of all the bulbs.\n\t\t\tButton 2: Flips the status of all the bulbs with even labels (i.e., 2, 4, ...).\n\t\t\tButton 3: Flips the status of all the bulbs with odd labels (i.e., 1, 3, ...).\n\t\t\tButton 4: Flips the status of all the bulbs with a label j = 3k + 1 where k = 0, 1, 2, ... (i.e., 1, 4, 7, 10, ...).\n\t\tYou must make exactly presses button presses in total. For each press, you may pick any of the four buttons to press.\n\t\tGiven the two integers n and presses, return the number of different possible statuses after performing all presses button presses.\n\t\tExample 1:\n\t\tInput: n = 1, presses = 1\n\t\tOutput: 2\n\t\tExplanation: Status can be:\n\t\t- [off] by pressing button 1\n\t\t- [on] by pressing button 2\n\t\tExample 2:\n\t\tInput: n = 2, presses = 1\n\t\tOutput: 3\n\t\tExplanation: Status can be:\n\t\t- [off, off] by pressing button 1\n\t\t- [on, off] by pressing button 2\n\t\t- [off, on] by pressing button 3\n\t\tExample 3:\n\t\tInput: n = 3, presses = 1\n\t\tOutput: 4\n\t\tExplanation: Status can be:\n\t\t- [off, off, off] by pressing button 1\n\t\t- [off, on, off] by pressing button 2\n\t\t- [on, off, on] by pressing button 3\n\t\t- [off, on, on] by pressing button 4\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 673, - "question": "class Solution:\n def findNumberOfLIS(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tGiven an integer array nums, return the number of longest increasing subsequences.\n\t\tNotice that the sequence has to be strictly increasing.\n\t\tExample 1:\n\t\tInput: nums = [1,3,5,4,7]\n\t\tOutput: 2\n\t\tExplanation: The two longest increasing subsequences are [1, 3, 4, 7] and [1, 3, 5, 7].\n\t\tExample 2:\n\t\tInput: nums = [2,2,2,2,2]\n\t\tOutput: 5\n\t\tExplanation: The length of the longest increasing subsequence is 1, and there are 5 increasing subsequences of length 1, so output 5.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 674, - "question": "class Solution:\n def findLengthOfLCIS(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tGiven an unsorted array of integers nums, return the length of the longest continuous increasing subsequence (i.e. subarray). The subsequence must be strictly increasing.\n\t\tA continuous increasing subsequence is defined by two indices l and r (l < r) such that it is [nums[l], nums[l + 1], ..., nums[r - 1], nums[r]] and for each l <= i < r, nums[i] < nums[i + 1].\n\t\tExample 1:\n\t\tInput: nums = [1,3,5,4,7]\n\t\tOutput: 3\n\t\tExplanation: The longest continuous increasing subsequence is [1,3,5] with length 3.\n\t\tEven though [1,3,5,7] is an increasing subsequence, it is not continuous as elements 5 and 7 are separated by element\n\t\t4.\n\t\tExample 2:\n\t\tInput: nums = [2,2,2,2,2]\n\t\tOutput: 1\n\t\tExplanation: The longest continuous increasing subsequence is [2] with length 1. Note that it must be strictly\n\t\tincreasing.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 675, - "question": "class Solution:\n def cutOffTree(self, forest: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tYou are asked to cut off all the trees in a forest for a golf event. The forest is represented as an m x n matrix. In this matrix:\n\t\t\t0 means the cell cannot be walked through.\n\t\t\t1 represents an empty cell that can be walked through.\n\t\t\tA number greater than 1 represents a tree in a cell that can be walked through, and this number is the tree's height.\n\t\tIn one step, you can walk in any of the four directions: north, east, south, and west. If you are standing in a cell with a tree, you can choose whether to cut it off.\n\t\tYou must cut off the trees in order from shortest to tallest. When you cut off a tree, the value at its cell becomes 1 (an empty cell).\n\t\tStarting from the point (0, 0), return the minimum steps you need to walk to cut off all the trees. If you cannot cut off all the trees, return -1.\n\t\tNote: The input is generated such that no two trees have the same height, and there is at least one tree needs to be cut off.\n\t\tExample 1:\n\t\tInput: forest = [[1,2,3],[0,0,4],[7,6,5]]\n\t\tOutput: 6\n\t\tExplanation: Following the path above allows you to cut off the trees from shortest to tallest in 6 steps.\n\t\tExample 2:\n\t\tInput: forest = [[1,2,3],[0,0,0],[7,6,5]]\n\t\tOutput: -1\n\t\tExplanation: The trees in the bottom row cannot be accessed as the middle row is blocked.\n\t\tExample 3:\n\t\tInput: forest = [[2,3,4],[0,0,5],[8,7,6]]\n\t\tOutput: 6\n\t\tExplanation: You can follow the same path as Example 1 to cut off all the trees.\n\t\tNote that you can cut off the first tree at (0, 0) before making any steps.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 676, - "question": "class MagicDictionary:\n def __init__(self):\n def buildDict(self, dictionary: List[str]) -> None:\n def search(self, searchWord: str) -> bool:\n\t\t\"\"\"\n\t\tDesign a data structure that is initialized with a list of different words. Provided a string, you should determine if you can change exactly one character in this string to match any word in the data structure.\n\t\tImplement the MagicDictionary class:\n\t\t\tMagicDictionary() Initializes the object.\n\t\t\tvoid buildDict(String[] dictionary) Sets the data structure with an array of distinct strings dictionary.\n\t\t\tbool search(String searchWord) Returns true if you can change exactly one character in searchWord to match any string in the data structure, otherwise returns false.\n\t\tExample 1:\n\t\tInput\n\t\t[\"MagicDictionary\", \"buildDict\", \"search\", \"search\", \"search\", \"search\"]\n\t\t[[], [[\"hello\", \"leetcode\"]], [\"hello\"], [\"hhllo\"], [\"hell\"], [\"leetcoded\"]]\n\t\tOutput\n\t\t[null, null, false, true, false, false]\n\t\tExplanation\n\t\tMagicDictionary magicDictionary = new MagicDictionary();\n\t\tmagicDictionary.buildDict([\"hello\", \"leetcode\"]);\n\t\tmagicDictionary.search(\"hello\"); // return False\n\t\tmagicDictionary.search(\"hhllo\"); // We can change the second 'h' to 'e' to match \"hello\" so we return True\n\t\tmagicDictionary.search(\"hell\"); // return False\n\t\tmagicDictionary.search(\"leetcoded\"); // return False\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 677, - "question": "class MapSum:\n def __init__(self):\n def insert(self, key: str, val: int) -> None:\n def sum(self, prefix: str) -> int:\n\t\t\"\"\"\n\t\tDesign a map that allows you to do the following:\n\t\t\tMaps a string key to a given value.\n\t\t\tReturns the sum of the values that have a key with a prefix equal to a given string.\n\t\tImplement the MapSum class:\n\t\t\tMapSum() Initializes the MapSum object.\n\t\t\tvoid insert(String key, int val) Inserts the key-val pair into the map. If the key already existed, the original key-value pair will be overridden to the new one.\n\t\t\tint sum(string prefix) Returns the sum of all the pairs' value whose key starts with the prefix.\n\t\tExample 1:\n\t\tInput\n\t\t[\"MapSum\", \"insert\", \"sum\", \"insert\", \"sum\"]\n\t\t[[], [\"apple\", 3], [\"ap\"], [\"app\", 2], [\"ap\"]]\n\t\tOutput\n\t\t[null, null, 3, null, 5]\n\t\tExplanation\n\t\tMapSum mapSum = new MapSum();\n\t\tmapSum.insert(\"apple\", 3); \n\t\tmapSum.sum(\"ap\"); // return 3 (apple = 3)\n\t\tmapSum.insert(\"app\", 2); \n\t\tmapSum.sum(\"ap\"); // return 5 (apple + app = 3 + 2 = 5)\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 678, - "question": "class Solution:\n def checkValidString(self, s: str) -> bool:\n\t\t\"\"\"\n\t\tGiven a string s containing only three types of characters: '(', ')' and '*', return true if s is valid.\n\t\tThe following rules define a valid string:\n\t\t\tAny left parenthesis '(' must have a corresponding right parenthesis ')'.\n\t\t\tAny right parenthesis ')' must have a corresponding left parenthesis '('.\n\t\t\tLeft parenthesis '(' must go before the corresponding right parenthesis ')'.\n\t\t\t'*' could be treated as a single right parenthesis ')' or a single left parenthesis '(' or an empty string \"\".\n\t\tExample 1:\n\t\tInput: s = \"()\"\n\t\tOutput: true\n\t\tExample 2:\n\t\tInput: s = \"(*)\"\n\t\tOutput: true\n\t\tExample 3:\n\t\tInput: s = \"(*))\"\n\t\tOutput: true\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 679, - "question": "class Solution:\n def judgePoint24(self, cards: List[int]) -> bool:\n\t\t\"\"\"\n\t\tYou are given an integer array cards of length 4. You have four cards, each containing a number in the range [1, 9]. You should arrange the numbers on these cards in a mathematical expression using the operators ['+', '-', '*', '/'] and the parentheses '(' and ')' to get the value 24.\n\t\tYou are restricted with the following rules:\n\t\t\tThe division operator '/' represents real division, not integer division.\n\t\t\t\tFor example, 4 / (1 - 2 / 3) = 4 / (1 / 3) = 12.\n\t\t\tEvery operation done is between two numbers. In particular, we cannot use '-' as a unary operator.\n\t\t\t\tFor example, if cards = [1, 1, 1, 1], the expression \"-1 - 1 - 1 - 1\" is not allowed.\n\t\t\tYou cannot concatenate numbers together\n\t\t\t\tFor example, if cards = [1, 2, 1, 2], the expression \"12 + 12\" is not valid.\n\t\tReturn true if you can get such expression that evaluates to 24, and false otherwise.\n\t\tExample 1:\n\t\tInput: cards = [4,1,8,7]\n\t\tOutput: true\n\t\tExplanation: (8-4) * (7-1) = 24\n\t\tExample 2:\n\t\tInput: cards = [1,2,1,2]\n\t\tOutput: false\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 680, - "question": "class Solution:\n def validPalindrome(self, s: str) -> bool:\n\t\t\"\"\"\n\t\tGiven a string s, return true if the s can be palindrome after deleting at most one character from it.\n\t\tExample 1:\n\t\tInput: s = \"aba\"\n\t\tOutput: true\n\t\tExample 2:\n\t\tInput: s = \"abca\"\n\t\tOutput: true\n\t\tExplanation: You could delete the character 'c'.\n\t\tExample 3:\n\t\tInput: s = \"abc\"\n\t\tOutput: false\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 682, - "question": "class Solution:\n def calPoints(self, operations: List[str]) -> int:\n\t\t\"\"\"\n\t\tYou are keeping the scores for a baseball game with strange rules. At the beginning of the game, you start with an empty record.\n\t\tYou are given a list of strings operations, where operations[i] is the ith operation you must apply to the record and is one of the following:\n\t\t\tAn integer x.\n\t\t\t\tRecord a new score of x.\n\t\t\t'+'.\n\t\t\t\tRecord a new score that is the sum of the previous two scores.\n\t\t\t'D'.\n\t\t\t\tRecord a new score that is the double of the previous score.\n\t\t\t'C'.\n\t\t\t\tInvalidate the previous score, removing it from the record.\n\t\tReturn the sum of all the scores on the record after applying all the operations.\n\t\tThe test cases are generated such that the answer and all intermediate calculations fit in a 32-bit integer and that all operations are valid.\n\t\tExample 1:\n\t\tInput: ops = [\"5\",\"2\",\"C\",\"D\",\"+\"]\n\t\tOutput: 30\n\t\tExplanation:\n\t\t\"5\" - Add 5 to the record, record is now [5].\n\t\t\"2\" - Add 2 to the record, record is now [5, 2].\n\t\t\"C\" - Invalidate and remove the previous score, record is now [5].\n\t\t\"D\" - Add 2 * 5 = 10 to the record, record is now [5, 10].\n\t\t\"+\" - Add 5 + 10 = 15 to the record, record is now [5, 10, 15].\n\t\tThe total sum is 5 + 10 + 15 = 30.\n\t\tExample 2:\n\t\tInput: ops = [\"5\",\"-2\",\"4\",\"C\",\"D\",\"9\",\"+\",\"+\"]\n\t\tOutput: 27\n\t\tExplanation:\n\t\t\"5\" - Add 5 to the record, record is now [5].\n\t\t\"-2\" - Add -2 to the record, record is now [5, -2].\n\t\t\"4\" - Add 4 to the record, record is now [5, -2, 4].\n\t\t\"C\" - Invalidate and remove the previous score, record is now [5, -2].\n\t\t\"D\" - Add 2 * -2 = -4 to the record, record is now [5, -2, -4].\n\t\t\"9\" - Add 9 to the record, record is now [5, -2, -4, 9].\n\t\t\"+\" - Add -4 + 9 = 5 to the record, record is now [5, -2, -4, 9, 5].\n\t\t\"+\" - Add 9 + 5 = 14 to the record, record is now [5, -2, -4, 9, 5, 14].\n\t\tThe total sum is 5 + -2 + -4 + 9 + 5 + 14 = 27.\n\t\tExample 3:\n\t\tInput: ops = [\"1\",\"C\"]\n\t\tOutput: 0\n\t\tExplanation:\n\t\t\"1\" - Add 1 to the record, record is now [1].\n\t\t\"C\" - Invalidate and remove the previous score, record is now [].\n\t\tSince the record is empty, the total sum is 0.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 684, - "question": "class Solution:\n def findRedundantConnection(self, edges: List[List[int]]) -> List[int]:\n\t\t\"\"\"\n\t\tIn this problem, a tree is an undirected graph that is connected and has no cycles.\n\t\tYou are given a graph that started as a tree with n nodes labeled from 1 to n, with one additional edge added. The added edge has two different vertices chosen from 1 to n, and was not an edge that already existed. The graph is represented as an array edges of length n where edges[i] = [ai, bi] indicates that there is an edge between nodes ai and bi in the graph.\n\t\tReturn an edge that can be removed so that the resulting graph is a tree of n nodes. If there are multiple answers, return the answer that occurs last in the input.\n\t\tExample 1:\n\t\tInput: edges = [[1,2],[1,3],[2,3]]\n\t\tOutput: [2,3]\n\t\tExample 2:\n\t\tInput: edges = [[1,2],[2,3],[3,4],[1,4],[1,5]]\n\t\tOutput: [1,4]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 685, - "question": "class Solution:\n def findRedundantDirectedConnection(self, edges: List[List[int]]) -> List[int]:\n\t\t\"\"\"\n\t\tIn this problem, a rooted tree is a directed graph such that, there is exactly one node (the root) for which all other nodes are descendants of this node, plus every node has exactly one parent, except for the root node which has no parents.\n\t\tThe given input is a directed graph that started as a rooted tree with n nodes (with distinct values from 1 to n), with one additional directed edge added. The added edge has two different vertices chosen from 1 to n, and was not an edge that already existed.\n\t\tThe resulting graph is given as a 2D-array of edges. Each element of edges is a pair [ui, vi] that represents a directed edge connecting nodes ui and vi, where ui is a parent of child vi.\n\t\tReturn an edge that can be removed so that the resulting graph is a rooted tree of n nodes. If there are multiple answers, return the answer that occurs last in the given 2D-array.\n\t\tExample 1:\n\t\tInput: edges = [[1,2],[1,3],[2,3]]\n\t\tOutput: [2,3]\n\t\tExample 2:\n\t\tInput: edges = [[1,2],[2,3],[3,4],[4,1],[1,5]]\n\t\tOutput: [4,1]\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 686, - "question": "class Solution:\n def repeatedStringMatch(self, a: str, b: str) -> int:\n\t\t\"\"\"\n\t\tGiven two strings a and b, return the minimum number of times you should repeat string a so that string b is a substring of it. If it is impossible for b\u200b\u200b\u200b\u200b\u200b\u200b to be a substring of a after repeating it, return -1.\n\t\tNotice: string \"abc\" repeated 0 times is \"\", repeated 1 time is \"abc\" and repeated 2 times is \"abcabc\".\n\t\tExample 1:\n\t\tInput: a = \"abcd\", b = \"cdabcdab\"\n\t\tOutput: 3\n\t\tExplanation: We return 3 because by repeating a three times \"abcdabcdabcd\", b is a substring of it.\n\t\tExample 2:\n\t\tInput: a = \"a\", b = \"aa\"\n\t\tOutput: 2\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 687, - "question": "class Solution:\n def longestUnivaluePath(self, root: Optional[TreeNode]) -> int:\n\t\t\"\"\"\n\t\tGiven the root of a binary tree, return the length of the longest path, where each node in the path has the same value. This path may or may not pass through the root.\n\t\tThe length of the path between two nodes is represented by the number of edges between them.\n\t\tExample 1:\n\t\tInput: root = [5,4,5,1,1,null,5]\n\t\tOutput: 2\n\t\tExplanation: The shown image shows that the longest path of the same value (i.e. 5).\n\t\tExample 2:\n\t\tInput: root = [1,4,5,4,4,null,5]\n\t\tOutput: 2\n\t\tExplanation: The shown image shows that the longest path of the same value (i.e. 4).\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 688, - "question": "class Solution:\n def knightProbability(self, n: int, k: int, row: int, column: int) -> float:\n\t\t\"\"\"\n\t\tOn an n x n chessboard, a knight starts at the cell (row, column) and attempts to make exactly k moves. The rows and columns are 0-indexed, so the top-left cell is (0, 0), and the bottom-right cell is (n - 1, n - 1).\n\t\tA chess knight has eight possible moves it can make, as illustrated below. Each move is two cells in a cardinal direction, then one cell in an orthogonal direction.\n\t\tEach time the knight is to move, it chooses one of eight possible moves uniformly at random (even if the piece would go off the chessboard) and moves there.\n\t\tThe knight continues moving until it has made exactly k moves or has moved off the chessboard.\n\t\tReturn the probability that the knight remains on the board after it has stopped moving.\n\t\tExample 1:\n\t\tInput: n = 3, k = 2, row = 0, column = 0\n\t\tOutput: 0.06250\n\t\tExplanation: There are two moves (to (1,2), (2,1)) that will keep the knight on the board.\n\t\tFrom each of those positions, there are also two moves that will keep the knight on the board.\n\t\tThe total probability the knight stays on the board is 0.0625.\n\t\tExample 2:\n\t\tInput: n = 1, k = 0, row = 0, column = 0\n\t\tOutput: 1.00000\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 689, - "question": "class Solution:\n def maxSumOfThreeSubarrays(self, nums: List[int], k: int) -> List[int]:\n\t\t\"\"\"\n\t\tGiven an integer array nums and an integer k, find three non-overlapping subarrays of length k with maximum sum and return them.\n\t\tReturn the result as a list of indices representing the starting position of each interval (0-indexed). If there are multiple answers, return the lexicographically smallest one.\n\t\tExample 1:\n\t\tInput: nums = [1,2,1,2,6,7,5,1], k = 2\n\t\tOutput: [0,3,5]\n\t\tExplanation: Subarrays [1, 2], [2, 6], [7, 5] correspond to the starting indices [0, 3, 5].\n\t\tWe could have also taken [2, 1], but an answer of [1, 3, 5] would be lexicographically larger.\n\t\tExample 2:\n\t\tInput: nums = [1,2,1,2,1,2,1,2,1], k = 2\n\t\tOutput: [0,2,4]\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 690, - "question": "\n\t\t\"\"\"\nclass Employee:\n def __init__(self, id: int, importance: int, subordinates: List[int]):\n self.id = id\n self.importance = importance\n self.subordinates = subordinates\n\t\tYou have a data structure of employee information, including the employee's unique ID, importance value, and direct subordinates' IDs.\n\t\tYou are given an array of employees employees where:\n\t\t\temployees[i].id is the ID of the ith employee.\n\t\t\temployees[i].importance is the importance value of the ith employee.\n\t\t\temployees[i].subordinates is a list of the IDs of the direct subordinates of the ith employee.\n\t\tGiven an integer id that represents an employee's ID, return the total importance value of this employee and all their direct and indirect subordinates.\n\t\tExample 1:\n\t\tInput: employees = [[1,5,[2,3]],[2,3,[]],[3,3,[]]], id = 1\n\t\tOutput: 11\n\t\tExplanation: Employee 1 has an importance value of 5 and has two direct subordinates: employee 2 and employee 3.\n\t\tThey both have an importance value of 3.\n\t\tThus, the total importance value of employee 1 is 5 + 3 + 3 = 11.\n\t\tExample 2:\n\t\tInput: employees = [[1,2,[5]],[5,-3,[]]], id = 5\n\t\tOutput: -3\n\t\tExplanation: Employee 5 has an importance value of -3 and has no direct subordinates.\n\t\tThus, the total importance value of employee 5 is -3.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 691, - "question": "class Solution:\n def minStickers(self, stickers: List[str], target: str) -> int:\n\t\t\"\"\"\n\t\tWe are given n different types of stickers. Each sticker has a lowercase English word on it.\n\t\tYou would like to spell out the given string target by cutting individual letters from your collection of stickers and rearranging them. You can use each sticker more than once if you want, and you have infinite quantities of each sticker.\n\t\tReturn the minimum number of stickers that you need to spell out target. If the task is impossible, return -1.\n\t\tNote: In all test cases, all words were chosen randomly from the 1000 most common US English words, and target was chosen as a concatenation of two random words.\n\t\tExample 1:\n\t\tInput: stickers = [\"with\",\"example\",\"science\"], target = \"thehat\"\n\t\tOutput: 3\n\t\tExplanation:\n\t\tWe can use 2 \"with\" stickers, and 1 \"example\" sticker.\n\t\tAfter cutting and rearrange the letters of those stickers, we can form the target \"thehat\".\n\t\tAlso, this is the minimum number of stickers necessary to form the target string.\n\t\tExample 2:\n\t\tInput: stickers = [\"notice\",\"possible\"], target = \"basicbasic\"\n\t\tOutput: -1\n\t\tExplanation:\n\t\tWe cannot form the target \"basicbasic\" from cutting letters from the given stickers.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 692, - "question": "class Solution:\n def topKFrequent(self, words: List[str], k: int) -> List[str]:\n\t\t\"\"\"\n\t\tGiven an array of strings words and an integer k, return the k most frequent strings.\n\t\tReturn the answer sorted by the frequency from highest to lowest. Sort the words with the same frequency by their lexicographical order.\n\t\tExample 1:\n\t\tInput: words = [\"i\",\"love\",\"leetcode\",\"i\",\"love\",\"coding\"], k = 2\n\t\tOutput: [\"i\",\"love\"]\n\t\tExplanation: \"i\" and \"love\" are the two most frequent words.\n\t\tNote that \"i\" comes before \"love\" due to a lower alphabetical order.\n\t\tExample 2:\n\t\tInput: words = [\"the\",\"day\",\"is\",\"sunny\",\"the\",\"the\",\"the\",\"sunny\",\"is\",\"is\"], k = 4\n\t\tOutput: [\"the\",\"is\",\"sunny\",\"day\"]\n\t\tExplanation: \"the\", \"is\", \"sunny\" and \"day\" are the four most frequent words, with the number of occurrence being 4, 3, 2 and 1 respectively.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 693, - "question": "class Solution:\n def hasAlternatingBits(self, n: int) -> bool:\n\t\t\"\"\"\n\t\tGiven a positive integer, check whether it has alternating bits: namely, if two adjacent bits will always have different values.\n\t\tExample 1:\n\t\tInput: n = 5\n\t\tOutput: true\n\t\tExplanation: The binary representation of 5 is: 101\n\t\tExample 2:\n\t\tInput: n = 7\n\t\tOutput: false\n\t\tExplanation: The binary representation of 7 is: 111.\n\t\tExample 3:\n\t\tInput: n = 11\n\t\tOutput: false\n\t\tExplanation: The binary representation of 11 is: 1011.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 695, - "question": "class Solution:\n def maxAreaOfIsland(self, grid: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tYou are given an m x n binary matrix grid. An island is a group of 1's (representing land) connected 4-directionally (horizontal or vertical.) You may assume all four edges of the grid are surrounded by water.\n\t\tThe area of an island is the number of cells with a value 1 in the island.\n\t\tReturn the maximum area of an island in grid. If there is no island, return 0.\n\t\tExample 1:\n\t\tInput: grid = [[0,0,1,0,0,0,0,1,0,0,0,0,0],[0,0,0,0,0,0,0,1,1,1,0,0,0],[0,1,1,0,1,0,0,0,0,0,0,0,0],[0,1,0,0,1,1,0,0,1,0,1,0,0],[0,1,0,0,1,1,0,0,1,1,1,0,0],[0,0,0,0,0,0,0,0,0,0,1,0,0],[0,0,0,0,0,0,0,1,1,1,0,0,0],[0,0,0,0,0,0,0,1,1,0,0,0,0]]\n\t\tOutput: 6\n\t\tExplanation: The answer is not 11, because the island must be connected 4-directionally.\n\t\tExample 2:\n\t\tInput: grid = [[0,0,0,0,0,0,0,0]]\n\t\tOutput: 0\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 696, - "question": "class Solution:\n def countBinarySubstrings(self, s: str) -> int:\n\t\t\"\"\"\n\t\tGiven a binary string s, return the number of non-empty substrings that have the same number of 0's and 1's, and all the 0's and all the 1's in these substrings are grouped consecutively.\n\t\tSubstrings that occur multiple times are counted the number of times they occur.\n\t\tExample 1:\n\t\tInput: s = \"00110011\"\n\t\tOutput: 6\n\t\tExplanation: There are 6 substrings that have equal number of consecutive 1's and 0's: \"0011\", \"01\", \"1100\", \"10\", \"0011\", and \"01\".\n\t\tNotice that some of these substrings repeat and are counted the number of times they occur.\n\t\tAlso, \"00110011\" is not a valid substring because all the 0's (and 1's) are not grouped together.\n\t\tExample 2:\n\t\tInput: s = \"10101\"\n\t\tOutput: 4\n\t\tExplanation: There are 4 substrings: \"10\", \"01\", \"10\", \"01\" that have equal number of consecutive 1's and 0's.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 697, - "question": "class Solution:\n def findShortestSubArray(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tGiven a non-empty array of non-negative integers nums, the degree of this array is defined as the maximum frequency of any one of its elements.\n\t\tYour task is to find the smallest possible length of a (contiguous) subarray of nums, that has the same degree as nums.\n\t\tExample 1:\n\t\tInput: nums = [1,2,2,3,1]\n\t\tOutput: 2\n\t\tExplanation: \n\t\tThe input array has a degree of 2 because both elements 1 and 2 appear twice.\n\t\tOf the subarrays that have the same degree:\n\t\t[1, 2, 2, 3, 1], [1, 2, 2, 3], [2, 2, 3, 1], [1, 2, 2], [2, 2, 3], [2, 2]\n\t\tThe shortest length is 2. So return 2.\n\t\tExample 2:\n\t\tInput: nums = [1,2,2,3,1,4,2]\n\t\tOutput: 6\n\t\tExplanation: \n\t\tThe degree is 3 because the element 2 is repeated 3 times.\n\t\tSo [2,2,3,1,4,2] is the shortest subarray, therefore returning 6.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 698, - "question": "class Solution:\n def canPartitionKSubsets(self, nums: List[int], k: int) -> bool:\n\t\t\"\"\"\n\t\tGiven an integer array nums and an integer k, return true if it is possible to divide this array into k non-empty subsets whose sums are all equal.\n\t\tExample 1:\n\t\tInput: nums = [4,3,2,3,5,2,1], k = 4\n\t\tOutput: true\n\t\tExplanation: It is possible to divide it into 4 subsets (5), (1, 4), (2,3), (2,3) with equal sums.\n\t\tExample 2:\n\t\tInput: nums = [1,2,3,4], k = 3\n\t\tOutput: false\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 699, - "question": "class Solution:\n def fallingSquares(self, positions: List[List[int]]) -> List[int]:\n\t\t\"\"\"\n\t\tThere are several squares being dropped onto the X-axis of a 2D plane.\n\t\tYou are given a 2D integer array positions where positions[i] = [lefti, sideLengthi] represents the ith square with a side length of sideLengthi that is dropped with its left edge aligned with X-coordinate lefti.\n\t\tEach square is dropped one at a time from a height above any landed squares. It then falls downward (negative Y direction) until it either lands on the top side of another square or on the X-axis. A square brushing the left/right side of another square does not count as landing on it. Once it lands, it freezes in place and cannot be moved.\n\t\tAfter each square is dropped, you must record the height of the current tallest stack of squares.\n\t\tReturn an integer array ans where ans[i] represents the height described above after dropping the ith square.\n\t\tExample 1:\n\t\tInput: positions = [[1,2],[2,3],[6,1]]\n\t\tOutput: [2,5,5]\n\t\tExplanation:\n\t\tAfter the first drop, the tallest stack is square 1 with a height of 2.\n\t\tAfter the second drop, the tallest stack is squares 1 and 2 with a height of 5.\n\t\tAfter the third drop, the tallest stack is still squares 1 and 2 with a height of 5.\n\t\tThus, we return an answer of [2, 5, 5].\n\t\tExample 2:\n\t\tInput: positions = [[100,100],[200,100]]\n\t\tOutput: [100,100]\n\t\tExplanation:\n\t\tAfter the first drop, the tallest stack is square 1 with a height of 100.\n\t\tAfter the second drop, the tallest stack is either square 1 or square 2, both with heights of 100.\n\t\tThus, we return an answer of [100, 100].\n\t\tNote that square 2 only brushes the right side of square 1, which does not count as landing on it.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 712, - "question": "class Solution:\n def minimumDeleteSum(self, s1: str, s2: str) -> int:\n\t\t\"\"\"\n\t\tGiven two strings s1 and s2, return the lowest ASCII sum of deleted characters to make two strings equal.\n\t\tExample 1:\n\t\tInput: s1 = \"sea\", s2 = \"eat\"\n\t\tOutput: 231\n\t\tExplanation: Deleting \"s\" from \"sea\" adds the ASCII value of \"s\" (115) to the sum.\n\t\tDeleting \"t\" from \"eat\" adds 116 to the sum.\n\t\tAt the end, both strings are equal, and 115 + 116 = 231 is the minimum sum possible to achieve this.\n\t\tExample 2:\n\t\tInput: s1 = \"delete\", s2 = \"leet\"\n\t\tOutput: 403\n\t\tExplanation: Deleting \"dee\" from \"delete\" to turn the string into \"let\",\n\t\tadds 100[d] + 101[e] + 101[e] to the sum.\n\t\tDeleting \"e\" from \"leet\" adds 101[e] to the sum.\n\t\tAt the end, both strings are equal to \"let\", and the answer is 100+101+101+101 = 403.\n\t\tIf instead we turned both strings into \"lee\" or \"eet\", we would get answers of 433 or 417, which are higher.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 713, - "question": "class Solution:\n def numSubarrayProductLessThanK(self, nums: List[int], k: int) -> int:\n\t\t\"\"\"\n\t\tGiven an array of integers nums and an integer k, return the number of contiguous subarrays where the product of all the elements in the subarray is strictly less than k.\n\t\tExample 1:\n\t\tInput: nums = [10,5,2,6], k = 100\n\t\tOutput: 8\n\t\tExplanation: The 8 subarrays that have product less than 100 are:\n\t\t[10], [5], [2], [6], [10, 5], [5, 2], [2, 6], [5, 2, 6]\n\t\tNote that [10, 5, 2] is not included as the product of 100 is not strictly less than k.\n\t\tExample 2:\n\t\tInput: nums = [1,2,3], k = 0\n\t\tOutput: 0\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 714, - "question": "class Solution:\n def maxProfit(self, prices: List[int], fee: int) -> int:\n\t\t\"\"\"\n\t\tYou are given an array prices where prices[i] is the price of a given stock on the ith day, and an integer fee representing a transaction fee.\n\t\tFind the maximum profit you can achieve. You may complete as many transactions as you like, but you need to pay the transaction fee for each transaction.\n\t\tNote: You may not engage in multiple transactions simultaneously (i.e., you must sell the stock before you buy again).\n\t\tExample 1:\n\t\tInput: prices = [1,3,2,8,4,9], fee = 2\n\t\tOutput: 8\n\t\tExplanation: The maximum profit can be achieved by:\n\t\t- Buying at prices[0] = 1\n\t\t- Selling at prices[3] = 8\n\t\t- Buying at prices[4] = 4\n\t\t- Selling at prices[5] = 9\n\t\tThe total profit is ((8 - 1) - 2) + ((9 - 4) - 2) = 8.\n\t\tExample 2:\n\t\tInput: prices = [1,3,7,5,10,3], fee = 3\n\t\tOutput: 6\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 715, - "question": "class RangeModule:\n def __init__(self):\n def addRange(self, left: int, right: int) -> None:\n def queryRange(self, left: int, right: int) -> bool:\n def removeRange(self, left: int, right: int) -> None:\n\t\t\"\"\"\n\t\tA Range Module is a module that tracks ranges of numbers. Design a data structure to track the ranges represented as half-open intervals and query about them.\n\t\tA half-open interval [left, right) denotes all the real numbers x where left <= x < right.\n\t\tImplement the RangeModule class:\n\t\t\tRangeModule() Initializes the object of the data structure.\n\t\t\tvoid addRange(int left, int right) Adds the half-open interval [left, right), tracking every real number in that interval. Adding an interval that partially overlaps with currently tracked numbers should add any numbers in the interval [left, right) that are not already tracked.\n\t\t\tboolean queryRange(int left, int right) Returns true if every real number in the interval [left, right) is currently being tracked, and false otherwise.\n\t\t\tvoid removeRange(int left, int right) Stops tracking every real number currently being tracked in the half-open interval [left, right).\n\t\tExample 1:\n\t\tInput\n\t\t[\"RangeModule\", \"addRange\", \"removeRange\", \"queryRange\", \"queryRange\", \"queryRange\"]\n\t\t[[], [10, 20], [14, 16], [10, 14], [13, 15], [16, 17]]\n\t\tOutput\n\t\t[null, null, null, true, false, true]\n\t\tExplanation\n\t\tRangeModule rangeModule = new RangeModule();\n\t\trangeModule.addRange(10, 20);\n\t\trangeModule.removeRange(14, 16);\n\t\trangeModule.queryRange(10, 14); // return True,(Every number in [10, 14) is being tracked)\n\t\trangeModule.queryRange(13, 15); // return False,(Numbers like 14, 14.03, 14.17 in [13, 15) are not being tracked)\n\t\trangeModule.queryRange(16, 17); // return True, (The number 16 in [16, 17) is still being tracked, despite the remove operation)\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 717, - "question": "class Solution:\n def isOneBitCharacter(self, bits: List[int]) -> bool:\n\t\t\"\"\"\n\t\tWe have two special characters:\n\t\t\tThe first character can be represented by one bit 0.\n\t\t\tThe second character can be represented by two bits (10 or 11).\n\t\tGiven a binary array bits that ends with 0, return true if the last character must be a one-bit character.\n\t\tExample 1:\n\t\tInput: bits = [1,0,0]\n\t\tOutput: true\n\t\tExplanation: The only way to decode it is two-bit character and one-bit character.\n\t\tSo the last character is one-bit character.\n\t\tExample 2:\n\t\tInput: bits = [1,1,1,0]\n\t\tOutput: false\n\t\tExplanation: The only way to decode it is two-bit character and two-bit character.\n\t\tSo the last character is not one-bit character.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 718, - "question": "class Solution:\n def findLength(self, nums1: List[int], nums2: List[int]) -> int:\n\t\t\"\"\"\n\t\tGiven two integer arrays nums1 and nums2, return the maximum length of a subarray that appears in both arrays.\n\t\tExample 1:\n\t\tInput: nums1 = [1,2,3,2,1], nums2 = [3,2,1,4,7]\n\t\tOutput: 3\n\t\tExplanation: The repeated subarray with maximum length is [3,2,1].\n\t\tExample 2:\n\t\tInput: nums1 = [0,0,0,0,0], nums2 = [0,0,0,0,0]\n\t\tOutput: 5\n\t\tExplanation: The repeated subarray with maximum length is [0,0,0,0,0].\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 719, - "question": "class Solution:\n def smallestDistancePair(self, nums: List[int], k: int) -> int:\n\t\t\"\"\"\n\t\tThe distance of a pair of integers a and b is defined as the absolute difference between a and b.\n\t\tGiven an integer array nums and an integer k, return the kth smallest distance among all the pairs nums[i] and nums[j] where 0 <= i < j < nums.length.\n\t\tExample 1:\n\t\tInput: nums = [1,3,1], k = 1\n\t\tOutput: 0\n\t\tExplanation: Here are all the pairs:\n\t\t(1,3) -> 2\n\t\t(1,1) -> 0\n\t\t(3,1) -> 2\n\t\tThen the 1st smallest distance pair is (1,1), and its distance is 0.\n\t\tExample 2:\n\t\tInput: nums = [1,1,1], k = 2\n\t\tOutput: 0\n\t\tExample 3:\n\t\tInput: nums = [1,6,1], k = 3\n\t\tOutput: 5\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 720, - "question": "class Solution:\n def longestWord(self, words: List[str]) -> str:\n\t\t\"\"\"\n\t\tGiven an array of strings words representing an English Dictionary, return the longest word in words that can be built one character at a time by other words in words.\n\t\tIf there is more than one possible answer, return the longest word with the smallest lexicographical order. If there is no answer, return the empty string.\n\t\tNote that the word should be built from left to right with each additional character being added to the end of a previous word. \n\t\tExample 1:\n\t\tInput: words = [\"w\",\"wo\",\"wor\",\"worl\",\"world\"]\n\t\tOutput: \"world\"\n\t\tExplanation: The word \"world\" can be built one character at a time by \"w\", \"wo\", \"wor\", and \"worl\".\n\t\tExample 2:\n\t\tInput: words = [\"a\",\"banana\",\"app\",\"appl\",\"ap\",\"apply\",\"apple\"]\n\t\tOutput: \"apple\"\n\t\tExplanation: Both \"apply\" and \"apple\" can be built from other words in the dictionary. However, \"apple\" is lexicographically smaller than \"apply\".\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 721, - "question": "class Solution:\n def accountsMerge(self, accounts: List[List[str]]) -> List[List[str]]:\n\t\t\"\"\"\n\t\tGiven a list of accounts where each element accounts[i] is a list of strings, where the first element accounts[i][0] is a name, and the rest of the elements are emails representing emails of the account.\n\t\tNow, we would like to merge these accounts. Two accounts definitely belong to the same person if there is some common email to both accounts. Note that even if two accounts have the same name, they may belong to different people as people could have the same name. A person can have any number of accounts initially, but all of their accounts definitely have the same name.\n\t\tAfter merging the accounts, return the accounts in the following format: the first element of each account is the name, and the rest of the elements are emails in sorted order. The accounts themselves can be returned in any order.\n\t\tExample 1:\n\t\tInput: accounts = [[\"John\",\"johnsmith@mail.com\",\"john_newyork@mail.com\"],[\"John\",\"johnsmith@mail.com\",\"john00@mail.com\"],[\"Mary\",\"mary@mail.com\"],[\"John\",\"johnnybravo@mail.com\"]]\n\t\tOutput: [[\"John\",\"john00@mail.com\",\"john_newyork@mail.com\",\"johnsmith@mail.com\"],[\"Mary\",\"mary@mail.com\"],[\"John\",\"johnnybravo@mail.com\"]]\n\t\tExplanation:\n\t\tThe first and second John's are the same person as they have the common email \"johnsmith@mail.com\".\n\t\tThe third John and Mary are different people as none of their email addresses are used by other accounts.\n\t\tWe could return these lists in any order, for example the answer [['Mary', 'mary@mail.com'], ['John', 'johnnybravo@mail.com'], \n\t\t['John', 'john00@mail.com', 'john_newyork@mail.com', 'johnsmith@mail.com']] would still be accepted.\n\t\tExample 2:\n\t\tInput: accounts = [[\"Gabe\",\"Gabe0@m.co\",\"Gabe3@m.co\",\"Gabe1@m.co\"],[\"Kevin\",\"Kevin3@m.co\",\"Kevin5@m.co\",\"Kevin0@m.co\"],[\"Ethan\",\"Ethan5@m.co\",\"Ethan4@m.co\",\"Ethan0@m.co\"],[\"Hanzo\",\"Hanzo3@m.co\",\"Hanzo1@m.co\",\"Hanzo0@m.co\"],[\"Fern\",\"Fern5@m.co\",\"Fern1@m.co\",\"Fern0@m.co\"]]\n\t\tOutput: [[\"Ethan\",\"Ethan0@m.co\",\"Ethan4@m.co\",\"Ethan5@m.co\"],[\"Gabe\",\"Gabe0@m.co\",\"Gabe1@m.co\",\"Gabe3@m.co\"],[\"Hanzo\",\"Hanzo0@m.co\",\"Hanzo1@m.co\",\"Hanzo3@m.co\"],[\"Kevin\",\"Kevin0@m.co\",\"Kevin3@m.co\",\"Kevin5@m.co\"],[\"Fern\",\"Fern0@m.co\",\"Fern1@m.co\",\"Fern5@m.co\"]]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 722, - "question": "class Solution:\n def removeComments(self, source: List[str]) -> List[str]:\n\t\t\"\"\"\n\t\tGiven a C++ program, remove comments from it. The program source is an array of strings source where source[i] is the ith line of the source code. This represents the result of splitting the original source code string by the newline character '\\n'.\n\t\tIn C++, there are two types of comments, line comments, and block comments.\n\t\t\tThe string \"//\" denotes a line comment, which represents that it and the rest of the characters to the right of it in the same line should be ignored.\n\t\t\tThe string \"/*\" denotes a block comment, which represents that all characters until the next (non-overlapping) occurrence of \"*/\" should be ignored. (Here, occurrences happen in reading order: line by line from left to right.) To be clear, the string \"/*/\" does not yet end the block comment, as the ending would be overlapping the beginning.\n\t\tThe first effective comment takes precedence over others.\n\t\t\tFor example, if the string \"//\" occurs in a block comment, it is ignored.\n\t\t\tSimilarly, if the string \"/*\" occurs in a line or block comment, it is also ignored.\n\t\tIf a certain line of code is empty after removing comments, you must not output that line: each string in the answer list will be non-empty.\n\t\tThere will be no control characters, single quote, or double quote characters.\n\t\t\tFor example, source = \"string s = \"/* Not a comment. */\";\" will not be a test case.\n\t\tAlso, nothing else such as defines or macros will interfere with the comments.\n\t\tIt is guaranteed that every open block comment will eventually be closed, so \"/*\" outside of a line or block comment always starts a new comment.\n\t\tFinally, implicit newline characters can be deleted by block comments. Please see the examples below for details.\n\t\tAfter removing the comments from the source code, return the source code in the same format.\n\t\tExample 1:\n\t\tInput: source = [\"/*Test program */\", \"int main()\", \"{ \", \" // variable declaration \", \"int a, b, c;\", \"/* This is a test\", \" multiline \", \" comment for \", \" testing */\", \"a = b + c;\", \"}\"]\n\t\tOutput: [\"int main()\",\"{ \",\" \",\"int a, b, c;\",\"a = b + c;\",\"}\"]\n\t\tExplanation: The line by line code is visualized as below:\n\t\t/*Test program */\n\t\tint main()\n\t\t{ \n\t\t // variable declaration \n\t\tint a, b, c;\n\t\t/* This is a test\n\t\t multiline \n\t\t comment for \n\t\t testing */\n\t\ta = b + c;\n\t\t}\n\t\tThe string /* denotes a block comment, including line 1 and lines 6-9. The string // denotes line 4 as comments.\n\t\tThe line by line output code is visualized as below:\n\t\tint main()\n\t\t{ \n\t\tint a, b, c;\n\t\ta = b + c;\n\t\t}\n\t\tExample 2:\n\t\tInput: source = [\"a/*comment\", \"line\", \"more_comment*/b\"]\n\t\tOutput: [\"ab\"]\n\t\tExplanation: The original source string is \"a/*comment\\nline\\nmore_comment*/b\", where we have bolded the newline characters. After deletion, the implicit newline characters are deleted, leaving the string \"ab\", which when delimited by newline characters becomes [\"ab\"].\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 724, - "question": "class Solution:\n def pivotIndex(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tGiven an array of integers nums, calculate the pivot index of this array.\n\t\tThe pivot index is the index where the sum of all the numbers strictly to the left of the index is equal to the sum of all the numbers strictly to the index's right.\n\t\tIf the index is on the left edge of the array, then the left sum is 0 because there are no elements to the left. This also applies to the right edge of the array.\n\t\tReturn the leftmost pivot index. If no such index exists, return -1.\n\t\tExample 1:\n\t\tInput: nums = [1,7,3,6,5,6]\n\t\tOutput: 3\n\t\tExplanation:\n\t\tThe pivot index is 3.\n\t\tLeft sum = nums[0] + nums[1] + nums[2] = 1 + 7 + 3 = 11\n\t\tRight sum = nums[4] + nums[5] = 5 + 6 = 11\n\t\tExample 2:\n\t\tInput: nums = [1,2,3]\n\t\tOutput: -1\n\t\tExplanation:\n\t\tThere is no index that satisfies the conditions in the problem statement.\n\t\tExample 3:\n\t\tInput: nums = [2,1,-1]\n\t\tOutput: 0\n\t\tExplanation:\n\t\tThe pivot index is 0.\n\t\tLeft sum = 0 (no elements to the left of index 0)\n\t\tRight sum = nums[1] + nums[2] = 1 + -1 = 0\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 725, - "question": "class Solution:\n def splitListToParts(self, head: Optional[ListNode], k: int) -> List[Optional[ListNode]]:\n\t\t\"\"\"\n\t\tGiven the head of a singly linked list and an integer k, split the linked list into k consecutive linked list parts.\n\t\tThe length of each part should be as equal as possible: no two parts should have a size differing by more than one. This may lead to some parts being null.\n\t\tThe parts should be in the order of occurrence in the input list, and parts occurring earlier should always have a size greater than or equal to parts occurring later.\n\t\tReturn an array of the k parts.\n\t\tExample 1:\n\t\tInput: head = [1,2,3], k = 5\n\t\tOutput: [[1],[2],[3],[],[]]\n\t\tExplanation:\n\t\tThe first element output[0] has output[0].val = 1, output[0].next = null.\n\t\tThe last element output[4] is null, but its string representation as a ListNode is [].\n\t\tExample 2:\n\t\tInput: head = [1,2,3,4,5,6,7,8,9,10], k = 3\n\t\tOutput: [[1,2,3,4],[5,6,7],[8,9,10]]\n\t\tExplanation:\n\t\tThe input has been split into consecutive parts with size difference at most 1, and earlier parts are a larger size than the later parts.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 726, - "question": "class Solution:\n def countOfAtoms(self, formula: str) -> str:\n\t\t\"\"\"\n\t\tGiven a string formula representing a chemical formula, return the count of each atom.\n\t\tThe atomic element always starts with an uppercase character, then zero or more lowercase letters, representing the name.\n\t\tOne or more digits representing that element's count may follow if the count is greater than 1. If the count is 1, no digits will follow.\n\t\t\tFor example, \"H2O\" and \"H2O2\" are possible, but \"H1O2\" is impossible.\n\t\tTwo formulas are concatenated together to produce another formula.\n\t\t\tFor example, \"H2O2He3Mg4\" is also a formula.\n\t\tA formula placed in parentheses, and a count (optionally added) is also a formula.\n\t\t\tFor example, \"(H2O2)\" and \"(H2O2)3\" are formulas.\n\t\tReturn the count of all elements as a string in the following form: the first name (in sorted order), followed by its count (if that count is more than 1), followed by the second name (in sorted order), followed by its count (if that count is more than 1), and so on.\n\t\tThe test cases are generated so that all the values in the output fit in a 32-bit integer.\n\t\tExample 1:\n\t\tInput: formula = \"H2O\"\n\t\tOutput: \"H2O\"\n\t\tExplanation: The count of elements are {'H': 2, 'O': 1}.\n\t\tExample 2:\n\t\tInput: formula = \"Mg(OH)2\"\n\t\tOutput: \"H2MgO2\"\n\t\tExplanation: The count of elements are {'H': 2, 'Mg': 1, 'O': 2}.\n\t\tExample 3:\n\t\tInput: formula = \"K4(ON(SO3)2)2\"\n\t\tOutput: \"K4N2O14S4\"\n\t\tExplanation: The count of elements are {'K': 4, 'N': 2, 'O': 14, 'S': 4}.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 728, - "question": "class Solution:\n def selfDividingNumbers(self, left: int, right: int) -> List[int]:\n\t\t\"\"\"\n\t\tA self-dividing number is a number that is divisible by every digit it contains.\n\t\t\tFor example, 128 is a self-dividing number because 128 % 1 == 0, 128 % 2 == 0, and 128 % 8 == 0.\n\t\tA self-dividing number is not allowed to contain the digit zero.\n\t\tGiven two integers left and right, return a list of all the self-dividing numbers in the range [left, right].\n\t\tExample 1:\n\t\tInput: left = 1, right = 22\n\t\tOutput: [1,2,3,4,5,6,7,8,9,11,12,15,22]\n\t\tExample 2:\n\t\tInput: left = 47, right = 85\n\t\tOutput: [48,55,66,77]\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 729, - "question": "class MyCalendar:\n def __init__(self):\n def book(self, start: int, end: int) -> bool:\n\t\t\"\"\"\n\t\tYou are implementing a program to use as your calendar. We can add a new event if adding the event will not cause a double booking.\n\t\tA double booking happens when two events have some non-empty intersection (i.e., some moment is common to both events.).\n\t\tThe event can be represented as a pair of integers start and end that represents a booking on the half-open interval [start, end), the range of real numbers x such that start <= x < end.\n\t\tImplement the MyCalendar class:\n\t\t\tMyCalendar() Initializes the calendar object.\n\t\t\tboolean book(int start, int end) Returns true if the event can be added to the calendar successfully without causing a double booking. Otherwise, return false and do not add the event to the calendar.\n\t\tExample 1:\n\t\tInput\n\t\t[\"MyCalendar\", \"book\", \"book\", \"book\"]\n\t\t[[], [10, 20], [15, 25], [20, 30]]\n\t\tOutput\n\t\t[null, true, false, true]\n\t\tExplanation\n\t\tMyCalendar myCalendar = new MyCalendar();\n\t\tmyCalendar.book(10, 20); // return True\n\t\tmyCalendar.book(15, 25); // return False, It can not be booked because time 15 is already booked by another event.\n\t\tmyCalendar.book(20, 30); // return True, The event can be booked, as the first event takes every time less than 20, but not including 20.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 730, - "question": "class Solution:\n def countPalindromicSubsequences(self, s: str) -> int:\n\t\t\"\"\"\n\t\tGiven a string s, return the number of different non-empty palindromic subsequences in s. Since the answer may be very large, return it modulo 109 + 7.\n\t\tA subsequence of a string is obtained by deleting zero or more characters from the string.\n\t\tA sequence is palindromic if it is equal to the sequence reversed.\n\t\tTwo sequences a1, a2, ... and b1, b2, ... are different if there is some i for which ai != bi.\n\t\tExample 1:\n\t\tInput: s = \"bccb\"\n\t\tOutput: 6\n\t\tExplanation: The 6 different non-empty palindromic subsequences are 'b', 'c', 'bb', 'cc', 'bcb', 'bccb'.\n\t\tNote that 'bcb' is counted only once, even though it occurs twice.\n\t\tExample 2:\n\t\tInput: s = \"abcdabcdabcdabcdabcdabcdabcdabcddcbadcbadcbadcbadcbadcbadcbadcba\"\n\t\tOutput: 104860361\n\t\tExplanation: There are 3104860382 different non-empty palindromic subsequences, which is 104860361 modulo 109 + 7.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 731, - "question": "class MyCalendarTwo:\n def __init__(self):\n def book(self, start: int, end: int) -> bool:\n\t\t\"\"\"\n\t\tYou are implementing a program to use as your calendar. We can add a new event if adding the event will not cause a triple booking.\n\t\tA triple booking happens when three events have some non-empty intersection (i.e., some moment is common to all the three events.).\n\t\tThe event can be represented as a pair of integers start and end that represents a booking on the half-open interval [start, end), the range of real numbers x such that start <= x < end.\n\t\tImplement the MyCalendarTwo class:\n\t\t\tMyCalendarTwo() Initializes the calendar object.\n\t\t\tboolean book(int start, int end) Returns true if the event can be added to the calendar successfully without causing a triple booking. Otherwise, return false and do not add the event to the calendar.\n\t\tExample 1:\n\t\tInput\n\t\t[\"MyCalendarTwo\", \"book\", \"book\", \"book\", \"book\", \"book\", \"book\"]\n\t\t[[], [10, 20], [50, 60], [10, 40], [5, 15], [5, 10], [25, 55]]\n\t\tOutput\n\t\t[null, true, true, true, false, true, true]\n\t\tExplanation\n\t\tMyCalendarTwo myCalendarTwo = new MyCalendarTwo();\n\t\tmyCalendarTwo.book(10, 20); // return True, The event can be booked. \n\t\tmyCalendarTwo.book(50, 60); // return True, The event can be booked. \n\t\tmyCalendarTwo.book(10, 40); // return True, The event can be double booked. \n\t\tmyCalendarTwo.book(5, 15); // return False, The event cannot be booked, because it would result in a triple booking.\n\t\tmyCalendarTwo.book(5, 10); // return True, The event can be booked, as it does not use time 10 which is already double booked.\n\t\tmyCalendarTwo.book(25, 55); // return True, The event can be booked, as the time in [25, 40) will be double booked with the third event, the time [40, 50) will be single booked, and the time [50, 55) will be double booked with the second event.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 732, - "question": "class MyCalendarThree:\n def __init__(self):\n def book(self, startTime: int, endTime: int) -> int:\n\t\t\"\"\"\n\t\tA k-booking happens when k events have some non-empty intersection (i.e., there is some time that is common to all k events.)\n\t\tYou are given some events [startTime, endTime), after each given event, return an integer k representing the maximum k-booking between all the previous events.\n\t\tImplement the MyCalendarThree class:\n\t\t\tMyCalendarThree() Initializes the object.\n\t\t\tint book(int startTime, int endTime) Returns an integer k representing the largest integer such that there exists a k-booking in the calendar.\n\t\tExample 1:\n\t\tInput\n\t\t[\"MyCalendarThree\", \"book\", \"book\", \"book\", \"book\", \"book\", \"book\"]\n\t\t[[], [10, 20], [50, 60], [10, 40], [5, 15], [5, 10], [25, 55]]\n\t\tOutput\n\t\t[null, 1, 1, 2, 3, 3, 3]\n\t\tExplanation\n\t\tMyCalendarThree myCalendarThree = new MyCalendarThree();\n\t\tmyCalendarThree.book(10, 20); // return 1\n\t\tmyCalendarThree.book(50, 60); // return 1\n\t\tmyCalendarThree.book(10, 40); // return 2\n\t\tmyCalendarThree.book(5, 15); // return 3\n\t\tmyCalendarThree.book(5, 10); // return 3\n\t\tmyCalendarThree.book(25, 55); // return 3\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 733, - "question": "class Solution:\n def floodFill(self, image: List[List[int]], sr: int, sc: int, color: int) -> List[List[int]]:\n\t\t\"\"\"\n\t\tAn image is represented by an m x n integer grid image where image[i][j] represents the pixel value of the image.\n\t\tYou are also given three integers sr, sc, and color. You should perform a flood fill on the image starting from the pixel image[sr][sc].\n\t\tTo perform a flood fill, consider the starting pixel, plus any pixels connected 4-directionally to the starting pixel of the same color as the starting pixel, plus any pixels connected 4-directionally to those pixels (also with the same color), and so on. Replace the color of all of the aforementioned pixels with color.\n\t\tReturn the modified image after performing the flood fill.\n\t\tExample 1:\n\t\tInput: image = [[1,1,1],[1,1,0],[1,0,1]], sr = 1, sc = 1, color = 2\n\t\tOutput: [[2,2,2],[2,2,0],[2,0,1]]\n\t\tExplanation: From the center of the image with position (sr, sc) = (1, 1) (i.e., the red pixel), all pixels connected by a path of the same color as the starting pixel (i.e., the blue pixels) are colored with the new color.\n\t\tNote the bottom corner is not colored 2, because it is not 4-directionally connected to the starting pixel.\n\t\tExample 2:\n\t\tInput: image = [[0,0,0],[0,0,0]], sr = 0, sc = 0, color = 0\n\t\tOutput: [[0,0,0],[0,0,0]]\n\t\tExplanation: The starting pixel is already colored 0, so no changes are made to the image.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 735, - "question": "class Solution:\n def asteroidCollision(self, asteroids: List[int]) -> List[int]:\n\t\t\"\"\"\n\t\tWe are given an array asteroids of integers representing asteroids in a row.\n\t\tFor each asteroid, the absolute value represents its size, and the sign represents its direction (positive meaning right, negative meaning left). Each asteroid moves at the same speed.\n\t\tFind out the state of the asteroids after all collisions. If two asteroids meet, the smaller one will explode. If both are the same size, both will explode. Two asteroids moving in the same direction will never meet.\n\t\tExample 1:\n\t\tInput: asteroids = [5,10,-5]\n\t\tOutput: [5,10]\n\t\tExplanation: The 10 and -5 collide resulting in 10. The 5 and 10 never collide.\n\t\tExample 2:\n\t\tInput: asteroids = [8,-8]\n\t\tOutput: []\n\t\tExplanation: The 8 and -8 collide exploding each other.\n\t\tExample 3:\n\t\tInput: asteroids = [10,2,-5]\n\t\tOutput: [10]\n\t\tExplanation: The 2 and -5 collide resulting in -5. The 10 and -5 collide resulting in 10.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 736, - "question": "class Solution:\n def evaluate(self, expression: str) -> int:\n\t\t\"\"\"\n\t\tYou are given a string expression representing a Lisp-like expression to return the integer value of.\n\t\tThe syntax for these expressions is given as follows.\n\t\t\tAn expression is either an integer, let expression, add expression, mult expression, or an assigned variable. Expressions always evaluate to a single integer.\n\t\t\t(An integer could be positive or negative.)\n\t\t\tA let expression takes the form \"(let v1 e1 v2 e2 ... vn en expr)\", where let is always the string \"let\", then there are one or more pairs of alternating variables and expressions, meaning that the first variable v1 is assigned the value of the expression e1, the second variable v2 is assigned the value of the expression e2, and so on sequentially; and then the value of this let expression is the value of the expression expr.\n\t\t\tAn add expression takes the form \"(add e1 e2)\" where add is always the string \"add\", there are always two expressions e1, e2 and the result is the addition of the evaluation of e1 and the evaluation of e2.\n\t\t\tA mult expression takes the form \"(mult e1 e2)\" where mult is always the string \"mult\", there are always two expressions e1, e2 and the result is the multiplication of the evaluation of e1 and the evaluation of e2.\n\t\t\tFor this question, we will use a smaller subset of variable names. A variable starts with a lowercase letter, then zero or more lowercase letters or digits. Additionally, for your convenience, the names \"add\", \"let\", and \"mult\" are protected and will never be used as variable names.\n\t\t\tFinally, there is the concept of scope. When an expression of a variable name is evaluated, within the context of that evaluation, the innermost scope (in terms of parentheses) is checked first for the value of that variable, and then outer scopes are checked sequentially. It is guaranteed that every expression is legal. Please see the examples for more details on the scope.\n\t\tExample 1:\n\t\tInput: expression = \"(let x 2 (mult x (let x 3 y 4 (add x y))))\"\n\t\tOutput: 14\n\t\tExplanation: In the expression (add x y), when checking for the value of the variable x,\n\t\twe check from the innermost scope to the outermost in the context of the variable we are trying to evaluate.\n\t\tSince x = 3 is found first, the value of x is 3.\n\t\tExample 2:\n\t\tInput: expression = \"(let x 3 x 2 x)\"\n\t\tOutput: 2\n\t\tExplanation: Assignment in let statements is processed sequentially.\n\t\tExample 3:\n\t\tInput: expression = \"(let x 1 y 2 x (add x y) (add x y))\"\n\t\tOutput: 5\n\t\tExplanation: The first (add x y) evaluates as 3, and is assigned to x.\n\t\tThe second (add x y) evaluates as 3+2 = 5.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 738, - "question": "class Solution:\n def monotoneIncreasingDigits(self, n: int) -> int:\n\t\t\"\"\"\n\t\tAn integer has monotone increasing digits if and only if each pair of adjacent digits x and y satisfy x <= y.\n\t\tGiven an integer n, return the largest number that is less than or equal to n with monotone increasing digits.\n\t\tExample 1:\n\t\tInput: n = 10\n\t\tOutput: 9\n\t\tExample 2:\n\t\tInput: n = 1234\n\t\tOutput: 1234\n\t\tExample 3:\n\t\tInput: n = 332\n\t\tOutput: 299\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 739, - "question": "class Solution:\n def dailyTemperatures(self, temperatures: List[int]) -> List[int]:\n\t\t\"\"\"\n\t\tGiven an array of integers temperatures represents the daily temperatures, return an array answer such that answer[i] is the number of days you have to wait after the ith day to get a warmer temperature. If there is no future day for which this is possible, keep answer[i] == 0 instead.\n\t\tExample 1:\n\t\tInput: temperatures = [73,74,75,71,69,72,76,73]\n\t\tOutput: [1,1,4,2,1,1,0,0]\n\t\tExample 2:\n\t\tInput: temperatures = [30,40,50,60]\n\t\tOutput: [1,1,1,0]\n\t\tExample 3:\n\t\tInput: temperatures = [30,60,90]\n\t\tOutput: [1,1,0]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 740, - "question": "class Solution:\n def deleteAndEarn(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou are given an integer array nums. You want to maximize the number of points you get by performing the following operation any number of times:\n\t\t\tPick any nums[i] and delete it to earn nums[i] points. Afterwards, you must delete every element equal to nums[i] - 1 and every element equal to nums[i] + 1.\n\t\tReturn the maximum number of points you can earn by applying the above operation some number of times.\n\t\tExample 1:\n\t\tInput: nums = [3,4,2]\n\t\tOutput: 6\n\t\tExplanation: You can perform the following operations:\n\t\t- Delete 4 to earn 4 points. Consequently, 3 is also deleted. nums = [2].\n\t\t- Delete 2 to earn 2 points. nums = [].\n\t\tYou earn a total of 6 points.\n\t\tExample 2:\n\t\tInput: nums = [2,2,3,3,3,4]\n\t\tOutput: 9\n\t\tExplanation: You can perform the following operations:\n\t\t- Delete a 3 to earn 3 points. All 2's and 4's are also deleted. nums = [3,3].\n\t\t- Delete a 3 again to earn 3 points. nums = [3].\n\t\t- Delete a 3 once more to earn 3 points. nums = [].\n\t\tYou earn a total of 9 points.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 741, - "question": "class Solution:\n def cherryPickup(self, grid: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tYou are given an n x n grid representing a field of cherries, each cell is one of three possible integers.\n\t\t\t0 means the cell is empty, so you can pass through,\n\t\t\t1 means the cell contains a cherry that you can pick up and pass through, or\n\t\t\t-1 means the cell contains a thorn that blocks your way.\n\t\tReturn the maximum number of cherries you can collect by following the rules below:\n\t\t\tStarting at the position (0, 0) and reaching (n - 1, n - 1) by moving right or down through valid path cells (cells with value 0 or 1).\n\t\t\tAfter reaching (n - 1, n - 1), returning to (0, 0) by moving left or up through valid path cells.\n\t\t\tWhen passing through a path cell containing a cherry, you pick it up, and the cell becomes an empty cell 0.\n\t\t\tIf there is no valid path between (0, 0) and (n - 1, n - 1), then no cherries can be collected.\n\t\tExample 1:\n\t\tInput: grid = [[0,1,-1],[1,0,-1],[1,1,1]]\n\t\tOutput: 5\n\t\tExplanation: The player started at (0, 0) and went down, down, right right to reach (2, 2).\n\t\t4 cherries were picked up during this single trip, and the matrix becomes [[0,1,-1],[0,0,-1],[0,0,0]].\n\t\tThen, the player went left, up, up, left to return home, picking up one more cherry.\n\t\tThe total number of cherries picked up is 5, and this is the maximum possible.\n\t\tExample 2:\n\t\tInput: grid = [[1,1,-1],[1,-1,1],[-1,1,1]]\n\t\tOutput: 0\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 742, - "question": "class Solution:\n def toLowerCase(self, s: str) -> str:\n\t\t\"\"\"\n\t\tGiven a string s, return the string after replacing every uppercase letter with the same lowercase letter.\n\t\tExample 1:\n\t\tInput: s = \"Hello\"\n\t\tOutput: \"hello\"\n\t\tExample 2:\n\t\tInput: s = \"here\"\n\t\tOutput: \"here\"\n\t\tExample 3:\n\t\tInput: s = \"LOVELY\"\n\t\tOutput: \"lovely\"\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 744, - "question": "class Solution:\n def networkDelayTime(self, times: List[List[int]], n: int, k: int) -> int:\n\t\t\"\"\"\n\t\tYou are given a network of n nodes, labeled from 1 to n. You are also given times, a list of travel times as directed edges times[i] = (ui, vi, wi), where ui is the source node, vi is the target node, and wi is the time it takes for a signal to travel from source to target.\n\t\tWe will send a signal from a given node k. Return the minimum time it takes for all the n nodes to receive the signal. If it is impossible for all the n nodes to receive the signal, return -1.\n\t\tExample 1:\n\t\tInput: times = [[2,1,1],[2,3,1],[3,4,1]], n = 4, k = 2\n\t\tOutput: 2\n\t\tExample 2:\n\t\tInput: times = [[1,2,1]], n = 2, k = 1\n\t\tOutput: 1\n\t\tExample 3:\n\t\tInput: times = [[1,2,1]], n = 2, k = 2\n\t\tOutput: -1\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 745, - "question": "class Solution:\n def nextGreatestLetter(self, letters: List[str], target: str) -> str:\n\t\t\"\"\"\n\t\tYou are given an array of characters letters that is sorted in non-decreasing order, and a character target. There are at least two different characters in letters.\n\t\tReturn the smallest character in letters that is lexicographically greater than target. If such a character does not exist, return the first character in letters.\n\t\tExample 1:\n\t\tInput: letters = [\"c\",\"f\",\"j\"], target = \"a\"\n\t\tOutput: \"c\"\n\t\tExplanation: The smallest character that is lexicographically greater than 'a' in letters is 'c'.\n\t\tExample 2:\n\t\tInput: letters = [\"c\",\"f\",\"j\"], target = \"c\"\n\t\tOutput: \"f\"\n\t\tExplanation: The smallest character that is lexicographically greater than 'c' in letters is 'f'.\n\t\tExample 3:\n\t\tInput: letters = [\"x\",\"x\",\"y\",\"y\"], target = \"z\"\n\t\tOutput: \"x\"\n\t\tExplanation: There are no characters in letters that is lexicographically greater than 'z' so we return letters[0].\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 746, - "question": "class WordFilter:\n def __init__(self, words: List[str]):\n def f(self, pref: str, suff: str) -> int:\n\t\t\"\"\"\n\t\tDesign a special dictionary that searches the words in it by a prefix and a suffix.\n\t\tImplement the WordFilter class:\n\t\t\tWordFilter(string[] words) Initializes the object with the words in the dictionary.\n\t\t\tf(string pref, string suff) Returns the index of the word in the dictionary, which has the prefix pref and the suffix suff. If there is more than one valid index, return the largest of them. If there is no such word in the dictionary, return -1.\n\t\tExample 1:\n\t\tInput\n\t\t[\"WordFilter\", \"f\"]\n\t\t[[[\"apple\"]], [\"a\", \"e\"]]\n\t\tOutput\n\t\t[null, 0]\n\t\tExplanation\n\t\tWordFilter wordFilter = new WordFilter([\"apple\"]);\n\t\twordFilter.f(\"a\", \"e\"); // return 0, because the word at index 0 has prefix = \"a\" and suffix = \"e\".\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 747, - "question": "class Solution:\n def minCostClimbingStairs(self, cost: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou are given an integer array cost where cost[i] is the cost of ith step on a staircase. Once you pay the cost, you can either climb one or two steps.\n\t\tYou can either start from the step with index 0, or the step with index 1.\n\t\tReturn the minimum cost to reach the top of the floor.\n\t\tExample 1:\n\t\tInput: cost = [10,15,20]\n\t\tOutput: 15\n\t\tExplanation: You will start at index 1.\n\t\t- Pay 15 and climb two steps to reach the top.\n\t\tThe total cost is 15.\n\t\tExample 2:\n\t\tInput: cost = [1,100,1,1,1,100,1,1,100,1]\n\t\tOutput: 6\n\t\tExplanation: You will start at index 0.\n\t\t- Pay 1 and climb two steps to reach index 2.\n\t\t- Pay 1 and climb two steps to reach index 4.\n\t\t- Pay 1 and climb two steps to reach index 6.\n\t\t- Pay 1 and climb one step to reach index 7.\n\t\t- Pay 1 and climb two steps to reach index 9.\n\t\t- Pay 1 and climb one step to reach the top.\n\t\tThe total cost is 6.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 748, - "question": "class Solution:\n def dominantIndex(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou are given an integer array nums where the largest integer is unique.\n\t\tDetermine whether the largest element in the array is at least twice as much as every other number in the array. If it is, return the index of the largest element, or return -1 otherwise.\n\t\tExample 1:\n\t\tInput: nums = [3,6,1,0]\n\t\tOutput: 1\n\t\tExplanation: 6 is the largest integer.\n\t\tFor every other number in the array x, 6 is at least twice as big as x.\n\t\tThe index of value 6 is 1, so we return 1.\n\t\tExample 2:\n\t\tInput: nums = [1,2,3,4]\n\t\tOutput: -1\n\t\tExplanation: 4 is less than twice the value of 3, so we return -1.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 749, - "question": "class Solution:\n def shortestCompletingWord(self, licensePlate: str, words: List[str]) -> str:\n\t\t\"\"\"\n\t\tGiven a string licensePlate and an array of strings words, find the shortest completing word in words.\n\t\tA completing word is a word that contains all the letters in licensePlate. Ignore numbers and spaces in licensePlate, and treat letters as case insensitive. If a letter appears more than once in licensePlate, then it must appear in the word the same number of times or more.\n\t\tFor example, if licensePlate = \"aBc 12c\", then it contains letters 'a', 'b' (ignoring case), and 'c' twice. Possible completing words are \"abccdef\", \"caaacab\", and \"cbca\".\n\t\tReturn the shortest completing word in words. It is guaranteed an answer exists. If there are multiple shortest completing words, return the first one that occurs in words.\n\t\tExample 1:\n\t\tInput: licensePlate = \"1s3 PSt\", words = [\"step\",\"steps\",\"stripe\",\"stepple\"]\n\t\tOutput: \"steps\"\n\t\tExplanation: licensePlate contains letters 's', 'p', 's' (ignoring case), and 't'.\n\t\t\"step\" contains 't' and 'p', but only contains 1 's'.\n\t\t\"steps\" contains 't', 'p', and both 's' characters.\n\t\t\"stripe\" is missing an 's'.\n\t\t\"stepple\" is missing an 's'.\n\t\tSince \"steps\" is the only word containing all the letters, that is the answer.\n\t\tExample 2:\n\t\tInput: licensePlate = \"1s3 456\", words = [\"looks\",\"pest\",\"stew\",\"show\"]\n\t\tOutput: \"pest\"\n\t\tExplanation: licensePlate only contains the letter 's'. All the words contain 's', but among these \"pest\", \"stew\", and \"show\" are shortest. The answer is \"pest\" because it is the word that appears earliest of the 3.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 750, - "question": "class Solution:\n def containVirus(self, isInfected: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tA virus is spreading rapidly, and your task is to quarantine the infected area by installing walls.\n\t\tThe world is modeled as an m x n binary grid isInfected, where isInfected[i][j] == 0 represents uninfected cells, and isInfected[i][j] == 1 represents cells contaminated with the virus. A wall (and only one wall) can be installed between any two 4-directionally adjacent cells, on the shared boundary.\n\t\tEvery night, the virus spreads to all neighboring cells in all four directions unless blocked by a wall. Resources are limited. Each day, you can install walls around only one region (i.e., the affected area (continuous block of infected cells) that threatens the most uninfected cells the following night). There will never be a tie.\n\t\tReturn the number of walls used to quarantine all the infected regions. If the world will become fully infected, return the number of walls used.\n\t\tExample 1:\n\t\tInput: isInfected = [[0,1,0,0,0,0,0,1],[0,1,0,0,0,0,0,1],[0,0,0,0,0,0,0,1],[0,0,0,0,0,0,0,0]]\n\t\tOutput: 10\n\t\tExplanation: There are 2 contaminated regions.\n\t\tOn the first day, add 5 walls to quarantine the viral region on the left. The board after the virus spreads is:\n\t\tOn the second day, add 5 walls to quarantine the viral region on the right. The virus is fully contained.\n\t\tExample 2:\n\t\tInput: isInfected = [[1,1,1],[1,0,1],[1,1,1]]\n\t\tOutput: 4\n\t\tExplanation: Even though there is only one cell saved, there are 4 walls built.\n\t\tNotice that walls are only built on the shared boundary of two different cells.\n\t\tExample 3:\n\t\tInput: isInfected = [[1,1,1,0,0,0,0,0,0],[1,0,1,0,1,1,1,1,1],[1,1,1,0,0,0,0,0,0]]\n\t\tOutput: 13\n\t\tExplanation: The region on the left only builds two new walls.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 753, - "question": "class Solution:\n def openLock(self, deadends: List[str], target: str) -> int:\n\t\t\"\"\"\n\t\tYou have a lock in front of you with 4 circular wheels. Each wheel has 10 slots: '0', '1', '2', '3', '4', '5', '6', '7', '8', '9'. The wheels can rotate freely and wrap around: for example we can turn '9' to be '0', or '0' to be '9'. Each move consists of turning one wheel one slot.\n\t\tThe lock initially starts at '0000', a string representing the state of the 4 wheels.\n\t\tYou are given a list of deadends dead ends, meaning if the lock displays any of these codes, the wheels of the lock will stop turning and you will be unable to open it.\n\t\tGiven a target representing the value of the wheels that will unlock the lock, return the minimum total number of turns required to open the lock, or -1 if it is impossible.\n\t\tExample 1:\n\t\tInput: deadends = [\"0201\",\"0101\",\"0102\",\"1212\",\"2002\"], target = \"0202\"\n\t\tOutput: 6\n\t\tExplanation: \n\t\tA sequence of valid moves would be \"0000\" -> \"1000\" -> \"1100\" -> \"1200\" -> \"1201\" -> \"1202\" -> \"0202\".\n\t\tNote that a sequence like \"0000\" -> \"0001\" -> \"0002\" -> \"0102\" -> \"0202\" would be invalid,\n\t\tbecause the wheels of the lock become stuck after the display becomes the dead end \"0102\".\n\t\tExample 2:\n\t\tInput: deadends = [\"8888\"], target = \"0009\"\n\t\tOutput: 1\n\t\tExplanation: We can turn the last wheel in reverse to move from \"0000\" -> \"0009\".\n\t\tExample 3:\n\t\tInput: deadends = [\"8887\",\"8889\",\"8878\",\"8898\",\"8788\",\"8988\",\"7888\",\"9888\"], target = \"8888\"\n\t\tOutput: -1\n\t\tExplanation: We cannot reach the target without getting stuck.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 754, - "question": "class Solution:\n def crackSafe(self, n: int, k: int) -> str:\n\t\t\"\"\"\n\t\tThere is a safe protected by a password. The password is a sequence of n digits where each digit can be in the range [0, k - 1].\n\t\tThe safe has a peculiar way of checking the password. When you enter in a sequence, it checks the most recent n digits that were entered each time you type a digit.\n\t\t\tFor example, the correct password is \"345\" and you enter in \"012345\":\n\t\t\t\tAfter typing 0, the most recent 3 digits is \"0\", which is incorrect.\n\t\t\t\tAfter typing 1, the most recent 3 digits is \"01\", which is incorrect.\n\t\t\t\tAfter typing 2, the most recent 3 digits is \"012\", which is incorrect.\n\t\t\t\tAfter typing 3, the most recent 3 digits is \"123\", which is incorrect.\n\t\t\t\tAfter typing 4, the most recent 3 digits is \"234\", which is incorrect.\n\t\t\t\tAfter typing 5, the most recent 3 digits is \"345\", which is correct and the safe unlocks.\n\t\tReturn any string of minimum length that will unlock the safe at some point of entering it.\n\t\tExample 1:\n\t\tInput: n = 1, k = 2\n\t\tOutput: \"10\"\n\t\tExplanation: The password is a single digit, so enter each digit. \"01\" would also unlock the safe.\n\t\tExample 2:\n\t\tInput: n = 2, k = 2\n\t\tOutput: \"01100\"\n\t\tExplanation: For each possible password:\n\t\t- \"00\" is typed in starting from the 4th digit.\n\t\t- \"01\" is typed in starting from the 1st digit.\n\t\t- \"10\" is typed in starting from the 3rd digit.\n\t\t- \"11\" is typed in starting from the 2nd digit.\n\t\tThus \"01100\" will unlock the safe. \"01100\", \"10011\", and \"11001\" would also unlock the safe.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 755, - "question": "class Solution:\n def reachNumber(self, target: int) -> int:\n\t\t\"\"\"\n\t\tYou are standing at position 0 on an infinite number line. There is a destination at position target.\n\t\tYou can make some number of moves numMoves so that:\n\t\t\tOn each move, you can either go left or right.\n\t\t\tDuring the ith move (starting from i == 1 to i == numMoves), you take i steps in the chosen direction.\n\t\tGiven the integer target, return the minimum number of moves required (i.e., the minimum numMoves) to reach the destination.\n\t\tExample 1:\n\t\tInput: target = 2\n\t\tOutput: 3\n\t\tExplanation:\n\t\tOn the 1st move, we step from 0 to 1 (1 step).\n\t\tOn the 2nd move, we step from 1 to -1 (2 steps).\n\t\tOn the 3rd move, we step from -1 to 2 (3 steps).\n\t\tExample 2:\n\t\tInput: target = 3\n\t\tOutput: 2\n\t\tExplanation:\n\t\tOn the 1st move, we step from 0 to 1 (1 step).\n\t\tOn the 2nd move, we step from 1 to 3 (2 steps).\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 757, - "question": "class Solution:\n def pyramidTransition(self, bottom: str, allowed: List[str]) -> bool:\n\t\t\"\"\"\n\t\tYou are stacking blocks to form a pyramid. Each block has a color, which is represented by a single letter. Each row of blocks contains one less block than the row beneath it and is centered on top.\n\t\tTo make the pyramid aesthetically pleasing, there are only specific triangular patterns that are allowed. A triangular pattern consists of a single block stacked on top of two blocks. The patterns are given as a list of three-letter strings allowed, where the first two characters of a pattern represent the left and right bottom blocks respectively, and the third character is the top block.\n\t\t\tFor example, \"ABC\" represents a triangular pattern with a 'C' block stacked on top of an 'A' (left) and 'B' (right) block. Note that this is different from \"BAC\" where 'B' is on the left bottom and 'A' is on the right bottom.\n\t\tYou start with a bottom row of blocks bottom, given as a single string, that you must use as the base of the pyramid.\n\t\tGiven bottom and allowed, return true if you can build the pyramid all the way to the top such that every triangular pattern in the pyramid is in allowed, or false otherwise.\n\t\tExample 1:\n\t\tInput: bottom = \"BCD\", allowed = [\"BCC\",\"CDE\",\"CEA\",\"FFF\"]\n\t\tOutput: true\n\t\tExplanation: The allowed triangular patterns are shown on the right.\n\t\tStarting from the bottom (level 3), we can build \"CE\" on level 2 and then build \"A\" on level 1.\n\t\tThere are three triangular patterns in the pyramid, which are \"BCC\", \"CDE\", and \"CEA\". All are allowed.\n\t\tExample 2:\n\t\tInput: bottom = \"AAAA\", allowed = [\"AAB\",\"AAC\",\"BCD\",\"BBE\",\"DEF\"]\n\t\tOutput: false\n\t\tExplanation: The allowed triangular patterns are shown on the right.\n\t\tStarting from the bottom (level 4), there are multiple ways to build level 3, but trying all the possibilites, you will get always stuck before building level 1.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 759, - "question": "class Solution:\n def intersectionSizeTwo(self, intervals: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tYou are given a 2D integer array intervals where intervals[i] = [starti, endi] represents all the integers from starti to endi inclusively.\n\t\tA containing set is an array nums where each interval from intervals has at least two integers in nums.\n\t\t\tFor example, if intervals = [[1,3], [3,7], [8,9]], then [1,2,4,7,8,9] and [2,3,4,8,9] are containing sets.\n\t\tReturn the minimum possible size of a containing set.\n\t\tExample 1:\n\t\tInput: intervals = [[1,3],[3,7],[8,9]]\n\t\tOutput: 5\n\t\tExplanation: let nums = [2, 3, 4, 8, 9].\n\t\tIt can be shown that there cannot be any containing array of size 4.\n\t\tExample 2:\n\t\tInput: intervals = [[1,3],[1,4],[2,5],[3,5]]\n\t\tOutput: 3\n\t\tExplanation: let nums = [2, 3, 4].\n\t\tIt can be shown that there cannot be any containing array of size 2.\n\t\tExample 3:\n\t\tInput: intervals = [[1,2],[2,3],[2,4],[4,5]]\n\t\tOutput: 5\n\t\tExplanation: let nums = [1, 2, 3, 4, 5].\n\t\tIt can be shown that there cannot be any containing array of size 4.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 763, - "question": "class Solution:\n def makeLargestSpecial(self, s: str) -> str:\n\t\t\"\"\"\n\t\tSpecial binary strings are binary strings with the following two properties:\n\t\t\tThe number of 0's is equal to the number of 1's.\n\t\t\tEvery prefix of the binary string has at least as many 1's as 0's.\n\t\tYou are given a special binary string s.\n\t\tA move consists of choosing two consecutive, non-empty, special substrings of s, and swapping them. Two strings are consecutive if the last character of the first string is exactly one index before the first character of the second string.\n\t\tReturn the lexicographically largest resulting string possible after applying the mentioned operations on the string.\n\t\tExample 1:\n\t\tInput: s = \"11011000\"\n\t\tOutput: \"11100100\"\n\t\tExplanation: The strings \"10\" [occuring at s[1]] and \"1100\" [at s[3]] are swapped.\n\t\tThis is the lexicographically largest string possible after some number of swaps.\n\t\tExample 2:\n\t\tInput: s = \"10\"\n\t\tOutput: \"10\"\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 764, - "question": "\n\t\t\"\"\"\nclass Node:\n def __init__(self, val=None, children=None):\n self.val = val\n self.children = children\n\t\tGiven an n-ary tree, return the level order traversal of its nodes' values.\n\t\tNary-Tree input serialization is represented in their level order traversal, each group of children is separated by the null value (See examples).\n\t\tExample 1:\n\t\tInput: root = [1,null,3,2,4,null,5,6]\n\t\tOutput: [[1],[3,2,4],[5,6]]\n\t\tExample 2:\n\t\tInput: root = [1,null,2,3,4,5,null,null,6,7,null,8,null,9,10,null,null,11,null,12,null,13,null,null,14]\n\t\tOutput: [[1],[2,3,4,5],[6,7,8,9,10],[11,12,13],[14]]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 766, - "question": "\n\t\t\"\"\"\nclass Node:\n def __init__(self, val, prev, next, child):\n self.val = val\n self.prev = prev\n self.next = next\n self.child = child\n\t\tYou are given a doubly linked list, which contains nodes that have a next pointer, a previous pointer, and an additional child pointer. This child pointer may or may not point to a separate doubly linked list, also containing these special nodes. These child lists may have one or more children of their own, and so on, to produce a multilevel data structure as shown in the example below.\n\t\tGiven the head of the first level of the list, flatten the list so that all the nodes appear in a single-level, doubly linked list. Let curr be a node with a child list. The nodes in the child list should appear after curr and before curr.next in the flattened list.\n\t\tReturn the head of the flattened list. The nodes in the list must have all of their child pointers set to null.\n\t\tExample 1:\n\t\tInput: head = [1,2,3,4,5,6,null,null,null,7,8,9,10,null,null,11,12]\n\t\tOutput: [1,2,3,7,8,11,12,9,10,4,5,6]\n\t\tExplanation: The multilevel linked list in the input is shown.\n\t\tAfter flattening the multilevel linked list it becomes:\n\t\tExample 2:\n\t\tInput: head = [1,2,null,3]\n\t\tOutput: [1,3,2]\n\t\tExplanation: The multilevel linked list in the input is shown.\n\t\tAfter flattening the multilevel linked list it becomes:\n\t\tExample 3:\n\t\tInput: head = []\n\t\tOutput: []\n\t\tExplanation: There could be empty list in the input.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 767, - "question": "class Solution:\n def countPrimeSetBits(self, left: int, right: int) -> int:\n\t\t\"\"\"\n\t\tGiven two integers left and right, return the count of numbers in the inclusive range [left, right] having a prime number of set bits in their binary representation.\n\t\tRecall that the number of set bits an integer has is the number of 1's present when written in binary.\n\t\t\tFor example, 21 written in binary is 10101, which has 3 set bits.\n\t\tExample 1:\n\t\tInput: left = 6, right = 10\n\t\tOutput: 4\n\t\tExplanation:\n\t\t6 -> 110 (2 set bits, 2 is prime)\n\t\t7 -> 111 (3 set bits, 3 is prime)\n\t\t8 -> 1000 (1 set bit, 1 is not prime)\n\t\t9 -> 1001 (2 set bits, 2 is prime)\n\t\t10 -> 1010 (2 set bits, 2 is prime)\n\t\t4 numbers have a prime number of set bits.\n\t\tExample 2:\n\t\tInput: left = 10, right = 15\n\t\tOutput: 5\n\t\tExplanation:\n\t\t10 -> 1010 (2 set bits, 2 is prime)\n\t\t11 -> 1011 (3 set bits, 3 is prime)\n\t\t12 -> 1100 (2 set bits, 2 is prime)\n\t\t13 -> 1101 (3 set bits, 3 is prime)\n\t\t14 -> 1110 (3 set bits, 3 is prime)\n\t\t15 -> 1111 (4 set bits, 4 is not prime)\n\t\t5 numbers have a prime number of set bits.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 768, - "question": "class Solution:\n def partitionLabels(self, s: str) -> List[int]:\n\t\t\"\"\"\n\t\tYou are given a string s. We want to partition the string into as many parts as possible so that each letter appears in at most one part.\n\t\tNote that the partition is done so that after concatenating all the parts in order, the resultant string should be s.\n\t\tReturn a list of integers representing the size of these parts.\n\t\tExample 1:\n\t\tInput: s = \"ababcbacadefegdehijhklij\"\n\t\tOutput: [9,7,8]\n\t\tExplanation:\n\t\tThe partition is \"ababcbaca\", \"defegde\", \"hijhklij\".\n\t\tThis is a partition so that each letter appears in at most one part.\n\t\tA partition like \"ababcbacadefegde\", \"hijhklij\" is incorrect, because it splits s into less parts.\n\t\tExample 2:\n\t\tInput: s = \"eccbbbbdec\"\n\t\tOutput: [10]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 769, - "question": "class Solution:\n def orderOfLargestPlusSign(self, n: int, mines: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tYou are given an integer n. You have an n x n binary grid grid with all values initially 1's except for some indices given in the array mines. The ith element of the array mines is defined as mines[i] = [xi, yi] where grid[xi][yi] == 0.\n\t\tReturn the order of the largest axis-aligned plus sign of 1's contained in grid. If there is none, return 0.\n\t\tAn axis-aligned plus sign of 1's of order k has some center grid[r][c] == 1 along with four arms of length k - 1 going up, down, left, and right, and made of 1's. Note that there could be 0's or 1's beyond the arms of the plus sign, only the relevant area of the plus sign is checked for 1's.\n\t\tExample 1:\n\t\tInput: n = 5, mines = [[4,2]]\n\t\tOutput: 2\n\t\tExplanation: In the above grid, the largest plus sign can only be of order 2. One of them is shown.\n\t\tExample 2:\n\t\tInput: n = 1, mines = [[0,0]]\n\t\tOutput: 0\n\t\tExplanation: There is no plus sign, so return 0.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 770, - "question": "class Solution:\n def minSwapsCouples(self, row: List[int]) -> int:\n\t\t\"\"\"\n\t\tThere are n couples sitting in 2n seats arranged in a row and want to hold hands.\n\t\tThe people and seats are represented by an integer array row where row[i] is the ID of the person sitting in the ith seat. The couples are numbered in order, the first couple being (0, 1), the second couple being (2, 3), and so on with the last couple being (2n - 2, 2n - 1).\n\t\tReturn the minimum number of swaps so that every couple is sitting side by side. A swap consists of choosing any two people, then they stand up and switch seats.\n\t\tExample 1:\n\t\tInput: row = [0,2,1,3]\n\t\tOutput: 1\n\t\tExplanation: We only need to swap the second (row[1]) and third (row[2]) person.\n\t\tExample 2:\n\t\tInput: row = [3,2,0,1]\n\t\tOutput: 0\n\t\tExplanation: All couples are already seated side by side.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 772, - "question": "\n\t\t\"\"\"\nclass Node:\n def __init__(self, val, isLeaf, topLeft, topRight, bottomLeft, bottomRight):\n self.val = val\n self.isLeaf = isLeaf\n self.topLeft = topLeft\n self.topRight = topRight\n self.bottomLeft = bottomLeft\n self.bottomRight = bottomRight\n\t\tGiven a n * n matrix grid of 0's and 1's only. We want to represent the grid with a Quad-Tree.\n\t\tReturn the root of the Quad-Tree representing the grid.\n\t\tNotice that you can assign the value of a node to True or False when isLeaf is False, and both are accepted in the answer.\n\t\tA Quad-Tree is a tree data structure in which each internal node has exactly four children. Besides, each node has two attributes:\n\t\t\tval: True if the node represents a grid of 1's or False if the node represents a grid of 0's.\n\t\t\tisLeaf: True if the node is leaf node on the tree or False if the node has the four children.\n\t\tclass Node {\n\t\t public boolean val;\n\t\t public boolean isLeaf;\n\t\t public Node topLeft;\n\t\t public Node topRight;\n\t\t public Node bottomLeft;\n\t\t public Node bottomRight;\n\t\t}\n\t\tWe can construct a Quad-Tree from a two-dimensional area using the following steps:\n\t\t\tIf the current grid has the same value (i.e all 1's or all 0's) set isLeaf True and set val to the value of the grid and set the four children to Null and stop.\n\t\t\tIf the current grid has different values, set isLeaf to False and set val to any value and divide the current grid into four sub-grids as shown in the photo.\n\t\t\tRecurse for each of the children with the proper sub-grid.\n\t\tIf you want to know more about the Quad-Tree, you can refer to the wiki.\n\t\tQuad-Tree format:\n\t\tThe output represents the serialized format of a Quad-Tree using level order traversal, where null signifies a path terminator where no node exists below.\n\t\tIt is very similar to the serialization of the binary tree. The only difference is that the node is represented as a list [isLeaf, val].\n\t\tIf the value of isLeaf or val is True we represent it as 1 in the list [isLeaf, val] and if the value of isLeaf or val is False we represent it as 0.\n\t\tExample 1:\n\t\tInput: grid = [[0,1],[1,0]]\n\t\tOutput: [[0,1],[1,0],[1,1],[1,1],[1,0]]\n\t\tExplanation: The explanation of this example is shown below:\n\t\tNotice that 0 represnts False and 1 represents True in the photo representing the Quad-Tree.\n\t\tExample 2:\n\t\tInput: grid = [[1,1,1,1,0,0,0,0],[1,1,1,1,0,0,0,0],[1,1,1,1,1,1,1,1],[1,1,1,1,1,1,1,1],[1,1,1,1,0,0,0,0],[1,1,1,1,0,0,0,0],[1,1,1,1,0,0,0,0],[1,1,1,1,0,0,0,0]]\n\t\tOutput: [[0,1],[1,1],[0,1],[1,1],[1,0],null,null,null,null,[1,0],[1,0],[1,1],[1,1]]\n\t\tExplanation: All values in the grid are not the same. We divide the grid into four sub-grids.\n\t\tThe topLeft, bottomLeft and bottomRight each has the same value.\n\t\tThe topRight have different values so we divide it into 4 sub-grids where each has the same value.\n\t\tExplanation is shown in the photo below:\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 773, - "question": "\n\t\t\"\"\"\nclass Node:\n def __init__(self, val, isLeaf, topLeft, topRight, bottomLeft, bottomRight):\n self.val = val\n self.isLeaf = isLeaf\n self.topLeft = topLeft\n self.topRight = topRight\n self.bottomLeft = bottomLeft\n self.bottomRight = bottomRight\n\t\tA Binary Matrix is a matrix in which all the elements are either 0 or 1.\n\t\tGiven quadTree1 and quadTree2. quadTree1 represents a n * n binary matrix and quadTree2 represents another n * n binary matrix.\n\t\tReturn a Quad-Tree representing the n * n binary matrix which is the result of logical bitwise OR of the two binary matrixes represented by quadTree1 and quadTree2.\n\t\tNotice that you can assign the value of a node to True or False when isLeaf is False, and both are accepted in the answer.\n\t\tA Quad-Tree is a tree data structure in which each internal node has exactly four children. Besides, each node has two attributes:\n\t\t\tval: True if the node represents a grid of 1's or False if the node represents a grid of 0's.\n\t\t\tisLeaf: True if the node is leaf node on the tree or False if the node has the four children.\n\t\tclass Node {\n\t\t public boolean val;\n\t\t public boolean isLeaf;\n\t\t public Node topLeft;\n\t\t public Node topRight;\n\t\t public Node bottomLeft;\n\t\t public Node bottomRight;\n\t\t}\n\t\tWe can construct a Quad-Tree from a two-dimensional area using the following steps:\n\t\t\tIf the current grid has the same value (i.e all 1's or all 0's) set isLeaf True and set val to the value of the grid and set the four children to Null and stop.\n\t\t\tIf the current grid has different values, set isLeaf to False and set val to any value and divide the current grid into four sub-grids as shown in the photo.\n\t\t\tRecurse for each of the children with the proper sub-grid.\n\t\tIf you want to know more about the Quad-Tree, you can refer to the wiki.\n\t\tQuad-Tree format:\n\t\tThe input/output represents the serialized format of a Quad-Tree using level order traversal, where null signifies a path terminator where no node exists below.\n\t\tIt is very similar to the serialization of the binary tree. The only difference is that the node is represented as a list [isLeaf, val].\n\t\tIf the value of isLeaf or val is True we represent it as 1 in the list [isLeaf, val] and if the value of isLeaf or val is False we represent it as 0.\n\t\tExample 1:\n\t\tInput: quadTree1 = [[0,1],[1,1],[1,1],[1,0],[1,0]]\n\t\t, quadTree2 = [[0,1],[1,1],[0,1],[1,1],[1,0],null,null,null,null,[1,0],[1,0],[1,1],[1,1]]\n\t\tOutput: [[0,0],[1,1],[1,1],[1,1],[1,0]]\n\t\tExplanation: quadTree1 and quadTree2 are shown above. You can see the binary matrix which is represented by each Quad-Tree.\n\t\tIf we apply logical bitwise OR on the two binary matrices we get the binary matrix below which is represented by the result Quad-Tree.\n\t\tNotice that the binary matrices shown are only for illustration, you don't have to construct the binary matrix to get the result tree.\n\t\tExample 2:\n\t\tInput: quadTree1 = [[1,0]], quadTree2 = [[1,0]]\n\t\tOutput: [[1,0]]\n\t\tExplanation: Each tree represents a binary matrix of size 1*1. Each matrix contains only zero.\n\t\tThe resulting matrix is of size 1*1 with also zero.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 774, - "question": "\n\t\t\"\"\"\nclass Node:\n def __init__(self, val=None, children=None):\n self.val = val\n self.children = children\n\t\tGiven a n-ary tree, find its maximum depth.\n\t\tThe maximum depth is the number of nodes along the longest path from the root node down to the farthest leaf node.\n\t\tNary-Tree input serialization is represented in their level order traversal, each group of children is separated by the null value (See examples).\n\t\tExample 1:\n\t\tInput: root = [1,null,3,2,4,null,5,6]\n\t\tOutput: 3\n\t\tExample 2:\n\t\tInput: root = [1,null,2,3,4,5,null,null,6,7,null,8,null,9,10,null,null,11,null,12,null,13,null,null,14]\n\t\tOutput: 5\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 775, - "question": "\n\t\t\"\"\"\nclass Node:\n def __init__(self, val=None, children=None):\n self.val = val\n self.children = children\n\t\tGiven the root of an n-ary tree, return the preorder traversal of its nodes' values.\n\t\tNary-Tree input serialization is represented in their level order traversal. Each group of children is separated by the null value (See examples)\n\t\tExample 1:\n\t\tInput: root = [1,null,3,2,4,null,5,6]\n\t\tOutput: [1,3,5,6,2,4]\n\t\tExample 2:\n\t\tInput: root = [1,null,2,3,4,5,null,null,6,7,null,8,null,9,10,null,null,11,null,12,null,13,null,null,14]\n\t\tOutput: [1,2,3,6,7,11,14,4,8,12,5,9,13,10]\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 776, - "question": "\n\t\t\"\"\"\nclass Node:\n def __init__(self, val=None, children=None):\n self.val = val\n self.children = children\n\t\tGiven the root of an n-ary tree, return the postorder traversal of its nodes' values.\n\t\tNary-Tree input serialization is represented in their level order traversal. Each group of children is separated by the null value (See examples)\n\t\tExample 1:\n\t\tInput: root = [1,null,3,2,4,null,5,6]\n\t\tOutput: [5,6,3,2,4,1]\n\t\tExample 2:\n\t\tInput: root = [1,null,2,3,4,5,null,null,6,7,null,8,null,9,10,null,null,11,null,12,null,13,null,null,14]\n\t\tOutput: [2,6,14,11,7,3,12,8,4,13,9,10,5,1]\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 777, - "question": "class Solution:\n def isToeplitzMatrix(self, matrix: List[List[int]]) -> bool:\n\t\t\"\"\"\n\t\tGiven an m x n matrix, return true if the matrix is Toeplitz. Otherwise, return false.\n\t\tA matrix is Toeplitz if every diagonal from top-left to bottom-right has the same elements.\n\t\tExample 1:\n\t\tInput: matrix = [[1,2,3,4],[5,1,2,3],[9,5,1,2]]\n\t\tOutput: true\n\t\tExplanation:\n\t\tIn the above grid, the diagonals are:\n\t\t\"[9]\", \"[5, 5]\", \"[1, 1, 1]\", \"[2, 2, 2]\", \"[3, 3]\", \"[4]\".\n\t\tIn each diagonal all elements are the same, so the answer is True.\n\t\tExample 2:\n\t\tInput: matrix = [[1,2],[2,2]]\n\t\tOutput: false\n\t\tExplanation:\n\t\tThe diagonal \"[1, 2]\" has different elements.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 778, - "question": "class Solution:\n def reorganizeString(self, s: str) -> str:\n\t\t\"\"\"\n\t\tGiven a string s, rearrange the characters of s so that any two adjacent characters are not the same.\n\t\tReturn any possible rearrangement of s or return \"\" if not possible.\n\t\tExample 1:\n\t\tInput: s = \"aab\"\n\t\tOutput: \"aba\"\n\t\tExample 2:\n\t\tInput: s = \"aaab\"\n\t\tOutput: \"\"\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 779, - "question": "class Solution:\n def maxChunksToSorted(self, arr: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou are given an integer array arr.\n\t\tWe split arr into some number of chunks (i.e., partitions), and individually sort each chunk. After concatenating them, the result should equal the sorted array.\n\t\tReturn the largest number of chunks we can make to sort the array.\n\t\tExample 1:\n\t\tInput: arr = [5,4,3,2,1]\n\t\tOutput: 1\n\t\tExplanation:\n\t\tSplitting into two or more chunks will not return the required result.\n\t\tFor example, splitting into [5, 4], [3, 2, 1] will result in [4, 5, 1, 2, 3], which isn't sorted.\n\t\tExample 2:\n\t\tInput: arr = [2,1,3,4,4]\n\t\tOutput: 4\n\t\tExplanation:\n\t\tWe can split into two chunks, such as [2, 1], [3, 4, 4].\n\t\tHowever, splitting into [2, 1], [3], [4], [4] is the highest number of chunks possible.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 780, - "question": "class Solution:\n def maxChunksToSorted(self, arr: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou are given an integer array arr of length n that represents a permutation of the integers in the range [0, n - 1].\n\t\tWe split arr into some number of chunks (i.e., partitions), and individually sort each chunk. After concatenating them, the result should equal the sorted array.\n\t\tReturn the largest number of chunks we can make to sort the array.\n\t\tExample 1:\n\t\tInput: arr = [4,3,2,1,0]\n\t\tOutput: 1\n\t\tExplanation:\n\t\tSplitting into two or more chunks will not return the required result.\n\t\tFor example, splitting into [4, 3], [2, 1, 0] will result in [3, 4, 0, 1, 2], which isn't sorted.\n\t\tExample 2:\n\t\tInput: arr = [1,0,2,3,4]\n\t\tOutput: 4\n\t\tExplanation:\n\t\tWe can split into two chunks, such as [1, 0], [2, 3, 4].\n\t\tHowever, splitting into [1, 0], [2], [3], [4] is the highest number of chunks possible.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 781, - "question": "class Solution:\n def basicCalculatorIV(self, expression: str, evalvars: List[str], evalints: List[int]) -> List[str]:\n\t\t\"\"\"\n\t\tGiven an expression such as expression = \"e + 8 - a + 5\" and an evaluation map such as {\"e\": 1} (given in terms of evalvars = [\"e\"] and evalints = [1]), return a list of tokens representing the simplified expression, such as [\"-1*a\",\"14\"]\n\t\t\tAn expression alternates chunks and symbols, with a space separating each chunk and symbol.\n\t\t\tA chunk is either an expression in parentheses, a variable, or a non-negative integer.\n\t\t\tA variable is a string of lowercase letters (not including digits.) Note that variables can be multiple letters, and note that variables never have a leading coefficient or unary operator like \"2x\" or \"-x\".\n\t\tExpressions are evaluated in the usual order: brackets first, then multiplication, then addition and subtraction.\n\t\t\tFor example, expression = \"1 + 2 * 3\" has an answer of [\"7\"].\n\t\tThe format of the output is as follows:\n\t\t\tFor each term of free variables with a non-zero coefficient, we write the free variables within a term in sorted order lexicographically.\n\t\t\t\tFor example, we would never write a term like \"b*a*c\", only \"a*b*c\".\n\t\t\tTerms have degrees equal to the number of free variables being multiplied, counting multiplicity. We write the largest degree terms of our answer first, breaking ties by lexicographic order ignoring the leading coefficient of the term.\n\t\t\t\tFor example, \"a*a*b*c\" has degree 4.\n\t\t\tThe leading coefficient of the term is placed directly to the left with an asterisk separating it from the variables (if they exist.) A leading coefficient of 1 is still printed.\n\t\t\tAn example of a well-formatted answer is [\"-2*a*a*a\", \"3*a*a*b\", \"3*b*b\", \"4*a\", \"5*c\", \"-6\"].\n\t\t\tTerms (including constant terms) with coefficient 0 are not included.\n\t\t\t\tFor example, an expression of \"0\" has an output of [].\n\t\tNote: You may assume that the given expression is always valid. All intermediate results will be in the range of [-231, 231 - 1].\n\t\tExample 1:\n\t\tInput: expression = \"e + 8 - a + 5\", evalvars = [\"e\"], evalints = [1]\n\t\tOutput: [\"-1*a\",\"14\"]\n\t\tExample 2:\n\t\tInput: expression = \"e - 8 + temperature - pressure\", evalvars = [\"e\", \"temperature\"], evalints = [1, 12]\n\t\tOutput: [\"-1*pressure\",\"5\"]\n\t\tExample 3:\n\t\tInput: expression = \"(e + 8) * (e - 8)\", evalvars = [], evalints = []\n\t\tOutput: [\"1*e*e\",\"-64\"]\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 782, - "question": "class Solution:\n def numJewelsInStones(self, jewels: str, stones: str) -> int:\n\t\t\"\"\"\n\t\tYou're given strings jewels representing the types of stones that are jewels, and stones representing the stones you have. Each character in stones is a type of stone you have. You want to know how many of the stones you have are also jewels.\n\t\tLetters are case sensitive, so \"a\" is considered a different type of stone from \"A\".\n\t\tExample 1:\n\t\tInput: jewels = \"aA\", stones = \"aAAbbbb\"\n\t\tOutput: 3\n\t\tExample 2:\n\t\tInput: jewels = \"z\", stones = \"ZZ\"\n\t\tOutput: 0\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 783, - "question": "class Solution:\n def searchBST(self, root: Optional[TreeNode], val: int) -> Optional[TreeNode]:\n\t\t\"\"\"\n\t\tYou are given the root of a binary search tree (BST) and an integer val.\n\t\tFind the node in the BST that the node's value equals val and return the subtree rooted with that node. If such a node does not exist, return null.\n\t\tExample 1:\n\t\tInput: root = [4,2,7,1,3], val = 2\n\t\tOutput: [2,1,3]\n\t\tExample 2:\n\t\tInput: root = [4,2,7,1,3], val = 5\n\t\tOutput: []\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 784, - "question": "class Solution:\n def insertIntoBST(self, root: Optional[TreeNode], val: int) -> Optional[TreeNode]:\n\t\t\"\"\"\n\t\tYou are given the root node of a binary search tree (BST) and a value to insert into the tree. Return the root node of the BST after the insertion. It is guaranteed that the new value does not exist in the original BST.\n\t\tNotice that there may exist multiple valid ways for the insertion, as long as the tree remains a BST after insertion. You can return any of them.\n\t\tExample 1:\n\t\tInput: root = [4,2,7,1,3], val = 5\n\t\tOutput: [4,2,7,1,3,5]\n\t\tExplanation: Another accepted tree is:\n\t\tExample 2:\n\t\tInput: root = [40,20,60,10,30,50,70], val = 25\n\t\tOutput: [40,20,60,10,30,50,70,null,null,25]\n\t\tExample 3:\n\t\tInput: root = [4,2,7,1,3,null,null,null,null,null,null], val = 5\n\t\tOutput: [4,2,7,1,3,5]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 787, - "question": "class Solution:\n def slidingPuzzle(self, board: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tOn an 2 x 3 board, there are five tiles labeled from 1 to 5, and an empty square represented by 0. A move consists of choosing 0 and a 4-directionally adjacent number and swapping it.\n\t\tThe state of the board is solved if and only if the board is [[1,2,3],[4,5,0]].\n\t\tGiven the puzzle board board, return the least number of moves required so that the state of the board is solved. If it is impossible for the state of the board to be solved, return -1.\n\t\tExample 1:\n\t\tInput: board = [[1,2,3],[4,0,5]]\n\t\tOutput: 1\n\t\tExplanation: Swap the 0 and the 5 in one move.\n\t\tExample 2:\n\t\tInput: board = [[1,2,3],[5,4,0]]\n\t\tOutput: -1\n\t\tExplanation: No number of moves will make the board solved.\n\t\tExample 3:\n\t\tInput: board = [[4,1,2],[5,0,3]]\n\t\tOutput: 5\n\t\tExplanation: 5 is the smallest number of moves that solves the board.\n\t\tAn example path:\n\t\tAfter move 0: [[4,1,2],[5,0,3]]\n\t\tAfter move 1: [[4,1,2],[0,5,3]]\n\t\tAfter move 2: [[0,1,2],[4,5,3]]\n\t\tAfter move 3: [[1,0,2],[4,5,3]]\n\t\tAfter move 4: [[1,2,0],[4,5,3]]\n\t\tAfter move 5: [[1,2,3],[4,5,0]]\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 789, - "question": "class KthLargest:\n def __init__(self, k: int, nums: List[int]):\n def add(self, val: int) -> int:\n\t\t\"\"\"\n\t\tDesign a class to find the kth largest element in a stream. Note that it is the kth largest element in the sorted order, not the kth distinct element.\n\t\tImplement KthLargest class:\n\t\t\tKthLargest(int k, int[] nums) Initializes the object with the integer k and the stream of integers nums.\n\t\t\tint add(int val) Appends the integer val to the stream and returns the element representing the kth largest element in the stream.\n\t\tExample 1:\n\t\tInput\n\t\t[\"KthLargest\", \"add\", \"add\", \"add\", \"add\", \"add\"]\n\t\t[[3, [4, 5, 8, 2]], [3], [5], [10], [9], [4]]\n\t\tOutput\n\t\t[null, 4, 5, 5, 8, 8]\n\t\tExplanation\n\t\tKthLargest kthLargest = new KthLargest(3, [4, 5, 8, 2]);\n\t\tkthLargest.add(3); // return 4\n\t\tkthLargest.add(5); // return 5\n\t\tkthLargest.add(10); // return 5\n\t\tkthLargest.add(9); // return 8\n\t\tkthLargest.add(4); // return 8\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 790, - "question": "class Solution:\n def isIdealPermutation(self, nums: List[int]) -> bool:\n\t\t\"\"\"\n\t\tYou are given an integer array nums of length n which represents a permutation of all the integers in the range [0, n - 1].\n\t\tThe number of global inversions is the number of the different pairs (i, j) where:\n\t\t\t0 <= i < j < n\n\t\t\tnums[i] > nums[j]\n\t\tThe number of local inversions is the number of indices i where:\n\t\t\t0 <= i < n - 1\n\t\t\tnums[i] > nums[i + 1]\n\t\tReturn true if the number of global inversions is equal to the number of local inversions.\n\t\tExample 1:\n\t\tInput: nums = [1,0,2]\n\t\tOutput: true\n\t\tExplanation: There is 1 global inversion and 1 local inversion.\n\t\tExample 2:\n\t\tInput: nums = [1,2,0]\n\t\tOutput: false\n\t\tExplanation: There are 2 global inversions and 1 local inversion.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 792, - "question": "class Solution:\n def search(self, nums: List[int], target: int) -> int:\n\t\t\"\"\"\n\t\tGiven an array of integers nums which is sorted in ascending order, and an integer target, write a function to search target in nums. If target exists, then return its index. Otherwise, return -1.\n\t\tYou must write an algorithm with O(log n) runtime complexity.\n\t\tExample 1:\n\t\tInput: nums = [-1,0,3,5,9,12], target = 9\n\t\tOutput: 4\n\t\tExplanation: 9 exists in nums and its index is 4\n\t\tExample 2:\n\t\tInput: nums = [-1,0,3,5,9,12], target = 2\n\t\tOutput: -1\n\t\tExplanation: 2 does not exist in nums so return -1\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 793, - "question": "class Solution:\n def canTransform(self, start: str, end: str) -> bool:\n\t\t\"\"\"\n\t\tIn a string composed of 'L', 'R', and 'X' characters, like \"RXXLRXRXL\", a move consists of either replacing one occurrence of \"XL\" with \"LX\", or replacing one occurrence of \"RX\" with \"XR\". Given the starting string start and the ending string end, return True if and only if there exists a sequence of moves to transform one string to the other.\n\t\tExample 1:\n\t\tInput: start = \"RXXLRXRXL\", end = \"XRLXXRRLX\"\n\t\tOutput: true\n\t\tExplanation: We can transform start to end following these steps:\n\t\tRXXLRXRXL ->\n\t\tXRXLRXRXL ->\n\t\tXRLXRXRXL ->\n\t\tXRLXXRRXL ->\n\t\tXRLXXRRLX\n\t\tExample 2:\n\t\tInput: start = \"X\", end = \"L\"\n\t\tOutput: false\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 794, - "question": "class Solution:\n def swimInWater(self, grid: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tYou are given an n x n integer matrix grid where each value grid[i][j] represents the elevation at that point (i, j).\n\t\tThe rain starts to fall. At time t, the depth of the water everywhere is t. You can swim from a square to another 4-directionally adjacent square if and only if the elevation of both squares individually are at most t. You can swim infinite distances in zero time. Of course, you must stay within the boundaries of the grid during your swim.\n\t\tReturn the least time until you can reach the bottom right square (n - 1, n - 1) if you start at the top left square (0, 0).\n\t\tExample 1:\n\t\tInput: grid = [[0,2],[1,3]]\n\t\tOutput: 3\n\t\tExplanation:\n\t\tAt time 0, you are in grid location (0, 0).\n\t\tYou cannot go anywhere else because 4-directionally adjacent neighbors have a higher elevation than t = 0.\n\t\tYou cannot reach point (1, 1) until time 3.\n\t\tWhen the depth of water is 3, we can swim anywhere inside the grid.\n\t\tExample 2:\n\t\tInput: grid = [[0,1,2,3,4],[24,23,22,21,5],[12,13,14,15,16],[11,17,18,19,20],[10,9,8,7,6]]\n\t\tOutput: 16\n\t\tExplanation: The final route is shown.\n\t\tWe need to wait until time 16 so that (0, 0) and (4, 4) are connected.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 795, - "question": "class Solution:\n def kthGrammar(self, n: int, k: int) -> int:\n\t\t\"\"\"\n\t\tWe build a table of n rows (1-indexed). We start by writing 0 in the 1st row. Now in every subsequent row, we look at the previous row and replace each occurrence of 0 with 01, and each occurrence of 1 with 10.\n\t\t\tFor example, for n = 3, the 1st row is 0, the 2nd row is 01, and the 3rd row is 0110.\n\t\tGiven two integer n and k, return the kth (1-indexed) symbol in the nth row of a table of n rows.\n\t\tExample 1:\n\t\tInput: n = 1, k = 1\n\t\tOutput: 0\n\t\tExplanation: row 1: 0\n\t\tExample 2:\n\t\tInput: n = 2, k = 1\n\t\tOutput: 0\n\t\tExplanation: \n\t\trow 1: 0\n\t\trow 2: 01\n\t\tExample 3:\n\t\tInput: n = 2, k = 2\n\t\tOutput: 1\n\t\tExplanation: \n\t\trow 1: 0\n\t\trow 2: 01\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 796, - "question": "class Solution:\n def reachingPoints(self, sx: int, sy: int, tx: int, ty: int) -> bool:\n\t\t\"\"\"\n\t\tGiven four integers sx, sy, tx, and ty, return true if it is possible to convert the point (sx, sy) to the point (tx, ty) through some operations, or false otherwise.\n\t\tThe allowed operation on some point (x, y) is to convert it to either (x, x + y) or (x + y, y).\n\t\tExample 1:\n\t\tInput: sx = 1, sy = 1, tx = 3, ty = 5\n\t\tOutput: true\n\t\tExplanation:\n\t\tOne series of moves that transforms the starting point to the target is:\n\t\t(1, 1) -> (1, 2)\n\t\t(1, 2) -> (3, 2)\n\t\t(3, 2) -> (3, 5)\n\t\tExample 2:\n\t\tInput: sx = 1, sy = 1, tx = 2, ty = 2\n\t\tOutput: false\n\t\tExample 3:\n\t\tInput: sx = 1, sy = 1, tx = 1, ty = 1\n\t\tOutput: true\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 797, - "question": "class Solution:\n def numRabbits(self, answers: List[int]) -> int:\n\t\t\"\"\"\n\t\tThere is a forest with an unknown number of rabbits. We asked n rabbits \"How many rabbits have the same color as you?\" and collected the answers in an integer array answers where answers[i] is the answer of the ith rabbit.\n\t\tGiven the array answers, return the minimum number of rabbits that could be in the forest.\n\t\tExample 1:\n\t\tInput: answers = [1,1,2]\n\t\tOutput: 5\n\t\tExplanation:\n\t\tThe two rabbits that answered \"1\" could both be the same color, say red.\n\t\tThe rabbit that answered \"2\" can't be red or the answers would be inconsistent.\n\t\tSay the rabbit that answered \"2\" was blue.\n\t\tThen there should be 2 other blue rabbits in the forest that didn't answer into the array.\n\t\tThe smallest possible number of rabbits in the forest is therefore 5: 3 that answered plus 2 that didn't.\n\t\tExample 2:\n\t\tInput: answers = [10,10,10]\n\t\tOutput: 11\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 798, - "question": "class Solution:\n def movesToChessboard(self, board: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tYou are given an n x n binary grid board. In each move, you can swap any two rows with each other, or any two columns with each other.\n\t\tReturn the minimum number of moves to transform the board into a chessboard board. If the task is impossible, return -1.\n\t\tA chessboard board is a board where no 0's and no 1's are 4-directionally adjacent.\n\t\tExample 1:\n\t\tInput: board = [[0,1,1,0],[0,1,1,0],[1,0,0,1],[1,0,0,1]]\n\t\tOutput: 2\n\t\tExplanation: One potential sequence of moves is shown.\n\t\tThe first move swaps the first and second column.\n\t\tThe second move swaps the second and third row.\n\t\tExample 2:\n\t\tInput: board = [[0,1],[1,0]]\n\t\tOutput: 0\n\t\tExplanation: Also note that the board with 0 in the top left corner, is also a valid chessboard.\n\t\tExample 3:\n\t\tInput: board = [[1,0],[1,0]]\n\t\tOutput: -1\n\t\tExplanation: No matter what sequence of moves you make, you cannot end with a valid chessboard.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 799, - "question": "class Solution:\n def minDiffInBST(self, root: Optional[TreeNode]) -> int:\n\t\t\"\"\"\n\t\tGiven the root of a Binary Search Tree (BST), return the minimum difference between the values of any two different nodes in the tree.\n\t\tExample 1:\n\t\tInput: root = [4,2,6,1,3]\n\t\tOutput: 1\n\t\tExample 2:\n\t\tInput: root = [1,0,48,null,null,12,49]\n\t\tOutput: 1\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 800, - "question": "class Solution:\n def letterCasePermutation(self, s: str) -> List[str]:\n\t\t\"\"\"\n\t\tGiven a string s, you can transform every letter individually to be lowercase or uppercase to create another string.\n\t\tReturn a list of all possible strings we could create. Return the output in any order.\n\t\tExample 1:\n\t\tInput: s = \"a1b2\"\n\t\tOutput: [\"a1b2\",\"a1B2\",\"A1b2\",\"A1B2\"]\n\t\tExample 2:\n\t\tInput: s = \"3z4\"\n\t\tOutput: [\"3z4\",\"3Z4\"]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 801, - "question": "class Solution:\n def isBipartite(self, graph: List[List[int]]) -> bool:\n\t\t\"\"\"\n\t\tThere is an undirected graph with n nodes, where each node is numbered between 0 and n - 1. You are given a 2D array graph, where graph[u] is an array of nodes that node u is adjacent to. More formally, for each v in graph[u], there is an undirected edge between node u and node v. The graph has the following properties:\n\t\t\tThere are no self-edges (graph[u] does not contain u).\n\t\t\tThere are no parallel edges (graph[u] does not contain duplicate values).\n\t\t\tIf v is in graph[u], then u is in graph[v] (the graph is undirected).\n\t\t\tThe graph may not be connected, meaning there may be two nodes u and v such that there is no path between them.\n\t\tA graph is bipartite if the nodes can be partitioned into two independent sets A and B such that every edge in the graph connects a node in set A and a node in set B.\n\t\tReturn true if and only if it is bipartite.\n\t\tExample 1:\n\t\tInput: graph = [[1,2,3],[0,2],[0,1,3],[0,2]]\n\t\tOutput: false\n\t\tExplanation: There is no way to partition the nodes into two independent sets such that every edge connects a node in one and a node in the other.\n\t\tExample 2:\n\t\tInput: graph = [[1,3],[0,2],[1,3],[0,2]]\n\t\tOutput: true\n\t\tExplanation: We can partition the nodes into two sets: {0, 2} and {1, 3}.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 802, - "question": "class Solution:\n def kthSmallestPrimeFraction(self, arr: List[int], k: int) -> List[int]:\n\t\t\"\"\"\n\t\tYou are given a sorted integer array arr containing 1 and prime numbers, where all the integers of arr are unique. You are also given an integer k.\n\t\tFor every i and j where 0 <= i < j < arr.length, we consider the fraction arr[i] / arr[j].\n\t\tReturn the kth smallest fraction considered. Return your answer as an array of integers of size 2, where answer[0] == arr[i] and answer[1] == arr[j].\n\t\tExample 1:\n\t\tInput: arr = [1,2,3,5], k = 3\n\t\tOutput: [2,5]\n\t\tExplanation: The fractions to be considered in sorted order are:\n\t\t1/5, 1/3, 2/5, 1/2, 3/5, and 2/3.\n\t\tThe third fraction is 2/5.\n\t\tExample 2:\n\t\tInput: arr = [1,7], k = 1\n\t\tOutput: [1,7]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 803, - "question": "class Solution:\n def findCheapestPrice(self, n: int, flights: List[List[int]], src: int, dst: int, k: int) -> int:\n\t\t\"\"\"\n\t\tThere are n cities connected by some number of flights. You are given an array flights where flights[i] = [fromi, toi, pricei] indicates that there is a flight from city fromi to city toi with cost pricei.\n\t\tYou are also given three integers src, dst, and k, return the cheapest price from src to dst with at most k stops. If there is no such route, return -1.\n\t\tExample 1:\n\t\tInput: n = 4, flights = [[0,1,100],[1,2,100],[2,0,100],[1,3,600],[2,3,200]], src = 0, dst = 3, k = 1\n\t\tOutput: 700\n\t\tExplanation:\n\t\tThe graph is shown above.\n\t\tThe optimal path with at most 1 stop from city 0 to 3 is marked in red and has cost 100 + 600 = 700.\n\t\tNote that the path through cities [0,1,2,3] is cheaper but is invalid because it uses 2 stops.\n\t\tExample 2:\n\t\tInput: n = 3, flights = [[0,1,100],[1,2,100],[0,2,500]], src = 0, dst = 2, k = 1\n\t\tOutput: 200\n\t\tExplanation:\n\t\tThe graph is shown above.\n\t\tThe optimal path with at most 1 stop from city 0 to 2 is marked in red and has cost 100 + 100 = 200.\n\t\tExample 3:\n\t\tInput: n = 3, flights = [[0,1,100],[1,2,100],[0,2,500]], src = 0, dst = 2, k = 0\n\t\tOutput: 500\n\t\tExplanation:\n\t\tThe graph is shown above.\n\t\tThe optimal path with no stops from city 0 to 2 is marked in red and has cost 500.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 804, - "question": "class Solution:\n def rotatedDigits(self, n: int) -> int:\n\t\t\"\"\"\n\t\tAn integer x is a good if after rotating each digit individually by 180 degrees, we get a valid number that is different from x. Each digit must be rotated - we cannot choose to leave it alone.\n\t\tA number is valid if each digit remains a digit after rotation. For example:\n\t\t\t0, 1, and 8 rotate to themselves,\n\t\t\t2 and 5 rotate to each other (in this case they are rotated in a different direction, in other words, 2 or 5 gets mirrored),\n\t\t\t6 and 9 rotate to each other, and\n\t\t\tthe rest of the numbers do not rotate to any other number and become invalid.\n\t\tGiven an integer n, return the number of good integers in the range [1, n].\n\t\tExample 1:\n\t\tInput: n = 10\n\t\tOutput: 4\n\t\tExplanation: There are four good numbers in the range [1, 10] : 2, 5, 6, 9.\n\t\tNote that 1 and 10 are not good numbers, since they remain unchanged after rotating.\n\t\tExample 2:\n\t\tInput: n = 1\n\t\tOutput: 0\n\t\tExample 3:\n\t\tInput: n = 2\n\t\tOutput: 1\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 805, - "question": "class Solution:\n def escapeGhosts(self, ghosts: List[List[int]], target: List[int]) -> bool:\n\t\t\"\"\"\n\t\tYou are playing a simplified PAC-MAN game on an infinite 2-D grid. You start at the point [0, 0], and you are given a destination point target = [xtarget, ytarget] that you are trying to get to. There are several ghosts on the map with their starting positions given as a 2D array ghosts, where ghosts[i] = [xi, yi] represents the starting position of the ith ghost. All inputs are integral coordinates.\n\t\tEach turn, you and all the ghosts may independently choose to either move 1 unit in any of the four cardinal directions: north, east, south, or west, or stay still. All actions happen simultaneously.\n\t\tYou escape if and only if you can reach the target before any ghost reaches you. If you reach any square (including the target) at the same time as a ghost, it does not count as an escape.\n\t\tReturn true if it is possible to escape regardless of how the ghosts move, otherwise return false.\n\t\tExample 1:\n\t\tInput: ghosts = [[1,0],[0,3]], target = [0,1]\n\t\tOutput: true\n\t\tExplanation: You can reach the destination (0, 1) after 1 turn, while the ghosts located at (1, 0) and (0, 3) cannot catch up with you.\n\t\tExample 2:\n\t\tInput: ghosts = [[1,0]], target = [2,0]\n\t\tOutput: false\n\t\tExplanation: You need to reach the destination (2, 0), but the ghost at (1, 0) lies between you and the destination.\n\t\tExample 3:\n\t\tInput: ghosts = [[2,0]], target = [1,0]\n\t\tOutput: false\n\t\tExplanation: The ghost can reach the target at the same time as you.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 806, - "question": "class Solution:\n def numTilings(self, n: int) -> int:\n\t\t\"\"\"\n\t\tYou have two types of tiles: a 2 x 1 domino shape and a tromino shape. You may rotate these shapes.\n\t\tGiven an integer n, return the number of ways to tile an 2 x n board. Since the answer may be very large, return it modulo 109 + 7.\n\t\tIn a tiling, every square must be covered by a tile. Two tilings are different if and only if there are two 4-directionally adjacent cells on the board such that exactly one of the tilings has both squares occupied by a tile.\n\t\tExample 1:\n\t\tInput: n = 3\n\t\tOutput: 5\n\t\tExplanation: The five different ways are show above.\n\t\tExample 2:\n\t\tInput: n = 1\n\t\tOutput: 1\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 807, - "question": "class Solution:\n def customSortString(self, order: str, s: str) -> str:\n\t\t\"\"\"\n\t\tYou are given two strings order and s. All the characters of order are unique and were sorted in some custom order previously.\n\t\tPermute the characters of s so that they match the order that order was sorted. More specifically, if a character x occurs before a character y in order, then x should occur before y in the permuted string.\n\t\tReturn any permutation of s that satisfies this property.\n\t\tExample 1:\n\t\tInput: order = \"cba\", s = \"abcd\"\n\t\tOutput: \"cbad\"\n\t\tExplanation: \n\t\t\"a\", \"b\", \"c\" appear in order, so the order of \"a\", \"b\", \"c\" should be \"c\", \"b\", and \"a\". \n\t\tSince \"d\" does not appear in order, it can be at any position in the returned string. \"dcba\", \"cdba\", \"cbda\" are also valid outputs.\n\t\tExample 2:\n\t\tInput: order = \"cbafg\", s = \"abcd\"\n\t\tOutput: \"cbad\"\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 808, - "question": "class Solution:\n def numMatchingSubseq(self, s: str, words: List[str]) -> int:\n\t\t\"\"\"\n\t\tGiven a string s and an array of strings words, return the number of words[i] that is a subsequence of s.\n\t\tA subsequence of a string is a new string generated from the original string with some characters (can be none) deleted without changing the relative order of the remaining characters.\n\t\t\tFor example, \"ace\" is a subsequence of \"abcde\".\n\t\tExample 1:\n\t\tInput: s = \"abcde\", words = [\"a\",\"bb\",\"acd\",\"ace\"]\n\t\tOutput: 3\n\t\tExplanation: There are three strings in words that are a subsequence of s: \"a\", \"acd\", \"ace\".\n\t\tExample 2:\n\t\tInput: s = \"dsahjpjauf\", words = [\"ahjpjau\",\"ja\",\"ahbwzgqnuk\",\"tnmlanowax\"]\n\t\tOutput: 2\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 809, - "question": "class Solution:\n def preimageSizeFZF(self, k: int) -> int:\n\t\t\"\"\"\n\t\tLet f(x) be the number of zeroes at the end of x!. Recall that x! = 1 * 2 * 3 * ... * x and by convention, 0! = 1.\n\t\t\tFor example, f(3) = 0 because 3! = 6 has no zeroes at the end, while f(11) = 2 because 11! = 39916800 has two zeroes at the end.\n\t\tGiven an integer k, return the number of non-negative integers x have the property that f(x) = k.\n\t\tExample 1:\n\t\tInput: k = 0\n\t\tOutput: 5\n\t\tExplanation: 0!, 1!, 2!, 3!, and 4! end with k = 0 zeroes.\n\t\tExample 2:\n\t\tInput: k = 5\n\t\tOutput: 0\n\t\tExplanation: There is no x such that x! ends in k = 5 zeroes.\n\t\tExample 3:\n\t\tInput: k = 3\n\t\tOutput: 5\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 810, - "question": "class Solution:\n def validTicTacToe(self, board: List[str]) -> bool:\n\t\t\"\"\"\n\t\tGiven a Tic-Tac-Toe board as a string array board, return true if and only if it is possible to reach this board position during the course of a valid tic-tac-toe game.\n\t\tThe board is a 3 x 3 array that consists of characters ' ', 'X', and 'O'. The ' ' character represents an empty square.\n\t\tHere are the rules of Tic-Tac-Toe:\n\t\t\tPlayers take turns placing characters into empty squares ' '.\n\t\t\tThe first player always places 'X' characters, while the second player always places 'O' characters.\n\t\t\t'X' and 'O' characters are always placed into empty squares, never filled ones.\n\t\t\tThe game ends when there are three of the same (non-empty) character filling any row, column, or diagonal.\n\t\t\tThe game also ends if all squares are non-empty.\n\t\t\tNo more moves can be played if the game is over.\n\t\tExample 1:\n\t\tInput: board = [\"O \",\" \",\" \"]\n\t\tOutput: false\n\t\tExplanation: The first player always plays \"X\".\n\t\tExample 2:\n\t\tInput: board = [\"XOX\",\" X \",\" \"]\n\t\tOutput: false\n\t\tExplanation: Players take turns making moves.\n\t\tExample 3:\n\t\tInput: board = [\"XOX\",\"O O\",\"XOX\"]\n\t\tOutput: true\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 811, - "question": "class Solution:\n def numSubarrayBoundedMax(self, nums: List[int], left: int, right: int) -> int:\n\t\t\"\"\"\n\t\tGiven an integer array nums and two integers left and right, return the number of contiguous non-empty subarrays such that the value of the maximum array element in that subarray is in the range [left, right].\n\t\tThe test cases are generated so that the answer will fit in a 32-bit integer.\n\t\tExample 1:\n\t\tInput: nums = [2,1,4,3], left = 2, right = 3\n\t\tOutput: 3\n\t\tExplanation: There are three subarrays that meet the requirements: [2], [2, 1], [3].\n\t\tExample 2:\n\t\tInput: nums = [2,9,2,5,6], left = 2, right = 8\n\t\tOutput: 7\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 812, - "question": "class Solution:\n def rotateString(self, s: str, goal: str) -> bool:\n\t\t\"\"\"\n\t\tGiven two strings s and goal, return true if and only if s can become goal after some number of shifts on s.\n\t\tA shift on s consists of moving the leftmost character of s to the rightmost position.\n\t\t\tFor example, if s = \"abcde\", then it will be \"bcdea\" after one shift.\n\t\tExample 1:\n\t\tInput: s = \"abcde\", goal = \"cdeab\"\n\t\tOutput: true\n\t\tExample 2:\n\t\tInput: s = \"abcde\", goal = \"abced\"\n\t\tOutput: false\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 813, - "question": "class Solution:\n def allPathsSourceTarget(self, graph: List[List[int]]) -> List[List[int]]:\n\t\t\"\"\"\n\t\tGiven a directed acyclic graph (DAG) of n nodes labeled from 0 to n - 1, find all possible paths from node 0 to node n - 1 and return them in any order.\n\t\tThe graph is given as follows: graph[i] is a list of all nodes you can visit from node i (i.e., there is a directed edge from node i to node graph[i][j]).\n\t\tExample 1:\n\t\tInput: graph = [[1,2],[3],[3],[]]\n\t\tOutput: [[0,1,3],[0,2,3]]\n\t\tExplanation: There are two paths: 0 -> 1 -> 3 and 0 -> 2 -> 3.\n\t\tExample 2:\n\t\tInput: graph = [[4,3,1],[3,2,4],[3],[4],[]]\n\t\tOutput: [[0,4],[0,3,4],[0,1,3,4],[0,1,2,3,4],[0,1,4]]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 814, - "question": "class Solution:\n def bestRotation(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou are given an array nums. You can rotate it by a non-negative integer k so that the array becomes [nums[k], nums[k + 1], ... nums[nums.length - 1], nums[0], nums[1], ..., nums[k-1]]. Afterward, any entries that are less than or equal to their index are worth one point.\n\t\t\tFor example, if we have nums = [2,4,1,3,0], and we rotate by k = 2, it becomes [1,3,0,2,4]. This is worth 3 points because 1 > 0 [no points], 3 > 1 [no points], 0 <= 2 [one point], 2 <= 3 [one point], 4 <= 4 [one point].\n\t\tReturn the rotation index k that corresponds to the highest score we can achieve if we rotated nums by it. If there are multiple answers, return the smallest such index k.\n\t\tExample 1:\n\t\tInput: nums = [2,3,1,4,0]\n\t\tOutput: 3\n\t\tExplanation: Scores for each k are listed below: \n\t\tk = 0, nums = [2,3,1,4,0], score 2\n\t\tk = 1, nums = [3,1,4,0,2], score 3\n\t\tk = 2, nums = [1,4,0,2,3], score 3\n\t\tk = 3, nums = [4,0,2,3,1], score 4\n\t\tk = 4, nums = [0,2,3,1,4], score 3\n\t\tSo we should choose k = 3, which has the highest score.\n\t\tExample 2:\n\t\tInput: nums = [1,3,0,2,4]\n\t\tOutput: 0\n\t\tExplanation: nums will always have 3 points no matter how it shifts.\n\t\tSo we will choose the smallest k, which is 0.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 815, - "question": "class Solution:\n def champagneTower(self, poured: int, query_row: int, query_glass: int) -> float:\n\t\t\"\"\"\n\t\tWe stack glasses in a pyramid, where the first row has 1 glass, the second row has 2 glasses, and so on until the 100th row. Each glass holds one cup of champagne.\r\n\t\tThen, some champagne is poured into the first glass at the top. When the topmost glass is full, any excess liquid poured will fall equally to the glass immediately to the left and right of it. When those glasses become full, any excess champagne will fall equally to the left and right of those glasses, and so on. (A glass at the bottom row has its excess champagne fall on the floor.)\r\n\t\tFor example, after one cup of champagne is poured, the top most glass is full. After two cups of champagne are poured, the two glasses on the second row are half full. After three cups of champagne are poured, those two cups become full - there are 3 full glasses total now. After four cups of champagne are poured, the third row has the middle glass half full, and the two outside glasses are a quarter full, as pictured below.\r\n\t\tNow after pouring some non-negative integer cups of champagne, return how full the jth glass in the ith row is (both i and j are 0-indexed.)\r\n\t\tExample 1:\r\n\t\tInput: poured = 1, query_row = 1, query_glass = 1\r\n\t\tOutput: 0.00000\r\n\t\tExplanation: We poured 1 cup of champange to the top glass of the tower (which is indexed as (0, 0)). There will be no excess liquid so all the glasses under the top glass will remain empty.\r\n\t\tExample 2:\r\n\t\tInput: poured = 2, query_row = 1, query_glass = 1\r\n\t\tOutput: 0.50000\r\n\t\tExplanation: We poured 2 cups of champange to the top glass of the tower (which is indexed as (0, 0)). There is one cup of excess liquid. The glass indexed as (1, 0) and the glass indexed as (1, 1) will share the excess liquid equally, and each will get half cup of champange.\r\n\t\tExample 3:\r\n\t\tInput: poured = 100000009, query_row = 33, query_glass = 17\r\n\t\tOutput: 1.00000\r\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 816, - "question": "class MyHashSet:\n def __init__(self):\n def add(self, key: int) -> None:\n def remove(self, key: int) -> None:\n def contains(self, key: int) -> bool:\n\t\t\"\"\"\n\t\tDesign a HashSet without using any built-in hash table libraries.\n\t\tImplement MyHashSet class:\n\t\t\tvoid add(key) Inserts the value key into the HashSet.\n\t\t\tbool contains(key) Returns whether the value key exists in the HashSet or not.\n\t\t\tvoid remove(key) Removes the value key in the HashSet. If key does not exist in the HashSet, do nothing.\n\t\tExample 1:\n\t\tInput\n\t\t[\"MyHashSet\", \"add\", \"add\", \"contains\", \"contains\", \"add\", \"contains\", \"remove\", \"contains\"]\n\t\t[[], [1], [2], [1], [3], [2], [2], [2], [2]]\n\t\tOutput\n\t\t[null, null, null, true, false, null, true, null, false]\n\t\tExplanation\n\t\tMyHashSet myHashSet = new MyHashSet();\n\t\tmyHashSet.add(1); // set = [1]\n\t\tmyHashSet.add(2); // set = [1, 2]\n\t\tmyHashSet.contains(1); // return True\n\t\tmyHashSet.contains(3); // return False, (not found)\n\t\tmyHashSet.add(2); // set = [1, 2]\n\t\tmyHashSet.contains(2); // return True\n\t\tmyHashSet.remove(2); // set = [1]\n\t\tmyHashSet.contains(2); // return False, (already removed)\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 817, - "question": "class MyHashMap:\n def __init__(self):\n def put(self, key: int, value: int) -> None:\n def get(self, key: int) -> int:\n def remove(self, key: int) -> None:\n\t\t\"\"\"\n\t\tDesign a HashMap without using any built-in hash table libraries.\n\t\tImplement the MyHashMap class:\n\t\t\tMyHashMap() initializes the object with an empty map.\n\t\t\tvoid put(int key, int value) inserts a (key, value) pair into the HashMap. If the key already exists in the map, update the corresponding value.\n\t\t\tint get(int key) returns the value to which the specified key is mapped, or -1 if this map contains no mapping for the key.\n\t\t\tvoid remove(key) removes the key and its corresponding value if the map contains the mapping for the key.\n\t\tExample 1:\n\t\tInput\n\t\t[\"MyHashMap\", \"put\", \"put\", \"get\", \"get\", \"put\", \"get\", \"remove\", \"get\"]\n\t\t[[], [1, 1], [2, 2], [1], [3], [2, 1], [2], [2], [2]]\n\t\tOutput\n\t\t[null, null, null, 1, -1, null, 1, null, -1]\n\t\tExplanation\n\t\tMyHashMap myHashMap = new MyHashMap();\n\t\tmyHashMap.put(1, 1); // The map is now [[1,1]]\n\t\tmyHashMap.put(2, 2); // The map is now [[1,1], [2,2]]\n\t\tmyHashMap.get(1); // return 1, The map is now [[1,1], [2,2]]\n\t\tmyHashMap.get(3); // return -1 (i.e., not found), The map is now [[1,1], [2,2]]\n\t\tmyHashMap.put(2, 1); // The map is now [[1,1], [2,1]] (i.e., update the existing value)\n\t\tmyHashMap.get(2); // return 1, The map is now [[1,1], [2,1]]\n\t\tmyHashMap.remove(2); // remove the mapping for 2, The map is now [[1,1]]\n\t\tmyHashMap.get(2); // return -1 (i.e., not found), The map is now [[1,1]]\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 819, - "question": "class Solution:\n def minSwap(self, nums1: List[int], nums2: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou are given two integer arrays of the same length nums1 and nums2. In one operation, you are allowed to swap nums1[i] with nums2[i].\n\t\t\tFor example, if nums1 = [1,2,3,8], and nums2 = [5,6,7,4], you can swap the element at i = 3 to obtain nums1 = [1,2,3,4] and nums2 = [5,6,7,8].\n\t\tReturn the minimum number of needed operations to make nums1 and nums2 strictly increasing. The test cases are generated so that the given input always makes it possible.\n\t\tAn array arr is strictly increasing if and only if arr[0] < arr[1] < arr[2] < ... < arr[arr.length - 1].\n\t\tExample 1:\n\t\tInput: nums1 = [1,3,5,4], nums2 = [1,2,3,7]\n\t\tOutput: 1\n\t\tExplanation: \n\t\tSwap nums1[3] and nums2[3]. Then the sequences are:\n\t\tnums1 = [1, 3, 5, 7] and nums2 = [1, 2, 3, 4]\n\t\twhich are both strictly increasing.\n\t\tExample 2:\n\t\tInput: nums1 = [0,3,5,8,9], nums2 = [2,1,4,6,9]\n\t\tOutput: 1\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 820, - "question": "class Solution:\n def eventualSafeNodes(self, graph: List[List[int]]) -> List[int]:\n\t\t\"\"\"\n\t\tThere is a directed graph of n nodes with each node labeled from 0 to n - 1. The graph is represented by a 0-indexed 2D integer array graph where graph[i] is an integer array of nodes adjacent to node i, meaning there is an edge from node i to each node in graph[i].\n\t\tA node is a terminal node if there are no outgoing edges. A node is a safe node if every possible path starting from that node leads to a terminal node (or another safe node).\n\t\tReturn an array containing all the safe nodes of the graph. The answer should be sorted in ascending order.\n\t\tExample 1:\n\t\tInput: graph = [[1,2],[2,3],[5],[0],[5],[],[]]\n\t\tOutput: [2,4,5,6]\n\t\tExplanation: The given graph is shown above.\n\t\tNodes 5 and 6 are terminal nodes as there are no outgoing edges from either of them.\n\t\tEvery path starting at nodes 2, 4, 5, and 6 all lead to either node 5 or 6.\n\t\tExample 2:\n\t\tInput: graph = [[1,2,3,4],[1,2],[3,4],[0,4],[]]\n\t\tOutput: [4]\n\t\tExplanation:\n\t\tOnly node 4 is a terminal node, and every path starting at node 4 leads to node 4.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 821, - "question": "class Solution:\n def hitBricks(self, grid: List[List[int]], hits: List[List[int]]) -> List[int]:\n\t\t\"\"\"\n\t\tYou are given an m x n binary grid, where each 1 represents a brick and 0 represents an empty space. A brick is stable if:\n\t\t\tIt is directly connected to the top of the grid, or\n\t\t\tAt least one other brick in its four adjacent cells is stable.\n\t\tYou are also given an array hits, which is a sequence of erasures we want to apply. Each time we want to erase the brick at the location hits[i] = (rowi, coli). The brick on that location (if it exists) will disappear. Some other bricks may no longer be stable because of that erasure and will fall. Once a brick falls, it is immediately erased from the grid (i.e., it does not land on other stable bricks).\n\t\tReturn an array result, where each result[i] is the number of bricks that will fall after the ith erasure is applied.\n\t\tNote that an erasure may refer to a location with no brick, and if it does, no bricks drop.\n\t\tExample 1:\n\t\tInput: grid = [[1,0,0,0],[1,1,1,0]], hits = [[1,0]]\n\t\tOutput: [2]\n\t\tExplanation: Starting with the grid:\n\t\t[[1,0,0,0],\n\t\t [1,1,1,0]]\n\t\tWe erase the underlined brick at (1,0), resulting in the grid:\n\t\t[[1,0,0,0],\n\t\t [0,1,1,0]]\n\t\tThe two underlined bricks are no longer stable as they are no longer connected to the top nor adjacent to another stable brick, so they will fall. The resulting grid is:\n\t\t[[1,0,0,0],\n\t\t [0,0,0,0]]\n\t\tHence the result is [2].\n\t\tExample 2:\n\t\tInput: grid = [[1,0,0,0],[1,1,0,0]], hits = [[1,1],[1,0]]\n\t\tOutput: [0,0]\n\t\tExplanation: Starting with the grid:\n\t\t[[1,0,0,0],\n\t\t [1,1,0,0]]\n\t\tWe erase the underlined brick at (1,1), resulting in the grid:\n\t\t[[1,0,0,0],\n\t\t [1,0,0,0]]\n\t\tAll remaining bricks are still stable, so no bricks fall. The grid remains the same:\n\t\t[[1,0,0,0],\n\t\t [1,0,0,0]]\n\t\tNext, we erase the underlined brick at (1,0), resulting in the grid:\n\t\t[[1,0,0,0],\n\t\t [0,0,0,0]]\n\t\tOnce again, all remaining bricks are still stable, so no bricks fall.\n\t\tHence the result is [0,0].\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 822, - "question": "class Solution:\n def uniqueMorseRepresentations(self, words: List[str]) -> int:\n\t\t\"\"\"\n\t\tInternational Morse Code defines a standard encoding where each letter is mapped to a series of dots and dashes, as follows:\n\t\t\t'a' maps to \".-\",\n\t\t\t'b' maps to \"-...\",\n\t\t\t'c' maps to \"-.-.\", and so on.\n\t\tFor convenience, the full table for the 26 letters of the English alphabet is given below:\n\t\t[\".-\",\"-...\",\"-.-.\",\"-..\",\".\",\"..-.\",\"--.\",\"....\",\"..\",\".---\",\"-.-\",\".-..\",\"--\",\"-.\",\"---\",\".--.\",\"--.-\",\".-.\",\"...\",\"-\",\"..-\",\"...-\",\".--\",\"-..-\",\"-.--\",\"--..\"]\n\t\tGiven an array of strings words where each word can be written as a concatenation of the Morse code of each letter.\n\t\t\tFor example, \"cab\" can be written as \"-.-..--...\", which is the concatenation of \"-.-.\", \".-\", and \"-...\". We will call such a concatenation the transformation of a word.\n\t\tReturn the number of different transformations among all words we have.\n\t\tExample 1:\n\t\tInput: words = [\"gin\",\"zen\",\"gig\",\"msg\"]\n\t\tOutput: 2\n\t\tExplanation: The transformation of each word is:\n\t\t\"gin\" -> \"--...-.\"\n\t\t\"zen\" -> \"--...-.\"\n\t\t\"gig\" -> \"--...--.\"\n\t\t\"msg\" -> \"--...--.\"\n\t\tThere are 2 different transformations: \"--...-.\" and \"--...--.\".\n\t\tExample 2:\n\t\tInput: words = [\"a\"]\n\t\tOutput: 1\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 823, - "question": "class Solution:\n def splitArraySameAverage(self, nums: List[int]) -> bool:\n\t\t\"\"\"\n\t\tYou are given an integer array nums.\n\t\tYou should move each element of nums into one of the two arrays A and B such that A and B are non-empty, and average(A) == average(B).\n\t\tReturn true if it is possible to achieve that and false otherwise.\n\t\tNote that for an array arr, average(arr) is the sum of all the elements of arr over the length of arr.\n\t\tExample 1:\n\t\tInput: nums = [1,2,3,4,5,6,7,8]\n\t\tOutput: true\n\t\tExplanation: We can split the array into [1,4,5,8] and [2,3,6,7], and both of them have an average of 4.5.\n\t\tExample 2:\n\t\tInput: nums = [3,1]\n\t\tOutput: false\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 824, - "question": "class Solution:\n def numberOfLines(self, widths: List[int], s: str) -> List[int]:\n\t\t\"\"\"\n\t\tYou are given a string s of lowercase English letters and an array widths denoting how many pixels wide each lowercase English letter is. Specifically, widths[0] is the width of 'a', widths[1] is the width of 'b', and so on.\n\t\tYou are trying to write s across several lines, where each line is no longer than 100 pixels. Starting at the beginning of s, write as many letters on the first line such that the total width does not exceed 100 pixels. Then, from where you stopped in s, continue writing as many letters as you can on the second line. Continue this process until you have written all of s.\n\t\tReturn an array result of length 2 where:\n\t\t\tresult[0] is the total number of lines.\n\t\t\tresult[1] is the width of the last line in pixels.\n\t\tExample 1:\n\t\tInput: widths = [10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10], s = \"abcdefghijklmnopqrstuvwxyz\"\n\t\tOutput: [3,60]\n\t\tExplanation: You can write s as follows:\n\t\tabcdefghij // 100 pixels wide\n\t\tklmnopqrst // 100 pixels wide\n\t\tuvwxyz // 60 pixels wide\n\t\tThere are a total of 3 lines, and the last line is 60 pixels wide.\n\t\tExample 2:\n\t\tInput: widths = [4,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10], s = \"bbbcccdddaaa\"\n\t\tOutput: [2,4]\n\t\tExplanation: You can write s as follows:\n\t\tbbbcccdddaa // 98 pixels wide\n\t\ta // 4 pixels wide\n\t\tThere are a total of 2 lines, and the last line is 4 pixels wide.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 825, - "question": "class Solution:\n def maxIncreaseKeepingSkyline(self, grid: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tThere is a city composed of n x n blocks, where each block contains a single building shaped like a vertical square prism. You are given a 0-indexed n x n integer matrix grid where grid[r][c] represents the height of the building located in the block at row r and column c.\n\t\tA city's skyline is the the outer contour formed by all the building when viewing the side of the city from a distance. The skyline from each cardinal direction north, east, south, and west may be different.\n\t\tWe are allowed to increase the height of any number of buildings by any amount (the amount can be different per building). The height of a 0-height building can also be increased. However, increasing the height of a building should not affect the city's skyline from any cardinal direction.\n\t\tReturn the maximum total sum that the height of the buildings can be increased by without changing the city's skyline from any cardinal direction.\n\t\tExample 1:\n\t\tInput: grid = [[3,0,8,4],[2,4,5,7],[9,2,6,3],[0,3,1,0]]\n\t\tOutput: 35\n\t\tExplanation: The building heights are shown in the center of the above image.\n\t\tThe skylines when viewed from each cardinal direction are drawn in red.\n\t\tThe grid after increasing the height of buildings without affecting skylines is:\n\t\tgridNew = [ [8, 4, 8, 7],\n\t\t [7, 4, 7, 7],\n\t\t [9, 4, 8, 7],\n\t\t [3, 3, 3, 3] ]\n\t\tExample 2:\n\t\tInput: grid = [[0,0,0],[0,0,0],[0,0,0]]\n\t\tOutput: 0\n\t\tExplanation: Increasing the height of any building will result in the skyline changing.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 826, - "question": "class Solution:\n def soupServings(self, n: int) -> float:\n\t\t\"\"\"\n\t\tThere are two types of soup: type A and type B. Initially, we have n ml of each type of soup. There are four kinds of operations:\n\t\t\tServe 100 ml of soup A and 0 ml of soup B,\n\t\t\tServe 75 ml of soup A and 25 ml of soup B,\n\t\t\tServe 50 ml of soup A and 50 ml of soup B, and\n\t\t\tServe 25 ml of soup A and 75 ml of soup B.\n\t\tWhen we serve some soup, we give it to someone, and we no longer have it. Each turn, we will choose from the four operations with an equal probability 0.25. If the remaining volume of soup is not enough to complete the operation, we will serve as much as possible. We stop once we no longer have some quantity of both types of soup.\n\t\tNote that we do not have an operation where all 100 ml's of soup B are used first.\n\t\tReturn the probability that soup A will be empty first, plus half the probability that A and B become empty at the same time. Answers within 10-5 of the actual answer will be accepted.\n\t\tExample 1:\n\t\tInput: n = 50\n\t\tOutput: 0.62500\n\t\tExplanation: If we choose the first two operations, A will become empty first.\n\t\tFor the third operation, A and B will become empty at the same time.\n\t\tFor the fourth operation, B will become empty first.\n\t\tSo the total probability of A becoming empty first plus half the probability that A and B become empty at the same time, is 0.25 * (1 + 1 + 0.5 + 0) = 0.625.\n\t\tExample 2:\n\t\tInput: n = 100\n\t\tOutput: 0.71875\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 827, - "question": "class Solution:\n def expressiveWords(self, s: str, words: List[str]) -> int:\n\t\t\"\"\"\n\t\tSometimes people repeat letters to represent extra feeling. For example:\n\t\t\t\"hello\" -> \"heeellooo\"\n\t\t\t\"hi\" -> \"hiiii\"\n\t\tIn these strings like \"heeellooo\", we have groups of adjacent letters that are all the same: \"h\", \"eee\", \"ll\", \"ooo\".\n\t\tYou are given a string s and an array of query strings words. A query word is stretchy if it can be made to be equal to s by any number of applications of the following extension operation: choose a group consisting of characters c, and add some number of characters c to the group so that the size of the group is three or more.\n\t\t\tFor example, starting with \"hello\", we could do an extension on the group \"o\" to get \"hellooo\", but we cannot get \"helloo\" since the group \"oo\" has a size less than three. Also, we could do another extension like \"ll\" -> \"lllll\" to get \"helllllooo\". If s = \"helllllooo\", then the query word \"hello\" would be stretchy because of these two extension operations: query = \"hello\" -> \"hellooo\" -> \"helllllooo\" = s.\n\t\tReturn the number of query strings that are stretchy.\n\t\tExample 1:\n\t\tInput: s = \"heeellooo\", words = [\"hello\", \"hi\", \"helo\"]\n\t\tOutput: 1\n\t\tExplanation: \n\t\tWe can extend \"e\" and \"o\" in the word \"hello\" to get \"heeellooo\".\n\t\tWe can't extend \"helo\" to get \"heeellooo\" because the group \"ll\" is not size 3 or more.\n\t\tExample 2:\n\t\tInput: s = \"zzzzzyyyyy\", words = [\"zzyy\",\"zy\",\"zyy\"]\n\t\tOutput: 3\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 828, - "question": "class Solution:\n def xorGame(self, nums: List[int]) -> bool:\n\t\t\"\"\"\n\t\tYou are given an array of integers nums represents the numbers written on a chalkboard.\n\t\tAlice and Bob take turns erasing exactly one number from the chalkboard, with Alice starting first. If erasing a number causes the bitwise XOR of all the elements of the chalkboard to become 0, then that player loses. The bitwise XOR of one element is that element itself, and the bitwise XOR of no elements is 0.\n\t\tAlso, if any player starts their turn with the bitwise XOR of all the elements of the chalkboard equal to 0, then that player wins.\n\t\tReturn true if and only if Alice wins the game, assuming both players play optimally.\n\t\tExample 1:\n\t\tInput: nums = [1,1,2]\n\t\tOutput: false\n\t\tExplanation: \n\t\tAlice has two choices: erase 1 or erase 2. \n\t\tIf she erases 1, the nums array becomes [1, 2]. The bitwise XOR of all the elements of the chalkboard is 1 XOR 2 = 3. Now Bob can remove any element he wants, because Alice will be the one to erase the last element and she will lose. \n\t\tIf Alice erases 2 first, now nums become [1, 1]. The bitwise XOR of all the elements of the chalkboard is 1 XOR 1 = 0. Alice will lose.\n\t\tExample 2:\n\t\tInput: nums = [0,1]\n\t\tOutput: true\n\t\tExample 3:\n\t\tInput: nums = [1,2,3]\n\t\tOutput: true\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 829, - "question": "class Solution:\n def subdomainVisits(self, cpdomains: List[str]) -> List[str]:\n\t\t\"\"\"\n\t\tA website domain \"discuss.leetcode.com\" consists of various subdomains. At the top level, we have \"com\", at the next level, we have \"leetcode.com\" and at the lowest level, \"discuss.leetcode.com\". When we visit a domain like \"discuss.leetcode.com\", we will also visit the parent domains \"leetcode.com\" and \"com\" implicitly.\n\t\tA count-paired domain is a domain that has one of the two formats \"rep d1.d2.d3\" or \"rep d1.d2\" where rep is the number of visits to the domain and d1.d2.d3 is the domain itself.\n\t\t\tFor example, \"9001 discuss.leetcode.com\" is a count-paired domain that indicates that discuss.leetcode.com was visited 9001 times.\n\t\tGiven an array of count-paired domains cpdomains, return an array of the count-paired domains of each subdomain in the input. You may return the answer in any order.\n\t\tExample 1:\n\t\tInput: cpdomains = [\"9001 discuss.leetcode.com\"]\n\t\tOutput: [\"9001 leetcode.com\",\"9001 discuss.leetcode.com\",\"9001 com\"]\n\t\tExplanation: We only have one website domain: \"discuss.leetcode.com\".\n\t\tAs discussed above, the subdomain \"leetcode.com\" and \"com\" will also be visited. So they will all be visited 9001 times.\n\t\tExample 2:\n\t\tInput: cpdomains = [\"900 google.mail.com\", \"50 yahoo.com\", \"1 intel.mail.com\", \"5 wiki.org\"]\n\t\tOutput: [\"901 mail.com\",\"50 yahoo.com\",\"900 google.mail.com\",\"5 wiki.org\",\"5 org\",\"1 intel.mail.com\",\"951 com\"]\n\t\tExplanation: We will visit \"google.mail.com\" 900 times, \"yahoo.com\" 50 times, \"intel.mail.com\" once and \"wiki.org\" 5 times.\n\t\tFor the subdomains, we will visit \"mail.com\" 900 + 1 = 901 times, \"com\" 900 + 50 + 1 = 951 times, and \"org\" 5 times.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 830, - "question": "class Solution:\n def largestTriangleArea(self, points: List[List[int]]) -> float:\n\t\t\"\"\"\n\t\tGiven an array of points on the X-Y plane points where points[i] = [xi, yi], return the area of the largest triangle that can be formed by any three different points. Answers within 10-5 of the actual answer will be accepted.\n\t\tExample 1:\n\t\tInput: points = [[0,0],[0,1],[1,0],[0,2],[2,0]]\n\t\tOutput: 2.00000\n\t\tExplanation: The five points are shown in the above figure. The red triangle is the largest.\n\t\tExample 2:\n\t\tInput: points = [[1,0],[0,0],[0,1]]\n\t\tOutput: 0.50000\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 831, - "question": "class Solution:\n def largestSumOfAverages(self, nums: List[int], k: int) -> float:\n\t\t\"\"\"\n\t\tYou are given an integer array nums and an integer k. You can partition the array into at most k non-empty adjacent subarrays. The score of a partition is the sum of the averages of each subarray.\n\t\tNote that the partition must use every integer in nums, and that the score is not necessarily an integer.\n\t\tReturn the maximum score you can achieve of all the possible partitions. Answers within 10-6 of the actual answer will be accepted.\n\t\tExample 1:\n\t\tInput: nums = [9,1,2,3,9], k = 3\n\t\tOutput: 20.00000\n\t\tExplanation: \n\t\tThe best choice is to partition nums into [9], [1, 2, 3], [9]. The answer is 9 + (1 + 2 + 3) / 3 + 9 = 20.\n\t\tWe could have also partitioned nums into [9, 1], [2], [3, 9], for example.\n\t\tThat partition would lead to a score of 5 + 2 + 6 = 13, which is worse.\n\t\tExample 2:\n\t\tInput: nums = [1,2,3,4,5,6,7], k = 4\n\t\tOutput: 20.50000\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 832, - "question": "class Solution:\n def pruneTree(self, root: Optional[TreeNode]) -> Optional[TreeNode]:\n\t\t\"\"\"\n\t\tGiven the root of a binary tree, return the same tree where every subtree (of the given tree) not containing a 1 has been removed.\n\t\tA subtree of a node node is node plus every node that is a descendant of node.\n\t\tExample 1:\n\t\tInput: root = [1,null,0,0,1]\n\t\tOutput: [1,null,0,null,1]\n\t\tExplanation: \n\t\tOnly the red nodes satisfy the property \"every subtree not containing a 1\".\n\t\tThe diagram on the right represents the answer.\n\t\tExample 2:\n\t\tInput: root = [1,0,1,0,0,0,1]\n\t\tOutput: [1,null,1,null,1]\n\t\tExample 3:\n\t\tInput: root = [1,1,0,1,1,0,1,0]\n\t\tOutput: [1,1,0,1,1,null,1]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 833, - "question": "class Solution:\n def numBusesToDestination(self, routes: List[List[int]], source: int, target: int) -> int:\n\t\t\"\"\"\n\t\tYou are given an array routes representing bus routes where routes[i] is a bus route that the ith bus repeats forever.\n\t\t\tFor example, if routes[0] = [1, 5, 7], this means that the 0th bus travels in the sequence 1 -> 5 -> 7 -> 1 -> 5 -> 7 -> 1 -> ... forever.\n\t\tYou will start at the bus stop source (You are not on any bus initially), and you want to go to the bus stop target. You can travel between bus stops by buses only.\n\t\tReturn the least number of buses you must take to travel from source to target. Return -1 if it is not possible.\n\t\tExample 1:\n\t\tInput: routes = [[1,2,7],[3,6,7]], source = 1, target = 6\n\t\tOutput: 2\n\t\tExplanation: The best strategy is take the first bus to the bus stop 7, then take the second bus to the bus stop 6.\n\t\tExample 2:\n\t\tInput: routes = [[7,12],[4,5,15],[6],[15,19],[9,12,13]], source = 15, target = 12\n\t\tOutput: -1\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 834, - "question": "class Solution:\n def ambiguousCoordinates(self, s: str) -> List[str]:\n\t\t\"\"\"\n\t\tWe had some 2-dimensional coordinates, like \"(1, 3)\" or \"(2, 0.5)\". Then, we removed all commas, decimal points, and spaces and ended up with the string s.\n\t\t\tFor example, \"(1, 3)\" becomes s = \"(13)\" and \"(2, 0.5)\" becomes s = \"(205)\".\n\t\tReturn a list of strings representing all possibilities for what our original coordinates could have been.\n\t\tOur original representation never had extraneous zeroes, so we never started with numbers like \"00\", \"0.0\", \"0.00\", \"1.0\", \"001\", \"00.01\", or any other number that can be represented with fewer digits. Also, a decimal point within a number never occurs without at least one digit occurring before it, so we never started with numbers like \".1\".\n\t\tThe final answer list can be returned in any order. All coordinates in the final answer have exactly one space between them (occurring after the comma.)\n\t\tExample 1:\n\t\tInput: s = \"(123)\"\n\t\tOutput: [\"(1, 2.3)\",\"(1, 23)\",\"(1.2, 3)\",\"(12, 3)\"]\n\t\tExample 2:\n\t\tInput: s = \"(0123)\"\n\t\tOutput: [\"(0, 1.23)\",\"(0, 12.3)\",\"(0, 123)\",\"(0.1, 2.3)\",\"(0.1, 23)\",\"(0.12, 3)\"]\n\t\tExplanation: 0.0, 00, 0001 or 00.01 are not allowed.\n\t\tExample 3:\n\t\tInput: s = \"(00011)\"\n\t\tOutput: [\"(0, 0.011)\",\"(0.001, 1)\"]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 835, - "question": "class Solution:\n def numComponents(self, head: Optional[ListNode], nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou are given the head of a linked list containing unique integer values and an integer array nums that is a subset of the linked list values.\n\t\tReturn the number of connected components in nums where two values are connected if they appear consecutively in the linked list.\n\t\tExample 1:\n\t\tInput: head = [0,1,2,3], nums = [0,1,3]\n\t\tOutput: 2\n\t\tExplanation: 0 and 1 are connected, so [0, 1] and [3] are the two connected components.\n\t\tExample 2:\n\t\tInput: head = [0,1,2,3,4], nums = [0,3,1,4]\n\t\tOutput: 2\n\t\tExplanation: 0 and 1 are connected, 3 and 4 are connected, so [0, 1] and [3, 4] are the two connected components.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 836, - "question": "class Solution:\n def racecar(self, target: int) -> int:\n\t\t\"\"\"\n\t\tYour car starts at position 0 and speed +1 on an infinite number line. Your car can go into negative positions. Your car drives automatically according to a sequence of instructions 'A' (accelerate) and 'R' (reverse):\n\t\t\tWhen you get an instruction 'A', your car does the following:\n\t\t\t\tposition += speed\n\t\t\t\tspeed *= 2\n\t\t\tWhen you get an instruction 'R', your car does the following:\n\t\t\t\tIf your speed is positive then speed = -1\n\t\t\t\totherwise speed = 1\n\t\t\tYour position stays the same.\n\t\tFor example, after commands \"AAR\", your car goes to positions 0 --> 1 --> 3 --> 3, and your speed goes to 1 --> 2 --> 4 --> -1.\n\t\tGiven a target position target, return the length of the shortest sequence of instructions to get there.\n\t\tExample 1:\n\t\tInput: target = 3\n\t\tOutput: 2\n\t\tExplanation: \n\t\tThe shortest instruction sequence is \"AA\".\n\t\tYour position goes from 0 --> 1 --> 3.\n\t\tExample 2:\n\t\tInput: target = 6\n\t\tOutput: 5\n\t\tExplanation: \n\t\tThe shortest instruction sequence is \"AAARA\".\n\t\tYour position goes from 0 --> 1 --> 3 --> 7 --> 7 --> 6.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 837, - "question": "class Solution:\n def mostCommonWord(self, paragraph: str, banned: List[str]) -> str:\n\t\t\"\"\"\n\t\tGiven a string paragraph and a string array of the banned words banned, return the most frequent word that is not banned. It is guaranteed there is at least one word that is not banned, and that the answer is unique.\n\t\tThe words in paragraph are case-insensitive and the answer should be returned in lowercase.\n\t\tExample 1:\n\t\tInput: paragraph = \"Bob hit a ball, the hit BALL flew far after it was hit.\", banned = [\"hit\"]\n\t\tOutput: \"ball\"\n\t\tExplanation: \n\t\t\"hit\" occurs 3 times, but it is a banned word.\n\t\t\"ball\" occurs twice (and no other word does), so it is the most frequent non-banned word in the paragraph. \n\t\tNote that words in the paragraph are not case sensitive,\n\t\tthat punctuation is ignored (even if adjacent to words, such as \"ball,\"), \n\t\tand that \"hit\" isn't the answer even though it occurs more because it is banned.\n\t\tExample 2:\n\t\tInput: paragraph = \"a.\", banned = []\n\t\tOutput: \"a\"\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 838, - "question": "class MyLinkedList:\n def __init__(self):\n def get(self, index: int) -> int:\n def addAtHead(self, val: int) -> None:\n def addAtTail(self, val: int) -> None:\n def addAtIndex(self, index: int, val: int) -> None:\n def deleteAtIndex(self, index: int) -> None:\n\t\t\"\"\"\n\t\tDesign your implementation of the linked list. You can choose to use a singly or doubly linked list.\n\t\tA node in a singly linked list should have two attributes: val and next. val is the value of the current node, and next is a pointer/reference to the next node.\n\t\tIf you want to use the doubly linked list, you will need one more attribute prev to indicate the previous node in the linked list. Assume all nodes in the linked list are 0-indexed.\n\t\tImplement the MyLinkedList class:\n\t\t\tMyLinkedList() Initializes the MyLinkedList object.\n\t\t\tint get(int index) Get the value of the indexth node in the linked list. If the index is invalid, return -1.\n\t\t\tvoid addAtHead(int val) Add a node of value val before the first element of the linked list. After the insertion, the new node will be the first node of the linked list.\n\t\t\tvoid addAtTail(int val) Append a node of value val as the last element of the linked list.\n\t\t\tvoid addAtIndex(int index, int val) Add a node of value val before the indexth node in the linked list. If index equals the length of the linked list, the node will be appended to the end of the linked list. If index is greater than the length, the node will not be inserted.\n\t\t\tvoid deleteAtIndex(int index) Delete the indexth node in the linked list, if the index is valid.\n\t\tExample 1:\n\t\tInput\n\t\t[\"MyLinkedList\", \"addAtHead\", \"addAtTail\", \"addAtIndex\", \"get\", \"deleteAtIndex\", \"get\"]\n\t\t[[], [1], [3], [1, 2], [1], [1], [1]]\n\t\tOutput\n\t\t[null, null, null, null, 2, null, 3]\n\t\tExplanation\n\t\tMyLinkedList myLinkedList = new MyLinkedList();\n\t\tmyLinkedList.addAtHead(1);\n\t\tmyLinkedList.addAtTail(3);\n\t\tmyLinkedList.addAtIndex(1, 2); // linked list becomes 1->2->3\n\t\tmyLinkedList.get(1); // return 2\n\t\tmyLinkedList.deleteAtIndex(1); // now the linked list is 1->3\n\t\tmyLinkedList.get(1); // return 3\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 839, - "question": "class Solution:\n def minimumLengthEncoding(self, words: List[str]) -> int:\n\t\t\"\"\"\n\t\tA valid encoding of an array of words is any reference string s and array of indices indices such that:\n\t\t\twords.length == indices.length\n\t\t\tThe reference string s ends with the '#' character.\n\t\t\tFor each index indices[i], the substring of s starting from indices[i] and up to (but not including) the next '#' character is equal to words[i].\n\t\tGiven an array of words, return the length of the shortest reference string s possible of any valid encoding of words.\n\t\tExample 1:\n\t\tInput: words = [\"time\", \"me\", \"bell\"]\n\t\tOutput: 10\n\t\tExplanation: A valid encoding would be s = \"time#bell#\" and indices = [0, 2, 5].\n\t\twords[0] = \"time\", the substring of s starting from indices[0] = 0 to the next '#' is underlined in \"time#bell#\"\n\t\twords[1] = \"me\", the substring of s starting from indices[1] = 2 to the next '#' is underlined in \"time#bell#\"\n\t\twords[2] = \"bell\", the substring of s starting from indices[2] = 5 to the next '#' is underlined in \"time#bell#\"\n\t\tExample 2:\n\t\tInput: words = [\"t\"]\n\t\tOutput: 2\n\t\tExplanation: A valid encoding would be s = \"t#\" and indices = [0].\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 841, - "question": "class Solution:\n def shortestToChar(self, s: str, c: str) -> List[int]:\n\t\t\"\"\"\n\t\tGiven a string s and a character c that occurs in s, return an array of integers answer where answer.length == s.length and answer[i] is the distance from index i to the closest occurrence of character c in s.\n\t\tThe distance between two indices i and j is abs(i - j), where abs is the absolute value function.\n\t\tExample 1:\n\t\tInput: s = \"loveleetcode\", c = \"e\"\n\t\tOutput: [3,2,1,0,1,0,0,1,2,2,1,0]\n\t\tExplanation: The character 'e' appears at indices 3, 5, 6, and 11 (0-indexed).\n\t\tThe closest occurrence of 'e' for index 0 is at index 3, so the distance is abs(0 - 3) = 3.\n\t\tThe closest occurrence of 'e' for index 1 is at index 3, so the distance is abs(1 - 3) = 2.\n\t\tFor index 4, there is a tie between the 'e' at index 3 and the 'e' at index 5, but the distance is still the same: abs(4 - 3) == abs(4 - 5) = 1.\n\t\tThe closest occurrence of 'e' for index 8 is at index 6, so the distance is abs(8 - 6) = 2.\n\t\tExample 2:\n\t\tInput: s = \"aaab\", c = \"b\"\n\t\tOutput: [3,2,1,0]\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 842, - "question": "class Solution:\n def flipgame(self, fronts: List[int], backs: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou are given two 0-indexed integer arrays fronts and backs of length n, where the ith card has the positive integer fronts[i] printed on the front and backs[i] printed on the back. Initially, each card is placed on a table such that the front number is facing up and the other is facing down. You may flip over any number of cards (possibly zero).\n\t\tAfter flipping the cards, an integer is considered good if it is facing down on some card and not facing up on any card.\n\t\tReturn the minimum possible good integer after flipping the cards. If there are no good integers, return 0.\n\t\tExample 1:\n\t\tInput: fronts = [1,2,4,4,7], backs = [1,3,4,1,3]\n\t\tOutput: 2\n\t\tExplanation:\n\t\tIf we flip the second card, the face up numbers are [1,3,4,4,7] and the face down are [1,2,4,1,3].\n\t\t2 is the minimum good integer as it appears facing down but not facing up.\n\t\tIt can be shown that 2 is the minimum possible good integer obtainable after flipping some cards.\n\t\tExample 2:\n\t\tInput: fronts = [1], backs = [1]\n\t\tOutput: 0\n\t\tExplanation:\n\t\tThere are no good integers no matter how we flip the cards, so we return 0.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 843, - "question": "class Solution:\n def numFactoredBinaryTrees(self, arr: List[int]) -> int:\n\t\t\"\"\"\n\t\tGiven an array of unique integers, arr, where each integer arr[i] is strictly greater than 1.\n\t\tWe make a binary tree using these integers, and each number may be used for any number of times. Each non-leaf node's value should be equal to the product of the values of its children.\n\t\tReturn the number of binary trees we can make. The answer may be too large so return the answer modulo 109 + 7.\n\t\tExample 1:\n\t\tInput: arr = [2,4]\n\t\tOutput: 3\n\t\tExplanation: We can make these trees: [2], [4], [4, 2, 2]\n\t\tExample 2:\n\t\tInput: arr = [2,4,5,10]\n\t\tOutput: 7\n\t\tExplanation: We can make these trees: [2], [4], [5], [10], [4, 2, 2], [10, 2, 5], [10, 5, 2].\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 851, - "question": "class Solution:\n def toGoatLatin(self, sentence: str) -> str:\n\t\t\"\"\"\n\t\tYou are given a string sentence that consist of words separated by spaces. Each word consists of lowercase and uppercase letters only.\n\t\tWe would like to convert the sentence to \"Goat Latin\" (a made-up language similar to Pig Latin.) The rules of Goat Latin are as follows:\n\t\t\tIf a word begins with a vowel ('a', 'e', 'i', 'o', or 'u'), append \"ma\" to the end of the word.\n\t\t\t\tFor example, the word \"apple\" becomes \"applema\".\n\t\t\tIf a word begins with a consonant (i.e., not a vowel), remove the first letter and append it to the end, then add \"ma\".\n\t\t\t\tFor example, the word \"goat\" becomes \"oatgma\".\n\t\t\tAdd one letter 'a' to the end of each word per its word index in the sentence, starting with 1.\n\t\t\t\tFor example, the first word gets \"a\" added to the end, the second word gets \"aa\" added to the end, and so on.\n\t\tReturn the final sentence representing the conversion from sentence to Goat Latin.\n\t\tExample 1:\n\t\tInput: sentence = \"I speak Goat Latin\"\n\t\tOutput: \"Imaa peaksmaaa oatGmaaaa atinLmaaaaa\"\n\t\tExample 2:\n\t\tInput: sentence = \"The quick brown fox jumped over the lazy dog\"\n\t\tOutput: \"heTmaa uickqmaaa rownbmaaaa oxfmaaaaa umpedjmaaaaaa overmaaaaaaa hetmaaaaaaaa azylmaaaaaaaaa ogdmaaaaaaaaaa\"\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 852, - "question": "class Solution:\n def numFriendRequests(self, ages: List[int]) -> int:\n\t\t\"\"\"\n\t\tThere are n persons on a social media website. You are given an integer array ages where ages[i] is the age of the ith person.\n\t\tA Person x will not send a friend request to a person y (x != y) if any of the following conditions is true:\n\t\t\tage[y] <= 0.5 * age[x] + 7\n\t\t\tage[y] > age[x]\n\t\t\tage[y] > 100 && age[x] < 100\n\t\tOtherwise, x will send a friend request to y.\n\t\tNote that if x sends a request to y, y will not necessarily send a request to x. Also, a person will not send a friend request to themself.\n\t\tReturn the total number of friend requests made.\n\t\tExample 1:\n\t\tInput: ages = [16,16]\n\t\tOutput: 2\n\t\tExplanation: 2 people friend request each other.\n\t\tExample 2:\n\t\tInput: ages = [16,17,18]\n\t\tOutput: 2\n\t\tExplanation: Friend requests are made 17 -> 16, 18 -> 17.\n\t\tExample 3:\n\t\tInput: ages = [20,30,100,110,120]\n\t\tOutput: 3\n\t\tExplanation: Friend requests are made 110 -> 100, 120 -> 110, 120 -> 100.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 853, - "question": "class Solution:\n def maxProfitAssignment(self, difficulty: List[int], profit: List[int], worker: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou have n jobs and m workers. You are given three arrays: difficulty, profit, and worker where:\n\t\t\tdifficulty[i] and profit[i] are the difficulty and the profit of the ith job, and\n\t\t\tworker[j] is the ability of jth worker (i.e., the jth worker can only complete a job with difficulty at most worker[j]).\n\t\tEvery worker can be assigned at most one job, but one job can be completed multiple times.\n\t\t\tFor example, if three workers attempt the same job that pays $1, then the total profit will be $3. If a worker cannot complete any job, their profit is $0.\n\t\tReturn the maximum profit we can achieve after assigning the workers to the jobs.\n\t\tExample 1:\n\t\tInput: difficulty = [2,4,6,8,10], profit = [10,20,30,40,50], worker = [4,5,6,7]\n\t\tOutput: 100\n\t\tExplanation: Workers are assigned jobs of difficulty [4,4,6,6] and they get a profit of [20,20,30,30] separately.\n\t\tExample 2:\n\t\tInput: difficulty = [85,47,57], profit = [24,66,99], worker = [40,25,25]\n\t\tOutput: 0\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 854, - "question": "class Solution:\n def largestIsland(self, grid: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tYou are given an n x n binary matrix grid. You are allowed to change at most one 0 to be 1.\r\n\t\tReturn the size of the largest island in grid after applying this operation.\r\n\t\tAn island is a 4-directionally connected group of 1s.\r\n\t\tExample 1:\r\n\t\tInput: grid = [[1,0],[0,1]]\r\n\t\tOutput: 3\r\n\t\tExplanation: Change one 0 to 1 and connect two 1s, then we get an island with area = 3.\r\n\t\tExample 2:\r\n\t\tInput: grid = [[1,1],[1,0]]\r\n\t\tOutput: 4\r\n\t\tExplanation: Change the 0 to 1 and make the island bigger, only one island with area = 4.\r\n\t\tExample 3:\r\n\t\tInput: grid = [[1,1],[1,1]]\r\n\t\tOutput: 4\r\n\t\tExplanation: Can't change any 0 to 1, only one island with area = 4.\r\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 855, - "question": "class Solution:\n def uniqueLetterString(self, s: str) -> int:\n\t\t\"\"\"\n\t\tLet's define a function countUniqueChars(s) that returns the number of unique characters on s.\n\t\t\tFor example, calling countUniqueChars(s) if s = \"LEETCODE\" then \"L\", \"T\", \"C\", \"O\", \"D\" are the unique characters since they appear only once in s, therefore countUniqueChars(s) = 5.\n\t\tGiven a string s, return the sum of countUniqueChars(t) where t is a substring of s. The test cases are generated such that the answer fits in a 32-bit integer.\n\t\tNotice that some substrings can be repeated so in this case you have to count the repeated ones too.\n\t\tExample 1:\n\t\tInput: s = \"ABC\"\n\t\tOutput: 10\n\t\tExplanation: All possible substrings are: \"A\",\"B\",\"C\",\"AB\",\"BC\" and \"ABC\".\n\t\tEvery substring is composed with only unique letters.\n\t\tSum of lengths of all substring is 1 + 1 + 1 + 2 + 2 + 3 = 10\n\t\tExample 2:\n\t\tInput: s = \"ABA\"\n\t\tOutput: 8\n\t\tExplanation: The same as example 1, except countUniqueChars(\"ABA\") = 1.\n\t\tExample 3:\n\t\tInput: s = \"LEETCODE\"\n\t\tOutput: 92\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 856, - "question": "class Solution:\n def consecutiveNumbersSum(self, n: int) -> int:\n\t\t\"\"\"\n\t\tGiven an integer n, return the number of ways you can write n as the sum of consecutive positive integers.\n\t\tExample 1:\n\t\tInput: n = 5\n\t\tOutput: 2\n\t\tExplanation: 5 = 2 + 3\n\t\tExample 2:\n\t\tInput: n = 9\n\t\tOutput: 3\n\t\tExplanation: 9 = 4 + 5 = 2 + 3 + 4\n\t\tExample 3:\n\t\tInput: n = 15\n\t\tOutput: 4\n\t\tExplanation: 15 = 8 + 7 = 4 + 5 + 6 = 1 + 2 + 3 + 4 + 5\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 857, - "question": "class Solution:\n def largeGroupPositions(self, s: str) -> List[List[int]]:\n\t\t\"\"\"\n\t\tIn a string s of lowercase letters, these letters form consecutive groups of the same character.\n\t\tFor example, a string like s = \"abbxxxxzyy\" has the groups \"a\", \"bb\", \"xxxx\", \"z\", and \"yy\".\n\t\tA group is identified by an interval [start, end], where start and end denote the start and end indices (inclusive) of the group. In the above example, \"xxxx\" has the interval [3,6].\n\t\tA group is considered large if it has 3 or more characters.\n\t\tReturn the intervals of every large group sorted in increasing order by start index.\n\t\tExample 1:\n\t\tInput: s = \"abbxxxxzzy\"\n\t\tOutput: [[3,6]]\n\t\tExplanation: \"xxxx\" is the only large group with start index 3 and end index 6.\n\t\tExample 2:\n\t\tInput: s = \"abc\"\n\t\tOutput: []\n\t\tExplanation: We have groups \"a\", \"b\", and \"c\", none of which are large groups.\n\t\tExample 3:\n\t\tInput: s = \"abcdddeeeeaabbbcd\"\n\t\tOutput: [[3,5],[6,9],[12,14]]\n\t\tExplanation: The large groups are \"ddd\", \"eeee\", and \"bbb\".\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 858, - "question": "class Solution:\n def maskPII(self, s: str) -> str:\n\t\t\"\"\"\n\t\tYou are given a personal information string s, representing either an email address or a phone number. Return the masked personal information using the below rules.\n\t\tEmail address:\n\t\tAn email address is:\n\t\t\tA name consisting of uppercase and lowercase English letters, followed by\n\t\t\tThe '@' symbol, followed by\n\t\t\tThe domain consisting of uppercase and lowercase English letters with a dot '.' somewhere in the middle (not the first or last character).\n\t\tTo mask an email:\n\t\t\tThe uppercase letters in the name and domain must be converted to lowercase letters.\n\t\t\tThe middle letters of the name (i.e., all but the first and last letters) must be replaced by 5 asterisks \"*****\".\n\t\tPhone number:\n\t\tA phone number is formatted as follows:\n\t\t\tThe phone number contains 10-13 digits.\n\t\t\tThe last 10 digits make up the local number.\n\t\t\tThe remaining 0-3 digits, in the beginning, make up the country code.\n\t\t\tSeparation characters from the set {'+', '-', '(', ')', ' '} separate the above digits in some way.\n\t\tTo mask a phone number:\n\t\t\tRemove all separation characters.\n\t\t\tThe masked phone number should have the form:\n\t\t\t\t\"***-***-XXXX\" if the country code has 0 digits.\n\t\t\t\t\"+*-***-***-XXXX\" if the country code has 1 digit.\n\t\t\t\t\"+**-***-***-XXXX\" if the country code has 2 digits.\n\t\t\t\t\"+***-***-***-XXXX\" if the country code has 3 digits.\n\t\t\t\"XXXX\" is the last 4 digits of the local number.\n\t\tExample 1:\n\t\tInput: s = \"LeetCode@LeetCode.com\"\n\t\tOutput: \"l*****e@leetcode.com\"\n\t\tExplanation: s is an email address.\n\t\tThe name and domain are converted to lowercase, and the middle of the name is replaced by 5 asterisks.\n\t\tExample 2:\n\t\tInput: s = \"AB@qq.com\"\n\t\tOutput: \"a*****b@qq.com\"\n\t\tExplanation: s is an email address.\n\t\tThe name and domain are converted to lowercase, and the middle of the name is replaced by 5 asterisks.\n\t\tNote that even though \"ab\" is 2 characters, it still must have 5 asterisks in the middle.\n\t\tExample 3:\n\t\tInput: s = \"1(234)567-890\"\n\t\tOutput: \"***-***-7890\"\n\t\tExplanation: s is a phone number.\n\t\tThere are 10 digits, so the local number is 10 digits and the country code is 0 digits.\n\t\tThus, the resulting masked number is \"***-***-7890\".\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 859, - "question": "class MyCircularDeque:\n def __init__(self, k: int):\n def insertFront(self, value: int) -> bool:\n def insertLast(self, value: int) -> bool:\n def deleteFront(self) -> bool:\n def deleteLast(self) -> bool:\n def getFront(self) -> int:\n def getRear(self) -> int:\n def isEmpty(self) -> bool:\n def isFull(self) -> bool:\n\t\t\"\"\"\n\t\tDesign your implementation of the circular double-ended queue (deque).\n\t\tImplement the MyCircularDeque class:\n\t\t\tMyCircularDeque(int k) Initializes the deque with a maximum size of k.\n\t\t\tboolean insertFront() Adds an item at the front of Deque. Returns true if the operation is successful, or false otherwise.\n\t\t\tboolean insertLast() Adds an item at the rear of Deque. Returns true if the operation is successful, or false otherwise.\n\t\t\tboolean deleteFront() Deletes an item from the front of Deque. Returns true if the operation is successful, or false otherwise.\n\t\t\tboolean deleteLast() Deletes an item from the rear of Deque. Returns true if the operation is successful, or false otherwise.\n\t\t\tint getFront() Returns the front item from the Deque. Returns -1 if the deque is empty.\n\t\t\tint getRear() Returns the last item from Deque. Returns -1 if the deque is empty.\n\t\t\tboolean isEmpty() Returns true if the deque is empty, or false otherwise.\n\t\t\tboolean isFull() Returns true if the deque is full, or false otherwise.\n\t\tExample 1:\n\t\tInput\n\t\t[\"MyCircularDeque\", \"insertLast\", \"insertLast\", \"insertFront\", \"insertFront\", \"getRear\", \"isFull\", \"deleteLast\", \"insertFront\", \"getFront\"]\n\t\t[[3], [1], [2], [3], [4], [], [], [], [4], []]\n\t\tOutput\n\t\t[null, true, true, true, false, 2, true, true, true, 4]\n\t\tExplanation\n\t\tMyCircularDeque myCircularDeque = new MyCircularDeque(3);\n\t\tmyCircularDeque.insertLast(1); // return True\n\t\tmyCircularDeque.insertLast(2); // return True\n\t\tmyCircularDeque.insertFront(3); // return True\n\t\tmyCircularDeque.insertFront(4); // return False, the queue is full.\n\t\tmyCircularDeque.getRear(); // return 2\n\t\tmyCircularDeque.isFull(); // return True\n\t\tmyCircularDeque.deleteLast(); // return True\n\t\tmyCircularDeque.insertFront(4); // return True\n\t\tmyCircularDeque.getFront(); // return 4\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 860, - "question": "class MyCircularQueue:\n def __init__(self, k: int):\n def enQueue(self, value: int) -> bool:\n def deQueue(self) -> bool:\n def Front(self) -> int:\n def Rear(self) -> int:\n def isEmpty(self) -> bool:\n def isFull(self) -> bool:\n\t\t\"\"\"\n\t\tDesign your implementation of the circular queue. The circular queue is a linear data structure in which the operations are performed based on FIFO (First In First Out) principle, and the last position is connected back to the first position to make a circle. It is also called \"Ring Buffer\".\n\t\tOne of the benefits of the circular queue is that we can make use of the spaces in front of the queue. In a normal queue, once the queue becomes full, we cannot insert the next element even if there is a space in front of the queue. But using the circular queue, we can use the space to store new values.\n\t\tImplement the MyCircularQueue class:\n\t\t\tMyCircularQueue(k) Initializes the object with the size of the queue to be k.\n\t\t\tint Front() Gets the front item from the queue. If the queue is empty, return -1.\n\t\t\tint Rear() Gets the last item from the queue. If the queue is empty, return -1.\n\t\t\tboolean enQueue(int value) Inserts an element into the circular queue. Return true if the operation is successful.\n\t\t\tboolean deQueue() Deletes an element from the circular queue. Return true if the operation is successful.\n\t\t\tboolean isEmpty() Checks whether the circular queue is empty or not.\n\t\t\tboolean isFull() Checks whether the circular queue is full or not.\n\t\tYou must solve the problem without using the built-in queue data structure in your programming language. \n\t\tExample 1:\n\t\tInput\n\t\t[\"MyCircularQueue\", \"enQueue\", \"enQueue\", \"enQueue\", \"enQueue\", \"Rear\", \"isFull\", \"deQueue\", \"enQueue\", \"Rear\"]\n\t\t[[3], [1], [2], [3], [4], [], [], [], [4], []]\n\t\tOutput\n\t\t[null, true, true, true, false, 3, true, true, true, 4]\n\t\tExplanation\n\t\tMyCircularQueue myCircularQueue = new MyCircularQueue(3);\n\t\tmyCircularQueue.enQueue(1); // return True\n\t\tmyCircularQueue.enQueue(2); // return True\n\t\tmyCircularQueue.enQueue(3); // return True\n\t\tmyCircularQueue.enQueue(4); // return False\n\t\tmyCircularQueue.Rear(); // return 3\n\t\tmyCircularQueue.isFull(); // return True\n\t\tmyCircularQueue.deQueue(); // return True\n\t\tmyCircularQueue.enQueue(4); // return True\n\t\tmyCircularQueue.Rear(); // return 4\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 861, - "question": "class Solution:\n def flipAndInvertImage(self, image: List[List[int]]) -> List[List[int]]:\n\t\t\"\"\"\n\t\tGiven an n x n binary matrix image, flip the image horizontally, then invert it, and return the resulting image.\n\t\tTo flip an image horizontally means that each row of the image is reversed.\n\t\t\tFor example, flipping [1,1,0] horizontally results in [0,1,1].\n\t\tTo invert an image means that each 0 is replaced by 1, and each 1 is replaced by 0.\n\t\t\tFor example, inverting [0,1,1] results in [1,0,0].\n\t\tExample 1:\n\t\tInput: image = [[1,1,0],[1,0,1],[0,0,0]]\n\t\tOutput: [[1,0,0],[0,1,0],[1,1,1]]\n\t\tExplanation: First reverse each row: [[0,1,1],[1,0,1],[0,0,0]].\n\t\tThen, invert the image: [[1,0,0],[0,1,0],[1,1,1]]\n\t\tExample 2:\n\t\tInput: image = [[1,1,0,0],[1,0,0,1],[0,1,1,1],[1,0,1,0]]\n\t\tOutput: [[1,1,0,0],[0,1,1,0],[0,0,0,1],[1,0,1,0]]\n\t\tExplanation: First reverse each row: [[0,0,1,1],[1,0,0,1],[1,1,1,0],[0,1,0,1]].\n\t\tThen invert the image: [[1,1,0,0],[0,1,1,0],[0,0,0,1],[1,0,1,0]]\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 862, - "question": "class Solution:\n def findReplaceString(self, s: str, indices: List[int], sources: List[str], targets: List[str]) -> str:\n\t\t\"\"\"\n\t\tYou are given a 0-indexed string s that you must perform k replacement operations on. The replacement operations are given as three 0-indexed parallel arrays, indices, sources, and targets, all of length k.\n\t\tTo complete the ith replacement operation:\n\t\t\tCheck if the substring sources[i] occurs at index indices[i] in the original string s.\n\t\t\tIf it does not occur, do nothing.\n\t\t\tOtherwise if it does occur, replace that substring with targets[i].\n\t\tFor example, if s = \"abcd\", indices[i] = 0, sources[i] = \"ab\", and targets[i] = \"eee\", then the result of this replacement will be \"eeecd\".\n\t\tAll replacement operations must occur simultaneously, meaning the replacement operations should not affect the indexing of each other. The testcases will be generated such that the replacements will not overlap.\n\t\t\tFor example, a testcase with s = \"abc\", indices = [0, 1], and sources = [\"ab\",\"bc\"] will not be generated because the \"ab\" and \"bc\" replacements overlap.\n\t\tReturn the resulting string after performing all replacement operations on s.\n\t\tA substring is a contiguous sequence of characters in a string.\n\t\tExample 1:\n\t\tInput: s = \"abcd\", indices = [0, 2], sources = [\"a\", \"cd\"], targets = [\"eee\", \"ffff\"]\n\t\tOutput: \"eeebffff\"\n\t\tExplanation:\n\t\t\"a\" occurs at index 0 in s, so we replace it with \"eee\".\n\t\t\"cd\" occurs at index 2 in s, so we replace it with \"ffff\".\n\t\tExample 2:\n\t\tInput: s = \"abcd\", indices = [0, 2], sources = [\"ab\",\"ec\"], targets = [\"eee\",\"ffff\"]\n\t\tOutput: \"eeecd\"\n\t\tExplanation:\n\t\t\"ab\" occurs at index 0 in s, so we replace it with \"eee\".\n\t\t\"ec\" does not occur at index 2 in s, so we do nothing.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 863, - "question": "class Solution:\n def sumOfDistancesInTree(self, n: int, edges: List[List[int]]) -> List[int]:\n\t\t\"\"\"\n\t\tThere is an undirected connected tree with n nodes labeled from 0 to n - 1 and n - 1 edges.\n\t\tYou are given the integer n and the array edges where edges[i] = [ai, bi] indicates that there is an edge between nodes ai and bi in the tree.\n\t\tReturn an array answer of length n where answer[i] is the sum of the distances between the ith node in the tree and all other nodes.\n\t\tExample 1:\n\t\tInput: n = 6, edges = [[0,1],[0,2],[2,3],[2,4],[2,5]]\n\t\tOutput: [8,12,6,10,10,10]\n\t\tExplanation: The tree is shown above.\n\t\tWe can see that dist(0,1) + dist(0,2) + dist(0,3) + dist(0,4) + dist(0,5)\n\t\tequals 1 + 1 + 2 + 2 + 2 = 8.\n\t\tHence, answer[0] = 8, and so on.\n\t\tExample 2:\n\t\tInput: n = 1, edges = []\n\t\tOutput: [0]\n\t\tExample 3:\n\t\tInput: n = 2, edges = [[1,0]]\n\t\tOutput: [1,1]\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 864, - "question": "class Solution:\n def largestOverlap(self, img1: List[List[int]], img2: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tYou are given two images, img1 and img2, represented as binary, square matrices of size n x n. A binary matrix has only 0s and 1s as values.\n\t\tWe translate one image however we choose by sliding all the 1 bits left, right, up, and/or down any number of units. We then place it on top of the other image. We can then calculate the overlap by counting the number of positions that have a 1 in both images.\n\t\tNote also that a translation does not include any kind of rotation. Any 1 bits that are translated outside of the matrix borders are erased.\n\t\tReturn the largest possible overlap.\n\t\tExample 1:\n\t\tInput: img1 = [[1,1,0],[0,1,0],[0,1,0]], img2 = [[0,0,0],[0,1,1],[0,0,1]]\n\t\tOutput: 3\n\t\tExplanation: We translate img1 to right by 1 unit and down by 1 unit.\n\t\tThe number of positions that have a 1 in both images is 3 (shown in red).\n\t\tExample 2:\n\t\tInput: img1 = [[1]], img2 = [[1]]\n\t\tOutput: 1\n\t\tExample 3:\n\t\tInput: img1 = [[0]], img2 = [[0]]\n\t\tOutput: 0\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 866, - "question": "class Solution:\n def isRectangleOverlap(self, rec1: List[int], rec2: List[int]) -> bool:\n\t\t\"\"\"\n\t\tAn axis-aligned rectangle is represented as a list [x1, y1, x2, y2], where (x1, y1) is the coordinate of its bottom-left corner, and (x2, y2) is the coordinate of its top-right corner. Its top and bottom edges are parallel to the X-axis, and its left and right edges are parallel to the Y-axis.\n\t\tTwo rectangles overlap if the area of their intersection is positive. To be clear, two rectangles that only touch at the corner or edges do not overlap.\n\t\tGiven two axis-aligned rectangles rec1 and rec2, return true if they overlap, otherwise return false.\n\t\tExample 1:\n\t\tInput: rec1 = [0,0,2,2], rec2 = [1,1,3,3]\n\t\tOutput: true\n\t\tExample 2:\n\t\tInput: rec1 = [0,0,1,1], rec2 = [1,0,2,1]\n\t\tOutput: false\n\t\tExample 3:\n\t\tInput: rec1 = [0,0,1,1], rec2 = [2,2,3,3]\n\t\tOutput: false\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 867, - "question": "class Solution:\n def new21Game(self, n: int, k: int, maxPts: int) -> float:\n\t\t\"\"\"\n\t\tAlice plays the following game, loosely based on the card game \"21\".\n\t\tAlice starts with 0 points and draws numbers while she has less than k points. During each draw, she gains an integer number of points randomly from the range [1, maxPts], where maxPts is an integer. Each draw is independent and the outcomes have equal probabilities.\n\t\tAlice stops drawing numbers when she gets k or more points.\n\t\tReturn the probability that Alice has n or fewer points.\n\t\tAnswers within 10-5 of the actual answer are considered accepted.\n\t\tExample 1:\n\t\tInput: n = 10, k = 1, maxPts = 10\n\t\tOutput: 1.00000\n\t\tExplanation: Alice gets a single card, then stops.\n\t\tExample 2:\n\t\tInput: n = 6, k = 1, maxPts = 10\n\t\tOutput: 0.60000\n\t\tExplanation: Alice gets a single card, then stops.\n\t\tIn 6 out of 10 possibilities, she is at or below 6 points.\n\t\tExample 3:\n\t\tInput: n = 21, k = 17, maxPts = 10\n\t\tOutput: 0.73278\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 868, - "question": "class Solution:\n def pushDominoes(self, dominoes: str) -> str:\n\t\t\"\"\"\n\t\tThere are n dominoes in a line, and we place each domino vertically upright. In the beginning, we simultaneously push some of the dominoes either to the left or to the right.\n\t\tAfter each second, each domino that is falling to the left pushes the adjacent domino on the left. Similarly, the dominoes falling to the right push their adjacent dominoes standing on the right.\n\t\tWhen a vertical domino has dominoes falling on it from both sides, it stays still due to the balance of the forces.\n\t\tFor the purposes of this question, we will consider that a falling domino expends no additional force to a falling or already fallen domino.\n\t\tYou are given a string dominoes representing the initial state where:\n\t\t\tdominoes[i] = 'L', if the ith domino has been pushed to the left,\n\t\t\tdominoes[i] = 'R', if the ith domino has been pushed to the right, and\n\t\t\tdominoes[i] = '.', if the ith domino has not been pushed.\n\t\tReturn a string representing the final state.\n\t\tExample 1:\n\t\tInput: dominoes = \"RR.L\"\n\t\tOutput: \"RR.L\"\n\t\tExplanation: The first domino expends no additional force on the second domino.\n\t\tExample 2:\n\t\tInput: dominoes = \".L.R...LR..L..\"\n\t\tOutput: \"LL.RR.LLRRLL..\"\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 869, - "question": "class Solution:\n def numSimilarGroups(self, strs: List[str]) -> int:\n\t\t\"\"\"\n\t\tTwo strings X and Y are similar if we can swap two letters (in different positions) of X, so that it equals Y. Also two strings X and Y are similar if they are equal.\n\t\tFor example, \"tars\" and \"rats\" are similar (swapping at positions 0 and 2), and \"rats\" and \"arts\" are similar, but \"star\" is not similar to \"tars\", \"rats\", or \"arts\".\n\t\tTogether, these form two connected groups by similarity: {\"tars\", \"rats\", \"arts\"} and {\"star\"}. Notice that \"tars\" and \"arts\" are in the same group even though they are not similar. Formally, each group is such that a word is in the group if and only if it is similar to at least one other word in the group.\n\t\tWe are given a list strs of strings where every string in strs is an anagram of every other string in strs. How many groups are there?\n\t\tExample 1:\n\t\tInput: strs = [\"tars\",\"rats\",\"arts\",\"star\"]\n\t\tOutput: 2\n\t\tExample 2:\n\t\tInput: strs = [\"omv\",\"ovm\"]\n\t\tOutput: 1\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 870, - "question": "class Solution:\n def numMagicSquaresInside(self, grid: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tA 3 x 3 magic square is a 3 x 3 grid filled with distinct numbers from 1 to 9 such that each row, column, and both diagonals all have the same sum.\n\t\tGiven a row x col grid of integers, how many 3 x 3 \"magic square\" subgrids are there? (Each subgrid is contiguous).\n\t\tExample 1:\n\t\tInput: grid = [[4,3,8,4],[9,5,1,9],[2,7,6,2]]\n\t\tOutput: 1\n\t\tExplanation: \n\t\tThe following subgrid is a 3 x 3 magic square:\n\t\twhile this one is not:\n\t\tIn total, there is only one magic square inside the given grid.\n\t\tExample 2:\n\t\tInput: grid = [[8]]\n\t\tOutput: 0\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 871, - "question": "class Solution:\n def canVisitAllRooms(self, rooms: List[List[int]]) -> bool:\n\t\t\"\"\"\n\t\tThere are n rooms labeled from 0 to n - 1 and all the rooms are locked except for room 0. Your goal is to visit all the rooms. However, you cannot enter a locked room without having its key.\n\t\tWhen you visit a room, you may find a set of distinct keys in it. Each key has a number on it, denoting which room it unlocks, and you can take all of them with you to unlock the other rooms.\n\t\tGiven an array rooms where rooms[i] is the set of keys that you can obtain if you visited room i, return true if you can visit all the rooms, or false otherwise.\n\t\tExample 1:\n\t\tInput: rooms = [[1],[2],[3],[]]\n\t\tOutput: true\n\t\tExplanation: \n\t\tWe visit room 0 and pick up key 1.\n\t\tWe then visit room 1 and pick up key 2.\n\t\tWe then visit room 2 and pick up key 3.\n\t\tWe then visit room 3.\n\t\tSince we were able to visit every room, we return true.\n\t\tExample 2:\n\t\tInput: rooms = [[1,3],[3,0,1],[2],[0]]\n\t\tOutput: false\n\t\tExplanation: We can not enter room number 2 since the only key that unlocks it is in that room.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 872, - "question": "class Solution:\n def splitIntoFibonacci(self, num: str) -> List[int]:\n\t\t\"\"\"\n\t\tYou are given a string of digits num, such as \"123456579\". We can split it into a Fibonacci-like sequence [123, 456, 579].\n\t\tFormally, a Fibonacci-like sequence is a list f of non-negative integers such that:\n\t\t\t0 <= f[i] < 231, (that is, each integer fits in a 32-bit signed integer type),\n\t\t\tf.length >= 3, and\n\t\t\tf[i] + f[i + 1] == f[i + 2] for all 0 <= i < f.length - 2.\n\t\tNote that when splitting the string into pieces, each piece must not have extra leading zeroes, except if the piece is the number 0 itself.\n\t\tReturn any Fibonacci-like sequence split from num, or return [] if it cannot be done.\n\t\tExample 1:\n\t\tInput: num = \"1101111\"\n\t\tOutput: [11,0,11,11]\n\t\tExplanation: The output [110, 1, 111] would also be accepted.\n\t\tExample 2:\n\t\tInput: num = \"112358130\"\n\t\tOutput: []\n\t\tExplanation: The task is impossible.\n\t\tExample 3:\n\t\tInput: num = \"0123\"\n\t\tOutput: []\n\t\tExplanation: Leading zeroes are not allowed, so \"01\", \"2\", \"3\" is not valid.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 873, - "question": "\t\t\"\"\"\n\t\tYou are given an array of unique strings words where words[i] is six letters long. One word of words was chosen as a secret word.\n\t\tYou are also given the helper object Master. You may call Master.guess(word) where word is a six-letter-long string, and it must be from words. Master.guess(word) returns:\n\t\t\t-1 if word is not from words, or\n\t\t\tan integer representing the number of exact matches (value and position) of your guess to the secret word.\n\t\tThere is a parameter allowedGuesses for each test case where allowedGuesses is the maximum number of times you can call Master.guess(word).\n\t\tFor each test case, you should call Master.guess with the secret word without exceeding the maximum number of allowed guesses. You will get:\n\t\t\t\"Either you took too many guesses, or you did not find the secret word.\" if you called Master.guess more than allowedGuesses times or if you did not call Master.guess with the secret word, or\n\t\t\t\"You guessed the secret word correctly.\" if you called Master.guess with the secret word with the number of calls to Master.guess less than or equal to allowedGuesses.\n\t\tThe test cases are generated such that you can guess the secret word with a reasonable strategy (other than using the bruteforce method).\n\t\tExample 1:\n\t\tInput: secret = \"acckzz\", words = [\"acckzz\",\"ccbazz\",\"eiowzz\",\"abcczz\"], allowedGuesses = 10\n\t\tOutput: You guessed the secret word correctly.\n\t\tExplanation:\n\t\tmaster.guess(\"aaaaaa\") returns -1, because \"aaaaaa\" is not in wordlist.\n\t\tmaster.guess(\"acckzz\") returns 6, because \"acckzz\" is secret and has all 6 matches.\n\t\tmaster.guess(\"ccbazz\") returns 3, because \"ccbazz\" has 3 matches.\n\t\tmaster.guess(\"eiowzz\") returns 2, because \"eiowzz\" has 2 matches.\n\t\tmaster.guess(\"abcczz\") returns 4, because \"abcczz\" has 4 matches.\n\t\tWe made 5 calls to master.guess, and one of them was the secret, so we pass the test case.\n\t\tExample 2:\n\t\tInput: secret = \"hamada\", words = [\"hamada\",\"khaled\"], allowedGuesses = 10\n\t\tOutput: You guessed the secret word correctly.\n\t\tExplanation: Since there are two words, you can guess both.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 874, - "question": "class Solution:\n def backspaceCompare(self, s: str, t: str) -> bool:\n\t\t\"\"\"\n\t\tGiven two strings s and t, return true if they are equal when both are typed into empty text editors. '#' means a backspace character.\n\t\tNote that after backspacing an empty text, the text will continue empty.\n\t\tExample 1:\n\t\tInput: s = \"ab#c\", t = \"ad#c\"\n\t\tOutput: true\n\t\tExplanation: Both s and t become \"ac\".\n\t\tExample 2:\n\t\tInput: s = \"ab##\", t = \"c#d#\"\n\t\tOutput: true\n\t\tExplanation: Both s and t become \"\".\n\t\tExample 3:\n\t\tInput: s = \"a#c\", t = \"b\"\n\t\tOutput: false\n\t\tExplanation: s becomes \"c\" while t becomes \"b\".\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 875, - "question": "class Solution:\n def longestMountain(self, arr: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou may recall that an array arr is a mountain array if and only if:\n\t\t\tarr.length >= 3\n\t\t\tThere exists some index i (0-indexed) with 0 < i < arr.length - 1 such that:\n\t\t\t\tarr[0] < arr[1] < ... < arr[i - 1] < arr[i]\n\t\t\t\tarr[i] > arr[i + 1] > ... > arr[arr.length - 1]\n\t\tGiven an integer array arr, return the length of the longest subarray, which is a mountain. Return 0 if there is no mountain subarray.\n\t\tExample 1:\n\t\tInput: arr = [2,1,4,7,3,2,5]\n\t\tOutput: 5\n\t\tExplanation: The largest mountain is [1,4,7,3,2] which has length 5.\n\t\tExample 2:\n\t\tInput: arr = [2,2,2]\n\t\tOutput: 0\n\t\tExplanation: There is no mountain.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 876, - "question": "class Solution:\n def isNStraightHand(self, hand: List[int], groupSize: int) -> bool:\n\t\t\"\"\"\n\t\tAlice has some number of cards and she wants to rearrange the cards into groups so that each group is of size groupSize, and consists of groupSize consecutive cards.\n\t\tGiven an integer array hand where hand[i] is the value written on the ith card and an integer groupSize, return true if she can rearrange the cards, or false otherwise.\n\t\tExample 1:\n\t\tInput: hand = [1,2,3,6,2,3,4,7,8], groupSize = 3\n\t\tOutput: true\n\t\tExplanation: Alice's hand can be rearranged as [1,2,3],[2,3,4],[6,7,8]\n\t\tExample 2:\n\t\tInput: hand = [1,2,3,4,5], groupSize = 4\n\t\tOutput: false\n\t\tExplanation: Alice's hand can not be rearranged into groups of 4.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 877, - "question": "class Solution:\n def shortestPathLength(self, graph: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tYou have an undirected, connected graph of n nodes labeled from 0 to n - 1. You are given an array graph where graph[i] is a list of all the nodes connected with node i by an edge.\n\t\tReturn the length of the shortest path that visits every node. You may start and stop at any node, you may revisit nodes multiple times, and you may reuse edges.\n\t\tExample 1:\n\t\tInput: graph = [[1,2,3],[0],[0],[0]]\n\t\tOutput: 4\n\t\tExplanation: One possible path is [1,0,2,0,3]\n\t\tExample 2:\n\t\tInput: graph = [[1],[0,2,4],[1,3,4],[2],[1,2]]\n\t\tOutput: 4\n\t\tExplanation: One possible path is [0,1,4,2,3]\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 878, - "question": "class Solution:\n def shiftingLetters(self, s: str, shifts: List[int]) -> str:\n\t\t\"\"\"\n\t\tYou are given a string s of lowercase English letters and an integer array shifts of the same length.\n\t\tCall the shift() of a letter, the next letter in the alphabet, (wrapping around so that 'z' becomes 'a').\n\t\t\tFor example, shift('a') = 'b', shift('t') = 'u', and shift('z') = 'a'.\n\t\tNow for each shifts[i] = x, we want to shift the first i + 1 letters of s, x times.\n\t\tReturn the final string after all such shifts to s are applied.\n\t\tExample 1:\n\t\tInput: s = \"abc\", shifts = [3,5,9]\n\t\tOutput: \"rpl\"\n\t\tExplanation: We start with \"abc\".\n\t\tAfter shifting the first 1 letters of s by 3, we have \"dbc\".\n\t\tAfter shifting the first 2 letters of s by 5, we have \"igc\".\n\t\tAfter shifting the first 3 letters of s by 9, we have \"rpl\", the answer.\n\t\tExample 2:\n\t\tInput: s = \"aaa\", shifts = [1,2,3]\n\t\tOutput: \"gfd\"\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 879, - "question": "class Solution:\n def maxDistToClosest(self, seats: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou are given an array representing a row of seats where seats[i] = 1 represents a person sitting in the ith seat, and seats[i] = 0 represents that the ith seat is empty (0-indexed).\n\t\tThere is at least one empty seat, and at least one person sitting.\n\t\tAlex wants to sit in the seat such that the distance between him and the closest person to him is maximized. \n\t\tReturn that maximum distance to the closest person.\n\t\tExample 1:\n\t\tInput: seats = [1,0,0,0,1,0,1]\n\t\tOutput: 2\n\t\tExplanation: \n\t\tIf Alex sits in the second open seat (i.e. seats[2]), then the closest person has distance 2.\n\t\tIf Alex sits in any other open seat, the closest person has distance 1.\n\t\tThus, the maximum distance to the closest person is 2.\n\t\tExample 2:\n\t\tInput: seats = [1,0,0,0]\n\t\tOutput: 3\n\t\tExplanation: \n\t\tIf Alex sits in the last seat (i.e. seats[3]), the closest person is 3 seats away.\n\t\tThis is the maximum distance possible, so the answer is 3.\n\t\tExample 3:\n\t\tInput: seats = [0,1]\n\t\tOutput: 1\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 880, - "question": "class Solution:\n def rectangleArea(self, rectangles: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tYou are given a 2D array of axis-aligned rectangles. Each rectangle[i] = [xi1, yi1, xi2, yi2] denotes the ith rectangle where (xi1, yi1) are the coordinates of the bottom-left corner, and (xi2, yi2) are the coordinates of the top-right corner.\n\t\tCalculate the total area covered by all rectangles in the plane. Any area covered by two or more rectangles should only be counted once.\n\t\tReturn the total area. Since the answer may be too large, return it modulo 109 + 7.\n\t\tExample 1:\n\t\tInput: rectangles = [[0,0,2,2],[1,0,2,3],[1,0,3,1]]\n\t\tOutput: 6\n\t\tExplanation: A total area of 6 is covered by all three rectangles, as illustrated in the picture.\n\t\tFrom (1,1) to (2,2), the green and red rectangles overlap.\n\t\tFrom (1,0) to (2,3), all three rectangles overlap.\n\t\tExample 2:\n\t\tInput: rectangles = [[0,0,1000000000,1000000000]]\n\t\tOutput: 49\n\t\tExplanation: The answer is 1018 modulo (109 + 7), which is 49.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 881, - "question": "class Solution:\n def loudAndRich(self, richer: List[List[int]], quiet: List[int]) -> List[int]:\n\t\t\"\"\"\n\t\tThere is a group of n people labeled from 0 to n - 1 where each person has a different amount of money and a different level of quietness.\n\t\tYou are given an array richer where richer[i] = [ai, bi] indicates that ai has more money than bi and an integer array quiet where quiet[i] is the quietness of the ith person. All the given data in richer are logically correct (i.e., the data will not lead you to a situation where x is richer than y and y is richer than x at the same time).\n\t\tReturn an integer array answer where answer[x] = y if y is the least quiet person (that is, the person y with the smallest value of quiet[y]) among all people who definitely have equal to or more money than the person x.\n\t\tExample 1:\n\t\tInput: richer = [[1,0],[2,1],[3,1],[3,7],[4,3],[5,3],[6,3]], quiet = [3,2,5,4,6,1,7,0]\n\t\tOutput: [5,5,2,5,4,5,6,7]\n\t\tExplanation: \n\t\tanswer[0] = 5.\n\t\tPerson 5 has more money than 3, which has more money than 1, which has more money than 0.\n\t\tThe only person who is quieter (has lower quiet[x]) is person 7, but it is not clear if they have more money than person 0.\n\t\tanswer[7] = 7.\n\t\tAmong all people that definitely have equal to or more money than person 7 (which could be persons 3, 4, 5, 6, or 7), the person who is the quietest (has lower quiet[x]) is person 7.\n\t\tThe other answers can be filled out with similar reasoning.\n\t\tExample 2:\n\t\tInput: richer = [], quiet = [0]\n\t\tOutput: [0]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 882, - "question": "class Solution:\n def peakIndexInMountainArray(self, arr: List[int]) -> int:\n\t\t\"\"\"\n\t\tAn array arr a mountain if the following properties hold:\n\t\t\tarr.length >= 3\n\t\t\tThere exists some i with 0 < i < arr.length - 1 such that:\n\t\t\t\tarr[0] < arr[1] < ... < arr[i - 1] < arr[i] \n\t\t\t\tarr[i] > arr[i + 1] > ... > arr[arr.length - 1]\n\t\tGiven a mountain array arr, return the index i such that arr[0] < arr[1] < ... < arr[i - 1] < arr[i] > arr[i + 1] > ... > arr[arr.length - 1].\n\t\tYou must solve it in O(log(arr.length)) time complexity.\n\t\tExample 1:\n\t\tInput: arr = [0,1,0]\n\t\tOutput: 1\n\t\tExample 2:\n\t\tInput: arr = [0,2,1,0]\n\t\tOutput: 1\n\t\tExample 3:\n\t\tInput: arr = [0,10,5,2]\n\t\tOutput: 1\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 883, - "question": "class Solution:\n def carFleet(self, target: int, position: List[int], speed: List[int]) -> int:\n\t\t\"\"\"\n\t\tThere are n cars going to the same destination along a one-lane road. The destination is target miles away.\n\t\tYou are given two integer array position and speed, both of length n, where position[i] is the position of the ith car and speed[i] is the speed of the ith car (in miles per hour).\n\t\tA car can never pass another car ahead of it, but it can catch up to it and drive bumper to bumper at the same speed. The faster car will slow down to match the slower car's speed. The distance between these two cars is ignored (i.e., they are assumed to have the same position).\n\t\tA car fleet is some non-empty set of cars driving at the same position and same speed. Note that a single car is also a car fleet.\n\t\tIf a car catches up to a car fleet right at the destination point, it will still be considered as one car fleet.\n\t\tReturn the number of car fleets that will arrive at the destination.\n\t\tExample 1:\n\t\tInput: target = 12, position = [10,8,0,5,3], speed = [2,4,1,1,3]\n\t\tOutput: 3\n\t\tExplanation:\n\t\tThe cars starting at 10 (speed 2) and 8 (speed 4) become a fleet, meeting each other at 12.\n\t\tThe car starting at 0 does not catch up to any other car, so it is a fleet by itself.\n\t\tThe cars starting at 5 (speed 1) and 3 (speed 3) become a fleet, meeting each other at 6. The fleet moves at speed 1 until it reaches target.\n\t\tNote that no other cars meet these fleets before the destination, so the answer is 3.\n\t\tExample 2:\n\t\tInput: target = 10, position = [3], speed = [3]\n\t\tOutput: 1\n\t\tExplanation: There is only one car, hence there is only one fleet.\n\t\tExample 3:\n\t\tInput: target = 100, position = [0,2,4], speed = [4,2,1]\n\t\tOutput: 1\n\t\tExplanation:\n\t\tThe cars starting at 0 (speed 4) and 2 (speed 2) become a fleet, meeting each other at 4. The fleet moves at speed 2.\n\t\tThen, the fleet (speed 2) and the car starting at 4 (speed 1) become one fleet, meeting each other at 6. The fleet moves at speed 1 until it reaches target.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 884, - "question": "class Solution:\n def kSimilarity(self, s1: str, s2: str) -> int:\n\t\t\"\"\"\n\t\tStrings s1 and s2 are k-similar (for some non-negative integer k) if we can swap the positions of two letters in s1 exactly k times so that the resulting string equals s2.\n\t\tGiven two anagrams s1 and s2, return the smallest k for which s1 and s2 are k-similar.\n\t\tExample 1:\n\t\tInput: s1 = \"ab\", s2 = \"ba\"\n\t\tOutput: 1\n\t\tExplanation: The two string are 1-similar because we can use one swap to change s1 to s2: \"ab\" --> \"ba\".\n\t\tExample 2:\n\t\tInput: s1 = \"abc\", s2 = \"bca\"\n\t\tOutput: 2\n\t\tExplanation: The two strings are 2-similar because we can use two swaps to change s1 to s2: \"abc\" --> \"bac\" --> \"bca\".\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 885, - "question": "class ExamRoom:\n def __init__(self, n: int):\n def seat(self) -> int:\n def leave(self, p: int) -> None:\n\t\t\"\"\"\n\t\tThere is an exam room with n seats in a single row labeled from 0 to n - 1.\n\t\tWhen a student enters the room, they must sit in the seat that maximizes the distance to the closest person. If there are multiple such seats, they sit in the seat with the lowest number. If no one is in the room, then the student sits at seat number 0.\n\t\tDesign a class that simulates the mentioned exam room.\n\t\tImplement the ExamRoom class:\n\t\t\tExamRoom(int n) Initializes the object of the exam room with the number of the seats n.\n\t\t\tint seat() Returns the label of the seat at which the next student will set.\n\t\t\tvoid leave(int p) Indicates that the student sitting at seat p will leave the room. It is guaranteed that there will be a student sitting at seat p.\n\t\tExample 1:\n\t\tInput\n\t\t[\"ExamRoom\", \"seat\", \"seat\", \"seat\", \"seat\", \"leave\", \"seat\"]\n\t\t[[10], [], [], [], [], [4], []]\n\t\tOutput\n\t\t[null, 0, 9, 4, 2, null, 5]\n\t\tExplanation\n\t\tExamRoom examRoom = new ExamRoom(10);\n\t\texamRoom.seat(); // return 0, no one is in the room, then the student sits at seat number 0.\n\t\texamRoom.seat(); // return 9, the student sits at the last seat number 9.\n\t\texamRoom.seat(); // return 4, the student sits at the last seat number 4.\n\t\texamRoom.seat(); // return 2, the student sits at the last seat number 2.\n\t\texamRoom.leave(4);\n\t\texamRoom.seat(); // return 5, the student sits at the last seat number 5.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 886, - "question": "class Solution:\n def scoreOfParentheses(self, s: str) -> int:\n\t\t\"\"\"\n\t\tGiven a balanced parentheses string s, return the score of the string.\n\t\tThe score of a balanced parentheses string is based on the following rule:\n\t\t\t\"()\" has score 1.\n\t\t\tAB has score A + B, where A and B are balanced parentheses strings.\n\t\t\t(A) has score 2 * A, where A is a balanced parentheses string.\n\t\tExample 1:\n\t\tInput: s = \"()\"\n\t\tOutput: 1\n\t\tExample 2:\n\t\tInput: s = \"(())\"\n\t\tOutput: 2\n\t\tExample 3:\n\t\tInput: s = \"()()\"\n\t\tOutput: 2\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 887, - "question": "class Solution:\n def mincostToHireWorkers(self, quality: List[int], wage: List[int], k: int) -> float:\n\t\t\"\"\"\n\t\tThere are n workers. You are given two integer arrays quality and wage where quality[i] is the quality of the ith worker and wage[i] is the minimum wage expectation for the ith worker.\n\t\tWe want to hire exactly k workers to form a paid group. To hire a group of k workers, we must pay them according to the following rules:\n\t\t\tEvery worker in the paid group should be paid in the ratio of their quality compared to other workers in the paid group.\n\t\t\tEvery worker in the paid group must be paid at least their minimum wage expectation.\n\t\tGiven the integer k, return the least amount of money needed to form a paid group satisfying the above conditions. Answers within 10-5 of the actual answer will be accepted.\n\t\tExample 1:\n\t\tInput: quality = [10,20,5], wage = [70,50,30], k = 2\n\t\tOutput: 105.00000\n\t\tExplanation: We pay 70 to 0th worker and 35 to 2nd worker.\n\t\tExample 2:\n\t\tInput: quality = [3,1,10,10,1], wage = [4,8,2,2,7], k = 3\n\t\tOutput: 30.66667\n\t\tExplanation: We pay 4 to 0th worker, 13.33333 to 2nd and 3rd workers separately.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 888, - "question": "class Solution:\n def mirrorReflection(self, p: int, q: int) -> int:\n\t\t\"\"\"\n\t\tThere is a special square room with mirrors on each of the four walls. Except for the southwest corner, there are receptors on each of the remaining corners, numbered 0, 1, and 2.\n\t\tThe square room has walls of length p and a laser ray from the southwest corner first meets the east wall at a distance q from the 0th receptor.\n\t\tGiven the two integers p and q, return the number of the receptor that the ray meets first.\n\t\tThe test cases are guaranteed so that the ray will meet a receptor eventually.\n\t\tExample 1:\n\t\tInput: p = 2, q = 1\n\t\tOutput: 2\n\t\tExplanation: The ray meets receptor 2 the first time it gets reflected back to the left wall.\n\t\tExample 2:\n\t\tInput: p = 3, q = 1\n\t\tOutput: 1\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 889, - "question": "class Solution:\n def buddyStrings(self, s: str, goal: str) -> bool:\n\t\t\"\"\"\n\t\tGiven two strings s and goal, return true if you can swap two letters in s so the result is equal to goal, otherwise, return false.\n\t\tSwapping letters is defined as taking two indices i and j (0-indexed) such that i != j and swapping the characters at s[i] and s[j].\n\t\t\tFor example, swapping at indices 0 and 2 in \"abcd\" results in \"cbad\".\n\t\tExample 1:\n\t\tInput: s = \"ab\", goal = \"ba\"\n\t\tOutput: true\n\t\tExplanation: You can swap s[0] = 'a' and s[1] = 'b' to get \"ba\", which is equal to goal.\n\t\tExample 2:\n\t\tInput: s = \"ab\", goal = \"ab\"\n\t\tOutput: false\n\t\tExplanation: The only letters you can swap are s[0] = 'a' and s[1] = 'b', which results in \"ba\" != goal.\n\t\tExample 3:\n\t\tInput: s = \"aa\", goal = \"aa\"\n\t\tOutput: true\n\t\tExplanation: You can swap s[0] = 'a' and s[1] = 'a' to get \"aa\", which is equal to goal.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 890, - "question": "class Solution:\n def lemonadeChange(self, bills: List[int]) -> bool:\n\t\t\"\"\"\n\t\tAt a lemonade stand, each lemonade costs $5. Customers are standing in a queue to buy from you and order one at a time (in the order specified by bills). Each customer will only buy one lemonade and pay with either a $5, $10, or $20 bill. You must provide the correct change to each customer so that the net transaction is that the customer pays $5.\n\t\tNote that you do not have any change in hand at first.\n\t\tGiven an integer array bills where bills[i] is the bill the ith customer pays, return true if you can provide every customer with the correct change, or false otherwise.\n\t\tExample 1:\n\t\tInput: bills = [5,5,5,10,20]\n\t\tOutput: true\n\t\tExplanation: \n\t\tFrom the first 3 customers, we collect three $5 bills in order.\n\t\tFrom the fourth customer, we collect a $10 bill and give back a $5.\n\t\tFrom the fifth customer, we give a $10 bill and a $5 bill.\n\t\tSince all customers got correct change, we output true.\n\t\tExample 2:\n\t\tInput: bills = [5,5,10,10,20]\n\t\tOutput: false\n\t\tExplanation: \n\t\tFrom the first two customers in order, we collect two $5 bills.\n\t\tFor the next two customers in order, we collect a $10 bill and give back a $5 bill.\n\t\tFor the last customer, we can not give the change of $15 back because we only have two $10 bills.\n\t\tSince not every customer received the correct change, the answer is false.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 891, - "question": "class Solution:\n def matrixScore(self, grid: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tYou are given an m x n binary matrix grid.\n\t\tA move consists of choosing any row or column and toggling each value in that row or column (i.e., changing all 0's to 1's, and all 1's to 0's).\n\t\tEvery row of the matrix is interpreted as a binary number, and the score of the matrix is the sum of these numbers.\n\t\tReturn the highest possible score after making any number of moves (including zero moves).\n\t\tExample 1:\n\t\tInput: grid = [[0,0,1,1],[1,0,1,0],[1,1,0,0]]\n\t\tOutput: 39\n\t\tExplanation: 0b1111 + 0b1001 + 0b1111 = 15 + 9 + 15 = 39\n\t\tExample 2:\n\t\tInput: grid = [[0]]\n\t\tOutput: 1\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 892, - "question": "class Solution:\n def shortestSubarray(self, nums: List[int], k: int) -> int:\n\t\t\"\"\"\n\t\tGiven an integer array nums and an integer k, return the length of the shortest non-empty subarray of nums with a sum of at least k. If there is no such subarray, return -1.\n\t\tA subarray is a contiguous part of an array.\n\t\tExample 1:\n\t\tInput: nums = [1], k = 1\n\t\tOutput: 1\n\t\tExample 2:\n\t\tInput: nums = [1,2], k = 4\n\t\tOutput: -1\n\t\tExample 3:\n\t\tInput: nums = [2,-1,2], k = 3\n\t\tOutput: 3\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 893, - "question": "class Solution:\n def distanceK(self, root: TreeNode, target: TreeNode, k: int) -> List[int]:\n\t\t\"\"\"\n\t\tGiven the root of a binary tree, the value of a target node target, and an integer k, return an array of the values of all nodes that have a distance k from the target node.\n\t\tYou can return the answer in any order.\n\t\tExample 1:\n\t\tInput: root = [3,5,1,6,2,0,8,null,null,7,4], target = 5, k = 2\n\t\tOutput: [7,4,1]\n\t\tExplanation: The nodes that are a distance 2 from the target node (with value 5) have values 7, 4, and 1.\n\t\tExample 2:\n\t\tInput: root = [1], target = 1, k = 3\n\t\tOutput: []\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 894, - "question": "class Solution:\n def __init__(self, n: int, blacklist: List[int]):\n def pick(self) -> int:\n\t\t\"\"\"\n\t\tYou are given an integer n and an array of unique integers blacklist. Design an algorithm to pick a random integer in the range [0, n - 1] that is not in blacklist. Any integer that is in the mentioned range and not in blacklist should be equally likely to be returned.\n\t\tOptimize your algorithm such that it minimizes the number of calls to the built-in random function of your language.\n\t\tImplement the Solution class:\n\t\t\tSolution(int n, int[] blacklist) Initializes the object with the integer n and the blacklisted integers blacklist.\n\t\t\tint pick() Returns a random integer in the range [0, n - 1] and not in blacklist.\n\t\tExample 1:\n\t\tInput\n\t\t[\"Solution\", \"pick\", \"pick\", \"pick\", \"pick\", \"pick\", \"pick\", \"pick\"]\n\t\t[[7, [2, 3, 5]], [], [], [], [], [], [], []]\n\t\tOutput\n\t\t[null, 0, 4, 1, 6, 1, 0, 4]\n\t\tExplanation\n\t\tSolution solution = new Solution(7, [2, 3, 5]);\n\t\tsolution.pick(); // return 0, any integer from [0,1,4,6] should be ok. Note that for every call of pick,\n\t\t // 0, 1, 4, and 6 must be equally likely to be returned (i.e., with probability 1/4).\n\t\tsolution.pick(); // return 4\n\t\tsolution.pick(); // return 1\n\t\tsolution.pick(); // return 6\n\t\tsolution.pick(); // return 1\n\t\tsolution.pick(); // return 0\n\t\tsolution.pick(); // return 4\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 895, - "question": "class Solution:\n def shortestPathAllKeys(self, grid: List[str]) -> int:\n\t\t\"\"\"\n\t\tYou are given an m x n grid grid where:\n\t\t\t'.' is an empty cell.\n\t\t\t'#' is a wall.\n\t\t\t'@' is the starting point.\n\t\t\tLowercase letters represent keys.\n\t\t\tUppercase letters represent locks.\n\t\tYou start at the starting point and one move consists of walking one space in one of the four cardinal directions. You cannot walk outside the grid, or walk into a wall.\n\t\tIf you walk over a key, you can pick it up and you cannot walk over a lock unless you have its corresponding key.\n\t\tFor some 1 <= k <= 6, there is exactly one lowercase and one uppercase letter of the first k letters of the English alphabet in the grid. This means that there is exactly one key for each lock, and one lock for each key; and also that the letters used to represent the keys and locks were chosen in the same order as the English alphabet.\n\t\tReturn the lowest number of moves to acquire all keys. If it is impossible, return -1.\n\t\tExample 1:\n\t\tInput: grid = [\"@.a..\",\"###.#\",\"b.A.B\"]\n\t\tOutput: 8\n\t\tExplanation: Note that the goal is to obtain all the keys not to open all the locks.\n\t\tExample 2:\n\t\tInput: grid = [\"@..aA\",\"..B#.\",\"....b\"]\n\t\tOutput: 6\n\t\tExample 3:\n\t\tInput: grid = [\"@Aa\"]\n\t\tOutput: -1\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 896, - "question": "class Solution:\n def subtreeWithAllDeepest(self, root: TreeNode) -> TreeNode:\n\t\t\"\"\"\n\t\tGiven the root of a binary tree, the depth of each node is the shortest distance to the root.\n\t\tReturn the smallest subtree such that it contains all the deepest nodes in the original tree.\n\t\tA node is called the deepest if it has the largest depth possible among any node in the entire tree.\n\t\tThe subtree of a node is a tree consisting of that node, plus the set of all descendants of that node.\n\t\tExample 1:\n\t\tInput: root = [3,5,1,6,2,0,8,null,null,7,4]\n\t\tOutput: [2,7,4]\n\t\tExplanation: We return the node with value 2, colored in yellow in the diagram.\n\t\tThe nodes coloured in blue are the deepest nodes of the tree.\n\t\tNotice that nodes 5, 3 and 2 contain the deepest nodes in the tree but node 2 is the smallest subtree among them, so we return it.\n\t\tExample 2:\n\t\tInput: root = [1]\n\t\tOutput: [1]\n\t\tExplanation: The root is the deepest node in the tree.\n\t\tExample 3:\n\t\tInput: root = [0,1,3,null,2]\n\t\tOutput: [2]\n\t\tExplanation: The deepest node in the tree is 2, the valid subtrees are the subtrees of nodes 2, 1 and 0 but the subtree of node 2 is the smallest.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 897, - "question": "class Solution:\n def primePalindrome(self, n: int) -> int:\n\t\t\"\"\"\n\t\tGiven an integer n, return the smallest prime palindrome greater than or equal to n.\n\t\tAn integer is prime if it has exactly two divisors: 1 and itself. Note that 1 is not a prime number.\n\t\t\tFor example, 2, 3, 5, 7, 11, and 13 are all primes.\n\t\tAn integer is a palindrome if it reads the same from left to right as it does from right to left.\n\t\t\tFor example, 101 and 12321 are palindromes.\n\t\tThe test cases are generated so that the answer always exists and is in the range [2, 2 * 108].\n\t\tExample 1:\n\t\tInput: n = 6\n\t\tOutput: 7\n\t\tExample 2:\n\t\tInput: n = 8\n\t\tOutput: 11\n\t\tExample 3:\n\t\tInput: n = 13\n\t\tOutput: 101\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 898, - "question": "class Solution:\n def transpose(self, matrix: List[List[int]]) -> List[List[int]]:\n\t\t\"\"\"\n\t\tGiven a 2D integer array matrix, return the transpose of matrix.\n\t\tThe transpose of a matrix is the matrix flipped over its main diagonal, switching the matrix's row and column indices.\n\t\tExample 1:\n\t\tInput: matrix = [[1,2,3],[4,5,6],[7,8,9]]\n\t\tOutput: [[1,4,7],[2,5,8],[3,6,9]]\n\t\tExample 2:\n\t\tInput: matrix = [[1,2,3],[4,5,6]]\n\t\tOutput: [[1,4],[2,5],[3,6]]\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 899, - "question": "class Solution:\n def binaryGap(self, n: int) -> int:\n\t\t\"\"\"\n\t\tGiven a positive integer n, find and return the longest distance between any two adjacent 1's in the binary representation of n. If there are no two adjacent 1's, return 0.\n\t\tTwo 1's are adjacent if there are only 0's separating them (possibly no 0's). The distance between two 1's is the absolute difference between their bit positions. For example, the two 1's in \"1001\" have a distance of 3.\n\t\tExample 1:\n\t\tInput: n = 22\n\t\tOutput: 2\n\t\tExplanation: 22 in binary is \"10110\".\n\t\tThe first adjacent pair of 1's is \"10110\" with a distance of 2.\n\t\tThe second adjacent pair of 1's is \"10110\" with a distance of 1.\n\t\tThe answer is the largest of these two distances, which is 2.\n\t\tNote that \"10110\" is not a valid pair since there is a 1 separating the two 1's underlined.\n\t\tExample 2:\n\t\tInput: n = 8\n\t\tOutput: 0\n\t\tExplanation: 8 in binary is \"1000\".\n\t\tThere are not any adjacent pairs of 1's in the binary representation of 8, so we return 0.\n\t\tExample 3:\n\t\tInput: n = 5\n\t\tOutput: 2\n\t\tExplanation: 5 in binary is \"101\".\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 900, - "question": "class Solution:\n def reorderedPowerOf2(self, n: int) -> bool:\n\t\t\"\"\"\n\t\tYou are given an integer n. We reorder the digits in any order (including the original order) such that the leading digit is not zero.\n\t\tReturn true if and only if we can do this so that the resulting number is a power of two.\n\t\tExample 1:\n\t\tInput: n = 1\n\t\tOutput: true\n\t\tExample 2:\n\t\tInput: n = 10\n\t\tOutput: false\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 901, - "question": "class Solution:\n def advantageCount(self, nums1: List[int], nums2: List[int]) -> List[int]:\n\t\t\"\"\"\n\t\tYou are given two integer arrays nums1 and nums2 both of the same length. The advantage of nums1 with respect to nums2 is the number of indices i for which nums1[i] > nums2[i].\n\t\tReturn any permutation of nums1 that maximizes its advantage with respect to nums2.\n\t\tExample 1:\n\t\tInput: nums1 = [2,7,11,15], nums2 = [1,10,4,11]\n\t\tOutput: [2,11,7,15]\n\t\tExample 2:\n\t\tInput: nums1 = [12,24,8,32], nums2 = [13,25,32,11]\n\t\tOutput: [24,32,8,12]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 902, - "question": "class Solution:\n def minRefuelStops(self, target: int, startFuel: int, stations: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tA car travels from a starting position to a destination which is target miles east of the starting position.\n\t\tThere are gas stations along the way. The gas stations are represented as an array stations where stations[i] = [positioni, fueli] indicates that the ith gas station is positioni miles east of the starting position and has fueli liters of gas.\n\t\tThe car starts with an infinite tank of gas, which initially has startFuel liters of fuel in it. It uses one liter of gas per one mile that it drives. When the car reaches a gas station, it may stop and refuel, transferring all the gas from the station into the car.\n\t\tReturn the minimum number of refueling stops the car must make in order to reach its destination. If it cannot reach the destination, return -1.\n\t\tNote that if the car reaches a gas station with 0 fuel left, the car can still refuel there. If the car reaches the destination with 0 fuel left, it is still considered to have arrived.\n\t\tExample 1:\n\t\tInput: target = 1, startFuel = 1, stations = []\n\t\tOutput: 0\n\t\tExplanation: We can reach the target without refueling.\n\t\tExample 2:\n\t\tInput: target = 100, startFuel = 1, stations = [[10,100]]\n\t\tOutput: -1\n\t\tExplanation: We can not reach the target (or even the first gas station).\n\t\tExample 3:\n\t\tInput: target = 100, startFuel = 10, stations = [[10,60],[20,30],[30,30],[60,40]]\n\t\tOutput: 2\n\t\tExplanation: We start with 10 liters of fuel.\n\t\tWe drive to position 10, expending 10 liters of fuel. We refuel from 0 liters to 60 liters of gas.\n\t\tThen, we drive from position 10 to position 60 (expending 50 liters of fuel),\n\t\tand refuel from 10 liters to 50 liters of gas. We then drive to and reach the target.\n\t\tWe made 2 refueling stops along the way, so we return 2.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 903, - "question": "class Solution:\n def rand10(self):\n\t\t\"\"\"\n :rtype: int\n\t\tGiven the API rand7() that generates a uniform random integer in the range [1, 7], write a function rand10() that generates a uniform random integer in the range [1, 10]. You can only call the API rand7(), and you shouldn't call any other API. Please do not use a language's built-in random API.\n\t\tEach test case will have one internal argument n, the number of times that your implemented function rand10() will be called while testing. Note that this is not an argument passed to rand10().\n\t\tExample 1:\n\t\tInput: n = 1\n\t\tOutput: [2]\n\t\tExample 2:\n\t\tInput: n = 2\n\t\tOutput: [2,8]\n\t\tExample 3:\n\t\tInput: n = 3\n\t\tOutput: [3,8,10]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 904, - "question": "class Solution:\n def leafSimilar(self, root1: Optional[TreeNode], root2: Optional[TreeNode]) -> bool:\n\t\t\"\"\"\n\t\tConsider all the leaves of a binary tree, from left to right order, the values of those leaves form a leaf value sequence.\n\t\tFor example, in the given tree above, the leaf value sequence is (6, 7, 4, 9, 8).\n\t\tTwo binary trees are considered leaf-similar if their leaf value sequence is the same.\n\t\tReturn true if and only if the two given trees with head nodes root1 and root2 are leaf-similar.\n\t\tExample 1:\n\t\tInput: root1 = [3,5,1,6,2,9,8,null,null,7,4], root2 = [3,5,1,6,7,4,2,null,null,null,null,null,null,9,8]\n\t\tOutput: true\n\t\tExample 2:\n\t\tInput: root1 = [1,2,3], root2 = [1,3,2]\n\t\tOutput: false\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 905, - "question": "class Solution:\n def lenLongestFibSubseq(self, arr: List[int]) -> int:\n\t\t\"\"\"\n\t\tA sequence x1, x2, ..., xn is Fibonacci-like if:\n\t\t\tn >= 3\n\t\t\txi + xi+1 == xi+2 for all i + 2 <= n\n\t\tGiven a strictly increasing array arr of positive integers forming a sequence, return the length of the longest Fibonacci-like subsequence of arr. If one does not exist, return 0.\n\t\tA subsequence is derived from another sequence arr by deleting any number of elements (including none) from arr, without changing the order of the remaining elements. For example, [3, 5, 8] is a subsequence of [3, 4, 5, 6, 7, 8].\n\t\tExample 1:\n\t\tInput: arr = [1,2,3,4,5,6,7,8]\n\t\tOutput: 5\n\t\tExplanation: The longest subsequence that is fibonacci-like: [1,2,3,5,8].\n\t\tExample 2:\n\t\tInput: arr = [1,3,7,11,12,14,18]\n\t\tOutput: 3\n\t\tExplanation: The longest subsequence that is fibonacci-like: [1,11,12], [3,11,14] or [7,11,18].\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 906, - "question": "class Solution:\n def robotSim(self, commands: List[int], obstacles: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tA robot on an infinite XY-plane starts at point (0, 0) facing north. The robot can receive a sequence of these three possible types of commands:\n\t\t\t-2: Turn left 90 degrees.\n\t\t\t-1: Turn right 90 degrees.\n\t\t\t1 <= k <= 9: Move forward k units, one unit at a time.\n\t\tSome of the grid squares are obstacles. The ith obstacle is at grid point obstacles[i] = (xi, yi). If the robot runs into an obstacle, then it will instead stay in its current location and move on to the next command.\n\t\tReturn the maximum Euclidean distance that the robot ever gets from the origin squared (i.e. if the distance is 5, return 25).\n\t\tNote:\n\t\t\tNorth means +Y direction.\n\t\t\tEast means +X direction.\n\t\t\tSouth means -Y direction.\n\t\t\tWest means -X direction.\n\t\tExample 1:\n\t\tInput: commands = [4,-1,3], obstacles = []\n\t\tOutput: 25\n\t\tExplanation: The robot starts at (0, 0):\n\t\t1. Move north 4 units to (0, 4).\n\t\t2. Turn right.\n\t\t3. Move east 3 units to (3, 4).\n\t\tThe furthest point the robot ever gets from the origin is (3, 4), which squared is 32 + 42 = 25 units away.\n\t\tExample 2:\n\t\tInput: commands = [4,-1,4,-2,4], obstacles = [[2,4]]\n\t\tOutput: 65\n\t\tExplanation: The robot starts at (0, 0):\n\t\t1. Move north 4 units to (0, 4).\n\t\t2. Turn right.\n\t\t3. Move east 1 unit and get blocked by the obstacle at (2, 4), robot is at (1, 4).\n\t\t4. Turn left.\n\t\t5. Move north 4 units to (1, 8).\n\t\tThe furthest point the robot ever gets from the origin is (1, 8), which squared is 12 + 82 = 65 units away.\n\t\tExample 3:\n\t\tInput: commands = [6,-1,-1,6], obstacles = []\n\t\tOutput: 36\n\t\tExplanation: The robot starts at (0, 0):\n\t\t1. Move north 6 units to (0, 6).\n\t\t2. Turn right.\n\t\t3. Turn right.\n\t\t4. Move south 6 units to (0, 0).\n\t\tThe furthest point the robot ever gets from the origin is (0, 6), which squared is 62 = 36 units away.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 907, - "question": "class Solution:\n def minEatingSpeed(self, piles: List[int], h: int) -> int:\n\t\t\"\"\"\n\t\tKoko loves to eat bananas. There are n piles of bananas, the ith pile has piles[i] bananas. The guards have gone and will come back in h hours.\n\t\tKoko can decide her bananas-per-hour eating speed of k. Each hour, she chooses some pile of bananas and eats k bananas from that pile. If the pile has less than k bananas, she eats all of them instead and will not eat any more bananas during this hour.\n\t\tKoko likes to eat slowly but still wants to finish eating all the bananas before the guards return.\n\t\tReturn the minimum integer k such that she can eat all the bananas within h hours.\n\t\tExample 1:\n\t\tInput: piles = [3,6,7,11], h = 8\n\t\tOutput: 4\n\t\tExample 2:\n\t\tInput: piles = [30,11,23,4,20], h = 5\n\t\tOutput: 30\n\t\tExample 3:\n\t\tInput: piles = [30,11,23,4,20], h = 6\n\t\tOutput: 23\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 908, - "question": "class Solution:\n def middleNode(self, head: Optional[ListNode]) -> Optional[ListNode]:\n\t\t\"\"\"\n\t\tGiven the head of a singly linked list, return the middle node of the linked list.\n\t\tIf there are two middle nodes, return the second middle node.\n\t\tExample 1:\n\t\tInput: head = [1,2,3,4,5]\n\t\tOutput: [3,4,5]\n\t\tExplanation: The middle node of the list is node 3.\n\t\tExample 2:\n\t\tInput: head = [1,2,3,4,5,6]\n\t\tOutput: [4,5,6]\n\t\tExplanation: Since the list has two middle nodes with values 3 and 4, we return the second one.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 909, - "question": "class Solution:\n def stoneGame(self, piles: List[int]) -> bool:\n\t\t\"\"\"\n\t\tAlice and Bob play a game with piles of stones. There are an even number of piles arranged in a row, and each pile has a positive integer number of stones piles[i].\n\t\tThe objective of the game is to end with the most stones. The total number of stones across all the piles is odd, so there are no ties.\n\t\tAlice and Bob take turns, with Alice starting first. Each turn, a player takes the entire pile of stones either from the beginning or from the end of the row. This continues until there are no more piles left, at which point the person with the most stones wins.\n\t\tAssuming Alice and Bob play optimally, return true if Alice wins the game, or false if Bob wins.\n\t\tExample 1:\n\t\tInput: piles = [5,3,4,5]\n\t\tOutput: true\n\t\tExplanation: \n\t\tAlice starts first, and can only take the first 5 or the last 5.\n\t\tSay she takes the first 5, so that the row becomes [3, 4, 5].\n\t\tIf Bob takes 3, then the board is [4, 5], and Alice takes 5 to win with 10 points.\n\t\tIf Bob takes the last 5, then the board is [3, 4], and Alice takes 4 to win with 9 points.\n\t\tThis demonstrated that taking the first 5 was a winning move for Alice, so we return true.\n\t\tExample 2:\n\t\tInput: piles = [3,7,2,3]\n\t\tOutput: true\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 910, - "question": "class Solution:\n def nthMagicalNumber(self, n: int, a: int, b: int) -> int:\n\t\t\"\"\"\n\t\tA positive integer is magical if it is divisible by either a or b.\n\t\tGiven the three integers n, a, and b, return the nth magical number. Since the answer may be very large, return it modulo 109 + 7.\n\t\tExample 1:\n\t\tInput: n = 1, a = 2, b = 3\n\t\tOutput: 2\n\t\tExample 2:\n\t\tInput: n = 4, a = 2, b = 3\n\t\tOutput: 6\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 911, - "question": "class Solution:\n def profitableSchemes(self, n: int, minProfit: int, group: List[int], profit: List[int]) -> int:\n\t\t\"\"\"\n\t\tThere is a group of n members, and a list of various crimes they could commit. The ith crime generates a profit[i] and requires group[i] members to participate in it. If a member participates in one crime, that member can't participate in another crime.\n\t\tLet's call a profitable scheme any subset of these crimes that generates at least minProfit profit, and the total number of members participating in that subset of crimes is at most n.\n\t\tReturn the number of schemes that can be chosen. Since the answer may be very large, return it modulo 109 + 7.\n\t\tExample 1:\n\t\tInput: n = 5, minProfit = 3, group = [2,2], profit = [2,3]\n\t\tOutput: 2\n\t\tExplanation: To make a profit of at least 3, the group could either commit crimes 0 and 1, or just crime 1.\n\t\tIn total, there are 2 schemes.\n\t\tExample 2:\n\t\tInput: n = 10, minProfit = 5, group = [2,3,5], profit = [6,7,8]\n\t\tOutput: 7\n\t\tExplanation: To make a profit of at least 5, the group could commit any crimes, as long as they commit one.\n\t\tThere are 7 possible schemes: (0), (1), (2), (0,1), (0,2), (1,2), and (0,1,2).\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 912, - "question": "class Solution:\n def __init__(self, w: List[int]):\n def pickIndex(self) -> int:\n\t\t\"\"\"\n\t\tYou are given a 0-indexed array of positive integers w where w[i] describes the weight of the ith index.\n\t\tYou need to implement the function pickIndex(), which randomly picks an index in the range [0, w.length - 1] (inclusive) and returns it. The probability of picking an index i is w[i] / sum(w).\n\t\t\tFor example, if w = [1, 3], the probability of picking index 0 is 1 / (1 + 3) = 0.25 (i.e., 25%), and the probability of picking index 1 is 3 / (1 + 3) = 0.75 (i.e., 75%).\n\t\tExample 1:\n\t\tInput\n\t\t[\"Solution\",\"pickIndex\"]\n\t\t[[[1]],[]]\n\t\tOutput\n\t\t[null,0]\n\t\tExplanation\n\t\tSolution solution = new Solution([1]);\n\t\tsolution.pickIndex(); // return 0. The only option is to return 0 since there is only one element in w.\n\t\tExample 2:\n\t\tInput\n\t\t[\"Solution\",\"pickIndex\",\"pickIndex\",\"pickIndex\",\"pickIndex\",\"pickIndex\"]\n\t\t[[[1,3]],[],[],[],[],[]]\n\t\tOutput\n\t\t[null,1,1,1,1,0]\n\t\tExplanation\n\t\tSolution solution = new Solution([1, 3]);\n\t\tsolution.pickIndex(); // return 1. It is returning the second element (index = 1) that has a probability of 3/4.\n\t\tsolution.pickIndex(); // return 1\n\t\tsolution.pickIndex(); // return 1\n\t\tsolution.pickIndex(); // return 1\n\t\tsolution.pickIndex(); // return 0. It is returning the first element (index = 0) that has a probability of 1/4.\n\t\tSince this is a randomization problem, multiple answers are allowed.\n\t\tAll of the following outputs can be considered correct:\n\t\t[null,1,1,1,1,0]\n\t\t[null,1,1,1,1,1]\n\t\t[null,1,1,1,0,0]\n\t\t[null,1,1,1,0,1]\n\t\t[null,1,0,1,0,0]\n\t\t......\n\t\tand so on.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 913, - "question": "class Solution:\n def __init__(self, m: int, n: int):\n def flip(self) -> List[int]:\n def reset(self) -> None:\n\t\t\"\"\"\n\t\tThere is an m x n binary grid matrix with all the values set 0 initially. Design an algorithm to randomly pick an index (i, j) where matrix[i][j] == 0 and flips it to 1. All the indices (i, j) where matrix[i][j] == 0 should be equally likely to be returned.\n\t\tOptimize your algorithm to minimize the number of calls made to the built-in random function of your language and optimize the time and space complexity.\n\t\tImplement the Solution class:\n\t\t\tSolution(int m, int n) Initializes the object with the size of the binary matrix m and n.\n\t\t\tint[] flip() Returns a random index [i, j] of the matrix where matrix[i][j] == 0 and flips it to 1.\n\t\t\tvoid reset() Resets all the values of the matrix to be 0.\n\t\tExample 1:\n\t\tInput\n\t\t[\"Solution\", \"flip\", \"flip\", \"flip\", \"reset\", \"flip\"]\n\t\t[[3, 1], [], [], [], [], []]\n\t\tOutput\n\t\t[null, [1, 0], [2, 0], [0, 0], null, [2, 0]]\n\t\tExplanation\n\t\tSolution solution = new Solution(3, 1);\n\t\tsolution.flip(); // return [1, 0], [0,0], [1,0], and [2,0] should be equally likely to be returned.\n\t\tsolution.flip(); // return [2, 0], Since [1,0] was returned, [2,0] and [0,0]\n\t\tsolution.flip(); // return [0, 0], Based on the previously returned indices, only [0,0] can be returned.\n\t\tsolution.reset(); // All the values are reset to 0 and can be returned.\n\t\tsolution.flip(); // return [2, 0], [0,0], [1,0], and [2,0] should be equally likely to be returned.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 914, - "question": "class Solution:\n def __init__(self, rects: List[List[int]]):\n def pick(self) -> List[int]:\n\t\t\"\"\"\n\t\tYou are given an array of non-overlapping axis-aligned rectangles rects where rects[i] = [ai, bi, xi, yi] indicates that (ai, bi) is the bottom-left corner point of the ith rectangle and (xi, yi) is the top-right corner point of the ith rectangle. Design an algorithm to pick a random integer point inside the space covered by one of the given rectangles. A point on the perimeter of a rectangle is included in the space covered by the rectangle.\n\t\tAny integer point inside the space covered by one of the given rectangles should be equally likely to be returned.\n\t\tNote that an integer point is a point that has integer coordinates.\n\t\tImplement the Solution class:\n\t\t\tSolution(int[][] rects) Initializes the object with the given rectangles rects.\n\t\t\tint[] pick() Returns a random integer point [u, v] inside the space covered by one of the given rectangles.\n\t\tExample 1:\n\t\tInput\n\t\t[\"Solution\", \"pick\", \"pick\", \"pick\", \"pick\", \"pick\"]\n\t\t[[[[-2, -2, 1, 1], [2, 2, 4, 6]]], [], [], [], [], []]\n\t\tOutput\n\t\t[null, [1, -2], [1, -1], [-1, -2], [-2, -2], [0, 0]]\n\t\tExplanation\n\t\tSolution solution = new Solution([[-2, -2, 1, 1], [2, 2, 4, 6]]);\n\t\tsolution.pick(); // return [1, -2]\n\t\tsolution.pick(); // return [1, -1]\n\t\tsolution.pick(); // return [-1, -2]\n\t\tsolution.pick(); // return [-2, -2]\n\t\tsolution.pick(); // return [0, 0]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 915, - "question": "class Solution:\n def __init__(self, radius: float, x_center: float, y_center: float):\n def randPoint(self) -> List[float]:\n\t\t\"\"\"\n\t\tGiven the radius and the position of the center of a circle, implement the function randPoint which generates a uniform random point inside the circle.\n\t\tImplement the Solution class:\n\t\t\tSolution(double radius, double x_center, double y_center) initializes the object with the radius of the circle radius and the position of the center (x_center, y_center).\n\t\t\trandPoint() returns a random point inside the circle. A point on the circumference of the circle is considered to be in the circle. The answer is returned as an array [x, y].\n\t\tExample 1:\n\t\tInput\n\t\t[\"Solution\", \"randPoint\", \"randPoint\", \"randPoint\"]\n\t\t[[1.0, 0.0, 0.0], [], [], []]\n\t\tOutput\n\t\t[null, [-0.02493, -0.38077], [0.82314, 0.38945], [0.36572, 0.17248]]\n\t\tExplanation\n\t\tSolution solution = new Solution(1.0, 0.0, 0.0);\n\t\tsolution.randPoint(); // return [-0.02493, -0.38077]\n\t\tsolution.randPoint(); // return [0.82314, 0.38945]\n\t\tsolution.randPoint(); // return [0.36572, 0.17248]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 916, - "question": "class Solution:\n def decodeAtIndex(self, s: str, k: int) -> str:\n\t\t\"\"\"\n\t\tYou are given an encoded string s. To decode the string to a tape, the encoded string is read one character at a time and the following steps are taken:\n\t\t\tIf the character read is a letter, that letter is written onto the tape.\n\t\t\tIf the character read is a digit d, the entire current tape is repeatedly written d - 1 more times in total.\n\t\tGiven an integer k, return the kth letter (1-indexed) in the decoded string.\n\t\tExample 1:\n\t\tInput: s = \"leet2code3\", k = 10\n\t\tOutput: \"o\"\n\t\tExplanation: The decoded string is \"leetleetcodeleetleetcodeleetleetcode\".\n\t\tThe 10th letter in the string is \"o\".\n\t\tExample 2:\n\t\tInput: s = \"ha22\", k = 5\n\t\tOutput: \"h\"\n\t\tExplanation: The decoded string is \"hahahaha\".\n\t\tThe 5th letter is \"h\".\n\t\tExample 3:\n\t\tInput: s = \"a2345678999999999999999\", k = 1\n\t\tOutput: \"a\"\n\t\tExplanation: The decoded string is \"a\" repeated 8301530446056247680 times.\n\t\tThe 1st letter is \"a\".\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 917, - "question": "class Solution:\n def numRescueBoats(self, people: List[int], limit: int) -> int:\n\t\t\"\"\"\n\t\tYou are given an array people where people[i] is the weight of the ith person, and an infinite number of boats where each boat can carry a maximum weight of limit. Each boat carries at most two people at the same time, provided the sum of the weight of those people is at most limit.\n\t\tReturn the minimum number of boats to carry every given person.\n\t\tExample 1:\n\t\tInput: people = [1,2], limit = 3\n\t\tOutput: 1\n\t\tExplanation: 1 boat (1, 2)\n\t\tExample 2:\n\t\tInput: people = [3,2,2,1], limit = 3\n\t\tOutput: 3\n\t\tExplanation: 3 boats (1, 2), (2) and (3)\n\t\tExample 3:\n\t\tInput: people = [3,5,3,4], limit = 5\n\t\tOutput: 4\n\t\tExplanation: 4 boats (3), (3), (4), (5)\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 918, - "question": "class Solution:\n def reachableNodes(self, edges: List[List[int]], maxMoves: int, n: int) -> int:\n\t\t\"\"\"\n\t\tYou are given an undirected graph (the \"original graph\") with n nodes labeled from 0 to n - 1. You decide to subdivide each edge in the graph into a chain of nodes, with the number of new nodes varying between each edge.\n\t\tThe graph is given as a 2D array of edges where edges[i] = [ui, vi, cnti] indicates that there is an edge between nodes ui and vi in the original graph, and cnti is the total number of new nodes that you will subdivide the edge into. Note that cnti == 0 means you will not subdivide the edge.\n\t\tTo subdivide the edge [ui, vi], replace it with (cnti + 1) new edges and cnti new nodes. The new nodes are x1, x2, ..., xcnti, and the new edges are [ui, x1], [x1, x2], [x2, x3], ..., [xcnti-1, xcnti], [xcnti, vi].\n\t\tIn this new graph, you want to know how many nodes are reachable from the node 0, where a node is reachable if the distance is maxMoves or less.\n\t\tGiven the original graph and maxMoves, return the number of nodes that are reachable from node 0 in the new graph.\n\t\tExample 1:\n\t\tInput: edges = [[0,1,10],[0,2,1],[1,2,2]], maxMoves = 6, n = 3\n\t\tOutput: 13\n\t\tExplanation: The edge subdivisions are shown in the image above.\n\t\tThe nodes that are reachable are highlighted in yellow.\n\t\tExample 2:\n\t\tInput: edges = [[0,1,4],[1,2,6],[0,2,8],[1,3,1]], maxMoves = 10, n = 4\n\t\tOutput: 23\n\t\tExample 3:\n\t\tInput: edges = [[1,2,4],[1,4,5],[1,3,1],[2,3,4],[3,4,5]], maxMoves = 17, n = 5\n\t\tOutput: 1\n\t\tExplanation: Node 0 is disconnected from the rest of the graph, so only node 0 is reachable.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 919, - "question": "class Solution:\n def projectionArea(self, grid: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tYou are given an n x n grid where we place some 1 x 1 x 1 cubes that are axis-aligned with the x, y, and z axes.\n\t\tEach value v = grid[i][j] represents a tower of v cubes placed on top of the cell (i, j).\n\t\tWe view the projection of these cubes onto the xy, yz, and zx planes.\n\t\tA projection is like a shadow, that maps our 3-dimensional figure to a 2-dimensional plane. We are viewing the \"shadow\" when looking at the cubes from the top, the front, and the side.\n\t\tReturn the total area of all three projections.\n\t\tExample 1:\n\t\tInput: grid = [[1,2],[3,4]]\n\t\tOutput: 17\n\t\tExplanation: Here are the three projections (\"shadows\") of the shape made with each axis-aligned plane.\n\t\tExample 2:\n\t\tInput: grid = [[2]]\n\t\tOutput: 5\n\t\tExample 3:\n\t\tInput: grid = [[1,0],[0,2]]\n\t\tOutput: 8\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 920, - "question": "class Solution:\n def uncommonFromSentences(self, s1: str, s2: str) -> List[str]:\n\t\t\"\"\"\n\t\tA sentence is a string of single-space separated words where each word consists only of lowercase letters.\n\t\tA word is uncommon if it appears exactly once in one of the sentences, and does not appear in the other sentence.\n\t\tGiven two sentences s1 and s2, return a list of all the uncommon words. You may return the answer in any order.\n\t\tExample 1:\n\t\tInput: s1 = \"this apple is sweet\", s2 = \"this apple is sour\"\n\t\tOutput: [\"sweet\",\"sour\"]\n\t\tExample 2:\n\t\tInput: s1 = \"apple apple\", s2 = \"banana\"\n\t\tOutput: [\"banana\"]\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 921, - "question": "class Solution:\n def spiralMatrixIII(self, rows: int, cols: int, rStart: int, cStart: int) -> List[List[int]]:\n\t\t\"\"\"\n\t\tYou start at the cell (rStart, cStart) of an rows x cols grid facing east. The northwest corner is at the first row and column in the grid, and the southeast corner is at the last row and column.\n\t\tYou will walk in a clockwise spiral shape to visit every position in this grid. Whenever you move outside the grid's boundary, we continue our walk outside the grid (but may return to the grid boundary later.). Eventually, we reach all rows * cols spaces of the grid.\n\t\tReturn an array of coordinates representing the positions of the grid in the order you visited them.\n\t\tExample 1:\n\t\tInput: rows = 1, cols = 4, rStart = 0, cStart = 0\n\t\tOutput: [[0,0],[0,1],[0,2],[0,3]]\n\t\tExample 2:\n\t\tInput: rows = 5, cols = 6, rStart = 1, cStart = 4\n\t\tOutput: [[1,4],[1,5],[2,5],[2,4],[2,3],[1,3],[0,3],[0,4],[0,5],[3,5],[3,4],[3,3],[3,2],[2,2],[1,2],[0,2],[4,5],[4,4],[4,3],[4,2],[4,1],[3,1],[2,1],[1,1],[0,1],[4,0],[3,0],[2,0],[1,0],[0,0]]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 922, - "question": "class Solution:\n def possibleBipartition(self, n: int, dislikes: List[List[int]]) -> bool:\n\t\t\"\"\"\n\t\tWe want to split a group of n people (labeled from 1 to n) into two groups of any size. Each person may dislike some other people, and they should not go into the same group.\n\t\tGiven the integer n and the array dislikes where dislikes[i] = [ai, bi] indicates that the person labeled ai does not like the person labeled bi, return true if it is possible to split everyone into two groups in this way.\n\t\tExample 1:\n\t\tInput: n = 4, dislikes = [[1,2],[1,3],[2,4]]\n\t\tOutput: true\n\t\tExplanation: The first group has [1,4], and the second group has [2,3].\n\t\tExample 2:\n\t\tInput: n = 3, dislikes = [[1,2],[1,3],[2,3]]\n\t\tOutput: false\n\t\tExplanation: We need at least 3 groups to divide them. We cannot put them in two groups.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 923, - "question": "class Solution:\n def superEggDrop(self, k: int, n: int) -> int:\n\t\t\"\"\"\n\t\tYou are given k identical eggs and you have access to a building with n floors labeled from 1 to n.\n\t\tYou know that there exists a floor f where 0 <= f <= n such that any egg dropped at a floor higher than f will break, and any egg dropped at or below floor f will not break.\n\t\tEach move, you may take an unbroken egg and drop it from any floor x (where 1 <= x <= n). If the egg breaks, you can no longer use it. However, if the egg does not break, you may reuse it in future moves.\n\t\tReturn the minimum number of moves that you need to determine with certainty what the value of f is.\n\t\tExample 1:\n\t\tInput: k = 1, n = 2\n\t\tOutput: 2\n\t\tExplanation: \n\t\tDrop the egg from floor 1. If it breaks, we know that f = 0.\n\t\tOtherwise, drop the egg from floor 2. If it breaks, we know that f = 1.\n\t\tIf it does not break, then we know f = 2.\n\t\tHence, we need at minimum 2 moves to determine with certainty what the value of f is.\n\t\tExample 2:\n\t\tInput: k = 2, n = 6\n\t\tOutput: 3\n\t\tExample 3:\n\t\tInput: k = 3, n = 14\n\t\tOutput: 4\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 924, - "question": "class Solution:\n def fairCandySwap(self, aliceSizes: List[int], bobSizes: List[int]) -> List[int]:\n\t\t\"\"\"\n\t\tAlice and Bob have a different total number of candies. You are given two integer arrays aliceSizes and bobSizes where aliceSizes[i] is the number of candies of the ith box of candy that Alice has and bobSizes[j] is the number of candies of the jth box of candy that Bob has.\n\t\tSince they are friends, they would like to exchange one candy box each so that after the exchange, they both have the same total amount of candy. The total amount of candy a person has is the sum of the number of candies in each box they have.\n\t\tReturn an integer array answer where answer[0] is the number of candies in the box that Alice must exchange, and answer[1] is the number of candies in the box that Bob must exchange. If there are multiple answers, you may return any one of them. It is guaranteed that at least one answer exists.\n\t\tExample 1:\n\t\tInput: aliceSizes = [1,1], bobSizes = [2,2]\n\t\tOutput: [1,2]\n\t\tExample 2:\n\t\tInput: aliceSizes = [1,2], bobSizes = [2,3]\n\t\tOutput: [1,2]\n\t\tExample 3:\n\t\tInput: aliceSizes = [2], bobSizes = [1,3]\n\t\tOutput: [2,3]\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 925, - "question": "class Solution:\n def constructFromPrePost(self, preorder: List[int], postorder: List[int]) -> Optional[TreeNode]:\n\t\t\"\"\"\n\t\tGiven two integer arrays, preorder and postorder where preorder is the preorder traversal of a binary tree of distinct values and postorder is the postorder traversal of the same tree, reconstruct and return the binary tree.\n\t\tIf there exist multiple answers, you can return any of them.\n\t\tExample 1:\n\t\tInput: preorder = [1,2,4,5,3,6,7], postorder = [4,5,2,6,7,3,1]\n\t\tOutput: [1,2,3,4,5,6,7]\n\t\tExample 2:\n\t\tInput: preorder = [1], postorder = [1]\n\t\tOutput: [1]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 926, - "question": "class Solution:\n def findAndReplacePattern(self, words: List[str], pattern: str) -> List[str]:\n\t\t\"\"\"\n\t\tGiven a list of strings words and a string pattern, return a list of words[i] that match pattern. You may return the answer in any order.\n\t\tA word matches the pattern if there exists a permutation of letters p so that after replacing every letter x in the pattern with p(x), we get the desired word.\n\t\tRecall that a permutation of letters is a bijection from letters to letters: every letter maps to another letter, and no two letters map to the same letter.\n\t\tExample 1:\n\t\tInput: words = [\"abc\",\"deq\",\"mee\",\"aqq\",\"dkd\",\"ccc\"], pattern = \"abb\"\n\t\tOutput: [\"mee\",\"aqq\"]\n\t\tExplanation: \"mee\" matches the pattern because there is a permutation {a -> m, b -> e, ...}. \n\t\t\"ccc\" does not match the pattern because {a -> c, b -> c, ...} is not a permutation, since a and b map to the same letter.\n\t\tExample 2:\n\t\tInput: words = [\"a\",\"b\",\"c\"], pattern = \"a\"\n\t\tOutput: [\"a\",\"b\",\"c\"]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 927, - "question": "class Solution:\n def sumSubseqWidths(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tThe width of a sequence is the difference between the maximum and minimum elements in the sequence.\n\t\tGiven an array of integers nums, return the sum of the widths of all the non-empty subsequences of nums. Since the answer may be very large, return it modulo 109 + 7.\n\t\tA subsequence is a sequence that can be derived from an array by deleting some or no elements without changing the order of the remaining elements. For example, [3,6,2,7] is a subsequence of the array [0,3,1,6,2,2,7].\n\t\tExample 1:\n\t\tInput: nums = [2,1,3]\n\t\tOutput: 6\n\t\tExplanation: The subsequences are [1], [2], [3], [2,1], [2,3], [1,3], [2,1,3].\n\t\tThe corresponding widths are 0, 0, 0, 1, 1, 2, 2.\n\t\tThe sum of these widths is 6.\n\t\tExample 2:\n\t\tInput: nums = [2]\n\t\tOutput: 0\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 928, - "question": "class Solution:\n def surfaceArea(self, grid: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tYou are given an n x n grid where you have placed some 1 x 1 x 1 cubes. Each value v = grid[i][j] represents a tower of v cubes placed on top of cell (i, j).\n\t\tAfter placing these cubes, you have decided to glue any directly adjacent cubes to each other, forming several irregular 3D shapes.\n\t\tReturn the total surface area of the resulting shapes.\n\t\tNote: The bottom face of each shape counts toward its surface area.\n\t\tExample 1:\n\t\tInput: grid = [[1,2],[3,4]]\n\t\tOutput: 34\n\t\tExample 2:\n\t\tInput: grid = [[1,1,1],[1,0,1],[1,1,1]]\n\t\tOutput: 32\n\t\tExample 3:\n\t\tInput: grid = [[2,2,2],[2,1,2],[2,2,2]]\n\t\tOutput: 46\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 929, - "question": "class Solution:\n def numSpecialEquivGroups(self, words: List[str]) -> int:\n\t\t\"\"\"\n\t\tYou are given an array of strings of the same length words.\n\t\tIn one move, you can swap any two even indexed characters or any two odd indexed characters of a string words[i].\n\t\tTwo strings words[i] and words[j] are special-equivalent if after any number of moves, words[i] == words[j].\n\t\t\tFor example, words[i] = \"zzxy\" and words[j] = \"xyzz\" are special-equivalent because we may make the moves \"zzxy\" -> \"xzzy\" -> \"xyzz\".\n\t\tA group of special-equivalent strings from words is a non-empty subset of words such that:\n\t\t\tEvery pair of strings in the group are special equivalent, and\n\t\t\tThe group is the largest size possible (i.e., there is not a string words[i] not in the group such that words[i] is special-equivalent to every string in the group).\n\t\tReturn the number of groups of special-equivalent strings from words.\n\t\tExample 1:\n\t\tInput: words = [\"abcd\",\"cdab\",\"cbad\",\"xyzz\",\"zzxy\",\"zzyx\"]\n\t\tOutput: 3\n\t\tExplanation: \n\t\tOne group is [\"abcd\", \"cdab\", \"cbad\"], since they are all pairwise special equivalent, and none of the other strings is all pairwise special equivalent to these.\n\t\tThe other two groups are [\"xyzz\", \"zzxy\"] and [\"zzyx\"].\n\t\tNote that in particular, \"zzxy\" is not special equivalent to \"zzyx\".\n\t\tExample 2:\n\t\tInput: words = [\"abc\",\"acb\",\"bac\",\"bca\",\"cab\",\"cba\"]\n\t\tOutput: 3\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 930, - "question": "class Solution:\n def allPossibleFBT(self, n: int) -> List[Optional[TreeNode]]:\n\t\t\"\"\"\n\t\tGiven an integer n, return a list of all possible full binary trees with n nodes. Each node of each tree in the answer must have Node.val == 0.\n\t\tEach element of the answer is the root node of one possible tree. You may return the final list of trees in any order.\n\t\tA full binary tree is a binary tree where each node has exactly 0 or 2 children.\n\t\tExample 1:\n\t\tInput: n = 7\n\t\tOutput: [[0,0,0,null,null,0,0,null,null,0,0],[0,0,0,null,null,0,0,0,0],[0,0,0,0,0,0,0],[0,0,0,0,0,null,null,null,null,0,0],[0,0,0,0,0,null,null,0,0]]\n\t\tExample 2:\n\t\tInput: n = 3\n\t\tOutput: [[0,0,0]]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 931, - "question": "class FreqStack:\n def __init__(self):\n def push(self, val: int) -> None:\n def pop(self) -> int:\n\t\t\"\"\"\n\t\tDesign a stack-like data structure to push elements to the stack and pop the most frequent element from the stack.\n\t\tImplement the FreqStack class:\n\t\t\tFreqStack() constructs an empty frequency stack.\n\t\t\tvoid push(int val) pushes an integer val onto the top of the stack.\n\t\t\tint pop() removes and returns the most frequent element in the stack.\n\t\t\t\tIf there is a tie for the most frequent element, the element closest to the stack's top is removed and returned.\n\t\tExample 1:\n\t\tInput\n\t\t[\"FreqStack\", \"push\", \"push\", \"push\", \"push\", \"push\", \"push\", \"pop\", \"pop\", \"pop\", \"pop\"]\n\t\t[[], [5], [7], [5], [7], [4], [5], [], [], [], []]\n\t\tOutput\n\t\t[null, null, null, null, null, null, null, 5, 7, 5, 4]\n\t\tExplanation\n\t\tFreqStack freqStack = new FreqStack();\n\t\tfreqStack.push(5); // The stack is [5]\n\t\tfreqStack.push(7); // The stack is [5,7]\n\t\tfreqStack.push(5); // The stack is [5,7,5]\n\t\tfreqStack.push(7); // The stack is [5,7,5,7]\n\t\tfreqStack.push(4); // The stack is [5,7,5,7,4]\n\t\tfreqStack.push(5); // The stack is [5,7,5,7,4,5]\n\t\tfreqStack.pop(); // return 5, as 5 is the most frequent. The stack becomes [5,7,5,7,4].\n\t\tfreqStack.pop(); // return 7, as 5 and 7 is the most frequent, but 7 is closest to the top. The stack becomes [5,7,5,4].\n\t\tfreqStack.pop(); // return 5, as 5 is the most frequent. The stack becomes [5,7,4].\n\t\tfreqStack.pop(); // return 4, as 4, 5 and 7 is the most frequent, but 4 is closest to the top. The stack becomes [5,7].\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 932, - "question": "class Solution:\n def isMonotonic(self, nums: List[int]) -> bool:\n\t\t\"\"\"\n\t\tAn array is monotonic if it is either monotone increasing or monotone decreasing.\n\t\tAn array nums is monotone increasing if for all i <= j, nums[i] <= nums[j]. An array nums is monotone decreasing if for all i <= j, nums[i] >= nums[j].\n\t\tGiven an integer array nums, return true if the given array is monotonic, or false otherwise.\n\t\tExample 1:\n\t\tInput: nums = [1,2,2,3]\n\t\tOutput: true\n\t\tExample 2:\n\t\tInput: nums = [6,5,4,4]\n\t\tOutput: true\n\t\tExample 3:\n\t\tInput: nums = [1,3,2]\n\t\tOutput: false\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 933, - "question": "class Solution:\n def increasingBST(self, root: TreeNode) -> TreeNode:\n\t\t\"\"\"\n\t\tGiven the root of a binary search tree, rearrange the tree in in-order so that the leftmost node in the tree is now the root of the tree, and every node has no left child and only one right child.\n\t\tExample 1:\n\t\tInput: root = [5,3,6,2,4,null,8,1,null,null,null,7,9]\n\t\tOutput: [1,null,2,null,3,null,4,null,5,null,6,null,7,null,8,null,9]\n\t\tExample 2:\n\t\tInput: root = [5,1,7]\n\t\tOutput: [1,null,5,null,7]\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 934, - "question": "class Solution:\n def subarrayBitwiseORs(self, arr: List[int]) -> int:\n\t\t\"\"\"\n\t\tGiven an integer array arr, return the number of distinct bitwise ORs of all the non-empty subarrays of arr.\n\t\tThe bitwise OR of a subarray is the bitwise OR of each integer in the subarray. The bitwise OR of a subarray of one integer is that integer.\n\t\tA subarray is a contiguous non-empty sequence of elements within an array.\n\t\tExample 1:\n\t\tInput: arr = [0]\n\t\tOutput: 1\n\t\tExplanation: There is only one possible result: 0.\n\t\tExample 2:\n\t\tInput: arr = [1,1,2]\n\t\tOutput: 3\n\t\tExplanation: The possible subarrays are [1], [1], [2], [1, 1], [1, 2], [1, 1, 2].\n\t\tThese yield the results 1, 1, 2, 1, 3, 3.\n\t\tThere are 3 unique values, so the answer is 3.\n\t\tExample 3:\n\t\tInput: arr = [1,2,4]\n\t\tOutput: 6\n\t\tExplanation: The possible results are 1, 2, 3, 4, 6, and 7.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 935, - "question": "class Solution:\n def orderlyQueue(self, s: str, k: int) -> str:\n\t\t\"\"\"\n\t\tYou are given a string s and an integer k. You can choose one of the first k letters of s and append it at the end of the string..\n\t\tReturn the lexicographically smallest string you could have after applying the mentioned step any number of moves.\n\t\tExample 1:\n\t\tInput: s = \"cba\", k = 1\n\t\tOutput: \"acb\"\n\t\tExplanation: \n\t\tIn the first move, we move the 1st character 'c' to the end, obtaining the string \"bac\".\n\t\tIn the second move, we move the 1st character 'b' to the end, obtaining the final result \"acb\".\n\t\tExample 2:\n\t\tInput: s = \"baaca\", k = 3\n\t\tOutput: \"aaabc\"\n\t\tExplanation: \n\t\tIn the first move, we move the 1st character 'b' to the end, obtaining the string \"aacab\".\n\t\tIn the second move, we move the 3rd character 'c' to the end, obtaining the final result \"aaabc\".\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 936, - "question": "class RLEIterator:\n def __init__(self, encoding: List[int]):\n def next(self, n: int) -> int:\n\t\t\"\"\"\n\t\tWe can use run-length encoding (i.e., RLE) to encode a sequence of integers. In a run-length encoded array of even length encoding (0-indexed), for all even i, encoding[i] tells us the number of times that the non-negative integer value encoding[i + 1] is repeated in the sequence.\n\t\t\tFor example, the sequence arr = [8,8,8,5,5] can be encoded to be encoding = [3,8,2,5]. encoding = [3,8,0,9,2,5] and encoding = [2,8,1,8,2,5] are also valid RLE of arr.\n\t\tGiven a run-length encoded array, design an iterator that iterates through it.\n\t\tImplement the RLEIterator class:\n\t\t\tRLEIterator(int[] encoded) Initializes the object with the encoded array encoded.\n\t\t\tint next(int n) Exhausts the next n elements and returns the last element exhausted in this way. If there is no element left to exhaust, return -1 instead.\n\t\tExample 1:\n\t\tInput\n\t\t[\"RLEIterator\", \"next\", \"next\", \"next\", \"next\"]\n\t\t[[[3, 8, 0, 9, 2, 5]], [2], [1], [1], [2]]\n\t\tOutput\n\t\t[null, 8, 8, 5, -1]\n\t\tExplanation\n\t\tRLEIterator rLEIterator = new RLEIterator([3, 8, 0, 9, 2, 5]); // This maps to the sequence [8,8,8,5,5].\n\t\trLEIterator.next(2); // exhausts 2 terms of the sequence, returning 8. The remaining sequence is now [8, 5, 5].\n\t\trLEIterator.next(1); // exhausts 1 term of the sequence, returning 8. The remaining sequence is now [5, 5].\n\t\trLEIterator.next(1); // exhausts 1 term of the sequence, returning 5. The remaining sequence is now [5].\n\t\trLEIterator.next(2); // exhausts 2 terms, returning -1. This is because the first term exhausted was 5,\n\t\tbut the second term did not exist. Since the last term exhausted does not exist, we return -1.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 937, - "question": "class StockSpanner:\n def __init__(self):\n def next(self, price: int) -> int:\n\t\t\"\"\"\n\t\tDesign an algorithm that collects daily price quotes for some stock and returns the span of that stock's price for the current day.\n\t\tThe span of the stock's price in one day is the maximum number of consecutive days (starting from that day and going backward) for which the stock price was less than or equal to the price of that day.\n\t\t\tFor example, if the prices of the stock in the last four days is [7,2,1,2] and the price of the stock today is 2, then the span of today is 4 because starting from today, the price of the stock was less than or equal 2 for 4 consecutive days.\n\t\t\tAlso, if the prices of the stock in the last four days is [7,34,1,2] and the price of the stock today is 8, then the span of today is 3 because starting from today, the price of the stock was less than or equal 8 for 3 consecutive days.\n\t\tImplement the StockSpanner class:\n\t\t\tStockSpanner() Initializes the object of the class.\n\t\t\tint next(int price) Returns the span of the stock's price given that today's price is price.\n\t\tExample 1:\n\t\tInput\n\t\t[\"StockSpanner\", \"next\", \"next\", \"next\", \"next\", \"next\", \"next\", \"next\"]\n\t\t[[], [100], [80], [60], [70], [60], [75], [85]]\n\t\tOutput\n\t\t[null, 1, 1, 1, 2, 1, 4, 6]\n\t\tExplanation\n\t\tStockSpanner stockSpanner = new StockSpanner();\n\t\tstockSpanner.next(100); // return 1\n\t\tstockSpanner.next(80); // return 1\n\t\tstockSpanner.next(60); // return 1\n\t\tstockSpanner.next(70); // return 2\n\t\tstockSpanner.next(60); // return 1\n\t\tstockSpanner.next(75); // return 4, because the last 4 prices (including today's price of 75) were less than or equal to today's price.\n\t\tstockSpanner.next(85); // return 6\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 938, - "question": "class Solution:\n def atMostNGivenDigitSet(self, digits: List[str], n: int) -> int:\n\t\t\"\"\"\n\t\tGiven an array of digits which is sorted in non-decreasing order. You can write numbers using each digits[i] as many times as we want. For example, if digits = ['1','3','5'], we may write numbers such as '13', '551', and '1351315'.\n\t\tReturn the number of positive integers that can be generated that are less than or equal to a given integer n.\n\t\tExample 1:\n\t\tInput: digits = [\"1\",\"3\",\"5\",\"7\"], n = 100\n\t\tOutput: 20\n\t\tExplanation: \n\t\tThe 20 numbers that can be written are:\n\t\t1, 3, 5, 7, 11, 13, 15, 17, 31, 33, 35, 37, 51, 53, 55, 57, 71, 73, 75, 77.\n\t\tExample 2:\n\t\tInput: digits = [\"1\",\"4\",\"9\"], n = 1000000000\n\t\tOutput: 29523\n\t\tExplanation: \n\t\tWe can write 3 one digit numbers, 9 two digit numbers, 27 three digit numbers,\n\t\t81 four digit numbers, 243 five digit numbers, 729 six digit numbers,\n\t\t2187 seven digit numbers, 6561 eight digit numbers, and 19683 nine digit numbers.\n\t\tIn total, this is 29523 integers that can be written using the digits array.\n\t\tExample 3:\n\t\tInput: digits = [\"7\"], n = 8\n\t\tOutput: 1\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 939, - "question": "class Solution:\n def numPermsDISequence(self, s: str) -> int:\n\t\t\"\"\"\n\t\tYou are given a string s of length n where s[i] is either:\n\t\t\t'D' means decreasing, or\n\t\t\t'I' means increasing.\n\t\tA permutation perm of n + 1 integers of all the integers in the range [0, n] is called a valid permutation if for all valid i:\n\t\t\tIf s[i] == 'D', then perm[i] > perm[i + 1], and\n\t\t\tIf s[i] == 'I', then perm[i] < perm[i + 1].\n\t\tReturn the number of valid permutations perm. Since the answer may be large, return it modulo 109 + 7.\n\t\tExample 1:\n\t\tInput: s = \"DID\"\n\t\tOutput: 5\n\t\tExplanation: The 5 valid permutations of (0, 1, 2, 3) are:\n\t\t(1, 0, 3, 2)\n\t\t(2, 0, 3, 1)\n\t\t(2, 1, 3, 0)\n\t\t(3, 0, 2, 1)\n\t\t(3, 1, 2, 0)\n\t\tExample 2:\n\t\tInput: s = \"D\"\n\t\tOutput: 1\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 940, - "question": "class Solution:\n def totalFruit(self, fruits: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou are visiting a farm that has a single row of fruit trees arranged from left to right. The trees are represented by an integer array fruits where fruits[i] is the type of fruit the ith tree produces.\n\t\tYou want to collect as much fruit as possible. However, the owner has some strict rules that you must follow:\n\t\t\tYou only have two baskets, and each basket can only hold a single type of fruit. There is no limit on the amount of fruit each basket can hold.\n\t\t\tStarting from any tree of your choice, you must pick exactly one fruit from every tree (including the start tree) while moving to the right. The picked fruits must fit in one of your baskets.\n\t\t\tOnce you reach a tree with fruit that cannot fit in your baskets, you must stop.\n\t\tGiven the integer array fruits, return the maximum number of fruits you can pick.\n\t\tExample 1:\n\t\tInput: fruits = [1,2,1]\n\t\tOutput: 3\n\t\tExplanation: We can pick from all 3 trees.\n\t\tExample 2:\n\t\tInput: fruits = [0,1,2,2]\n\t\tOutput: 3\n\t\tExplanation: We can pick from trees [1,2,2].\n\t\tIf we had started at the first tree, we would only pick from trees [0,1].\n\t\tExample 3:\n\t\tInput: fruits = [1,2,3,2,2]\n\t\tOutput: 4\n\t\tExplanation: We can pick from trees [2,3,2,2].\n\t\tIf we had started at the first tree, we would only pick from trees [1,2].\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 941, - "question": "class Solution:\n def sortArrayByParity(self, nums: List[int]) -> List[int]:\n\t\t\"\"\"\n\t\tGiven an integer array nums, move all the even integers at the beginning of the array followed by all the odd integers.\n\t\tReturn any array that satisfies this condition.\n\t\tExample 1:\n\t\tInput: nums = [3,1,2,4]\n\t\tOutput: [2,4,3,1]\n\t\tExplanation: The outputs [4,2,3,1], [2,4,1,3], and [4,2,1,3] would also be accepted.\n\t\tExample 2:\n\t\tInput: nums = [0]\n\t\tOutput: [0]\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 942, - "question": "class Solution:\n def superpalindromesInRange(self, left: str, right: str) -> int:\n\t\t\"\"\"\n\t\tLet's say a positive integer is a super-palindrome if it is a palindrome, and it is also the square of a palindrome.\n\t\tGiven two positive integers left and right represented as strings, return the number of super-palindromes integers in the inclusive range [left, right].\n\t\tExample 1:\n\t\tInput: left = \"4\", right = \"1000\"\n\t\tOutput: 4\n\t\tExplanation: 4, 9, 121, and 484 are superpalindromes.\n\t\tNote that 676 is not a superpalindrome: 26 * 26 = 676, but 26 is not a palindrome.\n\t\tExample 2:\n\t\tInput: left = \"1\", right = \"2\"\n\t\tOutput: 1\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 943, - "question": "class Solution:\n def sumSubarrayMins(self, arr: List[int]) -> int:\n\t\t\"\"\"\n\t\tGiven an array of integers arr, find the sum of min(b), where b ranges over every (contiguous) subarray of arr. Since the answer may be large, return the answer modulo 109 + 7.\n\t\tExample 1:\n\t\tInput: arr = [3,1,2,4]\n\t\tOutput: 17\n\t\tExplanation: \n\t\tSubarrays are [3], [1], [2], [4], [3,1], [1,2], [2,4], [3,1,2], [1,2,4], [3,1,2,4]. \n\t\tMinimums are 3, 1, 2, 4, 1, 1, 2, 1, 1, 1.\n\t\tSum is 17.\n\t\tExample 2:\n\t\tInput: arr = [11,81,94,43,3]\n\t\tOutput: 444\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 944, - "question": "class Solution:\n def smallestRangeI(self, nums: List[int], k: int) -> int:\n\t\t\"\"\"\n\t\tYou are given an integer array nums and an integer k.\n\t\tIn one operation, you can choose any index i where 0 <= i < nums.length and change nums[i] to nums[i] + x where x is an integer from the range [-k, k]. You can apply this operation at most once for each index i.\n\t\tThe score of nums is the difference between the maximum and minimum elements in nums.\n\t\tReturn the minimum score of nums after applying the mentioned operation at most once for each index in it.\n\t\tExample 1:\n\t\tInput: nums = [1], k = 0\n\t\tOutput: 0\n\t\tExplanation: The score is max(nums) - min(nums) = 1 - 1 = 0.\n\t\tExample 2:\n\t\tInput: nums = [0,10], k = 2\n\t\tOutput: 6\n\t\tExplanation: Change nums to be [2, 8]. The score is max(nums) - min(nums) = 8 - 2 = 6.\n\t\tExample 3:\n\t\tInput: nums = [1,3,6], k = 3\n\t\tOutput: 0\n\t\tExplanation: Change nums to be [4, 4, 4]. The score is max(nums) - min(nums) = 4 - 4 = 0.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 945, - "question": "class Solution:\n def snakesAndLadders(self, board: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tYou are given an n x n integer matrix board where the cells are labeled from 1 to n2 in a Boustrophedon style starting from the bottom left of the board (i.e. board[n - 1][0]) and alternating direction each row.\n\t\tYou start on square 1 of the board. In each move, starting from square curr, do the following:\n\t\t\tChoose a destination square next with a label in the range [curr + 1, min(curr + 6, n2)].\n\t\t\t\tThis choice simulates the result of a standard 6-sided die roll: i.e., there are always at most 6 destinations, regardless of the size of the board.\n\t\t\tIf next has a snake or ladder, you must move to the destination of that snake or ladder. Otherwise, you move to next.\n\t\t\tThe game ends when you reach the square n2.\n\t\tA board square on row r and column c has a snake or ladder if board[r][c] != -1. The destination of that snake or ladder is board[r][c]. Squares 1 and n2 do not have a snake or ladder.\n\t\tNote that you only take a snake or ladder at most once per move. If the destination to a snake or ladder is the start of another snake or ladder, you do not follow the subsequent snake or ladder.\n\t\t\tFor example, suppose the board is [[-1,4],[-1,3]], and on the first move, your destination square is 2. You follow the ladder to square 3, but do not follow the subsequent ladder to 4.\n\t\tReturn the least number of moves required to reach the square n2. If it is not possible to reach the square, return -1.\n\t\tExample 1:\n\t\tInput: board = [[-1,-1,-1,-1,-1,-1],[-1,-1,-1,-1,-1,-1],[-1,-1,-1,-1,-1,-1],[-1,35,-1,-1,13,-1],[-1,-1,-1,-1,-1,-1],[-1,15,-1,-1,-1,-1]]\n\t\tOutput: 4\n\t\tExplanation: \n\t\tIn the beginning, you start at square 1 (at row 5, column 0).\n\t\tYou decide to move to square 2 and must take the ladder to square 15.\n\t\tYou then decide to move to square 17 and must take the snake to square 13.\n\t\tYou then decide to move to square 14 and must take the ladder to square 35.\n\t\tYou then decide to move to square 36, ending the game.\n\t\tThis is the lowest possible number of moves to reach the last square, so return 4.\n\t\tExample 2:\n\t\tInput: board = [[-1,-1],[-1,3]]\n\t\tOutput: 1\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 946, - "question": "class Solution:\n def smallestRangeII(self, nums: List[int], k: int) -> int:\n\t\t\"\"\"\n\t\tYou are given an integer array nums and an integer k.\n\t\tFor each index i where 0 <= i < nums.length, change nums[i] to be either nums[i] + k or nums[i] - k.\n\t\tThe score of nums is the difference between the maximum and minimum elements in nums.\n\t\tReturn the minimum score of nums after changing the values at each index.\n\t\tExample 1:\n\t\tInput: nums = [1], k = 0\n\t\tOutput: 0\n\t\tExplanation: The score is max(nums) - min(nums) = 1 - 1 = 0.\n\t\tExample 2:\n\t\tInput: nums = [0,10], k = 2\n\t\tOutput: 6\n\t\tExplanation: Change nums to be [2, 8]. The score is max(nums) - min(nums) = 8 - 2 = 6.\n\t\tExample 3:\n\t\tInput: nums = [1,3,6], k = 3\n\t\tOutput: 3\n\t\tExplanation: Change nums to be [4, 6, 3]. The score is max(nums) - min(nums) = 6 - 3 = 3.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 947, - "question": "class TopVotedCandidate:\n def __init__(self, persons: List[int], times: List[int]):\n def q(self, t: int) -> int:\n\t\t\"\"\"\n\t\tYou are given two integer arrays persons and times. In an election, the ith vote was cast for persons[i] at time times[i].\n\t\tFor each query at a time t, find the person that was leading the election at time t. Votes cast at time t will count towards our query. In the case of a tie, the most recent vote (among tied candidates) wins.\n\t\tImplement the TopVotedCandidate class:\n\t\t\tTopVotedCandidate(int[] persons, int[] times) Initializes the object with the persons and times arrays.\n\t\t\tint q(int t) Returns the number of the person that was leading the election at time t according to the mentioned rules.\n\t\tExample 1:\n\t\tInput\n\t\t[\"TopVotedCandidate\", \"q\", \"q\", \"q\", \"q\", \"q\", \"q\"]\n\t\t[[[0, 1, 1, 0, 0, 1, 0], [0, 5, 10, 15, 20, 25, 30]], [3], [12], [25], [15], [24], [8]]\n\t\tOutput\n\t\t[null, 0, 1, 1, 0, 0, 1]\n\t\tExplanation\n\t\tTopVotedCandidate topVotedCandidate = new TopVotedCandidate([0, 1, 1, 0, 0, 1, 0], [0, 5, 10, 15, 20, 25, 30]);\n\t\ttopVotedCandidate.q(3); // return 0, At time 3, the votes are [0], and 0 is leading.\n\t\ttopVotedCandidate.q(12); // return 1, At time 12, the votes are [0,1,1], and 1 is leading.\n\t\ttopVotedCandidate.q(25); // return 1, At time 25, the votes are [0,1,1,0,0,1], and 1 is leading (as ties go to the most recent vote.)\n\t\ttopVotedCandidate.q(15); // return 0\n\t\ttopVotedCandidate.q(24); // return 0\n\t\ttopVotedCandidate.q(8); // return 1\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 948, - "question": "class Solution:\n def sortArray(self, nums: List[int]) -> List[int]:\n\t\t\"\"\"\n\t\tGiven an array of integers nums, sort the array in ascending order and return it.\n\t\tYou must solve the problem without using any built-in functions in O(nlog(n)) time complexity and with the smallest space complexity possible.\n\t\tExample 1:\n\t\tInput: nums = [5,2,3,1]\n\t\tOutput: [1,2,3,5]\n\t\tExplanation: After sorting the array, the positions of some numbers are not changed (for example, 2 and 3), while the positions of other numbers are changed (for example, 1 and 5).\n\t\tExample 2:\n\t\tInput: nums = [5,1,1,2,0,0]\n\t\tOutput: [0,0,1,1,2,5]\n\t\tExplanation: Note that the values of nums are not necessairly unique.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 949, - "question": "class Solution:\n def catMouseGame(self, graph: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tA game on an undirected graph is played by two players, Mouse and Cat, who alternate turns.\n\t\tThe graph is given as follows: graph[a] is a list of all nodes b such that ab is an edge of the graph.\n\t\tThe mouse starts at node 1 and goes first, the cat starts at node 2 and goes second, and there is a hole at node 0.\n\t\tDuring each player's turn, they must travel along one edge of the graph that meets where they are. For example, if the Mouse is at node 1, it must travel to any node in graph[1].\n\t\tAdditionally, it is not allowed for the Cat to travel to the Hole (node 0.)\n\t\tThen, the game can end in three ways:\n\t\t\tIf ever the Cat occupies the same node as the Mouse, the Cat wins.\n\t\t\tIf ever the Mouse reaches the Hole, the Mouse wins.\n\t\t\tIf ever a position is repeated (i.e., the players are in the same position as a previous turn, and it is the same player's turn to move), the game is a draw.\n\t\tGiven a graph, and assuming both players play optimally, return\n\t\t\t1 if the mouse wins the game,\n\t\t\t2 if the cat wins the game, or\n\t\t\t0 if the game is a draw.\n\t\tExample 1:\n\t\tInput: graph = [[2,5],[3],[0,4,5],[1,4,5],[2,3],[0,2,3]]\n\t\tOutput: 0\n\t\tExample 2:\n\t\tInput: graph = [[1,3],[0],[3],[0,2]]\n\t\tOutput: 1\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 950, - "question": "class Solution:\n def hasGroupsSizeX(self, deck: List[int]) -> bool:\n\t\t\"\"\"\n\t\tYou are given an integer array deck where deck[i] represents the number written on the ith card.\n\t\tPartition the cards into one or more groups such that:\n\t\t\tEach group has exactly x cards where x > 1, and\n\t\t\tAll the cards in one group have the same integer written on them.\n\t\tReturn true if such partition is possible, or false otherwise.\n\t\tExample 1:\n\t\tInput: deck = [1,2,3,4,4,3,2,1]\n\t\tOutput: true\n\t\tExplanation: Possible partition [1,1],[2,2],[3,3],[4,4].\n\t\tExample 2:\n\t\tInput: deck = [1,1,1,2,2,2,3,3]\n\t\tOutput: false\n\t\tExplanation: No possible partition.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 951, - "question": "class Solution:\n def partitionDisjoint(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tGiven an integer array nums, partition it into two (contiguous) subarrays left and right so that:\n\t\t\tEvery element in left is less than or equal to every element in right.\n\t\t\tleft and right are non-empty.\n\t\t\tleft has the smallest possible size.\n\t\tReturn the length of left after such a partitioning.\n\t\tTest cases are generated such that partitioning exists.\n\t\tExample 1:\n\t\tInput: nums = [5,0,3,8,6]\n\t\tOutput: 3\n\t\tExplanation: left = [5,0,3], right = [8,6]\n\t\tExample 2:\n\t\tInput: nums = [1,1,1,0,6,12]\n\t\tOutput: 4\n\t\tExplanation: left = [1,1,1,0], right = [6,12]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 952, - "question": "class Solution:\n def wordSubsets(self, words1: List[str], words2: List[str]) -> List[str]:\n\t\t\"\"\"\n\t\tYou are given two string arrays words1 and words2.\n\t\tA string b is a subset of string a if every letter in b occurs in a including multiplicity.\n\t\t\tFor example, \"wrr\" is a subset of \"warrior\" but is not a subset of \"world\".\n\t\tA string a from words1 is universal if for every string b in words2, b is a subset of a.\n\t\tReturn an array of all the universal strings in words1. You may return the answer in any order.\n\t\tExample 1:\n\t\tInput: words1 = [\"amazon\",\"apple\",\"facebook\",\"google\",\"leetcode\"], words2 = [\"e\",\"o\"]\n\t\tOutput: [\"facebook\",\"google\",\"leetcode\"]\n\t\tExample 2:\n\t\tInput: words1 = [\"amazon\",\"apple\",\"facebook\",\"google\",\"leetcode\"], words2 = [\"l\",\"e\"]\n\t\tOutput: [\"apple\",\"google\",\"leetcode\"]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 953, - "question": "class Solution:\n def reverseOnlyLetters(self, s: str) -> str:\n\t\t\"\"\"\n\t\tGiven a string s, reverse the string according to the following rules:\n\t\t\tAll the characters that are not English letters remain in the same position.\n\t\t\tAll the English letters (lowercase or uppercase) should be reversed.\n\t\tReturn s after reversing it.\n\t\tExample 1:\n\t\tInput: s = \"ab-cd\"\n\t\tOutput: \"dc-ba\"\n\t\tExample 2:\n\t\tInput: s = \"a-bC-dEf-ghIj\"\n\t\tOutput: \"j-Ih-gfE-dCba\"\n\t\tExample 3:\n\t\tInput: s = \"Test1ng-Leet=code-Q!\"\n\t\tOutput: \"Qedo1ct-eeLg=ntse-T!\"\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 954, - "question": "class Solution:\n def maxSubarraySumCircular(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tGiven a circular integer array nums of length n, return the maximum possible sum of a non-empty subarray of nums.\n\t\tA circular array means the end of the array connects to the beginning of the array. Formally, the next element of nums[i] is nums[(i + 1) % n] and the previous element of nums[i] is nums[(i - 1 + n) % n].\n\t\tA subarray may only include each element of the fixed buffer nums at most once. Formally, for a subarray nums[i], nums[i + 1], ..., nums[j], there does not exist i <= k1, k2 <= j with k1 % n == k2 % n.\n\t\tExample 1:\n\t\tInput: nums = [1,-2,3,-2]\n\t\tOutput: 3\n\t\tExplanation: Subarray [3] has maximum sum 3.\n\t\tExample 2:\n\t\tInput: nums = [5,-3,5]\n\t\tOutput: 10\n\t\tExplanation: Subarray [5,5] has maximum sum 5 + 5 = 10.\n\t\tExample 3:\n\t\tInput: nums = [-3,-2,-3]\n\t\tOutput: -2\n\t\tExplanation: Subarray [-2] has maximum sum -2.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 955, - "question": "class CBTInserter:\n def __init__(self, root: Optional[TreeNode]):\n def insert(self, val: int) -> int:\n def get_root(self) -> Optional[TreeNode]:\n\t\t\"\"\"\n\t\tA complete binary tree is a binary tree in which every level, except possibly the last, is completely filled, and all nodes are as far left as possible.\n\t\tDesign an algorithm to insert a new node to a complete binary tree keeping it complete after the insertion.\n\t\tImplement the CBTInserter class:\n\t\t\tCBTInserter(TreeNode root) Initializes the data structure with the root of the complete binary tree.\n\t\t\tint insert(int v) Inserts a TreeNode into the tree with value Node.val == val so that the tree remains complete, and returns the value of the parent of the inserted TreeNode.\n\t\t\tTreeNode get_root() Returns the root node of the tree.\n\t\tExample 1:\n\t\tInput\n\t\t[\"CBTInserter\", \"insert\", \"insert\", \"get_root\"]\n\t\t[[[1, 2]], [3], [4], []]\n\t\tOutput\n\t\t[null, 1, 2, [1, 2, 3, 4]]\n\t\tExplanation\n\t\tCBTInserter cBTInserter = new CBTInserter([1, 2]);\n\t\tcBTInserter.insert(3); // return 1\n\t\tcBTInserter.insert(4); // return 2\n\t\tcBTInserter.get_root(); // return [1, 2, 3, 4]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 956, - "question": "class Solution:\n def numMusicPlaylists(self, n: int, goal: int, k: int) -> int:\n\t\t\"\"\"\n\t\tYour music player contains n different songs. You want to listen to goal songs (not necessarily different) during your trip. To avoid boredom, you will create a playlist so that:\n\t\t\tEvery song is played at least once.\n\t\t\tA song can only be played again only if k other songs have been played.\n\t\tGiven n, goal, and k, return the number of possible playlists that you can create. Since the answer can be very large, return it modulo 109 + 7.\n\t\tExample 1:\n\t\tInput: n = 3, goal = 3, k = 1\n\t\tOutput: 6\n\t\tExplanation: There are 6 possible playlists: [1, 2, 3], [1, 3, 2], [2, 1, 3], [2, 3, 1], [3, 1, 2], and [3, 2, 1].\n\t\tExample 2:\n\t\tInput: n = 2, goal = 3, k = 0\n\t\tOutput: 6\n\t\tExplanation: There are 6 possible playlists: [1, 1, 2], [1, 2, 1], [2, 1, 1], [2, 2, 1], [2, 1, 2], and [1, 2, 2].\n\t\tExample 3:\n\t\tInput: n = 2, goal = 3, k = 1\n\t\tOutput: 2\n\t\tExplanation: There are 2 possible playlists: [1, 2, 1] and [2, 1, 2].\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 957, - "question": "class Solution:\n def minAddToMakeValid(self, s: str) -> int:\n\t\t\"\"\"\n\t\tA parentheses string is valid if and only if:\n\t\t\tIt is the empty string,\n\t\t\tIt can be written as AB (A concatenated with B), where A and B are valid strings, or\n\t\t\tIt can be written as (A), where A is a valid string.\n\t\tYou are given a parentheses string s. In one move, you can insert a parenthesis at any position of the string.\n\t\t\tFor example, if s = \"()))\", you can insert an opening parenthesis to be \"(()))\" or a closing parenthesis to be \"())))\".\n\t\tReturn the minimum number of moves required to make s valid.\n\t\tExample 1:\n\t\tInput: s = \"())\"\n\t\tOutput: 1\n\t\tExample 2:\n\t\tInput: s = \"(((\"\n\t\tOutput: 3\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 958, - "question": "class Solution:\n def sortArrayByParityII(self, nums: List[int]) -> List[int]:\n\t\t\"\"\"\n\t\tGiven an array of integers nums, half of the integers in nums are odd, and the other half are even.\n\t\tSort the array so that whenever nums[i] is odd, i is odd, and whenever nums[i] is even, i is even.\n\t\tReturn any answer array that satisfies this condition.\n\t\tExample 1:\n\t\tInput: nums = [4,2,5,7]\n\t\tOutput: [4,5,2,7]\n\t\tExplanation: [4,7,2,5], [2,5,4,7], [2,7,4,5] would also have been accepted.\n\t\tExample 2:\n\t\tInput: nums = [2,3]\n\t\tOutput: [2,3]\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 959, - "question": "class Solution:\n def threeSumMulti(self, arr: List[int], target: int) -> int:\n\t\t\"\"\"\n\t\tGiven an integer array arr, and an integer target, return the number of tuples i, j, k such that i < j < k and arr[i] + arr[j] + arr[k] == target.\n\t\tAs the answer can be very large, return it modulo 109 + 7.\n\t\tExample 1:\n\t\tInput: arr = [1,1,2,2,3,3,4,4,5,5], target = 8\n\t\tOutput: 20\n\t\tExplanation: \n\t\tEnumerating by the values (arr[i], arr[j], arr[k]):\n\t\t(1, 2, 5) occurs 8 times;\n\t\t(1, 3, 4) occurs 8 times;\n\t\t(2, 2, 4) occurs 2 times;\n\t\t(2, 3, 3) occurs 2 times.\n\t\tExample 2:\n\t\tInput: arr = [1,1,2,2,2,2], target = 5\n\t\tOutput: 12\n\t\tExplanation: \n\t\tarr[i] = 1, arr[j] = arr[k] = 2 occurs 12 times:\n\t\tWe choose one 1 from [1,1] in 2 ways,\n\t\tand two 2s from [2,2,2,2] in 6 ways.\n\t\tExample 3:\n\t\tInput: arr = [2,1,3], target = 6\n\t\tOutput: 1\n\t\tExplanation: (1, 2, 3) occured one time in the array so we return 1.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 960, - "question": "class Solution:\n def minMalwareSpread(self, graph: List[List[int]], initial: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou are given a network of n nodes represented as an n x n adjacency matrix graph, where the ith node is directly connected to the jth node if graph[i][j] == 1.\n\t\tSome nodes initial are initially infected by malware. Whenever two nodes are directly connected, and at least one of those two nodes is infected by malware, both nodes will be infected by malware. This spread of malware will continue until no more nodes can be infected in this manner.\n\t\tSuppose M(initial) is the final number of nodes infected with malware in the entire network after the spread of malware stops. We will remove exactly one node from initial.\n\t\tReturn the node that, if removed, would minimize M(initial). If multiple nodes could be removed to minimize M(initial), return such a node with the smallest index.\n\t\tNote that if a node was removed from the initial list of infected nodes, it might still be infected later due to the malware spread.\n\t\tExample 1:\n\t\tInput: graph = [[1,1,0],[1,1,0],[0,0,1]], initial = [0,1]\n\t\tOutput: 0\n\t\tExample 2:\n\t\tInput: graph = [[1,0,0],[0,1,0],[0,0,1]], initial = [0,2]\n\t\tOutput: 0\n\t\tExample 3:\n\t\tInput: graph = [[1,1,1],[1,1,1],[1,1,1]], initial = [1,2]\n\t\tOutput: 1\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 961, - "question": "class Solution:\n def isLongPressedName(self, name: str, typed: str) -> bool:\n\t\t\"\"\"\n\t\tYour friend is typing his name into a keyboard. Sometimes, when typing a character c, the key might get long pressed, and the character will be typed 1 or more times.\n\t\tYou examine the typed characters of the keyboard. Return True if it is possible that it was your friends name, with some characters (possibly none) being long pressed.\n\t\tExample 1:\n\t\tInput: name = \"alex\", typed = \"aaleex\"\n\t\tOutput: true\n\t\tExplanation: 'a' and 'e' in 'alex' were long pressed.\n\t\tExample 2:\n\t\tInput: name = \"saeed\", typed = \"ssaaedd\"\n\t\tOutput: false\n\t\tExplanation: 'e' must have been pressed twice, but it was not in the typed output.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 962, - "question": "class Solution:\n def minFlipsMonoIncr(self, s: str) -> int:\n\t\t\"\"\"\n\t\tA binary string is monotone increasing if it consists of some number of 0's (possibly none), followed by some number of 1's (also possibly none).\n\t\tYou are given a binary string s. You can flip s[i] changing it from 0 to 1 or from 1 to 0.\n\t\tReturn the minimum number of flips to make s monotone increasing.\n\t\tExample 1:\n\t\tInput: s = \"00110\"\n\t\tOutput: 1\n\t\tExplanation: We flip the last digit to get 00111.\n\t\tExample 2:\n\t\tInput: s = \"010110\"\n\t\tOutput: 2\n\t\tExplanation: We flip to get 011111, or alternatively 000111.\n\t\tExample 3:\n\t\tInput: s = \"00011000\"\n\t\tOutput: 2\n\t\tExplanation: We flip to get 00000000.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 963, - "question": "class Solution:\n def threeEqualParts(self, arr: List[int]) -> List[int]:\n\t\t\"\"\"\n\t\tYou are given an array arr which consists of only zeros and ones, divide the array into three non-empty parts such that all of these parts represent the same binary value.\n\t\tIf it is possible, return any [i, j] with i + 1 < j, such that:\n\t\t\tarr[0], arr[1], ..., arr[i] is the first part,\n\t\t\tarr[i + 1], arr[i + 2], ..., arr[j - 1] is the second part, and\n\t\t\tarr[j], arr[j + 1], ..., arr[arr.length - 1] is the third part.\n\t\t\tAll three parts have equal binary values.\n\t\tIf it is not possible, return [-1, -1].\n\t\tNote that the entire part is used when considering what binary value it represents. For example, [1,1,0] represents 6 in decimal, not 3. Also, leading zeros are allowed, so [0,1,1] and [1,1] represent the same value.\n\t\tExample 1:\n\t\tInput: arr = [1,0,1,0,1]\n\t\tOutput: [0,3]\n\t\tExample 2:\n\t\tInput: arr = [1,1,0,1,1]\n\t\tOutput: [-1,-1]\n\t\tExample 3:\n\t\tInput: arr = [1,1,0,0,1]\n\t\tOutput: [0,2]\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 964, - "question": "class Solution:\n def minMalwareSpread(self, graph: List[List[int]], initial: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou are given a network of n nodes represented as an n x n adjacency matrix graph, where the ith node is directly connected to the jth node if graph[i][j] == 1.\n\t\tSome nodes initial are initially infected by malware. Whenever two nodes are directly connected, and at least one of those two nodes is infected by malware, both nodes will be infected by malware. This spread of malware will continue until no more nodes can be infected in this manner.\n\t\tSuppose M(initial) is the final number of nodes infected with malware in the entire network after the spread of malware stops.\n\t\tWe will remove exactly one node from initial, completely removing it and any connections from this node to any other node.\n\t\tReturn the node that, if removed, would minimize M(initial). If multiple nodes could be removed to minimize M(initial), return such a node with the smallest index.\n\t\tExample 1:\n\t\tInput: graph = [[1,1,0],[1,1,0],[0,0,1]], initial = [0,1]\n\t\tOutput: 0\n\t\tExample 2:\n\t\tInput: graph = [[1,1,0],[1,1,1],[0,1,1]], initial = [0,1]\n\t\tOutput: 1\n\t\tExample 3:\n\t\tInput: graph = [[1,1,0,0],[1,1,1,0],[0,1,1,1],[0,0,1,1]], initial = [0,1]\n\t\tOutput: 1\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 965, - "question": "class Solution:\n def numUniqueEmails(self, emails: List[str]) -> int:\n\t\t\"\"\"\n\t\tEvery valid email consists of a local name and a domain name, separated by the '@' sign. Besides lowercase letters, the email may contain one or more '.' or '+'.\n\t\t\tFor example, in \"alice@leetcode.com\", \"alice\" is the local name, and \"leetcode.com\" is the domain name.\n\t\tIf you add periods '.' between some characters in the local name part of an email address, mail sent there will be forwarded to the same address without dots in the local name. Note that this rule does not apply to domain names.\n\t\t\tFor example, \"alice.z@leetcode.com\" and \"alicez@leetcode.com\" forward to the same email address.\n\t\tIf you add a plus '+' in the local name, everything after the first plus sign will be ignored. This allows certain emails to be filtered. Note that this rule does not apply to domain names.\n\t\t\tFor example, \"m.y+name@email.com\" will be forwarded to \"my@email.com\".\n\t\tIt is possible to use both of these rules at the same time.\n\t\tGiven an array of strings emails where we send one email to each emails[i], return the number of different addresses that actually receive mails.\n\t\tExample 1:\n\t\tInput: emails = [\"test.email+alex@leetcode.com\",\"test.e.mail+bob.cathy@leetcode.com\",\"testemail+david@lee.tcode.com\"]\n\t\tOutput: 2\n\t\tExplanation: \"testemail@leetcode.com\" and \"testemail@lee.tcode.com\" actually receive mails.\n\t\tExample 2:\n\t\tInput: emails = [\"a@leetcode.com\",\"b@leetcode.com\",\"c@leetcode.com\"]\n\t\tOutput: 3\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 966, - "question": "class Solution:\n def numSubarraysWithSum(self, nums: List[int], goal: int) -> int:\n\t\t\"\"\"\n\t\tGiven a binary array nums and an integer goal, return the number of non-empty subarrays with a sum goal.\r\n\t\tA subarray is a contiguous part of the array.\r\n\t\tExample 1:\r\n\t\tInput: nums = [1,0,1,0,1], goal = 2\r\n\t\tOutput: 4\r\n\t\tExplanation: The 4 subarrays are bolded and underlined below:\r\n\t\t[1,0,1,0,1]\r\n\t\t[1,0,1,0,1]\r\n\t\t[1,0,1,0,1]\r\n\t\t[1,0,1,0,1]\r\n\t\tExample 2:\r\n\t\tInput: nums = [0,0,0,0,0], goal = 0\r\n\t\tOutput: 15\r\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 967, - "question": "class Solution:\n def minFallingPathSum(self, matrix: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tGiven an n x n array of integers matrix, return the minimum sum of any falling path through matrix.\n\t\tA falling path starts at any element in the first row and chooses the element in the next row that is either directly below or diagonally left/right. Specifically, the next element from position (row, col) will be (row + 1, col - 1), (row + 1, col), or (row + 1, col + 1).\n\t\tExample 1:\n\t\tInput: matrix = [[2,1,3],[6,5,4],[7,8,9]]\n\t\tOutput: 13\n\t\tExplanation: There are two falling paths with a minimum sum as shown.\n\t\tExample 2:\n\t\tInput: matrix = [[-19,57],[-40,-5]]\n\t\tOutput: -59\n\t\tExplanation: The falling path with a minimum sum is shown.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 968, - "question": "class Solution:\n def beautifulArray(self, n: int) -> List[int]:\n\t\t\"\"\"\n\t\tAn array nums of length n is beautiful if:\n\t\t\tnums is a permutation of the integers in the range [1, n].\n\t\t\tFor every 0 <= i < j < n, there is no index k with i < k < j where 2 * nums[k] == nums[i] + nums[j].\n\t\tGiven the integer n, return any beautiful array nums of length n. There will be at least one valid answer for the given n.\n\t\tExample 1:\n\t\tInput: n = 4\n\t\tOutput: [2,1,4,3]\n\t\tExample 2:\n\t\tInput: n = 5\n\t\tOutput: [3,1,2,5,4]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 969, - "question": "class RecentCounter:\n def __init__(self):\n def ping(self, t: int) -> int:\n\t\t\"\"\"\n\t\tYou have a RecentCounter class which counts the number of recent requests within a certain time frame.\n\t\tImplement the RecentCounter class:\n\t\t\tRecentCounter() Initializes the counter with zero recent requests.\n\t\t\tint ping(int t) Adds a new request at time t, where t represents some time in milliseconds, and returns the number of requests that has happened in the past 3000 milliseconds (including the new request). Specifically, return the number of requests that have happened in the inclusive range [t - 3000, t].\n\t\tIt is guaranteed that every call to ping uses a strictly larger value of t than the previous call.\n\t\tExample 1:\n\t\tInput\n\t\t[\"RecentCounter\", \"ping\", \"ping\", \"ping\", \"ping\"]\n\t\t[[], [1], [100], [3001], [3002]]\n\t\tOutput\n\t\t[null, 1, 2, 3, 3]\n\t\tExplanation\n\t\tRecentCounter recentCounter = new RecentCounter();\n\t\trecentCounter.ping(1); // requests = [1], range is [-2999,1], return 1\n\t\trecentCounter.ping(100); // requests = [1, 100], range is [-2900,100], return 2\n\t\trecentCounter.ping(3001); // requests = [1, 100, 3001], range is [1,3001], return 3\n\t\trecentCounter.ping(3002); // requests = [1, 100, 3001, 3002], range is [2,3002], return 3\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 971, - "question": "class Solution:\n def shortestBridge(self, grid: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tYou are given an n x n binary matrix grid where 1 represents land and 0 represents water.\n\t\tAn island is a 4-directionally connected group of 1's not connected to any other 1's. There are exactly two islands in grid.\n\t\tYou may change 0's to 1's to connect the two islands to form one island.\n\t\tReturn the smallest number of 0's you must flip to connect the two islands.\n\t\tExample 1:\n\t\tInput: grid = [[0,1],[1,0]]\n\t\tOutput: 1\n\t\tExample 2:\n\t\tInput: grid = [[0,1,0],[0,0,0],[0,0,1]]\n\t\tOutput: 2\n\t\tExample 3:\n\t\tInput: grid = [[1,1,1,1,1],[1,0,0,0,1],[1,0,1,0,1],[1,0,0,0,1],[1,1,1,1,1]]\n\t\tOutput: 1\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 972, - "question": "class Solution:\n def knightDialer(self, n: int) -> int:\n\t\t\"\"\"\n\t\tThe chess knight has a unique movement, it may move two squares vertically and one square horizontally, or two squares horizontally and one square vertically (with both forming the shape of an L). The possible movements of chess knight are shown in this diagaram:\n\t\tA chess knight can move as indicated in the chess diagram below:\n\t\tWe have a chess knight and a phone pad as shown below, the knight can only stand on a numeric cell (i.e. blue cell).\n\t\tGiven an integer n, return how many distinct phone numbers of length n we can dial.\n\t\tYou are allowed to place the knight on any numeric cell initially and then you should perform n - 1 jumps to dial a number of length n. All jumps should be valid knight jumps.\n\t\tAs the answer may be very large, return the answer modulo 109 + 7.\n\t\tExample 1:\n\t\tInput: n = 1\n\t\tOutput: 10\n\t\tExplanation: We need to dial a number of length 1, so placing the knight over any numeric cell of the 10 cells is sufficient.\n\t\tExample 2:\n\t\tInput: n = 2\n\t\tOutput: 20\n\t\tExplanation: All the valid number we can dial are [04, 06, 16, 18, 27, 29, 34, 38, 40, 43, 49, 60, 61, 67, 72, 76, 81, 83, 92, 94]\n\t\tExample 3:\n\t\tInput: n = 3131\n\t\tOutput: 136006598\n\t\tExplanation: Please take care of the mod.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 973, - "question": "class Solution:\n def movesToStamp(self, stamp: str, target: str) -> List[int]:\n\t\t\"\"\"\n\t\tYou are given two strings stamp and target. Initially, there is a string s of length target.length with all s[i] == '?'.\n\t\tIn one turn, you can place stamp over s and replace every letter in the s with the corresponding letter from stamp.\n\t\t\tFor example, if stamp = \"abc\" and target = \"abcba\", then s is \"?????\" initially. In one turn you can:\n\t\t\t\tplace stamp at index 0 of s to obtain \"abc??\",\n\t\t\t\tplace stamp at index 1 of s to obtain \"?abc?\", or\n\t\t\t\tplace stamp at index 2 of s to obtain \"??abc\".\n\t\t\tNote that stamp must be fully contained in the boundaries of s in order to stamp (i.e., you cannot place stamp at index 3 of s).\n\t\tWe want to convert s to target using at most 10 * target.length turns.\n\t\tReturn an array of the index of the left-most letter being stamped at each turn. If we cannot obtain target from s within 10 * target.length turns, return an empty array.\n\t\tExample 1:\n\t\tInput: stamp = \"abc\", target = \"ababc\"\n\t\tOutput: [0,2]\n\t\tExplanation: Initially s = \"?????\".\n\t\t- Place stamp at index 0 to get \"abc??\".\n\t\t- Place stamp at index 2 to get \"ababc\".\n\t\t[1,0,2] would also be accepted as an answer, as well as some other answers.\n\t\tExample 2:\n\t\tInput: stamp = \"abca\", target = \"aabcaca\"\n\t\tOutput: [3,0,1]\n\t\tExplanation: Initially s = \"???????\".\n\t\t- Place stamp at index 3 to get \"???abca\".\n\t\t- Place stamp at index 0 to get \"abcabca\".\n\t\t- Place stamp at index 1 to get \"aabcaca\".\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 974, - "question": "class Solution:\n def reorderLogFiles(self, logs: List[str]) -> List[str]:\n\t\t\"\"\"\n\t\tYou are given an array of logs. Each log is a space-delimited string of words, where the first word is the identifier.\n\t\tThere are two types of logs:\n\t\t\tLetter-logs: All words (except the identifier) consist of lowercase English letters.\n\t\t\tDigit-logs: All words (except the identifier) consist of digits.\n\t\tReorder these logs so that:\n\t\t\tThe letter-logs come before all digit-logs.\n\t\t\tThe letter-logs are sorted lexicographically by their contents. If their contents are the same, then sort them lexicographically by their identifiers.\n\t\t\tThe digit-logs maintain their relative ordering.\n\t\tReturn the final order of the logs.\n\t\tExample 1:\n\t\tInput: logs = [\"dig1 8 1 5 1\",\"let1 art can\",\"dig2 3 6\",\"let2 own kit dig\",\"let3 art zero\"]\n\t\tOutput: [\"let1 art can\",\"let3 art zero\",\"let2 own kit dig\",\"dig1 8 1 5 1\",\"dig2 3 6\"]\n\t\tExplanation:\n\t\tThe letter-log contents are all different, so their ordering is \"art can\", \"art zero\", \"own kit dig\".\n\t\tThe digit-logs have a relative order of \"dig1 8 1 5 1\", \"dig2 3 6\".\n\t\tExample 2:\n\t\tInput: logs = [\"a1 9 2 3 1\",\"g1 act car\",\"zo4 4 7\",\"ab1 off key dog\",\"a8 act zoo\"]\n\t\tOutput: [\"g1 act car\",\"a8 act zoo\",\"ab1 off key dog\",\"a1 9 2 3 1\",\"zo4 4 7\"]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 975, - "question": "class Solution:\n def rangeSumBST(self, root: Optional[TreeNode], low: int, high: int) -> int:\n\t\t\"\"\"\n\t\tGiven the root node of a binary search tree and two integers low and high, return the sum of values of all nodes with a value in the inclusive range [low, high].\n\t\tExample 1:\n\t\tInput: root = [10,5,15,3,7,null,18], low = 7, high = 15\n\t\tOutput: 32\n\t\tExplanation: Nodes 7, 10, and 15 are in the range [7, 15]. 7 + 10 + 15 = 32.\n\t\tExample 2:\n\t\tInput: root = [10,5,15,3,7,13,18,1,null,6], low = 6, high = 10\n\t\tOutput: 23\n\t\tExplanation: Nodes 6, 7, and 10 are in the range [6, 10]. 6 + 7 + 10 = 23.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 976, - "question": "class Solution:\n def minAreaRect(self, points: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tYou are given an array of points in the X-Y plane points where points[i] = [xi, yi].\n\t\tReturn the minimum area of a rectangle formed from these points, with sides parallel to the X and Y axes. If there is not any such rectangle, return 0.\n\t\tExample 1:\n\t\tInput: points = [[1,1],[1,3],[3,1],[3,3],[2,2]]\n\t\tOutput: 4\n\t\tExample 2:\n\t\tInput: points = [[1,1],[1,3],[3,1],[3,3],[4,1],[4,3]]\n\t\tOutput: 2\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 977, - "question": "class Solution:\n def distinctSubseqII(self, s: str) -> int:\n\t\t\"\"\"\n\t\tGiven a string s, return the number of distinct non-empty subsequences of s. Since the answer may be very large, return it modulo 109 + 7.\n\t\tA subsequence of a string is a new string that is formed from the original string by deleting some (can be none) of the characters without disturbing the relative positions of the remaining characters. (i.e., \"ace\" is a subsequence of \"abcde\" while \"aec\" is not.\n\t\tExample 1:\n\t\tInput: s = \"abc\"\n\t\tOutput: 7\n\t\tExplanation: The 7 distinct subsequences are \"a\", \"b\", \"c\", \"ab\", \"ac\", \"bc\", and \"abc\".\n\t\tExample 2:\n\t\tInput: s = \"aba\"\n\t\tOutput: 6\n\t\tExplanation: The 6 distinct subsequences are \"a\", \"b\", \"ab\", \"aa\", \"ba\", and \"aba\".\n\t\tExample 3:\n\t\tInput: s = \"aaa\"\n\t\tOutput: 3\n\t\tExplanation: The 3 distinct subsequences are \"a\", \"aa\" and \"aaa\".\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 978, - "question": "class Solution:\n def validMountainArray(self, arr: List[int]) -> bool:\n\t\t\"\"\"\n\t\tGiven an array of integers arr, return true if and only if it is a valid mountain array.\n\t\tRecall that arr is a mountain array if and only if:\n\t\t\tarr.length >= 3\n\t\t\tThere exists some i with 0 < i < arr.length - 1 such that:\n\t\t\t\tarr[0] < arr[1] < ... < arr[i - 1] < arr[i] \n\t\t\t\tarr[i] > arr[i + 1] > ... > arr[arr.length - 1]\n\t\tExample 1:\n\t\tInput: arr = [2,1]\n\t\tOutput: false\n\t\tExample 2:\n\t\tInput: arr = [3,5,5]\n\t\tOutput: false\n\t\tExample 3:\n\t\tInput: arr = [0,3,2,1]\n\t\tOutput: true\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 979, - "question": "class Solution:\n def diStringMatch(self, s: str) -> List[int]:\n\t\t\"\"\"\n\t\tA permutation perm of n + 1 integers of all the integers in the range [0, n] can be represented as a string s of length n where:\n\t\t\ts[i] == 'I' if perm[i] < perm[i + 1], and\n\t\t\ts[i] == 'D' if perm[i] > perm[i + 1].\n\t\tGiven a string s, reconstruct the permutation perm and return it. If there are multiple valid permutations perm, return any of them.\n\t\tExample 1:\n\t\tInput: s = \"IDID\"\n\t\tOutput: [0,4,1,3,2]\n\t\tExample 2:\n\t\tInput: s = \"III\"\n\t\tOutput: [0,1,2,3]\n\t\tExample 3:\n\t\tInput: s = \"DDI\"\n\t\tOutput: [3,2,0,1]\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 980, - "question": "class Solution:\n def shortestSuperstring(self, words: List[str]) -> str:\n\t\t\"\"\"\n\t\tGiven an array of strings words, return the smallest string that contains each string in words as a substring. If there are multiple valid strings of the smallest length, return any of them.\n\t\tYou may assume that no string in words is a substring of another string in words.\n\t\tExample 1:\n\t\tInput: words = [\"alex\",\"loves\",\"leetcode\"]\n\t\tOutput: \"alexlovesleetcode\"\n\t\tExplanation: All permutations of \"alex\",\"loves\",\"leetcode\" would also be accepted.\n\t\tExample 2:\n\t\tInput: words = [\"catg\",\"ctaagt\",\"gcta\",\"ttca\",\"atgcatc\"]\n\t\tOutput: \"gctaagttcatgcatc\"\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 981, - "question": "class Solution:\n def minDeletionSize(self, strs: List[str]) -> int:\n\t\t\"\"\"\n\t\tYou are given an array of n strings strs, all of the same length.\n\t\tThe strings can be arranged such that there is one on each line, making a grid.\n\t\t\tFor example, strs = [\"abc\", \"bce\", \"cae\"] can be arranged as follows:\n\t\tabc\n\t\tbce\n\t\tcae\n\t\tYou want to delete the columns that are not sorted lexicographically. In the above example (0-indexed), columns 0 ('a', 'b', 'c') and 2 ('c', 'e', 'e') are sorted, while column 1 ('b', 'c', 'a') is not, so you would delete column 1.\n\t\tReturn the number of columns that you will delete.\n\t\tExample 1:\n\t\tInput: strs = [\"cba\",\"daf\",\"ghi\"]\n\t\tOutput: 1\n\t\tExplanation: The grid looks as follows:\n\t\t cba\n\t\t daf\n\t\t ghi\n\t\tColumns 0 and 2 are sorted, but column 1 is not, so you only need to delete 1 column.\n\t\tExample 2:\n\t\tInput: strs = [\"a\",\"b\"]\n\t\tOutput: 0\n\t\tExplanation: The grid looks as follows:\n\t\t a\n\t\t b\n\t\tColumn 0 is the only column and is sorted, so you will not delete any columns.\n\t\tExample 3:\n\t\tInput: strs = [\"zyx\",\"wvu\",\"tsr\"]\n\t\tOutput: 3\n\t\tExplanation: The grid looks as follows:\n\t\t zyx\n\t\t wvu\n\t\t tsr\n\t\tAll 3 columns are not sorted, so you will delete all 3.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 982, - "question": "class Solution:\n def minIncrementForUnique(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou are given an integer array nums. In one move, you can pick an index i where 0 <= i < nums.length and increment nums[i] by 1.\n\t\tReturn the minimum number of moves to make every value in nums unique.\n\t\tThe test cases are generated so that the answer fits in a 32-bit integer.\n\t\tExample 1:\n\t\tInput: nums = [1,2,2]\n\t\tOutput: 1\n\t\tExplanation: After 1 move, the array could be [1, 2, 3].\n\t\tExample 2:\n\t\tInput: nums = [3,2,1,2,1,7]\n\t\tOutput: 6\n\t\tExplanation: After 6 moves, the array could be [3, 4, 1, 2, 5, 7].\n\t\tIt can be shown with 5 or less moves that it is impossible for the array to have all unique values.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 983, - "question": "class Solution:\n def validateStackSequences(self, pushed: List[int], popped: List[int]) -> bool:\n\t\t\"\"\"\n\t\tGiven two integer arrays pushed and popped each with distinct values, return true if this could have been the result of a sequence of push and pop operations on an initially empty stack, or false otherwise.\n\t\tExample 1:\n\t\tInput: pushed = [1,2,3,4,5], popped = [4,5,3,2,1]\n\t\tOutput: true\n\t\tExplanation: We might do the following sequence:\n\t\tpush(1), push(2), push(3), push(4),\n\t\tpop() -> 4,\n\t\tpush(5),\n\t\tpop() -> 5, pop() -> 3, pop() -> 2, pop() -> 1\n\t\tExample 2:\n\t\tInput: pushed = [1,2,3,4,5], popped = [4,3,5,1,2]\n\t\tOutput: false\n\t\tExplanation: 1 cannot be popped before 2.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 984, - "question": "class Solution:\n def removeStones(self, stones: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tOn a 2D plane, we place n stones at some integer coordinate points. Each coordinate point may have at most one stone.\n\t\tA stone can be removed if it shares either the same row or the same column as another stone that has not been removed.\n\t\tGiven an array stones of length n where stones[i] = [xi, yi] represents the location of the ith stone, return the largest possible number of stones that can be removed.\n\t\tExample 1:\n\t\tInput: stones = [[0,0],[0,1],[1,0],[1,2],[2,1],[2,2]]\n\t\tOutput: 5\n\t\tExplanation: One way to remove 5 stones is as follows:\n\t\t1. Remove stone [2,2] because it shares the same row as [2,1].\n\t\t2. Remove stone [2,1] because it shares the same column as [0,1].\n\t\t3. Remove stone [1,2] because it shares the same row as [1,0].\n\t\t4. Remove stone [1,0] because it shares the same column as [0,0].\n\t\t5. Remove stone [0,1] because it shares the same row as [0,0].\n\t\tStone [0,0] cannot be removed since it does not share a row/column with another stone still on the plane.\n\t\tExample 2:\n\t\tInput: stones = [[0,0],[0,2],[1,1],[2,0],[2,2]]\n\t\tOutput: 3\n\t\tExplanation: One way to make 3 moves is as follows:\n\t\t1. Remove stone [2,2] because it shares the same row as [2,0].\n\t\t2. Remove stone [2,0] because it shares the same column as [0,0].\n\t\t3. Remove stone [0,2] because it shares the same row as [0,0].\n\t\tStones [0,0] and [1,1] cannot be removed since they do not share a row/column with another stone still on the plane.\n\t\tExample 3:\n\t\tInput: stones = [[0,0]]\n\t\tOutput: 0\n\t\tExplanation: [0,0] is the only stone on the plane, so you cannot remove it.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 985, - "question": "class Solution:\n def bagOfTokensScore(self, tokens: List[int], power: int) -> int:\n\t\t\"\"\"\n\t\tYou have an initial power of power, an initial score of 0, and a bag of tokens where tokens[i] is the value of the ith token (0-indexed).\n\t\tYour goal is to maximize your total score by potentially playing each token in one of two ways:\n\t\t\tIf your current power is at least tokens[i], you may play the ith token face up, losing tokens[i] power and gaining 1 score.\n\t\t\tIf your current score is at least 1, you may play the ith token face down, gaining tokens[i] power and losing 1 score.\n\t\tEach token may be played at most once and in any order. You do not have to play all the tokens.\n\t\tReturn the largest possible score you can achieve after playing any number of tokens.\n\t\tExample 1:\n\t\tInput: tokens = [100], power = 50\n\t\tOutput: 0\n\t\tExplanation: Playing the only token in the bag is impossible because you either have too little power or too little score.\n\t\tExample 2:\n\t\tInput: tokens = [100,200], power = 150\n\t\tOutput: 1\n\t\tExplanation: Play the 0th token (100) face up, your power becomes 50 and score becomes 1.\n\t\tThere is no need to play the 1st token since you cannot play it face up to add to your score.\n\t\tExample 3:\n\t\tInput: tokens = [100,200,300,400], power = 200\n\t\tOutput: 2\n\t\tExplanation: Play the tokens in this order to get a score of 2:\n\t\t1. Play the 0th token (100) face up, your power becomes 100 and score becomes 1.\n\t\t2. Play the 3rd token (400) face down, your power becomes 500 and score becomes 0.\n\t\t3. Play the 1st token (200) face up, your power becomes 300 and score becomes 1.\n\t\t4. Play the 2nd token (300) face up, your power becomes 0 and score becomes 2.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 986, - "question": "class Solution:\n def largestTimeFromDigits(self, arr: List[int]) -> str:\n\t\t\"\"\"\n\t\tGiven an array arr of 4 digits, find the latest 24-hour time that can be made using each digit exactly once.\n\t\t24-hour times are formatted as \"HH:MM\", where HH is between 00 and 23, and MM is between 00 and 59. The earliest 24-hour time is 00:00, and the latest is 23:59.\n\t\tReturn the latest 24-hour time in \"HH:MM\" format. If no valid time can be made, return an empty string.\n\t\tExample 1:\n\t\tInput: arr = [1,2,3,4]\n\t\tOutput: \"23:41\"\n\t\tExplanation: The valid 24-hour times are \"12:34\", \"12:43\", \"13:24\", \"13:42\", \"14:23\", \"14:32\", \"21:34\", \"21:43\", \"23:14\", and \"23:41\". Of these times, \"23:41\" is the latest.\n\t\tExample 2:\n\t\tInput: arr = [5,5,5,5]\n\t\tOutput: \"\"\n\t\tExplanation: There are no valid 24-hour times as \"55:55\" is not valid.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 987, - "question": "class Solution:\n def deckRevealedIncreasing(self, deck: List[int]) -> List[int]:\n\t\t\"\"\"\n\t\tYou are given an integer array deck. There is a deck of cards where every card has a unique integer. The integer on the ith card is deck[i].\n\t\tYou can order the deck in any order you want. Initially, all the cards start face down (unrevealed) in one deck.\n\t\tYou will do the following steps repeatedly until all cards are revealed:\n\t\t\tTake the top card of the deck, reveal it, and take it out of the deck.\n\t\t\tIf there are still cards in the deck then put the next top card of the deck at the bottom of the deck.\n\t\t\tIf there are still unrevealed cards, go back to step 1. Otherwise, stop.\n\t\tReturn an ordering of the deck that would reveal the cards in increasing order.\n\t\tNote that the first entry in the answer is considered to be the top of the deck.\n\t\tExample 1:\n\t\tInput: deck = [17,13,11,2,3,5,7]\n\t\tOutput: [2,13,3,11,5,17,7]\n\t\tExplanation: \n\t\tWe get the deck in the order [17,13,11,2,3,5,7] (this order does not matter), and reorder it.\n\t\tAfter reordering, the deck starts as [2,13,3,11,5,17,7], where 2 is the top of the deck.\n\t\tWe reveal 2, and move 13 to the bottom. The deck is now [3,11,5,17,7,13].\n\t\tWe reveal 3, and move 11 to the bottom. The deck is now [5,17,7,13,11].\n\t\tWe reveal 5, and move 17 to the bottom. The deck is now [7,13,11,17].\n\t\tWe reveal 7, and move 13 to the bottom. The deck is now [11,17,13].\n\t\tWe reveal 11, and move 17 to the bottom. The deck is now [13,17].\n\t\tWe reveal 13, and move 17 to the bottom. The deck is now [17].\n\t\tWe reveal 17.\n\t\tSince all the cards revealed are in increasing order, the answer is correct.\n\t\tExample 2:\n\t\tInput: deck = [1,1000]\n\t\tOutput: [1,1000]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 988, - "question": "class Solution:\n def flipEquiv(self, root1: Optional[TreeNode], root2: Optional[TreeNode]) -> bool:\n\t\t\"\"\"\n\t\tFor a binary tree T, we can define a flip operation as follows: choose any node, and swap the left and right child subtrees.\n\t\tA binary tree X is flip equivalent to a binary tree Y if and only if we can make X equal to Y after some number of flip operations.\n\t\tGiven the roots of two binary trees root1 and root2, return true if the two trees are flip equivalent or false otherwise.\n\t\tExample 1:\n\t\tInput: root1 = [1,2,3,4,5,6,null,null,null,7,8], root2 = [1,3,2,null,6,4,5,null,null,null,null,8,7]\n\t\tOutput: true\n\t\tExplanation: We flipped at nodes with values 1, 3, and 5.\n\t\tExample 2:\n\t\tInput: root1 = [], root2 = []\n\t\tOutput: true\n\t\tExample 3:\n\t\tInput: root1 = [], root2 = [1]\n\t\tOutput: false\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 989, - "question": "class Solution:\n def largestComponentSize(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou are given an integer array of unique positive integers nums. Consider the following graph:\n\t\t\tThere are nums.length nodes, labeled nums[0] to nums[nums.length - 1],\n\t\t\tThere is an undirected edge between nums[i] and nums[j] if nums[i] and nums[j] share a common factor greater than 1.\n\t\tReturn the size of the largest connected component in the graph.\n\t\tExample 1:\n\t\tInput: nums = [4,6,15,35]\n\t\tOutput: 4\n\t\tExample 2:\n\t\tInput: nums = [20,50,9,63]\n\t\tOutput: 2\n\t\tExample 3:\n\t\tInput: nums = [2,3,6,7,4,12,21,39]\n\t\tOutput: 8\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 990, - "question": "class Solution:\n def isAlienSorted(self, words: List[str], order: str) -> bool:\n\t\t\"\"\"\n\t\tIn an alien language, surprisingly, they also use English lowercase letters, but possibly in a different order. The order of the alphabet is some permutation of lowercase letters.\n\t\tGiven a sequence of words written in the alien language, and the order of the alphabet, return true if and only if the given words are sorted lexicographically in this alien language.\n\t\tExample 1:\n\t\tInput: words = [\"hello\",\"leetcode\"], order = \"hlabcdefgijkmnopqrstuvwxyz\"\n\t\tOutput: true\n\t\tExplanation: As 'h' comes before 'l' in this language, then the sequence is sorted.\n\t\tExample 2:\n\t\tInput: words = [\"word\",\"world\",\"row\"], order = \"worldabcefghijkmnpqstuvxyz\"\n\t\tOutput: false\n\t\tExplanation: As 'd' comes after 'l' in this language, then words[0] > words[1], hence the sequence is unsorted.\n\t\tExample 3:\n\t\tInput: words = [\"apple\",\"app\"], order = \"abcdefghijklmnopqrstuvwxyz\"\n\t\tOutput: false\n\t\tExplanation: The first three characters \"app\" match, and the second string is shorter (in size.) According to lexicographical rules \"apple\" > \"app\", because 'l' > '\u2205', where '\u2205' is defined as the blank character which is less than any other character (More info).\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 991, - "question": "class Solution:\n def canReorderDoubled(self, arr: List[int]) -> bool:\n\t\t\"\"\"\n\t\tGiven an integer array of even length arr, return true if it is possible to reorder arr such that arr[2 * i + 1] = 2 * arr[2 * i] for every 0 <= i < len(arr) / 2, or false otherwise.\n\t\tExample 1:\n\t\tInput: arr = [3,1,3,6]\n\t\tOutput: false\n\t\tExample 2:\n\t\tInput: arr = [2,1,2,6]\n\t\tOutput: false\n\t\tExample 3:\n\t\tInput: arr = [4,-2,2,-4]\n\t\tOutput: true\n\t\tExplanation: We can take two groups, [-2,-4] and [2,4] to form [-2,-4,2,4] or [2,4,-2,-4].\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 992, - "question": "class Solution:\n def minDeletionSize(self, strs: List[str]) -> int:\n\t\t\"\"\"\n\t\tYou are given an array of n strings strs, all of the same length.\n\t\tWe may choose any deletion indices, and we delete all the characters in those indices for each string.\n\t\tFor example, if we have strs = [\"abcdef\",\"uvwxyz\"] and deletion indices {0, 2, 3}, then the final array after deletions is [\"bef\", \"vyz\"].\n\t\tSuppose we chose a set of deletion indices answer such that after deletions, the final array has its elements in lexicographic order (i.e., strs[0] <= strs[1] <= strs[2] <= ... <= strs[n - 1]). Return the minimum possible value of answer.length.\n\t\tExample 1:\n\t\tInput: strs = [\"ca\",\"bb\",\"ac\"]\n\t\tOutput: 1\n\t\tExplanation: \n\t\tAfter deleting the first column, strs = [\"a\", \"b\", \"c\"].\n\t\tNow strs is in lexicographic order (ie. strs[0] <= strs[1] <= strs[2]).\n\t\tWe require at least 1 deletion since initially strs was not in lexicographic order, so the answer is 1.\n\t\tExample 2:\n\t\tInput: strs = [\"xc\",\"yb\",\"za\"]\n\t\tOutput: 0\n\t\tExplanation: \n\t\tstrs is already in lexicographic order, so we do not need to delete anything.\n\t\tNote that the rows of strs are not necessarily in lexicographic order:\n\t\ti.e., it is NOT necessarily true that (strs[0][0] <= strs[0][1] <= ...)\n\t\tExample 3:\n\t\tInput: strs = [\"zyx\",\"wvu\",\"tsr\"]\n\t\tOutput: 3\n\t\tExplanation: We have to delete every column.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 993, - "question": "class Solution:\n def tallestBillboard(self, rods: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou are installing a billboard and want it to have the largest height. The billboard will have two steel supports, one on each side. Each steel support must be an equal height.\n\t\tYou are given a collection of rods that can be welded together. For example, if you have rods of lengths 1, 2, and 3, you can weld them together to make a support of length 6.\n\t\tReturn the largest possible height of your billboard installation. If you cannot support the billboard, return 0.\n\t\tExample 1:\n\t\tInput: rods = [1,2,3,6]\n\t\tOutput: 6\n\t\tExplanation: We have two disjoint subsets {1,2,3} and {6}, which have the same sum = 6.\n\t\tExample 2:\n\t\tInput: rods = [1,2,3,4,5,6]\n\t\tOutput: 10\n\t\tExplanation: We have two disjoint subsets {2,3,5} and {4,6}, which have the same sum = 10.\n\t\tExample 3:\n\t\tInput: rods = [1,2]\n\t\tOutput: 0\n\t\tExplanation: The billboard cannot be supported, so we return 0.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 994, - "question": "class Solution:\n def prisonAfterNDays(self, cells: List[int], n: int) -> List[int]:\n\t\t\"\"\"\n\t\tThere are 8 prison cells in a row and each cell is either occupied or vacant.\n\t\tEach day, whether the cell is occupied or vacant changes according to the following rules:\n\t\t\tIf a cell has two adjacent neighbors that are both occupied or both vacant, then the cell becomes occupied.\n\t\t\tOtherwise, it becomes vacant.\n\t\tNote that because the prison is a row, the first and the last cells in the row can't have two adjacent neighbors.\n\t\tYou are given an integer array cells where cells[i] == 1 if the ith cell is occupied and cells[i] == 0 if the ith cell is vacant, and you are given an integer n.\n\t\tReturn the state of the prison after n days (i.e., n such changes described above).\n\t\tExample 1:\n\t\tInput: cells = [0,1,0,1,1,0,0,1], n = 7\n\t\tOutput: [0,0,1,1,0,0,0,0]\n\t\tExplanation: The following table summarizes the state of the prison on each day:\n\t\tDay 0: [0, 1, 0, 1, 1, 0, 0, 1]\n\t\tDay 1: [0, 1, 1, 0, 0, 0, 0, 0]\n\t\tDay 2: [0, 0, 0, 0, 1, 1, 1, 0]\n\t\tDay 3: [0, 1, 1, 0, 0, 1, 0, 0]\n\t\tDay 4: [0, 0, 0, 0, 0, 1, 0, 0]\n\t\tDay 5: [0, 1, 1, 1, 0, 1, 0, 0]\n\t\tDay 6: [0, 0, 1, 0, 1, 1, 0, 0]\n\t\tDay 7: [0, 0, 1, 1, 0, 0, 0, 0]\n\t\tExample 2:\n\t\tInput: cells = [1,0,0,1,0,0,1,0], n = 1000000000\n\t\tOutput: [0,0,1,1,1,1,1,0]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 998, - "question": "class Solution:\n def isCompleteTree(self, root: Optional[TreeNode]) -> bool:\n\t\t\"\"\"\n\t\tGiven the root of a binary tree, determine if it is a complete binary tree.\n\t\tIn a complete binary tree, every level, except possibly the last, is completely filled, and all nodes in the last level are as far left as possible. It can have between 1 and 2h nodes inclusive at the last level h.\n\t\tExample 1:\n\t\tInput: root = [1,2,3,4,5,6]\n\t\tOutput: true\n\t\tExplanation: Every level before the last is full (ie. levels with node-values {1} and {2, 3}), and all nodes in the last level ({4, 5, 6}) are as far left as possible.\n\t\tExample 2:\n\t\tInput: root = [1,2,3,4,5,null,7]\n\t\tOutput: false\n\t\tExplanation: The node with value 7 isn't as far left as possible.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 999, - "question": "class Solution:\n def regionsBySlashes(self, grid: List[str]) -> int:\n\t\t\"\"\"\n\t\tAn n x n grid is composed of 1 x 1 squares where each 1 x 1 square consists of a '/', '\\', or blank space ' '. These characters divide the square into contiguous regions.\n\t\tGiven the grid grid represented as a string array, return the number of regions.\n\t\tNote that backslash characters are escaped, so a '\\' is represented as '\\\\'.\n\t\tExample 1:\n\t\tInput: grid = [\" /\",\"/ \"]\n\t\tOutput: 2\n\t\tExample 2:\n\t\tInput: grid = [\" /\",\" \"]\n\t\tOutput: 1\n\t\tExample 3:\n\t\tInput: grid = [\"/\\\\\",\"\\\\/\"]\n\t\tOutput: 5\n\t\tExplanation: Recall that because \\ characters are escaped, \"\\\\/\" refers to \\/, and \"/\\\\\" refers to /\\.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1000, - "question": "class Solution:\n def minDeletionSize(self, strs: List[str]) -> int:\n\t\t\"\"\"\n\t\tYou are given an array of n strings strs, all of the same length.\n\t\tWe may choose any deletion indices, and we delete all the characters in those indices for each string.\n\t\tFor example, if we have strs = [\"abcdef\",\"uvwxyz\"] and deletion indices {0, 2, 3}, then the final array after deletions is [\"bef\", \"vyz\"].\n\t\tSuppose we chose a set of deletion indices answer such that after deletions, the final array has every string (row) in lexicographic order. (i.e., (strs[0][0] <= strs[0][1] <= ... <= strs[0][strs[0].length - 1]), and (strs[1][0] <= strs[1][1] <= ... <= strs[1][strs[1].length - 1]), and so on). Return the minimum possible value of answer.length.\n\t\tExample 1:\n\t\tInput: strs = [\"babca\",\"bbazb\"]\n\t\tOutput: 3\n\t\tExplanation: After deleting columns 0, 1, and 4, the final array is strs = [\"bc\", \"az\"].\n\t\tBoth these rows are individually in lexicographic order (ie. strs[0][0] <= strs[0][1] and strs[1][0] <= strs[1][1]).\n\t\tNote that strs[0] > strs[1] - the array strs is not necessarily in lexicographic order.\n\t\tExample 2:\n\t\tInput: strs = [\"edcba\"]\n\t\tOutput: 4\n\t\tExplanation: If we delete less than 4 columns, the only row will not be lexicographically sorted.\n\t\tExample 3:\n\t\tInput: strs = [\"ghi\",\"def\",\"abc\"]\n\t\tOutput: 0\n\t\tExplanation: All rows are already lexicographically sorted.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1001, - "question": "class Solution:\n def repeatedNTimes(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou are given an integer array nums with the following properties:\n\t\t\tnums.length == 2 * n.\n\t\t\tnums contains n + 1 unique elements.\n\t\t\tExactly one element of nums is repeated n times.\n\t\tReturn the element that is repeated n times.\n\t\tExample 1:\n\t\tInput: nums = [1,2,3,3]\n\t\tOutput: 3\n\t\tExample 2:\n\t\tInput: nums = [2,1,2,5,3,2]\n\t\tOutput: 2\n\t\tExample 3:\n\t\tInput: nums = [5,1,5,2,5,3,5,4]\n\t\tOutput: 5\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1002, - "question": "class Solution:\n def maxWidthRamp(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tA ramp in an integer array nums is a pair (i, j) for which i < j and nums[i] <= nums[j]. The width of such a ramp is j - i.\n\t\tGiven an integer array nums, return the maximum width of a ramp in nums. If there is no ramp in nums, return 0.\n\t\tExample 1:\n\t\tInput: nums = [6,0,8,2,1,5]\n\t\tOutput: 4\n\t\tExplanation: The maximum width ramp is achieved at (i, j) = (1, 5): nums[1] = 0 and nums[5] = 5.\n\t\tExample 2:\n\t\tInput: nums = [9,8,1,0,1,9,4,0,4,1]\n\t\tOutput: 7\n\t\tExplanation: The maximum width ramp is achieved at (i, j) = (2, 9): nums[2] = 1 and nums[9] = 1.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1003, - "question": "class Solution:\n def minAreaFreeRect(self, points: List[List[int]]) -> float:\n\t\t\"\"\"\n\t\tYou are given an array of points in the X-Y plane points where points[i] = [xi, yi].\n\t\tReturn the minimum area of any rectangle formed from these points, with sides not necessarily parallel to the X and Y axes. If there is not any such rectangle, return 0.\n\t\tAnswers within 10-5 of the actual answer will be accepted.\n\t\tExample 1:\n\t\tInput: points = [[1,2],[2,1],[1,0],[0,1]]\n\t\tOutput: 2.00000\n\t\tExplanation: The minimum area rectangle occurs at [1,2],[2,1],[1,0],[0,1], with an area of 2.\n\t\tExample 2:\n\t\tInput: points = [[0,1],[2,1],[1,1],[1,0],[2,0]]\n\t\tOutput: 1.00000\n\t\tExplanation: The minimum area rectangle occurs at [1,0],[1,1],[2,1],[2,0], with an area of 1.\n\t\tExample 3:\n\t\tInput: points = [[0,3],[1,2],[3,1],[1,3],[2,1]]\n\t\tOutput: 0\n\t\tExplanation: There is no possible rectangle to form from these points.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1004, - "question": "class Solution:\n def leastOpsExpressTarget(self, x: int, target: int) -> int:\n\t\t\"\"\"\n\t\tGiven a single positive integer x, we will write an expression of the form x (op1) x (op2) x (op3) x ... where each operator op1, op2, etc. is either addition, subtraction, multiplication, or division (+, -, *, or /). For example, with x = 3, we might write 3 * 3 / 3 + 3 - 3 which is a value of 3.\n\t\tWhen writing such an expression, we adhere to the following conventions:\n\t\t\tThe division operator (/) returns rational numbers.\n\t\t\tThere are no parentheses placed anywhere.\n\t\t\tWe use the usual order of operations: multiplication and division happen before addition and subtraction.\n\t\t\tIt is not allowed to use the unary negation operator (-). For example, \"x - x\" is a valid expression as it only uses subtraction, but \"-x + x\" is not because it uses negation.\n\t\tWe would like to write an expression with the least number of operators such that the expression equals the given target. Return the least number of operators used.\n\t\tExample 1:\n\t\tInput: x = 3, target = 19\n\t\tOutput: 5\n\t\tExplanation: 3 * 3 + 3 * 3 + 3 / 3.\n\t\tThe expression contains 5 operations.\n\t\tExample 2:\n\t\tInput: x = 5, target = 501\n\t\tOutput: 8\n\t\tExplanation: 5 * 5 * 5 * 5 - 5 * 5 * 5 + 5 / 5.\n\t\tThe expression contains 8 operations.\n\t\tExample 3:\n\t\tInput: x = 100, target = 100000000\n\t\tOutput: 3\n\t\tExplanation: 100 * 100 * 100 * 100.\n\t\tThe expression contains 3 operations.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1005, - "question": "class Solution:\n def isUnivalTree(self, root: Optional[TreeNode]) -> bool:\n\t\t\"\"\"\n\t\tA binary tree is uni-valued if every node in the tree has the same value.\n\t\tGiven the root of a binary tree, return true if the given tree is uni-valued, or false otherwise.\n\t\tExample 1:\n\t\tInput: root = [1,1,1,1,1,null,1]\n\t\tOutput: true\n\t\tExample 2:\n\t\tInput: root = [2,2,2,5,2]\n\t\tOutput: false\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1006, - "question": "class Solution:\n def spellchecker(self, wordlist: List[str], queries: List[str]) -> List[str]:\n\t\t\"\"\"\n\t\tGiven a wordlist, we want to implement a spellchecker that converts a query word into a correct word.\n\t\tFor a given query word, the spell checker handles two categories of spelling mistakes:\n\t\t\tCapitalization: If the query matches a word in the wordlist (case-insensitive), then the query word is returned with the same case as the case in the wordlist.\n\t\t\t\tExample: wordlist = [\"yellow\"], query = \"YellOw\": correct = \"yellow\"\n\t\t\t\tExample: wordlist = [\"Yellow\"], query = \"yellow\": correct = \"Yellow\"\n\t\t\t\tExample: wordlist = [\"yellow\"], query = \"yellow\": correct = \"yellow\"\n\t\t\tVowel Errors: If after replacing the vowels ('a', 'e', 'i', 'o', 'u') of the query word with any vowel individually, it matches a word in the wordlist (case-insensitive), then the query word is returned with the same case as the match in the wordlist.\n\t\t\t\tExample: wordlist = [\"YellOw\"], query = \"yollow\": correct = \"YellOw\"\n\t\t\t\tExample: wordlist = [\"YellOw\"], query = \"yeellow\": correct = \"\" (no match)\n\t\t\t\tExample: wordlist = [\"YellOw\"], query = \"yllw\": correct = \"\" (no match)\n\t\tIn addition, the spell checker operates under the following precedence rules:\n\t\t\tWhen the query exactly matches a word in the wordlist (case-sensitive), you should return the same word back.\n\t\t\tWhen the query matches a word up to capitlization, you should return the first such match in the wordlist.\n\t\t\tWhen the query matches a word up to vowel errors, you should return the first such match in the wordlist.\n\t\t\tIf the query has no matches in the wordlist, you should return the empty string.\n\t\tGiven some queries, return a list of words answer, where answer[i] is the correct word for query = queries[i].\n\t\tExample 1:\n\t\tInput: wordlist = [\"KiTe\",\"kite\",\"hare\",\"Hare\"], queries = [\"kite\",\"Kite\",\"KiTe\",\"Hare\",\"HARE\",\"Hear\",\"hear\",\"keti\",\"keet\",\"keto\"]\n\t\tOutput: [\"kite\",\"KiTe\",\"KiTe\",\"Hare\",\"hare\",\"\",\"\",\"KiTe\",\"\",\"KiTe\"]\n\t\tExample 2:\n\t\tInput: wordlist = [\"yellow\"], queries = [\"YellOw\"]\n\t\tOutput: [\"yellow\"]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1007, - "question": "class Solution:\n def numsSameConsecDiff(self, n: int, k: int) -> List[int]:\n\t\t\"\"\"\n\t\tGiven two integers n and k, return an array of all the integers of length n where the difference between every two consecutive digits is k. You may return the answer in any order.\n\t\tNote that the integers should not have leading zeros. Integers as 02 and 043 are not allowed.\n\t\tExample 1:\n\t\tInput: n = 3, k = 7\n\t\tOutput: [181,292,707,818,929]\n\t\tExplanation: Note that 070 is not a valid number, because it has leading zeroes.\n\t\tExample 2:\n\t\tInput: n = 2, k = 1\n\t\tOutput: [10,12,21,23,32,34,43,45,54,56,65,67,76,78,87,89,98]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1008, - "question": "class Solution:\n def minCameraCover(self, root: Optional[TreeNode]) -> int:\n\t\t\"\"\"\n\t\tYou are given the root of a binary tree. We install cameras on the tree nodes where each camera at a node can monitor its parent, itself, and its immediate children.\n\t\tReturn the minimum number of cameras needed to monitor all nodes of the tree.\n\t\tExample 1:\n\t\tInput: root = [0,0,null,0,0]\n\t\tOutput: 1\n\t\tExplanation: One camera is enough to monitor all nodes if placed as shown.\n\t\tExample 2:\n\t\tInput: root = [0,0,null,0,null,0,null,null,0]\n\t\tOutput: 2\n\t\tExplanation: At least two cameras are needed to monitor all nodes of the tree. The above image shows one of the valid configurations of camera placement.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1009, - "question": "class Solution:\n def pancakeSort(self, arr: List[int]) -> List[int]:\n\t\t\"\"\"\n\t\tGiven an array of integers arr, sort the array by performing a series of pancake flips.\n\t\tIn one pancake flip we do the following steps:\n\t\t\tChoose an integer k where 1 <= k <= arr.length.\n\t\t\tReverse the sub-array arr[0...k-1] (0-indexed).\n\t\tFor example, if arr = [3,2,1,4] and we performed a pancake flip choosing k = 3, we reverse the sub-array [3,2,1], so arr = [1,2,3,4] after the pancake flip at k = 3.\n\t\tReturn an array of the k-values corresponding to a sequence of pancake flips that sort arr. Any valid answer that sorts the array within 10 * arr.length flips will be judged as correct.\n\t\tExample 1:\n\t\tInput: arr = [3,2,4,1]\n\t\tOutput: [4,2,4,3]\n\t\tExplanation: \n\t\tWe perform 4 pancake flips, with k values 4, 2, 4, and 3.\n\t\tStarting state: arr = [3, 2, 4, 1]\n\t\tAfter 1st flip (k = 4): arr = [1, 4, 2, 3]\n\t\tAfter 2nd flip (k = 2): arr = [4, 1, 2, 3]\n\t\tAfter 3rd flip (k = 4): arr = [3, 2, 1, 4]\n\t\tAfter 4th flip (k = 3): arr = [1, 2, 3, 4], which is sorted.\n\t\tExample 2:\n\t\tInput: arr = [1,2,3]\n\t\tOutput: []\n\t\tExplanation: The input is already sorted, so there is no need to flip anything.\n\t\tNote that other answers, such as [3, 3], would also be accepted.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1010, - "question": "class Solution:\n def powerfulIntegers(self, x: int, y: int, bound: int) -> List[int]:\n\t\t\"\"\"\n\t\tGiven three integers x, y, and bound, return a list of all the powerful integers that have a value less than or equal to bound.\n\t\tAn integer is powerful if it can be represented as xi + yj for some integers i >= 0 and j >= 0.\n\t\tYou may return the answer in any order. In your answer, each value should occur at most once.\n\t\tExample 1:\n\t\tInput: x = 2, y = 3, bound = 10\n\t\tOutput: [2,3,4,5,7,9,10]\n\t\tExplanation:\n\t\t2 = 20 + 30\n\t\t3 = 21 + 30\n\t\t4 = 20 + 31\n\t\t5 = 21 + 31\n\t\t7 = 22 + 31\n\t\t9 = 23 + 30\n\t\t10 = 20 + 32\n\t\tExample 2:\n\t\tInput: x = 3, y = 5, bound = 15\n\t\tOutput: [2,4,6,8,10,14]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1011, - "question": "class Solution:\n def flipMatchVoyage(self, root: Optional[TreeNode], voyage: List[int]) -> List[int]:\n\t\t\"\"\"\n\t\tYou are given the root of a binary tree with n nodes, where each node is uniquely assigned a value from 1 to n. You are also given a sequence of n values voyage, which is the desired pre-order traversal of the binary tree.\n\t\tAny node in the binary tree can be flipped by swapping its left and right subtrees. For example, flipping node 1 will have the following effect:\n\t\tFlip the smallest number of nodes so that the pre-order traversal of the tree matches voyage.\n\t\tReturn a list of the values of all flipped nodes. You may return the answer in any order. If it is impossible to flip the nodes in the tree to make the pre-order traversal match voyage, return the list [-1].\n\t\tExample 1:\n\t\tInput: root = [1,2], voyage = [2,1]\n\t\tOutput: [-1]\n\t\tExplanation: It is impossible to flip the nodes such that the pre-order traversal matches voyage.\n\t\tExample 2:\n\t\tInput: root = [1,2,3], voyage = [1,3,2]\n\t\tOutput: [1]\n\t\tExplanation: Flipping node 1 swaps nodes 2 and 3, so the pre-order traversal matches voyage.\n\t\tExample 3:\n\t\tInput: root = [1,2,3], voyage = [1,2,3]\n\t\tOutput: []\n\t\tExplanation: The tree's pre-order traversal already matches voyage, so no nodes need to be flipped.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1012, - "question": "class Solution:\n def isRationalEqual(self, s: str, t: str) -> bool:\n\t\t\"\"\"\n\t\tGiven two strings s and t, each of which represents a non-negative rational number, return true if and only if they represent the same number. The strings may use parentheses to denote the repeating part of the rational number.\n\t\tA rational number can be represented using up to three parts: , , and a . The number will be represented in one of the following three ways:\n\t\t\t\n\t\t\t\tFor example, 12, 0, and 123.\n\t\t\t<.>\n\t\t\t\tFor example, 0.5, 1., 2.12, and 123.0001.\n\t\t\t<.><(><)>\n\t\t\t\tFor example, 0.1(6), 1.(9), 123.00(1212).\n\t\tThe repeating portion of a decimal expansion is conventionally denoted within a pair of round brackets. For example:\n\t\t\t1/6 = 0.16666666... = 0.1(6) = 0.1666(6) = 0.166(66).\n\t\tExample 1:\n\t\tInput: s = \"0.(52)\", t = \"0.5(25)\"\n\t\tOutput: true\n\t\tExplanation: Because \"0.(52)\" represents 0.52525252..., and \"0.5(25)\" represents 0.52525252525..... , the strings represent the same number.\n\t\tExample 2:\n\t\tInput: s = \"0.1666(6)\", t = \"0.166(66)\"\n\t\tOutput: true\n\t\tExample 3:\n\t\tInput: s = \"0.9(9)\", t = \"1.\"\n\t\tOutput: true\n\t\tExplanation: \"0.9(9)\" represents 0.999999999... repeated forever, which equals 1. [See this link for an explanation.]\n\t\t\"1.\" represents the number 1, which is formed correctly: (IntegerPart) = \"1\" and (NonRepeatingPart) = \"\".\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1013, - "question": "class Solution:\n def fib(self, n: int) -> int:\n\t\t\"\"\"\n\t\tThe Fibonacci numbers, commonly denoted F(n) form a sequence, called the Fibonacci sequence, such that each number is the sum of the two preceding ones, starting from 0 and 1. That is,\n\t\tF(0) = 0, F(1) = 1\n\t\tF(n) = F(n - 1) + F(n - 2), for n > 1.\n\t\tGiven n, calculate F(n).\n\t\tExample 1:\n\t\tInput: n = 2\n\t\tOutput: 1\n\t\tExplanation: F(2) = F(1) + F(0) = 1 + 0 = 1.\n\t\tExample 2:\n\t\tInput: n = 3\n\t\tOutput: 2\n\t\tExplanation: F(3) = F(2) + F(1) = 1 + 1 = 2.\n\t\tExample 3:\n\t\tInput: n = 4\n\t\tOutput: 3\n\t\tExplanation: F(4) = F(3) + F(2) = 2 + 1 = 3.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1014, - "question": "class Solution:\n def kClosest(self, points: List[List[int]], k: int) -> List[List[int]]:\n\t\t\"\"\"\n\t\tGiven an array of points where points[i] = [xi, yi] represents a point on the X-Y plane and an integer k, return the k closest points to the origin (0, 0).\n\t\tThe distance between two points on the X-Y plane is the Euclidean distance (i.e., \u221a(x1 - x2)2 + (y1 - y2)2).\n\t\tYou may return the answer in any order. The answer is guaranteed to be unique (except for the order that it is in).\n\t\tExample 1:\n\t\tInput: points = [[1,3],[-2,2]], k = 1\n\t\tOutput: [[-2,2]]\n\t\tExplanation:\n\t\tThe distance between (1, 3) and the origin is sqrt(10).\n\t\tThe distance between (-2, 2) and the origin is sqrt(8).\n\t\tSince sqrt(8) < sqrt(10), (-2, 2) is closer to the origin.\n\t\tWe only want the closest k = 1 points from the origin, so the answer is just [[-2,2]].\n\t\tExample 2:\n\t\tInput: points = [[3,3],[5,-1],[-2,4]], k = 2\n\t\tOutput: [[3,3],[-2,4]]\n\t\tExplanation: The answer [[-2,4],[3,3]] would also be accepted.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1016, - "question": "class Solution:\n def subarraysDivByK(self, nums: List[int], k: int) -> int:\n\t\t\"\"\"\n\t\tGiven an integer array nums and an integer k, return the number of non-empty subarrays that have a sum divisible by k.\n\t\tA subarray is a contiguous part of an array.\n\t\tExample 1:\n\t\tInput: nums = [4,5,0,-2,-3,1], k = 5\n\t\tOutput: 7\n\t\tExplanation: There are 7 subarrays with a sum divisible by k = 5:\n\t\t[4, 5, 0, -2, -3, 1], [5], [5, 0], [5, 0, -2, -3], [0], [0, -2, -3], [-2, -3]\n\t\tExample 2:\n\t\tInput: nums = [5], k = 9\n\t\tOutput: 0\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1017, - "question": "class Solution:\n def oddEvenJumps(self, arr: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou are given an integer array arr. From some starting index, you can make a series of jumps. The (1st, 3rd, 5th, ...) jumps in the series are called odd-numbered jumps, and the (2nd, 4th, 6th, ...) jumps in the series are called even-numbered jumps. Note that the jumps are numbered, not the indices.\n\t\tYou may jump forward from index i to index j (with i < j) in the following way:\n\t\t\tDuring odd-numbered jumps (i.e., jumps 1, 3, 5, ...), you jump to the index j such that arr[i] <= arr[j] and arr[j] is the smallest possible value. If there are multiple such indices j, you can only jump to the smallest such index j.\n\t\t\tDuring even-numbered jumps (i.e., jumps 2, 4, 6, ...), you jump to the index j such that arr[i] >= arr[j] and arr[j] is the largest possible value. If there are multiple such indices j, you can only jump to the smallest such index j.\n\t\t\tIt may be the case that for some index i, there are no legal jumps.\n\t\tA starting index is good if, starting from that index, you can reach the end of the array (index arr.length - 1) by jumping some number of times (possibly 0 or more than once).\n\t\tReturn the number of good starting indices.\n\t\tExample 1:\n\t\tInput: arr = [10,13,12,14,15]\n\t\tOutput: 2\n\t\tExplanation: \n\t\tFrom starting index i = 0, we can make our 1st jump to i = 2 (since arr[2] is the smallest among arr[1], arr[2], arr[3], arr[4] that is greater or equal to arr[0]), then we cannot jump any more.\n\t\tFrom starting index i = 1 and i = 2, we can make our 1st jump to i = 3, then we cannot jump any more.\n\t\tFrom starting index i = 3, we can make our 1st jump to i = 4, so we have reached the end.\n\t\tFrom starting index i = 4, we have reached the end already.\n\t\tIn total, there are 2 different starting indices i = 3 and i = 4, where we can reach the end with some number of\n\t\tjumps.\n\t\tExample 2:\n\t\tInput: arr = [2,3,1,1,4]\n\t\tOutput: 3\n\t\tExplanation: \n\t\tFrom starting index i = 0, we make jumps to i = 1, i = 2, i = 3:\n\t\tDuring our 1st jump (odd-numbered), we first jump to i = 1 because arr[1] is the smallest value in [arr[1], arr[2], arr[3], arr[4]] that is greater than or equal to arr[0].\n\t\tDuring our 2nd jump (even-numbered), we jump from i = 1 to i = 2 because arr[2] is the largest value in [arr[2], arr[3], arr[4]] that is less than or equal to arr[1]. arr[3] is also the largest value, but 2 is a smaller index, so we can only jump to i = 2 and not i = 3\n\t\tDuring our 3rd jump (odd-numbered), we jump from i = 2 to i = 3 because arr[3] is the smallest value in [arr[3], arr[4]] that is greater than or equal to arr[2].\n\t\tWe can't jump from i = 3 to i = 4, so the starting index i = 0 is not good.\n\t\tIn a similar manner, we can deduce that:\n\t\tFrom starting index i = 1, we jump to i = 4, so we reach the end.\n\t\tFrom starting index i = 2, we jump to i = 3, and then we can't jump anymore.\n\t\tFrom starting index i = 3, we jump to i = 4, so we reach the end.\n\t\tFrom starting index i = 4, we are already at the end.\n\t\tIn total, there are 3 different starting indices i = 1, i = 3, and i = 4, where we can reach the end with some\n\t\tnumber of jumps.\n\t\tExample 3:\n\t\tInput: arr = [5,1,3,4,2]\n\t\tOutput: 3\n\t\tExplanation: We can reach the end from starting indices 1, 2, and 4.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1018, - "question": "class Solution:\n def largestPerimeter(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tGiven an integer array nums, return the largest perimeter of a triangle with a non-zero area, formed from three of these lengths. If it is impossible to form any triangle of a non-zero area, return 0.\n\t\tExample 1:\n\t\tInput: nums = [2,1,2]\n\t\tOutput: 5\n\t\tExplanation: You can form a triangle with three side lengths: 1, 2, and 2.\n\t\tExample 2:\n\t\tInput: nums = [1,2,1,10]\n\t\tOutput: 0\n\t\tExplanation: \n\t\tYou cannot use the side lengths 1, 1, and 2 to form a triangle.\n\t\tYou cannot use the side lengths 1, 1, and 10 to form a triangle.\n\t\tYou cannot use the side lengths 1, 2, and 10 to form a triangle.\n\t\tAs we cannot use any three side lengths to form a triangle of non-zero area, we return 0.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1019, - "question": "class Solution:\n def sortedSquares(self, nums: List[int]) -> List[int]:\n\t\t\"\"\"\n\t\tGiven an integer array nums sorted in non-decreasing order, return an array of the squares of each number sorted in non-decreasing order.\n\t\tExample 1:\n\t\tInput: nums = [-4,-1,0,3,10]\n\t\tOutput: [0,1,9,16,100]\n\t\tExplanation: After squaring, the array becomes [16,1,0,9,100].\n\t\tAfter sorting, it becomes [0,1,9,16,100].\n\t\tExample 2:\n\t\tInput: nums = [-7,-3,2,3,11]\n\t\tOutput: [4,9,9,49,121]\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1020, - "question": "class Solution:\n def maxTurbulenceSize(self, arr: List[int]) -> int:\n\t\t\"\"\"\n\t\tGiven an integer array arr, return the length of a maximum size turbulent subarray of arr.\n\t\tA subarray is turbulent if the comparison sign flips between each adjacent pair of elements in the subarray.\n\t\tMore formally, a subarray [arr[i], arr[i + 1], ..., arr[j]] of arr is said to be turbulent if and only if:\n\t\t\tFor i <= k < j:\n\t\t\t\tarr[k] > arr[k + 1] when k is odd, and\n\t\t\t\tarr[k] < arr[k + 1] when k is even.\n\t\t\tOr, for i <= k < j:\n\t\t\t\tarr[k] > arr[k + 1] when k is even, and\n\t\t\t\tarr[k] < arr[k + 1] when k is odd.\n\t\tExample 1:\n\t\tInput: arr = [9,4,2,10,7,8,8,1,9]\n\t\tOutput: 5\n\t\tExplanation: arr[1] > arr[2] < arr[3] > arr[4] < arr[5]\n\t\tExample 2:\n\t\tInput: arr = [4,8,12,16]\n\t\tOutput: 2\n\t\tExample 3:\n\t\tInput: arr = [100]\n\t\tOutput: 1\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1021, - "question": "class Solution:\n def distributeCoins(self, root: Optional[TreeNode]) -> int:\n\t\t\"\"\"\n\t\tYou are given the root of a binary tree with n nodes where each node in the tree has node.val coins. There are n coins in total throughout the whole tree.\n\t\tIn one move, we may choose two adjacent nodes and move one coin from one node to another. A move may be from parent to child, or from child to parent.\n\t\tReturn the minimum number of moves required to make every node have exactly one coin.\n\t\tExample 1:\n\t\tInput: root = [3,0,0]\n\t\tOutput: 2\n\t\tExplanation: From the root of the tree, we move one coin to its left child, and one coin to its right child.\n\t\tExample 2:\n\t\tInput: root = [0,3,0]\n\t\tOutput: 3\n\t\tExplanation: From the left child of the root, we move two coins to the root [taking two moves]. Then, we move one coin from the root of the tree to the right child.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1022, - "question": "class Solution:\n def uniquePathsIII(self, grid: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tYou are given an m x n integer array grid where grid[i][j] could be:\n\t\t\t1 representing the starting square. There is exactly one starting square.\n\t\t\t2 representing the ending square. There is exactly one ending square.\n\t\t\t0 representing empty squares we can walk over.\n\t\t\t-1 representing obstacles that we cannot walk over.\n\t\tReturn the number of 4-directional walks from the starting square to the ending square, that walk over every non-obstacle square exactly once.\n\t\tExample 1:\n\t\tInput: grid = [[1,0,0,0],[0,0,0,0],[0,0,2,-1]]\n\t\tOutput: 2\n\t\tExplanation: We have the following two paths: \n\t\t1. (0,0),(0,1),(0,2),(0,3),(1,3),(1,2),(1,1),(1,0),(2,0),(2,1),(2,2)\n\t\t2. (0,0),(1,0),(2,0),(2,1),(1,1),(0,1),(0,2),(0,3),(1,3),(1,2),(2,2)\n\t\tExample 2:\n\t\tInput: grid = [[1,0,0,0],[0,0,0,0],[0,0,0,2]]\n\t\tOutput: 4\n\t\tExplanation: We have the following four paths: \n\t\t1. (0,0),(0,1),(0,2),(0,3),(1,3),(1,2),(1,1),(1,0),(2,0),(2,1),(2,2),(2,3)\n\t\t2. (0,0),(0,1),(1,1),(1,0),(2,0),(2,1),(2,2),(1,2),(0,2),(0,3),(1,3),(2,3)\n\t\t3. (0,0),(1,0),(2,0),(2,1),(2,2),(1,2),(1,1),(0,1),(0,2),(0,3),(1,3),(2,3)\n\t\t4. (0,0),(1,0),(2,0),(2,1),(1,1),(0,1),(0,2),(0,3),(1,3),(1,2),(2,2),(2,3)\n\t\tExample 3:\n\t\tInput: grid = [[0,1],[2,0]]\n\t\tOutput: 0\n\t\tExplanation: There is no path that walks over every empty square exactly once.\n\t\tNote that the starting and ending square can be anywhere in the grid.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1023, - "question": "class TimeMap:\n def __init__(self):\n def set(self, key: str, value: str, timestamp: int) -> None:\n def get(self, key: str, timestamp: int) -> str:\n\t\t\"\"\"\n\t\tDesign a time-based key-value data structure that can store multiple values for the same key at different time stamps and retrieve the key's value at a certain timestamp.\n\t\tImplement the TimeMap class:\n\t\t\tTimeMap() Initializes the object of the data structure.\n\t\t\tvoid set(String key, String value, int timestamp) Stores the key key with the value value at the given time timestamp.\n\t\t\tString get(String key, int timestamp) Returns a value such that set was called previously, with timestamp_prev <= timestamp. If there are multiple such values, it returns the value associated with the largest timestamp_prev. If there are no values, it returns \"\".\n\t\tExample 1:\n\t\tInput\n\t\t[\"TimeMap\", \"set\", \"get\", \"get\", \"set\", \"get\", \"get\"]\n\t\t[[], [\"foo\", \"bar\", 1], [\"foo\", 1], [\"foo\", 3], [\"foo\", \"bar2\", 4], [\"foo\", 4], [\"foo\", 5]]\n\t\tOutput\n\t\t[null, null, \"bar\", \"bar\", null, \"bar2\", \"bar2\"]\n\t\tExplanation\n\t\tTimeMap timeMap = new TimeMap();\n\t\ttimeMap.set(\"foo\", \"bar\", 1); // store the key \"foo\" and value \"bar\" along with timestamp = 1.\n\t\ttimeMap.get(\"foo\", 1); // return \"bar\"\n\t\ttimeMap.get(\"foo\", 3); // return \"bar\", since there is no value corresponding to foo at timestamp 3 and timestamp 2, then the only value is at timestamp 1 is \"bar\".\n\t\ttimeMap.set(\"foo\", \"bar2\", 4); // store the key \"foo\" and value \"bar2\" along with timestamp = 4.\n\t\ttimeMap.get(\"foo\", 4); // return \"bar2\"\n\t\ttimeMap.get(\"foo\", 5); // return \"bar2\"\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1024, - "question": "class Solution:\n def countTriplets(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tGiven an integer array nums, return the number of AND triples.\n\t\tAn AND triple is a triple of indices (i, j, k) such that:\n\t\t\t0 <= i < nums.length\n\t\t\t0 <= j < nums.length\n\t\t\t0 <= k < nums.length\n\t\t\tnums[i] & nums[j] & nums[k] == 0, where & represents the bitwise-AND operator.\n\t\tExample 1:\n\t\tInput: nums = [2,1,3]\n\t\tOutput: 12\n\t\tExplanation: We could choose the following i, j, k triples:\n\t\t(i=0, j=0, k=1) : 2 & 2 & 1\n\t\t(i=0, j=1, k=0) : 2 & 1 & 2\n\t\t(i=0, j=1, k=1) : 2 & 1 & 1\n\t\t(i=0, j=1, k=2) : 2 & 1 & 3\n\t\t(i=0, j=2, k=1) : 2 & 3 & 1\n\t\t(i=1, j=0, k=0) : 1 & 2 & 2\n\t\t(i=1, j=0, k=1) : 1 & 2 & 1\n\t\t(i=1, j=0, k=2) : 1 & 2 & 3\n\t\t(i=1, j=1, k=0) : 1 & 1 & 2\n\t\t(i=1, j=2, k=0) : 1 & 3 & 2\n\t\t(i=2, j=0, k=1) : 3 & 2 & 1\n\t\t(i=2, j=1, k=0) : 3 & 1 & 2\n\t\tExample 2:\n\t\tInput: nums = [0,0,0]\n\t\tOutput: 27\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1025, - "question": "class Solution:\n def mincostTickets(self, days: List[int], costs: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou have planned some train traveling one year in advance. The days of the year in which you will travel are given as an integer array days. Each day is an integer from 1 to 365.\n\t\tTrain tickets are sold in three different ways:\n\t\t\ta 1-day pass is sold for costs[0] dollars,\n\t\t\ta 7-day pass is sold for costs[1] dollars, and\n\t\t\ta 30-day pass is sold for costs[2] dollars.\n\t\tThe passes allow that many days of consecutive travel.\n\t\t\tFor example, if we get a 7-day pass on day 2, then we can travel for 7 days: 2, 3, 4, 5, 6, 7, and 8.\n\t\tReturn the minimum number of dollars you need to travel every day in the given list of days.\n\t\tExample 1:\n\t\tInput: days = [1,4,6,7,8,20], costs = [2,7,15]\n\t\tOutput: 11\n\t\tExplanation: For example, here is one way to buy passes that lets you travel your travel plan:\n\t\tOn day 1, you bought a 1-day pass for costs[0] = $2, which covered day 1.\n\t\tOn day 3, you bought a 7-day pass for costs[1] = $7, which covered days 3, 4, ..., 9.\n\t\tOn day 20, you bought a 1-day pass for costs[0] = $2, which covered day 20.\n\t\tIn total, you spent $11 and covered all the days of your travel.\n\t\tExample 2:\n\t\tInput: days = [1,2,3,4,5,6,7,8,9,10,30,31], costs = [2,7,15]\n\t\tOutput: 17\n\t\tExplanation: For example, here is one way to buy passes that lets you travel your travel plan:\n\t\tOn day 1, you bought a 30-day pass for costs[2] = $15 which covered days 1, 2, ..., 30.\n\t\tOn day 31, you bought a 1-day pass for costs[0] = $2 which covered day 31.\n\t\tIn total, you spent $17 and covered all the days of your travel.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1026, - "question": "class Solution:\n def strWithout3a3b(self, a: int, b: int) -> str:\n\t\t\"\"\"\n\t\tGiven two integers a and b, return any string s such that:\n\t\t\ts has length a + b and contains exactly a 'a' letters, and exactly b 'b' letters,\n\t\t\tThe substring 'aaa' does not occur in s, and\n\t\t\tThe substring 'bbb' does not occur in s.\n\t\tExample 1:\n\t\tInput: a = 1, b = 2\n\t\tOutput: \"abb\"\n\t\tExplanation: \"abb\", \"bab\" and \"bba\" are all correct answers.\n\t\tExample 2:\n\t\tInput: a = 4, b = 1\n\t\tOutput: \"aabaa\"\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1027, - "question": "class Solution:\n def sumEvenAfterQueries(self, nums: List[int], queries: List[List[int]]) -> List[int]:\n\t\t\"\"\"\n\t\tYou are given an integer array nums and an array queries where queries[i] = [vali, indexi].\n\t\tFor each query i, first, apply nums[indexi] = nums[indexi] + vali, then print the sum of the even values of nums.\n\t\tReturn an integer array answer where answer[i] is the answer to the ith query.\n\t\tExample 1:\n\t\tInput: nums = [1,2,3,4], queries = [[1,0],[-3,1],[-4,0],[2,3]]\n\t\tOutput: [8,6,2,4]\n\t\tExplanation: At the beginning, the array is [1,2,3,4].\n\t\tAfter adding 1 to nums[0], the array is [2,2,3,4], and the sum of even values is 2 + 2 + 4 = 8.\n\t\tAfter adding -3 to nums[1], the array is [2,-1,3,4], and the sum of even values is 2 + 4 = 6.\n\t\tAfter adding -4 to nums[0], the array is [-2,-1,3,4], and the sum of even values is -2 + 4 = 2.\n\t\tAfter adding 2 to nums[3], the array is [-2,-1,3,6], and the sum of even values is -2 + 6 = 4.\n\t\tExample 2:\n\t\tInput: nums = [1], queries = [[4,0]]\n\t\tOutput: [0]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1028, - "question": "class Solution:\n def intervalIntersection(self, firstList: List[List[int]], secondList: List[List[int]]) -> List[List[int]]:\n\t\t\"\"\"\n\t\tYou are given two lists of closed intervals, firstList and secondList, where firstList[i] = [starti, endi] and secondList[j] = [startj, endj]. Each list of intervals is pairwise disjoint and in sorted order.\n\t\tReturn the intersection of these two interval lists.\n\t\tA closed interval [a, b] (with a <= b) denotes the set of real numbers x with a <= x <= b.\n\t\tThe intersection of two closed intervals is a set of real numbers that are either empty or represented as a closed interval. For example, the intersection of [1, 3] and [2, 4] is [2, 3].\n\t\tExample 1:\n\t\tInput: firstList = [[0,2],[5,10],[13,23],[24,25]], secondList = [[1,5],[8,12],[15,24],[25,26]]\n\t\tOutput: [[1,2],[5,5],[8,10],[15,23],[24,24],[25,25]]\n\t\tExample 2:\n\t\tInput: firstList = [[1,3],[5,9]], secondList = []\n\t\tOutput: []\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1029, - "question": "class Solution:\n def verticalTraversal(self, root: Optional[TreeNode]) -> List[List[int]]:\n\t\t\"\"\"\n\t\tGiven the root of a binary tree, calculate the vertical order traversal of the binary tree.\n\t\tFor each node at position (row, col), its left and right children will be at positions (row + 1, col - 1) and (row + 1, col + 1) respectively. The root of the tree is at (0, 0).\n\t\tThe vertical order traversal of a binary tree is a list of top-to-bottom orderings for each column index starting from the leftmost column and ending on the rightmost column. There may be multiple nodes in the same row and same column. In such a case, sort these nodes by their values.\n\t\tReturn the vertical order traversal of the binary tree.\n\t\tExample 1:\n\t\tInput: root = [3,9,20,null,null,15,7]\n\t\tOutput: [[9],[3,15],[20],[7]]\n\t\tExplanation:\n\t\tColumn -1: Only node 9 is in this column.\n\t\tColumn 0: Nodes 3 and 15 are in this column in that order from top to bottom.\n\t\tColumn 1: Only node 20 is in this column.\n\t\tColumn 2: Only node 7 is in this column.\n\t\tExample 2:\n\t\tInput: root = [1,2,3,4,5,6,7]\n\t\tOutput: [[4],[2],[1,5,6],[3],[7]]\n\t\tExplanation:\n\t\tColumn -2: Only node 4 is in this column.\n\t\tColumn -1: Only node 2 is in this column.\n\t\tColumn 0: Nodes 1, 5, and 6 are in this column.\n\t\t 1 is at the top, so it comes first.\n\t\t 5 and 6 are at the same position (2, 0), so we order them by their value, 5 before 6.\n\t\tColumn 1: Only node 3 is in this column.\n\t\tColumn 2: Only node 7 is in this column.\n\t\tExample 3:\n\t\tInput: root = [1,2,3,4,6,5,7]\n\t\tOutput: [[4],[2],[1,5,6],[3],[7]]\n\t\tExplanation:\n\t\tThis case is the exact same as example 2, but with nodes 5 and 6 swapped.\n\t\tNote that the solution remains the same since 5 and 6 are in the same location and should be ordered by their values.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1030, - "question": "class Solution:\n def smallestFromLeaf(self, root: Optional[TreeNode]) -> str:\n\t\t\"\"\"\n\t\tYou are given the root of a binary tree where each node has a value in the range [0, 25] representing the letters 'a' to 'z'.\n\t\tReturn the lexicographically smallest string that starts at a leaf of this tree and ends at the root.\n\t\tAs a reminder, any shorter prefix of a string is lexicographically smaller.\n\t\t\tFor example, \"ab\" is lexicographically smaller than \"aba\".\n\t\tA leaf of a node is a node that has no children.\n\t\tExample 1:\n\t\tInput: root = [0,1,2,3,4,3,4]\n\t\tOutput: \"dba\"\n\t\tExample 2:\n\t\tInput: root = [25,1,3,1,3,0,2]\n\t\tOutput: \"adz\"\n\t\tExample 3:\n\t\tInput: root = [2,2,1,null,1,0,null,0]\n\t\tOutput: \"abc\"\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1031, - "question": "class Solution:\n def addToArrayForm(self, num: List[int], k: int) -> List[int]:\n\t\t\"\"\"\n\t\tThe array-form of an integer num is an array representing its digits in left to right order.\n\t\t\tFor example, for num = 1321, the array form is [1,3,2,1].\n\t\tGiven num, the array-form of an integer, and an integer k, return the array-form of the integer num + k.\n\t\tExample 1:\n\t\tInput: num = [1,2,0,0], k = 34\n\t\tOutput: [1,2,3,4]\n\t\tExplanation: 1200 + 34 = 1234\n\t\tExample 2:\n\t\tInput: num = [2,7,4], k = 181\n\t\tOutput: [4,5,5]\n\t\tExplanation: 274 + 181 = 455\n\t\tExample 3:\n\t\tInput: num = [2,1,5], k = 806\n\t\tOutput: [1,0,2,1]\n\t\tExplanation: 215 + 806 = 1021\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1032, - "question": "class Solution:\n def equationsPossible(self, equations: List[str]) -> bool:\n\t\t\"\"\"\n\t\tYou are given an array of strings equations that represent relationships between variables where each string equations[i] is of length 4 and takes one of two different forms: \"xi==yi\" or \"xi!=yi\".Here, xi and yi are lowercase letters (not necessarily different) that represent one-letter variable names.\n\t\tReturn true if it is possible to assign integers to variable names so as to satisfy all the given equations, or false otherwise.\n\t\tExample 1:\n\t\tInput: equations = [\"a==b\",\"b!=a\"]\n\t\tOutput: false\n\t\tExplanation: If we assign say, a = 1 and b = 1, then the first equation is satisfied, but not the second.\n\t\tThere is no way to assign the variables to satisfy both equations.\n\t\tExample 2:\n\t\tInput: equations = [\"b==a\",\"a==b\"]\n\t\tOutput: true\n\t\tExplanation: We could assign a = 1 and b = 1 to satisfy both equations.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1033, - "question": "class Solution:\n def brokenCalc(self, startValue: int, target: int) -> int:\n\t\t\"\"\"\n\t\tThere is a broken calculator that has the integer startValue on its display initially. In one operation, you can:\n\t\t\tmultiply the number on display by 2, or\n\t\t\tsubtract 1 from the number on display.\n\t\tGiven two integers startValue and target, return the minimum number of operations needed to display target on the calculator.\n\t\tExample 1:\n\t\tInput: startValue = 2, target = 3\n\t\tOutput: 2\n\t\tExplanation: Use double operation and then decrement operation {2 -> 4 -> 3}.\n\t\tExample 2:\n\t\tInput: startValue = 5, target = 8\n\t\tOutput: 2\n\t\tExplanation: Use decrement and then double {5 -> 4 -> 8}.\n\t\tExample 3:\n\t\tInput: startValue = 3, target = 10\n\t\tOutput: 3\n\t\tExplanation: Use double, decrement and double {3 -> 6 -> 5 -> 10}.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1034, - "question": "class Solution:\n def subarraysWithKDistinct(self, nums: List[int], k: int) -> int:\n\t\t\"\"\"\n\t\tGiven an integer array nums and an integer k, return the number of good subarrays of nums.\n\t\tA good array is an array where the number of different integers in that array is exactly k.\n\t\t\tFor example, [1,2,3,1,2] has 3 different integers: 1, 2, and 3.\n\t\tA subarray is a contiguous part of an array.\n\t\tExample 1:\n\t\tInput: nums = [1,2,1,2,3], k = 2\n\t\tOutput: 7\n\t\tExplanation: Subarrays formed with exactly 2 different integers: [1,2], [2,1], [1,2], [2,3], [1,2,1], [2,1,2], [1,2,1,2]\n\t\tExample 2:\n\t\tInput: nums = [1,2,1,3,4], k = 3\n\t\tOutput: 3\n\t\tExplanation: Subarrays formed with exactly 3 different integers: [1,2,1,3], [2,1,3], [1,3,4].\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1035, - "question": "class Solution:\n def isCousins(self, root: Optional[TreeNode], x: int, y: int) -> bool:\n\t\t\"\"\"\n\t\tGiven the root of a binary tree with unique values and the values of two different nodes of the tree x and y, return true if the nodes corresponding to the values x and y in the tree are cousins, or false otherwise.\n\t\tTwo nodes of a binary tree are cousins if they have the same depth with different parents.\n\t\tNote that in a binary tree, the root node is at the depth 0, and children of each depth k node are at the depth k + 1.\n\t\tExample 1:\n\t\tInput: root = [1,2,3,4], x = 4, y = 3\n\t\tOutput: false\n\t\tExample 2:\n\t\tInput: root = [1,2,3,null,4,null,5], x = 5, y = 4\n\t\tOutput: true\n\t\tExample 3:\n\t\tInput: root = [1,2,3,null,4], x = 2, y = 3\n\t\tOutput: false\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1036, - "question": "class Solution:\n def orangesRotting(self, grid: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tYou are given an m x n grid where each cell can have one of three values:\n\t\t\t0 representing an empty cell,\n\t\t\t1 representing a fresh orange, or\n\t\t\t2 representing a rotten orange.\n\t\tEvery minute, any fresh orange that is 4-directionally adjacent to a rotten orange becomes rotten.\n\t\tReturn the minimum number of minutes that must elapse until no cell has a fresh orange. If this is impossible, return -1.\n\t\tExample 1:\n\t\tInput: grid = [[2,1,1],[1,1,0],[0,1,1]]\n\t\tOutput: 4\n\t\tExample 2:\n\t\tInput: grid = [[2,1,1],[0,1,1],[1,0,1]]\n\t\tOutput: -1\n\t\tExplanation: The orange in the bottom left corner (row 2, column 0) is never rotten, because rotting only happens 4-directionally.\n\t\tExample 3:\n\t\tInput: grid = [[0,2]]\n\t\tOutput: 0\n\t\tExplanation: Since there are already no fresh oranges at minute 0, the answer is just 0.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1037, - "question": "class Solution:\n def minKBitFlips(self, nums: List[int], k: int) -> int:\n\t\t\"\"\"\n\t\tYou are given a binary array nums and an integer k.\n\t\tA k-bit flip is choosing a subarray of length k from nums and simultaneously changing every 0 in the subarray to 1, and every 1 in the subarray to 0.\n\t\tReturn the minimum number of k-bit flips required so that there is no 0 in the array. If it is not possible, return -1.\n\t\tA subarray is a contiguous part of an array.\n\t\tExample 1:\n\t\tInput: nums = [0,1,0], k = 1\n\t\tOutput: 2\n\t\tExplanation: Flip nums[0], then flip nums[2].\n\t\tExample 2:\n\t\tInput: nums = [1,1,0], k = 2\n\t\tOutput: -1\n\t\tExplanation: No matter how we flip subarrays of size 2, we cannot make the array become [1,1,1].\n\t\tExample 3:\n\t\tInput: nums = [0,0,0,1,0,1,1,0], k = 3\n\t\tOutput: 3\n\t\tExplanation: \n\t\tFlip nums[0],nums[1],nums[2]: nums becomes [1,1,1,1,0,1,1,0]\n\t\tFlip nums[4],nums[5],nums[6]: nums becomes [1,1,1,1,1,0,0,0]\n\t\tFlip nums[5],nums[6],nums[7]: nums becomes [1,1,1,1,1,1,1,1]\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1038, - "question": "class Solution:\n def numSquarefulPerms(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tAn array is squareful if the sum of every pair of adjacent elements is a perfect square.\n\t\tGiven an integer array nums, return the number of permutations of nums that are squareful.\n\t\tTwo permutations perm1 and perm2 are different if there is some index i such that perm1[i] != perm2[i].\n\t\tExample 1:\n\t\tInput: nums = [1,17,8]\n\t\tOutput: 2\n\t\tExplanation: [1,8,17] and [17,8,1] are the valid permutations.\n\t\tExample 2:\n\t\tInput: nums = [2,2,2]\n\t\tOutput: 1\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1039, - "question": "class Solution:\n def findJudge(self, n: int, trust: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tIn a town, there are n people labeled from 1 to n. There is a rumor that one of these people is secretly the town judge.\n\t\tIf the town judge exists, then:\n\t\t\tThe town judge trusts nobody.\n\t\t\tEverybody (except for the town judge) trusts the town judge.\n\t\t\tThere is exactly one person that satisfies properties 1 and 2.\n\t\tYou are given an array trust where trust[i] = [ai, bi] representing that the person labeled ai trusts the person labeled bi. If a trust relationship does not exist in trust array, then such a trust relationship does not exist.\n\t\tReturn the label of the town judge if the town judge exists and can be identified, or return -1 otherwise.\n\t\tExample 1:\n\t\tInput: n = 2, trust = [[1,2]]\n\t\tOutput: 2\n\t\tExample 2:\n\t\tInput: n = 3, trust = [[1,3],[2,3]]\n\t\tOutput: 3\n\t\tExample 3:\n\t\tInput: n = 3, trust = [[1,3],[2,3],[3,1]]\n\t\tOutput: -1\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1040, - "question": "class Solution:\n def insertIntoMaxTree(self, root: Optional[TreeNode], val: int) -> Optional[TreeNode]:\n\t\t\"\"\"\n\t\tA maximum tree is a tree where every node has a value greater than any other value in its subtree.\n\t\tYou are given the root of a maximum binary tree and an integer val.\n\t\tJust as in the previous problem, the given tree was constructed from a list a (root = Construct(a)) recursively with the following Construct(a) routine:\n\t\t\tIf a is empty, return null.\n\t\t\tOtherwise, let a[i] be the largest element of a. Create a root node with the value a[i].\n\t\t\tThe left child of root will be Construct([a[0], a[1], ..., a[i - 1]]).\n\t\t\tThe right child of root will be Construct([a[i + 1], a[i + 2], ..., a[a.length - 1]]).\n\t\t\tReturn root.\n\t\tNote that we were not given a directly, only a root node root = Construct(a).\n\t\tSuppose b is a copy of a with the value val appended to it. It is guaranteed that b has unique values.\n\t\tReturn Construct(b).\n\t\tExample 1:\n\t\tInput: root = [4,1,3,null,null,2], val = 5\n\t\tOutput: [5,4,null,1,3,null,null,2]\n\t\tExplanation: a = [1,4,2,3], b = [1,4,2,3,5]\n\t\tExample 2:\n\t\tInput: root = [5,2,4,null,1], val = 3\n\t\tOutput: [5,2,4,null,1,null,3]\n\t\tExplanation: a = [2,1,5,4], b = [2,1,5,4,3]\n\t\tExample 3:\n\t\tInput: root = [5,2,3,null,1], val = 4\n\t\tOutput: [5,2,4,null,1,3]\n\t\tExplanation: a = [2,1,5,3], b = [2,1,5,3,4]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1041, - "question": "class Solution:\n def numRookCaptures(self, board: List[List[str]]) -> int:\n\t\t\"\"\"\n\t\tOn an 8 x 8 chessboard, there is exactly one white rook 'R' and some number of white bishops 'B', black pawns 'p', and empty squares '.'.\n\t\tWhen the rook moves, it chooses one of four cardinal directions (north, east, south, or west), then moves in that direction until it chooses to stop, reaches the edge of the board, captures a black pawn, or is blocked by a white bishop. A rook is considered attacking a pawn if the rook can capture the pawn on the rook's turn. The number of available captures for the white rook is the number of pawns that the rook is attacking.\n\t\tReturn the number of available captures for the white rook.\n\t\tExample 1:\n\t\tInput: board = [[\".\",\".\",\".\",\".\",\".\",\".\",\".\",\".\"],[\".\",\".\",\".\",\"p\",\".\",\".\",\".\",\".\"],[\".\",\".\",\".\",\"R\",\".\",\".\",\".\",\"p\"],[\".\",\".\",\".\",\".\",\".\",\".\",\".\",\".\"],[\".\",\".\",\".\",\".\",\".\",\".\",\".\",\".\"],[\".\",\".\",\".\",\"p\",\".\",\".\",\".\",\".\"],[\".\",\".\",\".\",\".\",\".\",\".\",\".\",\".\"],[\".\",\".\",\".\",\".\",\".\",\".\",\".\",\".\"]]\n\t\tOutput: 3\n\t\tExplanation: In this example, the rook is attacking all the pawns.\n\t\tExample 2:\n\t\tInput: board = [[\".\",\".\",\".\",\".\",\".\",\".\",\".\",\".\"],[\".\",\"p\",\"p\",\"p\",\"p\",\"p\",\".\",\".\"],[\".\",\"p\",\"p\",\"B\",\"p\",\"p\",\".\",\".\"],[\".\",\"p\",\"B\",\"R\",\"B\",\"p\",\".\",\".\"],[\".\",\"p\",\"p\",\"B\",\"p\",\"p\",\".\",\".\"],[\".\",\"p\",\"p\",\"p\",\"p\",\"p\",\".\",\".\"],[\".\",\".\",\".\",\".\",\".\",\".\",\".\",\".\"],[\".\",\".\",\".\",\".\",\".\",\".\",\".\",\".\"]]\n\t\tOutput: 0\n\t\tExplanation: The bishops are blocking the rook from attacking any of the pawns.\n\t\tExample 3:\n\t\tInput: board = [[\".\",\".\",\".\",\".\",\".\",\".\",\".\",\".\"],[\".\",\".\",\".\",\"p\",\".\",\".\",\".\",\".\"],[\".\",\".\",\".\",\"p\",\".\",\".\",\".\",\".\"],[\"p\",\"p\",\".\",\"R\",\".\",\"p\",\"B\",\".\"],[\".\",\".\",\".\",\".\",\".\",\".\",\".\",\".\"],[\".\",\".\",\".\",\"B\",\".\",\".\",\".\",\".\"],[\".\",\".\",\".\",\"p\",\".\",\".\",\".\",\".\"],[\".\",\".\",\".\",\".\",\".\",\".\",\".\",\".\"]]\n\t\tOutput: 3\n\t\tExplanation: The rook is attacking the pawns at positions b5, d6, and f5.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1042, - "question": "class Solution:\n def mergeStones(self, stones: List[int], k: int) -> int:\n\t\t\"\"\"\n\t\tThere are n piles of stones arranged in a row. The ith pile has stones[i] stones.\n\t\tA move consists of merging exactly k consecutive piles into one pile, and the cost of this move is equal to the total number of stones in these k piles.\n\t\tReturn the minimum cost to merge all piles of stones into one pile. If it is impossible, return -1.\n\t\tExample 1:\n\t\tInput: stones = [3,2,4,1], k = 2\n\t\tOutput: 20\n\t\tExplanation: We start with [3, 2, 4, 1].\n\t\tWe merge [3, 2] for a cost of 5, and we are left with [5, 4, 1].\n\t\tWe merge [4, 1] for a cost of 5, and we are left with [5, 5].\n\t\tWe merge [5, 5] for a cost of 10, and we are left with [10].\n\t\tThe total cost was 20, and this is the minimum possible.\n\t\tExample 2:\n\t\tInput: stones = [3,2,4,1], k = 3\n\t\tOutput: -1\n\t\tExplanation: After any merge operation, there are 2 piles left, and we can't merge anymore. So the task is impossible.\n\t\tExample 3:\n\t\tInput: stones = [3,5,1,2,6], k = 3\n\t\tOutput: 25\n\t\tExplanation: We start with [3, 5, 1, 2, 6].\n\t\tWe merge [5, 1, 2] for a cost of 8, and we are left with [3, 8, 6].\n\t\tWe merge [3, 8, 6] for a cost of 17, and we are left with [17].\n\t\tThe total cost was 25, and this is the minimum possible.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1043, - "question": "class Solution:\n def gridIllumination(self, n: int, lamps: List[List[int]], queries: List[List[int]]) -> List[int]:\n\t\t\"\"\"\n\t\tThere is a 2D grid of size n x n where each cell of this grid has a lamp that is initially turned off.\n\t\tYou are given a 2D array of lamp positions lamps, where lamps[i] = [rowi, coli] indicates that the lamp at grid[rowi][coli] is turned on. Even if the same lamp is listed more than once, it is turned on.\n\t\tWhen a lamp is turned on, it illuminates its cell and all other cells in the same row, column, or diagonal.\n\t\tYou are also given another 2D array queries, where queries[j] = [rowj, colj]. For the jth query, determine whether grid[rowj][colj] is illuminated or not. After answering the jth query, turn off the lamp at grid[rowj][colj] and its 8 adjacent lamps if they exist. A lamp is adjacent if its cell shares either a side or corner with grid[rowj][colj].\n\t\tReturn an array of integers ans, where ans[j] should be 1 if the cell in the jth query was illuminated, or 0 if the lamp was not.\n\t\tExample 1:\n\t\tInput: n = 5, lamps = [[0,0],[4,4]], queries = [[1,1],[1,0]]\n\t\tOutput: [1,0]\n\t\tExplanation: We have the initial grid with all lamps turned off. In the above picture we see the grid after turning on the lamp at grid[0][0] then turning on the lamp at grid[4][4].\n\t\tThe 0th query asks if the lamp at grid[1][1] is illuminated or not (the blue square). It is illuminated, so set ans[0] = 1. Then, we turn off all lamps in the red square.\n\t\tThe 1st query asks if the lamp at grid[1][0] is illuminated or not (the blue square). It is not illuminated, so set ans[1] = 0. Then, we turn off all lamps in the red rectangle.\n\t\tExample 2:\n\t\tInput: n = 5, lamps = [[0,0],[4,4]], queries = [[1,1],[1,1]]\n\t\tOutput: [1,1]\n\t\tExample 3:\n\t\tInput: n = 5, lamps = [[0,0],[0,4]], queries = [[0,4],[0,1],[1,4]]\n\t\tOutput: [1,1,0]\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1044, - "question": "class Solution:\n def commonChars(self, words: List[str]) -> List[str]:\n\t\t\"\"\"\n\t\tGiven a string array words, return an array of all characters that show up in all strings within the words (including duplicates). You may return the answer in any order.\n\t\tExample 1:\n\t\tInput: words = [\"bella\",\"label\",\"roller\"]\n\t\tOutput: [\"e\",\"l\",\"l\"]\n\t\tExample 2:\n\t\tInput: words = [\"cool\",\"lock\",\"cook\"]\n\t\tOutput: [\"c\",\"o\"]\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1045, - "question": "class Solution:\n def isValid(self, s: str) -> bool:\n\t\t\"\"\"\n\t\tGiven a string s, determine if it is valid.\n\t\tA string s is valid if, starting with an empty string t = \"\", you can transform t into s after performing the following operation any number of times:\n\t\t\tInsert string \"abc\" into any position in t. More formally, t becomes tleft + \"abc\" + tright, where t == tleft + tright. Note that tleft and tright may be empty.\n\t\tReturn true if s is a valid string, otherwise, return false.\n\t\tExample 1:\n\t\tInput: s = \"aabcbc\"\n\t\tOutput: true\n\t\tExplanation:\n\t\t\"\" -> \"abc\" -> \"aabcbc\"\n\t\tThus, \"aabcbc\" is valid.\n\t\tExample 2:\n\t\tInput: s = \"abcabcababcc\"\n\t\tOutput: true\n\t\tExplanation:\n\t\t\"\" -> \"abc\" -> \"abcabc\" -> \"abcabcabc\" -> \"abcabcababcc\"\n\t\tThus, \"abcabcababcc\" is valid.\n\t\tExample 3:\n\t\tInput: s = \"abccba\"\n\t\tOutput: false\n\t\tExplanation: It is impossible to get \"abccba\" using the operation.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1046, - "question": "class Solution:\n def longestOnes(self, nums: List[int], k: int) -> int:\n\t\t\"\"\"\n\t\tGiven a binary array nums and an integer k, return the maximum number of consecutive 1's in the array if you can flip at most k 0's.\n\t\tExample 1:\n\t\tInput: nums = [1,1,1,0,0,0,1,1,1,1,0], k = 2\n\t\tOutput: 6\n\t\tExplanation: [1,1,1,0,0,1,1,1,1,1,1]\n\t\tBolded numbers were flipped from 0 to 1. The longest subarray is underlined.\n\t\tExample 2:\n\t\tInput: nums = [0,0,1,1,0,0,1,1,1,0,1,1,0,0,0,1,1,1,1], k = 3\n\t\tOutput: 10\n\t\tExplanation: [0,0,1,1,1,1,1,1,1,1,1,1,0,0,0,1,1,1,1]\n\t\tBolded numbers were flipped from 0 to 1. The longest subarray is underlined.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1047, - "question": "class Solution:\n def largestSumAfterKNegations(self, nums: List[int], k: int) -> int:\n\t\t\"\"\"\n\t\tGiven an integer array nums and an integer k, modify the array in the following way:\n\t\t\tchoose an index i and replace nums[i] with -nums[i].\n\t\tYou should apply this process exactly k times. You may choose the same index i multiple times.\n\t\tReturn the largest possible sum of the array after modifying it in this way.\n\t\tExample 1:\n\t\tInput: nums = [4,2,3], k = 1\n\t\tOutput: 5\n\t\tExplanation: Choose index 1 and nums becomes [4,-2,3].\n\t\tExample 2:\n\t\tInput: nums = [3,-1,0,2], k = 3\n\t\tOutput: 6\n\t\tExplanation: Choose indices (1, 2, 2) and nums becomes [3,1,0,2].\n\t\tExample 3:\n\t\tInput: nums = [2,-3,-1,5,-4], k = 2\n\t\tOutput: 13\n\t\tExplanation: Choose indices (1, 4) and nums becomes [2,3,-1,5,4].\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1048, - "question": "class Solution:\n def clumsy(self, n: int) -> int:\n\t\t\"\"\"\n\t\tThe factorial of a positive integer n is the product of all positive integers less than or equal to n.\n\t\t\tFor example, factorial(10) = 10 * 9 * 8 * 7 * 6 * 5 * 4 * 3 * 2 * 1.\n\t\tWe make a clumsy factorial using the integers in decreasing order by swapping out the multiply operations for a fixed rotation of operations with multiply '*', divide '/', add '+', and subtract '-' in this order.\n\t\t\tFor example, clumsy(10) = 10 * 9 / 8 + 7 - 6 * 5 / 4 + 3 - 2 * 1.\n\t\tHowever, these operations are still applied using the usual order of operations of arithmetic. We do all multiplication and division steps before any addition or subtraction steps, and multiplication and division steps are processed left to right.\n\t\tAdditionally, the division that we use is floor division such that 10 * 9 / 8 = 90 / 8 = 11.\n\t\tGiven an integer n, return the clumsy factorial of n.\n\t\tExample 1:\n\t\tInput: n = 4\n\t\tOutput: 7\n\t\tExplanation: 7 = 4 * 3 / 2 + 1\n\t\tExample 2:\n\t\tInput: n = 10\n\t\tOutput: 12\n\t\tExplanation: 12 = 10 * 9 / 8 + 7 - 6 * 5 / 4 + 3 - 2 * 1\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1049, - "question": "class Solution:\n def minDominoRotations(self, tops: List[int], bottoms: List[int]) -> int:\n\t\t\"\"\"\n\t\tIn a row of dominoes, tops[i] and bottoms[i] represent the top and bottom halves of the ith domino. (A domino is a tile with two numbers from 1 to 6 - one on each half of the tile.)\n\t\tWe may rotate the ith domino, so that tops[i] and bottoms[i] swap values.\n\t\tReturn the minimum number of rotations so that all the values in tops are the same, or all the values in bottoms are the same.\n\t\tIf it cannot be done, return -1.\n\t\tExample 1:\n\t\tInput: tops = [2,1,2,4,2,2], bottoms = [5,2,6,2,3,2]\n\t\tOutput: 2\n\t\tExplanation: \n\t\tThe first figure represents the dominoes as given by tops and bottoms: before we do any rotations.\n\t\tIf we rotate the second and fourth dominoes, we can make every value in the top row equal to 2, as indicated by the second figure.\n\t\tExample 2:\n\t\tInput: tops = [3,5,1,2,3], bottoms = [3,6,3,3,4]\n\t\tOutput: -1\n\t\tExplanation: \n\t\tIn this case, it is not possible to rotate the dominoes to make one row of values equal.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1050, - "question": "class Solution:\n def bstFromPreorder(self, preorder: List[int]) -> Optional[TreeNode]:\n\t\t\"\"\"\n\t\tGiven an array of integers preorder, which represents the preorder traversal of a BST (i.e., binary search tree), construct the tree and return its root.\n\t\tIt is guaranteed that there is always possible to find a binary search tree with the given requirements for the given test cases.\n\t\tA binary search tree is a binary tree where for every node, any descendant of Node.left has a value strictly less than Node.val, and any descendant of Node.right has a value strictly greater than Node.val.\n\t\tA preorder traversal of a binary tree displays the value of the node first, then traverses Node.left, then traverses Node.right.\n\t\tExample 1:\n\t\tInput: preorder = [8,5,1,7,10,12]\n\t\tOutput: [8,5,10,1,7,null,12]\n\t\tExample 2:\n\t\tInput: preorder = [1,3]\n\t\tOutput: [1,null,3]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1054, - "question": "class Solution:\n def bitwiseComplement(self, n: int) -> int:\n\t\t\"\"\"\n\t\tThe complement of an integer is the integer you get when you flip all the 0's to 1's and all the 1's to 0's in its binary representation.\n\t\t\tFor example, The integer 5 is \"101\" in binary and its complement is \"010\" which is the integer 2.\n\t\tGiven an integer n, return its complement.\n\t\tExample 1:\n\t\tInput: n = 5\n\t\tOutput: 2\n\t\tExplanation: 5 is \"101\" in binary, with complement \"010\" in binary, which is 2 in base-10.\n\t\tExample 2:\n\t\tInput: n = 7\n\t\tOutput: 0\n\t\tExplanation: 7 is \"111\" in binary, with complement \"000\" in binary, which is 0 in base-10.\n\t\tExample 3:\n\t\tInput: n = 10\n\t\tOutput: 5\n\t\tExplanation: 10 is \"1010\" in binary, with complement \"0101\" in binary, which is 5 in base-10.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1055, - "question": "class Solution:\n def numPairsDivisibleBy60(self, time: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou are given a list of songs where the ith song has a duration of time[i] seconds.\n\t\tReturn the number of pairs of songs for which their total duration in seconds is divisible by 60. Formally, we want the number of indices i, j such that i < j with (time[i] + time[j]) % 60 == 0.\n\t\tExample 1:\n\t\tInput: time = [30,20,150,100,40]\n\t\tOutput: 3\n\t\tExplanation: Three pairs have a total duration divisible by 60:\n\t\t(time[0] = 30, time[2] = 150): total duration 180\n\t\t(time[1] = 20, time[3] = 100): total duration 120\n\t\t(time[1] = 20, time[4] = 40): total duration 60\n\t\tExample 2:\n\t\tInput: time = [60,60,60]\n\t\tOutput: 3\n\t\tExplanation: All three pairs have a total duration of 120, which is divisible by 60.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1056, - "question": "class Solution:\n def shipWithinDays(self, weights: List[int], days: int) -> int:\n\t\t\"\"\"\n\t\tA conveyor belt has packages that must be shipped from one port to another within days days.\n\t\tThe ith package on the conveyor belt has a weight of weights[i]. Each day, we load the ship with packages on the conveyor belt (in the order given by weights). We may not load more weight than the maximum weight capacity of the ship.\n\t\tReturn the least weight capacity of the ship that will result in all the packages on the conveyor belt being shipped within days days.\n\t\tExample 1:\n\t\tInput: weights = [1,2,3,4,5,6,7,8,9,10], days = 5\n\t\tOutput: 15\n\t\tExplanation: A ship capacity of 15 is the minimum to ship all the packages in 5 days like this:\n\t\t1st day: 1, 2, 3, 4, 5\n\t\t2nd day: 6, 7\n\t\t3rd day: 8\n\t\t4th day: 9\n\t\t5th day: 10\n\t\tNote that the cargo must be shipped in the order given, so using a ship of capacity 14 and splitting the packages into parts like (2, 3, 4, 5), (1, 6, 7), (8), (9), (10) is not allowed.\n\t\tExample 2:\n\t\tInput: weights = [3,2,2,4,1,4], days = 3\n\t\tOutput: 6\n\t\tExplanation: A ship capacity of 6 is the minimum to ship all the packages in 3 days like this:\n\t\t1st day: 3, 2\n\t\t2nd day: 2, 4\n\t\t3rd day: 1, 4\n\t\tExample 3:\n\t\tInput: weights = [1,2,3,1,1], days = 4\n\t\tOutput: 3\n\t\tExplanation:\n\t\t1st day: 1\n\t\t2nd day: 2\n\t\t3rd day: 3\n\t\t4th day: 1, 1\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1057, - "question": "class Solution:\n def numDupDigitsAtMostN(self, n: int) -> int:\n\t\t\"\"\"\n\t\tGiven an integer n, return the number of positive integers in the range [1, n] that have at least one repeated digit.\n\t\tExample 1:\n\t\tInput: n = 20\n\t\tOutput: 1\n\t\tExplanation: The only positive number (<= 20) with at least 1 repeated digit is 11.\n\t\tExample 2:\n\t\tInput: n = 100\n\t\tOutput: 10\n\t\tExplanation: The positive numbers (<= 100) with atleast 1 repeated digit are 11, 22, 33, 44, 55, 66, 77, 88, 99, and 100.\n\t\tExample 3:\n\t\tInput: n = 1000\n\t\tOutput: 262\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1058, - "question": "class Solution:\n def smallestEquivalentString(self, s1: str, s2: str, baseStr: str) -> str:\n\t\t\"\"\"\n\t\tYou are given two strings of the same length s1 and s2 and a string baseStr.\n\t\tWe say s1[i] and s2[i] are equivalent characters.\n\t\t\tFor example, if s1 = \"abc\" and s2 = \"cde\", then we have 'a' == 'c', 'b' == 'd', and 'c' == 'e'.\n\t\tEquivalent characters follow the usual rules of any equivalence relation:\n\t\t\tReflexivity: 'a' == 'a'.\n\t\t\tSymmetry: 'a' == 'b' implies 'b' == 'a'.\n\t\t\tTransitivity: 'a' == 'b' and 'b' == 'c' implies 'a' == 'c'.\n\t\tFor example, given the equivalency information from s1 = \"abc\" and s2 = \"cde\", \"acd\" and \"aab\" are equivalent strings of baseStr = \"eed\", and \"aab\" is the lexicographically smallest equivalent string of baseStr.\n\t\tReturn the lexicographically smallest equivalent string of baseStr by using the equivalency information from s1 and s2.\n\t\tExample 1:\n\t\tInput: s1 = \"parker\", s2 = \"morris\", baseStr = \"parser\"\n\t\tOutput: \"makkek\"\n\t\tExplanation: Based on the equivalency information in s1 and s2, we can group their characters as [m,p], [a,o], [k,r,s], [e,i].\n\t\tThe characters in each group are equivalent and sorted in lexicographical order.\n\t\tSo the answer is \"makkek\".\n\t\tExample 2:\n\t\tInput: s1 = \"hello\", s2 = \"world\", baseStr = \"hold\"\n\t\tOutput: \"hdld\"\n\t\tExplanation: Based on the equivalency information in s1 and s2, we can group their characters as [h,w], [d,e,o], [l,r].\n\t\tSo only the second letter 'o' in baseStr is changed to 'd', the answer is \"hdld\".\n\t\tExample 3:\n\t\tInput: s1 = \"leetcode\", s2 = \"programs\", baseStr = \"sourcecode\"\n\t\tOutput: \"aauaaaaada\"\n\t\tExplanation: We group the equivalent characters in s1 and s2 as [a,o,e,r,s,c], [l,p], [g,t] and [d,m], thus all letters in baseStr except 'u' and 'd' are transformed to 'a', the answer is \"aauaaaaada\".\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1062, - "question": "class Solution:\n def canThreePartsEqualSum(self, arr: List[int]) -> bool:\n\t\t\"\"\"\n\t\tGiven an array of integers arr, return true if we can partition the array into three non-empty parts with equal sums.\n\t\tFormally, we can partition the array if we can find indexes i + 1 < j with (arr[0] + arr[1] + ... + arr[i] == arr[i + 1] + arr[i + 2] + ... + arr[j - 1] == arr[j] + arr[j + 1] + ... + arr[arr.length - 1])\n\t\tExample 1:\n\t\tInput: arr = [0,2,1,-6,6,-7,9,1,2,0,1]\n\t\tOutput: true\n\t\tExplanation: 0 + 2 + 1 = -6 + 6 - 7 + 9 + 1 = 2 + 0 + 1\n\t\tExample 2:\n\t\tInput: arr = [0,2,1,-6,6,7,9,-1,2,0,1]\n\t\tOutput: false\n\t\tExample 3:\n\t\tInput: arr = [3,3,6,5,-2,2,5,1,-9,4]\n\t\tOutput: true\n\t\tExplanation: 3 + 3 = 6 = 5 - 2 + 2 + 5 + 1 - 9 + 4\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1063, - "question": "class Solution:\n def maxScoreSightseeingPair(self, values: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou are given an integer array values where values[i] represents the value of the ith sightseeing spot. Two sightseeing spots i and j have a distance j - i between them.\n\t\tThe score of a pair (i < j) of sightseeing spots is values[i] + values[j] + i - j: the sum of the values of the sightseeing spots, minus the distance between them.\n\t\tReturn the maximum score of a pair of sightseeing spots.\n\t\tExample 1:\n\t\tInput: values = [8,1,5,2,6]\n\t\tOutput: 11\n\t\tExplanation: i = 0, j = 2, values[i] + values[j] + i - j = 8 + 5 + 0 - 2 = 11\n\t\tExample 2:\n\t\tInput: values = [1,2]\n\t\tOutput: 2\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1064, - "question": "class Solution:\n def smallestRepunitDivByK(self, k: int) -> int:\n\t\t\"\"\"\n\t\tGiven a positive integer k, you need to find the length of the smallest positive integer n such that n is divisible by k, and n only contains the digit 1.\n\t\tReturn the length of n. If there is no such n, return -1.\n\t\tNote: n may not fit in a 64-bit signed integer.\n\t\tExample 1:\n\t\tInput: k = 1\n\t\tOutput: 1\n\t\tExplanation: The smallest answer is n = 1, which has length 1.\n\t\tExample 2:\n\t\tInput: k = 2\n\t\tOutput: -1\n\t\tExplanation: There is no such positive integer n divisible by 2.\n\t\tExample 3:\n\t\tInput: k = 3\n\t\tOutput: 3\n\t\tExplanation: The smallest answer is n = 111, which has length 3.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1065, - "question": "class Solution:\n def queryString(self, s: str, n: int) -> bool:\n\t\t\"\"\"\n\t\tGiven a binary string s and a positive integer n, return true if the binary representation of all the integers in the range [1, n] are substrings of s, or false otherwise.\n\t\tA substring is a contiguous sequence of characters within a string.\n\t\tExample 1:\n\t\tInput: s = \"0110\", n = 3\n\t\tOutput: true\n\t\tExample 2:\n\t\tInput: s = \"0110\", n = 4\n\t\tOutput: false\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1070, - "question": "class Solution:\n def baseNeg2(self, n: int) -> str:\n\t\t\"\"\"\n\t\tGiven an integer n, return a binary string representing its representation in base -2.\n\t\tNote that the returned string should not have leading zeros unless the string is \"0\".\n\t\tExample 1:\n\t\tInput: n = 2\n\t\tOutput: \"110\"\n\t\tExplantion: (-2)2 + (-2)1 = 2\n\t\tExample 2:\n\t\tInput: n = 3\n\t\tOutput: \"111\"\n\t\tExplantion: (-2)2 + (-2)1 + (-2)0 = 3\n\t\tExample 3:\n\t\tInput: n = 4\n\t\tOutput: \"100\"\n\t\tExplantion: (-2)2 = 4\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1071, - "question": "class Solution:\n def prefixesDivBy5(self, nums: List[int]) -> List[bool]:\n\t\t\"\"\"\n\t\tYou are given a binary array nums (0-indexed).\n\t\tWe define xi as the number whose binary representation is the subarray nums[0..i] (from most-significant-bit to least-significant-bit).\n\t\t\tFor example, if nums = [1,0,1], then x0 = 1, x1 = 2, and x2 = 5.\n\t\tReturn an array of booleans answer where answer[i] is true if xi is divisible by 5.\n\t\tExample 1:\n\t\tInput: nums = [0,1,1]\n\t\tOutput: [true,false,false]\n\t\tExplanation: The input numbers in binary are 0, 01, 011; which are 0, 1, and 3 in base-10.\n\t\tOnly the first number is divisible by 5, so answer[0] is true.\n\t\tExample 2:\n\t\tInput: nums = [1,1,1]\n\t\tOutput: [false,false,false]\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1072, - "question": "class Solution:\n def nextLargerNodes(self, head: Optional[ListNode]) -> List[int]:\n\t\t\"\"\"\n\t\tYou are given the head of a linked list with n nodes.\n\t\tFor each node in the list, find the value of the next greater node. That is, for each node, find the value of the first node that is next to it and has a strictly larger value than it.\n\t\tReturn an integer array answer where answer[i] is the value of the next greater node of the ith node (1-indexed). If the ith node does not have a next greater node, set answer[i] = 0.\n\t\tExample 1:\n\t\tInput: head = [2,1,5]\n\t\tOutput: [5,5,0]\n\t\tExample 2:\n\t\tInput: head = [2,7,4,3,5]\n\t\tOutput: [7,0,5,5,0]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1073, - "question": "class Solution:\n def numEnclaves(self, grid: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tYou are given an m x n binary matrix grid, where 0 represents a sea cell and 1 represents a land cell.\n\t\tA move consists of walking from one land cell to another adjacent (4-directionally) land cell or walking off the boundary of the grid.\n\t\tReturn the number of land cells in grid for which we cannot walk off the boundary of the grid in any number of moves.\n\t\tExample 1:\n\t\tInput: grid = [[0,0,0,0],[1,0,1,0],[0,1,1,0],[0,0,0,0]]\n\t\tOutput: 3\n\t\tExplanation: There are three 1s that are enclosed by 0s, and one 1 that is not enclosed because its on the boundary.\n\t\tExample 2:\n\t\tInput: grid = [[0,1,1,0],[0,0,1,0],[0,0,1,0],[0,0,0,0]]\n\t\tOutput: 0\n\t\tExplanation: All 1s are either on the boundary or can reach the boundary.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1078, - "question": "class Solution:\n def removeOuterParentheses(self, s: str) -> str:\n\t\t\"\"\"\n\t\tA valid parentheses string is either empty \"\", \"(\" + A + \")\", or A + B, where A and B are valid parentheses strings, and + represents string concatenation.\n\t\t\tFor example, \"\", \"()\", \"(())()\", and \"(()(()))\" are all valid parentheses strings.\n\t\tA valid parentheses string s is primitive if it is nonempty, and there does not exist a way to split it into s = A + B, with A and B nonempty valid parentheses strings.\n\t\tGiven a valid parentheses string s, consider its primitive decomposition: s = P1 + P2 + ... + Pk, where Pi are primitive valid parentheses strings.\n\t\tReturn s after removing the outermost parentheses of every primitive string in the primitive decomposition of s.\n\t\tExample 1:\n\t\tInput: s = \"(()())(())\"\n\t\tOutput: \"()()()\"\n\t\tExplanation: \n\t\tThe input string is \"(()())(())\", with primitive decomposition \"(()())\" + \"(())\".\n\t\tAfter removing outer parentheses of each part, this is \"()()\" + \"()\" = \"()()()\".\n\t\tExample 2:\n\t\tInput: s = \"(()())(())(()(()))\"\n\t\tOutput: \"()()()()(())\"\n\t\tExplanation: \n\t\tThe input string is \"(()())(())(()(()))\", with primitive decomposition \"(()())\" + \"(())\" + \"(()(()))\".\n\t\tAfter removing outer parentheses of each part, this is \"()()\" + \"()\" + \"()(())\" = \"()()()()(())\".\n\t\tExample 3:\n\t\tInput: s = \"()()\"\n\t\tOutput: \"\"\n\t\tExplanation: \n\t\tThe input string is \"()()\", with primitive decomposition \"()\" + \"()\".\n\t\tAfter removing outer parentheses of each part, this is \"\" + \"\" = \"\".\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1079, - "question": "class Solution:\n def sumRootToLeaf(self, root: Optional[TreeNode]) -> int:\n\t\t\"\"\"\n\t\tYou are given the root of a binary tree where each node has a value 0 or 1. Each root-to-leaf path represents a binary number starting with the most significant bit.\n\t\t\tFor example, if the path is 0 -> 1 -> 1 -> 0 -> 1, then this could represent 01101 in binary, which is 13.\n\t\tFor all leaves in the tree, consider the numbers represented by the path from the root to that leaf. Return the sum of these numbers.\n\t\tThe test cases are generated so that the answer fits in a 32-bits integer.\n\t\tExample 1:\n\t\tInput: root = [1,0,1,0,1,0,1]\n\t\tOutput: 22\n\t\tExplanation: (100) + (101) + (110) + (111) = 4 + 5 + 6 + 7 = 22\n\t\tExample 2:\n\t\tInput: root = [0]\n\t\tOutput: 0\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1080, - "question": "class Solution:\n def camelMatch(self, queries: List[str], pattern: str) -> List[bool]:\n\t\t\"\"\"\n\t\tGiven an array of strings queries and a string pattern, return a boolean array answer where answer[i] is true if queries[i] matches pattern, and false otherwise.\n\t\tA query word queries[i] matches pattern if you can insert lowercase English letters pattern so that it equals the query. You may insert each character at any position and you may not insert any characters.\n\t\tExample 1:\n\t\tInput: queries = [\"FooBar\",\"FooBarTest\",\"FootBall\",\"FrameBuffer\",\"ForceFeedBack\"], pattern = \"FB\"\n\t\tOutput: [true,false,true,true,false]\n\t\tExplanation: \"FooBar\" can be generated like this \"F\" + \"oo\" + \"B\" + \"ar\".\n\t\t\"FootBall\" can be generated like this \"F\" + \"oot\" + \"B\" + \"all\".\n\t\t\"FrameBuffer\" can be generated like this \"F\" + \"rame\" + \"B\" + \"uffer\".\n\t\tExample 2:\n\t\tInput: queries = [\"FooBar\",\"FooBarTest\",\"FootBall\",\"FrameBuffer\",\"ForceFeedBack\"], pattern = \"FoBa\"\n\t\tOutput: [true,false,true,false,false]\n\t\tExplanation: \"FooBar\" can be generated like this \"Fo\" + \"o\" + \"Ba\" + \"r\".\n\t\t\"FootBall\" can be generated like this \"Fo\" + \"ot\" + \"Ba\" + \"ll\".\n\t\tExample 3:\n\t\tInput: queries = [\"FooBar\",\"FooBarTest\",\"FootBall\",\"FrameBuffer\",\"ForceFeedBack\"], pattern = \"FoBaT\"\n\t\tOutput: [false,true,false,false,false]\n\t\tExplanation: \"FooBarTest\" can be generated like this \"Fo\" + \"o\" + \"Ba\" + \"r\" + \"T\" + \"est\".\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1081, - "question": "class Solution:\n def videoStitching(self, clips: List[List[int]], time: int) -> int:\n\t\t\"\"\"\n\t\tYou are given a series of video clips from a sporting event that lasted time seconds. These video clips can be overlapping with each other and have varying lengths.\n\t\tEach video clip is described by an array clips where clips[i] = [starti, endi] indicates that the ith clip started at starti and ended at endi.\n\t\tWe can cut these clips into segments freely.\n\t\t\tFor example, a clip [0, 7] can be cut into segments [0, 1] + [1, 3] + [3, 7].\n\t\tReturn the minimum number of clips needed so that we can cut the clips into segments that cover the entire sporting event [0, time]. If the task is impossible, return -1.\n\t\tExample 1:\n\t\tInput: clips = [[0,2],[4,6],[8,10],[1,9],[1,5],[5,9]], time = 10\n\t\tOutput: 3\n\t\tExplanation: We take the clips [0,2], [8,10], [1,9]; a total of 3 clips.\n\t\tThen, we can reconstruct the sporting event as follows:\n\t\tWe cut [1,9] into segments [1,2] + [2,8] + [8,9].\n\t\tNow we have segments [0,2] + [2,8] + [8,10] which cover the sporting event [0, 10].\n\t\tExample 2:\n\t\tInput: clips = [[0,1],[1,2]], time = 5\n\t\tOutput: -1\n\t\tExplanation: We cannot cover [0,5] with only [0,1] and [1,2].\n\t\tExample 3:\n\t\tInput: clips = [[0,1],[6,8],[0,2],[5,6],[0,4],[0,3],[6,7],[1,3],[4,7],[1,4],[2,5],[2,6],[3,4],[4,5],[5,7],[6,9]], time = 9\n\t\tOutput: 3\n\t\tExplanation: We can take clips [0,4], [4,7], and [6,9].\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1086, - "question": "class Solution:\n def divisorGame(self, n: int) -> bool:\n\t\t\"\"\"\n\t\tAlice and Bob take turns playing a game, with Alice starting first.\n\t\tInitially, there is a number n on the chalkboard. On each player's turn, that player makes a move consisting of:\n\t\t\tChoosing any x with 0 < x < n and n % x == 0.\n\t\t\tReplacing the number n on the chalkboard with n - x.\n\t\tAlso, if a player cannot make a move, they lose the game.\n\t\tReturn true if and only if Alice wins the game, assuming both players play optimally.\n\t\tExample 1:\n\t\tInput: n = 2\n\t\tOutput: true\n\t\tExplanation: Alice chooses 1, and Bob has no more moves.\n\t\tExample 2:\n\t\tInput: n = 3\n\t\tOutput: false\n\t\tExplanation: Alice chooses 1, Bob chooses 1, and Alice has no more moves.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1087, - "question": "class Solution:\n def longestArithSeqLength(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tGiven an array nums of integers, return the length of the longest arithmetic subsequence in nums.\n\t\tNote that:\n\t\t\tA subsequence is an array that can be derived from another array by deleting some or no elements without changing the order of the remaining elements.\n\t\t\tA sequence seq is arithmetic if seq[i + 1] - seq[i] are all the same value (for 0 <= i < seq.length - 1).\n\t\tExample 1:\n\t\tInput: nums = [3,6,9,12]\n\t\tOutput: 4\n\t\tExplanation: The whole array is an arithmetic sequence with steps of length = 3.\n\t\tExample 2:\n\t\tInput: nums = [9,4,7,2,10]\n\t\tOutput: 3\n\t\tExplanation: The longest arithmetic subsequence is [4,7,10].\n\t\tExample 3:\n\t\tInput: nums = [20,1,15,3,10,5,8]\n\t\tOutput: 4\n\t\tExplanation: The longest arithmetic subsequence is [20,15,10,5].\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1092, - "question": "class Solution:\n def maxAncestorDiff(self, root: Optional[TreeNode]) -> int:\n\t\t\"\"\"\n\t\tGiven the root of a binary tree, find the maximum value v for which there exist different nodes a and b where v = |a.val - b.val| and a is an ancestor of b.\n\t\tA node a is an ancestor of b if either: any child of a is equal to b or any child of a is an ancestor of b.\n\t\tExample 1:\n\t\tInput: root = [8,3,10,1,6,null,14,null,null,4,7,13]\n\t\tOutput: 7\n\t\tExplanation: We have various ancestor-node differences, some of which are given below :\n\t\t|8 - 3| = 5\n\t\t|3 - 7| = 4\n\t\t|8 - 1| = 7\n\t\t|10 - 13| = 3\n\t\tAmong all possible differences, the maximum value of 7 is obtained by |8 - 1| = 7.\n\t\tExample 2:\n\t\tInput: root = [1,null,2,null,0,3]\n\t\tOutput: 3\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1093, - "question": "class Solution:\n def recoverFromPreorder(self, traversal: str) -> Optional[TreeNode]:\n\t\t\"\"\"\n\t\tWe run a preorder depth-first search (DFS) on the root of a binary tree.\n\t\tAt each node in this traversal, we output D dashes (where D is the depth of this node), then we output the value of this node. If the depth of a node is D, the depth of its immediate child is D + 1. The depth of the root node is 0.\n\t\tIf a node has only one child, that child is guaranteed to be the left child.\n\t\tGiven the output traversal of this traversal, recover the tree and return its root.\n\t\tExample 1:\n\t\tInput: traversal = \"1-2--3--4-5--6--7\"\n\t\tOutput: [1,2,5,3,4,6,7]\n\t\tExample 2:\n\t\tInput: traversal = \"1-2--3---4-5--6---7\"\n\t\tOutput: [1,2,5,3,null,6,null,4,null,7]\n\t\tExample 3:\n\t\tInput: traversal = \"1-401--349---90--88\"\n\t\tOutput: [1,401,null,349,88,90]\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1094, - "question": "class Solution:\n def allCellsDistOrder(self, rows: int, cols: int, rCenter: int, cCenter: int) -> List[List[int]]:\n\t\t\"\"\"\n\t\tYou are given four integers row, cols, rCenter, and cCenter. There is a rows x cols matrix and you are on the cell with the coordinates (rCenter, cCenter).\n\t\tReturn the coordinates of all cells in the matrix, sorted by their distance from (rCenter, cCenter) from the smallest distance to the largest distance. You may return the answer in any order that satisfies this condition.\n\t\tThe distance between two cells (r1, c1) and (r2, c2) is |r1 - r2| + |c1 - c2|.\n\t\tExample 1:\n\t\tInput: rows = 1, cols = 2, rCenter = 0, cCenter = 0\n\t\tOutput: [[0,0],[0,1]]\n\t\tExplanation: The distances from (0, 0) to other cells are: [0,1]\n\t\tExample 2:\n\t\tInput: rows = 2, cols = 2, rCenter = 0, cCenter = 1\n\t\tOutput: [[0,1],[0,0],[1,1],[1,0]]\n\t\tExplanation: The distances from (0, 1) to other cells are: [0,1,1,2]\n\t\tThe answer [[0,1],[1,1],[0,0],[1,0]] would also be accepted as correct.\n\t\tExample 3:\n\t\tInput: rows = 2, cols = 3, rCenter = 1, cCenter = 2\n\t\tOutput: [[1,2],[0,2],[1,1],[0,1],[1,0],[0,0]]\n\t\tExplanation: The distances from (1, 2) to other cells are: [0,1,1,2,2,3]\n\t\tThere are other answers that would also be accepted as correct, such as [[1,2],[1,1],[0,2],[1,0],[0,1],[0,0]].\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1095, - "question": "class Solution:\n def twoCitySchedCost(self, costs: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tA company is planning to interview 2n people. Given the array costs where costs[i] = [aCosti, bCosti], the cost of flying the ith person to city a is aCosti, and the cost of flying the ith person to city b is bCosti.\n\t\tReturn the minimum cost to fly every person to a city such that exactly n people arrive in each city.\n\t\tExample 1:\n\t\tInput: costs = [[10,20],[30,200],[400,50],[30,20]]\n\t\tOutput: 110\n\t\tExplanation: \n\t\tThe first person goes to city A for a cost of 10.\n\t\tThe second person goes to city A for a cost of 30.\n\t\tThe third person goes to city B for a cost of 50.\n\t\tThe fourth person goes to city B for a cost of 20.\n\t\tThe total minimum cost is 10 + 30 + 50 + 20 = 110 to have half the people interviewing in each city.\n\t\tExample 2:\n\t\tInput: costs = [[259,770],[448,54],[926,667],[184,139],[840,118],[577,469]]\n\t\tOutput: 1859\n\t\tExample 3:\n\t\tInput: costs = [[515,563],[451,713],[537,709],[343,819],[855,779],[457,60],[650,359],[631,42]]\n\t\tOutput: 3086\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1096, - "question": "class Solution:\n def maxSumTwoNoOverlap(self, nums: List[int], firstLen: int, secondLen: int) -> int:\n\t\t\"\"\"\n\t\tGiven an integer array nums and two integers firstLen and secondLen, return the maximum sum of elements in two non-overlapping subarrays with lengths firstLen and secondLen.\n\t\tThe array with length firstLen could occur before or after the array with length secondLen, but they have to be non-overlapping.\n\t\tA subarray is a contiguous part of an array.\n\t\tExample 1:\n\t\tInput: nums = [0,6,5,2,2,5,1,9,4], firstLen = 1, secondLen = 2\n\t\tOutput: 20\n\t\tExplanation: One choice of subarrays is [9] with length 1, and [6,5] with length 2.\n\t\tExample 2:\n\t\tInput: nums = [3,8,1,3,2,1,8,9,0], firstLen = 3, secondLen = 2\n\t\tOutput: 29\n\t\tExplanation: One choice of subarrays is [3,8,1] with length 3, and [8,9] with length 2.\n\t\tExample 3:\n\t\tInput: nums = [2,1,5,6,0,9,5,0,3,8], firstLen = 4, secondLen = 3\n\t\tOutput: 31\n\t\tExplanation: One choice of subarrays is [5,6,0,9] with length 4, and [0,3,8] with length 3.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1097, - "question": "class StreamChecker:\n def __init__(self, words: List[str]):\n def query(self, letter: str) -> bool:\n\t\t\"\"\"\n\t\tDesign an algorithm that accepts a stream of characters and checks if a suffix of these characters is a string of a given array of strings words.\n\t\tFor example, if words = [\"abc\", \"xyz\"] and the stream added the four characters (one by one) 'a', 'x', 'y', and 'z', your algorithm should detect that the suffix \"xyz\" of the characters \"axyz\" matches \"xyz\" from words.\n\t\tImplement the StreamChecker class:\n\t\t\tStreamChecker(String[] words) Initializes the object with the strings array words.\n\t\t\tboolean query(char letter) Accepts a new character from the stream and returns true if any non-empty suffix from the stream forms a word that is in words.\n\t\tExample 1:\n\t\tInput\n\t\t[\"StreamChecker\", \"query\", \"query\", \"query\", \"query\", \"query\", \"query\", \"query\", \"query\", \"query\", \"query\", \"query\", \"query\"]\n\t\t[[[\"cd\", \"f\", \"kl\"]], [\"a\"], [\"b\"], [\"c\"], [\"d\"], [\"e\"], [\"f\"], [\"g\"], [\"h\"], [\"i\"], [\"j\"], [\"k\"], [\"l\"]]\n\t\tOutput\n\t\t[null, false, false, false, true, false, true, false, false, false, false, false, true]\n\t\tExplanation\n\t\tStreamChecker streamChecker = new StreamChecker([\"cd\", \"f\", \"kl\"]);\n\t\tstreamChecker.query(\"a\"); // return False\n\t\tstreamChecker.query(\"b\"); // return False\n\t\tstreamChecker.query(\"c\"); // return False\n\t\tstreamChecker.query(\"d\"); // return True, because 'cd' is in the wordlist\n\t\tstreamChecker.query(\"e\"); // return False\n\t\tstreamChecker.query(\"f\"); // return True, because 'f' is in the wordlist\n\t\tstreamChecker.query(\"g\"); // return False\n\t\tstreamChecker.query(\"h\"); // return False\n\t\tstreamChecker.query(\"i\"); // return False\n\t\tstreamChecker.query(\"j\"); // return False\n\t\tstreamChecker.query(\"k\"); // return False\n\t\tstreamChecker.query(\"l\"); // return True, because 'kl' is in the wordlist\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1103, - "question": "class Solution:\n def numMovesStones(self, a: int, b: int, c: int) -> List[int]:\n\t\t\"\"\"\n\t\tThere are three stones in different positions on the X-axis. You are given three integers a, b, and c, the positions of the stones.\n\t\tIn one move, you pick up a stone at an endpoint (i.e., either the lowest or highest position stone), and move it to an unoccupied position between those endpoints. Formally, let's say the stones are currently at positions x, y, and z with x < y < z. You pick up the stone at either position x or position z, and move that stone to an integer position k, with x < k < z and k != y.\n\t\tThe game ends when you cannot make any more moves (i.e., the stones are in three consecutive positions).\n\t\tReturn an integer array answer of length 2 where:\n\t\t\tanswer[0] is the minimum number of moves you can play, and\n\t\t\tanswer[1] is the maximum number of moves you can play.\n\t\tExample 1:\n\t\tInput: a = 1, b = 2, c = 5\n\t\tOutput: [1,2]\n\t\tExplanation: Move the stone from 5 to 3, or move the stone from 5 to 4 to 3.\n\t\tExample 2:\n\t\tInput: a = 4, b = 3, c = 2\n\t\tOutput: [0,0]\n\t\tExplanation: We cannot make any moves.\n\t\tExample 3:\n\t\tInput: a = 3, b = 5, c = 1\n\t\tOutput: [1,2]\n\t\tExplanation: Move the stone from 1 to 4; or move the stone from 1 to 2 to 4.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1104, - "question": "class Solution:\n def colorBorder(self, grid: List[List[int]], row: int, col: int, color: int) -> List[List[int]]:\n\t\t\"\"\"\n\t\tYou are given an m x n integer matrix grid, and three integers row, col, and color. Each value in the grid represents the color of the grid square at that location.\n\t\tTwo squares belong to the same connected component if they have the same color and are next to each other in any of the 4 directions.\n\t\tThe border of a connected component is all the squares in the connected component that are either 4-directionally adjacent to a square not in the component, or on the boundary of the grid (the first or last row or column).\n\t\tYou should color the border of the connected component that contains the square grid[row][col] with color.\n\t\tReturn the final grid.\n\t\tExample 1:\n\t\tInput: grid = [[1,1],[1,2]], row = 0, col = 0, color = 3\n\t\tOutput: [[3,3],[3,2]]\n\t\tExample 2:\n\t\tInput: grid = [[1,2,2],[2,3,2]], row = 0, col = 1, color = 3\n\t\tOutput: [[1,3,3],[2,3,3]]\n\t\tExample 3:\n\t\tInput: grid = [[1,1,1],[1,1,1],[1,1,1]], row = 1, col = 1, color = 2\n\t\tOutput: [[2,2,2],[2,1,2],[2,2,2]]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1105, - "question": "class Solution:\n def maxUncrossedLines(self, nums1: List[int], nums2: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou are given two integer arrays nums1 and nums2. We write the integers of nums1 and nums2 (in the order they are given) on two separate horizontal lines.\n\t\tWe may draw connecting lines: a straight line connecting two numbers nums1[i] and nums2[j] such that:\n\t\t\tnums1[i] == nums2[j], and\n\t\t\tthe line we draw does not intersect any other connecting (non-horizontal) line.\n\t\tNote that a connecting line cannot intersect even at the endpoints (i.e., each number can only belong to one connecting line).\n\t\tReturn the maximum number of connecting lines we can draw in this way.\n\t\tExample 1:\n\t\tInput: nums1 = [1,4,2], nums2 = [1,2,4]\n\t\tOutput: 2\n\t\tExplanation: We can draw 2 uncrossed lines as in the diagram.\n\t\tWe cannot draw 3 uncrossed lines, because the line from nums1[1] = 4 to nums2[2] = 4 will intersect the line from nums1[2]=2 to nums2[1]=2.\n\t\tExample 2:\n\t\tInput: nums1 = [2,5,1,2,5], nums2 = [10,5,2,1,5,2]\n\t\tOutput: 3\n\t\tExample 3:\n\t\tInput: nums1 = [1,3,7,1,7,5], nums2 = [1,9,2,5,1]\n\t\tOutput: 2\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1106, - "question": "class Solution:\n def isEscapePossible(self, blocked: List[List[int]], source: List[int], target: List[int]) -> bool:\n\t\t\"\"\"\n\t\tThere is a 1 million by 1 million grid on an XY-plane, and the coordinates of each grid square are (x, y).\n\t\tWe start at the source = [sx, sy] square and want to reach the target = [tx, ty] square. There is also an array of blocked squares, where each blocked[i] = [xi, yi] represents a blocked square with coordinates (xi, yi).\n\t\tEach move, we can walk one square north, east, south, or west if the square is not in the array of blocked squares. We are also not allowed to walk outside of the grid.\n\t\tReturn true if and only if it is possible to reach the target square from the source square through a sequence of valid moves.\n\t\tExample 1:\n\t\tInput: blocked = [[0,1],[1,0]], source = [0,0], target = [0,2]\n\t\tOutput: false\n\t\tExplanation: The target square is inaccessible starting from the source square because we cannot move.\n\t\tWe cannot move north or east because those squares are blocked.\n\t\tWe cannot move south or west because we cannot go outside of the grid.\n\t\tExample 2:\n\t\tInput: blocked = [], source = [0,0], target = [999999,999999]\n\t\tOutput: true\n\t\tExplanation: Because there are no blocked cells, it is possible to reach the target square.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1111, - "question": "class Solution:\n def minScoreTriangulation(self, values: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou have a convex n-sided polygon where each vertex has an integer value. You are given an integer array values where values[i] is the value of the ith vertex (i.e., clockwise order).\n\t\tYou will triangulate the polygon into n - 2 triangles. For each triangle, the value of that triangle is the product of the values of its vertices, and the total score of the triangulation is the sum of these values over all n - 2 triangles in the triangulation.\n\t\tReturn the smallest possible total score that you can achieve with some triangulation of the polygon.\n\t\tExample 1:\n\t\tInput: values = [1,2,3]\n\t\tOutput: 6\n\t\tExplanation: The polygon is already triangulated, and the score of the only triangle is 6.\n\t\tExample 2:\n\t\tInput: values = [3,7,4,5]\n\t\tOutput: 144\n\t\tExplanation: There are two triangulations, with possible scores: 3*7*5 + 4*5*7 = 245, or 3*4*5 + 3*4*7 = 144.\n\t\tThe minimum score is 144.\n\t\tExample 3:\n\t\tInput: values = [1,3,1,4,1,5]\n\t\tOutput: 13\n\t\tExplanation: The minimum score triangulation has score 1*1*3 + 1*1*4 + 1*1*5 + 1*1*1 = 13.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1112, - "question": "class Solution:\n def countCharacters(self, words: List[str], chars: str) -> int:\n\t\t\"\"\"\n\t\tYou are given an array of strings words and a string chars.\n\t\tA string is good if it can be formed by characters from chars (each character can only be used once).\n\t\tReturn the sum of lengths of all good strings in words.\n\t\tExample 1:\n\t\tInput: words = [\"cat\",\"bt\",\"hat\",\"tree\"], chars = \"atach\"\n\t\tOutput: 6\n\t\tExplanation: The strings that can be formed are \"cat\" and \"hat\" so the answer is 3 + 3 = 6.\n\t\tExample 2:\n\t\tInput: words = [\"hello\",\"world\",\"leetcode\"], chars = \"welldonehoneyr\"\n\t\tOutput: 10\n\t\tExplanation: The strings that can be formed are \"hello\" and \"world\" so the answer is 5 + 5 = 10.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1113, - "question": "class Solution:\n def numMovesStonesII(self, stones: List[int]) -> List[int]:\n\t\t\"\"\"\n\t\tThere are some stones in different positions on the X-axis. You are given an integer array stones, the positions of the stones.\n\t\tCall a stone an endpoint stone if it has the smallest or largest position. In one move, you pick up an endpoint stone and move it to an unoccupied position so that it is no longer an endpoint stone.\n\t\t\tIn particular, if the stones are at say, stones = [1,2,5], you cannot move the endpoint stone at position 5, since moving it to any position (such as 0, or 3) will still keep that stone as an endpoint stone.\n\t\tThe game ends when you cannot make any more moves (i.e., the stones are in three consecutive positions).\n\t\tReturn an integer array answer of length 2 where:\n\t\t\tanswer[0] is the minimum number of moves you can play, and\n\t\t\tanswer[1] is the maximum number of moves you can play.\n\t\tExample 1:\n\t\tInput: stones = [7,4,9]\n\t\tOutput: [1,2]\n\t\tExplanation: We can move 4 -> 8 for one move to finish the game.\n\t\tOr, we can move 9 -> 5, 4 -> 6 for two moves to finish the game.\n\t\tExample 2:\n\t\tInput: stones = [6,5,4,3,10]\n\t\tOutput: [2,3]\n\t\tExplanation: We can move 3 -> 8 then 10 -> 7 to finish the game.\n\t\tOr, we can move 3 -> 7, 4 -> 8, 5 -> 9 to finish the game.\n\t\tNotice we cannot move 10 -> 2 to finish the game, because that would be an illegal move.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1114, - "question": "class Solution:\n def bstToGst(self, root: TreeNode) -> TreeNode:\n\t\t\"\"\"\n\t\tGiven the root of a Binary Search Tree (BST), convert it to a Greater Tree such that every key of the original BST is changed to the original key plus the sum of all keys greater than the original key in BST.\n\t\tAs a reminder, a binary search tree is a tree that satisfies these constraints:\n\t\t\tThe left subtree of a node contains only nodes with keys less than the node's key.\n\t\t\tThe right subtree of a node contains only nodes with keys greater than the node's key.\n\t\t\tBoth the left and right subtrees must also be binary search trees.\n\t\tExample 1:\n\t\tInput: root = [4,1,6,0,2,5,7,null,null,null,3,null,null,null,8]\n\t\tOutput: [30,36,21,36,35,26,15,null,null,null,33,null,null,null,8]\n\t\tExample 2:\n\t\tInput: root = [0,null,1]\n\t\tOutput: [1,null,1]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1115, - "question": "class Solution:\n def isBoomerang(self, points: List[List[int]]) -> bool:\n\t\t\"\"\"\n\t\tGiven an array points where points[i] = [xi, yi] represents a point on the X-Y plane, return true if these points are a boomerang.\n\t\tA boomerang is a set of three points that are all distinct and not in a straight line.\n\t\tExample 1:\n\t\tInput: points = [[1,1],[2,3],[3,2]]\n\t\tOutput: true\n\t\tExample 2:\n\t\tInput: points = [[1,1],[2,2],[3,3]]\n\t\tOutput: false\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1116, - "question": "class Solution:\n def maxLevelSum(self, root: Optional[TreeNode]) -> int:\n\t\t\"\"\"\n\t\tGiven the root of a binary tree, the level of its root is 1, the level of its children is 2, and so on.\n\t\tReturn the smallest level x such that the sum of all the values of nodes at level x is maximal.\n\t\tExample 1:\n\t\tInput: root = [1,7,0,7,-8,null,null]\n\t\tOutput: 2\n\t\tExplanation: \n\t\tLevel 1 sum = 1.\n\t\tLevel 2 sum = 7 + 0 = 7.\n\t\tLevel 3 sum = 7 + -8 = -1.\n\t\tSo we return the level with the maximum sum which is level 2.\n\t\tExample 2:\n\t\tInput: root = [989,null,10250,98693,-89388,null,null,null,-32127]\n\t\tOutput: 2\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1117, - "question": "class Solution:\n def maxDistance(self, grid: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tGiven an n x n grid containing only values 0 and 1, where 0 represents water and 1 represents land, find a water cell such that its distance to the nearest land cell is maximized, and return the distance. If no land or water exists in the grid, return -1.\n\t\tThe distance used in this problem is the Manhattan distance: the distance between two cells (x0, y0) and (x1, y1) is |x0 - x1| + |y0 - y1|.\n\t\tExample 1:\n\t\tInput: grid = [[1,0,1],[0,0,0],[1,0,1]]\n\t\tOutput: 2\n\t\tExplanation: The cell (1, 1) is as far as possible from all the land with distance 2.\n\t\tExample 2:\n\t\tInput: grid = [[1,0,0],[0,0,0],[0,0,0]]\n\t\tOutput: 4\n\t\tExplanation: The cell (2, 2) is as far as possible from all the land with distance 4.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1119, - "question": "class Solution:\n def isRobotBounded(self, instructions: str) -> bool:\n\t\t\"\"\"\n\t\tOn an infinite plane, a robot initially stands at (0, 0) and faces north. Note that:\n\t\t\tThe north direction is the positive direction of the y-axis.\n\t\t\tThe south direction is the negative direction of the y-axis.\n\t\t\tThe east direction is the positive direction of the x-axis.\n\t\t\tThe west direction is the negative direction of the x-axis.\n\t\tThe robot can receive one of three instructions:\n\t\t\t\"G\": go straight 1 unit.\n\t\t\t\"L\": turn 90 degrees to the left (i.e., anti-clockwise direction).\n\t\t\t\"R\": turn 90 degrees to the right (i.e., clockwise direction).\n\t\tThe robot performs the instructions given in order, and repeats them forever.\n\t\tReturn true if and only if there exists a circle in the plane such that the robot never leaves the circle.\n\t\tExample 1:\n\t\tInput: instructions = \"GGLLGG\"\n\t\tOutput: true\n\t\tExplanation: The robot is initially at (0, 0) facing the north direction.\n\t\t\"G\": move one step. Position: (0, 1). Direction: North.\n\t\t\"G\": move one step. Position: (0, 2). Direction: North.\n\t\t\"L\": turn 90 degrees anti-clockwise. Position: (0, 2). Direction: West.\n\t\t\"L\": turn 90 degrees anti-clockwise. Position: (0, 2). Direction: South.\n\t\t\"G\": move one step. Position: (0, 1). Direction: South.\n\t\t\"G\": move one step. Position: (0, 0). Direction: South.\n\t\tRepeating the instructions, the robot goes into the cycle: (0, 0) --> (0, 1) --> (0, 2) --> (0, 1) --> (0, 0).\n\t\tBased on that, we return true.\n\t\tExample 2:\n\t\tInput: instructions = \"GG\"\n\t\tOutput: false\n\t\tExplanation: The robot is initially at (0, 0) facing the north direction.\n\t\t\"G\": move one step. Position: (0, 1). Direction: North.\n\t\t\"G\": move one step. Position: (0, 2). Direction: North.\n\t\tRepeating the instructions, keeps advancing in the north direction and does not go into cycles.\n\t\tBased on that, we return false.\n\t\tExample 3:\n\t\tInput: instructions = \"GL\"\n\t\tOutput: true\n\t\tExplanation: The robot is initially at (0, 0) facing the north direction.\n\t\t\"G\": move one step. Position: (0, 1). Direction: North.\n\t\t\"L\": turn 90 degrees anti-clockwise. Position: (0, 1). Direction: West.\n\t\t\"G\": move one step. Position: (-1, 1). Direction: West.\n\t\t\"L\": turn 90 degrees anti-clockwise. Position: (-1, 1). Direction: South.\n\t\t\"G\": move one step. Position: (-1, 0). Direction: South.\n\t\t\"L\": turn 90 degrees anti-clockwise. Position: (-1, 0). Direction: East.\n\t\t\"G\": move one step. Position: (0, 0). Direction: East.\n\t\t\"L\": turn 90 degrees anti-clockwise. Position: (0, 0). Direction: North.\n\t\tRepeating the instructions, the robot goes into the cycle: (0, 0) --> (0, 1) --> (-1, 1) --> (-1, 0) --> (0, 0).\n\t\tBased on that, we return true.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1120, - "question": "class Solution:\n def gardenNoAdj(self, n: int, paths: List[List[int]]) -> List[int]:\n\t\t\"\"\"\n\t\tYou have n gardens, labeled from 1 to n, and an array paths where paths[i] = [xi, yi] describes a bidirectional path between garden xi to garden yi. In each garden, you want to plant one of 4 types of flowers.\n\t\tAll gardens have at most 3 paths coming into or leaving it.\n\t\tYour task is to choose a flower type for each garden such that, for any two gardens connected by a path, they have different types of flowers.\n\t\tReturn any such a choice as an array answer, where answer[i] is the type of flower planted in the (i+1)th garden. The flower types are denoted 1, 2, 3, or 4. It is guaranteed an answer exists.\n\t\tExample 1:\n\t\tInput: n = 3, paths = [[1,2],[2,3],[3,1]]\n\t\tOutput: [1,2,3]\n\t\tExplanation:\n\t\tGardens 1 and 2 have different types.\n\t\tGardens 2 and 3 have different types.\n\t\tGardens 3 and 1 have different types.\n\t\tHence, [1,2,3] is a valid answer. Other valid answers include [1,2,4], [1,4,2], and [3,2,1].\n\t\tExample 2:\n\t\tInput: n = 4, paths = [[1,2],[3,4]]\n\t\tOutput: [1,2,1,2]\n\t\tExample 3:\n\t\tInput: n = 4, paths = [[1,2],[2,3],[3,4],[4,1],[1,3],[2,4]]\n\t\tOutput: [1,2,3,4]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1121, - "question": "class Solution:\n def maxSumAfterPartitioning(self, arr: List[int], k: int) -> int:\n\t\t\"\"\"\n\t\tGiven an integer array arr, partition the array into (contiguous) subarrays of length at most k. After partitioning, each subarray has their values changed to become the maximum value of that subarray.\n\t\tReturn the largest sum of the given array after partitioning. Test cases are generated so that the answer fits in a 32-bit integer.\n\t\tExample 1:\n\t\tInput: arr = [1,15,7,9,2,5,10], k = 3\n\t\tOutput: 84\n\t\tExplanation: arr becomes [15,15,15,9,10,10,10]\n\t\tExample 2:\n\t\tInput: arr = [1,4,1,5,7,3,6,1,9,9,3], k = 4\n\t\tOutput: 83\n\t\tExample 3:\n\t\tInput: arr = [1], k = 1\n\t\tOutput: 1\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1122, - "question": "class Solution:\n def longestDupSubstring(self, s: str) -> str:\n\t\t\"\"\"\n\t\tGiven a string s, consider all duplicated substrings: (contiguous) substrings of s that occur 2 or more times. The occurrences may overlap.\n\t\tReturn any duplicated substring that has the longest possible length. If s does not have a duplicated substring, the answer is \"\".\n\t\tExample 1:\n\t\tInput: s = \"banana\"\n\t\tOutput: \"ana\"\n\t\tExample 2:\n\t\tInput: s = \"abcd\"\n\t\tOutput: \"\"\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1127, - "question": "class Solution:\n def lastStoneWeight(self, stones: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou are given an array of integers stones where stones[i] is the weight of the ith stone.\n\t\tWe are playing a game with the stones. On each turn, we choose the heaviest two stones and smash them together. Suppose the heaviest two stones have weights x and y with x <= y. The result of this smash is:\n\t\t\tIf x == y, both stones are destroyed, and\n\t\t\tIf x != y, the stone of weight x is destroyed, and the stone of weight y has new weight y - x.\n\t\tAt the end of the game, there is at most one stone left.\n\t\tReturn the weight of the last remaining stone. If there are no stones left, return 0.\n\t\tExample 1:\n\t\tInput: stones = [2,7,4,1,8,1]\n\t\tOutput: 1\n\t\tExplanation: \n\t\tWe combine 7 and 8 to get 1 so the array converts to [2,4,1,1,1] then,\n\t\twe combine 2 and 4 to get 2 so the array converts to [2,1,1,1] then,\n\t\twe combine 2 and 1 to get 1 so the array converts to [1,1,1] then,\n\t\twe combine 1 and 1 to get 0 so the array converts to [1] then that's the value of the last stone.\n\t\tExample 2:\n\t\tInput: stones = [1]\n\t\tOutput: 1\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1128, - "question": "class Solution:\n def removeDuplicates(self, s: str) -> str:\n\t\t\"\"\"\n\t\tYou are given a string s consisting of lowercase English letters. A duplicate removal consists of choosing two adjacent and equal letters and removing them.\n\t\tWe repeatedly make duplicate removals on s until we no longer can.\n\t\tReturn the final string after all such duplicate removals have been made. It can be proven that the answer is unique.\n\t\tExample 1:\n\t\tInput: s = \"abbaca\"\n\t\tOutput: \"ca\"\n\t\tExplanation: \n\t\tFor example, in \"abbaca\" we could remove \"bb\" since the letters are adjacent and equal, and this is the only possible move. The result of this move is that the string is \"aaca\", of which only \"aa\" is possible, so the final string is \"ca\".\n\t\tExample 2:\n\t\tInput: s = \"azxxzy\"\n\t\tOutput: \"ay\"\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1129, - "question": "class Solution:\n def longestStrChain(self, words: List[str]) -> int:\n\t\t\"\"\"\n\t\tYou are given an array of words where each word consists of lowercase English letters.\n\t\twordA is a predecessor of wordB if and only if we can insert exactly one letter anywhere in wordA without changing the order of the other characters to make it equal to wordB.\n\t\t\tFor example, \"abc\" is a predecessor of \"abac\", while \"cba\" is not a predecessor of \"bcad\".\n\t\tA word chain is a sequence of words [word1, word2, ..., wordk] with k >= 1, where word1 is a predecessor of word2, word2 is a predecessor of word3, and so on. A single word is trivially a word chain with k == 1.\n\t\tReturn the length of the longest possible word chain with words chosen from the given list of words.\n\t\tExample 1:\n\t\tInput: words = [\"a\",\"b\",\"ba\",\"bca\",\"bda\",\"bdca\"]\n\t\tOutput: 4\n\t\tExplanation: One of the longest word chains is [\"a\",\"ba\",\"bda\",\"bdca\"].\n\t\tExample 2:\n\t\tInput: words = [\"xbc\",\"pcxbcf\",\"xb\",\"cxbc\",\"pcxbc\"]\n\t\tOutput: 5\n\t\tExplanation: All the words can be put in a word chain [\"xb\", \"xbc\", \"cxbc\", \"pcxbc\", \"pcxbcf\"].\n\t\tExample 3:\n\t\tInput: words = [\"abcd\",\"dbqca\"]\n\t\tOutput: 1\n\t\tExplanation: The trivial word chain [\"abcd\"] is one of the longest word chains.\n\t\t[\"abcd\",\"dbqca\"] is not a valid word chain because the ordering of the letters is changed.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1130, - "question": "class Solution:\n def lastStoneWeightII(self, stones: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou are given an array of integers stones where stones[i] is the weight of the ith stone.\n\t\tWe are playing a game with the stones. On each turn, we choose any two stones and smash them together. Suppose the stones have weights x and y with x <= y. The result of this smash is:\n\t\t\tIf x == y, both stones are destroyed, and\n\t\t\tIf x != y, the stone of weight x is destroyed, and the stone of weight y has new weight y - x.\n\t\tAt the end of the game, there is at most one stone left.\n\t\tReturn the smallest possible weight of the left stone. If there are no stones left, return 0.\n\t\tExample 1:\n\t\tInput: stones = [2,7,4,1,8,1]\n\t\tOutput: 1\n\t\tExplanation:\n\t\tWe can combine 2 and 4 to get 2, so the array converts to [2,7,1,8,1] then,\n\t\twe can combine 7 and 8 to get 1, so the array converts to [2,1,1,1] then,\n\t\twe can combine 2 and 1 to get 1, so the array converts to [1,1,1] then,\n\t\twe can combine 1 and 1 to get 0, so the array converts to [1], then that's the optimal value.\n\t\tExample 2:\n\t\tInput: stones = [31,26,33,21,40]\n\t\tOutput: 5\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1133, - "question": "class Solution:\n def lastSubstring(self, s: str) -> str:\n\t\t\"\"\"\n\t\tGiven a string s, return the last substring of s in lexicographical order.\n\t\tExample 1:\n\t\tInput: s = \"abab\"\n\t\tOutput: \"bab\"\n\t\tExplanation: The substrings are [\"a\", \"ab\", \"aba\", \"abab\", \"b\", \"ba\", \"bab\"]. The lexicographically maximum substring is \"bab\".\n\t\tExample 2:\n\t\tInput: s = \"leetcode\"\n\t\tOutput: \"tcode\"\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1137, - "question": "class Solution:\n def heightChecker(self, heights: List[int]) -> int:\n\t\t\"\"\"\n\t\tA school is trying to take an annual photo of all the students. The students are asked to stand in a single file line in non-decreasing order by height. Let this ordering be represented by the integer array expected where expected[i] is the expected height of the ith student in line.\n\t\tYou are given an integer array heights representing the current order that the students are standing in. Each heights[i] is the height of the ith student in line (0-indexed).\n\t\tReturn the number of indices where heights[i] != expected[i].\n\t\tExample 1:\n\t\tInput: heights = [1,1,4,2,1,3]\n\t\tOutput: 3\n\t\tExplanation: \n\t\theights: [1,1,4,2,1,3]\n\t\texpected: [1,1,1,2,3,4]\n\t\tIndices 2, 4, and 5 do not match.\n\t\tExample 2:\n\t\tInput: heights = [5,1,2,3,4]\n\t\tOutput: 5\n\t\tExplanation:\n\t\theights: [5,1,2,3,4]\n\t\texpected: [1,2,3,4,5]\n\t\tAll indices do not match.\n\t\tExample 3:\n\t\tInput: heights = [1,2,3,4,5]\n\t\tOutput: 0\n\t\tExplanation:\n\t\theights: [1,2,3,4,5]\n\t\texpected: [1,2,3,4,5]\n\t\tAll indices match.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1138, - "question": "class Solution:\n def maxSatisfied(self, customers: List[int], grumpy: List[int], minutes: int) -> int:\n\t\t\"\"\"\n\t\tThere is a bookstore owner that has a store open for n minutes. Every minute, some number of customers enter the store. You are given an integer array customers of length n where customers[i] is the number of the customer that enters the store at the start of the ith minute and all those customers leave after the end of that minute.\n\t\tOn some minutes, the bookstore owner is grumpy. You are given a binary array grumpy where grumpy[i] is 1 if the bookstore owner is grumpy during the ith minute, and is 0 otherwise.\n\t\tWhen the bookstore owner is grumpy, the customers of that minute are not satisfied, otherwise, they are satisfied.\n\t\tThe bookstore owner knows a secret technique to keep themselves not grumpy for minutes consecutive minutes, but can only use it once.\n\t\tReturn the maximum number of customers that can be satisfied throughout the day.\n\t\tExample 1:\n\t\tInput: customers = [1,0,1,2,1,1,7,5], grumpy = [0,1,0,1,0,1,0,1], minutes = 3\n\t\tOutput: 16\n\t\tExplanation: The bookstore owner keeps themselves not grumpy for the last 3 minutes. \n\t\tThe maximum number of customers that can be satisfied = 1 + 1 + 1 + 1 + 7 + 5 = 16.\n\t\tExample 2:\n\t\tInput: customers = [1], grumpy = [0], minutes = 1\n\t\tOutput: 1\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1139, - "question": "class Solution:\n def prevPermOpt1(self, arr: List[int]) -> List[int]:\n\t\t\"\"\"\n\t\tGiven an array of positive integers arr (not necessarily distinct), return the lexicographically largest permutation that is smaller than arr, that can be made with exactly one swap. If it cannot be done, then return the same array.\n\t\tNote that a swap exchanges the positions of two numbers arr[i] and arr[j]\n\t\tExample 1:\n\t\tInput: arr = [3,2,1]\n\t\tOutput: [3,1,2]\n\t\tExplanation: Swapping 2 and 1.\n\t\tExample 2:\n\t\tInput: arr = [1,1,5]\n\t\tOutput: [1,1,5]\n\t\tExplanation: This is already the smallest permutation.\n\t\tExample 3:\n\t\tInput: arr = [1,9,4,6,7]\n\t\tOutput: [1,7,4,6,9]\n\t\tExplanation: Swapping 9 and 7.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1140, - "question": "class Solution:\n def rearrangeBarcodes(self, barcodes: List[int]) -> List[int]:\n\t\t\"\"\"\n\t\tIn a warehouse, there is a row of barcodes, where the ith barcode is barcodes[i].\n\t\tRearrange the barcodes so that no two adjacent barcodes are equal. You may return any answer, and it is guaranteed an answer exists.\n\t\tExample 1:\n\t\tInput: barcodes = [1,1,1,2,2,2]\n\t\tOutput: [2,1,2,1,2,1]\n\t\tExample 2:\n\t\tInput: barcodes = [1,1,1,1,2,2,3,3]\n\t\tOutput: [1,3,1,3,1,2,1,2]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1145, - "question": "class Solution:\n def numSubmatrixSumTarget(self, matrix: List[List[int]], target: int) -> int:\n\t\t\"\"\"\n\t\tGiven a matrix and a target, return the number of non-empty submatrices that sum to target.\n\t\tA submatrix x1, y1, x2, y2 is the set of all cells matrix[x][y] with x1 <= x <= x2 and y1 <= y <= y2.\n\t\tTwo submatrices (x1, y1, x2, y2) and (x1', y1', x2', y2') are different if they have some coordinate that is different: for example, if x1 != x1'.\n\t\tExample 1:\n\t\tInput: matrix = [[0,1,0],[1,1,1],[0,1,0]], target = 0\n\t\tOutput: 4\n\t\tExplanation: The four 1x1 submatrices that only contain 0.\n\t\tExample 2:\n\t\tInput: matrix = [[1,-1],[-1,1]], target = 0\n\t\tOutput: 5\n\t\tExplanation: The two 1x2 submatrices, plus the two 2x1 submatrices, plus the 2x2 submatrix.\n\t\tExample 3:\n\t\tInput: matrix = [[904]], target = 0\n\t\tOutput: 0\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1146, - "question": "class Solution:\n def gcdOfStrings(self, str1: str, str2: str) -> str:\n\t\t\"\"\"\n\t\tFor two strings s and t, we say \"t divides s\" if and only if s = t + ... + t (i.e., t is concatenated with itself one or more times).\n\t\tGiven two strings str1 and str2, return the largest string x such that x divides both str1 and str2.\n\t\tExample 1:\n\t\tInput: str1 = \"ABCABC\", str2 = \"ABC\"\n\t\tOutput: \"ABC\"\n\t\tExample 2:\n\t\tInput: str1 = \"ABABAB\", str2 = \"ABAB\"\n\t\tOutput: \"AB\"\n\t\tExample 3:\n\t\tInput: str1 = \"LEET\", str2 = \"CODE\"\n\t\tOutput: \"\"\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1147, - "question": "class Solution:\n def maxEqualRowsAfterFlips(self, matrix: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tYou are given an m x n binary matrix matrix.\n\t\tYou can choose any number of columns in the matrix and flip every cell in that column (i.e., Change the value of the cell from 0 to 1 or vice versa).\n\t\tReturn the maximum number of rows that have all values equal after some number of flips.\n\t\tExample 1:\n\t\tInput: matrix = [[0,1],[1,1]]\n\t\tOutput: 1\n\t\tExplanation: After flipping no values, 1 row has all values equal.\n\t\tExample 2:\n\t\tInput: matrix = [[0,1],[1,0]]\n\t\tOutput: 2\n\t\tExplanation: After flipping values in the first column, both rows have equal values.\n\t\tExample 3:\n\t\tInput: matrix = [[0,0,0],[0,0,1],[1,1,0]]\n\t\tOutput: 2\n\t\tExplanation: After flipping values in the first two columns, the last two rows have equal values.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1148, - "question": "class Solution:\n def addNegabinary(self, arr1: List[int], arr2: List[int]) -> List[int]:\n\t\t\"\"\"\n\t\tGiven two numbers arr1 and arr2 in base -2, return the result of adding them together.\n\t\tEach number is given in array format: as an array of 0s and 1s, from most significant bit to least significant bit. For example, arr = [1,1,0,1] represents the number (-2)^3 + (-2)^2 + (-2)^0 = -3. A number arr in array, format is also guaranteed to have no leading zeros: either arr == [0] or arr[0] == 1.\n\t\tReturn the result of adding arr1 and arr2 in the same format: as an array of 0s and 1s with no leading zeros.\n\t\tExample 1:\n\t\tInput: arr1 = [1,1,1,1,1], arr2 = [1,0,1]\n\t\tOutput: [1,0,0,0,0]\n\t\tExplanation: arr1 represents 11, arr2 represents 5, the output represents 16.\n\t\tExample 2:\n\t\tInput: arr1 = [0], arr2 = [0]\n\t\tOutput: [0]\n\t\tExample 3:\n\t\tInput: arr1 = [0], arr2 = [1]\n\t\tOutput: [1]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1156, - "question": "class Solution:\n def findOcurrences(self, text: str, first: str, second: str) -> List[str]:\n\t\t\"\"\"\n\t\tGiven two strings first and second, consider occurrences in some text of the form \"first second third\", where second comes immediately after first, and third comes immediately after second.\n\t\tReturn an array of all the words third for each occurrence of \"first second third\".\n\t\tExample 1:\n\t\tInput: text = \"alice is a good girl she is a good student\", first = \"a\", second = \"good\"\n\t\tOutput: [\"girl\",\"student\"]\n\t\tExample 2:\n\t\tInput: text = \"we will we will rock you\", first = \"we\", second = \"will\"\n\t\tOutput: [\"we\",\"rock\"]\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1157, - "question": "class Solution:\n def sufficientSubset(self, root: Optional[TreeNode], limit: int) -> Optional[TreeNode]:\n\t\t\"\"\"\n\t\tGiven the root of a binary tree and an integer limit, delete all insufficient nodes in the tree simultaneously, and return the root of the resulting binary tree.\n\t\tA node is insufficient if every root to leaf path intersecting this node has a sum strictly less than limit.\n\t\tA leaf is a node with no children.\n\t\tExample 1:\n\t\tInput: root = [1,2,3,4,-99,-99,7,8,9,-99,-99,12,13,-99,14], limit = 1\n\t\tOutput: [1,2,3,4,null,null,7,8,9,null,14]\n\t\tExample 2:\n\t\tInput: root = [5,4,8,11,null,17,4,7,1,null,null,5,3], limit = 22\n\t\tOutput: [5,4,8,11,null,17,4,7,null,null,null,5]\n\t\tExample 3:\n\t\tInput: root = [1,2,-3,-5,null,4,null], limit = -1\n\t\tOutput: [1,null,-3,4]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1159, - "question": "class Solution:\n def smallestSubsequence(self, s: str) -> str:\n\t\t\"\"\"\n\t\tGiven a string s, return the lexicographically smallest subsequence of s that contains all the distinct characters of s exactly once.\n\t\tExample 1:\n\t\tInput: s = \"bcabc\"\n\t\tOutput: \"abc\"\n\t\tExample 2:\n\t\tInput: s = \"cbacdcbc\"\n\t\tOutput: \"acdb\"\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1160, - "question": "class Solution:\n def numTilePossibilities(self, tiles: str) -> int:\n\t\t\"\"\"\n\t\tYou have n tiles, where each tile has one letter tiles[i] printed on it.\n\t\tReturn the number of possible non-empty sequences of letters you can make using the letters printed on those tiles.\n\t\tExample 1:\n\t\tInput: tiles = \"AAB\"\n\t\tOutput: 8\n\t\tExplanation: The possible sequences are \"A\", \"B\", \"AA\", \"AB\", \"BA\", \"AAB\", \"ABA\", \"BAA\".\n\t\tExample 2:\n\t\tInput: tiles = \"AAABBC\"\n\t\tOutput: 188\n\t\tExample 3:\n\t\tInput: tiles = \"V\"\n\t\tOutput: 1\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1168, - "question": "class Solution:\n def duplicateZeros(self, arr: List[int]) -> None:\n\t\t\"\"\"\n Do not return anything, modify arr in-place instead.\n\t\tGiven a fixed-length integer array arr, duplicate each occurrence of zero, shifting the remaining elements to the right.\n\t\tNote that elements beyond the length of the original array are not written. Do the above modifications to the input array in place and do not return anything.\n\t\tExample 1:\n\t\tInput: arr = [1,0,2,3,0,4,5,0]\n\t\tOutput: [1,0,0,2,3,0,0,4]\n\t\tExplanation: After calling your function, the input array is modified to: [1,0,0,2,3,0,0,4]\n\t\tExample 2:\n\t\tInput: arr = [1,2,3]\n\t\tOutput: [1,2,3]\n\t\tExplanation: After calling your function, the input array is modified to: [1,2,3]\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1169, - "question": "class Solution:\n def largestValsFromLabels(self, values: List[int], labels: List[int], numWanted: int, useLimit: int) -> int:\n\t\t\"\"\"\n\t\tThere is a set of n items. You are given two integer arrays values and labels where the value and the label of the ith element are values[i] and labels[i] respectively. You are also given two integers numWanted and useLimit.\n\t\tChoose a subset s of the n elements such that:\n\t\t\tThe size of the subset s is less than or equal to numWanted.\n\t\t\tThere are at most useLimit items with the same label in s.\n\t\tThe score of a subset is the sum of the values in the subset.\n\t\tReturn the maximum score of a subset s.\n\t\tExample 1:\n\t\tInput: values = [5,4,3,2,1], labels = [1,1,2,2,3], numWanted = 3, useLimit = 1\n\t\tOutput: 9\n\t\tExplanation: The subset chosen is the first, third, and fifth items.\n\t\tExample 2:\n\t\tInput: values = [5,4,3,2,1], labels = [1,3,3,3,2], numWanted = 3, useLimit = 2\n\t\tOutput: 12\n\t\tExplanation: The subset chosen is the first, second, and third items.\n\t\tExample 3:\n\t\tInput: values = [9,8,8,7,6], labels = [0,0,0,1,1], numWanted = 3, useLimit = 1\n\t\tOutput: 16\n\t\tExplanation: The subset chosen is the first and fourth items.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1170, - "question": "class Solution:\n def shortestCommonSupersequence(self, str1: str, str2: str) -> str:\n\t\t\"\"\"\n\t\tGiven two strings str1 and str2, return the shortest string that has both str1 and str2 as subsequences. If there are multiple valid strings, return any of them.\n\t\tA string s is a subsequence of string t if deleting some number of characters from t (possibly 0) results in the string s.\n\t\tExample 1:\n\t\tInput: str1 = \"abac\", str2 = \"cab\"\n\t\tOutput: \"cabac\"\n\t\tExplanation: \n\t\tstr1 = \"abac\" is a subsequence of \"cabac\" because we can delete the first \"c\".\n\t\tstr2 = \"cab\" is a subsequence of \"cabac\" because we can delete the last \"ac\".\n\t\tThe answer provided is the shortest such string that satisfies these properties.\n\t\tExample 2:\n\t\tInput: str1 = \"aaaaaaaa\", str2 = \"aaaaaaaa\"\n\t\tOutput: \"aaaaaaaa\"\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1171, - "question": "class Solution:\n def shortestPathBinaryMatrix(self, grid: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tGiven an n x n binary matrix grid, return the length of the shortest clear path in the matrix. If there is no clear path, return -1.\n\t\tA clear path in a binary matrix is a path from the top-left cell (i.e., (0, 0)) to the bottom-right cell (i.e., (n - 1, n - 1)) such that:\n\t\t\tAll the visited cells of the path are 0.\n\t\t\tAll the adjacent cells of the path are 8-directionally connected (i.e., they are different and they share an edge or a corner).\n\t\tThe length of a clear path is the number of visited cells of this path.\n\t\tExample 1:\n\t\tInput: grid = [[0,1],[1,0]]\n\t\tOutput: 2\n\t\tExample 2:\n\t\tInput: grid = [[0,0,0],[1,1,0],[1,1,0]]\n\t\tOutput: 4\n\t\tExample 3:\n\t\tInput: grid = [[1,0,0],[1,1,0],[1,1,0]]\n\t\tOutput: -1\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1183, - "question": "class Solution:\n def sampleStats(self, count: List[int]) -> List[float]:\n\t\t\"\"\"\n\t\tYou are given a large sample of integers in the range [0, 255]. Since the sample is so large, it is represented by an array count where count[k] is the number of times that k appears in the sample.\n\t\tCalculate the following statistics:\n\t\t\tminimum: The minimum element in the sample.\n\t\t\tmaximum: The maximum element in the sample.\n\t\t\tmean: The average of the sample, calculated as the total sum of all elements divided by the total number of elements.\n\t\t\tmedian:\n\t\t\t\tIf the sample has an odd number of elements, then the median is the middle element once the sample is sorted.\n\t\t\t\tIf the sample has an even number of elements, then the median is the average of the two middle elements once the sample is sorted.\n\t\t\tmode: The number that appears the most in the sample. It is guaranteed to be unique.\n\t\tReturn the statistics of the sample as an array of floating-point numbers [minimum, maximum, mean, median, mode]. Answers within 10-5 of the actual answer will be accepted.\n\t\tExample 1:\n\t\tInput: count = [0,1,3,4,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0]\n\t\tOutput: [1.00000,3.00000,2.37500,2.50000,3.00000]\n\t\tExplanation: The sample represented by count is [1,2,2,2,3,3,3,3].\n\t\tThe minimum and maximum are 1 and 3 respectively.\n\t\tThe mean is (1+2+2+2+3+3+3+3) / 8 = 19 / 8 = 2.375.\n\t\tSince the size of the sample is even, the median is the average of the two middle elements 2 and 3, which is 2.5.\n\t\tThe mode is 3 as it appears the most in the sample.\n\t\tExample 2:\n\t\tInput: count = [0,4,3,2,2,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0]\n\t\tOutput: [1.00000,4.00000,2.18182,2.00000,1.00000]\n\t\tExplanation: The sample represented by count is [1,1,1,1,2,2,2,3,3,4,4].\n\t\tThe minimum and maximum are 1 and 4 respectively.\n\t\tThe mean is (1+1+1+1+2+2+2+3+3+4+4) / 11 = 24 / 11 = 2.18181818... (for display purposes, the output shows the rounded number 2.18182).\n\t\tSince the size of the sample is odd, the median is the middle element 2.\n\t\tThe mode is 1 as it appears the most in the sample.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1184, - "question": "class Solution:\n def carPooling(self, trips: List[List[int]], capacity: int) -> bool:\n\t\t\"\"\"\n\t\tThere is a car with capacity empty seats. The vehicle only drives east (i.e., it cannot turn around and drive west).\n\t\tYou are given the integer capacity and an array trips where trips[i] = [numPassengersi, fromi, toi] indicates that the ith trip has numPassengersi passengers and the locations to pick them up and drop them off are fromi and toi respectively. The locations are given as the number of kilometers due east from the car's initial location.\n\t\tReturn true if it is possible to pick up and drop off all passengers for all the given trips, or false otherwise.\n\t\tExample 1:\n\t\tInput: trips = [[2,1,5],[3,3,7]], capacity = 4\n\t\tOutput: false\n\t\tExample 2:\n\t\tInput: trips = [[2,1,5],[3,3,7]], capacity = 5\n\t\tOutput: true\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1185, - "question": "\t\t\"\"\"\n\t\t(This problem is an interactive problem.)\n\t\tYou may recall that an array arr is a mountain array if and only if:\n\t\t\tarr.length >= 3\n\t\t\tThere exists some i with 0 < i < arr.length - 1 such that:\n\t\t\t\tarr[0] < arr[1] < ... < arr[i - 1] < arr[i]\n\t\t\t\tarr[i] > arr[i + 1] > ... > arr[arr.length - 1]\n\t\tGiven a mountain array mountainArr, return the minimum index such that mountainArr.get(index) == target. If such an index does not exist, return -1.\n\t\tYou cannot access the mountain array directly. You may only access the array using a MountainArray interface:\n\t\t\tMountainArray.get(k) returns the element of the array at index k (0-indexed).\n\t\t\tMountainArray.length() returns the length of the array.\n\t\tSubmissions making more than 100 calls to MountainArray.get will be judged Wrong Answer. Also, any solutions that attempt to circumvent the judge will result in disqualification.\n\t\tExample 1:\n\t\tInput: array = [1,2,3,4,5,3,1], target = 3\n\t\tOutput: 2\n\t\tExplanation: 3 exists in the array, at index=2 and index=5. Return the minimum index, which is 2.\n\t\tExample 2:\n\t\tInput: array = [0,1,2,4,2,1], target = 3\n\t\tOutput: -1\n\t\tExplanation: 3 does not exist in the array, so we return -1.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1186, - "question": "class H2O:\n def __init__(self):\n pass\n def hydrogen(self, releaseHydrogen: 'Callable[[], None]') -> None:\n releaseHydrogen()\n def oxygen(self, releaseOxygen: 'Callable[[], None]') -> None:\n releaseOxygen()\n\t\t\"\"\"\n\t\tThere are two kinds of threads: oxygen and hydrogen. Your goal is to group these threads to form water molecules.\n\t\tThere is a barrier where each thread has to wait until a complete molecule can be formed. Hydrogen and oxygen threads will be given releaseHydrogen and releaseOxygen methods respectively, which will allow them to pass the barrier. These threads should pass the barrier in groups of three, and they must immediately bond with each other to form a water molecule. You must guarantee that all the threads from one molecule bond before any other threads from the next molecule do.\n\t\tIn other words:\n\t\t\tIf an oxygen thread arrives at the barrier when no hydrogen threads are present, it must wait for two hydrogen threads.\n\t\t\tIf a hydrogen thread arrives at the barrier when no other threads are present, it must wait for an oxygen thread and another hydrogen thread.\n\t\tWe do not have to worry about matching the threads up explicitly; the threads do not necessarily know which other threads they are paired up with. The key is that threads pass the barriers in complete sets; thus, if we examine the sequence of threads that bind and divide them into groups of three, each group should contain one oxygen and two hydrogen threads.\n\t\tWrite synchronization code for oxygen and hydrogen molecules that enforces these constraints.\n\t\tExample 1:\n\t\tInput: water = \"HOH\"\n\t\tOutput: \"HHO\"\n\t\tExplanation: \"HOH\" and \"OHH\" are also valid answers.\n\t\tExample 2:\n\t\tInput: water = \"OOHHHH\"\n\t\tOutput: \"HHOHHO\"\n\t\tExplanation: \"HOHHHO\", \"OHHHHO\", \"HHOHOH\", \"HOHHOH\", \"OHHHOH\", \"HHOOHH\", \"HOHOHH\" and \"OHHOHH\" are also valid answers.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1187, - "question": "class FooBar:\n def __init__(self, n):\n self.n = n\n def foo(self, printFoo: 'Callable[[], None]') -> None:\n for i in range(self.n):\n \tprintFoo()\n def bar(self, printBar: 'Callable[[], None]') -> None:\n for i in range(self.n):\n \tprintBar()\n\t\t\"\"\"\n\t\tSuppose you are given the following code:\n\t\tclass FooBar {\n\t\t public void foo() {\n\t\t for (int i = 0; i < n; i++) {\n\t\t print(\"foo\");\n\t\t }\n\t\t }\n\t\t public void bar() {\n\t\t for (int i = 0; i < n; i++) {\n\t\t print(\"bar\");\n\t\t }\n\t\t }\n\t\t}\n\t\tThe same instance of FooBar will be passed to two different threads:\n\t\t\tthread A will call foo(), while\n\t\t\tthread B will call bar().\n\t\tModify the given program to output \"foobar\" n times.\n\t\tExample 1:\n\t\tInput: n = 1\n\t\tOutput: \"foobar\"\n\t\tExplanation: There are two threads being fired asynchronously. One of them calls foo(), while the other calls bar().\n\t\t\"foobar\" is being output 1 time.\n\t\tExample 2:\n\t\tInput: n = 2\n\t\tOutput: \"foobarfoobar\"\n\t\tExplanation: \"foobar\" is being output 2 times.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1188, - "question": "class Solution:\n def braceExpansionII(self, expression: str) -> List[str]:\n\t\t\"\"\"\n\t\tUnder the grammar given below, strings can represent a set of lowercase words. Let R(expr) denote the set of words the expression represents.\n\t\tThe grammar can best be understood through simple examples:\n\t\t\tSingle letters represent a singleton set containing that word.\n\t\t\t\tR(\"a\") = {\"a\"}\n\t\t\t\tR(\"w\") = {\"w\"}\n\t\t\tWhen we take a comma-delimited list of two or more expressions, we take the union of possibilities.\n\t\t\t\tR(\"{a,b,c}\") = {\"a\",\"b\",\"c\"}\n\t\t\t\tR(\"{{a,b},{b,c}}\") = {\"a\",\"b\",\"c\"} (notice the final set only contains each word at most once)\n\t\t\tWhen we concatenate two expressions, we take the set of possible concatenations between two words where the first word comes from the first expression and the second word comes from the second expression.\n\t\t\t\tR(\"{a,b}{c,d}\") = {\"ac\",\"ad\",\"bc\",\"bd\"}\n\t\t\t\tR(\"a{b,c}{d,e}f{g,h}\") = {\"abdfg\", \"abdfh\", \"abefg\", \"abefh\", \"acdfg\", \"acdfh\", \"acefg\", \"acefh\"}\n\t\tFormally, the three rules for our grammar:\n\t\t\tFor every lowercase letter x, we have R(x) = {x}.\n\t\t\tFor expressions e1, e2, ... , ek with k >= 2, we have R({e1, e2, ...}) = R(e1) \u222a R(e2) \u222a ...\n\t\t\tFor expressions e1 and e2, we have R(e1 + e2) = {a + b for (a, b) in R(e1) \u00d7 R(e2)}, where + denotes concatenation, and \u00d7 denotes the cartesian product.\n\t\tGiven an expression representing a set of words under the given grammar, return the sorted list of words that the expression represents.\n\t\tExample 1:\n\t\tInput: expression = \"{a,b}{c,{d,e}}\"\n\t\tOutput: [\"ac\",\"ad\",\"ae\",\"bc\",\"bd\",\"be\"]\n\t\tExample 2:\n\t\tInput: expression = \"{{a,z},a{b,c},{ab,z}}\"\n\t\tOutput: [\"a\",\"ab\",\"ac\",\"z\"]\n\t\tExplanation: Each distinct word is written only once in the final answer.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1194, - "question": "class Solution:\n def pathInZigZagTree(self, label: int) -> List[int]:\n\t\t\"\"\"\n\t\tIn an infinite binary tree where every node has two children, the nodes are labelled in row order.\n\t\tIn the odd numbered rows (ie., the first, third, fifth,...), the labelling is left to right, while in the even numbered rows (second, fourth, sixth,...), the labelling is right to left.\n\t\tGiven the label of a node in this tree, return the labels in the path from the root of the tree to the node with that label.\n\t\tExample 1:\n\t\tInput: label = 14\n\t\tOutput: [1,3,4,14]\n\t\tExample 2:\n\t\tInput: label = 26\n\t\tOutput: [1,2,6,10,26]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1195, - "question": "class Solution:\n def distributeCandies(self, candies: int, num_people: int) -> List[int]:\n\t\t\"\"\"\n\t\tWe distribute some number of candies, to a row of n = num_people people in the following way:\n\t\tWe then give 1 candy to the first person, 2 candies to the second person, and so on until we give n candies to the last person.\n\t\tThen, we go back to the start of the row, giving n + 1 candies to the first person, n + 2 candies to the second person, and so on until we give 2 * n candies to the last person.\n\t\tThis process repeats (with us giving one more candy each time, and moving to the start of the row after we reach the end) until we run out of candies. The last person will receive all of our remaining candies (not necessarily one more than the previous gift).\n\t\tReturn an array (of length num_people and sum candies) that represents the final distribution of candies.\n\t\tExample 1:\n\t\tInput: candies = 7, num_people = 4\n\t\tOutput: [1,2,3,1]\n\t\tExplanation:\n\t\tOn the first turn, ans[0] += 1, and the array is [1,0,0,0].\n\t\tOn the second turn, ans[1] += 2, and the array is [1,2,0,0].\n\t\tOn the third turn, ans[2] += 3, and the array is [1,2,3,0].\n\t\tOn the fourth turn, ans[3] += 1 (because there is only one candy left), and the final array is [1,2,3,1].\n\t\tExample 2:\n\t\tInput: candies = 10, num_people = 3\n\t\tOutput: [5,2,3]\n\t\tExplanation: \n\t\tOn the first turn, ans[0] += 1, and the array is [1,0,0].\n\t\tOn the second turn, ans[1] += 2, and the array is [1,2,0].\n\t\tOn the third turn, ans[2] += 3, and the array is [1,2,3].\n\t\tOn the fourth turn, ans[0] += 4, and the final array is [5,2,3].\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1196, - "question": "class Solution:\n def minHeightShelves(self, books: List[List[int]], shelfWidth: int) -> int:\n\t\t\"\"\"\n\t\tYou are given an array books where books[i] = [thicknessi, heighti] indicates the thickness and height of the ith book. You are also given an integer shelfWidth.\n\t\tWe want to place these books in order onto bookcase shelves that have a total width shelfWidth.\n\t\tWe choose some of the books to place on this shelf such that the sum of their thickness is less than or equal to shelfWidth, then build another level of the shelf of the bookcase so that the total height of the bookcase has increased by the maximum height of the books we just put down. We repeat this process until there are no more books to place.\n\t\tNote that at each step of the above process, the order of the books we place is the same order as the given sequence of books.\n\t\t\tFor example, if we have an ordered list of 5 books, we might place the first and second book onto the first shelf, the third book on the second shelf, and the fourth and fifth book on the last shelf.\n\t\tReturn the minimum possible height that the total bookshelf can be after placing shelves in this manner.\n\t\tExample 1:\n\t\tInput: books = [[1,1],[2,3],[2,3],[1,1],[1,1],[1,1],[1,2]], shelfWidth = 4\n\t\tOutput: 6\n\t\tExplanation:\n\t\tThe sum of the heights of the 3 shelves is 1 + 3 + 2 = 6.\n\t\tNotice that book number 2 does not have to be on the first shelf.\n\t\tExample 2:\n\t\tInput: books = [[1,3],[2,4],[3,2]], shelfWidth = 6\n\t\tOutput: 4\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1197, - "question": "class Solution:\n def parseBoolExpr(self, expression: str) -> bool:\n\t\t\"\"\"\n\t\tA boolean expression is an expression that evaluates to either true or false. It can be in one of the following shapes:\n\t\t\t't' that evaluates to true.\n\t\t\t'f' that evaluates to false.\n\t\t\t'!(subExpr)' that evaluates to the logical NOT of the inner expression subExpr.\n\t\t\t'&(subExpr1, subExpr2, ..., subExprn)' that evaluates to the logical AND of the inner expressions subExpr1, subExpr2, ..., subExprn where n >= 1.\n\t\t\t'|(subExpr1, subExpr2, ..., subExprn)' that evaluates to the logical OR of the inner expressions subExpr1, subExpr2, ..., subExprn where n >= 1.\n\t\tGiven a string expression that represents a boolean expression, return the evaluation of that expression.\n\t\tIt is guaranteed that the given expression is valid and follows the given rules.\n\t\tExample 1:\n\t\tInput: expression = \"&(|(f))\"\n\t\tOutput: false\n\t\tExplanation: \n\t\tFirst, evaluate |(f) --> f. The expression is now \"&(f)\".\n\t\tThen, evaluate &(f) --> f. The expression is now \"f\".\n\t\tFinally, return false.\n\t\tExample 2:\n\t\tInput: expression = \"|(f,f,f,t)\"\n\t\tOutput: true\n\t\tExplanation: The evaluation of (false OR false OR false OR true) is true.\n\t\tExample 3:\n\t\tInput: expression = \"!(&(f,t))\"\n\t\tOutput: true\n\t\tExplanation: \n\t\tFirst, evaluate &(f,t) --> (false AND true) --> false --> f. The expression is now \"!(f)\".\n\t\tThen, evaluate !(f) --> NOT false --> true. We return true.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1203, - "question": "class Foo:\n def __init__(self):\n pass\n def first(self, printFirst: 'Callable[[], None]') -> None:\n printFirst()\n def second(self, printSecond: 'Callable[[], None]') -> None:\n printSecond()\n def third(self, printThird: 'Callable[[], None]') -> None:\n printThird()\n\t\t\"\"\"\n\t\tSuppose we have a class:\n\t\tpublic class Foo {\n\t\t public void first() { print(\"first\"); }\n\t\t public void second() { print(\"second\"); }\n\t\t public void third() { print(\"third\"); }\n\t\t}\n\t\tThe same instance of Foo will be passed to three different threads. Thread A will call first(), thread B will call second(), and thread C will call third(). Design a mechanism and modify the program to ensure that second() is executed after first(), and third() is executed after second().\n\t\tNote:\n\t\tWe do not know how the threads will be scheduled in the operating system, even though the numbers in the input seem to imply the ordering. The input format you see is mainly to ensure our tests' comprehensiveness.\n\t\tExample 1:\n\t\tInput: nums = [1,2,3]\n\t\tOutput: \"firstsecondthird\"\n\t\tExplanation: There are three threads being fired asynchronously. The input [1,2,3] means thread A calls first(), thread B calls second(), and thread C calls third(). \"firstsecondthird\" is the correct output.\n\t\tExample 2:\n\t\tInput: nums = [1,3,2]\n\t\tOutput: \"firstsecondthird\"\n\t\tExplanation: The input [1,3,2] means thread A calls first(), thread B calls third(), and thread C calls second(). \"firstsecondthird\" is the correct output.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1205, - "question": "class Solution:\n def defangIPaddr(self, address: str) -> str:\n\t\t\"\"\"\n\t\tGiven a valid (IPv4) IP address, return a defanged version of that IP address.\r\n\t\tA defanged IP address replaces every period \".\" with \"[.]\".\r\n\t\tExample 1:\r\n\t\tInput: address = \"1.1.1.1\"\r\n\t\tOutput: \"1[.]1[.]1[.]1\"\r\n\t\tExample 2:\r\n\t\tInput: address = \"255.100.50.0\"\r\n\t\tOutput: \"255[.]100[.]50[.]0\"\r\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1206, - "question": "class Solution:\n def corpFlightBookings(self, bookings: List[List[int]], n: int) -> List[int]:\n\t\t\"\"\"\n\t\tThere are n flights that are labeled from 1 to n.\n\t\tYou are given an array of flight bookings bookings, where bookings[i] = [firsti, lasti, seatsi] represents a booking for flights firsti through lasti (inclusive) with seatsi seats reserved for each flight in the range.\n\t\tReturn an array answer of length n, where answer[i] is the total number of seats reserved for flight i.\n\t\tExample 1:\n\t\tInput: bookings = [[1,2,10],[2,3,20],[2,5,25]], n = 5\n\t\tOutput: [10,55,45,25,25]\n\t\tExplanation:\n\t\tFlight labels: 1 2 3 4 5\n\t\tBooking 1 reserved: 10 10\n\t\tBooking 2 reserved: 20 20\n\t\tBooking 3 reserved: 25 25 25 25\n\t\tTotal seats: 10 55 45 25 25\n\t\tHence, answer = [10,55,45,25,25]\n\t\tExample 2:\n\t\tInput: bookings = [[1,2,10],[2,2,15]], n = 2\n\t\tOutput: [10,25]\n\t\tExplanation:\n\t\tFlight labels: 1 2\n\t\tBooking 1 reserved: 10 10\n\t\tBooking 2 reserved: 15\n\t\tTotal seats: 10 25\n\t\tHence, answer = [10,25]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1207, - "question": "class Solution:\n def delNodes(self, root: Optional[TreeNode], to_delete: List[int]) -> List[TreeNode]:\n\t\t\"\"\"\n\t\tGiven the root of a binary tree, each node in the tree has a distinct value.\n\t\tAfter deleting all nodes with a value in to_delete, we are left with a forest (a disjoint union of trees).\n\t\tReturn the roots of the trees in the remaining forest. You may return the result in any order.\n\t\tExample 1:\n\t\tInput: root = [1,2,3,4,5,6,7], to_delete = [3,5]\n\t\tOutput: [[1,2,null,4],[6],[7]]\n\t\tExample 2:\n\t\tInput: root = [1,2,4,null,3], to_delete = [3]\n\t\tOutput: [[1,2,4]]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1208, - "question": "class Solution:\n def maxDepthAfterSplit(self, seq: str) -> List[int]:\n\t\t\"\"\"\n\t\tA string is a valid parentheses string (denoted VPS) if and only if it consists of \"(\" and \")\" characters only, and:\r\n\t\t\tIt is the empty string, or\r\n\t\t\tIt can be written as AB (A concatenated with B), where A and B are VPS's, or\r\n\t\t\tIt can be written as (A), where A is a VPS.\r\n\t\tWe can similarly define the nesting depth depth(S) of any VPS S as follows:\r\n\t\t\tdepth(\"\") = 0\r\n\t\t\tdepth(A + B) = max(depth(A), depth(B)), where A and B are VPS's\r\n\t\t\tdepth(\"(\" + A + \")\") = 1 + depth(A), where A is a VPS.\r\n\t\tFor example, \"\", \"()()\", and \"()(()())\" are VPS's (with nesting depths 0, 1, and 2), and \")(\" and \"(()\" are not VPS's.\r\n\t\tGiven a VPS seq, split it into two disjoint subsequences A and B, such that A and B are VPS's (and A.length + B.length = seq.length).\r\n\t\tNow choose any such A and B such that max(depth(A), depth(B)) is the minimum possible value.\r\n\t\tReturn an answer array (of length seq.length) that encodes such a choice of A and B: answer[i] = 0 if seq[i] is part of A, else answer[i] = 1. Note that even though multiple answers may exist, you may return any of them.\r\n\t\tExample 1:\n\t\tInput: seq = \"(()())\"\n\t\tOutput: [0,1,1,1,1,0]\n\t\tExample 2:\n\t\tInput: seq = \"()(())()\"\n\t\tOutput: [0,0,0,1,1,0,1,1]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1210, - "question": "class Solution:\n def trimMean(self, arr: List[int]) -> float:\n\t\t\"\"\"\n\t\tGiven an integer array arr, return the mean of the remaining integers after removing the smallest 5% and the largest 5% of the elements.\n\t\tAnswers within 10-5 of the actual answer will be considered accepted.\n\t\tExample 1:\n\t\tInput: arr = [1,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,3]\n\t\tOutput: 2.00000\n\t\tExplanation: After erasing the minimum and the maximum values of this array, all elements are equal to 2, so the mean is 2.\n\t\tExample 2:\n\t\tInput: arr = [6,2,7,5,1,2,0,3,10,2,5,0,5,5,0,8,7,6,8,0]\n\t\tOutput: 4.00000\n\t\tExample 3:\n\t\tInput: arr = [6,0,7,0,7,5,7,8,3,4,0,7,8,1,6,8,1,1,2,4,8,1,9,5,4,3,8,5,10,8,6,6,1,0,6,10,8,2,3,4]\n\t\tOutput: 4.77778\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1211, - "question": "class CombinationIterator:\n def __init__(self, characters: str, combinationLength: int):\n def next(self) -> str:\n def hasNext(self) -> bool:\n\t\t\"\"\"\n\t\tDesign the CombinationIterator class:\n\t\t\tCombinationIterator(string characters, int combinationLength) Initializes the object with a string characters of sorted distinct lowercase English letters and a number combinationLength as arguments.\n\t\t\tnext() Returns the next combination of length combinationLength in lexicographical order.\n\t\t\thasNext() Returns true if and only if there exists a next combination.\n\t\tExample 1:\n\t\tInput\n\t\t[\"CombinationIterator\", \"next\", \"hasNext\", \"next\", \"hasNext\", \"next\", \"hasNext\"]\n\t\t[[\"abc\", 2], [], [], [], [], [], []]\n\t\tOutput\n\t\t[null, \"ab\", true, \"ac\", true, \"bc\", false]\n\t\tExplanation\n\t\tCombinationIterator itr = new CombinationIterator(\"abc\", 2);\n\t\titr.next(); // return \"ab\"\n\t\titr.hasNext(); // return True\n\t\titr.next(); // return \"ac\"\n\t\titr.hasNext(); // return True\n\t\titr.next(); // return \"bc\"\n\t\titr.hasNext(); // return False\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1212, - "question": "class Solution:\n def sequentialDigits(self, low: int, high: int) -> List[int]:\n\t\t\"\"\"\n\t\tAn integer has sequential digits if and only if each digit in the number is one more than the previous digit.\n\t\tReturn a sorted list of all the integers in the range [low, high] inclusive that have sequential digits.\n\t\tExample 1:\n\t\tInput: low = 100, high = 300\n\t\tOutput: [123,234]\n\t\tExample 2:\n\t\tInput: low = 1000, high = 13000\n\t\tOutput: [1234,2345,3456,4567,5678,6789,12345]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1216, - "question": "class ZeroEvenOdd:\n def __init__(self, n):\n self.n = n\n def zero(self, printNumber: 'Callable[[int], None]') -> None:\n def even(self, printNumber: 'Callable[[int], None]') -> None:\n def odd(self, printNumber: 'Callable[[int], None]') -> None:\n\t\t\"\"\"\n\t\tYou have a function printNumber that can be called with an integer parameter and prints it to the console.\n\t\t\tFor example, calling printNumber(7) prints 7 to the console.\n\t\tYou are given an instance of the class ZeroEvenOdd that has three functions: zero, even, and odd. The same instance of ZeroEvenOdd will be passed to three different threads:\n\t\t\tThread A: calls zero() that should only output 0's.\n\t\t\tThread B: calls even() that should only output even numbers.\n\t\t\tThread C: calls odd() that should only output odd numbers.\n\t\tModify the given class to output the series \"010203040506...\" where the length of the series must be 2n.\n\t\tImplement the ZeroEvenOdd class:\n\t\t\tZeroEvenOdd(int n) Initializes the object with the number n that represents the numbers that should be printed.\n\t\t\tvoid zero(printNumber) Calls printNumber to output one zero.\n\t\t\tvoid even(printNumber) Calls printNumber to output one even number.\n\t\t\tvoid odd(printNumber) Calls printNumber to output one odd number.\n\t\tExample 1:\n\t\tInput: n = 2\n\t\tOutput: \"0102\"\n\t\tExplanation: There are three threads being fired asynchronously.\n\t\tOne of them calls zero(), the other calls even(), and the last one calls odd().\n\t\t\"0102\" is the correct output.\n\t\tExample 2:\n\t\tInput: n = 5\n\t\tOutput: \"0102030405\"\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1217, - "question": "class Solution:\n def relativeSortArray(self, arr1: List[int], arr2: List[int]) -> List[int]:\n\t\t\"\"\"\n\t\tGiven two arrays arr1 and arr2, the elements of arr2 are distinct, and all elements in arr2 are also in arr1.\n\t\tSort the elements of arr1 such that the relative ordering of items in arr1 are the same as in arr2. Elements that do not appear in arr2 should be placed at the end of arr1 in ascending order.\n\t\tExample 1:\n\t\tInput: arr1 = [2,3,1,3,2,4,6,7,9,2,19], arr2 = [2,1,4,3,9,6]\n\t\tOutput: [2,2,2,1,4,3,3,9,6,7,19]\n\t\tExample 2:\n\t\tInput: arr1 = [28,6,22,8,44,17], arr2 = [22,28,8,6]\n\t\tOutput: [22,28,8,6,17,44]\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1218, - "question": "class Solution:\n def lcaDeepestLeaves(self, root: Optional[TreeNode]) -> Optional[TreeNode]:\n\t\t\"\"\"\n\t\tGiven the root of a binary tree, return the lowest common ancestor of its deepest leaves.\n\t\tRecall that:\n\t\t\tThe node of a binary tree is a leaf if and only if it has no children\n\t\t\tThe depth of the root of the tree is 0. if the depth of a node is d, the depth of each of its children is d + 1.\n\t\t\tThe lowest common ancestor of a set S of nodes, is the node A with the largest depth such that every node in S is in the subtree with root A.\n\t\tExample 1:\n\t\tInput: root = [3,5,1,6,2,0,8,null,null,7,4]\n\t\tOutput: [2,7,4]\n\t\tExplanation: We return the node with value 2, colored in yellow in the diagram.\n\t\tThe nodes coloured in blue are the deepest leaf-nodes of the tree.\n\t\tNote that nodes 6, 0, and 8 are also leaf nodes, but the depth of them is 2, but the depth of nodes 7 and 4 is 3.\n\t\tExample 2:\n\t\tInput: root = [1]\n\t\tOutput: [1]\n\t\tExplanation: The root is the deepest node in the tree, and it's the lca of itself.\n\t\tExample 3:\n\t\tInput: root = [0,1,3,null,2]\n\t\tOutput: [2]\n\t\tExplanation: The deepest leaf node in the tree is 2, the lca of one node is itself.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1219, - "question": "class Solution:\n def longestWPI(self, hours: List[int]) -> int:\n\t\t\"\"\"\n\t\tWe are given hours, a list of the number of hours worked per day for a given employee.\n\t\tA day is considered to be a tiring day if and only if the number of hours worked is (strictly) greater than 8.\n\t\tA well-performing interval is an interval of days for which the number of tiring days is strictly larger than the number of non-tiring days.\n\t\tReturn the length of the longest well-performing interval.\n\t\tExample 1:\n\t\tInput: hours = [9,9,6,0,6,6,9]\n\t\tOutput: 3\n\t\tExplanation: The longest well-performing interval is [9,9,6].\n\t\tExample 2:\n\t\tInput: hours = [6,6,6]\n\t\tOutput: 0\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1220, - "question": "class Solution:\n def smallestSufficientTeam(self, req_skills: List[str], people: List[List[str]]) -> List[int]:\n\t\t\"\"\"\n\t\tIn a project, you have a list of required skills req_skills, and a list of people. The ith person people[i] contains a list of skills that the person has.\n\t\tConsider a sufficient team: a set of people such that for every required skill in req_skills, there is at least one person in the team who has that skill. We can represent these teams by the index of each person.\n\t\t\tFor example, team = [0, 1, 3] represents the people with skills people[0], people[1], and people[3].\n\t\tReturn any sufficient team of the smallest possible size, represented by the index of each person. You may return the answer in any order.\n\t\tIt is guaranteed an answer exists.\n\t\tExample 1:\n\t\tInput: req_skills = [\"java\",\"nodejs\",\"reactjs\"], people = [[\"java\"],[\"nodejs\"],[\"nodejs\",\"reactjs\"]]\n\t\tOutput: [0,2]\n\t\tExample 2:\n\t\tInput: req_skills = [\"algorithms\",\"math\",\"java\",\"reactjs\",\"csharp\",\"aws\"], people = [[\"algorithms\",\"math\",\"java\"],[\"algorithms\",\"math\",\"reactjs\"],[\"java\",\"csharp\",\"aws\"],[\"reactjs\",\"csharp\"],[\"csharp\",\"math\"],[\"aws\",\"java\"]]\n\t\tOutput: [1,2]\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1221, - "question": "class Solution:\n def findSpecialInteger(self, arr: List[int]) -> int:\n\t\t\"\"\"\n\t\tGiven an integer array sorted in non-decreasing order, there is exactly one integer in the array that occurs more than 25% of the time, return that integer.\n\t\tExample 1:\n\t\tInput: arr = [1,2,2,6,6,6,6,7,10]\n\t\tOutput: 6\n\t\tExample 2:\n\t\tInput: arr = [1,1]\n\t\tOutput: 1\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1222, - "question": "class Solution:\n def removeCoveredIntervals(self, intervals: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tGiven an array intervals where intervals[i] = [li, ri] represent the interval [li, ri), remove all intervals that are covered by another interval in the list.\n\t\tThe interval [a, b) is covered by the interval [c, d) if and only if c <= a and b <= d.\n\t\tReturn the number of remaining intervals.\n\t\tExample 1:\n\t\tInput: intervals = [[1,4],[3,6],[2,8]]\n\t\tOutput: 2\n\t\tExplanation: Interval [3,6] is covered by [2,8], therefore it is removed.\n\t\tExample 2:\n\t\tInput: intervals = [[1,4],[2,3]]\n\t\tOutput: 1\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1223, - "question": "class Solution:\n def areConnected(self, n: int, threshold: int, queries: List[List[int]]) -> List[bool]:\n\t\t\"\"\"\n\t\tWe have n cities labeled from 1 to n. Two different cities with labels x and y are directly connected by a bidirectional road if and only if x and y share a common divisor strictly greater than some threshold. More formally, cities with labels x and y have a road between them if there exists an integer z such that all of the following are true:\n\t\t\tx % z == 0,\n\t\t\ty % z == 0, and\n\t\t\tz > threshold.\n\t\tGiven the two integers, n and threshold, and an array of queries, you must determine for each queries[i] = [ai, bi] if cities ai and bi are connected directly or indirectly. (i.e. there is some path between them).\n\t\tReturn an array answer, where answer.length == queries.length and answer[i] is true if for the ith query, there is a path between ai and bi, or answer[i] is false if there is no path.\n\t\tExample 1:\n\t\tInput: n = 6, threshold = 2, queries = [[1,4],[2,5],[3,6]]\n\t\tOutput: [false,false,true]\n\t\tExplanation: The divisors for each number:\n\t\t1: 1\n\t\t2: 1, 2\n\t\t3: 1, 3\n\t\t4: 1, 2, 4\n\t\t5: 1, 5\n\t\t6: 1, 2, 3, 6\n\t\tUsing the underlined divisors above the threshold, only cities 3 and 6 share a common divisor, so they are the\n\t\tonly ones directly connected. The result of each query:\n\t\t[1,4] 1 is not connected to 4\n\t\t[2,5] 2 is not connected to 5\n\t\t[3,6] 3 is connected to 6 through path 3--6\n\t\tExample 2:\n\t\tInput: n = 6, threshold = 0, queries = [[4,5],[3,4],[3,2],[2,6],[1,3]]\n\t\tOutput: [true,true,true,true,true]\n\t\tExplanation: The divisors for each number are the same as the previous example. However, since the threshold is 0,\n\t\tall divisors can be used. Since all numbers share 1 as a divisor, all cities are connected.\n\t\tExample 3:\n\t\tInput: n = 5, threshold = 1, queries = [[4,5],[4,5],[3,2],[2,3],[3,4]]\n\t\tOutput: [false,false,false,false,false]\n\t\tExplanation: Only cities 2 and 4 share a common divisor 2 which is strictly greater than the threshold 1, so they are the only ones directly connected.\n\t\tPlease notice that there can be multiple queries for the same pair of nodes [x, y], and that the query [x, y] is equivalent to the query [y, x].\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1224, - "question": "class Solution:\n def minFallingPathSum(self, grid: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tGiven an n x n integer matrix grid, return the minimum sum of a falling path with non-zero shifts.\n\t\tA falling path with non-zero shifts is a choice of exactly one element from each row of grid such that no two elements chosen in adjacent rows are in the same column.\n\t\tExample 1:\n\t\tInput: arr = [[1,2,3],[4,5,6],[7,8,9]]\n\t\tOutput: 13\n\t\tExplanation: \n\t\tThe possible falling paths are:\n\t\t[1,5,9], [1,5,7], [1,6,7], [1,6,8],\n\t\t[2,4,8], [2,4,9], [2,6,7], [2,6,8],\n\t\t[3,4,8], [3,4,9], [3,5,7], [3,5,9]\n\t\tThe falling path with the smallest sum is [1,5,7], so the answer is 13.\n\t\tExample 2:\n\t\tInput: grid = [[7]]\n\t\tOutput: 7\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1227, - "question": "class Solution:\n def numEquivDominoPairs(self, dominoes: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tGiven a list of dominoes, dominoes[i] = [a, b] is equivalent to dominoes[j] = [c, d] if and only if either (a == c and b == d), or (a == d and b == c) - that is, one domino can be rotated to be equal to another domino.\n\t\tReturn the number of pairs (i, j) for which 0 <= i < j < dominoes.length, and dominoes[i] is equivalent to dominoes[j].\n\t\tExample 1:\n\t\tInput: dominoes = [[1,2],[2,1],[3,4],[5,6]]\n\t\tOutput: 1\n\t\tExample 2:\n\t\tInput: dominoes = [[1,2],[1,2],[1,1],[1,2],[2,2]]\n\t\tOutput: 3\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1228, - "question": "class Solution:\n def mctFromLeafValues(self, arr: List[int]) -> int:\n\t\t\"\"\"\n\t\tGiven an array arr of positive integers, consider all binary trees such that:\n\t\t\tEach node has either 0 or 2 children;\n\t\t\tThe values of arr correspond to the values of each leaf in an in-order traversal of the tree.\n\t\t\tThe value of each non-leaf node is equal to the product of the largest leaf value in its left and right subtree, respectively.\n\t\tAmong all possible binary trees considered, return the smallest possible sum of the values of each non-leaf node. It is guaranteed this sum fits into a 32-bit integer.\n\t\tA node is a leaf if and only if it has zero children.\n\t\tExample 1:\n\t\tInput: arr = [6,2,4]\n\t\tOutput: 32\n\t\tExplanation: There are two possible trees shown.\n\t\tThe first has a non-leaf node sum 36, and the second has non-leaf node sum 32.\n\t\tExample 2:\n\t\tInput: arr = [4,11]\n\t\tOutput: 44\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1229, - "question": "class Solution:\n def shortestAlternatingPaths(self, n: int, redEdges: List[List[int]], blueEdges: List[List[int]]) -> List[int]:\n\t\t\"\"\"\n\t\tYou are given an integer n, the number of nodes in a directed graph where the nodes are labeled from 0 to n - 1. Each edge is red or blue in this graph, and there could be self-edges and parallel edges.\n\t\tYou are given two arrays redEdges and blueEdges where:\n\t\t\tredEdges[i] = [ai, bi] indicates that there is a directed red edge from node ai to node bi in the graph, and\n\t\t\tblueEdges[j] = [uj, vj] indicates that there is a directed blue edge from node uj to node vj in the graph.\n\t\tReturn an array answer of length n, where each answer[x] is the length of the shortest path from node 0 to node x such that the edge colors alternate along the path, or -1 if such a path does not exist.\n\t\tExample 1:\n\t\tInput: n = 3, redEdges = [[0,1],[1,2]], blueEdges = []\n\t\tOutput: [0,1,-1]\n\t\tExample 2:\n\t\tInput: n = 3, redEdges = [[0,1]], blueEdges = [[2,1]]\n\t\tOutput: [0,1,-1]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1230, - "question": "class Solution:\n def maxAbsValExpr(self, arr1: List[int], arr2: List[int]) -> int:\n\t\t\"\"\"\n\t\tGiven two arrays of integers with equal lengths, return the maximum value of:\r\n\t\t|arr1[i] - arr1[j]| + |arr2[i] - arr2[j]| + |i - j|\r\n\t\twhere the maximum is taken over all 0 <= i, j < arr1.length.\r\n\t\tExample 1:\n\t\tInput: arr1 = [1,2,3,4], arr2 = [-1,4,5,6]\n\t\tOutput: 13\n\t\tExample 2:\n\t\tInput: arr1 = [1,-2,-5,0,10], arr2 = [0,-2,-1,-7,-4]\n\t\tOutput: 20\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1231, - "question": "class Solution:\n def replaceElements(self, arr: List[int]) -> List[int]:\n\t\t\"\"\"\n\t\tGiven an array arr, replace every element in that array with the greatest element among the elements to its right, and replace the last element with -1.\n\t\tAfter doing so, return the array.\n\t\tExample 1:\n\t\tInput: arr = [17,18,5,4,6,1]\n\t\tOutput: [18,6,6,6,1,-1]\n\t\tExplanation: \n\t\t- index 0 --> the greatest element to the right of index 0 is index 1 (18).\n\t\t- index 1 --> the greatest element to the right of index 1 is index 4 (6).\n\t\t- index 2 --> the greatest element to the right of index 2 is index 4 (6).\n\t\t- index 3 --> the greatest element to the right of index 3 is index 4 (6).\n\t\t- index 4 --> the greatest element to the right of index 4 is index 5 (1).\n\t\t- index 5 --> there are no elements to the right of index 5, so we put -1.\n\t\tExample 2:\n\t\tInput: arr = [400]\n\t\tOutput: [-1]\n\t\tExplanation: There are no elements to the right of index 0.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1232, - "question": "class Solution:\n def findBestValue(self, arr: List[int], target: int) -> int:\n\t\t\"\"\"\n\t\tGiven an integer array arr and a target value target, return the integer value such that when we change all the integers larger than value in the given array to be equal to value, the sum of the array gets as close as possible (in absolute difference) to target.\n\t\tIn case of a tie, return the minimum such integer.\n\t\tNotice that the answer is not neccesarilly a number from arr.\n\t\tExample 1:\n\t\tInput: arr = [4,9,3], target = 10\n\t\tOutput: 3\n\t\tExplanation: When using 3 arr converts to [3, 3, 3] which sums 9 and that's the optimal answer.\n\t\tExample 2:\n\t\tInput: arr = [2,3,5], target = 10\n\t\tOutput: 5\n\t\tExample 3:\n\t\tInput: arr = [60864,25176,27249,21296,20204], target = 56803\n\t\tOutput: 11361\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1234, - "question": "class Solution:\n def pathsWithMaxScore(self, board: List[str]) -> List[int]:\n\t\t\"\"\"\n\t\tYou are given a square board of characters. You can move on the board starting at the bottom right square marked with the character 'S'.\r\n\t\tYou need to reach the top left square marked with the character 'E'. The rest of the squares are labeled either with a numeric character 1, 2, ..., 9 or with an obstacle 'X'. In one move you can go up, left or up-left (diagonally) only if there is no obstacle there.\r\n\t\tReturn a list of two integers: the first integer is the maximum sum of numeric characters you can collect, and the second is the number of such paths that you can take to get that maximum sum, taken modulo 10^9 + 7.\r\n\t\tIn case there is no path, return [0, 0].\r\n\t\tExample 1:\r\n\t\tInput: board = [\"E23\",\"2X2\",\"12S\"]\r\n\t\tOutput: [7,1]\r\n\t\tExample 2:\r\n\t\tInput: board = [\"E12\",\"1X1\",\"21S\"]\r\n\t\tOutput: [4,2]\r\n\t\tExample 3:\r\n\t\tInput: board = [\"E11\",\"XXX\",\"11S\"]\r\n\t\tOutput: [0,0]\r\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1236, - "question": "class Solution:\n def tribonacci(self, n: int) -> int:\n\t\t\"\"\"\n\t\tThe Tribonacci sequence Tn is defined as follows: \r\n\t\tT0 = 0, T1 = 1, T2 = 1, and Tn+3 = Tn + Tn+1 + Tn+2 for n >= 0.\r\n\t\tGiven n, return the value of Tn.\r\n\t\tExample 1:\r\n\t\tInput: n = 4\r\n\t\tOutput: 4\r\n\t\tExplanation:\r\n\t\tT_3 = 0 + 1 + 1 = 2\r\n\t\tT_4 = 1 + 1 + 2 = 4\r\n\t\tExample 2:\r\n\t\tInput: n = 25\r\n\t\tOutput: 1389537\r\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1238, - "question": "class Solution:\n def alphabetBoardPath(self, target: str) -> str:\n\t\t\"\"\"\n\t\tOn an alphabet board, we start at position (0, 0), corresponding to character board[0][0].\r\n\t\tHere, board = [\"abcde\", \"fghij\", \"klmno\", \"pqrst\", \"uvwxy\", \"z\"], as shown in the diagram below.\r\n\t\tWe may make the following moves:\r\n\t\t\t'U' moves our position up one row, if the position exists on the board;\r\n\t\t\t'D' moves our position down one row, if the position exists on the board;\r\n\t\t\t'L' moves our position left one column, if the position exists on the board;\r\n\t\t\t'R' moves our position right one column, if the position exists on the board;\r\n\t\t\t'!' adds the character board[r][c] at our current position (r, c) to the answer.\r\n\t\t(Here, the only positions that exist on the board are positions with letters on them.)\r\n\t\tReturn a sequence of moves that makes our answer equal to target in the minimum number of moves. You may return any path that does so.\r\n\t\tExample 1:\r\n\t\tInput: target = \"leet\"\r\n\t\tOutput: \"DDR!UURRR!!DDD!\"\r\n\t\tExample 2:\r\n\t\tInput: target = \"code\"\r\n\t\tOutput: \"RR!DDRR!UUL!R!\"\r\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1239, - "question": "class Solution:\n def largest1BorderedSquare(self, grid: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tGiven a 2D grid of 0s and 1s, return the number of elements in the largest square subgrid that has all 1s on its border, or 0 if such a subgrid doesn't exist in the grid.\r\n\t\tExample 1:\r\n\t\tInput: grid = [[1,1,1],[1,0,1],[1,1,1]]\r\n\t\tOutput: 9\r\n\t\tExample 2:\r\n\t\tInput: grid = [[1,1,0,0]]\r\n\t\tOutput: 1\r\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1240, - "question": "class Solution:\n def stoneGameII(self, piles: List[int]) -> int:\n\t\t\"\"\"\n\t\tAlice and Bob continue their games with piles of stones. There are a number of piles arranged in a row, and each pile has a positive integer number of stones piles[i]. The objective of the game is to end with the most stones. \n\t\tAlice and Bob take turns, with Alice starting first. Initially, M = 1.\n\t\tOn each player's turn, that player can take all the stones in the first X remaining piles, where 1 <= X <= 2M. Then, we set M = max(M, X).\n\t\tThe game continues until all the stones have been taken.\n\t\tAssuming Alice and Bob play optimally, return the maximum number of stones Alice can get.\n\t\tExample 1:\n\t\tInput: piles = [2,7,9,4,4]\n\t\tOutput: 10\n\t\tExplanation: If Alice takes one pile at the beginning, Bob takes two piles, then Alice takes 2 piles again. Alice can get 2 + 4 + 4 = 10 piles in total. If Alice takes two piles at the beginning, then Bob can take all three piles left. In this case, Alice get 2 + 7 = 9 piles in total. So we return 10 since it's larger. \n\t\tExample 2:\n\t\tInput: piles = [1,2,3,4,5,100]\n\t\tOutput: 104\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1241, - "question": "class Solution:\n def decompressRLElist(self, nums: List[int]) -> List[int]:\n\t\t\"\"\"\n\t\tWe are given a list nums of integers representing a list compressed with run-length encoding.\n\t\tConsider each adjacent pair of elements [freq, val] = [nums[2*i], nums[2*i+1]] (with i >= 0). For each such pair, there are freq elements with value val concatenated in a sublist. Concatenate all the sublists from left to right to generate the decompressed list.\n\t\tReturn the decompressed list.\n\t\tExample 1:\n\t\tInput: nums = [1,2,3,4]\n\t\tOutput: [2,4,4,4]\n\t\tExplanation: The first pair [1,2] means we have freq = 1 and val = 2 so we generate the array [2].\n\t\tThe second pair [3,4] means we have freq = 3 and val = 4 so we generate [4,4,4].\n\t\tAt the end the concatenation [2] + [4,4,4] is [2,4,4,4].\n\t\tExample 2:\n\t\tInput: nums = [1,1,2,3]\n\t\tOutput: [1,3,3]\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1242, - "question": "class Solution:\n def matrixBlockSum(self, mat: List[List[int]], k: int) -> List[List[int]]:\n\t\t\"\"\"\n\t\tGiven a m x n matrix mat and an integer k, return a matrix answer where each answer[i][j] is the sum of all elements mat[r][c] for:\n\t\t\ti - k <= r <= i + k,\n\t\t\tj - k <= c <= j + k, and\n\t\t\t(r, c) is a valid position in the matrix.\n\t\tExample 1:\n\t\tInput: mat = [[1,2,3],[4,5,6],[7,8,9]], k = 1\n\t\tOutput: [[12,21,16],[27,45,33],[24,39,28]]\n\t\tExample 2:\n\t\tInput: mat = [[1,2,3],[4,5,6],[7,8,9]], k = 2\n\t\tOutput: [[45,45,45],[45,45,45],[45,45,45]]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1243, - "question": "class Solution:\n def sumEvenGrandparent(self, root: TreeNode) -> int:\n\t\t\"\"\"\n\t\tGiven the root of a binary tree, return the sum of values of nodes with an even-valued grandparent. If there are no nodes with an even-valued grandparent, return 0.\n\t\tA grandparent of a node is the parent of its parent if it exists.\n\t\tExample 1:\n\t\tInput: root = [6,7,8,2,7,1,3,9,null,1,4,null,null,null,5]\n\t\tOutput: 18\n\t\tExplanation: The red nodes are the nodes with even-value grandparent while the blue nodes are the even-value grandparents.\n\t\tExample 2:\n\t\tInput: root = [1]\n\t\tOutput: 0\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1244, - "question": "class Solution:\n def distinctEchoSubstrings(self, text: str) -> int:\n\t\t\"\"\"\n\t\tReturn the number of distinct non-empty substrings of text that can be written as the concatenation of some string with itself (i.e. it can be written as a + a where a is some string).\n\t\tExample 1:\n\t\tInput: text = \"abcabcabc\"\n\t\tOutput: 3\n\t\tExplanation: The 3 substrings are \"abcabc\", \"bcabca\" and \"cabcab\".\n\t\tExample 2:\n\t\tInput: text = \"leetcodeleetcode\"\n\t\tOutput: 2\n\t\tExplanation: The 2 substrings are \"ee\" and \"leetcodeleetcode\".\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1247, - "question": "class Solution:\n def movesToMakeZigzag(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tGiven an array nums of integers, a move consists of choosing any element and decreasing it by 1.\n\t\tAn array A is a zigzag array if either:\n\t\t\tEvery even-indexed element is greater than adjacent elements, ie. A[0] > A[1] < A[2] > A[3] < A[4] > ...\n\t\t\tOR, every odd-indexed element is greater than adjacent elements, ie. A[0] < A[1] > A[2] < A[3] > A[4] < ...\n\t\tReturn the minimum number of moves to transform the given array nums into a zigzag array.\n\t\tExample 1:\n\t\tInput: nums = [1,2,3]\n\t\tOutput: 2\n\t\tExplanation: We can decrease 2 to 0 or 3 to 1.\n\t\tExample 2:\n\t\tInput: nums = [9,6,1,6,2]\n\t\tOutput: 4\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1248, - "question": "class Solution:\n def btreeGameWinningMove(self, root: Optional[TreeNode], n: int, x: int) -> bool:\n\t\t\"\"\"\n\t\tTwo players play a turn based game on a binary tree. We are given the root of this binary tree, and the number of nodes n in the tree. n is odd, and each node has a distinct value from 1 to n.\n\t\tInitially, the first player names a value x with 1 <= x <= n, and the second player names a value y with 1 <= y <= n and y != x. The first player colors the node with value x red, and the second player colors the node with value y blue.\n\t\tThen, the players take turns starting with the first player. In each turn, that player chooses a node of their color (red if player 1, blue if player 2) and colors an uncolored neighbor of the chosen node (either the left child, right child, or parent of the chosen node.)\n\t\tIf (and only if) a player cannot choose such a node in this way, they must pass their turn. If both players pass their turn, the game ends, and the winner is the player that colored more nodes.\n\t\tYou are the second player. If it is possible to choose such a y to ensure you win the game, return true. If it is not possible, return false.\n\t\tExample 1:\n\t\tInput: root = [1,2,3,4,5,6,7,8,9,10,11], n = 11, x = 3\n\t\tOutput: true\n\t\tExplanation: The second player can choose the node with value 2.\n\t\tExample 2:\n\t\tInput: root = [1,2,3], n = 3, x = 1\n\t\tOutput: false\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1249, - "question": "class SnapshotArray:\n def __init__(self, length: int):\n def set(self, index: int, val: int) -> None:\n def snap(self) -> int:\n def get(self, index: int, snap_id: int) -> int:\n\t\t\"\"\"\n\t\tImplement a SnapshotArray that supports the following interface:\n\t\t\tSnapshotArray(int length) initializes an array-like data structure with the given length. Initially, each element equals 0.\n\t\t\tvoid set(index, val) sets the element at the given index to be equal to val.\n\t\t\tint snap() takes a snapshot of the array and returns the snap_id: the total number of times we called snap() minus 1.\n\t\t\tint get(index, snap_id) returns the value at the given index, at the time we took the snapshot with the given snap_id\n\t\tExample 1:\n\t\tInput: [\"SnapshotArray\",\"set\",\"snap\",\"set\",\"get\"]\n\t\t[[3],[0,5],[],[0,6],[0,0]]\n\t\tOutput: [null,null,0,null,5]\n\t\tExplanation: \n\t\tSnapshotArray snapshotArr = new SnapshotArray(3); // set the length to be 3\n\t\tsnapshotArr.set(0,5); // Set array[0] = 5\n\t\tsnapshotArr.snap(); // Take a snapshot, return snap_id = 0\n\t\tsnapshotArr.set(0,6);\n\t\tsnapshotArr.get(0,0); // Get the value of array[0] with snap_id = 0, return 5\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1250, - "question": "class Solution:\n def longestCommonSubsequence(self, text1: str, text2: str) -> int:\n\t\t\"\"\"\n\t\tGiven two strings text1 and text2, return the length of their longest common subsequence. If there is no common subsequence, return 0.\n\t\tA subsequence of a string is a new string generated from the original string with some characters (can be none) deleted without changing the relative order of the remaining characters.\n\t\t\tFor example, \"ace\" is a subsequence of \"abcde\".\n\t\tA common subsequence of two strings is a subsequence that is common to both strings.\n\t\tExample 1:\n\t\tInput: text1 = \"abcde\", text2 = \"ace\" \n\t\tOutput: 3 \n\t\tExplanation: The longest common subsequence is \"ace\" and its length is 3.\n\t\tExample 2:\n\t\tInput: text1 = \"abc\", text2 = \"abc\"\n\t\tOutput: 3\n\t\tExplanation: The longest common subsequence is \"abc\" and its length is 3.\n\t\tExample 3:\n\t\tInput: text1 = \"abc\", text2 = \"def\"\n\t\tOutput: 0\n\t\tExplanation: There is no such common subsequence, so the result is 0.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1251, - "question": "class Solution:\n def longestDecomposition(self, text: str) -> int:\n\t\t\"\"\"\n\t\tYou are given a string text. You should split it to k substrings (subtext1, subtext2, ..., subtextk) such that:\n\t\t\tsubtexti is a non-empty string.\n\t\t\tThe concatenation of all the substrings is equal to text (i.e., subtext1 + subtext2 + ... + subtextk == text).\n\t\t\tsubtexti == subtextk - i + 1 for all valid values of i (i.e., 1 <= i <= k).\n\t\tReturn the largest possible value of k.\n\t\tExample 1:\n\t\tInput: text = \"ghiabcdefhelloadamhelloabcdefghi\"\n\t\tOutput: 7\n\t\tExplanation: We can split the string on \"(ghi)(abcdef)(hello)(adam)(hello)(abcdef)(ghi)\".\n\t\tExample 2:\n\t\tInput: text = \"merchant\"\n\t\tOutput: 1\n\t\tExplanation: We can split the string on \"(merchant)\".\n\t\tExample 3:\n\t\tInput: text = \"antaprezatepzapreanta\"\n\t\tOutput: 11\n\t\tExplanation: We can split the string on \"(a)(nt)(a)(pre)(za)(tep)(za)(pre)(a)(nt)(a)\".\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1252, - "question": "class Solution:\n def breakPalindrome(self, palindrome: str) -> str:\n\t\t\"\"\"\n\t\tGiven a palindromic string of lowercase English letters palindrome, replace exactly one character with any lowercase English letter so that the resulting string is not a palindrome and that it is the lexicographically smallest one possible.\n\t\tReturn the resulting string. If there is no way to replace a character to make it not a palindrome, return an empty string.\n\t\tA string a is lexicographically smaller than a string b (of the same length) if in the first position where a and b differ, a has a character strictly smaller than the corresponding character in b. For example, \"abcc\" is lexicographically smaller than \"abcd\" because the first position they differ is at the fourth character, and 'c' is smaller than 'd'.\n\t\tExample 1:\n\t\tInput: palindrome = \"abccba\"\n\t\tOutput: \"aaccba\"\n\t\tExplanation: There are many ways to make \"abccba\" not a palindrome, such as \"zbccba\", \"aaccba\", and \"abacba\".\n\t\tOf all the ways, \"aaccba\" is the lexicographically smallest.\n\t\tExample 2:\n\t\tInput: palindrome = \"a\"\n\t\tOutput: \"\"\n\t\tExplanation: There is no way to replace a single character to make \"a\" not a palindrome, so return an empty string.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1253, - "question": "class Solution:\n def diagonalSort(self, mat: List[List[int]]) -> List[List[int]]:\n\t\t\"\"\"\n\t\tA matrix diagonal is a diagonal line of cells starting from some cell in either the topmost row or leftmost column and going in the bottom-right direction until reaching the matrix's end. For example, the matrix diagonal starting from mat[2][0], where mat is a 6 x 3 matrix, includes cells mat[2][0], mat[3][1], and mat[4][2].\n\t\tGiven an m x n matrix mat of integers, sort each matrix diagonal in ascending order and return the resulting matrix.\n\t\tExample 1:\n\t\tInput: mat = [[3,3,1,1],[2,2,1,2],[1,1,1,2]]\n\t\tOutput: [[1,1,1,1],[1,2,2,2],[1,2,3,3]]\n\t\tExample 2:\n\t\tInput: mat = [[11,25,66,1,69,7],[23,55,17,45,15,52],[75,31,36,44,58,8],[22,27,33,25,68,4],[84,28,14,11,5,50]]\n\t\tOutput: [[5,17,4,1,52,7],[11,11,25,45,8,69],[14,23,25,44,58,15],[22,27,31,36,50,66],[84,28,75,33,55,68]]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1254, - "question": "class Solution:\n def deepestLeavesSum(self, root: Optional[TreeNode]) -> int:\n\t\t\"\"\"\n\t\tGiven the root of a binary tree, return the sum of values of its deepest leaves.\n\t\tExample 1:\n\t\tInput: root = [1,2,3,4,5,null,6,7,null,null,null,null,8]\n\t\tOutput: 15\n\t\tExample 2:\n\t\tInput: root = [6,7,8,2,7,1,3,9,null,1,4,null,null,null,5]\n\t\tOutput: 19\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1255, - "question": "class Solution:\n def maxValueAfterReverse(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou are given an integer array nums. The value of this array is defined as the sum of |nums[i] - nums[i + 1]| for all 0 <= i < nums.length - 1.\n\t\tYou are allowed to select any subarray of the given array and reverse it. You can perform this operation only once.\n\t\tFind maximum possible value of the final array.\n\t\tExample 1:\n\t\tInput: nums = [2,3,1,5,4]\n\t\tOutput: 10\n\t\tExplanation: By reversing the subarray [3,1,5] the array becomes [2,5,1,3,4] whose value is 10.\n\t\tExample 2:\n\t\tInput: nums = [2,4,9,24,2,1,10]\n\t\tOutput: 68\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1256, - "question": "class Solution:\n def arrayRankTransform(self, arr: List[int]) -> List[int]:\n\t\t\"\"\"\n\t\tGiven an array of integers arr, replace each element with its rank.\n\t\tThe rank represents how large the element is. The rank has the following rules:\n\t\t\tRank is an integer starting from 1.\n\t\t\tThe larger the element, the larger the rank. If two elements are equal, their rank must be the same.\n\t\t\tRank should be as small as possible.\n\t\tExample 1:\n\t\tInput: arr = [40,10,20,30]\n\t\tOutput: [4,1,2,3]\n\t\tExplanation: 40 is the largest element. 10 is the smallest. 20 is the second smallest. 30 is the third smallest.\n\t\tExample 2:\n\t\tInput: arr = [100,100,100]\n\t\tOutput: [1,1,1]\n\t\tExplanation: Same elements share the same rank.\n\t\tExample 3:\n\t\tInput: arr = [37,12,28,9,100,56,80,5,12]\n\t\tOutput: [5,3,4,2,8,6,7,1,3]\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1257, - "question": "class Solution:\n def matrixRankTransform(self, matrix: List[List[int]]) -> List[List[int]]:\n\t\t\"\"\"\n\t\tGiven an m x n matrix, return a new matrix answer where answer[row][col] is the rank of matrix[row][col].\n\t\tThe rank is an integer that represents how large an element is compared to other elements. It is calculated using the following rules:\n\t\t\tThe rank is an integer starting from 1.\n\t\t\tIf two elements p and q are in the same row or column, then:\n\t\t\t\tIf p < q then rank(p) < rank(q)\n\t\t\t\tIf p == q then rank(p) == rank(q)\n\t\t\t\tIf p > q then rank(p) > rank(q)\n\t\t\tThe rank should be as small as possible.\n\t\tThe test cases are generated so that answer is unique under the given rules.\n\t\tExample 1:\n\t\tInput: matrix = [[1,2],[3,4]]\n\t\tOutput: [[1,2],[2,3]]\n\t\tExplanation:\n\t\tThe rank of matrix[0][0] is 1 because it is the smallest integer in its row and column.\n\t\tThe rank of matrix[0][1] is 2 because matrix[0][1] > matrix[0][0] and matrix[0][0] is rank 1.\n\t\tThe rank of matrix[1][0] is 2 because matrix[1][0] > matrix[0][0] and matrix[0][0] is rank 1.\n\t\tThe rank of matrix[1][1] is 3 because matrix[1][1] > matrix[0][1], matrix[1][1] > matrix[1][0], and both matrix[0][1] and matrix[1][0] are rank 2.\n\t\tExample 2:\n\t\tInput: matrix = [[7,7],[7,7]]\n\t\tOutput: [[1,1],[1,1]]\n\t\tExample 3:\n\t\tInput: matrix = [[20,-21,14],[-19,4,19],[22,-47,24],[-19,4,19]]\n\t\tOutput: [[4,2,3],[1,3,4],[5,1,6],[1,3,4]]\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1260, - "question": "class Solution:\n def dayOfYear(self, date: str) -> int:\n\t\t\"\"\"\n\t\tGiven a string date representing a Gregorian calendar date formatted as YYYY-MM-DD, return the day number of the year.\n\t\tExample 1:\n\t\tInput: date = \"2019-01-09\"\n\t\tOutput: 9\n\t\tExplanation: Given date is the 9th day of the year in 2019.\n\t\tExample 2:\n\t\tInput: date = \"2019-02-10\"\n\t\tOutput: 41\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1261, - "question": "class Solution:\n def maxRepOpt1(self, text: str) -> int:\n\t\t\"\"\"\n\t\tYou are given a string text. You can swap two of the characters in the text.\n\t\tReturn the length of the longest substring with repeated characters.\n\t\tExample 1:\n\t\tInput: text = \"ababa\"\n\t\tOutput: 3\n\t\tExplanation: We can swap the first 'b' with the last 'a', or the last 'b' with the first 'a'. Then, the longest repeated character substring is \"aaa\" with length 3.\n\t\tExample 2:\n\t\tInput: text = \"aaabaaa\"\n\t\tOutput: 6\n\t\tExplanation: Swap 'b' with the last 'a' (or the first 'a'), and we get longest repeated character substring \"aaaaaa\" with length 6.\n\t\tExample 3:\n\t\tInput: text = \"aaaaa\"\n\t\tOutput: 5\n\t\tExplanation: No need to swap, longest repeated character substring is \"aaaaa\" with length is 5.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1262, - "question": "class MajorityChecker:\n def __init__(self, arr: List[int]):\n def query(self, left: int, right: int, threshold: int) -> int:\n\t\t\"\"\"\n\t\tDesign a data structure that efficiently finds the majority element of a given subarray.\n\t\tThe majority element of a subarray is an element that occurs threshold times or more in the subarray.\n\t\tImplementing the MajorityChecker class:\n\t\t\tMajorityChecker(int[] arr) Initializes the instance of the class with the given array arr.\n\t\t\tint query(int left, int right, int threshold) returns the element in the subarray arr[left...right] that occurs at least threshold times, or -1 if no such element exists.\n\t\tExample 1:\n\t\tInput\n\t\t[\"MajorityChecker\", \"query\", \"query\", \"query\"]\n\t\t[[[1, 1, 2, 2, 1, 1]], [0, 5, 4], [0, 3, 3], [2, 3, 2]]\n\t\tOutput\n\t\t[null, 1, -1, 2]\n\t\tExplanation\n\t\tMajorityChecker majorityChecker = new MajorityChecker([1, 1, 2, 2, 1, 1]);\n\t\tmajorityChecker.query(0, 5, 4); // return 1\n\t\tmajorityChecker.query(0, 3, 3); // return -1\n\t\tmajorityChecker.query(2, 3, 2); // return 2\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1263, - "question": "class Solution:\n def numRollsToTarget(self, n: int, k: int, target: int) -> int:\n\t\t\"\"\"\n\t\tYou have n dice, and each die has k faces numbered from 1 to k.\n\t\tGiven three integers n, k, and target, return the number of possible ways (out of the kn total ways) to roll the dice, so the sum of the face-up numbers equals target. Since the answer may be too large, return it modulo 109 + 7.\n\t\tExample 1:\n\t\tInput: n = 1, k = 6, target = 3\n\t\tOutput: 1\n\t\tExplanation: You throw one die with 6 faces.\n\t\tThere is only one way to get a sum of 3.\n\t\tExample 2:\n\t\tInput: n = 2, k = 6, target = 7\n\t\tOutput: 6\n\t\tExplanation: You throw two dice, each with 6 faces.\n\t\tThere are 6 ways to get a sum of 7: 1+6, 2+5, 3+4, 4+3, 5+2, 6+1.\n\t\tExample 3:\n\t\tInput: n = 30, k = 30, target = 500\n\t\tOutput: 222616187\n\t\tExplanation: The answer must be returned modulo 109 + 7.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1264, - "question": "class Solution:\n def canBeTypedWords(self, text: str, brokenLetters: str) -> int:\n\t\t\"\"\"\n\t\tThere is a malfunctioning keyboard where some letter keys do not work. All other keys on the keyboard work properly.\n\t\tGiven a string text of words separated by a single space (no leading or trailing spaces) and a string brokenLetters of all distinct letter keys that are broken, return the number of words in text you can fully type using this keyboard.\n\t\tExample 1:\n\t\tInput: text = \"hello world\", brokenLetters = \"ad\"\n\t\tOutput: 1\n\t\tExplanation: We cannot type \"world\" because the 'd' key is broken.\n\t\tExample 2:\n\t\tInput: text = \"leet code\", brokenLetters = \"lt\"\n\t\tOutput: 1\n\t\tExplanation: We cannot type \"leet\" because the 'l' and 't' keys are broken.\n\t\tExample 3:\n\t\tInput: text = \"leet code\", brokenLetters = \"e\"\n\t\tOutput: 0\n\t\tExplanation: We cannot type either word because the 'e' key is broken.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1267, - "question": "class Solution:\n def removeZeroSumSublists(self, head: Optional[ListNode]) -> Optional[ListNode]:\n\t\t\"\"\"\n\t\tGiven the head of a linked list, we repeatedly delete consecutive sequences of nodes that sum to 0 until there are no such sequences.\r\n\t\tAfter doing so, return the head of the final linked list. You may return any such answer.\r\n\t\t(Note that in the examples below, all sequences are serializations of ListNode objects.)\n\t\tExample 1:\n\t\tInput: head = [1,2,-3,3,1]\n\t\tOutput: [3,1]\n\t\tNote: The answer [1,2,1] would also be accepted.\n\t\tExample 2:\n\t\tInput: head = [1,2,3,-3,4]\n\t\tOutput: [1,2,4]\n\t\tExample 3:\n\t\tInput: head = [1,2,3,-3,-2]\n\t\tOutput: [1]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1270, - "question": "class DinnerPlates:\n def __init__(self, capacity: int):\n def push(self, val: int) -> None:\n def pop(self) -> int:\n def popAtStack(self, index: int) -> int:\n\t\t\"\"\"\n\t\tYou have an infinite number of stacks arranged in a row and numbered (left to right) from 0, each of the stacks has the same maximum capacity.\n\t\tImplement the DinnerPlates class:\n\t\t\tDinnerPlates(int capacity) Initializes the object with the maximum capacity of the stacks capacity.\n\t\t\tvoid push(int val) Pushes the given integer val into the leftmost stack with a size less than capacity.\n\t\t\tint pop() Returns the value at the top of the rightmost non-empty stack and removes it from that stack, and returns -1 if all the stacks are empty.\n\t\t\tint popAtStack(int index) Returns the value at the top of the stack with the given index index and removes it from that stack or returns -1 if the stack with that given index is empty.\n\t\tExample 1:\n\t\tInput\n\t\t[\"DinnerPlates\", \"push\", \"push\", \"push\", \"push\", \"push\", \"popAtStack\", \"push\", \"push\", \"popAtStack\", \"popAtStack\", \"pop\", \"pop\", \"pop\", \"pop\", \"pop\"]\n\t\t[[2], [1], [2], [3], [4], [5], [0], [20], [21], [0], [2], [], [], [], [], []]\n\t\tOutput\n\t\t[null, null, null, null, null, null, 2, null, null, 20, 21, 5, 4, 3, 1, -1]\n\t\tExplanation: \n\t\tDinnerPlates D = DinnerPlates(2); // Initialize with capacity = 2\n\t\tD.push(1);\n\t\tD.push(2);\n\t\tD.push(3);\n\t\tD.push(4);\n\t\tD.push(5); // The stacks are now: 2 4\n\t\t 1 3 5\n\t\t \ufe48 \ufe48 \ufe48\n\t\tD.popAtStack(0); // Returns 2. The stacks are now: 4\n\t\t 1 3 5\n\t\t \ufe48 \ufe48 \ufe48\n\t\tD.push(20); // The stacks are now: 20 4\n\t\t 1 3 5\n\t\t \ufe48 \ufe48 \ufe48\n\t\tD.push(21); // The stacks are now: 20 4 21\n\t\t 1 3 5\n\t\t \ufe48 \ufe48 \ufe48\n\t\tD.popAtStack(0); // Returns 20. The stacks are now: 4 21\n\t\t 1 3 5\n\t\t \ufe48 \ufe48 \ufe48\n\t\tD.popAtStack(2); // Returns 21. The stacks are now: 4\n\t\t 1 3 5\n\t\t \ufe48 \ufe48 \ufe48 \n\t\tD.pop() // Returns 5. The stacks are now: 4\n\t\t 1 3 \n\t\t \ufe48 \ufe48 \n\t\tD.pop() // Returns 4. The stacks are now: 1 3 \n\t\t \ufe48 \ufe48 \n\t\tD.pop() // Returns 3. The stacks are now: 1 \n\t\t \ufe48 \n\t\tD.pop() // Returns 1. There are no stacks.\n\t\tD.pop() // Returns -1. There are still no stacks.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1272, - "question": "class Solution:\n def invalidTransactions(self, transactions: List[str]) -> List[str]:\n\t\t\"\"\"\n\t\tA transaction is possibly invalid if:\n\t\t\tthe amount exceeds $1000, or;\n\t\t\tif it occurs within (and including) 60 minutes of another transaction with the same name in a different city.\n\t\tYou are given an array of strings transaction where transactions[i] consists of comma-separated values representing the name, time (in minutes), amount, and city of the transaction.\n\t\tReturn a list of transactions that are possibly invalid. You may return the answer in any order.\n\t\tExample 1:\n\t\tInput: transactions = [\"alice,20,800,mtv\",\"alice,50,100,beijing\"]\n\t\tOutput: [\"alice,20,800,mtv\",\"alice,50,100,beijing\"]\n\t\tExplanation: The first transaction is invalid because the second transaction occurs within a difference of 60 minutes, have the same name and is in a different city. Similarly the second one is invalid too.\n\t\tExample 2:\n\t\tInput: transactions = [\"alice,20,800,mtv\",\"alice,50,1200,mtv\"]\n\t\tOutput: [\"alice,50,1200,mtv\"]\n\t\tExample 3:\n\t\tInput: transactions = [\"alice,20,800,mtv\",\"bob,50,1200,mtv\"]\n\t\tOutput: [\"bob,50,1200,mtv\"]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1273, - "question": "class Solution:\n def numSmallerByFrequency(self, queries: List[str], words: List[str]) -> List[int]:\n\t\t\"\"\"\n\t\tLet the function f(s) be the frequency of the lexicographically smallest character in a non-empty string s. For example, if s = \"dcce\" then f(s) = 2 because the lexicographically smallest character is 'c', which has a frequency of 2.\n\t\tYou are given an array of strings words and another array of query strings queries. For each query queries[i], count the number of words in words such that f(queries[i]) < f(W) for each W in words.\n\t\tReturn an integer array answer, where each answer[i] is the answer to the ith query.\n\t\tExample 1:\n\t\tInput: queries = [\"cbd\"], words = [\"zaaaz\"]\n\t\tOutput: [1]\n\t\tExplanation: On the first query we have f(\"cbd\") = 1, f(\"zaaaz\") = 3 so f(\"cbd\") < f(\"zaaaz\").\n\t\tExample 2:\n\t\tInput: queries = [\"bbb\",\"cc\"], words = [\"a\",\"aa\",\"aaa\",\"aaaa\"]\n\t\tOutput: [1,2]\n\t\tExplanation: On the first query only f(\"bbb\") < f(\"aaaa\"). On the second query both f(\"aaa\") and f(\"aaaa\") are both > f(\"cc\").\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1274, - "question": "class Solution:\n def daysBetweenDates(self, date1: str, date2: str) -> int:\n\t\t\"\"\"\n\t\tWrite a program to count the number of days between two dates.\n\t\tThe two dates are given as strings, their format is YYYY-MM-DD as shown in the examples.\n\t\tExample 1:\n\t\tInput: date1 = \"2019-06-29\", date2 = \"2019-06-30\"\n\t\tOutput: 1\n\t\tExample 2:\n\t\tInput: date1 = \"2020-01-15\", date2 = \"2019-12-31\"\n\t\tOutput: 15\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1275, - "question": "class Solution:\n def validateBinaryTreeNodes(self, n: int, leftChild: List[int], rightChild: List[int]) -> bool:\n\t\t\"\"\"\n\t\tYou have n binary tree nodes numbered from 0 to n - 1 where node i has two children leftChild[i] and rightChild[i], return true if and only if all the given nodes form exactly one valid binary tree.\n\t\tIf node i has no left child then leftChild[i] will equal -1, similarly for the right child.\n\t\tNote that the nodes have no values and that we only use the node numbers in this problem.\n\t\tExample 1:\n\t\tInput: n = 4, leftChild = [1,-1,3,-1], rightChild = [2,-1,-1,-1]\n\t\tOutput: true\n\t\tExample 2:\n\t\tInput: n = 4, leftChild = [1,-1,3,-1], rightChild = [2,3,-1,-1]\n\t\tOutput: false\n\t\tExample 3:\n\t\tInput: n = 2, leftChild = [1,0], rightChild = [-1,-1]\n\t\tOutput: false\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1276, - "question": "class Solution:\n def closestDivisors(self, num: int) -> List[int]:\n\t\t\"\"\"\n\t\tGiven an integer num, find the closest two integers in absolute difference whose product equals num + 1 or num + 2.\n\t\tReturn the two integers in any order.\n\t\tExample 1:\n\t\tInput: num = 8\n\t\tOutput: [3,3]\n\t\tExplanation: For num + 1 = 9, the closest divisors are 3 & 3, for num + 2 = 10, the closest divisors are 2 & 5, hence 3 & 3 is chosen.\n\t\tExample 2:\n\t\tInput: num = 123\n\t\tOutput: [5,25]\n\t\tExample 3:\n\t\tInput: num = 999\n\t\tOutput: [40,25]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1277, - "question": "class Solution:\n def largestMultipleOfThree(self, digits: List[int]) -> str:\n\t\t\"\"\"\n\t\tGiven an array of digits digits, return the largest multiple of three that can be formed by concatenating some of the given digits in any order. If there is no answer return an empty string.\n\t\tSince the answer may not fit in an integer data type, return the answer as a string. Note that the returning answer must not contain unnecessary leading zeros.\n\t\tExample 1:\n\t\tInput: digits = [8,1,9]\n\t\tOutput: \"981\"\n\t\tExample 2:\n\t\tInput: digits = [8,6,7,1,0]\n\t\tOutput: \"8760\"\n\t\tExample 3:\n\t\tInput: digits = [1]\n\t\tOutput: \"\"\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1279, - "question": "class Solution:\n def numPrimeArrangements(self, n: int) -> int:\n\t\t\"\"\"\n\t\tReturn the number of permutations of 1 to n so that prime numbers are at prime indices (1-indexed.)\n\t\t(Recall that an integer is prime if and only if it is greater than 1, and cannot be written as a product of two positive integers both smaller than it.)\n\t\tSince the answer may be large, return the answer modulo 10^9 + 7.\n\t\tExample 1:\n\t\tInput: n = 5\n\t\tOutput: 12\n\t\tExplanation: For example [1,2,5,4,3] is a valid permutation, but [5,2,3,4,1] is not because the prime number 5 is at index 1.\n\t\tExample 2:\n\t\tInput: n = 100\n\t\tOutput: 682289015\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1281, - "question": "class Solution:\n def canMakePaliQueries(self, s: str, queries: List[List[int]]) -> List[bool]:\n\t\t\"\"\"\n\t\tYou are given a string s and array queries where queries[i] = [lefti, righti, ki]. We may rearrange the substring s[lefti...righti] for each query and then choose up to ki of them to replace with any lowercase English letter.\n\t\tIf the substring is possible to be a palindrome string after the operations above, the result of the query is true. Otherwise, the result is false.\n\t\tReturn a boolean array answer where answer[i] is the result of the ith query queries[i].\n\t\tNote that each letter is counted individually for replacement, so if, for example s[lefti...righti] = \"aaa\", and ki = 2, we can only replace two of the letters. Also, note that no query modifies the initial string s.\n\t\tExample :\n\t\tInput: s = \"abcda\", queries = [[3,3,0],[1,2,0],[0,3,1],[0,3,2],[0,4,1]]\n\t\tOutput: [true,false,false,true,true]\n\t\tExplanation:\n\t\tqueries[0]: substring = \"d\", is palidrome.\n\t\tqueries[1]: substring = \"bc\", is not palidrome.\n\t\tqueries[2]: substring = \"abcd\", is not palidrome after replacing only 1 character.\n\t\tqueries[3]: substring = \"abcd\", could be changed to \"abba\" which is palidrome. Also this can be changed to \"baab\" first rearrange it \"bacd\" then replace \"cd\" with \"ab\".\n\t\tqueries[4]: substring = \"abcda\", could be changed to \"abcba\" which is palidrome.\n\t\tExample 2:\n\t\tInput: s = \"lyb\", queries = [[0,1,0],[2,2,1]]\n\t\tOutput: [false,true]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1282, - "question": "class Solution:\n def findNumOfValidWords(self, words: List[str], puzzles: List[str]) -> List[int]:\n\t\t\"\"\"\n\t\tWith respect to a given puzzle string, a word is valid if both the following conditions are satisfied:\n\t\t\tword contains the first letter of puzzle.\n\t\t\tFor each letter in word, that letter is in puzzle.\n\t\t\t\tFor example, if the puzzle is \"abcdefg\", then valid words are \"faced\", \"cabbage\", and \"baggage\", while\n\t\t\t\tinvalid words are \"beefed\" (does not include 'a') and \"based\" (includes 's' which is not in the puzzle).\n\t\tReturn an array answer, where answer[i] is the number of words in the given word list words that is valid with respect to the puzzle puzzles[i].\n\t\tExample 1:\n\t\tInput: words = [\"aaaa\",\"asas\",\"able\",\"ability\",\"actt\",\"actor\",\"access\"], puzzles = [\"aboveyz\",\"abrodyz\",\"abslute\",\"absoryz\",\"actresz\",\"gaswxyz\"]\n\t\tOutput: [1,1,3,2,4,0]\n\t\tExplanation: \n\t\t1 valid word for \"aboveyz\" : \"aaaa\" \n\t\t1 valid word for \"abrodyz\" : \"aaaa\"\n\t\t3 valid words for \"abslute\" : \"aaaa\", \"asas\", \"able\"\n\t\t2 valid words for \"absoryz\" : \"aaaa\", \"asas\"\n\t\t4 valid words for \"actresz\" : \"aaaa\", \"asas\", \"actt\", \"access\"\n\t\tThere are no valid words for \"gaswxyz\" cause none of the words in the list contains letter 'g'.\n\t\tExample 2:\n\t\tInput: words = [\"apple\",\"pleas\",\"please\"], puzzles = [\"aelwxyz\",\"aelpxyz\",\"aelpsxy\",\"saelpxy\",\"xaelpsy\"]\n\t\tOutput: [0,1,3,2,0]\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1283, - "question": "class Solution:\n def reformatDate(self, date: str) -> str:\n\t\t\"\"\"\n\t\tGiven a date string in the form Day Month Year, where:\n\t\t\tDay is in the set {\"1st\", \"2nd\", \"3rd\", \"4th\", ..., \"30th\", \"31st\"}.\n\t\t\tMonth is in the set {\"Jan\", \"Feb\", \"Mar\", \"Apr\", \"May\", \"Jun\", \"Jul\", \"Aug\", \"Sep\", \"Oct\", \"Nov\", \"Dec\"}.\n\t\t\tYear is in the range [1900, 2100].\n\t\tConvert the date string to the format YYYY-MM-DD, where:\n\t\t\tYYYY denotes the 4 digit year.\n\t\t\tMM denotes the 2 digit month.\n\t\t\tDD denotes the 2 digit day.\n\t\tExample 1:\n\t\tInput: date = \"20th Oct 2052\"\n\t\tOutput: \"2052-10-20\"\n\t\tExample 2:\n\t\tInput: date = \"6th Jun 1933\"\n\t\tOutput: \"1933-06-06\"\n\t\tExample 3:\n\t\tInput: date = \"26th May 1960\"\n\t\tOutput: \"1960-05-26\"\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1284, - "question": "class Solution:\n def sumFourDivisors(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tGiven an integer array nums, return the sum of divisors of the integers in that array that have exactly four divisors. If there is no such integer in the array, return 0.\n\t\tExample 1:\n\t\tInput: nums = [21,4,7]\n\t\tOutput: 32\n\t\tExplanation: \n\t\t21 has 4 divisors: 1, 3, 7, 21\n\t\t4 has 3 divisors: 1, 2, 4\n\t\t7 has 2 divisors: 1, 7\n\t\tThe answer is the sum of divisors of 21 only.\n\t\tExample 2:\n\t\tInput: nums = [21,21]\n\t\tOutput: 64\n\t\tExample 3:\n\t\tInput: nums = [1,2,3,4,5]\n\t\tOutput: 0\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1285, - "question": "class Solution:\n def balanceBST(self, root: TreeNode) -> TreeNode:\n\t\t\"\"\"\n\t\tGiven the root of a binary search tree, return a balanced binary search tree with the same node values. If there is more than one answer, return any of them.\n\t\tA binary search tree is balanced if the depth of the two subtrees of every node never differs by more than 1.\n\t\tExample 1:\n\t\tInput: root = [1,null,2,null,3,null,4,null,null]\n\t\tOutput: [2,1,3,null,null,null,4]\n\t\tExplanation: This is not the only correct answer, [3,1,4,null,2] is also correct.\n\t\tExample 2:\n\t\tInput: root = [2,1,3]\n\t\tOutput: [2,1,3]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1286, - "question": "class Solution:\n def constrainedSubsetSum(self, nums: List[int], k: int) -> int:\n\t\t\"\"\"\n\t\tGiven an integer array nums and an integer k, return the maximum sum of a non-empty subsequence of that array such that for every two consecutive integers in the subsequence, nums[i] and nums[j], where i < j, the condition j - i <= k is satisfied.\n\t\tA subsequence of an array is obtained by deleting some number of elements (can be zero) from the array, leaving the remaining elements in their original order.\n\t\tExample 1:\n\t\tInput: nums = [10,2,-10,5,20], k = 2\n\t\tOutput: 37\n\t\tExplanation: The subsequence is [10, 2, 5, 20].\n\t\tExample 2:\n\t\tInput: nums = [-1,-2,-3], k = 1\n\t\tOutput: -1\n\t\tExplanation: The subsequence must be non-empty, so we choose the largest number.\n\t\tExample 3:\n\t\tInput: nums = [10,-2,-10,-5,20], k = 2\n\t\tOutput: 23\n\t\tExplanation: The subsequence is [10, -2, -5, 20].\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1287, - "question": "class Solution:\n def distanceBetweenBusStops(self, distance: List[int], start: int, destination: int) -> int:\n\t\t\"\"\"\n\t\tA bus has n stops numbered from 0 to n - 1 that form a circle. We know the distance between all pairs of neighboring stops where distance[i] is the distance between the stops number i and (i + 1) % n.\r\n\t\tThe bus goes along both directions i.e. clockwise and counterclockwise.\r\n\t\tReturn the shortest distance between the given start and destination stops.\r\n\t\tExample 1:\r\n\t\tInput: distance = [1,2,3,4], start = 0, destination = 1\r\n\t\tOutput: 1\r\n\t\tExplanation: Distance between 0 and 1 is 1 or 9, minimum is 1.\r\n\t\tExample 2:\r\n\t\tInput: distance = [1,2,3,4], start = 0, destination = 2\r\n\t\tOutput: 3\r\n\t\tExplanation: Distance between 0 and 2 is 3 or 7, minimum is 3.\r\n\t\tExample 3:\r\n\t\tInput: distance = [1,2,3,4], start = 0, destination = 3\r\n\t\tOutput: 4\r\n\t\tExplanation: Distance between 0 and 3 is 6 or 4, minimum is 4.\r\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1288, - "question": "class Solution:\n def maximumSum(self, arr: List[int]) -> int:\n\t\t\"\"\"\n\t\tGiven an array of integers, return the maximum sum for a non-empty subarray (contiguous elements) with at most one element deletion. In other words, you want to choose a subarray and optionally delete one element from it so that there is still at least one element left and the sum of the remaining elements is maximum possible.\n\t\tNote that the subarray needs to be non-empty after deleting one element.\n\t\tExample 1:\n\t\tInput: arr = [1,-2,0,3]\n\t\tOutput: 4\n\t\tExplanation: Because we can choose [1, -2, 0, 3] and drop -2, thus the subarray [1, 0, 3] becomes the maximum value.\n\t\tExample 2:\n\t\tInput: arr = [1,-2,-2,3]\n\t\tOutput: 3\n\t\tExplanation: We just choose [3] and it's the maximum sum.\n\t\tExample 3:\n\t\tInput: arr = [-1,-1,-1,-1]\n\t\tOutput: -1\n\t\tExplanation: The final subarray needs to be non-empty. You can't choose [-1] and delete -1 from it, then get an empty subarray to make the sum equals to 0.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1289, - "question": "class Solution:\n def dayOfTheWeek(self, day: int, month: int, year: int) -> str:\n\t\t\"\"\"\n\t\tGiven a date, return the corresponding day of the week for that date.\n\t\tThe input is given as three integers representing the day, month and year respectively.\n\t\tReturn the answer as one of the following values {\"Sunday\", \"Monday\", \"Tuesday\", \"Wednesday\", \"Thursday\", \"Friday\", \"Saturday\"}.\n\t\tExample 1:\n\t\tInput: day = 31, month = 8, year = 2019\n\t\tOutput: \"Saturday\"\n\t\tExample 2:\n\t\tInput: day = 18, month = 7, year = 1999\n\t\tOutput: \"Sunday\"\n\t\tExample 3:\n\t\tInput: day = 15, month = 8, year = 1993\n\t\tOutput: \"Sunday\"\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1290, - "question": "class Solution:\n def makeArrayIncreasing(self, arr1: List[int], arr2: List[int]) -> int:\n\t\t\"\"\"\n\t\tGiven two integer arrays arr1 and arr2, return the minimum number of operations (possibly zero) needed to make arr1 strictly increasing.\r\n\t\tIn one operation, you can choose two indices 0 <= i < arr1.length and 0 <= j < arr2.length and do the assignment arr1[i] = arr2[j].\r\n\t\tIf there is no way to make arr1 strictly increasing, return -1.\r\n\t\tExample 1:\r\n\t\tInput: arr1 = [1,5,3,6,7], arr2 = [1,3,2,4]\r\n\t\tOutput: 1\r\n\t\tExplanation: Replace 5 with 2, then arr1 = [1, 2, 3, 6, 7].\r\n\t\tExample 2:\r\n\t\tInput: arr1 = [1,5,3,6,7], arr2 = [4,3,1]\r\n\t\tOutput: 2\r\n\t\tExplanation: Replace 5 with 3 and then replace 3 with 4. arr1 = [1, 3, 4, 6, 7].\r\n\t\tExample 3:\r\n\t\tInput: arr1 = [1,5,3,6,7], arr2 = [1,6,3,3]\r\n\t\tOutput: -1\r\n\t\tExplanation: You can't make arr1 strictly increasing.\r\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1293, - "question": "class Solution:\n def threeConsecutiveOdds(self, arr: List[int]) -> bool:\n\t\t\"\"\"\n\t\tGiven an integer array arr, return true if there are three consecutive odd numbers in the array. Otherwise, return false.\n\t\tExample 1:\n\t\tInput: arr = [2,6,4,1]\n\t\tOutput: false\n\t\tExplanation: There are no three consecutive odds.\n\t\tExample 2:\n\t\tInput: arr = [1,2,34,3,4,5,7,23,12]\n\t\tOutput: true\n\t\tExplanation: [5,7,23] are three consecutive odds.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1294, - "question": "class RangeFreqQuery:\n def __init__(self, arr: List[int]):\n def query(self, left: int, right: int, value: int) -> int:\n\t\t\"\"\"\n\t\tDesign a data structure to find the frequency of a given value in a given subarray.\n\t\tThe frequency of a value in a subarray is the number of occurrences of that value in the subarray.\n\t\tImplement the RangeFreqQuery class:\n\t\t\tRangeFreqQuery(int[] arr) Constructs an instance of the class with the given 0-indexed integer array arr.\n\t\t\tint query(int left, int right, int value) Returns the frequency of value in the subarray arr[left...right].\n\t\tA subarray is a contiguous sequence of elements within an array. arr[left...right] denotes the subarray that contains the elements of nums between indices left and right (inclusive).\n\t\tExample 1:\n\t\tInput\n\t\t[\"RangeFreqQuery\", \"query\", \"query\"]\n\t\t[[[12, 33, 4, 56, 22, 2, 34, 33, 22, 12, 34, 56]], [1, 2, 4], [0, 11, 33]]\n\t\tOutput\n\t\t[null, 1, 2]\n\t\tExplanation\n\t\tRangeFreqQuery rangeFreqQuery = new RangeFreqQuery([12, 33, 4, 56, 22, 2, 34, 33, 22, 12, 34, 56]);\n\t\trangeFreqQuery.query(1, 2, 4); // return 1. The value 4 occurs 1 time in the subarray [33, 4]\n\t\trangeFreqQuery.query(0, 11, 33); // return 2. The value 33 occurs 2 times in the whole array.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1295, - "question": "class Solution:\n def minimumPerimeter(self, neededApples: int) -> int:\n\t\t\"\"\"\n\t\tIn a garden represented as an infinite 2D grid, there is an apple tree planted at every integer coordinate. The apple tree planted at an integer coordinate (i, j) has |i| + |j| apples growing on it.\n\t\tYou will buy an axis-aligned square plot of land that is centered at (0, 0).\n\t\tGiven an integer neededApples, return the minimum perimeter of a plot such that at least neededApples apples are inside or on the perimeter of that plot.\n\t\tThe value of |x| is defined as:\n\t\t\tx if x >= 0\n\t\t\t-x if x < 0\n\t\tExample 1:\n\t\tInput: neededApples = 1\n\t\tOutput: 8\n\t\tExplanation: A square plot of side length 1 does not contain any apples.\n\t\tHowever, a square plot of side length 2 has 12 apples inside (as depicted in the image above).\n\t\tThe perimeter is 2 * 4 = 8.\n\t\tExample 2:\n\t\tInput: neededApples = 13\n\t\tOutput: 16\n\t\tExample 3:\n\t\tInput: neededApples = 1000000000\n\t\tOutput: 5040\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1296, - "question": "class TreeAncestor:\n def __init__(self, n: int, parent: List[int]):\n def getKthAncestor(self, node: int, k: int) -> int:\n\t\t\"\"\"\n\t\tYou are given a tree with n nodes numbered from 0 to n - 1 in the form of a parent array parent where parent[i] is the parent of ith node. The root of the tree is node 0. Find the kth ancestor of a given node.\n\t\tThe kth ancestor of a tree node is the kth node in the path from that node to the root node.\n\t\tImplement the TreeAncestor class:\n\t\t\tTreeAncestor(int n, int[] parent) Initializes the object with the number of nodes in the tree and the parent array.\n\t\t\tint getKthAncestor(int node, int k) return the kth ancestor of the given node node. If there is no such ancestor, return -1.\n\t\tExample 1:\n\t\tInput\n\t\t[\"TreeAncestor\", \"getKthAncestor\", \"getKthAncestor\", \"getKthAncestor\"]\n\t\t[[7, [-1, 0, 0, 1, 1, 2, 2]], [3, 1], [5, 2], [6, 3]]\n\t\tOutput\n\t\t[null, 1, 0, -1]\n\t\tExplanation\n\t\tTreeAncestor treeAncestor = new TreeAncestor(7, [-1, 0, 0, 1, 1, 2, 2]);\n\t\ttreeAncestor.getKthAncestor(3, 1); // returns 1 which is the parent of 3\n\t\ttreeAncestor.getKthAncestor(5, 2); // returns 0 which is the grandparent of 5\n\t\ttreeAncestor.getKthAncestor(6, 3); // returns -1 because there is no such ancestor\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1297, - "question": "class Solution:\n def maxNumberOfBalloons(self, text: str) -> int:\n\t\t\"\"\"\n\t\tGiven a string text, you want to use the characters of text to form as many instances of the word \"balloon\" as possible.\n\t\tYou can use each character in text at most once. Return the maximum number of instances that can be formed.\n\t\tExample 1:\n\t\tInput: text = \"nlaebolko\"\n\t\tOutput: 1\n\t\tExample 2:\n\t\tInput: text = \"loonbalxballpoon\"\n\t\tOutput: 2\n\t\tExample 3:\n\t\tInput: text = \"leetcode\"\n\t\tOutput: 0\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1298, - "question": "class Solution:\n def reverseParentheses(self, s: str) -> str:\n\t\t\"\"\"\n\t\tYou are given a string s that consists of lower case English letters and brackets.\n\t\tReverse the strings in each pair of matching parentheses, starting from the innermost one.\n\t\tYour result should not contain any brackets.\n\t\tExample 1:\n\t\tInput: s = \"(abcd)\"\n\t\tOutput: \"dcba\"\n\t\tExample 2:\n\t\tInput: s = \"(u(love)i)\"\n\t\tOutput: \"iloveu\"\n\t\tExplanation: The substring \"love\" is reversed first, then the whole string is reversed.\n\t\tExample 3:\n\t\tInput: s = \"(ed(et(oc))el)\"\n\t\tOutput: \"leetcode\"\n\t\tExplanation: First, we reverse the substring \"oc\", then \"etco\", and finally, the whole string.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1299, - "question": "class Solution:\n def kConcatenationMaxSum(self, arr: List[int], k: int) -> int:\n\t\t\"\"\"\n\t\tGiven an integer array arr and an integer k, modify the array by repeating it k times.\n\t\tFor example, if arr = [1, 2] and k = 3 then the modified array will be [1, 2, 1, 2, 1, 2].\n\t\tReturn the maximum sub-array sum in the modified array. Note that the length of the sub-array can be 0 and its sum in that case is 0.\n\t\tAs the answer can be very large, return the answer modulo 109 + 7.\n\t\tExample 1:\n\t\tInput: arr = [1,2], k = 3\n\t\tOutput: 9\n\t\tExample 2:\n\t\tInput: arr = [1,-2,1], k = 5\n\t\tOutput: 2\n\t\tExample 3:\n\t\tInput: arr = [-1,-2], k = 7\n\t\tOutput: 0\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1300, - "question": "class Solution:\n def criticalConnections(self, n: int, connections: List[List[int]]) -> List[List[int]]:\n\t\t\"\"\"\n\t\tThere are n servers numbered from 0 to n - 1 connected by undirected server-to-server connections forming a network where connections[i] = [ai, bi] represents a connection between servers ai and bi. Any server can reach other servers directly or indirectly through the network.\n\t\tA critical connection is a connection that, if removed, will make some servers unable to reach some other server.\n\t\tReturn all critical connections in the network in any order.\n\t\tExample 1:\n\t\tInput: n = 4, connections = [[0,1],[1,2],[2,0],[1,3]]\n\t\tOutput: [[1,3]]\n\t\tExplanation: [[3,1]] is also accepted.\n\t\tExample 2:\n\t\tInput: n = 2, connections = [[0,1]]\n\t\tOutput: [[0,1]]\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1302, - "question": "class Solution:\n def makeFancyString(self, s: str) -> str:\n\t\t\"\"\"\n\t\tA fancy string is a string where no three consecutive characters are equal.\n\t\tGiven a string s, delete the minimum possible number of characters from s to make it fancy.\n\t\tReturn the final string after the deletion. It can be shown that the answer will always be unique.\n\t\tExample 1:\n\t\tInput: s = \"leeetcode\"\n\t\tOutput: \"leetcode\"\n\t\tExplanation:\n\t\tRemove an 'e' from the first group of 'e's to create \"leetcode\".\n\t\tNo three consecutive characters are equal, so return \"leetcode\".\n\t\tExample 2:\n\t\tInput: s = \"aaabaaaa\"\n\t\tOutput: \"aabaa\"\n\t\tExplanation:\n\t\tRemove an 'a' from the first group of 'a's to create \"aabaaaa\".\n\t\tRemove two 'a's from the second group of 'a's to create \"aabaa\".\n\t\tNo three consecutive characters are equal, so return \"aabaa\".\n\t\tExample 3:\n\t\tInput: s = \"aab\"\n\t\tOutput: \"aab\"\n\t\tExplanation: No three consecutive characters are equal, so return \"aab\".\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1303, - "question": "class Solution:\n def minMoves(self, target: int, maxDoubles: int) -> int:\n\t\t\"\"\"\n\t\tYou are playing a game with integers. You start with the integer 1 and you want to reach the integer target.\n\t\tIn one move, you can either:\n\t\t\tIncrement the current integer by one (i.e., x = x + 1).\n\t\t\tDouble the current integer (i.e., x = 2 * x).\n\t\tYou can use the increment operation any number of times, however, you can only use the double operation at most maxDoubles times.\n\t\tGiven the two integers target and maxDoubles, return the minimum number of moves needed to reach target starting with 1.\n\t\tExample 1:\n\t\tInput: target = 5, maxDoubles = 0\n\t\tOutput: 4\n\t\tExplanation: Keep incrementing by 1 until you reach target.\n\t\tExample 2:\n\t\tInput: target = 19, maxDoubles = 2\n\t\tOutput: 7\n\t\tExplanation: Initially, x = 1\n\t\tIncrement 3 times so x = 4\n\t\tDouble once so x = 8\n\t\tIncrement once so x = 9\n\t\tDouble again so x = 18\n\t\tIncrement once so x = 19\n\t\tExample 3:\n\t\tInput: target = 10, maxDoubles = 4\n\t\tOutput: 4\n\t\tExplanation: Initially, x = 1\n\t\tIncrement once so x = 2\n\t\tDouble once so x = 4\n\t\tIncrement once so x = 5\n\t\tDouble again so x = 10\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1304, - "question": "class Solution:\n def longestDiverseString(self, a: int, b: int, c: int) -> str:\n\t\t\"\"\"\n\t\tA string s is called happy if it satisfies the following conditions:\n\t\t\ts only contains the letters 'a', 'b', and 'c'.\n\t\t\ts does not contain any of \"aaa\", \"bbb\", or \"ccc\" as a substring.\n\t\t\ts contains at most a occurrences of the letter 'a'.\n\t\t\ts contains at most b occurrences of the letter 'b'.\n\t\t\ts contains at most c occurrences of the letter 'c'.\n\t\tGiven three integers a, b, and c, return the longest possible happy string. If there are multiple longest happy strings, return any of them. If there is no such string, return the empty string \"\".\n\t\tA substring is a contiguous sequence of characters within a string.\n\t\tExample 1:\n\t\tInput: a = 1, b = 1, c = 7\n\t\tOutput: \"ccaccbcc\"\n\t\tExplanation: \"ccbccacc\" would also be a correct answer.\n\t\tExample 2:\n\t\tInput: a = 7, b = 1, c = 0\n\t\tOutput: \"aabaa\"\n\t\tExplanation: It is the only correct answer in this case.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1305, - "question": "class Solution:\n def canSeePersonsCount(self, heights: List[int]) -> List[int]:\n\t\t\"\"\"\n\t\tThere are n people standing in a queue, and they numbered from 0 to n - 1 in left to right order. You are given an array heights of distinct integers where heights[i] represents the height of the ith person.\n\t\tA person can see another person to their right in the queue if everybody in between is shorter than both of them. More formally, the ith person can see the jth person if i < j and min(heights[i], heights[j]) > max(heights[i+1], heights[i+2], ..., heights[j-1]).\n\t\tReturn an array answer of length n where answer[i] is the number of people the ith person can see to their right in the queue.\n\t\tExample 1:\n\t\tInput: heights = [10,6,8,5,11,9]\n\t\tOutput: [3,1,2,1,1,0]\n\t\tExplanation:\n\t\tPerson 0 can see person 1, 2, and 4.\n\t\tPerson 1 can see person 2.\n\t\tPerson 2 can see person 3 and 4.\n\t\tPerson 3 can see person 4.\n\t\tPerson 4 can see person 5.\n\t\tPerson 5 can see no one since nobody is to the right of them.\n\t\tExample 2:\n\t\tInput: heights = [5,1,2,3,10]\n\t\tOutput: [4,1,1,1,0]\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1306, - "question": "class Solution:\n def minimumAbsDifference(self, arr: List[int]) -> List[List[int]]:\n\t\t\"\"\"\n\t\tGiven an array of distinct integers arr, find all pairs of elements with the minimum absolute difference of any two elements.\n\t\tReturn a list of pairs in ascending order(with respect to pairs), each pair [a, b] follows\n\t\t\ta, b are from arr\n\t\t\ta < b\n\t\t\tb - a equals to the minimum absolute difference of any two elements in arr\n\t\tExample 1:\n\t\tInput: arr = [4,2,1,3]\n\t\tOutput: [[1,2],[2,3],[3,4]]\n\t\tExplanation: The minimum absolute difference is 1. List all pairs with difference equal to 1 in ascending order.\n\t\tExample 2:\n\t\tInput: arr = [1,3,6,10,15]\n\t\tOutput: [[1,3]]\n\t\tExample 3:\n\t\tInput: arr = [3,8,-10,23,19,-4,-14,27]\n\t\tOutput: [[-14,-10],[19,23],[23,27]]\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1307, - "question": "class Solution:\n def nthUglyNumber(self, n: int, a: int, b: int, c: int) -> int:\n\t\t\"\"\"\n\t\tAn ugly number is a positive integer that is divisible by a, b, or c.\n\t\tGiven four integers n, a, b, and c, return the nth ugly number.\n\t\tExample 1:\n\t\tInput: n = 3, a = 2, b = 3, c = 5\n\t\tOutput: 4\n\t\tExplanation: The ugly numbers are 2, 3, 4, 5, 6, 8, 9, 10... The 3rd is 4.\n\t\tExample 2:\n\t\tInput: n = 4, a = 2, b = 3, c = 4\n\t\tOutput: 6\n\t\tExplanation: The ugly numbers are 2, 3, 4, 6, 8, 9, 10, 12... The 4th is 6.\n\t\tExample 3:\n\t\tInput: n = 5, a = 2, b = 11, c = 13\n\t\tOutput: 10\n\t\tExplanation: The ugly numbers are 2, 4, 6, 8, 10, 11, 12, 13... The 5th is 10.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1308, - "question": "class Solution:\n def smallestStringWithSwaps(self, s: str, pairs: List[List[int]]) -> str:\n\t\t\"\"\"\n\t\tYou are given a string s, and an array of pairs of indices in the string pairs where pairs[i] = [a, b] indicates 2 indices(0-indexed) of the string.\n\t\tYou can swap the characters at any pair of indices in the given pairs any number of times.\n\t\tReturn the lexicographically smallest string that s can be changed to after using the swaps.\n\t\tExample 1:\n\t\tInput: s = \"dcab\", pairs = [[0,3],[1,2]]\n\t\tOutput: \"bacd\"\n\t\tExplaination: \n\t\tSwap s[0] and s[3], s = \"bcad\"\n\t\tSwap s[1] and s[2], s = \"bacd\"\n\t\tExample 2:\n\t\tInput: s = \"dcab\", pairs = [[0,3],[1,2],[0,2]]\n\t\tOutput: \"abcd\"\n\t\tExplaination: \n\t\tSwap s[0] and s[3], s = \"bcad\"\n\t\tSwap s[0] and s[2], s = \"acbd\"\n\t\tSwap s[1] and s[2], s = \"abcd\"\n\t\tExample 3:\n\t\tInput: s = \"cba\", pairs = [[0,1],[1,2]]\n\t\tOutput: \"abc\"\n\t\tExplaination: \n\t\tSwap s[0] and s[1], s = \"bca\"\n\t\tSwap s[1] and s[2], s = \"bac\"\n\t\tSwap s[0] and s[1], s = \"abc\"\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1309, - "question": "class Solution:\n def sortItems(self, n: int, m: int, group: List[int], beforeItems: List[List[int]]) -> List[int]:\n\t\t\"\"\"\n\t\tThere are n items each belonging to zero or one of m groups where group[i] is the group that the i-th item belongs to and it's equal to -1 if the i-th item belongs to no group. The items and the groups are zero indexed. A group can have no item belonging to it.\n\t\tReturn a sorted list of the items such that:\n\t\t\tThe items that belong to the same group are next to each other in the sorted list.\n\t\t\tThere are some relations between these items where beforeItems[i] is a list containing all the items that should come before the i-th item in the sorted array (to the left of the i-th item).\n\t\tReturn any solution if there is more than one solution and return an empty list if there is no solution.\n\t\tExample 1:\n\t\tInput: n = 8, m = 2, group = [-1,-1,1,0,0,1,0,-1], beforeItems = [[],[6],[5],[6],[3,6],[],[],[]]\n\t\tOutput: [6,3,4,1,5,2,0,7]\n\t\tExample 2:\n\t\tInput: n = 8, m = 2, group = [-1,-1,1,0,0,1,0,-1], beforeItems = [[],[6],[5],[6],[3],[],[4],[]]\n\t\tOutput: []\n\t\tExplanation: This is the same as example 1 except that 4 needs to be before 6 in the sorted list.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1310, - "question": "class Solution:\n def wateringPlants(self, plants: List[int], capacity: int) -> int:\n\t\t\"\"\"\n\t\tYou want to water n plants in your garden with a watering can. The plants are arranged in a row and are labeled from 0 to n - 1 from left to right where the ith plant is located at x = i. There is a river at x = -1 that you can refill your watering can at.\n\t\tEach plant needs a specific amount of water. You will water the plants in the following way:\n\t\t\tWater the plants in order from left to right.\n\t\t\tAfter watering the current plant, if you do not have enough water to completely water the next plant, return to the river to fully refill the watering can.\n\t\t\tYou cannot refill the watering can early.\n\t\tYou are initially at the river (i.e., x = -1). It takes one step to move one unit on the x-axis.\n\t\tGiven a 0-indexed integer array plants of n integers, where plants[i] is the amount of water the ith plant needs, and an integer capacity representing the watering can capacity, return the number of steps needed to water all the plants.\n\t\tExample 1:\n\t\tInput: plants = [2,2,3,3], capacity = 5\n\t\tOutput: 14\n\t\tExplanation: Start at the river with a full watering can:\n\t\t- Walk to plant 0 (1 step) and water it. Watering can has 3 units of water.\n\t\t- Walk to plant 1 (1 step) and water it. Watering can has 1 unit of water.\n\t\t- Since you cannot completely water plant 2, walk back to the river to refill (2 steps).\n\t\t- Walk to plant 2 (3 steps) and water it. Watering can has 2 units of water.\n\t\t- Since you cannot completely water plant 3, walk back to the river to refill (3 steps).\n\t\t- Walk to plant 3 (4 steps) and water it.\n\t\tSteps needed = 1 + 1 + 2 + 3 + 3 + 4 = 14.\n\t\tExample 2:\n\t\tInput: plants = [1,1,1,4,2,3], capacity = 4\n\t\tOutput: 30\n\t\tExplanation: Start at the river with a full watering can:\n\t\t- Water plants 0, 1, and 2 (3 steps). Return to river (3 steps).\n\t\t- Water plant 3 (4 steps). Return to river (4 steps).\n\t\t- Water plant 4 (5 steps). Return to river (5 steps).\n\t\t- Water plant 5 (6 steps).\n\t\tSteps needed = 3 + 3 + 4 + 4 + 5 + 5 + 6 = 30.\n\t\tExample 3:\n\t\tInput: plants = [7,7,7,7,7,7,7], capacity = 8\n\t\tOutput: 49\n\t\tExplanation: You have to refill before watering each plant.\n\t\tSteps needed = 1 + 1 + 2 + 2 + 3 + 3 + 4 + 4 + 5 + 5 + 6 + 6 + 7 = 49.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1311, - "question": "class Solution:\n def largestMagicSquare(self, grid: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tA k x k magic square is a k x k grid filled with integers such that every row sum, every column sum, and both diagonal sums are all equal. The integers in the magic square do not have to be distinct. Every 1 x 1 grid is trivially a magic square.\n\t\tGiven an m x n integer grid, return the size (i.e., the side length k) of the largest magic square that can be found within this grid.\n\t\tExample 1:\n\t\tInput: grid = [[7,1,4,5,6],[2,5,1,6,4],[1,5,4,3,2],[1,2,7,3,4]]\n\t\tOutput: 3\n\t\tExplanation: The largest magic square has a size of 3.\n\t\tEvery row sum, column sum, and diagonal sum of this magic square is equal to 12.\n\t\t- Row sums: 5+1+6 = 5+4+3 = 2+7+3 = 12\n\t\t- Column sums: 5+5+2 = 1+4+7 = 6+3+3 = 12\n\t\t- Diagonal sums: 5+4+3 = 6+4+2 = 12\n\t\tExample 2:\n\t\tInput: grid = [[5,1,3,1],[9,3,3,1],[1,3,3,8]]\n\t\tOutput: 2\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1312, - "question": "class Solution:\n def digArtifacts(self, n: int, artifacts: List[List[int]], dig: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tThere is an n x n 0-indexed grid with some artifacts buried in it. You are given the integer n and a 0-indexed 2D integer array artifacts describing the positions of the rectangular artifacts where artifacts[i] = [r1i, c1i, r2i, c2i] denotes that the ith artifact is buried in the subgrid where:\n\t\t\t(r1i, c1i) is the coordinate of the top-left cell of the ith artifact and\n\t\t\t(r2i, c2i) is the coordinate of the bottom-right cell of the ith artifact.\n\t\tYou will excavate some cells of the grid and remove all the mud from them. If the cell has a part of an artifact buried underneath, it will be uncovered. If all the parts of an artifact are uncovered, you can extract it.\n\t\tGiven a 0-indexed 2D integer array dig where dig[i] = [ri, ci] indicates that you will excavate the cell (ri, ci), return the number of artifacts that you can extract.\n\t\tThe test cases are generated such that:\n\t\t\tNo two artifacts overlap.\n\t\t\tEach artifact only covers at most 4 cells.\n\t\t\tThe entries of dig are unique.\n\t\tExample 1:\n\t\tInput: n = 2, artifacts = [[0,0,0,0],[0,1,1,1]], dig = [[0,0],[0,1]]\n\t\tOutput: 1\n\t\tExplanation: \n\t\tThe different colors represent different artifacts. Excavated cells are labeled with a 'D' in the grid.\n\t\tThere is 1 artifact that can be extracted, namely the red artifact.\n\t\tThe blue artifact has one part in cell (1,1) which remains uncovered, so we cannot extract it.\n\t\tThus, we return 1.\n\t\tExample 2:\n\t\tInput: n = 2, artifacts = [[0,0,0,0],[0,1,1,1]], dig = [[0,0],[0,1],[1,1]]\n\t\tOutput: 2\n\t\tExplanation: Both the red and blue artifacts have all parts uncovered (labeled with a 'D') and can be extracted, so we return 2. \n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1313, - "question": "class Solution:\n def waysToBuildRooms(self, prevRoom: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou are an ant tasked with adding n new rooms numbered 0 to n-1 to your colony. You are given the expansion plan as a 0-indexed integer array of length n, prevRoom, where prevRoom[i] indicates that you must build room prevRoom[i] before building room i, and these two rooms must be connected directly. Room 0 is already built, so prevRoom[0] = -1. The expansion plan is given such that once all the rooms are built, every room will be reachable from room 0.\r\n\t\tYou can only build one room at a time, and you can travel freely between rooms you have already built only if they are connected. You can choose to build any room as long as its previous room is already built.\r\n\t\tReturn the number of different orders you can build all the rooms in. Since the answer may be large, return it modulo 109 + 7.\r\n\t\tExample 1:\r\n\t\tInput: prevRoom = [-1,0,1]\r\n\t\tOutput: 1\r\n\t\tExplanation: There is only one way to build the additional rooms: 0 \u2192 1 \u2192 2\r\n\t\tExample 2:\r\n\t\tInput: prevRoom = [-1,0,0,1,2]\r\n\t\tOutput: 6\r\n\t\tExplanation:\r\n\t\tThe 6 ways are:\r\n\t\t0 \u2192 1 \u2192 3 \u2192 2 \u2192 4\r\n\t\t0 \u2192 2 \u2192 4 \u2192 1 \u2192 3\r\n\t\t0 \u2192 1 \u2192 2 \u2192 3 \u2192 4\r\n\t\t0 \u2192 1 \u2192 2 \u2192 4 \u2192 3\r\n\t\t0 \u2192 2 \u2192 1 \u2192 3 \u2192 4\r\n\t\t0 \u2192 2 \u2192 1 \u2192 4 \u2192 3\r\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1316, - "question": "class FizzBuzz:\n def __init__(self, n: int):\n self.n = n\n def fizz(self, printFizz: 'Callable[[], None]') -> None:\n def buzz(self, printBuzz: 'Callable[[], None]') -> None:\n def fizzbuzz(self, printFizzBuzz: 'Callable[[], None]') -> None:\n def number(self, printNumber: 'Callable[[int], None]') -> None:\n\t\t\"\"\"\n\t\tYou have the four functions:\n\t\t\tprintFizz that prints the word \"fizz\" to the console,\n\t\t\tprintBuzz that prints the word \"buzz\" to the console,\n\t\t\tprintFizzBuzz that prints the word \"fizzbuzz\" to the console, and\n\t\t\tprintNumber that prints a given integer to the console.\n\t\tYou are given an instance of the class FizzBuzz that has four functions: fizz, buzz, fizzbuzz and number. The same instance of FizzBuzz will be passed to four different threads:\n\t\t\tThread A: calls fizz() that should output the word \"fizz\".\n\t\t\tThread B: calls buzz() that should output the word \"buzz\".\n\t\t\tThread C: calls fizzbuzz() that should output the word \"fizzbuzz\".\n\t\t\tThread D: calls number() that should only output the integers.\n\t\tModify the given class to output the series [1, 2, \"fizz\", 4, \"buzz\", ...] where the ith token (1-indexed) of the series is:\n\t\t\t\"fizzbuzz\" if i is divisible by 3 and 5,\n\t\t\t\"fizz\" if i is divisible by 3 and not 5,\n\t\t\t\"buzz\" if i is divisible by 5 and not 3, or\n\t\t\ti if i is not divisible by 3 or 5.\n\t\tImplement the FizzBuzz class:\n\t\t\tFizzBuzz(int n) Initializes the object with the number n that represents the length of the sequence that should be printed.\n\t\t\tvoid fizz(printFizz) Calls printFizz to output \"fizz\".\n\t\t\tvoid buzz(printBuzz) Calls printBuzz to output \"buzz\".\n\t\t\tvoid fizzbuzz(printFizzBuzz) Calls printFizzBuzz to output \"fizzbuzz\".\n\t\t\tvoid number(printNumber) Calls printnumber to output the numbers.\n\t\tExample 1:\n\t\tInput: n = 15\n\t\tOutput: [1,2,\"fizz\",4,\"buzz\",\"fizz\",7,8,\"fizz\",\"buzz\",11,\"fizz\",13,14,\"fizzbuzz\"]\n\t\tExample 2:\n\t\tInput: n = 5\n\t\tOutput: [1,2,\"fizz\",4,\"buzz\"]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1319, - "question": "class Solution:\n def uniqueOccurrences(self, arr: List[int]) -> bool:\n\t\t\"\"\"\n\t\tGiven an array of integers arr, return true if the number of occurrences of each value in the array is unique or false otherwise.\n\t\tExample 1:\n\t\tInput: arr = [1,2,2,1,1,3]\n\t\tOutput: true\n\t\tExplanation: The value 1 has 3 occurrences, 2 has 2 and 3 has 1. No two values have the same number of occurrences.\n\t\tExample 2:\n\t\tInput: arr = [1,2]\n\t\tOutput: false\n\t\tExample 3:\n\t\tInput: arr = [-3,0,1,-3,1,1,1,-3,10,0]\n\t\tOutput: true\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1320, - "question": "class Solution:\n def removeDuplicates(self, s: str, k: int) -> str:\n\t\t\"\"\"\n\t\tYou are given a string s and an integer k, a k duplicate removal consists of choosing k adjacent and equal letters from s and removing them, causing the left and the right side of the deleted substring to concatenate together.\n\t\tWe repeatedly make k duplicate removals on s until we no longer can.\n\t\tReturn the final string after all such duplicate removals have been made. It is guaranteed that the answer is unique.\n\t\tExample 1:\n\t\tInput: s = \"abcd\", k = 2\n\t\tOutput: \"abcd\"\n\t\tExplanation: There's nothing to delete.\n\t\tExample 2:\n\t\tInput: s = \"deeedbbcccbdaa\", k = 3\n\t\tOutput: \"aa\"\n\t\tExplanation: \n\t\tFirst delete \"eee\" and \"ccc\", get \"ddbbbdaa\"\n\t\tThen delete \"bbb\", get \"dddaa\"\n\t\tFinally delete \"ddd\", get \"aa\"\n\t\tExample 3:\n\t\tInput: s = \"pbbcggttciiippooaais\", k = 2\n\t\tOutput: \"ps\"\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1321, - "question": "class Solution:\n def equalSubstring(self, s: str, t: str, maxCost: int) -> int:\n\t\t\"\"\"\n\t\tYou are given two strings s and t of the same length and an integer maxCost.\n\t\tYou want to change s to t. Changing the ith character of s to ith character of t costs |s[i] - t[i]| (i.e., the absolute difference between the ASCII values of the characters).\n\t\tReturn the maximum length of a substring of s that can be changed to be the same as the corresponding substring of t with a cost less than or equal to maxCost. If there is no substring from s that can be changed to its corresponding substring from t, return 0.\n\t\tExample 1:\n\t\tInput: s = \"abcd\", t = \"bcdf\", maxCost = 3\n\t\tOutput: 3\n\t\tExplanation: \"abc\" of s can change to \"bcd\".\n\t\tThat costs 3, so the maximum length is 3.\n\t\tExample 2:\n\t\tInput: s = \"abcd\", t = \"cdef\", maxCost = 3\n\t\tOutput: 1\n\t\tExplanation: Each character in s costs 2 to change to character in t, so the maximum length is 1.\n\t\tExample 3:\n\t\tInput: s = \"abcd\", t = \"acde\", maxCost = 0\n\t\tOutput: 1\n\t\tExplanation: You cannot make any change, so the maximum length is 1.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1322, - "question": "class Solution:\n def minimumMoves(self, grid: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tIn an n*n grid, there is a snake that spans 2 cells and starts moving from the top left corner at (0, 0) and (0, 1). The grid has empty cells represented by zeros and blocked cells represented by ones. The snake wants to reach the lower right corner at (n-1, n-2) and (n-1, n-1).\n\t\tIn one move the snake can:\n\t\t\tMove one cell to the right if there are no blocked cells there. This move keeps the horizontal/vertical position of the snake as it is.\n\t\t\tMove down one cell if there are no blocked cells there. This move keeps the horizontal/vertical position of the snake as it is.\n\t\t\tRotate clockwise if it's in a horizontal position and the two cells under it are both empty. In that case the snake moves from (r, c) and (r, c+1) to (r, c) and (r+1, c).\n\t\t\tRotate counterclockwise if it's in a vertical position and the two cells to its right are both empty. In that case the snake moves from (r, c) and (r+1, c) to (r, c) and (r, c+1).\n\t\tReturn the minimum number of moves to reach the target.\n\t\tIf there is no way to reach the target, return -1.\n\t\tExample 1:\n\t\tInput: grid = [[0,0,0,0,0,1],\n\t\t [1,1,0,0,1,0],\n\t\t [0,0,0,0,1,1],\n\t\t [0,0,1,0,1,0],\n\t\t [0,1,1,0,0,0],\n\t\t [0,1,1,0,0,0]]\n\t\tOutput: 11\n\t\tExplanation:\n\t\tOne possible solution is [right, right, rotate clockwise, right, down, down, down, down, rotate counterclockwise, right, down].\n\t\tExample 2:\n\t\tInput: grid = [[0,0,1,1,1,1],\n\t\t [0,0,0,0,1,1],\n\t\t [1,1,0,0,0,1],\n\t\t [1,1,1,0,0,1],\n\t\t [1,1,1,0,0,1],\n\t\t [1,1,1,0,0,0]]\n\t\tOutput: 9\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1324, - "question": "class Solution:\n def findBall(self, grid: List[List[int]]) -> List[int]:\n\t\t\"\"\"\n\t\tYou have a 2-D grid of size m x n representing a box, and you have n balls. The box is open on the top and bottom sides.\n\t\tEach cell in the box has a diagonal board spanning two corners of the cell that can redirect a ball to the right or to the left.\n\t\t\tA board that redirects the ball to the right spans the top-left corner to the bottom-right corner and is represented in the grid as 1.\n\t\t\tA board that redirects the ball to the left spans the top-right corner to the bottom-left corner and is represented in the grid as -1.\n\t\tWe drop one ball at the top of each column of the box. Each ball can get stuck in the box or fall out of the bottom. A ball gets stuck if it hits a \"V\" shaped pattern between two boards or if a board redirects the ball into either wall of the box.\n\t\tReturn an array answer of size n where answer[i] is the column that the ball falls out of at the bottom after dropping the ball from the ith column at the top, or -1 if the ball gets stuck in the box.\n\t\tExample 1:\n\t\tInput: grid = [[1,1,1,-1,-1],[1,1,1,-1,-1],[-1,-1,-1,1,1],[1,1,1,1,-1],[-1,-1,-1,-1,-1]]\n\t\tOutput: [1,-1,-1,-1,-1]\n\t\tExplanation: This example is shown in the photo.\n\t\tBall b0 is dropped at column 0 and falls out of the box at column 1.\n\t\tBall b1 is dropped at column 1 and will get stuck in the box between column 2 and 3 and row 1.\n\t\tBall b2 is dropped at column 2 and will get stuck on the box between column 2 and 3 and row 0.\n\t\tBall b3 is dropped at column 3 and will get stuck on the box between column 2 and 3 and row 0.\n\t\tBall b4 is dropped at column 4 and will get stuck on the box between column 2 and 3 and row 1.\n\t\tExample 2:\n\t\tInput: grid = [[-1]]\n\t\tOutput: [-1]\n\t\tExplanation: The ball gets stuck against the left wall.\n\t\tExample 3:\n\t\tInput: grid = [[1,1,1,1,1,1],[-1,-1,-1,-1,-1,-1],[1,1,1,1,1,1],[-1,-1,-1,-1,-1,-1]]\n\t\tOutput: [0,1,2,3,4,-1]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1325, - "question": "class Solution:\n def maxProbability(self, n: int, edges: List[List[int]], succProb: List[float], start: int, end: int) -> float:\n\t\t\"\"\"\n\t\tYou are given an undirected weighted graph of n nodes (0-indexed), represented by an edge list where edges[i] = [a, b] is an undirected edge connecting the nodes a and b with a probability of success of traversing that edge succProb[i].\n\t\tGiven two nodes start and end, find the path with the maximum probability of success to go from start to end and return its success probability.\n\t\tIf there is no path from start to end, return 0. Your answer will be accepted if it differs from the correct answer by at most 1e-5.\n\t\tExample 1:\n\t\tInput: n = 3, edges = [[0,1],[1,2],[0,2]], succProb = [0.5,0.5,0.2], start = 0, end = 2\n\t\tOutput: 0.25000\n\t\tExplanation: There are two paths from start to end, one having a probability of success = 0.2 and the other has 0.5 * 0.5 = 0.25.\n\t\tExample 2:\n\t\tInput: n = 3, edges = [[0,1],[1,2],[0,2]], succProb = [0.5,0.5,0.3], start = 0, end = 2\n\t\tOutput: 0.30000\n\t\tExample 3:\n\t\tInput: n = 3, edges = [[0,1]], succProb = [0.5], start = 0, end = 2\n\t\tOutput: 0.00000\n\t\tExplanation: There is no path between 0 and 2.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1326, - "question": "class Solution:\n def sumOfFlooredPairs(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tGiven an integer array nums, return the sum of floor(nums[i] / nums[j]) for all pairs of indices 0 <= i, j < nums.length in the array. Since the answer may be too large, return it modulo 109 + 7.\n\t\tThe floor() function returns the integer part of the division.\n\t\tExample 1:\n\t\tInput: nums = [2,5,9]\n\t\tOutput: 10\n\t\tExplanation:\n\t\tfloor(2 / 5) = floor(2 / 9) = floor(5 / 9) = 0\n\t\tfloor(2 / 2) = floor(5 / 5) = floor(9 / 9) = 1\n\t\tfloor(5 / 2) = 2\n\t\tfloor(9 / 2) = 4\n\t\tfloor(9 / 5) = 1\n\t\tWe calculate the floor of the division for every pair of indices in the array then sum them up.\n\t\tExample 2:\n\t\tInput: nums = [7,7,7,7,7,7,7]\n\t\tOutput: 49\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1329, - "question": "class Solution:\n def minCostToMoveChips(self, position: List[int]) -> int:\n\t\t\"\"\"\n\t\tWe have n chips, where the position of the ith chip is position[i].\n\t\tWe need to move all the chips to the same position. In one step, we can change the position of the ith chip from position[i] to:\n\t\t\tposition[i] + 2 or position[i] - 2 with cost = 0.\n\t\t\tposition[i] + 1 or position[i] - 1 with cost = 1.\n\t\tReturn the minimum cost needed to move all the chips to the same position.\n\t\tExample 1:\n\t\tInput: position = [1,2,3]\n\t\tOutput: 1\n\t\tExplanation: First step: Move the chip at position 3 to position 1 with cost = 0.\n\t\tSecond step: Move the chip at position 2 to position 1 with cost = 1.\n\t\tTotal cost is 1.\n\t\tExample 2:\n\t\tInput: position = [2,2,2,3,3]\n\t\tOutput: 2\n\t\tExplanation: We can move the two chips at position 3 to position 2. Each move has cost = 1. The total cost = 2.\n\t\tExample 3:\n\t\tInput: position = [1,1000000000]\n\t\tOutput: 1\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1330, - "question": "class Solution:\n def longestSubsequence(self, arr: List[int], difference: int) -> int:\n\t\t\"\"\"\n\t\tGiven an integer array arr and an integer difference, return the length of the longest subsequence in arr which is an arithmetic sequence such that the difference between adjacent elements in the subsequence equals difference.\n\t\tA subsequence is a sequence that can be derived from arr by deleting some or no elements without changing the order of the remaining elements.\n\t\tExample 1:\n\t\tInput: arr = [1,2,3,4], difference = 1\n\t\tOutput: 4\n\t\tExplanation: The longest arithmetic subsequence is [1,2,3,4].\n\t\tExample 2:\n\t\tInput: arr = [1,3,5,7], difference = 1\n\t\tOutput: 1\n\t\tExplanation: The longest arithmetic subsequence is any single element.\n\t\tExample 3:\n\t\tInput: arr = [1,5,7,8,5,3,4,2,1], difference = -2\n\t\tOutput: 4\n\t\tExplanation: The longest arithmetic subsequence is [7,5,3,1].\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1331, - "question": "class Solution:\n def getMaximumGold(self, grid: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tIn a gold mine grid of size m x n, each cell in this mine has an integer representing the amount of gold in that cell, 0 if it is empty.\n\t\tReturn the maximum amount of gold you can collect under the conditions:\n\t\t\tEvery time you are located in a cell you will collect all the gold in that cell.\n\t\t\tFrom your position, you can walk one step to the left, right, up, or down.\n\t\t\tYou can't visit the same cell more than once.\n\t\t\tNever visit a cell with 0 gold.\n\t\t\tYou can start and stop collecting gold from any position in the grid that has some gold.\n\t\tExample 1:\n\t\tInput: grid = [[0,6,0],[5,8,7],[0,9,0]]\n\t\tOutput: 24\n\t\tExplanation:\n\t\t[[0,6,0],\n\t\t [5,8,7],\n\t\t [0,9,0]]\n\t\tPath to get the maximum gold, 9 -> 8 -> 7.\n\t\tExample 2:\n\t\tInput: grid = [[1,0,7],[2,0,6],[3,4,5],[0,3,0],[9,0,20]]\n\t\tOutput: 28\n\t\tExplanation:\n\t\t[[1,0,7],\n\t\t [2,0,6],\n\t\t [3,4,5],\n\t\t [0,3,0],\n\t\t [9,0,20]]\n\t\tPath to get the maximum gold, 1 -> 2 -> 3 -> 4 -> 5 -> 6 -> 7.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1332, - "question": "class Solution:\n def countVowelPermutation(self, n: int) -> int:\n\t\t\"\"\"\n\t\tGiven an integer n, your task is to count how many strings of length n can be formed under the following rules:\n\t\t\tEach character is a lower case vowel ('a', 'e', 'i', 'o', 'u')\n\t\t\tEach vowel 'a' may only be followed by an 'e'.\n\t\t\tEach vowel 'e' may only be followed by an 'a' or an 'i'.\n\t\t\tEach vowel 'i' may not be followed by another 'i'.\n\t\t\tEach vowel 'o' may only be followed by an 'i' or a 'u'.\n\t\t\tEach vowel 'u' may only be followed by an 'a'.\n\t\tSince the answer may be too large, return it modulo 10^9 + 7.\n\t\tExample 1:\n\t\tInput: n = 1\n\t\tOutput: 5\n\t\tExplanation: All possible strings are: \"a\", \"e\", \"i\" , \"o\" and \"u\".\n\t\tExample 2:\n\t\tInput: n = 2\n\t\tOutput: 10\n\t\tExplanation: All possible strings are: \"ae\", \"ea\", \"ei\", \"ia\", \"ie\", \"io\", \"iu\", \"oi\", \"ou\" and \"ua\".\n\t\tExample 3: \n\t\tInput: n = 5\n\t\tOutput: 68\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1333, - "question": "class Solution:\n def sortJumbled(self, mapping: List[int], nums: List[int]) -> List[int]:\n\t\t\"\"\"\n\t\tYou are given a 0-indexed integer array mapping which represents the mapping rule of a shuffled decimal system. mapping[i] = j means digit i should be mapped to digit j in this system.\n\t\tThe mapped value of an integer is the new integer obtained by replacing each occurrence of digit i in the integer with mapping[i] for all 0 <= i <= 9.\n\t\tYou are also given another integer array nums. Return the array nums sorted in non-decreasing order based on the mapped values of its elements.\n\t\tNotes:\n\t\t\tElements with the same mapped values should appear in the same relative order as in the input.\n\t\t\tThe elements of nums should only be sorted based on their mapped values and not be replaced by them.\n\t\tExample 1:\n\t\tInput: mapping = [8,9,4,0,2,1,3,5,7,6], nums = [991,338,38]\n\t\tOutput: [338,38,991]\n\t\tExplanation: \n\t\tMap the number 991 as follows:\n\t\t1. mapping[9] = 6, so all occurrences of the digit 9 will become 6.\n\t\t2. mapping[1] = 9, so all occurrences of the digit 1 will become 9.\n\t\tTherefore, the mapped value of 991 is 669.\n\t\t338 maps to 007, or 7 after removing the leading zeros.\n\t\t38 maps to 07, which is also 7 after removing leading zeros.\n\t\tSince 338 and 38 share the same mapped value, they should remain in the same relative order, so 338 comes before 38.\n\t\tThus, the sorted array is [338,38,991].\n\t\tExample 2:\n\t\tInput: mapping = [0,1,2,3,4,5,6,7,8,9], nums = [789,456,123]\n\t\tOutput: [123,456,789]\n\t\tExplanation: 789 maps to 789, 456 maps to 456, and 123 maps to 123. Thus, the sorted array is [123,456,789].\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1334, - "question": "class Solution:\n def minimumNumbers(self, num: int, k: int) -> int:\n\t\t\"\"\"\n\t\tGiven two integers num and k, consider a set of positive integers with the following properties:\n\t\t\tThe units digit of each integer is k.\n\t\t\tThe sum of the integers is num.\n\t\tReturn the minimum possible size of such a set, or -1 if no such set exists.\n\t\tNote:\n\t\t\tThe set can contain multiple instances of the same integer, and the sum of an empty set is considered 0.\n\t\t\tThe units digit of a number is the rightmost digit of the number.\n\t\tExample 1:\n\t\tInput: num = 58, k = 9\n\t\tOutput: 2\n\t\tExplanation:\n\t\tOne valid set is [9,49], as the sum is 58 and each integer has a units digit of 9.\n\t\tAnother valid set is [19,39].\n\t\tIt can be shown that 2 is the minimum possible size of a valid set.\n\t\tExample 2:\n\t\tInput: num = 37, k = 2\n\t\tOutput: -1\n\t\tExplanation: It is not possible to obtain a sum of 37 using only integers that have a units digit of 2.\n\t\tExample 3:\n\t\tInput: num = 0, k = 7\n\t\tOutput: 0\n\t\tExplanation: The sum of an empty set is considered 0.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1335, - "question": "class Solution:\n def maximumCandies(self, candies: List[int], k: int) -> int:\n\t\t\"\"\"\n\t\tYou are given a 0-indexed integer array candies. Each element in the array denotes a pile of candies of size candies[i]. You can divide each pile into any number of sub piles, but you cannot merge two piles together.\n\t\tYou are also given an integer k. You should allocate piles of candies to k children such that each child gets the same number of candies. Each child can take at most one pile of candies and some piles of candies may go unused.\n\t\tReturn the maximum number of candies each child can get.\n\t\tExample 1:\n\t\tInput: candies = [5,8,6], k = 3\n\t\tOutput: 5\n\t\tExplanation: We can divide candies[1] into 2 piles of size 5 and 3, and candies[2] into 2 piles of size 5 and 1. We now have five piles of candies of sizes 5, 5, 3, 5, and 1. We can allocate the 3 piles of size 5 to 3 children. It can be proven that each child cannot receive more than 5 candies.\n\t\tExample 2:\n\t\tInput: candies = [2,5], k = 11\n\t\tOutput: 0\n\t\tExplanation: There are 11 children but only 7 candies in total, so it is impossible to ensure each child receives at least one candy. Thus, each child gets no candy and the answer is 0.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1336, - "question": "class Solution:\n def maxProduct(self, s: str) -> int:\n\t\t\"\"\"\n\t\tYou are given a 0-indexed string s and are tasked with finding two non-intersecting palindromic substrings of odd length such that the product of their lengths is maximized.\n\t\tMore formally, you want to choose four integers i, j, k, l such that 0 <= i <= j < k <= l < s.length and both the substrings s[i...j] and s[k...l] are palindromes and have odd lengths. s[i...j] denotes a substring from index i to index j inclusive.\n\t\tReturn the maximum possible product of the lengths of the two non-intersecting palindromic substrings.\n\t\tA palindrome is a string that is the same forward and backward. A substring is a contiguous sequence of characters in a string.\n\t\tExample 1:\n\t\tInput: s = \"ababbb\"\n\t\tOutput: 9\n\t\tExplanation: Substrings \"aba\" and \"bbb\" are palindromes with odd length. product = 3 * 3 = 9.\n\t\tExample 2:\n\t\tInput: s = \"zaaaxbbby\"\n\t\tOutput: 9\n\t\tExplanation: Substrings \"aaa\" and \"bbb\" are palindromes with odd length. product = 3 * 3 = 9.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1337, - "question": "class Skiplist:\n def __init__(self):\n def search(self, target: int) -> bool:\n def add(self, num: int) -> None:\n def erase(self, num: int) -> bool:\n\t\t\"\"\"\n\t\tDesign a Skiplist without using any built-in libraries.\n\t\tA skiplist is a data structure that takes O(log(n)) time to add, erase and search. Comparing with treap and red-black tree which has the same function and performance, the code length of Skiplist can be comparatively short and the idea behind Skiplists is just simple linked lists.\n\t\tFor example, we have a Skiplist containing [30,40,50,60,70,90] and we want to add 80 and 45 into it. The Skiplist works this way:\n\t\tArtyom Kalinin [CC BY-SA 3.0], via Wikimedia Commons\n\t\tYou can see there are many layers in the Skiplist. Each layer is a sorted linked list. With the help of the top layers, add, erase and search can be faster than O(n). It can be proven that the average time complexity for each operation is O(log(n)) and space complexity is O(n).\n\t\tSee more about Skiplist: https://en.wikipedia.org/wiki/Skip_list\n\t\tImplement the Skiplist class:\n\t\t\tSkiplist() Initializes the object of the skiplist.\n\t\t\tbool search(int target) Returns true if the integer target exists in the Skiplist or false otherwise.\n\t\t\tvoid add(int num) Inserts the value num into the SkipList.\n\t\t\tbool erase(int num) Removes the value num from the Skiplist and returns true. If num does not exist in the Skiplist, do nothing and return false. If there exist multiple num values, removing any one of them is fine.\n\t\tNote that duplicates may exist in the Skiplist, your code needs to handle this situation.\n\t\tExample 1:\n\t\tInput\n\t\t[\"Skiplist\", \"add\", \"add\", \"add\", \"search\", \"add\", \"search\", \"erase\", \"erase\", \"search\"]\n\t\t[[], [1], [2], [3], [0], [4], [1], [0], [1], [1]]\n\t\tOutput\n\t\t[null, null, null, null, false, null, true, false, true, false]\n\t\tExplanation\n\t\tSkiplist skiplist = new Skiplist();\n\t\tskiplist.add(1);\n\t\tskiplist.add(2);\n\t\tskiplist.add(3);\n\t\tskiplist.search(0); // return False\n\t\tskiplist.add(4);\n\t\tskiplist.search(1); // return True\n\t\tskiplist.erase(0); // return False, 0 is not in skiplist.\n\t\tskiplist.erase(1); // return True\n\t\tskiplist.search(1); // return False, 1 has already been erased.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1340, - "question": "class DiningPhilosophers:\n def wantsToEat(self,\n philosopher: int,\n pickLeftFork: 'Callable[[], None]',\n pickRightFork: 'Callable[[], None]',\n eat: 'Callable[[], None]',\n putLeftFork: 'Callable[[], None]',\n putRightFork: 'Callable[[], None]') -> None:\n\t\t\"\"\"\n\t\tFive silent philosophers sit at a round table with bowls of spaghetti. Forks are placed between each pair of adjacent philosophers.\n\t\tEach philosopher must alternately think and eat. However, a philosopher can only eat spaghetti when they have both left and right forks. Each fork can be held by only one philosopher and so a philosopher can use the fork only if it is not being used by another philosopher. After an individual philosopher finishes eating, they need to put down both forks so that the forks become available to others. A philosopher can take the fork on their right or the one on their left as they become available, but cannot start eating before getting both forks.\n\t\tEating is not limited by the remaining amounts of spaghetti or stomach space; an infinite supply and an infinite demand are assumed.\n\t\tDesign a discipline of behaviour (a concurrent algorithm) such that no philosopher will starve; i.e., each can forever continue to alternate between eating and thinking, assuming that no philosopher can know when others may want to eat or think.\n\t\tThe problem statement and the image above are taken from wikipedia.org\n\t\tThe philosophers' ids are numbered from 0 to 4 in a clockwise order. Implement the function void wantsToEat(philosopher, pickLeftFork, pickRightFork, eat, putLeftFork, putRightFork) where:\n\t\t\tphilosopher is the id of the philosopher who wants to eat.\n\t\t\tpickLeftFork and pickRightFork are functions you can call to pick the corresponding forks of that philosopher.\n\t\t\teat is a function you can call to let the philosopher eat once he has picked both forks.\n\t\t\tputLeftFork and putRightFork are functions you can call to put down the corresponding forks of that philosopher.\n\t\t\tThe philosophers are assumed to be thinking as long as they are not asking to eat (the function is not being called with their number).\n\t\tFive threads, each representing a philosopher, will simultaneously use one object of your class to simulate the process. The function may be called for the same philosopher more than once, even before the last call ends.\n\t\tExample 1:\n\t\tInput: n = 1\n\t\tOutput: [[4,2,1],[4,1,1],[0,1,1],[2,2,1],[2,1,1],[2,0,3],[2,1,2],[2,2,2],[4,0,3],[4,1,2],[0,2,1],[4,2,2],[3,2,1],[3,1,1],[0,0,3],[0,1,2],[0,2,2],[1,2,1],[1,1,1],[3,0,3],[3,1,2],[3,2,2],[1,0,3],[1,1,2],[1,2,2]]\n\t\tExplanation:\n\t\tn is the number of times each philosopher will call the function.\n\t\tThe output array describes the calls you made to the functions controlling the forks and the eat function, its format is:\n\t\toutput[i] = [a, b, c] (three integers)\n\t\t- a is the id of a philosopher.\n\t\t- b specifies the fork: {1 : left, 2 : right}.\n\t\t- c specifies the operation: {1 : pick, 2 : put, 3 : eat}.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1341, - "question": "class Solution:\n def balancedStringSplit(self, s: str) -> int:\n\t\t\"\"\"\n\t\tBalanced strings are those that have an equal quantity of 'L' and 'R' characters.\n\t\tGiven a balanced string s, split it into some number of substrings such that:\n\t\t\tEach substring is balanced.\n\t\tReturn the maximum number of balanced strings you can obtain.\n\t\tExample 1:\n\t\tInput: s = \"RLRRLLRLRL\"\n\t\tOutput: 4\n\t\tExplanation: s can be split into \"RL\", \"RRLL\", \"RL\", \"RL\", each substring contains same number of 'L' and 'R'.\n\t\tExample 2:\n\t\tInput: s = \"RLRRRLLRLL\"\n\t\tOutput: 2\n\t\tExplanation: s can be split into \"RL\", \"RRRLLRLL\", each substring contains same number of 'L' and 'R'.\n\t\tNote that s cannot be split into \"RL\", \"RR\", \"RL\", \"LR\", \"LL\", because the 2nd and 5th substrings are not balanced.\n\t\tExample 3:\n\t\tInput: s = \"LLLLRRRR\"\n\t\tOutput: 1\n\t\tExplanation: s can be split into \"LLLLRRRR\".\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1342, - "question": "class Solution:\n def queensAttacktheKing(self, queens: List[List[int]], king: List[int]) -> List[List[int]]:\n\t\t\"\"\"\n\t\tOn a 0-indexed 8 x 8 chessboard, there can be multiple black queens ad one white king.\n\t\tYou are given a 2D integer array queens where queens[i] = [xQueeni, yQueeni] represents the position of the ith black queen on the chessboard. You are also given an integer array king of length 2 where king = [xKing, yKing] represents the position of the white king.\n\t\tReturn the coordinates of the black queens that can directly attack the king. You may return the answer in any order.\n\t\tExample 1:\n\t\tInput: queens = [[0,1],[1,0],[4,0],[0,4],[3,3],[2,4]], king = [0,0]\n\t\tOutput: [[0,1],[1,0],[3,3]]\n\t\tExplanation: The diagram above shows the three queens that can directly attack the king and the three queens that cannot attack the king (i.e., marked with red dashes).\n\t\tExample 2:\n\t\tInput: queens = [[0,0],[1,1],[2,2],[3,4],[3,5],[4,4],[4,5]], king = [3,3]\n\t\tOutput: [[2,2],[3,4],[4,4]]\n\t\tExplanation: The diagram above shows the three queens that can directly attack the king and the three queens that cannot attack the king (i.e., marked with red dashes).\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1343, - "question": "class Solution:\n def dieSimulator(self, n: int, rollMax: List[int]) -> int:\n\t\t\"\"\"\n\t\tA die simulator generates a random number from 1 to 6 for each roll. You introduced a constraint to the generator such that it cannot roll the number i more than rollMax[i] (1-indexed) consecutive times.\n\t\tGiven an array of integers rollMax and an integer n, return the number of distinct sequences that can be obtained with exact n rolls. Since the answer may be too large, return it modulo 109 + 7.\n\t\tTwo sequences are considered different if at least one element differs from each other.\n\t\tExample 1:\n\t\tInput: n = 2, rollMax = [1,1,2,2,2,3]\n\t\tOutput: 34\n\t\tExplanation: There will be 2 rolls of die, if there are no constraints on the die, there are 6 * 6 = 36 possible combinations. In this case, looking at rollMax array, the numbers 1 and 2 appear at most once consecutively, therefore sequences (1,1) and (2,2) cannot occur, so the final answer is 36-2 = 34.\n\t\tExample 2:\n\t\tInput: n = 2, rollMax = [1,1,1,1,1,1]\n\t\tOutput: 30\n\t\tExample 3:\n\t\tInput: n = 3, rollMax = [1,1,1,2,2,3]\n\t\tOutput: 181\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1344, - "question": "class Solution:\n def maxEqualFreq(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tGiven an array nums of positive integers, return the longest possible length of an array prefix of nums, such that it is possible to remove exactly one element from this prefix so that every number that has appeared in it will have the same number of occurrences.\n\t\tIf after removing one element there are no remaining elements, it's still considered that every appeared number has the same number of ocurrences (0).\n\t\tExample 1:\n\t\tInput: nums = [2,2,1,1,5,3,3,5]\n\t\tOutput: 7\n\t\tExplanation: For the subarray [2,2,1,1,5,3,3] of length 7, if we remove nums[4] = 5, we will get [2,2,1,1,3,3], so that each number will appear exactly twice.\n\t\tExample 2:\n\t\tInput: nums = [1,1,1,2,2,2,3,3,3,4,4,4,5]\n\t\tOutput: 13\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1346, - "question": "class Solution:\n def maximumTop(self, nums: List[int], k: int) -> int:\n\t\t\"\"\"\n\t\tYou are given a 0-indexed integer array nums representing the contents of a pile, where nums[0] is the topmost element of the pile.\n\t\tIn one move, you can perform either of the following:\n\t\t\tIf the pile is not empty, remove the topmost element of the pile.\n\t\t\tIf there are one or more removed elements, add any one of them back onto the pile. This element becomes the new topmost element.\n\t\tYou are also given an integer k, which denotes the total number of moves to be made.\n\t\tReturn the maximum value of the topmost element of the pile possible after exactly k moves. In case it is not possible to obtain a non-empty pile after k moves, return -1.\n\t\tExample 1:\n\t\tInput: nums = [5,2,2,4,0,6], k = 4\n\t\tOutput: 5\n\t\tExplanation:\n\t\tOne of the ways we can end with 5 at the top of the pile after 4 moves is as follows:\n\t\t- Step 1: Remove the topmost element = 5. The pile becomes [2,2,4,0,6].\n\t\t- Step 2: Remove the topmost element = 2. The pile becomes [2,4,0,6].\n\t\t- Step 3: Remove the topmost element = 2. The pile becomes [4,0,6].\n\t\t- Step 4: Add 5 back onto the pile. The pile becomes [5,4,0,6].\n\t\tNote that this is not the only way to end with 5 at the top of the pile. It can be shown that 5 is the largest answer possible after 4 moves.\n\t\tExample 2:\n\t\tInput: nums = [2], k = 1\n\t\tOutput: -1\n\t\tExplanation: \n\t\tIn the first move, our only option is to pop the topmost element of the pile.\n\t\tSince it is not possible to obtain a non-empty pile after one move, we return -1.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1348, - "question": "class Solution:\n def maximumsSplicedArray(self, nums1: List[int], nums2: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou are given two 0-indexed integer arrays nums1 and nums2, both of length n.\n\t\tYou can choose two integers left and right where 0 <= left <= right < n and swap the subarray nums1[left...right] with the subarray nums2[left...right].\n\t\t\tFor example, if nums1 = [1,2,3,4,5] and nums2 = [11,12,13,14,15] and you choose left = 1 and right = 2, nums1 becomes [1,12,13,4,5] and nums2 becomes [11,2,3,14,15].\n\t\tYou may choose to apply the mentioned operation once or not do anything.\n\t\tThe score of the arrays is the maximum of sum(nums1) and sum(nums2), where sum(arr) is the sum of all the elements in the array arr.\n\t\tReturn the maximum possible score.\n\t\tA subarray is a contiguous sequence of elements within an array. arr[left...right] denotes the subarray that contains the elements of nums between indices left and right (inclusive).\n\t\tExample 1:\n\t\tInput: nums1 = [60,60,60], nums2 = [10,90,10]\n\t\tOutput: 210\n\t\tExplanation: Choosing left = 1 and right = 1, we have nums1 = [60,90,60] and nums2 = [10,60,10].\n\t\tThe score is max(sum(nums1), sum(nums2)) = max(210, 80) = 210.\n\t\tExample 2:\n\t\tInput: nums1 = [20,40,20,70,30], nums2 = [50,20,50,40,20]\n\t\tOutput: 220\n\t\tExplanation: Choosing left = 3, right = 4, we have nums1 = [20,40,20,40,20] and nums2 = [50,20,50,70,30].\n\t\tThe score is max(sum(nums1), sum(nums2)) = max(140, 220) = 220.\n\t\tExample 3:\n\t\tInput: nums1 = [7,11,13], nums2 = [1,1,1]\n\t\tOutput: 31\n\t\tExplanation: We choose not to swap any subarray.\n\t\tThe score is max(sum(nums1), sum(nums2)) = max(31, 3) = 31.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1349, - "question": "class Solution:\n def checkStraightLine(self, coordinates: List[List[int]]) -> bool:\n\t\t\"\"\"\n\t\tYou are given an array coordinates, coordinates[i] = [x, y], where [x, y] represents the coordinate of a point. Check if these points make a straight line in the XY plane.\r\n\t\tExample 1:\r\n\t\tInput: coordinates = [[1,2],[2,3],[3,4],[4,5],[5,6],[6,7]]\r\n\t\tOutput: true\r\n\t\tExample 2:\r\n\t\tInput: coordinates = [[1,1],[2,2],[3,4],[4,5],[5,6],[7,7]]\r\n\t\tOutput: false\r\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1350, - "question": "class Solution:\n def removeSubfolders(self, folder: List[str]) -> List[str]:\n\t\t\"\"\"\n\t\tGiven a list of folders folder, return the folders after removing all sub-folders in those folders. You may return the answer in any order.\n\t\tIf a folder[i] is located within another folder[j], it is called a sub-folder of it.\n\t\tThe format of a path is one or more concatenated strings of the form: '/' followed by one or more lowercase English letters.\n\t\t\tFor example, \"/leetcode\" and \"/leetcode/problems\" are valid paths while an empty string and \"/\" are not.\n\t\tExample 1:\n\t\tInput: folder = [\"/a\",\"/a/b\",\"/c/d\",\"/c/d/e\",\"/c/f\"]\n\t\tOutput: [\"/a\",\"/c/d\",\"/c/f\"]\n\t\tExplanation: Folders \"/a/b\" is a subfolder of \"/a\" and \"/c/d/e\" is inside of folder \"/c/d\" in our filesystem.\n\t\tExample 2:\n\t\tInput: folder = [\"/a\",\"/a/b/c\",\"/a/b/d\"]\n\t\tOutput: [\"/a\"]\n\t\tExplanation: Folders \"/a/b/c\" and \"/a/b/d\" will be removed because they are subfolders of \"/a\".\n\t\tExample 3:\n\t\tInput: folder = [\"/a/b/c\",\"/a/b/ca\",\"/a/b/d\"]\n\t\tOutput: [\"/a/b/c\",\"/a/b/ca\",\"/a/b/d\"]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1351, - "question": "class Solution:\n def balancedString(self, s: str) -> int:\n\t\t\"\"\"\n\t\tYou are given a string s of length n containing only four kinds of characters: 'Q', 'W', 'E', and 'R'.\n\t\tA string is said to be balanced if each of its characters appears n / 4 times where n is the length of the string.\n\t\tReturn the minimum length of the substring that can be replaced with any other string of the same length to make s balanced. If s is already balanced, return 0.\n\t\tExample 1:\n\t\tInput: s = \"QWER\"\n\t\tOutput: 0\n\t\tExplanation: s is already balanced.\n\t\tExample 2:\n\t\tInput: s = \"QQWE\"\n\t\tOutput: 1\n\t\tExplanation: We need to replace a 'Q' to 'R', so that \"RQWE\" (or \"QRWE\") is balanced.\n\t\tExample 3:\n\t\tInput: s = \"QQQW\"\n\t\tOutput: 2\n\t\tExplanation: We can replace the first \"QQ\" to \"ER\". \n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1352, - "question": "class Solution:\n def jobScheduling(self, startTime: List[int], endTime: List[int], profit: List[int]) -> int:\n\t\t\"\"\"\n\t\tWe have n jobs, where every job is scheduled to be done from startTime[i] to endTime[i], obtaining a profit of profit[i].\n\t\tYou're given the startTime, endTime and profit arrays, return the maximum profit you can take such that there are no two jobs in the subset with overlapping time range.\n\t\tIf you choose a job that ends at time X you will be able to start another job that starts at time X.\n\t\tExample 1:\n\t\tInput: startTime = [1,2,3,3], endTime = [3,4,5,6], profit = [50,10,40,70]\n\t\tOutput: 120\n\t\tExplanation: The subset chosen is the first and fourth job. \n\t\tTime range [1-3]+[3-6] , we get profit of 120 = 50 + 70.\n\t\tExample 2:\n\t\tInput: startTime = [1,2,3,4,6], endTime = [3,5,10,6,9], profit = [20,20,100,70,60]\n\t\tOutput: 150\n\t\tExplanation: The subset chosen is the first, fourth and fifth job. \n\t\tProfit obtained 150 = 20 + 70 + 60.\n\t\tExample 3:\n\t\tInput: startTime = [1,1,1], endTime = [2,3,4], profit = [5,6,4]\n\t\tOutput: 6\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1353, - "question": "class Solution:\n def removeAnagrams(self, words: List[str]) -> List[str]:\n\t\t\"\"\"\n\t\tYou are given a 0-indexed string array words, where words[i] consists of lowercase English letters.\n\t\tIn one operation, select any index i such that 0 < i < words.length and words[i - 1] and words[i] are anagrams, and delete words[i] from words. Keep performing this operation as long as you can select an index that satisfies the conditions.\n\t\tReturn words after performing all operations. It can be shown that selecting the indices for each operation in any arbitrary order will lead to the same result.\n\t\tAn Anagram is a word or phrase formed by rearranging the letters of a different word or phrase using all the original letters exactly once. For example, \"dacb\" is an anagram of \"abdc\".\n\t\tExample 1:\n\t\tInput: words = [\"abba\",\"baba\",\"bbaa\",\"cd\",\"cd\"]\n\t\tOutput: [\"abba\",\"cd\"]\n\t\tExplanation:\n\t\tOne of the ways we can obtain the resultant array is by using the following operations:\n\t\t- Since words[2] = \"bbaa\" and words[1] = \"baba\" are anagrams, we choose index 2 and delete words[2].\n\t\t Now words = [\"abba\",\"baba\",\"cd\",\"cd\"].\n\t\t- Since words[1] = \"baba\" and words[0] = \"abba\" are anagrams, we choose index 1 and delete words[1].\n\t\t Now words = [\"abba\",\"cd\",\"cd\"].\n\t\t- Since words[2] = \"cd\" and words[1] = \"cd\" are anagrams, we choose index 2 and delete words[2].\n\t\t Now words = [\"abba\",\"cd\"].\n\t\tWe can no longer perform any operations, so [\"abba\",\"cd\"] is the final answer.\n\t\tExample 2:\n\t\tInput: words = [\"a\",\"b\",\"c\",\"d\",\"e\"]\n\t\tOutput: [\"a\",\"b\",\"c\",\"d\",\"e\"]\n\t\tExplanation:\n\t\tNo two adjacent strings in words are anagrams of each other, so no operations are performed.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1354, - "question": "class Solution:\n def findWinners(self, matches: List[List[int]]) -> List[List[int]]:\n\t\t\"\"\"\n\t\tYou are given an integer array matches where matches[i] = [winneri, loseri] indicates that the player winneri defeated player loseri in a match.\n\t\tReturn a list answer of size 2 where:\n\t\t\tanswer[0] is a list of all players that have not lost any matches.\n\t\t\tanswer[1] is a list of all players that have lost exactly one match.\n\t\tThe values in the two lists should be returned in increasing order.\n\t\tNote:\n\t\t\tYou should only consider the players that have played at least one match.\n\t\t\tThe testcases will be generated such that no two matches will have the same outcome.\n\t\tExample 1:\n\t\tInput: matches = [[1,3],[2,3],[3,6],[5,6],[5,7],[4,5],[4,8],[4,9],[10,4],[10,9]]\n\t\tOutput: [[1,2,10],[4,5,7,8]]\n\t\tExplanation:\n\t\tPlayers 1, 2, and 10 have not lost any matches.\n\t\tPlayers 4, 5, 7, and 8 each have lost one match.\n\t\tPlayers 3, 6, and 9 each have lost two matches.\n\t\tThus, answer[0] = [1,2,10] and answer[1] = [4,5,7,8].\n\t\tExample 2:\n\t\tInput: matches = [[2,3],[1,3],[5,4],[6,4]]\n\t\tOutput: [[1,2,5,6],[]]\n\t\tExplanation:\n\t\tPlayers 1, 2, 5, and 6 have not lost any matches.\n\t\tPlayers 3 and 4 each have lost two matches.\n\t\tThus, answer[0] = [1,2,5,6] and answer[1] = [].\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1355, - "question": "class Solution:\n def minDeletion(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou are given a 0-indexed integer array nums. The array nums is beautiful if:\n\t\t\tnums.length is even.\n\t\t\tnums[i] != nums[i + 1] for all i % 2 == 0.\n\t\tNote that an empty array is considered beautiful.\n\t\tYou can delete any number of elements from nums. When you delete an element, all the elements to the right of the deleted element will be shifted one unit to the left to fill the gap created and all the elements to the left of the deleted element will remain unchanged.\n\t\tReturn the minimum number of elements to delete from nums to make it beautiful.\n\t\tExample 1:\n\t\tInput: nums = [1,1,2,3,5]\n\t\tOutput: 1\n\t\tExplanation: You can delete either nums[0] or nums[1] to make nums = [1,2,3,5] which is beautiful. It can be proven you need at least 1 deletion to make nums beautiful.\n\t\tExample 2:\n\t\tInput: nums = [1,1,2,2,3,3]\n\t\tOutput: 2\n\t\tExplanation: You can delete nums[0] and nums[5] to make nums = [1,2,2,3] which is beautiful. It can be proven you need at least 2 deletions to make nums beautiful.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1356, - "question": "class Solution:\n def minMovesToMakePalindrome(self, s: str) -> int:\n\t\t\"\"\"\n\t\tYou are given a string s consisting only of lowercase English letters.\n\t\tIn one move, you can select any two adjacent characters of s and swap them.\n\t\tReturn the minimum number of moves needed to make s a palindrome.\n\t\tNote that the input will be generated such that s can always be converted to a palindrome.\n\t\tExample 1:\n\t\tInput: s = \"aabb\"\n\t\tOutput: 2\n\t\tExplanation:\n\t\tWe can obtain two palindromes from s, \"abba\" and \"baab\". \n\t\t- We can obtain \"abba\" from s in 2 moves: \"aabb\" -> \"abab\" -> \"abba\".\n\t\t- We can obtain \"baab\" from s in 2 moves: \"aabb\" -> \"abab\" -> \"baab\".\n\t\tThus, the minimum number of moves needed to make s a palindrome is 2.\n\t\tExample 2:\n\t\tInput: s = \"letelt\"\n\t\tOutput: 2\n\t\tExplanation:\n\t\tOne of the palindromes we can obtain from s in 2 moves is \"lettel\".\n\t\tOne of the ways we can obtain it is \"letelt\" -> \"letetl\" -> \"lettel\".\n\t\tOther palindromes such as \"tleelt\" can also be obtained in 2 moves.\n\t\tIt can be shown that it is not possible to obtain a palindrome in less than 2 moves.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1358, - "question": "\n\t\t\"\"\"\n This is the custom function interface.\n You should not implement it, or speculate about its implementation\n class CustomFunction:\n def f(self, x, y):\n\t\tGiven a callable function f(x, y) with a hidden formula and a value z, reverse engineer the formula and return all positive integer pairs x and y where f(x,y) == z. You may return the pairs in any order.\n\t\tWhile the exact formula is hidden, the function is monotonically increasing, i.e.:\n\t\t\tf(x, y) < f(x + 1, y)\n\t\t\tf(x, y) < f(x, y + 1)\n\t\tThe function interface is defined like this:\n\t\tinterface CustomFunction {\n\t\tpublic:\n\t\t // Returns some positive integer f(x, y) for two positive integers x and y based on a formula.\n\t\t int f(int x, int y);\n\t\t};\n\t\tWe will judge your solution as follows:\n\t\t\tThe judge has a list of 9 hidden implementations of CustomFunction, along with a way to generate an answer key of all valid pairs for a specific z.\n\t\t\tThe judge will receive two inputs: a function_id (to determine which implementation to test your code with), and the target z.\n\t\t\tThe judge will call your findSolution and compare your results with the answer key.\n\t\t\tIf your results match the answer key, your solution will be Accepted.\n\t\tExample 1:\n\t\tInput: function_id = 1, z = 5\n\t\tOutput: [[1,4],[2,3],[3,2],[4,1]]\n\t\tExplanation: The hidden formula for function_id = 1 is f(x, y) = x + y.\n\t\tThe following positive integer values of x and y make f(x, y) equal to 5:\n\t\tx=1, y=4 -> f(1, 4) = 1 + 4 = 5.\n\t\tx=2, y=3 -> f(2, 3) = 2 + 3 = 5.\n\t\tx=3, y=2 -> f(3, 2) = 3 + 2 = 5.\n\t\tx=4, y=1 -> f(4, 1) = 4 + 1 = 5.\n\t\tExample 2:\n\t\tInput: function_id = 2, z = 5\n\t\tOutput: [[1,5],[5,1]]\n\t\tExplanation: The hidden formula for function_id = 2 is f(x, y) = x * y.\n\t\tThe following positive integer values of x and y make f(x, y) equal to 5:\n\t\tx=1, y=5 -> f(1, 5) = 1 * 5 = 5.\n\t\tx=5, y=1 -> f(5, 1) = 5 * 1 = 5.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1359, - "question": "class Solution:\n def circularPermutation(self, n: int, start: int) -> List[int]:\n\t\t\"\"\"\n\t\tGiven 2 integers n and start. Your task is return any permutation p of (0,1,2.....,2^n -1) such that :\r\n\t\t\tp[0] = start\r\n\t\t\tp[i] and p[i+1] differ by only one bit in their binary representation.\r\n\t\t\tp[0] and p[2^n -1] must also differ by only one bit in their binary representation.\r\n\t\tExample 1:\r\n\t\tInput: n = 2, start = 3\r\n\t\tOutput: [3,2,0,1]\r\n\t\tExplanation: The binary representation of the permutation is (11,10,00,01). \r\n\t\tAll the adjacent element differ by one bit. Another valid permutation is [3,1,0,2]\r\n\t\tExample 2:\r\n\t\tInput: n = 3, start = 2\r\n\t\tOutput: [2,6,7,5,4,0,1,3]\r\n\t\tExplanation: The binary representation of the permutation is (010,110,111,101,100,000,001,011).\r\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1360, - "question": "class Solution:\n def maxLength(self, arr: List[str]) -> int:\n\t\t\"\"\"\n\t\tYou are given an array of strings arr. A string s is formed by the concatenation of a subsequence of arr that has unique characters.\n\t\tReturn the maximum possible length of s.\n\t\tA subsequence is an array that can be derived from another array by deleting some or no elements without changing the order of the remaining elements.\n\t\tExample 1:\n\t\tInput: arr = [\"un\",\"iq\",\"ue\"]\n\t\tOutput: 4\n\t\tExplanation: All the valid concatenations are:\n\t\t- \"\"\n\t\t- \"un\"\n\t\t- \"iq\"\n\t\t- \"ue\"\n\t\t- \"uniq\" (\"un\" + \"iq\")\n\t\t- \"ique\" (\"iq\" + \"ue\")\n\t\tMaximum length is 4.\n\t\tExample 2:\n\t\tInput: arr = [\"cha\",\"r\",\"act\",\"ers\"]\n\t\tOutput: 6\n\t\tExplanation: Possible longest valid concatenations are \"chaers\" (\"cha\" + \"ers\") and \"acters\" (\"act\" + \"ers\").\n\t\tExample 3:\n\t\tInput: arr = [\"abcdefghijklmnopqrstuvwxyz\"]\n\t\tOutput: 26\n\t\tExplanation: The only string in arr has all 26 characters.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1361, - "question": "class Solution:\n def tilingRectangle(self, n: int, m: int) -> int:\n\t\t\"\"\"\n\t\tGiven a rectangle of size n x m, return the minimum number of integer-sided squares that tile the rectangle.\n\t\tExample 1:\n\t\tInput: n = 2, m = 3\n\t\tOutput: 3\n\t\tExplanation: 3 squares are necessary to cover the rectangle.\n\t\t2 (squares of 1x1)\n\t\t1 (square of 2x2)\n\t\tExample 2:\n\t\tInput: n = 5, m = 8\n\t\tOutput: 5\n\t\tExample 3:\n\t\tInput: n = 11, m = 13\n\t\tOutput: 6\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1362, - "question": "class Solution:\n def nthPersonGetsNthSeat(self, n: int) -> float:\n\t\t\"\"\"\n\t\tn passengers board an airplane with exactly n seats. The first passenger has lost the ticket and picks a seat randomly. But after that, the rest of the passengers will:\n\t\t\tTake their own seat if it is still available, and\n\t\t\tPick other seats randomly when they find their seat occupied\n\t\tReturn the probability that the nth person gets his own seat.\n\t\tExample 1:\n\t\tInput: n = 1\n\t\tOutput: 1.00000\n\t\tExplanation: The first person can only get the first seat.\n\t\tExample 2:\n\t\tInput: n = 2\n\t\tOutput: 0.50000\n\t\tExplanation: The second person has a probability of 0.5 to get the second seat (when first person gets the first seat).\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1363, - "question": "class Solution:\n def greatestLetter(self, s: str) -> str:\n\t\t\"\"\"\n\t\tGiven a string of English letters s, return the greatest English letter which occurs as both a lowercase and uppercase letter in s. The returned letter should be in uppercase. If no such letter exists, return an empty string.\n\t\tAn English letter b is greater than another letter a if b appears after a in the English alphabet.\n\t\tExample 1:\n\t\tInput: s = \"lEeTcOdE\"\n\t\tOutput: \"E\"\n\t\tExplanation:\n\t\tThe letter 'E' is the only letter to appear in both lower and upper case.\n\t\tExample 2:\n\t\tInput: s = \"arRAzFif\"\n\t\tOutput: \"R\"\n\t\tExplanation:\n\t\tThe letter 'R' is the greatest letter to appear in both lower and upper case.\n\t\tNote that 'A' and 'F' also appear in both lower and upper case, but 'R' is greater than 'F' or 'A'.\n\t\tExample 3:\n\t\tInput: s = \"AbCdEfGhIjK\"\n\t\tOutput: \"\"\n\t\tExplanation:\n\t\tThere is no letter that appears in both lower and upper case.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1364, - "question": "class Solution:\n def tupleSameProduct(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tGiven an array nums of distinct positive integers, return the number of tuples (a, b, c, d) such that a * b = c * d where a, b, c, and d are elements of nums, and a != b != c != d.\n\t\tExample 1:\n\t\tInput: nums = [2,3,4,6]\n\t\tOutput: 8\n\t\tExplanation: There are 8 valid tuples:\n\t\t(2,6,3,4) , (2,6,4,3) , (6,2,3,4) , (6,2,4,3)\n\t\t(3,4,2,6) , (4,3,2,6) , (3,4,6,2) , (4,3,6,2)\n\t\tExample 2:\n\t\tInput: nums = [1,2,4,5,10]\n\t\tOutput: 16\n\t\tExplanation: There are 16 valid tuples:\n\t\t(1,10,2,5) , (1,10,5,2) , (10,1,2,5) , (10,1,5,2)\n\t\t(2,5,1,10) , (2,5,10,1) , (5,2,1,10) , (5,2,10,1)\n\t\t(2,10,4,5) , (2,10,5,4) , (10,2,4,5) , (10,2,5,4)\n\t\t(4,5,2,10) , (4,5,10,2) , (5,4,2,10) , (5,4,10,2)\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1367, - "question": "class Solution:\n def maxHeight(self, cuboids: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tGiven n cuboids where the dimensions of the ith cuboid is cuboids[i] = [widthi, lengthi, heighti] (0-indexed). Choose a subset of cuboids and place them on each other.\n\t\tYou can place cuboid i on cuboid j if widthi <= widthj and lengthi <= lengthj and heighti <= heightj. You can rearrange any cuboid's dimensions by rotating it to put it on another cuboid.\n\t\tReturn the maximum height of the stacked cuboids.\n\t\tExample 1:\n\t\tInput: cuboids = [[50,45,20],[95,37,53],[45,23,12]]\n\t\tOutput: 190\n\t\tExplanation:\n\t\tCuboid 1 is placed on the bottom with the 53x37 side facing down with height 95.\n\t\tCuboid 0 is placed next with the 45x20 side facing down with height 50.\n\t\tCuboid 2 is placed next with the 23x12 side facing down with height 45.\n\t\tThe total height is 95 + 50 + 45 = 190.\n\t\tExample 2:\n\t\tInput: cuboids = [[38,25,45],[76,35,3]]\n\t\tOutput: 76\n\t\tExplanation:\n\t\tYou can't place any of the cuboids on the other.\n\t\tWe choose cuboid 1 and rotate it so that the 35x3 side is facing down and its height is 76.\n\t\tExample 3:\n\t\tInput: cuboids = [[7,11,17],[7,17,11],[11,7,17],[11,17,7],[17,7,11],[17,11,7]]\n\t\tOutput: 102\n\t\tExplanation:\n\t\tAfter rearranging the cuboids, you can see that all cuboids have the same dimension.\n\t\tYou can place the 11x7 side down on all cuboids so their heights are 17.\n\t\tThe maximum height of stacked cuboids is 6 * 17 = 102.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1369, - "question": "class Solution:\n def minimumSwap(self, s1: str, s2: str) -> int:\n\t\t\"\"\"\n\t\tYou are given two strings s1 and s2 of equal length consisting of letters \"x\" and \"y\" only. Your task is to make these two strings equal to each other. You can swap any two characters that belong to different strings, which means: swap s1[i] and s2[j].\n\t\tReturn the minimum number of swaps required to make s1 and s2 equal, or return -1 if it is impossible to do so.\n\t\tExample 1:\n\t\tInput: s1 = \"xx\", s2 = \"yy\"\n\t\tOutput: 1\n\t\tExplanation: Swap s1[0] and s2[1], s1 = \"yx\", s2 = \"yx\".\n\t\tExample 2:\n\t\tInput: s1 = \"xy\", s2 = \"yx\"\n\t\tOutput: 2\n\t\tExplanation: Swap s1[0] and s2[0], s1 = \"yy\", s2 = \"xx\".\n\t\tSwap s1[0] and s2[1], s1 = \"xy\", s2 = \"xy\".\n\t\tNote that you cannot swap s1[0] and s1[1] to make s1 equal to \"yx\", cause we can only swap chars in different strings.\n\t\tExample 3:\n\t\tInput: s1 = \"xx\", s2 = \"xy\"\n\t\tOutput: -1\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1370, - "question": "class Solution:\n def numberOfSubarrays(self, nums: List[int], k: int) -> int:\n\t\t\"\"\"\n\t\tGiven an array of integers nums and an integer k. A continuous subarray is called nice if there are k odd numbers on it.\r\n\t\tReturn the number of nice sub-arrays.\r\n\t\tExample 1:\r\n\t\tInput: nums = [1,1,2,1,1], k = 3\r\n\t\tOutput: 2\r\n\t\tExplanation: The only sub-arrays with 3 odd numbers are [1,1,2,1] and [1,2,1,1].\r\n\t\tExample 2:\r\n\t\tInput: nums = [2,4,6], k = 1\r\n\t\tOutput: 0\r\n\t\tExplanation: There is no odd numbers in the array.\r\n\t\tExample 3:\r\n\t\tInput: nums = [2,2,2,1,2,2,1,2,2,2], k = 2\r\n\t\tOutput: 16\r\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1371, - "question": "class Solution:\n def minRemoveToMakeValid(self, s: str) -> str:\n\t\t\"\"\"\n\t\tGiven a string s of '(' , ')' and lowercase English characters.\n\t\tYour task is to remove the minimum number of parentheses ( '(' or ')', in any positions ) so that the resulting parentheses string is valid and return any valid string.\n\t\tFormally, a parentheses string is valid if and only if:\n\t\t\tIt is the empty string, contains only lowercase characters, or\n\t\t\tIt can be written as AB (A concatenated with B), where A and B are valid strings, or\n\t\t\tIt can be written as (A), where A is a valid string.\n\t\tExample 1:\n\t\tInput: s = \"lee(t(c)o)de)\"\n\t\tOutput: \"lee(t(c)o)de\"\n\t\tExplanation: \"lee(t(co)de)\" , \"lee(t(c)ode)\" would also be accepted.\n\t\tExample 2:\n\t\tInput: s = \"a)b(c)d\"\n\t\tOutput: \"ab(c)d\"\n\t\tExample 3:\n\t\tInput: s = \"))((\"\n\t\tOutput: \"\"\n\t\tExplanation: An empty string is also valid.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1372, - "question": "class Solution:\n def isGoodArray(self, nums: List[int]) -> bool:\n\t\t\"\"\"\n\t\tGiven an array nums of positive integers. Your task is to select some subset of nums, multiply each element by an integer and add all these numbers. The array is said to be good if you can obtain a sum of 1 from the array by any possible subset and multiplicand.\n\t\tReturn True if the array is good otherwise return False.\n\t\tExample 1:\n\t\tInput: nums = [12,5,7,23]\n\t\tOutput: true\n\t\tExplanation: Pick numbers 5 and 7.\n\t\t5*3 + 7*(-2) = 1\n\t\tExample 2:\n\t\tInput: nums = [29,6,10]\n\t\tOutput: true\n\t\tExplanation: Pick numbers 29, 6 and 10.\n\t\t29*1 + 6*(-3) + 10*(-1) = 1\n\t\tExample 3:\n\t\tInput: nums = [3,6]\n\t\tOutput: false\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1375, - "question": "class Solution:\n def kthPalindrome(self, queries: List[int], intLength: int) -> List[int]:\n\t\t\"\"\"\n\t\tGiven an integer array queries and a positive integer intLength, return an array answer where answer[i] is either the queries[i]th smallest positive palindrome of length intLength or -1 if no such palindrome exists.\n\t\tA palindrome is a number that reads the same backwards and forwards. Palindromes cannot have leading zeros.\n\t\tExample 1:\n\t\tInput: queries = [1,2,3,4,5,90], intLength = 3\n\t\tOutput: [101,111,121,131,141,999]\n\t\tExplanation:\n\t\tThe first few palindromes of length 3 are:\n\t\t101, 111, 121, 131, 141, 151, 161, 171, 181, 191, 202, ...\n\t\tThe 90th palindrome of length 3 is 999.\n\t\tExample 2:\n\t\tInput: queries = [2,4,6], intLength = 4\n\t\tOutput: [1111,1331,1551]\n\t\tExplanation:\n\t\tThe first six palindromes of length 4 are:\n\t\t1001, 1111, 1221, 1331, 1441, and 1551.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1376, - "question": "class Solution:\n def sellingWood(self, m: int, n: int, prices: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tYou are given two integers m and n that represent the height and width of a rectangular piece of wood. You are also given a 2D integer array prices, where prices[i] = [hi, wi, pricei] indicates you can sell a rectangular piece of wood of height hi and width wi for pricei dollars.\n\t\tTo cut a piece of wood, you must make a vertical or horizontal cut across the entire height or width of the piece to split it into two smaller pieces. After cutting a piece of wood into some number of smaller pieces, you can sell pieces according to prices. You may sell multiple pieces of the same shape, and you do not have to sell all the shapes. The grain of the wood makes a difference, so you cannot rotate a piece to swap its height and width.\n\t\tReturn the maximum money you can earn after cutting an m x n piece of wood.\n\t\tNote that you can cut the piece of wood as many times as you want.\n\t\tExample 1:\n\t\tInput: m = 3, n = 5, prices = [[1,4,2],[2,2,7],[2,1,3]]\n\t\tOutput: 19\n\t\tExplanation: The diagram above shows a possible scenario. It consists of:\n\t\t- 2 pieces of wood shaped 2 x 2, selling for a price of 2 * 7 = 14.\n\t\t- 1 piece of wood shaped 2 x 1, selling for a price of 1 * 3 = 3.\n\t\t- 1 piece of wood shaped 1 x 4, selling for a price of 1 * 2 = 2.\n\t\tThis obtains a total of 14 + 3 + 2 = 19 money earned.\n\t\tIt can be shown that 19 is the maximum amount of money that can be earned.\n\t\tExample 2:\n\t\tInput: m = 4, n = 6, prices = [[3,2,10],[1,4,2],[4,1,3]]\n\t\tOutput: 32\n\t\tExplanation: The diagram above shows a possible scenario. It consists of:\n\t\t- 3 pieces of wood shaped 3 x 2, selling for a price of 3 * 10 = 30.\n\t\t- 1 piece of wood shaped 1 x 4, selling for a price of 1 * 2 = 2.\n\t\tThis obtains a total of 30 + 2 = 32 money earned.\n\t\tIt can be shown that 32 is the maximum amount of money that can be earned.\n\t\tNotice that we cannot rotate the 1 x 4 piece of wood to obtain a 4 x 1 piece of wood.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1378, - "question": "class Solution:\n def oddCells(self, m: int, n: int, indices: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tThere is an m x n matrix that is initialized to all 0's. There is also a 2D array indices where each indices[i] = [ri, ci] represents a 0-indexed location to perform some increment operations on the matrix.\n\t\tFor each location indices[i], do both of the following:\n\t\t\tIncrement all the cells on row ri.\n\t\t\tIncrement all the cells on column ci.\n\t\tGiven m, n, and indices, return the number of odd-valued cells in the matrix after applying the increment to all locations in indices.\n\t\tExample 1:\n\t\tInput: m = 2, n = 3, indices = [[0,1],[1,1]]\n\t\tOutput: 6\n\t\tExplanation: Initial matrix = [[0,0,0],[0,0,0]].\n\t\tAfter applying first increment it becomes [[1,2,1],[0,1,0]].\n\t\tThe final matrix is [[1,3,1],[1,3,1]], which contains 6 odd numbers.\n\t\tExample 2:\n\t\tInput: m = 2, n = 2, indices = [[1,1],[0,0]]\n\t\tOutput: 0\n\t\tExplanation: Final matrix = [[2,2],[2,2]]. There are no odd numbers in the final matrix.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1379, - "question": "class Solution:\n def reconstructMatrix(self, upper: int, lower: int, colsum: List[int]) -> List[List[int]]:\n\t\t\"\"\"\n\t\tGiven the following details of a matrix with n columns and 2 rows :\n\t\t\tThe matrix is a binary matrix, which means each element in the matrix can be 0 or 1.\n\t\t\tThe sum of elements of the 0-th(upper) row is given as upper.\n\t\t\tThe sum of elements of the 1-st(lower) row is given as lower.\n\t\t\tThe sum of elements in the i-th column(0-indexed) is colsum[i], where colsum is given as an integer array with length n.\n\t\tYour task is to reconstruct the matrix with upper, lower and colsum.\n\t\tReturn it as a 2-D integer array.\n\t\tIf there are more than one valid solution, any of them will be accepted.\n\t\tIf no valid solution exists, return an empty 2-D array.\n\t\tExample 1:\n\t\tInput: upper = 2, lower = 1, colsum = [1,1,1]\n\t\tOutput: [[1,1,0],[0,0,1]]\n\t\tExplanation: [[1,0,1],[0,1,0]], and [[0,1,1],[1,0,0]] are also correct answers.\n\t\tExample 2:\n\t\tInput: upper = 2, lower = 3, colsum = [2,2,1,1]\n\t\tOutput: []\n\t\tExample 3:\n\t\tInput: upper = 5, lower = 5, colsum = [2,1,2,0,1,0,1,2,0,1]\n\t\tOutput: [[1,1,1,0,1,0,0,1,0,0],[1,0,1,0,0,0,1,1,0,1]]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1380, - "question": "class Solution:\n def closedIsland(self, grid: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tGiven a 2D grid consists of 0s (land) and 1s (water). An island is a maximal 4-directionally connected group of 0s and a closed island is an island totally (all left, top, right, bottom) surrounded by 1s.\n\t\tReturn the number of closed islands.\n\t\tExample 1:\n\t\tInput: grid = [[1,1,1,1,1,1,1,0],[1,0,0,0,0,1,1,0],[1,0,1,0,1,1,1,0],[1,0,0,0,0,1,0,1],[1,1,1,1,1,1,1,0]]\n\t\tOutput: 2\n\t\tExplanation: \n\t\tIslands in gray are closed because they are completely surrounded by water (group of 1s).\n\t\tExample 2:\n\t\tInput: grid = [[0,0,1,0,0],[0,1,0,1,0],[0,1,1,1,0]]\n\t\tOutput: 1\n\t\tExample 3:\n\t\tInput: grid = [[1,1,1,1,1,1,1],\n\t\t [1,0,0,0,0,0,1],\n\t\t [1,0,1,1,1,0,1],\n\t\t [1,0,1,0,1,0,1],\n\t\t [1,0,1,1,1,0,1],\n\t\t [1,0,0,0,0,0,1],\n\t\t [1,1,1,1,1,1,1]]\n\t\tOutput: 2\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1381, - "question": "class Solution:\n def maxScoreWords(self, words: List[str], letters: List[str], score: List[int]) -> int:\n\t\t\"\"\"\n\t\tGiven a list of words, list of single letters (might be repeating) and score of every character.\n\t\tReturn the maximum score of any valid set of words formed by using the given letters (words[i] cannot be used two or more times).\n\t\tIt is not necessary to use all characters in letters and each letter can only be used once. Score of letters 'a', 'b', 'c', ... ,'z' is given by score[0], score[1], ... , score[25] respectively.\n\t\tExample 1:\n\t\tInput: words = [\"dog\",\"cat\",\"dad\",\"good\"], letters = [\"a\",\"a\",\"c\",\"d\",\"d\",\"d\",\"g\",\"o\",\"o\"], score = [1,0,9,5,0,0,3,0,0,0,0,0,0,0,2,0,0,0,0,0,0,0,0,0,0,0]\n\t\tOutput: 23\n\t\tExplanation:\n\t\tScore a=1, c=9, d=5, g=3, o=2\n\t\tGiven letters, we can form the words \"dad\" (5+1+5) and \"good\" (3+2+2+5) with a score of 23.\n\t\tWords \"dad\" and \"dog\" only get a score of 21.\n\t\tExample 2:\n\t\tInput: words = [\"xxxz\",\"ax\",\"bx\",\"cx\"], letters = [\"z\",\"a\",\"b\",\"c\",\"x\",\"x\",\"x\"], score = [4,4,4,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,5,0,10]\n\t\tOutput: 27\n\t\tExplanation:\n\t\tScore a=4, b=4, c=4, x=5, z=10\n\t\tGiven letters, we can form the words \"ax\" (4+5), \"bx\" (4+5) and \"cx\" (4+5) with a score of 27.\n\t\tWord \"xxxz\" only get a score of 25.\n\t\tExample 3:\n\t\tInput: words = [\"leetcode\"], letters = [\"l\",\"e\",\"t\",\"c\",\"o\",\"d\"], score = [0,0,1,1,1,0,0,0,0,0,0,1,0,0,1,0,0,0,0,1,0,0,0,0,0,0]\n\t\tOutput: 0\n\t\tExplanation:\n\t\tLetter \"e\" can only be used once.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1382, - "question": "class Solution:\n def calculateTax(self, brackets: List[List[int]], income: int) -> float:\n\t\t\"\"\"\n\t\tYou are given a 0-indexed 2D integer array brackets where brackets[i] = [upperi, percenti] means that the ith tax bracket has an upper bound of upperi and is taxed at a rate of percenti. The brackets are sorted by upper bound (i.e. upperi-1 < upperi for 0 < i < brackets.length).\n\t\tTax is calculated as follows:\n\t\t\tThe first upper0 dollars earned are taxed at a rate of percent0.\n\t\t\tThe next upper1 - upper0 dollars earned are taxed at a rate of percent1.\n\t\t\tThe next upper2 - upper1 dollars earned are taxed at a rate of percent2.\n\t\t\tAnd so on.\n\t\tYou are given an integer income representing the amount of money you earned. Return the amount of money that you have to pay in taxes. Answers within 10-5 of the actual answer will be accepted.\n\t\tExample 1:\n\t\tInput: brackets = [[3,50],[7,10],[12,25]], income = 10\n\t\tOutput: 2.65000\n\t\tExplanation:\n\t\tBased on your income, you have 3 dollars in the 1st tax bracket, 4 dollars in the 2nd tax bracket, and 3 dollars in the 3rd tax bracket.\n\t\tThe tax rate for the three tax brackets is 50%, 10%, and 25%, respectively.\n\t\tIn total, you pay $3 * 50% + $4 * 10% + $3 * 25% = $2.65 in taxes.\n\t\tExample 2:\n\t\tInput: brackets = [[1,0],[4,25],[5,50]], income = 2\n\t\tOutput: 0.25000\n\t\tExplanation:\n\t\tBased on your income, you have 1 dollar in the 1st tax bracket and 1 dollar in the 2nd tax bracket.\n\t\tThe tax rate for the two tax brackets is 0% and 25%, respectively.\n\t\tIn total, you pay $1 * 0% + $1 * 25% = $0.25 in taxes.\n\t\tExample 3:\n\t\tInput: brackets = [[2,50]], income = 0\n\t\tOutput: 0.00000\n\t\tExplanation:\n\t\tYou have no income to tax, so you have to pay a total of $0 in taxes.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1386, - "question": "class Solution:\n def shiftGrid(self, grid: List[List[int]], k: int) -> List[List[int]]:\n\t\t\"\"\"\n\t\tGiven a 2D grid of size m x n and an integer k. You need to shift the grid k times.\n\t\tIn one shift operation:\n\t\t\tElement at grid[i][j] moves to grid[i][j + 1].\n\t\t\tElement at grid[i][n - 1] moves to grid[i + 1][0].\n\t\t\tElement at grid[m - 1][n - 1] moves to grid[0][0].\n\t\tReturn the 2D grid after applying shift operation k times.\n\t\tExample 1:\n\t\tInput: grid = [[1,2,3],[4,5,6],[7,8,9]], k = 1\n\t\tOutput: [[9,1,2],[3,4,5],[6,7,8]]\n\t\tExample 2:\n\t\tInput: grid = [[3,8,1,9],[19,7,2,5],[4,6,11,10],[12,0,21,13]], k = 4\n\t\tOutput: [[12,0,21,13],[3,8,1,9],[19,7,2,5],[4,6,11,10]]\n\t\tExample 3:\n\t\tInput: grid = [[1,2,3],[4,5,6],[7,8,9]], k = 9\n\t\tOutput: [[1,2,3],[4,5,6],[7,8,9]]\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1387, - "question": "class FindElements:\n def __init__(self, root: Optional[TreeNode]):\n def find(self, target: int) -> bool:\n\t\t\"\"\"\n\t\tGiven a binary tree with the following rules:\n\t\t\troot.val == 0\n\t\t\tIf treeNode.val == x and treeNode.left != null, then treeNode.left.val == 2 * x + 1\n\t\t\tIf treeNode.val == x and treeNode.right != null, then treeNode.right.val == 2 * x + 2\n\t\tNow the binary tree is contaminated, which means all treeNode.val have been changed to -1.\n\t\tImplement the FindElements class:\n\t\t\tFindElements(TreeNode* root) Initializes the object with a contaminated binary tree and recovers it.\n\t\t\tbool find(int target) Returns true if the target value exists in the recovered binary tree.\n\t\tExample 1:\n\t\tInput\n\t\t[\"FindElements\",\"find\",\"find\"]\n\t\t[[[-1,null,-1]],[1],[2]]\n\t\tOutput\n\t\t[null,false,true]\n\t\tExplanation\n\t\tFindElements findElements = new FindElements([-1,null,-1]); \n\t\tfindElements.find(1); // return False \n\t\tfindElements.find(2); // return True \n\t\tExample 2:\n\t\tInput\n\t\t[\"FindElements\",\"find\",\"find\",\"find\"]\n\t\t[[[-1,-1,-1,-1,-1]],[1],[3],[5]]\n\t\tOutput\n\t\t[null,true,true,false]\n\t\tExplanation\n\t\tFindElements findElements = new FindElements([-1,-1,-1,-1,-1]);\n\t\tfindElements.find(1); // return True\n\t\tfindElements.find(3); // return True\n\t\tfindElements.find(5); // return False\n\t\tExample 3:\n\t\tInput\n\t\t[\"FindElements\",\"find\",\"find\",\"find\",\"find\"]\n\t\t[[[-1,null,-1,-1,null,-1]],[2],[3],[4],[5]]\n\t\tOutput\n\t\t[null,true,false,false,true]\n\t\tExplanation\n\t\tFindElements findElements = new FindElements([-1,null,-1,-1,null,-1]);\n\t\tfindElements.find(2); // return True\n\t\tfindElements.find(3); // return False\n\t\tfindElements.find(4); // return False\n\t\tfindElements.find(5); // return True\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1388, - "question": "class Solution:\n def maxSumDivThree(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tGiven an integer array nums, return the maximum possible sum of elements of the array such that it is divisible by three.\n\t\tExample 1:\n\t\tInput: nums = [3,6,5,1,8]\n\t\tOutput: 18\n\t\tExplanation: Pick numbers 3, 6, 1 and 8 their sum is 18 (maximum sum divisible by 3).\n\t\tExample 2:\n\t\tInput: nums = [4]\n\t\tOutput: 0\n\t\tExplanation: Since 4 is not divisible by 3, do not pick any number.\n\t\tExample 3:\n\t\tInput: nums = [1,2,3,4,4]\n\t\tOutput: 12\n\t\tExplanation: Pick numbers 1, 3, 4 and 4 their sum is 12 (maximum sum divisible by 3).\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1389, - "question": "class Solution:\n def minPushBox(self, grid: List[List[str]]) -> int:\n\t\t\"\"\"\n\t\tA storekeeper is a game in which the player pushes boxes around in a warehouse trying to get them to target locations.\n\t\tThe game is represented by an m x n grid of characters grid where each element is a wall, floor, or box.\n\t\tYour task is to move the box 'B' to the target position 'T' under the following rules:\n\t\t\tThe character 'S' represents the player. The player can move up, down, left, right in grid if it is a floor (empty cell).\n\t\t\tThe character '.' represents the floor which means a free cell to walk.\n\t\t\tThe character '#' represents the wall which means an obstacle (impossible to walk there).\n\t\t\tThere is only one box 'B' and one target cell 'T' in the grid.\n\t\t\tThe box can be moved to an adjacent free cell by standing next to the box and then moving in the direction of the box. This is a push.\n\t\t\tThe player cannot walk through the box.\n\t\tReturn the minimum number of pushes to move the box to the target. If there is no way to reach the target, return -1.\n\t\tExample 1:\n\t\tInput: grid = [[\"#\",\"#\",\"#\",\"#\",\"#\",\"#\"],\n\t\t [\"#\",\"T\",\"#\",\"#\",\"#\",\"#\"],\n\t\t [\"#\",\".\",\".\",\"B\",\".\",\"#\"],\n\t\t [\"#\",\".\",\"#\",\"#\",\".\",\"#\"],\n\t\t [\"#\",\".\",\".\",\".\",\"S\",\"#\"],\n\t\t [\"#\",\"#\",\"#\",\"#\",\"#\",\"#\"]]\n\t\tOutput: 3\n\t\tExplanation: We return only the number of times the box is pushed.\n\t\tExample 2:\n\t\tInput: grid = [[\"#\",\"#\",\"#\",\"#\",\"#\",\"#\"],\n\t\t [\"#\",\"T\",\"#\",\"#\",\"#\",\"#\"],\n\t\t [\"#\",\".\",\".\",\"B\",\".\",\"#\"],\n\t\t [\"#\",\"#\",\"#\",\"#\",\".\",\"#\"],\n\t\t [\"#\",\".\",\".\",\".\",\"S\",\"#\"],\n\t\t [\"#\",\"#\",\"#\",\"#\",\"#\",\"#\"]]\n\t\tOutput: -1\n\t\tExample 3:\n\t\tInput: grid = [[\"#\",\"#\",\"#\",\"#\",\"#\",\"#\"],\n\t\t [\"#\",\"T\",\".\",\".\",\"#\",\"#\"],\n\t\t [\"#\",\".\",\"#\",\"B\",\".\",\"#\"],\n\t\t [\"#\",\".\",\".\",\".\",\".\",\"#\"],\n\t\t [\"#\",\".\",\".\",\".\",\"S\",\"#\"],\n\t\t [\"#\",\"#\",\"#\",\"#\",\"#\",\"#\"]]\n\t\tOutput: 5\n\t\tExplanation: push the box down, left, left, up and up.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1392, - "question": "class Solution:\n def findDifference(self, nums1: List[int], nums2: List[int]) -> List[List[int]]:\n\t\t\"\"\"\n\t\tGiven two 0-indexed integer arrays nums1 and nums2, return a list answer of size 2 where:\n\t\t\tanswer[0] is a list of all distinct integers in nums1 which are not present in nums2.\n\t\t\tanswer[1] is a list of all distinct integers in nums2 which are not present in nums1.\n\t\tNote that the integers in the lists may be returned in any order.\n\t\tExample 1:\n\t\tInput: nums1 = [1,2,3], nums2 = [2,4,6]\n\t\tOutput: [[1,3],[4,6]]\n\t\tExplanation:\n\t\tFor nums1, nums1[1] = 2 is present at index 0 of nums2, whereas nums1[0] = 1 and nums1[2] = 3 are not present in nums2. Therefore, answer[0] = [1,3].\n\t\tFor nums2, nums2[0] = 2 is present at index 1 of nums1, whereas nums2[1] = 4 and nums2[2] = 6 are not present in nums2. Therefore, answer[1] = [4,6].\n\t\tExample 2:\n\t\tInput: nums1 = [1,2,3,3], nums2 = [1,1,2,2]\n\t\tOutput: [[3],[]]\n\t\tExplanation:\n\t\tFor nums1, nums1[2] and nums1[3] are not present in nums2. Since nums1[2] == nums1[3], their value is only included once and answer[0] = [3].\n\t\tEvery integer in nums2 is present in nums1. Therefore, answer[1] = [].\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1393, - "question": "class Solution:\n def maxValueOfCoins(self, piles: List[List[int]], k: int) -> int:\n\t\t\"\"\"\n\t\tThere are n piles of coins on a table. Each pile consists of a positive number of coins of assorted denominations.\n\t\tIn one move, you can choose any coin on top of any pile, remove it, and add it to your wallet.\n\t\tGiven a list piles, where piles[i] is a list of integers denoting the composition of the ith pile from top to bottom, and a positive integer k, return the maximum total value of coins you can have in your wallet if you choose exactly k coins optimally.\n\t\tExample 1:\n\t\tInput: piles = [[1,100,3],[7,8,9]], k = 2\n\t\tOutput: 101\n\t\tExplanation:\n\t\tThe above diagram shows the different ways we can choose k coins.\n\t\tThe maximum total we can obtain is 101.\n\t\tExample 2:\n\t\tInput: piles = [[100],[100],[100],[100],[100],[100],[1,1,1,1,1,1,700]], k = 7\n\t\tOutput: 706\n\t\tExplanation:\n\t\tThe maximum total can be obtained if we choose all coins from the last pile.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1394, - "question": "class Solution:\n def minPathCost(self, grid: List[List[int]], moveCost: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tYou are given a 0-indexed m x n integer matrix grid consisting of distinct integers from 0 to m * n - 1. You can move in this matrix from a cell to any other cell in the next row. That is, if you are in cell (x, y) such that x < m - 1, you can move to any of the cells (x + 1, 0), (x + 1, 1), ..., (x + 1, n - 1). Note that it is not possible to move from cells in the last row.\n\t\tEach possible move has a cost given by a 0-indexed 2D array moveCost of size (m * n) x n, where moveCost[i][j] is the cost of moving from a cell with value i to a cell in column j of the next row. The cost of moving from cells in the last row of grid can be ignored.\n\t\tThe cost of a path in grid is the sum of all values of cells visited plus the sum of costs of all the moves made. Return the minimum cost of a path that starts from any cell in the first row and ends at any cell in the last row.\n\t\tExample 1:\n\t\tInput: grid = [[5,3],[4,0],[2,1]], moveCost = [[9,8],[1,5],[10,12],[18,6],[2,4],[14,3]]\n\t\tOutput: 17\n\t\tExplanation: The path with the minimum possible cost is the path 5 -> 0 -> 1.\n\t\t- The sum of the values of cells visited is 5 + 0 + 1 = 6.\n\t\t- The cost of moving from 5 to 0 is 3.\n\t\t- The cost of moving from 0 to 1 is 8.\n\t\tSo the total cost of the path is 6 + 3 + 8 = 17.\n\t\tExample 2:\n\t\tInput: grid = [[5,1,2],[4,0,3]], moveCost = [[12,10,15],[20,23,8],[21,7,1],[8,1,13],[9,10,25],[5,3,2]]\n\t\tOutput: 6\n\t\tExplanation: The path with the minimum possible cost is the path 2 -> 3.\n\t\t- The sum of the values of cells visited is 2 + 3 = 5.\n\t\t- The cost of moving from 2 to 3 is 1.\n\t\tSo the total cost of this path is 5 + 1 = 6.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1395, - "question": "class Solution:\n def minTimeToVisitAllPoints(self, points: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tOn a 2D plane, there are n points with integer coordinates points[i] = [xi, yi]. Return the minimum time in seconds to visit all the points in the order given by points.\n\t\tYou can move according to these rules:\n\t\t\tIn 1 second, you can either:\n\t\t\t\tmove vertically by one unit,\n\t\t\t\tmove horizontally by one unit, or\n\t\t\t\tmove diagonally sqrt(2) units (in other words, move one unit vertically then one unit horizontally in 1 second).\n\t\t\tYou have to visit the points in the same order as they appear in the array.\n\t\t\tYou are allowed to pass through points that appear later in the order, but these do not count as visits.\n\t\tExample 1:\n\t\tInput: points = [[1,1],[3,4],[-1,0]]\n\t\tOutput: 7\n\t\tExplanation: One optimal path is [1,1] -> [2,2] -> [3,3] -> [3,4] -> [2,3] -> [1,2] -> [0,1] -> [-1,0] \n\t\tTime from [1,1] to [3,4] = 3 seconds \n\t\tTime from [3,4] to [-1,0] = 4 seconds\n\t\tTotal time = 7 seconds\n\t\tExample 2:\n\t\tInput: points = [[3,2],[-2,2]]\n\t\tOutput: 5\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1396, - "question": "class Solution:\n def countServers(self, grid: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tYou are given a map of a server center, represented as a m * n integer matrix grid, where 1 means that on that cell there is a server and 0 means that it is no server. Two servers are said to communicate if they are on the same row or on the same column.\n\t\tReturn the number of servers that communicate with any other server.\n\t\tExample 1:\n\t\tInput: grid = [[1,0],[0,1]]\n\t\tOutput: 0\n\t\tExplanation: No servers can communicate with others.\n\t\tExample 2:\n\t\tInput: grid = [[1,0],[1,1]]\n\t\tOutput: 3\n\t\tExplanation: All three servers can communicate with at least one other server.\n\t\tExample 3:\n\t\tInput: grid = [[1,1,0,0],[0,0,1,0],[0,0,1,0],[0,0,0,1]]\n\t\tOutput: 4\n\t\tExplanation: The two servers in the first row can communicate with each other. The two servers in the third column can communicate with each other. The server at right bottom corner can't communicate with any other server.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1397, - "question": "class Solution:\n def suggestedProducts(self, products: List[str], searchWord: str) -> List[List[str]]:\n\t\t\"\"\"\n\t\tYou are given an array of strings products and a string searchWord.\n\t\tDesign a system that suggests at most three product names from products after each character of searchWord is typed. Suggested products should have common prefix with searchWord. If there are more than three products with a common prefix return the three lexicographically minimums products.\n\t\tReturn a list of lists of the suggested products after each character of searchWord is typed.\n\t\tExample 1:\n\t\tInput: products = [\"mobile\",\"mouse\",\"moneypot\",\"monitor\",\"mousepad\"], searchWord = \"mouse\"\n\t\tOutput: [[\"mobile\",\"moneypot\",\"monitor\"],[\"mobile\",\"moneypot\",\"monitor\"],[\"mouse\",\"mousepad\"],[\"mouse\",\"mousepad\"],[\"mouse\",\"mousepad\"]]\n\t\tExplanation: products sorted lexicographically = [\"mobile\",\"moneypot\",\"monitor\",\"mouse\",\"mousepad\"].\n\t\tAfter typing m and mo all products match and we show user [\"mobile\",\"moneypot\",\"monitor\"].\n\t\tAfter typing mou, mous and mouse the system suggests [\"mouse\",\"mousepad\"].\n\t\tExample 2:\n\t\tInput: products = [\"havana\"], searchWord = \"havana\"\n\t\tOutput: [[\"havana\"],[\"havana\"],[\"havana\"],[\"havana\"],[\"havana\"],[\"havana\"]]\n\t\tExplanation: The only word \"havana\" will be always suggested while typing the search word.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1398, - "question": "class Solution:\n def numWays(self, steps: int, arrLen: int) -> int:\n\t\t\"\"\"\n\t\tYou have a pointer at index 0 in an array of size arrLen. At each step, you can move 1 position to the left, 1 position to the right in the array, or stay in the same place (The pointer should not be placed outside the array at any time).\n\t\tGiven two integers steps and arrLen, return the number of ways such that your pointer is still at index 0 after exactly steps steps. Since the answer may be too large, return it modulo 109 + 7.\n\t\tExample 1:\n\t\tInput: steps = 3, arrLen = 2\n\t\tOutput: 4\n\t\tExplanation: There are 4 differents ways to stay at index 0 after 3 steps.\n\t\tRight, Left, Stay\n\t\tStay, Right, Left\n\t\tRight, Stay, Left\n\t\tStay, Stay, Stay\n\t\tExample 2:\n\t\tInput: steps = 2, arrLen = 4\n\t\tOutput: 2\n\t\tExplanation: There are 2 differents ways to stay at index 0 after 2 steps\n\t\tRight, Left\n\t\tStay, Stay\n\t\tExample 3:\n\t\tInput: steps = 4, arrLen = 2\n\t\tOutput: 8\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1400, - "question": "class Solution:\n def tictactoe(self, moves: List[List[int]]) -> str:\n\t\t\"\"\"\n\t\tTic-tac-toe is played by two players A and B on a 3 x 3 grid. The rules of Tic-Tac-Toe are:\n\t\t\tPlayers take turns placing characters into empty squares ' '.\n\t\t\tThe first player A always places 'X' characters, while the second player B always places 'O' characters.\n\t\t\t'X' and 'O' characters are always placed into empty squares, never on filled ones.\n\t\t\tThe game ends when there are three of the same (non-empty) character filling any row, column, or diagonal.\n\t\t\tThe game also ends if all squares are non-empty.\n\t\t\tNo more moves can be played if the game is over.\n\t\tGiven a 2D integer array moves where moves[i] = [rowi, coli] indicates that the ith move will be played on grid[rowi][coli]. return the winner of the game if it exists (A or B). In case the game ends in a draw return \"Draw\". If there are still movements to play return \"Pending\".\n\t\tYou can assume that moves is valid (i.e., it follows the rules of Tic-Tac-Toe), the grid is initially empty, and A will play first.\n\t\tExample 1:\n\t\tInput: moves = [[0,0],[2,0],[1,1],[2,1],[2,2]]\n\t\tOutput: \"A\"\n\t\tExplanation: A wins, they always play first.\n\t\tExample 2:\n\t\tInput: moves = [[0,0],[1,1],[0,1],[0,2],[1,0],[2,0]]\n\t\tOutput: \"B\"\n\t\tExplanation: B wins.\n\t\tExample 3:\n\t\tInput: moves = [[0,0],[1,1],[2,0],[1,0],[1,2],[2,1],[0,1],[0,2],[2,2]]\n\t\tOutput: \"Draw\"\n\t\tExplanation: The game ends in a draw since there are no moves to make.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1401, - "question": "class Solution:\n def numOfBurgers(self, tomatoSlices: int, cheeseSlices: int) -> List[int]:\n\t\t\"\"\"\n\t\tGiven two integers tomatoSlices and cheeseSlices. The ingredients of different burgers are as follows:\n\t\t\tJumbo Burger: 4 tomato slices and 1 cheese slice.\n\t\t\tSmall Burger: 2 Tomato slices and 1 cheese slice.\n\t\tReturn [total_jumbo, total_small] so that the number of remaining tomatoSlices equal to 0 and the number of remaining cheeseSlices equal to 0. If it is not possible to make the remaining tomatoSlices and cheeseSlices equal to 0 return [].\n\t\tExample 1:\n\t\tInput: tomatoSlices = 16, cheeseSlices = 7\n\t\tOutput: [1,6]\n\t\tExplantion: To make one jumbo burger and 6 small burgers we need 4*1 + 2*6 = 16 tomato and 1 + 6 = 7 cheese.\n\t\tThere will be no remaining ingredients.\n\t\tExample 2:\n\t\tInput: tomatoSlices = 17, cheeseSlices = 4\n\t\tOutput: []\n\t\tExplantion: There will be no way to use all ingredients to make small and jumbo burgers.\n\t\tExample 3:\n\t\tInput: tomatoSlices = 4, cheeseSlices = 17\n\t\tOutput: []\n\t\tExplantion: Making 1 jumbo burger there will be 16 cheese remaining and making 2 small burgers there will be 15 cheese remaining.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1402, - "question": "class Solution:\n def countSquares(self, matrix: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tGiven a m * n matrix of ones and zeros, return how many square submatrices have all ones.\n\t\tExample 1:\n\t\tInput: matrix =\n\t\t[\n\t\t [0,1,1,1],\n\t\t [1,1,1,1],\n\t\t [0,1,1,1]\n\t\t]\n\t\tOutput: 15\n\t\tExplanation: \n\t\tThere are 10 squares of side 1.\n\t\tThere are 4 squares of side 2.\n\t\tThere is 1 square of side 3.\n\t\tTotal number of squares = 10 + 4 + 1 = 15.\n\t\tExample 2:\n\t\tInput: matrix = \n\t\t[\n\t\t [1,0,1],\n\t\t [1,1,0],\n\t\t [1,1,0]\n\t\t]\n\t\tOutput: 7\n\t\tExplanation: \n\t\tThere are 6 squares of side 1. \n\t\tThere is 1 square of side 2. \n\t\tTotal number of squares = 6 + 1 = 7.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1403, - "question": "class Solution:\n def palindromePartition(self, s: str, k: int) -> int:\n\t\t\"\"\"\n\t\tYou are given a string s containing lowercase letters and an integer k. You need to :\n\t\t\tFirst, change some characters of s to other lowercase English letters.\n\t\t\tThen divide s into k non-empty disjoint substrings such that each substring is a palindrome.\n\t\tReturn the minimal number of characters that you need to change to divide the string.\n\t\tExample 1:\n\t\tInput: s = \"abc\", k = 2\n\t\tOutput: 1\n\t\tExplanation: You can split the string into \"ab\" and \"c\", and change 1 character in \"ab\" to make it palindrome.\n\t\tExample 2:\n\t\tInput: s = \"aabbc\", k = 3\n\t\tOutput: 0\n\t\tExplanation: You can split the string into \"aa\", \"bb\" and \"c\", all of them are palindrome.\n\t\tExample 3:\n\t\tInput: s = \"leetcode\", k = 8\n\t\tOutput: 0\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1406, - "question": "class Solution:\n def subtractProductAndSum(self, n: int) -> int:\n\t\t\"\"\"\n\t\tGiven an integer number n, return the difference between the product of its digits and the sum of its digits.\n\t\tExample 1:\n\t\tInput: n = 234\n\t\tOutput: 15 \n\t\tExplanation: \n\t\tProduct of digits = 2 * 3 * 4 = 24 \n\t\tSum of digits = 2 + 3 + 4 = 9 \n\t\tResult = 24 - 9 = 15\n\t\tExample 2:\n\t\tInput: n = 4421\n\t\tOutput: 21\n\t\tExplanation: \n\t\tProduct of digits = 4 * 4 * 2 * 1 = 32 \n\t\tSum of digits = 4 + 4 + 2 + 1 = 11 \n\t\tResult = 32 - 11 = 21\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1407, - "question": "class Solution:\n def groupThePeople(self, groupSizes: List[int]) -> List[List[int]]:\n\t\t\"\"\"\n\t\tThere are n people that are split into some unknown number of groups. Each person is labeled with a unique ID from 0 to n - 1.\n\t\tYou are given an integer array groupSizes, where groupSizes[i] is the size of the group that person i is in. For example, if groupSizes[1] = 3, then person 1 must be in a group of size 3.\n\t\tReturn a list of groups such that each person i is in a group of size groupSizes[i].\n\t\tEach person should appear in exactly one group, and every person must be in a group. If there are multiple answers, return any of them. It is guaranteed that there will be at least one valid solution for the given input.\n\t\tExample 1:\n\t\tInput: groupSizes = [3,3,3,3,3,1,3]\n\t\tOutput: [[5],[0,1,2],[3,4,6]]\n\t\tExplanation: \n\t\tThe first group is [5]. The size is 1, and groupSizes[5] = 1.\n\t\tThe second group is [0,1,2]. The size is 3, and groupSizes[0] = groupSizes[1] = groupSizes[2] = 3.\n\t\tThe third group is [3,4,6]. The size is 3, and groupSizes[3] = groupSizes[4] = groupSizes[6] = 3.\n\t\tOther possible solutions are [[2,1,6],[5],[0,4,3]] and [[5],[0,6,2],[4,3,1]].\n\t\tExample 2:\n\t\tInput: groupSizes = [2,1,3,3,3,2]\n\t\tOutput: [[1],[0,5],[2,3,4]]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1408, - "question": "class Solution:\n def smallestDivisor(self, nums: List[int], threshold: int) -> int:\n\t\t\"\"\"\n\t\tGiven an array of integers nums and an integer threshold, we will choose a positive integer divisor, divide all the array by it, and sum the division's result. Find the smallest divisor such that the result mentioned above is less than or equal to threshold.\n\t\tEach result of the division is rounded to the nearest integer greater than or equal to that element. (For example: 7/3 = 3 and 10/2 = 5).\n\t\tThe test cases are generated so that there will be an answer.\n\t\tExample 1:\n\t\tInput: nums = [1,2,5,9], threshold = 6\n\t\tOutput: 5\n\t\tExplanation: We can get a sum to 17 (1+2+5+9) if the divisor is 1. \n\t\tIf the divisor is 4 we can get a sum of 7 (1+1+2+3) and if the divisor is 5 the sum will be 5 (1+1+1+2). \n\t\tExample 2:\n\t\tInput: nums = [44,22,33,11,1], threshold = 5\n\t\tOutput: 44\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1409, - "question": "class Solution:\n def minFlips(self, mat: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tGiven a m x n binary matrix mat. In one step, you can choose one cell and flip it and all the four neighbors of it if they exist (Flip is changing 1 to 0 and 0 to 1). A pair of cells are called neighbors if they share one edge.\n\t\tReturn the minimum number of steps required to convert mat to a zero matrix or -1 if you cannot.\n\t\tA binary matrix is a matrix with all cells equal to 0 or 1 only.\n\t\tA zero matrix is a matrix with all cells equal to 0.\n\t\tExample 1:\n\t\tInput: mat = [[0,0],[0,1]]\n\t\tOutput: 3\n\t\tExplanation: One possible solution is to flip (1, 0) then (0, 1) and finally (1, 1) as shown.\n\t\tExample 2:\n\t\tInput: mat = [[0]]\n\t\tOutput: 0\n\t\tExplanation: Given matrix is a zero matrix. We do not need to change it.\n\t\tExample 3:\n\t\tInput: mat = [[1,0,0],[1,0,0]]\n\t\tOutput: -1\n\t\tExplanation: Given matrix cannot be a zero matrix.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1411, - "question": "class Solution:\n def getDecimalValue(self, head: ListNode) -> int:\n\t\t\"\"\"\n\t\tGiven head which is a reference node to a singly-linked list. The value of each node in the linked list is either 0 or 1. The linked list holds the binary representation of a number.\n\t\tReturn the decimal value of the number in the linked list.\n\t\tThe most significant bit is at the head of the linked list.\n\t\tExample 1:\n\t\tInput: head = [1,0,1]\n\t\tOutput: 5\n\t\tExplanation: (101) in base 2 = (5) in base 10\n\t\tExample 2:\n\t\tInput: head = [0]\n\t\tOutput: 0\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1413, - "question": "class Solution:\n def maxSideLength(self, mat: List[List[int]], threshold: int) -> int:\n\t\t\"\"\"\n\t\tGiven a m x n matrix mat and an integer threshold, return the maximum side-length of a square with a sum less than or equal to threshold or return 0 if there is no such square.\n\t\tExample 1:\n\t\tInput: mat = [[1,1,3,2,4,3,2],[1,1,3,2,4,3,2],[1,1,3,2,4,3,2]], threshold = 4\n\t\tOutput: 2\n\t\tExplanation: The maximum side length of square with sum less than 4 is 2 as shown.\n\t\tExample 2:\n\t\tInput: mat = [[2,2,2,2,2],[2,2,2,2,2],[2,2,2,2,2],[2,2,2,2,2],[2,2,2,2,2]], threshold = 1\n\t\tOutput: 0\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1414, - "question": "class Solution:\n def shortestPath(self, grid: List[List[int]], k: int) -> int:\n\t\t\"\"\"\n\t\tYou are given an m x n integer matrix grid where each cell is either 0 (empty) or 1 (obstacle). You can move up, down, left, or right from and to an empty cell in one step.\n\t\tReturn the minimum number of steps to walk from the upper left corner (0, 0) to the lower right corner (m - 1, n - 1) given that you can eliminate at most k obstacles. If it is not possible to find such walk return -1.\n\t\tExample 1:\n\t\tInput: grid = [[0,0,0],[1,1,0],[0,0,0],[0,1,1],[0,0,0]], k = 1\n\t\tOutput: 6\n\t\tExplanation: \n\t\tThe shortest path without eliminating any obstacle is 10.\n\t\tThe shortest path with one obstacle elimination at position (3,2) is 6. Such path is (0,0) -> (0,1) -> (0,2) -> (1,2) -> (2,2) -> (3,2) -> (4,2).\n\t\tExample 2:\n\t\tInput: grid = [[0,1,1],[1,1,1],[1,0,0]], k = 1\n\t\tOutput: -1\n\t\tExplanation: We need to eliminate at least two obstacles to find such a walk.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1418, - "question": "class Solution:\n def distributeCookies(self, cookies: List[int], k: int) -> int:\n\t\t\"\"\"\n\t\tYou are given an integer array cookies, where cookies[i] denotes the number of cookies in the ith bag. You are also given an integer k that denotes the number of children to distribute all the bags of cookies to. All the cookies in the same bag must go to the same child and cannot be split up.\n\t\tThe unfairness of a distribution is defined as the maximum total cookies obtained by a single child in the distribution.\n\t\tReturn the minimum unfairness of all distributions.\n\t\tExample 1:\n\t\tInput: cookies = [8,15,10,20,8], k = 2\n\t\tOutput: 31\n\t\tExplanation: One optimal distribution is [8,15,8] and [10,20]\n\t\t- The 1st child receives [8,15,8] which has a total of 8 + 15 + 8 = 31 cookies.\n\t\t- The 2nd child receives [10,20] which has a total of 10 + 20 = 30 cookies.\n\t\tThe unfairness of the distribution is max(31,30) = 31.\n\t\tIt can be shown that there is no distribution with an unfairness less than 31.\n\t\tExample 2:\n\t\tInput: cookies = [6,1,3,2,2,4,1,2], k = 3\n\t\tOutput: 7\n\t\tExplanation: One optimal distribution is [6,1], [3,2,2], and [4,1,2]\n\t\t- The 1st child receives [6,1] which has a total of 6 + 1 = 7 cookies.\n\t\t- The 2nd child receives [3,2,2] which has a total of 3 + 2 + 2 = 7 cookies.\n\t\t- The 3rd child receives [4,1,2] which has a total of 4 + 1 + 2 = 7 cookies.\n\t\tThe unfairness of the distribution is max(7,7,7) = 7.\n\t\tIt can be shown that there is no distribution with an unfairness less than 7.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1421, - "question": "class Solution:\n def findNumbers(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tGiven an array nums of integers, return how many of them contain an even number of digits.\n\t\tExample 1:\n\t\tInput: nums = [12,345,2,6,7896]\n\t\tOutput: 2\n\t\tExplanation: \n\t\t12 contains 2 digits (even number of digits). \n\t\t345 contains 3 digits (odd number of digits). \n\t\t2 contains 1 digit (odd number of digits). \n\t\t6 contains 1 digit (odd number of digits). \n\t\t7896 contains 4 digits (even number of digits). \n\t\tTherefore only 12 and 7896 contain an even number of digits.\n\t\tExample 2:\n\t\tInput: nums = [555,901,482,1771]\n\t\tOutput: 1 \n\t\tExplanation: \n\t\tOnly 1771 contains an even number of digits.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1422, - "question": "class Solution:\n def isPossibleDivide(self, nums: List[int], k: int) -> bool:\n\t\t\"\"\"\n\t\tGiven an array of integers nums and a positive integer k, check whether it is possible to divide this array into sets of k consecutive numbers.\n\t\tReturn true if it is possible. Otherwise, return false.\n\t\tExample 1:\n\t\tInput: nums = [1,2,3,3,4,4,5,6], k = 4\n\t\tOutput: true\n\t\tExplanation: Array can be divided into [1,2,3,4] and [3,4,5,6].\n\t\tExample 2:\n\t\tInput: nums = [3,2,1,2,3,4,3,4,5,9,10,11], k = 3\n\t\tOutput: true\n\t\tExplanation: Array can be divided into [1,2,3] , [2,3,4] , [3,4,5] and [9,10,11].\n\t\tExample 3:\n\t\tInput: nums = [1,2,3,4], k = 3\n\t\tOutput: false\n\t\tExplanation: Each array should be divided in subarrays of size 3.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1423, - "question": "class Solution:\n def maxFreq(self, s: str, maxLetters: int, minSize: int, maxSize: int) -> int:\n\t\t\"\"\"\n\t\tGiven a string s, return the maximum number of ocurrences of any substring under the following rules:\n\t\t\tThe number of unique characters in the substring must be less than or equal to maxLetters.\n\t\t\tThe substring size must be between minSize and maxSize inclusive.\n\t\tExample 1:\n\t\tInput: s = \"aababcaab\", maxLetters = 2, minSize = 3, maxSize = 4\n\t\tOutput: 2\n\t\tExplanation: Substring \"aab\" has 2 ocurrences in the original string.\n\t\tIt satisfies the conditions, 2 unique letters and size 3 (between minSize and maxSize).\n\t\tExample 2:\n\t\tInput: s = \"aaaa\", maxLetters = 1, minSize = 3, maxSize = 3\n\t\tOutput: 2\n\t\tExplanation: Substring \"aaa\" occur 2 times in the string. It can overlap.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1424, - "question": "class Solution:\n def maxCandies(self, status: List[int], candies: List[int], keys: List[List[int]], containedBoxes: List[List[int]], initialBoxes: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou have n boxes labeled from 0 to n - 1. You are given four arrays: status, candies, keys, and containedBoxes where:\n\t\t\tstatus[i] is 1 if the ith box is open and 0 if the ith box is closed,\n\t\t\tcandies[i] is the number of candies in the ith box,\n\t\t\tkeys[i] is a list of the labels of the boxes you can open after opening the ith box.\n\t\t\tcontainedBoxes[i] is a list of the boxes you found inside the ith box.\n\t\tYou are given an integer array initialBoxes that contains the labels of the boxes you initially have. You can take all the candies in any open box and you can use the keys in it to open new boxes and you also can use the boxes you find in it.\n\t\tReturn the maximum number of candies you can get following the rules above.\n\t\tExample 1:\n\t\tInput: status = [1,0,1,0], candies = [7,5,4,100], keys = [[],[],[1],[]], containedBoxes = [[1,2],[3],[],[]], initialBoxes = [0]\n\t\tOutput: 16\n\t\tExplanation: You will be initially given box 0. You will find 7 candies in it and boxes 1 and 2.\n\t\tBox 1 is closed and you do not have a key for it so you will open box 2. You will find 4 candies and a key to box 1 in box 2.\n\t\tIn box 1, you will find 5 candies and box 3 but you will not find a key to box 3 so box 3 will remain closed.\n\t\tTotal number of candies collected = 7 + 4 + 5 = 16 candy.\n\t\tExample 2:\n\t\tInput: status = [1,0,0,0,0,0], candies = [1,1,1,1,1,1], keys = [[1,2,3,4,5],[],[],[],[],[]], containedBoxes = [[1,2,3,4,5],[],[],[],[],[]], initialBoxes = [0]\n\t\tOutput: 6\n\t\tExplanation: You have initially box 0. Opening it you can find boxes 1,2,3,4 and 5 and their keys.\n\t\tThe total number of candies will be 6.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1426, - "question": "class Solution:\n def sumZero(self, n: int) -> List[int]:\n\t\t\"\"\"\n\t\tGiven an integer n, return any array containing n unique integers such that they add up to 0.\n\t\tExample 1:\n\t\tInput: n = 5\n\t\tOutput: [-7,-1,1,3,4]\n\t\tExplanation: These arrays also are accepted [-5,-1,1,2,3] , [-3,-1,2,-2,4].\n\t\tExample 2:\n\t\tInput: n = 3\n\t\tOutput: [-1,0,1]\n\t\tExample 3:\n\t\tInput: n = 1\n\t\tOutput: [0]\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1427, - "question": "class Solution:\n def getAllElements(self, root1: TreeNode, root2: TreeNode) -> List[int]:\n\t\t\"\"\"\n\t\tGiven two binary search trees root1 and root2, return a list containing all the integers from both trees sorted in ascending order.\n\t\tExample 1:\n\t\tInput: root1 = [2,1,4], root2 = [1,0,3]\n\t\tOutput: [0,1,1,2,3,4]\n\t\tExample 2:\n\t\tInput: root1 = [1,null,8], root2 = [8,1]\n\t\tOutput: [1,1,8,8]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1428, - "question": "class Solution:\n def canReach(self, arr: List[int], start: int) -> bool:\n\t\t\"\"\"\n\t\tGiven an array of non-negative integers arr, you are initially positioned at start index of the array. When you are at index i, you can jump to i + arr[i] or i - arr[i], check if you can reach to any index with value 0.\n\t\tNotice that you can not jump outside of the array at any time.\n\t\tExample 1:\n\t\tInput: arr = [4,2,3,0,3,1,2], start = 5\n\t\tOutput: true\n\t\tExplanation: \n\t\tAll possible ways to reach at index 3 with value 0 are: \n\t\tindex 5 -> index 4 -> index 1 -> index 3 \n\t\tindex 5 -> index 6 -> index 4 -> index 1 -> index 3 \n\t\tExample 2:\n\t\tInput: arr = [4,2,3,0,3,1,2], start = 0\n\t\tOutput: true \n\t\tExplanation: \n\t\tOne possible way to reach at index 3 with value 0 is: \n\t\tindex 0 -> index 4 -> index 1 -> index 3\n\t\tExample 3:\n\t\tInput: arr = [3,0,2,1,2], start = 2\n\t\tOutput: false\n\t\tExplanation: There is no way to reach at index 1 with value 0.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1429, - "question": "class Solution:\n def isSolvable(self, words: List[str], result: str) -> bool:\n\t\t\"\"\"\n\t\tGiven an equation, represented by words on the left side and the result on the right side.\n\t\tYou need to check if the equation is solvable under the following rules:\n\t\t\tEach character is decoded as one digit (0 - 9).\n\t\t\tNo two characters can map to the same digit.\n\t\t\tEach words[i] and result are decoded as one number without leading zeros.\n\t\t\tSum of numbers on the left side (words) will equal to the number on the right side (result).\n\t\tReturn true if the equation is solvable, otherwise return false.\n\t\tExample 1:\n\t\tInput: words = [\"SEND\",\"MORE\"], result = \"MONEY\"\n\t\tOutput: true\n\t\tExplanation: Map 'S'-> 9, 'E'->5, 'N'->6, 'D'->7, 'M'->1, 'O'->0, 'R'->8, 'Y'->'2'\n\t\tSuch that: \"SEND\" + \"MORE\" = \"MONEY\" , 9567 + 1085 = 10652\n\t\tExample 2:\n\t\tInput: words = [\"SIX\",\"SEVEN\",\"SEVEN\"], result = \"TWENTY\"\n\t\tOutput: true\n\t\tExplanation: Map 'S'-> 6, 'I'->5, 'X'->0, 'E'->8, 'V'->7, 'N'->2, 'T'->1, 'W'->'3', 'Y'->4\n\t\tSuch that: \"SIX\" + \"SEVEN\" + \"SEVEN\" = \"TWENTY\" , 650 + 68782 + 68782 = 138214\n\t\tExample 3:\n\t\tInput: words = [\"LEET\",\"CODE\"], result = \"POINT\"\n\t\tOutput: false\n\t\tExplanation: There is no possible mapping to satisfy the equation, so we return false.\n\t\tNote that two different characters cannot map to the same digit.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1430, - "question": "class Solution:\n def divisorSubstrings(self, num: int, k: int) -> int:\n\t\t\"\"\"\n\t\tThe k-beauty of an integer num is defined as the number of substrings of num when it is read as a string that meet the following conditions:\n\t\t\tIt has a length of k.\n\t\t\tIt is a divisor of num.\n\t\tGiven integers num and k, return the k-beauty of num.\n\t\tNote:\n\t\t\tLeading zeros are allowed.\n\t\t\t0 is not a divisor of any value.\n\t\tA substring is a contiguous sequence of characters in a string.\n\t\tExample 1:\n\t\tInput: num = 240, k = 2\n\t\tOutput: 2\n\t\tExplanation: The following are the substrings of num of length k:\n\t\t- \"24\" from \"240\": 24 is a divisor of 240.\n\t\t- \"40\" from \"240\": 40 is a divisor of 240.\n\t\tTherefore, the k-beauty is 2.\n\t\tExample 2:\n\t\tInput: num = 430043, k = 2\n\t\tOutput: 2\n\t\tExplanation: The following are the substrings of num of length k:\n\t\t- \"43\" from \"430043\": 43 is a divisor of 430043.\n\t\t- \"30\" from \"430043\": 30 is not a divisor of 430043.\n\t\t- \"00\" from \"430043\": 0 is not a divisor of 430043.\n\t\t- \"04\" from \"430043\": 4 is not a divisor of 430043.\n\t\t- \"43\" from \"430043\": 43 is a divisor of 430043.\n\t\tTherefore, the k-beauty is 2.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1431, - "question": "class Solution:\n def getAncestors(self, n: int, edges: List[List[int]]) -> List[List[int]]:\n\t\t\"\"\"\n\t\tYou are given a positive integer n representing the number of nodes of a Directed Acyclic Graph (DAG). The nodes are numbered from 0 to n - 1 (inclusive).\n\t\tYou are also given a 2D integer array edges, where edges[i] = [fromi, toi] denotes that there is a unidirectional edge from fromi to toi in the graph.\n\t\tReturn a list answer, where answer[i] is the list of ancestors of the ith node, sorted in ascending order.\n\t\tA node u is an ancestor of another node v if u can reach v via a set of edges.\n\t\tExample 1:\n\t\tInput: n = 8, edgeList = [[0,3],[0,4],[1,3],[2,4],[2,7],[3,5],[3,6],[3,7],[4,6]]\n\t\tOutput: [[],[],[],[0,1],[0,2],[0,1,3],[0,1,2,3,4],[0,1,2,3]]\n\t\tExplanation:\n\t\tThe above diagram represents the input graph.\n\t\t- Nodes 0, 1, and 2 do not have any ancestors.\n\t\t- Node 3 has two ancestors 0 and 1.\n\t\t- Node 4 has two ancestors 0 and 2.\n\t\t- Node 5 has three ancestors 0, 1, and 3.\n\t\t- Node 6 has five ancestors 0, 1, 2, 3, and 4.\n\t\t- Node 7 has four ancestors 0, 1, 2, and 3.\n\t\tExample 2:\n\t\tInput: n = 5, edgeList = [[0,1],[0,2],[0,3],[0,4],[1,2],[1,3],[1,4],[2,3],[2,4],[3,4]]\n\t\tOutput: [[],[0],[0,1],[0,1,2],[0,1,2,3]]\n\t\tExplanation:\n\t\tThe above diagram represents the input graph.\n\t\t- Node 0 does not have any ancestor.\n\t\t- Node 1 has one ancestor 0.\n\t\t- Node 2 has two ancestors 0 and 1.\n\t\t- Node 3 has three ancestors 0, 1, and 2.\n\t\t- Node 4 has four ancestors 0, 1, 2, and 3.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1433, - "question": "class Encrypter:\n def __init__(self, keys: List[str], values: List[str], dictionary: List[str]):\n def encrypt(self, word1: str) -> str:\n def decrypt(self, word2: str) -> int:\n\t\t\"\"\"\n\t\tYou are given a character array keys containing unique characters and a string array values containing strings of length 2. You are also given another string array dictionary that contains all permitted original strings after decryption. You should implement a data structure that can encrypt or decrypt a 0-indexed string.\n\t\tA string is encrypted with the following process:\n\t\t\tFor each character c in the string, we find the index i satisfying keys[i] == c in keys.\n\t\t\tReplace c with values[i] in the string.\n\t\tNote that in case a character of the string is not present in keys, the encryption process cannot be carried out, and an empty string \"\" is returned.\n\t\tA string is decrypted with the following process:\n\t\t\tFor each substring s of length 2 occurring at an even index in the string, we find an i such that values[i] == s. If there are multiple valid i, we choose any one of them. This means a string could have multiple possible strings it can decrypt to.\n\t\t\tReplace s with keys[i] in the string.\n\t\tImplement the Encrypter class:\n\t\t\tEncrypter(char[] keys, String[] values, String[] dictionary) Initializes the Encrypter class with keys, values, and dictionary.\n\t\t\tString encrypt(String word1) Encrypts word1 with the encryption process described above and returns the encrypted string.\n\t\t\tint decrypt(String word2) Returns the number of possible strings word2 could decrypt to that also appear in dictionary.\n\t\tExample 1:\n\t\tInput\n\t\t[\"Encrypter\", \"encrypt\", \"decrypt\"]\n\t\t[[['a', 'b', 'c', 'd'], [\"ei\", \"zf\", \"ei\", \"am\"], [\"abcd\", \"acbd\", \"adbc\", \"badc\", \"dacb\", \"cadb\", \"cbda\", \"abad\"]], [\"abcd\"], [\"eizfeiam\"]]\n\t\tOutput\n\t\t[null, \"eizfeiam\", 2]\n\t\tExplanation\n\t\tEncrypter encrypter = new Encrypter([['a', 'b', 'c', 'd'], [\"ei\", \"zf\", \"ei\", \"am\"], [\"abcd\", \"acbd\", \"adbc\", \"badc\", \"dacb\", \"cadb\", \"cbda\", \"abad\"]);\n\t\tencrypter.encrypt(\"abcd\"); // return \"eizfeiam\". \n\t\t // 'a' maps to \"ei\", 'b' maps to \"zf\", 'c' maps to \"ei\", and 'd' maps to \"am\".\n\t\tencrypter.decrypt(\"eizfeiam\"); // return 2. \n\t\t // \"ei\" can map to 'a' or 'c', \"zf\" maps to 'b', and \"am\" maps to 'd'. \n\t\t // Thus, the possible strings after decryption are \"abad\", \"cbad\", \"abcd\", and \"cbcd\". \n\t\t // 2 of those strings, \"abad\" and \"abcd\", appear in dictionary, so the answer is 2.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1434, - "question": "class Solution:\n def freqAlphabets(self, s: str) -> str:\n\t\t\"\"\"\n\t\tYou are given a string s formed by digits and '#'. We want to map s to English lowercase characters as follows:\n\t\t\tCharacters ('a' to 'i') are represented by ('1' to '9') respectively.\n\t\t\tCharacters ('j' to 'z') are represented by ('10#' to '26#') respectively.\n\t\tReturn the string formed after mapping.\n\t\tThe test cases are generated so that a unique mapping will always exist.\n\t\tExample 1:\n\t\tInput: s = \"10#11#12\"\n\t\tOutput: \"jkab\"\n\t\tExplanation: \"j\" -> \"10#\" , \"k\" -> \"11#\" , \"a\" -> \"1\" , \"b\" -> \"2\".\n\t\tExample 2:\n\t\tInput: s = \"1326#\"\n\t\tOutput: \"acz\"\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1435, - "question": "class Solution:\n def xorQueries(self, arr: List[int], queries: List[List[int]]) -> List[int]:\n\t\t\"\"\"\n\t\tYou are given an array arr of positive integers. You are also given the array queries where queries[i] = [lefti, righti].\n\t\tFor each query i compute the XOR of elements from lefti to righti (that is, arr[lefti] XOR arr[lefti + 1] XOR ... XOR arr[righti] ).\n\t\tReturn an array answer where answer[i] is the answer to the ith query.\n\t\tExample 1:\n\t\tInput: arr = [1,3,4,8], queries = [[0,1],[1,2],[0,3],[3,3]]\n\t\tOutput: [2,7,14,8] \n\t\tExplanation: \n\t\tThe binary representation of the elements in the array are:\n\t\t1 = 0001 \n\t\t3 = 0011 \n\t\t4 = 0100 \n\t\t8 = 1000 \n\t\tThe XOR values for queries are:\n\t\t[0,1] = 1 xor 3 = 2 \n\t\t[1,2] = 3 xor 4 = 7 \n\t\t[0,3] = 1 xor 3 xor 4 xor 8 = 14 \n\t\t[3,3] = 8\n\t\tExample 2:\n\t\tInput: arr = [4,8,2,10], queries = [[2,3],[1,3],[0,0],[0,3]]\n\t\tOutput: [8,0,4,4]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1436, - "question": "class Solution:\n def watchedVideosByFriends(self, watchedVideos: List[List[str]], friends: List[List[int]], id: int, level: int) -> List[str]:\n\t\t\"\"\"\n\t\tThere are n people, each person has a unique id between 0 and n-1. Given the arrays watchedVideos and friends, where watchedVideos[i] and friends[i] contain the list of watched videos and the list of friends respectively for the person with id = i.\n\t\tLevel 1 of videos are all watched videos by your friends, level 2 of videos are all watched videos by the friends of your friends and so on. In general, the level k of videos are all watched videos by people with the shortest path exactly equal to k with you. Given your id and the level of videos, return the list of videos ordered by their frequencies (increasing). For videos with the same frequency order them alphabetically from least to greatest. \n\t\tExample 1:\n\t\tInput: watchedVideos = [[\"A\",\"B\"],[\"C\"],[\"B\",\"C\"],[\"D\"]], friends = [[1,2],[0,3],[0,3],[1,2]], id = 0, level = 1\n\t\tOutput: [\"B\",\"C\"] \n\t\tExplanation: \n\t\tYou have id = 0 (green color in the figure) and your friends are (yellow color in the figure):\n\t\tPerson with id = 1 -> watchedVideos = [\"C\"] \n\t\tPerson with id = 2 -> watchedVideos = [\"B\",\"C\"] \n\t\tThe frequencies of watchedVideos by your friends are: \n\t\tB -> 1 \n\t\tC -> 2\n\t\tExample 2:\n\t\tInput: watchedVideos = [[\"A\",\"B\"],[\"C\"],[\"B\",\"C\"],[\"D\"]], friends = [[1,2],[0,3],[0,3],[1,2]], id = 0, level = 2\n\t\tOutput: [\"D\"]\n\t\tExplanation: \n\t\tYou have id = 0 (green color in the figure) and the only friend of your friends is the person with id = 3 (yellow color in the figure).\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1437, - "question": "class Solution:\n def minInsertions(self, s: str) -> int:\n\t\t\"\"\"\n\t\tGiven a string s. In one step you can insert any character at any index of the string.\n\t\tReturn the minimum number of steps to make s palindrome.\n\t\tA Palindrome String is one that reads the same backward as well as forward.\n\t\tExample 1:\n\t\tInput: s = \"zzazz\"\n\t\tOutput: 0\n\t\tExplanation: The string \"zzazz\" is already palindrome we do not need any insertions.\n\t\tExample 2:\n\t\tInput: s = \"mbadm\"\n\t\tOutput: 2\n\t\tExplanation: String can be \"mbdadbm\" or \"mdbabdm\".\n\t\tExample 3:\n\t\tInput: s = \"leetcode\"\n\t\tOutput: 5\n\t\tExplanation: Inserting 5 characters the string becomes \"leetcodocteel\".\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1440, - "question": "class Solution:\n def getNoZeroIntegers(self, n: int) -> List[int]:\n\t\t\"\"\"\n\t\tNo-Zero integer is a positive integer that does not contain any 0 in its decimal representation.\n\t\tGiven an integer n, return a list of two integers [a, b] where:\n\t\t\ta and b are No-Zero integers.\n\t\t\ta + b = n\n\t\tThe test cases are generated so that there is at least one valid solution. If there are many valid solutions, you can return any of them.\n\t\tExample 1:\n\t\tInput: n = 2\n\t\tOutput: [1,1]\n\t\tExplanation: Let a = 1 and b = 1.\n\t\tBoth a and b are no-zero integers, and a + b = 2 = n.\n\t\tExample 2:\n\t\tInput: n = 11\n\t\tOutput: [2,9]\n\t\tExplanation: Let a = 2 and b = 9.\n\t\tBoth a and b are no-zero integers, and a + b = 9 = n.\n\t\tNote that there are other valid answers as [8, 3] that can be accepted.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1441, - "question": "class Solution:\n def minFlips(self, a: int, b: int, c: int) -> int:\n\t\t\"\"\"\n\t\tGiven 3 positives numbers a, b and c. Return the minimum flips required in some bits of a and b to make ( a OR b == c ). (bitwise OR operation).\r\n\t\tFlip operation consists of change any single bit 1 to 0 or change the bit 0 to 1 in their binary representation.\r\n\t\tExample 1:\r\n\t\tInput: a = 2, b = 6, c = 5\r\n\t\tOutput: 3\r\n\t\tExplanation: After flips a = 1 , b = 4 , c = 5 such that (a OR b == c)\r\n\t\tExample 2:\r\n\t\tInput: a = 4, b = 2, c = 7\r\n\t\tOutput: 1\r\n\t\tExample 3:\r\n\t\tInput: a = 1, b = 2, c = 3\r\n\t\tOutput: 0\r\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1442, - "question": "class Solution:\n def makeConnected(self, n: int, connections: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tThere are n computers numbered from 0 to n - 1 connected by ethernet cables connections forming a network where connections[i] = [ai, bi] represents a connection between computers ai and bi. Any computer can reach any other computer directly or indirectly through the network.\n\t\tYou are given an initial computer network connections. You can extract certain cables between two directly connected computers, and place them between any pair of disconnected computers to make them directly connected.\n\t\tReturn the minimum number of times you need to do this in order to make all the computers connected. If it is not possible, return -1.\n\t\tExample 1:\n\t\tInput: n = 4, connections = [[0,1],[0,2],[1,2]]\n\t\tOutput: 1\n\t\tExplanation: Remove cable between computer 1 and 2 and place between computers 1 and 3.\n\t\tExample 2:\n\t\tInput: n = 6, connections = [[0,1],[0,2],[0,3],[1,2],[1,3]]\n\t\tOutput: 2\n\t\tExample 3:\n\t\tInput: n = 6, connections = [[0,1],[0,2],[0,3],[1,2]]\n\t\tOutput: -1\n\t\tExplanation: There are not enough cables.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1443, - "question": "class Solution:\n def minimumDistance(self, word: str) -> int:\n\t\t\"\"\"\n\t\tYou have a keyboard layout as shown above in the X-Y plane, where each English uppercase letter is located at some coordinate.\n\t\t\tFor example, the letter 'A' is located at coordinate (0, 0), the letter 'B' is located at coordinate (0, 1), the letter 'P' is located at coordinate (2, 3) and the letter 'Z' is located at coordinate (4, 1).\n\t\tGiven the string word, return the minimum total distance to type such string using only two fingers.\n\t\tThe distance between coordinates (x1, y1) and (x2, y2) is |x1 - x2| + |y1 - y2|.\n\t\tNote that the initial positions of your two fingers are considered free so do not count towards your total distance, also your two fingers do not have to start at the first letter or the first two letters.\n\t\tExample 1:\n\t\tInput: word = \"CAKE\"\n\t\tOutput: 3\n\t\tExplanation: Using two fingers, one optimal way to type \"CAKE\" is: \n\t\tFinger 1 on letter 'C' -> cost = 0 \n\t\tFinger 1 on letter 'A' -> cost = Distance from letter 'C' to letter 'A' = 2 \n\t\tFinger 2 on letter 'K' -> cost = 0 \n\t\tFinger 2 on letter 'E' -> cost = Distance from letter 'K' to letter 'E' = 1 \n\t\tTotal distance = 3\n\t\tExample 2:\n\t\tInput: word = \"HAPPY\"\n\t\tOutput: 6\n\t\tExplanation: Using two fingers, one optimal way to type \"HAPPY\" is:\n\t\tFinger 1 on letter 'H' -> cost = 0\n\t\tFinger 1 on letter 'A' -> cost = Distance from letter 'H' to letter 'A' = 2\n\t\tFinger 2 on letter 'P' -> cost = 0\n\t\tFinger 2 on letter 'P' -> cost = Distance from letter 'P' to letter 'P' = 0\n\t\tFinger 1 on letter 'Y' -> cost = Distance from letter 'A' to letter 'Y' = 4\n\t\tTotal distance = 6\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1444, - "question": "class Solution:\n def numberOfSteps(self, num: int) -> int:\n\t\t\"\"\"\n\t\tGiven an integer num, return the number of steps to reduce it to zero.\n\t\tIn one step, if the current number is even, you have to divide it by 2, otherwise, you have to subtract 1 from it.\n\t\tExample 1:\n\t\tInput: num = 14\n\t\tOutput: 6\n\t\tExplanation: \n\t\tStep 1) 14 is even; divide by 2 and obtain 7. \n\t\tStep 2) 7 is odd; subtract 1 and obtain 6.\n\t\tStep 3) 6 is even; divide by 2 and obtain 3. \n\t\tStep 4) 3 is odd; subtract 1 and obtain 2. \n\t\tStep 5) 2 is even; divide by 2 and obtain 1. \n\t\tStep 6) 1 is odd; subtract 1 and obtain 0.\n\t\tExample 2:\n\t\tInput: num = 8\n\t\tOutput: 4\n\t\tExplanation: \n\t\tStep 1) 8 is even; divide by 2 and obtain 4. \n\t\tStep 2) 4 is even; divide by 2 and obtain 2. \n\t\tStep 3) 2 is even; divide by 2 and obtain 1. \n\t\tStep 4) 1 is odd; subtract 1 and obtain 0.\n\t\tExample 3:\n\t\tInput: num = 123\n\t\tOutput: 12\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1445, - "question": "class Solution:\n def numOfSubarrays(self, arr: List[int], k: int, threshold: int) -> int:\n\t\t\"\"\"\n\t\tGiven an array of integers arr and two integers k and threshold, return the number of sub-arrays of size k and average greater than or equal to threshold.\n\t\tExample 1:\n\t\tInput: arr = [2,2,2,2,5,5,5,8], k = 3, threshold = 4\n\t\tOutput: 3\n\t\tExplanation: Sub-arrays [2,5,5],[5,5,5] and [5,5,8] have averages 4, 5 and 6 respectively. All other sub-arrays of size 3 have averages less than 4 (the threshold).\n\t\tExample 2:\n\t\tInput: arr = [11,13,17,23,29,31,7,5,2,3], k = 3, threshold = 5\n\t\tOutput: 6\n\t\tExplanation: The first 6 sub-arrays of size 3 have averages greater than 5. Note that averages are not integers.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1446, - "question": "class Solution:\n def angleClock(self, hour: int, minutes: int) -> float:\n\t\t\"\"\"\n\t\tGiven two numbers, hour and minutes, return the smaller angle (in degrees) formed between the hour and the minute hand.\n\t\tAnswers within 10-5 of the actual value will be accepted as correct.\n\t\tExample 1:\n\t\tInput: hour = 12, minutes = 30\n\t\tOutput: 165\n\t\tExample 2:\n\t\tInput: hour = 3, minutes = 30\n\t\tOutput: 75\n\t\tExample 3:\n\t\tInput: hour = 3, minutes = 15\n\t\tOutput: 7.5\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1447, - "question": "class Solution:\n def minJumps(self, arr: List[int]) -> int:\n\t\t\"\"\"\n\t\tGiven an array of integers arr, you are initially positioned at the first index of the array.\n\t\tIn one step you can jump from index i to index:\n\t\t\ti + 1 where: i + 1 < arr.length.\n\t\t\ti - 1 where: i - 1 >= 0.\n\t\t\tj where: arr[i] == arr[j] and i != j.\n\t\tReturn the minimum number of steps to reach the last index of the array.\n\t\tNotice that you can not jump outside of the array at any time.\n\t\tExample 1:\n\t\tInput: arr = [100,-23,-23,404,100,23,23,23,3,404]\n\t\tOutput: 3\n\t\tExplanation: You need three jumps from index 0 --> 4 --> 3 --> 9. Note that index 9 is the last index of the array.\n\t\tExample 2:\n\t\tInput: arr = [7]\n\t\tOutput: 0\n\t\tExplanation: Start index is the last index. You do not need to jump.\n\t\tExample 3:\n\t\tInput: arr = [7,6,9,6,9,6,9,7]\n\t\tOutput: 1\n\t\tExplanation: You can jump directly from index 0 to index 7 which is last index of the array.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1448, - "question": "class Solution:\n def maximum69Number (self, num: int) -> int:\n\t\t\"\"\"\n\t\tYou are given a positive integer num consisting only of digits 6 and 9.\n\t\tReturn the maximum number you can get by changing at most one digit (6 becomes 9, and 9 becomes 6).\n\t\tExample 1:\n\t\tInput: num = 9669\n\t\tOutput: 9969\n\t\tExplanation: \n\t\tChanging the first digit results in 6669.\n\t\tChanging the second digit results in 9969.\n\t\tChanging the third digit results in 9699.\n\t\tChanging the fourth digit results in 9666.\n\t\tThe maximum number is 9969.\n\t\tExample 2:\n\t\tInput: num = 9996\n\t\tOutput: 9999\n\t\tExplanation: Changing the last digit 6 to 9 results in the maximum number.\n\t\tExample 3:\n\t\tInput: num = 9999\n\t\tOutput: 9999\n\t\tExplanation: It is better not to apply any change.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1449, - "question": "class Solution:\n def printVertically(self, s: str) -> List[str]:\n\t\t\"\"\"\n\t\tGiven a string s. Return all the words vertically in the same order in which they appear in s.\r\n\t\tWords are returned as a list of strings, complete with spaces when is necessary. (Trailing spaces are not allowed).\r\n\t\tEach word would be put on only one column and that in one column there will be only one word.\r\n\t\tExample 1:\r\n\t\tInput: s = \"HOW ARE YOU\"\r\n\t\tOutput: [\"HAY\",\"ORO\",\"WEU\"]\r\n\t\tExplanation: Each word is printed vertically. \r\n\t\t \"HAY\"\r\n\t\t \"ORO\"\r\n\t\t \"WEU\"\r\n\t\tExample 2:\r\n\t\tInput: s = \"TO BE OR NOT TO BE\"\r\n\t\tOutput: [\"TBONTB\",\"OEROOE\",\" T\"]\r\n\t\tExplanation: Trailing spaces is not allowed. \r\n\t\t\"TBONTB\"\r\n\t\t\"OEROOE\"\r\n\t\t\" T\"\r\n\t\tExample 3:\r\n\t\tInput: s = \"CONTEST IS COMING\"\r\n\t\tOutput: [\"CIC\",\"OSO\",\"N M\",\"T I\",\"E N\",\"S G\",\"T\"]\r\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1450, - "question": "class Solution:\n def removeLeafNodes(self, root: Optional[TreeNode], target: int) -> Optional[TreeNode]:\n\t\t\"\"\"\n\t\tGiven a binary tree root and an integer target, delete all the leaf nodes with value target.\n\t\tNote that once you delete a leaf node with value target, if its parent node becomes a leaf node and has the value target, it should also be deleted (you need to continue doing that until you cannot).\n\t\tExample 1:\n\t\tInput: root = [1,2,3,2,null,2,4], target = 2\n\t\tOutput: [1,null,3,null,4]\n\t\tExplanation: Leaf nodes in green with value (target = 2) are removed (Picture in left). \n\t\tAfter removing, new nodes become leaf nodes with value (target = 2) (Picture in center).\n\t\tExample 2:\n\t\tInput: root = [1,3,3,3,2], target = 3\n\t\tOutput: [1,3,null,null,2]\n\t\tExample 3:\n\t\tInput: root = [1,2,null,2,null,2], target = 2\n\t\tOutput: [1]\n\t\tExplanation: Leaf nodes in green with value (target = 2) are removed at each step.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1451, - "question": "class Solution:\n def minTaps(self, n: int, ranges: List[int]) -> int:\n\t\t\"\"\"\n\t\tThere is a one-dimensional garden on the x-axis. The garden starts at the point 0 and ends at the point n. (i.e The length of the garden is n).\n\t\tThere are n + 1 taps located at points [0, 1, ..., n] in the garden.\n\t\tGiven an integer n and an integer array ranges of length n + 1 where ranges[i] (0-indexed) means the i-th tap can water the area [i - ranges[i], i + ranges[i]] if it was open.\n\t\tReturn the minimum number of taps that should be open to water the whole garden, If the garden cannot be watered return -1.\n\t\tExample 1:\n\t\tInput: n = 5, ranges = [3,4,1,1,0,0]\n\t\tOutput: 1\n\t\tExplanation: The tap at point 0 can cover the interval [-3,3]\n\t\tThe tap at point 1 can cover the interval [-3,5]\n\t\tThe tap at point 2 can cover the interval [1,3]\n\t\tThe tap at point 3 can cover the interval [2,4]\n\t\tThe tap at point 4 can cover the interval [4,4]\n\t\tThe tap at point 5 can cover the interval [5,5]\n\t\tOpening Only the second tap will water the whole garden [0,5]\n\t\tExample 2:\n\t\tInput: n = 3, ranges = [0,0,0,0]\n\t\tOutput: -1\n\t\tExplanation: Even if you activate all the four taps you cannot water the whole garden.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1454, - "question": "class Solution:\n def removePalindromeSub(self, s: str) -> int:\n\t\t\"\"\"\n\t\tYou are given a string s consisting only of letters 'a' and 'b'. In a single step you can remove one palindromic subsequence from s.\n\t\tReturn the minimum number of steps to make the given string empty.\n\t\tA string is a subsequence of a given string if it is generated by deleting some characters of a given string without changing its order. Note that a subsequence does not necessarily need to be contiguous.\n\t\tA string is called palindrome if is one that reads the same backward as well as forward.\n\t\tExample 1:\n\t\tInput: s = \"ababa\"\n\t\tOutput: 1\n\t\tExplanation: s is already a palindrome, so its entirety can be removed in a single step.\n\t\tExample 2:\n\t\tInput: s = \"abb\"\n\t\tOutput: 2\n\t\tExplanation: \"abb\" -> \"bb\" -> \"\". \n\t\tRemove palindromic subsequence \"a\" then \"bb\".\n\t\tExample 3:\n\t\tInput: s = \"baabb\"\n\t\tOutput: 2\n\t\tExplanation: \"baabb\" -> \"b\" -> \"\". \n\t\tRemove palindromic subsequence \"baab\" then \"b\".\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1455, - "question": "class Solution:\n def filterRestaurants(self, restaurants: List[List[int]], veganFriendly: int, maxPrice: int, maxDistance: int) -> List[int]:\n\t\t\"\"\"\n\t\tGiven the array restaurants where restaurants[i] = [idi, ratingi, veganFriendlyi, pricei, distancei]. You have to filter the restaurants using three filters.\n\t\tThe veganFriendly filter will be either true (meaning you should only include restaurants with veganFriendlyi set to true) or false (meaning you can include any restaurant). In addition, you have the filters maxPrice and maxDistance which are the maximum value for price and distance of restaurants you should consider respectively.\n\t\tReturn the array of restaurant IDs after filtering, ordered by rating from highest to lowest. For restaurants with the same rating, order them by id from highest to lowest. For simplicity veganFriendlyi and veganFriendly take value 1 when it is true, and 0 when it is false.\n\t\tExample 1:\n\t\tInput: restaurants = [[1,4,1,40,10],[2,8,0,50,5],[3,8,1,30,4],[4,10,0,10,3],[5,1,1,15,1]], veganFriendly = 1, maxPrice = 50, maxDistance = 10\n\t\tOutput: [3,1,5] \n\t\tExplanation: \n\t\tThe restaurants are:\n\t\tRestaurant 1 [id=1, rating=4, veganFriendly=1, price=40, distance=10]\n\t\tRestaurant 2 [id=2, rating=8, veganFriendly=0, price=50, distance=5]\n\t\tRestaurant 3 [id=3, rating=8, veganFriendly=1, price=30, distance=4]\n\t\tRestaurant 4 [id=4, rating=10, veganFriendly=0, price=10, distance=3]\n\t\tRestaurant 5 [id=5, rating=1, veganFriendly=1, price=15, distance=1] \n\t\tAfter filter restaurants with veganFriendly = 1, maxPrice = 50 and maxDistance = 10 we have restaurant 3, restaurant 1 and restaurant 5 (ordered by rating from highest to lowest). \n\t\tExample 2:\n\t\tInput: restaurants = [[1,4,1,40,10],[2,8,0,50,5],[3,8,1,30,4],[4,10,0,10,3],[5,1,1,15,1]], veganFriendly = 0, maxPrice = 50, maxDistance = 10\n\t\tOutput: [4,3,2,1,5]\n\t\tExplanation: The restaurants are the same as in example 1, but in this case the filter veganFriendly = 0, therefore all restaurants are considered.\n\t\tExample 3:\n\t\tInput: restaurants = [[1,4,1,40,10],[2,8,0,50,5],[3,8,1,30,4],[4,10,0,10,3],[5,1,1,15,1]], veganFriendly = 0, maxPrice = 30, maxDistance = 3\n\t\tOutput: [4,5]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1456, - "question": "class Solution:\n def findTheCity(self, n: int, edges: List[List[int]], distanceThreshold: int) -> int:\n\t\t\"\"\"\n\t\tThere are n cities numbered from 0 to n-1. Given the array edges where edges[i] = [fromi, toi, weighti] represents a bidirectional and weighted edge between cities fromi and toi, and given the integer distanceThreshold.\n\t\tReturn the city with the smallest number of cities that are reachable through some path and whose distance is at most distanceThreshold, If there are multiple such cities, return the city with the greatest number.\n\t\tNotice that the distance of a path connecting cities i and j is equal to the sum of the edges' weights along that path.\n\t\tExample 1:\n\t\tInput: n = 4, edges = [[0,1,3],[1,2,1],[1,3,4],[2,3,1]], distanceThreshold = 4\n\t\tOutput: 3\n\t\tExplanation: The figure above describes the graph. \n\t\tThe neighboring cities at a distanceThreshold = 4 for each city are:\n\t\tCity 0 -> [City 1, City 2] \n\t\tCity 1 -> [City 0, City 2, City 3] \n\t\tCity 2 -> [City 0, City 1, City 3] \n\t\tCity 3 -> [City 1, City 2] \n\t\tCities 0 and 3 have 2 neighboring cities at a distanceThreshold = 4, but we have to return city 3 since it has the greatest number.\n\t\tExample 2:\n\t\tInput: n = 5, edges = [[0,1,2],[0,4,8],[1,2,3],[1,4,2],[2,3,1],[3,4,1]], distanceThreshold = 2\n\t\tOutput: 0\n\t\tExplanation: The figure above describes the graph. \n\t\tThe neighboring cities at a distanceThreshold = 2 for each city are:\n\t\tCity 0 -> [City 1] \n\t\tCity 1 -> [City 0, City 4] \n\t\tCity 2 -> [City 3, City 4] \n\t\tCity 3 -> [City 2, City 4]\n\t\tCity 4 -> [City 1, City 2, City 3] \n\t\tThe city 0 has 1 neighboring city at a distanceThreshold = 2.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1457, - "question": "class Solution:\n def minDifficulty(self, jobDifficulty: List[int], d: int) -> int:\n\t\t\"\"\"\n\t\tYou want to schedule a list of jobs in d days. Jobs are dependent (i.e To work on the ith job, you have to finish all the jobs j where 0 <= j < i).\n\t\tYou have to finish at least one task every day. The difficulty of a job schedule is the sum of difficulties of each day of the d days. The difficulty of a day is the maximum difficulty of a job done on that day.\n\t\tYou are given an integer array jobDifficulty and an integer d. The difficulty of the ith job is jobDifficulty[i].\n\t\tReturn the minimum difficulty of a job schedule. If you cannot find a schedule for the jobs return -1.\n\t\tExample 1:\n\t\tInput: jobDifficulty = [6,5,4,3,2,1], d = 2\n\t\tOutput: 7\n\t\tExplanation: First day you can finish the first 5 jobs, total difficulty = 6.\n\t\tSecond day you can finish the last job, total difficulty = 1.\n\t\tThe difficulty of the schedule = 6 + 1 = 7 \n\t\tExample 2:\n\t\tInput: jobDifficulty = [9,9,9], d = 4\n\t\tOutput: -1\n\t\tExplanation: If you finish a job per day you will still have a free day. you cannot find a schedule for the given jobs.\n\t\tExample 3:\n\t\tInput: jobDifficulty = [1,1,1], d = 3\n\t\tOutput: 3\n\t\tExplanation: The schedule is one job per day. total difficulty will be 3.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1458, - "question": "class Solution:\n def sortByBits(self, arr: List[int]) -> List[int]:\n\t\t\"\"\"\n\t\tYou are given an integer array arr. Sort the integers in the array in ascending order by the number of 1's in their binary representation and in case of two or more integers have the same number of 1's you have to sort them in ascending order.\n\t\tReturn the array after sorting it.\n\t\tExample 1:\n\t\tInput: arr = [0,1,2,3,4,5,6,7,8]\n\t\tOutput: [0,1,2,4,8,3,5,6,7]\n\t\tExplantion: [0] is the only integer with 0 bits.\n\t\t[1,2,4,8] all have 1 bit.\n\t\t[3,5,6] have 2 bits.\n\t\t[7] has 3 bits.\n\t\tThe sorted array by bits is [0,1,2,4,8,3,5,6,7]\n\t\tExample 2:\n\t\tInput: arr = [1024,512,256,128,64,32,16,8,4,2,1]\n\t\tOutput: [1,2,4,8,16,32,64,128,256,512,1024]\n\t\tExplantion: All integers have 1 bit in the binary representation, you should just sort them in ascending order.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1459, - "question": "class Cashier:\n def __init__(self, n: int, discount: int, products: List[int], prices: List[int]):\n def getBill(self, product: List[int], amount: List[int]) -> float:\n\t\t\"\"\"\n\t\tThere is a supermarket that is frequented by many customers. The products sold at the supermarket are represented as two parallel integer arrays products and prices, where the ith product has an ID of products[i] and a price of prices[i].\n\t\tWhen a customer is paying, their bill is represented as two parallel integer arrays product and amount, where the jth product they purchased has an ID of product[j], and amount[j] is how much of the product they bought. Their subtotal is calculated as the sum of each amount[j] * (price of the jth product).\n\t\tThe supermarket decided to have a sale. Every nth customer paying for their groceries will be given a percentage discount. The discount amount is given by discount, where they will be given discount percent off their subtotal. More formally, if their subtotal is bill, then they would actually pay bill * ((100 - discount) / 100).\n\t\tImplement the Cashier class:\n\t\t\tCashier(int n, int discount, int[] products, int[] prices) Initializes the object with n, the discount, and the products and their prices.\n\t\t\tdouble getBill(int[] product, int[] amount) Returns the final total of the bill with the discount applied (if any). Answers within 10-5 of the actual value will be accepted.\n\t\tExample 1:\n\t\tInput\n\t\t[\"Cashier\",\"getBill\",\"getBill\",\"getBill\",\"getBill\",\"getBill\",\"getBill\",\"getBill\"]\n\t\t[[3,50,[1,2,3,4,5,6,7],[100,200,300,400,300,200,100]],[[1,2],[1,2]],[[3,7],[10,10]],[[1,2,3,4,5,6,7],[1,1,1,1,1,1,1]],[[4],[10]],[[7,3],[10,10]],[[7,5,3,1,6,4,2],[10,10,10,9,9,9,7]],[[2,3,5],[5,3,2]]]\n\t\tOutput\n\t\t[null,500.0,4000.0,800.0,4000.0,4000.0,7350.0,2500.0]\n\t\tExplanation\n\t\tCashier cashier = new Cashier(3,50,[1,2,3,4,5,6,7],[100,200,300,400,300,200,100]);\n\t\tcashier.getBill([1,2],[1,2]); // return 500.0. 1st customer, no discount.\n\t\t // bill = 1 * 100 + 2 * 200 = 500.\n\t\tcashier.getBill([3,7],[10,10]); // return 4000.0. 2nd customer, no discount.\n\t\t // bill = 10 * 300 + 10 * 100 = 4000.\n\t\tcashier.getBill([1,2,3,4,5,6,7],[1,1,1,1,1,1,1]); // return 800.0. 3rd customer, 50% discount.\n\t\t // Original bill = 1600\n\t\t // Actual bill = 1600 * ((100 - 50) / 100) = 800.\n\t\tcashier.getBill([4],[10]); // return 4000.0. 4th customer, no discount.\n\t\tcashier.getBill([7,3],[10,10]); // return 4000.0. 5th customer, no discount.\n\t\tcashier.getBill([7,5,3,1,6,4,2],[10,10,10,9,9,9,7]); // return 7350.0. 6th customer, 50% discount.\n\t\t // Original bill = 14700, but with\n\t\t // Actual bill = 14700 * ((100 - 50) / 100) = 7350.\n\t\tcashier.getBill([2,3,5],[5,3,2]); // return 2500.0. 6th customer, no discount.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1460, - "question": "class Solution:\n def numberOfSubstrings(self, s: str) -> int:\n\t\t\"\"\"\n\t\tGiven a string s consisting only of characters a, b and c.\n\t\tReturn the number of substrings containing at least one occurrence of all these characters a, b and c.\n\t\tExample 1:\n\t\tInput: s = \"abcabc\"\n\t\tOutput: 10\n\t\tExplanation: The substrings containing at least one occurrence of the characters a, b and c are \"abc\", \"abca\", \"abcab\", \"abcabc\", \"bca\", \"bcab\", \"bcabc\", \"cab\", \"cabc\" and \"abc\" (again). \n\t\tExample 2:\n\t\tInput: s = \"aaacb\"\n\t\tOutput: 3\n\t\tExplanation: The substrings containing at least one occurrence of the characters a, b and c are \"aaacb\", \"aacb\" and \"acb\". \n\t\tExample 3:\n\t\tInput: s = \"abc\"\n\t\tOutput: 1\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1461, - "question": "class Solution:\n def countOrders(self, n: int) -> int:\n\t\t\"\"\"\n\t\tGiven n orders, each order consist in pickup and delivery services. \n\t\tCount all valid pickup/delivery possible sequences such that delivery(i) is always after of pickup(i). \n\t\tSince the answer may be too large, return it modulo 10^9 + 7.\n\t\tExample 1:\n\t\tInput: n = 1\n\t\tOutput: 1\n\t\tExplanation: Unique order (P1, D1), Delivery 1 always is after of Pickup 1.\n\t\tExample 2:\n\t\tInput: n = 2\n\t\tOutput: 6\n\t\tExplanation: All possible orders: \n\t\t(P1,P2,D1,D2), (P1,P2,D2,D1), (P1,D1,P2,D2), (P2,P1,D1,D2), (P2,P1,D2,D1) and (P2,D2,P1,D1).\n\t\tThis is an invalid order (P1,D2,P2,D1) because Pickup 2 is after of Delivery 2.\n\t\tExample 3:\n\t\tInput: n = 3\n\t\tOutput: 90\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1463, - "question": "class Solution:\n def kWeakestRows(self, mat: List[List[int]], k: int) -> List[int]:\n\t\t\"\"\"\n\t\tYou are given an m x n binary matrix mat of 1's (representing soldiers) and 0's (representing civilians). The soldiers are positioned in front of the civilians. That is, all the 1's will appear to the left of all the 0's in each row.\n\t\tA row i is weaker than a row j if one of the following is true:\n\t\t\tThe number of soldiers in row i is less than the number of soldiers in row j.\n\t\t\tBoth rows have the same number of soldiers and i < j.\n\t\tReturn the indices of the k weakest rows in the matrix ordered from weakest to strongest.\n\t\tExample 1:\n\t\tInput: mat = \n\t\t[[1,1,0,0,0],\n\t\t [1,1,1,1,0],\n\t\t [1,0,0,0,0],\n\t\t [1,1,0,0,0],\n\t\t [1,1,1,1,1]], \n\t\tk = 3\n\t\tOutput: [2,0,3]\n\t\tExplanation: \n\t\tThe number of soldiers in each row is: \n\t\t- Row 0: 2 \n\t\t- Row 1: 4 \n\t\t- Row 2: 1 \n\t\t- Row 3: 2 \n\t\t- Row 4: 5 \n\t\tThe rows ordered from weakest to strongest are [2,0,3,1,4].\n\t\tExample 2:\n\t\tInput: mat = \n\t\t[[1,0,0,0],\n\t\t [1,1,1,1],\n\t\t [1,0,0,0],\n\t\t [1,0,0,0]], \n\t\tk = 2\n\t\tOutput: [0,2]\n\t\tExplanation: \n\t\tThe number of soldiers in each row is: \n\t\t- Row 0: 1 \n\t\t- Row 1: 4 \n\t\t- Row 2: 1 \n\t\t- Row 3: 1 \n\t\tThe rows ordered from weakest to strongest are [0,2,3,1].\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1464, - "question": "class Solution:\n def minSetSize(self, arr: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou are given an integer array arr. You can choose a set of integers and remove all the occurrences of these integers in the array.\n\t\tReturn the minimum size of the set so that at least half of the integers of the array are removed.\n\t\tExample 1:\n\t\tInput: arr = [3,3,3,3,5,5,5,2,2,7]\n\t\tOutput: 2\n\t\tExplanation: Choosing {3,7} will make the new array [5,5,5,2,2] which has size 5 (i.e equal to half of the size of the old array).\n\t\tPossible sets of size 2 are {3,5},{3,2},{5,2}.\n\t\tChoosing set {2,7} is not possible as it will make the new array [3,3,3,3,5,5,5] which has a size greater than half of the size of the old array.\n\t\tExample 2:\n\t\tInput: arr = [7,7,7,7,7,7]\n\t\tOutput: 1\n\t\tExplanation: The only possible set you can choose is {7}. This will make the new array empty.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1465, - "question": "class Solution:\n def maxProduct(self, root: Optional[TreeNode]) -> int:\n\t\t\"\"\"\n\t\tGiven the root of a binary tree, split the binary tree into two subtrees by removing one edge such that the product of the sums of the subtrees is maximized.\n\t\tReturn the maximum product of the sums of the two subtrees. Since the answer may be too large, return it modulo 109 + 7.\n\t\tNote that you need to maximize the answer before taking the mod and not after taking it.\n\t\tExample 1:\n\t\tInput: root = [1,2,3,4,5,6]\n\t\tOutput: 110\n\t\tExplanation: Remove the red edge and get 2 binary trees with sum 11 and 10. Their product is 110 (11*10)\n\t\tExample 2:\n\t\tInput: root = [1,null,2,3,4,null,null,5,6]\n\t\tOutput: 90\n\t\tExplanation: Remove the red edge and get 2 binary trees with sum 15 and 6.Their product is 90 (15*6)\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1466, - "question": "class Solution:\n def maxJumps(self, arr: List[int], d: int) -> int:\n\t\t\"\"\"\n\t\tGiven an array of integers arr and an integer d. In one step you can jump from index i to index:\n\t\t\ti + x where: i + x < arr.length and 0 < x <= d.\n\t\t\ti - x where: i - x >= 0 and 0 < x <= d.\n\t\tIn addition, you can only jump from index i to index j if arr[i] > arr[j] and arr[i] > arr[k] for all indices k between i and j (More formally min(i, j) < k < max(i, j)).\n\t\tYou can choose any index of the array and start jumping. Return the maximum number of indices you can visit.\n\t\tNotice that you can not jump outside of the array at any time.\n\t\tExample 1:\n\t\tInput: arr = [6,4,14,6,8,13,9,7,10,6,12], d = 2\n\t\tOutput: 4\n\t\tExplanation: You can start at index 10. You can jump 10 --> 8 --> 6 --> 7 as shown.\n\t\tNote that if you start at index 6 you can only jump to index 7. You cannot jump to index 5 because 13 > 9. You cannot jump to index 4 because index 5 is between index 4 and 6 and 13 > 9.\n\t\tSimilarly You cannot jump from index 3 to index 2 or index 1.\n\t\tExample 2:\n\t\tInput: arr = [3,3,3,3,3], d = 3\n\t\tOutput: 1\n\t\tExplanation: You can start at any index. You always cannot jump to any index.\n\t\tExample 3:\n\t\tInput: arr = [7,6,5,4,3,2,1], d = 1\n\t\tOutput: 7\n\t\tExplanation: Start at index 0. You can visit all the indicies. \n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1468, - "question": "class Solution:\n def checkIfExist(self, arr: List[int]) -> bool:\n\t\t\"\"\"\n\t\tGiven an array arr of integers, check if there exist two indices i and j such that :\n\t\t\ti != j\n\t\t\t0 <= i, j < arr.length\n\t\t\tarr[i] == 2 * arr[j]\n\t\tExample 1:\n\t\tInput: arr = [10,2,5,3]\n\t\tOutput: true\n\t\tExplanation: For i = 0 and j = 2, arr[i] == 10 == 2 * 5 == 2 * arr[j]\n\t\tExample 2:\n\t\tInput: arr = [3,1,7,11]\n\t\tOutput: false\n\t\tExplanation: There is no i and j that satisfy the conditions.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1469, - "question": "class Solution:\n def minSteps(self, s: str, t: str) -> int:\n\t\t\"\"\"\n\t\tYou are given two strings of the same length s and t. In one step you can choose any character of t and replace it with another character.\n\t\tReturn the minimum number of steps to make t an anagram of s.\n\t\tAn Anagram of a string is a string that contains the same characters with a different (or the same) ordering.\n\t\tExample 1:\n\t\tInput: s = \"bab\", t = \"aba\"\n\t\tOutput: 1\n\t\tExplanation: Replace the first 'a' in t with b, t = \"bba\" which is anagram of s.\n\t\tExample 2:\n\t\tInput: s = \"leetcode\", t = \"practice\"\n\t\tOutput: 5\n\t\tExplanation: Replace 'p', 'r', 'a', 'i' and 'c' from t with proper characters to make t anagram of s.\n\t\tExample 3:\n\t\tInput: s = \"anagram\", t = \"mangaar\"\n\t\tOutput: 0\n\t\tExplanation: \"anagram\" and \"mangaar\" are anagrams. \n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1470, - "question": "class TweetCounts:\n def __init__(self):\n def recordTweet(self, tweetName: str, time: int) -> None:\n def getTweetCountsPerFrequency(self, freq: str, tweetName: str, startTime: int, endTime: int) -> List[int]:\n\t\t\"\"\"\n\t\tA social media company is trying to monitor activity on their site by analyzing the number of tweets that occur in select periods of time. These periods can be partitioned into smaller time chunks based on a certain frequency (every minute, hour, or day).\n\t\tFor example, the period [10, 10000] (in seconds) would be partitioned into the following time chunks with these frequencies:\n\t\t\tEvery minute (60-second chunks): [10,69], [70,129], [130,189], ..., [9970,10000]\n\t\t\tEvery hour (3600-second chunks): [10,3609], [3610,7209], [7210,10000]\n\t\t\tEvery day (86400-second chunks): [10,10000]\n\t\tNotice that the last chunk may be shorter than the specified frequency's chunk size and will always end with the end time of the period (10000 in the above example).\n\t\tDesign and implement an API to help the company with their analysis.\n\t\tImplement the TweetCounts class:\n\t\t\tTweetCounts() Initializes the TweetCounts object.\n\t\t\tvoid recordTweet(String tweetName, int time) Stores the tweetName at the recorded time (in seconds).\n\t\t\tList getTweetCountsPerFrequency(String freq, String tweetName, int startTime, int endTime) Returns a list of integers representing the number of tweets with tweetName in each time chunk for the given period of time [startTime, endTime] (in seconds) and frequency freq.\n\t\t\t\tfreq is one of \"minute\", \"hour\", or \"day\" representing a frequency of every minute, hour, or day respectively.\n\t\tExample:\n\t\tInput\n\t\t[\"TweetCounts\",\"recordTweet\",\"recordTweet\",\"recordTweet\",\"getTweetCountsPerFrequency\",\"getTweetCountsPerFrequency\",\"recordTweet\",\"getTweetCountsPerFrequency\"]\n\t\t[[],[\"tweet3\",0],[\"tweet3\",60],[\"tweet3\",10],[\"minute\",\"tweet3\",0,59],[\"minute\",\"tweet3\",0,60],[\"tweet3\",120],[\"hour\",\"tweet3\",0,210]]\n\t\tOutput\n\t\t[null,null,null,null,[2],[2,1],null,[4]]\n\t\tExplanation\n\t\tTweetCounts tweetCounts = new TweetCounts();\n\t\ttweetCounts.recordTweet(\"tweet3\", 0); // New tweet \"tweet3\" at time 0\n\t\ttweetCounts.recordTweet(\"tweet3\", 60); // New tweet \"tweet3\" at time 60\n\t\ttweetCounts.recordTweet(\"tweet3\", 10); // New tweet \"tweet3\" at time 10\n\t\ttweetCounts.getTweetCountsPerFrequency(\"minute\", \"tweet3\", 0, 59); // return [2]; chunk [0,59] had 2 tweets\n\t\ttweetCounts.getTweetCountsPerFrequency(\"minute\", \"tweet3\", 0, 60); // return [2,1]; chunk [0,59] had 2 tweets, chunk [60,60] had 1 tweet\n\t\ttweetCounts.recordTweet(\"tweet3\", 120); // New tweet \"tweet3\" at time 120\n\t\ttweetCounts.getTweetCountsPerFrequency(\"hour\", \"tweet3\", 0, 210); // return [4]; chunk [0,210] had 4 tweets\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1471, - "question": "class Solution:\n def maxStudents(self, seats: List[List[str]]) -> int:\n\t\t\"\"\"\n\t\tGiven a m * n matrix seats that represent seats distributions in a classroom. If a seat is broken, it is denoted by '#' character otherwise it is denoted by a '.' character.\n\t\tStudents can see the answers of those sitting next to the left, right, upper left and upper right, but he cannot see the answers of the student sitting directly in front or behind him. Return the maximum number of students that can take the exam together without any cheating being possible..\n\t\tStudents must be placed in seats in good condition.\n\t\tExample 1:\n\t\tInput: seats = [[\"#\",\".\",\"#\",\"#\",\".\",\"#\"],\n\t\t [\".\",\"#\",\"#\",\"#\",\"#\",\".\"],\n\t\t [\"#\",\".\",\"#\",\"#\",\".\",\"#\"]]\n\t\tOutput: 4\n\t\tExplanation: Teacher can place 4 students in available seats so they don't cheat on the exam. \n\t\tExample 2:\n\t\tInput: seats = [[\".\",\"#\"],\n\t\t [\"#\",\"#\"],\n\t\t [\"#\",\".\"],\n\t\t [\"#\",\"#\"],\n\t\t [\".\",\"#\"]]\n\t\tOutput: 3\n\t\tExplanation: Place all students in available seats. \n\t\tExample 3:\n\t\tInput: seats = [[\"#\",\".\",\".\",\".\",\"#\"],\n\t\t [\".\",\"#\",\".\",\"#\",\".\"],\n\t\t [\".\",\".\",\"#\",\".\",\".\"],\n\t\t [\".\",\"#\",\".\",\"#\",\".\"],\n\t\t [\"#\",\".\",\".\",\".\",\"#\"]]\n\t\tOutput: 10\n\t\tExplanation: Place students in available seats in column 1, 3 and 5.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1472, - "question": "class Solution:\n def sortString(self, s: str) -> str:\n\t\t\"\"\"\n\t\tYou are given a string s. Reorder the string using the following algorithm:\n\t\t\tPick the smallest character from s and append it to the result.\n\t\t\tPick the smallest character from s which is greater than the last appended character to the result and append it.\n\t\t\tRepeat step 2 until you cannot pick more characters.\n\t\t\tPick the largest character from s and append it to the result.\n\t\t\tPick the largest character from s which is smaller than the last appended character to the result and append it.\n\t\t\tRepeat step 5 until you cannot pick more characters.\n\t\t\tRepeat the steps from 1 to 6 until you pick all characters from s.\n\t\tIn each step, If the smallest or the largest character appears more than once you can choose any occurrence and append it to the result.\n\t\tReturn the result string after sorting s with this algorithm.\n\t\tExample 1:\n\t\tInput: s = \"aaaabbbbcccc\"\n\t\tOutput: \"abccbaabccba\"\n\t\tExplanation: After steps 1, 2 and 3 of the first iteration, result = \"abc\"\n\t\tAfter steps 4, 5 and 6 of the first iteration, result = \"abccba\"\n\t\tFirst iteration is done. Now s = \"aabbcc\" and we go back to step 1\n\t\tAfter steps 1, 2 and 3 of the second iteration, result = \"abccbaabc\"\n\t\tAfter steps 4, 5 and 6 of the second iteration, result = \"abccbaabccba\"\n\t\tExample 2:\n\t\tInput: s = \"rat\"\n\t\tOutput: \"art\"\n\t\tExplanation: The word \"rat\" becomes \"art\" after re-ordering it with the mentioned algorithm.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1473, - "question": "class Solution:\n def findTheLongestSubstring(self, s: str) -> int:\n\t\t\"\"\"\n\t\tGiven the string s, return the size of the longest substring containing each vowel an even number of times. That is, 'a', 'e', 'i', 'o', and 'u' must appear an even number of times.\n\t\tExample 1:\n\t\tInput: s = \"eleetminicoworoep\"\n\t\tOutput: 13\n\t\tExplanation: The longest substring is \"leetminicowor\" which contains two each of the vowels: e, i and o and zero of the vowels: a and u.\n\t\tExample 2:\n\t\tInput: s = \"leetcodeisgreat\"\n\t\tOutput: 5\n\t\tExplanation: The longest substring is \"leetc\" which contains two e's.\n\t\tExample 3:\n\t\tInput: s = \"bcbcbc\"\n\t\tOutput: 6\n\t\tExplanation: In this case, the given string \"bcbcbc\" is the longest because all vowels: a, e, i, o and u appear zero times.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1474, - "question": "class Solution:\n def longestZigZag(self, root: Optional[TreeNode]) -> int:\n\t\t\"\"\"\n\t\tYou are given the root of a binary tree.\n\t\tA ZigZag path for a binary tree is defined as follow:\n\t\t\tChoose any node in the binary tree and a direction (right or left).\n\t\t\tIf the current direction is right, move to the right child of the current node; otherwise, move to the left child.\n\t\t\tChange the direction from right to left or from left to right.\n\t\t\tRepeat the second and third steps until you can't move in the tree.\n\t\tZigzag length is defined as the number of nodes visited - 1. (A single node has a length of 0).\n\t\tReturn the longest ZigZag path contained in that tree.\n\t\tExample 1:\n\t\tInput: root = [1,null,1,1,1,null,null,1,1,null,1,null,null,null,1,null,1]\n\t\tOutput: 3\n\t\tExplanation: Longest ZigZag path in blue nodes (right -> left -> right).\n\t\tExample 2:\n\t\tInput: root = [1,1,1,null,1,null,null,1,1,null,1]\n\t\tOutput: 4\n\t\tExplanation: Longest ZigZag path in blue nodes (left -> right -> left -> right).\n\t\tExample 3:\n\t\tInput: root = [1]\n\t\tOutput: 0\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1475, - "question": "class Solution:\n def maxSumBST(self, root: Optional[TreeNode]) -> int:\n\t\t\"\"\"\n\t\tGiven a binary tree root, return the maximum sum of all keys of any sub-tree which is also a Binary Search Tree (BST).\n\t\tAssume a BST is defined as follows:\n\t\t\tThe left subtree of a node contains only nodes with keys less than the node's key.\n\t\t\tThe right subtree of a node contains only nodes with keys greater than the node's key.\n\t\t\tBoth the left and right subtrees must also be binary search trees.\n\t\tExample 1:\n\t\tInput: root = [1,4,3,2,4,2,5,null,null,null,null,null,null,4,6]\n\t\tOutput: 20\n\t\tExplanation: Maximum sum in a valid Binary search tree is obtained in root node with key equal to 3.\n\t\tExample 2:\n\t\tInput: root = [4,3,null,1,2]\n\t\tOutput: 2\n\t\tExplanation: Maximum sum in a valid Binary search tree is obtained in a single root node with key equal to 2.\n\t\tExample 3:\n\t\tInput: root = [-4,-2,-5]\n\t\tOutput: 0\n\t\tExplanation: All values are negatives. Return an empty BST.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1476, - "question": "class Solution:\n def countNegatives(self, grid: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tGiven a m x n matrix grid which is sorted in non-increasing order both row-wise and column-wise, return the number of negative numbers in grid.\n\t\tExample 1:\n\t\tInput: grid = [[4,3,2,-1],[3,2,1,-1],[1,1,-1,-2],[-1,-1,-2,-3]]\n\t\tOutput: 8\n\t\tExplanation: There are 8 negatives number in the matrix.\n\t\tExample 2:\n\t\tInput: grid = [[3,2],[1,0]]\n\t\tOutput: 0\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1477, - "question": "class ProductOfNumbers:\n def __init__(self):\n def add(self, num: int) -> None:\n def getProduct(self, k: int) -> int:\n\t\t\"\"\"\n\t\tDesign an algorithm that accepts a stream of integers and retrieves the product of the last k integers of the stream.\n\t\tImplement the ProductOfNumbers class:\n\t\t\tProductOfNumbers() Initializes the object with an empty stream.\n\t\t\tvoid add(int num) Appends the integer num to the stream.\n\t\t\tint getProduct(int k) Returns the product of the last k numbers in the current list. You can assume that always the current list has at least k numbers.\n\t\tThe test cases are generated so that, at any time, the product of any contiguous sequence of numbers will fit into a single 32-bit integer without overflowing.\n\t\tExample:\n\t\tInput\n\t\t[\"ProductOfNumbers\",\"add\",\"add\",\"add\",\"add\",\"add\",\"getProduct\",\"getProduct\",\"getProduct\",\"add\",\"getProduct\"]\n\t\t[[],[3],[0],[2],[5],[4],[2],[3],[4],[8],[2]]\n\t\tOutput\n\t\t[null,null,null,null,null,null,20,40,0,null,32]\n\t\tExplanation\n\t\tProductOfNumbers productOfNumbers = new ProductOfNumbers();\n\t\tproductOfNumbers.add(3); // [3]\n\t\tproductOfNumbers.add(0); // [3,0]\n\t\tproductOfNumbers.add(2); // [3,0,2]\n\t\tproductOfNumbers.add(5); // [3,0,2,5]\n\t\tproductOfNumbers.add(4); // [3,0,2,5,4]\n\t\tproductOfNumbers.getProduct(2); // return 20. The product of the last 2 numbers is 5 * 4 = 20\n\t\tproductOfNumbers.getProduct(3); // return 40. The product of the last 3 numbers is 2 * 5 * 4 = 40\n\t\tproductOfNumbers.getProduct(4); // return 0. The product of the last 4 numbers is 0 * 2 * 5 * 4 = 0\n\t\tproductOfNumbers.add(8); // [3,0,2,5,4,8]\n\t\tproductOfNumbers.getProduct(2); // return 32. The product of the last 2 numbers is 4 * 8 = 32 \n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1478, - "question": "class Solution:\n def maxEvents(self, events: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tYou are given an array of events where events[i] = [startDayi, endDayi]. Every event i starts at startDayi and ends at endDayi.\n\t\tYou can attend an event i at any day d where startTimei <= d <= endTimei. You can only attend one event at any time d.\n\t\tReturn the maximum number of events you can attend.\n\t\tExample 1:\n\t\tInput: events = [[1,2],[2,3],[3,4]]\n\t\tOutput: 3\n\t\tExplanation: You can attend all the three events.\n\t\tOne way to attend them all is as shown.\n\t\tAttend the first event on day 1.\n\t\tAttend the second event on day 2.\n\t\tAttend the third event on day 3.\n\t\tExample 2:\n\t\tInput: events= [[1,2],[2,3],[3,4],[1,2]]\n\t\tOutput: 4\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1479, - "question": "class Solution:\n def isPossible(self, target: List[int]) -> bool:\n\t\t\"\"\"\n\t\tYou are given an array target of n integers. From a starting array arr consisting of n 1's, you may perform the following procedure :\n\t\t\tlet x be the sum of all elements currently in your array.\n\t\t\tchoose index i, such that 0 <= i < n and set the value of arr at index i to x.\n\t\t\tYou may repeat this procedure as many times as needed.\n\t\tReturn true if it is possible to construct the target array from arr, otherwise, return false.\n\t\tExample 1:\n\t\tInput: target = [9,3,5]\n\t\tOutput: true\n\t\tExplanation: Start with arr = [1, 1, 1] \n\t\t[1, 1, 1], sum = 3 choose index 1\n\t\t[1, 3, 1], sum = 5 choose index 2\n\t\t[1, 3, 5], sum = 9 choose index 0\n\t\t[9, 3, 5] Done\n\t\tExample 2:\n\t\tInput: target = [1,1,1,2]\n\t\tOutput: false\n\t\tExplanation: Impossible to create target array from [1,1,1,1].\n\t\tExample 3:\n\t\tInput: target = [8,5]\n\t\tOutput: true\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1482, - "question": "class Solution:\n def smallerNumbersThanCurrent(self, nums: List[int]) -> List[int]:\n\t\t\"\"\"\n\t\tGiven the array nums, for each nums[i] find out how many numbers in the array are smaller than it. That is, for each nums[i] you have to count the number of valid j's such that j != i and nums[j] < nums[i].\n\t\tReturn the answer in an array.\n\t\tExample 1:\n\t\tInput: nums = [8,1,2,2,3]\n\t\tOutput: [4,0,1,1,3]\n\t\tExplanation: \n\t\tFor nums[0]=8 there exist four smaller numbers than it (1, 2, 2 and 3). \n\t\tFor nums[1]=1 does not exist any smaller number than it.\n\t\tFor nums[2]=2 there exist one smaller number than it (1). \n\t\tFor nums[3]=2 there exist one smaller number than it (1). \n\t\tFor nums[4]=3 there exist three smaller numbers than it (1, 2 and 2).\n\t\tExample 2:\n\t\tInput: nums = [6,5,4,8]\n\t\tOutput: [2,1,0,3]\n\t\tExample 3:\n\t\tInput: nums = [7,7,7,7]\n\t\tOutput: [0,0,0,0]\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1483, - "question": "class Solution:\n def rankTeams(self, votes: List[str]) -> str:\n\t\t\"\"\"\n\t\tIn a special ranking system, each voter gives a rank from highest to lowest to all teams participating in the competition.\n\t\tThe ordering of teams is decided by who received the most position-one votes. If two or more teams tie in the first position, we consider the second position to resolve the conflict, if they tie again, we continue this process until the ties are resolved. If two or more teams are still tied after considering all positions, we rank them alphabetically based on their team letter.\n\t\tYou are given an array of strings votes which is the votes of all voters in the ranking systems. Sort all teams according to the ranking system described above.\n\t\tReturn a string of all teams sorted by the ranking system.\n\t\tExample 1:\n\t\tInput: votes = [\"ABC\",\"ACB\",\"ABC\",\"ACB\",\"ACB\"]\n\t\tOutput: \"ACB\"\n\t\tExplanation: \n\t\tTeam A was ranked first place by 5 voters. No other team was voted as first place, so team A is the first team.\n\t\tTeam B was ranked second by 2 voters and ranked third by 3 voters.\n\t\tTeam C was ranked second by 3 voters and ranked third by 2 voters.\n\t\tAs most of the voters ranked C second, team C is the second team, and team B is the third.\n\t\tExample 2:\n\t\tInput: votes = [\"WXYZ\",\"XYZW\"]\n\t\tOutput: \"XWYZ\"\n\t\tExplanation:\n\t\tX is the winner due to the tie-breaking rule. X has the same votes as W for the first position, but X has one vote in the second position, while W does not have any votes in the second position. \n\t\tExample 3:\n\t\tInput: votes = [\"ZMNAGUEDSJYLBOPHRQICWFXTVK\"]\n\t\tOutput: \"ZMNAGUEDSJYLBOPHRQICWFXTVK\"\n\t\tExplanation: Only one voter, so their votes are used for the ranking.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1484, - "question": "class Solution:\n def isSubPath(self, head: Optional[ListNode], root: Optional[TreeNode]) -> bool:\n\t\t\"\"\"\n\t\tGiven a binary tree root and a linked list with head as the first node. \n\t\tReturn True if all the elements in the linked list starting from the head correspond to some downward path connected in the binary tree otherwise return False.\n\t\tIn this context downward path means a path that starts at some node and goes downwards.\n\t\tExample 1:\n\t\tInput: head = [4,2,8], root = [1,4,4,null,2,2,null,1,null,6,8,null,null,null,null,1,3]\n\t\tOutput: true\n\t\tExplanation: Nodes in blue form a subpath in the binary Tree. \n\t\tExample 2:\n\t\tInput: head = [1,4,2,6], root = [1,4,4,null,2,2,null,1,null,6,8,null,null,null,null,1,3]\n\t\tOutput: true\n\t\tExample 3:\n\t\tInput: head = [1,4,2,6,8], root = [1,4,4,null,2,2,null,1,null,6,8,null,null,null,null,1,3]\n\t\tOutput: false\n\t\tExplanation: There is no path in the binary tree that contains all the elements of the linked list from head.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1485, - "question": "class Solution:\n def minCost(self, grid: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tGiven an m x n grid. Each cell of the grid has a sign pointing to the next cell you should visit if you are currently in this cell. The sign of grid[i][j] can be:\n\t\t\t1 which means go to the cell to the right. (i.e go from grid[i][j] to grid[i][j + 1])\n\t\t\t2 which means go to the cell to the left. (i.e go from grid[i][j] to grid[i][j - 1])\n\t\t\t3 which means go to the lower cell. (i.e go from grid[i][j] to grid[i + 1][j])\n\t\t\t4 which means go to the upper cell. (i.e go from grid[i][j] to grid[i - 1][j])\n\t\tNotice that there could be some signs on the cells of the grid that point outside the grid.\n\t\tYou will initially start at the upper left cell (0, 0). A valid path in the grid is a path that starts from the upper left cell (0, 0) and ends at the bottom-right cell (m - 1, n - 1) following the signs on the grid. The valid path does not have to be the shortest.\n\t\tYou can modify the sign on a cell with cost = 1. You can modify the sign on a cell one time only.\n\t\tReturn the minimum cost to make the grid have at least one valid path.\n\t\tExample 1:\n\t\tInput: grid = [[1,1,1,1],[2,2,2,2],[1,1,1,1],[2,2,2,2]]\n\t\tOutput: 3\n\t\tExplanation: You will start at point (0, 0).\n\t\tThe path to (3, 3) is as follows. (0, 0) --> (0, 1) --> (0, 2) --> (0, 3) change the arrow to down with cost = 1 --> (1, 3) --> (1, 2) --> (1, 1) --> (1, 0) change the arrow to down with cost = 1 --> (2, 0) --> (2, 1) --> (2, 2) --> (2, 3) change the arrow to down with cost = 1 --> (3, 3)\n\t\tThe total cost = 3.\n\t\tExample 2:\n\t\tInput: grid = [[1,1,3],[3,2,2],[1,1,4]]\n\t\tOutput: 0\n\t\tExplanation: You can follow the path from (0, 0) to (2, 2).\n\t\tExample 3:\n\t\tInput: grid = [[1,2],[4,3]]\n\t\tOutput: 1\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1486, - "question": "class Solution:\n def findTheDistanceValue(self, arr1: List[int], arr2: List[int], d: int) -> int:\n\t\t\"\"\"\n\t\tGiven two integer arrays arr1 and arr2, and the integer d, return the distance value between the two arrays.\n\t\tThe distance value is defined as the number of elements arr1[i] such that there is not any element arr2[j] where |arr1[i]-arr2[j]| <= d.\n\t\tExample 1:\n\t\tInput: arr1 = [4,5,8], arr2 = [10,9,1,8], d = 2\n\t\tOutput: 2\n\t\tExplanation: \n\t\tFor arr1[0]=4 we have: \n\t\t|4-10|=6 > d=2 \n\t\t|4-9|=5 > d=2 \n\t\t|4-1|=3 > d=2 \n\t\t|4-8|=4 > d=2 \n\t\tFor arr1[1]=5 we have: \n\t\t|5-10|=5 > d=2 \n\t\t|5-9|=4 > d=2 \n\t\t|5-1|=4 > d=2 \n\t\t|5-8|=3 > d=2\n\t\tFor arr1[2]=8 we have:\n\t\t|8-10|=2 <= d=2\n\t\t|8-9|=1 <= d=2\n\t\t|8-1|=7 > d=2\n\t\t|8-8|=0 <= d=2\n\t\tExample 2:\n\t\tInput: arr1 = [1,4,2,3], arr2 = [-4,-3,6,10,20,30], d = 3\n\t\tOutput: 2\n\t\tExample 3:\n\t\tInput: arr1 = [2,1,100,3], arr2 = [-5,-2,10,-3,7], d = 6\n\t\tOutput: 1\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1487, - "question": "class Solution:\n def maxNumberOfFamilies(self, n: int, reservedSeats: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tA cinema has n rows of seats, numbered from 1 to n and there are ten seats in each row, labelled from 1 to 10 as shown in the figure above.\n\t\tGiven the array reservedSeats containing the numbers of seats already reserved, for example, reservedSeats[i] = [3,8] means the seat located in row 3 and labelled with 8 is already reserved.\n\t\tReturn the maximum number of four-person groups you can assign on the cinema seats. A four-person group occupies four adjacent seats in one single row. Seats across an aisle (such as [3,3] and [3,4]) are not considered to be adjacent, but there is an exceptional case on which an aisle split a four-person group, in that case, the aisle split a four-person group in the middle, which means to have two people on each side.\n\t\tExample 1:\n\t\tInput: n = 3, reservedSeats = [[1,2],[1,3],[1,8],[2,6],[3,1],[3,10]]\n\t\tOutput: 4\n\t\tExplanation: The figure above shows the optimal allocation for four groups, where seats mark with blue are already reserved and contiguous seats mark with orange are for one group.\n\t\tExample 2:\n\t\tInput: n = 2, reservedSeats = [[2,1],[1,8],[2,6]]\n\t\tOutput: 2\n\t\tExample 3:\n\t\tInput: n = 4, reservedSeats = [[4,3],[1,4],[4,6],[1,7]]\n\t\tOutput: 4\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1488, - "question": "class Solution:\n def getKth(self, lo: int, hi: int, k: int) -> int:\n\t\t\"\"\"\n\t\tThe power of an integer x is defined as the number of steps needed to transform x into 1 using the following steps:\n\t\t\tif x is even then x = x / 2\n\t\t\tif x is odd then x = 3 * x + 1\n\t\tFor example, the power of x = 3 is 7 because 3 needs 7 steps to become 1 (3 --> 10 --> 5 --> 16 --> 8 --> 4 --> 2 --> 1).\n\t\tGiven three integers lo, hi and k. The task is to sort all integers in the interval [lo, hi] by the power value in ascending order, if two or more integers have the same power value sort them by ascending order.\n\t\tReturn the kth integer in the range [lo, hi] sorted by the power value.\n\t\tNotice that for any integer x (lo <= x <= hi) it is guaranteed that x will transform into 1 using these steps and that the power of x is will fit in a 32-bit signed integer.\n\t\tExample 1:\n\t\tInput: lo = 12, hi = 15, k = 2\n\t\tOutput: 13\n\t\tExplanation: The power of 12 is 9 (12 --> 6 --> 3 --> 10 --> 5 --> 16 --> 8 --> 4 --> 2 --> 1)\n\t\tThe power of 13 is 9\n\t\tThe power of 14 is 17\n\t\tThe power of 15 is 17\n\t\tThe interval sorted by the power value [12,13,14,15]. For k = 2 answer is the second element which is 13.\n\t\tNotice that 12 and 13 have the same power value and we sorted them in ascending order. Same for 14 and 15.\n\t\tExample 2:\n\t\tInput: lo = 7, hi = 11, k = 4\n\t\tOutput: 7\n\t\tExplanation: The power array corresponding to the interval [7, 8, 9, 10, 11] is [16, 3, 19, 6, 14].\n\t\tThe interval sorted by power is [8, 10, 11, 7, 9].\n\t\tThe fourth number in the sorted array is 7.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1489, - "question": "class Solution:\n def maxSizeSlices(self, slices: List[int]) -> int:\n\t\t\"\"\"\n\t\tThere is a pizza with 3n slices of varying size, you and your friends will take slices of pizza as follows:\n\t\t\tYou will pick any pizza slice.\n\t\t\tYour friend Alice will pick the next slice in the anti-clockwise direction of your pick.\n\t\t\tYour friend Bob will pick the next slice in the clockwise direction of your pick.\n\t\t\tRepeat until there are no more slices of pizzas.\n\t\tGiven an integer array slices that represent the sizes of the pizza slices in a clockwise direction, return the maximum possible sum of slice sizes that you can pick.\n\t\tExample 1:\n\t\tInput: slices = [1,2,3,4,5,6]\n\t\tOutput: 10\n\t\tExplanation: Pick pizza slice of size 4, Alice and Bob will pick slices with size 3 and 5 respectively. Then Pick slices with size 6, finally Alice and Bob will pick slice of size 2 and 1 respectively. Total = 4 + 6.\n\t\tExample 2:\n\t\tInput: slices = [8,9,8,6,1,1]\n\t\tOutput: 16\n\t\tExplanation: Pick pizza slice of size 8 in each turn. If you pick slice with size 9 your partners will pick slices of size 8.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1490, - "question": "class Solution:\n def generateTheString(self, n: int) -> str:\n\t\t\"\"\"\n\t\tGiven an integer n, return a string with n characters such that each character in such string occurs an odd number of times.\n\t\tThe returned string must contain only lowercase English letters. If there are multiples valid strings, return any of them. \n\t\tExample 1:\n\t\tInput: n = 4\n\t\tOutput: \"pppz\"\n\t\tExplanation: \"pppz\" is a valid string since the character 'p' occurs three times and the character 'z' occurs once. Note that there are many other valid strings such as \"ohhh\" and \"love\".\n\t\tExample 2:\n\t\tInput: n = 2\n\t\tOutput: \"xy\"\n\t\tExplanation: \"xy\" is a valid string since the characters 'x' and 'y' occur once. Note that there are many other valid strings such as \"ag\" and \"ur\".\n\t\tExample 3:\n\t\tInput: n = 7\n\t\tOutput: \"holasss\"\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1491, - "question": "class Solution:\n def numTimesAllBlue(self, flips: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou have a 1-indexed binary string of length n where all the bits are 0 initially. We will flip all the bits of this binary string (i.e., change them from 0 to 1) one by one. You are given a 1-indexed integer array flips where flips[i] indicates that the bit at index i will be flipped in the ith step.\n\t\tA binary string is prefix-aligned if, after the ith step, all the bits in the inclusive range [1, i] are ones and all the other bits are zeros.\n\t\tReturn the number of times the binary string is prefix-aligned during the flipping process.\n\t\tExample 1:\n\t\tInput: flips = [3,2,4,1,5]\n\t\tOutput: 2\n\t\tExplanation: The binary string is initially \"00000\".\n\t\tAfter applying step 1: The string becomes \"00100\", which is not prefix-aligned.\n\t\tAfter applying step 2: The string becomes \"01100\", which is not prefix-aligned.\n\t\tAfter applying step 3: The string becomes \"01110\", which is not prefix-aligned.\n\t\tAfter applying step 4: The string becomes \"11110\", which is prefix-aligned.\n\t\tAfter applying step 5: The string becomes \"11111\", which is prefix-aligned.\n\t\tWe can see that the string was prefix-aligned 2 times, so we return 2.\n\t\tExample 2:\n\t\tInput: flips = [4,1,2,3]\n\t\tOutput: 1\n\t\tExplanation: The binary string is initially \"0000\".\n\t\tAfter applying step 1: The string becomes \"0001\", which is not prefix-aligned.\n\t\tAfter applying step 2: The string becomes \"1001\", which is not prefix-aligned.\n\t\tAfter applying step 3: The string becomes \"1101\", which is not prefix-aligned.\n\t\tAfter applying step 4: The string becomes \"1111\", which is prefix-aligned.\n\t\tWe can see that the string was prefix-aligned 1 time, so we return 1.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1492, - "question": "class Solution:\n def numOfMinutes(self, n: int, headID: int, manager: List[int], informTime: List[int]) -> int:\n\t\t\"\"\"\n\t\tA company has n employees with a unique ID for each employee from 0 to n - 1. The head of the company is the one with headID.\n\t\tEach employee has one direct manager given in the manager array where manager[i] is the direct manager of the i-th employee, manager[headID] = -1. Also, it is guaranteed that the subordination relationships have a tree structure.\n\t\tThe head of the company wants to inform all the company employees of an urgent piece of news. He will inform his direct subordinates, and they will inform their subordinates, and so on until all employees know about the urgent news.\n\t\tThe i-th employee needs informTime[i] minutes to inform all of his direct subordinates (i.e., After informTime[i] minutes, all his direct subordinates can start spreading the news).\n\t\tReturn the number of minutes needed to inform all the employees about the urgent news.\n\t\tExample 1:\n\t\tInput: n = 1, headID = 0, manager = [-1], informTime = [0]\n\t\tOutput: 0\n\t\tExplanation: The head of the company is the only employee in the company.\n\t\tExample 2:\n\t\tInput: n = 6, headID = 2, manager = [2,2,-1,2,2,2], informTime = [0,0,1,0,0,0]\n\t\tOutput: 1\n\t\tExplanation: The head of the company with id = 2 is the direct manager of all the employees in the company and needs 1 minute to inform them all.\n\t\tThe tree structure of the employees in the company is shown.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1493, - "question": "class Solution:\n def frogPosition(self, n: int, edges: List[List[int]], t: int, target: int) -> float:\n\t\t\"\"\"\n\t\tGiven an undirected tree consisting of n vertices numbered from 1 to n. A frog starts jumping from vertex 1. In one second, the frog jumps from its current vertex to another unvisited vertex if they are directly connected. The frog can not jump back to a visited vertex. In case the frog can jump to several vertices, it jumps randomly to one of them with the same probability. Otherwise, when the frog can not jump to any unvisited vertex, it jumps forever on the same vertex.\n\t\tThe edges of the undirected tree are given in the array edges, where edges[i] = [ai, bi] means that exists an edge connecting the vertices ai and bi.\n\t\tReturn the probability that after t seconds the frog is on the vertex target. Answers within 10-5 of the actual answer will be accepted.\n\t\tExample 1:\n\t\tInput: n = 7, edges = [[1,2],[1,3],[1,7],[2,4],[2,6],[3,5]], t = 2, target = 4\n\t\tOutput: 0.16666666666666666 \n\t\tExplanation: The figure above shows the given graph. The frog starts at vertex 1, jumping with 1/3 probability to the vertex 2 after second 1 and then jumping with 1/2 probability to vertex 4 after second 2. Thus the probability for the frog is on the vertex 4 after 2 seconds is 1/3 * 1/2 = 1/6 = 0.16666666666666666. \n\t\tExample 2:\n\t\tInput: n = 7, edges = [[1,2],[1,3],[1,7],[2,4],[2,6],[3,5]], t = 1, target = 7\n\t\tOutput: 0.3333333333333333\n\t\tExplanation: The figure above shows the given graph. The frog starts at vertex 1, jumping with 1/3 = 0.3333333333333333 probability to the vertex 7 after second 1. \n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1496, - "question": "class Solution:\n def luckyNumbers (self, matrix: List[List[int]]) -> List[int]:\n\t\t\"\"\"\n\t\tGiven an m x n matrix of distinct numbers, return all lucky numbers in the matrix in any order.\n\t\tA lucky number is an element of the matrix such that it is the minimum element in its row and maximum in its column.\n\t\tExample 1:\n\t\tInput: matrix = [[3,7,8],[9,11,13],[15,16,17]]\n\t\tOutput: [15]\n\t\tExplanation: 15 is the only lucky number since it is the minimum in its row and the maximum in its column.\n\t\tExample 2:\n\t\tInput: matrix = [[1,10,4,2],[9,3,8,7],[15,16,17,12]]\n\t\tOutput: [12]\n\t\tExplanation: 12 is the only lucky number since it is the minimum in its row and the maximum in its column.\n\t\tExample 3:\n\t\tInput: matrix = [[7,8],[1,2]]\n\t\tOutput: [7]\n\t\tExplanation: 7 is the only lucky number since it is the minimum in its row and the maximum in its column.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1497, - "question": "class CustomStack:\n def __init__(self, maxSize: int):\n def push(self, x: int) -> None:\n def pop(self) -> int:\n def increment(self, k: int, val: int) -> None:\n\t\t\"\"\"\n\t\tDesign a stack that supports increment operations on its elements.\n\t\tImplement the CustomStack class:\n\t\t\tCustomStack(int maxSize) Initializes the object with maxSize which is the maximum number of elements in the stack.\n\t\t\tvoid push(int x) Adds x to the top of the stack if the stack has not reached the maxSize.\n\t\t\tint pop() Pops and returns the top of the stack or -1 if the stack is empty.\n\t\t\tvoid inc(int k, int val) Increments the bottom k elements of the stack by val. If there are less than k elements in the stack, increment all the elements in the stack.\n\t\tExample 1:\n\t\tInput\n\t\t[\"CustomStack\",\"push\",\"push\",\"pop\",\"push\",\"push\",\"push\",\"increment\",\"increment\",\"pop\",\"pop\",\"pop\",\"pop\"]\n\t\t[[3],[1],[2],[],[2],[3],[4],[5,100],[2,100],[],[],[],[]]\n\t\tOutput\n\t\t[null,null,null,2,null,null,null,null,null,103,202,201,-1]\n\t\tExplanation\n\t\tCustomStack stk = new CustomStack(3); // Stack is Empty []\n\t\tstk.push(1); // stack becomes [1]\n\t\tstk.push(2); // stack becomes [1, 2]\n\t\tstk.pop(); // return 2 --> Return top of the stack 2, stack becomes [1]\n\t\tstk.push(2); // stack becomes [1, 2]\n\t\tstk.push(3); // stack becomes [1, 2, 3]\n\t\tstk.push(4); // stack still [1, 2, 3], Do not add another elements as size is 4\n\t\tstk.increment(5, 100); // stack becomes [101, 102, 103]\n\t\tstk.increment(2, 100); // stack becomes [201, 202, 103]\n\t\tstk.pop(); // return 103 --> Return top of the stack 103, stack becomes [201, 202]\n\t\tstk.pop(); // return 202 --> Return top of the stack 202, stack becomes [201]\n\t\tstk.pop(); // return 201 --> Return top of the stack 201, stack becomes []\n\t\tstk.pop(); // return -1 --> Stack is empty return -1.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1498, - "question": "class Solution:\n def getTargetCopy(self, original: TreeNode, cloned: TreeNode, target: TreeNode) -> TreeNode:\n\t\t\"\"\"\n\t\tGiven two binary trees original and cloned and given a reference to a node target in the original tree.\n\t\tThe cloned tree is a copy of the original tree.\n\t\tReturn a reference to the same node in the cloned tree.\n\t\tNote that you are not allowed to change any of the two trees or the target node and the answer must be a reference to a node in the cloned tree.\n\t\tExample 1:\n\t\tInput: tree = [7,4,3,null,null,6,19], target = 3\n\t\tOutput: 3\n\t\tExplanation: In all examples the original and cloned trees are shown. The target node is a green node from the original tree. The answer is the yellow node from the cloned tree.\n\t\tExample 2:\n\t\tInput: tree = [7], target = 7\n\t\tOutput: 7\n\t\tExample 3:\n\t\tInput: tree = [8,null,6,null,5,null,4,null,3,null,2,null,1], target = 4\n\t\tOutput: 4\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1499, - "question": "class Solution:\n def maxPerformance(self, n: int, speed: List[int], efficiency: List[int], k: int) -> int:\n\t\t\"\"\"\n\t\tYou are given two integers n and k and two integer arrays speed and efficiency both of length n. There are n engineers numbered from 1 to n. speed[i] and efficiency[i] represent the speed and efficiency of the ith engineer respectively.\n\t\tChoose at most k different engineers out of the n engineers to form a team with the maximum performance.\n\t\tThe performance of a team is the sum of their engineers' speeds multiplied by the minimum efficiency among their engineers.\n\t\tReturn the maximum performance of this team. Since the answer can be a huge number, return it modulo 109 + 7.\n\t\tExample 1:\n\t\tInput: n = 6, speed = [2,10,3,1,5,8], efficiency = [5,4,3,9,7,2], k = 2\n\t\tOutput: 60\n\t\tExplanation: \n\t\tWe have the maximum performance of the team by selecting engineer 2 (with speed=10 and efficiency=4) and engineer 5 (with speed=5 and efficiency=7). That is, performance = (10 + 5) * min(4, 7) = 60.\n\t\tExample 2:\n\t\tInput: n = 6, speed = [2,10,3,1,5,8], efficiency = [5,4,3,9,7,2], k = 3\n\t\tOutput: 68\n\t\tExplanation:\n\t\tThis is the same example as the first but k = 3. We can select engineer 1, engineer 2 and engineer 5 to get the maximum performance of the team. That is, performance = (2 + 10 + 5) * min(5, 4, 7) = 68.\n\t\tExample 3:\n\t\tInput: n = 6, speed = [2,10,3,1,5,8], efficiency = [5,4,3,9,7,2], k = 4\n\t\tOutput: 72\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1500, - "question": "class Solution:\n def countLargestGroup(self, n: int) -> int:\n\t\t\"\"\"\n\t\tYou are given an integer n.\n\t\tEach number from 1 to n is grouped according to the sum of its digits.\n\t\tReturn the number of groups that have the largest size.\n\t\tExample 1:\n\t\tInput: n = 13\n\t\tOutput: 4\n\t\tExplanation: There are 9 groups in total, they are grouped according sum of its digits of numbers from 1 to 13:\n\t\t[1,10], [2,11], [3,12], [4,13], [5], [6], [7], [8], [9].\n\t\tThere are 4 groups with largest size.\n\t\tExample 2:\n\t\tInput: n = 2\n\t\tOutput: 2\n\t\tExplanation: There are 2 groups [1], [2] of size 1.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1501, - "question": "class Solution:\n def checkOverlap(self, radius: int, xCenter: int, yCenter: int, x1: int, y1: int, x2: int, y2: int) -> bool:\n\t\t\"\"\"\n\t\tYou are given a circle represented as (radius, xCenter, yCenter) and an axis-aligned rectangle represented as (x1, y1, x2, y2), where (x1, y1) are the coordinates of the bottom-left corner, and (x2, y2) are the coordinates of the top-right corner of the rectangle.\n\t\tReturn true if the circle and rectangle are overlapped otherwise return false. In other words, check if there is any point (xi, yi) that belongs to the circle and the rectangle at the same time.\n\t\tExample 1:\n\t\tInput: radius = 1, xCenter = 0, yCenter = 0, x1 = 1, y1 = -1, x2 = 3, y2 = 1\n\t\tOutput: true\n\t\tExplanation: Circle and rectangle share the point (1,0).\n\t\tExample 2:\n\t\tInput: radius = 1, xCenter = 1, yCenter = 1, x1 = 1, y1 = -3, x2 = 2, y2 = -1\n\t\tOutput: false\n\t\tExample 3:\n\t\tInput: radius = 1, xCenter = 0, yCenter = 0, x1 = -1, y1 = 0, x2 = 0, y2 = 1\n\t\tOutput: true\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1502, - "question": "class Solution:\n def canConstruct(self, s: str, k: int) -> bool:\n\t\t\"\"\"\n\t\tGiven a string s and an integer k, return true if you can use all the characters in s to construct k palindrome strings or false otherwise.\n\t\tExample 1:\n\t\tInput: s = \"annabelle\", k = 2\n\t\tOutput: true\n\t\tExplanation: You can construct two palindromes using all characters in s.\n\t\tSome possible constructions \"anna\" + \"elble\", \"anbna\" + \"elle\", \"anellena\" + \"b\"\n\t\tExample 2:\n\t\tInput: s = \"leetcode\", k = 3\n\t\tOutput: false\n\t\tExplanation: It is impossible to construct 3 palindromes using all the characters of s.\n\t\tExample 3:\n\t\tInput: s = \"true\", k = 4\n\t\tOutput: true\n\t\tExplanation: The only possible solution is to put each character in a separate string.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1503, - "question": "class Solution:\n def maxSatisfaction(self, satisfaction: List[int]) -> int:\n\t\t\"\"\"\n\t\tA chef has collected data on the satisfaction level of his n dishes. Chef can cook any dish in 1 unit of time.\n\t\tLike-time coefficient of a dish is defined as the time taken to cook that dish including previous dishes multiplied by its satisfaction level i.e. time[i] * satisfaction[i].\n\t\tReturn the maximum sum of like-time coefficient that the chef can obtain after dishes preparation.\n\t\tDishes can be prepared in any order and the chef can discard some dishes to get this maximum value.\n\t\tExample 1:\n\t\tInput: satisfaction = [-1,-8,0,5,-9]\n\t\tOutput: 14\n\t\tExplanation: After Removing the second and last dish, the maximum total like-time coefficient will be equal to (-1*1 + 0*2 + 5*3 = 14).\n\t\tEach dish is prepared in one unit of time.\n\t\tExample 2:\n\t\tInput: satisfaction = [4,3,2]\n\t\tOutput: 20\n\t\tExplanation: Dishes can be prepared in any order, (2*1 + 3*2 + 4*3 = 20)\n\t\tExample 3:\n\t\tInput: satisfaction = [-1,-4,-5]\n\t\tOutput: 0\n\t\tExplanation: People do not like the dishes. No dish is prepared.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1505, - "question": "class Solution:\n def createTargetArray(self, nums: List[int], index: List[int]) -> List[int]:\n\t\t\"\"\"\n\t\tGiven two arrays of integers nums and index. Your task is to create target array under the following rules:\n\t\t\tInitially target array is empty.\n\t\t\tFrom left to right read nums[i] and index[i], insert at index index[i] the value nums[i] in target array.\n\t\t\tRepeat the previous step until there are no elements to read in nums and index.\n\t\tReturn the target array.\n\t\tIt is guaranteed that the insertion operations will be valid.\n\t\tExample 1:\n\t\tInput: nums = [0,1,2,3,4], index = [0,1,2,2,1]\n\t\tOutput: [0,4,1,3,2]\n\t\tExplanation:\n\t\tnums index target\n\t\t0 0 [0]\n\t\t1 1 [0,1]\n\t\t2 2 [0,1,2]\n\t\t3 2 [0,1,3,2]\n\t\t4 1 [0,4,1,3,2]\n\t\tExample 2:\n\t\tInput: nums = [1,2,3,4,0], index = [0,1,2,3,0]\n\t\tOutput: [0,1,2,3,4]\n\t\tExplanation:\n\t\tnums index target\n\t\t1 0 [1]\n\t\t2 1 [1,2]\n\t\t3 2 [1,2,3]\n\t\t4 3 [1,2,3,4]\n\t\t0 0 [0,1,2,3,4]\n\t\tExample 3:\n\t\tInput: nums = [1], index = [0]\n\t\tOutput: [1]\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1507, - "question": "class Solution:\n def hasValidPath(self, grid: List[List[int]]) -> bool:\n\t\t\"\"\"\n\t\tYou are given an m x n grid. Each cell of grid represents a street. The street of grid[i][j] can be:\n\t\t\t1 which means a street connecting the left cell and the right cell.\n\t\t\t2 which means a street connecting the upper cell and the lower cell.\n\t\t\t3 which means a street connecting the left cell and the lower cell.\n\t\t\t4 which means a street connecting the right cell and the lower cell.\n\t\t\t5 which means a street connecting the left cell and the upper cell.\n\t\t\t6 which means a street connecting the right cell and the upper cell.\n\t\tYou will initially start at the street of the upper-left cell (0, 0). A valid path in the grid is a path that starts from the upper left cell (0, 0) and ends at the bottom-right cell (m - 1, n - 1). The path should only follow the streets.\n\t\tNotice that you are not allowed to change any street.\n\t\tReturn true if there is a valid path in the grid or false otherwise.\n\t\tExample 1:\n\t\tInput: grid = [[2,4,3],[6,5,2]]\n\t\tOutput: true\n\t\tExplanation: As shown you can start at cell (0, 0) and visit all the cells of the grid to reach (m - 1, n - 1).\n\t\tExample 2:\n\t\tInput: grid = [[1,2,1],[1,2,1]]\n\t\tOutput: false\n\t\tExplanation: As shown you the street at cell (0, 0) is not connected with any street of any other cell and you will get stuck at cell (0, 0)\n\t\tExample 3:\n\t\tInput: grid = [[1,1,2]]\n\t\tOutput: false\n\t\tExplanation: You will get stuck at cell (0, 1) and you cannot reach cell (0, 2).\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1508, - "question": "class Solution:\n def longestPrefix(self, s: str) -> str:\n\t\t\"\"\"\n\t\tA string is called a happy prefix if is a non-empty prefix which is also a suffix (excluding itself).\n\t\tGiven a string s, return the longest happy prefix of s. Return an empty string \"\" if no such prefix exists.\n\t\tExample 1:\n\t\tInput: s = \"level\"\n\t\tOutput: \"l\"\n\t\tExplanation: s contains 4 prefix excluding itself (\"l\", \"le\", \"lev\", \"leve\"), and suffix (\"l\", \"el\", \"vel\", \"evel\"). The largest prefix which is also suffix is given by \"l\".\n\t\tExample 2:\n\t\tInput: s = \"ababab\"\n\t\tOutput: \"abab\"\n\t\tExplanation: \"abab\" is the largest prefix which is also suffix. They can overlap in the original string.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1510, - "question": "class Solution:\n def findLucky(self, arr: List[int]) -> int:\n\t\t\"\"\"\n\t\tGiven an array of integers arr, a lucky integer is an integer that has a frequency in the array equal to its value.\n\t\tReturn the largest lucky integer in the array. If there is no lucky integer return -1.\n\t\tExample 1:\n\t\tInput: arr = [2,2,3,4]\n\t\tOutput: 2\n\t\tExplanation: The only lucky number in the array is 2 because frequency[2] == 2.\n\t\tExample 2:\n\t\tInput: arr = [1,2,2,3,3,3]\n\t\tOutput: 3\n\t\tExplanation: 1, 2 and 3 are all lucky numbers, return the largest of them.\n\t\tExample 3:\n\t\tInput: arr = [2,2,2,3,3]\n\t\tOutput: -1\n\t\tExplanation: There are no lucky numbers in the array.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1511, - "question": "class Solution:\n def numTeams(self, rating: List[int]) -> int:\n\t\t\"\"\"\n\t\tThere are n soldiers standing in a line. Each soldier is assigned a unique rating value.\n\t\tYou have to form a team of 3 soldiers amongst them under the following rules:\n\t\t\tChoose 3 soldiers with index (i, j, k) with rating (rating[i], rating[j], rating[k]).\n\t\t\tA team is valid if: (rating[i] < rating[j] < rating[k]) or (rating[i] > rating[j] > rating[k]) where (0 <= i < j < k < n).\n\t\tReturn the number of teams you can form given the conditions. (soldiers can be part of multiple teams).\n\t\tExample 1:\n\t\tInput: rating = [2,5,3,4,1]\n\t\tOutput: 3\n\t\tExplanation: We can form three teams given the conditions. (2,3,4), (5,4,1), (5,3,1). \n\t\tExample 2:\n\t\tInput: rating = [2,1,3]\n\t\tOutput: 0\n\t\tExplanation: We can't form any team given the conditions.\n\t\tExample 3:\n\t\tInput: rating = [1,2,3,4]\n\t\tOutput: 4\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1512, - "question": "class UndergroundSystem:\n def __init__(self):\n def checkIn(self, id: int, stationName: str, t: int) -> None:\n def checkOut(self, id: int, stationName: str, t: int) -> None:\n def getAverageTime(self, startStation: str, endStation: str) -> float:\n\t\t\"\"\"\n\t\tAn underground railway system is keeping track of customer travel times between different stations. They are using this data to calculate the average time it takes to travel from one station to another.\n\t\tImplement the UndergroundSystem class:\n\t\t\tvoid checkIn(int id, string stationName, int t)\n\t\t\t\tA customer with a card ID equal to id, checks in at the station stationName at time t.\n\t\t\t\tA customer can only be checked into one place at a time.\n\t\t\tvoid checkOut(int id, string stationName, int t)\n\t\t\t\tA customer with a card ID equal to id, checks out from the station stationName at time t.\n\t\t\tdouble getAverageTime(string startStation, string endStation)\n\t\t\t\tReturns the average time it takes to travel from startStation to endStation.\n\t\t\t\tThe average time is computed from all the previous traveling times from startStation to endStation that happened directly, meaning a check in at startStation followed by a check out from endStation.\n\t\t\t\tThe time it takes to travel from startStation to endStation may be different from the time it takes to travel from endStation to startStation.\n\t\t\t\tThere will be at least one customer that has traveled from startStation to endStation before getAverageTime is called.\n\t\tYou may assume all calls to the checkIn and checkOut methods are consistent. If a customer checks in at time t1 then checks out at time t2, then t1 < t2. All events happen in chronological order.\n\t\tExample 1:\n\t\tInput\n\t\t[\"UndergroundSystem\",\"checkIn\",\"checkIn\",\"checkIn\",\"checkOut\",\"checkOut\",\"checkOut\",\"getAverageTime\",\"getAverageTime\",\"checkIn\",\"getAverageTime\",\"checkOut\",\"getAverageTime\"]\n\t\t[[],[45,\"Leyton\",3],[32,\"Paradise\",8],[27,\"Leyton\",10],[45,\"Waterloo\",15],[27,\"Waterloo\",20],[32,\"Cambridge\",22],[\"Paradise\",\"Cambridge\"],[\"Leyton\",\"Waterloo\"],[10,\"Leyton\",24],[\"Leyton\",\"Waterloo\"],[10,\"Waterloo\",38],[\"Leyton\",\"Waterloo\"]]\n\t\tOutput\n\t\t[null,null,null,null,null,null,null,14.00000,11.00000,null,11.00000,null,12.00000]\n\t\tExplanation\n\t\tUndergroundSystem undergroundSystem = new UndergroundSystem();\n\t\tundergroundSystem.checkIn(45, \"Leyton\", 3);\n\t\tundergroundSystem.checkIn(32, \"Paradise\", 8);\n\t\tundergroundSystem.checkIn(27, \"Leyton\", 10);\n\t\tundergroundSystem.checkOut(45, \"Waterloo\", 15); // Customer 45 \"Leyton\" -> \"Waterloo\" in 15-3 = 12\n\t\tundergroundSystem.checkOut(27, \"Waterloo\", 20); // Customer 27 \"Leyton\" -> \"Waterloo\" in 20-10 = 10\n\t\tundergroundSystem.checkOut(32, \"Cambridge\", 22); // Customer 32 \"Paradise\" -> \"Cambridge\" in 22-8 = 14\n\t\tundergroundSystem.getAverageTime(\"Paradise\", \"Cambridge\"); // return 14.00000. One trip \"Paradise\" -> \"Cambridge\", (14) / 1 = 14\n\t\tundergroundSystem.getAverageTime(\"Leyton\", \"Waterloo\"); // return 11.00000. Two trips \"Leyton\" -> \"Waterloo\", (10 + 12) / 2 = 11\n\t\tundergroundSystem.checkIn(10, \"Leyton\", 24);\n\t\tundergroundSystem.getAverageTime(\"Leyton\", \"Waterloo\"); // return 11.00000\n\t\tundergroundSystem.checkOut(10, \"Waterloo\", 38); // Customer 10 \"Leyton\" -> \"Waterloo\" in 38-24 = 14\n\t\tundergroundSystem.getAverageTime(\"Leyton\", \"Waterloo\"); // return 12.00000. Three trips \"Leyton\" -> \"Waterloo\", (10 + 12 + 14) / 3 = 12\n\t\tExample 2:\n\t\tInput\n\t\t[\"UndergroundSystem\",\"checkIn\",\"checkOut\",\"getAverageTime\",\"checkIn\",\"checkOut\",\"getAverageTime\",\"checkIn\",\"checkOut\",\"getAverageTime\"]\n\t\t[[],[10,\"Leyton\",3],[10,\"Paradise\",8],[\"Leyton\",\"Paradise\"],[5,\"Leyton\",10],[5,\"Paradise\",16],[\"Leyton\",\"Paradise\"],[2,\"Leyton\",21],[2,\"Paradise\",30],[\"Leyton\",\"Paradise\"]]\n\t\tOutput\n\t\t[null,null,null,5.00000,null,null,5.50000,null,null,6.66667]\n\t\tExplanation\n\t\tUndergroundSystem undergroundSystem = new UndergroundSystem();\n\t\tundergroundSystem.checkIn(10, \"Leyton\", 3);\n\t\tundergroundSystem.checkOut(10, \"Paradise\", 8); // Customer 10 \"Leyton\" -> \"Paradise\" in 8-3 = 5\n\t\tundergroundSystem.getAverageTime(\"Leyton\", \"Paradise\"); // return 5.00000, (5) / 1 = 5\n\t\tundergroundSystem.checkIn(5, \"Leyton\", 10);\n\t\tundergroundSystem.checkOut(5, \"Paradise\", 16); // Customer 5 \"Leyton\" -> \"Paradise\" in 16-10 = 6\n\t\tundergroundSystem.getAverageTime(\"Leyton\", \"Paradise\"); // return 5.50000, (5 + 6) / 2 = 5.5\n\t\tundergroundSystem.checkIn(2, \"Leyton\", 21);\n\t\tundergroundSystem.checkOut(2, \"Paradise\", 30); // Customer 2 \"Leyton\" -> \"Paradise\" in 30-21 = 9\n\t\tundergroundSystem.getAverageTime(\"Leyton\", \"Paradise\"); // return 6.66667, (5 + 6 + 9) / 3 = 6.66667\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1513, - "question": "class Solution:\n def findGoodStrings(self, n: int, s1: str, s2: str, evil: str) -> int:\n\t\t\"\"\"\n\t\tGiven the strings s1 and s2 of size n and the string evil, return the number of good strings.\n\t\tA good string has size n, it is alphabetically greater than or equal to s1, it is alphabetically smaller than or equal to s2, and it does not contain the string evil as a substring. Since the answer can be a huge number, return this modulo 109 + 7.\n\t\tExample 1:\n\t\tInput: n = 2, s1 = \"aa\", s2 = \"da\", evil = \"b\"\n\t\tOutput: 51 \n\t\tExplanation: There are 25 good strings starting with 'a': \"aa\",\"ac\",\"ad\",...,\"az\". Then there are 25 good strings starting with 'c': \"ca\",\"cc\",\"cd\",...,\"cz\" and finally there is one good string starting with 'd': \"da\". \n\t\tExample 2:\n\t\tInput: n = 8, s1 = \"leetcode\", s2 = \"leetgoes\", evil = \"leet\"\n\t\tOutput: 0 \n\t\tExplanation: All strings greater than or equal to s1 and smaller than or equal to s2 start with the prefix \"leet\", therefore, there is not any good string.\n\t\tExample 3:\n\t\tInput: n = 2, s1 = \"gx\", s2 = \"gz\", evil = \"x\"\n\t\tOutput: 2\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1514, - "question": "class Solution:\n def minStartValue(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tGiven an array of integers nums, you start with an initial positive value startValue.\n\t\tIn each iteration, you calculate the step by step sum of startValue plus elements in nums (from left to right).\n\t\tReturn the minimum positive value of startValue such that the step by step sum is never less than 1.\n\t\tExample 1:\n\t\tInput: nums = [-3,2,-3,4,2]\n\t\tOutput: 5\n\t\tExplanation: If you choose startValue = 4, in the third iteration your step by step sum is less than 1.\n\t\tstep by step sum\n\t\tstartValue = 4 | startValue = 5 | nums\n\t\t (4 -3 ) = 1 | (5 -3 ) = 2 | -3\n\t\t (1 +2 ) = 3 | (2 +2 ) = 4 | 2\n\t\t (3 -3 ) = 0 | (4 -3 ) = 1 | -3\n\t\t (0 +4 ) = 4 | (1 +4 ) = 5 | 4\n\t\t (4 +2 ) = 6 | (5 +2 ) = 7 | 2\n\t\tExample 2:\n\t\tInput: nums = [1,2]\n\t\tOutput: 1\n\t\tExplanation: Minimum start value should be positive. \n\t\tExample 3:\n\t\tInput: nums = [1,-2,-3]\n\t\tOutput: 5\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1515, - "question": "class Solution:\n def findMinFibonacciNumbers(self, k: int) -> int:\n\t\t\"\"\"\n\t\tGiven an integer k, return the minimum number of Fibonacci numbers whose sum is equal to k. The same Fibonacci number can be used multiple times.\n\t\tThe Fibonacci numbers are defined as:\n\t\t\tF1 = 1\n\t\t\tF2 = 1\n\t\t\tFn = Fn-1 + Fn-2 for n > 2.\n\t\tIt is guaranteed that for the given constraints we can always find such Fibonacci numbers that sum up to k.\n\t\tExample 1:\n\t\tInput: k = 7\n\t\tOutput: 2 \n\t\tExplanation: The Fibonacci numbers are: 1, 1, 2, 3, 5, 8, 13, ... \n\t\tFor k = 7 we can use 2 + 5 = 7.\n\t\tExample 2:\n\t\tInput: k = 10\n\t\tOutput: 2 \n\t\tExplanation: For k = 10 we can use 2 + 8 = 10.\n\t\tExample 3:\n\t\tInput: k = 19\n\t\tOutput: 3 \n\t\tExplanation: For k = 19 we can use 1 + 5 + 13 = 19.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1516, - "question": "class Solution:\n def getHappyString(self, n: int, k: int) -> str:\n\t\t\"\"\"\n\t\tA happy string is a string that:\n\t\t\tconsists only of letters of the set ['a', 'b', 'c'].\n\t\t\ts[i] != s[i + 1] for all values of i from 1 to s.length - 1 (string is 1-indexed).\n\t\tFor example, strings \"abc\", \"ac\", \"b\" and \"abcbabcbcb\" are all happy strings and strings \"aa\", \"baa\" and \"ababbc\" are not happy strings.\n\t\tGiven two integers n and k, consider a list of all happy strings of length n sorted in lexicographical order.\n\t\tReturn the kth string of this list or return an empty string if there are less than k happy strings of length n.\n\t\tExample 1:\n\t\tInput: n = 1, k = 3\n\t\tOutput: \"c\"\n\t\tExplanation: The list [\"a\", \"b\", \"c\"] contains all happy strings of length 1. The third string is \"c\".\n\t\tExample 2:\n\t\tInput: n = 1, k = 4\n\t\tOutput: \"\"\n\t\tExplanation: There are only 3 happy strings of length 1.\n\t\tExample 3:\n\t\tInput: n = 3, k = 9\n\t\tOutput: \"cab\"\n\t\tExplanation: There are 12 different happy string of length 3 [\"aba\", \"abc\", \"aca\", \"acb\", \"bab\", \"bac\", \"bca\", \"bcb\", \"cab\", \"cac\", \"cba\", \"cbc\"]. You will find the 9th string = \"cab\"\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1517, - "question": "class Solution:\n def numberOfArrays(self, s: str, k: int) -> int:\n\t\t\"\"\"\n\t\tA program was supposed to print an array of integers. The program forgot to print whitespaces and the array is printed as a string of digits s and all we know is that all integers in the array were in the range [1, k] and there are no leading zeros in the array.\n\t\tGiven the string s and the integer k, return the number of the possible arrays that can be printed as s using the mentioned program. Since the answer may be very large, return it modulo 109 + 7.\n\t\tExample 1:\n\t\tInput: s = \"1000\", k = 10000\n\t\tOutput: 1\n\t\tExplanation: The only possible array is [1000]\n\t\tExample 2:\n\t\tInput: s = \"1000\", k = 10\n\t\tOutput: 0\n\t\tExplanation: There cannot be an array that was printed this way and has all integer >= 1 and <= 10.\n\t\tExample 3:\n\t\tInput: s = \"1317\", k = 2000\n\t\tOutput: 8\n\t\tExplanation: Possible arrays are [1317],[131,7],[13,17],[1,317],[13,1,7],[1,31,7],[1,3,17],[1,3,1,7]\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1519, - "question": "class Solution:\n def minSubsequence(self, nums: List[int]) -> List[int]:\n\t\t\"\"\"\n\t\tGiven the array nums, obtain a subsequence of the array whose sum of elements is strictly greater than the sum of the non included elements in such subsequence. \n\t\tIf there are multiple solutions, return the subsequence with minimum size and if there still exist multiple solutions, return the subsequence with the maximum total sum of all its elements. A subsequence of an array can be obtained by erasing some (possibly zero) elements from the array. \n\t\tNote that the solution with the given constraints is guaranteed to be unique. Also return the answer sorted in non-increasing order.\n\t\tExample 1:\n\t\tInput: nums = [4,3,10,9,8]\n\t\tOutput: [10,9] \n\t\tExplanation: The subsequences [10,9] and [10,8] are minimal such that the sum of their elements is strictly greater than the sum of elements not included. However, the subsequence [10,9] has the maximum total sum of its elements. \n\t\tExample 2:\n\t\tInput: nums = [4,4,7,6,7]\n\t\tOutput: [7,7,6] \n\t\tExplanation: The subsequence [7,7] has the sum of its elements equal to 14 which is not strictly greater than the sum of elements not included (14 = 4 + 4 + 6). Therefore, the subsequence [7,6,7] is the minimal satisfying the conditions. Note the subsequence has to be returned in non-decreasing order. \n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1520, - "question": "class Solution:\n def numSteps(self, s: str) -> int:\n\t\t\"\"\"\n\t\tGiven the binary representation of an integer as a string s, return the number of steps to reduce it to 1 under the following rules:\n\t\t\tIf the current number is even, you have to divide it by 2.\n\t\t\tIf the current number is odd, you have to add 1 to it.\n\t\tIt is guaranteed that you can always reach one for all test cases.\n\t\tExample 1:\n\t\tInput: s = \"1101\"\n\t\tOutput: 6\n\t\tExplanation: \"1101\" corressponds to number 13 in their decimal representation.\n\t\tStep 1) 13 is odd, add 1 and obtain 14. \n\t\tStep 2) 14 is even, divide by 2 and obtain 7.\n\t\tStep 3) 7 is odd, add 1 and obtain 8.\n\t\tStep 4) 8 is even, divide by 2 and obtain 4. \n\t\tStep 5) 4 is even, divide by 2 and obtain 2. \n\t\tStep 6) 2 is even, divide by 2 and obtain 1. \n\t\tExample 2:\n\t\tInput: s = \"10\"\n\t\tOutput: 1\n\t\tExplanation: \"10\" corressponds to number 2 in their decimal representation.\n\t\tStep 1) 2 is even, divide by 2 and obtain 1. \n\t\tExample 3:\n\t\tInput: s = \"1\"\n\t\tOutput: 0\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1522, - "question": "class Solution:\n def stoneGameIII(self, stoneValue: List[int]) -> str:\n\t\t\"\"\"\n\t\tAlice and Bob continue their games with piles of stones. There are several stones arranged in a row, and each stone has an associated value which is an integer given in the array stoneValue.\n\t\tAlice and Bob take turns, with Alice starting first. On each player's turn, that player can take 1, 2, or 3 stones from the first remaining stones in the row.\n\t\tThe score of each player is the sum of the values of the stones taken. The score of each player is 0 initially.\n\t\tThe objective of the game is to end with the highest score, and the winner is the player with the highest score and there could be a tie. The game continues until all the stones have been taken.\n\t\tAssume Alice and Bob play optimally.\n\t\tReturn \"Alice\" if Alice will win, \"Bob\" if Bob will win, or \"Tie\" if they will end the game with the same score.\n\t\tExample 1:\n\t\tInput: values = [1,2,3,7]\n\t\tOutput: \"Bob\"\n\t\tExplanation: Alice will always lose. Her best move will be to take three piles and the score become 6. Now the score of Bob is 7 and Bob wins.\n\t\tExample 2:\n\t\tInput: values = [1,2,3,-9]\n\t\tOutput: \"Alice\"\n\t\tExplanation: Alice must choose all the three piles at the first move to win and leave Bob with negative score.\n\t\tIf Alice chooses one pile her score will be 1 and the next move Bob's score becomes 5. In the next move, Alice will take the pile with value = -9 and lose.\n\t\tIf Alice chooses two piles her score will be 3 and the next move Bob's score becomes 3. In the next move, Alice will take the pile with value = -9 and also lose.\n\t\tRemember that both play optimally so here Alice will choose the scenario that makes her win.\n\t\tExample 3:\n\t\tInput: values = [1,2,3,6]\n\t\tOutput: \"Tie\"\n\t\tExplanation: Alice cannot win this game. She can end the game in a draw if she decided to choose all the first three piles, otherwise she will lose.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1524, - "question": "class Solution:\n def stringMatching(self, words: List[str]) -> List[str]:\n\t\t\"\"\"\n\t\tGiven an array of string words, return all strings in words that is a substring of another word. You can return the answer in any order.\n\t\tA substring is a contiguous sequence of characters within a string\n\t\tExample 1:\n\t\tInput: words = [\"mass\",\"as\",\"hero\",\"superhero\"]\n\t\tOutput: [\"as\",\"hero\"]\n\t\tExplanation: \"as\" is substring of \"mass\" and \"hero\" is substring of \"superhero\".\n\t\t[\"hero\",\"as\"] is also a valid answer.\n\t\tExample 2:\n\t\tInput: words = [\"leetcode\",\"et\",\"code\"]\n\t\tOutput: [\"et\",\"code\"]\n\t\tExplanation: \"et\", \"code\" are substring of \"leetcode\".\n\t\tExample 3:\n\t\tInput: words = [\"blue\",\"green\",\"bu\"]\n\t\tOutput: []\n\t\tExplanation: No string of words is substring of another string.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1525, - "question": "class Solution:\n def processQueries(self, queries: List[int], m: int) -> List[int]:\n\t\t\"\"\"\n\t\tGiven the array queries of positive integers between 1 and m, you have to process all queries[i] (from i=0 to i=queries.length-1) according to the following rules:\r\n\t\t\tIn the beginning, you have the permutation P=[1,2,3,...,m].\r\n\t\t\tFor the current i, find the position of queries[i] in the permutation P (indexing from 0) and then move this at the beginning of the permutation P. Notice that the position of queries[i] in P is the result for queries[i].\r\n\t\tReturn an array containing the result for the given queries.\r\n\t\tExample 1:\r\n\t\tInput: queries = [3,1,2,1], m = 5\r\n\t\tOutput: [2,1,2,1] \r\n\t\tExplanation: The queries are processed as follow: \r\n\t\tFor i=0: queries[i]=3, P=[1,2,3,4,5], position of 3 in P is 2, then we move 3 to the beginning of P resulting in P=[3,1,2,4,5]. \r\n\t\tFor i=1: queries[i]=1, P=[3,1,2,4,5], position of 1 in P is 1, then we move 1 to the beginning of P resulting in P=[1,3,2,4,5]. \r\n\t\tFor i=2: queries[i]=2, P=[1,3,2,4,5], position of 2 in P is 2, then we move 2 to the beginning of P resulting in P=[2,1,3,4,5]. \r\n\t\tFor i=3: queries[i]=1, P=[2,1,3,4,5], position of 1 in P is 1, then we move 1 to the beginning of P resulting in P=[1,2,3,4,5]. \r\n\t\tTherefore, the array containing the result is [2,1,2,1]. \r\n\t\tExample 2:\r\n\t\tInput: queries = [4,1,2,2], m = 4\r\n\t\tOutput: [3,1,2,0]\r\n\t\tExample 3:\r\n\t\tInput: queries = [7,5,5,8,3], m = 8\r\n\t\tOutput: [6,5,0,7,5]\r\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1526, - "question": "class Solution:\n def entityParser(self, text: str) -> str:\n\t\t\"\"\"\n\t\tHTML entity parser is the parser that takes HTML code as input and replace all the entities of the special characters by the characters itself.\n\t\tThe special characters and their entities for HTML are:\n\t\t\tQuotation Mark: the entity is " and symbol character is \".\n\t\t\tSingle Quote Mark: the entity is ' and symbol character is '.\n\t\t\tAmpersand: the entity is & and symbol character is &.\n\t\t\tGreater Than Sign: the entity is > and symbol character is >.\n\t\t\tLess Than Sign: the entity is < and symbol character is <.\n\t\t\tSlash: the entity is ⁄ and symbol character is /.\n\t\tGiven the input text string to the HTML parser, you have to implement the entity parser.\n\t\tReturn the text after replacing the entities by the special characters.\n\t\tExample 1:\n\t\tInput: text = \"& is an HTML entity but &ambassador; is not.\"\n\t\tOutput: \"& is an HTML entity but &ambassador; is not.\"\n\t\tExplanation: The parser will replace the & entity by &\n\t\tExample 2:\n\t\tInput: text = \"and I quote: "..."\"\n\t\tOutput: \"and I quote: \\\"...\\\"\"\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1527, - "question": "class Solution:\n def numOfWays(self, n: int) -> int:\n\t\t\"\"\"\n\t\tYou have a grid of size n x 3 and you want to paint each cell of the grid with exactly one of the three colors: Red, Yellow, or Green while making sure that no two adjacent cells have the same color (i.e., no two cells that share vertical or horizontal sides have the same color).\n\t\tGiven n the number of rows of the grid, return the number of ways you can paint this grid. As the answer may grow large, the answer must be computed modulo 109 + 7.\n\t\tExample 1:\n\t\tInput: n = 1\n\t\tOutput: 12\n\t\tExplanation: There are 12 possible way to paint the grid as shown.\n\t\tExample 2:\n\t\tInput: n = 5000\n\t\tOutput: 30228214\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1528, - "question": "class Solution:\n def kidsWithCandies(self, candies: List[int], extraCandies: int) -> List[bool]:\n\t\t\"\"\"\n\t\tThere are n kids with candies. You are given an integer array candies, where each candies[i] represents the number of candies the ith kid has, and an integer extraCandies, denoting the number of extra candies that you have.\n\t\tReturn a boolean array result of length n, where result[i] is true if, after giving the ith kid all the extraCandies, they will have the greatest number of candies among all the kids, or false otherwise.\n\t\tNote that multiple kids can have the greatest number of candies.\n\t\tExample 1:\n\t\tInput: candies = [2,3,5,1,3], extraCandies = 3\n\t\tOutput: [true,true,true,false,true] \n\t\tExplanation: If you give all extraCandies to:\n\t\t- Kid 1, they will have 2 + 3 = 5 candies, which is the greatest among the kids.\n\t\t- Kid 2, they will have 3 + 3 = 6 candies, which is the greatest among the kids.\n\t\t- Kid 3, they will have 5 + 3 = 8 candies, which is the greatest among the kids.\n\t\t- Kid 4, they will have 1 + 3 = 4 candies, which is not the greatest among the kids.\n\t\t- Kid 5, they will have 3 + 3 = 6 candies, which is the greatest among the kids.\n\t\tExample 2:\n\t\tInput: candies = [4,2,1,1,2], extraCandies = 1\n\t\tOutput: [true,false,false,false,false] \n\t\tExplanation: There is only 1 extra candy.\n\t\tKid 1 will always have the greatest number of candies, even if a different kid is given the extra candy.\n\t\tExample 3:\n\t\tInput: candies = [12,1,12], extraCandies = 10\n\t\tOutput: [true,false,true]\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1529, - "question": "class Solution:\n def maxDiff(self, num: int) -> int:\n\t\t\"\"\"\n\t\tYou are given an integer num. You will apply the following steps exactly two times:\n\t\t\tPick a digit x (0 <= x <= 9).\n\t\t\tPick another digit y (0 <= y <= 9). The digit y can be equal to x.\n\t\t\tReplace all the occurrences of x in the decimal representation of num by y.\n\t\t\tThe new integer cannot have any leading zeros, also the new integer cannot be 0.\n\t\tLet a and b be the results of applying the operations to num the first and second times, respectively.\n\t\tReturn the max difference between a and b.\n\t\tExample 1:\n\t\tInput: num = 555\n\t\tOutput: 888\n\t\tExplanation: The first time pick x = 5 and y = 9 and store the new integer in a.\n\t\tThe second time pick x = 5 and y = 1 and store the new integer in b.\n\t\tWe have now a = 999 and b = 111 and max difference = 888\n\t\tExample 2:\n\t\tInput: num = 9\n\t\tOutput: 8\n\t\tExplanation: The first time pick x = 9 and y = 9 and store the new integer in a.\n\t\tThe second time pick x = 9 and y = 1 and store the new integer in b.\n\t\tWe have now a = 9 and b = 1 and max difference = 8\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1530, - "question": "class Solution:\n def checkIfCanBreak(self, s1: str, s2: str) -> bool:\n\t\t\"\"\"\n\t\tGiven two strings: s1 and s2 with the same size, check if some permutation of string s1 can break some permutation of string s2 or vice-versa. In other words s2 can break s1 or vice-versa.\n\t\tA string x can break string y (both of size n) if x[i] >= y[i] (in alphabetical order) for all i between 0 and n-1.\n\t\tExample 1:\n\t\tInput: s1 = \"abc\", s2 = \"xya\"\n\t\tOutput: true\n\t\tExplanation: \"ayx\" is a permutation of s2=\"xya\" which can break to string \"abc\" which is a permutation of s1=\"abc\".\n\t\tExample 2:\n\t\tInput: s1 = \"abe\", s2 = \"acd\"\n\t\tOutput: false \n\t\tExplanation: All permutations for s1=\"abe\" are: \"abe\", \"aeb\", \"bae\", \"bea\", \"eab\" and \"eba\" and all permutation for s2=\"acd\" are: \"acd\", \"adc\", \"cad\", \"cda\", \"dac\" and \"dca\". However, there is not any permutation from s1 which can break some permutation from s2 and vice-versa.\n\t\tExample 3:\n\t\tInput: s1 = \"leetcodee\", s2 = \"interview\"\n\t\tOutput: true\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1531, - "question": "class Solution:\n def numberWays(self, hats: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tThere are n people and 40 types of hats labeled from 1 to 40.\n\t\tGiven a 2D integer array hats, where hats[i] is a list of all hats preferred by the ith person.\n\t\tReturn the number of ways that the n people wear different hats to each other.\n\t\tSince the answer may be too large, return it modulo 109 + 7.\n\t\tExample 1:\n\t\tInput: hats = [[3,4],[4,5],[5]]\n\t\tOutput: 1\n\t\tExplanation: There is only one way to choose hats given the conditions. \n\t\tFirst person choose hat 3, Second person choose hat 4 and last one hat 5.\n\t\tExample 2:\n\t\tInput: hats = [[3,5,1],[3,5]]\n\t\tOutput: 4\n\t\tExplanation: There are 4 ways to choose hats:\n\t\t(3,5), (5,3), (1,3) and (1,5)\n\t\tExample 3:\n\t\tInput: hats = [[1,2,3,4],[1,2,3,4],[1,2,3,4],[1,2,3,4]]\n\t\tOutput: 24\n\t\tExplanation: Each person can choose hats labeled from 1 to 4.\n\t\tNumber of Permutations of (1,2,3,4) = 24.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1532, - "question": "class Solution:\n def reformat(self, s: str) -> str:\n\t\t\"\"\"\n\t\tYou are given an alphanumeric string s. (Alphanumeric string is a string consisting of lowercase English letters and digits).\n\t\tYou have to find a permutation of the string where no letter is followed by another letter and no digit is followed by another digit. That is, no two adjacent characters have the same type.\n\t\tReturn the reformatted string or return an empty string if it is impossible to reformat the string.\n\t\tExample 1:\n\t\tInput: s = \"a0b1c2\"\n\t\tOutput: \"0a1b2c\"\n\t\tExplanation: No two adjacent characters have the same type in \"0a1b2c\". \"a0b1c2\", \"0a1b2c\", \"0c2a1b\" are also valid permutations.\n\t\tExample 2:\n\t\tInput: s = \"leetcode\"\n\t\tOutput: \"\"\n\t\tExplanation: \"leetcode\" has only characters so we cannot separate them by digits.\n\t\tExample 3:\n\t\tInput: s = \"1229857369\"\n\t\tOutput: \"\"\n\t\tExplanation: \"1229857369\" has only digits so we cannot separate them by characters.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1533, - "question": "class Solution:\n def displayTable(self, orders: List[List[str]]) -> List[List[str]]:\n\t\t\"\"\"\n\t\tGiven the array orders, which represents the orders that customers have done in a restaurant. More specifically orders[i]=[customerNamei,tableNumberi,foodItemi] where customerNamei is the name of the customer, tableNumberi is the table customer sit at, and foodItemi is the item customer orders.\r\n\t\tReturn the restaurant's \u201cdisplay table\u201d. The \u201cdisplay table\u201d is a table whose row entries denote how many of each food item each table ordered. The first column is the table number and the remaining columns correspond to each food item in alphabetical order. The first row should be a header whose first column is \u201cTable\u201d, followed by the names of the food items. Note that the customer names are not part of the table. Additionally, the rows should be sorted in numerically increasing order.\r\n\t\tExample 1:\r\n\t\tInput: orders = [[\"David\",\"3\",\"Ceviche\"],[\"Corina\",\"10\",\"Beef Burrito\"],[\"David\",\"3\",\"Fried Chicken\"],[\"Carla\",\"5\",\"Water\"],[\"Carla\",\"5\",\"Ceviche\"],[\"Rous\",\"3\",\"Ceviche\"]]\r\n\t\tOutput: [[\"Table\",\"Beef Burrito\",\"Ceviche\",\"Fried Chicken\",\"Water\"],[\"3\",\"0\",\"2\",\"1\",\"0\"],[\"5\",\"0\",\"1\",\"0\",\"1\"],[\"10\",\"1\",\"0\",\"0\",\"0\"]] \r\n\t\tExplanation:\r\n\t\tThe displaying table looks like:\r\n\t\tTable,Beef Burrito,Ceviche,Fried Chicken,Water\r\n\t\t3 ,0 ,2 ,1 ,0\r\n\t\t5 ,0 ,1 ,0 ,1\r\n\t\t10 ,1 ,0 ,0 ,0\r\n\t\tFor the table 3: David orders \"Ceviche\" and \"Fried Chicken\", and Rous orders \"Ceviche\".\r\n\t\tFor the table 5: Carla orders \"Water\" and \"Ceviche\".\r\n\t\tFor the table 10: Corina orders \"Beef Burrito\". \r\n\t\tExample 2:\r\n\t\tInput: orders = [[\"James\",\"12\",\"Fried Chicken\"],[\"Ratesh\",\"12\",\"Fried Chicken\"],[\"Amadeus\",\"12\",\"Fried Chicken\"],[\"Adam\",\"1\",\"Canadian Waffles\"],[\"Brianna\",\"1\",\"Canadian Waffles\"]]\r\n\t\tOutput: [[\"Table\",\"Canadian Waffles\",\"Fried Chicken\"],[\"1\",\"2\",\"0\"],[\"12\",\"0\",\"3\"]] \r\n\t\tExplanation: \r\n\t\tFor the table 1: Adam and Brianna order \"Canadian Waffles\".\r\n\t\tFor the table 12: James, Ratesh and Amadeus order \"Fried Chicken\".\r\n\t\tExample 3:\r\n\t\tInput: orders = [[\"Laura\",\"2\",\"Bean Burrito\"],[\"Jhon\",\"2\",\"Beef Burrito\"],[\"Melissa\",\"2\",\"Soda\"]]\r\n\t\tOutput: [[\"Table\",\"Bean Burrito\",\"Beef Burrito\",\"Soda\"],[\"2\",\"1\",\"1\",\"1\"]]\r\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1534, - "question": "class Solution:\n def minNumberOfFrogs(self, croakOfFrogs: str) -> int:\n\t\t\"\"\"\n\t\tYou are given the string croakOfFrogs, which represents a combination of the string \"croak\" from different frogs, that is, multiple frogs can croak at the same time, so multiple \"croak\" are mixed.\n\t\tReturn the minimum number of different frogs to finish all the croaks in the given string.\n\t\tA valid \"croak\" means a frog is printing five letters 'c', 'r', 'o', 'a', and 'k' sequentially. The frogs have to print all five letters to finish a croak. If the given string is not a combination of a valid \"croak\" return -1.\n\t\tExample 1:\n\t\tInput: croakOfFrogs = \"croakcroak\"\n\t\tOutput: 1 \n\t\tExplanation: One frog yelling \"croak\" twice.\n\t\tExample 2:\n\t\tInput: croakOfFrogs = \"crcoakroak\"\n\t\tOutput: 2 \n\t\tExplanation: The minimum number of frogs is two. \n\t\tThe first frog could yell \"crcoakroak\".\n\t\tThe second frog could yell later \"crcoakroak\".\n\t\tExample 3:\n\t\tInput: croakOfFrogs = \"croakcrook\"\n\t\tOutput: -1\n\t\tExplanation: The given string is an invalid combination of \"croak\" from different frogs.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1535, - "question": "class Solution:\n def numOfArrays(self, n: int, m: int, k: int) -> int:\n\t\t\"\"\"\n\t\tYou are given three integers n, m and k. Consider the following algorithm to find the maximum element of an array of positive integers:\n\t\tYou should build the array arr which has the following properties:\n\t\t\tarr has exactly n integers.\n\t\t\t1 <= arr[i] <= m where (0 <= i < n).\n\t\t\tAfter applying the mentioned algorithm to arr, the value search_cost is equal to k.\n\t\tReturn the number of ways to build the array arr under the mentioned conditions. As the answer may grow large, the answer must be computed modulo 109 + 7.\n\t\tExample 1:\n\t\tInput: n = 2, m = 3, k = 1\n\t\tOutput: 6\n\t\tExplanation: The possible arrays are [1, 1], [2, 1], [2, 2], [3, 1], [3, 2] [3, 3]\n\t\tExample 2:\n\t\tInput: n = 5, m = 2, k = 3\n\t\tOutput: 0\n\t\tExplanation: There are no possible arrays that satisify the mentioned conditions.\n\t\tExample 3:\n\t\tInput: n = 9, m = 1, k = 1\n\t\tOutput: 1\n\t\tExplanation: The only possible array is [1, 1, 1, 1, 1, 1, 1, 1, 1]\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1537, - "question": "class Solution:\n def maxScore(self, s: str) -> int:\n\t\t\"\"\"\n\t\tGiven a string s of zeros and ones, return the maximum score after splitting the string into two non-empty substrings (i.e. left substring and right substring).\n\t\tThe score after splitting a string is the number of zeros in the left substring plus the number of ones in the right substring.\n\t\tExample 1:\n\t\tInput: s = \"011101\"\n\t\tOutput: 5 \n\t\tExplanation: \n\t\tAll possible ways of splitting s into two non-empty substrings are:\n\t\tleft = \"0\" and right = \"11101\", score = 1 + 4 = 5 \n\t\tleft = \"01\" and right = \"1101\", score = 1 + 3 = 4 \n\t\tleft = \"011\" and right = \"101\", score = 1 + 2 = 3 \n\t\tleft = \"0111\" and right = \"01\", score = 1 + 1 = 2 \n\t\tleft = \"01110\" and right = \"1\", score = 2 + 1 = 3\n\t\tExample 2:\n\t\tInput: s = \"00111\"\n\t\tOutput: 5\n\t\tExplanation: When left = \"00\" and right = \"111\", we get the maximum score = 2 + 3 = 5\n\t\tExample 3:\n\t\tInput: s = \"1111\"\n\t\tOutput: 3\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1538, - "question": "class Solution:\n def maxScore(self, cardPoints: List[int], k: int) -> int:\n\t\t\"\"\"\n\t\tThere are several cards arranged in a row, and each card has an associated number of points. The points are given in the integer array cardPoints.\n\t\tIn one step, you can take one card from the beginning or from the end of the row. You have to take exactly k cards.\n\t\tYour score is the sum of the points of the cards you have taken.\n\t\tGiven the integer array cardPoints and the integer k, return the maximum score you can obtain.\n\t\tExample 1:\n\t\tInput: cardPoints = [1,2,3,4,5,6,1], k = 3\n\t\tOutput: 12\n\t\tExplanation: After the first step, your score will always be 1. However, choosing the rightmost card first will maximize your total score. The optimal strategy is to take the three cards on the right, giving a final score of 1 + 6 + 5 = 12.\n\t\tExample 2:\n\t\tInput: cardPoints = [2,2,2], k = 2\n\t\tOutput: 4\n\t\tExplanation: Regardless of which two cards you take, your score will always be 4.\n\t\tExample 3:\n\t\tInput: cardPoints = [9,7,7,9,7,7,9], k = 7\n\t\tOutput: 55\n\t\tExplanation: You have to take all the cards. Your score is the sum of points of all cards.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1539, - "question": "class Solution:\n def findDiagonalOrder(self, nums: List[List[int]]) -> List[int]:\n\t\t\"\"\"\n\t\tGiven a 2D integer array nums, return all elements of nums in diagonal order as shown in the below images.\n\t\tExample 1:\n\t\tInput: nums = [[1,2,3],[4,5,6],[7,8,9]]\n\t\tOutput: [1,4,2,7,5,3,8,6,9]\n\t\tExample 2:\n\t\tInput: nums = [[1,2,3,4,5],[6,7],[8],[9,10,11],[12,13,14,15,16]]\n\t\tOutput: [1,6,2,8,7,3,9,4,12,10,5,13,11,14,15,16]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1542, - "question": "class Solution:\n def maxPower(self, s: str) -> int:\n\t\t\"\"\"\n\t\tThe power of the string is the maximum length of a non-empty substring that contains only one unique character.\n\t\tGiven a string s, return the power of s.\n\t\tExample 1:\n\t\tInput: s = \"leetcode\"\n\t\tOutput: 2\n\t\tExplanation: The substring \"ee\" is of length 2 with the character 'e' only.\n\t\tExample 2:\n\t\tInput: s = \"abbcccddddeeeeedcba\"\n\t\tOutput: 5\n\t\tExplanation: The substring \"eeeee\" is of length 5 with the character 'e' only.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1543, - "question": "class Solution:\n def simplifiedFractions(self, n: int) -> List[str]:\n\t\t\"\"\"\n\t\tGiven an integer n, return a list of all simplified fractions between 0 and 1 (exclusive) such that the denominator is less-than-or-equal-to n. You can return the answer in any order.\n\t\tExample 1:\n\t\tInput: n = 2\n\t\tOutput: [\"1/2\"]\n\t\tExplanation: \"1/2\" is the only unique fraction with a denominator less-than-or-equal-to 2.\n\t\tExample 2:\n\t\tInput: n = 3\n\t\tOutput: [\"1/2\",\"1/3\",\"2/3\"]\n\t\tExample 3:\n\t\tInput: n = 4\n\t\tOutput: [\"1/2\",\"1/3\",\"1/4\",\"2/3\",\"3/4\"]\n\t\tExplanation: \"2/4\" is not a simplified fraction because it can be simplified to \"1/2\".\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1544, - "question": "class Solution:\n def goodNodes(self, root: TreeNode) -> int:\n\t\t\"\"\"\n\t\tGiven a binary tree root, a node X in the tree is named good if in the path from root to X there are no nodes with a value greater than X.\r\n\t\tReturn the number of good nodes in the binary tree.\r\n\t\tExample 1:\r\n\t\tInput: root = [3,1,4,3,null,1,5]\r\n\t\tOutput: 4\r\n\t\tExplanation: Nodes in blue are good.\r\n\t\tRoot Node (3) is always a good node.\r\n\t\tNode 4 -> (3,4) is the maximum value in the path starting from the root.\r\n\t\tNode 5 -> (3,4,5) is the maximum value in the path\r\n\t\tNode 3 -> (3,1,3) is the maximum value in the path.\r\n\t\tExample 2:\r\n\t\tInput: root = [3,3,null,4,2]\r\n\t\tOutput: 3\r\n\t\tExplanation: Node 2 -> (3, 3, 2) is not good, because \"3\" is higher than it.\r\n\t\tExample 3:\r\n\t\tInput: root = [1]\r\n\t\tOutput: 1\r\n\t\tExplanation: Root is considered as good.\r\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1545, - "question": "class Solution:\n def largestNumber(self, cost: List[int], target: int) -> str:\n\t\t\"\"\"\n\t\tGiven an array of integers cost and an integer target, return the maximum integer you can paint under the following rules:\n\t\t\tThe cost of painting a digit (i + 1) is given by cost[i] (0-indexed).\n\t\t\tThe total cost used must be equal to target.\n\t\t\tThe integer does not have 0 digits.\n\t\tSince the answer may be very large, return it as a string. If there is no way to paint any integer given the condition, return \"0\".\n\t\tExample 1:\n\t\tInput: cost = [4,3,2,5,6,7,2,5,5], target = 9\n\t\tOutput: \"7772\"\n\t\tExplanation: The cost to paint the digit '7' is 2, and the digit '2' is 3. Then cost(\"7772\") = 2*3+ 3*1 = 9. You could also paint \"977\", but \"7772\" is the largest number.\n\t\tDigit cost\n\t\t 1 -> 4\n\t\t 2 -> 3\n\t\t 3 -> 2\n\t\t 4 -> 5\n\t\t 5 -> 6\n\t\t 6 -> 7\n\t\t 7 -> 2\n\t\t 8 -> 5\n\t\t 9 -> 5\n\t\tExample 2:\n\t\tInput: cost = [7,6,5,5,5,6,8,7,8], target = 12\n\t\tOutput: \"85\"\n\t\tExplanation: The cost to paint the digit '8' is 7, and the digit '5' is 5. Then cost(\"85\") = 7 + 5 = 12.\n\t\tExample 3:\n\t\tInput: cost = [2,4,6,2,4,6,4,4,4], target = 5\n\t\tOutput: \"0\"\n\t\tExplanation: It is impossible to paint any integer with total cost equal to target.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1547, - "question": "class Solution:\n def destCity(self, paths: List[List[str]]) -> str:\n\t\t\"\"\"\n\t\tYou are given the array paths, where paths[i] = [cityAi, cityBi] means there exists a direct path going from cityAi to cityBi. Return the destination city, that is, the city without any path outgoing to another city.\n\t\tIt is guaranteed that the graph of paths forms a line without any loop, therefore, there will be exactly one destination city.\n\t\tExample 1:\n\t\tInput: paths = [[\"London\",\"New York\"],[\"New York\",\"Lima\"],[\"Lima\",\"Sao Paulo\"]]\n\t\tOutput: \"Sao Paulo\" \n\t\tExplanation: Starting at \"London\" city you will reach \"Sao Paulo\" city which is the destination city. Your trip consist of: \"London\" -> \"New York\" -> \"Lima\" -> \"Sao Paulo\".\n\t\tExample 2:\n\t\tInput: paths = [[\"B\",\"C\"],[\"D\",\"B\"],[\"C\",\"A\"]]\n\t\tOutput: \"A\"\n\t\tExplanation: All possible trips are: \n\t\t\"D\" -> \"B\" -> \"C\" -> \"A\". \n\t\t\"B\" -> \"C\" -> \"A\". \n\t\t\"C\" -> \"A\". \n\t\t\"A\". \n\t\tClearly the destination city is \"A\".\n\t\tExample 3:\n\t\tInput: paths = [[\"A\",\"Z\"]]\n\t\tOutput: \"Z\"\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1548, - "question": "class Solution:\n def kLengthApart(self, nums: List[int], k: int) -> bool:\n\t\t\"\"\"\n\t\tGiven an binary array nums and an integer k, return true if all 1's are at least k places away from each other, otherwise return false.\n\t\tExample 1:\n\t\tInput: nums = [1,0,0,0,1,0,0,1], k = 2\n\t\tOutput: true\n\t\tExplanation: Each of the 1s are at least 2 places away from each other.\n\t\tExample 2:\n\t\tInput: nums = [1,0,0,1,0,1], k = 2\n\t\tOutput: false\n\t\tExplanation: The second 1 and third 1 are only one apart from each other.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1549, - "question": "class Solution:\n def longestSubarray(self, nums: List[int], limit: int) -> int:\n\t\t\"\"\"\n\t\tGiven an array of integers nums and an integer limit, return the size of the longest non-empty subarray such that the absolute difference between any two elements of this subarray is less than or equal to limit.\n\t\tExample 1:\n\t\tInput: nums = [8,2,4,7], limit = 4\n\t\tOutput: 2 \n\t\tExplanation: All subarrays are: \n\t\t[8] with maximum absolute diff |8-8| = 0 <= 4.\n\t\t[8,2] with maximum absolute diff |8-2| = 6 > 4. \n\t\t[8,2,4] with maximum absolute diff |8-2| = 6 > 4.\n\t\t[8,2,4,7] with maximum absolute diff |8-2| = 6 > 4.\n\t\t[2] with maximum absolute diff |2-2| = 0 <= 4.\n\t\t[2,4] with maximum absolute diff |2-4| = 2 <= 4.\n\t\t[2,4,7] with maximum absolute diff |2-7| = 5 > 4.\n\t\t[4] with maximum absolute diff |4-4| = 0 <= 4.\n\t\t[4,7] with maximum absolute diff |4-7| = 3 <= 4.\n\t\t[7] with maximum absolute diff |7-7| = 0 <= 4. \n\t\tTherefore, the size of the longest subarray is 2.\n\t\tExample 2:\n\t\tInput: nums = [10,1,2,4,7,2], limit = 5\n\t\tOutput: 4 \n\t\tExplanation: The subarray [2,4,7,2] is the longest since the maximum absolute diff is |2-7| = 5 <= 5.\n\t\tExample 3:\n\t\tInput: nums = [4,2,2,2,4,4,2,2], limit = 0\n\t\tOutput: 3\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1550, - "question": "class Solution:\n def kthSmallest(self, mat: List[List[int]], k: int) -> int:\n\t\t\"\"\"\n\t\tYou are given an m x n matrix mat that has its rows sorted in non-decreasing order and an integer k.\n\t\tYou are allowed to choose exactly one element from each row to form an array.\n\t\tReturn the kth smallest array sum among all possible arrays.\n\t\tExample 1:\n\t\tInput: mat = [[1,3,11],[2,4,6]], k = 5\n\t\tOutput: 7\n\t\tExplanation: Choosing one element from each row, the first k smallest sum are:\n\t\t[1,2], [1,4], [3,2], [3,4], [1,6]. Where the 5th sum is 7.\n\t\tExample 2:\n\t\tInput: mat = [[1,3,11],[2,4,6]], k = 9\n\t\tOutput: 17\n\t\tExample 3:\n\t\tInput: mat = [[1,10,10],[1,4,5],[2,3,6]], k = 7\n\t\tOutput: 9\n\t\tExplanation: Choosing one element from each row, the first k smallest sum are:\n\t\t[1,1,2], [1,1,3], [1,4,2], [1,4,3], [1,1,6], [1,5,2], [1,5,3]. Where the 7th sum is 9. \n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1552, - "question": "class Solution:\n def buildArray(self, target: List[int], n: int) -> List[str]:\n\t\t\"\"\"\n\t\tYou are given an integer array target and an integer n.\n\t\tYou have an empty stack with the two following operations:\n\t\t\t\"Push\": pushes an integer to the top of the stack.\n\t\t\t\"Pop\": removes the integer on the top of the stack.\n\t\tYou also have a stream of the integers in the range [1, n].\n\t\tUse the two stack operations to make the numbers in the stack (from the bottom to the top) equal to target. You should follow the following rules:\n\t\t\tIf the stream of the integers is not empty, pick the next integer from the stream and push it to the top of the stack.\n\t\t\tIf the stack is not empty, pop the integer at the top of the stack.\n\t\t\tIf, at any moment, the elements in the stack (from the bottom to the top) are equal to target, do not read new integers from the stream and do not do more operations on the stack.\n\t\tReturn the stack operations needed to build target following the mentioned rules. If there are multiple valid answers, return any of them.\n\t\tExample 1:\n\t\tInput: target = [1,3], n = 3\n\t\tOutput: [\"Push\",\"Push\",\"Pop\",\"Push\"]\n\t\tExplanation: Initially the stack s is empty. The last element is the top of the stack.\n\t\tRead 1 from the stream and push it to the stack. s = [1].\n\t\tRead 2 from the stream and push it to the stack. s = [1,2].\n\t\tPop the integer on the top of the stack. s = [1].\n\t\tRead 3 from the stream and push it to the stack. s = [1,3].\n\t\tExample 2:\n\t\tInput: target = [1,2,3], n = 3\n\t\tOutput: [\"Push\",\"Push\",\"Push\"]\n\t\tExplanation: Initially the stack s is empty. The last element is the top of the stack.\n\t\tRead 1 from the stream and push it to the stack. s = [1].\n\t\tRead 2 from the stream and push it to the stack. s = [1,2].\n\t\tRead 3 from the stream and push it to the stack. s = [1,2,3].\n\t\tExample 3:\n\t\tInput: target = [1,2], n = 4\n\t\tOutput: [\"Push\",\"Push\"]\n\t\tExplanation: Initially the stack s is empty. The last element is the top of the stack.\n\t\tRead 1 from the stream and push it to the stack. s = [1].\n\t\tRead 2 from the stream and push it to the stack. s = [1,2].\n\t\tSince the stack (from the bottom to the top) is equal to target, we stop the stack operations.\n\t\tThe answers that read integer 3 from the stream are not accepted.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1553, - "question": "class Solution:\n def countTriplets(self, arr: List[int]) -> int:\n\t\t\"\"\"\n\t\tGiven an array of integers arr.\n\t\tWe want to select three indices i, j and k where (0 <= i < j <= k < arr.length).\n\t\tLet's define a and b as follows:\n\t\t\ta = arr[i] ^ arr[i + 1] ^ ... ^ arr[j - 1]\n\t\t\tb = arr[j] ^ arr[j + 1] ^ ... ^ arr[k]\n\t\tNote that ^ denotes the bitwise-xor operation.\n\t\tReturn the number of triplets (i, j and k) Where a == b.\n\t\tExample 1:\n\t\tInput: arr = [2,3,1,6,7]\n\t\tOutput: 4\n\t\tExplanation: The triplets are (0,1,2), (0,2,2), (2,3,4) and (2,4,4)\n\t\tExample 2:\n\t\tInput: arr = [1,1,1,1,1]\n\t\tOutput: 10\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1554, - "question": "class Solution:\n def minTime(self, n: int, edges: List[List[int]], hasApple: List[bool]) -> int:\n\t\t\"\"\"\n\t\tGiven an undirected tree consisting of n vertices numbered from 0 to n-1, which has some apples in their vertices. You spend 1 second to walk over one edge of the tree. Return the minimum time in seconds you have to spend to collect all apples in the tree, starting at vertex 0 and coming back to this vertex.\n\t\tThe edges of the undirected tree are given in the array edges, where edges[i] = [ai, bi] means that exists an edge connecting the vertices ai and bi. Additionally, there is a boolean array hasApple, where hasApple[i] = true means that vertex i has an apple; otherwise, it does not have any apple.\n\t\tExample 1:\n\t\tInput: n = 7, edges = [[0,1],[0,2],[1,4],[1,5],[2,3],[2,6]], hasApple = [false,false,true,false,true,true,false]\n\t\tOutput: 8 \n\t\tExplanation: The figure above represents the given tree where red vertices have an apple. One optimal path to collect all apples is shown by the green arrows. \n\t\tExample 2:\n\t\tInput: n = 7, edges = [[0,1],[0,2],[1,4],[1,5],[2,3],[2,6]], hasApple = [false,false,true,false,false,true,false]\n\t\tOutput: 6\n\t\tExplanation: The figure above represents the given tree where red vertices have an apple. One optimal path to collect all apples is shown by the green arrows. \n\t\tExample 3:\n\t\tInput: n = 7, edges = [[0,1],[0,2],[1,4],[1,5],[2,3],[2,6]], hasApple = [false,false,false,false,false,false,false]\n\t\tOutput: 0\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1555, - "question": "class Solution:\n def ways(self, pizza: List[str], k: int) -> int:\n\t\t\"\"\"\n\t\tGiven a rectangular pizza represented as a rows x cols matrix containing the following characters: 'A' (an apple) and '.' (empty cell) and given the integer k. You have to cut the pizza into k pieces using k-1 cuts. \r\n\t\tFor each cut you choose the direction: vertical or horizontal, then you choose a cut position at the cell boundary and cut the pizza into two pieces. If you cut the pizza vertically, give the left part of the pizza to a person. If you cut the pizza horizontally, give the upper part of the pizza to a person. Give the last piece of pizza to the last person.\r\n\t\tReturn the number of ways of cutting the pizza such that each piece contains at least one apple. Since the answer can be a huge number, return this modulo 10^9 + 7.\r\n\t\tExample 1:\r\n\t\tInput: pizza = [\"A..\",\"AAA\",\"...\"], k = 3\r\n\t\tOutput: 3 \r\n\t\tExplanation: The figure above shows the three ways to cut the pizza. Note that pieces must contain at least one apple.\r\n\t\tExample 2:\r\n\t\tInput: pizza = [\"A..\",\"AA.\",\"...\"], k = 3\r\n\t\tOutput: 1\r\n\t\tExample 3:\r\n\t\tInput: pizza = [\"A..\",\"A..\",\"...\"], k = 1\r\n\t\tOutput: 1\r\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1556, - "question": "class Solution:\n def canBeEqual(self, target: List[int], arr: List[int]) -> bool:\n\t\t\"\"\"\n\t\tYou are given two integer arrays of equal length target and arr. In one step, you can select any non-empty subarray of arr and reverse it. You are allowed to make any number of steps.\n\t\tReturn true if you can make arr equal to target or false otherwise.\n\t\tExample 1:\n\t\tInput: target = [1,2,3,4], arr = [2,4,1,3]\n\t\tOutput: true\n\t\tExplanation: You can follow the next steps to convert arr to target:\n\t\t1- Reverse subarray [2,4,1], arr becomes [1,4,2,3]\n\t\t2- Reverse subarray [4,2], arr becomes [1,2,4,3]\n\t\t3- Reverse subarray [4,3], arr becomes [1,2,3,4]\n\t\tThere are multiple ways to convert arr to target, this is not the only way to do so.\n\t\tExample 2:\n\t\tInput: target = [7], arr = [7]\n\t\tOutput: true\n\t\tExplanation: arr is equal to target without any reverses.\n\t\tExample 3:\n\t\tInput: target = [3,7,9], arr = [3,7,11]\n\t\tOutput: false\n\t\tExplanation: arr does not have value 9 and it can never be converted to target.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1557, - "question": "class Solution:\n def hasAllCodes(self, s: str, k: int) -> bool:\n\t\t\"\"\"\n\t\tGiven a binary string s and an integer k, return true if every binary code of length k is a substring of s. Otherwise, return false.\n\t\tExample 1:\n\t\tInput: s = \"00110110\", k = 2\n\t\tOutput: true\n\t\tExplanation: The binary codes of length 2 are \"00\", \"01\", \"10\" and \"11\". They can be all found as substrings at indices 0, 1, 3 and 2 respectively.\n\t\tExample 2:\n\t\tInput: s = \"0110\", k = 1\n\t\tOutput: true\n\t\tExplanation: The binary codes of length 1 are \"0\" and \"1\", it is clear that both exist as a substring. \n\t\tExample 3:\n\t\tInput: s = \"0110\", k = 2\n\t\tOutput: false\n\t\tExplanation: The binary code \"00\" is of length 2 and does not exist in the array.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1558, - "question": "class Solution:\n def checkIfPrerequisite(self, numCourses: int, prerequisites: List[List[int]], queries: List[List[int]]) -> List[bool]:\n\t\t\"\"\"\n\t\tThere are a total of numCourses courses you have to take, labeled from 0 to numCourses - 1. You are given an array prerequisites where prerequisites[i] = [ai, bi] indicates that you must take course ai first if you want to take course bi.\n\t\t\tFor example, the pair [0, 1] indicates that you have to take course 0 before you can take course 1.\n\t\tPrerequisites can also be indirect. If course a is a prerequisite of course b, and course b is a prerequisite of course c, then course a is a prerequisite of course c.\n\t\tYou are also given an array queries where queries[j] = [uj, vj]. For the jth query, you should answer whether course uj is a prerequisite of course vj or not.\n\t\tReturn a boolean array answer, where answer[j] is the answer to the jth query.\n\t\tExample 1:\n\t\tInput: numCourses = 2, prerequisites = [[1,0]], queries = [[0,1],[1,0]]\n\t\tOutput: [false,true]\n\t\tExplanation: The pair [1, 0] indicates that you have to take course 1 before you can take course 0.\n\t\tCourse 0 is not a prerequisite of course 1, but the opposite is true.\n\t\tExample 2:\n\t\tInput: numCourses = 2, prerequisites = [], queries = [[1,0],[0,1]]\n\t\tOutput: [false,false]\n\t\tExplanation: There are no prerequisites, and each course is independent.\n\t\tExample 3:\n\t\tInput: numCourses = 3, prerequisites = [[1,2],[1,0],[2,0]], queries = [[1,0],[1,2]]\n\t\tOutput: [true,true]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1559, - "question": "class Solution:\n def cherryPickup(self, grid: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tYou are given a rows x cols matrix grid representing a field of cherries where grid[i][j] represents the number of cherries that you can collect from the (i, j) cell.\n\t\tYou have two robots that can collect cherries for you:\n\t\t\tRobot #1 is located at the top-left corner (0, 0), and\n\t\t\tRobot #2 is located at the top-right corner (0, cols - 1).\n\t\tReturn the maximum number of cherries collection using both robots by following the rules below:\n\t\t\tFrom a cell (i, j), robots can move to cell (i + 1, j - 1), (i + 1, j), or (i + 1, j + 1).\n\t\t\tWhen any robot passes through a cell, It picks up all cherries, and the cell becomes an empty cell.\n\t\t\tWhen both robots stay in the same cell, only one takes the cherries.\n\t\t\tBoth robots cannot move outside of the grid at any moment.\n\t\t\tBoth robots should reach the bottom row in grid.\n\t\tExample 1:\n\t\tInput: grid = [[3,1,1],[2,5,1],[1,5,5],[2,1,1]]\n\t\tOutput: 24\n\t\tExplanation: Path of robot #1 and #2 are described in color green and blue respectively.\n\t\tCherries taken by Robot #1, (3 + 2 + 5 + 2) = 12.\n\t\tCherries taken by Robot #2, (1 + 5 + 5 + 1) = 12.\n\t\tTotal of cherries: 12 + 12 = 24.\n\t\tExample 2:\n\t\tInput: grid = [[1,0,0,0,0,0,1],[2,0,0,0,0,3,0],[2,0,9,0,0,0,0],[0,3,0,5,4,0,0],[1,0,2,3,0,0,6]]\n\t\tOutput: 28\n\t\tExplanation: Path of robot #1 and #2 are described in color green and blue respectively.\n\t\tCherries taken by Robot #1, (1 + 9 + 5 + 2) = 17.\n\t\tCherries taken by Robot #2, (1 + 3 + 4 + 3) = 11.\n\t\tTotal of cherries: 17 + 11 = 28.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1560, - "question": "class Solution:\n def busyStudent(self, startTime: List[int], endTime: List[int], queryTime: int) -> int:\n\t\t\"\"\"\n\t\tGiven two integer arrays startTime and endTime and given an integer queryTime.\n\t\tThe ith student started doing their homework at the time startTime[i] and finished it at time endTime[i].\n\t\tReturn the number of students doing their homework at time queryTime. More formally, return the number of students where queryTime lays in the interval [startTime[i], endTime[i]] inclusive.\n\t\tExample 1:\n\t\tInput: startTime = [1,2,3], endTime = [3,2,7], queryTime = 4\n\t\tOutput: 1\n\t\tExplanation: We have 3 students where:\n\t\tThe first student started doing homework at time 1 and finished at time 3 and wasn't doing anything at time 4.\n\t\tThe second student started doing homework at time 2 and finished at time 2 and also wasn't doing anything at time 4.\n\t\tThe third student started doing homework at time 3 and finished at time 7 and was the only student doing homework at time 4.\n\t\tExample 2:\n\t\tInput: startTime = [4], endTime = [4], queryTime = 4\n\t\tOutput: 1\n\t\tExplanation: The only student was doing their homework at the queryTime.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1561, - "question": "class Solution:\n def arrangeWords(self, text: str) -> str:\n\t\t\"\"\"\n\t\tGiven a sentence text (A sentence is a string of space-separated words) in the following format:\n\t\t\tFirst letter is in upper case.\n\t\t\tEach word in text are separated by a single space.\n\t\tYour task is to rearrange the words in text such that all words are rearranged in an increasing order of their lengths. If two words have the same length, arrange them in their original order.\n\t\tReturn the new text following the format shown above.\n\t\tExample 1:\n\t\tInput: text = \"Leetcode is cool\"\n\t\tOutput: \"Is cool leetcode\"\n\t\tExplanation: There are 3 words, \"Leetcode\" of length 8, \"is\" of length 2 and \"cool\" of length 4.\n\t\tOutput is ordered by length and the new first word starts with capital letter.\n\t\tExample 2:\n\t\tInput: text = \"Keep calm and code on\"\n\t\tOutput: \"On and keep calm code\"\n\t\tExplanation: Output is ordered as follows:\n\t\t\"On\" 2 letters.\n\t\t\"and\" 3 letters.\n\t\t\"keep\" 4 letters in case of tie order by position in original text.\n\t\t\"calm\" 4 letters.\n\t\t\"code\" 4 letters.\n\t\tExample 3:\n\t\tInput: text = \"To be or not to be\"\n\t\tOutput: \"To be or to be not\"\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1562, - "question": "class Solution:\n def peopleIndexes(self, favoriteCompanies: List[List[str]]) -> List[int]:\n\t\t\"\"\"\n\t\tGiven the array favoriteCompanies where favoriteCompanies[i] is the list of favorites companies for the ith person (indexed from 0).\n\t\tReturn the indices of people whose list of favorite companies is not a subset of any other list of favorites companies. You must return the indices in increasing order.\n\t\tExample 1:\n\t\tInput: favoriteCompanies = [[\"leetcode\",\"google\",\"facebook\"],[\"google\",\"microsoft\"],[\"google\",\"facebook\"],[\"google\"],[\"amazon\"]]\n\t\tOutput: [0,1,4] \n\t\tExplanation: \n\t\tPerson with index=2 has favoriteCompanies[2]=[\"google\",\"facebook\"] which is a subset of favoriteCompanies[0]=[\"leetcode\",\"google\",\"facebook\"] corresponding to the person with index 0. \n\t\tPerson with index=3 has favoriteCompanies[3]=[\"google\"] which is a subset of favoriteCompanies[0]=[\"leetcode\",\"google\",\"facebook\"] and favoriteCompanies[1]=[\"google\",\"microsoft\"]. \n\t\tOther lists of favorite companies are not a subset of another list, therefore, the answer is [0,1,4].\n\t\tExample 2:\n\t\tInput: favoriteCompanies = [[\"leetcode\",\"google\",\"facebook\"],[\"leetcode\",\"amazon\"],[\"facebook\",\"google\"]]\n\t\tOutput: [0,1] \n\t\tExplanation: In this case favoriteCompanies[2]=[\"facebook\",\"google\"] is a subset of favoriteCompanies[0]=[\"leetcode\",\"google\",\"facebook\"], therefore, the answer is [0,1].\n\t\tExample 3:\n\t\tInput: favoriteCompanies = [[\"leetcode\"],[\"google\"],[\"facebook\"],[\"amazon\"]]\n\t\tOutput: [0,1,2,3]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1563, - "question": "class Solution:\n def numPoints(self, darts: List[List[int]], r: int) -> int:\n\t\t\"\"\"\n\t\tAlice is throwing n darts on a very large wall. You are given an array darts where darts[i] = [xi, yi] is the position of the ith dart that Alice threw on the wall.\n\t\tBob knows the positions of the n darts on the wall. He wants to place a dartboard of radius r on the wall so that the maximum number of darts that Alice throws lies on the dartboard.\n\t\tGiven the integer r, return the maximum number of darts that can lie on the dartboard.\n\t\tExample 1:\n\t\tInput: darts = [[-2,0],[2,0],[0,2],[0,-2]], r = 2\n\t\tOutput: 4\n\t\tExplanation: Circle dartboard with center in (0,0) and radius = 2 contain all points.\n\t\tExample 2:\n\t\tInput: darts = [[-3,0],[3,0],[2,6],[5,4],[0,9],[7,8]], r = 5\n\t\tOutput: 5\n\t\tExplanation: Circle dartboard with center in (0,4) and radius = 5 contain all points except the point (7,8).\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1566, - "question": "class Solution:\n def isPrefixOfWord(self, sentence: str, searchWord: str) -> int:\n\t\t\"\"\"\n\t\tGiven a sentence that consists of some words separated by a single space, and a searchWord, check if searchWord is a prefix of any word in sentence.\n\t\tReturn the index of the word in sentence (1-indexed) where searchWord is a prefix of this word. If searchWord is a prefix of more than one word, return the index of the first word (minimum index). If there is no such word return -1.\n\t\tA prefix of a string s is any leading contiguous substring of s.\n\t\tExample 1:\n\t\tInput: sentence = \"i love eating burger\", searchWord = \"burg\"\n\t\tOutput: 4\n\t\tExplanation: \"burg\" is prefix of \"burger\" which is the 4th word in the sentence.\n\t\tExample 2:\n\t\tInput: sentence = \"this problem is an easy problem\", searchWord = \"pro\"\n\t\tOutput: 2\n\t\tExplanation: \"pro\" is prefix of \"problem\" which is the 2nd and the 6th word in the sentence, but we return 2 as it's the minimal index.\n\t\tExample 3:\n\t\tInput: sentence = \"i am tired\", searchWord = \"you\"\n\t\tOutput: -1\n\t\tExplanation: \"you\" is not a prefix of any word in the sentence.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1567, - "question": "class Solution:\n def maxVowels(self, s: str, k: int) -> int:\n\t\t\"\"\"\n\t\tGiven a string s and an integer k, return the maximum number of vowel letters in any substring of s with length k.\n\t\tVowel letters in English are 'a', 'e', 'i', 'o', and 'u'.\n\t\tExample 1:\n\t\tInput: s = \"abciiidef\", k = 3\n\t\tOutput: 3\n\t\tExplanation: The substring \"iii\" contains 3 vowel letters.\n\t\tExample 2:\n\t\tInput: s = \"aeiou\", k = 2\n\t\tOutput: 2\n\t\tExplanation: Any substring of length 2 contains 2 vowels.\n\t\tExample 3:\n\t\tInput: s = \"leetcode\", k = 3\n\t\tOutput: 2\n\t\tExplanation: \"lee\", \"eet\" and \"ode\" contain 2 vowels.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1568, - "question": "class Solution:\n def pseudoPalindromicPaths (self, root: Optional[TreeNode]) -> int:\n\t\t\"\"\"\n\t\tGiven a binary tree where node values are digits from 1 to 9. A path in the binary tree is said to be pseudo-palindromic if at least one permutation of the node values in the path is a palindrome.\n\t\tReturn the number of pseudo-palindromic paths going from the root node to leaf nodes.\n\t\tExample 1:\n\t\tInput: root = [2,3,1,3,1,null,1]\n\t\tOutput: 2 \n\t\tExplanation: The figure above represents the given binary tree. There are three paths going from the root node to leaf nodes: the red path [2,3,3], the green path [2,1,1], and the path [2,3,1]. Among these paths only red path and green path are pseudo-palindromic paths since the red path [2,3,3] can be rearranged in [3,2,3] (palindrome) and the green path [2,1,1] can be rearranged in [1,2,1] (palindrome).\n\t\tExample 2:\n\t\tInput: root = [2,1,1,1,3,null,null,null,null,null,1]\n\t\tOutput: 1 \n\t\tExplanation: The figure above represents the given binary tree. There are three paths going from the root node to leaf nodes: the green path [2,1,1], the path [2,1,3,1], and the path [2,1]. Among these paths only the green path is pseudo-palindromic since [2,1,1] can be rearranged in [1,2,1] (palindrome).\n\t\tExample 3:\n\t\tInput: root = [9]\n\t\tOutput: 1\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1569, - "question": "class Solution:\n def maxDotProduct(self, nums1: List[int], nums2: List[int]) -> int:\n\t\t\"\"\"\n\t\tGiven two arrays nums1 and nums2.\n\t\tReturn the maximum dot product between non-empty subsequences of nums1 and nums2 with the same length.\n\t\tA subsequence of a array is a new array which is formed from the original array by deleting some (can be none) of the characters without disturbing the relative positions of the remaining characters. (ie, [2,3,5] is a subsequence of [1,2,3,4,5] while [1,5,3] is not).\n\t\tExample 1:\n\t\tInput: nums1 = [2,1,-2,5], nums2 = [3,0,-6]\n\t\tOutput: 18\n\t\tExplanation: Take subsequence [2,-2] from nums1 and subsequence [3,-6] from nums2.\n\t\tTheir dot product is (2*3 + (-2)*(-6)) = 18.\n\t\tExample 2:\n\t\tInput: nums1 = [3,-2], nums2 = [2,-6,7]\n\t\tOutput: 21\n\t\tExplanation: Take subsequence [3] from nums1 and subsequence [7] from nums2.\n\t\tTheir dot product is (3*7) = 21.\n\t\tExample 3:\n\t\tInput: nums1 = [-1,-1], nums2 = [1,1]\n\t\tOutput: -1\n\t\tExplanation: Take subsequence [-1] from nums1 and subsequence [1] from nums2.\n\t\tTheir dot product is -1.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1570, - "question": "class Solution:\n def finalPrices(self, prices: List[int]) -> List[int]:\n\t\t\"\"\"\n\t\tYou are given an integer array prices where prices[i] is the price of the ith item in a shop.\n\t\tThere is a special discount for items in the shop. If you buy the ith item, then you will receive a discount equivalent to prices[j] where j is the minimum index such that j > i and prices[j] <= prices[i]. Otherwise, you will not receive any discount at all.\n\t\tReturn an integer array answer where answer[i] is the final price you will pay for the ith item of the shop, considering the special discount.\n\t\tExample 1:\n\t\tInput: prices = [8,4,6,2,3]\n\t\tOutput: [4,2,4,2,3]\n\t\tExplanation: \n\t\tFor item 0 with price[0]=8 you will receive a discount equivalent to prices[1]=4, therefore, the final price you will pay is 8 - 4 = 4.\n\t\tFor item 1 with price[1]=4 you will receive a discount equivalent to prices[3]=2, therefore, the final price you will pay is 4 - 2 = 2.\n\t\tFor item 2 with price[2]=6 you will receive a discount equivalent to prices[3]=2, therefore, the final price you will pay is 6 - 2 = 4.\n\t\tFor items 3 and 4 you will not receive any discount at all.\n\t\tExample 2:\n\t\tInput: prices = [1,2,3,4,5]\n\t\tOutput: [1,2,3,4,5]\n\t\tExplanation: In this case, for all items, you will not receive any discount at all.\n\t\tExample 3:\n\t\tInput: prices = [10,1,1,6]\n\t\tOutput: [9,0,1,6]\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1571, - "question": "class Solution:\n def minDistance(self, houses: List[int], k: int) -> int:\n\t\t\"\"\"\n\t\tGiven the array houses where houses[i] is the location of the ith house along a street and an integer k, allocate k mailboxes in the street.\n\t\tReturn the minimum total distance between each house and its nearest mailbox.\n\t\tThe test cases are generated so that the answer fits in a 32-bit integer.\n\t\tExample 1:\n\t\tInput: houses = [1,4,8,10,20], k = 3\n\t\tOutput: 5\n\t\tExplanation: Allocate mailboxes in position 3, 9 and 20.\n\t\tMinimum total distance from each houses to nearest mailboxes is |3-1| + |4-3| + |9-8| + |10-9| + |20-20| = 5 \n\t\tExample 2:\n\t\tInput: houses = [2,3,5,12,18], k = 2\n\t\tOutput: 9\n\t\tExplanation: Allocate mailboxes in position 3 and 14.\n\t\tMinimum total distance from each houses to nearest mailboxes is |2-3| + |3-3| + |5-3| + |12-14| + |18-14| = 9.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1572, - "question": "class SubrectangleQueries:\n def __init__(self, rectangle: List[List[int]]):\n def updateSubrectangle(self, row1: int, col1: int, row2: int, col2: int, newValue: int) -> None:\n def getValue(self, row: int, col: int) -> int:\n\t\t\"\"\"\n\t\tImplement the class SubrectangleQueries which receives a rows x cols rectangle as a matrix of integers in the constructor and supports two methods:\n\t\t1. updateSubrectangle(int row1, int col1, int row2, int col2, int newValue)\n\t\t\tUpdates all values with newValue in the subrectangle whose upper left coordinate is (row1,col1) and bottom right coordinate is (row2,col2).\n\t\t2. getValue(int row, int col)\n\t\t\tReturns the current value of the coordinate (row,col) from the rectangle.\n\t\tExample 1:\n\t\tInput\n\t\t[\"SubrectangleQueries\",\"getValue\",\"updateSubrectangle\",\"getValue\",\"getValue\",\"updateSubrectangle\",\"getValue\",\"getValue\"]\n\t\t[[[[1,2,1],[4,3,4],[3,2,1],[1,1,1]]],[0,2],[0,0,3,2,5],[0,2],[3,1],[3,0,3,2,10],[3,1],[0,2]]\n\t\tOutput\n\t\t[null,1,null,5,5,null,10,5]\n\t\tExplanation\n\t\tSubrectangleQueries subrectangleQueries = new SubrectangleQueries([[1,2,1],[4,3,4],[3,2,1],[1,1,1]]); \n\t\t// The initial rectangle (4x3) looks like:\n\t\t// 1 2 1\n\t\t// 4 3 4\n\t\t// 3 2 1\n\t\t// 1 1 1\n\t\tsubrectangleQueries.getValue(0, 2); // return 1\n\t\tsubrectangleQueries.updateSubrectangle(0, 0, 3, 2, 5);\n\t\t// After this update the rectangle looks like:\n\t\t// 5 5 5\n\t\t// 5 5 5\n\t\t// 5 5 5\n\t\t// 5 5 5 \n\t\tsubrectangleQueries.getValue(0, 2); // return 5\n\t\tsubrectangleQueries.getValue(3, 1); // return 5\n\t\tsubrectangleQueries.updateSubrectangle(3, 0, 3, 2, 10);\n\t\t// After this update the rectangle looks like:\n\t\t// 5 5 5\n\t\t// 5 5 5\n\t\t// 5 5 5\n\t\t// 10 10 10 \n\t\tsubrectangleQueries.getValue(3, 1); // return 10\n\t\tsubrectangleQueries.getValue(0, 2); // return 5\n\t\tExample 2:\n\t\tInput\n\t\t[\"SubrectangleQueries\",\"getValue\",\"updateSubrectangle\",\"getValue\",\"getValue\",\"updateSubrectangle\",\"getValue\"]\n\t\t[[[[1,1,1],[2,2,2],[3,3,3]]],[0,0],[0,0,2,2,100],[0,0],[2,2],[1,1,2,2,20],[2,2]]\n\t\tOutput\n\t\t[null,1,null,100,100,null,20]\n\t\tExplanation\n\t\tSubrectangleQueries subrectangleQueries = new SubrectangleQueries([[1,1,1],[2,2,2],[3,3,3]]);\n\t\tsubrectangleQueries.getValue(0, 0); // return 1\n\t\tsubrectangleQueries.updateSubrectangle(0, 0, 2, 2, 100);\n\t\tsubrectangleQueries.getValue(0, 0); // return 100\n\t\tsubrectangleQueries.getValue(2, 2); // return 100\n\t\tsubrectangleQueries.updateSubrectangle(1, 1, 2, 2, 20);\n\t\tsubrectangleQueries.getValue(2, 2); // return 20\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1573, - "question": "class Solution:\n def minSumOfLengths(self, arr: List[int], target: int) -> int:\n\t\t\"\"\"\n\t\tYou are given an array of integers arr and an integer target.\n\t\tYou have to find two non-overlapping sub-arrays of arr each with a sum equal target. There can be multiple answers so you have to find an answer where the sum of the lengths of the two sub-arrays is minimum.\n\t\tReturn the minimum sum of the lengths of the two required sub-arrays, or return -1 if you cannot find such two sub-arrays.\n\t\tExample 1:\n\t\tInput: arr = [3,2,2,4,3], target = 3\n\t\tOutput: 2\n\t\tExplanation: Only two sub-arrays have sum = 3 ([3] and [3]). The sum of their lengths is 2.\n\t\tExample 2:\n\t\tInput: arr = [7,3,4,7], target = 7\n\t\tOutput: 2\n\t\tExplanation: Although we have three non-overlapping sub-arrays of sum = 7 ([7], [3,4] and [7]), but we will choose the first and third sub-arrays as the sum of their lengths is 2.\n\t\tExample 3:\n\t\tInput: arr = [4,3,2,6,2,3,4], target = 6\n\t\tOutput: -1\n\t\tExplanation: We have only one sub-array of sum = 6.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1574, - "question": "class Solution:\n def maxProduct(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tGiven the array of integers nums, you will choose two different indices i and j of that array. Return the maximum value of (nums[i]-1)*(nums[j]-1).\n\t\tExample 1:\n\t\tInput: nums = [3,4,5,2]\n\t\tOutput: 12 \n\t\tExplanation: If you choose the indices i=1 and j=2 (indexed from 0), you will get the maximum value, that is, (nums[1]-1)*(nums[2]-1) = (4-1)*(5-1) = 3*4 = 12. \n\t\tExample 2:\n\t\tInput: nums = [1,5,4,5]\n\t\tOutput: 16\n\t\tExplanation: Choosing the indices i=1 and j=3 (indexed from 0), you will get the maximum value of (5-1)*(5-1) = 16.\n\t\tExample 3:\n\t\tInput: nums = [3,7]\n\t\tOutput: 12\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1575, - "question": "class Solution:\n def maxArea(self, h: int, w: int, horizontalCuts: List[int], verticalCuts: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou are given a rectangular cake of size h x w and two arrays of integers horizontalCuts and verticalCuts where:\n\t\t\thorizontalCuts[i] is the distance from the top of the rectangular cake to the ith horizontal cut and similarly, and\n\t\t\tverticalCuts[j] is the distance from the left of the rectangular cake to the jth vertical cut.\n\t\tReturn the maximum area of a piece of cake after you cut at each horizontal and vertical position provided in the arrays horizontalCuts and verticalCuts. Since the answer can be a large number, return this modulo 109 + 7.\n\t\tExample 1:\n\t\tInput: h = 5, w = 4, horizontalCuts = [1,2,4], verticalCuts = [1,3]\n\t\tOutput: 4 \n\t\tExplanation: The figure above represents the given rectangular cake. Red lines are the horizontal and vertical cuts. After you cut the cake, the green piece of cake has the maximum area.\n\t\tExample 2:\n\t\tInput: h = 5, w = 4, horizontalCuts = [3,1], verticalCuts = [1]\n\t\tOutput: 6\n\t\tExplanation: The figure above represents the given rectangular cake. Red lines are the horizontal and vertical cuts. After you cut the cake, the green and yellow pieces of cake have the maximum area.\n\t\tExample 3:\n\t\tInput: h = 5, w = 4, horizontalCuts = [3], verticalCuts = [3]\n\t\tOutput: 9\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1576, - "question": "class Solution:\n def minReorder(self, n: int, connections: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tThere are n cities numbered from 0 to n - 1 and n - 1 roads such that there is only one way to travel between two different cities (this network form a tree). Last year, The ministry of transport decided to orient the roads in one direction because they are too narrow.\n\t\tRoads are represented by connections where connections[i] = [ai, bi] represents a road from city ai to city bi.\n\t\tThis year, there will be a big event in the capital (city 0), and many people want to travel to this city.\n\t\tYour task consists of reorienting some roads such that each city can visit the city 0. Return the minimum number of edges changed.\n\t\tIt's guaranteed that each city can reach city 0 after reorder.\n\t\tExample 1:\n\t\tInput: n = 6, connections = [[0,1],[1,3],[2,3],[4,0],[4,5]]\n\t\tOutput: 3\n\t\tExplanation: Change the direction of edges show in red such that each node can reach the node 0 (capital).\n\t\tExample 2:\n\t\tInput: n = 5, connections = [[1,0],[1,2],[3,2],[3,4]]\n\t\tOutput: 2\n\t\tExplanation: Change the direction of edges show in red such that each node can reach the node 0 (capital).\n\t\tExample 3:\n\t\tInput: n = 3, connections = [[1,0],[2,0]]\n\t\tOutput: 0\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1577, - "question": "class Solution:\n def getProbability(self, balls: List[int]) -> float:\n\t\t\"\"\"\n\t\tGiven 2n balls of k distinct colors. You will be given an integer array balls of size k where balls[i] is the number of balls of color i.\n\t\tAll the balls will be shuffled uniformly at random, then we will distribute the first n balls to the first box and the remaining n balls to the other box (Please read the explanation of the second example carefully).\n\t\tPlease note that the two boxes are considered different. For example, if we have two balls of colors a and b, and two boxes [] and (), then the distribution [a] (b) is considered different than the distribution [b] (a) (Please read the explanation of the first example carefully).\n\t\tReturn the probability that the two boxes have the same number of distinct balls. Answers within 10-5 of the actual value will be accepted as correct.\n\t\tExample 1:\n\t\tInput: balls = [1,1]\n\t\tOutput: 1.00000\n\t\tExplanation: Only 2 ways to divide the balls equally:\n\t\t- A ball of color 1 to box 1 and a ball of color 2 to box 2\n\t\t- A ball of color 2 to box 1 and a ball of color 1 to box 2\n\t\tIn both ways, the number of distinct colors in each box is equal. The probability is 2/2 = 1\n\t\tExample 2:\n\t\tInput: balls = [2,1,1]\n\t\tOutput: 0.66667\n\t\tExplanation: We have the set of balls [1, 1, 2, 3]\n\t\tThis set of balls will be shuffled randomly and we may have one of the 12 distinct shuffles with equal probability (i.e. 1/12):\n\t\t[1,1 / 2,3], [1,1 / 3,2], [1,2 / 1,3], [1,2 / 3,1], [1,3 / 1,2], [1,3 / 2,1], [2,1 / 1,3], [2,1 / 3,1], [2,3 / 1,1], [3,1 / 1,2], [3,1 / 2,1], [3,2 / 1,1]\n\t\tAfter that, we add the first two balls to the first box and the second two balls to the second box.\n\t\tWe can see that 8 of these 12 possible random distributions have the same number of distinct colors of balls in each box.\n\t\tProbability is 8/12 = 0.66667\n\t\tExample 3:\n\t\tInput: balls = [1,2,1,2]\n\t\tOutput: 0.60000\n\t\tExplanation: The set of balls is [1, 2, 2, 3, 4, 4]. It is hard to display all the 180 possible random shuffles of this set but it is easy to check that 108 of them will have the same number of distinct colors in each box.\n\t\tProbability = 108 / 180 = 0.6\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1580, - "question": "class Solution:\n def shuffle(self, nums: List[int], n: int) -> List[int]:\n\t\t\"\"\"\n\t\tGiven the array nums consisting of 2n elements in the form [x1,x2,...,xn,y1,y2,...,yn].\r\n\t\tReturn the array in the form [x1,y1,x2,y2,...,xn,yn].\r\n\t\tExample 1:\r\n\t\tInput: nums = [2,5,1,3,4,7], n = 3\r\n\t\tOutput: [2,3,5,4,1,7] \r\n\t\tExplanation: Since x1=2, x2=5, x3=1, y1=3, y2=4, y3=7 then the answer is [2,3,5,4,1,7].\r\n\t\tExample 2:\r\n\t\tInput: nums = [1,2,3,4,4,3,2,1], n = 4\r\n\t\tOutput: [1,4,2,3,3,2,4,1]\r\n\t\tExample 3:\r\n\t\tInput: nums = [1,1,2,2], n = 2\r\n\t\tOutput: [1,2,1,2]\r\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1581, - "question": "class Solution:\n def getStrongest(self, arr: List[int], k: int) -> List[int]:\n\t\t\"\"\"\n\t\tGiven an array of integers arr and an integer k.\n\t\tA value arr[i] is said to be stronger than a value arr[j] if |arr[i] - m| > |arr[j] - m| where m is the median of the array.\n\t\tIf |arr[i] - m| == |arr[j] - m|, then arr[i] is said to be stronger than arr[j] if arr[i] > arr[j].\n\t\tReturn a list of the strongest k values in the array. return the answer in any arbitrary order.\n\t\tMedian is the middle value in an ordered integer list. More formally, if the length of the list is n, the median is the element in position ((n - 1) / 2) in the sorted list (0-indexed).\n\t\t\tFor arr = [6, -3, 7, 2, 11], n = 5 and the median is obtained by sorting the array arr = [-3, 2, 6, 7, 11] and the median is arr[m] where m = ((5 - 1) / 2) = 2. The median is 6.\n\t\t\tFor arr = [-7, 22, 17,\u20093], n = 4 and the median is obtained by sorting the array arr = [-7, 3, 17, 22] and the median is arr[m] where m = ((4 - 1) / 2) = 1. The median is 3.\n\t\tExample 1:\n\t\tInput: arr = [1,2,3,4,5], k = 2\n\t\tOutput: [5,1]\n\t\tExplanation: Median is 3, the elements of the array sorted by the strongest are [5,1,4,2,3]. The strongest 2 elements are [5, 1]. [1, 5] is also accepted answer.\n\t\tPlease note that although |5 - 3| == |1 - 3| but 5 is stronger than 1 because 5 > 1.\n\t\tExample 2:\n\t\tInput: arr = [1,1,3,5,5], k = 2\n\t\tOutput: [5,5]\n\t\tExplanation: Median is 3, the elements of the array sorted by the strongest are [5,5,1,1,3]. The strongest 2 elements are [5, 5].\n\t\tExample 3:\n\t\tInput: arr = [6,7,11,7,6,8], k = 5\n\t\tOutput: [11,8,6,6,7]\n\t\tExplanation: Median is 7, the elements of the array sorted by the strongest are [11,8,6,6,7,7].\n\t\tAny permutation of [11,8,6,6,7] is accepted.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1582, - "question": "class BrowserHistory:\n def __init__(self, homepage: str):\n def visit(self, url: str) -> None:\n def back(self, steps: int) -> str:\n def forward(self, steps: int) -> str:\n\t\t\"\"\"\n\t\tYou have a browser of one tab where you start on the homepage and you can visit another url, get back in the history number of steps or move forward in the history number of steps.\n\t\tImplement the BrowserHistory class:\n\t\t\tBrowserHistory(string homepage) Initializes the object with the homepage of the browser.\n\t\t\tvoid visit(string url) Visits url from the current page. It clears up all the forward history.\n\t\t\tstring back(int steps) Move steps back in history. If you can only return x steps in the history and steps > x, you will return only x steps. Return the current url after moving back in history at most steps.\n\t\t\tstring forward(int steps) Move steps forward in history. If you can only forward x steps in the history and steps > x, you will forward only x steps. Return the current url after forwarding in history at most steps.\n\t\tExample:\n\t\tInput:\n\t\t[\"BrowserHistory\",\"visit\",\"visit\",\"visit\",\"back\",\"back\",\"forward\",\"visit\",\"forward\",\"back\",\"back\"]\n\t\t[[\"leetcode.com\"],[\"google.com\"],[\"facebook.com\"],[\"youtube.com\"],[1],[1],[1],[\"linkedin.com\"],[2],[2],[7]]\n\t\tOutput:\n\t\t[null,null,null,null,\"facebook.com\",\"google.com\",\"facebook.com\",null,\"linkedin.com\",\"google.com\",\"leetcode.com\"]\n\t\tExplanation:\n\t\tBrowserHistory browserHistory = new BrowserHistory(\"leetcode.com\");\n\t\tbrowserHistory.visit(\"google.com\"); // You are in \"leetcode.com\". Visit \"google.com\"\n\t\tbrowserHistory.visit(\"facebook.com\"); // You are in \"google.com\". Visit \"facebook.com\"\n\t\tbrowserHistory.visit(\"youtube.com\"); // You are in \"facebook.com\". Visit \"youtube.com\"\n\t\tbrowserHistory.back(1); // You are in \"youtube.com\", move back to \"facebook.com\" return \"facebook.com\"\n\t\tbrowserHistory.back(1); // You are in \"facebook.com\", move back to \"google.com\" return \"google.com\"\n\t\tbrowserHistory.forward(1); // You are in \"google.com\", move forward to \"facebook.com\" return \"facebook.com\"\n\t\tbrowserHistory.visit(\"linkedin.com\"); // You are in \"facebook.com\". Visit \"linkedin.com\"\n\t\tbrowserHistory.forward(2); // You are in \"linkedin.com\", you cannot move forward any steps.\n\t\tbrowserHistory.back(2); // You are in \"linkedin.com\", move back two steps to \"facebook.com\" then to \"google.com\". return \"google.com\"\n\t\tbrowserHistory.back(7); // You are in \"google.com\", you can move back only one step to \"leetcode.com\". return \"leetcode.com\"\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1583, - "question": "class Solution:\n def minCost(self, houses: List[int], cost: List[List[int]], m: int, n: int, target: int) -> int:\n\t\t\"\"\"\n\t\tThere is a row of m houses in a small city, each house must be painted with one of the n colors (labeled from 1 to n), some houses that have been painted last summer should not be painted again.\n\t\tA neighborhood is a maximal group of continuous houses that are painted with the same color.\n\t\t\tFor example: houses = [1,2,2,3,3,2,1,1] contains 5 neighborhoods [{1}, {2,2}, {3,3}, {2}, {1,1}].\n\t\tGiven an array houses, an m x n matrix cost and an integer target where:\n\t\t\thouses[i]: is the color of the house i, and 0 if the house is not painted yet.\n\t\t\tcost[i][j]: is the cost of paint the house i with the color j + 1.\n\t\tReturn the minimum cost of painting all the remaining houses in such a way that there are exactly target neighborhoods. If it is not possible, return -1.\n\t\tExample 1:\n\t\tInput: houses = [0,0,0,0,0], cost = [[1,10],[10,1],[10,1],[1,10],[5,1]], m = 5, n = 2, target = 3\n\t\tOutput: 9\n\t\tExplanation: Paint houses of this way [1,2,2,1,1]\n\t\tThis array contains target = 3 neighborhoods, [{1}, {2,2}, {1,1}].\n\t\tCost of paint all houses (1 + 1 + 1 + 1 + 5) = 9.\n\t\tExample 2:\n\t\tInput: houses = [0,2,1,2,0], cost = [[1,10],[10,1],[10,1],[1,10],[5,1]], m = 5, n = 2, target = 3\n\t\tOutput: 11\n\t\tExplanation: Some houses are already painted, Paint the houses of this way [2,2,1,2,2]\n\t\tThis array contains target = 3 neighborhoods, [{2,2}, {1}, {2,2}]. \n\t\tCost of paint the first and last house (10 + 1) = 11.\n\t\tExample 3:\n\t\tInput: houses = [3,1,2,3], cost = [[1,1,1],[1,1,1],[1,1,1],[1,1,1]], m = 4, n = 3, target = 3\n\t\tOutput: -1\n\t\tExplanation: Houses are already painted with a total of 4 neighborhoods [{3},{1},{2},{3}] different of target = 3.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1584, - "question": "class Solution:\n def average(self, salary: List[int]) -> float:\n\t\t\"\"\"\n\t\tYou are given an array of unique integers salary where salary[i] is the salary of the ith employee.\n\t\tReturn the average salary of employees excluding the minimum and maximum salary. Answers within 10-5 of the actual answer will be accepted.\n\t\tExample 1:\n\t\tInput: salary = [4000,3000,1000,2000]\n\t\tOutput: 2500.00000\n\t\tExplanation: Minimum salary and maximum salary are 1000 and 4000 respectively.\n\t\tAverage salary excluding minimum and maximum salary is (2000+3000) / 2 = 2500\n\t\tExample 2:\n\t\tInput: salary = [1000,2000,3000]\n\t\tOutput: 2000.00000\n\t\tExplanation: Minimum salary and maximum salary are 1000 and 3000 respectively.\n\t\tAverage salary excluding minimum and maximum salary is (2000) / 1 = 2000\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1585, - "question": "class Solution:\n def kthFactor(self, n: int, k: int) -> int:\n\t\t\"\"\"\n\t\tYou are given two positive integers n and k. A factor of an integer n is defined as an integer i where n % i == 0.\n\t\tConsider a list of all factors of n sorted in ascending order, return the kth factor in this list or return -1 if n has less than k factors.\n\t\tExample 1:\n\t\tInput: n = 12, k = 3\n\t\tOutput: 3\n\t\tExplanation: Factors list is [1, 2, 3, 4, 6, 12], the 3rd factor is 3.\n\t\tExample 2:\n\t\tInput: n = 7, k = 2\n\t\tOutput: 7\n\t\tExplanation: Factors list is [1, 7], the 2nd factor is 7.\n\t\tExample 3:\n\t\tInput: n = 4, k = 4\n\t\tOutput: -1\n\t\tExplanation: Factors list is [1, 2, 4], there is only 3 factors. We should return -1.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1586, - "question": "class Solution:\n def longestSubarray(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tGiven a binary array nums, you should delete one element from it.\n\t\tReturn the size of the longest non-empty subarray containing only 1's in the resulting array. Return 0 if there is no such subarray.\n\t\tExample 1:\n\t\tInput: nums = [1,1,0,1]\n\t\tOutput: 3\n\t\tExplanation: After deleting the number in position 2, [1,1,1] contains 3 numbers with value of 1's.\n\t\tExample 2:\n\t\tInput: nums = [0,1,1,1,0,1,1,0,1]\n\t\tOutput: 5\n\t\tExplanation: After deleting the number in position 4, [0,1,1,1,1,1,0,1] longest subarray with value of 1's is [1,1,1,1,1].\n\t\tExample 3:\n\t\tInput: nums = [1,1,1]\n\t\tOutput: 2\n\t\tExplanation: You must delete one element.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1587, - "question": "class Solution:\n def minNumberOfSemesters(self, n: int, relations: List[List[int]], k: int) -> int:\n\t\t\"\"\"\n\t\tYou are given an integer n, which indicates that there are n courses labeled from 1 to n. You are also given an array relations where relations[i] = [prevCoursei, nextCoursei], representing a prerequisite relationship between course prevCoursei and course nextCoursei: course prevCoursei has to be taken before course nextCoursei. Also, you are given the integer k.\n\t\tIn one semester, you can take at most k courses as long as you have taken all the prerequisites in the previous semesters for the courses you are taking.\n\t\tReturn the minimum number of semesters needed to take all courses. The testcases will be generated such that it is possible to take every course.\n\t\tExample 1:\n\t\tInput: n = 4, relations = [[2,1],[3,1],[1,4]], k = 2\n\t\tOutput: 3\n\t\tExplanation: The figure above represents the given graph.\n\t\tIn the first semester, you can take courses 2 and 3.\n\t\tIn the second semester, you can take course 1.\n\t\tIn the third semester, you can take course 4.\n\t\tExample 2:\n\t\tInput: n = 5, relations = [[2,1],[3,1],[4,1],[1,5]], k = 2\n\t\tOutput: 4\n\t\tExplanation: The figure above represents the given graph.\n\t\tIn the first semester, you can only take courses 2 and 3 since you cannot take more than two per semester.\n\t\tIn the second semester, you can take course 4.\n\t\tIn the third semester, you can take course 1.\n\t\tIn the fourth semester, you can take course 5.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1603, - "question": "class Solution:\n def runningSum(self, nums: List[int]) -> List[int]:\n\t\t\"\"\"\n\t\tGiven an array nums. We define a running sum of an array as runningSum[i] = sum(nums[0]\u2026nums[i]).\r\n\t\tReturn the running sum of nums.\r\n\t\tExample 1:\r\n\t\tInput: nums = [1,2,3,4]\r\n\t\tOutput: [1,3,6,10]\r\n\t\tExplanation: Running sum is obtained as follows: [1, 1+2, 1+2+3, 1+2+3+4].\r\n\t\tExample 2:\r\n\t\tInput: nums = [1,1,1,1,1]\r\n\t\tOutput: [1,2,3,4,5]\r\n\t\tExplanation: Running sum is obtained as follows: [1, 1+1, 1+1+1, 1+1+1+1, 1+1+1+1+1].\r\n\t\tExample 3:\r\n\t\tInput: nums = [3,1,2,10,1]\r\n\t\tOutput: [3,4,6,16,17]\r\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1604, - "question": "class Solution:\n def findLeastNumOfUniqueInts(self, arr: List[int], k: int) -> int:\n\t\t\"\"\"\n\t\tGiven an array of integers arr and an integer k. Find the least number of unique integers after removing exactly k elements.\r\n\t\tExample 1:\r\n\t\tInput: arr = [5,5,4], k = 1\r\n\t\tOutput: 1\r\n\t\tExplanation: Remove the single 4, only 5 is left.\r\n\t\tExample 2:\r\n\t\tInput: arr = [4,3,1,1,3,3,2], k = 3\r\n\t\tOutput: 2\r\n\t\tExplanation: Remove 4, 2 and either one of the two 1s or three 3s. 1 and 3 will be left.\r\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1605, - "question": "class Solution:\n def minDays(self, bloomDay: List[int], m: int, k: int) -> int:\n\t\t\"\"\"\n\t\tYou are given an integer array bloomDay, an integer m and an integer k.\n\t\tYou want to make m bouquets. To make a bouquet, you need to use k adjacent flowers from the garden.\n\t\tThe garden consists of n flowers, the ith flower will bloom in the bloomDay[i] and then can be used in exactly one bouquet.\n\t\tReturn the minimum number of days you need to wait to be able to make m bouquets from the garden. If it is impossible to make m bouquets return -1.\n\t\tExample 1:\n\t\tInput: bloomDay = [1,10,3,10,2], m = 3, k = 1\n\t\tOutput: 3\n\t\tExplanation: Let us see what happened in the first three days. x means flower bloomed and _ means flower did not bloom in the garden.\n\t\tWe need 3 bouquets each should contain 1 flower.\n\t\tAfter day 1: [x, _, _, _, _] // we can only make one bouquet.\n\t\tAfter day 2: [x, _, _, _, x] // we can only make two bouquets.\n\t\tAfter day 3: [x, _, x, _, x] // we can make 3 bouquets. The answer is 3.\n\t\tExample 2:\n\t\tInput: bloomDay = [1,10,3,10,2], m = 3, k = 2\n\t\tOutput: -1\n\t\tExplanation: We need 3 bouquets each has 2 flowers, that means we need 6 flowers. We only have 5 flowers so it is impossible to get the needed bouquets and we return -1.\n\t\tExample 3:\n\t\tInput: bloomDay = [7,7,7,7,12,7,7], m = 2, k = 3\n\t\tOutput: 12\n\t\tExplanation: We need 2 bouquets each should have 3 flowers.\n\t\tHere is the garden after the 7 and 12 days:\n\t\tAfter day 7: [x, x, x, x, _, x, x]\n\t\tWe can make one bouquet of the first three flowers that bloomed. We cannot make another bouquet from the last three flowers that bloomed because they are not adjacent.\n\t\tAfter day 12: [x, x, x, x, x, x, x]\n\t\tIt is obvious that we can make two bouquets in different ways.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1610, - "question": "class Solution:\n def xorOperation(self, n: int, start: int) -> int:\n\t\t\"\"\"\n\t\tYou are given an integer n and an integer start.\n\t\tDefine an array nums where nums[i] = start + 2 * i (0-indexed) and n == nums.length.\n\t\tReturn the bitwise XOR of all elements of nums.\n\t\tExample 1:\n\t\tInput: n = 5, start = 0\n\t\tOutput: 8\n\t\tExplanation: Array nums is equal to [0, 2, 4, 6, 8] where (0 ^ 2 ^ 4 ^ 6 ^ 8) = 8.\n\t\tWhere \"^\" corresponds to bitwise XOR operator.\n\t\tExample 2:\n\t\tInput: n = 4, start = 3\n\t\tOutput: 8\n\t\tExplanation: Array nums is equal to [3, 5, 7, 9] where (3 ^ 5 ^ 7 ^ 9) = 8.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1611, - "question": "class Solution:\n def getFolderNames(self, names: List[str]) -> List[str]:\n\t\t\"\"\"\n\t\tGiven an array of strings names of size n. You will create n folders in your file system such that, at the ith minute, you will create a folder with the name names[i].\n\t\tSince two files cannot have the same name, if you enter a folder name that was previously used, the system will have a suffix addition to its name in the form of (k), where, k is the smallest positive integer such that the obtained name remains unique.\n\t\tReturn an array of strings of length n where ans[i] is the actual name the system will assign to the ith folder when you create it.\n\t\tExample 1:\n\t\tInput: names = [\"pes\",\"fifa\",\"gta\",\"pes(2019)\"]\n\t\tOutput: [\"pes\",\"fifa\",\"gta\",\"pes(2019)\"]\n\t\tExplanation: Let's see how the file system creates folder names:\n\t\t\"pes\" --> not assigned before, remains \"pes\"\n\t\t\"fifa\" --> not assigned before, remains \"fifa\"\n\t\t\"gta\" --> not assigned before, remains \"gta\"\n\t\t\"pes(2019)\" --> not assigned before, remains \"pes(2019)\"\n\t\tExample 2:\n\t\tInput: names = [\"gta\",\"gta(1)\",\"gta\",\"avalon\"]\n\t\tOutput: [\"gta\",\"gta(1)\",\"gta(2)\",\"avalon\"]\n\t\tExplanation: Let's see how the file system creates folder names:\n\t\t\"gta\" --> not assigned before, remains \"gta\"\n\t\t\"gta(1)\" --> not assigned before, remains \"gta(1)\"\n\t\t\"gta\" --> the name is reserved, system adds (k), since \"gta(1)\" is also reserved, systems put k = 2. it becomes \"gta(2)\"\n\t\t\"avalon\" --> not assigned before, remains \"avalon\"\n\t\tExample 3:\n\t\tInput: names = [\"onepiece\",\"onepiece(1)\",\"onepiece(2)\",\"onepiece(3)\",\"onepiece\"]\n\t\tOutput: [\"onepiece\",\"onepiece(1)\",\"onepiece(2)\",\"onepiece(3)\",\"onepiece(4)\"]\n\t\tExplanation: When the last folder is created, the smallest positive valid k is 4, and it becomes \"onepiece(4)\".\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1612, - "question": "class Solution:\n def avoidFlood(self, rains: List[int]) -> List[int]:\n\t\t\"\"\"\n\t\tYour country has an infinite number of lakes. Initially, all the lakes are empty, but when it rains over the nth lake, the nth lake becomes full of water. If it rains over a lake that is full of water, there will be a flood. Your goal is to avoid floods in any lake.\n\t\tGiven an integer array rains where:\n\t\t\trains[i] > 0 means there will be rains over the rains[i] lake.\n\t\t\trains[i] == 0 means there are no rains this day and you can choose one lake this day and dry it.\n\t\tReturn an array ans where:\n\t\t\tans.length == rains.length\n\t\t\tans[i] == -1 if rains[i] > 0.\n\t\t\tans[i] is the lake you choose to dry in the ith day if rains[i] == 0.\n\t\tIf there are multiple valid answers return any of them. If it is impossible to avoid flood return an empty array.\n\t\tNotice that if you chose to dry a full lake, it becomes empty, but if you chose to dry an empty lake, nothing changes.\n\t\tExample 1:\n\t\tInput: rains = [1,2,3,4]\n\t\tOutput: [-1,-1,-1,-1]\n\t\tExplanation: After the first day full lakes are [1]\n\t\tAfter the second day full lakes are [1,2]\n\t\tAfter the third day full lakes are [1,2,3]\n\t\tAfter the fourth day full lakes are [1,2,3,4]\n\t\tThere's no day to dry any lake and there is no flood in any lake.\n\t\tExample 2:\n\t\tInput: rains = [1,2,0,0,2,1]\n\t\tOutput: [-1,-1,2,1,-1,-1]\n\t\tExplanation: After the first day full lakes are [1]\n\t\tAfter the second day full lakes are [1,2]\n\t\tAfter the third day, we dry lake 2. Full lakes are [1]\n\t\tAfter the fourth day, we dry lake 1. There is no full lakes.\n\t\tAfter the fifth day, full lakes are [2].\n\t\tAfter the sixth day, full lakes are [1,2].\n\t\tIt is easy that this scenario is flood-free. [-1,-1,1,2,-1,-1] is another acceptable scenario.\n\t\tExample 3:\n\t\tInput: rains = [1,2,0,1,2]\n\t\tOutput: []\n\t\tExplanation: After the second day, full lakes are [1,2]. We have to dry one lake in the third day.\n\t\tAfter that, it will rain over lakes [1,2]. It's easy to prove that no matter which lake you choose to dry in the 3rd day, the other one will flood.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1613, - "question": "class Solution:\n def findCriticalAndPseudoCriticalEdges(self, n: int, edges: List[List[int]]) -> List[List[int]]:\n\t\t\"\"\"\n\t\tGiven a weighted undirected connected graph with n vertices numbered from 0 to n - 1, and an array edges where edges[i] = [ai, bi, weighti] represents a bidirectional and weighted edge between nodes ai and bi. A minimum spanning tree (MST) is a subset of the graph's edges that connects all vertices without cycles and with the minimum possible total edge weight.\n\t\tFind all the critical and pseudo-critical edges in the given graph's minimum spanning tree (MST). An MST edge whose deletion from the graph would cause the MST weight to increase is called a critical edge. On the other hand, a pseudo-critical edge is that which can appear in some MSTs but not all.\n\t\tNote that you can return the indices of the edges in any order.\n\t\tExample 1:\n\t\tInput: n = 5, edges = [[0,1,1],[1,2,1],[2,3,2],[0,3,2],[0,4,3],[3,4,3],[1,4,6]]\n\t\tOutput: [[0,1],[2,3,4,5]]\n\t\tExplanation: The figure above describes the graph.\n\t\tThe following figure shows all the possible MSTs:\n\t\tNotice that the two edges 0 and 1 appear in all MSTs, therefore they are critical edges, so we return them in the first list of the output.\n\t\tThe edges 2, 3, 4, and 5 are only part of some MSTs, therefore they are considered pseudo-critical edges. We add them to the second list of the output.\n\t\tExample 2:\n\t\tInput: n = 4, edges = [[0,1,1],[1,2,1],[2,3,1],[0,3,1]]\n\t\tOutput: [[],[0,1,2,3]]\n\t\tExplanation: We can observe that since all 4 edges have equal weight, choosing any 3 edges from the given 4 will yield an MST. Therefore all 4 edges are pseudo-critical.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1615, - "question": "class Solution:\n def rangeSum(self, nums: List[int], n: int, left: int, right: int) -> int:\n\t\t\"\"\"\n\t\tYou are given the array nums consisting of n positive integers. You computed the sum of all non-empty continuous subarrays from the array and then sorted them in non-decreasing order, creating a new array of n * (n + 1) / 2 numbers.\n\t\tReturn the sum of the numbers from index left to index right (indexed from 1), inclusive, in the new array. Since the answer can be a huge number return it modulo 109 + 7.\n\t\tExample 1:\n\t\tInput: nums = [1,2,3,4], n = 4, left = 1, right = 5\n\t\tOutput: 13 \n\t\tExplanation: All subarray sums are 1, 3, 6, 10, 2, 5, 9, 3, 7, 4. After sorting them in non-decreasing order we have the new array [1, 2, 3, 3, 4, 5, 6, 7, 9, 10]. The sum of the numbers from index le = 1 to ri = 5 is 1 + 2 + 3 + 3 + 4 = 13. \n\t\tExample 2:\n\t\tInput: nums = [1,2,3,4], n = 4, left = 3, right = 4\n\t\tOutput: 6\n\t\tExplanation: The given array is the same as example 1. We have the new array [1, 2, 3, 3, 4, 5, 6, 7, 9, 10]. The sum of the numbers from index le = 3 to ri = 4 is 3 + 3 = 6.\n\t\tExample 3:\n\t\tInput: nums = [1,2,3,4], n = 4, left = 1, right = 10\n\t\tOutput: 50\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1616, - "question": "class Solution:\n def minDifference(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou are given an integer array nums.\n\t\tIn one move, you can choose one element of nums and change it to any value.\n\t\tReturn the minimum difference between the largest and smallest value of nums after performing at most three moves.\n\t\tExample 1:\n\t\tInput: nums = [5,3,2,4]\n\t\tOutput: 0\n\t\tExplanation: We can make at most 3 moves.\n\t\tIn the first move, change 2 to 3. nums becomes [5,3,3,4].\n\t\tIn the second move, change 4 to 3. nums becomes [5,3,3,3].\n\t\tIn the third move, change 5 to 3. nums becomes [3,3,3,3].\n\t\tAfter performing 3 moves, the difference between the minimum and maximum is 3 - 3 = 0.\n\t\tExample 2:\n\t\tInput: nums = [1,5,0,10,14]\n\t\tOutput: 1\n\t\tExplanation: We can make at most 3 moves.\n\t\tIn the first move, change 5 to 0. nums becomes [1,0,0,10,14].\n\t\tIn the second move, change 10 to 0. nums becomes [1,0,0,0,14].\n\t\tIn the third move, change 14 to 1. nums becomes [1,0,0,0,1].\n\t\tAfter performing 3 moves, the difference between the minimum and maximum is 1 - 0 = 0.\n\t\tIt can be shown that there is no way to make the difference 0 in 3 moves.\n\t\tExample 3:\n\t\tInput: nums = [3,100,20]\n\t\tOutput: 0\n\t\tExplanation: We can make at most 3 moves.\n\t\tIn the first move, change 100 to 7. nums becomes [4,7,20].\n\t\tIn the second move, change 20 to 7. nums becomes [4,7,7].\n\t\tIn the third move, change 4 to 3. nums becomes [7,7,7].\n\t\tAfter performing 3 moves, the difference between the minimum and maximum is 7 - 7 = 0.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1617, - "question": "class Solution:\n def winnerSquareGame(self, n: int) -> bool:\n\t\t\"\"\"\n\t\tAlice and Bob take turns playing a game, with Alice starting first.\n\t\tInitially, there are n stones in a pile. On each player's turn, that player makes a move consisting of removing any non-zero square number of stones in the pile.\n\t\tAlso, if a player cannot make a move, he/she loses the game.\n\t\tGiven a positive integer n, return true if and only if Alice wins the game otherwise return false, assuming both players play optimally.\n\t\tExample 1:\n\t\tInput: n = 1\n\t\tOutput: true\n\t\tExplanation: Alice can remove 1 stone winning the game because Bob doesn't have any moves.\n\t\tExample 2:\n\t\tInput: n = 2\n\t\tOutput: false\n\t\tExplanation: Alice can only remove 1 stone, after that Bob removes the last one winning the game (2 -> 1 -> 0).\n\t\tExample 3:\n\t\tInput: n = 4\n\t\tOutput: true\n\t\tExplanation: n is already a perfect square, Alice can win with one move, removing 4 stones (4 -> 0).\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1619, - "question": "class Solution:\n def isPathCrossing(self, path: str) -> bool:\n\t\t\"\"\"\n\t\tGiven a string path, where path[i] = 'N', 'S', 'E' or 'W', each representing moving one unit north, south, east, or west, respectively. You start at the origin (0, 0) on a 2D plane and walk on the path specified by path.\n\t\tReturn true if the path crosses itself at any point, that is, if at any time you are on a location you have previously visited. Return false otherwise.\n\t\tExample 1:\n\t\tInput: path = \"NES\"\n\t\tOutput: false \n\t\tExplanation: Notice that the path doesn't cross any point more than once.\n\t\tExample 2:\n\t\tInput: path = \"NESWW\"\n\t\tOutput: true\n\t\tExplanation: Notice that the path visits the origin twice.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1620, - "question": "class Solution:\n def canArrange(self, arr: List[int], k: int) -> bool:\n\t\t\"\"\"\n\t\tGiven an array of integers arr of even length n and an integer k.\n\t\tWe want to divide the array into exactly n / 2 pairs such that the sum of each pair is divisible by k.\n\t\tReturn true If you can find a way to do that or false otherwise.\n\t\tExample 1:\n\t\tInput: arr = [1,2,3,4,5,10,6,7,8,9], k = 5\n\t\tOutput: true\n\t\tExplanation: Pairs are (1,9),(2,8),(3,7),(4,6) and (5,10).\n\t\tExample 2:\n\t\tInput: arr = [1,2,3,4,5,6], k = 7\n\t\tOutput: true\n\t\tExplanation: Pairs are (1,6),(2,5) and(3,4).\n\t\tExample 3:\n\t\tInput: arr = [1,2,3,4,5,6], k = 10\n\t\tOutput: false\n\t\tExplanation: You can try all possible pairs to see that there is no way to divide arr into 3 pairs each with sum divisible by 10.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1621, - "question": "class Solution:\n def numSubseq(self, nums: List[int], target: int) -> int:\n\t\t\"\"\"\n\t\tYou are given an array of integers nums and an integer target.\n\t\tReturn the number of non-empty subsequences of nums such that the sum of the minimum and maximum element on it is less or equal to target. Since the answer may be too large, return it modulo 109 + 7.\n\t\tExample 1:\n\t\tInput: nums = [3,5,6,7], target = 9\n\t\tOutput: 4\n\t\tExplanation: There are 4 subsequences that satisfy the condition.\n\t\t[3] -> Min value + max value <= target (3 + 3 <= 9)\n\t\t[3,5] -> (3 + 5 <= 9)\n\t\t[3,5,6] -> (3 + 6 <= 9)\n\t\t[3,6] -> (3 + 6 <= 9)\n\t\tExample 2:\n\t\tInput: nums = [3,3,6,8], target = 10\n\t\tOutput: 6\n\t\tExplanation: There are 6 subsequences that satisfy the condition. (nums can have repeated numbers).\n\t\t[3] , [3] , [3,3], [3,6] , [3,6] , [3,3,6]\n\t\tExample 3:\n\t\tInput: nums = [2,3,3,4,6,7], target = 12\n\t\tOutput: 61\n\t\tExplanation: There are 63 non-empty subsequences, two of them do not satisfy the condition ([6,7], [7]).\n\t\tNumber of valid subsequences (63 - 2 = 61).\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1622, - "question": "class Solution:\n def findMaxValueOfEquation(self, points: List[List[int]], k: int) -> int:\n\t\t\"\"\"\n\t\tYou are given an array points containing the coordinates of points on a 2D plane, sorted by the x-values, where points[i] = [xi, yi] such that xi < xj for all 1 <= i < j <= points.length. You are also given an integer k.\n\t\tReturn the maximum value of the equation yi + yj + |xi - xj| where |xi - xj| <= k and 1 <= i < j <= points.length.\n\t\tIt is guaranteed that there exists at least one pair of points that satisfy the constraint |xi - xj| <= k.\n\t\tExample 1:\n\t\tInput: points = [[1,3],[2,0],[5,10],[6,-10]], k = 1\n\t\tOutput: 4\n\t\tExplanation: The first two points satisfy the condition |xi - xj| <= 1 and if we calculate the equation we get 3 + 0 + |1 - 2| = 4. Third and fourth points also satisfy the condition and give a value of 10 + -10 + |5 - 6| = 1.\n\t\tNo other pairs satisfy the condition, so we return the max of 4 and 1.\n\t\tExample 2:\n\t\tInput: points = [[0,0],[3,0],[9,2]], k = 3\n\t\tOutput: 3\n\t\tExplanation: Only the first two points have an absolute difference of 3 or less in the x-values, and give the value of 0 + 0 + |0 - 3| = 3.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1626, - "question": "class Solution:\n def canMakeArithmeticProgression(self, arr: List[int]) -> bool:\n\t\t\"\"\"\n\t\tA sequence of numbers is called an arithmetic progression if the difference between any two consecutive elements is the same.\n\t\tGiven an array of numbers arr, return true if the array can be rearranged to form an arithmetic progression. Otherwise, return false.\n\t\tExample 1:\n\t\tInput: arr = [3,5,1]\n\t\tOutput: true\n\t\tExplanation: We can reorder the elements as [1,3,5] or [5,3,1] with differences 2 and -2 respectively, between each consecutive elements.\n\t\tExample 2:\n\t\tInput: arr = [1,2,4]\n\t\tOutput: false\n\t\tExplanation: There is no way to reorder the elements to obtain an arithmetic progression.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1627, - "question": "class Solution:\n def getLastMoment(self, n: int, left: List[int], right: List[int]) -> int:\n\t\t\"\"\"\n\t\tWe have a wooden plank of the length n units. Some ants are walking on the plank, each ant moves with a speed of 1 unit per second. Some of the ants move to the left, the other move to the right.\n\t\tWhen two ants moving in two different directions meet at some point, they change their directions and continue moving again. Assume changing directions does not take any additional time.\n\t\tWhen an ant reaches one end of the plank at a time t, it falls out of the plank immediately.\n\t\tGiven an integer n and two integer arrays left and right, the positions of the ants moving to the left and the right, return the moment when the last ant(s) fall out of the plank.\n\t\tExample 1:\n\t\tInput: n = 4, left = [4,3], right = [0,1]\n\t\tOutput: 4\n\t\tExplanation: In the image above:\n\t\t-The ant at index 0 is named A and going to the right.\n\t\t-The ant at index 1 is named B and going to the right.\n\t\t-The ant at index 3 is named C and going to the left.\n\t\t-The ant at index 4 is named D and going to the left.\n\t\tThe last moment when an ant was on the plank is t = 4 seconds. After that, it falls immediately out of the plank. (i.e., We can say that at t = 4.0000000001, there are no ants on the plank).\n\t\tExample 2:\n\t\tInput: n = 7, left = [], right = [0,1,2,3,4,5,6,7]\n\t\tOutput: 7\n\t\tExplanation: All ants are going to the right, the ant at index 0 needs 7 seconds to fall.\n\t\tExample 3:\n\t\tInput: n = 7, left = [0,1,2,3,4,5,6,7], right = []\n\t\tOutput: 7\n\t\tExplanation: All ants are going to the left, the ant at index 7 needs 7 seconds to fall.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1628, - "question": "class Solution:\n def numSubmat(self, mat: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tGiven an m x n binary matrix mat, return the number of submatrices that have all ones.\n\t\tExample 1:\n\t\tInput: mat = [[1,0,1],[1,1,0],[1,1,0]]\n\t\tOutput: 13\n\t\tExplanation: \n\t\tThere are 6 rectangles of side 1x1.\n\t\tThere are 2 rectangles of side 1x2.\n\t\tThere are 3 rectangles of side 2x1.\n\t\tThere is 1 rectangle of side 2x2. \n\t\tThere is 1 rectangle of side 3x1.\n\t\tTotal number of rectangles = 6 + 2 + 3 + 1 + 1 = 13.\n\t\tExample 2:\n\t\tInput: mat = [[0,1,1,0],[0,1,1,1],[1,1,1,0]]\n\t\tOutput: 24\n\t\tExplanation: \n\t\tThere are 8 rectangles of side 1x1.\n\t\tThere are 5 rectangles of side 1x2.\n\t\tThere are 2 rectangles of side 1x3. \n\t\tThere are 4 rectangles of side 2x1.\n\t\tThere are 2 rectangles of side 2x2. \n\t\tThere are 2 rectangles of side 3x1. \n\t\tThere is 1 rectangle of side 3x2. \n\t\tTotal number of rectangles = 8 + 5 + 2 + 4 + 2 + 2 + 1 = 24.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1629, - "question": "class Solution:\n def minInteger(self, num: str, k: int) -> str:\n\t\t\"\"\"\n\t\tYou are given a string num representing the digits of a very large integer and an integer k. You are allowed to swap any two adjacent digits of the integer at most k times.\n\t\tReturn the minimum integer you can obtain also as a string.\n\t\tExample 1:\n\t\tInput: num = \"4321\", k = 4\n\t\tOutput: \"1342\"\n\t\tExplanation: The steps to obtain the minimum integer from 4321 with 4 adjacent swaps are shown.\n\t\tExample 2:\n\t\tInput: num = \"100\", k = 1\n\t\tOutput: \"010\"\n\t\tExplanation: It's ok for the output to have leading zeros, but the input is guaranteed not to have any leading zeros.\n\t\tExample 3:\n\t\tInput: num = \"36789\", k = 1000\n\t\tOutput: \"36789\"\n\t\tExplanation: We can keep the number without any swaps.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1630, - "question": "class Solution:\n def countOdds(self, low: int, high: int) -> int:\n\t\t\"\"\"\n\t\tGiven two non-negative integers low and high. Return the count of odd numbers between low and high (inclusive).\r\n\t\tExample 1:\r\n\t\tInput: low = 3, high = 7\r\n\t\tOutput: 3\r\n\t\tExplanation: The odd numbers between 3 and 7 are [3,5,7].\r\n\t\tExample 2:\r\n\t\tInput: low = 8, high = 10\r\n\t\tOutput: 1\r\n\t\tExplanation: The odd numbers between 8 and 10 are [9].\r\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1631, - "question": "class Solution:\n def numOfSubarrays(self, arr: List[int]) -> int:\n\t\t\"\"\"\n\t\tGiven an array of integers arr, return the number of subarrays with an odd sum.\n\t\tSince the answer can be very large, return it modulo 109 + 7.\n\t\tExample 1:\n\t\tInput: arr = [1,3,5]\n\t\tOutput: 4\n\t\tExplanation: All subarrays are [[1],[1,3],[1,3,5],[3],[3,5],[5]]\n\t\tAll sub-arrays sum are [1,4,9,3,8,5].\n\t\tOdd sums are [1,9,3,5] so the answer is 4.\n\t\tExample 2:\n\t\tInput: arr = [2,4,6]\n\t\tOutput: 0\n\t\tExplanation: All subarrays are [[2],[2,4],[2,4,6],[4],[4,6],[6]]\n\t\tAll sub-arrays sum are [2,6,12,4,10,6].\n\t\tAll sub-arrays have even sum and the answer is 0.\n\t\tExample 3:\n\t\tInput: arr = [1,2,3,4,5,6,7]\n\t\tOutput: 16\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1632, - "question": "class Solution:\n def numSplits(self, s: str) -> int:\n\t\t\"\"\"\n\t\tYou are given a string s.\n\t\tA split is called good if you can split s into two non-empty strings sleft and sright where their concatenation is equal to s (i.e., sleft + sright = s) and the number of distinct letters in sleft and sright is the same.\n\t\tReturn the number of good splits you can make in s.\n\t\tExample 1:\n\t\tInput: s = \"aacaba\"\n\t\tOutput: 2\n\t\tExplanation: There are 5 ways to split \"aacaba\" and 2 of them are good. \n\t\t(\"a\", \"acaba\") Left string and right string contains 1 and 3 different letters respectively.\n\t\t(\"aa\", \"caba\") Left string and right string contains 1 and 3 different letters respectively.\n\t\t(\"aac\", \"aba\") Left string and right string contains 2 and 2 different letters respectively (good split).\n\t\t(\"aaca\", \"ba\") Left string and right string contains 2 and 2 different letters respectively (good split).\n\t\t(\"aacab\", \"a\") Left string and right string contains 3 and 1 different letters respectively.\n\t\tExample 2:\n\t\tInput: s = \"abcd\"\n\t\tOutput: 1\n\t\tExplanation: Split the string as follows (\"ab\", \"cd\").\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1633, - "question": "class Solution:\n def minNumberOperations(self, target: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou are given an integer array target. You have an integer array initial of the same size as target with all elements initially zeros.\n\t\tIn one operation you can choose any subarray from initial and increment each value by one.\n\t\tReturn the minimum number of operations to form a target array from initial.\n\t\tThe test cases are generated so that the answer fits in a 32-bit integer.\n\t\tExample 1:\n\t\tInput: target = [1,2,3,2,1]\n\t\tOutput: 3\n\t\tExplanation: We need at least 3 operations to form the target array from the initial array.\n\t\t[0,0,0,0,0] increment 1 from index 0 to 4 (inclusive).\n\t\t[1,1,1,1,1] increment 1 from index 1 to 3 (inclusive).\n\t\t[1,2,2,2,1] increment 1 at index 2.\n\t\t[1,2,3,2,1] target array is formed.\n\t\tExample 2:\n\t\tInput: target = [3,1,1,2]\n\t\tOutput: 4\n\t\tExplanation: [0,0,0,0] -> [1,1,1,1] -> [1,1,1,2] -> [2,1,1,2] -> [3,1,1,2]\n\t\tExample 3:\n\t\tInput: target = [3,1,5,4,2]\n\t\tOutput: 7\n\t\tExplanation: [0,0,0,0,0] -> [1,1,1,1,1] -> [2,1,1,1,1] -> [3,1,1,1,1] -> [3,1,2,2,2] -> [3,1,3,3,2] -> [3,1,4,4,2] -> [3,1,5,4,2].\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1635, - "question": "class Solution:\n def numIdenticalPairs(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tGiven an array of integers nums, return the number of good pairs.\n\t\tA pair (i, j) is called good if nums[i] == nums[j] and i < j.\n\t\tExample 1:\n\t\tInput: nums = [1,2,3,1,1,3]\n\t\tOutput: 4\n\t\tExplanation: There are 4 good pairs (0,3), (0,4), (3,4), (2,5) 0-indexed.\n\t\tExample 2:\n\t\tInput: nums = [1,1,1,1]\n\t\tOutput: 6\n\t\tExplanation: Each pair in the array are good.\n\t\tExample 3:\n\t\tInput: nums = [1,2,3]\n\t\tOutput: 0\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1636, - "question": "class Solution:\n def numSub(self, s: str) -> int:\n\t\t\"\"\"\n\t\tGiven a binary string s, return the number of substrings with all characters 1's. Since the answer may be too large, return it modulo 109 + 7.\n\t\tExample 1:\n\t\tInput: s = \"0110111\"\n\t\tOutput: 9\n\t\tExplanation: There are 9 substring in total with only 1's characters.\n\t\t\"1\" -> 5 times.\n\t\t\"11\" -> 3 times.\n\t\t\"111\" -> 1 time.\n\t\tExample 2:\n\t\tInput: s = \"101\"\n\t\tOutput: 2\n\t\tExplanation: Substring \"1\" is shown 2 times in s.\n\t\tExample 3:\n\t\tInput: s = \"111111\"\n\t\tOutput: 21\n\t\tExplanation: Each substring contains only 1's characters.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1637, - "question": "class Solution:\n def getLengthOfOptimalCompression(self, s: str, k: int) -> int:\n\t\t\"\"\"\n\t\tRun-length encoding is a string compression method that works by replacing consecutive identical characters (repeated 2 or more times) with the concatenation of the character and the number marking the count of the characters (length of the run). For example, to compress the string \"aabccc\" we replace \"aa\" by \"a2\" and replace \"ccc\" by \"c3\". Thus the compressed string becomes \"a2bc3\".\n\t\tNotice that in this problem, we are not adding '1' after single characters.\n\t\tGiven a string s and an integer k. You need to delete at most k characters from s such that the run-length encoded version of s has minimum length.\n\t\tFind the minimum length of the run-length encoded version of s after deleting at most k characters.\n\t\tExample 1:\n\t\tInput: s = \"aaabcccd\", k = 2\n\t\tOutput: 4\n\t\tExplanation: Compressing s without deleting anything will give us \"a3bc3d\" of length 6. Deleting any of the characters 'a' or 'c' would at most decrease the length of the compressed string to 5, for instance delete 2 'a' then we will have s = \"abcccd\" which compressed is abc3d. Therefore, the optimal way is to delete 'b' and 'd', then the compressed version of s will be \"a3c3\" of length 4.\n\t\tExample 2:\n\t\tInput: s = \"aabbaa\", k = 2\n\t\tOutput: 2\n\t\tExplanation: If we delete both 'b' characters, the resulting compressed string would be \"a4\" of length 2.\n\t\tExample 3:\n\t\tInput: s = \"aaaaaaaaaaa\", k = 0\n\t\tOutput: 3\n\t\tExplanation: Since k is zero, we cannot delete anything. The compressed string is \"a11\" of length 3.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1638, - "question": "class Solution:\n def getMinDistSum(self, positions: List[List[int]]) -> float:\n\t\t\"\"\"\n\t\tA delivery company wants to build a new service center in a new city. The company knows the positions of all the customers in this city on a 2D-Map and wants to build the new center in a position such that the sum of the euclidean distances to all customers is minimum.\n\t\tGiven an array positions where positions[i] = [xi, yi] is the position of the ith customer on the map, return the minimum sum of the euclidean distances to all customers.\n\t\tIn other words, you need to choose the position of the service center [xcentre, ycentre] such that the following formula is minimized:\n\t\tAnswers within 10-5 of the actual value will be accepted.\n\t\tExample 1:\n\t\tInput: positions = [[0,1],[1,0],[1,2],[2,1]]\n\t\tOutput: 4.00000\n\t\tExplanation: As shown, you can see that choosing [xcentre, ycentre] = [1, 1] will make the distance to each customer = 1, the sum of all distances is 4 which is the minimum possible we can achieve.\n\t\tExample 2:\n\t\tInput: positions = [[1,1],[3,3]]\n\t\tOutput: 2.82843\n\t\tExplanation: The minimum possible sum of distances = sqrt(2) + sqrt(2) = 2.82843\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1642, - "question": "class Solution:\n def numWaterBottles(self, numBottles: int, numExchange: int) -> int:\n\t\t\"\"\"\n\t\tThere are numBottles water bottles that are initially full of water. You can exchange numExchange empty water bottles from the market with one full water bottle.\n\t\tThe operation of drinking a full water bottle turns it into an empty bottle.\n\t\tGiven the two integers numBottles and numExchange, return the maximum number of water bottles you can drink.\n\t\tExample 1:\n\t\tInput: numBottles = 9, numExchange = 3\n\t\tOutput: 13\n\t\tExplanation: You can exchange 3 empty bottles to get 1 full water bottle.\n\t\tNumber of water bottles you can drink: 9 + 3 + 1 = 13.\n\t\tExample 2:\n\t\tInput: numBottles = 15, numExchange = 4\n\t\tOutput: 19\n\t\tExplanation: You can exchange 4 empty bottles to get 1 full water bottle. \n\t\tNumber of water bottles you can drink: 15 + 3 + 1 = 19.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1643, - "question": "class Solution:\n def countSubTrees(self, n: int, edges: List[List[int]], labels: str) -> List[int]:\n\t\t\"\"\"\n\t\tYou are given a tree (i.e. a connected, undirected graph that has no cycles) consisting of n nodes numbered from 0 to n - 1 and exactly n - 1 edges. The root of the tree is the node 0, and each node of the tree has a label which is a lower-case character given in the string labels (i.e. The node with the number i has the label labels[i]).\n\t\tThe edges array is given on the form edges[i] = [ai, bi], which means there is an edge between nodes ai and bi in the tree.\n\t\tReturn an array of size n where ans[i] is the number of nodes in the subtree of the ith node which have the same label as node i.\n\t\tA subtree of a tree T is the tree consisting of a node in T and all of its descendant nodes.\n\t\tExample 1:\n\t\tInput: n = 7, edges = [[0,1],[0,2],[1,4],[1,5],[2,3],[2,6]], labels = \"abaedcd\"\n\t\tOutput: [2,1,1,1,1,1,1]\n\t\tExplanation: Node 0 has label 'a' and its sub-tree has node 2 with label 'a' as well, thus the answer is 2. Notice that any node is part of its sub-tree.\n\t\tNode 1 has a label 'b'. The sub-tree of node 1 contains nodes 1,4 and 5, as nodes 4 and 5 have different labels than node 1, the answer is just 1 (the node itself).\n\t\tExample 2:\n\t\tInput: n = 4, edges = [[0,1],[1,2],[0,3]], labels = \"bbbb\"\n\t\tOutput: [4,2,1,1]\n\t\tExplanation: The sub-tree of node 2 contains only node 2, so the answer is 1.\n\t\tThe sub-tree of node 3 contains only node 3, so the answer is 1.\n\t\tThe sub-tree of node 1 contains nodes 1 and 2, both have label 'b', thus the answer is 2.\n\t\tThe sub-tree of node 0 contains nodes 0, 1, 2 and 3, all with label 'b', thus the answer is 4.\n\t\tExample 3:\n\t\tInput: n = 5, edges = [[0,1],[0,2],[1,3],[0,4]], labels = \"aabab\"\n\t\tOutput: [3,2,1,1,1]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1644, - "question": "class Solution:\n def maxNumOfSubstrings(self, s: str) -> List[str]:\n\t\t\"\"\"\n\t\tGiven a string s of lowercase letters, you need to find the maximum number of non-empty substrings of s that meet the following conditions:\n\t\t\tThe substrings do not overlap, that is for any two substrings s[i..j] and s[x..y], either j < x or i > y is true.\n\t\t\tA substring that contains a certain character c must also contain all occurrences of c.\n\t\tFind the maximum number of substrings that meet the above conditions. If there are multiple solutions with the same number of substrings, return the one with minimum total length. It can be shown that there exists a unique solution of minimum total length.\n\t\tNotice that you can return the substrings in any order.\n\t\tExample 1:\n\t\tInput: s = \"adefaddaccc\"\n\t\tOutput: [\"e\",\"f\",\"ccc\"]\n\t\tExplanation: The following are all the possible substrings that meet the conditions:\n\t\t[\n\t\t \"adefaddaccc\"\n\t\t \"adefadda\",\n\t\t \"ef\",\n\t\t \"e\",\n\t\t \"f\",\n\t\t \"ccc\",\n\t\t]\n\t\tIf we choose the first string, we cannot choose anything else and we'd get only 1. If we choose \"adefadda\", we are left with \"ccc\" which is the only one that doesn't overlap, thus obtaining 2 substrings. Notice also, that it's not optimal to choose \"ef\" since it can be split into two. Therefore, the optimal way is to choose [\"e\",\"f\",\"ccc\"] which gives us 3 substrings. No other solution of the same number of substrings exist.\n\t\tExample 2:\n\t\tInput: s = \"abbaccd\"\n\t\tOutput: [\"d\",\"bb\",\"cc\"]\n\t\tExplanation: Notice that while the set of substrings [\"d\",\"abba\",\"cc\"] also has length 3, it's considered incorrect since it has larger total length.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1645, - "question": "class Solution:\n def closestToTarget(self, arr: List[int], target: int) -> int:\n\t\t\"\"\"\n\t\tWinston was given the above mysterious function func. He has an integer array arr and an integer target and he wants to find the values l and r that make the value |func(arr, l, r) - target| minimum possible.\n\t\tReturn the minimum possible value of |func(arr, l, r) - target|.\n\t\tNotice that func should be called with the values l and r where 0 <= l, r < arr.length.\n\t\tExample 1:\n\t\tInput: arr = [9,12,3,7,15], target = 5\n\t\tOutput: 2\n\t\tExplanation: Calling func with all the pairs of [l,r] = [[0,0],[1,1],[2,2],[3,3],[4,4],[0,1],[1,2],[2,3],[3,4],[0,2],[1,3],[2,4],[0,3],[1,4],[0,4]], Winston got the following results [9,12,3,7,15,8,0,3,7,0,0,3,0,0,0]. The value closest to 5 is 7 and 3, thus the minimum difference is 2.\n\t\tExample 2:\n\t\tInput: arr = [1000000,1000000,1000000], target = 1\n\t\tOutput: 999999\n\t\tExplanation: Winston called the func with all possible values of [l,r] and he always got 1000000, thus the min difference is 999999.\n\t\tExample 3:\n\t\tInput: arr = [1,2,4,8,16], target = 0\n\t\tOutput: 0\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1646, - "question": "class Solution:\n def findKthPositive(self, arr: List[int], k: int) -> int:\n\t\t\"\"\"\n\t\tGiven an array arr of positive integers sorted in a strictly increasing order, and an integer k.\n\t\tReturn the kth positive integer that is missing from this array.\n\t\tExample 1:\n\t\tInput: arr = [2,3,4,7,11], k = 5\n\t\tOutput: 9\n\t\tExplanation: The missing positive integers are [1,5,6,8,9,10,12,13,...]. The 5th missing positive integer is 9.\n\t\tExample 2:\n\t\tInput: arr = [1,2,3,4], k = 2\n\t\tOutput: 6\n\t\tExplanation: The missing positive integers are [5,6,7,...]. The 2nd missing positive integer is 6.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1647, - "question": "class Solution:\n def canConvertString(self, s: str, t: str, k: int) -> bool:\n\t\t\"\"\"\n\t\tGiven two strings s and t, your goal is to convert s into t in k moves or less.\n\t\tDuring the ith (1 <= i <= k) move you can:\n\t\t\tChoose any index j (1-indexed) from s, such that 1 <= j <= s.length and j has not been chosen in any previous move, and shift the character at that index i times.\n\t\t\tDo nothing.\n\t\tShifting a character means replacing it by the next letter in the alphabet (wrapping around so that 'z' becomes 'a'). Shifting a character by i means applying the shift operations i times.\n\t\tRemember that any index j can be picked at most once.\n\t\tReturn true if it's possible to convert s into t in no more than k moves, otherwise return false.\n\t\tExample 1:\n\t\tInput: s = \"input\", t = \"ouput\", k = 9\n\t\tOutput: true\n\t\tExplanation: In the 6th move, we shift 'i' 6 times to get 'o'. And in the 7th move we shift 'n' to get 'u'.\n\t\tExample 2:\n\t\tInput: s = \"abc\", t = \"bcd\", k = 10\n\t\tOutput: false\n\t\tExplanation: We need to shift each character in s one time to convert it into t. We can shift 'a' to 'b' during the 1st move. However, there is no way to shift the other characters in the remaining moves to obtain t from s.\n\t\tExample 3:\n\t\tInput: s = \"aab\", t = \"bbb\", k = 27\n\t\tOutput: true\n\t\tExplanation: In the 1st move, we shift the first 'a' 1 time to get 'b'. In the 27th move, we shift the second 'a' 27 times to get 'b'.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1648, - "question": "class Solution:\n def minInsertions(self, s: str) -> int:\n\t\t\"\"\"\n\t\tGiven a parentheses string s containing only the characters '(' and ')'. A parentheses string is balanced if:\n\t\t\tAny left parenthesis '(' must have a corresponding two consecutive right parenthesis '))'.\n\t\t\tLeft parenthesis '(' must go before the corresponding two consecutive right parenthesis '))'.\n\t\tIn other words, we treat '(' as an opening parenthesis and '))' as a closing parenthesis.\n\t\t\tFor example, \"())\", \"())(())))\" and \"(())())))\" are balanced, \")()\", \"()))\" and \"(()))\" are not balanced.\n\t\tYou can insert the characters '(' and ')' at any position of the string to balance it if needed.\n\t\tReturn the minimum number of insertions needed to make s balanced.\n\t\tExample 1:\n\t\tInput: s = \"(()))\"\n\t\tOutput: 1\n\t\tExplanation: The second '(' has two matching '))', but the first '(' has only ')' matching. We need to add one more ')' at the end of the string to be \"(())))\" which is balanced.\n\t\tExample 2:\n\t\tInput: s = \"())\"\n\t\tOutput: 0\n\t\tExplanation: The string is already balanced.\n\t\tExample 3:\n\t\tInput: s = \"))())(\"\n\t\tOutput: 3\n\t\tExplanation: Add '(' to match the first '))', Add '))' to match the last '('.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1649, - "question": "class Solution:\n def maxNonOverlapping(self, nums: List[int], target: int) -> int:\n\t\t\"\"\"\n\t\tGiven an array nums and an integer target, return the maximum number of non-empty non-overlapping subarrays such that the sum of values in each subarray is equal to target.\n\t\tExample 1:\n\t\tInput: nums = [1,1,1,1,1], target = 2\n\t\tOutput: 2\n\t\tExplanation: There are 2 non-overlapping subarrays [1,1,1,1,1] with sum equals to target(2).\n\t\tExample 2:\n\t\tInput: nums = [-1,3,5,1,4,2,-9], target = 6\n\t\tOutput: 2\n\t\tExplanation: There are 3 subarrays with sum equal to 6.\n\t\t([5,1], [4,2], [3,5,1,4,2,-9]) but only the first 2 are non-overlapping.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1651, - "question": "class Solution:\n def restoreString(self, s: str, indices: List[int]) -> str:\n\t\t\"\"\"\n\t\tYou are given a string s and an integer array indices of the same length. The string s will be shuffled such that the character at the ith position moves to indices[i] in the shuffled string.\n\t\tReturn the shuffled string.\n\t\tExample 1:\n\t\tInput: s = \"codeleet\", indices = [4,5,6,7,0,2,1,3]\n\t\tOutput: \"leetcode\"\n\t\tExplanation: As shown, \"codeleet\" becomes \"leetcode\" after shuffling.\n\t\tExample 2:\n\t\tInput: s = \"abc\", indices = [0,1,2]\n\t\tOutput: \"abc\"\n\t\tExplanation: After shuffling, each character remains in its position.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1652, - "question": "class Solution:\n def minFlips(self, target: str) -> int:\n\t\t\"\"\"\n\t\tYou are given a 0-indexed binary string target of length n. You have another binary string s of length n that is initially set to all zeros. You want to make s equal to target.\n\t\tIn one operation, you can pick an index i where 0 <= i < n and flip all bits in the inclusive range [i, n - 1]. Flip means changing '0' to '1' and '1' to '0'.\n\t\tReturn the minimum number of operations needed to make s equal to target.\n\t\tExample 1:\n\t\tInput: target = \"10111\"\n\t\tOutput: 3\n\t\tExplanation: Initially, s = \"00000\".\n\t\tChoose index i = 2: \"00000\" -> \"00111\"\n\t\tChoose index i = 0: \"00111\" -> \"11000\"\n\t\tChoose index i = 1: \"11000\" -> \"10111\"\n\t\tWe need at least 3 flip operations to form target.\n\t\tExample 2:\n\t\tInput: target = \"101\"\n\t\tOutput: 3\n\t\tExplanation: Initially, s = \"000\".\n\t\tChoose index i = 0: \"000\" -> \"111\"\n\t\tChoose index i = 1: \"111\" -> \"100\"\n\t\tChoose index i = 2: \"100\" -> \"101\"\n\t\tWe need at least 3 flip operations to form target.\n\t\tExample 3:\n\t\tInput: target = \"00000\"\n\t\tOutput: 0\n\t\tExplanation: We do not need any operations since the initial s already equals target.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1653, - "question": "class Solution:\n def countPairs(self, root: TreeNode, distance: int) -> int:\n\t\t\"\"\"\n\t\tYou are given the root of a binary tree and an integer distance. A pair of two different leaf nodes of a binary tree is said to be good if the length of the shortest path between them is less than or equal to distance.\n\t\tReturn the number of good leaf node pairs in the tree.\n\t\tExample 1:\n\t\tInput: root = [1,2,3,null,4], distance = 3\n\t\tOutput: 1\n\t\tExplanation: The leaf nodes of the tree are 3 and 4 and the length of the shortest path between them is 3. This is the only good pair.\n\t\tExample 2:\n\t\tInput: root = [1,2,3,4,5,6,7], distance = 3\n\t\tOutput: 2\n\t\tExplanation: The good pairs are [4,5] and [6,7] with shortest path = 2. The pair [4,6] is not good because the length of ther shortest path between them is 4.\n\t\tExample 3:\n\t\tInput: root = [7,1,4,6,null,5,3,null,null,null,null,null,2], distance = 3\n\t\tOutput: 1\n\t\tExplanation: The only good pair is [2,5].\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1656, - "question": "class Solution:\n def countGoodTriplets(self, arr: List[int], a: int, b: int, c: int) -> int:\n\t\t\"\"\"\n\t\tGiven an array of integers arr, and three integers a, b and c. You need to find the number of good triplets.\r\n\t\tA triplet (arr[i], arr[j], arr[k]) is good if the following conditions are true:\r\n\t\t\t0 <= i < j < k < arr.length\r\n\t\t\t|arr[i] - arr[j]| <= a\r\n\t\t\t|arr[j] - arr[k]| <= b\r\n\t\t\t|arr[i] - arr[k]| <= c\r\n\t\tWhere |x| denotes the absolute value of x.\r\n\t\tReturn the number of good triplets.\r\n\t\tExample 1:\r\n\t\tInput: arr = [3,0,1,1,9,7], a = 7, b = 2, c = 3\r\n\t\tOutput: 4\r\n\t\tExplanation: There are 4 good triplets: [(3,0,1), (3,0,1), (3,1,1), (0,1,1)].\r\n\t\tExample 2:\r\n\t\tInput: arr = [1,1,2,2,3], a = 0, b = 0, c = 1\r\n\t\tOutput: 0\r\n\t\tExplanation: No triplet satisfies all conditions.\r\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1657, - "question": "class Solution:\n def getWinner(self, arr: List[int], k: int) -> int:\n\t\t\"\"\"\n\t\tGiven an integer array arr of distinct integers and an integer k.\n\t\tA game will be played between the first two elements of the array (i.e. arr[0] and arr[1]). In each round of the game, we compare arr[0] with arr[1], the larger integer wins and remains at position 0, and the smaller integer moves to the end of the array. The game ends when an integer wins k consecutive rounds.\n\t\tReturn the integer which will win the game.\n\t\tIt is guaranteed that there will be a winner of the game.\n\t\tExample 1:\n\t\tInput: arr = [2,1,3,5,4,6,7], k = 2\n\t\tOutput: 5\n\t\tExplanation: Let's see the rounds of the game:\n\t\tRound | arr | winner | win_count\n\t\t 1 | [2,1,3,5,4,6,7] | 2 | 1\n\t\t 2 | [2,3,5,4,6,7,1] | 3 | 1\n\t\t 3 | [3,5,4,6,7,1,2] | 5 | 1\n\t\t 4 | [5,4,6,7,1,2,3] | 5 | 2\n\t\tSo we can see that 4 rounds will be played and 5 is the winner because it wins 2 consecutive games.\n\t\tExample 2:\n\t\tInput: arr = [3,2,1], k = 10\n\t\tOutput: 3\n\t\tExplanation: 3 will win the first 10 rounds consecutively.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1658, - "question": "class Solution:\n def minSwaps(self, grid: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tGiven an n x n binary grid, in one step you can choose two adjacent rows of the grid and swap them.\n\t\tA grid is said to be valid if all the cells above the main diagonal are zeros.\n\t\tReturn the minimum number of steps needed to make the grid valid, or -1 if the grid cannot be valid.\n\t\tThe main diagonal of a grid is the diagonal that starts at cell (1, 1) and ends at cell (n, n).\n\t\tExample 1:\n\t\tInput: grid = [[0,0,1],[1,1,0],[1,0,0]]\n\t\tOutput: 3\n\t\tExample 2:\n\t\tInput: grid = [[0,1,1,0],[0,1,1,0],[0,1,1,0],[0,1,1,0]]\n\t\tOutput: -1\n\t\tExplanation: All rows are similar, swaps have no effect on the grid.\n\t\tExample 3:\n\t\tInput: grid = [[1,0,0],[1,1,0],[1,1,1]]\n\t\tOutput: 0\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1659, - "question": "class Solution:\n def maxSum(self, nums1: List[int], nums2: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou are given two sorted arrays of distinct integers nums1 and nums2.\n\t\tA valid path is defined as follows:\n\t\t\tChoose array nums1 or nums2 to traverse (from index-0).\n\t\t\tTraverse the current array from left to right.\n\t\t\tIf you are reading any value that is present in nums1 and nums2 you are allowed to change your path to the other array. (Only one repeated value is considered in the valid path).\n\t\tThe score is defined as the sum of uniques values in a valid path.\n\t\tReturn the maximum score you can obtain of all possible valid paths. Since the answer may be too large, return it modulo 109 + 7.\n\t\tExample 1:\n\t\tInput: nums1 = [2,4,5,8,10], nums2 = [4,6,8,9]\n\t\tOutput: 30\n\t\tExplanation: Valid paths:\n\t\t[2,4,5,8,10], [2,4,5,8,9], [2,4,6,8,9], [2,4,6,8,10], (starting from nums1)\n\t\t[4,6,8,9], [4,5,8,10], [4,5,8,9], [4,6,8,10] (starting from nums2)\n\t\tThe maximum is obtained with the path in green [2,4,6,8,10].\n\t\tExample 2:\n\t\tInput: nums1 = [1,3,5,7,9], nums2 = [3,5,100]\n\t\tOutput: 109\n\t\tExplanation: Maximum sum is obtained with the path [1,3,5,100].\n\t\tExample 3:\n\t\tInput: nums1 = [1,2,3,4,5], nums2 = [6,7,8,9,10]\n\t\tOutput: 40\n\t\tExplanation: There are no common elements between nums1 and nums2.\n\t\tMaximum sum is obtained with the path [6,7,8,9,10].\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1660, - "question": "class Solution:\n def thousandSeparator(self, n: int) -> str:\n\t\t\"\"\"\n\t\tGiven an integer n, add a dot (\".\") as the thousands separator and return it in string format.\n\t\tExample 1:\n\t\tInput: n = 987\n\t\tOutput: \"987\"\n\t\tExample 2:\n\t\tInput: n = 1234\n\t\tOutput: \"1.234\"\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1661, - "question": "class Solution:\n def findSmallestSetOfVertices(self, n: int, edges: List[List[int]]) -> List[int]:\n\t\t\"\"\"\n\t\tGiven a directed acyclic graph, with n vertices numbered from 0 to n-1, and an array edges where edges[i] = [fromi, toi] represents a directed edge from node fromi to node toi.\r\n\t\tFind the smallest set of vertices from which all nodes in the graph are reachable. It's guaranteed that a unique solution exists.\r\n\t\tNotice that you can return the vertices in any order.\r\n\t\tExample 1:\r\n\t\tInput: n = 6, edges = [[0,1],[0,2],[2,5],[3,4],[4,2]]\r\n\t\tOutput: [0,3]\r\n\t\tExplanation: It's not possible to reach all the nodes from a single vertex. From 0 we can reach [0,1,2,5]. From 3 we can reach [3,4,2,5]. So we output [0,3].\r\n\t\tExample 2:\r\n\t\tInput: n = 5, edges = [[0,1],[2,1],[3,1],[1,4],[2,4]]\r\n\t\tOutput: [0,2,3]\r\n\t\tExplanation: Notice that vertices 0, 3 and 2 are not reachable from any other node, so we must include them. Also any of these vertices can reach nodes 1 and 4.\r\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1662, - "question": "class Solution:\n def minOperations(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou are given an integer array nums. You have an integer array arr of the same length with all values set to 0 initially. You also have the following modify function:\n\t\tYou want to use the modify function to covert arr to nums using the minimum number of calls.\n\t\tReturn the minimum number of function calls to make nums from arr.\n\t\tThe test cases are generated so that the answer fits in a 32-bit signed integer.\n\t\tExample 1:\n\t\tInput: nums = [1,5]\n\t\tOutput: 5\n\t\tExplanation: Increment by 1 (second element): [0, 0] to get [0, 1] (1 operation).\n\t\tDouble all the elements: [0, 1] -> [0, 2] -> [0, 4] (2 operations).\n\t\tIncrement by 1 (both elements) [0, 4] -> [1, 4] -> [1, 5] (2 operations).\n\t\tTotal of operations: 1 + 2 + 2 = 5.\n\t\tExample 2:\n\t\tInput: nums = [2,2]\n\t\tOutput: 3\n\t\tExplanation: Increment by 1 (both elements) [0, 0] -> [0, 1] -> [1, 1] (2 operations).\n\t\tDouble all the elements: [1, 1] -> [2, 2] (1 operation).\n\t\tTotal of operations: 2 + 1 = 3.\n\t\tExample 3:\n\t\tInput: nums = [4,2,5]\n\t\tOutput: 6\n\t\tExplanation: (initial)[0,0,0] -> [1,0,0] -> [1,0,1] -> [2,0,2] -> [2,1,2] -> [4,2,4] -> [4,2,5](nums).\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1663, - "question": "class Solution:\n def containsCycle(self, grid: List[List[str]]) -> bool:\n\t\t\"\"\"\n\t\tGiven a 2D array of characters grid of size m x n, you need to find if there exists any cycle consisting of the same value in grid.\n\t\tA cycle is a path of length 4 or more in the grid that starts and ends at the same cell. From a given cell, you can move to one of the cells adjacent to it - in one of the four directions (up, down, left, or right), if it has the same value of the current cell.\n\t\tAlso, you cannot move to the cell that you visited in your last move. For example, the cycle (1, 1) -> (1, 2) -> (1, 1) is invalid because from (1, 2) we visited (1, 1) which was the last visited cell.\n\t\tReturn true if any cycle of the same value exists in grid, otherwise, return false.\n\t\tExample 1:\n\t\tInput: grid = [[\"a\",\"a\",\"a\",\"a\"],[\"a\",\"b\",\"b\",\"a\"],[\"a\",\"b\",\"b\",\"a\"],[\"a\",\"a\",\"a\",\"a\"]]\n\t\tOutput: true\n\t\tExplanation: There are two valid cycles shown in different colors in the image below:\n\t\tExample 2:\n\t\tInput: grid = [[\"c\",\"c\",\"c\",\"a\"],[\"c\",\"d\",\"c\",\"c\"],[\"c\",\"c\",\"e\",\"c\"],[\"f\",\"c\",\"c\",\"c\"]]\n\t\tOutput: true\n\t\tExplanation: There is only one valid cycle highlighted in the image below:\n\t\tExample 3:\n\t\tInput: grid = [[\"a\",\"b\",\"b\"],[\"b\",\"z\",\"b\"],[\"b\",\"b\",\"a\"]]\n\t\tOutput: false\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1666, - "question": "class Solution:\n def makeGood(self, s: str) -> str:\n\t\t\"\"\"\n\t\tGiven a string s of lower and upper case English letters.\n\t\tA good string is a string which doesn't have two adjacent characters s[i] and s[i + 1] where:\n\t\t\t0 <= i <= s.length - 2\n\t\t\ts[i] is a lower-case letter and s[i + 1] is the same letter but in upper-case or vice-versa.\n\t\tTo make the string good, you can choose two adjacent characters that make the string bad and remove them. You can keep doing this until the string becomes good.\n\t\tReturn the string after making it good. The answer is guaranteed to be unique under the given constraints.\n\t\tNotice that an empty string is also good.\n\t\tExample 1:\n\t\tInput: s = \"leEeetcode\"\n\t\tOutput: \"leetcode\"\n\t\tExplanation: In the first step, either you choose i = 1 or i = 2, both will result \"leEeetcode\" to be reduced to \"leetcode\".\n\t\tExample 2:\n\t\tInput: s = \"abBAcC\"\n\t\tOutput: \"\"\n\t\tExplanation: We have many possible scenarios, and all lead to the same answer. For example:\n\t\t\"abBAcC\" --> \"aAcC\" --> \"cC\" --> \"\"\n\t\t\"abBAcC\" --> \"abBA\" --> \"aA\" --> \"\"\n\t\tExample 3:\n\t\tInput: s = \"s\"\n\t\tOutput: \"s\"\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1667, - "question": "class Solution:\n def findKthBit(self, n: int, k: int) -> str:\n\t\t\"\"\"\n\t\tGiven two positive integers n and k, the binary string Sn is formed as follows:\n\t\t\tS1 = \"0\"\n\t\t\tSi = Si - 1 + \"1\" + reverse(invert(Si - 1)) for i > 1\n\t\tWhere + denotes the concatenation operation, reverse(x) returns the reversed string x, and invert(x) inverts all the bits in x (0 changes to 1 and 1 changes to 0).\n\t\tFor example, the first four strings in the above sequence are:\n\t\t\tS1 = \"0\"\n\t\t\tS2 = \"011\"\n\t\t\tS3 = \"0111001\"\n\t\t\tS4 = \"011100110110001\"\n\t\tReturn the kth bit in Sn. It is guaranteed that k is valid for the given n.\n\t\tExample 1:\n\t\tInput: n = 3, k = 1\n\t\tOutput: \"0\"\n\t\tExplanation: S3 is \"0111001\".\n\t\tThe 1st bit is \"0\".\n\t\tExample 2:\n\t\tInput: n = 4, k = 11\n\t\tOutput: \"1\"\n\t\tExplanation: S4 is \"011100110110001\".\n\t\tThe 11th bit is \"1\".\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1668, - "question": "class Solution:\n def longestAwesome(self, s: str) -> int:\n\t\t\"\"\"\n\t\tYou are given a string s. An awesome substring is a non-empty substring of s such that we can make any number of swaps in order to make it a palindrome.\n\t\tReturn the length of the maximum length awesome substring of s.\n\t\tExample 1:\n\t\tInput: s = \"3242415\"\n\t\tOutput: 5\n\t\tExplanation: \"24241\" is the longest awesome substring, we can form the palindrome \"24142\" with some swaps.\n\t\tExample 2:\n\t\tInput: s = \"12345678\"\n\t\tOutput: 1\n\t\tExample 3:\n\t\tInput: s = \"213123\"\n\t\tOutput: 6\n\t\tExplanation: \"213123\" is the longest awesome substring, we can form the palindrome \"231132\" with some swaps.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1669, - "question": "class Solution:\n def minCost(self, n: int, cuts: List[int]) -> int:\n\t\t\"\"\"\n\t\tGiven a wooden stick of length n units. The stick is labelled from 0 to n. For example, a stick of length 6 is labelled as follows:\n\t\tGiven an integer array cuts where cuts[i] denotes a position you should perform a cut at.\n\t\tYou should perform the cuts in order, you can change the order of the cuts as you wish.\n\t\tThe cost of one cut is the length of the stick to be cut, the total cost is the sum of costs of all cuts. When you cut a stick, it will be split into two smaller sticks (i.e. the sum of their lengths is the length of the stick before the cut). Please refer to the first example for a better explanation.\n\t\tReturn the minimum total cost of the cuts.\n\t\tExample 1:\n\t\tInput: n = 7, cuts = [1,3,4,5]\n\t\tOutput: 16\n\t\tExplanation: Using cuts order = [1, 3, 4, 5] as in the input leads to the following scenario:\n\t\tThe first cut is done to a rod of length 7 so the cost is 7. The second cut is done to a rod of length 6 (i.e. the second part of the first cut), the third is done to a rod of length 4 and the last cut is to a rod of length 3. The total cost is 7 + 6 + 4 + 3 = 20.\n\t\tRearranging the cuts to be [3, 5, 1, 4] for example will lead to a scenario with total cost = 16 (as shown in the example photo 7 + 4 + 3 + 2 = 16).\n\t\tExample 2:\n\t\tInput: n = 9, cuts = [5,6,1,4,2]\n\t\tOutput: 22\n\t\tExplanation: If you try the given cuts ordering the cost will be 25.\n\t\tThere are much ordering with total cost <= 25, for example, the order [4, 6, 5, 2, 1] has total cost = 22 which is the minimum possible.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1674, - "question": "class Solution:\n def minOperations(self, n: int) -> int:\n\t\t\"\"\"\n\t\tYou have an array arr of length n where arr[i] = (2 * i) + 1 for all valid values of i (i.e., 0 <= i < n).\n\t\tIn one operation, you can select two indices x and y where 0 <= x, y < n and subtract 1 from arr[x] and add 1 to arr[y] (i.e., perform arr[x] -=1 and arr[y] += 1). The goal is to make all the elements of the array equal. It is guaranteed that all the elements of the array can be made equal using some operations.\n\t\tGiven an integer n, the length of the array, return the minimum number of operations needed to make all the elements of arr equal.\n\t\tExample 1:\n\t\tInput: n = 3\n\t\tOutput: 2\n\t\tExplanation: arr = [1, 3, 5]\n\t\tFirst operation choose x = 2 and y = 0, this leads arr to be [2, 3, 4]\n\t\tIn the second operation choose x = 2 and y = 0 again, thus arr = [3, 3, 3].\n\t\tExample 2:\n\t\tInput: n = 6\n\t\tOutput: 9\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1675, - "question": "class Solution:\n def maxDistance(self, position: List[int], m: int) -> int:\n\t\t\"\"\"\n\t\tIn the universe Earth C-137, Rick discovered a special form of magnetic force between two balls if they are put in his new invented basket. Rick has n empty baskets, the ith basket is at position[i], Morty has m balls and needs to distribute the balls into the baskets such that the minimum magnetic force between any two balls is maximum.\n\t\tRick stated that magnetic force between two different balls at positions x and y is |x - y|.\n\t\tGiven the integer array position and the integer m. Return the required force.\n\t\tExample 1:\n\t\tInput: position = [1,2,3,4,7], m = 3\n\t\tOutput: 3\n\t\tExplanation: Distributing the 3 balls into baskets 1, 4 and 7 will make the magnetic force between ball pairs [3, 3, 6]. The minimum magnetic force is 3. We cannot achieve a larger minimum magnetic force than 3.\n\t\tExample 2:\n\t\tInput: position = [5,4,3,2,1,1000000000], m = 2\n\t\tOutput: 999999999\n\t\tExplanation: We can use baskets 1 and 1000000000.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1676, - "question": "class Solution:\n def minDays(self, n: int) -> int:\n\t\t\"\"\"\n\t\tThere are n oranges in the kitchen and you decided to eat some of these oranges every day as follows:\n\t\t\tEat one orange.\n\t\t\tIf the number of remaining oranges n is divisible by 2 then you can eat n / 2 oranges.\n\t\t\tIf the number of remaining oranges n is divisible by 3 then you can eat 2 * (n / 3) oranges.\n\t\tYou can only choose one of the actions per day.\n\t\tGiven the integer n, return the minimum number of days to eat n oranges.\n\t\tExample 1:\n\t\tInput: n = 10\n\t\tOutput: 4\n\t\tExplanation: You have 10 oranges.\n\t\tDay 1: Eat 1 orange, 10 - 1 = 9. \n\t\tDay 2: Eat 6 oranges, 9 - 2*(9/3) = 9 - 6 = 3. (Since 9 is divisible by 3)\n\t\tDay 3: Eat 2 oranges, 3 - 2*(3/3) = 3 - 2 = 1. \n\t\tDay 4: Eat the last orange 1 - 1 = 0.\n\t\tYou need at least 4 days to eat the 10 oranges.\n\t\tExample 2:\n\t\tInput: n = 6\n\t\tOutput: 3\n\t\tExplanation: You have 6 oranges.\n\t\tDay 1: Eat 3 oranges, 6 - 6/2 = 6 - 3 = 3. (Since 6 is divisible by 2).\n\t\tDay 2: Eat 2 oranges, 3 - 2*(3/3) = 3 - 2 = 1. (Since 3 is divisible by 3)\n\t\tDay 3: Eat the last orange 1 - 1 = 0.\n\t\tYou need at least 3 days to eat the 6 oranges.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1677, - "question": "class Solution:\n def diagonalSum(self, mat: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tGiven a square matrix mat, return the sum of the matrix diagonals.\n\t\tOnly include the sum of all the elements on the primary diagonal and all the elements on the secondary diagonal that are not part of the primary diagonal.\n\t\tExample 1:\n\t\tInput: mat = [[1,2,3],\n\t\t [4,5,6],\n\t\t [7,8,9]]\n\t\tOutput: 25\n\t\tExplanation: Diagonals sum: 1 + 5 + 9 + 3 + 7 = 25\n\t\tNotice that element mat[1][1] = 5 is counted only once.\n\t\tExample 2:\n\t\tInput: mat = [[1,1,1,1],\n\t\t [1,1,1,1],\n\t\t [1,1,1,1],\n\t\t [1,1,1,1]]\n\t\tOutput: 8\n\t\tExample 3:\n\t\tInput: mat = [[5]]\n\t\tOutput: 5\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1678, - "question": "class Solution:\n def numWays(self, s: str) -> int:\n\t\t\"\"\"\n\t\tGiven a binary string s, you can split s into 3 non-empty strings s1, s2, and s3 where s1 + s2 + s3 = s.\n\t\tReturn the number of ways s can be split such that the number of ones is the same in s1, s2, and s3. Since the answer may be too large, return it modulo 109 + 7.\n\t\tExample 1:\n\t\tInput: s = \"10101\"\n\t\tOutput: 4\n\t\tExplanation: There are four ways to split s in 3 parts where each part contain the same number of letters '1'.\n\t\t\"1|010|1\"\n\t\t\"1|01|01\"\n\t\t\"10|10|1\"\n\t\t\"10|1|01\"\n\t\tExample 2:\n\t\tInput: s = \"1001\"\n\t\tOutput: 0\n\t\tExample 3:\n\t\tInput: s = \"0000\"\n\t\tOutput: 3\n\t\tExplanation: There are three ways to split s in 3 parts.\n\t\t\"0|0|00\"\n\t\t\"0|00|0\"\n\t\t\"00|0|0\"\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1679, - "question": "class Solution:\n def findLengthOfShortestSubarray(self, arr: List[int]) -> int:\n\t\t\"\"\"\n\t\tGiven an integer array arr, remove a subarray (can be empty) from arr such that the remaining elements in arr are non-decreasing.\n\t\tReturn the length of the shortest subarray to remove.\n\t\tA subarray is a contiguous subsequence of the array.\n\t\tExample 1:\n\t\tInput: arr = [1,2,3,10,4,2,3,5]\n\t\tOutput: 3\n\t\tExplanation: The shortest subarray we can remove is [10,4,2] of length 3. The remaining elements after that will be [1,2,3,3,5] which are sorted.\n\t\tAnother correct solution is to remove the subarray [3,10,4].\n\t\tExample 2:\n\t\tInput: arr = [5,4,3,2,1]\n\t\tOutput: 4\n\t\tExplanation: Since the array is strictly decreasing, we can only keep a single element. Therefore we need to remove a subarray of length 4, either [5,4,3,2] or [4,3,2,1].\n\t\tExample 3:\n\t\tInput: arr = [1,2,3]\n\t\tOutput: 0\n\t\tExplanation: The array is already non-decreasing. We do not need to remove any elements.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1680, - "question": "class Solution:\n def countRoutes(self, locations: List[int], start: int, finish: int, fuel: int) -> int:\n\t\t\"\"\"\n\t\tYou are given an array of distinct positive integers locations where locations[i] represents the position of city i. You are also given integers start, finish and fuel representing the starting city, ending city, and the initial amount of fuel you have, respectively.\n\t\tAt each step, if you are at city i, you can pick any city j such that j != i and 0 <= j < locations.length and move to city j. Moving from city i to city j reduces the amount of fuel you have by |locations[i] - locations[j]|. Please notice that |x| denotes the absolute value of x.\n\t\tNotice that fuel cannot become negative at any point in time, and that you are allowed to visit any city more than once (including start and finish).\n\t\tReturn the count of all possible routes from start to finish. Since the answer may be too large, return it modulo 109 + 7.\n\t\tExample 1:\n\t\tInput: locations = [2,3,6,8,4], start = 1, finish = 3, fuel = 5\n\t\tOutput: 4\n\t\tExplanation: The following are all possible routes, each uses 5 units of fuel:\n\t\t1 -> 3\n\t\t1 -> 2 -> 3\n\t\t1 -> 4 -> 3\n\t\t1 -> 4 -> 2 -> 3\n\t\tExample 2:\n\t\tInput: locations = [4,3,1], start = 1, finish = 0, fuel = 6\n\t\tOutput: 5\n\t\tExplanation: The following are all possible routes:\n\t\t1 -> 0, used fuel = 1\n\t\t1 -> 2 -> 0, used fuel = 5\n\t\t1 -> 2 -> 1 -> 0, used fuel = 5\n\t\t1 -> 0 -> 1 -> 0, used fuel = 3\n\t\t1 -> 0 -> 1 -> 0 -> 1 -> 0, used fuel = 5\n\t\tExample 3:\n\t\tInput: locations = [5,2,1], start = 0, finish = 2, fuel = 3\n\t\tOutput: 0\n\t\tExplanation: It is impossible to get from 0 to 2 using only 3 units of fuel since the shortest route needs 4 units of fuel.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1682, - "question": "class Solution:\n def mostVisited(self, n: int, rounds: List[int]) -> List[int]:\n\t\t\"\"\"\n\t\tGiven an integer n and an integer array rounds. We have a circular track which consists of n sectors labeled from 1 to n. A marathon will be held on this track, the marathon consists of m rounds. The ith round starts at sector rounds[i - 1] and ends at sector rounds[i]. For example, round 1 starts at sector rounds[0] and ends at sector rounds[1]\n\t\tReturn an array of the most visited sectors sorted in ascending order.\n\t\tNotice that you circulate the track in ascending order of sector numbers in the counter-clockwise direction (See the first example).\n\t\tExample 1:\n\t\tInput: n = 4, rounds = [1,3,1,2]\n\t\tOutput: [1,2]\n\t\tExplanation: The marathon starts at sector 1. The order of the visited sectors is as follows:\n\t\t1 --> 2 --> 3 (end of round 1) --> 4 --> 1 (end of round 2) --> 2 (end of round 3 and the marathon)\n\t\tWe can see that both sectors 1 and 2 are visited twice and they are the most visited sectors. Sectors 3 and 4 are visited only once.\n\t\tExample 2:\n\t\tInput: n = 2, rounds = [2,1,2,1,2,1,2,1,2]\n\t\tOutput: [2]\n\t\tExample 3:\n\t\tInput: n = 7, rounds = [1,3,5,7]\n\t\tOutput: [1,2,3,4,5,6,7]\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1683, - "question": "class Solution:\n def maxCoins(self, piles: List[int]) -> int:\n\t\t\"\"\"\n\t\tThere are 3n piles of coins of varying size, you and your friends will take piles of coins as follows:\n\t\t\tIn each step, you will choose any 3 piles of coins (not necessarily consecutive).\n\t\t\tOf your choice, Alice will pick the pile with the maximum number of coins.\n\t\t\tYou will pick the next pile with the maximum number of coins.\n\t\t\tYour friend Bob will pick the last pile.\n\t\t\tRepeat until there are no more piles of coins.\n\t\tGiven an array of integers piles where piles[i] is the number of coins in the ith pile.\n\t\tReturn the maximum number of coins that you can have.\n\t\tExample 1:\n\t\tInput: piles = [2,4,1,2,7,8]\n\t\tOutput: 9\n\t\tExplanation: Choose the triplet (2, 7, 8), Alice Pick the pile with 8 coins, you the pile with 7 coins and Bob the last one.\n\t\tChoose the triplet (1, 2, 4), Alice Pick the pile with 4 coins, you the pile with 2 coins and Bob the last one.\n\t\tThe maximum number of coins which you can have are: 7 + 2 = 9.\n\t\tOn the other hand if we choose this arrangement (1, 2, 8), (2, 4, 7) you only get 2 + 4 = 6 coins which is not optimal.\n\t\tExample 2:\n\t\tInput: piles = [2,4,5]\n\t\tOutput: 4\n\t\tExample 3:\n\t\tInput: piles = [9,8,7,6,5,1,2,3,4]\n\t\tOutput: 18\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1684, - "question": "class Solution:\n def findLatestStep(self, arr: List[int], m: int) -> int:\n\t\t\"\"\"\n\t\tGiven an array arr that represents a permutation of numbers from 1 to n.\n\t\tYou have a binary string of size n that initially has all its bits set to zero. At each step i (assuming both the binary string and arr are 1-indexed) from 1 to n, the bit at position arr[i] is set to 1.\n\t\tYou are also given an integer m. Find the latest step at which there exists a group of ones of length m. A group of ones is a contiguous substring of 1's such that it cannot be extended in either direction.\n\t\tReturn the latest step at which there exists a group of ones of length exactly m. If no such group exists, return -1.\n\t\tExample 1:\n\t\tInput: arr = [3,5,1,2,4], m = 1\n\t\tOutput: 4\n\t\tExplanation: \n\t\tStep 1: \"00100\", groups: [\"1\"]\n\t\tStep 2: \"00101\", groups: [\"1\", \"1\"]\n\t\tStep 3: \"10101\", groups: [\"1\", \"1\", \"1\"]\n\t\tStep 4: \"11101\", groups: [\"111\", \"1\"]\n\t\tStep 5: \"11111\", groups: [\"11111\"]\n\t\tThe latest step at which there exists a group of size 1 is step 4.\n\t\tExample 2:\n\t\tInput: arr = [3,1,5,4,2], m = 2\n\t\tOutput: -1\n\t\tExplanation: \n\t\tStep 1: \"00100\", groups: [\"1\"]\n\t\tStep 2: \"10100\", groups: [\"1\", \"1\"]\n\t\tStep 3: \"10101\", groups: [\"1\", \"1\", \"1\"]\n\t\tStep 4: \"10111\", groups: [\"1\", \"111\"]\n\t\tStep 5: \"11111\", groups: [\"11111\"]\n\t\tNo group of size 2 exists during any step.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1685, - "question": "class Solution:\n def stoneGameV(self, stoneValue: List[int]) -> int:\n\t\t\"\"\"\n\t\tThere are several stones arranged in a row, and each stone has an associated value which is an integer given in the array stoneValue.\n\t\tIn each round of the game, Alice divides the row into two non-empty rows (i.e. left row and right row), then Bob calculates the value of each row which is the sum of the values of all the stones in this row. Bob throws away the row which has the maximum value, and Alice's score increases by the value of the remaining row. If the value of the two rows are equal, Bob lets Alice decide which row will be thrown away. The next round starts with the remaining row.\n\t\tThe game ends when there is only one stone remaining. Alice's is initially zero.\n\t\tReturn the maximum score that Alice can obtain.\n\t\tExample 1:\n\t\tInput: stoneValue = [6,2,3,4,5,5]\n\t\tOutput: 18\n\t\tExplanation: In the first round, Alice divides the row to [6,2,3], [4,5,5]. The left row has the value 11 and the right row has value 14. Bob throws away the right row and Alice's score is now 11.\n\t\tIn the second round Alice divides the row to [6], [2,3]. This time Bob throws away the left row and Alice's score becomes 16 (11 + 5).\n\t\tThe last round Alice has only one choice to divide the row which is [2], [3]. Bob throws away the right row and Alice's score is now 18 (16 + 2). The game ends because only one stone is remaining in the row.\n\t\tExample 2:\n\t\tInput: stoneValue = [7,7,7,7,7,7,7]\n\t\tOutput: 28\n\t\tExample 3:\n\t\tInput: stoneValue = [4]\n\t\tOutput: 0\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1689, - "question": "class Solution:\n def containsPattern(self, arr: List[int], m: int, k: int) -> bool:\n\t\t\"\"\"\n\t\tGiven an array of positive integers arr, find a pattern of length m that is repeated k or more times.\n\t\tA pattern is a subarray (consecutive sub-sequence) that consists of one or more values, repeated multiple times consecutively without overlapping. A pattern is defined by its length and the number of repetitions.\n\t\tReturn true if there exists a pattern of length m that is repeated k or more times, otherwise return false.\n\t\tExample 1:\n\t\tInput: arr = [1,2,4,4,4,4], m = 1, k = 3\n\t\tOutput: true\n\t\tExplanation: The pattern (4) of length 1 is repeated 4 consecutive times. Notice that pattern can be repeated k or more times but not less.\n\t\tExample 2:\n\t\tInput: arr = [1,2,1,2,1,1,1,3], m = 2, k = 2\n\t\tOutput: true\n\t\tExplanation: The pattern (1,2) of length 2 is repeated 2 consecutive times. Another valid pattern (2,1) is also repeated 2 times.\n\t\tExample 3:\n\t\tInput: arr = [1,2,1,2,1,3], m = 2, k = 3\n\t\tOutput: false\n\t\tExplanation: The pattern (1,2) is of length 2 but is repeated only 2 times. There is no pattern of length 2 that is repeated 3 or more times.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1690, - "question": "class Solution:\n def getMaxLen(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tGiven an array of integers nums, find the maximum length of a subarray where the product of all its elements is positive.\n\t\tA subarray of an array is a consecutive sequence of zero or more values taken out of that array.\n\t\tReturn the maximum length of a subarray with positive product.\n\t\tExample 1:\n\t\tInput: nums = [1,-2,-3,4]\n\t\tOutput: 4\n\t\tExplanation: The array nums already has a positive product of 24.\n\t\tExample 2:\n\t\tInput: nums = [0,1,-2,-3,-4]\n\t\tOutput: 3\n\t\tExplanation: The longest subarray with positive product is [1,-2,-3] which has a product of 6.\n\t\tNotice that we cannot include 0 in the subarray since that'll make the product 0 which is not positive.\n\t\tExample 3:\n\t\tInput: nums = [-1,-2,-3,0,1]\n\t\tOutput: 2\n\t\tExplanation: The longest subarray with positive product is [-1,-2] or [-2,-3].\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1691, - "question": "class Solution:\n def minDays(self, grid: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tYou are given an m x n binary grid grid where 1 represents land and 0 represents water. An island is a maximal 4-directionally (horizontal or vertical) connected group of 1's.\n\t\tThe grid is said to be connected if we have exactly one island, otherwise is said disconnected.\n\t\tIn one day, we are allowed to change any single land cell (1) into a water cell (0).\n\t\tReturn the minimum number of days to disconnect the grid.\n\t\tExample 1:\n\t\tInput: grid = [[0,1,1,0],[0,1,1,0],[0,0,0,0]]\n\t\tOutput: 2\n\t\tExplanation: We need at least 2 days to get a disconnected grid.\n\t\tChange land grid[1][1] and grid[0][2] to water and get 2 disconnected island.\n\t\tExample 2:\n\t\tInput: grid = [[1,1]]\n\t\tOutput: 2\n\t\tExplanation: Grid of full water is also disconnected ([[1,1]] -> [[0,0]]), 0 islands.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1692, - "question": "class Solution:\n def numOfWays(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tGiven an array nums that represents a permutation of integers from 1 to n. We are going to construct a binary search tree (BST) by inserting the elements of nums in order into an initially empty BST. Find the number of different ways to reorder nums so that the constructed BST is identical to that formed from the original array nums.\n\t\t\tFor example, given nums = [2,1,3], we will have 2 as the root, 1 as a left child, and 3 as a right child. The array [2,3,1] also yields the same BST but [3,2,1] yields a different BST.\n\t\tReturn the number of ways to reorder nums such that the BST formed is identical to the original BST formed from nums.\n\t\tSince the answer may be very large, return it modulo 109 + 7.\n\t\tExample 1:\n\t\tInput: nums = [2,1,3]\n\t\tOutput: 1\n\t\tExplanation: We can reorder nums to be [2,3,1] which will yield the same BST. There are no other ways to reorder nums which will yield the same BST.\n\t\tExample 2:\n\t\tInput: nums = [3,4,5,1,2]\n\t\tOutput: 5\n\t\tExplanation: The following 5 arrays will yield the same BST: \n\t\t[3,1,2,4,5]\n\t\t[3,1,4,2,5]\n\t\t[3,1,4,5,2]\n\t\t[3,4,1,2,5]\n\t\t[3,4,1,5,2]\n\t\tExample 3:\n\t\tInput: nums = [1,2,3]\n\t\tOutput: 0\n\t\tExplanation: There are no other orderings of nums that will yield the same BST.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1693, - "question": "class Solution:\n def sumOddLengthSubarrays(self, arr: List[int]) -> int:\n\t\t\"\"\"\n\t\tGiven an array of positive integers arr, return the sum of all possible odd-length subarrays of arr.\n\t\tA subarray is a contiguous subsequence of the array.\n\t\tExample 1:\n\t\tInput: arr = [1,4,2,5,3]\n\t\tOutput: 58\n\t\tExplanation: The odd-length subarrays of arr and their sums are:\n\t\t[1] = 1\n\t\t[4] = 4\n\t\t[2] = 2\n\t\t[5] = 5\n\t\t[3] = 3\n\t\t[1,4,2] = 7\n\t\t[4,2,5] = 11\n\t\t[2,5,3] = 10\n\t\t[1,4,2,5,3] = 15\n\t\tIf we add all these together we get 1 + 4 + 2 + 5 + 3 + 7 + 11 + 10 + 15 = 58\n\t\tExample 2:\n\t\tInput: arr = [1,2]\n\t\tOutput: 3\n\t\tExplanation: There are only 2 subarrays of odd length, [1] and [2]. Their sum is 3.\n\t\tExample 3:\n\t\tInput: arr = [10,11,12]\n\t\tOutput: 66\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1694, - "question": "class Solution:\n def minSubarray(self, nums: List[int], p: int) -> int:\n\t\t\"\"\"\n\t\tGiven an array of positive integers nums, remove the smallest subarray (possibly empty) such that the sum of the remaining elements is divisible by p. It is not allowed to remove the whole array.\n\t\tReturn the length of the smallest subarray that you need to remove, or -1 if it's impossible.\n\t\tA subarray is defined as a contiguous block of elements in the array.\n\t\tExample 1:\n\t\tInput: nums = [3,1,4,2], p = 6\n\t\tOutput: 1\n\t\tExplanation: The sum of the elements in nums is 10, which is not divisible by 6. We can remove the subarray [4], and the sum of the remaining elements is 6, which is divisible by 6.\n\t\tExample 2:\n\t\tInput: nums = [6,3,5,2], p = 9\n\t\tOutput: 2\n\t\tExplanation: We cannot remove a single element to get a sum divisible by 9. The best way is to remove the subarray [5,2], leaving us with [6,3] with sum 9.\n\t\tExample 3:\n\t\tInput: nums = [1,2,3], p = 3\n\t\tOutput: 0\n\t\tExplanation: Here the sum is 6. which is already divisible by 3. Thus we do not need to remove anything.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1695, - "question": "class Solution:\n def maxSumRangeQuery(self, nums: List[int], requests: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tWe have an array of integers, nums, and an array of requests where requests[i] = [starti, endi]. The ith request asks for the sum of nums[starti] + nums[starti + 1] + ... + nums[endi - 1] + nums[endi]. Both starti and endi are 0-indexed.\n\t\tReturn the maximum total sum of all requests among all permutations of nums.\n\t\tSince the answer may be too large, return it modulo 109 + 7.\n\t\tExample 1:\n\t\tInput: nums = [1,2,3,4,5], requests = [[1,3],[0,1]]\n\t\tOutput: 19\n\t\tExplanation: One permutation of nums is [2,1,3,4,5] with the following result: \n\t\trequests[0] -> nums[1] + nums[2] + nums[3] = 1 + 3 + 4 = 8\n\t\trequests[1] -> nums[0] + nums[1] = 2 + 1 = 3\n\t\tTotal sum: 8 + 3 = 11.\n\t\tA permutation with a higher total sum is [3,5,4,2,1] with the following result:\n\t\trequests[0] -> nums[1] + nums[2] + nums[3] = 5 + 4 + 2 = 11\n\t\trequests[1] -> nums[0] + nums[1] = 3 + 5 = 8\n\t\tTotal sum: 11 + 8 = 19, which is the best that you can do.\n\t\tExample 2:\n\t\tInput: nums = [1,2,3,4,5,6], requests = [[0,1]]\n\t\tOutput: 11\n\t\tExplanation: A permutation with the max total sum is [6,5,4,3,2,1] with request sums [11].\n\t\tExample 3:\n\t\tInput: nums = [1,2,3,4,5,10], requests = [[0,2],[1,3],[1,1]]\n\t\tOutput: 47\n\t\tExplanation: A permutation with the max total sum is [4,10,5,3,2,1] with request sums [19,18,10].\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1696, - "question": "class Solution:\n def isPrintable(self, targetGrid: List[List[int]]) -> bool:\n\t\t\"\"\"\n\t\tThere is a strange printer with the following two special requirements:\n\t\t\tOn each turn, the printer will print a solid rectangular pattern of a single color on the grid. This will cover up the existing colors in the rectangle.\n\t\t\tOnce the printer has used a color for the above operation, the same color cannot be used again.\n\t\tYou are given a m x n matrix targetGrid, where targetGrid[row][col] is the color in the position (row, col) of the grid.\n\t\tReturn true if it is possible to print the matrix targetGrid, otherwise, return false.\n\t\tExample 1:\n\t\tInput: targetGrid = [[1,1,1,1],[1,2,2,1],[1,2,2,1],[1,1,1,1]]\n\t\tOutput: true\n\t\tExample 2:\n\t\tInput: targetGrid = [[1,1,1,1],[1,1,3,3],[1,1,3,4],[5,5,1,4]]\n\t\tOutput: true\n\t\tExample 3:\n\t\tInput: targetGrid = [[1,2,1],[2,1,2],[1,2,1]]\n\t\tOutput: false\n\t\tExplanation: It is impossible to form targetGrid because it is not allowed to print the same color in different turns.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1698, - "question": "class Solution:\n def modifyString(self, s: str) -> str:\n\t\t\"\"\"\n\t\tGiven a string s containing only lowercase English letters and the '?' character, convert all the '?' characters into lowercase letters such that the final string does not contain any consecutive repeating characters. You cannot modify the non '?' characters.\n\t\tIt is guaranteed that there are no consecutive repeating characters in the given string except for '?'.\n\t\tReturn the final string after all the conversions (possibly zero) have been made. If there is more than one solution, return any of them. It can be shown that an answer is always possible with the given constraints.\n\t\tExample 1:\n\t\tInput: s = \"?zs\"\n\t\tOutput: \"azs\"\n\t\tExplanation: There are 25 solutions for this problem. From \"azs\" to \"yzs\", all are valid. Only \"z\" is an invalid modification as the string will consist of consecutive repeating characters in \"zzs\".\n\t\tExample 2:\n\t\tInput: s = \"ubv?w\"\n\t\tOutput: \"ubvaw\"\n\t\tExplanation: There are 24 solutions for this problem. Only \"v\" and \"w\" are invalid modifications as the strings will consist of consecutive repeating characters in \"ubvvw\" and \"ubvww\".\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1699, - "question": "class Solution:\n def numTriplets(self, nums1: List[int], nums2: List[int]) -> int:\n\t\t\"\"\"\n\t\tGiven two arrays of integers nums1 and nums2, return the number of triplets formed (type 1 and type 2) under the following rules:\n\t\t\tType 1: Triplet (i, j, k) if nums1[i]2 == nums2[j] * nums2[k] where 0 <= i < nums1.length and 0 <= j < k < nums2.length.\n\t\t\tType 2: Triplet (i, j, k) if nums2[i]2 == nums1[j] * nums1[k] where 0 <= i < nums2.length and 0 <= j < k < nums1.length.\n\t\tExample 1:\n\t\tInput: nums1 = [7,4], nums2 = [5,2,8,9]\n\t\tOutput: 1\n\t\tExplanation: Type 1: (1, 1, 2), nums1[1]2 = nums2[1] * nums2[2]. (42 = 2 * 8). \n\t\tExample 2:\n\t\tInput: nums1 = [1,1], nums2 = [1,1,1]\n\t\tOutput: 9\n\t\tExplanation: All Triplets are valid, because 12 = 1 * 1.\n\t\tType 1: (0,0,1), (0,0,2), (0,1,2), (1,0,1), (1,0,2), (1,1,2). nums1[i]2 = nums2[j] * nums2[k].\n\t\tType 2: (0,0,1), (1,0,1), (2,0,1). nums2[i]2 = nums1[j] * nums1[k].\n\t\tExample 3:\n\t\tInput: nums1 = [7,7,8,3], nums2 = [1,2,9,7]\n\t\tOutput: 2\n\t\tExplanation: There are 2 valid triplets.\n\t\tType 1: (3,0,2). nums1[3]2 = nums2[0] * nums2[2].\n\t\tType 2: (3,0,1). nums2[3]2 = nums1[0] * nums1[1].\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1700, - "question": "class Solution:\n def minCost(self, colors: str, neededTime: List[int]) -> int:\n\t\t\"\"\"\n\t\tAlice has n balloons arranged on a rope. You are given a 0-indexed string colors where colors[i] is the color of the ith balloon.\n\t\tAlice wants the rope to be colorful. She does not want two consecutive balloons to be of the same color, so she asks Bob for help. Bob can remove some balloons from the rope to make it colorful. You are given a 0-indexed integer array neededTime where neededTime[i] is the time (in seconds) that Bob needs to remove the ith balloon from the rope.\n\t\tReturn the minimum time Bob needs to make the rope colorful.\n\t\tExample 1:\n\t\tInput: colors = \"abaac\", neededTime = [1,2,3,4,5]\n\t\tOutput: 3\n\t\tExplanation: In the above image, 'a' is blue, 'b' is red, and 'c' is green.\n\t\tBob can remove the blue balloon at index 2. This takes 3 seconds.\n\t\tThere are no longer two consecutive balloons of the same color. Total time = 3.\n\t\tExample 2:\n\t\tInput: colors = \"abc\", neededTime = [1,2,3]\n\t\tOutput: 0\n\t\tExplanation: The rope is already colorful. Bob does not need to remove any balloons from the rope.\n\t\tExample 3:\n\t\tInput: colors = \"aabaa\", neededTime = [1,2,3,4,1]\n\t\tOutput: 2\n\t\tExplanation: Bob will remove the ballons at indices 0 and 4. Each ballon takes 1 second to remove.\n\t\tThere are no longer two consecutive balloons of the same color. Total time = 1 + 1 = 2.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1701, - "question": "class Solution:\n def maxNumEdgesToRemove(self, n: int, edges: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tAlice and Bob have an undirected graph of n nodes and three types of edges:\n\t\t\tType 1: Can be traversed by Alice only.\n\t\t\tType 2: Can be traversed by Bob only.\n\t\t\tType 3: Can be traversed by both Alice and Bob.\n\t\tGiven an array edges where edges[i] = [typei, ui, vi] represents a bidirectional edge of type typei between nodes ui and vi, find the maximum number of edges you can remove so that after removing the edges, the graph can still be fully traversed by both Alice and Bob. The graph is fully traversed by Alice and Bob if starting from any node, they can reach all other nodes.\n\t\tReturn the maximum number of edges you can remove, or return -1 if Alice and Bob cannot fully traverse the graph.\n\t\tExample 1:\n\t\tInput: n = 4, edges = [[3,1,2],[3,2,3],[1,1,3],[1,2,4],[1,1,2],[2,3,4]]\n\t\tOutput: 2\n\t\tExplanation: If we remove the 2 edges [1,1,2] and [1,1,3]. The graph will still be fully traversable by Alice and Bob. Removing any additional edge will not make it so. So the maximum number of edges we can remove is 2.\n\t\tExample 2:\n\t\tInput: n = 4, edges = [[3,1,2],[3,2,3],[1,1,4],[2,1,4]]\n\t\tOutput: 0\n\t\tExplanation: Notice that removing any edge will not make the graph fully traversable by Alice and Bob.\n\t\tExample 3:\n\t\tInput: n = 4, edges = [[3,2,3],[1,1,2],[2,3,4]]\n\t\tOutput: -1\n\t\tExplanation: In the current graph, Alice cannot reach node 4 from the other nodes. Likewise, Bob cannot reach 1. Therefore it's impossible to make the graph fully traversable.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1704, - "question": "class Solution:\n def numSpecial(self, mat: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tGiven an m x n binary matrix mat, return the number of special positions in mat.\n\t\tA position (i, j) is called special if mat[i][j] == 1 and all other elements in row i and column j are 0 (rows and columns are 0-indexed).\n\t\tExample 1:\n\t\tInput: mat = [[1,0,0],[0,0,1],[1,0,0]]\n\t\tOutput: 1\n\t\tExplanation: (1, 2) is a special position because mat[1][2] == 1 and all other elements in row 1 and column 2 are 0.\n\t\tExample 2:\n\t\tInput: mat = [[1,0,0],[0,1,0],[0,0,1]]\n\t\tOutput: 3\n\t\tExplanation: (0, 0), (1, 1) and (2, 2) are special positions.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1705, - "question": "class Solution:\n def unhappyFriends(self, n: int, preferences: List[List[int]], pairs: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tYou are given a list of preferences for n friends, where n is always even.\n\t\tFor each person i, preferences[i] contains a list of friends sorted in the order of preference. In other words, a friend earlier in the list is more preferred than a friend later in the list. Friends in each list are denoted by integers from 0 to n-1.\n\t\tAll the friends are divided into pairs. The pairings are given in a list pairs, where pairs[i] = [xi, yi] denotes xi is paired with yi and yi is paired with xi.\n\t\tHowever, this pairing may cause some of the friends to be unhappy. A friend x is unhappy if x is paired with y and there exists a friend u who is paired with v but:\n\t\t\tx prefers u over y, and\n\t\t\tu prefers x over v.\n\t\tReturn the number of unhappy friends.\n\t\tExample 1:\n\t\tInput: n = 4, preferences = [[1, 2, 3], [3, 2, 0], [3, 1, 0], [1, 2, 0]], pairs = [[0, 1], [2, 3]]\n\t\tOutput: 2\n\t\tExplanation:\n\t\tFriend 1 is unhappy because:\n\t\t- 1 is paired with 0 but prefers 3 over 0, and\n\t\t- 3 prefers 1 over 2.\n\t\tFriend 3 is unhappy because:\n\t\t- 3 is paired with 2 but prefers 1 over 2, and\n\t\t- 1 prefers 3 over 0.\n\t\tFriends 0 and 2 are happy.\n\t\tExample 2:\n\t\tInput: n = 2, preferences = [[1], [0]], pairs = [[1, 0]]\n\t\tOutput: 0\n\t\tExplanation: Both friends 0 and 1 are happy.\n\t\tExample 3:\n\t\tInput: n = 4, preferences = [[1, 3, 2], [2, 3, 0], [1, 3, 0], [0, 2, 1]], pairs = [[1, 3], [0, 2]]\n\t\tOutput: 4\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1706, - "question": "class Solution:\n def minCostConnectPoints(self, points: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tYou are given an array points representing integer coordinates of some points on a 2D-plane, where points[i] = [xi, yi].\n\t\tThe cost of connecting two points [xi, yi] and [xj, yj] is the manhattan distance between them: |xi - xj| + |yi - yj|, where |val| denotes the absolute value of val.\n\t\tReturn the minimum cost to make all points connected. All points are connected if there is exactly one simple path between any two points.\n\t\tExample 1:\n\t\tInput: points = [[0,0],[2,2],[3,10],[5,2],[7,0]]\n\t\tOutput: 20\n\t\tExplanation: \n\t\tWe can connect the points as shown above to get the minimum cost of 20.\n\t\tNotice that there is a unique path between every pair of points.\n\t\tExample 2:\n\t\tInput: points = [[3,12],[-2,5],[-4,1]]\n\t\tOutput: 18\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1707, - "question": "class Solution:\n def isTransformable(self, s: str, t: str) -> bool:\n\t\t\"\"\"\n\t\tGiven two strings s and t, transform string s into string t using the following operation any number of times:\n\t\t\tChoose a non-empty substring in s and sort it in place so the characters are in ascending order.\n\t\t\t\tFor example, applying the operation on the underlined substring in \"14234\" results in \"12344\".\n\t\tReturn true if it is possible to transform s into t. Otherwise, return false.\n\t\tA substring is a contiguous sequence of characters within a string.\n\t\tExample 1:\n\t\tInput: s = \"84532\", t = \"34852\"\n\t\tOutput: true\n\t\tExplanation: You can transform s into t using the following sort operations:\n\t\t\"84532\" (from index 2 to 3) -> \"84352\"\n\t\t\"84352\" (from index 0 to 2) -> \"34852\"\n\t\tExample 2:\n\t\tInput: s = \"34521\", t = \"23415\"\n\t\tOutput: true\n\t\tExplanation: You can transform s into t using the following sort operations:\n\t\t\"34521\" -> \"23451\"\n\t\t\"23451\" -> \"23415\"\n\t\tExample 3:\n\t\tInput: s = \"12345\", t = \"12435\"\n\t\tOutput: false\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1708, - "question": "class ParkingSystem:\n def __init__(self, big: int, medium: int, small: int):\n def addCar(self, carType: int) -> bool:\n\t\t\"\"\"\n\t\tDesign a parking system for a parking lot. The parking lot has three kinds of parking spaces: big, medium, and small, with a fixed number of slots for each size.\n\t\tImplement the ParkingSystem class:\n\t\t\tParkingSystem(int big, int medium, int small) Initializes object of the ParkingSystem class. The number of slots for each parking space are given as part of the constructor.\n\t\t\tbool addCar(int carType) Checks whether there is a parking space of carType for the car that wants to get into the parking lot. carType can be of three kinds: big, medium, or small, which are represented by 1, 2, and 3 respectively. A car can only park in a parking space of its carType. If there is no space available, return false, else park the car in that size space and return true.\n\t\tExample 1:\n\t\tInput\n\t\t[\"ParkingSystem\", \"addCar\", \"addCar\", \"addCar\", \"addCar\"]\n\t\t[[1, 1, 0], [1], [2], [3], [1]]\n\t\tOutput\n\t\t[null, true, true, false, false]\n\t\tExplanation\n\t\tParkingSystem parkingSystem = new ParkingSystem(1, 1, 0);\n\t\tparkingSystem.addCar(1); // return true because there is 1 available slot for a big car\n\t\tparkingSystem.addCar(2); // return true because there is 1 available slot for a medium car\n\t\tparkingSystem.addCar(3); // return false because there is no available slot for a small car\n\t\tparkingSystem.addCar(1); // return false because there is no available slot for a big car. It is already occupied.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1709, - "question": "class Solution:\n def alertNames(self, keyName: List[str], keyTime: List[str]) -> List[str]:\n\t\t\"\"\"\n\t\tLeetCode company workers use key-cards to unlock office doors. Each time a worker uses their key-card, the security system saves the worker's name and the time when it was used. The system emits an alert if any worker uses the key-card three or more times in a one-hour period.\n\t\tYou are given a list of strings keyName and keyTime where [keyName[i], keyTime[i]] corresponds to a person's name and the time when their key-card was used in a single day.\n\t\tAccess times are given in the 24-hour time format \"HH:MM\", such as \"23:51\" and \"09:49\".\n\t\tReturn a list of unique worker names who received an alert for frequent keycard use. Sort the names in ascending order alphabetically.\n\t\tNotice that \"10:00\" - \"11:00\" is considered to be within a one-hour period, while \"22:51\" - \"23:52\" is not considered to be within a one-hour period.\n\t\tExample 1:\n\t\tInput: keyName = [\"daniel\",\"daniel\",\"daniel\",\"luis\",\"luis\",\"luis\",\"luis\"], keyTime = [\"10:00\",\"10:40\",\"11:00\",\"09:00\",\"11:00\",\"13:00\",\"15:00\"]\n\t\tOutput: [\"daniel\"]\n\t\tExplanation: \"daniel\" used the keycard 3 times in a one-hour period (\"10:00\",\"10:40\", \"11:00\").\n\t\tExample 2:\n\t\tInput: keyName = [\"alice\",\"alice\",\"alice\",\"bob\",\"bob\",\"bob\",\"bob\"], keyTime = [\"12:01\",\"12:00\",\"18:00\",\"21:00\",\"21:20\",\"21:30\",\"23:00\"]\n\t\tOutput: [\"bob\"]\n\t\tExplanation: \"bob\" used the keycard 3 times in a one-hour period (\"21:00\",\"21:20\", \"21:30\").\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1710, - "question": "class Solution:\n def busiestServers(self, k: int, arrival: List[int], load: List[int]) -> List[int]:\n\t\t\"\"\"\n\t\tYou have k servers numbered from 0 to k-1 that are being used to handle multiple requests simultaneously. Each server has infinite computational capacity but cannot handle more than one request at a time. The requests are assigned to servers according to a specific algorithm:\n\t\t\tThe ith (0-indexed) request arrives.\n\t\t\tIf all servers are busy, the request is dropped (not handled at all).\n\t\t\tIf the (i % k)th server is available, assign the request to that server.\n\t\t\tOtherwise, assign the request to the next available server (wrapping around the list of servers and starting from 0 if necessary). For example, if the ith server is busy, try to assign the request to the (i+1)th server, then the (i+2)th server, and so on.\n\t\tYou are given a strictly increasing array arrival of positive integers, where arrival[i] represents the arrival time of the ith request, and another array load, where load[i] represents the load of the ith request (the time it takes to complete). Your goal is to find the busiest server(s). A server is considered busiest if it handled the most number of requests successfully among all the servers.\n\t\tReturn a list containing the IDs (0-indexed) of the busiest server(s). You may return the IDs in any order.\n\t\tExample 1:\n\t\tInput: k = 3, arrival = [1,2,3,4,5], load = [5,2,3,3,3] \n\t\tOutput: [1] \n\t\tExplanation: \n\t\tAll of the servers start out available.\n\t\tThe first 3 requests are handled by the first 3 servers in order.\n\t\tRequest 3 comes in. Server 0 is busy, so it's assigned to the next available server, which is 1.\n\t\tRequest 4 comes in. It cannot be handled since all servers are busy, so it is dropped.\n\t\tServers 0 and 2 handled one request each, while server 1 handled two requests. Hence server 1 is the busiest server.\n\t\tExample 2:\n\t\tInput: k = 3, arrival = [1,2,3,4], load = [1,2,1,2]\n\t\tOutput: [0]\n\t\tExplanation: \n\t\tThe first 3 requests are handled by first 3 servers.\n\t\tRequest 3 comes in. It is handled by server 0 since the server is available.\n\t\tServer 0 handled two requests, while servers 1 and 2 handled one request each. Hence server 0 is the busiest server.\n\t\tExample 3:\n\t\tInput: k = 3, arrival = [1,2,3], load = [10,12,11]\n\t\tOutput: [0,1,2]\n\t\tExplanation: Each server handles a single request, so they are all considered the busiest.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1711, - "question": "class Solution:\n def restoreMatrix(self, rowSum: List[int], colSum: List[int]) -> List[List[int]]:\n\t\t\"\"\"\n\t\tYou are given two arrays rowSum and colSum of non-negative integers where rowSum[i] is the sum of the elements in the ith row and colSum[j] is the sum of the elements of the jth column of a 2D matrix. In other words, you do not know the elements of the matrix, but you do know the sums of each row and column.\n\t\tFind any matrix of non-negative integers of size rowSum.length x colSum.length that satisfies the rowSum and colSum requirements.\n\t\tReturn a 2D array representing any matrix that fulfills the requirements. It's guaranteed that at least one matrix that fulfills the requirements exists.\n\t\tExample 1:\n\t\tInput: rowSum = [3,8], colSum = [4,7]\n\t\tOutput: [[3,0],\n\t\t [1,7]]\n\t\tExplanation: \n\t\t0th row: 3 + 0 = 3 == rowSum[0]\n\t\t1st row: 1 + 7 = 8 == rowSum[1]\n\t\t0th column: 3 + 1 = 4 == colSum[0]\n\t\t1st column: 0 + 7 = 7 == colSum[1]\n\t\tThe row and column sums match, and all matrix elements are non-negative.\n\t\tAnother possible matrix is: [[1,2],\n\t\t [3,5]]\n\t\tExample 2:\n\t\tInput: rowSum = [5,7,10], colSum = [8,6,8]\n\t\tOutput: [[0,5,0],\n\t\t [6,1,0],\n\t\t [2,0,8]]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1714, - "question": "class Solution:\n def reorderSpaces(self, text: str) -> str:\n\t\t\"\"\"\n\t\tYou are given a string text of words that are placed among some number of spaces. Each word consists of one or more lowercase English letters and are separated by at least one space. It's guaranteed that text contains at least one word.\n\t\tRearrange the spaces so that there is an equal number of spaces between every pair of adjacent words and that number is maximized. If you cannot redistribute all the spaces equally, place the extra spaces at the end, meaning the returned string should be the same length as text.\n\t\tReturn the string after rearranging the spaces.\n\t\tExample 1:\n\t\tInput: text = \" this is a sentence \"\n\t\tOutput: \"this is a sentence\"\n\t\tExplanation: There are a total of 9 spaces and 4 words. We can evenly divide the 9 spaces between the words: 9 / (4-1) = 3 spaces.\n\t\tExample 2:\n\t\tInput: text = \" practice makes perfect\"\n\t\tOutput: \"practice makes perfect \"\n\t\tExplanation: There are a total of 7 spaces and 3 words. 7 / (3-1) = 3 spaces plus 1 extra space. We place this extra space at the end of the string.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1715, - "question": "class Solution:\n def maxUniqueSplit(self, s: str) -> int:\n\t\t\"\"\"\n\t\tGiven a string s, return the maximum number of unique substrings that the given string can be split into.\n\t\tYou can split string s into any list of non-empty substrings, where the concatenation of the substrings forms the original string. However, you must split the substrings such that all of them are unique.\n\t\tA substring is a contiguous sequence of characters within a string.\n\t\tExample 1:\n\t\tInput: s = \"ababccc\"\n\t\tOutput: 5\n\t\tExplanation: One way to split maximally is ['a', 'b', 'ab', 'c', 'cc']. Splitting like ['a', 'b', 'a', 'b', 'c', 'cc'] is not valid as you have 'a' and 'b' multiple times.\n\t\tExample 2:\n\t\tInput: s = \"aba\"\n\t\tOutput: 2\n\t\tExplanation: One way to split maximally is ['a', 'ba'].\n\t\tExample 3:\n\t\tInput: s = \"aa\"\n\t\tOutput: 1\n\t\tExplanation: It is impossible to split the string any further.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1716, - "question": "class Solution:\n def maxProductPath(self, grid: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tYou are given a m x n matrix grid. Initially, you are located at the top-left corner (0, 0), and in each step, you can only move right or down in the matrix.\n\t\tAmong all possible paths starting from the top-left corner (0, 0) and ending in the bottom-right corner (m - 1, n - 1), find the path with the maximum non-negative product. The product of a path is the product of all integers in the grid cells visited along the path.\n\t\tReturn the maximum non-negative product modulo 109 + 7. If the maximum product is negative, return -1.\n\t\tNotice that the modulo is performed after getting the maximum product.\n\t\tExample 1:\n\t\tInput: grid = [[-1,-2,-3],[-2,-3,-3],[-3,-3,-2]]\n\t\tOutput: -1\n\t\tExplanation: It is not possible to get non-negative product in the path from (0, 0) to (2, 2), so return -1.\n\t\tExample 2:\n\t\tInput: grid = [[1,-2,1],[1,-2,1],[3,-4,1]]\n\t\tOutput: 8\n\t\tExplanation: Maximum non-negative product is shown (1 * 1 * -2 * -4 * 1 = 8).\n\t\tExample 3:\n\t\tInput: grid = [[1,3],[0,-4]]\n\t\tOutput: 0\n\t\tExplanation: Maximum non-negative product is shown (1 * 0 * -4 = 0).\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1717, - "question": "class Solution:\n def connectTwoGroups(self, cost: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tYou are given two groups of points where the first group has size1 points, the second group has size2 points, and size1 >= size2.\n\t\tThe cost of the connection between any two points are given in an size1 x size2 matrix where cost[i][j] is the cost of connecting point i of the first group and point j of the second group. The groups are connected if each point in both groups is connected to one or more points in the opposite group. In other words, each point in the first group must be connected to at least one point in the second group, and each point in the second group must be connected to at least one point in the first group.\n\t\tReturn the minimum cost it takes to connect the two groups.\n\t\tExample 1:\n\t\tInput: cost = [[15, 96], [36, 2]]\n\t\tOutput: 17\n\t\tExplanation: The optimal way of connecting the groups is:\n\t\t1--A\n\t\t2--B\n\t\tThis results in a total cost of 17.\n\t\tExample 2:\n\t\tInput: cost = [[1, 3, 5], [4, 1, 1], [1, 5, 3]]\n\t\tOutput: 4\n\t\tExplanation: The optimal way of connecting the groups is:\n\t\t1--A\n\t\t2--B\n\t\t2--C\n\t\t3--A\n\t\tThis results in a total cost of 4.\n\t\tNote that there are multiple points connected to point 2 in the first group and point A in the second group. This does not matter as there is no limit to the number of points that can be connected. We only care about the minimum total cost.\n\t\tExample 3:\n\t\tInput: cost = [[2, 5, 1], [3, 4, 7], [8, 1, 2], [6, 2, 4], [3, 8, 8]]\n\t\tOutput: 10\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1720, - "question": "class Solution:\n def minOperations(self, logs: List[str]) -> int:\n\t\t\"\"\"\n\t\tThe Leetcode file system keeps a log each time some user performs a change folder operation.\n\t\tThe operations are described below:\n\t\t\t\"../\" : Move to the parent folder of the current folder. (If you are already in the main folder, remain in the same folder).\n\t\t\t\"./\" : Remain in the same folder.\n\t\t\t\"x/\" : Move to the child folder named x (This folder is guaranteed to always exist).\n\t\tYou are given a list of strings logs where logs[i] is the operation performed by the user at the ith step.\n\t\tThe file system starts in the main folder, then the operations in logs are performed.\n\t\tReturn the minimum number of operations needed to go back to the main folder after the change folder operations.\n\t\tExample 1:\n\t\tInput: logs = [\"d1/\",\"d2/\",\"../\",\"d21/\",\"./\"]\n\t\tOutput: 2\n\t\tExplanation: Use this change folder operation \"../\" 2 times and go back to the main folder.\n\t\tExample 2:\n\t\tInput: logs = [\"d1/\",\"d2/\",\"./\",\"d3/\",\"../\",\"d31/\"]\n\t\tOutput: 3\n\t\tExample 3:\n\t\tInput: logs = [\"d1/\",\"../\",\"../\",\"../\"]\n\t\tOutput: 0\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1721, - "question": "class Solution:\n def minOperationsMaxProfit(self, customers: List[int], boardingCost: int, runningCost: int) -> int:\n\t\t\"\"\"\n\t\tYou are the operator of a Centennial Wheel that has four gondolas, and each gondola has room for up to four people. You have the ability to rotate the gondolas counterclockwise, which costs you runningCost dollars.\n\t\tYou are given an array customers of length n where customers[i] is the number of new customers arriving just before the ith rotation (0-indexed). This means you must rotate the wheel i times before the customers[i] customers arrive. You cannot make customers wait if there is room in the gondola. Each customer pays boardingCost dollars when they board on the gondola closest to the ground and will exit once that gondola reaches the ground again.\n\t\tYou can stop the wheel at any time, including before serving all customers. If you decide to stop serving customers, all subsequent rotations are free in order to get all the customers down safely. Note that if there are currently more than four customers waiting at the wheel, only four will board the gondola, and the rest will wait for the next rotation.\n\t\tReturn the minimum number of rotations you need to perform to maximize your profit. If there is no scenario where the profit is positive, return -1.\n\t\tExample 1:\n\t\tInput: customers = [8,3], boardingCost = 5, runningCost = 6\n\t\tOutput: 3\n\t\tExplanation: The numbers written on the gondolas are the number of people currently there.\n\t\t1. 8 customers arrive, 4 board and 4 wait for the next gondola, the wheel rotates. Current profit is 4 * $5 - 1 * $6 = $14.\n\t\t2. 3 customers arrive, the 4 waiting board the wheel and the other 3 wait, the wheel rotates. Current profit is 8 * $5 - 2 * $6 = $28.\n\t\t3. The final 3 customers board the gondola, the wheel rotates. Current profit is 11 * $5 - 3 * $6 = $37.\n\t\tThe highest profit was $37 after rotating the wheel 3 times.\n\t\tExample 2:\n\t\tInput: customers = [10,9,6], boardingCost = 6, runningCost = 4\n\t\tOutput: 7\n\t\tExplanation:\n\t\t1. 10 customers arrive, 4 board and 6 wait for the next gondola, the wheel rotates. Current profit is 4 * $6 - 1 * $4 = $20.\n\t\t2. 9 customers arrive, 4 board and 11 wait (2 originally waiting, 9 newly waiting), the wheel rotates. Current profit is 8 * $6 - 2 * $4 = $40.\n\t\t3. The final 6 customers arrive, 4 board and 13 wait, the wheel rotates. Current profit is 12 * $6 - 3 * $4 = $60.\n\t\t4. 4 board and 9 wait, the wheel rotates. Current profit is 16 * $6 - 4 * $4 = $80.\n\t\t5. 4 board and 5 wait, the wheel rotates. Current profit is 20 * $6 - 5 * $4 = $100.\n\t\t6. 4 board and 1 waits, the wheel rotates. Current profit is 24 * $6 - 6 * $4 = $120.\n\t\t7. 1 boards, the wheel rotates. Current profit is 25 * $6 - 7 * $4 = $122.\n\t\tThe highest profit was $122 after rotating the wheel 7 times.\n\t\tExample 3:\n\t\tInput: customers = [3,4,0,5,1], boardingCost = 1, runningCost = 92\n\t\tOutput: -1\n\t\tExplanation:\n\t\t1. 3 customers arrive, 3 board and 0 wait, the wheel rotates. Current profit is 3 * $1 - 1 * $92 = -$89.\n\t\t2. 4 customers arrive, 4 board and 0 wait, the wheel rotates. Current profit is 7 * $1 - 2 * $92 = -$177.\n\t\t3. 0 customers arrive, 0 board and 0 wait, the wheel rotates. Current profit is 7 * $1 - 3 * $92 = -$269.\n\t\t4. 5 customers arrive, 4 board and 1 waits, the wheel rotates. Current profit is 11 * $1 - 4 * $92 = -$357.\n\t\t5. 1 customer arrives, 2 board and 0 wait, the wheel rotates. Current profit is 13 * $1 - 5 * $92 = -$447.\n\t\tThe profit was never positive, so return -1.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1722, - "question": "class ThroneInheritance:\n def __init__(self, kingName: str):\n def birth(self, parentName: str, childName: str) -> None:\n def death(self, name: str) -> None:\n def getInheritanceOrder(self) -> List[str]:\n\t\t\"\"\"\n\t\tA kingdom consists of a king, his children, his grandchildren, and so on. Every once in a while, someone in the family dies or a child is born.\n\t\tThe kingdom has a well-defined order of inheritance that consists of the king as the first member. Let's define the recursive function Successor(x, curOrder), which given a person x and the inheritance order so far, returns who should be the next person after x in the order of inheritance.\n\t\tSuccessor(x, curOrder):\n\t\t if x has no children or all of x's children are in curOrder:\n\t\t if x is the king return null\n\t\t else return Successor(x's parent, curOrder)\n\t\t else return x's oldest child who's not in curOrder\n\t\tFor example, assume we have a kingdom that consists of the king, his children Alice and Bob (Alice is older than Bob), and finally Alice's son Jack.\n\t\t\tIn the beginning, curOrder will be [\"king\"].\n\t\t\tCalling Successor(king, curOrder) will return Alice, so we append to curOrder to get [\"king\", \"Alice\"].\n\t\t\tCalling Successor(Alice, curOrder) will return Jack, so we append to curOrder to get [\"king\", \"Alice\", \"Jack\"].\n\t\t\tCalling Successor(Jack, curOrder) will return Bob, so we append to curOrder to get [\"king\", \"Alice\", \"Jack\", \"Bob\"].\n\t\t\tCalling Successor(Bob, curOrder) will return null. Thus the order of inheritance will be [\"king\", \"Alice\", \"Jack\", \"Bob\"].\n\t\tUsing the above function, we can always obtain a unique order of inheritance.\n\t\tImplement the ThroneInheritance class:\n\t\t\tThroneInheritance(string kingName) Initializes an object of the ThroneInheritance class. The name of the king is given as part of the constructor.\n\t\t\tvoid birth(string parentName, string childName) Indicates that parentName gave birth to childName.\n\t\t\tvoid death(string name) Indicates the death of name. The death of the person doesn't affect the Successor function nor the current inheritance order. You can treat it as just marking the person as dead.\n\t\t\tstring[] getInheritanceOrder() Returns a list representing the current order of inheritance excluding dead people.\n\t\tExample 1:\n\t\tInput\n\t\t[\"ThroneInheritance\", \"birth\", \"birth\", \"birth\", \"birth\", \"birth\", \"birth\", \"getInheritanceOrder\", \"death\", \"getInheritanceOrder\"]\n\t\t[[\"king\"], [\"king\", \"andy\"], [\"king\", \"bob\"], [\"king\", \"catherine\"], [\"andy\", \"matthew\"], [\"bob\", \"alex\"], [\"bob\", \"asha\"], [null], [\"bob\"], [null]]\n\t\tOutput\n\t\t[null, null, null, null, null, null, null, [\"king\", \"andy\", \"matthew\", \"bob\", \"alex\", \"asha\", \"catherine\"], null, [\"king\", \"andy\", \"matthew\", \"alex\", \"asha\", \"catherine\"]]\n\t\tExplanation\n\t\tThroneInheritance t= new ThroneInheritance(\"king\"); // order: king\n\t\tt.birth(\"king\", \"andy\"); // order: king > andy\n\t\tt.birth(\"king\", \"bob\"); // order: king > andy > bob\n\t\tt.birth(\"king\", \"catherine\"); // order: king > andy > bob > catherine\n\t\tt.birth(\"andy\", \"matthew\"); // order: king > andy > matthew > bob > catherine\n\t\tt.birth(\"bob\", \"alex\"); // order: king > andy > matthew > bob > alex > catherine\n\t\tt.birth(\"bob\", \"asha\"); // order: king > andy > matthew > bob > alex > asha > catherine\n\t\tt.getInheritanceOrder(); // return [\"king\", \"andy\", \"matthew\", \"bob\", \"alex\", \"asha\", \"catherine\"]\n\t\tt.death(\"bob\"); // order: king > andy > matthew > bob > alex > asha > catherine\n\t\tt.getInheritanceOrder(); // return [\"king\", \"andy\", \"matthew\", \"alex\", \"asha\", \"catherine\"]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1723, - "question": "class Solution:\n def maximumRequests(self, n: int, requests: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tWe have n buildings numbered from 0 to n - 1. Each building has a number of employees. It's transfer season, and some employees want to change the building they reside in.\n\t\tYou are given an array requests where requests[i] = [fromi, toi] represents an employee's request to transfer from building fromi to building toi.\n\t\tAll buildings are full, so a list of requests is achievable only if for each building, the net change in employee transfers is zero. This means the number of employees leaving is equal to the number of employees moving in. For example if n = 3 and two employees are leaving building 0, one is leaving building 1, and one is leaving building 2, there should be two employees moving to building 0, one employee moving to building 1, and one employee moving to building 2.\n\t\tReturn the maximum number of achievable requests.\n\t\tExample 1:\n\t\tInput: n = 5, requests = [[0,1],[1,0],[0,1],[1,2],[2,0],[3,4]]\n\t\tOutput: 5\n\t\tExplantion: Let's see the requests:\n\t\tFrom building 0 we have employees x and y and both want to move to building 1.\n\t\tFrom building 1 we have employees a and b and they want to move to buildings 2 and 0 respectively.\n\t\tFrom building 2 we have employee z and they want to move to building 0.\n\t\tFrom building 3 we have employee c and they want to move to building 4.\n\t\tFrom building 4 we don't have any requests.\n\t\tWe can achieve the requests of users x and b by swapping their places.\n\t\tWe can achieve the requests of users y, a and z by swapping the places in the 3 buildings.\n\t\tExample 2:\n\t\tInput: n = 3, requests = [[0,0],[1,2],[2,1]]\n\t\tOutput: 3\n\t\tExplantion: Let's see the requests:\n\t\tFrom building 0 we have employee x and they want to stay in the same building 0.\n\t\tFrom building 1 we have employee y and they want to move to building 2.\n\t\tFrom building 2 we have employee z and they want to move to building 1.\n\t\tWe can achieve all the requests. \n\t\tExample 3:\n\t\tInput: n = 4, requests = [[0,3],[3,1],[1,2],[2,0]]\n\t\tOutput: 4\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1725, - "question": "class Solution:\n def numberOfSets(self, n: int, k: int) -> int:\n\t\t\"\"\"\n\t\tGiven n points on a 1-D plane, where the ith point (from 0 to n-1) is at x = i, find the number of ways we can draw exactly k non-overlapping line segments such that each segment covers two or more points. The endpoints of each segment must have integral coordinates. The k line segments do not have to cover all n points, and they are allowed to share endpoints.\n\t\tReturn the number of ways we can draw k non-overlapping line segments. Since this number can be huge, return it modulo 109 + 7.\n\t\tExample 1:\n\t\tInput: n = 4, k = 2\n\t\tOutput: 5\n\t\tExplanation: The two line segments are shown in red and blue.\n\t\tThe image above shows the 5 different ways {(0,2),(2,3)}, {(0,1),(1,3)}, {(0,1),(2,3)}, {(1,2),(2,3)}, {(0,1),(1,2)}.\n\t\tExample 2:\n\t\tInput: n = 3, k = 1\n\t\tOutput: 3\n\t\tExplanation: The 3 ways are {(0,1)}, {(0,2)}, {(1,2)}.\n\t\tExample 3:\n\t\tInput: n = 30, k = 7\n\t\tOutput: 796297179\n\t\tExplanation: The total number of possible ways to draw 7 line segments is 3796297200. Taking this number modulo 109 + 7 gives us 796297179.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1726, - "question": "class Solution:\n def bestCoordinate(self, towers: List[List[int]], radius: int) -> List[int]:\n\t\t\"\"\"\n\t\tYou are given an array of network towers towers, where towers[i] = [xi, yi, qi] denotes the ith network tower with location (xi, yi) and quality factor qi. All the coordinates are integral coordinates on the X-Y plane, and the distance between the two coordinates is the Euclidean distance.\n\t\tYou are also given an integer radius where a tower is reachable if the distance is less than or equal to radius. Outside that distance, the signal becomes garbled, and the tower is not reachable.\n\t\tThe signal quality of the ith tower at a coordinate (x, y) is calculated with the formula \u230aqi / (1 + d)\u230b, where d is the distance between the tower and the coordinate. The network quality at a coordinate is the sum of the signal qualities from all the reachable towers.\n\t\tReturn the array [cx, cy] representing the integral coordinate (cx, cy) where the network quality is maximum. If there are multiple coordinates with the same network quality, return the lexicographically minimum non-negative coordinate.\n\t\tNote:\n\t\t\tA coordinate (x1, y1) is lexicographically smaller than (x2, y2) if either:\n\t\t\t\tx1 < x2, or\n\t\t\t\tx1 == x2 and y1 < y2.\n\t\t\t\u230aval\u230b is the greatest integer less than or equal to val (the floor function).\n\t\tExample 1:\n\t\tInput: towers = [[1,2,5],[2,1,7],[3,1,9]], radius = 2\n\t\tOutput: [2,1]\n\t\tExplanation: At coordinate (2, 1) the total quality is 13.\n\t\t- Quality of 7 from (2, 1) results in \u230a7 / (1 + sqrt(0)\u230b = \u230a7\u230b = 7\n\t\t- Quality of 5 from (1, 2) results in \u230a5 / (1 + sqrt(2)\u230b = \u230a2.07\u230b = 2\n\t\t- Quality of 9 from (3, 1) results in \u230a9 / (1 + sqrt(1)\u230b = \u230a4.5\u230b = 4\n\t\tNo other coordinate has a higher network quality.\n\t\tExample 2:\n\t\tInput: towers = [[23,11,21]], radius = 9\n\t\tOutput: [23,11]\n\t\tExplanation: Since there is only one tower, the network quality is highest right at the tower's location.\n\t\tExample 3:\n\t\tInput: towers = [[1,2,13],[2,1,7],[0,1,9]], radius = 2\n\t\tOutput: [1,2]\n\t\tExplanation: Coordinate (1, 2) has the highest network quality.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1727, - "question": "class Solution:\n def canMouseWin(self, grid: List[str], catJump: int, mouseJump: int) -> bool:\n\t\t\"\"\"\n\t\tA game is played by a cat and a mouse named Cat and Mouse.\n\t\tThe environment is represented by a grid of size rows x cols, where each element is a wall, floor, player (Cat, Mouse), or food.\n\t\t\tPlayers are represented by the characters 'C'(Cat),'M'(Mouse).\n\t\t\tFloors are represented by the character '.' and can be walked on.\n\t\t\tWalls are represented by the character '#' and cannot be walked on.\n\t\t\tFood is represented by the character 'F' and can be walked on.\n\t\t\tThere is only one of each character 'C', 'M', and 'F' in grid.\n\t\tMouse and Cat play according to the following rules:\n\t\t\tMouse moves first, then they take turns to move.\n\t\t\tDuring each turn, Cat and Mouse can jump in one of the four directions (left, right, up, down). They cannot jump over the wall nor outside of the grid.\n\t\t\tcatJump, mouseJump are the maximum lengths Cat and Mouse can jump at a time, respectively. Cat and Mouse can jump less than the maximum length.\n\t\t\tStaying in the same position is allowed.\n\t\t\tMouse can jump over Cat.\n\t\tThe game can end in 4 ways:\n\t\t\tIf Cat occupies the same position as Mouse, Cat wins.\n\t\t\tIf Cat reaches the food first, Cat wins.\n\t\t\tIf Mouse reaches the food first, Mouse wins.\n\t\t\tIf Mouse cannot get to the food within 1000 turns, Cat wins.\n\t\tGiven a rows x cols matrix grid and two integers catJump and mouseJump, return true if Mouse can win the game if both Cat and Mouse play optimally, otherwise return false.\n\t\tExample 1:\n\t\tInput: grid = [\"####F\",\"#C...\",\"M....\"], catJump = 1, mouseJump = 2\n\t\tOutput: true\n\t\tExplanation: Cat cannot catch Mouse on its turn nor can it get the food before Mouse.\n\t\tExample 2:\n\t\tInput: grid = [\"M.C...F\"], catJump = 1, mouseJump = 4\n\t\tOutput: true\n\t\tExample 3:\n\t\tInput: grid = [\"M.C...F\"], catJump = 1, mouseJump = 3\n\t\tOutput: false\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1728, - "question": "class Fancy:\n def __init__(self):\n def append(self, val: int) -> None:\n def addAll(self, inc: int) -> None:\n def multAll(self, m: int) -> None:\n def getIndex(self, idx: int) -> int:\n\t\t\"\"\"\n\t\tWrite an API that generates fancy sequences using the append, addAll, and multAll operations.\n\t\tImplement the Fancy class:\n\t\t\tFancy() Initializes the object with an empty sequence.\n\t\t\tvoid append(val) Appends an integer val to the end of the sequence.\n\t\t\tvoid addAll(inc) Increments all existing values in the sequence by an integer inc.\n\t\t\tvoid multAll(m) Multiplies all existing values in the sequence by an integer m.\n\t\t\tint getIndex(idx) Gets the current value at index idx (0-indexed) of the sequence modulo 109 + 7. If the index is greater or equal than the length of the sequence, return -1.\n\t\tExample 1:\n\t\tInput\n\t\t[\"Fancy\", \"append\", \"addAll\", \"append\", \"multAll\", \"getIndex\", \"addAll\", \"append\", \"multAll\", \"getIndex\", \"getIndex\", \"getIndex\"]\n\t\t[[], [2], [3], [7], [2], [0], [3], [10], [2], [0], [1], [2]]\n\t\tOutput\n\t\t[null, null, null, null, null, 10, null, null, null, 26, 34, 20]\n\t\tExplanation\n\t\tFancy fancy = new Fancy();\n\t\tfancy.append(2); // fancy sequence: [2]\n\t\tfancy.addAll(3); // fancy sequence: [2+3] -> [5]\n\t\tfancy.append(7); // fancy sequence: [5, 7]\n\t\tfancy.multAll(2); // fancy sequence: [5*2, 7*2] -> [10, 14]\n\t\tfancy.getIndex(0); // return 10\n\t\tfancy.addAll(3); // fancy sequence: [10+3, 14+3] -> [13, 17]\n\t\tfancy.append(10); // fancy sequence: [13, 17, 10]\n\t\tfancy.multAll(2); // fancy sequence: [13*2, 17*2, 10*2] -> [26, 34, 20]\n\t\tfancy.getIndex(0); // return 26\n\t\tfancy.getIndex(1); // return 34\n\t\tfancy.getIndex(2); // return 20\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1730, - "question": "class Solution:\n def specialArray(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou are given an array nums of non-negative integers. nums is considered special if there exists a number x such that there are exactly x numbers in nums that are greater than or equal to x.\n\t\tNotice that x does not have to be an element in nums.\n\t\tReturn x if the array is special, otherwise, return -1. It can be proven that if nums is special, the value for x is unique.\n\t\tExample 1:\n\t\tInput: nums = [3,5]\n\t\tOutput: 2\n\t\tExplanation: There are 2 values (3 and 5) that are greater than or equal to 2.\n\t\tExample 2:\n\t\tInput: nums = [0,0]\n\t\tOutput: -1\n\t\tExplanation: No numbers fit the criteria for x.\n\t\tIf x = 0, there should be 0 numbers >= x, but there are 2.\n\t\tIf x = 1, there should be 1 number >= x, but there are 0.\n\t\tIf x = 2, there should be 2 numbers >= x, but there are 0.\n\t\tx cannot be greater since there are only 2 numbers in nums.\n\t\tExample 3:\n\t\tInput: nums = [0,4,3,0,4]\n\t\tOutput: 3\n\t\tExplanation: There are 3 values that are greater than or equal to 3.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1731, - "question": "class Solution:\n def isEvenOddTree(self, root: Optional[TreeNode]) -> bool:\n\t\t\"\"\"\n\t\tA binary tree is named Even-Odd if it meets the following conditions:\n\t\t\tThe root of the binary tree is at level index 0, its children are at level index 1, their children are at level index 2, etc.\n\t\t\tFor every even-indexed level, all nodes at the level have odd integer values in strictly increasing order (from left to right).\n\t\t\tFor every odd-indexed level, all nodes at the level have even integer values in strictly decreasing order (from left to right).\n\t\tGiven the root of a binary tree, return true if the binary tree is Even-Odd, otherwise return false.\n\t\tExample 1:\n\t\tInput: root = [1,10,4,3,null,7,9,12,8,6,null,null,2]\n\t\tOutput: true\n\t\tExplanation: The node values on each level are:\n\t\tLevel 0: [1]\n\t\tLevel 1: [10,4]\n\t\tLevel 2: [3,7,9]\n\t\tLevel 3: [12,8,6,2]\n\t\tSince levels 0 and 2 are all odd and increasing and levels 1 and 3 are all even and decreasing, the tree is Even-Odd.\n\t\tExample 2:\n\t\tInput: root = [5,4,2,3,3,7]\n\t\tOutput: false\n\t\tExplanation: The node values on each level are:\n\t\tLevel 0: [5]\n\t\tLevel 1: [4,2]\n\t\tLevel 2: [3,3,7]\n\t\tNode values in level 2 must be in strictly increasing order, so the tree is not Even-Odd.\n\t\tExample 3:\n\t\tInput: root = [5,9,1,3,5,7]\n\t\tOutput: false\n\t\tExplanation: Node values in the level 1 should be even integers.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1732, - "question": "class Solution:\n def minimumOneBitOperations(self, n: int) -> int:\n\t\t\"\"\"\n\t\tGiven an integer n, you must transform it into 0 using the following operations any number of times:\n\t\t\tChange the rightmost (0th) bit in the binary representation of n.\n\t\t\tChange the ith bit in the binary representation of n if the (i-1)th bit is set to 1 and the (i-2)th through 0th bits are set to 0.\n\t\tReturn the minimum number of operations to transform n into 0.\n\t\tExample 1:\n\t\tInput: n = 3\n\t\tOutput: 2\n\t\tExplanation: The binary representation of 3 is \"11\".\n\t\t\"11\" -> \"01\" with the 2nd operation since the 0th bit is 1.\n\t\t\"01\" -> \"00\" with the 1st operation.\n\t\tExample 2:\n\t\tInput: n = 6\n\t\tOutput: 4\n\t\tExplanation: The binary representation of 6 is \"110\".\n\t\t\"110\" -> \"010\" with the 2nd operation since the 1st bit is 1 and 0th through 0th bits are 0.\n\t\t\"010\" -> \"011\" with the 1st operation.\n\t\t\"011\" -> \"001\" with the 2nd operation since the 0th bit is 1.\n\t\t\"001\" -> \"000\" with the 1st operation.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1733, - "question": "class Solution:\n def visiblePoints(self, points: List[List[int]], angle: int, location: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou are given an array points, an integer angle, and your location, where location = [posx, posy] and points[i] = [xi, yi] both denote integral coordinates on the X-Y plane.\n\t\tInitially, you are facing directly east from your position. You cannot move from your position, but you can rotate. In other words, posx and posy cannot be changed. Your field of view in degrees is represented by angle, determining how wide you can see from any given view direction. Let d be the amount in degrees that you rotate counterclockwise. Then, your field of view is the inclusive range of angles [d - angle/2, d + angle/2].\n\t\tYour browser does not support the video tag or this video format.\n\t\tYou can see some set of points if, for each point, the angle formed by the point, your position, and the immediate east direction from your position is in your field of view.\n\t\tThere can be multiple points at one coordinate. There may be points at your location, and you can always see these points regardless of your rotation. Points do not obstruct your vision to other points.\n\t\tReturn the maximum number of points you can see.\n\t\tExample 1:\n\t\tInput: points = [[2,1],[2,2],[3,3]], angle = 90, location = [1,1]\n\t\tOutput: 3\n\t\tExplanation: The shaded region represents your field of view. All points can be made visible in your field of view, including [3,3] even though [2,2] is in front and in the same line of sight.\n\t\tExample 2:\n\t\tInput: points = [[2,1],[2,2],[3,4],[1,1]], angle = 90, location = [1,1]\n\t\tOutput: 4\n\t\tExplanation: All points can be made visible in your field of view, including the one at your location.\n\t\tExample 3:\n\t\tInput: points = [[1,0],[2,1]], angle = 13, location = [1,1]\n\t\tOutput: 1\n\t\tExplanation: You can only see one of the two points, as shown above.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1737, - "question": "class Solution:\n def maxDepth(self, s: str) -> int:\n\t\t\"\"\"\n\t\tA string is a valid parentheses string (denoted VPS) if it meets one of the following:\n\t\t\tIt is an empty string \"\", or a single character not equal to \"(\" or \")\",\n\t\t\tIt can be written as AB (A concatenated with B), where A and B are VPS's, or\n\t\t\tIt can be written as (A), where A is a VPS.\n\t\tWe can similarly define the nesting depth depth(S) of any VPS S as follows:\n\t\t\tdepth(\"\") = 0\n\t\t\tdepth(C) = 0, where C is a string with a single character not equal to \"(\" or \")\".\n\t\t\tdepth(A + B) = max(depth(A), depth(B)), where A and B are VPS's.\n\t\t\tdepth(\"(\" + A + \")\") = 1 + depth(A), where A is a VPS.\n\t\tFor example, \"\", \"()()\", and \"()(()())\" are VPS's (with nesting depths 0, 1, and 2), and \")(\" and \"(()\" are not VPS's.\n\t\tGiven a VPS represented as string s, return the nesting depth of s.\n\t\tExample 1:\n\t\tInput: s = \"(1+(2*3)+((8)/4))+1\"\n\t\tOutput: 3\n\t\tExplanation: Digit 8 is inside of 3 nested parentheses in the string.\n\t\tExample 2:\n\t\tInput: s = \"(1)+((2))+(((3)))\"\n\t\tOutput: 3\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1738, - "question": "class Solution:\n def maximalNetworkRank(self, n: int, roads: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tThere is an infrastructure of n cities with some number of roads connecting these cities. Each roads[i] = [ai, bi] indicates that there is a bidirectional road between cities ai and bi.\n\t\tThe network rank of two different cities is defined as the total number of directly connected roads to either city. If a road is directly connected to both cities, it is only counted once.\n\t\tThe maximal network rank of the infrastructure is the maximum network rank of all pairs of different cities.\n\t\tGiven the integer n and the array roads, return the maximal network rank of the entire infrastructure.\n\t\tExample 1:\n\t\tInput: n = 4, roads = [[0,1],[0,3],[1,2],[1,3]]\n\t\tOutput: 4\n\t\tExplanation: The network rank of cities 0 and 1 is 4 as there are 4 roads that are connected to either 0 or 1. The road between 0 and 1 is only counted once.\n\t\tExample 2:\n\t\tInput: n = 5, roads = [[0,1],[0,3],[1,2],[1,3],[2,3],[2,4]]\n\t\tOutput: 5\n\t\tExplanation: There are 5 roads that are connected to cities 1 or 2.\n\t\tExample 3:\n\t\tInput: n = 8, roads = [[0,1],[1,2],[2,3],[2,4],[5,6],[5,7]]\n\t\tOutput: 5\n\t\tExplanation: The network rank of 2 and 5 is 5. Notice that all the cities do not have to be connected.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1739, - "question": "class Solution:\n def checkPalindromeFormation(self, a: str, b: str) -> bool:\n\t\t\"\"\"\n\t\tYou are given two strings a and b of the same length. Choose an index and split both strings at the same index, splitting a into two strings: aprefix and asuffix where a = aprefix + asuffix, and splitting b into two strings: bprefix and bsuffix where b = bprefix + bsuffix. Check if aprefix + bsuffix or bprefix + asuffix forms a palindrome.\n\t\tWhen you split a string s into sprefix and ssuffix, either ssuffix or sprefix is allowed to be empty. For example, if s = \"abc\", then \"\" + \"abc\", \"a\" + \"bc\", \"ab\" + \"c\" , and \"abc\" + \"\" are valid splits.\n\t\tReturn true if it is possible to form a palindrome string, otherwise return false.\n\t\tNotice that x + y denotes the concatenation of strings x and y.\n\t\tExample 1:\n\t\tInput: a = \"x\", b = \"y\"\n\t\tOutput: true\n\t\tExplaination: If either a or b are palindromes the answer is true since you can split in the following way:\n\t\taprefix = \"\", asuffix = \"x\"\n\t\tbprefix = \"\", bsuffix = \"y\"\n\t\tThen, aprefix + bsuffix = \"\" + \"y\" = \"y\", which is a palindrome.\n\t\tExample 2:\n\t\tInput: a = \"xbdef\", b = \"xecab\"\n\t\tOutput: false\n\t\tExample 3:\n\t\tInput: a = \"ulacfd\", b = \"jizalu\"\n\t\tOutput: true\n\t\tExplaination: Split them at index 3:\n\t\taprefix = \"ula\", asuffix = \"cfd\"\n\t\tbprefix = \"jiz\", bsuffix = \"alu\"\n\t\tThen, aprefix + bsuffix = \"ula\" + \"alu\" = \"ulaalu\", which is a palindrome.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1740, - "question": "class Solution:\n def countSubgraphsForEachDiameter(self, n: int, edges: List[List[int]]) -> List[int]:\n\t\t\"\"\"\n\t\tThere are n cities numbered from 1 to n. You are given an array edges of size n-1, where edges[i] = [ui, vi] represents a bidirectional edge between cities ui and vi. There exists a unique path between each pair of cities. In other words, the cities form a tree.\r\n\t\tA subtree is a subset of cities where every city is reachable from every other city in the subset, where the path between each pair passes through only the cities from the subset. Two subtrees are different if there is a city in one subtree that is not present in the other.\r\n\t\tFor each d from 1 to n-1, find the number of subtrees in which the maximum distance between any two cities in the subtree is equal to d.\r\n\t\tReturn an array of size n-1 where the dth element (1-indexed) is the number of subtrees in which the maximum distance between any two cities is equal to d.\r\n\t\tNotice that the distance between the two cities is the number of edges in the path between them.\r\n\t\tExample 1:\r\n\t\tInput: n = 4, edges = [[1,2],[2,3],[2,4]]\r\n\t\tOutput: [3,4,0]\r\n\t\tExplanation:\r\n\t\tThe subtrees with subsets {1,2}, {2,3} and {2,4} have a max distance of 1.\r\n\t\tThe subtrees with subsets {1,2,3}, {1,2,4}, {2,3,4} and {1,2,3,4} have a max distance of 2.\r\n\t\tNo subtree has two nodes where the max distance between them is 3.\r\n\t\tExample 2:\r\n\t\tInput: n = 2, edges = [[1,2]]\r\n\t\tOutput: [1]\r\n\t\tExample 3:\r\n\t\tInput: n = 3, edges = [[1,2],[2,3]]\r\n\t\tOutput: [2,1]\r\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1741, - "question": "class Solution:\n def frequencySort(self, nums: List[int]) -> List[int]:\n\t\t\"\"\"\n\t\tGiven an array of integers nums, sort the array in increasing order based on the frequency of the values. If multiple values have the same frequency, sort them in decreasing order.\n\t\tReturn the sorted array.\n\t\tExample 1:\n\t\tInput: nums = [1,1,2,2,2,3]\n\t\tOutput: [3,1,1,2,2,2]\n\t\tExplanation: '3' has a frequency of 1, '1' has a frequency of 2, and '2' has a frequency of 3.\n\t\tExample 2:\n\t\tInput: nums = [2,3,1,3,2]\n\t\tOutput: [1,3,3,2,2]\n\t\tExplanation: '2' and '3' both have a frequency of 2, so they are sorted in decreasing order.\n\t\tExample 3:\n\t\tInput: nums = [-1,1,-6,4,5,-6,1,4,1]\n\t\tOutput: [5,-1,4,4,-6,-6,1,1,1]\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1742, - "question": "class Solution:\n def maxWidthOfVerticalArea(self, points: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tGiven n points on a 2D plane where points[i] = [xi, yi], Return the widest vertical area between two points such that no points are inside the area.\n\t\tA vertical area is an area of fixed-width extending infinitely along the y-axis (i.e., infinite height). The widest vertical area is the one with the maximum width.\n\t\tNote that points on the edge of a vertical area are not considered included in the area.\n\t\tExample 1:\n\t\t\u200b\n\t\tInput: points = [[8,7],[9,9],[7,4],[9,7]]\n\t\tOutput: 1\n\t\tExplanation: Both the red and the blue area are optimal.\n\t\tExample 2:\n\t\tInput: points = [[3,1],[9,0],[1,0],[1,4],[5,3],[8,8]]\n\t\tOutput: 3\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1743, - "question": "class Solution:\n def countSubstrings(self, s: str, t: str) -> int:\n\t\t\"\"\"\n\t\tGiven two strings s and t, find the number of ways you can choose a non-empty substring of s and replace a single character by a different character such that the resulting substring is a substring of t. In other words, find the number of substrings in s that differ from some substring in t by exactly one character.\n\t\tFor example, the underlined substrings in \"computer\" and \"computation\" only differ by the 'e'/'a', so this is a valid way.\n\t\tReturn the number of substrings that satisfy the condition above.\n\t\tA substring is a contiguous sequence of characters within a string.\n\t\tExample 1:\n\t\tInput: s = \"aba\", t = \"baba\"\n\t\tOutput: 6\n\t\tExplanation: The following are the pairs of substrings from s and t that differ by exactly 1 character:\n\t\t(\"aba\", \"baba\")\n\t\t(\"aba\", \"baba\")\n\t\t(\"aba\", \"baba\")\n\t\t(\"aba\", \"baba\")\n\t\t(\"aba\", \"baba\")\n\t\t(\"aba\", \"baba\")\n\t\tThe underlined portions are the substrings that are chosen from s and t.\n\t\t\u200b\u200bExample 2:\n\t\tInput: s = \"ab\", t = \"bb\"\n\t\tOutput: 3\n\t\tExplanation: The following are the pairs of substrings from s and t that differ by 1 character:\n\t\t(\"ab\", \"bb\")\n\t\t(\"ab\", \"bb\")\n\t\t(\"ab\", \"bb\")\n\t\t\u200b\u200b\u200b\u200bThe underlined portions are the substrings that are chosen from s and t.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1744, - "question": "class Solution:\n def numWays(self, words: List[str], target: str) -> int:\n\t\t\"\"\"\n\t\tYou are given a list of strings of the same length words and a string target.\n\t\tYour task is to form target using the given words under the following rules:\n\t\t\ttarget should be formed from left to right.\n\t\t\tTo form the ith character (0-indexed) of target, you can choose the kth character of the jth string in words if target[i] = words[j][k].\n\t\t\tOnce you use the kth character of the jth string of words, you can no longer use the xth character of any string in words where x <= k. In other words, all characters to the left of or at index k become unusuable for every string.\n\t\t\tRepeat the process until you form the string target.\n\t\tNotice that you can use multiple characters from the same string in words provided the conditions above are met.\n\t\tReturn the number of ways to form target from words. Since the answer may be too large, return it modulo 109 + 7.\n\t\tExample 1:\n\t\tInput: words = [\"acca\",\"bbbb\",\"caca\"], target = \"aba\"\n\t\tOutput: 6\n\t\tExplanation: There are 6 ways to form target.\n\t\t\"aba\" -> index 0 (\"acca\"), index 1 (\"bbbb\"), index 3 (\"caca\")\n\t\t\"aba\" -> index 0 (\"acca\"), index 2 (\"bbbb\"), index 3 (\"caca\")\n\t\t\"aba\" -> index 0 (\"acca\"), index 1 (\"bbbb\"), index 3 (\"acca\")\n\t\t\"aba\" -> index 0 (\"acca\"), index 2 (\"bbbb\"), index 3 (\"acca\")\n\t\t\"aba\" -> index 1 (\"caca\"), index 2 (\"bbbb\"), index 3 (\"acca\")\n\t\t\"aba\" -> index 1 (\"caca\"), index 2 (\"bbbb\"), index 3 (\"caca\")\n\t\tExample 2:\n\t\tInput: words = [\"abba\",\"baab\"], target = \"bab\"\n\t\tOutput: 4\n\t\tExplanation: There are 4 ways to form target.\n\t\t\"bab\" -> index 0 (\"baab\"), index 1 (\"baab\"), index 2 (\"abba\")\n\t\t\"bab\" -> index 0 (\"baab\"), index 1 (\"baab\"), index 3 (\"baab\")\n\t\t\"bab\" -> index 0 (\"baab\"), index 2 (\"baab\"), index 3 (\"baab\")\n\t\t\"bab\" -> index 1 (\"abba\"), index 2 (\"baab\"), index 3 (\"baab\")\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1746, - "question": "class Solution:\n def maxLengthBetweenEqualCharacters(self, s: str) -> int:\n\t\t\"\"\"\n\t\tGiven a string s, return the length of the longest substring between two equal characters, excluding the two characters. If there is no such substring return -1.\n\t\tA substring is a contiguous sequence of characters within a string.\n\t\tExample 1:\n\t\tInput: s = \"aa\"\n\t\tOutput: 0\n\t\tExplanation: The optimal substring here is an empty substring between the two 'a's.\n\t\tExample 2:\n\t\tInput: s = \"abca\"\n\t\tOutput: 2\n\t\tExplanation: The optimal substring here is \"bc\".\n\t\tExample 3:\n\t\tInput: s = \"cbzxy\"\n\t\tOutput: -1\n\t\tExplanation: There are no characters that appear twice in s.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1747, - "question": "class Solution:\n def findLexSmallestString(self, s: str, a: int, b: int) -> str:\n\t\t\"\"\"\n\t\tYou are given a string s of even length consisting of digits from 0 to 9, and two integers a and b.\n\t\tYou can apply either of the following two operations any number of times and in any order on s:\n\t\t\tAdd a to all odd indices of s (0-indexed). Digits post 9 are cycled back to 0. For example, if s = \"3456\" and a = 5, s becomes \"3951\".\n\t\t\tRotate s to the right by b positions. For example, if s = \"3456\" and b = 1, s becomes \"6345\".\n\t\tReturn the lexicographically smallest string you can obtain by applying the above operations any number of times on s.\n\t\tA string a is lexicographically smaller than a string b (of the same length) if in the first position where a and b differ, string a has a letter that appears earlier in the alphabet than the corresponding letter in b. For example, \"0158\" is lexicographically smaller than \"0190\" because the first position they differ is at the third letter, and '5' comes before '9'.\n\t\tExample 1:\n\t\tInput: s = \"5525\", a = 9, b = 2\n\t\tOutput: \"2050\"\n\t\tExplanation: We can apply the following operations:\n\t\tStart: \"5525\"\n\t\tRotate: \"2555\"\n\t\tAdd: \"2454\"\n\t\tAdd: \"2353\"\n\t\tRotate: \"5323\"\n\t\tAdd: \"5222\"\n\t\tAdd: \"5121\"\n\t\tRotate: \"2151\"\n\t\t\u200b\u200b\u200b\u200b\u200b\u200b\u200bAdd: \"2050\"\u200b\u200b\u200b\u200b\u200b\u200b\u200b\u200b\u200b\u200b\u200b\u200b\n\t\tThere is no way to obtain a string that is lexicographically smaller then \"2050\".\n\t\tExample 2:\n\t\tInput: s = \"74\", a = 5, b = 1\n\t\tOutput: \"24\"\n\t\tExplanation: We can apply the following operations:\n\t\tStart: \"74\"\n\t\tRotate: \"47\"\n\t\t\u200b\u200b\u200b\u200b\u200b\u200b\u200bAdd: \"42\"\n\t\t\u200b\u200b\u200b\u200b\u200b\u200b\u200bRotate: \"24\"\u200b\u200b\u200b\u200b\u200b\u200b\u200b\u200b\u200b\u200b\u200b\u200b\n\t\tThere is no way to obtain a string that is lexicographically smaller then \"24\".\n\t\tExample 3:\n\t\tInput: s = \"0011\", a = 4, b = 2\n\t\tOutput: \"0011\"\n\t\tExplanation: There are no sequence of operations that will give us a lexicographically smaller string than \"0011\".\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1748, - "question": "class Solution:\n def bestTeamScore(self, scores: List[int], ages: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou are the manager of a basketball team. For the upcoming tournament, you want to choose the team with the highest overall score. The score of the team is the sum of scores of all the players in the team.\n\t\tHowever, the basketball team is not allowed to have conflicts. A conflict exists if a younger player has a strictly higher score than an older player. A conflict does not occur between players of the same age.\n\t\tGiven two lists, scores and ages, where each scores[i] and ages[i] represents the score and age of the ith player, respectively, return the highest overall score of all possible basketball teams.\n\t\tExample 1:\n\t\tInput: scores = [1,3,5,10,15], ages = [1,2,3,4,5]\n\t\tOutput: 34\n\t\tExplanation: You can choose all the players.\n\t\tExample 2:\n\t\tInput: scores = [4,5,6,5], ages = [2,1,2,1]\n\t\tOutput: 16\n\t\tExplanation: It is best to choose the last 3 players. Notice that you are allowed to choose multiple people of the same age.\n\t\tExample 3:\n\t\tInput: scores = [1,2,3,5], ages = [8,9,10,1]\n\t\tOutput: 6\n\t\tExplanation: It is best to choose the first 3 players. \n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1751, - "question": "class Solution:\n def slowestKey(self, releaseTimes: List[int], keysPressed: str) -> str:\n\t\t\"\"\"\n\t\tA newly designed keypad was tested, where a tester pressed a sequence of n keys, one at a time.\n\t\tYou are given a string keysPressed of length n, where keysPressed[i] was the ith key pressed in the testing sequence, and a sorted list releaseTimes, where releaseTimes[i] was the time the ith key was released. Both arrays are 0-indexed. The 0th key was pressed at the time 0, and every subsequent key was pressed at the exact time the previous key was released.\n\t\tThe tester wants to know the key of the keypress that had the longest duration. The ith keypress had a duration of releaseTimes[i] - releaseTimes[i - 1], and the 0th keypress had a duration of releaseTimes[0].\n\t\tNote that the same key could have been pressed multiple times during the test, and these multiple presses of the same key may not have had the same duration.\n\t\tReturn the key of the keypress that had the longest duration. If there are multiple such keypresses, return the lexicographically largest key of the keypresses.\n\t\tExample 1:\n\t\tInput: releaseTimes = [9,29,49,50], keysPressed = \"cbcd\"\n\t\tOutput: \"c\"\n\t\tExplanation: The keypresses were as follows:\n\t\tKeypress for 'c' had a duration of 9 (pressed at time 0 and released at time 9).\n\t\tKeypress for 'b' had a duration of 29 - 9 = 20 (pressed at time 9 right after the release of the previous character and released at time 29).\n\t\tKeypress for 'c' had a duration of 49 - 29 = 20 (pressed at time 29 right after the release of the previous character and released at time 49).\n\t\tKeypress for 'd' had a duration of 50 - 49 = 1 (pressed at time 49 right after the release of the previous character and released at time 50).\n\t\tThe longest of these was the keypress for 'b' and the second keypress for 'c', both with duration 20.\n\t\t'c' is lexicographically larger than 'b', so the answer is 'c'.\n\t\tExample 2:\n\t\tInput: releaseTimes = [12,23,36,46,62], keysPressed = \"spuda\"\n\t\tOutput: \"a\"\n\t\tExplanation: The keypresses were as follows:\n\t\tKeypress for 's' had a duration of 12.\n\t\tKeypress for 'p' had a duration of 23 - 12 = 11.\n\t\tKeypress for 'u' had a duration of 36 - 23 = 13.\n\t\tKeypress for 'd' had a duration of 46 - 36 = 10.\n\t\tKeypress for 'a' had a duration of 62 - 46 = 16.\n\t\tThe longest of these was the keypress for 'a' with duration 16.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1752, - "question": "class Solution:\n def checkArithmeticSubarrays(self, nums: List[int], l: List[int], r: List[int]) -> List[bool]:\n\t\t\"\"\"\n\t\tA sequence of numbers is called arithmetic if it consists of at least two elements, and the difference between every two consecutive elements is the same. More formally, a sequence s is arithmetic if and only if s[i+1] - s[i] == s[1] - s[0] for all valid i.\n\t\tFor example, these are arithmetic sequences:\n\t\t1, 3, 5, 7, 9\n\t\t7, 7, 7, 7\n\t\t3, -1, -5, -9\n\t\tThe following sequence is not arithmetic:\n\t\t1, 1, 2, 5, 7\n\t\tYou are given an array of n integers, nums, and two arrays of m integers each, l and r, representing the m range queries, where the ith query is the range [l[i], r[i]]. All the arrays are 0-indexed.\n\t\tReturn a list of boolean elements answer, where answer[i] is true if the subarray nums[l[i]], nums[l[i]+1], ... , nums[r[i]] can be rearranged to form an arithmetic sequence, and false otherwise.\n\t\tExample 1:\n\t\tInput: nums = [4,6,5,9,3,7], l = [0,0,2], r = [2,3,5]\n\t\tOutput: [true,false,true]\n\t\tExplanation:\n\t\tIn the 0th query, the subarray is [4,6,5]. This can be rearranged as [6,5,4], which is an arithmetic sequence.\n\t\tIn the 1st query, the subarray is [4,6,5,9]. This cannot be rearranged as an arithmetic sequence.\n\t\tIn the 2nd query, the subarray is [5,9,3,7]. This can be rearranged as [3,5,7,9], which is an arithmetic sequence.\n\t\tExample 2:\n\t\tInput: nums = [-12,-9,-3,-12,-6,15,20,-25,-20,-15,-10], l = [0,1,6,4,8,7], r = [4,4,9,7,9,10]\n\t\tOutput: [false,true,false,false,true,true]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1753, - "question": "class Solution:\n def minimumEffortPath(self, heights: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tYou are a hiker preparing for an upcoming hike. You are given heights, a 2D array of size rows x columns, where heights[row][col] represents the height of cell (row, col). You are situated in the top-left cell, (0, 0), and you hope to travel to the bottom-right cell, (rows-1, columns-1) (i.e., 0-indexed). You can move up, down, left, or right, and you wish to find a route that requires the minimum effort.\r\n\t\tA route's effort is the maximum absolute difference in heights between two consecutive cells of the route.\r\n\t\tReturn the minimum effort required to travel from the top-left cell to the bottom-right cell.\r\n\t\tExample 1:\r\n\t\tInput: heights = [[1,2,2],[3,8,2],[5,3,5]]\r\n\t\tOutput: 2\r\n\t\tExplanation: The route of [1,3,5,3,5] has a maximum absolute difference of 2 in consecutive cells.\r\n\t\tThis is better than the route of [1,2,2,2,5], where the maximum absolute difference is 3.\r\n\t\tExample 2:\r\n\t\tInput: heights = [[1,2,3],[3,8,4],[5,3,5]]\r\n\t\tOutput: 1\r\n\t\tExplanation: The route of [1,2,3,4,5] has a maximum absolute difference of 1 in consecutive cells, which is better than route [1,3,5,3,5].\r\n\t\tExample 3:\r\n\t\tInput: heights = [[1,2,1,1,1],[1,2,1,2,1],[1,2,1,2,1],[1,2,1,2,1],[1,1,1,2,1]]\r\n\t\tOutput: 0\r\n\t\tExplanation: This route does not require any effort.\r\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1755, - "question": "class Solution:\n def decrypt(self, code: List[int], k: int) -> List[int]:\n\t\t\"\"\"\n\t\tYou have a bomb to defuse, and your time is running out! Your informer will provide you with a circular array code of length of n and a key k.\n\t\tTo decrypt the code, you must replace every number. All the numbers are replaced simultaneously.\n\t\t\tIf k > 0, replace the ith number with the sum of the next k numbers.\n\t\t\tIf k < 0, replace the ith number with the sum of the previous k numbers.\n\t\t\tIf k == 0, replace the ith number with 0.\n\t\tAs code is circular, the next element of code[n-1] is code[0], and the previous element of code[0] is code[n-1].\n\t\tGiven the circular array code and an integer key k, return the decrypted code to defuse the bomb!\n\t\tExample 1:\n\t\tInput: code = [5,7,1,4], k = 3\n\t\tOutput: [12,10,16,13]\n\t\tExplanation: Each number is replaced by the sum of the next 3 numbers. The decrypted code is [7+1+4, 1+4+5, 4+5+7, 5+7+1]. Notice that the numbers wrap around.\n\t\tExample 2:\n\t\tInput: code = [1,2,3,4], k = 0\n\t\tOutput: [0,0,0,0]\n\t\tExplanation: When k is zero, the numbers are replaced by 0. \n\t\tExample 3:\n\t\tInput: code = [2,4,9,3], k = -2\n\t\tOutput: [12,5,6,13]\n\t\tExplanation: The decrypted code is [3+9, 2+3, 4+2, 9+4]. Notice that the numbers wrap around again. If k is negative, the sum is of the previous numbers.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1756, - "question": "class Solution:\n def minimumDeletions(self, s: str) -> int:\n\t\t\"\"\"\n\t\tYou are given a string s consisting only of characters 'a' and 'b'\u200b\u200b\u200b\u200b.\n\t\tYou can delete any number of characters in s to make s balanced. s is balanced if there is no pair of indices (i,j) such that i < j and s[i] = 'b' and s[j]= 'a'.\n\t\tReturn the minimum number of deletions needed to make s balanced.\n\t\tExample 1:\n\t\tInput: s = \"aababbab\"\n\t\tOutput: 2\n\t\tExplanation: You can either:\n\t\tDelete the characters at 0-indexed positions 2 and 6 (\"aababbab\" -> \"aaabbb\"), or\n\t\tDelete the characters at 0-indexed positions 3 and 6 (\"aababbab\" -> \"aabbbb\").\n\t\tExample 2:\n\t\tInput: s = \"bbaaaaabb\"\n\t\tOutput: 2\n\t\tExplanation: The only solution is to delete the first two characters.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1757, - "question": "class Solution:\n def minimumJumps(self, forbidden: List[int], a: int, b: int, x: int) -> int:\n\t\t\"\"\"\n\t\tA certain bug's home is on the x-axis at position x. Help them get there from position 0.\n\t\tThe bug jumps according to the following rules:\n\t\t\tIt can jump exactly a positions forward (to the right).\n\t\t\tIt can jump exactly b positions backward (to the left).\n\t\t\tIt cannot jump backward twice in a row.\n\t\t\tIt cannot jump to any forbidden positions.\n\t\tThe bug may jump forward beyond its home, but it cannot jump to positions numbered with negative integers.\n\t\tGiven an array of integers forbidden, where forbidden[i] means that the bug cannot jump to the position forbidden[i], and integers a, b, and x, return the minimum number of jumps needed for the bug to reach its home. If there is no possible sequence of jumps that lands the bug on position x, return -1.\n\t\tExample 1:\n\t\tInput: forbidden = [14,4,18,1,15], a = 3, b = 15, x = 9\n\t\tOutput: 3\n\t\tExplanation: 3 jumps forward (0 -> 3 -> 6 -> 9) will get the bug home.\n\t\tExample 2:\n\t\tInput: forbidden = [8,3,16,6,12,20], a = 15, b = 13, x = 11\n\t\tOutput: -1\n\t\tExample 3:\n\t\tInput: forbidden = [1,6,2,14,5,17,4], a = 16, b = 9, x = 7\n\t\tOutput: 2\n\t\tExplanation: One jump forward (0 -> 16) then one jump backward (16 -> 7) will get the bug home.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1758, - "question": "class Solution:\n def canDistribute(self, nums: List[int], quantity: List[int]) -> bool:\n\t\t\"\"\"\n\t\tYou are given an array of n integers, nums, where there are at most 50 unique values in the array. You are also given an array of m customer order quantities, quantity, where quantity[i] is the amount of integers the ith customer ordered. Determine if it is possible to distribute nums such that:\n\t\t\tThe ith customer gets exactly quantity[i] integers,\n\t\t\tThe integers the ith customer gets are all equal, and\n\t\t\tEvery customer is satisfied.\n\t\tReturn true if it is possible to distribute nums according to the above conditions.\n\t\tExample 1:\n\t\tInput: nums = [1,2,3,4], quantity = [2]\n\t\tOutput: false\n\t\tExplanation: The 0th customer cannot be given two different integers.\n\t\tExample 2:\n\t\tInput: nums = [1,2,3,3], quantity = [2]\n\t\tOutput: true\n\t\tExplanation: The 0th customer is given [3,3]. The integers [1,2] are not used.\n\t\tExample 3:\n\t\tInput: nums = [1,1,2,2], quantity = [2,2]\n\t\tOutput: true\n\t\tExplanation: The 0th customer is given [1,1], and the 1st customer is given [2,2].\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1760, - "question": "class Solution:\n def canFormArray(self, arr: List[int], pieces: List[List[int]]) -> bool:\n\t\t\"\"\"\n\t\tYou are given an array of distinct integers arr and an array of integer arrays pieces, where the integers in pieces are distinct. Your goal is to form arr by concatenating the arrays in pieces in any order. However, you are not allowed to reorder the integers in each array pieces[i].\n\t\tReturn true if it is possible to form the array arr from pieces. Otherwise, return false.\n\t\tExample 1:\n\t\tInput: arr = [15,88], pieces = [[88],[15]]\n\t\tOutput: true\n\t\tExplanation: Concatenate [15] then [88]\n\t\tExample 2:\n\t\tInput: arr = [49,18,16], pieces = [[16,18,49]]\n\t\tOutput: false\n\t\tExplanation: Even though the numbers match, we cannot reorder pieces[0].\n\t\tExample 3:\n\t\tInput: arr = [91,4,64,78], pieces = [[78],[4,64],[91]]\n\t\tOutput: true\n\t\tExplanation: Concatenate [91] then [4,64] then [78]\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1761, - "question": "class Solution:\n def countVowelStrings(self, n: int) -> int:\n\t\t\"\"\"\n\t\tGiven an integer n, return the number of strings of length n that consist only of vowels (a, e, i, o, u) and are lexicographically sorted.\n\t\tA string s is lexicographically sorted if for all valid i, s[i] is the same as or comes before s[i+1] in the alphabet.\n\t\tExample 1:\n\t\tInput: n = 1\n\t\tOutput: 5\n\t\tExplanation: The 5 sorted strings that consist of vowels only are [\"a\",\"e\",\"i\",\"o\",\"u\"].\n\t\tExample 2:\n\t\tInput: n = 2\n\t\tOutput: 15\n\t\tExplanation: The 15 sorted strings that consist of vowels only are\n\t\t[\"aa\",\"ae\",\"ai\",\"ao\",\"au\",\"ee\",\"ei\",\"eo\",\"eu\",\"ii\",\"io\",\"iu\",\"oo\",\"ou\",\"uu\"].\n\t\tNote that \"ea\" is not a valid string since 'e' comes after 'a' in the alphabet.\n\t\tExample 3:\n\t\tInput: n = 33\n\t\tOutput: 66045\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1762, - "question": "class Solution:\n def furthestBuilding(self, heights: List[int], bricks: int, ladders: int) -> int:\n\t\t\"\"\"\n\t\tYou are given an integer array heights representing the heights of buildings, some bricks, and some ladders.\n\t\tYou start your journey from building 0 and move to the next building by possibly using bricks or ladders.\n\t\tWhile moving from building i to building i+1 (0-indexed),\n\t\t\tIf the current building's height is greater than or equal to the next building's height, you do not need a ladder or bricks.\n\t\t\tIf the current building's height is less than the next building's height, you can either use one ladder or (h[i+1] - h[i]) bricks.\n\t\tReturn the furthest building index (0-indexed) you can reach if you use the given ladders and bricks optimally.\n\t\tExample 1:\n\t\tInput: heights = [4,2,7,6,9,14,12], bricks = 5, ladders = 1\n\t\tOutput: 4\n\t\tExplanation: Starting at building 0, you can follow these steps:\n\t\t- Go to building 1 without using ladders nor bricks since 4 >= 2.\n\t\t- Go to building 2 using 5 bricks. You must use either bricks or ladders because 2 < 7.\n\t\t- Go to building 3 without using ladders nor bricks since 7 >= 6.\n\t\t- Go to building 4 using your only ladder. You must use either bricks or ladders because 6 < 9.\n\t\tIt is impossible to go beyond building 4 because you do not have any more bricks or ladders.\n\t\tExample 2:\n\t\tInput: heights = [4,12,2,7,3,18,20,3,19], bricks = 10, ladders = 2\n\t\tOutput: 7\n\t\tExample 3:\n\t\tInput: heights = [14,3,19,3], bricks = 17, ladders = 0\n\t\tOutput: 3\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1764, - "question": "class Solution:\n def maxRepeating(self, sequence: str, word: str) -> int:\n\t\t\"\"\"\n\t\tFor a string sequence, a string word is k-repeating if word concatenated k times is a substring of sequence. The word's maximum k-repeating value is the highest value k where word is k-repeating in sequence. If word is not a substring of sequence, word's maximum k-repeating value is 0.\n\t\tGiven strings sequence and word, return the maximum k-repeating value of word in sequence.\n\t\tExample 1:\n\t\tInput: sequence = \"ababc\", word = \"ab\"\n\t\tOutput: 2\n\t\tExplanation: \"abab\" is a substring in \"ababc\".\n\t\tExample 2:\n\t\tInput: sequence = \"ababc\", word = \"ba\"\n\t\tOutput: 1\n\t\tExplanation: \"ba\" is a substring in \"ababc\". \"baba\" is not a substring in \"ababc\".\n\t\tExample 3:\n\t\tInput: sequence = \"ababc\", word = \"ac\"\n\t\tOutput: 0\n\t\tExplanation: \"ac\" is not a substring in \"ababc\". \n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1765, - "question": "class Solution:\n def mergeInBetween(self, list1: ListNode, a: int, b: int, list2: ListNode) -> ListNode:\n\t\t\"\"\"\n\t\tYou are given two linked lists: list1 and list2 of sizes n and m respectively.\n\t\tRemove list1's nodes from the ath node to the bth node, and put list2 in their place.\n\t\tThe blue edges and nodes in the following figure indicate the result:\n\t\tBuild the result list and return its head.\n\t\tExample 1:\n\t\tInput: list1 = [0,1,2,3,4,5], a = 3, b = 4, list2 = [1000000,1000001,1000002]\n\t\tOutput: [0,1,2,1000000,1000001,1000002,5]\n\t\tExplanation: We remove the nodes 3 and 4 and put the entire list2 in their place. The blue edges and nodes in the above figure indicate the result.\n\t\tExample 2:\n\t\tInput: list1 = [0,1,2,3,4,5,6], a = 2, b = 5, list2 = [1000000,1000001,1000002,1000003,1000004]\n\t\tOutput: [0,1,1000000,1000001,1000002,1000003,1000004,6]\n\t\tExplanation: The blue edges and nodes in the above figure indicate the result.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1766, - "question": "class Solution:\n def minimumMountainRemovals(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou may recall that an array arr is a mountain array if and only if:\n\t\t\tarr.length >= 3\n\t\t\tThere exists some index i (0-indexed) with 0 < i < arr.length - 1 such that:\n\t\t\t\tarr[0] < arr[1] < ... < arr[i - 1] < arr[i]\n\t\t\t\tarr[i] > arr[i + 1] > ... > arr[arr.length - 1]\n\t\tGiven an integer array nums\u200b\u200b\u200b, return the minimum number of elements to remove to make nums\u200b\u200b\u200b a mountain array.\n\t\tExample 1:\n\t\tInput: nums = [1,3,1]\n\t\tOutput: 0\n\t\tExplanation: The array itself is a mountain array so we do not need to remove any elements.\n\t\tExample 2:\n\t\tInput: nums = [2,1,1,5,6,2,3,1]\n\t\tOutput: 3\n\t\tExplanation: One solution is to remove the elements at indices 0, 1, and 5, making the array nums = [1,5,6,3,1].\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1767, - "question": "class FrontMiddleBackQueue:\n def __init__(self):\n def pushFront(self, val: int) -> None:\n def pushMiddle(self, val: int) -> None:\n def pushBack(self, val: int) -> None:\n def popFront(self) -> int:\n def popMiddle(self) -> int:\n def popBack(self) -> int:\n\t\t\"\"\"\n\t\tDesign a queue that supports push and pop operations in the front, middle, and back.\n\t\tImplement the FrontMiddleBack class:\n\t\t\tFrontMiddleBack() Initializes the queue.\n\t\t\tvoid pushFront(int val) Adds val to the front of the queue.\n\t\t\tvoid pushMiddle(int val) Adds val to the middle of the queue.\n\t\t\tvoid pushBack(int val) Adds val to the back of the queue.\n\t\t\tint popFront() Removes the front element of the queue and returns it. If the queue is empty, return -1.\n\t\t\tint popMiddle() Removes the middle element of the queue and returns it. If the queue is empty, return -1.\n\t\t\tint popBack() Removes the back element of the queue and returns it. If the queue is empty, return -1.\n\t\tNotice that when there are two middle position choices, the operation is performed on the frontmost middle position choice. For example:\n\t\t\tPushing 6 into the middle of [1, 2, 3, 4, 5] results in [1, 2, 6, 3, 4, 5].\n\t\t\tPopping the middle from [1, 2, 3, 4, 5, 6] returns 3 and results in [1, 2, 4, 5, 6].\n\t\tExample 1:\n\t\tInput:\n\t\t[\"FrontMiddleBackQueue\", \"pushFront\", \"pushBack\", \"pushMiddle\", \"pushMiddle\", \"popFront\", \"popMiddle\", \"popMiddle\", \"popBack\", \"popFront\"]\n\t\t[[], [1], [2], [3], [4], [], [], [], [], []]\n\t\tOutput:\n\t\t[null, null, null, null, null, 1, 3, 4, 2, -1]\n\t\tExplanation:\n\t\tFrontMiddleBackQueue q = new FrontMiddleBackQueue();\n\t\tq.pushFront(1); // [1]\n\t\tq.pushBack(2); // [1, 2]\n\t\tq.pushMiddle(3); // [1, 3, 2]\n\t\tq.pushMiddle(4); // [1, 4, 3, 2]\n\t\tq.popFront(); // return 1 -> [4, 3, 2]\n\t\tq.popMiddle(); // return 3 -> [4, 2]\n\t\tq.popMiddle(); // return 4 -> [2]\n\t\tq.popBack(); // return 2 -> []\n\t\tq.popFront(); // return -1 -> [] (The queue is empty)\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1769, - "question": "class Solution:\n def getMaximumGenerated(self, n: int) -> int:\n\t\t\"\"\"\n\t\tYou are given an integer n. A 0-indexed integer array nums of length n + 1 is generated in the following way:\n\t\t\tnums[0] = 0\n\t\t\tnums[1] = 1\n\t\t\tnums[2 * i] = nums[i] when 2 <= 2 * i <= n\n\t\t\tnums[2 * i + 1] = nums[i] + nums[i + 1] when 2 <= 2 * i + 1 <= n\n\t\tReturn the maximum integer in the array nums\u200b\u200b\u200b.\n\t\tExample 1:\n\t\tInput: n = 7\n\t\tOutput: 3\n\t\tExplanation: According to the given rules:\n\t\t nums[0] = 0\n\t\t nums[1] = 1\n\t\t nums[(1 * 2) = 2] = nums[1] = 1\n\t\t nums[(1 * 2) + 1 = 3] = nums[1] + nums[2] = 1 + 1 = 2\n\t\t nums[(2 * 2) = 4] = nums[2] = 1\n\t\t nums[(2 * 2) + 1 = 5] = nums[2] + nums[3] = 1 + 2 = 3\n\t\t nums[(3 * 2) = 6] = nums[3] = 2\n\t\t nums[(3 * 2) + 1 = 7] = nums[3] + nums[4] = 2 + 1 = 3\n\t\tHence, nums = [0,1,1,2,1,3,2,3], and the maximum is max(0,1,1,2,1,3,2,3) = 3.\n\t\tExample 2:\n\t\tInput: n = 2\n\t\tOutput: 1\n\t\tExplanation: According to the given rules, nums = [0,1,1]. The maximum is max(0,1,1) = 1.\n\t\tExample 3:\n\t\tInput: n = 3\n\t\tOutput: 2\n\t\tExplanation: According to the given rules, nums = [0,1,1,2]. The maximum is max(0,1,1,2) = 2.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1770, - "question": "class Solution:\n def minDeletions(self, s: str) -> int:\n\t\t\"\"\"\n\t\tA string s is called good if there are no two different characters in s that have the same frequency.\n\t\tGiven a string s, return the minimum number of characters you need to delete to make s good.\n\t\tThe frequency of a character in a string is the number of times it appears in the string. For example, in the string \"aab\", the frequency of 'a' is 2, while the frequency of 'b' is 1.\n\t\tExample 1:\n\t\tInput: s = \"aab\"\n\t\tOutput: 0\n\t\tExplanation: s is already good.\n\t\tExample 2:\n\t\tInput: s = \"aaabbbcc\"\n\t\tOutput: 2\n\t\tExplanation: You can delete two 'b's resulting in the good string \"aaabcc\".\n\t\tAnother way it to delete one 'b' and one 'c' resulting in the good string \"aaabbc\".\n\t\tExample 3:\n\t\tInput: s = \"ceabaacb\"\n\t\tOutput: 2\n\t\tExplanation: You can delete both 'c's resulting in the good string \"eabaab\".\n\t\tNote that we only care about characters that are still in the string at the end (i.e. frequency of 0 is ignored).\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1771, - "question": "class Solution:\n def maxProfit(self, inventory: List[int], orders: int) -> int:\n\t\t\"\"\"\n\t\tYou have an inventory of different colored balls, and there is a customer that wants orders balls of any color.\n\t\tThe customer weirdly values the colored balls. Each colored ball's value is the number of balls of that color you currently have in your inventory. For example, if you own 6 yellow balls, the customer would pay 6 for the first yellow ball. After the transaction, there are only 5 yellow balls left, so the next yellow ball is then valued at 5 (i.e., the value of the balls decreases as you sell more to the customer).\n\t\tYou are given an integer array, inventory, where inventory[i] represents the number of balls of the ith color that you initially own. You are also given an integer orders, which represents the total number of balls that the customer wants. You can sell the balls in any order.\n\t\tReturn the maximum total value that you can attain after selling orders colored balls. As the answer may be too large, return it modulo 109 + 7.\n\t\tExample 1:\n\t\tInput: inventory = [2,5], orders = 4\n\t\tOutput: 14\n\t\tExplanation: Sell the 1st color 1 time (2) and the 2nd color 3 times (5 + 4 + 3).\n\t\tThe maximum total value is 2 + 5 + 4 + 3 = 14.\n\t\tExample 2:\n\t\tInput: inventory = [3,5], orders = 6\n\t\tOutput: 19\n\t\tExplanation: Sell the 1st color 2 times (3 + 2) and the 2nd color 4 times (5 + 4 + 3 + 2).\n\t\tThe maximum total value is 3 + 2 + 5 + 4 + 3 + 2 = 19.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1772, - "question": "class Solution:\n def createSortedArray(self, instructions: List[int]) -> int:\n\t\t\"\"\"\n\t\tGiven an integer array instructions, you are asked to create a sorted array from the elements in instructions. You start with an empty container nums. For each element from left to right in instructions, insert it into nums. The cost of each insertion is the minimum of the following:\r\n\t\t\tThe number of elements currently in nums that are strictly less than instructions[i].\r\n\t\t\tThe number of elements currently in nums that are strictly greater than instructions[i].\r\n\t\tFor example, if inserting element 3 into nums = [1,2,3,5], the cost of insertion is min(2, 1) (elements 1 and 2 are less than 3, element 5 is greater than 3) and nums will become [1,2,3,3,5].\r\n\t\tReturn the total cost to insert all elements from instructions into nums. Since the answer may be large, return it modulo 109 + 7\r\n\t\tExample 1:\r\n\t\tInput: instructions = [1,5,6,2]\r\n\t\tOutput: 1\r\n\t\tExplanation: Begin with nums = [].\r\n\t\tInsert 1 with cost min(0, 0) = 0, now nums = [1].\r\n\t\tInsert 5 with cost min(1, 0) = 0, now nums = [1,5].\r\n\t\tInsert 6 with cost min(2, 0) = 0, now nums = [1,5,6].\r\n\t\tInsert 2 with cost min(1, 2) = 1, now nums = [1,2,5,6].\r\n\t\tThe total cost is 0 + 0 + 0 + 1 = 1.\r\n\t\tExample 2:\r\n\t\tInput: instructions = [1,2,3,6,5,4]\r\n\t\tOutput: 3\r\n\t\tExplanation: Begin with nums = [].\r\n\t\tInsert 1 with cost min(0, 0) = 0, now nums = [1].\r\n\t\tInsert 2 with cost min(1, 0) = 0, now nums = [1,2].\r\n\t\tInsert 3 with cost min(2, 0) = 0, now nums = [1,2,3].\r\n\t\tInsert 6 with cost min(3, 0) = 0, now nums = [1,2,3,6].\r\n\t\tInsert 5 with cost min(3, 1) = 1, now nums = [1,2,3,5,6].\r\n\t\tInsert 4 with cost min(3, 2) = 2, now nums = [1,2,3,4,5,6].\r\n\t\tThe total cost is 0 + 0 + 0 + 0 + 1 + 2 = 3.\r\n\t\tExample 3:\r\n\t\tInput: instructions = [1,3,3,3,2,4,2,1,2]\r\n\t\tOutput: 4\r\n\t\tExplanation: Begin with nums = [].\r\n\t\tInsert 1 with cost min(0, 0) = 0, now nums = [1].\r\n\t\tInsert 3 with cost min(1, 0) = 0, now nums = [1,3].\r\n\t\tInsert 3 with cost min(1, 0) = 0, now nums = [1,3,3].\r\n\t\tInsert 3 with cost min(1, 0) = 0, now nums = [1,3,3,3].\r\n\t\tInsert 2 with cost min(1, 3) = 1, now nums = [1,2,3,3,3].\r\n\t\tInsert 4 with cost min(5, 0) = 0, now nums = [1,2,3,3,3,4].\r\n\t\t\u200b\u200b\u200b\u200b\u200b\u200b\u200bInsert 2 with cost min(1, 4) = 1, now nums = [1,2,2,3,3,3,4].\r\n\t\t\u200b\u200b\u200b\u200b\u200b\u200b\u200bInsert 1 with cost min(0, 6) = 0, now nums = [1,1,2,2,3,3,3,4].\r\n\t\t\u200b\u200b\u200b\u200b\u200b\u200b\u200bInsert 2 with cost min(2, 4) = 2, now nums = [1,1,2,2,2,3,3,3,4].\r\n\t\tThe total cost is 0 + 0 + 0 + 0 + 1 + 0 + 1 + 0 + 2 = 4.\r\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1775, - "question": "class OrderedStream:\n def __init__(self, n: int):\n def insert(self, idKey: int, value: str) -> List[str]:\n\t\t\"\"\"\n\t\tThere is a stream of n (idKey, value) pairs arriving in an arbitrary order, where idKey is an integer between 1 and n and value is a string. No two pairs have the same id.\n\t\tDesign a stream that returns the values in increasing order of their IDs by returning a chunk (list) of values after each insertion. The concatenation of all the chunks should result in a list of the sorted values.\n\t\tImplement the OrderedStream class:\n\t\t\tOrderedStream(int n) Constructs the stream to take n values.\n\t\t\tString[] insert(int idKey, String value) Inserts the pair (idKey, value) into the stream, then returns the largest possible chunk of currently inserted values that appear next in the order.\n\t\tExample:\n\t\tInput\n\t\t[\"OrderedStream\", \"insert\", \"insert\", \"insert\", \"insert\", \"insert\"]\n\t\t[[5], [3, \"ccccc\"], [1, \"aaaaa\"], [2, \"bbbbb\"], [5, \"eeeee\"], [4, \"ddddd\"]]\n\t\tOutput\n\t\t[null, [], [\"aaaaa\"], [\"bbbbb\", \"ccccc\"], [], [\"ddddd\", \"eeeee\"]]\n\t\tExplanation\n\t\t// Note that the values ordered by ID is [\"aaaaa\", \"bbbbb\", \"ccccc\", \"ddddd\", \"eeeee\"].\n\t\tOrderedStream os = new OrderedStream(5);\n\t\tos.insert(3, \"ccccc\"); // Inserts (3, \"ccccc\"), returns [].\n\t\tos.insert(1, \"aaaaa\"); // Inserts (1, \"aaaaa\"), returns [\"aaaaa\"].\n\t\tos.insert(2, \"bbbbb\"); // Inserts (2, \"bbbbb\"), returns [\"bbbbb\", \"ccccc\"].\n\t\tos.insert(5, \"eeeee\"); // Inserts (5, \"eeeee\"), returns [].\n\t\tos.insert(4, \"ddddd\"); // Inserts (4, \"ddddd\"), returns [\"ddddd\", \"eeeee\"].\n\t\t// Concatentating all the chunks returned:\n\t\t// [] + [\"aaaaa\"] + [\"bbbbb\", \"ccccc\"] + [] + [\"ddddd\", \"eeeee\"] = [\"aaaaa\", \"bbbbb\", \"ccccc\", \"ddddd\", \"eeeee\"]\n\t\t// The resulting order is the same as the order above.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1776, - "question": "class Solution:\n def minOperations(self, nums: List[int], x: int) -> int:\n\t\t\"\"\"\n\t\tYou are given an integer array nums and an integer x. In one operation, you can either remove the leftmost or the rightmost element from the array nums and subtract its value from x. Note that this modifies the array for future operations.\n\t\tReturn the minimum number of operations to reduce x to exactly 0 if it is possible, otherwise, return -1.\n\t\tExample 1:\n\t\tInput: nums = [1,1,4,2,3], x = 5\n\t\tOutput: 2\n\t\tExplanation: The optimal solution is to remove the last two elements to reduce x to zero.\n\t\tExample 2:\n\t\tInput: nums = [5,6,7,8,9], x = 4\n\t\tOutput: -1\n\t\tExample 3:\n\t\tInput: nums = [3,2,20,1,1,3], x = 10\n\t\tOutput: 5\n\t\tExplanation: The optimal solution is to remove the last three elements and the first two elements (5 operations in total) to reduce x to zero.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1777, - "question": "class Solution:\n def closeStrings(self, word1: str, word2: str) -> bool:\n\t\t\"\"\"\n\t\tTwo strings are considered close if you can attain one from the other using the following operations:\n\t\t\tOperation 1: Swap any two existing characters.\n\t\t\t\tFor example, abcde -> aecdb\n\t\t\tOperation 2: Transform every occurrence of one existing character into another existing character, and do the same with the other character.\n\t\t\t\tFor example, aacabb -> bbcbaa (all a's turn into b's, and all b's turn into a's)\n\t\tYou can use the operations on either string as many times as necessary.\n\t\tGiven two strings, word1 and word2, return true if word1 and word2 are close, and false otherwise.\n\t\tExample 1:\n\t\tInput: word1 = \"abc\", word2 = \"bca\"\n\t\tOutput: true\n\t\tExplanation: You can attain word2 from word1 in 2 operations.\n\t\tApply Operation 1: \"abc\" -> \"acb\"\n\t\tApply Operation 1: \"acb\" -> \"bca\"\n\t\tExample 2:\n\t\tInput: word1 = \"a\", word2 = \"aa\"\n\t\tOutput: false\n\t\tExplanation: It is impossible to attain word2 from word1, or vice versa, in any number of operations.\n\t\tExample 3:\n\t\tInput: word1 = \"cabbba\", word2 = \"abbccc\"\n\t\tOutput: true\n\t\tExplanation: You can attain word2 from word1 in 3 operations.\n\t\tApply Operation 1: \"cabbba\" -> \"caabbb\"\n\t\tApply Operation 2: \"caabbb\" -> \"baaccc\"\n\t\tApply Operation 2: \"baaccc\" -> \"abbccc\"\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1778, - "question": "class Solution:\n def getMaxGridHappiness(self, m: int, n: int, introvertsCount: int, extrovertsCount: int) -> int:\n\t\t\"\"\"\n\t\tYou are given four integers, m, n, introvertsCount, and extrovertsCount. You have an m x n grid, and there are two types of people: introverts and extroverts. There are introvertsCount introverts and extrovertsCount extroverts.\n\t\tYou should decide how many people you want to live in the grid and assign each of them one grid cell. Note that you do not have to have all the people living in the grid.\n\t\tThe happiness of each person is calculated as follows:\n\t\t\tIntroverts start with 120 happiness and lose 30 happiness for each neighbor (introvert or extrovert).\n\t\t\tExtroverts start with 40 happiness and gain 20 happiness for each neighbor (introvert or extrovert).\n\t\tNeighbors live in the directly adjacent cells north, east, south, and west of a person's cell.\n\t\tThe grid happiness is the sum of each person's happiness. Return the maximum possible grid happiness.\n\t\tExample 1:\n\t\tInput: m = 2, n = 3, introvertsCount = 1, extrovertsCount = 2\n\t\tOutput: 240\n\t\tExplanation: Assume the grid is 1-indexed with coordinates (row, column).\n\t\tWe can put the introvert in cell (1,1) and put the extroverts in cells (1,3) and (2,3).\n\t\t- Introvert at (1,1) happiness: 120 (starting happiness) - (0 * 30) (0 neighbors) = 120\n\t\t- Extrovert at (1,3) happiness: 40 (starting happiness) + (1 * 20) (1 neighbor) = 60\n\t\t- Extrovert at (2,3) happiness: 40 (starting happiness) + (1 * 20) (1 neighbor) = 60\n\t\tThe grid happiness is 120 + 60 + 60 = 240.\n\t\tThe above figure shows the grid in this example with each person's happiness. The introvert stays in the light green cell while the extroverts live on the light purple cells.\n\t\tExample 2:\n\t\tInput: m = 3, n = 1, introvertsCount = 2, extrovertsCount = 1\n\t\tOutput: 260\n\t\tExplanation: Place the two introverts in (1,1) and (3,1) and the extrovert at (2,1).\n\t\t- Introvert at (1,1) happiness: 120 (starting happiness) - (1 * 30) (1 neighbor) = 90\n\t\t- Extrovert at (2,1) happiness: 40 (starting happiness) + (2 * 20) (2 neighbors) = 80\n\t\t- Introvert at (3,1) happiness: 120 (starting happiness) - (1 * 30) (1 neighbor) = 90\n\t\tThe grid happiness is 90 + 80 + 90 = 260.\n\t\tExample 3:\n\t\tInput: m = 2, n = 2, introvertsCount = 4, extrovertsCount = 0\n\t\tOutput: 240\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1781, - "question": "class Solution:\n def arrayStringsAreEqual(self, word1: List[str], word2: List[str]) -> bool:\n\t\t\"\"\"\n\t\tGiven two string arrays word1 and word2, return true if the two arrays represent the same string, and false otherwise.\n\t\tA string is represented by an array if the array elements concatenated in order forms the string.\n\t\tExample 1:\n\t\tInput: word1 = [\"ab\", \"c\"], word2 = [\"a\", \"bc\"]\n\t\tOutput: true\n\t\tExplanation:\n\t\tword1 represents string \"ab\" + \"c\" -> \"abc\"\n\t\tword2 represents string \"a\" + \"bc\" -> \"abc\"\n\t\tThe strings are the same, so return true.\n\t\tExample 2:\n\t\tInput: word1 = [\"a\", \"cb\"], word2 = [\"ab\", \"c\"]\n\t\tOutput: false\n\t\tExample 3:\n\t\tInput: word1 = [\"abc\", \"d\", \"defg\"], word2 = [\"abcddefg\"]\n\t\tOutput: true\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1782, - "question": "class Solution:\n def getSmallestString(self, n: int, k: int) -> str:\n\t\t\"\"\"\n\t\tThe numeric value of a lowercase character is defined as its position (1-indexed) in the alphabet, so the numeric value of a is 1, the numeric value of b is 2, the numeric value of c is 3, and so on.\n\t\tThe numeric value of a string consisting of lowercase characters is defined as the sum of its characters' numeric values. For example, the numeric value of the string \"abe\" is equal to 1 + 2 + 5 = 8.\n\t\tYou are given two integers n and k. Return the lexicographically smallest string with length equal to n and numeric value equal to k.\n\t\tNote that a string x is lexicographically smaller than string y if x comes before y in dictionary order, that is, either x is a prefix of y, or if i is the first position such that x[i] != y[i], then x[i] comes before y[i] in alphabetic order.\n\t\tExample 1:\n\t\tInput: n = 3, k = 27\n\t\tOutput: \"aay\"\n\t\tExplanation: The numeric value of the string is 1 + 1 + 25 = 27, and it is the smallest string with such a value and length equal to 3.\n\t\tExample 2:\n\t\tInput: n = 5, k = 73\n\t\tOutput: \"aaszz\"\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1783, - "question": "class Solution:\n def waysToMakeFair(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou are given an integer array nums. You can choose exactly one index (0-indexed) and remove the element. Notice that the index of the elements may change after the removal.\n\t\tFor example, if nums = [6,1,7,4,1]:\n\t\t\tChoosing to remove index 1 results in nums = [6,7,4,1].\n\t\t\tChoosing to remove index 2 results in nums = [6,1,4,1].\n\t\t\tChoosing to remove index 4 results in nums = [6,1,7,4].\n\t\tAn array is fair if the sum of the odd-indexed values equals the sum of the even-indexed values.\n\t\tReturn the number of indices that you could choose such that after the removal, nums is fair. \n\t\tExample 1:\n\t\tInput: nums = [2,1,6,4]\n\t\tOutput: 1\n\t\tExplanation:\n\t\tRemove index 0: [1,6,4] -> Even sum: 1 + 4 = 5. Odd sum: 6. Not fair.\n\t\tRemove index 1: [2,6,4] -> Even sum: 2 + 4 = 6. Odd sum: 6. Fair.\n\t\tRemove index 2: [2,1,4] -> Even sum: 2 + 4 = 6. Odd sum: 1. Not fair.\n\t\tRemove index 3: [2,1,6] -> Even sum: 2 + 6 = 8. Odd sum: 1. Not fair.\n\t\tThere is 1 index that you can remove to make nums fair.\n\t\tExample 2:\n\t\tInput: nums = [1,1,1]\n\t\tOutput: 3\n\t\tExplanation: You can remove any index and the remaining array is fair.\n\t\tExample 3:\n\t\tInput: nums = [1,2,3]\n\t\tOutput: 0\n\t\tExplanation: You cannot make a fair array after removing any index.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1784, - "question": "class Solution:\n def minimumEffort(self, tasks: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tYou are given an array tasks where tasks[i] = [actuali, minimumi]:\n\t\t\tactuali is the actual amount of energy you spend to finish the ith task.\n\t\t\tminimumi is the minimum amount of energy you require to begin the ith task.\n\t\tFor example, if the task is [10, 12] and your current energy is 11, you cannot start this task. However, if your current energy is 13, you can complete this task, and your energy will be 3 after finishing it.\n\t\tYou can finish the tasks in any order you like.\n\t\tReturn the minimum initial amount of energy you will need to finish all the tasks.\n\t\tExample 1:\n\t\tInput: tasks = [[1,2],[2,4],[4,8]]\n\t\tOutput: 8\n\t\tExplanation:\n\t\tStarting with 8 energy, we finish the tasks in the following order:\n\t\t - 3rd task. Now energy = 8 - 4 = 4.\n\t\t - 2nd task. Now energy = 4 - 2 = 2.\n\t\t - 1st task. Now energy = 2 - 1 = 1.\n\t\tNotice that even though we have leftover energy, starting with 7 energy does not work because we cannot do the 3rd task.\n\t\tExample 2:\n\t\tInput: tasks = [[1,3],[2,4],[10,11],[10,12],[8,9]]\n\t\tOutput: 32\n\t\tExplanation:\n\t\tStarting with 32 energy, we finish the tasks in the following order:\n\t\t - 1st task. Now energy = 32 - 1 = 31.\n\t\t - 2nd task. Now energy = 31 - 2 = 29.\n\t\t - 3rd task. Now energy = 29 - 10 = 19.\n\t\t - 4th task. Now energy = 19 - 10 = 9.\n\t\t - 5th task. Now energy = 9 - 8 = 1.\n\t\tExample 3:\n\t\tInput: tasks = [[1,7],[2,8],[3,9],[4,10],[5,11],[6,12]]\n\t\tOutput: 27\n\t\tExplanation:\n\t\tStarting with 27 energy, we finish the tasks in the following order:\n\t\t - 5th task. Now energy = 27 - 5 = 22.\n\t\t - 2nd task. Now energy = 22 - 2 = 20.\n\t\t - 3rd task. Now energy = 20 - 3 = 17.\n\t\t - 1st task. Now energy = 17 - 1 = 16.\n\t\t - 4th task. Now energy = 16 - 4 = 12.\n\t\t - 6th task. Now energy = 12 - 6 = 6.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1786, - "question": "class Solution:\n def countConsistentStrings(self, allowed: str, words: List[str]) -> int:\n\t\t\"\"\"\n\t\tYou are given a string allowed consisting of distinct characters and an array of strings words. A string is consistent if all characters in the string appear in the string allowed.\n\t\tReturn the number of consistent strings in the array words.\n\t\tExample 1:\n\t\tInput: allowed = \"ab\", words = [\"ad\",\"bd\",\"aaab\",\"baa\",\"badab\"]\n\t\tOutput: 2\n\t\tExplanation: Strings \"aaab\" and \"baa\" are consistent since they only contain characters 'a' and 'b'.\n\t\tExample 2:\n\t\tInput: allowed = \"abc\", words = [\"a\",\"b\",\"c\",\"ab\",\"ac\",\"bc\",\"abc\"]\n\t\tOutput: 7\n\t\tExplanation: All strings are consistent.\n\t\tExample 3:\n\t\tInput: allowed = \"cad\", words = [\"cc\",\"acd\",\"b\",\"ba\",\"bac\",\"bad\",\"ac\",\"d\"]\n\t\tOutput: 4\n\t\tExplanation: Strings \"cc\", \"acd\", \"ac\", and \"d\" are consistent.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1787, - "question": "class Solution:\n def getSumAbsoluteDifferences(self, nums: List[int]) -> List[int]:\n\t\t\"\"\"\n\t\tYou are given an integer array nums sorted in non-decreasing order.\n\t\tBuild and return an integer array result with the same length as nums such that result[i] is equal to the summation of absolute differences between nums[i] and all the other elements in the array.\n\t\tIn other words, result[i] is equal to sum(|nums[i]-nums[j]|) where 0 <= j < nums.length and j != i (0-indexed).\n\t\tExample 1:\n\t\tInput: nums = [2,3,5]\n\t\tOutput: [4,3,5]\n\t\tExplanation: Assuming the arrays are 0-indexed, then\n\t\tresult[0] = |2-2| + |2-3| + |2-5| = 0 + 1 + 3 = 4,\n\t\tresult[1] = |3-2| + |3-3| + |3-5| = 1 + 0 + 2 = 3,\n\t\tresult[2] = |5-2| + |5-3| + |5-5| = 3 + 2 + 0 = 5.\n\t\tExample 2:\n\t\tInput: nums = [1,4,6,8,10]\n\t\tOutput: [24,15,13,15,21]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1788, - "question": "class Solution:\n def stoneGameVI(self, aliceValues: List[int], bobValues: List[int]) -> int:\n\t\t\"\"\"\n\t\tAlice and Bob take turns playing a game, with Alice starting first.\n\t\tThere are n stones in a pile. On each player's turn, they can remove a stone from the pile and receive points based on the stone's value. Alice and Bob may value the stones differently.\n\t\tYou are given two integer arrays of length n, aliceValues and bobValues. Each aliceValues[i] and bobValues[i] represents how Alice and Bob, respectively, value the ith stone.\n\t\tThe winner is the person with the most points after all the stones are chosen. If both players have the same amount of points, the game results in a draw. Both players will play optimally. Both players know the other's values.\n\t\tDetermine the result of the game, and:\n\t\t\tIf Alice wins, return 1.\n\t\t\tIf Bob wins, return -1.\n\t\t\tIf the game results in a draw, return 0.\n\t\tExample 1:\n\t\tInput: aliceValues = [1,3], bobValues = [2,1]\n\t\tOutput: 1\n\t\tExplanation:\n\t\tIf Alice takes stone 1 (0-indexed) first, Alice will receive 3 points.\n\t\tBob can only choose stone 0, and will only receive 2 points.\n\t\tAlice wins.\n\t\tExample 2:\n\t\tInput: aliceValues = [1,2], bobValues = [3,1]\n\t\tOutput: 0\n\t\tExplanation:\n\t\tIf Alice takes stone 0, and Bob takes stone 1, they will both have 1 point.\n\t\tDraw.\n\t\tExample 3:\n\t\tInput: aliceValues = [2,4,3], bobValues = [1,6,7]\n\t\tOutput: -1\n\t\tExplanation:\n\t\tRegardless of how Alice plays, Bob will be able to have more points than Alice.\n\t\tFor example, if Alice takes stone 1, Bob can take stone 2, and Alice takes stone 0, Alice will have 6 points to Bob's 7.\n\t\tBob wins.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1789, - "question": "class Solution:\n def boxDelivering(self, boxes: List[List[int]], portsCount: int, maxBoxes: int, maxWeight: int) -> int:\n\t\t\"\"\"\n\t\tYou have the task of delivering some boxes from storage to their ports using only one ship. However, this ship has a limit on the number of boxes and the total weight that it can carry.\n\t\tYou are given an array boxes, where boxes[i] = [ports\u200b\u200bi\u200b, weighti], and three integers portsCount, maxBoxes, and maxWeight.\n\t\t\tports\u200b\u200bi is the port where you need to deliver the ith box and weightsi is the weight of the ith box.\n\t\t\tportsCount is the number of ports.\n\t\t\tmaxBoxes and maxWeight are the respective box and weight limits of the ship.\n\t\tThe boxes need to be delivered in the order they are given. The ship will follow these steps:\n\t\t\tThe ship will take some number of boxes from the boxes queue, not violating the maxBoxes and maxWeight constraints.\n\t\t\tFor each loaded box in order, the ship will make a trip to the port the box needs to be delivered to and deliver it. If the ship is already at the correct port, no trip is needed, and the box can immediately be delivered.\n\t\t\tThe ship then makes a return trip to storage to take more boxes from the queue.\n\t\tThe ship must end at storage after all the boxes have been delivered.\n\t\tReturn the minimum number of trips the ship needs to make to deliver all boxes to their respective ports.\n\t\tExample 1:\n\t\tInput: boxes = [[1,1],[2,1],[1,1]], portsCount = 2, maxBoxes = 3, maxWeight = 3\n\t\tOutput: 4\n\t\tExplanation: The optimal strategy is as follows: \n\t\t- The ship takes all the boxes in the queue, goes to port 1, then port 2, then port 1 again, then returns to storage. 4 trips.\n\t\tSo the total number of trips is 4.\n\t\tNote that the first and third boxes cannot be delivered together because the boxes need to be delivered in order (i.e. the second box needs to be delivered at port 2 before the third box).\n\t\tExample 2:\n\t\tInput: boxes = [[1,2],[3,3],[3,1],[3,1],[2,4]], portsCount = 3, maxBoxes = 3, maxWeight = 6\n\t\tOutput: 6\n\t\tExplanation: The optimal strategy is as follows: \n\t\t- The ship takes the first box, goes to port 1, then returns to storage. 2 trips.\n\t\t- The ship takes the second, third and fourth boxes, goes to port 3, then returns to storage. 2 trips.\n\t\t- The ship takes the fifth box, goes to port 2, then returns to storage. 2 trips.\n\t\tSo the total number of trips is 2 + 2 + 2 = 6.\n\t\tExample 3:\n\t\tInput: boxes = [[1,4],[1,2],[2,1],[2,1],[3,2],[3,4]], portsCount = 3, maxBoxes = 6, maxWeight = 7\n\t\tOutput: 6\n\t\tExplanation: The optimal strategy is as follows:\n\t\t- The ship takes the first and second boxes, goes to port 1, then returns to storage. 2 trips.\n\t\t- The ship takes the third and fourth boxes, goes to port 2, then returns to storage. 2 trips.\n\t\t- The ship takes the fifth and sixth boxes, goes to port 3, then returns to storage. 2 trips.\n\t\tSo the total number of trips is 2 + 2 + 2 = 6.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1791, - "question": "class Solution:\n def maximumWealth(self, accounts: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tYou are given an m x n integer grid accounts where accounts[i][j] is the amount of money the i\u200b\u200b\u200b\u200b\u200b\u200b\u200b\u200b\u200b\u200b\u200bth\u200b\u200b\u200b\u200b customer has in the j\u200b\u200b\u200b\u200b\u200b\u200b\u200b\u200b\u200b\u200b\u200bth\u200b\u200b\u200b\u200b bank. Return the wealth that the richest customer has.\n\t\tA customer's wealth is the amount of money they have in all their bank accounts. The richest customer is the customer that has the maximum wealth.\n\t\tExample 1:\n\t\tInput: accounts = [[1,2,3],[3,2,1]]\n\t\tOutput: 6\n\t\tExplanation:\n\t\t1st customer has wealth = 1 + 2 + 3 = 6\n\t\t2nd customer has wealth = 3 + 2 + 1 = 6\n\t\tBoth customers are considered the richest with a wealth of 6 each, so return 6.\n\t\tExample 2:\n\t\tInput: accounts = [[1,5],[7,3],[3,5]]\n\t\tOutput: 10\n\t\tExplanation: \n\t\t1st customer has wealth = 6\n\t\t2nd customer has wealth = 10 \n\t\t3rd customer has wealth = 8\n\t\tThe 2nd customer is the richest with a wealth of 10.\n\t\tExample 3:\n\t\tInput: accounts = [[2,8,7],[7,1,3],[1,9,5]]\n\t\tOutput: 17\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1792, - "question": "class Solution:\n def mostCompetitive(self, nums: List[int], k: int) -> List[int]:\n\t\t\"\"\"\n\t\tGiven an integer array nums and a positive integer k, return the most competitive subsequence of nums of size k.\n\t\tAn array's subsequence is a resulting sequence obtained by erasing some (possibly zero) elements from the array.\n\t\tWe define that a subsequence a is more competitive than a subsequence b (of the same length) if in the first position where a and b differ, subsequence a has a number less than the corresponding number in b. For example, [1,3,4] is more competitive than [1,3,5] because the first position they differ is at the final number, and 4 is less than 5.\n\t\tExample 1:\n\t\tInput: nums = [3,5,2,6], k = 2\n\t\tOutput: [2,6]\n\t\tExplanation: Among the set of every possible subsequence: {[3,5], [3,2], [3,6], [5,2], [5,6], [2,6]}, [2,6] is the most competitive.\n\t\tExample 2:\n\t\tInput: nums = [2,4,3,3,5,4,9,6], k = 4\n\t\tOutput: [2,3,3,4]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1793, - "question": "class Solution:\n def minMoves(self, nums: List[int], limit: int) -> int:\n\t\t\"\"\"\n\t\tYou are given an integer array nums of even length n and an integer limit. In one move, you can replace any integer from nums with another integer between 1 and limit, inclusive.\n\t\tThe array nums is complementary if for all indices i (0-indexed), nums[i] + nums[n - 1 - i] equals the same number. For example, the array [1,2,3,4] is complementary because for all indices i, nums[i] + nums[n - 1 - i] = 5.\n\t\tReturn the minimum number of moves required to make nums complementary.\n\t\tExample 1:\n\t\tInput: nums = [1,2,4,3], limit = 4\n\t\tOutput: 1\n\t\tExplanation: In 1 move, you can change nums to [1,2,2,3] (underlined elements are changed).\n\t\tnums[0] + nums[3] = 1 + 3 = 4.\n\t\tnums[1] + nums[2] = 2 + 2 = 4.\n\t\tnums[2] + nums[1] = 2 + 2 = 4.\n\t\tnums[3] + nums[0] = 3 + 1 = 4.\n\t\tTherefore, nums[i] + nums[n-1-i] = 4 for every i, so nums is complementary.\n\t\tExample 2:\n\t\tInput: nums = [1,2,2,1], limit = 2\n\t\tOutput: 2\n\t\tExplanation: In 2 moves, you can change nums to [2,2,2,2]. You cannot change any number to 3 since 3 > limit.\n\t\tExample 3:\n\t\tInput: nums = [1,2,1,2], limit = 2\n\t\tOutput: 0\n\t\tExplanation: nums is already complementary.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1794, - "question": "class Solution:\n def minimumDeviation(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou are given an array nums of n positive integers.\n\t\tYou can perform two types of operations on any element of the array any number of times:\n\t\t\tIf the element is even, divide it by 2.\n\t\t\t\tFor example, if the array is [1,2,3,4], then you can do this operation on the last element, and the array will be [1,2,3,2].\n\t\t\tIf the element is odd, multiply it by 2.\n\t\t\t\tFor example, if the array is [1,2,3,4], then you can do this operation on the first element, and the array will be [2,2,3,4].\n\t\tThe deviation of the array is the maximum difference between any two elements in the array.\n\t\tReturn the minimum deviation the array can have after performing some number of operations.\n\t\tExample 1:\n\t\tInput: nums = [1,2,3,4]\n\t\tOutput: 1\n\t\tExplanation: You can transform the array to [1,2,3,2], then to [2,2,3,2], then the deviation will be 3 - 2 = 1.\n\t\tExample 2:\n\t\tInput: nums = [4,1,5,20,3]\n\t\tOutput: 3\n\t\tExplanation: You can transform the array after two operations to [4,2,5,5,3], then the deviation will be 5 - 2 = 3.\n\t\tExample 3:\n\t\tInput: nums = [2,10,8]\n\t\tOutput: 3\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1797, - "question": "class Solution:\n def interpret(self, command: str) -> str:\n\t\t\"\"\"\n\t\tYou own a Goal Parser that can interpret a string command. The command consists of an alphabet of \"G\", \"()\" and/or \"(al)\" in some order. The Goal Parser will interpret \"G\" as the string \"G\", \"()\" as the string \"o\", and \"(al)\" as the string \"al\". The interpreted strings are then concatenated in the original order.\n\t\tGiven the string command, return the Goal Parser's interpretation of command.\n\t\tExample 1:\n\t\tInput: command = \"G()(al)\"\n\t\tOutput: \"Goal\"\n\t\tExplanation: The Goal Parser interprets the command as follows:\n\t\tG -> G\n\t\t() -> o\n\t\t(al) -> al\n\t\tThe final concatenated result is \"Goal\".\n\t\tExample 2:\n\t\tInput: command = \"G()()()()(al)\"\n\t\tOutput: \"Gooooal\"\n\t\tExample 3:\n\t\tInput: command = \"(al)G(al)()()G\"\n\t\tOutput: \"alGalooG\"\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1798, - "question": "class Solution:\n def maxOperations(self, nums: List[int], k: int) -> int:\n\t\t\"\"\"\n\t\tYou are given an integer array nums and an integer k.\n\t\tIn one operation, you can pick two numbers from the array whose sum equals k and remove them from the array.\n\t\tReturn the maximum number of operations you can perform on the array.\n\t\tExample 1:\n\t\tInput: nums = [1,2,3,4], k = 5\n\t\tOutput: 2\n\t\tExplanation: Starting with nums = [1,2,3,4]:\n\t\t- Remove numbers 1 and 4, then nums = [2,3]\n\t\t- Remove numbers 2 and 3, then nums = []\n\t\tThere are no more pairs that sum up to 5, hence a total of 2 operations.\n\t\tExample 2:\n\t\tInput: nums = [3,1,3,4,3], k = 6\n\t\tOutput: 1\n\t\tExplanation: Starting with nums = [3,1,3,4,3]:\n\t\t- Remove the first two 3's, then nums = [1,4,3]\n\t\tThere are no more pairs that sum up to 6, hence a total of 1 operation.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1799, - "question": "class Solution:\n def minimumIncompatibility(self, nums: List[int], k: int) -> int:\n\t\t\"\"\"\n\t\tYou are given an integer array nums\u200b\u200b\u200b and an integer k. You are asked to distribute this array into k subsets of equal size such that there are no two equal elements in the same subset.\n\t\tA subset's incompatibility is the difference between the maximum and minimum elements in that array.\n\t\tReturn the minimum possible sum of incompatibilities of the k subsets after distributing the array optimally, or return -1 if it is not possible.\n\t\tA subset is a group integers that appear in the array with no particular order.\n\t\tExample 1:\n\t\tInput: nums = [1,2,1,4], k = 2\n\t\tOutput: 4\n\t\tExplanation: The optimal distribution of subsets is [1,2] and [1,4].\n\t\tThe incompatibility is (2-1) + (4-1) = 4.\n\t\tNote that [1,1] and [2,4] would result in a smaller sum, but the first subset contains 2 equal elements.\n\t\tExample 2:\n\t\tInput: nums = [6,3,8,1,3,1,2,2], k = 4\n\t\tOutput: 6\n\t\tExplanation: The optimal distribution of subsets is [1,2], [2,3], [6,8], and [1,3].\n\t\tThe incompatibility is (2-1) + (3-2) + (8-6) + (3-1) = 6.\n\t\tExample 3:\n\t\tInput: nums = [5,3,3,6,3,3], k = 3\n\t\tOutput: -1\n\t\tExplanation: It is impossible to distribute nums into 3 subsets where no two elements are equal in the same subset.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1800, - "question": "class Solution:\n def concatenatedBinary(self, n: int) -> int:\n\t\t\"\"\"\n\t\tGiven an integer n, return the decimal value of the binary string formed by concatenating the binary representations of 1 to n in order, modulo 109 + 7.\n\t\tExample 1:\n\t\tInput: n = 1\n\t\tOutput: 1\n\t\tExplanation: \"1\" in binary corresponds to the decimal value 1. \n\t\tExample 2:\n\t\tInput: n = 3\n\t\tOutput: 27\n\t\tExplanation: In binary, 1, 2, and 3 corresponds to \"1\", \"10\", and \"11\".\n\t\tAfter concatenating them, we have \"11011\", which corresponds to the decimal value 27.\n\t\tExample 3:\n\t\tInput: n = 12\n\t\tOutput: 505379714\n\t\tExplanation: The concatenation results in \"1101110010111011110001001101010111100\".\n\t\tThe decimal value of that is 118505380540.\n\t\tAfter modulo 109 + 7, the result is 505379714.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1802, - "question": "class Solution:\n def countStudents(self, students: List[int], sandwiches: List[int]) -> int:\n\t\t\"\"\"\n\t\tThe school cafeteria offers circular and square sandwiches at lunch break, referred to by numbers 0 and 1 respectively. All students stand in a queue. Each student either prefers square or circular sandwiches.\n\t\tThe number of sandwiches in the cafeteria is equal to the number of students. The sandwiches are placed in a stack. At each step:\n\t\t\tIf the student at the front of the queue prefers the sandwich on the top of the stack, they will take it and leave the queue.\n\t\t\tOtherwise, they will leave it and go to the queue's end.\n\t\tThis continues until none of the queue students want to take the top sandwich and are thus unable to eat.\n\t\tYou are given two integer arrays students and sandwiches where sandwiches[i] is the type of the i\u200b\u200b\u200b\u200b\u200b\u200bth sandwich in the stack (i = 0 is the top of the stack) and students[j] is the preference of the j\u200b\u200b\u200b\u200b\u200b\u200bth student in the initial queue (j = 0 is the front of the queue). Return the number of students that are unable to eat.\n\t\tExample 1:\n\t\tInput: students = [1,1,0,0], sandwiches = [0,1,0,1]\n\t\tOutput: 0 \n\t\tExplanation:\n\t\t- Front student leaves the top sandwich and returns to the end of the line making students = [1,0,0,1].\n\t\t- Front student leaves the top sandwich and returns to the end of the line making students = [0,0,1,1].\n\t\t- Front student takes the top sandwich and leaves the line making students = [0,1,1] and sandwiches = [1,0,1].\n\t\t- Front student leaves the top sandwich and returns to the end of the line making students = [1,1,0].\n\t\t- Front student takes the top sandwich and leaves the line making students = [1,0] and sandwiches = [0,1].\n\t\t- Front student leaves the top sandwich and returns to the end of the line making students = [0,1].\n\t\t- Front student takes the top sandwich and leaves the line making students = [1] and sandwiches = [1].\n\t\t- Front student takes the top sandwich and leaves the line making students = [] and sandwiches = [].\n\t\tHence all students are able to eat.\n\t\tExample 2:\n\t\tInput: students = [1,1,1,0,0,1], sandwiches = [1,0,0,0,1,1]\n\t\tOutput: 3\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1803, - "question": "class Solution:\n def averageWaitingTime(self, customers: List[List[int]]) -> float:\n\t\t\"\"\"\n\t\tThere is a restaurant with a single chef. You are given an array customers, where customers[i] = [arrivali, timei]:\n\t\t\tarrivali is the arrival time of the ith customer. The arrival times are sorted in non-decreasing order.\n\t\t\ttimei is the time needed to prepare the order of the ith customer.\n\t\tWhen a customer arrives, he gives the chef his order, and the chef starts preparing it once he is idle. The customer waits till the chef finishes preparing his order. The chef does not prepare food for more than one customer at a time. The chef prepares food for customers in the order they were given in the input.\n\t\tReturn the average waiting time of all customers. Solutions within 10-5 from the actual answer are considered accepted.\n\t\tExample 1:\n\t\tInput: customers = [[1,2],[2,5],[4,3]]\n\t\tOutput: 5.00000\n\t\tExplanation:\n\t\t1) The first customer arrives at time 1, the chef takes his order and starts preparing it immediately at time 1, and finishes at time 3, so the waiting time of the first customer is 3 - 1 = 2.\n\t\t2) The second customer arrives at time 2, the chef takes his order and starts preparing it at time 3, and finishes at time 8, so the waiting time of the second customer is 8 - 2 = 6.\n\t\t3) The third customer arrives at time 4, the chef takes his order and starts preparing it at time 8, and finishes at time 11, so the waiting time of the third customer is 11 - 4 = 7.\n\t\tSo the average waiting time = (2 + 6 + 7) / 3 = 5.\n\t\tExample 2:\n\t\tInput: customers = [[5,2],[5,4],[10,3],[20,1]]\n\t\tOutput: 3.25000\n\t\tExplanation:\n\t\t1) The first customer arrives at time 5, the chef takes his order and starts preparing it immediately at time 5, and finishes at time 7, so the waiting time of the first customer is 7 - 5 = 2.\n\t\t2) The second customer arrives at time 5, the chef takes his order and starts preparing it at time 7, and finishes at time 11, so the waiting time of the second customer is 11 - 5 = 6.\n\t\t3) The third customer arrives at time 10, the chef takes his order and starts preparing it at time 11, and finishes at time 14, so the waiting time of the third customer is 14 - 10 = 4.\n\t\t4) The fourth customer arrives at time 20, the chef takes his order and starts preparing it immediately at time 20, and finishes at time 21, so the waiting time of the fourth customer is 21 - 20 = 1.\n\t\tSo the average waiting time = (2 + 6 + 4 + 1) / 4 = 3.25.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1804, - "question": "class Solution:\n def maximumBinaryString(self, binary: str) -> str:\n\t\t\"\"\"\n\t\tYou are given a binary string binary consisting of only 0's or 1's. You can apply each of the following operations any number of times:\n\t\t\tOperation 1: If the number contains the substring \"00\", you can replace it with \"10\".\n\t\t\t\tFor example, \"00010\" -> \"10010\"\n\t\t\tOperation 2: If the number contains the substring \"10\", you can replace it with \"01\".\n\t\t\t\tFor example, \"00010\" -> \"00001\"\n\t\tReturn the maximum binary string you can obtain after any number of operations. Binary string x is greater than binary string y if x's decimal representation is greater than y's decimal representation.\n\t\tExample 1:\n\t\tInput: binary = \"000110\"\n\t\tOutput: \"111011\"\n\t\tExplanation: A valid transformation sequence can be:\n\t\t\"000110\" -> \"000101\" \n\t\t\"000101\" -> \"100101\" \n\t\t\"100101\" -> \"110101\" \n\t\t\"110101\" -> \"110011\" \n\t\t\"110011\" -> \"111011\"\n\t\tExample 2:\n\t\tInput: binary = \"01\"\n\t\tOutput: \"01\"\n\t\tExplanation: \"01\" cannot be transformed any further.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1805, - "question": "class Solution:\n def minMoves(self, nums: List[int], k: int) -> int:\n\t\t\"\"\"\n\t\tYou are given an integer array, nums, and an integer k. nums comprises of only 0's and 1's. In one move, you can choose two adjacent indices and swap their values.\n\t\tReturn the minimum number of moves required so that nums has k consecutive 1's.\n\t\tExample 1:\n\t\tInput: nums = [1,0,0,1,0,1], k = 2\n\t\tOutput: 1\n\t\tExplanation: In 1 move, nums could be [1,0,0,0,1,1] and have 2 consecutive 1's.\n\t\tExample 2:\n\t\tInput: nums = [1,0,0,0,0,0,1,1], k = 3\n\t\tOutput: 5\n\t\tExplanation: In 5 moves, the leftmost 1 can be shifted right until nums = [0,0,0,0,0,1,1,1].\n\t\tExample 3:\n\t\tInput: nums = [1,1,0,1], k = 2\n\t\tOutput: 0\n\t\tExplanation: nums already has 2 consecutive 1's.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1806, - "question": "class Solution:\n def numberOfMatches(self, n: int) -> int:\n\t\t\"\"\"\n\t\tYou are given an integer n, the number of teams in a tournament that has strange rules:\n\t\t\tIf the current number of teams is even, each team gets paired with another team. A total of n / 2 matches are played, and n / 2 teams advance to the next round.\n\t\t\tIf the current number of teams is odd, one team randomly advances in the tournament, and the rest gets paired. A total of (n - 1) / 2 matches are played, and (n - 1) / 2 + 1 teams advance to the next round.\n\t\tReturn the number of matches played in the tournament until a winner is decided.\n\t\tExample 1:\n\t\tInput: n = 7\n\t\tOutput: 6\n\t\tExplanation: Details of the tournament: \n\t\t- 1st Round: Teams = 7, Matches = 3, and 4 teams advance.\n\t\t- 2nd Round: Teams = 4, Matches = 2, and 2 teams advance.\n\t\t- 3rd Round: Teams = 2, Matches = 1, and 1 team is declared the winner.\n\t\tTotal number of matches = 3 + 2 + 1 = 6.\n\t\tExample 2:\n\t\tInput: n = 14\n\t\tOutput: 13\n\t\tExplanation: Details of the tournament:\n\t\t- 1st Round: Teams = 14, Matches = 7, and 7 teams advance.\n\t\t- 2nd Round: Teams = 7, Matches = 3, and 4 teams advance.\n\t\t- 3rd Round: Teams = 4, Matches = 2, and 2 teams advance.\n\t\t- 4th Round: Teams = 2, Matches = 1, and 1 team is declared the winner.\n\t\tTotal number of matches = 7 + 3 + 2 + 1 = 13.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1807, - "question": "class Solution:\n def minPartitions(self, n: str) -> int:\n\t\t\"\"\"\n\t\tA decimal number is called deci-binary if each of its digits is either 0 or 1 without any leading zeros. For example, 101 and 1100 are deci-binary, while 112 and 3001 are not.\n\t\tGiven a string n that represents a positive decimal integer, return the minimum number of positive deci-binary numbers needed so that they sum up to n.\n\t\tExample 1:\n\t\tInput: n = \"32\"\n\t\tOutput: 3\n\t\tExplanation: 10 + 11 + 11 = 32\n\t\tExample 2:\n\t\tInput: n = \"82734\"\n\t\tOutput: 8\n\t\tExample 3:\n\t\tInput: n = \"27346209830709182346\"\n\t\tOutput: 9\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1808, - "question": "class Solution:\n def stoneGameVII(self, stones: List[int]) -> int:\n\t\t\"\"\"\n\t\tAlice and Bob take turns playing a game, with Alice starting first.\n\t\tThere are n stones arranged in a row. On each player's turn, they can remove either the leftmost stone or the rightmost stone from the row and receive points equal to the sum of the remaining stones' values in the row. The winner is the one with the higher score when there are no stones left to remove.\n\t\tBob found that he will always lose this game (poor Bob, he always loses), so he decided to minimize the score's difference. Alice's goal is to maximize the difference in the score.\n\t\tGiven an array of integers stones where stones[i] represents the value of the ith stone from the left, return the difference in Alice and Bob's score if they both play optimally.\n\t\tExample 1:\n\t\tInput: stones = [5,3,1,4,2]\n\t\tOutput: 6\n\t\tExplanation: \n\t\t- Alice removes 2 and gets 5 + 3 + 1 + 4 = 13 points. Alice = 13, Bob = 0, stones = [5,3,1,4].\n\t\t- Bob removes 5 and gets 3 + 1 + 4 = 8 points. Alice = 13, Bob = 8, stones = [3,1,4].\n\t\t- Alice removes 3 and gets 1 + 4 = 5 points. Alice = 18, Bob = 8, stones = [1,4].\n\t\t- Bob removes 1 and gets 4 points. Alice = 18, Bob = 12, stones = [4].\n\t\t- Alice removes 4 and gets 0 points. Alice = 18, Bob = 12, stones = [].\n\t\tThe score difference is 18 - 12 = 6.\n\t\tExample 2:\n\t\tInput: stones = [7,90,5,1,100,10,10,2]\n\t\tOutput: 122\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1812, - "question": "class Solution:\n def reformatNumber(self, number: str) -> str:\n\t\t\"\"\"\n\t\tYou are given a phone number as a string number. number consists of digits, spaces ' ', and/or dashes '-'.\n\t\tYou would like to reformat the phone number in a certain manner. Firstly, remove all spaces and dashes. Then, group the digits from left to right into blocks of length 3 until there are 4 or fewer digits. The final digits are then grouped as follows:\n\t\t\t2 digits: A single block of length 2.\n\t\t\t3 digits: A single block of length 3.\n\t\t\t4 digits: Two blocks of length 2 each.\n\t\tThe blocks are then joined by dashes. Notice that the reformatting process should never produce any blocks of length 1 and produce at most two blocks of length 2.\n\t\tReturn the phone number after formatting.\n\t\tExample 1:\n\t\tInput: number = \"1-23-45 6\"\n\t\tOutput: \"123-456\"\n\t\tExplanation: The digits are \"123456\".\n\t\tStep 1: There are more than 4 digits, so group the next 3 digits. The 1st block is \"123\".\n\t\tStep 2: There are 3 digits remaining, so put them in a single block of length 3. The 2nd block is \"456\".\n\t\tJoining the blocks gives \"123-456\".\n\t\tExample 2:\n\t\tInput: number = \"123 4-567\"\n\t\tOutput: \"123-45-67\"\n\t\tExplanation: The digits are \"1234567\".\n\t\tStep 1: There are more than 4 digits, so group the next 3 digits. The 1st block is \"123\".\n\t\tStep 2: There are 4 digits left, so split them into two blocks of length 2. The blocks are \"45\" and \"67\".\n\t\tJoining the blocks gives \"123-45-67\".\n\t\tExample 3:\n\t\tInput: number = \"123 4-5678\"\n\t\tOutput: \"123-456-78\"\n\t\tExplanation: The digits are \"12345678\".\n\t\tStep 1: The 1st block is \"123\".\n\t\tStep 2: The 2nd block is \"456\".\n\t\tStep 3: There are 2 digits left, so put them in a single block of length 2. The 3rd block is \"78\".\n\t\tJoining the blocks gives \"123-456-78\".\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1813, - "question": "class Solution:\n def maximumUniqueSubarray(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou are given an array of positive integers nums and want to erase a subarray containing unique elements. The score you get by erasing the subarray is equal to the sum of its elements.\n\t\tReturn the maximum score you can get by erasing exactly one subarray.\n\t\tAn array b is called to be a subarray of a if it forms a contiguous subsequence of a, that is, if it is equal to a[l],a[l+1],...,a[r] for some (l,r).\n\t\tExample 1:\n\t\tInput: nums = [4,2,4,5,6]\n\t\tOutput: 17\n\t\tExplanation: The optimal subarray here is [2,4,5,6].\n\t\tExample 2:\n\t\tInput: nums = [5,2,1,2,5,2,1,2,5]\n\t\tOutput: 8\n\t\tExplanation: The optimal subarray here is [5,2,1] or [1,2,5].\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1814, - "question": "class Solution:\n def maxResult(self, nums: List[int], k: int) -> int:\n\t\t\"\"\"\n\t\tYou are given a 0-indexed integer array nums and an integer k.\n\t\tYou are initially standing at index 0. In one move, you can jump at most k steps forward without going outside the boundaries of the array. That is, you can jump from index i to any index in the range [i + 1, min(n - 1, i + k)] inclusive.\n\t\tYou want to reach the last index of the array (index n - 1). Your score is the sum of all nums[j] for each index j you visited in the array.\n\t\tReturn the maximum score you can get.\n\t\tExample 1:\n\t\tInput: nums = [1,-1,-2,4,-7,3], k = 2\n\t\tOutput: 7\n\t\tExplanation: You can choose your jumps forming the subsequence [1,-1,4,3] (underlined above). The sum is 7.\n\t\tExample 2:\n\t\tInput: nums = [10,-5,-2,4,0,3], k = 3\n\t\tOutput: 17\n\t\tExplanation: You can choose your jumps forming the subsequence [10,4,3] (underlined above). The sum is 17.\n\t\tExample 3:\n\t\tInput: nums = [1,-5,-20,4,-1,3,-6,-3], k = 2\n\t\tOutput: 0\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1815, - "question": "class Solution:\n def distanceLimitedPathsExist(self, n: int, edgeList: List[List[int]], queries: List[List[int]]) -> List[bool]:\n\t\t\"\"\"\n\t\tAn undirected graph of n nodes is defined by edgeList, where edgeList[i] = [ui, vi, disi] denotes an edge between nodes ui and vi with distance disi. Note that there may be multiple edges between two nodes.\n\t\tGiven an array queries, where queries[j] = [pj, qj, limitj], your task is to determine for each queries[j] whether there is a path between pj and qj such that each edge on the path has a distance strictly less than limitj .\n\t\tReturn a boolean array answer, where answer.length == queries.length and the jth value of answer is true if there is a path for queries[j] is true, and false otherwise.\n\t\tExample 1:\n\t\tInput: n = 3, edgeList = [[0,1,2],[1,2,4],[2,0,8],[1,0,16]], queries = [[0,1,2],[0,2,5]]\n\t\tOutput: [false,true]\n\t\tExplanation: The above figure shows the given graph. Note that there are two overlapping edges between 0 and 1 with distances 2 and 16.\n\t\tFor the first query, between 0 and 1 there is no path where each distance is less than 2, thus we return false for this query.\n\t\tFor the second query, there is a path (0 -> 1 -> 2) of two edges with distances less than 5, thus we return true for this query.\n\t\tExample 2:\n\t\tInput: n = 5, edgeList = [[0,1,10],[1,2,5],[2,3,9],[3,4,13]], queries = [[0,4,14],[1,4,13]]\n\t\tOutput: [true,false]\n\t\tExaplanation: The above figure shows the given graph.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1817, - "question": "class Solution:\n def totalMoney(self, n: int) -> int:\n\t\t\"\"\"\n\t\tHercy wants to save money for his first car. He puts money in the Leetcode bank every day.\n\t\tHe starts by putting in $1 on Monday, the first day. Every day from Tuesday to Sunday, he will put in $1 more than the day before. On every subsequent Monday, he will put in $1 more than the previous Monday. \n\t\tGiven n, return the total amount of money he will have in the Leetcode bank at the end of the nth day.\n\t\tExample 1:\n\t\tInput: n = 4\n\t\tOutput: 10\n\t\tExplanation: After the 4th day, the total is 1 + 2 + 3 + 4 = 10.\n\t\tExample 2:\n\t\tInput: n = 10\n\t\tOutput: 37\n\t\tExplanation: After the 10th day, the total is (1 + 2 + 3 + 4 + 5 + 6 + 7) + (2 + 3 + 4) = 37. Notice that on the 2nd Monday, Hercy only puts in $2.\n\t\tExample 3:\n\t\tInput: n = 20\n\t\tOutput: 96\n\t\tExplanation: After the 20th day, the total is (1 + 2 + 3 + 4 + 5 + 6 + 7) + (2 + 3 + 4 + 5 + 6 + 7 + 8) + (3 + 4 + 5 + 6 + 7 + 8) = 96.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1818, - "question": "class Solution:\n def maximumGain(self, s: str, x: int, y: int) -> int:\n\t\t\"\"\"\n\t\tYou are given a string s and two integers x and y. You can perform two types of operations any number of times.\n\t\t\tRemove substring \"ab\" and gain x points.\n\t\t\t\tFor example, when removing \"ab\" from \"cabxbae\" it becomes \"cxbae\".\n\t\t\tRemove substring \"ba\" and gain y points.\n\t\t\t\tFor example, when removing \"ba\" from \"cabxbae\" it becomes \"cabxe\".\n\t\tReturn the maximum points you can gain after applying the above operations on s.\n\t\tExample 1:\n\t\tInput: s = \"cdbcbbaaabab\", x = 4, y = 5\n\t\tOutput: 19\n\t\tExplanation:\n\t\t- Remove the \"ba\" underlined in \"cdbcbbaaabab\". Now, s = \"cdbcbbaaab\" and 5 points are added to the score.\n\t\t- Remove the \"ab\" underlined in \"cdbcbbaaab\". Now, s = \"cdbcbbaa\" and 4 points are added to the score.\n\t\t- Remove the \"ba\" underlined in \"cdbcbbaa\". Now, s = \"cdbcba\" and 5 points are added to the score.\n\t\t- Remove the \"ba\" underlined in \"cdbcba\". Now, s = \"cdbc\" and 5 points are added to the score.\n\t\tTotal score = 5 + 4 + 5 + 5 = 19.\n\t\tExample 2:\n\t\tInput: s = \"aabbaaxybbaabb\", x = 5, y = 4\n\t\tOutput: 20\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1819, - "question": "class Solution:\n def constructDistancedSequence(self, n: int) -> List[int]:\n\t\t\"\"\"\n\t\tGiven an integer n, find a sequence that satisfies all of the following:\n\t\t\tThe integer 1 occurs once in the sequence.\n\t\t\tEach integer between 2 and n occurs twice in the sequence.\n\t\t\tFor every integer i between 2 and n, the distance between the two occurrences of i is exactly i.\n\t\tThe distance between two numbers on the sequence, a[i] and a[j], is the absolute difference of their indices, |j - i|.\n\t\tReturn the lexicographically largest sequence. It is guaranteed that under the given constraints, there is always a solution. \n\t\tA sequence a is lexicographically larger than a sequence b (of the same length) if in the first position where a and b differ, sequence a has a number greater than the corresponding number in b. For example, [0,1,9,0] is lexicographically larger than [0,1,5,6] because the first position they differ is at the third number, and 9 is greater than 5.\n\t\tExample 1:\n\t\tInput: n = 3\n\t\tOutput: [3,1,2,3,2]\n\t\tExplanation: [2,3,2,1,3] is also a valid sequence, but [3,1,2,3,2] is the lexicographically largest valid sequence.\n\t\tExample 2:\n\t\tInput: n = 5\n\t\tOutput: [5,3,1,4,3,5,2,4,2]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1820, - "question": "class Solution:\n def checkWays(self, pairs: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tYou are given an array pairs, where pairs[i] = [xi, yi], and:\n\t\t\tThere are no duplicates.\n\t\t\txi < yi\n\t\tLet ways be the number of rooted trees that satisfy the following conditions:\n\t\t\tThe tree consists of nodes whose values appeared in pairs.\n\t\t\tA pair [xi, yi] exists in pairs if and only if xi is an ancestor of yi or yi is an ancestor of xi.\n\t\t\tNote: the tree does not have to be a binary tree.\n\t\tTwo ways are considered to be different if there is at least one node that has different parents in both ways.\n\t\tReturn:\n\t\t\t0 if ways == 0\n\t\t\t1 if ways == 1\n\t\t\t2 if ways > 1\n\t\tA rooted tree is a tree that has a single root node, and all edges are oriented to be outgoing from the root.\n\t\tAn ancestor of a node is any node on the path from the root to that node (excluding the node itself). The root has no ancestors.\n\t\tExample 1:\n\t\tInput: pairs = [[1,2],[2,3]]\n\t\tOutput: 1\n\t\tExplanation: There is exactly one valid rooted tree, which is shown in the above figure.\n\t\tExample 2:\n\t\tInput: pairs = [[1,2],[2,3],[1,3]]\n\t\tOutput: 2\n\t\tExplanation: There are multiple valid rooted trees. Three of them are shown in the above figures.\n\t\tExample 3:\n\t\tInput: pairs = [[1,2],[2,3],[2,4],[1,5]]\n\t\tOutput: 0\n\t\tExplanation: There are no valid rooted trees.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1823, - "question": "class Solution:\n def halvesAreAlike(self, s: str) -> bool:\n\t\t\"\"\"\n\t\tYou are given a string s of even length. Split this string into two halves of equal lengths, and let a be the first half and b be the second half.\n\t\tTwo strings are alike if they have the same number of vowels ('a', 'e', 'i', 'o', 'u', 'A', 'E', 'I', 'O', 'U'). Notice that s contains uppercase and lowercase letters.\n\t\tReturn true if a and b are alike. Otherwise, return false.\n\t\tExample 1:\n\t\tInput: s = \"book\"\n\t\tOutput: true\n\t\tExplanation: a = \"bo\" and b = \"ok\". a has 1 vowel and b has 1 vowel. Therefore, they are alike.\n\t\tExample 2:\n\t\tInput: s = \"textbook\"\n\t\tOutput: false\n\t\tExplanation: a = \"text\" and b = \"book\". a has 1 vowel whereas b has 2. Therefore, they are not alike.\n\t\tNotice that the vowel o is counted twice.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1824, - "question": "class Solution:\n def eatenApples(self, apples: List[int], days: List[int]) -> int:\n\t\t\"\"\"\n\t\tThere is a special kind of apple tree that grows apples every day for n days. On the ith day, the tree grows apples[i] apples that will rot after days[i] days, that is on day i + days[i] the apples will be rotten and cannot be eaten. On some days, the apple tree does not grow any apples, which are denoted by apples[i] == 0 and days[i] == 0.\n\t\tYou decided to eat at most one apple a day (to keep the doctors away). Note that you can keep eating after the first n days.\n\t\tGiven two integer arrays days and apples of length n, return the maximum number of apples you can eat.\n\t\tExample 1:\n\t\tInput: apples = [1,2,3,5,2], days = [3,2,1,4,2]\n\t\tOutput: 7\n\t\tExplanation: You can eat 7 apples:\n\t\t- On the first day, you eat an apple that grew on the first day.\n\t\t- On the second day, you eat an apple that grew on the second day.\n\t\t- On the third day, you eat an apple that grew on the second day. After this day, the apples that grew on the third day rot.\n\t\t- On the fourth to the seventh days, you eat apples that grew on the fourth day.\n\t\tExample 2:\n\t\tInput: apples = [3,0,0,0,0,2], days = [3,0,0,0,0,2]\n\t\tOutput: 5\n\t\tExplanation: You can eat 5 apples:\n\t\t- On the first to the third day you eat apples that grew on the first day.\n\t\t- Do nothing on the fouth and fifth days.\n\t\t- On the sixth and seventh days you eat apples that grew on the sixth day.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1825, - "question": "class Solution:\n def minimumTimeRequired(self, jobs: List[int], k: int) -> int:\n\t\t\"\"\"\n\t\tYou are given an integer array jobs, where jobs[i] is the amount of time it takes to complete the ith job.\n\t\tThere are k workers that you can assign jobs to. Each job should be assigned to exactly one worker. The working time of a worker is the sum of the time it takes to complete all jobs assigned to them. Your goal is to devise an optimal assignment such that the maximum working time of any worker is minimized.\n\t\tReturn the minimum possible maximum working time of any assignment. \n\t\tExample 1:\n\t\tInput: jobs = [3,2,3], k = 3\n\t\tOutput: 3\n\t\tExplanation: By assigning each person one job, the maximum time is 3.\n\t\tExample 2:\n\t\tInput: jobs = [1,2,4,7,8], k = 2\n\t\tOutput: 11\n\t\tExplanation: Assign the jobs the following way:\n\t\tWorker 1: 1, 2, 8 (working time = 1 + 2 + 8 = 11)\n\t\tWorker 2: 4, 7 (working time = 4 + 7 = 11)\n\t\tThe maximum working time is 11.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1826, - "question": "class Solution:\n def maximizeXor(self, nums: List[int], queries: List[List[int]]) -> List[int]:\n\t\t\"\"\"\n\t\tYou are given an array nums consisting of non-negative integers. You are also given a queries array, where queries[i] = [xi, mi].\n\t\tThe answer to the ith query is the maximum bitwise XOR value of xi and any element of nums that does not exceed mi. In other words, the answer is max(nums[j] XOR xi) for all j such that nums[j] <= mi. If all elements in nums are larger than mi, then the answer is -1.\n\t\tReturn an integer array answer where answer.length == queries.length and answer[i] is the answer to the ith query.\n\t\tExample 1:\n\t\tInput: nums = [0,1,2,3,4], queries = [[3,1],[1,3],[5,6]]\n\t\tOutput: [3,3,7]\n\t\tExplanation:\n\t\t1) 0 and 1 are the only two integers not greater than 1. 0 XOR 3 = 3 and 1 XOR 3 = 2. The larger of the two is 3.\n\t\t2) 1 XOR 2 = 3.\n\t\t3) 5 XOR 2 = 7.\n\t\tExample 2:\n\t\tInput: nums = [5,2,4,6,6,3], queries = [[12,4],[8,1],[6,3]]\n\t\tOutput: [15,-1,5]\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1829, - "question": "class Solution:\n def maximumUnits(self, boxTypes: List[List[int]], truckSize: int) -> int:\n\t\t\"\"\"\n\t\tYou are assigned to put some amount of boxes onto one truck. You are given a 2D array boxTypes, where boxTypes[i] = [numberOfBoxesi, numberOfUnitsPerBoxi]:\n\t\t\tnumberOfBoxesi is the number of boxes of type i.\n\t\t\tnumberOfUnitsPerBoxi is the number of units in each box of the type i.\n\t\tYou are also given an integer truckSize, which is the maximum number of boxes that can be put on the truck. You can choose any boxes to put on the truck as long as the number of boxes does not exceed truckSize.\n\t\tReturn the maximum total number of units that can be put on the truck.\n\t\tExample 1:\n\t\tInput: boxTypes = [[1,3],[2,2],[3,1]], truckSize = 4\n\t\tOutput: 8\n\t\tExplanation: There are:\n\t\t- 1 box of the first type that contains 3 units.\n\t\t- 2 boxes of the second type that contain 2 units each.\n\t\t- 3 boxes of the third type that contain 1 unit each.\n\t\tYou can take all the boxes of the first and second types, and one box of the third type.\n\t\tThe total number of units will be = (1 * 3) + (2 * 2) + (1 * 1) = 8.\n\t\tExample 2:\n\t\tInput: boxTypes = [[5,10],[2,5],[4,7],[3,9]], truckSize = 10\n\t\tOutput: 91\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1830, - "question": "class Solution:\n def countPairs(self, deliciousness: List[int]) -> int:\n\t\t\"\"\"\n\t\tA good meal is a meal that contains exactly two different food items with a sum of deliciousness equal to a power of two.\n\t\tYou can pick any two different foods to make a good meal.\n\t\tGiven an array of integers deliciousness where deliciousness[i] is the deliciousness of the i\u200b\u200b\u200b\u200b\u200b\u200bth\u200b\u200b\u200b\u200b\u200b\u200b\u200b\u200b item of food, return the number of different good meals you can make from this list modulo 109 + 7.\n\t\tNote that items with different indices are considered different even if they have the same deliciousness value.\n\t\tExample 1:\n\t\tInput: deliciousness = [1,3,5,7,9]\n\t\tOutput: 4\n\t\tExplanation: The good meals are (1,3), (1,7), (3,5) and, (7,9).\n\t\tTheir respective sums are 4, 8, 8, and 16, all of which are powers of 2.\n\t\tExample 2:\n\t\tInput: deliciousness = [1,1,1,3,3,3,7]\n\t\tOutput: 15\n\t\tExplanation: The good meals are (1,1) with 3 ways, (1,3) with 9 ways, and (1,7) with 3 ways.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1831, - "question": "class Solution:\n def waysToSplit(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tA split of an integer array is good if:\n\t\t\tThe array is split into three non-empty contiguous subarrays - named left, mid, right respectively from left to right.\n\t\t\tThe sum of the elements in left is less than or equal to the sum of the elements in mid, and the sum of the elements in mid is less than or equal to the sum of the elements in right.\n\t\tGiven nums, an array of non-negative integers, return the number of good ways to split nums. As the number may be too large, return it modulo 109 + 7.\n\t\tExample 1:\n\t\tInput: nums = [1,1,1]\n\t\tOutput: 1\n\t\tExplanation: The only good way to split nums is [1] [1] [1].\n\t\tExample 2:\n\t\tInput: nums = [1,2,2,2,5,0]\n\t\tOutput: 3\n\t\tExplanation: There are three good ways of splitting nums:\n\t\t[1] [2] [2,2,5,0]\n\t\t[1] [2,2] [2,5,0]\n\t\t[1,2] [2,2] [5,0]\n\t\tExample 3:\n\t\tInput: nums = [3,2,1]\n\t\tOutput: 0\n\t\tExplanation: There is no good way to split nums.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1832, - "question": "class Solution:\n def minOperations(self, target: List[int], arr: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou are given an array target that consists of distinct integers and another integer array arr that can have duplicates.\n\t\tIn one operation, you can insert any integer at any position in arr. For example, if arr = [1,4,1,2], you can add 3 in the middle and make it [1,4,3,1,2]. Note that you can insert the integer at the very beginning or end of the array.\n\t\tReturn the minimum number of operations needed to make target a subsequence of arr.\n\t\tA subsequence of an array is a new array generated from the original array by deleting some elements (possibly none) without changing the remaining elements' relative order. For example, [2,7,4] is a subsequence of [4,2,3,7,2,1,4] (the underlined elements), while [2,4,2] is not.\n\t\tExample 1:\n\t\tInput: target = [5,1,3], arr = [9,4,2,3,4]\n\t\tOutput: 2\n\t\tExplanation: You can add 5 and 1 in such a way that makes arr = [5,9,4,1,2,3,4], then target will be a subsequence of arr.\n\t\tExample 2:\n\t\tInput: target = [6,4,8,1,3,2], arr = [4,7,6,2,3,8,6,1]\n\t\tOutput: 3\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1833, - "question": "class Solution:\n def largestAltitude(self, gain: List[int]) -> int:\n\t\t\"\"\"\n\t\tThere is a biker going on a road trip. The road trip consists of n + 1 points at different altitudes. The biker starts his trip on point 0 with altitude equal 0.\n\t\tYou are given an integer array gain of length n where gain[i] is the net gain in altitude between points i\u200b\u200b\u200b\u200b\u200b\u200b and i + 1 for all (0 <= i < n). Return the highest altitude of a point.\n\t\tExample 1:\n\t\tInput: gain = [-5,1,5,0,-7]\n\t\tOutput: 1\n\t\tExplanation: The altitudes are [0,-5,-4,1,1,-6]. The highest is 1.\n\t\tExample 2:\n\t\tInput: gain = [-4,-3,-2,-1,4,3,2]\n\t\tOutput: 0\n\t\tExplanation: The altitudes are [0,-4,-7,-9,-10,-6,-3,-1]. The highest is 0.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1834, - "question": "class Solution:\n def minimumTeachings(self, n: int, languages: List[List[int]], friendships: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tOn a social network consisting of m users and some friendships between users, two users can communicate with each other if they know a common language.\n\t\tYou are given an integer n, an array languages, and an array friendships where:\n\t\t\tThere are n languages numbered 1 through n,\n\t\t\tlanguages[i] is the set of languages the i\u200b\u200b\u200b\u200b\u200b\u200bth\u200b\u200b\u200b\u200b user knows, and\n\t\t\tfriendships[i] = [u\u200b\u200b\u200b\u200b\u200b\u200bi\u200b\u200b\u200b, v\u200b\u200b\u200b\u200b\u200b\u200bi] denotes a friendship between the users u\u200b\u200b\u200b\u200b\u200b\u200b\u200b\u200b\u200b\u200b\u200bi\u200b\u200b\u200b\u200b\u200b and vi.\n\t\tYou can choose one language and teach it to some users so that all friends can communicate with each other. Return the minimum number of users you need to teach.\n\t\tNote that friendships are not transitive, meaning if x is a friend of y and y is a friend of z, this doesn't guarantee that x is a friend of z.\n\t\tExample 1:\n\t\tInput: n = 2, languages = [[1],[2],[1,2]], friendships = [[1,2],[1,3],[2,3]]\n\t\tOutput: 1\n\t\tExplanation: You can either teach user 1 the second language or user 2 the first language.\n\t\tExample 2:\n\t\tInput: n = 3, languages = [[2],[1,3],[1,2],[3]], friendships = [[1,4],[1,2],[3,4],[2,3]]\n\t\tOutput: 2\n\t\tExplanation: Teach the third language to users 1 and 3, yielding two users to teach.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1835, - "question": "class Solution:\n def decode(self, encoded: List[int]) -> List[int]:\n\t\t\"\"\"\n\t\tThere is an integer array perm that is a permutation of the first n positive integers, where n is always odd.\n\t\tIt was encoded into another integer array encoded of length n - 1, such that encoded[i] = perm[i] XOR perm[i + 1]. For example, if perm = [1,3,2], then encoded = [2,1].\n\t\tGiven the encoded array, return the original array perm. It is guaranteed that the answer exists and is unique.\n\t\tExample 1:\n\t\tInput: encoded = [3,1]\n\t\tOutput: [1,2,3]\n\t\tExplanation: If perm = [1,2,3], then encoded = [1 XOR 2,2 XOR 3] = [3,1]\n\t\tExample 2:\n\t\tInput: encoded = [6,5,4,6]\n\t\tOutput: [2,4,1,5,3]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1836, - "question": "class Solution:\n def waysToFillArray(self, queries: List[List[int]]) -> List[int]:\n\t\t\"\"\"\n\t\tYou are given a 2D integer array, queries. For each queries[i], where queries[i] = [ni, ki], find the number of different ways you can place positive integers into an array of size ni such that the product of the integers is ki. As the number of ways may be too large, the answer to the ith query is the number of ways modulo 109 + 7.\n\t\tReturn an integer array answer where answer.length == queries.length, and answer[i] is the answer to the ith query.\n\t\tExample 1:\n\t\tInput: queries = [[2,6],[5,1],[73,660]]\n\t\tOutput: [4,1,50734910]\n\t\tExplanation: Each query is independent.\n\t\t[2,6]: There are 4 ways to fill an array of size 2 that multiply to 6: [1,6], [2,3], [3,2], [6,1].\n\t\t[5,1]: There is 1 way to fill an array of size 5 that multiply to 1: [1,1,1,1,1].\n\t\t[73,660]: There are 1050734917 ways to fill an array of size 73 that multiply to 660. 1050734917 modulo 109 + 7 = 50734910.\n\t\tExample 2:\n\t\tInput: queries = [[1,1],[2,2],[3,3],[4,4],[5,5]]\n\t\tOutput: [1,2,3,10,5]\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1839, - "question": "class Solution:\n def decode(self, encoded: List[int], first: int) -> List[int]:\n\t\t\"\"\"\n\t\tThere is a hidden integer array arr that consists of n non-negative integers.\n\t\tIt was encoded into another integer array encoded of length n - 1, such that encoded[i] = arr[i] XOR arr[i + 1]. For example, if arr = [1,0,2,1], then encoded = [1,2,3].\n\t\tYou are given the encoded array. You are also given an integer first, that is the first element of arr, i.e. arr[0].\n\t\tReturn the original array arr. It can be proved that the answer exists and is unique.\n\t\tExample 1:\n\t\tInput: encoded = [1,2,3], first = 1\n\t\tOutput: [1,0,2,1]\n\t\tExplanation: If arr = [1,0,2,1], then first = 1 and encoded = [1 XOR 0, 0 XOR 2, 2 XOR 1] = [1,2,3]\n\t\tExample 2:\n\t\tInput: encoded = [6,2,7,3], first = 4\n\t\tOutput: [4,2,0,7,4]\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1840, - "question": "class Solution:\n def minimumHammingDistance(self, source: List[int], target: List[int], allowedSwaps: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tYou are given two integer arrays, source and target, both of length n. You are also given an array allowedSwaps where each allowedSwaps[i] = [ai, bi] indicates that you are allowed to swap the elements at index ai and index bi (0-indexed) of array source. Note that you can swap elements at a specific pair of indices multiple times and in any order.\n\t\tThe Hamming distance of two arrays of the same length, source and target, is the number of positions where the elements are different. Formally, it is the number of indices i for 0 <= i <= n-1 where source[i] != target[i] (0-indexed).\n\t\tReturn the minimum Hamming distance of source and target after performing any amount of swap operations on array source.\n\t\tExample 1:\n\t\tInput: source = [1,2,3,4], target = [2,1,4,5], allowedSwaps = [[0,1],[2,3]]\n\t\tOutput: 1\n\t\tExplanation: source can be transformed the following way:\n\t\t- Swap indices 0 and 1: source = [2,1,3,4]\n\t\t- Swap indices 2 and 3: source = [2,1,4,3]\n\t\tThe Hamming distance of source and target is 1 as they differ in 1 position: index 3.\n\t\tExample 2:\n\t\tInput: source = [1,2,3,4], target = [1,3,2,4], allowedSwaps = []\n\t\tOutput: 2\n\t\tExplanation: There are no allowed swaps.\n\t\tThe Hamming distance of source and target is 2 as they differ in 2 positions: index 1 and index 2.\n\t\tExample 3:\n\t\tInput: source = [5,1,2,4,3], target = [1,5,4,2,3], allowedSwaps = [[0,4],[4,2],[1,3],[1,4]]\n\t\tOutput: 0\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1843, - "question": "class Solution:\n def countGoodRectangles(self, rectangles: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tYou are given an array rectangles where rectangles[i] = [li, wi] represents the ith rectangle of length li and width wi.\r\n\t\tYou can cut the ith rectangle to form a square with a side length of k if both k <= li and k <= wi. For example, if you have a rectangle [4,6], you can cut it to get a square with a side length of at most 4.\r\n\t\tLet maxLen be the side length of the largest square you can obtain from any of the given rectangles.\r\n\t\tReturn the number of rectangles that can make a square with a side length of maxLen.\r\n\t\tExample 1:\r\n\t\tInput: rectangles = [[5,8],[3,9],[5,12],[16,5]]\r\n\t\tOutput: 3\r\n\t\tExplanation: The largest squares you can get from each rectangle are of lengths [5,3,5,5].\r\n\t\tThe largest possible square is of length 5, and you can get it out of 3 rectangles.\r\n\t\tExample 2:\r\n\t\tInput: rectangles = [[2,3],[3,7],[4,3],[3,7]]\r\n\t\tOutput: 3\r\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1844, - "question": "class Solution:\n def countBalls(self, lowLimit: int, highLimit: int) -> int:\n\t\t\"\"\"\n\t\tYou are working in a ball factory where you have n balls numbered from lowLimit up to highLimit inclusive (i.e., n == highLimit - lowLimit + 1), and an infinite number of boxes numbered from 1 to infinity.\n\t\tYour job at this factory is to put each ball in the box with a number equal to the sum of digits of the ball's number. For example, the ball number 321 will be put in the box number 3 + 2 + 1 = 6 and the ball number 10 will be put in the box number 1 + 0 = 1.\n\t\tGiven two integers lowLimit and highLimit, return the number of balls in the box with the most balls.\n\t\tExample 1:\n\t\tInput: lowLimit = 1, highLimit = 10\n\t\tOutput: 2\n\t\tExplanation:\n\t\tBox Number: 1 2 3 4 5 6 7 8 9 10 11 ...\n\t\tBall Count: 2 1 1 1 1 1 1 1 1 0 0 ...\n\t\tBox 1 has the most number of balls with 2 balls.\n\t\tExample 2:\n\t\tInput: lowLimit = 5, highLimit = 15\n\t\tOutput: 2\n\t\tExplanation:\n\t\tBox Number: 1 2 3 4 5 6 7 8 9 10 11 ...\n\t\tBall Count: 1 1 1 1 2 2 1 1 1 0 0 ...\n\t\tBoxes 5 and 6 have the most number of balls with 2 balls in each.\n\t\tExample 3:\n\t\tInput: lowLimit = 19, highLimit = 28\n\t\tOutput: 2\n\t\tExplanation:\n\t\tBox Number: 1 2 3 4 5 6 7 8 9 10 11 12 ...\n\t\tBall Count: 0 1 1 1 1 1 1 1 1 2 0 0 ...\n\t\tBox 10 has the most number of balls with 2 balls.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1845, - "question": "class Solution:\n def largestSubmatrix(self, matrix: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tYou are given a binary matrix matrix of size m x n, and you are allowed to rearrange the columns of the matrix in any order.\n\t\tReturn the area of the largest submatrix within matrix where every element of the submatrix is 1 after reordering the columns optimally.\n\t\tExample 1:\n\t\tInput: matrix = [[0,0,1],[1,1,1],[1,0,1]]\n\t\tOutput: 4\n\t\tExplanation: You can rearrange the columns as shown above.\n\t\tThe largest submatrix of 1s, in bold, has an area of 4.\n\t\tExample 2:\n\t\tInput: matrix = [[1,0,1,0,1]]\n\t\tOutput: 3\n\t\tExplanation: You can rearrange the columns as shown above.\n\t\tThe largest submatrix of 1s, in bold, has an area of 3.\n\t\tExample 3:\n\t\tInput: matrix = [[1,1,0],[1,0,1]]\n\t\tOutput: 2\n\t\tExplanation: Notice that you must rearrange entire columns, and there is no way to make a submatrix of 1s larger than an area of 2.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1848, - "question": "class Solution:\n def sumOfUnique(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou are given an integer array nums. The unique elements of an array are the elements that appear exactly once in the array.\n\t\tReturn the sum of all the unique elements of nums.\n\t\tExample 1:\n\t\tInput: nums = [1,2,3,2]\n\t\tOutput: 4\n\t\tExplanation: The unique elements are [1,3], and the sum is 4.\n\t\tExample 2:\n\t\tInput: nums = [1,1,1,1,1]\n\t\tOutput: 0\n\t\tExplanation: There are no unique elements, and the sum is 0.\n\t\tExample 3:\n\t\tInput: nums = [1,2,3,4,5]\n\t\tOutput: 15\n\t\tExplanation: The unique elements are [1,2,3,4,5], and the sum is 15.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1849, - "question": "class Solution:\n def maxAbsoluteSum(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou are given an integer array nums. The absolute sum of a subarray [numsl, numsl+1, ..., numsr-1, numsr] is abs(numsl + numsl+1 + ... + numsr-1 + numsr).\n\t\tReturn the maximum absolute sum of any (possibly empty) subarray of nums.\n\t\tNote that abs(x) is defined as follows:\n\t\t\tIf x is a negative integer, then abs(x) = -x.\n\t\t\tIf x is a non-negative integer, then abs(x) = x.\n\t\tExample 1:\n\t\tInput: nums = [1,-3,2,3,-4]\n\t\tOutput: 5\n\t\tExplanation: The subarray [2,3] has absolute sum = abs(2+3) = abs(5) = 5.\n\t\tExample 2:\n\t\tInput: nums = [2,-5,1,-4,3,-2]\n\t\tOutput: 8\n\t\tExplanation: The subarray [-5,1,-4] has absolute sum = abs(-5+1-4) = abs(-8) = 8.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1850, - "question": "class Solution:\n def minimumLength(self, s: str) -> int:\n\t\t\"\"\"\n\t\tGiven a string s consisting only of characters 'a', 'b', and 'c'. You are asked to apply the following algorithm on the string any number of times:\n\t\t\tPick a non-empty prefix from the string s where all the characters in the prefix are equal.\n\t\t\tPick a non-empty suffix from the string s where all the characters in this suffix are equal.\n\t\t\tThe prefix and the suffix should not intersect at any index.\n\t\t\tThe characters from the prefix and suffix must be the same.\n\t\t\tDelete both the prefix and the suffix.\n\t\tReturn the minimum length of s after performing the above operation any number of times (possibly zero times).\n\t\tExample 1:\n\t\tInput: s = \"ca\"\n\t\tOutput: 2\n\t\tExplanation: You can't remove any characters, so the string stays as is.\n\t\tExample 2:\n\t\tInput: s = \"cabaabac\"\n\t\tOutput: 0\n\t\tExplanation: An optimal sequence of operations is:\n\t\t- Take prefix = \"c\" and suffix = \"c\" and remove them, s = \"abaaba\".\n\t\t- Take prefix = \"a\" and suffix = \"a\" and remove them, s = \"baab\".\n\t\t- Take prefix = \"b\" and suffix = \"b\" and remove them, s = \"aa\".\n\t\t- Take prefix = \"a\" and suffix = \"a\" and remove them, s = \"\".\n\t\tExample 3:\n\t\tInput: s = \"aabccabba\"\n\t\tOutput: 3\n\t\tExplanation: An optimal sequence of operations is:\n\t\t- Take prefix = \"aa\" and suffix = \"a\" and remove them, s = \"bccabb\".\n\t\t- Take prefix = \"b\" and suffix = \"bb\" and remove them, s = \"cca\".\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1851, - "question": "class Solution:\n def maxValue(self, events: List[List[int]], k: int) -> int:\n\t\t\"\"\"\n\t\tYou are given an array of events where events[i] = [startDayi, endDayi, valuei]. The ith event starts at startDayi and ends at endDayi, and if you attend this event, you will receive a value of valuei. You are also given an integer k which represents the maximum number of events you can attend.\n\t\tYou can only attend one event at a time. If you choose to attend an event, you must attend the entire event. Note that the end day is inclusive: that is, you cannot attend two events where one of them starts and the other ends on the same day.\n\t\tReturn the maximum sum of values that you can receive by attending events.\n\t\tExample 1:\n\t\tInput: events = [[1,2,4],[3,4,3],[2,3,1]], k = 2\n\t\tOutput: 7\n\t\tExplanation: Choose the green events, 0 and 1 (0-indexed) for a total value of 4 + 3 = 7.\n\t\tExample 2:\n\t\tInput: events = [[1,2,4],[3,4,3],[2,3,10]], k = 2\n\t\tOutput: 10\n\t\tExplanation: Choose event 2 for a total value of 10.\n\t\tNotice that you cannot attend any other event as they overlap, and that you do not have to attend k events.\n\t\tExample 3:\n\t\tInput: events = [[1,1,1],[2,2,2],[3,3,3],[4,4,4]], k = 3\n\t\tOutput: 9\n\t\tExplanation: Although the events do not overlap, you can only attend 3 events. Pick the highest valued three.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1858, - "question": "class Solution:\n def maximumTime(self, time: str) -> str:\n\t\t\"\"\"\n\t\tYou are given a string time in the form of hh:mm, where some of the digits in the string are hidden (represented by ?).\n\t\tThe valid times are those inclusively between 00:00 and 23:59.\n\t\tReturn the latest valid time you can get from time by replacing the hidden digits.\n\t\tExample 1:\n\t\tInput: time = \"2?:?0\"\n\t\tOutput: \"23:50\"\n\t\tExplanation: The latest hour beginning with the digit '2' is 23 and the latest minute ending with the digit '0' is 50.\n\t\tExample 2:\n\t\tInput: time = \"0?:3?\"\n\t\tOutput: \"09:39\"\n\t\tExample 3:\n\t\tInput: time = \"1?:22\"\n\t\tOutput: \"19:22\"\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1859, - "question": "class Solution:\n def minCharacters(self, a: str, b: str) -> int:\n\t\t\"\"\"\n\t\tYou are given two strings a and b that consist of lowercase letters. In one operation, you can change any character in a or b to any lowercase letter.\n\t\tYour goal is to satisfy one of the following three conditions:\n\t\t\tEvery letter in a is strictly less than every letter in b in the alphabet.\n\t\t\tEvery letter in b is strictly less than every letter in a in the alphabet.\n\t\t\tBoth a and b consist of only one distinct letter.\n\t\tReturn the minimum number of operations needed to achieve your goal.\n\t\tExample 1:\n\t\tInput: a = \"aba\", b = \"caa\"\n\t\tOutput: 2\n\t\tExplanation: Consider the best way to make each condition true:\n\t\t1) Change b to \"ccc\" in 2 operations, then every letter in a is less than every letter in b.\n\t\t2) Change a to \"bbb\" and b to \"aaa\" in 3 operations, then every letter in b is less than every letter in a.\n\t\t3) Change a to \"aaa\" and b to \"aaa\" in 2 operations, then a and b consist of one distinct letter.\n\t\tThe best way was done in 2 operations (either condition 1 or condition 3).\n\t\tExample 2:\n\t\tInput: a = \"dabadd\", b = \"cda\"\n\t\tOutput: 3\n\t\tExplanation: The best way is to make condition 1 true by changing b to \"eee\".\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1860, - "question": "class Solution:\n def kthLargestValue(self, matrix: List[List[int]], k: int) -> int:\n\t\t\"\"\"\n\t\tYou are given a 2D matrix of size m x n, consisting of non-negative integers. You are also given an integer k.\n\t\tThe value of coordinate (a, b) of the matrix is the XOR of all matrix[i][j] where 0 <= i <= a < m and 0 <= j <= b < n (0-indexed).\n\t\tFind the kth largest value (1-indexed) of all the coordinates of matrix.\n\t\tExample 1:\n\t\tInput: matrix = [[5,2],[1,6]], k = 1\n\t\tOutput: 7\n\t\tExplanation: The value of coordinate (0,1) is 5 XOR 2 = 7, which is the largest value.\n\t\tExample 2:\n\t\tInput: matrix = [[5,2],[1,6]], k = 2\n\t\tOutput: 5\n\t\tExplanation: The value of coordinate (0,0) is 5 = 5, which is the 2nd largest value.\n\t\tExample 3:\n\t\tInput: matrix = [[5,2],[1,6]], k = 3\n\t\tOutput: 4\n\t\tExplanation: The value of coordinate (1,0) is 5 XOR 1 = 4, which is the 3rd largest value.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1861, - "question": "class Solution:\n def minimumBoxes(self, n: int) -> int:\n\t\t\"\"\"\n\t\tYou have a cubic storeroom where the width, length, and height of the room are all equal to n units. You are asked to place n boxes in this room where each box is a cube of unit side length. There are however some rules to placing the boxes:\n\t\t\tYou can place the boxes anywhere on the floor.\n\t\t\tIf box x is placed on top of the box y, then each side of the four vertical sides of the box y must either be adjacent to another box or to a wall.\n\t\tGiven an integer n, return the minimum possible number of boxes touching the floor.\n\t\tExample 1:\n\t\tInput: n = 3\n\t\tOutput: 3\n\t\tExplanation: The figure above is for the placement of the three boxes.\n\t\tThese boxes are placed in the corner of the room, where the corner is on the left side.\n\t\tExample 2:\n\t\tInput: n = 4\n\t\tOutput: 3\n\t\tExplanation: The figure above is for the placement of the four boxes.\n\t\tThese boxes are placed in the corner of the room, where the corner is on the left side.\n\t\tExample 3:\n\t\tInput: n = 10\n\t\tOutput: 6\n\t\tExplanation: The figure above is for the placement of the ten boxes.\n\t\tThese boxes are placed in the corner of the room, where the corner is on the back side.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1866, - "question": "class Solution:\n def restoreArray(self, adjacentPairs: List[List[int]]) -> List[int]:\n\t\t\"\"\"\n\t\tThere is an integer array nums that consists of n unique elements, but you have forgotten it. However, you do remember every pair of adjacent elements in nums.\n\t\tYou are given a 2D integer array adjacentPairs of size n - 1 where each adjacentPairs[i] = [ui, vi] indicates that the elements ui and vi are adjacent in nums.\n\t\tIt is guaranteed that every adjacent pair of elements nums[i] and nums[i+1] will exist in adjacentPairs, either as [nums[i], nums[i+1]] or [nums[i+1], nums[i]]. The pairs can appear in any order.\n\t\tReturn the original array nums. If there are multiple solutions, return any of them.\n\t\tExample 1:\n\t\tInput: adjacentPairs = [[2,1],[3,4],[3,2]]\n\t\tOutput: [1,2,3,4]\n\t\tExplanation: This array has all its adjacent pairs in adjacentPairs.\n\t\tNotice that adjacentPairs[i] may not be in left-to-right order.\n\t\tExample 2:\n\t\tInput: adjacentPairs = [[4,-2],[1,4],[-3,1]]\n\t\tOutput: [-2,4,1,-3]\n\t\tExplanation: There can be negative numbers.\n\t\tAnother solution is [-3,1,4,-2], which would also be accepted.\n\t\tExample 3:\n\t\tInput: adjacentPairs = [[100000,-100000]]\n\t\tOutput: [100000,-100000]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1871, - "question": "class Solution:\n def checkPartitioning(self, s: str) -> bool:\n\t\t\"\"\"\n\t\tGiven a string s, return true if it is possible to split the string s into three non-empty palindromic substrings. Otherwise, return false.\u200b\u200b\u200b\u200b\u200b\n\t\tA string is said to be palindrome if it the same string when reversed.\n\t\tExample 1:\n\t\tInput: s = \"abcbdd\"\n\t\tOutput: true\n\t\tExplanation: \"abcbdd\" = \"a\" + \"bcb\" + \"dd\", and all three substrings are palindromes.\n\t\tExample 2:\n\t\tInput: s = \"bcbddxy\"\n\t\tOutput: false\n\t\tExplanation: s cannot be split into 3 palindromes.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1872, - "question": "class Solution:\n def canEat(self, candiesCount: List[int], queries: List[List[int]]) -> List[bool]:\n\t\t\"\"\"\n\t\tYou are given a (0-indexed) array of positive integers candiesCount where candiesCount[i] represents the number of candies of the ith type you have. You are also given a 2D array queries where queries[i] = [favoriteTypei, favoriteDayi, dailyCapi].\n\t\tYou play a game with the following rules:\n\t\t\tYou start eating candies on day 0.\n\t\t\tYou cannot eat any candy of type i unless you have eaten all candies of type i - 1.\n\t\t\tYou must eat at least one candy per day until you have eaten all the candies.\n\t\tConstruct a boolean array answer such that answer.length == queries.length and answer[i] is true if you can eat a candy of type favoriteTypei on day favoriteDayi without eating more than dailyCapi candies on any day, and false otherwise. Note that you can eat different types of candy on the same day, provided that you follow rule 2.\n\t\tReturn the constructed array answer.\n\t\tExample 1:\n\t\tInput: candiesCount = [7,4,5,3,8], queries = [[0,2,2],[4,2,4],[2,13,1000000000]]\n\t\tOutput: [true,false,true]\n\t\tExplanation:\n\t\t1- If you eat 2 candies (type 0) on day 0 and 2 candies (type 0) on day 1, you will eat a candy of type 0 on day 2.\n\t\t2- You can eat at most 4 candies each day.\n\t\t If you eat 4 candies every day, you will eat 4 candies (type 0) on day 0 and 4 candies (type 0 and type 1) on day 1.\n\t\t On day 2, you can only eat 4 candies (type 1 and type 2), so you cannot eat a candy of type 4 on day 2.\n\t\t3- If you eat 1 candy each day, you will eat a candy of type 2 on day 13.\n\t\tExample 2:\n\t\tInput: candiesCount = [5,2,6,4,1], queries = [[3,1,2],[4,10,3],[3,10,100],[4,100,30],[1,3,1]]\n\t\tOutput: [false,true,true,false,false]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1873, - "question": "class Solution:\n def longestNiceSubstring(self, s: str) -> str:\n\t\t\"\"\"\n\t\tA string s is nice if, for every letter of the alphabet that s contains, it appears both in uppercase and lowercase. For example, \"abABB\" is nice because 'A' and 'a' appear, and 'B' and 'b' appear. However, \"abA\" is not because 'b' appears, but 'B' does not.\n\t\tGiven a string s, return the longest substring of s that is nice. If there are multiple, return the substring of the earliest occurrence. If there are none, return an empty string.\n\t\tExample 1:\n\t\tInput: s = \"YazaAay\"\n\t\tOutput: \"aAa\"\n\t\tExplanation: \"aAa\" is a nice string because 'A/a' is the only letter of the alphabet in s, and both 'A' and 'a' appear.\n\t\t\"aAa\" is the longest nice substring.\n\t\tExample 2:\n\t\tInput: s = \"Bb\"\n\t\tOutput: \"Bb\"\n\t\tExplanation: \"Bb\" is a nice string because both 'B' and 'b' appear. The whole string is a substring.\n\t\tExample 3:\n\t\tInput: s = \"c\"\n\t\tOutput: \"\"\n\t\tExplanation: There are no nice substrings.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1874, - "question": "class Solution:\n def canChoose(self, groups: List[List[int]], nums: List[int]) -> bool:\n\t\t\"\"\"\n\t\tYou are given a 2D integer array groups of length n. You are also given an integer array nums.\n\t\tYou are asked if you can choose n disjoint subarrays from the array nums such that the ith subarray is equal to groups[i] (0-indexed), and if i > 0, the (i-1)th subarray appears before the ith subarray in nums (i.e. the subarrays must be in the same order as groups).\n\t\tReturn true if you can do this task, and false otherwise.\n\t\tNote that the subarrays are disjoint if and only if there is no index k such that nums[k] belongs to more than one subarray. A subarray is a contiguous sequence of elements within an array.\n\t\tExample 1:\n\t\tInput: groups = [[1,-1,-1],[3,-2,0]], nums = [1,-1,0,1,-1,-1,3,-2,0]\n\t\tOutput: true\n\t\tExplanation: You can choose the 0th subarray as [1,-1,0,1,-1,-1,3,-2,0] and the 1st one as [1,-1,0,1,-1,-1,3,-2,0].\n\t\tThese subarrays are disjoint as they share no common nums[k] element.\n\t\tExample 2:\n\t\tInput: groups = [[10,-2],[1,2,3,4]], nums = [1,2,3,4,10,-2]\n\t\tOutput: false\n\t\tExplanation: Note that choosing the subarrays [1,2,3,4,10,-2] and [1,2,3,4,10,-2] is incorrect because they are not in the same order as in groups.\n\t\t[10,-2] must come before [1,2,3,4].\n\t\tExample 3:\n\t\tInput: groups = [[1,2,3],[3,4]], nums = [7,7,1,2,3,4,7,7]\n\t\tOutput: false\n\t\tExplanation: Note that choosing the subarrays [7,7,1,2,3,4,7,7] and [7,7,1,2,3,4,7,7] is invalid because they are not disjoint.\n\t\tThey share a common elements nums[4] (0-indexed).\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1875, - "question": "class Solution:\n def getCoprimes(self, nums: List[int], edges: List[List[int]]) -> List[int]:\n\t\t\"\"\"\n\t\tThere is a tree (i.e., a connected, undirected graph that has no cycles) consisting of n nodes numbered from 0 to n - 1 and exactly n - 1 edges. Each node has a value associated with it, and the root of the tree is node 0.\n\t\tTo represent this tree, you are given an integer array nums and a 2D array edges. Each nums[i] represents the ith node's value, and each edges[j] = [uj, vj] represents an edge between nodes uj and vj in the tree.\n\t\tTwo values x and y are coprime if gcd(x, y) == 1 where gcd(x, y) is the greatest common divisor of x and y.\n\t\tAn ancestor of a node i is any other node on the shortest path from node i to the root. A node is not considered an ancestor of itself.\n\t\tReturn an array ans of size n, where ans[i] is the closest ancestor to node i such that nums[i] and nums[ans[i]] are coprime, or -1 if there is no such ancestor.\n\t\tExample 1:\n\t\tInput: nums = [2,3,3,2], edges = [[0,1],[1,2],[1,3]]\n\t\tOutput: [-1,0,0,1]\n\t\tExplanation: In the above figure, each node's value is in parentheses.\n\t\t- Node 0 has no coprime ancestors.\n\t\t- Node 1 has only one ancestor, node 0. Their values are coprime (gcd(2,3) == 1).\n\t\t- Node 2 has two ancestors, nodes 1 and 0. Node 1's value is not coprime (gcd(3,3) == 3), but node 0's\n\t\t value is (gcd(2,3) == 1), so node 0 is the closest valid ancestor.\n\t\t- Node 3 has two ancestors, nodes 1 and 0. It is coprime with node 1 (gcd(3,2) == 1), so node 1 is its\n\t\t closest valid ancestor.\n\t\tExample 2:\n\t\tInput: nums = [5,6,10,2,3,6,15], edges = [[0,1],[0,2],[1,3],[1,4],[2,5],[2,6]]\n\t\tOutput: [-1,0,-1,0,0,0,-1]\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1876, - "question": "class Solution:\n def highestPeak(self, isWater: List[List[int]]) -> List[List[int]]:\n\t\t\"\"\"\n\t\tYou are given an integer matrix isWater of size m x n that represents a map of land and water cells.\n\t\t\tIf isWater[i][j] == 0, cell (i, j) is a land cell.\n\t\t\tIf isWater[i][j] == 1, cell (i, j) is a water cell.\n\t\tYou must assign each cell a height in a way that follows these rules:\n\t\t\tThe height of each cell must be non-negative.\n\t\t\tIf the cell is a water cell, its height must be 0.\n\t\t\tAny two adjacent cells must have an absolute height difference of at most 1. A cell is adjacent to another cell if the former is directly north, east, south, or west of the latter (i.e., their sides are touching).\n\t\tFind an assignment of heights such that the maximum height in the matrix is maximized.\n\t\tReturn an integer matrix height of size m x n where height[i][j] is cell (i, j)'s height. If there are multiple solutions, return any of them.\n\t\tExample 1:\n\t\tInput: isWater = [[0,1],[0,0]]\n\t\tOutput: [[1,0],[2,1]]\n\t\tExplanation: The image shows the assigned heights of each cell.\n\t\tThe blue cell is the water cell, and the green cells are the land cells.\n\t\tExample 2:\n\t\tInput: isWater = [[0,0,1],[1,0,0],[0,0,0]]\n\t\tOutput: [[1,1,0],[0,1,1],[1,2,2]]\n\t\tExplanation: A height of 2 is the maximum possible height of any assignment.\n\t\tAny height assignment that has a maximum height of 2 while still meeting the rules will also be accepted.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1878, - "question": "class Solution:\n def check(self, nums: List[int]) -> bool:\n\t\t\"\"\"\n\t\tGiven an array nums, return true if the array was originally sorted in non-decreasing order, then rotated some number of positions (including zero). Otherwise, return false.\n\t\tThere may be duplicates in the original array.\n\t\tNote: An array A rotated by x positions results in an array B of the same length such that A[i] == B[(i+x) % A.length], where % is the modulo operation.\n\t\tExample 1:\n\t\tInput: nums = [3,4,5,1,2]\n\t\tOutput: true\n\t\tExplanation: [1,2,3,4,5] is the original sorted array.\n\t\tYou can rotate the array by x = 3 positions to begin on the the element of value 3: [3,4,5,1,2].\n\t\tExample 2:\n\t\tInput: nums = [2,1,3,4]\n\t\tOutput: false\n\t\tExplanation: There is no sorted array once rotated that can make nums.\n\t\tExample 3:\n\t\tInput: nums = [1,2,3]\n\t\tOutput: true\n\t\tExplanation: [1,2,3] is the original sorted array.\n\t\tYou can rotate the array by x = 0 positions (i.e. no rotation) to make nums.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1879, - "question": "class Solution:\n def maximumScore(self, a: int, b: int, c: int) -> int:\n\t\t\"\"\"\n\t\tYou are playing a solitaire game with three piles of stones of sizes a\u200b\u200b\u200b\u200b\u200b\u200b, b,\u200b\u200b\u200b\u200b\u200b\u200b and c\u200b\u200b\u200b\u200b\u200b\u200b respectively. Each turn you choose two different non-empty piles, take one stone from each, and add 1 point to your score. The game stops when there are fewer than two non-empty piles (meaning there are no more available moves).\n\t\tGiven three integers a\u200b\u200b\u200b\u200b\u200b, b,\u200b\u200b\u200b\u200b\u200b and c\u200b\u200b\u200b\u200b\u200b, return the maximum score you can get.\n\t\tExample 1:\n\t\tInput: a = 2, b = 4, c = 6\n\t\tOutput: 6\n\t\tExplanation: The starting state is (2, 4, 6). One optimal set of moves is:\n\t\t- Take from 1st and 3rd piles, state is now (1, 4, 5)\n\t\t- Take from 1st and 3rd piles, state is now (0, 4, 4)\n\t\t- Take from 2nd and 3rd piles, state is now (0, 3, 3)\n\t\t- Take from 2nd and 3rd piles, state is now (0, 2, 2)\n\t\t- Take from 2nd and 3rd piles, state is now (0, 1, 1)\n\t\t- Take from 2nd and 3rd piles, state is now (0, 0, 0)\n\t\tThere are fewer than two non-empty piles, so the game ends. Total: 6 points.\n\t\tExample 2:\n\t\tInput: a = 4, b = 4, c = 6\n\t\tOutput: 7\n\t\tExplanation: The starting state is (4, 4, 6). One optimal set of moves is:\n\t\t- Take from 1st and 2nd piles, state is now (3, 3, 6)\n\t\t- Take from 1st and 3rd piles, state is now (2, 3, 5)\n\t\t- Take from 1st and 3rd piles, state is now (1, 3, 4)\n\t\t- Take from 1st and 3rd piles, state is now (0, 3, 3)\n\t\t- Take from 2nd and 3rd piles, state is now (0, 2, 2)\n\t\t- Take from 2nd and 3rd piles, state is now (0, 1, 1)\n\t\t- Take from 2nd and 3rd piles, state is now (0, 0, 0)\n\t\tThere are fewer than two non-empty piles, so the game ends. Total: 7 points.\n\t\tExample 3:\n\t\tInput: a = 1, b = 8, c = 8\n\t\tOutput: 8\n\t\tExplanation: One optimal set of moves is to take from the 2nd and 3rd piles for 8 turns until they are empty.\n\t\tAfter that, there are fewer than two non-empty piles, so the game ends.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1880, - "question": "class Solution:\n def largestMerge(self, word1: str, word2: str) -> str:\n\t\t\"\"\"\n\t\tYou are given two strings word1 and word2. You want to construct a string merge in the following way: while either word1 or word2 are non-empty, choose one of the following options:\n\t\t\tIf word1 is non-empty, append the first character in word1 to merge and delete it from word1.\n\t\t\t\tFor example, if word1 = \"abc\" and merge = \"dv\", then after choosing this operation, word1 = \"bc\" and merge = \"dva\".\n\t\t\tIf word2 is non-empty, append the first character in word2 to merge and delete it from word2.\n\t\t\t\tFor example, if word2 = \"abc\" and merge = \"\", then after choosing this operation, word2 = \"bc\" and merge = \"a\".\n\t\tReturn the lexicographically largest merge you can construct.\n\t\tA string a is lexicographically larger than a string b (of the same length) if in the first position where a and b differ, a has a character strictly larger than the corresponding character in b. For example, \"abcd\" is lexicographically larger than \"abcc\" because the first position they differ is at the fourth character, and d is greater than c.\n\t\tExample 1:\n\t\tInput: word1 = \"cabaa\", word2 = \"bcaaa\"\n\t\tOutput: \"cbcabaaaaa\"\n\t\tExplanation: One way to get the lexicographically largest merge is:\n\t\t- Take from word1: merge = \"c\", word1 = \"abaa\", word2 = \"bcaaa\"\n\t\t- Take from word2: merge = \"cb\", word1 = \"abaa\", word2 = \"caaa\"\n\t\t- Take from word2: merge = \"cbc\", word1 = \"abaa\", word2 = \"aaa\"\n\t\t- Take from word1: merge = \"cbca\", word1 = \"baa\", word2 = \"aaa\"\n\t\t- Take from word1: merge = \"cbcab\", word1 = \"aa\", word2 = \"aaa\"\n\t\t- Append the remaining 5 a's from word1 and word2 at the end of merge.\n\t\tExample 2:\n\t\tInput: word1 = \"abcabc\", word2 = \"abdcaba\"\n\t\tOutput: \"abdcabcabcaba\"\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1881, - "question": "class Solution:\n def minAbsDifference(self, nums: List[int], goal: int) -> int:\n\t\t\"\"\"\n\t\tYou are given an integer array nums and an integer goal.\n\t\tYou want to choose a subsequence of nums such that the sum of its elements is the closest possible to goal. That is, if the sum of the subsequence's elements is sum, then you want to minimize the absolute difference abs(sum - goal).\n\t\tReturn the minimum possible value of abs(sum - goal).\n\t\tNote that a subsequence of an array is an array formed by removing some elements (possibly all or none) of the original array.\n\t\tExample 1:\n\t\tInput: nums = [5,-7,3,5], goal = 6\n\t\tOutput: 0\n\t\tExplanation: Choose the whole array as a subsequence, with a sum of 6.\n\t\tThis is equal to the goal, so the absolute difference is 0.\n\t\tExample 2:\n\t\tInput: nums = [7,-9,15,-2], goal = -5\n\t\tOutput: 1\n\t\tExplanation: Choose the subsequence [7,-9,-2], with a sum of -4.\n\t\tThe absolute difference is abs(-4 - (-5)) = abs(1) = 1, which is the minimum.\n\t\tExample 3:\n\t\tInput: nums = [1,2,3], goal = -7\n\t\tOutput: 7\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1884, - "question": "class Solution:\n def minOperations(self, s: str) -> int:\n\t\t\"\"\"\n\t\tYou are given a string s consisting only of the characters '0' and '1'. In one operation, you can change any '0' to '1' or vice versa.\n\t\tThe string is called alternating if no two adjacent characters are equal. For example, the string \"010\" is alternating, while the string \"0100\" is not.\n\t\tReturn the minimum number of operations needed to make s alternating.\n\t\tExample 1:\n\t\tInput: s = \"0100\"\n\t\tOutput: 1\n\t\tExplanation: If you change the last character to '1', s will be \"0101\", which is alternating.\n\t\tExample 2:\n\t\tInput: s = \"10\"\n\t\tOutput: 0\n\t\tExplanation: s is already alternating.\n\t\tExample 3:\n\t\tInput: s = \"1111\"\n\t\tOutput: 2\n\t\tExplanation: You need two operations to reach \"0101\" or \"1010\".\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1885, - "question": "class Solution:\n def countHomogenous(self, s: str) -> int:\n\t\t\"\"\"\n\t\tGiven a string s, return the number of homogenous substrings of s. Since the answer may be too large, return it modulo 109 + 7.\r\n\t\tA string is homogenous if all the characters of the string are the same.\r\n\t\tA substring is a contiguous sequence of characters within a string.\r\n\t\tExample 1:\r\n\t\tInput: s = \"abbcccaa\"\r\n\t\tOutput: 13\r\n\t\tExplanation: The homogenous substrings are listed as below:\r\n\t\t\"a\" appears 3 times.\r\n\t\t\"aa\" appears 1 time.\r\n\t\t\"b\" appears 2 times.\r\n\t\t\"bb\" appears 1 time.\r\n\t\t\"c\" appears 3 times.\r\n\t\t\"cc\" appears 2 times.\r\n\t\t\"ccc\" appears 1 time.\r\n\t\t3 + 1 + 2 + 1 + 3 + 2 + 1 = 13.\r\n\t\tExample 2:\r\n\t\tInput: s = \"xy\"\r\n\t\tOutput: 2\r\n\t\tExplanation: The homogenous substrings are \"x\" and \"y\".\r\n\t\tExample 3:\r\n\t\tInput: s = \"zzzzz\"\r\n\t\tOutput: 15\r\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1886, - "question": "class Solution:\n def minimumSize(self, nums: List[int], maxOperations: int) -> int:\n\t\t\"\"\"\n\t\tYou are given an integer array nums where the ith bag contains nums[i] balls. You are also given an integer maxOperations.\n\t\tYou can perform the following operation at most maxOperations times:\n\t\t\tTake any bag of balls and divide it into two new bags with a positive number of balls.\n\t\t\t\tFor example, a bag of 5 balls can become two new bags of 1 and 4 balls, or two new bags of 2 and 3 balls.\n\t\tYour penalty is the maximum number of balls in a bag. You want to minimize your penalty after the operations.\n\t\tReturn the minimum possible penalty after performing the operations.\n\t\tExample 1:\n\t\tInput: nums = [9], maxOperations = 2\n\t\tOutput: 3\n\t\tExplanation: \n\t\t- Divide the bag with 9 balls into two bags of sizes 6 and 3. [9] -> [6,3].\n\t\t- Divide the bag with 6 balls into two bags of sizes 3 and 3. [6,3] -> [3,3,3].\n\t\tThe bag with the most number of balls has 3 balls, so your penalty is 3 and you should return 3.\n\t\tExample 2:\n\t\tInput: nums = [2,4,8,2], maxOperations = 4\n\t\tOutput: 2\n\t\tExplanation:\n\t\t- Divide the bag with 8 balls into two bags of sizes 4 and 4. [2,4,8,2] -> [2,4,4,4,2].\n\t\t- Divide the bag with 4 balls into two bags of sizes 2 and 2. [2,4,4,4,2] -> [2,2,2,4,4,2].\n\t\t- Divide the bag with 4 balls into two bags of sizes 2 and 2. [2,2,2,4,4,2] -> [2,2,2,2,2,4,2].\n\t\t- Divide the bag with 4 balls into two bags of sizes 2 and 2. [2,2,2,2,2,4,2] -> [2,2,2,2,2,2,2,2].\n\t\tThe bag with the most number of balls has 2 balls, so your penalty is 2, and you should return 2.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1887, - "question": "class Solution:\n def minTrioDegree(self, n: int, edges: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tYou are given an undirected graph. You are given an integer n which is the number of nodes in the graph and an array edges, where each edges[i] = [ui, vi] indicates that there is an undirected edge between ui and vi.\n\t\tA connected trio is a set of three nodes where there is an edge between every pair of them.\n\t\tThe degree of a connected trio is the number of edges where one endpoint is in the trio, and the other is not.\n\t\tReturn the minimum degree of a connected trio in the graph, or -1 if the graph has no connected trios.\n\t\tExample 1:\n\t\tInput: n = 6, edges = [[1,2],[1,3],[3,2],[4,1],[5,2],[3,6]]\n\t\tOutput: 3\n\t\tExplanation: There is exactly one trio, which is [1,2,3]. The edges that form its degree are bolded in the figure above.\n\t\tExample 2:\n\t\tInput: n = 7, edges = [[1,3],[4,1],[4,3],[2,5],[5,6],[6,7],[7,5],[2,6]]\n\t\tOutput: 0\n\t\tExplanation: There are exactly three trios:\n\t\t1) [1,4,3] with degree 0.\n\t\t2) [2,5,6] with degree 2.\n\t\t3) [5,6,7] with degree 2.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1888, - "question": "class Solution:\n def nearestValidPoint(self, x: int, y: int, points: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tYou are given two integers, x and y, which represent your current location on a Cartesian grid: (x, y). You are also given an array points where each points[i] = [ai, bi] represents that a point exists at (ai, bi). A point is valid if it shares the same x-coordinate or the same y-coordinate as your location.\n\t\tReturn the index (0-indexed) of the valid point with the smallest Manhattan distance from your current location. If there are multiple, return the valid point with the smallest index. If there are no valid points, return -1.\n\t\tThe Manhattan distance between two points (x1, y1) and (x2, y2) is abs(x1 - x2) + abs(y1 - y2).\n\t\tExample 1:\n\t\tInput: x = 3, y = 4, points = [[1,2],[3,1],[2,4],[2,3],[4,4]]\n\t\tOutput: 2\n\t\tExplanation: Of all the points, only [3,1], [2,4] and [4,4] are valid. Of the valid points, [2,4] and [4,4] have the smallest Manhattan distance from your current location, with a distance of 1. [2,4] has the smallest index, so return 2.\n\t\tExample 2:\n\t\tInput: x = 3, y = 4, points = [[3,4]]\n\t\tOutput: 0\n\t\tExplanation: The answer is allowed to be on the same location as your current location.\n\t\tExample 3:\n\t\tInput: x = 3, y = 4, points = [[2,3]]\n\t\tOutput: -1\n\t\tExplanation: There are no valid points.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1889, - "question": "class Solution:\n def checkPowersOfThree(self, n: int) -> bool:\n\t\t\"\"\"\n\t\tGiven an integer n, return true if it is possible to represent n as the sum of distinct powers of three. Otherwise, return false.\n\t\tAn integer y is a power of three if there exists an integer x such that y == 3x.\n\t\tExample 1:\n\t\tInput: n = 12\n\t\tOutput: true\n\t\tExplanation: 12 = 31 + 32\n\t\tExample 2:\n\t\tInput: n = 91\n\t\tOutput: true\n\t\tExplanation: 91 = 30 + 32 + 34\n\t\tExample 3:\n\t\tInput: n = 21\n\t\tOutput: false\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1890, - "question": "class Solution:\n def beautySum(self, s: str) -> int:\n\t\t\"\"\"\n\t\tThe beauty of a string is the difference in frequencies between the most frequent and least frequent characters.\n\t\t\tFor example, the beauty of \"abaacc\" is 3 - 1 = 2.\n\t\tGiven a string s, return the sum of beauty of all of its substrings.\n\t\tExample 1:\n\t\tInput: s = \"aabcb\"\n\t\tOutput: 5\n\t\tExplanation: The substrings with non-zero beauty are [\"aab\",\"aabc\",\"aabcb\",\"abcb\",\"bcb\"], each with beauty equal to 1.\n\t\tExample 2:\n\t\tInput: s = \"aabcbaa\"\n\t\tOutput: 17\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1891, - "question": "class Solution:\n def countPairs(self, n: int, edges: List[List[int]], queries: List[int]) -> List[int]:\n\t\t\"\"\"\n\t\tYou are given an undirected graph defined by an integer n, the number of nodes, and a 2D integer array edges, the edges in the graph, where edges[i] = [ui, vi] indicates that there is an undirected edge between ui and vi. You are also given an integer array queries.\n\t\tLet incident(a, b) be defined as the number of edges that are connected to either node a or b.\n\t\tThe answer to the jth query is the number of pairs of nodes (a, b) that satisfy both of the following conditions:\n\t\t\ta < b\n\t\t\tincident(a, b) > queries[j]\n\t\tReturn an array answers such that answers.length == queries.length and answers[j] is the answer of the jth query.\n\t\tNote that there can be multiple edges between the same two nodes.\n\t\tExample 1:\n\t\tInput: n = 4, edges = [[1,2],[2,4],[1,3],[2,3],[2,1]], queries = [2,3]\n\t\tOutput: [6,5]\n\t\tExplanation: The calculations for incident(a, b) are shown in the table above.\n\t\tThe answers for each of the queries are as follows:\n\t\t- answers[0] = 6. All the pairs have an incident(a, b) value greater than 2.\n\t\t- answers[1] = 5. All the pairs except (3, 4) have an incident(a, b) value greater than 3.\n\t\tExample 2:\n\t\tInput: n = 5, edges = [[1,5],[1,5],[3,4],[2,5],[1,3],[5,1],[2,3],[2,5]], queries = [1,2,3,4,5]\n\t\tOutput: [10,10,9,8,6]\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1894, - "question": "class Solution:\n def mergeAlternately(self, word1: str, word2: str) -> str:\n\t\t\"\"\"\n\t\tYou are given two strings word1 and word2. Merge the strings by adding letters in alternating order, starting with word1. If a string is longer than the other, append the additional letters onto the end of the merged string.\r\n\t\tReturn the merged string.\r\n\t\tExample 1:\r\n\t\tInput: word1 = \"abc\", word2 = \"pqr\"\r\n\t\tOutput: \"apbqcr\"\r\n\t\tExplanation: The merged string will be merged as so:\r\n\t\tword1: a b c\r\n\t\tword2: p q r\r\n\t\tmerged: a p b q c r\r\n\t\tExample 2:\r\n\t\tInput: word1 = \"ab\", word2 = \"pqrs\"\r\n\t\tOutput: \"apbqrs\"\r\n\t\tExplanation: Notice that as word2 is longer, \"rs\" is appended to the end.\r\n\t\tword1: a b \r\n\t\tword2: p q r s\r\n\t\tmerged: a p b q r s\r\n\t\tExample 3:\r\n\t\tInput: word1 = \"abcd\", word2 = \"pq\"\r\n\t\tOutput: \"apbqcd\"\r\n\t\tExplanation: Notice that as word1 is longer, \"cd\" is appended to the end.\r\n\t\tword1: a b c d\r\n\t\tword2: p q \r\n\t\tmerged: a p b q c d\r\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1895, - "question": "class Solution:\n def minOperations(self, boxes: str) -> List[int]:\n\t\t\"\"\"\n\t\tYou have n boxes. You are given a binary string boxes of length n, where boxes[i] is '0' if the ith box is empty, and '1' if it contains one ball.\n\t\tIn one operation, you can move one ball from a box to an adjacent box. Box i is adjacent to box j if abs(i - j) == 1. Note that after doing so, there may be more than one ball in some boxes.\n\t\tReturn an array answer of size n, where answer[i] is the minimum number of operations needed to move all the balls to the ith box.\n\t\tEach answer[i] is calculated considering the initial state of the boxes.\n\t\tExample 1:\n\t\tInput: boxes = \"110\"\n\t\tOutput: [1,1,3]\n\t\tExplanation: The answer for each box is as follows:\n\t\t1) First box: you will have to move one ball from the second box to the first box in one operation.\n\t\t2) Second box: you will have to move one ball from the first box to the second box in one operation.\n\t\t3) Third box: you will have to move one ball from the first box to the third box in two operations, and move one ball from the second box to the third box in one operation.\n\t\tExample 2:\n\t\tInput: boxes = \"001011\"\n\t\tOutput: [11,8,5,4,3,4]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1896, - "question": "class Solution:\n def maximumScore(self, nums: List[int], multipliers: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou are given two 0-indexed integer arrays nums and multipliers of size n and m respectively, where n >= m.\n\t\tYou begin with a score of 0. You want to perform exactly m operations. On the ith operation (0-indexed) you will:\n\t\t Choose one integer x from either the start or the end of the array nums.\n\t\t Add multipliers[i] * x to your score.\n\t\t Note that multipliers[0] corresponds to the first operation, multipliers[1] to the second operation, and so on.\n\t\t Remove x from nums.\n\t\tReturn the maximum score after performing m operations.\n\t\tExample 1:\n\t\tInput: nums = [1,2,3], multipliers = [3,2,1]\n\t\tOutput: 14\n\t\tExplanation: An optimal solution is as follows:\n\t\t- Choose from the end, [1,2,3], adding 3 * 3 = 9 to the score.\n\t\t- Choose from the end, [1,2], adding 2 * 2 = 4 to the score.\n\t\t- Choose from the end, [1], adding 1 * 1 = 1 to the score.\n\t\tThe total score is 9 + 4 + 1 = 14.\n\t\tExample 2:\n\t\tInput: nums = [-5,-3,-3,-2,7,1], multipliers = [-10,-5,3,4,6]\n\t\tOutput: 102\n\t\tExplanation: An optimal solution is as follows:\n\t\t- Choose from the start, [-5,-3,-3,-2,7,1], adding -5 * -10 = 50 to the score.\n\t\t- Choose from the start, [-3,-3,-2,7,1], adding -3 * -5 = 15 to the score.\n\t\t- Choose from the start, [-3,-2,7,1], adding -3 * 3 = -9 to the score.\n\t\t- Choose from the end, [-2,7,1], adding 1 * 4 = 4 to the score.\n\t\t- Choose from the end, [-2,7], adding 7 * 6 = 42 to the score. \n\t\tThe total score is 50 + 15 - 9 + 4 + 42 = 102.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1897, - "question": "class Solution:\n def longestPalindrome(self, word1: str, word2: str) -> int:\n\t\t\"\"\"\n\t\tYou are given two strings, word1 and word2. You want to construct a string in the following manner:\n\t\t\tChoose some non-empty subsequence subsequence1 from word1.\n\t\t\tChoose some non-empty subsequence subsequence2 from word2.\n\t\t\tConcatenate the subsequences: subsequence1 + subsequence2, to make the string.\n\t\tReturn the length of the longest palindrome that can be constructed in the described manner. If no palindromes can be constructed, return 0.\n\t\tA subsequence of a string s is a string that can be made by deleting some (possibly none) characters from s without changing the order of the remaining characters.\n\t\tA palindrome is a string that reads the same forward as well as backward.\n\t\tExample 1:\n\t\tInput: word1 = \"cacb\", word2 = \"cbba\"\n\t\tOutput: 5\n\t\tExplanation: Choose \"ab\" from word1 and \"cba\" from word2 to make \"abcba\", which is a palindrome.\n\t\tExample 2:\n\t\tInput: word1 = \"ab\", word2 = \"ab\"\n\t\tOutput: 3\n\t\tExplanation: Choose \"ab\" from word1 and \"a\" from word2 to make \"aba\", which is a palindrome.\n\t\tExample 3:\n\t\tInput: word1 = \"aa\", word2 = \"bb\"\n\t\tOutput: 0\n\t\tExplanation: You cannot construct a palindrome from the described method, so return 0.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1899, - "question": "class Solution:\n def countMatches(self, items: List[List[str]], ruleKey: str, ruleValue: str) -> int:\n\t\t\"\"\"\n\t\tYou are given an array items, where each items[i] = [typei, colori, namei] describes the type, color, and name of the ith item. You are also given a rule represented by two strings, ruleKey and ruleValue.\n\t\tThe ith item is said to match the rule if one of the following is true:\n\t\t\truleKey == \"type\" and ruleValue == typei.\n\t\t\truleKey == \"color\" and ruleValue == colori.\n\t\t\truleKey == \"name\" and ruleValue == namei.\n\t\tReturn the number of items that match the given rule.\n\t\tExample 1:\n\t\tInput: items = [[\"phone\",\"blue\",\"pixel\"],[\"computer\",\"silver\",\"lenovo\"],[\"phone\",\"gold\",\"iphone\"]], ruleKey = \"color\", ruleValue = \"silver\"\n\t\tOutput: 1\n\t\tExplanation: There is only one item matching the given rule, which is [\"computer\",\"silver\",\"lenovo\"].\n\t\tExample 2:\n\t\tInput: items = [[\"phone\",\"blue\",\"pixel\"],[\"computer\",\"silver\",\"phone\"],[\"phone\",\"gold\",\"iphone\"]], ruleKey = \"type\", ruleValue = \"phone\"\n\t\tOutput: 2\n\t\tExplanation: There are only two items matching the given rule, which are [\"phone\",\"blue\",\"pixel\"] and [\"phone\",\"gold\",\"iphone\"]. Note that the item [\"computer\",\"silver\",\"phone\"] does not match.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1900, - "question": "class Solution:\n def closestCost(self, baseCosts: List[int], toppingCosts: List[int], target: int) -> int:\n\t\t\"\"\"\n\t\tYou would like to make dessert and are preparing to buy the ingredients. You have n ice cream base flavors and m types of toppings to choose from. You must follow these rules when making your dessert:\n\t\t\tThere must be exactly one ice cream base.\n\t\t\tYou can add one or more types of topping or have no toppings at all.\n\t\t\tThere are at most two of each type of topping.\n\t\tYou are given three inputs:\n\t\t\tbaseCosts, an integer array of length n, where each baseCosts[i] represents the price of the ith ice cream base flavor.\n\t\t\ttoppingCosts, an integer array of length m, where each toppingCosts[i] is the price of one of the ith topping.\n\t\t\ttarget, an integer representing your target price for dessert.\n\t\tYou want to make a dessert with a total cost as close to target as possible.\n\t\tReturn the closest possible cost of the dessert to target. If there are multiple, return the lower one.\n\t\tExample 1:\n\t\tInput: baseCosts = [1,7], toppingCosts = [3,4], target = 10\n\t\tOutput: 10\n\t\tExplanation: Consider the following combination (all 0-indexed):\n\t\t- Choose base 1: cost 7\n\t\t- Take 1 of topping 0: cost 1 x 3 = 3\n\t\t- Take 0 of topping 1: cost 0 x 4 = 0\n\t\tTotal: 7 + 3 + 0 = 10.\n\t\tExample 2:\n\t\tInput: baseCosts = [2,3], toppingCosts = [4,5,100], target = 18\n\t\tOutput: 17\n\t\tExplanation: Consider the following combination (all 0-indexed):\n\t\t- Choose base 1: cost 3\n\t\t- Take 1 of topping 0: cost 1 x 4 = 4\n\t\t- Take 2 of topping 1: cost 2 x 5 = 10\n\t\t- Take 0 of topping 2: cost 0 x 100 = 0\n\t\tTotal: 3 + 4 + 10 + 0 = 17. You cannot make a dessert with a total cost of 18.\n\t\tExample 3:\n\t\tInput: baseCosts = [3,10], toppingCosts = [2,5], target = 9\n\t\tOutput: 8\n\t\tExplanation: It is possible to make desserts with cost 8 and 10. Return 8 as it is the lower cost.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1901, - "question": "class Solution:\n def minOperations(self, nums1: List[int], nums2: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou are given two arrays of integers nums1 and nums2, possibly of different lengths. The values in the arrays are between 1 and 6, inclusive.\n\t\tIn one operation, you can change any integer's value in any of the arrays to any value between 1 and 6, inclusive.\n\t\tReturn the minimum number of operations required to make the sum of values in nums1 equal to the sum of values in nums2. Return -1\u200b\u200b\u200b\u200b\u200b if it is not possible to make the sum of the two arrays equal.\n\t\tExample 1:\n\t\tInput: nums1 = [1,2,3,4,5,6], nums2 = [1,1,2,2,2,2]\n\t\tOutput: 3\n\t\tExplanation: You can make the sums of nums1 and nums2 equal with 3 operations. All indices are 0-indexed.\n\t\t- Change nums2[0] to 6. nums1 = [1,2,3,4,5,6], nums2 = [6,1,2,2,2,2].\n\t\t- Change nums1[5] to 1. nums1 = [1,2,3,4,5,1], nums2 = [6,1,2,2,2,2].\n\t\t- Change nums1[2] to 2. nums1 = [1,2,2,4,5,1], nums2 = [6,1,2,2,2,2].\n\t\tExample 2:\n\t\tInput: nums1 = [1,1,1,1,1,1,1], nums2 = [6]\n\t\tOutput: -1\n\t\tExplanation: There is no way to decrease the sum of nums1 or to increase the sum of nums2 to make them equal.\n\t\tExample 3:\n\t\tInput: nums1 = [6,6], nums2 = [1]\n\t\tOutput: 3\n\t\tExplanation: You can make the sums of nums1 and nums2 equal with 3 operations. All indices are 0-indexed. \n\t\t- Change nums1[0] to 2. nums1 = [2,6], nums2 = [1].\n\t\t- Change nums1[1] to 2. nums1 = [2,2], nums2 = [1].\n\t\t- Change nums2[0] to 4. nums1 = [2,2], nums2 = [4].\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1902, - "question": "class Solution:\n def getCollisionTimes(self, cars: List[List[int]]) -> List[float]:\n\t\t\"\"\"\n\t\tThere are n cars traveling at different speeds in the same direction along a one-lane road. You are given an array cars of length n, where cars[i] = [positioni, speedi] represents:\n\t\t\tpositioni is the distance between the ith car and the beginning of the road in meters. It is guaranteed that positioni < positioni+1.\n\t\t\tspeedi is the initial speed of the ith car in meters per second.\n\t\tFor simplicity, cars can be considered as points moving along the number line. Two cars collide when they occupy the same position. Once a car collides with another car, they unite and form a single car fleet. The cars in the formed fleet will have the same position and the same speed, which is the initial speed of the slowest car in the fleet.\n\t\tReturn an array answer, where answer[i] is the time, in seconds, at which the ith car collides with the next car, or -1 if the car does not collide with the next car. Answers within 10-5 of the actual answers are accepted.\n\t\tExample 1:\n\t\tInput: cars = [[1,2],[2,1],[4,3],[7,2]]\n\t\tOutput: [1.00000,-1.00000,3.00000,-1.00000]\n\t\tExplanation: After exactly one second, the first car will collide with the second car, and form a car fleet with speed 1 m/s. After exactly 3 seconds, the third car will collide with the fourth car, and form a car fleet with speed 2 m/s.\n\t\tExample 2:\n\t\tInput: cars = [[3,4],[5,4],[6,3],[9,1]]\n\t\tOutput: [2.00000,1.00000,1.50000,-1.00000]\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1904, - "question": "class Solution:\n def secondHighest(self, s: str) -> int:\n\t\t\"\"\"\n\t\tGiven an alphanumeric string s, return the second largest numerical digit that appears in s, or -1 if it does not exist.\n\t\tAn alphanumeric string is a string consisting of lowercase English letters and digits.\n\t\tExample 1:\n\t\tInput: s = \"dfa12321afd\"\n\t\tOutput: 2\n\t\tExplanation: The digits that appear in s are [1, 2, 3]. The second largest digit is 2.\n\t\tExample 2:\n\t\tInput: s = \"abc1111\"\n\t\tOutput: -1\n\t\tExplanation: The digits that appear in s are [1]. There is no second largest digit. \n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1905, - "question": "class AuthenticationManager:\n def __init__(self, timeToLive: int):\n def generate(self, tokenId: str, currentTime: int) -> None:\n def renew(self, tokenId: str, currentTime: int) -> None:\n def countUnexpiredTokens(self, currentTime: int) -> int:\n\t\t\"\"\"\n\t\tThere is an authentication system that works with authentication tokens. For each session, the user will receive a new authentication token that will expire timeToLive seconds after the currentTime. If the token is renewed, the expiry time will be extended to expire timeToLive seconds after the (potentially different) currentTime.\n\t\tImplement the AuthenticationManager class:\n\t\t\tAuthenticationManager(int timeToLive) constructs the AuthenticationManager and sets the timeToLive.\n\t\t\tgenerate(string tokenId, int currentTime) generates a new token with the given tokenId at the given currentTime in seconds.\n\t\t\trenew(string tokenId, int currentTime) renews the unexpired token with the given tokenId at the given currentTime in seconds. If there are no unexpired tokens with the given tokenId, the request is ignored, and nothing happens.\n\t\t\tcountUnexpiredTokens(int currentTime) returns the number of unexpired tokens at the given currentTime.\n\t\tNote that if a token expires at time t, and another action happens on time t (renew or countUnexpiredTokens), the expiration takes place before the other actions.\n\t\tExample 1:\n\t\tInput\n\t\t[\"AuthenticationManager\", \"renew\", \"generate\", \"countUnexpiredTokens\", \"generate\", \"renew\", \"renew\", \"countUnexpiredTokens\"]\n\t\t[[5], [\"aaa\", 1], [\"aaa\", 2], [6], [\"bbb\", 7], [\"aaa\", 8], [\"bbb\", 10], [15]]\n\t\tOutput\n\t\t[null, null, null, 1, null, null, null, 0]\n\t\tExplanation\n\t\tAuthenticationManager authenticationManager = new AuthenticationManager(5); // Constructs the AuthenticationManager with timeToLive = 5 seconds.\n\t\tauthenticationManager.renew(\"aaa\", 1); // No token exists with tokenId \"aaa\" at time 1, so nothing happens.\n\t\tauthenticationManager.generate(\"aaa\", 2); // Generates a new token with tokenId \"aaa\" at time 2.\n\t\tauthenticationManager.countUnexpiredTokens(6); // The token with tokenId \"aaa\" is the only unexpired one at time 6, so return 1.\n\t\tauthenticationManager.generate(\"bbb\", 7); // Generates a new token with tokenId \"bbb\" at time 7.\n\t\tauthenticationManager.renew(\"aaa\", 8); // The token with tokenId \"aaa\" expired at time 7, and 8 >= 7, so at time 8 the renew request is ignored, and nothing happens.\n\t\tauthenticationManager.renew(\"bbb\", 10); // The token with tokenId \"bbb\" is unexpired at time 10, so the renew request is fulfilled and now the token will expire at time 15.\n\t\tauthenticationManager.countUnexpiredTokens(15); // The token with tokenId \"bbb\" expires at time 15, and the token with tokenId \"aaa\" expired at time 7, so currently no token is unexpired, so return 0.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1906, - "question": "class Solution:\n def maxScore(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou are given nums, an array of positive integers of size 2 * n. You must perform n operations on this array.\n\t\tIn the ith operation (1-indexed), you will:\n\t\t\tChoose two elements, x and y.\n\t\t\tReceive a score of i * gcd(x, y).\n\t\t\tRemove x and y from nums.\n\t\tReturn the maximum score you can receive after performing n operations.\n\t\tThe function gcd(x, y) is the greatest common divisor of x and y.\n\t\tExample 1:\n\t\tInput: nums = [1,2]\n\t\tOutput: 1\n\t\tExplanation: The optimal choice of operations is:\n\t\t(1 * gcd(1, 2)) = 1\n\t\tExample 2:\n\t\tInput: nums = [3,4,6,8]\n\t\tOutput: 11\n\t\tExplanation: The optimal choice of operations is:\n\t\t(1 * gcd(3, 6)) + (2 * gcd(4, 8)) = 3 + 8 = 11\n\t\tExample 3:\n\t\tInput: nums = [1,2,3,4,5,6]\n\t\tOutput: 14\n\t\tExplanation: The optimal choice of operations is:\n\t\t(1 * gcd(1, 5)) + (2 * gcd(2, 4)) + (3 * gcd(3, 6)) = 1 + 4 + 9 = 14\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1907, - "question": "class Solution:\n def countPairs(self, nums: List[int], low: int, high: int) -> int:\n\t\t\"\"\"\n\t\tGiven a (0-indexed) integer array nums and two integers low and high, return the number of nice pairs.\r\n\t\tA nice pair is a pair (i, j) where 0 <= i < j < nums.length and low <= (nums[i] XOR nums[j]) <= high.\r\n\t\tExample 1:\r\n\t\tInput: nums = [1,4,2,7], low = 2, high = 6\r\n\t\tOutput: 6\r\n\t\tExplanation: All nice pairs (i, j) are as follows:\r\n\t\t - (0, 1): nums[0] XOR nums[1] = 5 \r\n\t\t - (0, 2): nums[0] XOR nums[2] = 3\r\n\t\t - (0, 3): nums[0] XOR nums[3] = 6\r\n\t\t - (1, 2): nums[1] XOR nums[2] = 6\r\n\t\t - (1, 3): nums[1] XOR nums[3] = 3\r\n\t\t - (2, 3): nums[2] XOR nums[3] = 5\r\n\t\tExample 2:\r\n\t\tInput: nums = [9,8,4,2,1], low = 5, high = 14\r\n\t\tOutput: 8\r\n\t\tExplanation: All nice pairs (i, j) are as follows:\r\n\t\t\u200b\u200b\u200b\u200b\u200b - (0, 2): nums[0] XOR nums[2] = 13\r\n\t\t - (0, 3): nums[0] XOR nums[3] = 11\r\n\t\t - (0, 4): nums[0] XOR nums[4] = 8\r\n\t\t - (1, 2): nums[1] XOR nums[2] = 12\r\n\t\t - (1, 3): nums[1] XOR nums[3] = 10\r\n\t\t - (1, 4): nums[1] XOR nums[4] = 9\r\n\t\t - (2, 3): nums[2] XOR nums[3] = 6\r\n\t\t - (2, 4): nums[2] XOR nums[4] = 5\r\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1910, - "question": "class Solution:\n def checkOnesSegment(self, s: str) -> bool:\n\t\t\"\"\"\n\t\tGiven a binary string s \u200b\u200b\u200b\u200b\u200bwithout leading zeros, return true\u200b\u200b\u200b if s contains at most one contiguous segment of ones. Otherwise, return false.\n\t\tExample 1:\n\t\tInput: s = \"1001\"\n\t\tOutput: false\n\t\tExplanation: The ones do not form a contiguous segment.\n\t\tExample 2:\n\t\tInput: s = \"110\"\n\t\tOutput: true\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1911, - "question": "class Solution:\n def minElements(self, nums: List[int], limit: int, goal: int) -> int:\n\t\t\"\"\"\n\t\tYou are given an integer array nums and two integers limit and goal. The array nums has an interesting property that abs(nums[i]) <= limit.\n\t\tReturn the minimum number of elements you need to add to make the sum of the array equal to goal. The array must maintain its property that abs(nums[i]) <= limit.\n\t\tNote that abs(x) equals x if x >= 0, and -x otherwise.\n\t\tExample 1:\n\t\tInput: nums = [1,-1,1], limit = 3, goal = -4\n\t\tOutput: 2\n\t\tExplanation: You can add -2 and -3, then the sum of the array will be 1 - 1 + 1 - 2 - 3 = -4.\n\t\tExample 2:\n\t\tInput: nums = [1,-10,9,1], limit = 100, goal = 0\n\t\tOutput: 1\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1912, - "question": "class Solution:\n def countRestrictedPaths(self, n: int, edges: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tThere is an undirected weighted connected graph. You are given a positive integer n which denotes that the graph has n nodes labeled from 1 to n, and an array edges where each edges[i] = [ui, vi, weighti] denotes that there is an edge between nodes ui and vi with weight equal to weighti.\n\t\tA path from node start to node end is a sequence of nodes [z0, z1, z2, ..., zk] such that z0 = start and zk = end and there is an edge between zi and zi+1 where 0 <= i <= k-1.\n\t\tThe distance of a path is the sum of the weights on the edges of the path. Let distanceToLastNode(x) denote the shortest distance of a path between node n and node x. A restricted path is a path that also satisfies that distanceToLastNode(zi) > distanceToLastNode(zi+1) where 0 <= i <= k-1.\n\t\tReturn the number of restricted paths from node 1 to node n. Since that number may be too large, return it modulo 109 + 7.\n\t\tExample 1:\n\t\tInput: n = 5, edges = [[1,2,3],[1,3,3],[2,3,1],[1,4,2],[5,2,2],[3,5,1],[5,4,10]]\n\t\tOutput: 3\n\t\tExplanation: Each circle contains the node number in black and its distanceToLastNode value in blue. The three restricted paths are:\n\t\t1) 1 --> 2 --> 5\n\t\t2) 1 --> 2 --> 3 --> 5\n\t\t3) 1 --> 3 --> 5\n\t\tExample 2:\n\t\tInput: n = 7, edges = [[1,3,1],[4,1,2],[7,3,4],[2,5,3],[5,6,1],[6,7,2],[7,5,3],[2,6,4]]\n\t\tOutput: 1\n\t\tExplanation: Each circle contains the node number in black and its distanceToLastNode value in blue. The only restricted path is 1 --> 3 --> 7.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1913, - "question": "class Solution:\n def minChanges(self, nums: List[int], k: int) -> int:\n\t\t\"\"\"\n\t\tYou are given an array nums\u200b\u200b\u200b and an integer k\u200b\u200b\u200b\u200b\u200b. The XOR of a segment [left, right] where left <= right is the XOR of all the elements with indices between left and right, inclusive: nums[left] XOR nums[left+1] XOR ... XOR nums[right].\n\t\tReturn the minimum number of elements to change in the array such that the XOR of all segments of size k\u200b\u200b\u200b\u200b\u200b\u200b is equal to zero.\n\t\tExample 1:\n\t\tInput: nums = [1,2,0,3,0], k = 1\n\t\tOutput: 3\n\t\tExplanation: Modify the array from [1,2,0,3,0] to from [0,0,0,0,0].\n\t\tExample 2:\n\t\tInput: nums = [3,4,5,2,1,7,3,4,7], k = 3\n\t\tOutput: 3\n\t\tExplanation: Modify the array from [3,4,5,2,1,7,3,4,7] to [3,4,7,3,4,7,3,4,7].\n\t\tExample 3:\n\t\tInput: nums = [1,2,4,1,2,5,1,2,6], k = 3\n\t\tOutput: 3\n\t\tExplanation: Modify the array from [1,2,4,1,2,5,1,2,6] to [1,2,3,1,2,3,1,2,3].\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1915, - "question": "class Solution:\n def areAlmostEqual(self, s1: str, s2: str) -> bool:\n\t\t\"\"\"\n\t\tYou are given two strings s1 and s2 of equal length. A string swap is an operation where you choose two indices in a string (not necessarily different) and swap the characters at these indices.\n\t\tReturn true if it is possible to make both strings equal by performing at most one string swap on exactly one of the strings. Otherwise, return false.\n\t\tExample 1:\n\t\tInput: s1 = \"bank\", s2 = \"kanb\"\n\t\tOutput: true\n\t\tExplanation: For example, swap the first character with the last character of s2 to make \"bank\".\n\t\tExample 2:\n\t\tInput: s1 = \"attack\", s2 = \"defend\"\n\t\tOutput: false\n\t\tExplanation: It is impossible to make them equal with one string swap.\n\t\tExample 3:\n\t\tInput: s1 = \"kelb\", s2 = \"kelb\"\n\t\tOutput: true\n\t\tExplanation: The two strings are already equal, so no string swap operation is required.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1916, - "question": "class Solution:\n def findCenter(self, edges: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tThere is an undirected star graph consisting of n nodes labeled from 1 to n. A star graph is a graph where there is one center node and exactly n - 1 edges that connect the center node with every other node.\n\t\tYou are given a 2D integer array edges where each edges[i] = [ui, vi] indicates that there is an edge between the nodes ui and vi. Return the center of the given star graph.\n\t\tExample 1:\n\t\tInput: edges = [[1,2],[2,3],[4,2]]\n\t\tOutput: 2\n\t\tExplanation: As shown in the figure above, node 2 is connected to every other node, so 2 is the center.\n\t\tExample 2:\n\t\tInput: edges = [[1,2],[5,1],[1,3],[1,4]]\n\t\tOutput: 1\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1917, - "question": "class Solution:\n def maxAverageRatio(self, classes: List[List[int]], extraStudents: int) -> float:\n\t\t\"\"\"\n\t\tThere is a school that has classes of students and each class will be having a final exam. You are given a 2D integer array classes, where classes[i] = [passi, totali]. You know beforehand that in the ith class, there are totali total students, but only passi number of students will pass the exam.\n\t\tYou are also given an integer extraStudents. There are another extraStudents brilliant students that are guaranteed to pass the exam of any class they are assigned to. You want to assign each of the extraStudents students to a class in a way that maximizes the average pass ratio across all the classes.\n\t\tThe pass ratio of a class is equal to the number of students of the class that will pass the exam divided by the total number of students of the class. The average pass ratio is the sum of pass ratios of all the classes divided by the number of the classes.\n\t\tReturn the maximum possible average pass ratio after assigning the extraStudents students. Answers within 10-5 of the actual answer will be accepted.\n\t\tExample 1:\n\t\tInput: classes = [[1,2],[3,5],[2,2]], extraStudents = 2\n\t\tOutput: 0.78333\n\t\tExplanation: You can assign the two extra students to the first class. The average pass ratio will be equal to (3/4 + 3/5 + 2/2) / 3 = 0.78333.\n\t\tExample 2:\n\t\tInput: classes = [[2,4],[3,9],[4,5],[2,10]], extraStudents = 4\n\t\tOutput: 0.53485\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1918, - "question": "class Solution:\n def maximumScore(self, nums: List[int], k: int) -> int:\n\t\t\"\"\"\n\t\tYou are given an array of integers nums (0-indexed) and an integer k.\n\t\tThe score of a subarray (i, j) is defined as min(nums[i], nums[i+1], ..., nums[j]) * (j - i + 1). A good subarray is a subarray where i <= k <= j.\n\t\tReturn the maximum possible score of a good subarray.\n\t\tExample 1:\n\t\tInput: nums = [1,4,3,7,4,5], k = 3\n\t\tOutput: 15\n\t\tExplanation: The optimal subarray is (1, 5) with a score of min(4,3,7,4,5) * (5-1+1) = 3 * 5 = 15. \n\t\tExample 2:\n\t\tInput: nums = [5,5,4,5,4,1,1,1], k = 0\n\t\tOutput: 20\n\t\tExplanation: The optimal subarray is (0, 4) with a score of min(5,5,4,5,4) * (4-0+1) = 4 * 5 = 20.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1920, - "question": "class Solution:\n def squareIsWhite(self, coordinates: str) -> bool:\n\t\t\"\"\"\n\t\tYou are given coordinates, a string that represents the coordinates of a square of the chessboard. Below is a chessboard for your reference.\n\t\tReturn true if the square is white, and false if the square is black.\n\t\tThe coordinate will always represent a valid chessboard square. The coordinate will always have the letter first, and the number second.\n\t\tExample 1:\n\t\tInput: coordinates = \"a1\"\n\t\tOutput: false\n\t\tExplanation: From the chessboard above, the square with coordinates \"a1\" is black, so return false.\n\t\tExample 2:\n\t\tInput: coordinates = \"h3\"\n\t\tOutput: true\n\t\tExplanation: From the chessboard above, the square with coordinates \"h3\" is white, so return true.\n\t\tExample 3:\n\t\tInput: coordinates = \"c7\"\n\t\tOutput: false\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1923, - "question": "class Solution:\n def areSentencesSimilar(self, sentence1: str, sentence2: str) -> bool:\n\t\t\"\"\"\n\t\tA sentence is a list of words that are separated by a single space with no leading or trailing spaces. For example, \"Hello World\", \"HELLO\", \"hello world hello world\" are all sentences. Words consist of only uppercase and lowercase English letters.\n\t\tTwo sentences sentence1 and sentence2 are similar if it is possible to insert an arbitrary sentence (possibly empty) inside one of these sentences such that the two sentences become equal. For example, sentence1 = \"Hello my name is Jane\" and sentence2 = \"Hello Jane\" can be made equal by inserting \"my name is\" between \"Hello\" and \"Jane\" in sentence2.\n\t\tGiven two sentences sentence1 and sentence2, return true if sentence1 and sentence2 are similar. Otherwise, return false.\n\t\tExample 1:\n\t\tInput: sentence1 = \"My name is Haley\", sentence2 = \"My Haley\"\n\t\tOutput: true\n\t\tExplanation: sentence2 can be turned to sentence1 by inserting \"name is\" between \"My\" and \"Haley\".\n\t\tExample 2:\n\t\tInput: sentence1 = \"of\", sentence2 = \"A lot of words\"\n\t\tOutput: false\n\t\tExplanation: No single sentence can be inserted inside one of the sentences to make it equal to the other.\n\t\tExample 3:\n\t\tInput: sentence1 = \"Eating right now\", sentence2 = \"Eating\"\n\t\tOutput: true\n\t\tExplanation: sentence2 can be turned to sentence1 by inserting \"right now\" at the end of the sentence.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1924, - "question": "class Solution:\n def maxHappyGroups(self, batchSize: int, groups: List[int]) -> int:\n\t\t\"\"\"\n\t\tThere is a donuts shop that bakes donuts in batches of batchSize. They have a rule where they must serve all of the donuts of a batch before serving any donuts of the next batch. You are given an integer batchSize and an integer array groups, where groups[i] denotes that there is a group of groups[i] customers that will visit the shop. Each customer will get exactly one donut.\n\t\tWhen a group visits the shop, all customers of the group must be served before serving any of the following groups. A group will be happy if they all get fresh donuts. That is, the first customer of the group does not receive a donut that was left over from the previous group.\n\t\tYou can freely rearrange the ordering of the groups. Return the maximum possible number of happy groups after rearranging the groups.\n\t\tExample 1:\n\t\tInput: batchSize = 3, groups = [1,2,3,4,5,6]\n\t\tOutput: 4\n\t\tExplanation: You can arrange the groups as [6,2,4,5,1,3]. Then the 1st, 2nd, 4th, and 6th groups will be happy.\n\t\tExample 2:\n\t\tInput: batchSize = 4, groups = [1,3,2,5,2,2,1,6]\n\t\tOutput: 4\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1925, - "question": "class Solution:\n def countNicePairs(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou are given an array nums that consists of non-negative integers. Let us define rev(x) as the reverse of the non-negative integer x. For example, rev(123) = 321, and rev(120) = 21. A pair of indices (i, j) is nice if it satisfies all of the following conditions:\n\t\t\t0 <= i < j < nums.length\n\t\t\tnums[i] + rev(nums[j]) == nums[j] + rev(nums[i])\n\t\tReturn the number of nice pairs of indices. Since that number can be too large, return it modulo 109 + 7.\n\t\tExample 1:\n\t\tInput: nums = [42,11,1,97]\n\t\tOutput: 2\n\t\tExplanation: The two pairs are:\n\t\t - (0,3) : 42 + rev(97) = 42 + 79 = 121, 97 + rev(42) = 97 + 24 = 121.\n\t\t - (1,2) : 11 + rev(1) = 11 + 1 = 12, 1 + rev(11) = 1 + 11 = 12.\n\t\tExample 2:\n\t\tInput: nums = [13,10,35,24,76]\n\t\tOutput: 4\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1927, - "question": "class Solution:\n def maxAscendingSum(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tGiven an array of positive integers nums, return the maximum possible sum of an ascending subarray in nums.\n\t\tA subarray is defined as a contiguous sequence of numbers in an array.\n\t\tA subarray [numsl, numsl+1, ..., numsr-1, numsr] is ascending if for all i where l <= i < r, numsi < numsi+1. Note that a subarray of size 1 is ascending.\n\t\tExample 1:\n\t\tInput: nums = [10,20,30,5,10,50]\n\t\tOutput: 65\n\t\tExplanation: [5,10,50] is the ascending subarray with the maximum sum of 65.\n\t\tExample 2:\n\t\tInput: nums = [10,20,30,40,50]\n\t\tOutput: 150\n\t\tExplanation: [10,20,30,40,50] is the ascending subarray with the maximum sum of 150.\n\t\tExample 3:\n\t\tInput: nums = [12,17,15,13,10,11,12]\n\t\tOutput: 33\n\t\tExplanation: [10,11,12] is the ascending subarray with the maximum sum of 33.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1928, - "question": "class Solution:\n def getNumberOfBacklogOrders(self, orders: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tYou are given a 2D integer array orders, where each orders[i] = [pricei, amounti, orderTypei] denotes that amounti orders have been placed of type orderTypei at the price pricei. The orderTypei is:\r\n\t\t\t0 if it is a batch of buy orders, or\r\n\t\t\t1 if it is a batch of sell orders.\r\n\t\tNote that orders[i] represents a batch of amounti independent orders with the same price and order type. All orders represented by orders[i] will be placed before all orders represented by orders[i+1] for all valid i.\r\n\t\tThere is a backlog that consists of orders that have not been executed. The backlog is initially empty. When an order is placed, the following happens:\r\n\t\t\tIf the order is a buy order, you look at the sell order with the smallest price in the backlog. If that sell order's price is smaller than or equal to the current buy order's price, they will match and be executed, and that sell order will be removed from the backlog. Else, the buy order is added to the backlog.\r\n\t\t\tVice versa, if the order is a sell order, you look at the buy order with the largest price in the backlog. If that buy order's price is larger than or equal to the current sell order's price, they will match and be executed, and that buy order will be removed from the backlog. Else, the sell order is added to the backlog.\r\n\t\tReturn the total amount of orders in the backlog after placing all the orders from the input. Since this number can be large, return it modulo 109 + 7.\r\n\t\tExample 1:\r\n\t\tInput: orders = [[10,5,0],[15,2,1],[25,1,1],[30,4,0]]\r\n\t\tOutput: 6\r\n\t\tExplanation: Here is what happens with the orders:\r\n\t\t- 5 orders of type buy with price 10 are placed. There are no sell orders, so the 5 orders are added to the backlog.\r\n\t\t- 2 orders of type sell with price 15 are placed. There are no buy orders with prices larger than or equal to 15, so the 2 orders are added to the backlog.\r\n\t\t- 1 order of type sell with price 25 is placed. There are no buy orders with prices larger than or equal to 25 in the backlog, so this order is added to the backlog.\r\n\t\t- 4 orders of type buy with price 30 are placed. The first 2 orders are matched with the 2 sell orders of the least price, which is 15 and these 2 sell orders are removed from the backlog. The 3rd order is matched with the sell order of the least price, which is 25 and this sell order is removed from the backlog. Then, there are no more sell orders in the backlog, so the 4th order is added to the backlog.\r\n\t\tFinally, the backlog has 5 buy orders with price 10, and 1 buy order with price 30. So the total number of orders in the backlog is 6.\r\n\t\tExample 2:\r\n\t\tInput: orders = [[7,1000000000,1],[15,3,0],[5,999999995,0],[5,1,1]]\r\n\t\tOutput: 999999984\r\n\t\tExplanation: Here is what happens with the orders:\r\n\t\t- 109 orders of type sell with price 7 are placed. There are no buy orders, so the 109 orders are added to the backlog.\r\n\t\t- 3 orders of type buy with price 15 are placed. They are matched with the 3 sell orders with the least price which is 7, and those 3 sell orders are removed from the backlog.\r\n\t\t- 999999995 orders of type buy with price 5 are placed. The least price of a sell order is 7, so the 999999995 orders are added to the backlog.\r\n\t\t- 1 order of type sell with price 5 is placed. It is matched with the buy order of the highest price, which is 5, and that buy order is removed from the backlog.\r\n\t\tFinally, the backlog has (1000000000-3) sell orders with price 7, and (999999995-1) buy orders with price 5. So the total number of orders = 1999999991, which is equal to 999999984 % (109 + 7).\r\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1929, - "question": "class Solution:\n def maxValue(self, n: int, index: int, maxSum: int) -> int:\n\t\t\"\"\"\n\t\tYou are given three positive integers: n, index, and maxSum. You want to construct an array nums (0-indexed) that satisfies the following conditions:\n\t\t\tnums.length == n\n\t\t\tnums[i] is a positive integer where 0 <= i < n.\n\t\t\tabs(nums[i] - nums[i+1]) <= 1 where 0 <= i < n-1.\n\t\t\tThe sum of all the elements of nums does not exceed maxSum.\n\t\t\tnums[index] is maximized.\n\t\tReturn nums[index] of the constructed array.\n\t\tNote that abs(x) equals x if x >= 0, and -x otherwise.\n\t\tExample 1:\n\t\tInput: n = 4, index = 2, maxSum = 6\n\t\tOutput: 2\n\t\tExplanation: nums = [1,2,2,1] is one array that satisfies all the conditions.\n\t\tThere are no arrays that satisfy all the conditions and have nums[2] == 3, so 2 is the maximum nums[2].\n\t\tExample 2:\n\t\tInput: n = 6, index = 1, maxSum = 10\n\t\tOutput: 3\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1930, - "question": "class Solution:\n def getMaximumConsecutive(self, coins: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou are given an integer array coins of length n which represents the n coins that you own. The value of the ith coin is coins[i]. You can make some value x if you can choose some of your n coins such that their values sum up to x.\n\t\tReturn the maximum number of consecutive integer values that you can make with your coins starting from and including 0.\n\t\tNote that you may have multiple coins of the same value.\n\t\tExample 1:\n\t\tInput: coins = [1,3]\n\t\tOutput: 2\n\t\tExplanation: You can make the following values:\n\t\t- 0: take []\n\t\t- 1: take [1]\n\t\tYou can make 2 consecutive integer values starting from 0.\n\t\tExample 2:\n\t\tInput: coins = [1,1,1,4]\n\t\tOutput: 8\n\t\tExplanation: You can make the following values:\n\t\t- 0: take []\n\t\t- 1: take [1]\n\t\t- 2: take [1,1]\n\t\t- 3: take [1,1,1]\n\t\t- 4: take [4]\n\t\t- 5: take [4,1]\n\t\t- 6: take [4,1,1]\n\t\t- 7: take [4,1,1,1]\n\t\tYou can make 8 consecutive integer values starting from 0.\n\t\tExample 3:\n\t\tInput: nums = [1,4,10,3,1]\n\t\tOutput: 20\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1933, - "question": "class Solution:\n def numDifferentIntegers(self, word: str) -> int:\n\t\t\"\"\"\n\t\tYou are given a string word that consists of digits and lowercase English letters.\n\t\tYou will replace every non-digit character with a space. For example, \"a123bc34d8ef34\" will become \" 123 34 8 34\". Notice that you are left with some integers that are separated by at least one space: \"123\", \"34\", \"8\", and \"34\".\n\t\tReturn the number of different integers after performing the replacement operations on word.\n\t\tTwo integers are considered different if their decimal representations without any leading zeros are different.\n\t\tExample 1:\n\t\tInput: word = \"a123bc34d8ef34\"\n\t\tOutput: 3\n\t\tExplanation: The three different integers are \"123\", \"34\", and \"8\". Notice that \"34\" is only counted once.\n\t\tExample 2:\n\t\tInput: word = \"leet1234code234\"\n\t\tOutput: 2\n\t\tExample 3:\n\t\tInput: word = \"a1b01c001\"\n\t\tOutput: 1\n\t\tExplanation: The three integers \"1\", \"01\", and \"001\" all represent the same integer because\n\t\tthe leading zeros are ignored when comparing their decimal values.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1934, - "question": "class Solution:\n def evaluate(self, s: str, knowledge: List[List[str]]) -> str:\n\t\t\"\"\"\n\t\tYou are given a string s that contains some bracket pairs, with each pair containing a non-empty key.\n\t\t\tFor example, in the string \"(name)is(age)yearsold\", there are two bracket pairs that contain the keys \"name\" and \"age\".\n\t\tYou know the values of a wide range of keys. This is represented by a 2D string array knowledge where each knowledge[i] = [keyi, valuei] indicates that key keyi has a value of valuei.\n\t\tYou are tasked to evaluate all of the bracket pairs. When you evaluate a bracket pair that contains some key keyi, you will:\n\t\t\tReplace keyi and the bracket pair with the key's corresponding valuei.\n\t\t\tIf you do not know the value of the key, you will replace keyi and the bracket pair with a question mark \"?\" (without the quotation marks).\n\t\tEach key will appear at most once in your knowledge. There will not be any nested brackets in s.\n\t\tReturn the resulting string after evaluating all of the bracket pairs.\n\t\tExample 1:\n\t\tInput: s = \"(name)is(age)yearsold\", knowledge = [[\"name\",\"bob\"],[\"age\",\"two\"]]\n\t\tOutput: \"bobistwoyearsold\"\n\t\tExplanation:\n\t\tThe key \"name\" has a value of \"bob\", so replace \"(name)\" with \"bob\".\n\t\tThe key \"age\" has a value of \"two\", so replace \"(age)\" with \"two\".\n\t\tExample 2:\n\t\tInput: s = \"hi(name)\", knowledge = [[\"a\",\"b\"]]\n\t\tOutput: \"hi?\"\n\t\tExplanation: As you do not know the value of the key \"name\", replace \"(name)\" with \"?\".\n\t\tExample 3:\n\t\tInput: s = \"(a)(a)(a)aaa\", knowledge = [[\"a\",\"yes\"]]\n\t\tOutput: \"yesyesyesaaa\"\n\t\tExplanation: The same key can appear multiple times.\n\t\tThe key \"a\" has a value of \"yes\", so replace all occurrences of \"(a)\" with \"yes\".\n\t\tNotice that the \"a\"s not in a bracket pair are not evaluated.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1935, - "question": "class Solution:\n def reinitializePermutation(self, n: int) -> int:\n\t\t\"\"\"\n\t\tYou are given an even integer n\u200b\u200b\u200b\u200b\u200b\u200b. You initially have a permutation perm of size n\u200b\u200b where perm[i] == i\u200b (0-indexed)\u200b\u200b\u200b\u200b.\n\t\tIn one operation, you will create a new array arr, and for each i:\n\t\t\tIf i % 2 == 0, then arr[i] = perm[i / 2].\n\t\t\tIf i % 2 == 1, then arr[i] = perm[n / 2 + (i - 1) / 2].\n\t\tYou will then assign arr\u200b\u200b\u200b\u200b to perm.\n\t\tReturn the minimum non-zero number of operations you need to perform on perm to return the permutation to its initial value.\n\t\tExample 1:\n\t\tInput: n = 2\n\t\tOutput: 1\n\t\tExplanation: perm = [0,1] initially.\n\t\tAfter the 1st operation, perm = [0,1]\n\t\tSo it takes only 1 operation.\n\t\tExample 2:\n\t\tInput: n = 4\n\t\tOutput: 2\n\t\tExplanation: perm = [0,1,2,3] initially.\n\t\tAfter the 1st operation, perm = [0,2,1,3]\n\t\tAfter the 2nd operation, perm = [0,1,2,3]\n\t\tSo it takes only 2 operations.\n\t\tExample 3:\n\t\tInput: n = 6\n\t\tOutput: 4\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1936, - "question": "class Solution:\n def maxNiceDivisors(self, primeFactors: int) -> int:\n\t\t\"\"\"\n\t\tYou are given a positive integer primeFactors. You are asked to construct a positive integer n that satisfies the following conditions:\r\n\t\t The number of prime factors of n (not necessarily distinct) is at most primeFactors.\r\n\t\t The number of nice divisors of n is maximized. Note that a divisor of n is nice if it is divisible by every prime factor of n. For example, if n = 12, then its prime factors are [2,2,3], then 6 and 12 are nice divisors, while 3 and 4 are not.\r\n\t\tReturn the number of nice divisors of n. Since that number can be too large, return it modulo 109 + 7.\r\n\t\tNote that a prime number is a natural number greater than 1 that is not a product of two smaller natural numbers. The prime factors of a number n is a list of prime numbers such that their product equals n.\r\n\t\tExample 1:\r\n\t\tInput: primeFactors = 5\r\n\t\tOutput: 6\r\n\t\tExplanation: 200 is a valid value of n.\r\n\t\tIt has 5 prime factors: [2,2,2,5,5], and it has 6 nice divisors: [10,20,40,50,100,200].\r\n\t\tThere is not other value of n that has at most 5 prime factors and more nice divisors.\r\n\t\tExample 2:\r\n\t\tInput: primeFactors = 8\r\n\t\tOutput: 18\r\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1938, - "question": "class Solution:\n def minOperations(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou are given an integer array nums (0-indexed). In one operation, you can choose an element of the array and increment it by 1.\r\n\t\t\tFor example, if nums = [1,2,3], you can choose to increment nums[1] to make nums = [1,3,3].\r\n\t\tReturn the minimum number of operations needed to make nums strictly increasing.\r\n\t\tAn array nums is strictly increasing if nums[i] < nums[i+1] for all 0 <= i < nums.length - 1. An array of length 1 is trivially strictly increasing.\r\n\t\tExample 1:\r\n\t\tInput: nums = [1,1,1]\r\n\t\tOutput: 3\r\n\t\tExplanation: You can do the following operations:\r\n\t\t1) Increment nums[2], so nums becomes [1,1,2].\r\n\t\t2) Increment nums[1], so nums becomes [1,2,2].\r\n\t\t3) Increment nums[2], so nums becomes [1,2,3].\r\n\t\tExample 2:\r\n\t\tInput: nums = [1,5,2,4,1]\r\n\t\tOutput: 14\r\n\t\tExample 3:\r\n\t\tInput: nums = [8]\r\n\t\tOutput: 0\r\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1939, - "question": "class Solution:\n def countPoints(self, points: List[List[int]], queries: List[List[int]]) -> List[int]:\n\t\t\"\"\"\n\t\tYou are given an array points where points[i] = [xi, yi] is the coordinates of the ith point on a 2D plane. Multiple points can have the same coordinates.\n\t\tYou are also given an array queries where queries[j] = [xj, yj, rj] describes a circle centered at (xj, yj) with a radius of rj.\n\t\tFor each query queries[j], compute the number of points inside the jth circle. Points on the border of the circle are considered inside.\n\t\tReturn an array answer, where answer[j] is the answer to the jth query.\n\t\tExample 1:\n\t\tInput: points = [[1,3],[3,3],[5,3],[2,2]], queries = [[2,3,1],[4,3,1],[1,1,2]]\n\t\tOutput: [3,2,2]\n\t\tExplanation: The points and circles are shown above.\n\t\tqueries[0] is the green circle, queries[1] is the red circle, and queries[2] is the blue circle.\n\t\tExample 2:\n\t\tInput: points = [[1,1],[2,2],[3,3],[4,4],[5,5]], queries = [[1,2,2],[2,2,2],[4,3,2],[4,3,3]]\n\t\tOutput: [2,3,2,4]\n\t\tExplanation: The points and circles are shown above.\n\t\tqueries[0] is green, queries[1] is red, queries[2] is blue, and queries[3] is purple.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1940, - "question": "class Solution:\n def getMaximumXor(self, nums: List[int], maximumBit: int) -> List[int]:\n\t\t\"\"\"\n\t\tYou are given a sorted array nums of n non-negative integers and an integer maximumBit. You want to perform the following query n times:\n\t\t\tFind a non-negative integer k < 2maximumBit such that nums[0] XOR nums[1] XOR ... XOR nums[nums.length-1] XOR k is maximized. k is the answer to the ith query.\n\t\t\tRemove the last element from the current array nums.\n\t\tReturn an array answer, where answer[i] is the answer to the ith query.\n\t\tExample 1:\n\t\tInput: nums = [0,1,1,3], maximumBit = 2\n\t\tOutput: [0,3,2,3]\n\t\tExplanation: The queries are answered as follows:\n\t\t1st query: nums = [0,1,1,3], k = 0 since 0 XOR 1 XOR 1 XOR 3 XOR 0 = 3.\n\t\t2nd query: nums = [0,1,1], k = 3 since 0 XOR 1 XOR 1 XOR 3 = 3.\n\t\t3rd query: nums = [0,1], k = 2 since 0 XOR 1 XOR 2 = 3.\n\t\t4th query: nums = [0], k = 3 since 0 XOR 3 = 3.\n\t\tExample 2:\n\t\tInput: nums = [2,3,4,7], maximumBit = 3\n\t\tOutput: [5,2,6,5]\n\t\tExplanation: The queries are answered as follows:\n\t\t1st query: nums = [2,3,4,7], k = 5 since 2 XOR 3 XOR 4 XOR 7 XOR 5 = 7.\n\t\t2nd query: nums = [2,3,4], k = 2 since 2 XOR 3 XOR 4 XOR 2 = 7.\n\t\t3rd query: nums = [2,3], k = 6 since 2 XOR 3 XOR 6 = 7.\n\t\t4th query: nums = [2], k = 5 since 2 XOR 5 = 7.\n\t\tExample 3:\n\t\tInput: nums = [0,1,2,2,5,7], maximumBit = 3\n\t\tOutput: [4,3,6,4,6,7]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1941, - "question": "class Solution:\n def makeStringSorted(self, s: str) -> int:\n\t\t\"\"\"\n\t\tYou are given a string s (0-indexed)\u200b\u200b\u200b\u200b\u200b\u200b. You are asked to perform the following operation on s\u200b\u200b\u200b\u200b\u200b\u200b until you get a sorted string:\n\t\t\tFind the largest index i such that 1 <= i < s.length and s[i] < s[i - 1].\n\t\t\tFind the largest index j such that i <= j < s.length and s[k] < s[i - 1] for all the possible values of k in the range [i, j] inclusive.\n\t\t\tSwap the two characters at indices i - 1\u200b\u200b\u200b\u200b and j\u200b\u200b\u200b\u200b\u200b.\n\t\t\tReverse the suffix starting at index i\u200b\u200b\u200b\u200b\u200b\u200b.\n\t\tReturn the number of operations needed to make the string sorted. Since the answer can be too large, return it modulo 109 + 7.\n\t\tExample 1:\n\t\tInput: s = \"cba\"\n\t\tOutput: 5\n\t\tExplanation: The simulation goes as follows:\n\t\tOperation 1: i=2, j=2. Swap s[1] and s[2] to get s=\"cab\", then reverse the suffix starting at 2. Now, s=\"cab\".\n\t\tOperation 2: i=1, j=2. Swap s[0] and s[2] to get s=\"bac\", then reverse the suffix starting at 1. Now, s=\"bca\".\n\t\tOperation 3: i=2, j=2. Swap s[1] and s[2] to get s=\"bac\", then reverse the suffix starting at 2. Now, s=\"bac\".\n\t\tOperation 4: i=1, j=1. Swap s[0] and s[1] to get s=\"abc\", then reverse the suffix starting at 1. Now, s=\"acb\".\n\t\tOperation 5: i=2, j=2. Swap s[1] and s[2] to get s=\"abc\", then reverse the suffix starting at 2. Now, s=\"abc\".\n\t\tExample 2:\n\t\tInput: s = \"aabaa\"\n\t\tOutput: 2\n\t\tExplanation: The simulation goes as follows:\n\t\tOperation 1: i=3, j=4. Swap s[2] and s[4] to get s=\"aaaab\", then reverse the substring starting at 3. Now, s=\"aaaba\".\n\t\tOperation 2: i=4, j=4. Swap s[3] and s[4] to get s=\"aaaab\", then reverse the substring starting at 4. Now, s=\"aaaab\".\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1944, - "question": "class Solution:\n def truncateSentence(self, s: str, k: int) -> str:\n\t\t\"\"\"\n\t\tA sentence is a list of words that are separated by a single space with no leading or trailing spaces. Each of the words consists of only uppercase and lowercase English letters (no punctuation).\n\t\t\tFor example, \"Hello World\", \"HELLO\", and \"hello world hello world\" are all sentences.\n\t\tYou are given a sentence s\u200b\u200b\u200b\u200b\u200b\u200b and an integer k\u200b\u200b\u200b\u200b\u200b\u200b. You want to truncate s\u200b\u200b\u200b\u200b\u200b\u200b such that it contains only the first k\u200b\u200b\u200b\u200b\u200b\u200b words. Return s\u200b\u200b\u200b\u200b\u200b\u200b after truncating it.\n\t\tExample 1:\n\t\tInput: s = \"Hello how are you Contestant\", k = 4\n\t\tOutput: \"Hello how are you\"\n\t\tExplanation:\n\t\tThe words in s are [\"Hello\", \"how\" \"are\", \"you\", \"Contestant\"].\n\t\tThe first 4 words are [\"Hello\", \"how\", \"are\", \"you\"].\n\t\tHence, you should return \"Hello how are you\".\n\t\tExample 2:\n\t\tInput: s = \"What is the solution to this problem\", k = 4\n\t\tOutput: \"What is the solution\"\n\t\tExplanation:\n\t\tThe words in s are [\"What\", \"is\" \"the\", \"solution\", \"to\", \"this\", \"problem\"].\n\t\tThe first 4 words are [\"What\", \"is\", \"the\", \"solution\"].\n\t\tHence, you should return \"What is the solution\".\n\t\tExample 3:\n\t\tInput: s = \"chopper is not a tanuki\", k = 5\n\t\tOutput: \"chopper is not a tanuki\"\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1945, - "question": "class Solution:\n def findingUsersActiveMinutes(self, logs: List[List[int]], k: int) -> List[int]:\n\t\t\"\"\"\n\t\tYou are given the logs for users' actions on LeetCode, and an integer k. The logs are represented by a 2D integer array logs where each logs[i] = [IDi, timei] indicates that the user with IDi performed an action at the minute timei.\n\t\tMultiple users can perform actions simultaneously, and a single user can perform multiple actions in the same minute.\n\t\tThe user active minutes (UAM) for a given user is defined as the number of unique minutes in which the user performed an action on LeetCode. A minute can only be counted once, even if multiple actions occur during it.\n\t\tYou are to calculate a 1-indexed array answer of size k such that, for each j (1 <= j <= k), answer[j] is the number of users whose UAM equals j.\n\t\tReturn the array answer as described above.\n\t\tExample 1:\n\t\tInput: logs = [[0,5],[1,2],[0,2],[0,5],[1,3]], k = 5\n\t\tOutput: [0,2,0,0,0]\n\t\tExplanation:\n\t\tThe user with ID=0 performed actions at minutes 5, 2, and 5 again. Hence, they have a UAM of 2 (minute 5 is only counted once).\n\t\tThe user with ID=1 performed actions at minutes 2 and 3. Hence, they have a UAM of 2.\n\t\tSince both users have a UAM of 2, answer[2] is 2, and the remaining answer[j] values are 0.\n\t\tExample 2:\n\t\tInput: logs = [[1,1],[2,2],[2,3]], k = 4\n\t\tOutput: [1,1,0,0]\n\t\tExplanation:\n\t\tThe user with ID=1 performed a single action at minute 1. Hence, they have a UAM of 1.\n\t\tThe user with ID=2 performed actions at minutes 2 and 3. Hence, they have a UAM of 2.\n\t\tThere is one user with a UAM of 1 and one with a UAM of 2.\n\t\tHence, answer[1] = 1, answer[2] = 1, and the remaining values are 0.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1946, - "question": "class Solution:\n def minAbsoluteSumDiff(self, nums1: List[int], nums2: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou are given two positive integer arrays nums1 and nums2, both of length n.\n\t\tThe absolute sum difference of arrays nums1 and nums2 is defined as the sum of |nums1[i] - nums2[i]| for each 0 <= i < n (0-indexed).\n\t\tYou can replace at most one element of nums1 with any other element in nums1 to minimize the absolute sum difference.\n\t\tReturn the minimum absolute sum difference after replacing at most one element in the array nums1. Since the answer may be large, return it modulo 109 + 7.\n\t\t|x| is defined as:\n\t\t\tx if x >= 0, or\n\t\t\t-x if x < 0.\n\t\tExample 1:\n\t\tInput: nums1 = [1,7,5], nums2 = [2,3,5]\n\t\tOutput: 3\n\t\tExplanation: There are two possible optimal solutions:\n\t\t- Replace the second element with the first: [1,7,5] => [1,1,5], or\n\t\t- Replace the second element with the third: [1,7,5] => [1,5,5].\n\t\tBoth will yield an absolute sum difference of |1-2| + (|1-3| or |5-3|) + |5-5| = 3.\n\t\tExample 2:\n\t\tInput: nums1 = [2,4,6,8,10], nums2 = [2,4,6,8,10]\n\t\tOutput: 0\n\t\tExplanation: nums1 is equal to nums2 so no replacement is needed. This will result in an \n\t\tabsolute sum difference of 0.\n\t\tExample 3:\n\t\tInput: nums1 = [1,10,4,4,2,7], nums2 = [9,3,5,1,7,4]\n\t\tOutput: 20\n\t\tExplanation: Replace the first element with the second: [1,10,4,4,2,7] => [10,10,4,4,2,7].\n\t\tThis yields an absolute sum difference of |10-9| + |10-3| + |4-5| + |4-1| + |2-7| + |7-4| = 20\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1947, - "question": "class Solution:\n def countDifferentSubsequenceGCDs(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou are given an array nums that consists of positive integers.\n\t\tThe GCD of a sequence of numbers is defined as the greatest integer that divides all the numbers in the sequence evenly.\n\t\t\tFor example, the GCD of the sequence [4,6,16] is 2.\n\t\tA subsequence of an array is a sequence that can be formed by removing some elements (possibly none) of the array.\n\t\t\tFor example, [2,5,10] is a subsequence of [1,2,1,2,4,1,5,10].\n\t\tReturn the number of different GCDs among all non-empty subsequences of nums.\n\t\tExample 1:\n\t\tInput: nums = [6,10,3]\n\t\tOutput: 5\n\t\tExplanation: The figure shows all the non-empty subsequences and their GCDs.\n\t\tThe different GCDs are 6, 10, 3, 2, and 1.\n\t\tExample 2:\n\t\tInput: nums = [5,15,40,5,6]\n\t\tOutput: 7\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1950, - "question": "class Solution:\n def arraySign(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tThere is a function signFunc(x) that returns:\n\t\t\t1 if x is positive.\n\t\t\t-1 if x is negative.\n\t\t\t0 if x is equal to 0.\n\t\tYou are given an integer array nums. Let product be the product of all values in the array nums.\n\t\tReturn signFunc(product).\n\t\tExample 1:\n\t\tInput: nums = [-1,-2,-3,-4,3,2,1]\n\t\tOutput: 1\n\t\tExplanation: The product of all values in the array is 144, and signFunc(144) = 1\n\t\tExample 2:\n\t\tInput: nums = [1,5,0,2,-3]\n\t\tOutput: 0\n\t\tExplanation: The product of all values in the array is 0, and signFunc(0) = 0\n\t\tExample 3:\n\t\tInput: nums = [-1,1,-1,1,-1]\n\t\tOutput: -1\n\t\tExplanation: The product of all values in the array is -1, and signFunc(-1) = -1\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1951, - "question": "class Solution:\n def findTheWinner(self, n: int, k: int) -> int:\n\t\t\"\"\"\n\t\tThere are n friends that are playing a game. The friends are sitting in a circle and are numbered from 1 to n in clockwise order. More formally, moving clockwise from the ith friend brings you to the (i+1)th friend for 1 <= i < n, and moving clockwise from the nth friend brings you to the 1st friend.\n\t\tThe rules of the game are as follows:\n\t\t\tStart at the 1st friend.\n\t\t\tCount the next k friends in the clockwise direction including the friend you started at. The counting wraps around the circle and may count some friends more than once.\n\t\t\tThe last friend you counted leaves the circle and loses the game.\n\t\t\tIf there is still more than one friend in the circle, go back to step 2 starting from the friend immediately clockwise of the friend who just lost and repeat.\n\t\t\tElse, the last friend in the circle wins the game.\n\t\tGiven the number of friends, n, and an integer k, return the winner of the game.\n\t\tExample 1:\n\t\tInput: n = 5, k = 2\n\t\tOutput: 3\n\t\tExplanation: Here are the steps of the game:\n\t\t1) Start at friend 1.\n\t\t2) Count 2 friends clockwise, which are friends 1 and 2.\n\t\t3) Friend 2 leaves the circle. Next start is friend 3.\n\t\t4) Count 2 friends clockwise, which are friends 3 and 4.\n\t\t5) Friend 4 leaves the circle. Next start is friend 5.\n\t\t6) Count 2 friends clockwise, which are friends 5 and 1.\n\t\t7) Friend 1 leaves the circle. Next start is friend 3.\n\t\t8) Count 2 friends clockwise, which are friends 3 and 5.\n\t\t9) Friend 5 leaves the circle. Only friend 3 is left, so they are the winner.\n\t\tExample 2:\n\t\tInput: n = 6, k = 5\n\t\tOutput: 1\n\t\tExplanation: The friends leave in this order: 5, 4, 6, 2, 3. The winner is friend 1.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1952, - "question": "class Solution:\n def minSideJumps(self, obstacles: List[int]) -> int:\n\t\t\"\"\"\n\t\tThere is a 3 lane road of length n that consists of n + 1 points labeled from 0 to n. A frog starts at point 0 in the second lane and wants to jump to point n. However, there could be obstacles along the way.\n\t\tYou are given an array obstacles of length n + 1 where each obstacles[i] (ranging from 0 to 3) describes an obstacle on the lane obstacles[i] at point i. If obstacles[i] == 0, there are no obstacles at point i. There will be at most one obstacle in the 3 lanes at each point.\n\t\t\tFor example, if obstacles[2] == 1, then there is an obstacle on lane 1 at point 2.\n\t\tThe frog can only travel from point i to point i + 1 on the same lane if there is not an obstacle on the lane at point i + 1. To avoid obstacles, the frog can also perform a side jump to jump to another lane (even if they are not adjacent) at the same point if there is no obstacle on the new lane.\n\t\t\tFor example, the frog can jump from lane 3 at point 3 to lane 1 at point 3.\n\t\tReturn the minimum number of side jumps the frog needs to reach any lane at point n starting from lane 2 at point 0.\n\t\tNote: There will be no obstacles on points 0 and n.\n\t\tExample 1:\n\t\tInput: obstacles = [0,1,2,3,0]\n\t\tOutput: 2 \n\t\tExplanation: The optimal solution is shown by the arrows above. There are 2 side jumps (red arrows).\n\t\tNote that the frog can jump over obstacles only when making side jumps (as shown at point 2).\n\t\tExample 2:\n\t\tInput: obstacles = [0,1,1,3,3,0]\n\t\tOutput: 0\n\t\tExplanation: There are no obstacles on lane 2. No side jumps are required.\n\t\tExample 3:\n\t\tInput: obstacles = [0,2,1,0,3,0]\n\t\tOutput: 2\n\t\tExplanation: The optimal solution is shown by the arrows above. There are 2 side jumps.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1953, - "question": "class MKAverage:\n def __init__(self, m: int, k: int):\n def addElement(self, num: int) -> None:\n def calculateMKAverage(self) -> int:\n\t\t\"\"\"\n\t\tYou are given two integers, m and k, and a stream of integers. You are tasked to implement a data structure that calculates the MKAverage for the stream.\n\t\tThe MKAverage can be calculated using these steps:\n\t\t\tIf the number of the elements in the stream is less than m you should consider the MKAverage to be -1. Otherwise, copy the last m elements of the stream to a separate container.\n\t\t\tRemove the smallest k elements and the largest k elements from the container.\n\t\t\tCalculate the average value for the rest of the elements rounded down to the nearest integer.\n\t\tImplement the MKAverage class:\n\t\t\tMKAverage(int m, int k) Initializes the MKAverage object with an empty stream and the two integers m and k.\n\t\t\tvoid addElement(int num) Inserts a new element num into the stream.\n\t\t\tint calculateMKAverage() Calculates and returns the MKAverage for the current stream rounded down to the nearest integer.\n\t\tExample 1:\n\t\tInput\n\t\t[\"MKAverage\", \"addElement\", \"addElement\", \"calculateMKAverage\", \"addElement\", \"calculateMKAverage\", \"addElement\", \"addElement\", \"addElement\", \"calculateMKAverage\"]\n\t\t[[3, 1], [3], [1], [], [10], [], [5], [5], [5], []]\n\t\tOutput\n\t\t[null, null, null, -1, null, 3, null, null, null, 5]\n\t\tExplanation\n\t\tMKAverage obj = new MKAverage(3, 1); \n\t\tobj.addElement(3); // current elements are [3]\n\t\tobj.addElement(1); // current elements are [3,1]\n\t\tobj.calculateMKAverage(); // return -1, because m = 3 and only 2 elements exist.\n\t\tobj.addElement(10); // current elements are [3,1,10]\n\t\tobj.calculateMKAverage(); // The last 3 elements are [3,1,10].\n\t\t // After removing smallest and largest 1 element the container will be [3].\n\t\t // The average of [3] equals 3/1 = 3, return 3\n\t\tobj.addElement(5); // current elements are [3,1,10,5]\n\t\tobj.addElement(5); // current elements are [3,1,10,5,5]\n\t\tobj.addElement(5); // current elements are [3,1,10,5,5,5]\n\t\tobj.calculateMKAverage(); // The last 3 elements are [5,5,5].\n\t\t // After removing smallest and largest 1 element the container will be [5].\n\t\t // The average of [5] equals 5/1 = 5, return 5\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1954, - "question": "class Solution:\n def replaceDigits(self, s: str) -> str:\n\t\t\"\"\"\n\t\tYou are given a 0-indexed string s that has lowercase English letters in its even indices and digits in its odd indices.\n\t\tThere is a function shift(c, x), where c is a character and x is a digit, that returns the xth character after c.\n\t\t\tFor example, shift('a', 5) = 'f' and shift('x', 0) = 'x'.\n\t\tFor every odd index i, you want to replace the digit s[i] with shift(s[i-1], s[i]).\n\t\tReturn s after replacing all digits. It is guaranteed that shift(s[i-1], s[i]) will never exceed 'z'.\n\t\tExample 1:\n\t\tInput: s = \"a1c1e1\"\n\t\tOutput: \"abcdef\"\n\t\tExplanation: The digits are replaced as follows:\n\t\t- s[1] -> shift('a',1) = 'b'\n\t\t- s[3] -> shift('c',1) = 'd'\n\t\t- s[5] -> shift('e',1) = 'f'\n\t\tExample 2:\n\t\tInput: s = \"a1b2c3d4e\"\n\t\tOutput: \"abbdcfdhe\"\n\t\tExplanation: The digits are replaced as follows:\n\t\t- s[1] -> shift('a',1) = 'b'\n\t\t- s[3] -> shift('b',2) = 'd'\n\t\t- s[5] -> shift('c',3) = 'f'\n\t\t- s[7] -> shift('d',4) = 'h'\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1955, - "question": "class SeatManager:\n def __init__(self, n: int):\n def reserve(self) -> int:\n def unreserve(self, seatNumber: int) -> None:\n\t\t\"\"\"\n\t\tDesign a system that manages the reservation state of n seats that are numbered from 1 to n.\n\t\tImplement the SeatManager class:\n\t\t\tSeatManager(int n) Initializes a SeatManager object that will manage n seats numbered from 1 to n. All seats are initially available.\n\t\t\tint reserve() Fetches the smallest-numbered unreserved seat, reserves it, and returns its number.\n\t\t\tvoid unreserve(int seatNumber) Unreserves the seat with the given seatNumber.\n\t\tExample 1:\n\t\tInput\n\t\t[\"SeatManager\", \"reserve\", \"reserve\", \"unreserve\", \"reserve\", \"reserve\", \"reserve\", \"reserve\", \"unreserve\"]\n\t\t[[5], [], [], [2], [], [], [], [], [5]]\n\t\tOutput\n\t\t[null, 1, 2, null, 2, 3, 4, 5, null]\n\t\tExplanation\n\t\tSeatManager seatManager = new SeatManager(5); // Initializes a SeatManager with 5 seats.\n\t\tseatManager.reserve(); // All seats are available, so return the lowest numbered seat, which is 1.\n\t\tseatManager.reserve(); // The available seats are [2,3,4,5], so return the lowest of them, which is 2.\n\t\tseatManager.unreserve(2); // Unreserve seat 2, so now the available seats are [2,3,4,5].\n\t\tseatManager.reserve(); // The available seats are [2,3,4,5], so return the lowest of them, which is 2.\n\t\tseatManager.reserve(); // The available seats are [3,4,5], so return the lowest of them, which is 3.\n\t\tseatManager.reserve(); // The available seats are [4,5], so return the lowest of them, which is 4.\n\t\tseatManager.reserve(); // The only available seat is seat 5, so return 5.\n\t\tseatManager.unreserve(5); // Unreserve seat 5, so now the available seats are [5].\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1956, - "question": "class Solution:\n def maximumElementAfterDecrementingAndRearranging(self, arr: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou are given an array of positive integers arr. Perform some operations (possibly none) on arr so that it satisfies these conditions:\n\t\t\tThe value of the first element in arr must be 1.\n\t\t\tThe absolute difference between any 2 adjacent elements must be less than or equal to 1. In other words, abs(arr[i] - arr[i - 1]) <= 1 for each i where 1 <= i < arr.length (0-indexed). abs(x) is the absolute value of x.\n\t\tThere are 2 types of operations that you can perform any number of times:\n\t\t\tDecrease the value of any element of arr to a smaller positive integer.\n\t\t\tRearrange the elements of arr to be in any order.\n\t\tReturn the maximum possible value of an element in arr after performing the operations to satisfy the conditions.\n\t\tExample 1:\n\t\tInput: arr = [2,2,1,2,1]\n\t\tOutput: 2\n\t\tExplanation: \n\t\tWe can satisfy the conditions by rearranging arr so it becomes [1,2,2,2,1].\n\t\tThe largest element in arr is 2.\n\t\tExample 2:\n\t\tInput: arr = [100,1,1000]\n\t\tOutput: 3\n\t\tExplanation: \n\t\tOne possible way to satisfy the conditions is by doing the following:\n\t\t1. Rearrange arr so it becomes [1,100,1000].\n\t\t2. Decrease the value of the second element to 2.\n\t\t3. Decrease the value of the third element to 3.\n\t\tNow arr = [1,2,3], which satisfies the conditions.\n\t\tThe largest element in arr is 3.\n\t\tExample 3:\n\t\tInput: arr = [1,2,3,4,5]\n\t\tOutput: 5\n\t\tExplanation: The array already satisfies the conditions, and the largest element is 5.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1957, - "question": "class Solution:\n def closestRoom(self, rooms: List[List[int]], queries: List[List[int]]) -> List[int]:\n\t\t\"\"\"\n\t\tThere is a hotel with n rooms. The rooms are represented by a 2D integer array rooms where rooms[i] = [roomIdi, sizei] denotes that there is a room with room number roomIdi and size equal to sizei. Each roomIdi is guaranteed to be unique.\n\t\tYou are also given k queries in a 2D array queries where queries[j] = [preferredj, minSizej]. The answer to the jth query is the room number id of a room such that:\n\t\t\tThe room has a size of at least minSizej, and\n\t\t\tabs(id - preferredj) is minimized, where abs(x) is the absolute value of x.\n\t\tIf there is a tie in the absolute difference, then use the room with the smallest such id. If there is no such room, the answer is -1.\n\t\tReturn an array answer of length k where answer[j] contains the answer to the jth query.\n\t\tExample 1:\n\t\tInput: rooms = [[2,2],[1,2],[3,2]], queries = [[3,1],[3,3],[5,2]]\n\t\tOutput: [3,-1,3]\n\t\tExplanation: The answers to the queries are as follows:\n\t\tQuery = [3,1]: Room number 3 is the closest as abs(3 - 3) = 0, and its size of 2 is at least 1. The answer is 3.\n\t\tQuery = [3,3]: There are no rooms with a size of at least 3, so the answer is -1.\n\t\tQuery = [5,2]: Room number 3 is the closest as abs(3 - 5) = 2, and its size of 2 is at least 2. The answer is 3.\n\t\tExample 2:\n\t\tInput: rooms = [[1,4],[2,3],[3,5],[4,1],[5,2]], queries = [[2,3],[2,4],[2,5]]\n\t\tOutput: [2,1,3]\n\t\tExplanation: The answers to the queries are as follows:\n\t\tQuery = [2,3]: Room number 2 is the closest as abs(2 - 2) = 0, and its size of 3 is at least 3. The answer is 2.\n\t\tQuery = [2,4]: Room numbers 1 and 3 both have sizes of at least 4. The answer is 1 since it is smaller.\n\t\tQuery = [2,5]: Room number 3 is the only room with a size of at least 5. The answer is 3.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1960, - "question": "class Solution:\n def checkIfPangram(self, sentence: str) -> bool:\n\t\t\"\"\"\n\t\tA pangram is a sentence where every letter of the English alphabet appears at least once.\n\t\tGiven a string sentence containing only lowercase English letters, return true if sentence is a pangram, or false otherwise.\n\t\tExample 1:\n\t\tInput: sentence = \"thequickbrownfoxjumpsoverthelazydog\"\n\t\tOutput: true\n\t\tExplanation: sentence contains at least one of every letter of the English alphabet.\n\t\tExample 2:\n\t\tInput: sentence = \"leetcode\"\n\t\tOutput: false\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1961, - "question": "class Solution:\n def maxIceCream(self, costs: List[int], coins: int) -> int:\n\t\t\"\"\"\n\t\tIt is a sweltering summer day, and a boy wants to buy some ice cream bars.\n\t\tAt the store, there are n ice cream bars. You are given an array costs of length n, where costs[i] is the price of the ith ice cream bar in coins. The boy initially has coins coins to spend, and he wants to buy as many ice cream bars as possible. \n\t\tNote: The boy can buy the ice cream bars in any order.\n\t\tReturn the maximum number of ice cream bars the boy can buy with coins coins.\n\t\tYou must solve the problem by counting sort.\n\t\tExample 1:\n\t\tInput: costs = [1,3,2,4,1], coins = 7\n\t\tOutput: 4\n\t\tExplanation: The boy can buy ice cream bars at indices 0,1,2,4 for a total price of 1 + 3 + 2 + 1 = 7.\n\t\tExample 2:\n\t\tInput: costs = [10,6,8,7,7,8], coins = 5\n\t\tOutput: 0\n\t\tExplanation: The boy cannot afford any of the ice cream bars.\n\t\tExample 3:\n\t\tInput: costs = [1,6,3,1,2,5], coins = 20\n\t\tOutput: 6\n\t\tExplanation: The boy can buy all the ice cream bars for a total price of 1 + 6 + 3 + 1 + 2 + 5 = 18.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1962, - "question": "class Solution:\n def getOrder(self, tasks: List[List[int]]) -> List[int]:\n\t\t\"\"\"\n\t\tYou are given n\u200b\u200b\u200b\u200b\u200b\u200b tasks labeled from 0 to n - 1 represented by a 2D integer array tasks, where tasks[i] = [enqueueTimei, processingTimei] means that the i\u200b\u200b\u200b\u200b\u200b\u200bth\u200b\u200b\u200b\u200b task will be available to process at enqueueTimei and will take processingTimei to finish processing.\n\t\tYou have a single-threaded CPU that can process at most one task at a time and will act in the following way:\n\t\t\tIf the CPU is idle and there are no available tasks to process, the CPU remains idle.\n\t\t\tIf the CPU is idle and there are available tasks, the CPU will choose the one with the shortest processing time. If multiple tasks have the same shortest processing time, it will choose the task with the smallest index.\n\t\t\tOnce a task is started, the CPU will process the entire task without stopping.\n\t\t\tThe CPU can finish a task then start a new one instantly.\n\t\tReturn the order in which the CPU will process the tasks.\n\t\tExample 1:\n\t\tInput: tasks = [[1,2],[2,4],[3,2],[4,1]]\n\t\tOutput: [0,2,3,1]\n\t\tExplanation: The events go as follows: \n\t\t- At time = 1, task 0 is available to process. Available tasks = {0}.\n\t\t- Also at time = 1, the idle CPU starts processing task 0. Available tasks = {}.\n\t\t- At time = 2, task 1 is available to process. Available tasks = {1}.\n\t\t- At time = 3, task 2 is available to process. Available tasks = {1, 2}.\n\t\t- Also at time = 3, the CPU finishes task 0 and starts processing task 2 as it is the shortest. Available tasks = {1}.\n\t\t- At time = 4, task 3 is available to process. Available tasks = {1, 3}.\n\t\t- At time = 5, the CPU finishes task 2 and starts processing task 3 as it is the shortest. Available tasks = {1}.\n\t\t- At time = 6, the CPU finishes task 3 and starts processing task 1. Available tasks = {}.\n\t\t- At time = 10, the CPU finishes task 1 and becomes idle.\n\t\tExample 2:\n\t\tInput: tasks = [[7,10],[7,12],[7,5],[7,4],[7,2]]\n\t\tOutput: [4,3,2,0,1]\n\t\tExplanation: The events go as follows:\n\t\t- At time = 7, all the tasks become available. Available tasks = {0,1,2,3,4}.\n\t\t- Also at time = 7, the idle CPU starts processing task 4. Available tasks = {0,1,2,3}.\n\t\t- At time = 9, the CPU finishes task 4 and starts processing task 3. Available tasks = {0,1,2}.\n\t\t- At time = 13, the CPU finishes task 3 and starts processing task 2. Available tasks = {0,1}.\n\t\t- At time = 18, the CPU finishes task 2 and starts processing task 0. Available tasks = {1}.\n\t\t- At time = 28, the CPU finishes task 0 and starts processing task 1. Available tasks = {}.\n\t\t- At time = 40, the CPU finishes task 1 and becomes idle.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1963, - "question": "class Solution:\n def getXORSum(self, arr1: List[int], arr2: List[int]) -> int:\n\t\t\"\"\"\n\t\tThe XOR sum of a list is the bitwise XOR of all its elements. If the list only contains one element, then its XOR sum will be equal to this element.\n\t\t\tFor example, the XOR sum of [1,2,3,4] is equal to 1 XOR 2 XOR 3 XOR 4 = 4, and the XOR sum of [3] is equal to 3.\n\t\tYou are given two 0-indexed arrays arr1 and arr2 that consist only of non-negative integers.\n\t\tConsider the list containing the result of arr1[i] AND arr2[j] (bitwise AND) for every (i, j) pair where 0 <= i < arr1.length and 0 <= j < arr2.length.\n\t\tReturn the XOR sum of the aforementioned list.\n\t\tExample 1:\n\t\tInput: arr1 = [1,2,3], arr2 = [6,5]\n\t\tOutput: 0\n\t\tExplanation: The list = [1 AND 6, 1 AND 5, 2 AND 6, 2 AND 5, 3 AND 6, 3 AND 5] = [0,1,2,0,2,1].\n\t\tThe XOR sum = 0 XOR 1 XOR 2 XOR 0 XOR 2 XOR 1 = 0.\n\t\tExample 2:\n\t\tInput: arr1 = [12], arr2 = [4]\n\t\tOutput: 4\n\t\tExplanation: The list = [12 AND 4] = [4]. The XOR sum = 4.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1965, - "question": "class Solution:\n def sumBase(self, n: int, k: int) -> int:\n\t\t\"\"\"\n\t\tGiven an integer n (in base 10) and a base k, return the sum of the digits of n after converting n from base 10 to base k.\n\t\tAfter converting, each digit should be interpreted as a base 10 number, and the sum should be returned in base 10.\n\t\tExample 1:\n\t\tInput: n = 34, k = 6\n\t\tOutput: 9\n\t\tExplanation: 34 (base 10) expressed in base 6 is 54. 5 + 4 = 9.\n\t\tExample 2:\n\t\tInput: n = 10, k = 10\n\t\tOutput: 1\n\t\tExplanation: n is already in base 10. 1 + 0 = 1.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1966, - "question": "class Solution:\n def maxFrequency(self, nums: List[int], k: int) -> int:\n\t\t\"\"\"\n\t\tThe frequency of an element is the number of times it occurs in an array.\n\t\tYou are given an integer array nums and an integer k. In one operation, you can choose an index of nums and increment the element at that index by 1.\n\t\tReturn the maximum possible frequency of an element after performing at most k operations.\n\t\tExample 1:\n\t\tInput: nums = [1,2,4], k = 5\n\t\tOutput: 3\n\t\tExplanation: Increment the first element three times and the second element two times to make nums = [4,4,4].\n\t\t4 has a frequency of 3.\n\t\tExample 2:\n\t\tInput: nums = [1,4,8,13], k = 5\n\t\tOutput: 2\n\t\tExplanation: There are multiple optimal solutions:\n\t\t- Increment the first element three times to make nums = [4,4,8,13]. 4 has a frequency of 2.\n\t\t- Increment the second element four times to make nums = [1,8,8,13]. 8 has a frequency of 2.\n\t\t- Increment the third element five times to make nums = [1,4,13,13]. 13 has a frequency of 2.\n\t\tExample 3:\n\t\tInput: nums = [3,9,6], k = 2\n\t\tOutput: 1\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1967, - "question": "class Solution:\n def longestBeautifulSubstring(self, word: str) -> int:\n\t\t\"\"\"\n\t\tA string is considered beautiful if it satisfies the following conditions:\n\t\t\tEach of the 5 English vowels ('a', 'e', 'i', 'o', 'u') must appear at least once in it.\n\t\t\tThe letters must be sorted in alphabetical order (i.e. all 'a's before 'e's, all 'e's before 'i's, etc.).\n\t\tFor example, strings \"aeiou\" and \"aaaaaaeiiiioou\" are considered beautiful, but \"uaeio\", \"aeoiu\", and \"aaaeeeooo\" are not beautiful.\n\t\tGiven a string word consisting of English vowels, return the length of the longest beautiful substring of word. If no such substring exists, return 0.\n\t\tA substring is a contiguous sequence of characters in a string.\n\t\tExample 1:\n\t\tInput: word = \"aeiaaioaaaaeiiiiouuuooaauuaeiu\"\n\t\tOutput: 13\n\t\tExplanation: The longest beautiful substring in word is \"aaaaeiiiiouuu\" of length 13.\n\t\tExample 2:\n\t\tInput: word = \"aeeeiiiioooauuuaeiou\"\n\t\tOutput: 5\n\t\tExplanation: The longest beautiful substring in word is \"aeiou\" of length 5.\n\t\tExample 3:\n\t\tInput: word = \"a\"\n\t\tOutput: 0\n\t\tExplanation: There is no beautiful substring, so return 0.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1968, - "question": "class Solution:\n def maxBuilding(self, n: int, restrictions: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tYou want to build n new buildings in a city. The new buildings will be built in a line and are labeled from 1 to n.\n\t\tHowever, there are city restrictions on the heights of the new buildings:\n\t\t\tThe height of each building must be a non-negative integer.\n\t\t\tThe height of the first building must be 0.\n\t\t\tThe height difference between any two adjacent buildings cannot exceed 1.\n\t\tAdditionally, there are city restrictions on the maximum height of specific buildings. These restrictions are given as a 2D integer array restrictions where restrictions[i] = [idi, maxHeighti] indicates that building idi must have a height less than or equal to maxHeighti.\n\t\tIt is guaranteed that each building will appear at most once in restrictions, and building 1 will not be in restrictions.\n\t\tReturn the maximum possible height of the tallest building.\n\t\tExample 1:\n\t\tInput: n = 5, restrictions = [[2,1],[4,1]]\n\t\tOutput: 2\n\t\tExplanation: The green area in the image indicates the maximum allowed height for each building.\n\t\tWe can build the buildings with heights [0,1,2,1,2], and the tallest building has a height of 2.\n\t\tExample 2:\n\t\tInput: n = 6, restrictions = []\n\t\tOutput: 5\n\t\tExplanation: The green area in the image indicates the maximum allowed height for each building.\n\t\tWe can build the buildings with heights [0,1,2,3,4,5], and the tallest building has a height of 5.\n\t\tExample 3:\n\t\tInput: n = 10, restrictions = [[5,3],[2,5],[7,4],[10,3]]\n\t\tOutput: 5\n\t\tExplanation: The green area in the image indicates the maximum allowed height for each building.\n\t\tWe can build the buildings with heights [0,1,2,3,3,4,4,5,4,3], and the tallest building has a height of 5.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1970, - "question": "class Solution:\n def sortSentence(self, s: str) -> str:\n\t\t\"\"\"\n\t\tA sentence is a list of words that are separated by a single space with no leading or trailing spaces. Each word consists of lowercase and uppercase English letters.\r\n\t\tA sentence can be shuffled by appending the 1-indexed word position to each word then rearranging the words in the sentence.\r\n\t\t\tFor example, the sentence \"This is a sentence\" can be shuffled as \"sentence4 a3 is2 This1\" or \"is2 sentence4 This1 a3\".\r\n\t\tGiven a shuffled sentence s containing no more than 9 words, reconstruct and return the original sentence.\r\n\t\tExample 1:\r\n\t\tInput: s = \"is2 sentence4 This1 a3\"\r\n\t\tOutput: \"This is a sentence\"\r\n\t\tExplanation: Sort the words in s to their original positions \"This1 is2 a3 sentence4\", then remove the numbers.\r\n\t\tExample 2:\r\n\t\tInput: s = \"Myself2 Me1 I4 and3\"\r\n\t\tOutput: \"Me Myself and I\"\r\n\t\tExplanation: Sort the words in s to their original positions \"Me1 Myself2 and3 I4\", then remove the numbers.\r\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1971, - "question": "class Solution:\n def memLeak(self, memory1: int, memory2: int) -> List[int]:\n\t\t\"\"\"\n\t\tYou are given two integers memory1 and memory2 representing the available memory in bits on two memory sticks. There is currently a faulty program running that consumes an increasing amount of memory every second.\n\t\tAt the ith second (starting from 1), i bits of memory are allocated to the stick with more available memory (or from the first memory stick if both have the same available memory). If neither stick has at least i bits of available memory, the program crashes.\n\t\tReturn an array containing [crashTime, memory1crash, memory2crash], where crashTime is the time (in seconds) when the program crashed and memory1crash and memory2crash are the available bits of memory in the first and second sticks respectively.\n\t\tExample 1:\n\t\tInput: memory1 = 2, memory2 = 2\n\t\tOutput: [3,1,0]\n\t\tExplanation: The memory is allocated as follows:\n\t\t- At the 1st second, 1 bit of memory is allocated to stick 1. The first stick now has 1 bit of available memory.\n\t\t- At the 2nd second, 2 bits of memory are allocated to stick 2. The second stick now has 0 bits of available memory.\n\t\t- At the 3rd second, the program crashes. The sticks have 1 and 0 bits available respectively.\n\t\tExample 2:\n\t\tInput: memory1 = 8, memory2 = 11\n\t\tOutput: [6,0,4]\n\t\tExplanation: The memory is allocated as follows:\n\t\t- At the 1st second, 1 bit of memory is allocated to stick 2. The second stick now has 10 bit of available memory.\n\t\t- At the 2nd second, 2 bits of memory are allocated to stick 2. The second stick now has 8 bits of available memory.\n\t\t- At the 3rd second, 3 bits of memory are allocated to stick 1. The first stick now has 5 bits of available memory.\n\t\t- At the 4th second, 4 bits of memory are allocated to stick 2. The second stick now has 4 bits of available memory.\n\t\t- At the 5th second, 5 bits of memory are allocated to stick 1. The first stick now has 0 bits of available memory.\n\t\t- At the 6th second, the program crashes. The sticks have 0 and 4 bits available respectively.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1972, - "question": "class Solution:\n def rotateTheBox(self, box: List[List[str]]) -> List[List[str]]:\n\t\t\"\"\"\n\t\tYou are given an m x n matrix of characters box representing a side-view of a box. Each cell of the box is one of the following:\r\n\t\t\tA stone '#'\r\n\t\t\tA stationary obstacle '*'\r\n\t\t\tEmpty '.'\r\n\t\tThe box is rotated 90 degrees clockwise, causing some of the stones to fall due to gravity. Each stone falls down until it lands on an obstacle, another stone, or the bottom of the box. Gravity does not affect the obstacles' positions, and the inertia from the box's rotation does not affect the stones' horizontal positions.\r\n\t\tIt is guaranteed that each stone in box rests on an obstacle, another stone, or the bottom of the box.\r\n\t\tReturn an n x m matrix representing the box after the rotation described above.\r\n\t\tExample 1:\r\n\t\tInput: box = [[\"#\",\".\",\"#\"]]\r\n\t\tOutput: [[\".\"],\r\n\t\t [\"#\"],\r\n\t\t [\"#\"]]\r\n\t\tExample 2:\r\n\t\tInput: box = [[\"#\",\".\",\"*\",\".\"],\r\n\t\t [\"#\",\"#\",\"*\",\".\"]]\r\n\t\tOutput: [[\"#\",\".\"],\r\n\t\t [\"#\",\"#\"],\r\n\t\t [\"*\",\"*\"],\r\n\t\t [\".\",\".\"]]\r\n\t\tExample 3:\r\n\t\tInput: box = [[\"#\",\"#\",\"*\",\".\",\"*\",\".\"],\r\n\t\t [\"#\",\"#\",\"#\",\"*\",\".\",\".\"],\r\n\t\t [\"#\",\"#\",\"#\",\".\",\"#\",\".\"]]\r\n\t\tOutput: [[\".\",\"#\",\"#\"],\r\n\t\t [\".\",\"#\",\"#\"],\r\n\t\t [\"#\",\"#\",\"*\"],\r\n\t\t [\"#\",\"*\",\".\"],\r\n\t\t [\"#\",\".\",\"*\"],\r\n\t\t [\"#\",\".\",\".\"]]\r\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1975, - "question": "class Solution:\n def getMinDistance(self, nums: List[int], target: int, start: int) -> int:\n\t\t\"\"\"\n\t\tGiven an integer array nums (0-indexed) and two integers target and start, find an index i such that nums[i] == target and abs(i - start) is minimized. Note that abs(x) is the absolute value of x.\n\t\tReturn abs(i - start).\n\t\tIt is guaranteed that target exists in nums.\n\t\tExample 1:\n\t\tInput: nums = [1,2,3,4,5], target = 5, start = 3\n\t\tOutput: 1\n\t\tExplanation: nums[4] = 5 is the only value equal to target, so the answer is abs(4 - 3) = 1.\n\t\tExample 2:\n\t\tInput: nums = [1], target = 1, start = 0\n\t\tOutput: 0\n\t\tExplanation: nums[0] = 1 is the only value equal to target, so the answer is abs(0 - 0) = 0.\n\t\tExample 3:\n\t\tInput: nums = [1,1,1,1,1,1,1,1,1,1], target = 1, start = 0\n\t\tOutput: 0\n\t\tExplanation: Every value of nums is 1, but nums[0] minimizes abs(i - start), which is abs(0 - 0) = 0.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1976, - "question": "class Solution:\n def splitString(self, s: str) -> bool:\n\t\t\"\"\"\n\t\tYou are given a string s that consists of only digits.\n\t\tCheck if we can split s into two or more non-empty substrings such that the numerical values of the substrings are in descending order and the difference between numerical values of every two adjacent substrings is equal to 1.\n\t\t\tFor example, the string s = \"0090089\" can be split into [\"0090\", \"089\"] with numerical values [90,89]. The values are in descending order and adjacent values differ by 1, so this way is valid.\n\t\t\tAnother example, the string s = \"001\" can be split into [\"0\", \"01\"], [\"00\", \"1\"], or [\"0\", \"0\", \"1\"]. However all the ways are invalid because they have numerical values [0,1], [0,1], and [0,0,1] respectively, all of which are not in descending order.\n\t\tReturn true if it is possible to split s\u200b\u200b\u200b\u200b\u200b\u200b as described above, or false otherwise.\n\t\tA substring is a contiguous sequence of characters in a string.\n\t\tExample 1:\n\t\tInput: s = \"1234\"\n\t\tOutput: false\n\t\tExplanation: There is no valid way to split s.\n\t\tExample 2:\n\t\tInput: s = \"050043\"\n\t\tOutput: true\n\t\tExplanation: s can be split into [\"05\", \"004\", \"3\"] with numerical values [5,4,3].\n\t\tThe values are in descending order with adjacent values differing by 1.\n\t\tExample 3:\n\t\tInput: s = \"9080701\"\n\t\tOutput: false\n\t\tExplanation: There is no valid way to split s.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1977, - "question": "class Solution:\n def minInterval(self, intervals: List[List[int]], queries: List[int]) -> List[int]:\n\t\t\"\"\"\n\t\tYou are given a 2D integer array intervals, where intervals[i] = [lefti, righti] describes the ith interval starting at lefti and ending at righti (inclusive). The size of an interval is defined as the number of integers it contains, or more formally righti - lefti + 1.\n\t\tYou are also given an integer array queries. The answer to the jth query is the size of the smallest interval i such that lefti <= queries[j] <= righti. If no such interval exists, the answer is -1.\n\t\tReturn an array containing the answers to the queries.\n\t\tExample 1:\n\t\tInput: intervals = [[1,4],[2,4],[3,6],[4,4]], queries = [2,3,4,5]\n\t\tOutput: [3,3,1,4]\n\t\tExplanation: The queries are processed as follows:\n\t\t- Query = 2: The interval [2,4] is the smallest interval containing 2. The answer is 4 - 2 + 1 = 3.\n\t\t- Query = 3: The interval [2,4] is the smallest interval containing 3. The answer is 4 - 2 + 1 = 3.\n\t\t- Query = 4: The interval [4,4] is the smallest interval containing 4. The answer is 4 - 4 + 1 = 1.\n\t\t- Query = 5: The interval [3,6] is the smallest interval containing 5. The answer is 6 - 3 + 1 = 4.\n\t\tExample 2:\n\t\tInput: intervals = [[2,3],[2,5],[1,8],[20,25]], queries = [2,19,5,22]\n\t\tOutput: [2,-1,4,6]\n\t\tExplanation: The queries are processed as follows:\n\t\t- Query = 2: The interval [2,3] is the smallest interval containing 2. The answer is 3 - 2 + 1 = 2.\n\t\t- Query = 19: None of the intervals contain 19. The answer is -1.\n\t\t- Query = 5: The interval [2,5] is the smallest interval containing 5. The answer is 5 - 2 + 1 = 4.\n\t\t- Query = 22: The interval [20,25] is the smallest interval containing 22. The answer is 25 - 20 + 1 = 6.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1978, - "question": "class Solution:\n def getMinSwaps(self, num: str, k: int) -> int:\n\t\t\"\"\"\n\t\tYou are given a string num, representing a large integer, and an integer k.\n\t\tWe call some integer wonderful if it is a permutation of the digits in num and is greater in value than num. There can be many wonderful integers. However, we only care about the smallest-valued ones.\n\t\t\tFor example, when num = \"5489355142\":\n\t\t\t\tThe 1st smallest wonderful integer is \"5489355214\".\n\t\t\t\tThe 2nd smallest wonderful integer is \"5489355241\".\n\t\t\t\tThe 3rd smallest wonderful integer is \"5489355412\".\n\t\t\t\tThe 4th smallest wonderful integer is \"5489355421\".\n\t\tReturn the minimum number of adjacent digit swaps that needs to be applied to num to reach the kth smallest wonderful integer.\n\t\tThe tests are generated in such a way that kth smallest wonderful integer exists.\n\t\tExample 1:\n\t\tInput: num = \"5489355142\", k = 4\n\t\tOutput: 2\n\t\tExplanation: The 4th smallest wonderful number is \"5489355421\". To get this number:\n\t\t- Swap index 7 with index 8: \"5489355142\" -> \"5489355412\"\n\t\t- Swap index 8 with index 9: \"5489355412\" -> \"5489355421\"\n\t\tExample 2:\n\t\tInput: num = \"11112\", k = 4\n\t\tOutput: 4\n\t\tExplanation: The 4th smallest wonderful number is \"21111\". To get this number:\n\t\t- Swap index 3 with index 4: \"11112\" -> \"11121\"\n\t\t- Swap index 2 with index 3: \"11121\" -> \"11211\"\n\t\t- Swap index 1 with index 2: \"11211\" -> \"12111\"\n\t\t- Swap index 0 with index 1: \"12111\" -> \"21111\"\n\t\tExample 3:\n\t\tInput: num = \"00123\", k = 1\n\t\tOutput: 1\n\t\tExplanation: The 1st smallest wonderful number is \"00132\". To get this number:\n\t\t- Swap index 3 with index 4: \"00123\" -> \"00132\"\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1983, - "question": "class Solution:\n def maximumPopulation(self, logs: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tYou are given a 2D integer array logs where each logs[i] = [birthi, deathi] indicates the birth and death years of the ith person.\n\t\tThe population of some year x is the number of people alive during that year. The ith person is counted in year x's population if x is in the inclusive range [birthi, deathi - 1]. Note that the person is not counted in the year that they die.\n\t\tReturn the earliest year with the maximum population.\n\t\tExample 1:\n\t\tInput: logs = [[1993,1999],[2000,2010]]\n\t\tOutput: 1993\n\t\tExplanation: The maximum population is 1, and 1993 is the earliest year with this population.\n\t\tExample 2:\n\t\tInput: logs = [[1950,1961],[1960,1971],[1970,1981]]\n\t\tOutput: 1960\n\t\tExplanation: \n\t\tThe maximum population is 2, and it had happened in years 1960 and 1970.\n\t\tThe earlier year between them is 1960.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1984, - "question": "class Solution:\n def maxDistance(self, nums1: List[int], nums2: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou are given two non-increasing 0-indexed integer arrays nums1\u200b\u200b\u200b\u200b\u200b\u200b and nums2\u200b\u200b\u200b\u200b\u200b\u200b.\n\t\tA pair of indices (i, j), where 0 <= i < nums1.length and 0 <= j < nums2.length, is valid if both i <= j and nums1[i] <= nums2[j]. The distance of the pair is j - i\u200b\u200b\u200b\u200b.\n\t\tReturn the maximum distance of any valid pair (i, j). If there are no valid pairs, return 0.\n\t\tAn array arr is non-increasing if arr[i-1] >= arr[i] for every 1 <= i < arr.length.\n\t\tExample 1:\n\t\tInput: nums1 = [55,30,5,4,2], nums2 = [100,20,10,10,5]\n\t\tOutput: 2\n\t\tExplanation: The valid pairs are (0,0), (2,2), (2,3), (2,4), (3,3), (3,4), and (4,4).\n\t\tThe maximum distance is 2 with pair (2,4).\n\t\tExample 2:\n\t\tInput: nums1 = [2,2,2], nums2 = [10,10,1]\n\t\tOutput: 1\n\t\tExplanation: The valid pairs are (0,0), (0,1), and (1,1).\n\t\tThe maximum distance is 1 with pair (0,1).\n\t\tExample 3:\n\t\tInput: nums1 = [30,29,19,5], nums2 = [25,25,25,25,25]\n\t\tOutput: 2\n\t\tExplanation: The valid pairs are (2,2), (2,3), (2,4), (3,3), and (3,4).\n\t\tThe maximum distance is 2 with pair (2,4).\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1985, - "question": "class Solution:\n def maxSumMinProduct(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tThe min-product of an array is equal to the minimum value in the array multiplied by the array's sum.\n\t\t\tFor example, the array [3,2,5] (minimum value is 2) has a min-product of 2 * (3+2+5) = 2 * 10 = 20.\n\t\tGiven an array of integers nums, return the maximum min-product of any non-empty subarray of nums. Since the answer may be large, return it modulo 109 + 7.\n\t\tNote that the min-product should be maximized before performing the modulo operation. Testcases are generated such that the maximum min-product without modulo will fit in a 64-bit signed integer.\n\t\tA subarray is a contiguous part of an array.\n\t\tExample 1:\n\t\tInput: nums = [1,2,3,2]\n\t\tOutput: 14\n\t\tExplanation: The maximum min-product is achieved with the subarray [2,3,2] (minimum value is 2).\n\t\t2 * (2+3+2) = 2 * 7 = 14.\n\t\tExample 2:\n\t\tInput: nums = [2,3,3,1,2]\n\t\tOutput: 18\n\t\tExplanation: The maximum min-product is achieved with the subarray [3,3] (minimum value is 3).\n\t\t3 * (3+3) = 3 * 6 = 18.\n\t\tExample 3:\n\t\tInput: nums = [3,1,5,6,4,2]\n\t\tOutput: 60\n\t\tExplanation: The maximum min-product is achieved with the subarray [5,6,4] (minimum value is 4).\n\t\t4 * (5+6+4) = 4 * 15 = 60.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1986, - "question": "class Solution:\n def largestPathValue(self, colors: str, edges: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tThere is a directed graph of n colored nodes and m edges. The nodes are numbered from 0 to n - 1.\r\n\t\tYou are given a string colors where colors[i] is a lowercase English letter representing the color of the ith node in this graph (0-indexed). You are also given a 2D array edges where edges[j] = [aj, bj] indicates that there is a directed edge from node aj to node bj.\r\n\t\tA valid path in the graph is a sequence of nodes x1 -> x2 -> x3 -> ... -> xk such that there is a directed edge from xi to xi+1 for every 1 <= i < k. The color value of the path is the number of nodes that are colored the most frequently occurring color along that path.\r\n\t\tReturn the largest color value of any valid path in the given graph, or -1 if the graph contains a cycle.\r\n\t\tExample 1:\r\n\t\tInput: colors = \"abaca\", edges = [[0,1],[0,2],[2,3],[3,4]]\r\n\t\tOutput: 3\r\n\t\tExplanation: The path 0 -> 2 -> 3 -> 4 contains 3 nodes that are colored \"a\" (red in the above image).\r\n\t\tExample 2:\r\n\t\tInput: colors = \"a\", edges = [[0,0]]\r\n\t\tOutput: -1\r\n\t\tExplanation: There is a cycle from 0 to 0.\r\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1987, - "question": "class Solution:\n def countGoodSubstrings(self, s: str) -> int:\n\t\t\"\"\"\n\t\tA string is good if there are no repeated characters.\n\t\tGiven a string s\u200b\u200b\u200b\u200b\u200b, return the number of good substrings of length three in s\u200b\u200b\u200b\u200b\u200b\u200b.\n\t\tNote that if there are multiple occurrences of the same substring, every occurrence should be counted.\n\t\tA substring is a contiguous sequence of characters in a string.\n\t\tExample 1:\n\t\tInput: s = \"xyzzaz\"\n\t\tOutput: 1\n\t\tExplanation: There are 4 substrings of size 3: \"xyz\", \"yzz\", \"zza\", and \"zaz\". \n\t\tThe only good substring of length 3 is \"xyz\".\n\t\tExample 2:\n\t\tInput: s = \"aababcabc\"\n\t\tOutput: 4\n\t\tExplanation: There are 7 substrings of size 3: \"aab\", \"aba\", \"bab\", \"abc\", \"bca\", \"cab\", and \"abc\".\n\t\tThe good substrings are \"abc\", \"bca\", \"cab\", and \"abc\".\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1988, - "question": "class Solution:\n def minPairSum(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tThe pair sum of a pair (a,b) is equal to a + b. The maximum pair sum is the largest pair sum in a list of pairs.\r\n\t\t\tFor example, if we have pairs (1,5), (2,3), and (4,4), the maximum pair sum would be max(1+5, 2+3, 4+4) = max(6, 5, 8) = 8.\r\n\t\tGiven an array nums of even length n, pair up the elements of nums into n / 2 pairs such that:\r\n\t\t\tEach element of nums is in exactly one pair, and\r\n\t\t\tThe maximum pair sum is minimized.\r\n\t\tReturn the minimized maximum pair sum after optimally pairing up the elements.\r\n\t\tExample 1:\r\n\t\tInput: nums = [3,5,2,3]\r\n\t\tOutput: 7\r\n\t\tExplanation: The elements can be paired up into pairs (3,3) and (5,2).\r\n\t\tThe maximum pair sum is max(3+3, 5+2) = max(6, 7) = 7.\r\n\t\tExample 2:\r\n\t\tInput: nums = [3,5,4,2,4,6]\r\n\t\tOutput: 8\r\n\t\tExplanation: The elements can be paired up into pairs (3,5), (4,4), and (6,2).\r\n\t\tThe maximum pair sum is max(3+5, 4+4, 6+2) = max(8, 8, 8) = 8.\r\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1989, - "question": "class Solution:\n def minimumXORSum(self, nums1: List[int], nums2: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou are given two integer arrays nums1 and nums2 of length n.\n\t\tThe XOR sum of the two integer arrays is (nums1[0] XOR nums2[0]) + (nums1[1] XOR nums2[1]) + ... + (nums1[n - 1] XOR nums2[n - 1]) (0-indexed).\n\t\t\tFor example, the XOR sum of [1,2,3] and [3,2,1] is equal to (1 XOR 3) + (2 XOR 2) + (3 XOR 1) = 2 + 0 + 2 = 4.\n\t\tRearrange the elements of nums2 such that the resulting XOR sum is minimized.\n\t\tReturn the XOR sum after the rearrangement.\n\t\tExample 1:\n\t\tInput: nums1 = [1,2], nums2 = [2,3]\n\t\tOutput: 2\n\t\tExplanation: Rearrange nums2 so that it becomes [3,2].\n\t\tThe XOR sum is (1 XOR 3) + (2 XOR 2) = 2 + 0 = 2.\n\t\tExample 2:\n\t\tInput: nums1 = [1,0,3], nums2 = [5,3,4]\n\t\tOutput: 8\n\t\tExplanation: Rearrange nums2 so that it becomes [5,4,3]. \n\t\tThe XOR sum is (1 XOR 5) + (0 XOR 4) + (3 XOR 3) = 4 + 4 + 0 = 8.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1990, - "question": "class Solution:\n def getBiggestThree(self, grid: List[List[int]]) -> List[int]:\n\t\t\"\"\"\n\t\tYou are given an m x n integer matrix grid\u200b\u200b\u200b.\n\t\tA rhombus sum is the sum of the elements that form the border of a regular rhombus shape in grid\u200b\u200b\u200b. The rhombus must have the shape of a square rotated 45 degrees with each of the corners centered in a grid cell. Below is an image of four valid rhombus shapes with the corresponding colored cells that should be included in each rhombus sum:\n\t\tNote that the rhombus can have an area of 0, which is depicted by the purple rhombus in the bottom right corner.\n\t\tReturn the biggest three distinct rhombus sums in the grid in descending order. If there are less than three distinct values, return all of them.\n\t\tExample 1:\n\t\tInput: grid = [[3,4,5,1,3],[3,3,4,2,3],[20,30,200,40,10],[1,5,5,4,1],[4,3,2,2,5]]\n\t\tOutput: [228,216,211]\n\t\tExplanation: The rhombus shapes for the three biggest distinct rhombus sums are depicted above.\n\t\t- Blue: 20 + 3 + 200 + 5 = 228\n\t\t- Red: 200 + 2 + 10 + 4 = 216\n\t\t- Green: 5 + 200 + 4 + 2 = 211\n\t\tExample 2:\n\t\tInput: grid = [[1,2,3],[4,5,6],[7,8,9]]\n\t\tOutput: [20,9,8]\n\t\tExplanation: The rhombus shapes for the three biggest distinct rhombus sums are depicted above.\n\t\t- Blue: 4 + 2 + 6 + 8 = 20\n\t\t- Red: 9 (area 0 rhombus in the bottom right corner)\n\t\t- Green: 8 (area 0 rhombus in the bottom middle)\n\t\tExample 3:\n\t\tInput: grid = [[7,7,7]]\n\t\tOutput: [7]\n\t\tExplanation: All three possible rhombus sums are the same, so return [7].\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1993, - "question": "class Solution:\n def subsetXORSum(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tThe XOR total of an array is defined as the bitwise XOR of all its elements, or 0 if the array is empty.\n\t\t\tFor example, the XOR total of the array [2,5,6] is 2 XOR 5 XOR 6 = 1.\n\t\tGiven an array nums, return the sum of all XOR totals for every subset of nums. \n\t\tNote: Subsets with the same elements should be counted multiple times.\n\t\tAn array a is a subset of an array b if a can be obtained from b by deleting some (possibly zero) elements of b.\n\t\tExample 1:\n\t\tInput: nums = [1,3]\n\t\tOutput: 6\n\t\tExplanation: The 4 subsets of [1,3] are:\n\t\t- The empty subset has an XOR total of 0.\n\t\t- [1] has an XOR total of 1.\n\t\t- [3] has an XOR total of 3.\n\t\t- [1,3] has an XOR total of 1 XOR 3 = 2.\n\t\t0 + 1 + 3 + 2 = 6\n\t\tExample 2:\n\t\tInput: nums = [5,1,6]\n\t\tOutput: 28\n\t\tExplanation: The 8 subsets of [5,1,6] are:\n\t\t- The empty subset has an XOR total of 0.\n\t\t- [5] has an XOR total of 5.\n\t\t- [1] has an XOR total of 1.\n\t\t- [6] has an XOR total of 6.\n\t\t- [5,1] has an XOR total of 5 XOR 1 = 4.\n\t\t- [5,6] has an XOR total of 5 XOR 6 = 3.\n\t\t- [1,6] has an XOR total of 1 XOR 6 = 7.\n\t\t- [5,1,6] has an XOR total of 5 XOR 1 XOR 6 = 2.\n\t\t0 + 5 + 1 + 6 + 4 + 3 + 7 + 2 = 28\n\t\tExample 3:\n\t\tInput: nums = [3,4,5,6,7,8]\n\t\tOutput: 480\n\t\tExplanation: The sum of all XOR totals for every subset is 480.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 1994, - "question": "class Solution:\n def minSwaps(self, s: str) -> int:\n\t\t\"\"\"\n\t\tGiven a binary string s, return the minimum number of character swaps to make it alternating, or -1 if it is impossible.\n\t\tThe string is called alternating if no two adjacent characters are equal. For example, the strings \"010\" and \"1010\" are alternating, while the string \"0100\" is not.\n\t\tAny two characters may be swapped, even if they are not adjacent.\n\t\tExample 1:\n\t\tInput: s = \"111000\"\n\t\tOutput: 1\n\t\tExplanation: Swap positions 1 and 4: \"111000\" -> \"101010\"\n\t\tThe string is now alternating.\n\t\tExample 2:\n\t\tInput: s = \"010\"\n\t\tOutput: 0\n\t\tExplanation: The string is already alternating, no swaps are needed.\n\t\tExample 3:\n\t\tInput: s = \"1110\"\n\t\tOutput: -1\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1995, - "question": "class FindSumPairs:\n def __init__(self, nums1: List[int], nums2: List[int]):\n def add(self, index: int, val: int) -> None:\n def count(self, tot: int) -> int:\n\t\t\"\"\"\n\t\tYou are given two integer arrays nums1 and nums2. You are tasked to implement a data structure that supports queries of two types:\n\t\t\tAdd a positive integer to an element of a given index in the array nums2.\n\t\t\tCount the number of pairs (i, j) such that nums1[i] + nums2[j] equals a given value (0 <= i < nums1.length and 0 <= j < nums2.length).\n\t\tImplement the FindSumPairs class:\n\t\t\tFindSumPairs(int[] nums1, int[] nums2) Initializes the FindSumPairs object with two integer arrays nums1 and nums2.\n\t\t\tvoid add(int index, int val) Adds val to nums2[index], i.e., apply nums2[index] += val.\n\t\t\tint count(int tot) Returns the number of pairs (i, j) such that nums1[i] + nums2[j] == tot.\n\t\tExample 1:\n\t\tInput\n\t\t[\"FindSumPairs\", \"count\", \"add\", \"count\", \"count\", \"add\", \"add\", \"count\"]\n\t\t[[[1, 1, 2, 2, 2, 3], [1, 4, 5, 2, 5, 4]], [7], [3, 2], [8], [4], [0, 1], [1, 1], [7]]\n\t\tOutput\n\t\t[null, 8, null, 2, 1, null, null, 11]\n\t\tExplanation\n\t\tFindSumPairs findSumPairs = new FindSumPairs([1, 1, 2, 2, 2, 3], [1, 4, 5, 2, 5, 4]);\n\t\tfindSumPairs.count(7); // return 8; pairs (2,2), (3,2), (4,2), (2,4), (3,4), (4,4) make 2 + 5 and pairs (5,1), (5,5) make 3 + 4\n\t\tfindSumPairs.add(3, 2); // now nums2 = [1,4,5,4,5,4]\n\t\tfindSumPairs.count(8); // return 2; pairs (5,2), (5,4) make 3 + 5\n\t\tfindSumPairs.count(4); // return 1; pair (5,0) makes 3 + 1\n\t\tfindSumPairs.add(0, 1); // now nums2 = [2,4,5,4,5,4]\n\t\tfindSumPairs.add(1, 1); // now nums2 = [2,5,5,4,5,4]\n\t\tfindSumPairs.count(7); // return 11; pairs (2,1), (2,2), (2,4), (3,1), (3,2), (3,4), (4,1), (4,2), (4,4) make 2 + 5 and pairs (5,3), (5,5) make 3 + 4\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 1996, - "question": "class Solution:\n def rearrangeSticks(self, n: int, k: int) -> int:\n\t\t\"\"\"\n\t\tThere are n uniquely-sized sticks whose lengths are integers from 1 to n. You want to arrange the sticks such that exactly k sticks are visible from the left. A stick is visible from the left if there are no longer sticks to the left of it.\n\t\t\tFor example, if the sticks are arranged [1,3,2,5,4], then the sticks with lengths 1, 3, and 5 are visible from the left.\n\t\tGiven n and k, return the number of such arrangements. Since the answer may be large, return it modulo 109 + 7.\n\t\tExample 1:\n\t\tInput: n = 3, k = 2\n\t\tOutput: 3\n\t\tExplanation: [1,3,2], [2,3,1], and [2,1,3] are the only arrangements such that exactly 2 sticks are visible.\n\t\tThe visible sticks are underlined.\n\t\tExample 2:\n\t\tInput: n = 5, k = 5\n\t\tOutput: 1\n\t\tExplanation: [1,2,3,4,5] is the only arrangement such that all 5 sticks are visible.\n\t\tThe visible sticks are underlined.\n\t\tExample 3:\n\t\tInput: n = 20, k = 11\n\t\tOutput: 647427950\n\t\tExplanation: There are 647427950 (mod 109 + 7) ways to rearrange the sticks such that exactly 11 sticks are visible.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 1999, - "question": "class Solution:\n def checkZeroOnes(self, s: str) -> bool:\n\t\t\"\"\"\n\t\tGiven a binary string s, return true if the longest contiguous segment of 1's is strictly longer than the longest contiguous segment of 0's in s, or return false otherwise.\n\t\t\tFor example, in s = \"110100010\" the longest continuous segment of 1s has length 2, and the longest continuous segment of 0s has length 3.\n\t\tNote that if there are no 0's, then the longest continuous segment of 0's is considered to have a length 0. The same applies if there is no 1's.\n\t\tExample 1:\n\t\tInput: s = \"1101\"\n\t\tOutput: true\n\t\tExplanation:\n\t\tThe longest contiguous segment of 1s has length 2: \"1101\"\n\t\tThe longest contiguous segment of 0s has length 1: \"1101\"\n\t\tThe segment of 1s is longer, so return true.\n\t\tExample 2:\n\t\tInput: s = \"111000\"\n\t\tOutput: false\n\t\tExplanation:\n\t\tThe longest contiguous segment of 1s has length 3: \"111000\"\n\t\tThe longest contiguous segment of 0s has length 3: \"111000\"\n\t\tThe segment of 1s is not longer, so return false.\n\t\tExample 3:\n\t\tInput: s = \"110100010\"\n\t\tOutput: false\n\t\tExplanation:\n\t\tThe longest contiguous segment of 1s has length 2: \"110100010\"\n\t\tThe longest contiguous segment of 0s has length 3: \"110100010\"\n\t\tThe segment of 1s is not longer, so return false.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 2000, - "question": "class Solution:\n def minSpeedOnTime(self, dist: List[int], hour: float) -> int:\n\t\t\"\"\"\n\t\tYou are given a floating-point number hour, representing the amount of time you have to reach the office. To commute to the office, you must take n trains in sequential order. You are also given an integer array dist of length n, where dist[i] describes the distance (in kilometers) of the ith train ride.\n\t\tEach train can only depart at an integer hour, so you may need to wait in between each train ride.\n\t\t\tFor example, if the 1st train ride takes 1.5 hours, you must wait for an additional 0.5 hours before you can depart on the 2nd train ride at the 2 hour mark.\n\t\tReturn the minimum positive integer speed (in kilometers per hour) that all the trains must travel at for you to reach the office on time, or -1 if it is impossible to be on time.\n\t\tTests are generated such that the answer will not exceed 107 and hour will have at most two digits after the decimal point.\n\t\tExample 1:\n\t\tInput: dist = [1,3,2], hour = 6\n\t\tOutput: 1\n\t\tExplanation: At speed 1:\n\t\t- The first train ride takes 1/1 = 1 hour.\n\t\t- Since we are already at an integer hour, we depart immediately at the 1 hour mark. The second train takes 3/1 = 3 hours.\n\t\t- Since we are already at an integer hour, we depart immediately at the 4 hour mark. The third train takes 2/1 = 2 hours.\n\t\t- You will arrive at exactly the 6 hour mark.\n\t\tExample 2:\n\t\tInput: dist = [1,3,2], hour = 2.7\n\t\tOutput: 3\n\t\tExplanation: At speed 3:\n\t\t- The first train ride takes 1/3 = 0.33333 hours.\n\t\t- Since we are not at an integer hour, we wait until the 1 hour mark to depart. The second train ride takes 3/3 = 1 hour.\n\t\t- Since we are already at an integer hour, we depart immediately at the 2 hour mark. The third train takes 2/3 = 0.66667 hours.\n\t\t- You will arrive at the 2.66667 hour mark.\n\t\tExample 3:\n\t\tInput: dist = [1,3,2], hour = 1.9\n\t\tOutput: -1\n\t\tExplanation: It is impossible because the earliest the third train can depart is at the 2 hour mark.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 2001, - "question": "class Solution:\n def canReach(self, s: str, minJump: int, maxJump: int) -> bool:\n\t\t\"\"\"\n\t\tYou are given a 0-indexed binary string s and two integers minJump and maxJump. In the beginning, you are standing at index 0, which is equal to '0'. You can move from index i to index j if the following conditions are fulfilled:\n\t\t\ti + minJump <= j <= min(i + maxJump, s.length - 1), and\n\t\t\ts[j] == '0'.\n\t\tReturn true if you can reach index s.length - 1 in s, or false otherwise.\n\t\tExample 1:\n\t\tInput: s = \"011010\", minJump = 2, maxJump = 3\n\t\tOutput: true\n\t\tExplanation:\n\t\tIn the first step, move from index 0 to index 3. \n\t\tIn the second step, move from index 3 to index 5.\n\t\tExample 2:\n\t\tInput: s = \"01101110\", minJump = 2, maxJump = 3\n\t\tOutput: false\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 2002, - "question": "class Solution:\n def stoneGameVIII(self, stones: List[int]) -> int:\n\t\t\"\"\"\n\t\tAlice and Bob take turns playing a game, with Alice starting first.\r\n\t\tThere are n stones arranged in a row. On each player's turn, while the number of stones is more than one, they will do the following:\r\n\t\t\tChoose an integer x > 1, and remove the leftmost x stones from the row.\r\n\t\t\tAdd the sum of the removed stones' values to the player's score.\r\n\t\t\tPlace a new stone, whose value is equal to that sum, on the left side of the row.\r\n\t\tThe game stops when only one stone is left in the row.\r\n\t\tThe score difference between Alice and Bob is (Alice's score - Bob's score). Alice's goal is to maximize the score difference, and Bob's goal is the minimize the score difference.\r\n\t\tGiven an integer array stones of length n where stones[i] represents the value of the ith stone from the left, return the score difference between Alice and Bob if they both play optimally.\r\n\t\tExample 1:\r\n\t\tInput: stones = [-1,2,-3,4,-5]\r\n\t\tOutput: 5\r\n\t\tExplanation:\r\n\t\t- Alice removes the first 4 stones, adds (-1) + 2 + (-3) + 4 = 2 to her score, and places a stone of\r\n\t\t value 2 on the left. stones = [2,-5].\r\n\t\t- Bob removes the first 2 stones, adds 2 + (-5) = -3 to his score, and places a stone of value -3 on\r\n\t\t the left. stones = [-3].\r\n\t\tThe difference between their scores is 2 - (-3) = 5.\r\n\t\tExample 2:\r\n\t\tInput: stones = [7,-6,5,10,5,-2,-6]\r\n\t\tOutput: 13\r\n\t\tExplanation:\r\n\t\t- Alice removes all stones, adds 7 + (-6) + 5 + 10 + 5 + (-2) + (-6) = 13 to her score, and places a\r\n\t\t stone of value 13 on the left. stones = [13].\r\n\t\tThe difference between their scores is 13 - 0 = 13.\r\n\t\tExample 3:\r\n\t\tInput: stones = [-10,-12]\r\n\t\tOutput: -22\r\n\t\tExplanation:\r\n\t\t- Alice can only make one move, which is to remove both stones. She adds (-10) + (-12) = -22 to her\r\n\t\t score and places a stone of value -22 on the left. stones = [-22].\r\n\t\tThe difference between their scores is (-22) - 0 = -22.\r\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 2005, - "question": "class Solution:\n def isCovered(self, ranges: List[List[int]], left: int, right: int) -> bool:\n\t\t\"\"\"\n\t\tYou are given a 2D integer array ranges and two integers left and right. Each ranges[i] = [starti, endi] represents an inclusive interval between starti and endi.\n\t\tReturn true if each integer in the inclusive range [left, right] is covered by at least one interval in ranges. Return false otherwise.\n\t\tAn integer x is covered by an interval ranges[i] = [starti, endi] if starti <= x <= endi.\n\t\tExample 1:\n\t\tInput: ranges = [[1,2],[3,4],[5,6]], left = 2, right = 5\n\t\tOutput: true\n\t\tExplanation: Every integer between 2 and 5 is covered:\n\t\t- 2 is covered by the first range.\n\t\t- 3 and 4 are covered by the second range.\n\t\t- 5 is covered by the third range.\n\t\tExample 2:\n\t\tInput: ranges = [[1,10],[10,20]], left = 21, right = 21\n\t\tOutput: false\n\t\tExplanation: 21 is not covered by any range.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 2006, - "question": "class Solution:\n def chalkReplacer(self, chalk: List[int], k: int) -> int:\n\t\t\"\"\"\n\t\tThere are n students in a class numbered from 0 to n - 1. The teacher will give each student a problem starting with the student number 0, then the student number 1, and so on until the teacher reaches the student number n - 1. After that, the teacher will restart the process, starting with the student number 0 again.\n\t\tYou are given a 0-indexed integer array chalk and an integer k. There are initially k pieces of chalk. When the student number i is given a problem to solve, they will use chalk[i] pieces of chalk to solve that problem. However, if the current number of chalk pieces is strictly less than chalk[i], then the student number i will be asked to replace the chalk.\n\t\tReturn the index of the student that will replace the chalk.\n\t\tExample 1:\n\t\tInput: chalk = [5,1,5], k = 22\n\t\tOutput: 0\n\t\tExplanation: The students go in turns as follows:\n\t\t- Student number 0 uses 5 chalk, so k = 17.\n\t\t- Student number 1 uses 1 chalk, so k = 16.\n\t\t- Student number 2 uses 5 chalk, so k = 11.\n\t\t- Student number 0 uses 5 chalk, so k = 6.\n\t\t- Student number 1 uses 1 chalk, so k = 5.\n\t\t- Student number 2 uses 5 chalk, so k = 0.\n\t\tStudent number 0 does not have enough chalk, so they will have to replace it.\n\t\tExample 2:\n\t\tInput: chalk = [3,4,1,2], k = 25\n\t\tOutput: 1\n\t\tExplanation: The students go in turns as follows:\n\t\t- Student number 0 uses 3 chalk so k = 22.\n\t\t- Student number 1 uses 4 chalk so k = 18.\n\t\t- Student number 2 uses 1 chalk so k = 17.\n\t\t- Student number 3 uses 2 chalk so k = 15.\n\t\t- Student number 0 uses 3 chalk so k = 12.\n\t\t- Student number 1 uses 4 chalk so k = 8.\n\t\t- Student number 2 uses 1 chalk so k = 7.\n\t\t- Student number 3 uses 2 chalk so k = 5.\n\t\t- Student number 0 uses 3 chalk so k = 2.\n\t\tStudent number 1 does not have enough chalk, so they will have to replace it.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 2008, - "question": "class Solution:\n def minOperationsToFlip(self, expression: str) -> int:\n\t\t\"\"\"\n\t\tYou are given a valid boolean expression as a string expression consisting of the characters '1','0','&' (bitwise AND operator),'|' (bitwise OR operator),'(', and ')'.\n\t\t\tFor example, \"()1|1\" and \"(1)&()\" are not valid while \"1\", \"(((1))|(0))\", and \"1|(0&(1))\" are valid expressions.\n\t\tReturn the minimum cost to change the final value of the expression.\n\t\t\tFor example, if expression = \"1|1|(0&0)&1\", its value is 1|1|(0&0)&1 = 1|1|0&1 = 1|0&1 = 1&1 = 1. We want to apply operations so that the new expression evaluates to 0.\n\t\tThe cost of changing the final value of an expression is the number of operations performed on the expression. The types of operations are described as follows:\n\t\t\tTurn a '1' into a '0'.\n\t\t\tTurn a '0' into a '1'.\n\t\t\tTurn a '&' into a '|'.\n\t\t\tTurn a '|' into a '&'.\n\t\tNote: '&' does not take precedence over '|' in the order of calculation. Evaluate parentheses first, then in left-to-right order.\n\t\tExample 1:\n\t\tInput: expression = \"1&(0|1)\"\n\t\tOutput: 1\n\t\tExplanation: We can turn \"1&(0|1)\" into \"1&(0&1)\" by changing the '|' to a '&' using 1 operation.\n\t\tThe new expression evaluates to 0. \n\t\tExample 2:\n\t\tInput: expression = \"(0&0)&(0&0&0)\"\n\t\tOutput: 3\n\t\tExplanation: We can turn \"(0&0)&(0&0&0)\" into \"(0|1)|(0&0&0)\" using 3 operations.\n\t\tThe new expression evaluates to 1.\n\t\tExample 3:\n\t\tInput: expression = \"(0|(1|0&1))\"\n\t\tOutput: 1\n\t\tExplanation: We can turn \"(0|(1|0&1))\" into \"(0|(0|0&1))\" using 1 operation.\n\t\tThe new expression evaluates to 0.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 2010, - "question": "class Solution:\n def isSumEqual(self, firstWord: str, secondWord: str, targetWord: str) -> bool:\n\t\t\"\"\"\n\t\tThe letter value of a letter is its position in the alphabet starting from 0 (i.e. 'a' -> 0, 'b' -> 1, 'c' -> 2, etc.).\n\t\tThe numerical value of some string of lowercase English letters s is the concatenation of the letter values of each letter in s, which is then converted into an integer.\n\t\t\tFor example, if s = \"acb\", we concatenate each letter's letter value, resulting in \"021\". After converting it, we get 21.\n\t\tYou are given three strings firstWord, secondWord, and targetWord, each consisting of lowercase English letters 'a' through 'j' inclusive.\n\t\tReturn true if the summation of the numerical values of firstWord and secondWord equals the numerical value of targetWord, or false otherwise.\n\t\tExample 1:\n\t\tInput: firstWord = \"acb\", secondWord = \"cba\", targetWord = \"cdb\"\n\t\tOutput: true\n\t\tExplanation:\n\t\tThe numerical value of firstWord is \"acb\" -> \"021\" -> 21.\n\t\tThe numerical value of secondWord is \"cba\" -> \"210\" -> 210.\n\t\tThe numerical value of targetWord is \"cdb\" -> \"231\" -> 231.\n\t\tWe return true because 21 + 210 == 231.\n\t\tExample 2:\n\t\tInput: firstWord = \"aaa\", secondWord = \"a\", targetWord = \"aab\"\n\t\tOutput: false\n\t\tExplanation: \n\t\tThe numerical value of firstWord is \"aaa\" -> \"000\" -> 0.\n\t\tThe numerical value of secondWord is \"a\" -> \"0\" -> 0.\n\t\tThe numerical value of targetWord is \"aab\" -> \"001\" -> 1.\n\t\tWe return false because 0 + 0 != 1.\n\t\tExample 3:\n\t\tInput: firstWord = \"aaa\", secondWord = \"a\", targetWord = \"aaaa\"\n\t\tOutput: true\n\t\tExplanation: \n\t\tThe numerical value of firstWord is \"aaa\" -> \"000\" -> 0.\n\t\tThe numerical value of secondWord is \"a\" -> \"0\" -> 0.\n\t\tThe numerical value of targetWord is \"aaaa\" -> \"0000\" -> 0.\n\t\tWe return true because 0 + 0 == 0.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 2011, - "question": "class Solution:\n def maxValue(self, n: str, x: int) -> str:\n\t\t\"\"\"\n\t\tYou are given a very large integer n, represented as a string,\u200b\u200b\u200b\u200b\u200b\u200b and an integer digit x. The digits in n and the digit x are in the inclusive range [1, 9], and n may represent a negative number.\n\t\tYou want to maximize n's numerical value by inserting x anywhere in the decimal representation of n\u200b\u200b\u200b\u200b\u200b\u200b. You cannot insert x to the left of the negative sign.\n\t\t\tFor example, if n = 73 and x = 6, it would be best to insert it between 7 and 3, making n = 763.\n\t\t\tIf n = -55 and x = 2, it would be best to insert it before the first 5, making n = -255.\n\t\tReturn a string representing the maximum value of n\u200b\u200b\u200b\u200b\u200b\u200b after the insertion.\n\t\tExample 1:\n\t\tInput: n = \"99\", x = 9\n\t\tOutput: \"999\"\n\t\tExplanation: The result is the same regardless of where you insert 9.\n\t\tExample 2:\n\t\tInput: n = \"-13\", x = 2\n\t\tOutput: \"-123\"\n\t\tExplanation: You can make n one of {-213, -123, -132}, and the largest of those three is -123.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 2012, - "question": "class Solution:\n def assignTasks(self, servers: List[int], tasks: List[int]) -> List[int]:\n\t\t\"\"\"\n\t\tYou are given two 0-indexed integer arrays servers and tasks of lengths n\u200b\u200b\u200b\u200b\u200b\u200b and m\u200b\u200b\u200b\u200b\u200b\u200b respectively. servers[i] is the weight of the i\u200b\u200b\u200b\u200b\u200b\u200bth\u200b\u200b\u200b\u200b server, and tasks[j] is the time needed to process the j\u200b\u200b\u200b\u200b\u200b\u200bth\u200b\u200b\u200b\u200b task in seconds.\n\t\tTasks are assigned to the servers using a task queue. Initially, all servers are free, and the queue is empty.\n\t\tAt second j, the jth task is inserted into the queue (starting with the 0th task being inserted at second 0). As long as there are free servers and the queue is not empty, the task in the front of the queue will be assigned to a free server with the smallest weight, and in case of a tie, it is assigned to a free server with the smallest index.\n\t\tIf there are no free servers and the queue is not empty, we wait until a server becomes free and immediately assign the next task. If multiple servers become free at the same time, then multiple tasks from the queue will be assigned in order of insertion following the weight and index priorities above.\n\t\tA server that is assigned task j at second t will be free again at second t + tasks[j].\n\t\tBuild an array ans\u200b\u200b\u200b\u200b of length m, where ans[j] is the index of the server the j\u200b\u200b\u200b\u200b\u200b\u200bth task will be assigned to.\n\t\tReturn the array ans\u200b\u200b\u200b\u200b.\n\t\tExample 1:\n\t\tInput: servers = [3,3,2], tasks = [1,2,3,2,1,2]\n\t\tOutput: [2,2,0,2,1,2]\n\t\tExplanation: Events in chronological order go as follows:\n\t\t- At second 0, task 0 is added and processed using server 2 until second 1.\n\t\t- At second 1, server 2 becomes free. Task 1 is added and processed using server 2 until second 3.\n\t\t- At second 2, task 2 is added and processed using server 0 until second 5.\n\t\t- At second 3, server 2 becomes free. Task 3 is added and processed using server 2 until second 5.\n\t\t- At second 4, task 4 is added and processed using server 1 until second 5.\n\t\t- At second 5, all servers become free. Task 5 is added and processed using server 2 until second 7.\n\t\tExample 2:\n\t\tInput: servers = [5,1,4,3,2], tasks = [2,1,2,4,5,2,1]\n\t\tOutput: [1,4,1,4,1,3,2]\n\t\tExplanation: Events in chronological order go as follows: \n\t\t- At second 0, task 0 is added and processed using server 1 until second 2.\n\t\t- At second 1, task 1 is added and processed using server 4 until second 2.\n\t\t- At second 2, servers 1 and 4 become free. Task 2 is added and processed using server 1 until second 4. \n\t\t- At second 3, task 3 is added and processed using server 4 until second 7.\n\t\t- At second 4, server 1 becomes free. Task 4 is added and processed using server 1 until second 9. \n\t\t- At second 5, task 5 is added and processed using server 3 until second 7.\n\t\t- At second 6, task 6 is added and processed using server 2 until second 7.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 2013, - "question": "class Solution:\n def minSkips(self, dist: List[int], speed: int, hoursBefore: int) -> int:\n\t\t\"\"\"\n\t\tYou are given an integer hoursBefore, the number of hours you have to travel to your meeting. To arrive at your meeting, you have to travel through n roads. The road lengths are given as an integer array dist of length n, where dist[i] describes the length of the ith road in kilometers. In addition, you are given an integer speed, which is the speed (in km/h) you will travel at.\n\t\tAfter you travel road i, you must rest and wait for the next integer hour before you can begin traveling on the next road. Note that you do not have to rest after traveling the last road because you are already at the meeting.\n\t\t\tFor example, if traveling a road takes 1.4 hours, you must wait until the 2 hour mark before traveling the next road. If traveling a road takes exactly 2 hours, you do not need to wait.\n\t\tHowever, you are allowed to skip some rests to be able to arrive on time, meaning you do not need to wait for the next integer hour. Note that this means you may finish traveling future roads at different hour marks.\n\t\t\tFor example, suppose traveling the first road takes 1.4 hours and traveling the second road takes 0.6 hours. Skipping the rest after the first road will mean you finish traveling the second road right at the 2 hour mark, letting you start traveling the third road immediately.\n\t\tReturn the minimum number of skips required to arrive at the meeting on time, or -1 if it is impossible.\n\t\tExample 1:\n\t\tInput: dist = [1,3,2], speed = 4, hoursBefore = 2\n\t\tOutput: 1\n\t\tExplanation:\n\t\tWithout skipping any rests, you will arrive in (1/4 + 3/4) + (3/4 + 1/4) + (2/4) = 2.5 hours.\n\t\tYou can skip the first rest to arrive in ((1/4 + 0) + (3/4 + 0)) + (2/4) = 1.5 hours.\n\t\tNote that the second rest is shortened because you finish traveling the second road at an integer hour due to skipping the first rest.\n\t\tExample 2:\n\t\tInput: dist = [7,3,5,5], speed = 2, hoursBefore = 10\n\t\tOutput: 2\n\t\tExplanation:\n\t\tWithout skipping any rests, you will arrive in (7/2 + 1/2) + (3/2 + 1/2) + (5/2 + 1/2) + (5/2) = 11.5 hours.\n\t\tYou can skip the first and third rest to arrive in ((7/2 + 0) + (3/2 + 0)) + ((5/2 + 0) + (5/2)) = 10 hours.\n\t\tExample 3:\n\t\tInput: dist = [7,3,5,5], speed = 1, hoursBefore = 10\n\t\tOutput: -1\n\t\tExplanation: It is impossible to arrive at the meeting on time even if you skip all the rests.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 2015, - "question": "class Solution:\n def findRotation(self, mat: List[List[int]], target: List[List[int]]) -> bool:\n\t\t\"\"\"\n\t\tGiven two n x n binary matrices mat and target, return true if it is possible to make mat equal to target by rotating mat in 90-degree increments, or false otherwise.\n\t\tExample 1:\n\t\tInput: mat = [[0,1],[1,0]], target = [[1,0],[0,1]]\n\t\tOutput: true\n\t\tExplanation: We can rotate mat 90 degrees clockwise to make mat equal target.\n\t\tExample 2:\n\t\tInput: mat = [[0,1],[1,1]], target = [[1,0],[0,1]]\n\t\tOutput: false\n\t\tExplanation: It is impossible to make mat equal to target by rotating mat.\n\t\tExample 3:\n\t\tInput: mat = [[0,0,0],[0,1,0],[1,1,1]], target = [[1,1,1],[0,1,0],[0,0,0]]\n\t\tOutput: true\n\t\tExplanation: We can rotate mat 90 degrees clockwise two times to make mat equal target.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 2016, - "question": "class Solution:\n def reductionOperations(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tGiven an integer array nums, your goal is to make all elements in nums equal. To complete one operation, follow these steps:\n\t\t\tFind the largest value in nums. Let its index be i (0-indexed) and its value be largest. If there are multiple elements with the largest value, pick the smallest i.\n\t\t\tFind the next largest value in nums strictly smaller than largest. Let its value be nextLargest.\n\t\t\tReduce nums[i] to nextLargest.\n\t\tReturn the number of operations to make all elements in nums equal.\n\t\tExample 1:\n\t\tInput: nums = [5,1,3]\n\t\tOutput: 3\n\t\tExplanation: It takes 3 operations to make all elements in nums equal:\n\t\t1. largest = 5 at index 0. nextLargest = 3. Reduce nums[0] to 3. nums = [3,1,3].\n\t\t2. largest = 3 at index 0. nextLargest = 1. Reduce nums[0] to 1. nums = [1,1,3].\n\t\t3. largest = 3 at index 2. nextLargest = 1. Reduce nums[2] to 1. nums = [1,1,1].\n\t\tExample 2:\n\t\tInput: nums = [1,1,1]\n\t\tOutput: 0\n\t\tExplanation: All elements in nums are already equal.\n\t\tExample 3:\n\t\tInput: nums = [1,1,2,2,3]\n\t\tOutput: 4\n\t\tExplanation: It takes 4 operations to make all elements in nums equal:\n\t\t1. largest = 3 at index 4. nextLargest = 2. Reduce nums[4] to 2. nums = [1,1,2,2,2].\n\t\t2. largest = 2 at index 2. nextLargest = 1. Reduce nums[2] to 1. nums = [1,1,1,2,2].\n\t\t3. largest = 2 at index 3. nextLargest = 1. Reduce nums[3] to 1. nums = [1,1,1,1,2].\n\t\t4. largest = 2 at index 4. nextLargest = 1. Reduce nums[4] to 1. nums = [1,1,1,1,1].\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 2017, - "question": "class Solution:\n def minFlips(self, s: str) -> int:\n\t\t\"\"\"\n\t\tYou are given a binary string s. You are allowed to perform two types of operations on the string in any sequence:\n\t\t\tType-1: Remove the character at the start of the string s and append it to the end of the string.\n\t\t\tType-2: Pick any character in s and flip its value, i.e., if its value is '0' it becomes '1' and vice-versa.\n\t\tReturn the minimum number of type-2 operations you need to perform such that s becomes alternating.\n\t\tThe string is called alternating if no two adjacent characters are equal.\n\t\t\tFor example, the strings \"010\" and \"1010\" are alternating, while the string \"0100\" is not.\n\t\tExample 1:\n\t\tInput: s = \"111000\"\n\t\tOutput: 2\n\t\tExplanation: Use the first operation two times to make s = \"100011\".\n\t\tThen, use the second operation on the third and sixth elements to make s = \"101010\".\n\t\tExample 2:\n\t\tInput: s = \"010\"\n\t\tOutput: 0\n\t\tExplanation: The string is already alternating.\n\t\tExample 3:\n\t\tInput: s = \"1110\"\n\t\tOutput: 1\n\t\tExplanation: Use the second operation on the second element to make s = \"1010\".\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 2018, - "question": "class Solution:\n def minWastedSpace(self, packages: List[int], boxes: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tYou have n packages that you are trying to place in boxes, one package in each box. There are m suppliers that each produce boxes of different sizes (with infinite supply). A package can be placed in a box if the size of the package is less than or equal to the size of the box.\n\t\tThe package sizes are given as an integer array packages, where packages[i] is the size of the ith package. The suppliers are given as a 2D integer array boxes, where boxes[j] is an array of box sizes that the jth supplier produces.\n\t\tYou want to choose a single supplier and use boxes from them such that the total wasted space is minimized. For each package in a box, we define the space wasted to be size of the box - size of the package. The total wasted space is the sum of the space wasted in all the boxes.\n\t\t\tFor example, if you have to fit packages with sizes [2,3,5] and the supplier offers boxes of sizes [4,8], you can fit the packages of size-2 and size-3 into two boxes of size-4 and the package with size-5 into a box of size-8. This would result in a waste of (4-2) + (4-3) + (8-5) = 6.\n\t\tReturn the minimum total wasted space by choosing the box supplier optimally, or -1 if it is impossible to fit all the packages inside boxes. Since the answer may be large, return it modulo 109 + 7.\n\t\tExample 1:\n\t\tInput: packages = [2,3,5], boxes = [[4,8],[2,8]]\n\t\tOutput: 6\n\t\tExplanation: It is optimal to choose the first supplier, using two size-4 boxes and one size-8 box.\n\t\tThe total waste is (4-2) + (4-3) + (8-5) = 6.\n\t\tExample 2:\n\t\tInput: packages = [2,3,5], boxes = [[1,4],[2,3],[3,4]]\n\t\tOutput: -1\n\t\tExplanation: There is no box that the package of size 5 can fit in.\n\t\tExample 3:\n\t\tInput: packages = [3,5,8,10,11,12], boxes = [[12],[11,9],[10,5,14]]\n\t\tOutput: 9\n\t\tExplanation: It is optimal to choose the third supplier, using two size-5 boxes, two size-10 boxes, and two size-14 boxes.\n\t\tThe total waste is (5-3) + (5-5) + (10-8) + (10-10) + (14-11) + (14-12) = 9.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 2020, - "question": "class Solution:\n def canBeIncreasing(self, nums: List[int]) -> bool:\n\t\t\"\"\"\n\t\tGiven a 0-indexed integer array nums, return true if it can be made strictly increasing after removing exactly one element, or false otherwise. If the array is already strictly increasing, return true.\n\t\tThe array nums is strictly increasing if nums[i - 1] < nums[i] for each index (1 <= i < nums.length).\n\t\tExample 1:\n\t\tInput: nums = [1,2,10,5,7]\n\t\tOutput: true\n\t\tExplanation: By removing 10 at index 2 from nums, it becomes [1,2,5,7].\n\t\t[1,2,5,7] is strictly increasing, so return true.\n\t\tExample 2:\n\t\tInput: nums = [2,3,1,2]\n\t\tOutput: false\n\t\tExplanation:\n\t\t[3,1,2] is the result of removing the element at index 0.\n\t\t[2,1,2] is the result of removing the element at index 1.\n\t\t[2,3,2] is the result of removing the element at index 2.\n\t\t[2,3,1] is the result of removing the element at index 3.\n\t\tNo resulting array is strictly increasing, so return false.\n\t\tExample 3:\n\t\tInput: nums = [1,1,1]\n\t\tOutput: false\n\t\tExplanation: The result of removing any element is [1,1].\n\t\t[1,1] is not strictly increasing, so return false.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 2021, - "question": "class Solution:\n def removeOccurrences(self, s: str, part: str) -> str:\n\t\t\"\"\"\n\t\tGiven two strings s and part, perform the following operation on s until all occurrences of the substring part are removed:\n\t\t\tFind the leftmost occurrence of the substring part and remove it from s.\n\t\tReturn s after removing all occurrences of part.\n\t\tA substring is a contiguous sequence of characters in a string.\n\t\tExample 1:\n\t\tInput: s = \"daabcbaabcbc\", part = \"abc\"\n\t\tOutput: \"dab\"\n\t\tExplanation: The following operations are done:\n\t\t- s = \"daabcbaabcbc\", remove \"abc\" starting at index 2, so s = \"dabaabcbc\".\n\t\t- s = \"dabaabcbc\", remove \"abc\" starting at index 4, so s = \"dababc\".\n\t\t- s = \"dababc\", remove \"abc\" starting at index 3, so s = \"dab\".\n\t\tNow s has no occurrences of \"abc\".\n\t\tExample 2:\n\t\tInput: s = \"axxxxyyyyb\", part = \"xy\"\n\t\tOutput: \"ab\"\n\t\tExplanation: The following operations are done:\n\t\t- s = \"axxxxyyyyb\", remove \"xy\" starting at index 4 so s = \"axxxyyyb\".\n\t\t- s = \"axxxyyyb\", remove \"xy\" starting at index 3 so s = \"axxyyb\".\n\t\t- s = \"axxyyb\", remove \"xy\" starting at index 2 so s = \"axyb\".\n\t\t- s = \"axyb\", remove \"xy\" starting at index 1 so s = \"ab\".\n\t\tNow s has no occurrences of \"xy\".\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 2022, - "question": "class Solution:\n def maxAlternatingSum(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tThe alternating sum of a 0-indexed array is defined as the sum of the elements at even indices minus the sum of the elements at odd indices.\r\n\t\t\tFor example, the alternating sum of [4,2,5,3] is (4 + 5) - (2 + 3) = 4.\r\n\t\tGiven an array nums, return the maximum alternating sum of any subsequence of nums (after reindexing the elements of the subsequence).\r\n\t\tA subsequence of an array is a new array generated from the original array by deleting some elements (possibly none) without changing the remaining elements' relative order. For example, [2,7,4] is a subsequence of [4,2,3,7,2,1,4] (the underlined elements), while [2,4,2] is not.\r\n\t\tExample 1:\r\n\t\tInput: nums = [4,2,5,3]\r\n\t\tOutput: 7\r\n\t\tExplanation: It is optimal to choose the subsequence [4,2,5] with alternating sum (4 + 5) - 2 = 7.\r\n\t\tExample 2:\r\n\t\tInput: nums = [5,6,7,8]\r\n\t\tOutput: 8\r\n\t\tExplanation: It is optimal to choose the subsequence [8] with alternating sum 8.\r\n\t\tExample 3:\r\n\t\tInput: nums = [6,2,1,2,4,5]\r\n\t\tOutput: 10\r\n\t\tExplanation: It is optimal to choose the subsequence [6,1,5] with alternating sum (6 + 5) - 1 = 10.\r\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 2023, - "question": "class MovieRentingSystem:\n def __init__(self, n: int, entries: List[List[int]]):\n def search(self, movie: int) -> List[int]:\n def rent(self, shop: int, movie: int) -> None:\n def drop(self, shop: int, movie: int) -> None:\n def report(self) -> List[List[int]]:\n\t\t\"\"\"\n\t\tYou have a movie renting company consisting of n shops. You want to implement a renting system that supports searching for, booking, and returning movies. The system should also support generating a report of the currently rented movies.\n\t\tEach movie is given as a 2D integer array entries where entries[i] = [shopi, moviei, pricei] indicates that there is a copy of movie moviei at shop shopi with a rental price of pricei. Each shop carries at most one copy of a movie moviei.\n\t\tThe system should support the following functions:\n\t\t\tSearch: Finds the cheapest 5 shops that have an unrented copy of a given movie. The shops should be sorted by price in ascending order, and in case of a tie, the one with the smaller shopi should appear first. If there are less than 5 matching shops, then all of them should be returned. If no shop has an unrented copy, then an empty list should be returned.\n\t\t\tRent: Rents an unrented copy of a given movie from a given shop.\n\t\t\tDrop: Drops off a previously rented copy of a given movie at a given shop.\n\t\t\tReport: Returns the cheapest 5 rented movies (possibly of the same movie ID) as a 2D list res where res[j] = [shopj, moviej] describes that the jth cheapest rented movie moviej was rented from the shop shopj. The movies in res should be sorted by price in ascending order, and in case of a tie, the one with the smaller shopj should appear first, and if there is still tie, the one with the smaller moviej should appear first. If there are fewer than 5 rented movies, then all of them should be returned. If no movies are currently being rented, then an empty list should be returned.\n\t\tImplement the MovieRentingSystem class:\n\t\t\tMovieRentingSystem(int n, int[][] entries) Initializes the MovieRentingSystem object with n shops and the movies in entries.\n\t\t\tList search(int movie) Returns a list of shops that have an unrented copy of the given movie as described above.\n\t\t\tvoid rent(int shop, int movie) Rents the given movie from the given shop.\n\t\t\tvoid drop(int shop, int movie) Drops off a previously rented movie at the given shop.\n\t\t\tList> report() Returns a list of cheapest rented movies as described above.\n\t\tNote: The test cases will be generated such that rent will only be called if the shop has an unrented copy of the movie, and drop will only be called if the shop had previously rented out the movie.\n\t\tExample 1:\n\t\tInput\n\t\t[\"MovieRentingSystem\", \"search\", \"rent\", \"rent\", \"report\", \"drop\", \"search\"]\n\t\t[[3, [[0, 1, 5], [0, 2, 6], [0, 3, 7], [1, 1, 4], [1, 2, 7], [2, 1, 5]]], [1], [0, 1], [1, 2], [], [1, 2], [2]]\n\t\tOutput\n\t\t[null, [1, 0, 2], null, null, [[0, 1], [1, 2]], null, [0, 1]]\n\t\tExplanation\n\t\tMovieRentingSystem movieRentingSystem = new MovieRentingSystem(3, [[0, 1, 5], [0, 2, 6], [0, 3, 7], [1, 1, 4], [1, 2, 7], [2, 1, 5]]);\n\t\tmovieRentingSystem.search(1); // return [1, 0, 2], Movies of ID 1 are unrented at shops 1, 0, and 2. Shop 1 is cheapest; shop 0 and 2 are the same price, so order by shop number.\n\t\tmovieRentingSystem.rent(0, 1); // Rent movie 1 from shop 0. Unrented movies at shop 0 are now [2,3].\n\t\tmovieRentingSystem.rent(1, 2); // Rent movie 2 from shop 1. Unrented movies at shop 1 are now [1].\n\t\tmovieRentingSystem.report(); // return [[0, 1], [1, 2]]. Movie 1 from shop 0 is cheapest, followed by movie 2 from shop 1.\n\t\tmovieRentingSystem.drop(1, 2); // Drop off movie 2 at shop 1. Unrented movies at shop 1 are now [1,2].\n\t\tmovieRentingSystem.search(2); // return [0, 1]. Movies of ID 2 are unrented at shops 0 and 1. Shop 0 is cheapest, followed by shop 1.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 2025, - "question": "class Solution:\n def makeEqual(self, words: List[str]) -> bool:\n\t\t\"\"\"\n\t\tYou are given an array of strings words (0-indexed).\n\t\tIn one operation, pick two distinct indices i and j, where words[i] is a non-empty string, and move any character from words[i] to any position in words[j].\n\t\tReturn true if you can make every string in words equal using any number of operations, and false otherwise.\n\t\tExample 1:\n\t\tInput: words = [\"abc\",\"aabc\",\"bc\"]\n\t\tOutput: true\n\t\tExplanation: Move the first 'a' in words[1] to the front of words[2],\n\t\tto make words[1] = \"abc\" and words[2] = \"abc\".\n\t\tAll the strings are now equal to \"abc\", so return true.\n\t\tExample 2:\n\t\tInput: words = [\"ab\",\"a\"]\n\t\tOutput: false\n\t\tExplanation: It is impossible to make all the strings equal using the operation.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 2026, - "question": "class Solution:\n def mergeTriplets(self, triplets: List[List[int]], target: List[int]) -> bool:\n\t\t\"\"\"\n\t\tA triplet is an array of three integers. You are given a 2D integer array triplets, where triplets[i] = [ai, bi, ci] describes the ith triplet. You are also given an integer array target = [x, y, z] that describes the triplet you want to obtain.\n\t\tTo obtain target, you may apply the following operation on triplets any number of times (possibly zero):\n\t\t\tChoose two indices (0-indexed) i and j (i != j) and update triplets[j] to become [max(ai, aj), max(bi, bj), max(ci, cj)].\n\t\t\t\tFor example, if triplets[i] = [2, 5, 3] and triplets[j] = [1, 7, 5], triplets[j] will be updated to [max(2, 1), max(5, 7), max(3, 5)] = [2, 7, 5].\n\t\tReturn true if it is possible to obtain the target triplet [x, y, z] as an element of triplets, or false otherwise.\n\t\tExample 1:\n\t\tInput: triplets = [[2,5,3],[1,8,4],[1,7,5]], target = [2,7,5]\n\t\tOutput: true\n\t\tExplanation: Perform the following operations:\n\t\t- Choose the first and last triplets [[2,5,3],[1,8,4],[1,7,5]]. Update the last triplet to be [max(2,1), max(5,7), max(3,5)] = [2,7,5]. triplets = [[2,5,3],[1,8,4],[2,7,5]]\n\t\tThe target triplet [2,7,5] is now an element of triplets.\n\t\tExample 2:\n\t\tInput: triplets = [[3,4,5],[4,5,6]], target = [3,2,5]\n\t\tOutput: false\n\t\tExplanation: It is impossible to have [3,2,5] as an element because there is no 2 in any of the triplets.\n\t\tExample 3:\n\t\tInput: triplets = [[2,5,3],[2,3,4],[1,2,5],[5,2,3]], target = [5,5,5]\n\t\tOutput: true\n\t\tExplanation: Perform the following operations:\n\t\t- Choose the first and third triplets [[2,5,3],[2,3,4],[1,2,5],[5,2,3]]. Update the third triplet to be [max(2,1), max(5,2), max(3,5)] = [2,5,5]. triplets = [[2,5,3],[2,3,4],[2,5,5],[5,2,3]].\n\t\t- Choose the third and fourth triplets [[2,5,3],[2,3,4],[2,5,5],[5,2,3]]. Update the fourth triplet to be [max(2,5), max(5,2), max(5,3)] = [5,5,5]. triplets = [[2,5,3],[2,3,4],[2,5,5],[5,5,5]].\n\t\tThe target triplet [5,5,5] is now an element of triplets.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 2027, - "question": "class Solution:\n def maximumRemovals(self, s: str, p: str, removable: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou are given two strings s and p where p is a subsequence of s. You are also given a distinct 0-indexed integer array removable containing a subset of indices of s (s is also 0-indexed).\n\t\tYou want to choose an integer k (0 <= k <= removable.length) such that, after removing k characters from s using the first k indices in removable, p is still a subsequence of s. More formally, you will mark the character at s[removable[i]] for each 0 <= i < k, then remove all marked characters and check if p is still a subsequence.\n\t\tReturn the maximum k you can choose such that p is still a subsequence of s after the removals.\n\t\tA subsequence of a string is a new string generated from the original string with some characters (can be none) deleted without changing the relative order of the remaining characters.\n\t\tExample 1:\n\t\tInput: s = \"abcacb\", p = \"ab\", removable = [3,1,0]\n\t\tOutput: 2\n\t\tExplanation: After removing the characters at indices 3 and 1, \"abcacb\" becomes \"accb\".\n\t\t\"ab\" is a subsequence of \"accb\".\n\t\tIf we remove the characters at indices 3, 1, and 0, \"abcacb\" becomes \"ccb\", and \"ab\" is no longer a subsequence.\n\t\tHence, the maximum k is 2.\n\t\tExample 2:\n\t\tInput: s = \"abcbddddd\", p = \"abcd\", removable = [3,2,1,4,5,6]\n\t\tOutput: 1\n\t\tExplanation: After removing the character at index 3, \"abcbddddd\" becomes \"abcddddd\".\n\t\t\"abcd\" is a subsequence of \"abcddddd\".\n\t\tExample 3:\n\t\tInput: s = \"abcab\", p = \"abc\", removable = [0,1,2,3,4]\n\t\tOutput: 0\n\t\tExplanation: If you remove the first index in the array removable, \"abc\" is no longer a subsequence.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 2028, - "question": "class Solution:\n def earliestAndLatest(self, n: int, firstPlayer: int, secondPlayer: int) -> List[int]:\n\t\t\"\"\"\n\t\tThere is a tournament where n players are participating. The players are standing in a single row and are numbered from 1 to n based on their initial standing position (player 1 is the first player in the row, player 2 is the second player in the row, etc.).\n\t\tThe tournament consists of multiple rounds (starting from round number 1). In each round, the ith player from the front of the row competes against the ith player from the end of the row, and the winner advances to the next round. When the number of players is odd for the current round, the player in the middle automatically advances to the next round.\n\t\t\tFor example, if the row consists of players 1, 2, 4, 6, 7\n\t\t\t\tPlayer 1 competes against player 7.\n\t\t\t\tPlayer 2 competes against player 6.\n\t\t\t\tPlayer 4 automatically advances to the next round.\n\t\tAfter each round is over, the winners are lined back up in the row based on the original ordering assigned to them initially (ascending order).\n\t\tThe players numbered firstPlayer and secondPlayer are the best in the tournament. They can win against any other player before they compete against each other. If any two other players compete against each other, either of them might win, and thus you may choose the outcome of this round.\n\t\tGiven the integers n, firstPlayer, and secondPlayer, return an integer array containing two values, the earliest possible round number and the latest possible round number in which these two players will compete against each other, respectively.\n\t\tExample 1:\n\t\tInput: n = 11, firstPlayer = 2, secondPlayer = 4\n\t\tOutput: [3,4]\n\t\tExplanation:\n\t\tOne possible scenario which leads to the earliest round number:\n\t\tFirst round: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11\n\t\tSecond round: 2, 3, 4, 5, 6, 11\n\t\tThird round: 2, 3, 4\n\t\tOne possible scenario which leads to the latest round number:\n\t\tFirst round: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11\n\t\tSecond round: 1, 2, 3, 4, 5, 6\n\t\tThird round: 1, 2, 4\n\t\tFourth round: 2, 4\n\t\tExample 2:\n\t\tInput: n = 5, firstPlayer = 1, secondPlayer = 5\n\t\tOutput: [1,1]\n\t\tExplanation: The players numbered 1 and 5 compete in the first round.\n\t\tThere is no way to make them compete in any other round.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 2031, - "question": "class Solution:\n def twoEggDrop(self, n: int) -> int:\n\t\t\"\"\"\n\t\tYou are given two identical eggs and you have access to a building with n floors labeled from 1 to n.\n\t\tYou know that there exists a floor f where 0 <= f <= n such that any egg dropped at a floor higher than f will break, and any egg dropped at or below floor f will not break.\n\t\tIn each move, you may take an unbroken egg and drop it from any floor x (where 1 <= x <= n). If the egg breaks, you can no longer use it. However, if the egg does not break, you may reuse it in future moves.\n\t\tReturn the minimum number of moves that you need to determine with certainty what the value of f is.\n\t\tExample 1:\n\t\tInput: n = 2\n\t\tOutput: 2\n\t\tExplanation: We can drop the first egg from floor 1 and the second egg from floor 2.\n\t\tIf the first egg breaks, we know that f = 0.\n\t\tIf the second egg breaks but the first egg didn't, we know that f = 1.\n\t\tOtherwise, if both eggs survive, we know that f = 2.\n\t\tExample 2:\n\t\tInput: n = 100\n\t\tOutput: 14\n\t\tExplanation: One optimal strategy is:\n\t\t- Drop the 1st egg at floor 9. If it breaks, we know f is between 0 and 8. Drop the 2nd egg starting from floor 1 and going up one at a time to find f within 8 more drops. Total drops is 1 + 8 = 9.\n\t\t- If the 1st egg does not break, drop the 1st egg again at floor 22. If it breaks, we know f is between 9 and 21. Drop the 2nd egg starting from floor 10 and going up one at a time to find f within 12 more drops. Total drops is 2 + 12 = 14.\n\t\t- If the 1st egg does not break again, follow a similar process dropping the 1st egg from floors 34, 45, 55, 64, 72, 79, 85, 90, 94, 97, 99, and 100.\n\t\tRegardless of the outcome, it takes at most 14 drops to determine f.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 2032, - "question": "class Solution:\n def largestOddNumber(self, num: str) -> str:\n\t\t\"\"\"\n\t\tYou are given a string num, representing a large integer. Return the largest-valued odd integer (as a string) that is a non-empty substring of num, or an empty string \"\" if no odd integer exists.\n\t\tA substring is a contiguous sequence of characters within a string.\n\t\tExample 1:\n\t\tInput: num = \"52\"\n\t\tOutput: \"5\"\n\t\tExplanation: The only non-empty substrings are \"5\", \"2\", and \"52\". \"5\" is the only odd number.\n\t\tExample 2:\n\t\tInput: num = \"4206\"\n\t\tOutput: \"\"\n\t\tExplanation: There are no odd numbers in \"4206\".\n\t\tExample 3:\n\t\tInput: num = \"35427\"\n\t\tOutput: \"35427\"\n\t\tExplanation: \"35427\" is already an odd number.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 2033, - "question": "class Solution:\n def numberOfRounds(self, loginTime: str, logoutTime: str) -> int:\n\t\t\"\"\"\n\t\tYou are participating in an online chess tournament. There is a chess round that starts every 15 minutes. The first round of the day starts at 00:00, and after every 15 minutes, a new round starts.\n\t\t\tFor example, the second round starts at 00:15, the fourth round starts at 00:45, and the seventh round starts at 01:30.\n\t\tYou are given two strings loginTime and logoutTime where:\n\t\t\tloginTime is the time you will login to the game, and\n\t\t\tlogoutTime is the time you will logout from the game.\n\t\tIf logoutTime is earlier than loginTime, this means you have played from loginTime to midnight and from midnight to logoutTime.\n\t\tReturn the number of full chess rounds you have played in the tournament.\n\t\tNote: All the given times follow the 24-hour clock. That means the first round of the day starts at 00:00 and the last round of the day starts at 23:45.\n\t\tExample 1:\n\t\tInput: loginTime = \"09:31\", logoutTime = \"10:14\"\n\t\tOutput: 1\n\t\tExplanation: You played one full round from 09:45 to 10:00.\n\t\tYou did not play the full round from 09:30 to 09:45 because you logged in at 09:31 after it began.\n\t\tYou did not play the full round from 10:00 to 10:15 because you logged out at 10:14 before it ended.\n\t\tExample 2:\n\t\tInput: loginTime = \"21:30\", logoutTime = \"03:00\"\n\t\tOutput: 22\n\t\tExplanation: You played 10 full rounds from 21:30 to 00:00 and 12 full rounds from 00:00 to 03:00.\n\t\t10 + 12 = 22.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 2034, - "question": "class Solution:\n def minDifference(self, nums: List[int], queries: List[List[int]]) -> List[int]:\n\t\t\"\"\"\n\t\tThe minimum absolute difference of an array a is defined as the minimum value of |a[i] - a[j]|, where 0 <= i < j < a.length and a[i] != a[j]. If all elements of a are the same, the minimum absolute difference is -1.\n\t\t\tFor example, the minimum absolute difference of the array [5,2,3,7,2] is |2 - 3| = 1. Note that it is not 0 because a[i] and a[j] must be different.\n\t\tYou are given an integer array nums and the array queries where queries[i] = [li, ri]. For each query i, compute the minimum absolute difference of the subarray nums[li...ri] containing the elements of nums between the 0-based indices li and ri (inclusive).\n\t\tReturn an array ans where ans[i] is the answer to the ith query.\n\t\tA subarray is a contiguous sequence of elements in an array.\n\t\tThe value of |x| is defined as:\n\t\t\tx if x >= 0.\n\t\t\t-x if x < 0.\n\t\tExample 1:\n\t\tInput: nums = [1,3,4,8], queries = [[0,1],[1,2],[2,3],[0,3]]\n\t\tOutput: [2,1,4,1]\n\t\tExplanation: The queries are processed as follows:\n\t\t- queries[0] = [0,1]: The subarray is [1,3] and the minimum absolute difference is |1-3| = 2.\n\t\t- queries[1] = [1,2]: The subarray is [3,4] and the minimum absolute difference is |3-4| = 1.\n\t\t- queries[2] = [2,3]: The subarray is [4,8] and the minimum absolute difference is |4-8| = 4.\n\t\t- queries[3] = [0,3]: The subarray is [1,3,4,8] and the minimum absolute difference is |3-4| = 1.\n\t\tExample 2:\n\t\tInput: nums = [4,5,2,2,7,10], queries = [[2,3],[0,2],[0,5],[3,5]]\n\t\tOutput: [-1,1,1,3]\n\t\tExplanation: The queries are processed as follows:\n\t\t- queries[0] = [2,3]: The subarray is [2,2] and the minimum absolute difference is -1 because all the\n\t\t elements are the same.\n\t\t- queries[1] = [0,2]: The subarray is [4,5,2] and the minimum absolute difference is |4-5| = 1.\n\t\t- queries[2] = [0,5]: The subarray is [4,5,2,2,7,10] and the minimum absolute difference is |4-5| = 1.\n\t\t- queries[3] = [3,5]: The subarray is [2,7,10] and the minimum absolute difference is |7-10| = 3.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 2035, - "question": "class Solution:\n def countSubIslands(self, grid1: List[List[int]], grid2: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tYou are given two m x n binary matrices grid1 and grid2 containing only 0's (representing water) and 1's (representing land). An island is a group of 1's connected 4-directionally (horizontal or vertical). Any cells outside of the grid are considered water cells.\n\t\tAn island in grid2 is considered a sub-island if there is an island in grid1 that contains all the cells that make up this island in grid2.\n\t\tReturn the number of islands in grid2 that are considered sub-islands.\n\t\tExample 1:\n\t\tInput: grid1 = [[1,1,1,0,0],[0,1,1,1,1],[0,0,0,0,0],[1,0,0,0,0],[1,1,0,1,1]], grid2 = [[1,1,1,0,0],[0,0,1,1,1],[0,1,0,0,0],[1,0,1,1,0],[0,1,0,1,0]]\n\t\tOutput: 3\n\t\tExplanation: In the picture above, the grid on the left is grid1 and the grid on the right is grid2.\n\t\tThe 1s colored red in grid2 are those considered to be part of a sub-island. There are three sub-islands.\n\t\tExample 2:\n\t\tInput: grid1 = [[1,0,1,0,1],[1,1,1,1,1],[0,0,0,0,0],[1,1,1,1,1],[1,0,1,0,1]], grid2 = [[0,0,0,0,0],[1,1,1,1,1],[0,1,0,1,0],[0,1,0,1,0],[1,0,0,0,1]]\n\t\tOutput: 2 \n\t\tExplanation: In the picture above, the grid on the left is grid1 and the grid on the right is grid2.\n\t\tThe 1s colored red in grid2 are those considered to be part of a sub-island. There are two sub-islands.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 2037, - "question": "class Solution:\n def countTriples(self, n: int) -> int:\n\t\t\"\"\"\n\t\tA square triple (a,b,c) is a triple where a, b, and c are integers and a2 + b2 = c2.\n\t\tGiven an integer n, return the number of square triples such that 1 <= a, b, c <= n.\n\t\tExample 1:\n\t\tInput: n = 5\n\t\tOutput: 2\n\t\tExplanation: The square triples are (3,4,5) and (4,3,5).\n\t\tExample 2:\n\t\tInput: n = 10\n\t\tOutput: 4\n\t\tExplanation: The square triples are (3,4,5), (4,3,5), (6,8,10), and (8,6,10).\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 2038, - "question": "class Solution:\n def nearestExit(self, maze: List[List[str]], entrance: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou are given an m x n matrix maze (0-indexed) with empty cells (represented as '.') and walls (represented as '+'). You are also given the entrance of the maze, where entrance = [entrancerow, entrancecol] denotes the row and column of the cell you are initially standing at.\n\t\tIn one step, you can move one cell up, down, left, or right. You cannot step into a cell with a wall, and you cannot step outside the maze. Your goal is to find the nearest exit from the entrance. An exit is defined as an empty cell that is at the border of the maze. The entrance does not count as an exit.\n\t\tReturn the number of steps in the shortest path from the entrance to the nearest exit, or -1 if no such path exists.\n\t\tExample 1:\n\t\tInput: maze = [[\"+\",\"+\",\".\",\"+\"],[\".\",\".\",\".\",\"+\"],[\"+\",\"+\",\"+\",\".\"]], entrance = [1,2]\n\t\tOutput: 1\n\t\tExplanation: There are 3 exits in this maze at [1,0], [0,2], and [2,3].\n\t\tInitially, you are at the entrance cell [1,2].\n\t\t- You can reach [1,0] by moving 2 steps left.\n\t\t- You can reach [0,2] by moving 1 step up.\n\t\tIt is impossible to reach [2,3] from the entrance.\n\t\tThus, the nearest exit is [0,2], which is 1 step away.\n\t\tExample 2:\n\t\tInput: maze = [[\"+\",\"+\",\"+\"],[\".\",\".\",\".\"],[\"+\",\"+\",\"+\"]], entrance = [1,0]\n\t\tOutput: 2\n\t\tExplanation: There is 1 exit in this maze at [1,2].\n\t\t[1,0] does not count as an exit since it is the entrance cell.\n\t\tInitially, you are at the entrance cell [1,0].\n\t\t- You can reach [1,2] by moving 2 steps right.\n\t\tThus, the nearest exit is [1,2], which is 2 steps away.\n\t\tExample 3:\n\t\tInput: maze = [[\".\",\"+\"]], entrance = [0,0]\n\t\tOutput: -1\n\t\tExplanation: There are no exits in this maze.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 2039, - "question": "class Solution:\n def sumGame(self, num: str) -> bool:\n\t\t\"\"\"\n\t\tAlice and Bob take turns playing a game, with Alice starting first.\n\t\tYou are given a string num of even length consisting of digits and '?' characters. On each turn, a player will do the following if there is still at least one '?' in num:\n\t\t\tChoose an index i where num[i] == '?'.\n\t\t\tReplace num[i] with any digit between '0' and '9'.\n\t\tThe game ends when there are no more '?' characters in num.\n\t\tFor Bob to win, the sum of the digits in the first half of num must be equal to the sum of the digits in the second half. For Alice to win, the sums must not be equal.\n\t\t\tFor example, if the game ended with num = \"243801\", then Bob wins because 2+4+3 = 8+0+1. If the game ended with num = \"243803\", then Alice wins because 2+4+3 != 8+0+3.\n\t\tAssuming Alice and Bob play optimally, return true if Alice will win and false if Bob will win.\n\t\tExample 1:\n\t\tInput: num = \"5023\"\n\t\tOutput: false\n\t\tExplanation: There are no moves to be made.\n\t\tThe sum of the first half is equal to the sum of the second half: 5 + 0 = 2 + 3.\n\t\tExample 2:\n\t\tInput: num = \"25??\"\n\t\tOutput: true\n\t\tExplanation: Alice can replace one of the '?'s with '9' and it will be impossible for Bob to make the sums equal.\n\t\tExample 3:\n\t\tInput: num = \"?3295???\"\n\t\tOutput: false\n\t\tExplanation: It can be proven that Bob will always win. One possible outcome is:\n\t\t- Alice replaces the first '?' with '9'. num = \"93295???\".\n\t\t- Bob replaces one of the '?' in the right half with '9'. num = \"932959??\".\n\t\t- Alice replaces one of the '?' in the right half with '2'. num = \"9329592?\".\n\t\t- Bob replaces the last '?' in the right half with '7'. num = \"93295927\".\n\t\tBob wins because 9 + 3 + 2 + 9 = 5 + 9 + 2 + 7.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 2040, - "question": "class Solution:\n def minCost(self, maxTime: int, edges: List[List[int]], passingFees: List[int]) -> int:\n\t\t\"\"\"\n\t\tThere is a country of n cities numbered from 0 to n - 1 where all the cities are connected by bi-directional roads. The roads are represented as a 2D integer array edges where edges[i] = [xi, yi, timei] denotes a road between cities xi and yi that takes timei minutes to travel. There may be multiple roads of differing travel times connecting the same two cities, but no road connects a city to itself.\n\t\tEach time you pass through a city, you must pay a passing fee. This is represented as a 0-indexed integer array passingFees of length n where passingFees[j] is the amount of dollars you must pay when you pass through city j.\n\t\tIn the beginning, you are at city 0 and want to reach city n - 1 in maxTime minutes or less. The cost of your journey is the summation of passing fees for each city that you passed through at some moment of your journey (including the source and destination cities).\n\t\tGiven maxTime, edges, and passingFees, return the minimum cost to complete your journey, or -1 if you cannot complete it within maxTime minutes.\n\t\tExample 1:\n\t\tInput: maxTime = 30, edges = [[0,1,10],[1,2,10],[2,5,10],[0,3,1],[3,4,10],[4,5,15]], passingFees = [5,1,2,20,20,3]\n\t\tOutput: 11\n\t\tExplanation: The path to take is 0 -> 1 -> 2 -> 5, which takes 30 minutes and has $11 worth of passing fees.\n\t\tExample 2:\n\t\tInput: maxTime = 29, edges = [[0,1,10],[1,2,10],[2,5,10],[0,3,1],[3,4,10],[4,5,15]], passingFees = [5,1,2,20,20,3]\n\t\tOutput: 48\n\t\tExplanation: The path to take is 0 -> 3 -> 4 -> 5, which takes 26 minutes and has $48 worth of passing fees.\n\t\tYou cannot take path 0 -> 1 -> 2 -> 5 since it would take too long.\n\t\tExample 3:\n\t\tInput: maxTime = 25, edges = [[0,1,10],[1,2,10],[2,5,10],[0,3,1],[3,4,10],[4,5,15]], passingFees = [5,1,2,20,20,3]\n\t\tOutput: -1\n\t\tExplanation: There is no way to reach city 5 from city 0 within 25 minutes.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 2042, - "question": "class Solution:\n def maxProductDifference(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tThe product difference between two pairs (a, b) and (c, d) is defined as (a * b) - (c * d).\r\n\t\t\tFor example, the product difference between (5, 6) and (2, 7) is (5 * 6) - (2 * 7) = 16.\r\n\t\tGiven an integer array nums, choose four distinct indices w, x, y, and z such that the product difference between pairs (nums[w], nums[x]) and (nums[y], nums[z]) is maximized.\r\n\t\tReturn the maximum such product difference.\r\n\t\tExample 1:\r\n\t\tInput: nums = [5,6,2,7,4]\r\n\t\tOutput: 34\r\n\t\tExplanation: We can choose indices 1 and 3 for the first pair (6, 7) and indices 2 and 4 for the second pair (2, 4).\r\n\t\tThe product difference is (6 * 7) - (2 * 4) = 34.\r\n\t\tExample 2:\r\n\t\tInput: nums = [4,2,5,9,7,4,8]\r\n\t\tOutput: 64\r\n\t\tExplanation: We can choose indices 3 and 6 for the first pair (9, 8) and indices 1 and 5 for the second pair (2, 4).\r\n\t\tThe product difference is (9 * 8) - (2 * 4) = 64.\r\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 2043, - "question": "class Solution:\n def rotateGrid(self, grid: List[List[int]], k: int) -> List[List[int]]:\n\t\t\"\"\"\n\t\tYou are given an m x n integer matrix grid\u200b\u200b\u200b, where m and n are both even integers, and an integer k.\r\n\t\tThe matrix is composed of several layers, which is shown in the below image, where each color is its own layer:\r\n\t\tA cyclic rotation of the matrix is done by cyclically rotating each layer in the matrix. To cyclically rotate a layer once, each element in the layer will take the place of the adjacent element in the counter-clockwise direction. An example rotation is shown below:\r\n\t\tReturn the matrix after applying k cyclic rotations to it.\r\n\t\tExample 1:\r\n\t\tInput: grid = [[40,10],[30,20]], k = 1\r\n\t\tOutput: [[10,20],[40,30]]\r\n\t\tExplanation: The figures above represent the grid at every state.\r\n\t\tExample 2:\r\n\t\tInput: grid = [[1,2,3,4],[5,6,7,8],[9,10,11,12],[13,14,15,16]], k = 2\r\n\t\tOutput: [[3,4,8,12],[2,11,10,16],[1,7,6,15],[5,9,13,14]]\r\n\t\tExplanation: The figures above represent the grid at every state.\r\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 2044, - "question": "class Solution:\n def wonderfulSubstrings(self, word: str) -> int:\n\t\t\"\"\"\n\t\tA wonderful string is a string where at most one letter appears an odd number of times.\r\n\t\t\tFor example, \"ccjjc\" and \"abab\" are wonderful, but \"ab\" is not.\r\n\t\tGiven a string word that consists of the first ten lowercase English letters ('a' through 'j'), return the number of wonderful non-empty substrings in word. If the same substring appears multiple times in word, then count each occurrence separately.\r\n\t\tA substring is a contiguous sequence of characters in a string.\r\n\t\tExample 1:\r\n\t\tInput: word = \"aba\"\r\n\t\tOutput: 4\r\n\t\tExplanation: The four wonderful substrings are underlined below:\r\n\t\t- \"aba\" -> \"a\"\r\n\t\t- \"aba\" -> \"b\"\r\n\t\t- \"aba\" -> \"a\"\r\n\t\t- \"aba\" -> \"aba\"\r\n\t\tExample 2:\r\n\t\tInput: word = \"aabb\"\r\n\t\tOutput: 9\r\n\t\tExplanation: The nine wonderful substrings are underlined below:\r\n\t\t- \"aabb\" -> \"a\"\r\n\t\t- \"aabb\" -> \"aa\"\r\n\t\t- \"aabb\" -> \"aab\"\r\n\t\t- \"aabb\" -> \"aabb\"\r\n\t\t- \"aabb\" -> \"a\"\r\n\t\t- \"aabb\" -> \"abb\"\r\n\t\t- \"aabb\" -> \"b\"\r\n\t\t- \"aabb\" -> \"bb\"\r\n\t\t- \"aabb\" -> \"b\"\r\n\t\tExample 3:\r\n\t\tInput: word = \"he\"\r\n\t\tOutput: 2\r\n\t\tExplanation: The two wonderful substrings are underlined below:\r\n\t\t- \"he\" -> \"h\"\r\n\t\t- \"he\" -> \"e\"\r\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 2047, - "question": "class Solution:\n def findPeakGrid(self, mat: List[List[int]]) -> List[int]:\n\t\t\"\"\"\n\t\tA peak element in a 2D grid is an element that is strictly greater than all of its adjacent neighbors to the left, right, top, and bottom.\n\t\tGiven a 0-indexed m x n matrix mat where no two adjacent cells are equal, find any peak element mat[i][j] and return the length 2 array [i,j].\n\t\tYou may assume that the entire matrix is surrounded by an outer perimeter with the value -1 in each cell.\n\t\tYou must write an algorithm that runs in O(m log(n)) or O(n log(m)) time.\n\t\tExample 1:\n\t\tInput: mat = [[1,4],[3,2]]\n\t\tOutput: [0,1]\n\t\tExplanation: Both 3 and 4 are peak elements so [1,0] and [0,1] are both acceptable answers.\n\t\tExample 2:\n\t\tInput: mat = [[10,20,15],[21,30,14],[7,16,32]]\n\t\tOutput: [1,1]\n\t\tExplanation: Both 30 and 32 are peak elements so [1,1] and [2,2] are both acceptable answers.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 2048, - "question": "class Solution:\n def buildArray(self, nums: List[int]) -> List[int]:\n\t\t\"\"\"\n\t\tGiven a zero-based permutation nums (0-indexed), build an array ans of the same length where ans[i] = nums[nums[i]] for each 0 <= i < nums.length and return it.\n\t\tA zero-based permutation nums is an array of distinct integers from 0 to nums.length - 1 (inclusive).\n\t\tExample 1:\n\t\tInput: nums = [0,2,1,5,3,4]\n\t\tOutput: [0,1,2,4,5,3]\n\t\tExplanation: The array ans is built as follows: \n\t\tans = [nums[nums[0]], nums[nums[1]], nums[nums[2]], nums[nums[3]], nums[nums[4]], nums[nums[5]]]\n\t\t = [nums[0], nums[2], nums[1], nums[5], nums[3], nums[4]]\n\t\t = [0,1,2,4,5,3]\n\t\tExample 2:\n\t\tInput: nums = [5,0,1,2,3,4]\n\t\tOutput: [4,5,0,1,2,3]\n\t\tExplanation: The array ans is built as follows:\n\t\tans = [nums[nums[0]], nums[nums[1]], nums[nums[2]], nums[nums[3]], nums[nums[4]], nums[nums[5]]]\n\t\t = [nums[5], nums[0], nums[1], nums[2], nums[3], nums[4]]\n\t\t = [4,5,0,1,2,3]\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 2049, - "question": "class Solution:\n def eliminateMaximum(self, dist: List[int], speed: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou are playing a video game where you are defending your city from a group of n monsters. You are given a 0-indexed integer array dist of size n, where dist[i] is the initial distance in kilometers of the ith monster from the city.\n\t\tThe monsters walk toward the city at a constant speed. The speed of each monster is given to you in an integer array speed of size n, where speed[i] is the speed of the ith monster in kilometers per minute.\n\t\tYou have a weapon that, once fully charged, can eliminate a single monster. However, the weapon takes one minute to charge.The weapon is fully charged at the very start.\n\t\tYou lose when any monster reaches your city. If a monster reaches the city at the exact moment the weapon is fully charged, it counts as a loss, and the game ends before you can use your weapon.\n\t\tReturn the maximum number of monsters that you can eliminate before you lose, or n if you can eliminate all the monsters before they reach the city.\n\t\tExample 1:\n\t\tInput: dist = [1,3,4], speed = [1,1,1]\n\t\tOutput: 3\n\t\tExplanation:\n\t\tIn the beginning, the distances of the monsters are [1,3,4]. You eliminate the first monster.\n\t\tAfter a minute, the distances of the monsters are [X,2,3]. You eliminate the second monster.\n\t\tAfter a minute, the distances of the monsters are [X,X,2]. You eliminate the thrid monster.\n\t\tAll 3 monsters can be eliminated.\n\t\tExample 2:\n\t\tInput: dist = [1,1,2,3], speed = [1,1,1,1]\n\t\tOutput: 1\n\t\tExplanation:\n\t\tIn the beginning, the distances of the monsters are [1,1,2,3]. You eliminate the first monster.\n\t\tAfter a minute, the distances of the monsters are [X,0,1,2], so you lose.\n\t\tYou can only eliminate 1 monster.\n\t\tExample 3:\n\t\tInput: dist = [3,2,4], speed = [5,3,2]\n\t\tOutput: 1\n\t\tExplanation:\n\t\tIn the beginning, the distances of the monsters are [3,2,4]. You eliminate the first monster.\n\t\tAfter a minute, the distances of the monsters are [X,0,2], so you lose.\n\t\tYou can only eliminate 1 monster.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 2050, - "question": "class Solution:\n def countGoodNumbers(self, n: int) -> int:\n\t\t\"\"\"\n\t\tA digit string is good if the digits (0-indexed) at even indices are even and the digits at odd indices are prime (2, 3, 5, or 7).\n\t\t\tFor example, \"2582\" is good because the digits (2 and 8) at even positions are even and the digits (5 and 2) at odd positions are prime. However, \"3245\" is not good because 3 is at an even index but is not even.\n\t\tGiven an integer n, return the total number of good digit strings of length n. Since the answer may be large, return it modulo 109 + 7.\n\t\tA digit string is a string consisting of digits 0 through 9 that may contain leading zeros.\n\t\tExample 1:\n\t\tInput: n = 1\n\t\tOutput: 5\n\t\tExplanation: The good numbers of length 1 are \"0\", \"2\", \"4\", \"6\", \"8\".\n\t\tExample 2:\n\t\tInput: n = 4\n\t\tOutput: 400\n\t\tExample 3:\n\t\tInput: n = 50\n\t\tOutput: 564908303\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 2051, - "question": "class Solution:\n def longestCommonSubpath(self, n: int, paths: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tThere is a country of n cities numbered from 0 to n - 1. In this country, there is a road connecting every pair of cities.\n\t\tThere are m friends numbered from 0 to m - 1 who are traveling through the country. Each one of them will take a path consisting of some cities. Each path is represented by an integer array that contains the visited cities in order. The path may contain a city more than once, but the same city will not be listed consecutively.\n\t\tGiven an integer n and a 2D integer array paths where paths[i] is an integer array representing the path of the ith friend, return the length of the longest common subpath that is shared by every friend's path, or 0 if there is no common subpath at all.\n\t\tA subpath of a path is a contiguous sequence of cities within that path.\n\t\tExample 1:\n\t\tInput: n = 5, paths = [[0,1,2,3,4],\n\t\t [2,3,4],\n\t\t [4,0,1,2,3]]\n\t\tOutput: 2\n\t\tExplanation: The longest common subpath is [2,3].\n\t\tExample 2:\n\t\tInput: n = 3, paths = [[0],[1],[2]]\n\t\tOutput: 0\n\t\tExplanation: There is no common subpath shared by the three paths.\n\t\tExample 3:\n\t\tInput: n = 5, paths = [[0,1,2,3,4],\n\t\t [4,3,2,1,0]]\n\t\tOutput: 1\n\t\tExplanation: The possible longest common subpaths are [0], [1], [2], [3], and [4]. All have a length of 1.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 2053, - "question": "class Solution:\n def areOccurrencesEqual(self, s: str) -> bool:\n\t\t\"\"\"\n\t\tGiven a string s, return true if s is a good string, or false otherwise.\n\t\tA string s is good if all the characters that appear in s have the same number of occurrences (i.e., the same frequency).\n\t\tExample 1:\n\t\tInput: s = \"abacbc\"\n\t\tOutput: true\n\t\tExplanation: The characters that appear in s are 'a', 'b', and 'c'. All characters occur 2 times in s.\n\t\tExample 2:\n\t\tInput: s = \"aaabb\"\n\t\tOutput: false\n\t\tExplanation: The characters that appear in s are 'a' and 'b'.\n\t\t'a' occurs 3 times while 'b' occurs 2 times, which is not the same number of times.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 2054, - "question": "class Solution:\n def smallestChair(self, times: List[List[int]], targetFriend: int) -> int:\n\t\t\"\"\"\n\t\tThere is a party where n friends numbered from 0 to n - 1 are attending. There is an infinite number of chairs in this party that are numbered from 0 to infinity. When a friend arrives at the party, they sit on the unoccupied chair with the smallest number.\n\t\t\tFor example, if chairs 0, 1, and 5 are occupied when a friend comes, they will sit on chair number 2.\n\t\tWhen a friend leaves the party, their chair becomes unoccupied at the moment they leave. If another friend arrives at that same moment, they can sit in that chair.\n\t\tYou are given a 0-indexed 2D integer array times where times[i] = [arrivali, leavingi], indicating the arrival and leaving times of the ith friend respectively, and an integer targetFriend. All arrival times are distinct.\n\t\tReturn the chair number that the friend numbered targetFriend will sit on.\n\t\tExample 1:\n\t\tInput: times = [[1,4],[2,3],[4,6]], targetFriend = 1\n\t\tOutput: 1\n\t\tExplanation: \n\t\t- Friend 0 arrives at time 1 and sits on chair 0.\n\t\t- Friend 1 arrives at time 2 and sits on chair 1.\n\t\t- Friend 1 leaves at time 3 and chair 1 becomes empty.\n\t\t- Friend 0 leaves at time 4 and chair 0 becomes empty.\n\t\t- Friend 2 arrives at time 4 and sits on chair 0.\n\t\tSince friend 1 sat on chair 1, we return 1.\n\t\tExample 2:\n\t\tInput: times = [[3,10],[1,5],[2,6]], targetFriend = 0\n\t\tOutput: 2\n\t\tExplanation: \n\t\t- Friend 1 arrives at time 1 and sits on chair 0.\n\t\t- Friend 2 arrives at time 2 and sits on chair 1.\n\t\t- Friend 0 arrives at time 3 and sits on chair 2.\n\t\t- Friend 1 leaves at time 5 and chair 0 becomes empty.\n\t\t- Friend 2 leaves at time 6 and chair 1 becomes empty.\n\t\t- Friend 0 leaves at time 10 and chair 2 becomes empty.\n\t\tSince friend 0 sat on chair 2, we return 2.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 2055, - "question": "class Solution:\n def splitPainting(self, segments: List[List[int]]) -> List[List[int]]:\n\t\t\"\"\"\n\t\tThere is a long and thin painting that can be represented by a number line. The painting was painted with multiple overlapping segments where each segment was painted with a unique color. You are given a 2D integer array segments, where segments[i] = [starti, endi, colori] represents the half-closed segment [starti, endi) with colori as the color.\n\t\tThe colors in the overlapping segments of the painting were mixed when it was painted. When two or more colors mix, they form a new color that can be represented as a set of mixed colors.\n\t\t\tFor example, if colors 2, 4, and 6 are mixed, then the resulting mixed color is {2,4,6}.\n\t\tFor the sake of simplicity, you should only output the sum of the elements in the set rather than the full set.\n\t\tYou want to describe the painting with the minimum number of non-overlapping half-closed segments of these mixed colors. These segments can be represented by the 2D array painting where painting[j] = [leftj, rightj, mixj] describes a half-closed segment [leftj, rightj) with the mixed color sum of mixj.\n\t\t\tFor example, the painting created with segments = [[1,4,5],[1,7,7]] can be described by painting = [[1,4,12],[4,7,7]] because:\n\t\t\t\t[1,4) is colored {5,7} (with a sum of 12) from both the first and second segments.\n\t\t\t\t[4,7) is colored {7} from only the second segment.\n\t\tReturn the 2D array painting describing the finished painting (excluding any parts that are not painted). You may return the segments in any order.\n\t\tA half-closed segment [a, b) is the section of the number line between points a and b including point a and not including point b.\n\t\tExample 1:\n\t\tInput: segments = [[1,4,5],[4,7,7],[1,7,9]]\n\t\tOutput: [[1,4,14],[4,7,16]]\n\t\tExplanation: The painting can be described as follows:\n\t\t- [1,4) is colored {5,9} (with a sum of 14) from the first and third segments.\n\t\t- [4,7) is colored {7,9} (with a sum of 16) from the second and third segments.\n\t\tExample 2:\n\t\tInput: segments = [[1,7,9],[6,8,15],[8,10,7]]\n\t\tOutput: [[1,6,9],[6,7,24],[7,8,15],[8,10,7]]\n\t\tExplanation: The painting can be described as follows:\n\t\t- [1,6) is colored 9 from the first segment.\n\t\t- [6,7) is colored {9,15} (with a sum of 24) from the first and second segments.\n\t\t- [7,8) is colored 15 from the second segment.\n\t\t- [8,10) is colored 7 from the third segment.\n\t\tExample 3:\n\t\tInput: segments = [[1,4,5],[1,4,7],[4,7,1],[4,7,11]]\n\t\tOutput: [[1,4,12],[4,7,12]]\n\t\tExplanation: The painting can be described as follows:\n\t\t- [1,4) is colored {5,7} (with a sum of 12) from the first and second segments.\n\t\t- [4,7) is colored {1,11} (with a sum of 12) from the third and fourth segments.\n\t\tNote that returning a single segment [1,7) is incorrect because the mixed color sets are different.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 2058, - "question": "class Solution:\n def getConcatenation(self, nums: List[int]) -> List[int]:\n\t\t\"\"\"\n\t\tGiven an integer array nums of length n, you want to create an array ans of length 2n where ans[i] == nums[i] and ans[i + n] == nums[i] for 0 <= i < n (0-indexed).\n\t\tSpecifically, ans is the concatenation of two nums arrays.\n\t\tReturn the array ans.\n\t\tExample 1:\n\t\tInput: nums = [1,2,1]\n\t\tOutput: [1,2,1,1,2,1]\n\t\tExplanation: The array ans is formed as follows:\n\t\t- ans = [nums[0],nums[1],nums[2],nums[0],nums[1],nums[2]]\n\t\t- ans = [1,2,1,1,2,1]\n\t\tExample 2:\n\t\tInput: nums = [1,3,2,1]\n\t\tOutput: [1,3,2,1,1,3,2,1]\n\t\tExplanation: The array ans is formed as follows:\n\t\t- ans = [nums[0],nums[1],nums[2],nums[3],nums[0],nums[1],nums[2],nums[3]]\n\t\t- ans = [1,3,2,1,1,3,2,1]\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 2059, - "question": "class Solution:\n def countPalindromicSubsequence(self, s: str) -> int:\n\t\t\"\"\"\n\t\tGiven a string s, return the number of unique palindromes of length three that are a subsequence of s.\n\t\tNote that even if there are multiple ways to obtain the same subsequence, it is still only counted once.\n\t\tA palindrome is a string that reads the same forwards and backwards.\n\t\tA subsequence of a string is a new string generated from the original string with some characters (can be none) deleted without changing the relative order of the remaining characters.\n\t\t\tFor example, \"ace\" is a subsequence of \"abcde\".\n\t\tExample 1:\n\t\tInput: s = \"aabca\"\n\t\tOutput: 3\n\t\tExplanation: The 3 palindromic subsequences of length 3 are:\n\t\t- \"aba\" (subsequence of \"aabca\")\n\t\t- \"aaa\" (subsequence of \"aabca\")\n\t\t- \"aca\" (subsequence of \"aabca\")\n\t\tExample 2:\n\t\tInput: s = \"adc\"\n\t\tOutput: 0\n\t\tExplanation: There are no palindromic subsequences of length 3 in \"adc\".\n\t\tExample 3:\n\t\tInput: s = \"bbcbaba\"\n\t\tOutput: 4\n\t\tExplanation: The 4 palindromic subsequences of length 3 are:\n\t\t- \"bbb\" (subsequence of \"bbcbaba\")\n\t\t- \"bcb\" (subsequence of \"bbcbaba\")\n\t\t- \"bab\" (subsequence of \"bbcbaba\")\n\t\t- \"aba\" (subsequence of \"bbcbaba\")\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 2060, - "question": "class Solution:\n def canMerge(self, trees: List[TreeNode]) -> Optional[TreeNode]:\n\t\t\"\"\"\n\t\tYou are given n BST (binary search tree) root nodes for n separate BSTs stored in an array trees (0-indexed). Each BST in trees has at most 3 nodes, and no two roots have the same value. In one operation, you can:\n\t\t\tSelect two distinct indices i and j such that the value stored at one of the leaves of trees[i] is equal to the root value of trees[j].\n\t\t\tReplace the leaf node in trees[i] with trees[j].\n\t\t\tRemove trees[j] from trees.\n\t\tReturn the root of the resulting BST if it is possible to form a valid BST after performing n - 1 operations, or null if it is impossible to create a valid BST.\n\t\tA BST (binary search tree) is a binary tree where each node satisfies the following property:\n\t\t\tEvery node in the node's left subtree has a value strictly less than the node's value.\n\t\t\tEvery node in the node's right subtree has a value strictly greater than the node's value.\n\t\tA leaf is a node that has no children.\n\t\tExample 1:\n\t\tInput: trees = [[2,1],[3,2,5],[5,4]]\n\t\tOutput: [3,2,5,1,null,4]\n\t\tExplanation:\n\t\tIn the first operation, pick i=1 and j=0, and merge trees[0] into trees[1].\n\t\tDelete trees[0], so trees = [[3,2,5,1],[5,4]].\n\t\tIn the second operation, pick i=0 and j=1, and merge trees[1] into trees[0].\n\t\tDelete trees[1], so trees = [[3,2,5,1,null,4]].\n\t\tThe resulting tree, shown above, is a valid BST, so return its root.\n\t\tExample 2:\n\t\tInput: trees = [[5,3,8],[3,2,6]]\n\t\tOutput: []\n\t\tExplanation:\n\t\tPick i=0 and j=1 and merge trees[1] into trees[0].\n\t\tDelete trees[1], so trees = [[5,3,8,2,6]].\n\t\tThe resulting tree is shown above. This is the only valid operation that can be performed, but the resulting tree is not a valid BST, so return null.\n\t\tExample 3:\n\t\tInput: trees = [[5,4],[3]]\n\t\tOutput: []\n\t\tExplanation: It is impossible to perform any operations.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 2061, - "question": "class Solution:\n def colorTheGrid(self, m: int, n: int) -> int:\n\t\t\"\"\"\n\t\tYou are given two integers m and n. Consider an m x n grid where each cell is initially white. You can paint each cell red, green, or blue. All cells must be painted.\n\t\tReturn the number of ways to color the grid with no two adjacent cells having the same color. Since the answer can be very large, return it modulo 109 + 7.\n\t\tExample 1:\n\t\tInput: m = 1, n = 1\n\t\tOutput: 3\n\t\tExplanation: The three possible colorings are shown in the image above.\n\t\tExample 2:\n\t\tInput: m = 1, n = 2\n\t\tOutput: 6\n\t\tExplanation: The six possible colorings are shown in the image above.\n\t\tExample 3:\n\t\tInput: m = 5, n = 5\n\t\tOutput: 580986\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 2066, - "question": "class Solution:\n def addRungs(self, rungs: List[int], dist: int) -> int:\n\t\t\"\"\"\n\t\tYou are given a strictly increasing integer array rungs that represents the height of rungs on a ladder. You are currently on the floor at height 0, and you want to reach the last rung.\n\t\tYou are also given an integer dist. You can only climb to the next highest rung if the distance between where you are currently at (the floor or on a rung) and the next rung is at most dist. You are able to insert rungs at any positive integer height if a rung is not already there.\n\t\tReturn the minimum number of rungs that must be added to the ladder in order for you to climb to the last rung.\n\t\tExample 1:\n\t\tInput: rungs = [1,3,5,10], dist = 2\n\t\tOutput: 2\n\t\tExplanation:\n\t\tYou currently cannot reach the last rung.\n\t\tAdd rungs at heights 7 and 8 to climb this ladder. \n\t\tThe ladder will now have rungs at [1,3,5,7,8,10].\n\t\tExample 2:\n\t\tInput: rungs = [3,6,8,10], dist = 3\n\t\tOutput: 0\n\t\tExplanation:\n\t\tThis ladder can be climbed without adding additional rungs.\n\t\tExample 3:\n\t\tInput: rungs = [3,4,6,7], dist = 2\n\t\tOutput: 1\n\t\tExplanation:\n\t\tYou currently cannot reach the first rung from the ground.\n\t\tAdd a rung at height 1 to climb this ladder.\n\t\tThe ladder will now have rungs at [1,3,4,6,7].\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 2067, - "question": "class Solution:\n def maxPoints(self, points: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tYou are given an m x n integer matrix points (0-indexed). Starting with 0 points, you want to maximize the number of points you can get from the matrix.\n\t\tTo gain points, you must pick one cell in each row. Picking the cell at coordinates (r, c) will add points[r][c] to your score.\n\t\tHowever, you will lose points if you pick a cell too far from the cell that you picked in the previous row. For every two adjacent rows r and r + 1 (where 0 <= r < m - 1), picking cells at coordinates (r, c1) and (r + 1, c2) will subtract abs(c1 - c2) from your score.\n\t\tReturn the maximum number of points you can achieve.\n\t\tabs(x) is defined as:\n\t\t\tx for x >= 0.\n\t\t\t-x for x < 0.\n\t\tExample 1: \n\t\tInput: points = [[1,2,3],[1,5,1],[3,1,1]]\n\t\tOutput: 9\n\t\tExplanation:\n\t\tThe blue cells denote the optimal cells to pick, which have coordinates (0, 2), (1, 1), and (2, 0).\n\t\tYou add 3 + 5 + 3 = 11 to your score.\n\t\tHowever, you must subtract abs(2 - 1) + abs(1 - 0) = 2 from your score.\n\t\tYour final score is 11 - 2 = 9.\n\t\tExample 2:\n\t\tInput: points = [[1,5],[2,3],[4,2]]\n\t\tOutput: 11\n\t\tExplanation:\n\t\tThe blue cells denote the optimal cells to pick, which have coordinates (0, 1), (1, 1), and (2, 0).\n\t\tYou add 5 + 3 + 4 = 12 to your score.\n\t\tHowever, you must subtract abs(1 - 1) + abs(1 - 0) = 1 from your score.\n\t\tYour final score is 12 - 1 = 11.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 2068, - "question": "class Solution:\n def maxGeneticDifference(self, parents: List[int], queries: List[List[int]]) -> List[int]:\n\t\t\"\"\"\n\t\tThere is a rooted tree consisting of n nodes numbered 0 to n - 1. Each node's number denotes its unique genetic value (i.e. the genetic value of node x is x). The genetic difference between two genetic values is defined as the bitwise-XOR of their values. You are given the integer array parents, where parents[i] is the parent for node i. If node x is the root of the tree, then parents[x] == -1.\n\t\tYou are also given the array queries where queries[i] = [nodei, vali]. For each query i, find the maximum genetic difference between vali and pi, where pi is the genetic value of any node that is on the path between nodei and the root (including nodei and the root). More formally, you want to maximize vali XOR pi.\n\t\tReturn an array ans where ans[i] is the answer to the ith query.\n\t\tExample 1:\n\t\tInput: parents = [-1,0,1,1], queries = [[0,2],[3,2],[2,5]]\n\t\tOutput: [2,3,7]\n\t\tExplanation: The queries are processed as follows:\n\t\t- [0,2]: The node with the maximum genetic difference is 0, with a difference of 2 XOR 0 = 2.\n\t\t- [3,2]: The node with the maximum genetic difference is 1, with a difference of 2 XOR 1 = 3.\n\t\t- [2,5]: The node with the maximum genetic difference is 2, with a difference of 5 XOR 2 = 7.\n\t\tExample 2:\n\t\tInput: parents = [3,7,-1,2,0,7,0,2], queries = [[4,6],[1,15],[0,5]]\n\t\tOutput: [6,14,7]\n\t\tExplanation: The queries are processed as follows:\n\t\t- [4,6]: The node with the maximum genetic difference is 0, with a difference of 6 XOR 0 = 6.\n\t\t- [1,15]: The node with the maximum genetic difference is 1, with a difference of 15 XOR 1 = 14.\n\t\t- [0,5]: The node with the maximum genetic difference is 2, with a difference of 5 XOR 2 = 7.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 2076, - "question": "class Solution:\n def getLucky(self, s: str, k: int) -> int:\n\t\t\"\"\"\n\t\tYou are given a string s consisting of lowercase English letters, and an integer k.\n\t\tFirst, convert s into an integer by replacing each letter with its position in the alphabet (i.e., replace 'a' with 1, 'b' with 2, ..., 'z' with 26). Then, transform the integer by replacing it with the sum of its digits. Repeat the transform operation k times in total.\n\t\tFor example, if s = \"zbax\" and k = 2, then the resulting integer would be 8 by the following operations:\n\t\t\tConvert: \"zbax\" \u279d \"(26)(2)(1)(24)\" \u279d \"262124\" \u279d 262124\n\t\t\tTransform #1: 262124 \u279d 2 + 6 + 2 + 1 + 2 + 4 \u279d 17\n\t\t\tTransform #2: 17 \u279d 1 + 7 \u279d 8\n\t\tReturn the resulting integer after performing the operations described above.\n\t\tExample 1:\n\t\tInput: s = \"iiii\", k = 1\n\t\tOutput: 36\n\t\tExplanation: The operations are as follows:\n\t\t- Convert: \"iiii\" \u279d \"(9)(9)(9)(9)\" \u279d \"9999\" \u279d 9999\n\t\t- Transform #1: 9999 \u279d 9 + 9 + 9 + 9 \u279d 36\n\t\tThus the resulting integer is 36.\n\t\tExample 2:\n\t\tInput: s = \"leetcode\", k = 2\n\t\tOutput: 6\n\t\tExplanation: The operations are as follows:\n\t\t- Convert: \"leetcode\" \u279d \"(12)(5)(5)(20)(3)(15)(4)(5)\" \u279d \"12552031545\" \u279d 12552031545\n\t\t- Transform #1: 12552031545 \u279d 1 + 2 + 5 + 5 + 2 + 0 + 3 + 1 + 5 + 4 + 5 \u279d 33\n\t\t- Transform #2: 33 \u279d 3 + 3 \u279d 6\n\t\tThus the resulting integer is 6.\n\t\tExample 3:\n\t\tInput: s = \"zbax\", k = 2\n\t\tOutput: 8\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 2077, - "question": "class Solution:\n def maximumNumber(self, num: str, change: List[int]) -> str:\n\t\t\"\"\"\n\t\tYou are given a string num, which represents a large integer. You are also given a 0-indexed integer array change of length 10 that maps each digit 0-9 to another digit. More formally, digit d maps to digit change[d].\n\t\tYou may choose to mutate a single substring of num. To mutate a substring, replace each digit num[i] with the digit it maps to in change (i.e. replace num[i] with change[num[i]]).\n\t\tReturn a string representing the largest possible integer after mutating (or choosing not to) a single substring of num.\n\t\tA substring is a contiguous sequence of characters within the string.\n\t\tExample 1:\n\t\tInput: num = \"132\", change = [9,8,5,0,3,6,4,2,6,8]\n\t\tOutput: \"832\"\n\t\tExplanation: Replace the substring \"1\":\n\t\t- 1 maps to change[1] = 8.\n\t\tThus, \"132\" becomes \"832\".\n\t\t\"832\" is the largest number that can be created, so return it.\n\t\tExample 2:\n\t\tInput: num = \"021\", change = [9,4,3,5,7,2,1,9,0,6]\n\t\tOutput: \"934\"\n\t\tExplanation: Replace the substring \"021\":\n\t\t- 0 maps to change[0] = 9.\n\t\t- 2 maps to change[2] = 3.\n\t\t- 1 maps to change[1] = 4.\n\t\tThus, \"021\" becomes \"934\".\n\t\t\"934\" is the largest number that can be created, so return it.\n\t\tExample 3:\n\t\tInput: num = \"5\", change = [1,4,7,5,3,2,5,6,9,4]\n\t\tOutput: \"5\"\n\t\tExplanation: \"5\" is already the largest number that can be created, so return it.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 2078, - "question": "class Solution:\n def maxCompatibilitySum(self, students: List[List[int]], mentors: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tThere is a survey that consists of n questions where each question's answer is either 0 (no) or 1 (yes).\n\t\tThe survey was given to m students numbered from 0 to m - 1 and m mentors numbered from 0 to m - 1. The answers of the students are represented by a 2D integer array students where students[i] is an integer array that contains the answers of the ith student (0-indexed). The answers of the mentors are represented by a 2D integer array mentors where mentors[j] is an integer array that contains the answers of the jth mentor (0-indexed).\n\t\tEach student will be assigned to one mentor, and each mentor will have one student assigned to them. The compatibility score of a student-mentor pair is the number of answers that are the same for both the student and the mentor.\n\t\t\tFor example, if the student's answers were [1, 0, 1] and the mentor's answers were [0, 0, 1], then their compatibility score is 2 because only the second and the third answers are the same.\n\t\tYou are tasked with finding the optimal student-mentor pairings to maximize the sum of the compatibility scores.\n\t\tGiven students and mentors, return the maximum compatibility score sum that can be achieved.\n\t\tExample 1:\n\t\tInput: students = [[1,1,0],[1,0,1],[0,0,1]], mentors = [[1,0,0],[0,0,1],[1,1,0]]\n\t\tOutput: 8\n\t\tExplanation: We assign students to mentors in the following way:\n\t\t- student 0 to mentor 2 with a compatibility score of 3.\n\t\t- student 1 to mentor 0 with a compatibility score of 2.\n\t\t- student 2 to mentor 1 with a compatibility score of 3.\n\t\tThe compatibility score sum is 3 + 2 + 3 = 8.\n\t\tExample 2:\n\t\tInput: students = [[0,0],[0,0],[0,0]], mentors = [[1,1],[1,1],[1,1]]\n\t\tOutput: 0\n\t\tExplanation: The compatibility score of any student-mentor pair is 0.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 2079, - "question": "class Solution:\n def deleteDuplicateFolder(self, paths: List[List[str]]) -> List[List[str]]:\n\t\t\"\"\"\n\t\tDue to a bug, there are many duplicate folders in a file system. You are given a 2D array paths, where paths[i] is an array representing an absolute path to the ith folder in the file system.\n\t\t\tFor example, [\"one\", \"two\", \"three\"] represents the path \"/one/two/three\".\n\t\tTwo folders (not necessarily on the same level) are identical if they contain the same non-empty set of identical subfolders and underlying subfolder structure. The folders do not need to be at the root level to be identical. If two or more folders are identical, then mark the folders as well as all their subfolders.\n\t\t\tFor example, folders \"/a\" and \"/b\" in the file structure below are identical. They (as well as their subfolders) should all be marked:\n\t\t\t\t/a\n\t\t\t\t/a/x\n\t\t\t\t/a/x/y\n\t\t\t\t/a/z\n\t\t\t\t/b\n\t\t\t\t/b/x\n\t\t\t\t/b/x/y\n\t\t\t\t/b/z\n\t\t\tHowever, if the file structure also included the path \"/b/w\", then the folders \"/a\" and \"/b\" would not be identical. Note that \"/a/x\" and \"/b/x\" would still be considered identical even with the added folder.\n\t\tOnce all the identical folders and their subfolders have been marked, the file system will delete all of them. The file system only runs the deletion once, so any folders that become identical after the initial deletion are not deleted.\n\t\tReturn the 2D array ans containing the paths of the remaining folders after deleting all the marked folders. The paths may be returned in any order.\n\t\tExample 1:\n\t\tInput: paths = [[\"a\"],[\"c\"],[\"d\"],[\"a\",\"b\"],[\"c\",\"b\"],[\"d\",\"a\"]]\n\t\tOutput: [[\"d\"],[\"d\",\"a\"]]\n\t\tExplanation: The file structure is as shown.\n\t\tFolders \"/a\" and \"/c\" (and their subfolders) are marked for deletion because they both contain an empty\n\t\tfolder named \"b\".\n\t\tExample 2:\n\t\tInput: paths = [[\"a\"],[\"c\"],[\"a\",\"b\"],[\"c\",\"b\"],[\"a\",\"b\",\"x\"],[\"a\",\"b\",\"x\",\"y\"],[\"w\"],[\"w\",\"y\"]]\n\t\tOutput: [[\"c\"],[\"c\",\"b\"],[\"a\"],[\"a\",\"b\"]]\n\t\tExplanation: The file structure is as shown. \n\t\tFolders \"/a/b/x\" and \"/w\" (and their subfolders) are marked for deletion because they both contain an empty folder named \"y\".\n\t\tNote that folders \"/a\" and \"/c\" are identical after the deletion, but they are not deleted because they were not marked beforehand.\n\t\tExample 3:\n\t\tInput: paths = [[\"a\",\"b\"],[\"c\",\"d\"],[\"c\"],[\"a\"]]\n\t\tOutput: [[\"c\"],[\"c\",\"d\"],[\"a\"],[\"a\",\"b\"]]\n\t\tExplanation: All folders are unique in the file system.\n\t\tNote that the returned array can be in a different order as the order does not matter.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 2080, - "question": "class Solution:\n def checkMove(self, board: List[List[str]], rMove: int, cMove: int, color: str) -> bool:\n\t\t\"\"\"\n\t\tYou are given a 0-indexed 8 x 8 grid board, where board[r][c] represents the cell (r, c) on a game board. On the board, free cells are represented by '.', white cells are represented by 'W', and black cells are represented by 'B'.\n\t\tEach move in this game consists of choosing a free cell and changing it to the color you are playing as (either white or black). However, a move is only legal if, after changing it, the cell becomes the endpoint of a good line (horizontal, vertical, or diagonal).\n\t\tA good line is a line of three or more cells (including the endpoints) where the endpoints of the line are one color, and the remaining cells in the middle are the opposite color (no cells in the line are free). You can find examples for good lines in the figure below:\n\t\tGiven two integers rMove and cMove and a character color representing the color you are playing as (white or black), return true if changing cell (rMove, cMove) to color color is a legal move, or false if it is not legal.\n\t\tExample 1:\n\t\tInput: board = [[\".\",\".\",\".\",\"B\",\".\",\".\",\".\",\".\"],[\".\",\".\",\".\",\"W\",\".\",\".\",\".\",\".\"],[\".\",\".\",\".\",\"W\",\".\",\".\",\".\",\".\"],[\".\",\".\",\".\",\"W\",\".\",\".\",\".\",\".\"],[\"W\",\"B\",\"B\",\".\",\"W\",\"W\",\"W\",\"B\"],[\".\",\".\",\".\",\"B\",\".\",\".\",\".\",\".\"],[\".\",\".\",\".\",\"B\",\".\",\".\",\".\",\".\"],[\".\",\".\",\".\",\"W\",\".\",\".\",\".\",\".\"]], rMove = 4, cMove = 3, color = \"B\"\n\t\tOutput: true\n\t\tExplanation: '.', 'W', and 'B' are represented by the colors blue, white, and black respectively, and cell (rMove, cMove) is marked with an 'X'.\n\t\tThe two good lines with the chosen cell as an endpoint are annotated above with the red rectangles.\n\t\tExample 2:\n\t\tInput: board = [[\".\",\".\",\".\",\".\",\".\",\".\",\".\",\".\"],[\".\",\"B\",\".\",\".\",\"W\",\".\",\".\",\".\"],[\".\",\".\",\"W\",\".\",\".\",\".\",\".\",\".\"],[\".\",\".\",\".\",\"W\",\"B\",\".\",\".\",\".\"],[\".\",\".\",\".\",\".\",\".\",\".\",\".\",\".\"],[\".\",\".\",\".\",\".\",\"B\",\"W\",\".\",\".\"],[\".\",\".\",\".\",\".\",\".\",\".\",\"W\",\".\"],[\".\",\".\",\".\",\".\",\".\",\".\",\".\",\"B\"]], rMove = 4, cMove = 4, color = \"W\"\n\t\tOutput: false\n\t\tExplanation: While there are good lines with the chosen cell as a middle cell, there are no good lines with the chosen cell as an endpoint.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 2081, - "question": "class Solution:\n def minSpaceWastedKResizing(self, nums: List[int], k: int) -> int:\n\t\t\"\"\"\n\t\tYou are currently designing a dynamic array. You are given a 0-indexed integer array nums, where nums[i] is the number of elements that will be in the array at time i. In addition, you are given an integer k, the maximum number of times you can resize the array (to any size).\n\t\tThe size of the array at time t, sizet, must be at least nums[t] because there needs to be enough space in the array to hold all the elements. The space wasted at time t is defined as sizet - nums[t], and the total space wasted is the sum of the space wasted across every time t where 0 <= t < nums.length.\n\t\tReturn the minimum total space wasted if you can resize the array at most k times.\n\t\tNote: The array can have any size at the start and does not count towards the number of resizing operations.\n\t\tExample 1:\n\t\tInput: nums = [10,20], k = 0\n\t\tOutput: 10\n\t\tExplanation: size = [20,20].\n\t\tWe can set the initial size to be 20.\n\t\tThe total wasted space is (20 - 10) + (20 - 20) = 10.\n\t\tExample 2:\n\t\tInput: nums = [10,20,30], k = 1\n\t\tOutput: 10\n\t\tExplanation: size = [20,20,30].\n\t\tWe can set the initial size to be 20 and resize to 30 at time 2. \n\t\tThe total wasted space is (20 - 10) + (20 - 20) + (30 - 30) = 10.\n\t\tExample 3:\n\t\tInput: nums = [10,20,15,30,20], k = 2\n\t\tOutput: 15\n\t\tExplanation: size = [10,20,20,30,30].\n\t\tWe can set the initial size to 10, resize to 20 at time 1, and resize to 30 at time 3.\n\t\tThe total wasted space is (10 - 10) + (20 - 20) + (20 - 15) + (30 - 30) + (30 - 20) = 15.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 2083, - "question": "class Solution:\n def isThree(self, n: int) -> bool:\n\t\t\"\"\"\n\t\tGiven an integer n, return true if n has exactly three positive divisors. Otherwise, return false.\n\t\tAn integer m is a divisor of n if there exists an integer k such that n = k * m.\n\t\tExample 1:\n\t\tInput: n = 2\n\t\tOutput: false\n\t\tExplantion: 2 has only two divisors: 1 and 2.\n\t\tExample 2:\n\t\tInput: n = 4\n\t\tOutput: true\n\t\tExplantion: 4 has three divisors: 1, 2, and 4.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 2084, - "question": "class Solution:\n def numberOfWeeks(self, milestones: List[int]) -> int:\n\t\t\"\"\"\n\t\tThere are n projects numbered from 0 to n - 1. You are given an integer array milestones where each milestones[i] denotes the number of milestones the ith project has.\n\t\tYou can work on the projects following these two rules:\n\t\t\tEvery week, you will finish exactly one milestone of one project. You must work every week.\n\t\t\tYou cannot work on two milestones from the same project for two consecutive weeks.\n\t\tOnce all the milestones of all the projects are finished, or if the only milestones that you can work on will cause you to violate the above rules, you will stop working. Note that you may not be able to finish every project's milestones due to these constraints.\n\t\tReturn the maximum number of weeks you would be able to work on the projects without violating the rules mentioned above.\n\t\tExample 1:\n\t\tInput: milestones = [1,2,3]\n\t\tOutput: 6\n\t\tExplanation: One possible scenario is:\n\t\t\u200b\u200b\u200b\u200b- During the 1st week, you will work on a milestone of project 0.\n\t\t- During the 2nd week, you will work on a milestone of project 2.\n\t\t- During the 3rd week, you will work on a milestone of project 1.\n\t\t- During the 4th week, you will work on a milestone of project 2.\n\t\t- During the 5th week, you will work on a milestone of project 1.\n\t\t- During the 6th week, you will work on a milestone of project 2.\n\t\tThe total number of weeks is 6.\n\t\tExample 2:\n\t\tInput: milestones = [5,2,1]\n\t\tOutput: 7\n\t\tExplanation: One possible scenario is:\n\t\t- During the 1st week, you will work on a milestone of project 0.\n\t\t- During the 2nd week, you will work on a milestone of project 1.\n\t\t- During the 3rd week, you will work on a milestone of project 0.\n\t\t- During the 4th week, you will work on a milestone of project 1.\n\t\t- During the 5th week, you will work on a milestone of project 0.\n\t\t- During the 6th week, you will work on a milestone of project 2.\n\t\t- During the 7th week, you will work on a milestone of project 0.\n\t\tThe total number of weeks is 7.\n\t\tNote that you cannot work on the last milestone of project 0 on 8th week because it would violate the rules.\n\t\tThus, one milestone in project 0 will remain unfinished.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 2085, - "question": "class Solution:\n def rearrangeArray(self, nums: List[int]) -> List[int]:\n\t\t\"\"\"\n\t\tYou are given a 0-indexed array nums of distinct integers. You want to rearrange the elements in the array such that every element in the rearranged array is not equal to the average of its neighbors.\n\t\tMore formally, the rearranged array should have the property such that for every i in the range 1 <= i < nums.length - 1, (nums[i-1] + nums[i+1]) / 2 is not equal to nums[i].\n\t\tReturn any rearrangement of nums that meets the requirements.\n\t\tExample 1:\n\t\tInput: nums = [1,2,3,4,5]\n\t\tOutput: [1,2,4,5,3]\n\t\tExplanation:\n\t\tWhen i=1, nums[i] = 2, and the average of its neighbors is (1+4) / 2 = 2.5.\n\t\tWhen i=2, nums[i] = 4, and the average of its neighbors is (2+5) / 2 = 3.5.\n\t\tWhen i=3, nums[i] = 5, and the average of its neighbors is (4+3) / 2 = 3.5.\n\t\tExample 2:\n\t\tInput: nums = [6,2,0,9,7]\n\t\tOutput: [9,7,6,2,0]\n\t\tExplanation:\n\t\tWhen i=1, nums[i] = 7, and the average of its neighbors is (9+6) / 2 = 7.5.\n\t\tWhen i=2, nums[i] = 6, and the average of its neighbors is (7+2) / 2 = 4.5.\n\t\tWhen i=3, nums[i] = 2, and the average of its neighbors is (6+0) / 2 = 3.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 2086, - "question": "class Solution:\n def countSpecialSubsequences(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tA sequence is special if it consists of a positive number of 0s, followed by a positive number of 1s, then a positive number of 2s.\n\t\t\tFor example, [0,1,2] and [0,0,1,1,1,2] are special.\n\t\t\tIn contrast, [2,1,0], [1], and [0,1,2,0] are not special.\n\t\tGiven an array nums (consisting of only integers 0, 1, and 2), return the number of different subsequences that are special. Since the answer may be very large, return it modulo 109 + 7.\n\t\tA subsequence of an array is a sequence that can be derived from the array by deleting some or no elements without changing the order of the remaining elements. Two subsequences are different if the set of indices chosen are different.\n\t\tExample 1:\n\t\tInput: nums = [0,1,2,2]\n\t\tOutput: 3\n\t\tExplanation: The special subsequences are bolded [0,1,2,2], [0,1,2,2], and [0,1,2,2].\n\t\tExample 2:\n\t\tInput: nums = [2,2,0,0]\n\t\tOutput: 0\n\t\tExplanation: There are no special subsequences in [2,2,0,0].\n\t\tExample 3:\n\t\tInput: nums = [0,1,2,0,1,2]\n\t\tOutput: 7\n\t\tExplanation: The special subsequences are bolded:\n\t\t- [0,1,2,0,1,2]\n\t\t- [0,1,2,0,1,2]\n\t\t- [0,1,2,0,1,2]\n\t\t- [0,1,2,0,1,2]\n\t\t- [0,1,2,0,1,2]\n\t\t- [0,1,2,0,1,2]\n\t\t- [0,1,2,0,1,2]\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 2088, - "question": "class Solution:\n def minTimeToType(self, word: str) -> int:\n\t\t\"\"\"\n\t\tThere is a special typewriter with lowercase English letters 'a' to 'z' arranged in a circle with a pointer. A character can only be typed if the pointer is pointing to that character. The pointer is initially pointing to the character 'a'.\n\t\tEach second, you may perform one of the following operations:\n\t\t\tMove the pointer one character counterclockwise or clockwise.\n\t\t\tType the character the pointer is currently on.\n\t\tGiven a string word, return the minimum number of seconds to type out the characters in word.\n\t\tExample 1:\n\t\tInput: word = \"abc\"\n\t\tOutput: 5\n\t\tExplanation: \n\t\tThe characters are printed as follows:\n\t\t- Type the character 'a' in 1 second since the pointer is initially on 'a'.\n\t\t- Move the pointer clockwise to 'b' in 1 second.\n\t\t- Type the character 'b' in 1 second.\n\t\t- Move the pointer clockwise to 'c' in 1 second.\n\t\t- Type the character 'c' in 1 second.\n\t\tExample 2:\n\t\tInput: word = \"bza\"\n\t\tOutput: 7\n\t\tExplanation:\n\t\tThe characters are printed as follows:\n\t\t- Move the pointer clockwise to 'b' in 1 second.\n\t\t- Type the character 'b' in 1 second.\n\t\t- Move the pointer counterclockwise to 'z' in 2 seconds.\n\t\t- Type the character 'z' in 1 second.\n\t\t- Move the pointer clockwise to 'a' in 1 second.\n\t\t- Type the character 'a' in 1 second.\n\t\tExample 3:\n\t\tInput: word = \"zjpc\"\n\t\tOutput: 34\n\t\tExplanation:\n\t\tThe characters are printed as follows:\n\t\t- Move the pointer counterclockwise to 'z' in 1 second.\n\t\t- Type the character 'z' in 1 second.\n\t\t- Move the pointer clockwise to 'j' in 10 seconds.\n\t\t- Type the character 'j' in 1 second.\n\t\t- Move the pointer clockwise to 'p' in 6 seconds.\n\t\t- Type the character 'p' in 1 second.\n\t\t- Move the pointer counterclockwise to 'c' in 13 seconds.\n\t\t- Type the character 'c' in 1 second.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 2089, - "question": "class Solution:\n def maxMatrixSum(self, matrix: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tYou are given an n x n integer matrix. You can do the following operation any number of times:\n\t\t\tChoose any two adjacent elements of matrix and multiply each of them by -1.\n\t\tTwo elements are considered adjacent if and only if they share a border.\n\t\tYour goal is to maximize the summation of the matrix's elements. Return the maximum sum of the matrix's elements using the operation mentioned above.\n\t\tExample 1:\n\t\tInput: matrix = [[1,-1],[-1,1]]\n\t\tOutput: 4\n\t\tExplanation: We can follow the following steps to reach sum equals 4:\n\t\t- Multiply the 2 elements in the first row by -1.\n\t\t- Multiply the 2 elements in the first column by -1.\n\t\tExample 2:\n\t\tInput: matrix = [[1,2,3],[-1,-2,-3],[1,2,3]]\n\t\tOutput: 16\n\t\tExplanation: We can follow the following step to reach sum equals 16:\n\t\t- Multiply the 2 last elements in the second row by -1.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 2090, - "question": "class Solution:\n def countPaths(self, n: int, roads: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tYou are in a city that consists of n intersections numbered from 0 to n - 1 with bi-directional roads between some intersections. The inputs are generated such that you can reach any intersection from any other intersection and that there is at most one road between any two intersections.\n\t\tYou are given an integer n and a 2D integer array roads where roads[i] = [ui, vi, timei] means that there is a road between intersections ui and vi that takes timei minutes to travel. You want to know in how many ways you can travel from intersection 0 to intersection n - 1 in the shortest amount of time.\n\t\tReturn the number of ways you can arrive at your destination in the shortest amount of time. Since the answer may be large, return it modulo 109 + 7.\n\t\tExample 1:\n\t\tInput: n = 7, roads = [[0,6,7],[0,1,2],[1,2,3],[1,3,3],[6,3,3],[3,5,1],[6,5,1],[2,5,1],[0,4,5],[4,6,2]]\n\t\tOutput: 4\n\t\tExplanation: The shortest amount of time it takes to go from intersection 0 to intersection 6 is 7 minutes.\n\t\tThe four ways to get there in 7 minutes are:\n\t\t- 0 \u279d 6\n\t\t- 0 \u279d 4 \u279d 6\n\t\t- 0 \u279d 1 \u279d 2 \u279d 5 \u279d 6\n\t\t- 0 \u279d 1 \u279d 3 \u279d 5 \u279d 6\n\t\tExample 2:\n\t\tInput: n = 2, roads = [[1,0,10]]\n\t\tOutput: 1\n\t\tExplanation: There is only one way to go from intersection 0 to intersection 1, and it takes 10 minutes.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 2091, - "question": "class Solution:\n def numberOfCombinations(self, num: str) -> int:\n\t\t\"\"\"\n\t\tYou wrote down many positive integers in a string called num. However, you realized that you forgot to add commas to seperate the different numbers. You remember that the list of integers was non-decreasing and that no integer had leading zeros.\n\t\tReturn the number of possible lists of integers that you could have written down to get the string num. Since the answer may be large, return it modulo 109 + 7.\n\t\tExample 1:\n\t\tInput: num = \"327\"\n\t\tOutput: 2\n\t\tExplanation: You could have written down the numbers:\n\t\t3, 27\n\t\t327\n\t\tExample 2:\n\t\tInput: num = \"094\"\n\t\tOutput: 0\n\t\tExplanation: No numbers can have leading zeros and all numbers must be positive.\n\t\tExample 3:\n\t\tInput: num = \"0\"\n\t\tOutput: 0\n\t\tExplanation: No numbers can have leading zeros and all numbers must be positive.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 2093, - "question": "class Solution:\n def isPrefixString(self, s: str, words: List[str]) -> bool:\n\t\t\"\"\"\n\t\tGiven a string s and an array of strings words, determine whether s is a prefix string of words.\n\t\tA string s is a prefix string of words if s can be made by concatenating the first k strings in words for some positive k no larger than words.length.\n\t\tReturn true if s is a prefix string of words, or false otherwise.\n\t\tExample 1:\n\t\tInput: s = \"iloveleetcode\", words = [\"i\",\"love\",\"leetcode\",\"apples\"]\n\t\tOutput: true\n\t\tExplanation:\n\t\ts can be made by concatenating \"i\", \"love\", and \"leetcode\" together.\n\t\tExample 2:\n\t\tInput: s = \"iloveleetcode\", words = [\"apples\",\"i\",\"love\",\"leetcode\"]\n\t\tOutput: false\n\t\tExplanation:\n\t\tIt is impossible to make s using a prefix of arr.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 2094, - "question": "class Solution:\n def minStoneSum(self, piles: List[int], k: int) -> int:\n\t\t\"\"\"\n\t\tYou are given a 0-indexed integer array piles, where piles[i] represents the number of stones in the ith pile, and an integer k. You should apply the following operation exactly k times:\n\t\t\tChoose any piles[i] and remove floor(piles[i] / 2) stones from it.\n\t\tNotice that you can apply the operation on the same pile more than once.\n\t\tReturn the minimum possible total number of stones remaining after applying the k operations.\n\t\tfloor(x) is the greatest integer that is smaller than or equal to x (i.e., rounds x down).\n\t\tExample 1:\n\t\tInput: piles = [5,4,9], k = 2\n\t\tOutput: 12\n\t\tExplanation: Steps of a possible scenario are:\n\t\t- Apply the operation on pile 2. The resulting piles are [5,4,5].\n\t\t- Apply the operation on pile 0. The resulting piles are [3,4,5].\n\t\tThe total number of stones in [3,4,5] is 12.\n\t\tExample 2:\n\t\tInput: piles = [4,3,6,7], k = 3\n\t\tOutput: 12\n\t\tExplanation: Steps of a possible scenario are:\n\t\t- Apply the operation on pile 2. The resulting piles are [4,3,3,7].\n\t\t- Apply the operation on pile 3. The resulting piles are [4,3,3,4].\n\t\t- Apply the operation on pile 0. The resulting piles are [2,3,3,4].\n\t\tThe total number of stones in [2,3,3,4] is 12.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 2095, - "question": "class Solution:\n def minSwaps(self, s: str) -> int:\n\t\t\"\"\"\n\t\tYou are given a 0-indexed string s of even length n. The string consists of exactly n / 2 opening brackets '[' and n / 2 closing brackets ']'.\n\t\tA string is called balanced if and only if:\n\t\t\tIt is the empty string, or\n\t\t\tIt can be written as AB, where both A and B are balanced strings, or\n\t\t\tIt can be written as [C], where C is a balanced string.\n\t\tYou may swap the brackets at any two indices any number of times.\n\t\tReturn the minimum number of swaps to make s balanced.\n\t\tExample 1:\n\t\tInput: s = \"][][\"\n\t\tOutput: 1\n\t\tExplanation: You can make the string balanced by swapping index 0 with index 3.\n\t\tThe resulting string is \"[[]]\".\n\t\tExample 2:\n\t\tInput: s = \"]]][[[\"\n\t\tOutput: 2\n\t\tExplanation: You can do the following to make the string balanced:\n\t\t- Swap index 0 with index 4. s = \"[]][][\".\n\t\t- Swap index 1 with index 5. s = \"[[][]]\".\n\t\tThe resulting string is \"[[][]]\".\n\t\tExample 3:\n\t\tInput: s = \"[]\"\n\t\tOutput: 0\n\t\tExplanation: The string is already balanced.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 2096, - "question": "class Solution:\n def longestObstacleCourseAtEachPosition(self, obstacles: List[int]) -> List[int]:\n\t\t\"\"\"\n\t\tYou want to build some obstacle courses. You are given a 0-indexed integer array obstacles of length n, where obstacles[i] describes the height of the ith obstacle.\n\t\tFor every index i between 0 and n - 1 (inclusive), find the length of the longest obstacle course in obstacles such that:\n\t\t\tYou choose any number of obstacles between 0 and i inclusive.\n\t\t\tYou must include the ith obstacle in the course.\n\t\t\tYou must put the chosen obstacles in the same order as they appear in obstacles.\n\t\t\tEvery obstacle (except the first) is taller than or the same height as the obstacle immediately before it.\n\t\tReturn an array ans of length n, where ans[i] is the length of the longest obstacle course for index i as described above.\n\t\tExample 1:\n\t\tInput: obstacles = [1,2,3,2]\n\t\tOutput: [1,2,3,3]\n\t\tExplanation: The longest valid obstacle course at each position is:\n\t\t- i = 0: [1], [1] has length 1.\n\t\t- i = 1: [1,2], [1,2] has length 2.\n\t\t- i = 2: [1,2,3], [1,2,3] has length 3.\n\t\t- i = 3: [1,2,3,2], [1,2,2] has length 3.\n\t\tExample 2:\n\t\tInput: obstacles = [2,2,1]\n\t\tOutput: [1,2,1]\n\t\tExplanation: The longest valid obstacle course at each position is:\n\t\t- i = 0: [2], [2] has length 1.\n\t\t- i = 1: [2,2], [2,2] has length 2.\n\t\t- i = 2: [2,2,1], [1] has length 1.\n\t\tExample 3:\n\t\tInput: obstacles = [3,1,5,6,4,2]\n\t\tOutput: [1,1,2,3,2,2]\n\t\tExplanation: The longest valid obstacle course at each position is:\n\t\t- i = 0: [3], [3] has length 1.\n\t\t- i = 1: [3,1], [1] has length 1.\n\t\t- i = 2: [3,1,5], [3,5] has length 2. [1,5] is also valid.\n\t\t- i = 3: [3,1,5,6], [3,5,6] has length 3. [1,5,6] is also valid.\n\t\t- i = 4: [3,1,5,6,4], [3,4] has length 2. [1,4] is also valid.\n\t\t- i = 5: [3,1,5,6,4,2], [1,2] has length 2.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 2099, - "question": "class Solution:\n def numOfStrings(self, patterns: List[str], word: str) -> int:\n\t\t\"\"\"\n\t\tGiven an array of strings patterns and a string word, return the number of strings in patterns that exist as a substring in word.\n\t\tA substring is a contiguous sequence of characters within a string.\n\t\tExample 1:\n\t\tInput: patterns = [\"a\",\"abc\",\"bc\",\"d\"], word = \"abc\"\n\t\tOutput: 3\n\t\tExplanation:\n\t\t- \"a\" appears as a substring in \"abc\".\n\t\t- \"abc\" appears as a substring in \"abc\".\n\t\t- \"bc\" appears as a substring in \"abc\".\n\t\t- \"d\" does not appear as a substring in \"abc\".\n\t\t3 of the strings in patterns appear as a substring in word.\n\t\tExample 2:\n\t\tInput: patterns = [\"a\",\"b\",\"c\"], word = \"aaaaabbbbb\"\n\t\tOutput: 2\n\t\tExplanation:\n\t\t- \"a\" appears as a substring in \"aaaaabbbbb\".\n\t\t- \"b\" appears as a substring in \"aaaaabbbbb\".\n\t\t- \"c\" does not appear as a substring in \"aaaaabbbbb\".\n\t\t2 of the strings in patterns appear as a substring in word.\n\t\tExample 3:\n\t\tInput: patterns = [\"a\",\"a\",\"a\"], word = \"ab\"\n\t\tOutput: 3\n\t\tExplanation: Each of the patterns appears as a substring in word \"ab\".\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 2100, - "question": "class Solution:\n def minNonZeroProduct(self, p: int) -> int:\n\t\t\"\"\"\n\t\tYou are given a positive integer p. Consider an array nums (1-indexed) that consists of the integers in the inclusive range [1, 2p - 1] in their binary representations. You are allowed to do the following operation any number of times:\n\t\t\tChoose two elements x and y from nums.\n\t\t\tChoose a bit in x and swap it with its corresponding bit in y. Corresponding bit refers to the bit that is in the same position in the other integer.\n\t\tFor example, if x = 1101 and y = 0011, after swapping the 2nd bit from the right, we have x = 1111 and y = 0001.\n\t\tFind the minimum non-zero product of nums after performing the above operation any number of times. Return this product modulo 109 + 7.\n\t\tNote: The answer should be the minimum product before the modulo operation is done.\n\t\tExample 1:\n\t\tInput: p = 1\n\t\tOutput: 1\n\t\tExplanation: nums = [1].\n\t\tThere is only one element, so the product equals that element.\n\t\tExample 2:\n\t\tInput: p = 2\n\t\tOutput: 6\n\t\tExplanation: nums = [01, 10, 11].\n\t\tAny swap would either make the product 0 or stay the same.\n\t\tThus, the array product of 1 * 2 * 3 = 6 is already minimized.\n\t\tExample 3:\n\t\tInput: p = 3\n\t\tOutput: 1512\n\t\tExplanation: nums = [001, 010, 011, 100, 101, 110, 111]\n\t\t- In the first operation we can swap the leftmost bit of the second and fifth elements.\n\t\t - The resulting array is [001, 110, 011, 100, 001, 110, 111].\n\t\t- In the second operation we can swap the middle bit of the third and fourth elements.\n\t\t - The resulting array is [001, 110, 001, 110, 001, 110, 111].\n\t\tThe array product is 1 * 6 * 1 * 6 * 1 * 6 * 7 = 1512, which is the minimum possible product.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 2101, - "question": "class Solution:\n def latestDayToCross(self, row: int, col: int, cells: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tThere is a 1-based binary matrix where 0 represents land and 1 represents water. You are given integers row and col representing the number of rows and columns in the matrix, respectively.\n\t\tInitially on day 0, the entire matrix is land. However, each day a new cell becomes flooded with water. You are given a 1-based 2D array cells, where cells[i] = [ri, ci] represents that on the ith day, the cell on the rith row and cith column (1-based coordinates) will be covered with water (i.e., changed to 1).\n\t\tYou want to find the last day that it is possible to walk from the top to the bottom by only walking on land cells. You can start from any cell in the top row and end at any cell in the bottom row. You can only travel in the four cardinal directions (left, right, up, and down).\n\t\tReturn the last day where it is possible to walk from the top to the bottom by only walking on land cells.\n\t\tExample 1:\n\t\tInput: row = 2, col = 2, cells = [[1,1],[2,1],[1,2],[2,2]]\n\t\tOutput: 2\n\t\tExplanation: The above image depicts how the matrix changes each day starting from day 0.\n\t\tThe last day where it is possible to cross from top to bottom is on day 2.\n\t\tExample 2:\n\t\tInput: row = 2, col = 2, cells = [[1,1],[1,2],[2,1],[2,2]]\n\t\tOutput: 1\n\t\tExplanation: The above image depicts how the matrix changes each day starting from day 0.\n\t\tThe last day where it is possible to cross from top to bottom is on day 1.\n\t\tExample 3:\n\t\tInput: row = 3, col = 3, cells = [[1,2],[2,1],[3,3],[2,2],[1,1],[1,3],[2,3],[3,2],[3,1]]\n\t\tOutput: 3\n\t\tExplanation: The above image depicts how the matrix changes each day starting from day 0.\n\t\tThe last day where it is possible to cross from top to bottom is on day 3.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 2102, - "question": "class Solution:\n def findMiddleIndex(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tGiven a 0-indexed integer array nums, find the leftmost middleIndex (i.e., the smallest amongst all the possible ones).\n\t\tA middleIndex is an index where nums[0] + nums[1] + ... + nums[middleIndex-1] == nums[middleIndex+1] + nums[middleIndex+2] + ... + nums[nums.length-1].\n\t\tIf middleIndex == 0, the left side sum is considered to be 0. Similarly, if middleIndex == nums.length - 1, the right side sum is considered to be 0.\n\t\tReturn the leftmost middleIndex that satisfies the condition, or -1 if there is no such index.\n\t\tExample 1:\n\t\tInput: nums = [2,3,-1,8,4]\n\t\tOutput: 3\n\t\tExplanation: The sum of the numbers before index 3 is: 2 + 3 + -1 = 4\n\t\tThe sum of the numbers after index 3 is: 4 = 4\n\t\tExample 2:\n\t\tInput: nums = [1,-1,4]\n\t\tOutput: 2\n\t\tExplanation: The sum of the numbers before index 2 is: 1 + -1 = 0\n\t\tThe sum of the numbers after index 2 is: 0\n\t\tExample 3:\n\t\tInput: nums = [2,5]\n\t\tOutput: -1\n\t\tExplanation: There is no valid middleIndex.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 2103, - "question": "class Solution:\n def findFarmland(self, land: List[List[int]]) -> List[List[int]]:\n\t\t\"\"\"\n\t\tYou are given a 0-indexed m x n binary matrix land where a 0 represents a hectare of forested land and a 1 represents a hectare of farmland.\n\t\tTo keep the land organized, there are designated rectangular areas of hectares that consist entirely of farmland. These rectangular areas are called groups. No two groups are adjacent, meaning farmland in one group is not four-directionally adjacent to another farmland in a different group.\n\t\tland can be represented by a coordinate system where the top left corner of land is (0, 0) and the bottom right corner of land is (m-1, n-1). Find the coordinates of the top left and bottom right corner of each group of farmland. A group of farmland with a top left corner at (r1, c1) and a bottom right corner at (r2, c2) is represented by the 4-length array [r1, c1, r2, c2].\n\t\tReturn a 2D array containing the 4-length arrays described above for each group of farmland in land. If there are no groups of farmland, return an empty array. You may return the answer in any order.\n\t\tExample 1:\n\t\tInput: land = [[1,0,0],[0,1,1],[0,1,1]]\n\t\tOutput: [[0,0,0,0],[1,1,2,2]]\n\t\tExplanation:\n\t\tThe first group has a top left corner at land[0][0] and a bottom right corner at land[0][0].\n\t\tThe second group has a top left corner at land[1][1] and a bottom right corner at land[2][2].\n\t\tExample 2:\n\t\tInput: land = [[1,1],[1,1]]\n\t\tOutput: [[0,0,1,1]]\n\t\tExplanation:\n\t\tThe first group has a top left corner at land[0][0] and a bottom right corner at land[1][1].\n\t\tExample 3:\n\t\tInput: land = [[0]]\n\t\tOutput: []\n\t\tExplanation:\n\t\tThere are no groups of farmland.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 2104, - "question": "class LockingTree:\n def __init__(self, parent: List[int]):\n def lock(self, num: int, user: int) -> bool:\n def unlock(self, num: int, user: int) -> bool:\n def upgrade(self, num: int, user: int) -> bool:\n\t\t\"\"\"\n\t\tYou are given a tree with n nodes numbered from 0 to n - 1 in the form of a parent array parent where parent[i] is the parent of the ith node. The root of the tree is node 0, so parent[0] = -1 since it has no parent. You want to design a data structure that allows users to lock, unlock, and upgrade nodes in the tree.\n\t\tThe data structure should support the following functions:\n\t\t\tLock: Locks the given node for the given user and prevents other users from locking the same node. You may only lock a node using this function if the node is unlocked.\n\t\t\tUnlock: Unlocks the given node for the given user. You may only unlock a node using this function if it is currently locked by the same user.\n\t\t\tUpgrade: Locks the given node for the given user and unlocks all of its descendants regardless of who locked it. You may only upgrade a node if all 3 conditions are true:\n\t\t\t\tThe node is unlocked,\n\t\t\t\tIt has at least one locked descendant (by any user), and\n\t\t\t\tIt does not have any locked ancestors.\n\t\tImplement the LockingTree class:\n\t\t\tLockingTree(int[] parent) initializes the data structure with the parent array.\n\t\t\tlock(int num, int user) returns true if it is possible for the user with id user to lock the node num, or false otherwise. If it is possible, the node num will become locked by the user with id user.\n\t\t\tunlock(int num, int user) returns true if it is possible for the user with id user to unlock the node num, or false otherwise. If it is possible, the node num will become unlocked.\n\t\t\tupgrade(int num, int user) returns true if it is possible for the user with id user to upgrade the node num, or false otherwise. If it is possible, the node num will be upgraded.\n\t\tExample 1:\n\t\tInput\n\t\t[\"LockingTree\", \"lock\", \"unlock\", \"unlock\", \"lock\", \"upgrade\", \"lock\"]\n\t\t[[[-1, 0, 0, 1, 1, 2, 2]], [2, 2], [2, 3], [2, 2], [4, 5], [0, 1], [0, 1]]\n\t\tOutput\n\t\t[null, true, false, true, true, true, false]\n\t\tExplanation\n\t\tLockingTree lockingTree = new LockingTree([-1, 0, 0, 1, 1, 2, 2]);\n\t\tlockingTree.lock(2, 2); // return true because node 2 is unlocked.\n\t\t // Node 2 will now be locked by user 2.\n\t\tlockingTree.unlock(2, 3); // return false because user 3 cannot unlock a node locked by user 2.\n\t\tlockingTree.unlock(2, 2); // return true because node 2 was previously locked by user 2.\n\t\t // Node 2 will now be unlocked.\n\t\tlockingTree.lock(4, 5); // return true because node 4 is unlocked.\n\t\t // Node 4 will now be locked by user 5.\n\t\tlockingTree.upgrade(0, 1); // return true because node 0 is unlocked and has at least one locked descendant (node 4).\n\t\t // Node 0 will now be locked by user 1 and node 4 will now be unlocked.\n\t\tlockingTree.lock(0, 1); // return false because node 0 is already locked.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 2105, - "question": "class Solution:\n def numberOfGoodSubsets(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou are given an integer array nums. We call a subset of nums good if its product can be represented as a product of one or more distinct prime numbers.\n\t\t\tFor example, if nums = [1, 2, 3, 4]:\n\t\t\t\t[2, 3], [1, 2, 3], and [1, 3] are good subsets with products 6 = 2*3, 6 = 2*3, and 3 = 3 respectively.\n\t\t\t\t[1, 4] and [4] are not good subsets with products 4 = 2*2 and 4 = 2*2 respectively.\n\t\tReturn the number of different good subsets in nums modulo 109 + 7.\n\t\tA subset of nums is any array that can be obtained by deleting some (possibly none or all) elements from nums. Two subsets are different if and only if the chosen indices to delete are different.\n\t\tExample 1:\n\t\tInput: nums = [1,2,3,4]\n\t\tOutput: 6\n\t\tExplanation: The good subsets are:\n\t\t- [1,2]: product is 2, which is the product of distinct prime 2.\n\t\t- [1,2,3]: product is 6, which is the product of distinct primes 2 and 3.\n\t\t- [1,3]: product is 3, which is the product of distinct prime 3.\n\t\t- [2]: product is 2, which is the product of distinct prime 2.\n\t\t- [2,3]: product is 6, which is the product of distinct primes 2 and 3.\n\t\t- [3]: product is 3, which is the product of distinct prime 3.\n\t\tExample 2:\n\t\tInput: nums = [4,2,3,15]\n\t\tOutput: 5\n\t\tExplanation: The good subsets are:\n\t\t- [2]: product is 2, which is the product of distinct prime 2.\n\t\t- [2,3]: product is 6, which is the product of distinct primes 2 and 3.\n\t\t- [2,15]: product is 30, which is the product of distinct primes 2, 3, and 5.\n\t\t- [3]: product is 3, which is the product of distinct prime 3.\n\t\t- [15]: product is 15, which is the product of distinct primes 3 and 5.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 2106, - "question": "class Solution:\n def findGCD(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tGiven an integer array nums, return the greatest common divisor of the smallest number and largest number in nums.\n\t\tThe greatest common divisor of two numbers is the largest positive integer that evenly divides both numbers.\n\t\tExample 1:\n\t\tInput: nums = [2,5,6,9,10]\n\t\tOutput: 2\n\t\tExplanation:\n\t\tThe smallest number in nums is 2.\n\t\tThe largest number in nums is 10.\n\t\tThe greatest common divisor of 2 and 10 is 2.\n\t\tExample 2:\n\t\tInput: nums = [7,5,6,8,3]\n\t\tOutput: 1\n\t\tExplanation:\n\t\tThe smallest number in nums is 3.\n\t\tThe largest number in nums is 8.\n\t\tThe greatest common divisor of 3 and 8 is 1.\n\t\tExample 3:\n\t\tInput: nums = [3,3]\n\t\tOutput: 3\n\t\tExplanation:\n\t\tThe smallest number in nums is 3.\n\t\tThe largest number in nums is 3.\n\t\tThe greatest common divisor of 3 and 3 is 3.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 2107, - "question": "class Solution:\n def findDifferentBinaryString(self, nums: List[str]) -> str:\n\t\t\"\"\"\n\t\tGiven an array of strings nums containing n unique binary strings each of length n, return a binary string of length n that does not appear in nums. If there are multiple answers, you may return any of them.\n\t\tExample 1:\n\t\tInput: nums = [\"01\",\"10\"]\n\t\tOutput: \"11\"\n\t\tExplanation: \"11\" does not appear in nums. \"00\" would also be correct.\n\t\tExample 2:\n\t\tInput: nums = [\"00\",\"01\"]\n\t\tOutput: \"11\"\n\t\tExplanation: \"11\" does not appear in nums. \"10\" would also be correct.\n\t\tExample 3:\n\t\tInput: nums = [\"111\",\"011\",\"001\"]\n\t\tOutput: \"101\"\n\t\tExplanation: \"101\" does not appear in nums. \"000\", \"010\", \"100\", and \"110\" would also be correct.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 2108, - "question": "class Solution:\n def minimizeTheDifference(self, mat: List[List[int]], target: int) -> int:\n\t\t\"\"\"\n\t\tYou are given an m x n integer matrix mat and an integer target.\n\t\tChoose one integer from each row in the matrix such that the absolute difference between target and the sum of the chosen elements is minimized.\n\t\tReturn the minimum absolute difference.\n\t\tThe absolute difference between two numbers a and b is the absolute value of a - b.\n\t\tExample 1:\n\t\tInput: mat = [[1,2,3],[4,5,6],[7,8,9]], target = 13\n\t\tOutput: 0\n\t\tExplanation: One possible choice is to:\n\t\t- Choose 1 from the first row.\n\t\t- Choose 5 from the second row.\n\t\t- Choose 7 from the third row.\n\t\tThe sum of the chosen elements is 13, which equals the target, so the absolute difference is 0.\n\t\tExample 2:\n\t\tInput: mat = [[1],[2],[3]], target = 100\n\t\tOutput: 94\n\t\tExplanation: The best possible choice is to:\n\t\t- Choose 1 from the first row.\n\t\t- Choose 2 from the second row.\n\t\t- Choose 3 from the third row.\n\t\tThe sum of the chosen elements is 6, and the absolute difference is 94.\n\t\tExample 3:\n\t\tInput: mat = [[1,2,9,8,7]], target = 6\n\t\tOutput: 1\n\t\tExplanation: The best choice is to choose 7 from the first row.\n\t\tThe absolute difference is 1.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 2109, - "question": "class Solution:\n def recoverArray(self, n: int, sums: List[int]) -> List[int]:\n\t\t\"\"\"\n\t\tYou are given an integer n representing the length of an unknown array that you are trying to recover. You are also given an array sums containing the values of all 2n subset sums of the unknown array (in no particular order).\n\t\tReturn the array ans of length n representing the unknown array. If multiple answers exist, return any of them.\n\t\tAn array sub is a subset of an array arr if sub can be obtained from arr by deleting some (possibly zero or all) elements of arr. The sum of the elements in sub is one possible subset sum of arr. The sum of an empty array is considered to be 0.\n\t\tNote: Test cases are generated such that there will always be at least one correct answer.\n\t\tExample 1:\n\t\tInput: n = 3, sums = [-3,-2,-1,0,0,1,2,3]\n\t\tOutput: [1,2,-3]\n\t\tExplanation: [1,2,-3] is able to achieve the given subset sums:\n\t\t- []: sum is 0\n\t\t- [1]: sum is 1\n\t\t- [2]: sum is 2\n\t\t- [1,2]: sum is 3\n\t\t- [-3]: sum is -3\n\t\t- [1,-3]: sum is -2\n\t\t- [2,-3]: sum is -1\n\t\t- [1,2,-3]: sum is 0\n\t\tNote that any permutation of [1,2,-3] and also any permutation of [-1,-2,3] will also be accepted.\n\t\tExample 2:\n\t\tInput: n = 2, sums = [0,0,0,0]\n\t\tOutput: [0,0]\n\t\tExplanation: The only correct answer is [0,0].\n\t\tExample 3:\n\t\tInput: n = 4, sums = [0,0,5,5,4,-1,4,9,9,-1,4,3,4,8,3,8]\n\t\tOutput: [0,-1,4,5]\n\t\tExplanation: [0,-1,4,5] is able to achieve the given subset sums.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 2112, - "question": "class Solution:\n def minimumDifference(self, nums: List[int], k: int) -> int:\n\t\t\"\"\"\n\t\tYou are given a 0-indexed integer array nums, where nums[i] represents the score of the ith student. You are also given an integer k.\n\t\tPick the scores of any k students from the array so that the difference between the highest and the lowest of the k scores is minimized.\n\t\tReturn the minimum possible difference.\n\t\tExample 1:\n\t\tInput: nums = [90], k = 1\n\t\tOutput: 0\n\t\tExplanation: There is one way to pick score(s) of one student:\n\t\t- [90]. The difference between the highest and lowest score is 90 - 90 = 0.\n\t\tThe minimum possible difference is 0.\n\t\tExample 2:\n\t\tInput: nums = [9,4,1,7], k = 2\n\t\tOutput: 2\n\t\tExplanation: There are six ways to pick score(s) of two students:\n\t\t- [9,4,1,7]. The difference between the highest and lowest score is 9 - 4 = 5.\n\t\t- [9,4,1,7]. The difference between the highest and lowest score is 9 - 1 = 8.\n\t\t- [9,4,1,7]. The difference between the highest and lowest score is 9 - 7 = 2.\n\t\t- [9,4,1,7]. The difference between the highest and lowest score is 4 - 1 = 3.\n\t\t- [9,4,1,7]. The difference between the highest and lowest score is 7 - 4 = 3.\n\t\t- [9,4,1,7]. The difference between the highest and lowest score is 7 - 1 = 6.\n\t\tThe minimum possible difference is 2.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 2113, - "question": "class Solution:\n def kthLargestNumber(self, nums: List[str], k: int) -> str:\n\t\t\"\"\"\n\t\tYou are given an array of strings nums and an integer k. Each string in nums represents an integer without leading zeros.\n\t\tReturn the string that represents the kth largest integer in nums.\n\t\tNote: Duplicate numbers should be counted distinctly. For example, if nums is [\"1\",\"2\",\"2\"], \"2\" is the first largest integer, \"2\" is the second-largest integer, and \"1\" is the third-largest integer.\n\t\tExample 1:\n\t\tInput: nums = [\"3\",\"6\",\"7\",\"10\"], k = 4\n\t\tOutput: \"3\"\n\t\tExplanation:\n\t\tThe numbers in nums sorted in non-decreasing order are [\"3\",\"6\",\"7\",\"10\"].\n\t\tThe 4th largest integer in nums is \"3\".\n\t\tExample 2:\n\t\tInput: nums = [\"2\",\"21\",\"12\",\"1\"], k = 3\n\t\tOutput: \"2\"\n\t\tExplanation:\n\t\tThe numbers in nums sorted in non-decreasing order are [\"1\",\"2\",\"12\",\"21\"].\n\t\tThe 3rd largest integer in nums is \"2\".\n\t\tExample 3:\n\t\tInput: nums = [\"0\",\"0\"], k = 2\n\t\tOutput: \"0\"\n\t\tExplanation:\n\t\tThe numbers in nums sorted in non-decreasing order are [\"0\",\"0\"].\n\t\tThe 2nd largest integer in nums is \"0\".\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 2114, - "question": "class Solution:\n def minSessions(self, tasks: List[int], sessionTime: int) -> int:\n\t\t\"\"\"\n\t\tThere are n tasks assigned to you. The task times are represented as an integer array tasks of length n, where the ith task takes tasks[i] hours to finish. A work session is when you work for at most sessionTime consecutive hours and then take a break.\n\t\tYou should finish the given tasks in a way that satisfies the following conditions:\n\t\t\tIf you start a task in a work session, you must complete it in the same work session.\n\t\t\tYou can start a new task immediately after finishing the previous one.\n\t\t\tYou may complete the tasks in any order.\n\t\tGiven tasks and sessionTime, return the minimum number of work sessions needed to finish all the tasks following the conditions above.\n\t\tThe tests are generated such that sessionTime is greater than or equal to the maximum element in tasks[i].\n\t\tExample 1:\n\t\tInput: tasks = [1,2,3], sessionTime = 3\n\t\tOutput: 2\n\t\tExplanation: You can finish the tasks in two work sessions.\n\t\t- First work session: finish the first and the second tasks in 1 + 2 = 3 hours.\n\t\t- Second work session: finish the third task in 3 hours.\n\t\tExample 2:\n\t\tInput: tasks = [3,1,3,1,1], sessionTime = 8\n\t\tOutput: 2\n\t\tExplanation: You can finish the tasks in two work sessions.\n\t\t- First work session: finish all the tasks except the last one in 3 + 1 + 3 + 1 = 8 hours.\n\t\t- Second work session: finish the last task in 1 hour.\n\t\tExample 3:\n\t\tInput: tasks = [1,2,3,4,5], sessionTime = 15\n\t\tOutput: 1\n\t\tExplanation: You can finish all the tasks in one work session.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 2115, - "question": "class Solution:\n def numberOfUniqueGoodSubsequences(self, binary: str) -> int:\n\t\t\"\"\"\n\t\tYou are given a binary string binary. A subsequence of binary is considered good if it is not empty and has no leading zeros (with the exception of \"0\").\n\t\tFind the number of unique good subsequences of binary.\n\t\t\tFor example, if binary = \"001\", then all the good subsequences are [\"0\", \"0\", \"1\"], so the unique good subsequences are \"0\" and \"1\". Note that subsequences \"00\", \"01\", and \"001\" are not good because they have leading zeros.\n\t\tReturn the number of unique good subsequences of binary. Since the answer may be very large, return it modulo 109 + 7.\n\t\tA subsequence is a sequence that can be derived from another sequence by deleting some or no elements without changing the order of the remaining elements.\n\t\tExample 1:\n\t\tInput: binary = \"001\"\n\t\tOutput: 2\n\t\tExplanation: The good subsequences of binary are [\"0\", \"0\", \"1\"].\n\t\tThe unique good subsequences are \"0\" and \"1\".\n\t\tExample 2:\n\t\tInput: binary = \"11\"\n\t\tOutput: 2\n\t\tExplanation: The good subsequences of binary are [\"1\", \"1\", \"11\"].\n\t\tThe unique good subsequences are \"1\" and \"11\".\n\t\tExample 3:\n\t\tInput: binary = \"101\"\n\t\tOutput: 5\n\t\tExplanation: The good subsequences of binary are [\"1\", \"0\", \"1\", \"10\", \"11\", \"101\"]. \n\t\tThe unique good subsequences are \"0\", \"1\", \"10\", \"11\", and \"101\".\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 2116, - "question": "class Solution:\n def countKDifference(self, nums: List[int], k: int) -> int:\n\t\t\"\"\"\n\t\tGiven an integer array nums and an integer k, return the number of pairs (i, j) where i < j such that |nums[i] - nums[j]| == k.\n\t\tThe value of |x| is defined as:\n\t\t\tx if x >= 0.\n\t\t\t-x if x < 0.\n\t\tExample 1:\n\t\tInput: nums = [1,2,2,1], k = 1\n\t\tOutput: 4\n\t\tExplanation: The pairs with an absolute difference of 1 are:\n\t\t- [1,2,2,1]\n\t\t- [1,2,2,1]\n\t\t- [1,2,2,1]\n\t\t- [1,2,2,1]\n\t\tExample 2:\n\t\tInput: nums = [1,3], k = 3\n\t\tOutput: 0\n\t\tExplanation: There are no pairs with an absolute difference of 3.\n\t\tExample 3:\n\t\tInput: nums = [3,2,1,5,4], k = 2\n\t\tOutput: 3\n\t\tExplanation: The pairs with an absolute difference of 2 are:\n\t\t- [3,2,1,5,4]\n\t\t- [3,2,1,5,4]\n\t\t- [3,2,1,5,4]\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 2117, - "question": "class Solution:\n def findOriginalArray(self, changed: List[int]) -> List[int]:\n\t\t\"\"\"\n\t\tAn integer array original is transformed into a doubled array changed by appending twice the value of every element in original, and then randomly shuffling the resulting array.\n\t\tGiven an array changed, return original if changed is a doubled array. If changed is not a doubled array, return an empty array. The elements in original may be returned in any order.\n\t\tExample 1:\n\t\tInput: changed = [1,3,4,2,6,8]\n\t\tOutput: [1,3,4]\n\t\tExplanation: One possible original array could be [1,3,4]:\n\t\t- Twice the value of 1 is 1 * 2 = 2.\n\t\t- Twice the value of 3 is 3 * 2 = 6.\n\t\t- Twice the value of 4 is 4 * 2 = 8.\n\t\tOther original arrays could be [4,3,1] or [3,1,4].\n\t\tExample 2:\n\t\tInput: changed = [6,3,0,1]\n\t\tOutput: []\n\t\tExplanation: changed is not a doubled array.\n\t\tExample 3:\n\t\tInput: changed = [1]\n\t\tOutput: []\n\t\tExplanation: changed is not a doubled array.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 2118, - "question": "class Solution:\n def maxTaxiEarnings(self, n: int, rides: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tThere are n points on a road you are driving your taxi on. The n points on the road are labeled from 1 to n in the direction you are going, and you want to drive from point 1 to point n to make money by picking up passengers. You cannot change the direction of the taxi.\n\t\tThe passengers are represented by a 0-indexed 2D integer array rides, where rides[i] = [starti, endi, tipi] denotes the ith passenger requesting a ride from point starti to point endi who is willing to give a tipi dollar tip.\n\t\tFor each passenger i you pick up, you earn endi - starti + tipi dollars. You may only drive at most one passenger at a time.\n\t\tGiven n and rides, return the maximum number of dollars you can earn by picking up the passengers optimally.\n\t\tNote: You may drop off a passenger and pick up a different passenger at the same point.\n\t\tExample 1:\n\t\tInput: n = 5, rides = [[2,5,4],[1,5,1]]\n\t\tOutput: 7\n\t\tExplanation: We can pick up passenger 0 to earn 5 - 2 + 4 = 7 dollars.\n\t\tExample 2:\n\t\tInput: n = 20, rides = [[1,6,1],[3,10,2],[10,12,3],[11,12,2],[12,15,2],[13,18,1]]\n\t\tOutput: 20\n\t\tExplanation: We will pick up the following passengers:\n\t\t- Drive passenger 1 from point 3 to point 10 for a profit of 10 - 3 + 2 = 9 dollars.\n\t\t- Drive passenger 2 from point 10 to point 12 for a profit of 12 - 10 + 3 = 5 dollars.\n\t\t- Drive passenger 5 from point 13 to point 18 for a profit of 18 - 13 + 1 = 6 dollars.\n\t\tWe earn 9 + 5 + 6 = 20 dollars in total.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 2119, - "question": "class Solution:\n def minOperations(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou are given an integer array nums. In one operation, you can replace any element in nums with any integer.\n\t\tnums is considered continuous if both of the following conditions are fulfilled:\n\t\t\tAll elements in nums are unique.\n\t\t\tThe difference between the maximum element and the minimum element in nums equals nums.length - 1.\n\t\tFor example, nums = [4, 2, 5, 3] is continuous, but nums = [1, 2, 3, 5, 6] is not continuous.\n\t\tReturn the minimum number of operations to make nums continuous.\n\t\tExample 1:\n\t\tInput: nums = [4,2,5,3]\n\t\tOutput: 0\n\t\tExplanation: nums is already continuous.\n\t\tExample 2:\n\t\tInput: nums = [1,2,3,5,6]\n\t\tOutput: 1\n\t\tExplanation: One possible solution is to change the last element to 4.\n\t\tThe resulting array is [1,2,3,5,4], which is continuous.\n\t\tExample 3:\n\t\tInput: nums = [1,10,100,1000]\n\t\tOutput: 3\n\t\tExplanation: One possible solution is to:\n\t\t- Change the second element to 2.\n\t\t- Change the third element to 3.\n\t\t- Change the fourth element to 4.\n\t\tThe resulting array is [1,2,3,4], which is continuous.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 2121, - "question": "class Solution:\n def validPath(self, n: int, edges: List[List[int]], source: int, destination: int) -> bool:\n\t\t\"\"\"\n\t\tThere is a bi-directional graph with n vertices, where each vertex is labeled from 0 to n - 1 (inclusive). The edges in the graph are represented as a 2D integer array edges, where each edges[i] = [ui, vi] denotes a bi-directional edge between vertex ui and vertex vi. Every vertex pair is connected by at most one edge, and no vertex has an edge to itself.\n\t\tYou want to determine if there is a valid path that exists from vertex source to vertex destination.\n\t\tGiven edges and the integers n, source, and destination, return true if there is a valid path from source to destination, or false otherwise.\n\t\tExample 1:\n\t\tInput: n = 3, edges = [[0,1],[1,2],[2,0]], source = 0, destination = 2\n\t\tOutput: true\n\t\tExplanation: There are two paths from vertex 0 to vertex 2:\n\t\t- 0 \u2192 1 \u2192 2\n\t\t- 0 \u2192 2\n\t\tExample 2:\n\t\tInput: n = 6, edges = [[0,1],[0,2],[3,5],[5,4],[4,3]], source = 0, destination = 5\n\t\tOutput: false\n\t\tExplanation: There is no path from vertex 0 to vertex 5.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 2122, - "question": "class Solution:\n def countQuadruplets(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tGiven a 0-indexed integer array nums, return the number of distinct quadruplets (a, b, c, d) such that:\n\t\t\tnums[a] + nums[b] + nums[c] == nums[d], and\n\t\t\ta < b < c < d\n\t\tExample 1:\n\t\tInput: nums = [1,2,3,6]\n\t\tOutput: 1\n\t\tExplanation: The only quadruplet that satisfies the requirement is (0, 1, 2, 3) because 1 + 2 + 3 == 6.\n\t\tExample 2:\n\t\tInput: nums = [3,3,6,4,5]\n\t\tOutput: 0\n\t\tExplanation: There are no such quadruplets in [3,3,6,4,5].\n\t\tExample 3:\n\t\tInput: nums = [1,1,1,3,5]\n\t\tOutput: 4\n\t\tExplanation: The 4 quadruplets that satisfy the requirement are:\n\t\t- (0, 1, 2, 3): 1 + 1 + 1 == 3\n\t\t- (0, 1, 3, 4): 1 + 1 + 3 == 5\n\t\t- (0, 2, 3, 4): 1 + 1 + 3 == 5\n\t\t- (1, 2, 3, 4): 1 + 1 + 3 == 5\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 2123, - "question": "class Solution:\n def numberOfWeakCharacters(self, properties: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tYou are playing a game that contains multiple characters, and each of the characters has two main properties: attack and defense. You are given a 2D integer array properties where properties[i] = [attacki, defensei] represents the properties of the ith character in the game.\n\t\tA character is said to be weak if any other character has both attack and defense levels strictly greater than this character's attack and defense levels. More formally, a character i is said to be weak if there exists another character j where attackj > attacki and defensej > defensei.\n\t\tReturn the number of weak characters.\n\t\tExample 1:\n\t\tInput: properties = [[5,5],[6,3],[3,6]]\n\t\tOutput: 0\n\t\tExplanation: No character has strictly greater attack and defense than the other.\n\t\tExample 2:\n\t\tInput: properties = [[2,2],[3,3]]\n\t\tOutput: 1\n\t\tExplanation: The first character is weak because the second character has a strictly greater attack and defense.\n\t\tExample 3:\n\t\tInput: properties = [[1,5],[10,4],[4,3]]\n\t\tOutput: 1\n\t\tExplanation: The third character is weak because the second character has a strictly greater attack and defense.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 2124, - "question": "class Solution:\n def firstDayBeenInAllRooms(self, nextVisit: List[int]) -> int:\n\t\t\"\"\"\n\t\tThere are n rooms you need to visit, labeled from 0 to n - 1. Each day is labeled, starting from 0. You will go in and visit one room a day.\n\t\tInitially on day 0, you visit room 0. The order you visit the rooms for the coming days is determined by the following rules and a given 0-indexed array nextVisit of length n:\n\t\t\tAssuming that on a day, you visit room i,\n\t\t\tif you have been in room i an odd number of times (including the current visit), on the next day you will visit a room with a lower or equal room number specified by nextVisit[i] where 0 <= nextVisit[i] <= i;\n\t\t\tif you have been in room i an even number of times (including the current visit), on the next day you will visit room (i + 1) mod n.\n\t\tReturn the label of the first day where you have been in all the rooms. It can be shown that such a day exists. Since the answer may be very large, return it modulo 109 + 7.\n\t\tExample 1:\n\t\tInput: nextVisit = [0,0]\n\t\tOutput: 2\n\t\tExplanation:\n\t\t- On day 0, you visit room 0. The total times you have been in room 0 is 1, which is odd.\n\t\t On the next day you will visit room nextVisit[0] = 0\n\t\t- On day 1, you visit room 0, The total times you have been in room 0 is 2, which is even.\n\t\t On the next day you will visit room (0 + 1) mod 2 = 1\n\t\t- On day 2, you visit room 1. This is the first day where you have been in all the rooms.\n\t\tExample 2:\n\t\tInput: nextVisit = [0,0,2]\n\t\tOutput: 6\n\t\tExplanation:\n\t\tYour room visiting order for each day is: [0,0,1,0,0,1,2,...].\n\t\tDay 6 is the first day where you have been in all the rooms.\n\t\tExample 3:\n\t\tInput: nextVisit = [0,1,2,0]\n\t\tOutput: 6\n\t\tExplanation:\n\t\tYour room visiting order for each day is: [0,0,1,1,2,2,3,...].\n\t\tDay 6 is the first day where you have been in all the rooms.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 2125, - "question": "class Solution:\n def gcdSort(self, nums: List[int]) -> bool:\n\t\t\"\"\"\n\t\tYou are given an integer array nums, and you can perform the following operation any number of times on nums:\n\t\t\tSwap the positions of two elements nums[i] and nums[j] if gcd(nums[i], nums[j]) > 1 where gcd(nums[i], nums[j]) is the greatest common divisor of nums[i] and nums[j].\n\t\tReturn true if it is possible to sort nums in non-decreasing order using the above swap method, or false otherwise.\n\t\tExample 1:\n\t\tInput: nums = [7,21,3]\n\t\tOutput: true\n\t\tExplanation: We can sort [7,21,3] by performing the following operations:\n\t\t- Swap 7 and 21 because gcd(7,21) = 7. nums = [21,7,3]\n\t\t- Swap 21 and 3 because gcd(21,3) = 3. nums = [3,7,21]\n\t\tExample 2:\n\t\tInput: nums = [5,2,6,2]\n\t\tOutput: false\n\t\tExplanation: It is impossible to sort the array because 5 cannot be swapped with any other element.\n\t\tExample 3:\n\t\tInput: nums = [10,5,9,3,15]\n\t\tOutput: true\n\t\tWe can sort [10,5,9,3,15] by performing the following operations:\n\t\t- Swap 10 and 15 because gcd(10,15) = 5. nums = [15,5,9,3,10]\n\t\t- Swap 15 and 3 because gcd(15,3) = 3. nums = [3,5,9,15,10]\n\t\t- Swap 10 and 15 because gcd(10,15) = 5. nums = [3,5,9,10,15]\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 2128, - "question": "class Solution:\n def reversePrefix(self, word: str, ch: str) -> str:\n\t\t\"\"\"\n\t\tGiven a 0-indexed string word and a character ch, reverse the segment of word that starts at index 0 and ends at the index of the first occurrence of ch (inclusive). If the character ch does not exist in word, do nothing.\n\t\t\tFor example, if word = \"abcdefd\" and ch = \"d\", then you should reverse the segment that starts at 0 and ends at 3 (inclusive). The resulting string will be \"dcbaefd\".\n\t\tReturn the resulting string.\n\t\tExample 1:\n\t\tInput: word = \"abcdefd\", ch = \"d\"\n\t\tOutput: \"dcbaefd\"\n\t\tExplanation: The first occurrence of \"d\" is at index 3. \n\t\tReverse the part of word from 0 to 3 (inclusive), the resulting string is \"dcbaefd\".\n\t\tExample 2:\n\t\tInput: word = \"xyxzxe\", ch = \"z\"\n\t\tOutput: \"zxyxxe\"\n\t\tExplanation: The first and only occurrence of \"z\" is at index 3.\n\t\tReverse the part of word from 0 to 3 (inclusive), the resulting string is \"zxyxxe\".\n\t\tExample 3:\n\t\tInput: word = \"abcd\", ch = \"z\"\n\t\tOutput: \"abcd\"\n\t\tExplanation: \"z\" does not exist in word.\n\t\tYou should not do any reverse operation, the resulting string is \"abcd\".\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 2129, - "question": "class Solution:\n def interchangeableRectangles(self, rectangles: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tYou are given n rectangles represented by a 0-indexed 2D integer array rectangles, where rectangles[i] = [widthi, heighti] denotes the width and height of the ith rectangle.\n\t\tTwo rectangles i and j (i < j) are considered interchangeable if they have the same width-to-height ratio. More formally, two rectangles are interchangeable if widthi/heighti == widthj/heightj (using decimal division, not integer division).\n\t\tReturn the number of pairs of interchangeable rectangles in rectangles.\n\t\tExample 1:\n\t\tInput: rectangles = [[4,8],[3,6],[10,20],[15,30]]\n\t\tOutput: 6\n\t\tExplanation: The following are the interchangeable pairs of rectangles by index (0-indexed):\n\t\t- Rectangle 0 with rectangle 1: 4/8 == 3/6.\n\t\t- Rectangle 0 with rectangle 2: 4/8 == 10/20.\n\t\t- Rectangle 0 with rectangle 3: 4/8 == 15/30.\n\t\t- Rectangle 1 with rectangle 2: 3/6 == 10/20.\n\t\t- Rectangle 1 with rectangle 3: 3/6 == 15/30.\n\t\t- Rectangle 2 with rectangle 3: 10/20 == 15/30.\n\t\tExample 2:\n\t\tInput: rectangles = [[4,5],[7,8]]\n\t\tOutput: 0\n\t\tExplanation: There are no interchangeable pairs of rectangles.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 2130, - "question": "class Solution:\n def maxProduct(self, s: str) -> int:\n\t\t\"\"\"\n\t\tGiven a string s, find two disjoint palindromic subsequences of s such that the product of their lengths is maximized. The two subsequences are disjoint if they do not both pick a character at the same index.\n\t\tReturn the maximum possible product of the lengths of the two palindromic subsequences.\n\t\tA subsequence is a string that can be derived from another string by deleting some or no characters without changing the order of the remaining characters. A string is palindromic if it reads the same forward and backward.\n\t\tExample 1:\n\t\tInput: s = \"leetcodecom\"\n\t\tOutput: 9\n\t\tExplanation: An optimal solution is to choose \"ete\" for the 1st subsequence and \"cdc\" for the 2nd subsequence.\n\t\tThe product of their lengths is: 3 * 3 = 9.\n\t\tExample 2:\n\t\tInput: s = \"bb\"\n\t\tOutput: 1\n\t\tExplanation: An optimal solution is to choose \"b\" (the first character) for the 1st subsequence and \"b\" (the second character) for the 2nd subsequence.\n\t\tThe product of their lengths is: 1 * 1 = 1.\n\t\tExample 3:\n\t\tInput: s = \"accbcaxxcxx\"\n\t\tOutput: 25\n\t\tExplanation: An optimal solution is to choose \"accca\" for the 1st subsequence and \"xxcxx\" for the 2nd subsequence.\n\t\tThe product of their lengths is: 5 * 5 = 25.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 2131, - "question": "class Solution:\n def smallestMissingValueSubtree(self, parents: List[int], nums: List[int]) -> List[int]:\n\t\t\"\"\"\n\t\tThere is a family tree rooted at 0 consisting of n nodes numbered 0 to n - 1. You are given a 0-indexed integer array parents, where parents[i] is the parent for node i. Since node 0 is the root, parents[0] == -1.\n\t\tThere are 105 genetic values, each represented by an integer in the inclusive range [1, 105]. You are given a 0-indexed integer array nums, where nums[i] is a distinct genetic value for node i.\n\t\tReturn an array ans of length n where ans[i] is the smallest genetic value that is missing from the subtree rooted at node i.\n\t\tThe subtree rooted at a node x contains node x and all of its descendant nodes.\n\t\tExample 1:\n\t\tInput: parents = [-1,0,0,2], nums = [1,2,3,4]\n\t\tOutput: [5,1,1,1]\n\t\tExplanation: The answer for each subtree is calculated as follows:\n\t\t- 0: The subtree contains nodes [0,1,2,3] with values [1,2,3,4]. 5 is the smallest missing value.\n\t\t- 1: The subtree contains only node 1 with value 2. 1 is the smallest missing value.\n\t\t- 2: The subtree contains nodes [2,3] with values [3,4]. 1 is the smallest missing value.\n\t\t- 3: The subtree contains only node 3 with value 4. 1 is the smallest missing value.\n\t\tExample 2:\n\t\tInput: parents = [-1,0,1,0,3,3], nums = [5,4,6,2,1,3]\n\t\tOutput: [7,1,1,4,2,1]\n\t\tExplanation: The answer for each subtree is calculated as follows:\n\t\t- 0: The subtree contains nodes [0,1,2,3,4,5] with values [5,4,6,2,1,3]. 7 is the smallest missing value.\n\t\t- 1: The subtree contains nodes [1,2] with values [4,6]. 1 is the smallest missing value.\n\t\t- 2: The subtree contains only node 2 with value 6. 1 is the smallest missing value.\n\t\t- 3: The subtree contains nodes [3,4,5] with values [2,1,3]. 4 is the smallest missing value.\n\t\t- 4: The subtree contains only node 4 with value 1. 2 is the smallest missing value.\n\t\t- 5: The subtree contains only node 5 with value 3. 1 is the smallest missing value.\n\t\tExample 3:\n\t\tInput: parents = [-1,2,3,0,2,4,1], nums = [2,3,4,5,6,7,8]\n\t\tOutput: [1,1,1,1,1,1,1]\n\t\tExplanation: The value 1 is missing from all the subtrees.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 2132, - "question": "class Solution:\n def construct2DArray(self, original: List[int], m: int, n: int) -> List[List[int]]:\n\t\t\"\"\"\n\t\tYou are given a 0-indexed 1-dimensional (1D) integer array original, and two integers, m and n. You are tasked with creating a 2-dimensional (2D) array with m rows and n columns using all the elements from original.\n\t\tThe elements from indices 0 to n - 1 (inclusive) of original should form the first row of the constructed 2D array, the elements from indices n to 2 * n - 1 (inclusive) should form the second row of the constructed 2D array, and so on.\n\t\tReturn an m x n 2D array constructed according to the above procedure, or an empty 2D array if it is impossible.\n\t\tExample 1:\n\t\tInput: original = [1,2,3,4], m = 2, n = 2\n\t\tOutput: [[1,2],[3,4]]\n\t\tExplanation: The constructed 2D array should contain 2 rows and 2 columns.\n\t\tThe first group of n=2 elements in original, [1,2], becomes the first row in the constructed 2D array.\n\t\tThe second group of n=2 elements in original, [3,4], becomes the second row in the constructed 2D array.\n\t\tExample 2:\n\t\tInput: original = [1,2,3], m = 1, n = 3\n\t\tOutput: [[1,2,3]]\n\t\tExplanation: The constructed 2D array should contain 1 row and 3 columns.\n\t\tPut all three elements in original into the first row of the constructed 2D array.\n\t\tExample 3:\n\t\tInput: original = [1,2], m = 1, n = 1\n\t\tOutput: []\n\t\tExplanation: There are 2 elements in original.\n\t\tIt is impossible to fit 2 elements in a 1x1 2D array, so return an empty 2D array.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 2133, - "question": "class Solution:\n def numOfPairs(self, nums: List[str], target: str) -> int:\n\t\t\"\"\"\n\t\tGiven an array of digit strings nums and a digit string target, return the number of pairs of indices (i, j) (where i != j) such that the concatenation of nums[i] + nums[j] equals target.\n\t\tExample 1:\n\t\tInput: nums = [\"777\",\"7\",\"77\",\"77\"], target = \"7777\"\n\t\tOutput: 4\n\t\tExplanation: Valid pairs are:\n\t\t- (0, 1): \"777\" + \"7\"\n\t\t- (1, 0): \"7\" + \"777\"\n\t\t- (2, 3): \"77\" + \"77\"\n\t\t- (3, 2): \"77\" + \"77\"\n\t\tExample 2:\n\t\tInput: nums = [\"123\",\"4\",\"12\",\"34\"], target = \"1234\"\n\t\tOutput: 2\n\t\tExplanation: Valid pairs are:\n\t\t- (0, 1): \"123\" + \"4\"\n\t\t- (2, 3): \"12\" + \"34\"\n\t\tExample 3:\n\t\tInput: nums = [\"1\",\"1\",\"1\"], target = \"11\"\n\t\tOutput: 6\n\t\tExplanation: Valid pairs are:\n\t\t- (0, 1): \"1\" + \"1\"\n\t\t- (1, 0): \"1\" + \"1\"\n\t\t- (0, 2): \"1\" + \"1\"\n\t\t- (2, 0): \"1\" + \"1\"\n\t\t- (1, 2): \"1\" + \"1\"\n\t\t- (2, 1): \"1\" + \"1\"\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 2134, - "question": "class Solution:\n def maxConsecutiveAnswers(self, answerKey: str, k: int) -> int:\n\t\t\"\"\"\n\t\tA teacher is writing a test with n true/false questions, with 'T' denoting true and 'F' denoting false. He wants to confuse the students by maximizing the number of consecutive questions with the same answer (multiple trues or multiple falses in a row).\n\t\tYou are given a string answerKey, where answerKey[i] is the original answer to the ith question. In addition, you are given an integer k, the maximum number of times you may perform the following operation:\n\t\t\tChange the answer key for any question to 'T' or 'F' (i.e., set answerKey[i] to 'T' or 'F').\n\t\tReturn the maximum number of consecutive 'T's or 'F's in the answer key after performing the operation at most k times.\n\t\tExample 1:\n\t\tInput: answerKey = \"TTFF\", k = 2\n\t\tOutput: 4\n\t\tExplanation: We can replace both the 'F's with 'T's to make answerKey = \"TTTT\".\n\t\tThere are four consecutive 'T's.\n\t\tExample 2:\n\t\tInput: answerKey = \"TFFT\", k = 1\n\t\tOutput: 3\n\t\tExplanation: We can replace the first 'T' with an 'F' to make answerKey = \"FFFT\".\n\t\tAlternatively, we can replace the second 'T' with an 'F' to make answerKey = \"TFFF\".\n\t\tIn both cases, there are three consecutive 'F's.\n\t\tExample 3:\n\t\tInput: answerKey = \"TTFTTFTT\", k = 1\n\t\tOutput: 5\n\t\tExplanation: We can replace the first 'F' to make answerKey = \"TTTTTFTT\"\n\t\tAlternatively, we can replace the second 'F' to make answerKey = \"TTFTTTTT\". \n\t\tIn both cases, there are five consecutive 'T's.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 2135, - "question": "class Solution:\n def waysToPartition(self, nums: List[int], k: int) -> int:\n\t\t\"\"\"\n\t\tYou are given a 0-indexed integer array nums of length n. The number of ways to partition nums is the number of pivot indices that satisfy both conditions:\n\t\t\t1 <= pivot < n\n\t\t\tnums[0] + nums[1] + ... + nums[pivot - 1] == nums[pivot] + nums[pivot + 1] + ... + nums[n - 1]\n\t\tYou are also given an integer k. You can choose to change the value of one element of nums to k, or to leave the array unchanged.\n\t\tReturn the maximum possible number of ways to partition nums to satisfy both conditions after changing at most one element.\n\t\tExample 1:\n\t\tInput: nums = [2,-1,2], k = 3\n\t\tOutput: 1\n\t\tExplanation: One optimal approach is to change nums[0] to k. The array becomes [3,-1,2].\n\t\tThere is one way to partition the array:\n\t\t- For pivot = 2, we have the partition [3,-1 | 2]: 3 + -1 == 2.\n\t\tExample 2:\n\t\tInput: nums = [0,0,0], k = 1\n\t\tOutput: 2\n\t\tExplanation: The optimal approach is to leave the array unchanged.\n\t\tThere are two ways to partition the array:\n\t\t- For pivot = 1, we have the partition [0 | 0,0]: 0 == 0 + 0.\n\t\t- For pivot = 2, we have the partition [0,0 | 0]: 0 + 0 == 0.\n\t\tExample 3:\n\t\tInput: nums = [22,4,-25,-20,-15,15,-16,7,19,-10,0,-13,-14], k = -33\n\t\tOutput: 4\n\t\tExplanation: One optimal approach is to change nums[2] to k. The array becomes [22,4,-33,-20,-15,15,-16,7,19,-10,0,-13,-14].\n\t\tThere are four ways to partition the array.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 2137, - "question": "class Solution:\n def finalValueAfterOperations(self, operations: List[str]) -> int:\n\t\t\"\"\"\n\t\tThere is a programming language with only four operations and one variable X:\n\t\t\t++X and X++ increments the value of the variable X by 1.\n\t\t\t--X and X-- decrements the value of the variable X by 1.\n\t\tInitially, the value of X is 0.\n\t\tGiven an array of strings operations containing a list of operations, return the final value of X after performing all the operations.\n\t\tExample 1:\n\t\tInput: operations = [\"--X\",\"X++\",\"X++\"]\n\t\tOutput: 1\n\t\tExplanation: The operations are performed as follows:\n\t\tInitially, X = 0.\n\t\t--X: X is decremented by 1, X = 0 - 1 = -1.\n\t\tX++: X is incremented by 1, X = -1 + 1 = 0.\n\t\tX++: X is incremented by 1, X = 0 + 1 = 1.\n\t\tExample 2:\n\t\tInput: operations = [\"++X\",\"++X\",\"X++\"]\n\t\tOutput: 3\n\t\tExplanation: The operations are performed as follows:\n\t\tInitially, X = 0.\n\t\t++X: X is incremented by 1, X = 0 + 1 = 1.\n\t\t++X: X is incremented by 1, X = 1 + 1 = 2.\n\t\tX++: X is incremented by 1, X = 2 + 1 = 3.\n\t\tExample 3:\n\t\tInput: operations = [\"X++\",\"++X\",\"--X\",\"X--\"]\n\t\tOutput: 0\n\t\tExplanation: The operations are performed as follows:\n\t\tInitially, X = 0.\n\t\tX++: X is incremented by 1, X = 0 + 1 = 1.\n\t\t++X: X is incremented by 1, X = 1 + 1 = 2.\n\t\t--X: X is decremented by 1, X = 2 - 1 = 1.\n\t\tX--: X is decremented by 1, X = 1 - 1 = 0.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 2138, - "question": "class Solution:\n def sumOfBeauties(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou are given a 0-indexed integer array nums. For each index i (1 <= i <= nums.length - 2) the beauty of nums[i] equals:\n\t\t\t2, if nums[j] < nums[i] < nums[k], for all 0 <= j < i and for all i < k <= nums.length - 1.\n\t\t\t1, if nums[i - 1] < nums[i] < nums[i + 1], and the previous condition is not satisfied.\n\t\t\t0, if none of the previous conditions holds.\n\t\tReturn the sum of beauty of all nums[i] where 1 <= i <= nums.length - 2.\n\t\tExample 1:\n\t\tInput: nums = [1,2,3]\n\t\tOutput: 2\n\t\tExplanation: For each index i in the range 1 <= i <= 1:\n\t\t- The beauty of nums[1] equals 2.\n\t\tExample 2:\n\t\tInput: nums = [2,4,6,4]\n\t\tOutput: 1\n\t\tExplanation: For each index i in the range 1 <= i <= 2:\n\t\t- The beauty of nums[1] equals 1.\n\t\t- The beauty of nums[2] equals 0.\n\t\tExample 3:\n\t\tInput: nums = [3,2,1]\n\t\tOutput: 0\n\t\tExplanation: For each index i in the range 1 <= i <= 1:\n\t\t- The beauty of nums[1] equals 0.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 2139, - "question": "class DetectSquares:\n def __init__(self):\n def add(self, point: List[int]) -> None:\n def count(self, point: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou are given a stream of points on the X-Y plane. Design an algorithm that:\n\t\t\tAdds new points from the stream into a data structure. Duplicate points are allowed and should be treated as different points.\n\t\t\tGiven a query point, counts the number of ways to choose three points from the data structure such that the three points and the query point form an axis-aligned square with positive area.\n\t\tAn axis-aligned square is a square whose edges are all the same length and are either parallel or perpendicular to the x-axis and y-axis.\n\t\tImplement the DetectSquares class:\n\t\t\tDetectSquares() Initializes the object with an empty data structure.\n\t\t\tvoid add(int[] point) Adds a new point point = [x, y] to the data structure.\n\t\t\tint count(int[] point) Counts the number of ways to form axis-aligned squares with point point = [x, y] as described above.\n\t\tExample 1:\n\t\tInput\n\t\t[\"DetectSquares\", \"add\", \"add\", \"add\", \"count\", \"count\", \"add\", \"count\"]\n\t\t[[], [[3, 10]], [[11, 2]], [[3, 2]], [[11, 10]], [[14, 8]], [[11, 2]], [[11, 10]]]\n\t\tOutput\n\t\t[null, null, null, null, 1, 0, null, 2]\n\t\tExplanation\n\t\tDetectSquares detectSquares = new DetectSquares();\n\t\tdetectSquares.add([3, 10]);\n\t\tdetectSquares.add([11, 2]);\n\t\tdetectSquares.add([3, 2]);\n\t\tdetectSquares.count([11, 10]); // return 1. You can choose:\n\t\t // - The first, second, and third points\n\t\tdetectSquares.count([14, 8]); // return 0. The query point cannot form a square with any points in the data structure.\n\t\tdetectSquares.add([11, 2]); // Adding duplicate points is allowed.\n\t\tdetectSquares.count([11, 10]); // return 2. You can choose:\n\t\t // - The first, second, and third points\n\t\t // - The first, third, and fourth points\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 2140, - "question": "class Solution:\n def longestSubsequenceRepeatedK(self, s: str, k: int) -> str:\n\t\t\"\"\"\n\t\tYou are given a string s of length n, and an integer k. You are tasked to find the longest subsequence repeated k times in string s.\n\t\tA subsequence is a string that can be derived from another string by deleting some or no characters without changing the order of the remaining characters.\n\t\tA subsequence seq is repeated k times in the string s if seq * k is a subsequence of s, where seq * k represents a string constructed by concatenating seq k times.\n\t\t\tFor example, \"bba\" is repeated 2 times in the string \"bababcba\", because the string \"bbabba\", constructed by concatenating \"bba\" 2 times, is a subsequence of the string \"bababcba\".\n\t\tReturn the longest subsequence repeated k times in string s. If multiple such subsequences are found, return the lexicographically largest one. If there is no such subsequence, return an empty string.\n\t\tExample 1:\n\t\tInput: s = \"letsleetcode\", k = 2\n\t\tOutput: \"let\"\n\t\tExplanation: There are two longest subsequences repeated 2 times: \"let\" and \"ete\".\n\t\t\"let\" is the lexicographically largest one.\n\t\tExample 2:\n\t\tInput: s = \"bb\", k = 2\n\t\tOutput: \"b\"\n\t\tExplanation: The longest subsequence repeated 2 times is \"b\".\n\t\tExample 3:\n\t\tInput: s = \"ab\", k = 2\n\t\tOutput: \"\"\n\t\tExplanation: There is no subsequence repeated 2 times. Empty string is returned.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 2144, - "question": "class Solution:\n def maximumDifference(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tGiven a 0-indexed integer array nums of size n, find the maximum difference between nums[i] and nums[j] (i.e., nums[j] - nums[i]), such that 0 <= i < j < n and nums[i] < nums[j].\n\t\tReturn the maximum difference. If no such i and j exists, return -1.\n\t\tExample 1:\n\t\tInput: nums = [7,1,5,4]\n\t\tOutput: 4\n\t\tExplanation:\n\t\tThe maximum difference occurs with i = 1 and j = 2, nums[j] - nums[i] = 5 - 1 = 4.\n\t\tNote that with i = 1 and j = 0, the difference nums[j] - nums[i] = 7 - 1 = 6, but i > j, so it is not valid.\n\t\tExample 2:\n\t\tInput: nums = [9,4,3,2]\n\t\tOutput: -1\n\t\tExplanation:\n\t\tThere is no i and j such that i < j and nums[i] < nums[j].\n\t\tExample 3:\n\t\tInput: nums = [1,5,2,10]\n\t\tOutput: 9\n\t\tExplanation:\n\t\tThe maximum difference occurs with i = 0 and j = 3, nums[j] - nums[i] = 10 - 1 = 9.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 2145, - "question": "class Solution:\n def gridGame(self, grid: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tYou are given a 0-indexed 2D array grid of size 2 x n, where grid[r][c] represents the number of points at position (r, c) on the matrix. Two robots are playing a game on this matrix.\n\t\tBoth robots initially start at (0, 0) and want to reach (1, n-1). Each robot may only move to the right ((r, c) to (r, c + 1)) or down ((r, c) to (r + 1, c)).\n\t\tAt the start of the game, the first robot moves from (0, 0) to (1, n-1), collecting all the points from the cells on its path. For all cells (r, c) traversed on the path, grid[r][c] is set to 0. Then, the second robot moves from (0, 0) to (1, n-1), collecting the points on its path. Note that their paths may intersect with one another.\n\t\tThe first robot wants to minimize the number of points collected by the second robot. In contrast, the second robot wants to maximize the number of points it collects. If both robots play optimally, return the number of points collected by the second robot.\n\t\tExample 1:\n\t\tInput: grid = [[2,5,4],[1,5,1]]\n\t\tOutput: 4\n\t\tExplanation: The optimal path taken by the first robot is shown in red, and the optimal path taken by the second robot is shown in blue.\n\t\tThe cells visited by the first robot are set to 0.\n\t\tThe second robot will collect 0 + 0 + 4 + 0 = 4 points.\n\t\tExample 2:\n\t\tInput: grid = [[3,3,1],[8,5,2]]\n\t\tOutput: 4\n\t\tExplanation: The optimal path taken by the first robot is shown in red, and the optimal path taken by the second robot is shown in blue.\n\t\tThe cells visited by the first robot are set to 0.\n\t\tThe second robot will collect 0 + 3 + 1 + 0 = 4 points.\n\t\tExample 3:\n\t\tInput: grid = [[1,3,1,15],[1,3,3,1]]\n\t\tOutput: 7\n\t\tExplanation: The optimal path taken by the first robot is shown in red, and the optimal path taken by the second robot is shown in blue.\n\t\tThe cells visited by the first robot are set to 0.\n\t\tThe second robot will collect 0 + 1 + 3 + 3 + 0 = 7 points.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 2146, - "question": "class Solution:\n def placeWordInCrossword(self, board: List[List[str]], word: str) -> bool:\n\t\t\"\"\"\n\t\tYou are given an m x n matrix board, representing the current state of a crossword puzzle. The crossword contains lowercase English letters (from solved words), ' ' to represent any empty cells, and '#' to represent any blocked cells.\n\t\tA word can be placed horizontally (left to right or right to left) or vertically (top to bottom or bottom to top) in the board if:\n\t\t\tIt does not occupy a cell containing the character '#'.\n\t\t\tThe cell each letter is placed in must either be ' ' (empty) or match the letter already on the board.\n\t\t\tThere must not be any empty cells ' ' or other lowercase letters directly left or right of the word if the word was placed horizontally.\n\t\t\tThere must not be any empty cells ' ' or other lowercase letters directly above or below the word if the word was placed vertically.\n\t\tGiven a string word, return true if word can be placed in board, or false otherwise.\n\t\tExample 1:\n\t\tInput: board = [[\"#\", \" \", \"#\"], [\" \", \" \", \"#\"], [\"#\", \"c\", \" \"]], word = \"abc\"\n\t\tOutput: true\n\t\tExplanation: The word \"abc\" can be placed as shown above (top to bottom).\n\t\tExample 2:\n\t\tInput: board = [[\" \", \"#\", \"a\"], [\" \", \"#\", \"c\"], [\" \", \"#\", \"a\"]], word = \"ac\"\n\t\tOutput: false\n\t\tExplanation: It is impossible to place the word because there will always be a space/letter above or below it.\n\t\tExample 3:\n\t\tInput: board = [[\"#\", \" \", \"#\"], [\" \", \" \", \"#\"], [\"#\", \" \", \"c\"]], word = \"ca\"\n\t\tOutput: true\n\t\tExplanation: The word \"ca\" can be placed as shown above (right to left). \n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 2147, - "question": "class Solution:\n def scoreOfStudents(self, s: str, answers: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou are given a string s that contains digits 0-9, addition symbols '+', and multiplication symbols '*' only, representing a valid math expression of single digit numbers (e.g., 3+5*2). This expression was given to n elementary school students. The students were instructed to get the answer of the expression by following this order of operations:\n\t\t\tCompute multiplication, reading from left to right; Then,\n\t\t\tCompute addition, reading from left to right.\n\t\tYou are given an integer array answers of length n, which are the submitted answers of the students in no particular order. You are asked to grade the answers, by following these rules:\n\t\t\tIf an answer equals the correct answer of the expression, this student will be rewarded 5 points;\n\t\t\tOtherwise, if the answer could be interpreted as if the student applied the operators in the wrong order but had correct arithmetic, this student will be rewarded 2 points;\n\t\t\tOtherwise, this student will be rewarded 0 points.\n\t\tReturn the sum of the points of the students.\n\t\tExample 1:\n\t\tInput: s = \"7+3*1*2\", answers = [20,13,42]\n\t\tOutput: 7\n\t\tExplanation: As illustrated above, the correct answer of the expression is 13, therefore one student is rewarded 5 points: [20,13,42]\n\t\tA student might have applied the operators in this wrong order: ((7+3)*1)*2 = 20. Therefore one student is rewarded 2 points: [20,13,42]\n\t\tThe points for the students are: [2,5,0]. The sum of the points is 2+5+0=7.\n\t\tExample 2:\n\t\tInput: s = \"3+5*2\", answers = [13,0,10,13,13,16,16]\n\t\tOutput: 19\n\t\tExplanation: The correct answer of the expression is 13, therefore three students are rewarded 5 points each: [13,0,10,13,13,16,16]\n\t\tA student might have applied the operators in this wrong order: ((3+5)*2 = 16. Therefore two students are rewarded 2 points: [13,0,10,13,13,16,16]\n\t\tThe points for the students are: [5,0,0,5,5,2,2]. The sum of the points is 5+0+0+5+5+2+2=19.\n\t\tExample 3:\n\t\tInput: s = \"6+0*1\", answers = [12,9,6,4,8,6]\n\t\tOutput: 10\n\t\tExplanation: The correct answer of the expression is 6.\n\t\tIf a student had incorrectly done (6+0)*1, the answer would also be 6.\n\t\tBy the rules of grading, the students will still be rewarded 5 points (as they got the correct answer), not 2 points.\n\t\tThe points for the students are: [0,0,5,0,0,5]. The sum of the points is 10.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 2148, - "question": "class Solution:\n def minMovesToSeat(self, seats: List[int], students: List[int]) -> int:\n\t\t\"\"\"\n\t\tThere are n seats and n students in a room. You are given an array seats of length n, where seats[i] is the position of the ith seat. You are also given the array students of length n, where students[j] is the position of the jth student.\n\t\tYou may perform the following move any number of times:\n\t\t\tIncrease or decrease the position of the ith student by 1 (i.e., moving the ith student from position x to x + 1 or x - 1)\n\t\tReturn the minimum number of moves required to move each student to a seat such that no two students are in the same seat.\n\t\tNote that there may be multiple seats or students in the same position at the beginning.\n\t\tExample 1:\n\t\tInput: seats = [3,1,5], students = [2,7,4]\n\t\tOutput: 4\n\t\tExplanation: The students are moved as follows:\n\t\t- The first student is moved from from position 2 to position 1 using 1 move.\n\t\t- The second student is moved from from position 7 to position 5 using 2 moves.\n\t\t- The third student is moved from from position 4 to position 3 using 1 move.\n\t\tIn total, 1 + 2 + 1 = 4 moves were used.\n\t\tExample 2:\n\t\tInput: seats = [4,1,5,9], students = [1,3,2,6]\n\t\tOutput: 7\n\t\tExplanation: The students are moved as follows:\n\t\t- The first student is not moved.\n\t\t- The second student is moved from from position 3 to position 4 using 1 move.\n\t\t- The third student is moved from from position 2 to position 5 using 3 moves.\n\t\t- The fourth student is moved from from position 6 to position 9 using 3 moves.\n\t\tIn total, 0 + 1 + 3 + 3 = 7 moves were used.\n\t\tExample 3:\n\t\tInput: seats = [2,2,6,6], students = [1,3,2,6]\n\t\tOutput: 4\n\t\tExplanation: Note that there are two seats at position 2 and two seats at position 6.\n\t\tThe students are moved as follows:\n\t\t- The first student is moved from from position 1 to position 2 using 1 move.\n\t\t- The second student is moved from from position 3 to position 6 using 3 moves.\n\t\t- The third student is not moved.\n\t\t- The fourth student is not moved.\n\t\tIn total, 1 + 3 + 0 + 0 = 4 moves were used.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 2149, - "question": "class Solution:\n def winnerOfGame(self, colors: str) -> bool:\n\t\t\"\"\"\n\t\tThere are n pieces arranged in a line, and each piece is colored either by 'A' or by 'B'. You are given a string colors of length n where colors[i] is the color of the ith piece.\n\t\tAlice and Bob are playing a game where they take alternating turns removing pieces from the line. In this game, Alice moves first.\n\t\t\tAlice is only allowed to remove a piece colored 'A' if both its neighbors are also colored 'A'. She is not allowed to remove pieces that are colored 'B'.\n\t\t\tBob is only allowed to remove a piece colored 'B' if both its neighbors are also colored 'B'. He is not allowed to remove pieces that are colored 'A'.\n\t\t\tAlice and Bob cannot remove pieces from the edge of the line.\n\t\t\tIf a player cannot make a move on their turn, that player loses and the other player wins.\n\t\tAssuming Alice and Bob play optimally, return true if Alice wins, or return false if Bob wins.\n\t\tExample 1:\n\t\tInput: colors = \"AAABABB\"\n\t\tOutput: true\n\t\tExplanation:\n\t\tAAABABB -> AABABB\n\t\tAlice moves first.\n\t\tShe removes the second 'A' from the left since that is the only 'A' whose neighbors are both 'A'.\n\t\tNow it's Bob's turn.\n\t\tBob cannot make a move on his turn since there are no 'B's whose neighbors are both 'B'.\n\t\tThus, Alice wins, so return true.\n\t\tExample 2:\n\t\tInput: colors = \"AA\"\n\t\tOutput: false\n\t\tExplanation:\n\t\tAlice has her turn first.\n\t\tThere are only two 'A's and both are on the edge of the line, so she cannot move on her turn.\n\t\tThus, Bob wins, so return false.\n\t\tExample 3:\n\t\tInput: colors = \"ABBBBBBBAAA\"\n\t\tOutput: false\n\t\tExplanation:\n\t\tABBBBBBBAAA -> ABBBBBBBAA\n\t\tAlice moves first.\n\t\tHer only option is to remove the second to last 'A' from the right.\n\t\tABBBBBBBAA -> ABBBBBBAA\n\t\tNext is Bob's turn.\n\t\tHe has many options for which 'B' piece to remove. He can pick any.\n\t\tOn Alice's second turn, she has no more pieces that she can remove.\n\t\tThus, Bob wins, so return false.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 2150, - "question": "class Solution:\n def kthSmallestProduct(self, nums1: List[int], nums2: List[int], k: int) -> int:\n\t\t\"\"\"\n\t\tGiven two sorted 0-indexed integer arrays nums1 and nums2 as well as an integer k, return the kth (1-based) smallest product of nums1[i] * nums2[j] where 0 <= i < nums1.length and 0 <= j < nums2.length.\n\t\tExample 1:\n\t\tInput: nums1 = [2,5], nums2 = [3,4], k = 2\n\t\tOutput: 8\n\t\tExplanation: The 2 smallest products are:\n\t\t- nums1[0] * nums2[0] = 2 * 3 = 6\n\t\t- nums1[0] * nums2[1] = 2 * 4 = 8\n\t\tThe 2nd smallest product is 8.\n\t\tExample 2:\n\t\tInput: nums1 = [-4,-2,0,3], nums2 = [2,4], k = 6\n\t\tOutput: 0\n\t\tExplanation: The 6 smallest products are:\n\t\t- nums1[0] * nums2[1] = (-4) * 4 = -16\n\t\t- nums1[0] * nums2[0] = (-4) * 2 = -8\n\t\t- nums1[1] * nums2[1] = (-2) * 4 = -8\n\t\t- nums1[1] * nums2[0] = (-2) * 2 = -4\n\t\t- nums1[2] * nums2[0] = 0 * 2 = 0\n\t\t- nums1[2] * nums2[1] = 0 * 4 = 0\n\t\tThe 6th smallest product is 0.\n\t\tExample 3:\n\t\tInput: nums1 = [-2,-1,0,1,2], nums2 = [-3,-1,2,4,5], k = 3\n\t\tOutput: -6\n\t\tExplanation: The 3 smallest products are:\n\t\t- nums1[0] * nums2[4] = (-2) * 5 = -10\n\t\t- nums1[0] * nums2[3] = (-2) * 4 = -8\n\t\t- nums1[4] * nums2[0] = 2 * (-3) = -6\n\t\tThe 3rd smallest product is -6.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 2151, - "question": "class Solution:\n def networkBecomesIdle(self, edges: List[List[int]], patience: List[int]) -> int:\n\t\t\"\"\"\n\t\tThere is a network of n servers, labeled from 0 to n - 1. You are given a 2D integer array edges, where edges[i] = [ui, vi] indicates there is a message channel between servers ui and vi, and they can pass any number of messages to each other directly in one second. You are also given a 0-indexed integer array patience of length n.\n\t\tAll servers are connected, i.e., a message can be passed from one server to any other server(s) directly or indirectly through the message channels.\n\t\tThe server labeled 0 is the master server. The rest are data servers. Each data server needs to send its message to the master server for processing and wait for a reply. Messages move between servers optimally, so every message takes the least amount of time to arrive at the master server. The master server will process all newly arrived messages instantly and send a reply to the originating server via the reversed path the message had gone through.\n\t\tAt the beginning of second 0, each data server sends its message to be processed. Starting from second 1, at the beginning of every second, each data server will check if it has received a reply to the message it sent (including any newly arrived replies) from the master server:\n\t\t\tIf it has not, it will resend the message periodically. The data server i will resend the message every patience[i] second(s), i.e., the data server i will resend the message if patience[i] second(s) have elapsed since the last time the message was sent from this server.\n\t\t\tOtherwise, no more resending will occur from this server.\n\t\tThe network becomes idle when there are no messages passing between servers or arriving at servers.\n\t\tReturn the earliest second starting from which the network becomes idle.\n\t\tExample 1:\n\t\tInput: edges = [[0,1],[1,2]], patience = [0,2,1]\n\t\tOutput: 8\n\t\tExplanation:\n\t\tAt (the beginning of) second 0,\n\t\t- Data server 1 sends its message (denoted 1A) to the master server.\n\t\t- Data server 2 sends its message (denoted 2A) to the master server.\n\t\tAt second 1,\n\t\t- Message 1A arrives at the master server. Master server processes message 1A instantly and sends a reply 1A back.\n\t\t- Server 1 has not received any reply. 1 second (1 < patience[1] = 2) elapsed since this server has sent the message, therefore it does not resend the message.\n\t\t- Server 2 has not received any reply. 1 second (1 == patience[2] = 1) elapsed since this server has sent the message, therefore it resends the message (denoted 2B).\n\t\tAt second 2,\n\t\t- The reply 1A arrives at server 1. No more resending will occur from server 1.\n\t\t- Message 2A arrives at the master server. Master server processes message 2A instantly and sends a reply 2A back.\n\t\t- Server 2 resends the message (denoted 2C).\n\t\t...\n\t\tAt second 4,\n\t\t- The reply 2A arrives at server 2. No more resending will occur from server 2.\n\t\t...\n\t\tAt second 7, reply 2D arrives at server 2.\n\t\tStarting from the beginning of the second 8, there are no messages passing between servers or arriving at servers.\n\t\tThis is the time when the network becomes idle.\n\t\tExample 2:\n\t\tInput: edges = [[0,1],[0,2],[1,2]], patience = [0,10,10]\n\t\tOutput: 3\n\t\tExplanation: Data servers 1 and 2 receive a reply back at the beginning of second 2.\n\t\tFrom the beginning of the second 3, the network becomes idle.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 2154, - "question": "class Solution:\n def minimumMoves(self, s: str) -> int:\n\t\t\"\"\"\n\t\tYou are given a string s consisting of n characters which are either 'X' or 'O'.\n\t\tA move is defined as selecting three consecutive characters of s and converting them to 'O'. Note that if a move is applied to the character 'O', it will stay the same.\n\t\tReturn the minimum number of moves required so that all the characters of s are converted to 'O'.\n\t\tExample 1:\n\t\tInput: s = \"XXX\"\n\t\tOutput: 1\n\t\tExplanation: XXX -> OOO\n\t\tWe select all the 3 characters and convert them in one move.\n\t\tExample 2:\n\t\tInput: s = \"XXOX\"\n\t\tOutput: 2\n\t\tExplanation: XXOX -> OOOX -> OOOO\n\t\tWe select the first 3 characters in the first move, and convert them to 'O'.\n\t\tThen we select the last 3 characters and convert them so that the final string contains all 'O's.\n\t\tExample 3:\n\t\tInput: s = \"OOOO\"\n\t\tOutput: 0\n\t\tExplanation: There are no 'X's in s to convert.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 2155, - "question": "class Solution:\n def missingRolls(self, rolls: List[int], mean: int, n: int) -> List[int]:\n\t\t\"\"\"\n\t\tYou have observations of n + m 6-sided dice rolls with each face numbered from 1 to 6. n of the observations went missing, and you only have the observations of m rolls. Fortunately, you have also calculated the average value of the n + m rolls.\n\t\tYou are given an integer array rolls of length m where rolls[i] is the value of the ith observation. You are also given the two integers mean and n.\n\t\tReturn an array of length n containing the missing observations such that the average value of the n + m rolls is exactly mean. If there are multiple valid answers, return any of them. If no such array exists, return an empty array.\n\t\tThe average value of a set of k numbers is the sum of the numbers divided by k.\n\t\tNote that mean is an integer, so the sum of the n + m rolls should be divisible by n + m.\n\t\tExample 1:\n\t\tInput: rolls = [3,2,4,3], mean = 4, n = 2\n\t\tOutput: [6,6]\n\t\tExplanation: The mean of all n + m rolls is (3 + 2 + 4 + 3 + 6 + 6) / 6 = 4.\n\t\tExample 2:\n\t\tInput: rolls = [1,5,6], mean = 3, n = 4\n\t\tOutput: [2,3,2,2]\n\t\tExplanation: The mean of all n + m rolls is (1 + 5 + 6 + 2 + 3 + 2 + 2) / 7 = 3.\n\t\tExample 3:\n\t\tInput: rolls = [1,2,3,4], mean = 6, n = 4\n\t\tOutput: []\n\t\tExplanation: It is impossible for the mean to be 6 no matter what the 4 missing rolls are.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 2156, - "question": "class Solution:\n def stoneGameIX(self, stones: List[int]) -> bool:\n\t\t\"\"\"\n\t\tAlice and Bob continue their games with stones. There is a row of n stones, and each stone has an associated value. You are given an integer array stones, where stones[i] is the value of the ith stone.\n\t\tAlice and Bob take turns, with Alice starting first. On each turn, the player may remove any stone from stones. The player who removes a stone loses if the sum of the values of all removed stones is divisible by 3. Bob will win automatically if there are no remaining stones (even if it is Alice's turn).\n\t\tAssuming both players play optimally, return true if Alice wins and false if Bob wins.\n\t\tExample 1:\n\t\tInput: stones = [2,1]\n\t\tOutput: true\n\t\tExplanation: The game will be played as follows:\n\t\t- Turn 1: Alice can remove either stone.\n\t\t- Turn 2: Bob removes the remaining stone. \n\t\tThe sum of the removed stones is 1 + 2 = 3 and is divisible by 3. Therefore, Bob loses and Alice wins the game.\n\t\tExample 2:\n\t\tInput: stones = [2]\n\t\tOutput: false\n\t\tExplanation: Alice will remove the only stone, and the sum of the values on the removed stones is 2. \n\t\tSince all the stones are removed and the sum of values is not divisible by 3, Bob wins the game.\n\t\tExample 3:\n\t\tInput: stones = [5,1,2,4,3]\n\t\tOutput: false\n\t\tExplanation: Bob will always win. One possible way for Bob to win is shown below:\n\t\t- Turn 1: Alice can remove the second stone with value 1. Sum of removed stones = 1.\n\t\t- Turn 2: Bob removes the fifth stone with value 3. Sum of removed stones = 1 + 3 = 4.\n\t\t- Turn 3: Alices removes the fourth stone with value 4. Sum of removed stones = 1 + 3 + 4 = 8.\n\t\t- Turn 4: Bob removes the third stone with value 2. Sum of removed stones = 1 + 3 + 4 + 2 = 10.\n\t\t- Turn 5: Alice removes the first stone with value 5. Sum of removed stones = 1 + 3 + 4 + 2 + 5 = 15.\n\t\tAlice loses the game because the sum of the removed stones (15) is divisible by 3. Bob wins the game.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 2157, - "question": "class Solution:\n def smallestSubsequence(self, s: str, k: int, letter: str, repetition: int) -> str:\n\t\t\"\"\"\n\t\tYou are given a string s, an integer k, a letter letter, and an integer repetition.\n\t\tReturn the lexicographically smallest subsequence of s of length k that has the letter letter appear at least repetition times. The test cases are generated so that the letter appears in s at least repetition times.\n\t\tA subsequence is a string that can be derived from another string by deleting some or no characters without changing the order of the remaining characters.\n\t\tA string a is lexicographically smaller than a string b if in the first position where a and b differ, string a has a letter that appears earlier in the alphabet than the corresponding letter in b.\n\t\tExample 1:\n\t\tInput: s = \"leet\", k = 3, letter = \"e\", repetition = 1\n\t\tOutput: \"eet\"\n\t\tExplanation: There are four subsequences of length 3 that have the letter 'e' appear at least 1 time:\n\t\t- \"lee\" (from \"leet\")\n\t\t- \"let\" (from \"leet\")\n\t\t- \"let\" (from \"leet\")\n\t\t- \"eet\" (from \"leet\")\n\t\tThe lexicographically smallest subsequence among them is \"eet\".\n\t\tExample 2:\n\t\tInput: s = \"leetcode\", k = 4, letter = \"e\", repetition = 2\n\t\tOutput: \"ecde\"\n\t\tExplanation: \"ecde\" is the lexicographically smallest subsequence of length 4 that has the letter \"e\" appear at least 2 times.\n\t\tExample 3:\n\t\tInput: s = \"bb\", k = 2, letter = \"b\", repetition = 2\n\t\tOutput: \"bb\"\n\t\tExplanation: \"bb\" is the only subsequence of length 2 that has the letter \"b\" appear at least 2 times.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 2159, - "question": "class Solution:\n def twoOutOfThree(self, nums1: List[int], nums2: List[int], nums3: List[int]) -> List[int]:\n\t\t\"\"\"\n\t\tGiven three integer arrays nums1, nums2, and nums3, return a distinct array containing all the values that are present in at least two out of the three arrays. You may return the values in any order.\n\t\tExample 1:\n\t\tInput: nums1 = [1,1,3,2], nums2 = [2,3], nums3 = [3]\n\t\tOutput: [3,2]\n\t\tExplanation: The values that are present in at least two arrays are:\n\t\t- 3, in all three arrays.\n\t\t- 2, in nums1 and nums2.\n\t\tExample 2:\n\t\tInput: nums1 = [3,1], nums2 = [2,3], nums3 = [1,2]\n\t\tOutput: [2,3,1]\n\t\tExplanation: The values that are present in at least two arrays are:\n\t\t- 2, in nums2 and nums3.\n\t\t- 3, in nums1 and nums2.\n\t\t- 1, in nums1 and nums3.\n\t\tExample 3:\n\t\tInput: nums1 = [1,2,2], nums2 = [4,3,3], nums3 = [5]\n\t\tOutput: []\n\t\tExplanation: No value is present in at least two arrays.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 2160, - "question": "class Solution:\n def minOperations(self, grid: List[List[int]], x: int) -> int:\n\t\t\"\"\"\n\t\tYou are given a 2D integer grid of size m x n and an integer x. In one operation, you can add x to or subtract x from any element in the grid.\n\t\tA uni-value grid is a grid where all the elements of it are equal.\n\t\tReturn the minimum number of operations to make the grid uni-value. If it is not possible, return -1.\n\t\tExample 1:\n\t\tInput: grid = [[2,4],[6,8]], x = 2\n\t\tOutput: 4\n\t\tExplanation: We can make every element equal to 4 by doing the following: \n\t\t- Add x to 2 once.\n\t\t- Subtract x from 6 once.\n\t\t- Subtract x from 8 twice.\n\t\tA total of 4 operations were used.\n\t\tExample 2:\n\t\tInput: grid = [[1,5],[2,3]], x = 1\n\t\tOutput: 5\n\t\tExplanation: We can make every element equal to 3.\n\t\tExample 3:\n\t\tInput: grid = [[1,2],[3,4]], x = 2\n\t\tOutput: -1\n\t\tExplanation: It is impossible to make every element equal.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 2161, - "question": "class StockPrice:\n def __init__(self):\n def update(self, timestamp: int, price: int) -> None:\n def current(self) -> int:\n def maximum(self) -> int:\n def minimum(self) -> int:\n\t\t\"\"\"\n\t\tYou are given a stream of records about a particular stock. Each record contains a timestamp and the corresponding price of the stock at that timestamp.\n\t\tUnfortunately due to the volatile nature of the stock market, the records do not come in order. Even worse, some records may be incorrect. Another record with the same timestamp may appear later in the stream correcting the price of the previous wrong record.\n\t\tDesign an algorithm that:\n\t\t\tUpdates the price of the stock at a particular timestamp, correcting the price from any previous records at the timestamp.\n\t\t\tFinds the latest price of the stock based on the current records. The latest price is the price at the latest timestamp recorded.\n\t\t\tFinds the maximum price the stock has been based on the current records.\n\t\t\tFinds the minimum price the stock has been based on the current records.\n\t\tImplement the StockPrice class:\n\t\t\tStockPrice() Initializes the object with no price records.\n\t\t\tvoid update(int timestamp, int price) Updates the price of the stock at the given timestamp.\n\t\t\tint current() Returns the latest price of the stock.\n\t\t\tint maximum() Returns the maximum price of the stock.\n\t\t\tint minimum() Returns the minimum price of the stock.\n\t\tExample 1:\n\t\tInput\n\t\t[\"StockPrice\", \"update\", \"update\", \"current\", \"maximum\", \"update\", \"maximum\", \"update\", \"minimum\"]\n\t\t[[], [1, 10], [2, 5], [], [], [1, 3], [], [4, 2], []]\n\t\tOutput\n\t\t[null, null, null, 5, 10, null, 5, null, 2]\n\t\tExplanation\n\t\tStockPrice stockPrice = new StockPrice();\n\t\tstockPrice.update(1, 10); // Timestamps are [1] with corresponding prices [10].\n\t\tstockPrice.update(2, 5); // Timestamps are [1,2] with corresponding prices [10,5].\n\t\tstockPrice.current(); // return 5, the latest timestamp is 2 with the price being 5.\n\t\tstockPrice.maximum(); // return 10, the maximum price is 10 at timestamp 1.\n\t\tstockPrice.update(1, 3); // The previous timestamp 1 had the wrong price, so it is updated to 3.\n\t\t // Timestamps are [1,2] with corresponding prices [3,5].\n\t\tstockPrice.maximum(); // return 5, the maximum price is 5 after the correction.\n\t\tstockPrice.update(4, 2); // Timestamps are [1,2,4] with corresponding prices [3,5,2].\n\t\tstockPrice.minimum(); // return 2, the minimum price is 2 at timestamp 4.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 2162, - "question": "class Solution:\n def minimumDifference(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou are given an integer array nums of 2 * n integers. You need to partition nums into two arrays of length n to minimize the absolute difference of the sums of the arrays. To partition nums, put each element of nums into one of the two arrays.\n\t\tReturn the minimum possible absolute difference.\n\t\tExample 1:\n\t\tInput: nums = [3,9,7,3]\n\t\tOutput: 2\n\t\tExplanation: One optimal partition is: [3,9] and [7,3].\n\t\tThe absolute difference between the sums of the arrays is abs((3 + 9) - (7 + 3)) = 2.\n\t\tExample 2:\n\t\tInput: nums = [-36,36]\n\t\tOutput: 72\n\t\tExplanation: One optimal partition is: [-36] and [36].\n\t\tThe absolute difference between the sums of the arrays is abs((-36) - (36)) = 72.\n\t\tExample 3:\n\t\tInput: nums = [2,-1,0,4,-2,-9]\n\t\tOutput: 0\n\t\tExplanation: One optimal partition is: [2,4,-9] and [-1,0,-2].\n\t\tThe absolute difference between the sums of the arrays is abs((2 + 4 + -9) - (-1 + 0 + -2)) = 0.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 2163, - "question": "class Solution:\n def kthDistinct(self, arr: List[str], k: int) -> str:\n\t\t\"\"\"\n\t\tA distinct string is a string that is present only once in an array.\n\t\tGiven an array of strings arr, and an integer k, return the kth distinct string present in arr. If there are fewer than k distinct strings, return an empty string \"\".\n\t\tNote that the strings are considered in the order in which they appear in the array.\n\t\tExample 1:\n\t\tInput: arr = [\"d\",\"b\",\"c\",\"b\",\"c\",\"a\"], k = 2\n\t\tOutput: \"a\"\n\t\tExplanation:\n\t\tThe only distinct strings in arr are \"d\" and \"a\".\n\t\t\"d\" appears 1st, so it is the 1st distinct string.\n\t\t\"a\" appears 2nd, so it is the 2nd distinct string.\n\t\tSince k == 2, \"a\" is returned. \n\t\tExample 2:\n\t\tInput: arr = [\"aaa\",\"aa\",\"a\"], k = 1\n\t\tOutput: \"aaa\"\n\t\tExplanation:\n\t\tAll strings in arr are distinct, so the 1st string \"aaa\" is returned.\n\t\tExample 3:\n\t\tInput: arr = [\"a\",\"b\",\"a\"], k = 3\n\t\tOutput: \"\"\n\t\tExplanation:\n\t\tThe only distinct string is \"b\". Since there are fewer than 3 distinct strings, we return an empty string \"\".\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 2164, - "question": "class Solution:\n def maxTwoEvents(self, events: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tYou are given a 0-indexed 2D integer array of events where events[i] = [startTimei, endTimei, valuei]. The ith event starts at startTimei and ends at endTimei, and if you attend this event, you will receive a value of valuei. You can choose at most two non-overlapping events to attend such that the sum of their values is maximized.\n\t\tReturn this maximum sum.\n\t\tNote that the start time and end time is inclusive: that is, you cannot attend two events where one of them starts and the other ends at the same time. More specifically, if you attend an event with end time t, the next event must start at or after t + 1.\n\t\tExample 1:\n\t\tInput: events = [[1,3,2],[4,5,2],[2,4,3]]\n\t\tOutput: 4\n\t\tExplanation: Choose the green events, 0 and 1 for a sum of 2 + 2 = 4.\n\t\tExample 2:\n\t\tInput: events = [[1,3,2],[4,5,2],[1,5,5]]\n\t\tOutput: 5\n\t\tExplanation: Choose event 2 for a sum of 5.\n\t\tExample 3:\n\t\tInput: events = [[1,5,3],[1,5,1],[6,6,5]]\n\t\tOutput: 8\n\t\tExplanation: Choose events 0 and 2 for a sum of 3 + 5 = 8.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 2165, - "question": "class Solution:\n def platesBetweenCandles(self, s: str, queries: List[List[int]]) -> List[int]:\n\t\t\"\"\"\n\t\tThere is a long table with a line of plates and candles arranged on top of it. You are given a 0-indexed string s consisting of characters '*' and '|' only, where a '*' represents a plate and a '|' represents a candle.\n\t\tYou are also given a 0-indexed 2D integer array queries where queries[i] = [lefti, righti] denotes the substring s[lefti...righti] (inclusive). For each query, you need to find the number of plates between candles that are in the substring. A plate is considered between candles if there is at least one candle to its left and at least one candle to its right in the substring.\n\t\t\tFor example, s = \"||**||**|*\", and a query [3, 8] denotes the substring \"*||**|\". The number of plates between candles in this substring is 2, as each of the two plates has at least one candle in the substring to its left and right.\n\t\tReturn an integer array answer where answer[i] is the answer to the ith query.\n\t\tExample 1:\n\t\tInput: s = \"**|**|***|\", queries = [[2,5],[5,9]]\n\t\tOutput: [2,3]\n\t\tExplanation:\n\t\t- queries[0] has two plates between candles.\n\t\t- queries[1] has three plates between candles.\n\t\tExample 2:\n\t\tInput: s = \"***|**|*****|**||**|*\", queries = [[1,17],[4,5],[14,17],[5,11],[15,16]]\n\t\tOutput: [9,0,0,0,0]\n\t\tExplanation:\n\t\t- queries[0] has nine plates between candles.\n\t\t- The other queries have zero plates between candles.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 2166, - "question": "class Solution:\n def countCombinations(self, pieces: List[str], positions: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tThere is an 8 x 8 chessboard containing n pieces (rooks, queens, or bishops). You are given a string array pieces of length n, where pieces[i] describes the type (rook, queen, or bishop) of the ith piece. In addition, you are given a 2D integer array positions also of length n, where positions[i] = [ri, ci] indicates that the ith piece is currently at the 1-based coordinate (ri, ci) on the chessboard.\n\t\tWhen making a move for a piece, you choose a destination square that the piece will travel toward and stop on.\n\t\t\tA rook can only travel horizontally or vertically from (r, c) to the direction of (r+1, c), (r-1, c), (r, c+1), or (r, c-1).\n\t\t\tA queen can only travel horizontally, vertically, or diagonally from (r, c) to the direction of (r+1, c), (r-1, c), (r, c+1), (r, c-1), (r+1, c+1), (r+1, c-1), (r-1, c+1), (r-1, c-1).\n\t\t\tA bishop can only travel diagonally from (r, c) to the direction of (r+1, c+1), (r+1, c-1), (r-1, c+1), (r-1, c-1).\n\t\tYou must make a move for every piece on the board simultaneously. A move combination consists of all the moves performed on all the given pieces. Every second, each piece will instantaneously travel one square towards their destination if they are not already at it. All pieces start traveling at the 0th second. A move combination is invalid if, at a given time, two or more pieces occupy the same square.\n\t\tReturn the number of valid move combinations\u200b\u200b\u200b\u200b\u200b.\n\t\tNotes:\n\t\t\tNo two pieces will start in the same square.\n\t\t\tYou may choose the square a piece is already on as its destination.\n\t\t\tIf two pieces are directly adjacent to each other, it is valid for them to move past each other and swap positions in one second.\n\t\tExample 1:\n\t\tInput: pieces = [\"rook\"], positions = [[1,1]]\n\t\tOutput: 15\n\t\tExplanation: The image above shows the possible squares the piece can move to.\n\t\tExample 2:\n\t\tInput: pieces = [\"queen\"], positions = [[1,1]]\n\t\tOutput: 22\n\t\tExplanation: The image above shows the possible squares the piece can move to.\n\t\tExample 3:\n\t\tInput: pieces = [\"bishop\"], positions = [[4,3]]\n\t\tOutput: 12\n\t\tExplanation: The image above shows the possible squares the piece can move to.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 2168, - "question": "class Solution:\n def areNumbersAscending(self, s: str) -> bool:\n\t\t\"\"\"\n\t\tA sentence is a list of tokens separated by a single space with no leading or trailing spaces. Every token is either a positive number consisting of digits 0-9 with no leading zeros, or a word consisting of lowercase English letters.\n\t\t\tFor example, \"a puppy has 2 eyes 4 legs\" is a sentence with seven tokens: \"2\" and \"4\" are numbers and the other tokens such as \"puppy\" are words.\n\t\tGiven a string s representing a sentence, you need to check if all the numbers in s are strictly increasing from left to right (i.e., other than the last number, each number is strictly smaller than the number on its right in s).\n\t\tReturn true if so, or false otherwise.\n\t\tExample 1:\n\t\tInput: s = \"1 box has 3 blue 4 red 6 green and 12 yellow marbles\"\n\t\tOutput: true\n\t\tExplanation: The numbers in s are: 1, 3, 4, 6, 12.\n\t\tThey are strictly increasing from left to right: 1 < 3 < 4 < 6 < 12.\n\t\tExample 2:\n\t\tInput: s = \"hello world 5 x 5\"\n\t\tOutput: false\n\t\tExplanation: The numbers in s are: 5, 5. They are not strictly increasing.\n\t\tExample 3:\n\t\tInput: s = \"sunset is at 7 51 pm overnight lows will be in the low 50 and 60 s\"\n\t\tOutput: false\n\t\tExplanation: The numbers in s are: 7, 51, 50, 60. They are not strictly increasing.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 2169, - "question": "class Bank:\n def __init__(self, balance: List[int]):\n def transfer(self, account1: int, account2: int, money: int) -> bool:\n def deposit(self, account: int, money: int) -> bool:\n def withdraw(self, account: int, money: int) -> bool:\n\t\t\"\"\"\n\t\tYou have been tasked with writing a program for a popular bank that will automate all its incoming transactions (transfer, deposit, and withdraw). The bank has n accounts numbered from 1 to n. The initial balance of each account is stored in a 0-indexed integer array balance, with the (i + 1)th account having an initial balance of balance[i].\n\t\tExecute all the valid transactions. A transaction is valid if:\n\t\t\tThe given account number(s) are between 1 and n, and\n\t\t\tThe amount of money withdrawn or transferred from is less than or equal to the balance of the account.\n\t\tImplement the Bank class:\n\t\t\tBank(long[] balance) Initializes the object with the 0-indexed integer array balance.\n\t\t\tboolean transfer(int account1, int account2, long money) Transfers money dollars from the account numbered account1 to the account numbered account2. Return true if the transaction was successful, false otherwise.\n\t\t\tboolean deposit(int account, long money) Deposit money dollars into the account numbered account. Return true if the transaction was successful, false otherwise.\n\t\t\tboolean withdraw(int account, long money) Withdraw money dollars from the account numbered account. Return true if the transaction was successful, false otherwise.\n\t\tExample 1:\n\t\tInput\n\t\t[\"Bank\", \"withdraw\", \"transfer\", \"deposit\", \"transfer\", \"withdraw\"]\n\t\t[[[10, 100, 20, 50, 30]], [3, 10], [5, 1, 20], [5, 20], [3, 4, 15], [10, 50]]\n\t\tOutput\n\t\t[null, true, true, true, false, false]\n\t\tExplanation\n\t\tBank bank = new Bank([10, 100, 20, 50, 30]);\n\t\tbank.withdraw(3, 10); // return true, account 3 has a balance of $20, so it is valid to withdraw $10.\n\t\t // Account 3 has $20 - $10 = $10.\n\t\tbank.transfer(5, 1, 20); // return true, account 5 has a balance of $30, so it is valid to transfer $20.\n\t\t // Account 5 has $30 - $20 = $10, and account 1 has $10 + $20 = $30.\n\t\tbank.deposit(5, 20); // return true, it is valid to deposit $20 to account 5.\n\t\t // Account 5 has $10 + $20 = $30.\n\t\tbank.transfer(3, 4, 15); // return false, the current balance of account 3 is $10,\n\t\t // so it is invalid to transfer $15 from it.\n\t\tbank.withdraw(10, 50); // return false, it is invalid because account 10 does not exist.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 2170, - "question": "class Solution:\n def countMaxOrSubsets(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tGiven an integer array nums, find the maximum possible bitwise OR of a subset of nums and return the number of different non-empty subsets with the maximum bitwise OR.\n\t\tAn array a is a subset of an array b if a can be obtained from b by deleting some (possibly zero) elements of b. Two subsets are considered different if the indices of the elements chosen are different.\n\t\tThe bitwise OR of an array a is equal to a[0] OR a[1] OR ... OR a[a.length - 1] (0-indexed).\n\t\tExample 1:\n\t\tInput: nums = [3,1]\n\t\tOutput: 2\n\t\tExplanation: The maximum possible bitwise OR of a subset is 3. There are 2 subsets with a bitwise OR of 3:\n\t\t- [3]\n\t\t- [3,1]\n\t\tExample 2:\n\t\tInput: nums = [2,2,2]\n\t\tOutput: 7\n\t\tExplanation: All non-empty subsets of [2,2,2] have a bitwise OR of 2. There are 23 - 1 = 7 total subsets.\n\t\tExample 3:\n\t\tInput: nums = [3,2,1,5]\n\t\tOutput: 6\n\t\tExplanation: The maximum possible bitwise OR of a subset is 7. There are 6 subsets with a bitwise OR of 7:\n\t\t- [3,5]\n\t\t- [3,1,5]\n\t\t- [3,2,5]\n\t\t- [3,2,1,5]\n\t\t- [2,5]\n\t\t- [2,1,5]\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 2171, - "question": "class Solution:\n def secondMinimum(self, n: int, edges: List[List[int]], time: int, change: int) -> int:\n\t\t\"\"\"\n\t\tA city is represented as a bi-directional connected graph with n vertices where each vertex is labeled from 1 to n (inclusive). The edges in the graph are represented as a 2D integer array edges, where each edges[i] = [ui, vi] denotes a bi-directional edge between vertex ui and vertex vi. Every vertex pair is connected by at most one edge, and no vertex has an edge to itself. The time taken to traverse any edge is time minutes.\n\t\tEach vertex has a traffic signal which changes its color from green to red and vice versa every change minutes. All signals change at the same time. You can enter a vertex at any time, but can leave a vertex only when the signal is green. You cannot wait at a vertex if the signal is green.\n\t\tThe second minimum value is defined as the smallest value strictly larger than the minimum value.\n\t\t\tFor example the second minimum value of [2, 3, 4] is 3, and the second minimum value of [2, 2, 4] is 4.\n\t\tGiven n, edges, time, and change, return the second minimum time it will take to go from vertex 1 to vertex n.\n\t\tNotes:\n\t\t\tYou can go through any vertex any number of times, including 1 and n.\n\t\t\tYou can assume that when the journey starts, all signals have just turned green.\n\t\tExample 1:\n\t\tInput: n = 5, edges = [[1,2],[1,3],[1,4],[3,4],[4,5]], time = 3, change = 5\n\t\tOutput: 13\n\t\tExplanation:\n\t\tThe figure on the left shows the given graph.\n\t\tThe blue path in the figure on the right is the minimum time path.\n\t\tThe time taken is:\n\t\t- Start at 1, time elapsed=0\n\t\t- 1 -> 4: 3 minutes, time elapsed=3\n\t\t- 4 -> 5: 3 minutes, time elapsed=6\n\t\tHence the minimum time needed is 6 minutes.\n\t\tThe red path shows the path to get the second minimum time.\n\t\t- Start at 1, time elapsed=0\n\t\t- 1 -> 3: 3 minutes, time elapsed=3\n\t\t- 3 -> 4: 3 minutes, time elapsed=6\n\t\t- Wait at 4 for 4 minutes, time elapsed=10\n\t\t- 4 -> 5: 3 minutes, time elapsed=13\n\t\tHence the second minimum time is 13 minutes. \n\t\tExample 2:\n\t\tInput: n = 2, edges = [[1,2]], time = 3, change = 2\n\t\tOutput: 11\n\t\tExplanation:\n\t\tThe minimum time path is 1 -> 2 with time = 3 minutes.\n\t\tThe second minimum time path is 1 -> 2 -> 1 -> 2 with time = 11 minutes.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 2173, - "question": "class Solution:\n def countValidWords(self, sentence: str) -> int:\n\t\t\"\"\"\n\t\tA sentence consists of lowercase letters ('a' to 'z'), digits ('0' to '9'), hyphens ('-'), punctuation marks ('!', '.', and ','), and spaces (' ') only. Each sentence can be broken down into one or more tokens separated by one or more spaces ' '.\n\t\tA token is a valid word if all three of the following are true:\n\t\t\tIt only contains lowercase letters, hyphens, and/or punctuation (no digits).\n\t\t\tThere is at most one hyphen '-'. If present, it must be surrounded by lowercase characters (\"a-b\" is valid, but \"-ab\" and \"ab-\" are not valid).\n\t\t\tThere is at most one punctuation mark. If present, it must be at the end of the token (\"ab,\", \"cd!\", and \".\" are valid, but \"a!b\" and \"c.,\" are not valid).\n\t\tExamples of valid words include \"a-b.\", \"afad\", \"ba-c\", \"a!\", and \"!\".\n\t\tGiven a string sentence, return the number of valid words in sentence.\n\t\tExample 1:\n\t\tInput: sentence = \"cat and dog\"\n\t\tOutput: 3\n\t\tExplanation: The valid words in the sentence are \"cat\", \"and\", and \"dog\".\n\t\tExample 2:\n\t\tInput: sentence = \"!this 1-s b8d!\"\n\t\tOutput: 0\n\t\tExplanation: There are no valid words in the sentence.\n\t\t\"!this\" is invalid because it starts with a punctuation mark.\n\t\t\"1-s\" and \"b8d\" are invalid because they contain digits.\n\t\tExample 3:\n\t\tInput: sentence = \"alice and bob are playing stone-game10\"\n\t\tOutput: 5\n\t\tExplanation: The valid words in the sentence are \"alice\", \"and\", \"bob\", \"are\", and \"playing\".\n\t\t\"stone-game10\" is invalid because it contains digits.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 2174, - "question": "class Solution:\n def nextBeautifulNumber(self, n: int) -> int:\n\t\t\"\"\"\n\t\tAn integer x is numerically balanced if for every digit d in the number x, there are exactly d occurrences of that digit in x.\n\t\tGiven an integer n, return the smallest numerically balanced number strictly greater than n.\n\t\tExample 1:\n\t\tInput: n = 1\n\t\tOutput: 22\n\t\tExplanation: \n\t\t22 is numerically balanced since:\n\t\t- The digit 2 occurs 2 times. \n\t\tIt is also the smallest numerically balanced number strictly greater than 1.\n\t\tExample 2:\n\t\tInput: n = 1000\n\t\tOutput: 1333\n\t\tExplanation: \n\t\t1333 is numerically balanced since:\n\t\t- The digit 1 occurs 1 time.\n\t\t- The digit 3 occurs 3 times. \n\t\tIt is also the smallest numerically balanced number strictly greater than 1000.\n\t\tNote that 1022 cannot be the answer because 0 appeared more than 0 times.\n\t\tExample 3:\n\t\tInput: n = 3000\n\t\tOutput: 3133\n\t\tExplanation: \n\t\t3133 is numerically balanced since:\n\t\t- The digit 1 occurs 1 time.\n\t\t- The digit 3 occurs 3 times.\n\t\tIt is also the smallest numerically balanced number strictly greater than 3000.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 2175, - "question": "class Solution:\n def countHighestScoreNodes(self, parents: List[int]) -> int:\n\t\t\"\"\"\n\t\tThere is a binary tree rooted at 0 consisting of n nodes. The nodes are labeled from 0 to n - 1. You are given a 0-indexed integer array parents representing the tree, where parents[i] is the parent of node i. Since node 0 is the root, parents[0] == -1.\n\t\tEach node has a score. To find the score of a node, consider if the node and the edges connected to it were removed. The tree would become one or more non-empty subtrees. The size of a subtree is the number of the nodes in it. The score of the node is the product of the sizes of all those subtrees.\n\t\tReturn the number of nodes that have the highest score.\n\t\tExample 1:\n\t\tInput: parents = [-1,2,0,2,0]\n\t\tOutput: 3\n\t\tExplanation:\n\t\t- The score of node 0 is: 3 * 1 = 3\n\t\t- The score of node 1 is: 4 = 4\n\t\t- The score of node 2 is: 1 * 1 * 2 = 2\n\t\t- The score of node 3 is: 4 = 4\n\t\t- The score of node 4 is: 4 = 4\n\t\tThe highest score is 4, and three nodes (node 1, node 3, and node 4) have the highest score.\n\t\tExample 2:\n\t\tInput: parents = [-1,2,0]\n\t\tOutput: 2\n\t\tExplanation:\n\t\t- The score of node 0 is: 2 = 2\n\t\t- The score of node 1 is: 2 = 2\n\t\t- The score of node 2 is: 1 * 1 = 1\n\t\tThe highest score is 2, and two nodes (node 0 and node 1) have the highest score.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 2176, - "question": "class Solution:\n def minimumTime(self, n: int, relations: List[List[int]], time: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou are given an integer n, which indicates that there are n courses labeled from 1 to n. You are also given a 2D integer array relations where relations[j] = [prevCoursej, nextCoursej] denotes that course prevCoursej has to be completed before course nextCoursej (prerequisite relationship). Furthermore, you are given a 0-indexed integer array time where time[i] denotes how many months it takes to complete the (i+1)th course.\n\t\tYou must find the minimum number of months needed to complete all the courses following these rules:\n\t\t\tYou may start taking a course at any time if the prerequisites are met.\n\t\t\tAny number of courses can be taken at the same time.\n\t\tReturn the minimum number of months needed to complete all the courses.\n\t\tNote: The test cases are generated such that it is possible to complete every course (i.e., the graph is a directed acyclic graph).\n\t\tExample 1:\n\t\tInput: n = 3, relations = [[1,3],[2,3]], time = [3,2,5]\n\t\tOutput: 8\n\t\tExplanation: The figure above represents the given graph and the time required to complete each course. \n\t\tWe start course 1 and course 2 simultaneously at month 0.\n\t\tCourse 1 takes 3 months and course 2 takes 2 months to complete respectively.\n\t\tThus, the earliest time we can start course 3 is at month 3, and the total time required is 3 + 5 = 8 months.\n\t\tExample 2:\n\t\tInput: n = 5, relations = [[1,5],[2,5],[3,5],[3,4],[4,5]], time = [1,2,3,4,5]\n\t\tOutput: 12\n\t\tExplanation: The figure above represents the given graph and the time required to complete each course.\n\t\tYou can start courses 1, 2, and 3 at month 0.\n\t\tYou can complete them after 1, 2, and 3 months respectively.\n\t\tCourse 4 can be taken only after course 3 is completed, i.e., after 3 months. It is completed after 3 + 4 = 7 months.\n\t\tCourse 5 can be taken only after courses 1, 2, 3, and 4 have been completed, i.e., after max(1,2,3,7) = 7 months.\n\t\tThus, the minimum time needed to complete all the courses is 7 + 5 = 12 months.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 2177, - "question": "class Solution:\n def checkAlmostEquivalent(self, word1: str, word2: str) -> bool:\n\t\t\"\"\"\n\t\tTwo strings word1 and word2 are considered almost equivalent if the differences between the frequencies of each letter from 'a' to 'z' between word1 and word2 is at most 3.\n\t\tGiven two strings word1 and word2, each of length n, return true if word1 and word2 are almost equivalent, or false otherwise.\n\t\tThe frequency of a letter x is the number of times it occurs in the string.\n\t\tExample 1:\n\t\tInput: word1 = \"aaaa\", word2 = \"bccb\"\n\t\tOutput: false\n\t\tExplanation: There are 4 'a's in \"aaaa\" but 0 'a's in \"bccb\".\n\t\tThe difference is 4, which is more than the allowed 3.\n\t\tExample 2:\n\t\tInput: word1 = \"abcdeef\", word2 = \"abaaacc\"\n\t\tOutput: true\n\t\tExplanation: The differences between the frequencies of each letter in word1 and word2 are at most 3:\n\t\t- 'a' appears 1 time in word1 and 4 times in word2. The difference is 3.\n\t\t- 'b' appears 1 time in word1 and 1 time in word2. The difference is 0.\n\t\t- 'c' appears 1 time in word1 and 2 times in word2. The difference is 1.\n\t\t- 'd' appears 1 time in word1 and 0 times in word2. The difference is 1.\n\t\t- 'e' appears 2 times in word1 and 0 times in word2. The difference is 2.\n\t\t- 'f' appears 1 time in word1 and 0 times in word2. The difference is 1.\n\t\tExample 3:\n\t\tInput: word1 = \"cccddabba\", word2 = \"babababab\"\n\t\tOutput: true\n\t\tExplanation: The differences between the frequencies of each letter in word1 and word2 are at most 3:\n\t\t- 'a' appears 2 times in word1 and 4 times in word2. The difference is 2.\n\t\t- 'b' appears 2 times in word1 and 5 times in word2. The difference is 3.\n\t\t- 'c' appears 3 times in word1 and 0 times in word2. The difference is 3.\n\t\t- 'd' appears 2 times in word1 and 0 times in word2. The difference is 2.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 2178, - "question": "class Robot:\n def __init__(self, width: int, height: int):\n def step(self, num: int) -> None:\n def getPos(self) -> List[int]:\n def getDir(self) -> str:\n\t\t\"\"\"\n\t\tA width x height grid is on an XY-plane with the bottom-left cell at (0, 0) and the top-right cell at (width - 1, height - 1). The grid is aligned with the four cardinal directions (\"North\", \"East\", \"South\", and \"West\"). A robot is initially at cell (0, 0) facing direction \"East\".\n\t\tThe robot can be instructed to move for a specific number of steps. For each step, it does the following.\n\t\t\tAttempts to move forward one cell in the direction it is facing.\n\t\t\tIf the cell the robot is moving to is out of bounds, the robot instead turns 90 degrees counterclockwise and retries the step.\n\t\tAfter the robot finishes moving the number of steps required, it stops and awaits the next instruction.\n\t\tImplement the Robot class:\n\t\t\tRobot(int width, int height) Initializes the width x height grid with the robot at (0, 0) facing \"East\".\n\t\t\tvoid step(int num) Instructs the robot to move forward num steps.\n\t\t\tint[] getPos() Returns the current cell the robot is at, as an array of length 2, [x, y].\n\t\t\tString getDir() Returns the current direction of the robot, \"North\", \"East\", \"South\", or \"West\".\n\t\tExample 1:\n\t\tInput\n\t\t[\"Robot\", \"step\", \"step\", \"getPos\", \"getDir\", \"step\", \"step\", \"step\", \"getPos\", \"getDir\"]\n\t\t[[6, 3], [2], [2], [], [], [2], [1], [4], [], []]\n\t\tOutput\n\t\t[null, null, null, [4, 0], \"East\", null, null, null, [1, 2], \"West\"]\n\t\tExplanation\n\t\tRobot robot = new Robot(6, 3); // Initialize the grid and the robot at (0, 0) facing East.\n\t\trobot.step(2); // It moves two steps East to (2, 0), and faces East.\n\t\trobot.step(2); // It moves two steps East to (4, 0), and faces East.\n\t\trobot.getPos(); // return [4, 0]\n\t\trobot.getDir(); // return \"East\"\n\t\trobot.step(2); // It moves one step East to (5, 0), and faces East.\n\t\t // Moving the next step East would be out of bounds, so it turns and faces North.\n\t\t // Then, it moves one step North to (5, 1), and faces North.\n\t\trobot.step(1); // It moves one step North to (5, 2), and faces North (not West).\n\t\trobot.step(4); // Moving the next step North would be out of bounds, so it turns and faces West.\n\t\t // Then, it moves four steps West to (1, 2), and faces West.\n\t\trobot.getPos(); // return [1, 2]\n\t\trobot.getDir(); // return \"West\"\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 2179, - "question": "class Solution:\n def maximumBeauty(self, items: List[List[int]], queries: List[int]) -> List[int]:\n\t\t\"\"\"\n\t\tYou are given a 2D integer array items where items[i] = [pricei, beautyi] denotes the price and beauty of an item respectively.\n\t\tYou are also given a 0-indexed integer array queries. For each queries[j], you want to determine the maximum beauty of an item whose price is less than or equal to queries[j]. If no such item exists, then the answer to this query is 0.\n\t\tReturn an array answer of the same length as queries where answer[j] is the answer to the jth query.\n\t\tExample 1:\n\t\tInput: items = [[1,2],[3,2],[2,4],[5,6],[3,5]], queries = [1,2,3,4,5,6]\n\t\tOutput: [2,4,5,5,6,6]\n\t\tExplanation:\n\t\t- For queries[0]=1, [1,2] is the only item which has price <= 1. Hence, the answer for this query is 2.\n\t\t- For queries[1]=2, the items which can be considered are [1,2] and [2,4]. \n\t\t The maximum beauty among them is 4.\n\t\t- For queries[2]=3 and queries[3]=4, the items which can be considered are [1,2], [3,2], [2,4], and [3,5].\n\t\t The maximum beauty among them is 5.\n\t\t- For queries[4]=5 and queries[5]=6, all items can be considered.\n\t\t Hence, the answer for them is the maximum beauty of all items, i.e., 6.\n\t\tExample 2:\n\t\tInput: items = [[1,2],[1,2],[1,3],[1,4]], queries = [1]\n\t\tOutput: [4]\n\t\tExplanation: \n\t\tThe price of every item is equal to 1, so we choose the item with the maximum beauty 4. \n\t\tNote that multiple items can have the same price and/or beauty. \n\t\tExample 3:\n\t\tInput: items = [[10,1000]], queries = [5]\n\t\tOutput: [0]\n\t\tExplanation:\n\t\tNo item has a price less than or equal to 5, so no item can be chosen.\n\t\tHence, the answer to the query is 0.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 2180, - "question": "class Solution:\n def maxTaskAssign(self, tasks: List[int], workers: List[int], pills: int, strength: int) -> int:\n\t\t\"\"\"\n\t\tYou have n tasks and m workers. Each task has a strength requirement stored in a 0-indexed integer array tasks, with the ith task requiring tasks[i] strength to complete. The strength of each worker is stored in a 0-indexed integer array workers, with the jth worker having workers[j] strength. Each worker can only be assigned to a single task and must have a strength greater than or equal to the task's strength requirement (i.e., workers[j] >= tasks[i]).\n\t\tAdditionally, you have pills magical pills that will increase a worker's strength by strength. You can decide which workers receive the magical pills, however, you may only give each worker at most one magical pill.\n\t\tGiven the 0-indexed integer arrays tasks and workers and the integers pills and strength, return the maximum number of tasks that can be completed.\n\t\tExample 1:\n\t\tInput: tasks = [3,2,1], workers = [0,3,3], pills = 1, strength = 1\n\t\tOutput: 3\n\t\tExplanation:\n\t\tWe can assign the magical pill and tasks as follows:\n\t\t- Give the magical pill to worker 0.\n\t\t- Assign worker 0 to task 2 (0 + 1 >= 1)\n\t\t- Assign worker 1 to task 1 (3 >= 2)\n\t\t- Assign worker 2 to task 0 (3 >= 3)\n\t\tExample 2:\n\t\tInput: tasks = [5,4], workers = [0,0,0], pills = 1, strength = 5\n\t\tOutput: 1\n\t\tExplanation:\n\t\tWe can assign the magical pill and tasks as follows:\n\t\t- Give the magical pill to worker 0.\n\t\t- Assign worker 0 to task 0 (0 + 5 >= 5)\n\t\tExample 3:\n\t\tInput: tasks = [10,15,30], workers = [0,10,10,10,10], pills = 3, strength = 10\n\t\tOutput: 2\n\t\tExplanation:\n\t\tWe can assign the magical pills and tasks as follows:\n\t\t- Give the magical pill to worker 0 and worker 1.\n\t\t- Assign worker 0 to task 0 (0 + 10 >= 10)\n\t\t- Assign worker 1 to task 1 (10 + 10 >= 15)\n\t\tThe last pill is not given because it will not make any worker strong enough for the last task.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 2181, - "question": "class Solution:\n def smallestEqual(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tGiven a 0-indexed integer array nums, return the smallest index i of nums such that i mod 10 == nums[i], or -1 if such index does not exist.\n\t\tx mod y denotes the remainder when x is divided by y.\n\t\tExample 1:\n\t\tInput: nums = [0,1,2]\n\t\tOutput: 0\n\t\tExplanation: \n\t\ti=0: 0 mod 10 = 0 == nums[0].\n\t\ti=1: 1 mod 10 = 1 == nums[1].\n\t\ti=2: 2 mod 10 = 2 == nums[2].\n\t\tAll indices have i mod 10 == nums[i], so we return the smallest index 0.\n\t\tExample 2:\n\t\tInput: nums = [4,3,2,1]\n\t\tOutput: 2\n\t\tExplanation: \n\t\ti=0: 0 mod 10 = 0 != nums[0].\n\t\ti=1: 1 mod 10 = 1 != nums[1].\n\t\ti=2: 2 mod 10 = 2 == nums[2].\n\t\ti=3: 3 mod 10 = 3 != nums[3].\n\t\t2 is the only index which has i mod 10 == nums[i].\n\t\tExample 3:\n\t\tInput: nums = [1,2,3,4,5,6,7,8,9,0]\n\t\tOutput: -1\n\t\tExplanation: No index satisfies i mod 10 == nums[i].\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 2182, - "question": "class Solution:\n def nodesBetweenCriticalPoints(self, head: Optional[ListNode]) -> List[int]:\n\t\t\"\"\"\n\t\tA critical point in a linked list is defined as either a local maxima or a local minima.\n\t\tA node is a local maxima if the current node has a value strictly greater than the previous node and the next node.\n\t\tA node is a local minima if the current node has a value strictly smaller than the previous node and the next node.\n\t\tNote that a node can only be a local maxima/minima if there exists both a previous node and a next node.\n\t\tGiven a linked list head, return an array of length 2 containing [minDistance, maxDistance] where minDistance is the minimum distance between any two distinct critical points and maxDistance is the maximum distance between any two distinct critical points. If there are fewer than two critical points, return [-1, -1].\n\t\tExample 1:\n\t\tInput: head = [3,1]\n\t\tOutput: [-1,-1]\n\t\tExplanation: There are no critical points in [3,1].\n\t\tExample 2:\n\t\tInput: head = [5,3,1,2,5,1,2]\n\t\tOutput: [1,3]\n\t\tExplanation: There are three critical points:\n\t\t- [5,3,1,2,5,1,2]: The third node is a local minima because 1 is less than 3 and 2.\n\t\t- [5,3,1,2,5,1,2]: The fifth node is a local maxima because 5 is greater than 2 and 1.\n\t\t- [5,3,1,2,5,1,2]: The sixth node is a local minima because 1 is less than 5 and 2.\n\t\tThe minimum distance is between the fifth and the sixth node. minDistance = 6 - 5 = 1.\n\t\tThe maximum distance is between the third and the sixth node. maxDistance = 6 - 3 = 3.\n\t\tExample 3:\n\t\tInput: head = [1,3,2,2,3,2,2,2,7]\n\t\tOutput: [3,3]\n\t\tExplanation: There are two critical points:\n\t\t- [1,3,2,2,3,2,2,2,7]: The second node is a local maxima because 3 is greater than 1 and 2.\n\t\t- [1,3,2,2,3,2,2,2,7]: The fifth node is a local maxima because 3 is greater than 2 and 2.\n\t\tBoth the minimum and maximum distances are between the second and the fifth node.\n\t\tThus, minDistance and maxDistance is 5 - 2 = 3.\n\t\tNote that the last node is not considered a local maxima because it does not have a next node.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 2183, - "question": "class Solution:\n def minimumOperations(self, nums: List[int], start: int, goal: int) -> int:\n\t\t\"\"\"\n\t\tYou are given a 0-indexed integer array nums containing distinct numbers, an integer start, and an integer goal. There is an integer x that is initially set to start, and you want to perform operations on x such that it is converted to goal. You can perform the following operation repeatedly on the number x:\n\t\tIf 0 <= x <= 1000, then for any index i in the array (0 <= i < nums.length), you can set x to any of the following:\n\t\t\tx + nums[i]\n\t\t\tx - nums[i]\n\t\t\tx ^ nums[i] (bitwise-XOR)\n\t\tNote that you can use each nums[i] any number of times in any order. Operations that set x to be out of the range 0 <= x <= 1000 are valid, but no more operations can be done afterward.\n\t\tReturn the minimum number of operations needed to convert x = start into goal, and -1 if it is not possible.\n\t\tExample 1:\n\t\tInput: nums = [2,4,12], start = 2, goal = 12\n\t\tOutput: 2\n\t\tExplanation: We can go from 2 \u2192 14 \u2192 12 with the following 2 operations.\n\t\t- 2 + 12 = 14\n\t\t- 14 - 2 = 12\n\t\tExample 2:\n\t\tInput: nums = [3,5,7], start = 0, goal = -4\n\t\tOutput: 2\n\t\tExplanation: We can go from 0 \u2192 3 \u2192 -4 with the following 2 operations. \n\t\t- 0 + 3 = 3\n\t\t- 3 - 7 = -4\n\t\tNote that the last operation sets x out of the range 0 <= x <= 1000, which is valid.\n\t\tExample 3:\n\t\tInput: nums = [2,8,16], start = 0, goal = 1\n\t\tOutput: -1\n\t\tExplanation: There is no way to convert 0 into 1.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 2184, - "question": "class Solution:\n def possiblyEquals(self, s1: str, s2: str) -> bool:\n\t\t\"\"\"\n\t\tAn original string, consisting of lowercase English letters, can be encoded by the following steps:\n\t\t\tArbitrarily split it into a sequence of some number of non-empty substrings.\n\t\t\tArbitrarily choose some elements (possibly none) of the sequence, and replace each with its length (as a numeric string).\n\t\t\tConcatenate the sequence as the encoded string.\n\t\tFor example, one way to encode an original string \"abcdefghijklmnop\" might be:\n\t\t\tSplit it as a sequence: [\"ab\", \"cdefghijklmn\", \"o\", \"p\"].\n\t\t\tChoose the second and third elements to be replaced by their lengths, respectively. The sequence becomes [\"ab\", \"12\", \"1\", \"p\"].\n\t\t\tConcatenate the elements of the sequence to get the encoded string: \"ab121p\".\n\t\tGiven two encoded strings s1 and s2, consisting of lowercase English letters and digits 1-9 (inclusive), return true if there exists an original string that could be encoded as both s1 and s2. Otherwise, return false.\n\t\tNote: The test cases are generated such that the number of consecutive digits in s1 and s2 does not exceed 3.\n\t\tExample 1:\n\t\tInput: s1 = \"internationalization\", s2 = \"i18n\"\n\t\tOutput: true\n\t\tExplanation: It is possible that \"internationalization\" was the original string.\n\t\t- \"internationalization\" \n\t\t -> Split: [\"internationalization\"]\n\t\t -> Do not replace any element\n\t\t -> Concatenate: \"internationalization\", which is s1.\n\t\t- \"internationalization\"\n\t\t -> Split: [\"i\", \"nternationalizatio\", \"n\"]\n\t\t -> Replace: [\"i\", \"18\", \"n\"]\n\t\t -> Concatenate: \"i18n\", which is s2\n\t\tExample 2:\n\t\tInput: s1 = \"l123e\", s2 = \"44\"\n\t\tOutput: true\n\t\tExplanation: It is possible that \"leetcode\" was the original string.\n\t\t- \"leetcode\" \n\t\t -> Split: [\"l\", \"e\", \"et\", \"cod\", \"e\"]\n\t\t -> Replace: [\"l\", \"1\", \"2\", \"3\", \"e\"]\n\t\t -> Concatenate: \"l123e\", which is s1.\n\t\t- \"leetcode\" \n\t\t -> Split: [\"leet\", \"code\"]\n\t\t -> Replace: [\"4\", \"4\"]\n\t\t -> Concatenate: \"44\", which is s2.\n\t\tExample 3:\n\t\tInput: s1 = \"a5b\", s2 = \"c5b\"\n\t\tOutput: false\n\t\tExplanation: It is impossible.\n\t\t- The original string encoded as s1 must start with the letter 'a'.\n\t\t- The original string encoded as s2 must start with the letter 'c'.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 2186, - "question": "class Solution:\n def countVowelSubstrings(self, word: str) -> int:\n\t\t\"\"\"\n\t\tA substring is a contiguous (non-empty) sequence of characters within a string.\n\t\tA vowel substring is a substring that only consists of vowels ('a', 'e', 'i', 'o', and 'u') and has all five vowels present in it.\n\t\tGiven a string word, return the number of vowel substrings in word.\n\t\tExample 1:\n\t\tInput: word = \"aeiouu\"\n\t\tOutput: 2\n\t\tExplanation: The vowel substrings of word are as follows (underlined):\n\t\t- \"aeiouu\"\n\t\t- \"aeiouu\"\n\t\tExample 2:\n\t\tInput: word = \"unicornarihan\"\n\t\tOutput: 0\n\t\tExplanation: Not all 5 vowels are present, so there are no vowel substrings.\n\t\tExample 3:\n\t\tInput: word = \"cuaieuouac\"\n\t\tOutput: 7\n\t\tExplanation: The vowel substrings of word are as follows (underlined):\n\t\t- \"cuaieuouac\"\n\t\t- \"cuaieuouac\"\n\t\t- \"cuaieuouac\"\n\t\t- \"cuaieuouac\"\n\t\t- \"cuaieuouac\"\n\t\t- \"cuaieuouac\"\n\t\t- \"cuaieuouac\"\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 2187, - "question": "class Solution:\n def countVowels(self, word: str) -> int:\n\t\t\"\"\"\n\t\tGiven a string word, return the sum of the number of vowels ('a', 'e', 'i', 'o', and 'u') in every substring of word.\n\t\tA substring is a contiguous (non-empty) sequence of characters within a string.\n\t\tNote: Due to the large constraints, the answer may not fit in a signed 32-bit integer. Please be careful during the calculations.\n\t\tExample 1:\n\t\tInput: word = \"aba\"\n\t\tOutput: 6\n\t\tExplanation: \n\t\tAll possible substrings are: \"a\", \"ab\", \"aba\", \"b\", \"ba\", and \"a\".\n\t\t- \"b\" has 0 vowels in it\n\t\t- \"a\", \"ab\", \"ba\", and \"a\" have 1 vowel each\n\t\t- \"aba\" has 2 vowels in it\n\t\tHence, the total sum of vowels = 0 + 1 + 1 + 1 + 1 + 2 = 6. \n\t\tExample 2:\n\t\tInput: word = \"abc\"\n\t\tOutput: 3\n\t\tExplanation: \n\t\tAll possible substrings are: \"a\", \"ab\", \"abc\", \"b\", \"bc\", and \"c\".\n\t\t- \"a\", \"ab\", and \"abc\" have 1 vowel each\n\t\t- \"b\", \"bc\", and \"c\" have 0 vowels each\n\t\tHence, the total sum of vowels = 1 + 1 + 1 + 0 + 0 + 0 = 3.\n\t\tExample 3:\n\t\tInput: word = \"ltcd\"\n\t\tOutput: 0\n\t\tExplanation: There are no vowels in any substring of \"ltcd\".\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 2188, - "question": "class Solution:\n def minimizedMaximum(self, n: int, quantities: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou are given an integer n indicating there are n specialty retail stores. There are m product types of varying amounts, which are given as a 0-indexed integer array quantities, where quantities[i] represents the number of products of the ith product type.\n\t\tYou need to distribute all products to the retail stores following these rules:\n\t\t\tA store can only be given at most one product type but can be given any amount of it.\n\t\t\tAfter distribution, each store will have been given some number of products (possibly 0). Let x represent the maximum number of products given to any store. You want x to be as small as possible, i.e., you want to minimize the maximum number of products that are given to any store.\n\t\tReturn the minimum possible x.\n\t\tExample 1:\n\t\tInput: n = 6, quantities = [11,6]\n\t\tOutput: 3\n\t\tExplanation: One optimal way is:\n\t\t- The 11 products of type 0 are distributed to the first four stores in these amounts: 2, 3, 3, 3\n\t\t- The 6 products of type 1 are distributed to the other two stores in these amounts: 3, 3\n\t\tThe maximum number of products given to any store is max(2, 3, 3, 3, 3, 3) = 3.\n\t\tExample 2:\n\t\tInput: n = 7, quantities = [15,10,10]\n\t\tOutput: 5\n\t\tExplanation: One optimal way is:\n\t\t- The 15 products of type 0 are distributed to the first three stores in these amounts: 5, 5, 5\n\t\t- The 10 products of type 1 are distributed to the next two stores in these amounts: 5, 5\n\t\t- The 10 products of type 2 are distributed to the last two stores in these amounts: 5, 5\n\t\tThe maximum number of products given to any store is max(5, 5, 5, 5, 5, 5, 5) = 5.\n\t\tExample 3:\n\t\tInput: n = 1, quantities = [100000]\n\t\tOutput: 100000\n\t\tExplanation: The only optimal way is:\n\t\t- The 100000 products of type 0 are distributed to the only store.\n\t\tThe maximum number of products given to any store is max(100000) = 100000.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 2189, - "question": "class Solution:\n def maximalPathQuality(self, values: List[int], edges: List[List[int]], maxTime: int) -> int:\n\t\t\"\"\"\n\t\tThere is an undirected graph with n nodes numbered from 0 to n - 1 (inclusive). You are given a 0-indexed integer array values where values[i] is the value of the ith node. You are also given a 0-indexed 2D integer array edges, where each edges[j] = [uj, vj, timej] indicates that there is an undirected edge between the nodes uj and vj, and it takes timej seconds to travel between the two nodes. Finally, you are given an integer maxTime.\n\t\tA valid path in the graph is any path that starts at node 0, ends at node 0, and takes at most maxTime seconds to complete. You may visit the same node multiple times. The quality of a valid path is the sum of the values of the unique nodes visited in the path (each node's value is added at most once to the sum).\n\t\tReturn the maximum quality of a valid path.\n\t\tNote: There are at most four edges connected to each node.\n\t\tExample 1:\n\t\tInput: values = [0,32,10,43], edges = [[0,1,10],[1,2,15],[0,3,10]], maxTime = 49\n\t\tOutput: 75\n\t\tExplanation:\n\t\tOne possible path is 0 -> 1 -> 0 -> 3 -> 0. The total time taken is 10 + 10 + 10 + 10 = 40 <= 49.\n\t\tThe nodes visited are 0, 1, and 3, giving a maximal path quality of 0 + 32 + 43 = 75.\n\t\tExample 2:\n\t\tInput: values = [5,10,15,20], edges = [[0,1,10],[1,2,10],[0,3,10]], maxTime = 30\n\t\tOutput: 25\n\t\tExplanation:\n\t\tOne possible path is 0 -> 3 -> 0. The total time taken is 10 + 10 = 20 <= 30.\n\t\tThe nodes visited are 0 and 3, giving a maximal path quality of 5 + 20 = 25.\n\t\tExample 3:\n\t\tInput: values = [1,2,3,4], edges = [[0,1,10],[1,2,11],[2,3,12],[1,3,13]], maxTime = 50\n\t\tOutput: 7\n\t\tExplanation:\n\t\tOne possible path is 0 -> 1 -> 3 -> 1 -> 0. The total time taken is 10 + 13 + 13 + 10 = 46 <= 50.\n\t\tThe nodes visited are 0, 1, and 3, giving a maximal path quality of 1 + 2 + 4 = 7.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 2190, - "question": "class Solution:\n def countWords(self, words1: List[str], words2: List[str]) -> int:\n\t\t\"\"\"\n\t\tGiven two string arrays words1 and words2, return the number of strings that appear exactly once in each of the two arrays.\n\t\tExample 1:\n\t\tInput: words1 = [\"leetcode\",\"is\",\"amazing\",\"as\",\"is\"], words2 = [\"amazing\",\"leetcode\",\"is\"]\n\t\tOutput: 2\n\t\tExplanation:\n\t\t- \"leetcode\" appears exactly once in each of the two arrays. We count this string.\n\t\t- \"amazing\" appears exactly once in each of the two arrays. We count this string.\n\t\t- \"is\" appears in each of the two arrays, but there are 2 occurrences of it in words1. We do not count this string.\n\t\t- \"as\" appears once in words1, but does not appear in words2. We do not count this string.\n\t\tThus, there are 2 strings that appear exactly once in each of the two arrays.\n\t\tExample 2:\n\t\tInput: words1 = [\"b\",\"bb\",\"bbb\"], words2 = [\"a\",\"aa\",\"aaa\"]\n\t\tOutput: 0\n\t\tExplanation: There are no strings that appear in each of the two arrays.\n\t\tExample 3:\n\t\tInput: words1 = [\"a\",\"ab\"], words2 = [\"a\",\"a\",\"a\",\"ab\"]\n\t\tOutput: 1\n\t\tExplanation: The only string that appears exactly once in each of the two arrays is \"ab\".\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 2191, - "question": "class Solution:\n def minimumBuckets(self, hamsters: str) -> int:\n\t\t\"\"\"\n\t\tYou are given a 0-indexed string hamsters where hamsters[i] is either:\n\t\t\t'H' indicating that there is a hamster at index i, or\n\t\t\t'.' indicating that index i is empty.\n\t\tYou will add some number of food buckets at the empty indices in order to feed the hamsters. A hamster can be fed if there is at least one food bucket to its left or to its right. More formally, a hamster at index i can be fed if you place a food bucket at index i - 1 and/or at index i + 1.\n\t\tReturn the minimum number of food buckets you should place at empty indices to feed all the hamsters or -1 if it is impossible to feed all of them.\n\t\tExample 1:\n\t\tInput: hamsters = \"H..H\"\n\t\tOutput: 2\n\t\tExplanation: We place two food buckets at indices 1 and 2.\n\t\tIt can be shown that if we place only one food bucket, one of the hamsters will not be fed.\n\t\tExample 2:\n\t\tInput: hamsters = \".H.H.\"\n\t\tOutput: 1\n\t\tExplanation: We place one food bucket at index 2.\n\t\tExample 3:\n\t\tInput: hamsters = \".HHH.\"\n\t\tOutput: -1\n\t\tExplanation: If we place a food bucket at every empty index as shown, the hamster at index 2 will not be able to eat.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 2192, - "question": "class Solution:\n def minCost(self, startPos: List[int], homePos: List[int], rowCosts: List[int], colCosts: List[int]) -> int:\n\t\t\"\"\"\n\t\tThere is an m x n grid, where (0, 0) is the top-left cell and (m - 1, n - 1) is the bottom-right cell. You are given an integer array startPos where startPos = [startrow, startcol] indicates that initially, a robot is at the cell (startrow, startcol). You are also given an integer array homePos where homePos = [homerow, homecol] indicates that its home is at the cell (homerow, homecol).\n\t\tThe robot needs to go to its home. It can move one cell in four directions: left, right, up, or down, and it can not move outside the boundary. Every move incurs some cost. You are further given two 0-indexed integer arrays: rowCosts of length m and colCosts of length n.\n\t\t\tIf the robot moves up or down into a cell whose row is r, then this move costs rowCosts[r].\n\t\t\tIf the robot moves left or right into a cell whose column is c, then this move costs colCosts[c].\n\t\tReturn the minimum total cost for this robot to return home.\n\t\tExample 1:\n\t\tInput: startPos = [1, 0], homePos = [2, 3], rowCosts = [5, 4, 3], colCosts = [8, 2, 6, 7]\n\t\tOutput: 18\n\t\tExplanation: One optimal path is that:\n\t\tStarting from (1, 0)\n\t\t-> It goes down to (2, 0). This move costs rowCosts[2] = 3.\n\t\t-> It goes right to (2, 1). This move costs colCosts[1] = 2.\n\t\t-> It goes right to (2, 2). This move costs colCosts[2] = 6.\n\t\t-> It goes right to (2, 3). This move costs colCosts[3] = 7.\n\t\tThe total cost is 3 + 2 + 6 + 7 = 18\n\t\tExample 2:\n\t\tInput: startPos = [0, 0], homePos = [0, 0], rowCosts = [5], colCosts = [26]\n\t\tOutput: 0\n\t\tExplanation: The robot is already at its home. Since no moves occur, the total cost is 0.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 2193, - "question": "class Solution:\n def countPyramids(self, grid: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tA farmer has a rectangular grid of land with m rows and n columns that can be divided into unit cells. Each cell is either fertile (represented by a 1) or barren (represented by a 0). All cells outside the grid are considered barren.\n\t\tA pyramidal plot of land can be defined as a set of cells with the following criteria:\n\t\t\tThe number of cells in the set has to be greater than 1 and all cells must be fertile.\n\t\t\tThe apex of a pyramid is the topmost cell of the pyramid. The height of a pyramid is the number of rows it covers. Let (r, c) be the apex of the pyramid, and its height be h. Then, the plot comprises of cells (i, j) where r <= i <= r + h - 1 and c - (i - r) <= j <= c + (i - r).\n\t\tAn inverse pyramidal plot of land can be defined as a set of cells with similar criteria:\n\t\t\tThe number of cells in the set has to be greater than 1 and all cells must be fertile.\n\t\t\tThe apex of an inverse pyramid is the bottommost cell of the inverse pyramid. The height of an inverse pyramid is the number of rows it covers. Let (r, c) be the apex of the pyramid, and its height be h. Then, the plot comprises of cells (i, j) where r - h + 1 <= i <= r and c - (r - i) <= j <= c + (r - i).\n\t\tSome examples of valid and invalid pyramidal (and inverse pyramidal) plots are shown below. Black cells indicate fertile cells.\n\t\tGiven a 0-indexed m x n binary matrix grid representing the farmland, return the total number of pyramidal and inverse pyramidal plots that can be found in grid.\n\t\tExample 1:\n\t\tInput: grid = [[0,1,1,0],[1,1,1,1]]\n\t\tOutput: 2\n\t\tExplanation: The 2 possible pyramidal plots are shown in blue and red respectively.\n\t\tThere are no inverse pyramidal plots in this grid. \n\t\tHence total number of pyramidal and inverse pyramidal plots is 2 + 0 = 2.\n\t\tExample 2:\n\t\tInput: grid = [[1,1,1],[1,1,1]]\n\t\tOutput: 2\n\t\tExplanation: The pyramidal plot is shown in blue, and the inverse pyramidal plot is shown in red. \n\t\tHence the total number of plots is 1 + 1 = 2.\n\t\tExample 3:\n\t\tInput: grid = [[1,1,1,1,0],[1,1,1,1,1],[1,1,1,1,1],[0,1,0,0,1]]\n\t\tOutput: 13\n\t\tExplanation: There are 7 pyramidal plots, 3 of which are shown in the 2nd and 3rd figures.\n\t\tThere are 6 inverse pyramidal plots, 2 of which are shown in the last figure.\n\t\tThe total number of plots is 7 + 6 = 13.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 2195, - "question": "class Solution:\n def timeRequiredToBuy(self, tickets: List[int], k: int) -> int:\n\t\t\"\"\"\n\t\tThere are n people in a line queuing to buy tickets, where the 0th person is at the front of the line and the (n - 1)th person is at the back of the line.\n\t\tYou are given a 0-indexed integer array tickets of length n where the number of tickets that the ith person would like to buy is tickets[i].\n\t\tEach person takes exactly 1 second to buy a ticket. A person can only buy 1 ticket at a time and has to go back to the end of the line (which happens instantaneously) in order to buy more tickets. If a person does not have any tickets left to buy, the person will leave the line.\n\t\tReturn the time taken for the person at position k (0-indexed) to finish buying tickets.\n\t\tExample 1:\n\t\tInput: tickets = [2,3,2], k = 2\n\t\tOutput: 6\n\t\tExplanation: \n\t\t- In the first pass, everyone in the line buys a ticket and the line becomes [1, 2, 1].\n\t\t- In the second pass, everyone in the line buys a ticket and the line becomes [0, 1, 0].\n\t\tThe person at position 2 has successfully bought 2 tickets and it took 3 + 3 = 6 seconds.\n\t\tExample 2:\n\t\tInput: tickets = [5,1,1,1], k = 0\n\t\tOutput: 8\n\t\tExplanation:\n\t\t- In the first pass, everyone in the line buys a ticket and the line becomes [4, 0, 0, 0].\n\t\t- In the next 4 passes, only the person in position 0 is buying tickets.\n\t\tThe person at position 0 has successfully bought 5 tickets and it took 4 + 1 + 1 + 1 + 1 = 8 seconds.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 2196, - "question": "class Solution:\n def reverseEvenLengthGroups(self, head: Optional[ListNode]) -> Optional[ListNode]:\n\t\t\"\"\"\n\t\tYou are given the head of a linked list.\n\t\tThe nodes in the linked list are sequentially assigned to non-empty groups whose lengths form the sequence of the natural numbers (1, 2, 3, 4, ...). The length of a group is the number of nodes assigned to it. In other words,\n\t\t\tThe 1st node is assigned to the first group.\n\t\t\tThe 2nd and the 3rd nodes are assigned to the second group.\n\t\t\tThe 4th, 5th, and 6th nodes are assigned to the third group, and so on.\n\t\tNote that the length of the last group may be less than or equal to 1 + the length of the second to last group.\n\t\tReverse the nodes in each group with an even length, and return the head of the modified linked list.\n\t\tExample 1:\n\t\tInput: head = [5,2,6,3,9,1,7,3,8,4]\n\t\tOutput: [5,6,2,3,9,1,4,8,3,7]\n\t\tExplanation:\n\t\t- The length of the first group is 1, which is odd, hence no reversal occurs.\n\t\t- The length of the second group is 2, which is even, hence the nodes are reversed.\n\t\t- The length of the third group is 3, which is odd, hence no reversal occurs.\n\t\t- The length of the last group is 4, which is even, hence the nodes are reversed.\n\t\tExample 2:\n\t\tInput: head = [1,1,0,6]\n\t\tOutput: [1,0,1,6]\n\t\tExplanation:\n\t\t- The length of the first group is 1. No reversal occurs.\n\t\t- The length of the second group is 2. The nodes are reversed.\n\t\t- The length of the last group is 1. No reversal occurs.\n\t\tExample 3:\n\t\tInput: head = [1,1,0,6,5]\n\t\tOutput: [1,0,1,5,6]\n\t\tExplanation:\n\t\t- The length of the first group is 1. No reversal occurs.\n\t\t- The length of the second group is 2. The nodes are reversed.\n\t\t- The length of the last group is 2. The nodes are reversed.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 2197, - "question": "class Solution:\n def decodeCiphertext(self, encodedText: str, rows: int) -> str:\n\t\t\"\"\"\n\t\tA string originalText is encoded using a slanted transposition cipher to a string encodedText with the help of a matrix having a fixed number of rows rows.\n\t\toriginalText is placed first in a top-left to bottom-right manner.\n\t\tThe blue cells are filled first, followed by the red cells, then the yellow cells, and so on, until we reach the end of originalText. The arrow indicates the order in which the cells are filled. All empty cells are filled with ' '. The number of columns is chosen such that the rightmost column will not be empty after filling in originalText.\n\t\tencodedText is then formed by appending all characters of the matrix in a row-wise fashion.\n\t\tThe characters in the blue cells are appended first to encodedText, then the red cells, and so on, and finally the yellow cells. The arrow indicates the order in which the cells are accessed.\n\t\tFor example, if originalText = \"cipher\" and rows = 3, then we encode it in the following manner:\n\t\tThe blue arrows depict how originalText is placed in the matrix, and the red arrows denote the order in which encodedText is formed. In the above example, encodedText = \"ch ie pr\".\n\t\tGiven the encoded string encodedText and number of rows rows, return the original string originalText.\n\t\tNote: originalText does not have any trailing spaces ' '. The test cases are generated such that there is only one possible originalText.\n\t\tExample 1:\n\t\tInput: encodedText = \"ch ie pr\", rows = 3\n\t\tOutput: \"cipher\"\n\t\tExplanation: This is the same example described in the problem description.\n\t\tExample 2:\n\t\tInput: encodedText = \"iveo eed l te olc\", rows = 4\n\t\tOutput: \"i love leetcode\"\n\t\tExplanation: The figure above denotes the matrix that was used to encode originalText. \n\t\tThe blue arrows show how we can find originalText from encodedText.\n\t\tExample 3:\n\t\tInput: encodedText = \"coding\", rows = 1\n\t\tOutput: \"coding\"\n\t\tExplanation: Since there is only 1 row, both originalText and encodedText are the same.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 2198, - "question": "class Solution:\n def friendRequests(self, n: int, restrictions: List[List[int]], requests: List[List[int]]) -> List[bool]:\n\t\t\"\"\"\n\t\tYou are given an integer n indicating the number of people in a network. Each person is labeled from 0 to n - 1.\n\t\tYou are also given a 0-indexed 2D integer array restrictions, where restrictions[i] = [xi, yi] means that person xi and person yi cannot become friends, either directly or indirectly through other people.\n\t\tInitially, no one is friends with each other. You are given a list of friend requests as a 0-indexed 2D integer array requests, where requests[j] = [uj, vj] is a friend request between person uj and person vj.\n\t\tA friend request is successful if uj and vj can be friends. Each friend request is processed in the given order (i.e., requests[j] occurs before requests[j + 1]), and upon a successful request, uj and vj become direct friends for all future friend requests.\n\t\tReturn a boolean array result, where each result[j] is true if the jth friend request is successful or false if it is not.\n\t\tNote: If uj and vj are already direct friends, the request is still successful.\n\t\tExample 1:\n\t\tInput: n = 3, restrictions = [[0,1]], requests = [[0,2],[2,1]]\n\t\tOutput: [true,false]\n\t\tExplanation:\n\t\tRequest 0: Person 0 and person 2 can be friends, so they become direct friends. \n\t\tRequest 1: Person 2 and person 1 cannot be friends since person 0 and person 1 would be indirect friends (1--2--0).\n\t\tExample 2:\n\t\tInput: n = 3, restrictions = [[0,1]], requests = [[1,2],[0,2]]\n\t\tOutput: [true,false]\n\t\tExplanation:\n\t\tRequest 0: Person 1 and person 2 can be friends, so they become direct friends.\n\t\tRequest 1: Person 0 and person 2 cannot be friends since person 0 and person 1 would be indirect friends (0--2--1).\n\t\tExample 3:\n\t\tInput: n = 5, restrictions = [[0,1],[1,2],[2,3]], requests = [[0,4],[1,2],[3,1],[3,4]]\n\t\tOutput: [true,false,true,false]\n\t\tExplanation:\n\t\tRequest 0: Person 0 and person 4 can be friends, so they become direct friends.\n\t\tRequest 1: Person 1 and person 2 cannot be friends since they are directly restricted.\n\t\tRequest 2: Person 3 and person 1 can be friends, so they become direct friends.\n\t\tRequest 3: Person 3 and person 4 cannot be friends since person 0 and person 1 would be indirect friends (0--4--3--1).\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 2199, - "question": "class Solution:\n def maxDistance(self, colors: List[int]) -> int:\n\t\t\"\"\"\n\t\tThere are n houses evenly lined up on the street, and each house is beautifully painted. You are given a 0-indexed integer array colors of length n, where colors[i] represents the color of the ith house.\n\t\tReturn the maximum distance between two houses with different colors.\n\t\tThe distance between the ith and jth houses is abs(i - j), where abs(x) is the absolute value of x.\n\t\tExample 1:\n\t\tInput: colors = [1,1,1,6,1,1,1]\n\t\tOutput: 3\n\t\tExplanation: In the above image, color 1 is blue, and color 6 is red.\n\t\tThe furthest two houses with different colors are house 0 and house 3.\n\t\tHouse 0 has color 1, and house 3 has color 6. The distance between them is abs(0 - 3) = 3.\n\t\tNote that houses 3 and 6 can also produce the optimal answer.\n\t\tExample 2:\n\t\tInput: colors = [1,8,3,8,3]\n\t\tOutput: 4\n\t\tExplanation: In the above image, color 1 is blue, color 8 is yellow, and color 3 is green.\n\t\tThe furthest two houses with different colors are house 0 and house 4.\n\t\tHouse 0 has color 1, and house 4 has color 3. The distance between them is abs(0 - 4) = 4.\n\t\tExample 3:\n\t\tInput: colors = [0,1]\n\t\tOutput: 1\n\t\tExplanation: The furthest two houses with different colors are house 0 and house 1.\n\t\tHouse 0 has color 0, and house 1 has color 1. The distance between them is abs(0 - 1) = 1.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 2200, - "question": "class Solution:\n def possibleToStamp(self, grid: List[List[int]], stampHeight: int, stampWidth: int) -> bool:\n\t\t\"\"\"\n\t\tYou are given an m x n binary matrix grid where each cell is either 0 (empty) or 1 (occupied).\n\t\tYou are then given stamps of size stampHeight x stampWidth. We want to fit the stamps such that they follow the given restrictions and requirements:\n\t\t\tCover all the empty cells.\n\t\t\tDo not cover any of the occupied cells.\n\t\t\tWe can put as many stamps as we want.\n\t\t\tStamps can overlap with each other.\n\t\t\tStamps are not allowed to be rotated.\n\t\t\tStamps must stay completely inside the grid.\n\t\tReturn true if it is possible to fit the stamps while following the given restrictions and requirements. Otherwise, return false.\n\t\tExample 1:\n\t\tInput: grid = [[1,0,0,0],[1,0,0,0],[1,0,0,0],[1,0,0,0],[1,0,0,0]], stampHeight = 4, stampWidth = 3\n\t\tOutput: true\n\t\tExplanation: We have two overlapping stamps (labeled 1 and 2 in the image) that are able to cover all the empty cells.\n\t\tExample 2:\n\t\tInput: grid = [[1,0,0,0],[0,1,0,0],[0,0,1,0],[0,0,0,1]], stampHeight = 2, stampWidth = 2 \n\t\tOutput: false \n\t\tExplanation: There is no way to fit the stamps onto all the empty cells without the stamps going outside the grid.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 2201, - "question": "class Solution:\n def validArrangement(self, pairs: List[List[int]]) -> List[List[int]]:\n\t\t\"\"\"\n\t\tYou are given a 0-indexed 2D integer array pairs where pairs[i] = [starti, endi]. An arrangement of pairs is valid if for every index i where 1 <= i < pairs.length, we have endi-1 == starti.\n\t\tReturn any valid arrangement of pairs.\n\t\tNote: The inputs will be generated such that there exists a valid arrangement of pairs.\n\t\tExample 1:\n\t\tInput: pairs = [[5,1],[4,5],[11,9],[9,4]]\n\t\tOutput: [[11,9],[9,4],[4,5],[5,1]]\n\t\tExplanation:\n\t\tThis is a valid arrangement since endi-1 always equals starti.\n\t\tend0 = 9 == 9 = start1 \n\t\tend1 = 4 == 4 = start2\n\t\tend2 = 5 == 5 = start3\n\t\tExample 2:\n\t\tInput: pairs = [[1,3],[3,2],[2,1]]\n\t\tOutput: [[1,3],[3,2],[2,1]]\n\t\tExplanation:\n\t\tThis is a valid arrangement since endi-1 always equals starti.\n\t\tend0 = 3 == 3 = start1\n\t\tend1 = 2 == 2 = start2\n\t\tThe arrangements [[2,1],[1,3],[3,2]] and [[3,2],[2,1],[1,3]] are also valid.\n\t\tExample 3:\n\t\tInput: pairs = [[1,2],[1,3],[2,1]]\n\t\tOutput: [[1,2],[2,1],[1,3]]\n\t\tExplanation:\n\t\tThis is a valid arrangement since endi-1 always equals starti.\n\t\tend0 = 2 == 2 = start1\n\t\tend1 = 1 == 1 = start2\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 2202, - "question": "class Solution:\n def kMirror(self, k: int, n: int) -> int:\n\t\t\"\"\"\n\t\tA k-mirror number is a positive integer without leading zeros that reads the same both forward and backward in base-10 as well as in base-k.\n\t\t\tFor example, 9 is a 2-mirror number. The representation of 9 in base-10 and base-2 are 9 and 1001 respectively, which read the same both forward and backward.\n\t\t\tOn the contrary, 4 is not a 2-mirror number. The representation of 4 in base-2 is 100, which does not read the same both forward and backward.\n\t\tGiven the base k and the number n, return the sum of the n smallest k-mirror numbers.\n\t\tExample 1:\n\t\tInput: k = 2, n = 5\n\t\tOutput: 25\n\t\tExplanation:\n\t\tThe 5 smallest 2-mirror numbers and their representations in base-2 are listed as follows:\n\t\t base-10 base-2\n\t\t 1 1\n\t\t 3 11\n\t\t 5 101\n\t\t 7 111\n\t\t 9 1001\n\t\tTheir sum = 1 + 3 + 5 + 7 + 9 = 25. \n\t\tExample 2:\n\t\tInput: k = 3, n = 7\n\t\tOutput: 499\n\t\tExplanation:\n\t\tThe 7 smallest 3-mirror numbers are and their representations in base-3 are listed as follows:\n\t\t base-10 base-3\n\t\t 1 1\n\t\t 2 2\n\t\t 4 11\n\t\t 8 22\n\t\t 121 11111\n\t\t 151 12121\n\t\t 212 21212\n\t\tTheir sum = 1 + 2 + 4 + 8 + 121 + 151 + 212 = 499.\n\t\tExample 3:\n\t\tInput: k = 7, n = 17\n\t\tOutput: 20379000\n\t\tExplanation: The 17 smallest 7-mirror numbers are:\n\t\t1, 2, 3, 4, 5, 6, 8, 121, 171, 242, 292, 16561, 65656, 2137312, 4602064, 6597956, 6958596\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 2204, - "question": "class Solution:\n def maxSubsequence(self, nums: List[int], k: int) -> List[int]:\n\t\t\"\"\"\n\t\tYou are given an integer array nums and an integer k. You want to find a subsequence of nums of length k that has the largest sum.\n\t\tReturn any such subsequence as an integer array of length k.\n\t\tA subsequence is an array that can be derived from another array by deleting some or no elements without changing the order of the remaining elements.\n\t\tExample 1:\n\t\tInput: nums = [2,1,3,3], k = 2\n\t\tOutput: [3,3]\n\t\tExplanation:\n\t\tThe subsequence has the largest sum of 3 + 3 = 6.\n\t\tExample 2:\n\t\tInput: nums = [-1,-2,3,4], k = 3\n\t\tOutput: [-1,3,4]\n\t\tExplanation: \n\t\tThe subsequence has the largest sum of -1 + 3 + 4 = 6.\n\t\tExample 3:\n\t\tInput: nums = [3,4,3,3], k = 2\n\t\tOutput: [3,4]\n\t\tExplanation:\n\t\tThe subsequence has the largest sum of 3 + 4 = 7. \n\t\tAnother possible subsequence is [4, 3].\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 2205, - "question": "class Solution:\n def goodDaysToRobBank(self, security: List[int], time: int) -> List[int]:\n\t\t\"\"\"\n\t\tYou and a gang of thieves are planning on robbing a bank. You are given a 0-indexed integer array security, where security[i] is the number of guards on duty on the ith day. The days are numbered starting from 0. You are also given an integer time.\n\t\tThe ith day is a good day to rob the bank if:\n\t\t\tThere are at least time days before and after the ith day,\n\t\t\tThe number of guards at the bank for the time days before i are non-increasing, and\n\t\t\tThe number of guards at the bank for the time days after i are non-decreasing.\n\t\tMore formally, this means day i is a good day to rob the bank if and only if security[i - time] >= security[i - time + 1] >= ... >= security[i] <= ... <= security[i + time - 1] <= security[i + time].\n\t\tReturn a list of all days (0-indexed) that are good days to rob the bank. The order that the days are returned in does not matter.\n\t\tExample 1:\n\t\tInput: security = [5,3,3,3,5,6,2], time = 2\n\t\tOutput: [2,3]\n\t\tExplanation:\n\t\tOn day 2, we have security[0] >= security[1] >= security[2] <= security[3] <= security[4].\n\t\tOn day 3, we have security[1] >= security[2] >= security[3] <= security[4] <= security[5].\n\t\tNo other days satisfy this condition, so days 2 and 3 are the only good days to rob the bank.\n\t\tExample 2:\n\t\tInput: security = [1,1,1,1,1], time = 0\n\t\tOutput: [0,1,2,3,4]\n\t\tExplanation:\n\t\tSince time equals 0, every day is a good day to rob the bank, so return every day.\n\t\tExample 3:\n\t\tInput: security = [1,2,3,4,5,6], time = 2\n\t\tOutput: []\n\t\tExplanation:\n\t\tNo day has 2 days before it that have a non-increasing number of guards.\n\t\tThus, no day is a good day to rob the bank, so return an empty list.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 2206, - "question": "class Solution:\n def maximumDetonation(self, bombs: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tYou are given a list of bombs. The range of a bomb is defined as the area where its effect can be felt. This area is in the shape of a circle with the center as the location of the bomb.\n\t\tThe bombs are represented by a 0-indexed 2D integer array bombs where bombs[i] = [xi, yi, ri]. xi and yi denote the X-coordinate and Y-coordinate of the location of the ith bomb, whereas ri denotes the radius of its range.\n\t\tYou may choose to detonate a single bomb. When a bomb is detonated, it will detonate all bombs that lie in its range. These bombs will further detonate the bombs that lie in their ranges.\n\t\tGiven the list of bombs, return the maximum number of bombs that can be detonated if you are allowed to detonate only one bomb.\n\t\tExample 1:\n\t\tInput: bombs = [[2,1,3],[6,1,4]]\n\t\tOutput: 2\n\t\tExplanation:\n\t\tThe above figure shows the positions and ranges of the 2 bombs.\n\t\tIf we detonate the left bomb, the right bomb will not be affected.\n\t\tBut if we detonate the right bomb, both bombs will be detonated.\n\t\tSo the maximum bombs that can be detonated is max(1, 2) = 2.\n\t\tExample 2:\n\t\tInput: bombs = [[1,1,5],[10,10,5]]\n\t\tOutput: 1\n\t\tExplanation:\n\t\tDetonating either bomb will not detonate the other bomb, so the maximum number of bombs that can be detonated is 1.\n\t\tExample 3:\n\t\tInput: bombs = [[1,2,3],[2,3,1],[3,4,2],[4,5,3],[5,6,4]]\n\t\tOutput: 5\n\t\tExplanation:\n\t\tThe best bomb to detonate is bomb 0 because:\n\t\t- Bomb 0 detonates bombs 1 and 2. The red circle denotes the range of bomb 0.\n\t\t- Bomb 2 detonates bomb 3. The blue circle denotes the range of bomb 2.\n\t\t- Bomb 3 detonates bomb 4. The green circle denotes the range of bomb 3.\n\t\tThus all 5 bombs are detonated.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 2207, - "question": "class SORTracker:\n def __init__(self):\n def add(self, name: str, score: int) -> None:\n def get(self) -> str:\n\t\t\"\"\"\n\t\tA scenic location is represented by its name and attractiveness score, where name is a unique string among all locations and score is an integer. Locations can be ranked from the best to the worst. The higher the score, the better the location. If the scores of two locations are equal, then the location with the lexicographically smaller name is better.\n\t\tYou are building a system that tracks the ranking of locations with the system initially starting with no locations. It supports:\n\t\t\tAdding scenic locations, one at a time.\n\t\t\tQuerying the ith best location of all locations already added, where i is the number of times the system has been queried (including the current query).\n\t\t\t\tFor example, when the system is queried for the 4th time, it returns the 4th best location of all locations already added.\n\t\tNote that the test data are generated so that at any time, the number of queries does not exceed the number of locations added to the system.\n\t\tImplement the SORTracker class:\n\t\t\tSORTracker() Initializes the tracker system.\n\t\t\tvoid add(string name, int score) Adds a scenic location with name and score to the system.\n\t\t\tstring get() Queries and returns the ith best location, where i is the number of times this method has been invoked (including this invocation).\n\t\tExample 1:\n\t\tInput\n\t\t[\"SORTracker\", \"add\", \"add\", \"get\", \"add\", \"get\", \"add\", \"get\", \"add\", \"get\", \"add\", \"get\", \"get\"]\n\t\t[[], [\"bradford\", 2], [\"branford\", 3], [], [\"alps\", 2], [], [\"orland\", 2], [], [\"orlando\", 3], [], [\"alpine\", 2], [], []]\n\t\tOutput\n\t\t[null, null, null, \"branford\", null, \"alps\", null, \"bradford\", null, \"bradford\", null, \"bradford\", \"orland\"]\n\t\tExplanation\n\t\tSORTracker tracker = new SORTracker(); // Initialize the tracker system.\n\t\ttracker.add(\"bradford\", 2); // Add location with name=\"bradford\" and score=2 to the system.\n\t\ttracker.add(\"branford\", 3); // Add location with name=\"branford\" and score=3 to the system.\n\t\ttracker.get(); // The sorted locations, from best to worst, are: branford, bradford.\n\t\t // Note that branford precedes bradford due to its higher score (3 > 2).\n\t\t // This is the 1st time get() is called, so return the best location: \"branford\".\n\t\ttracker.add(\"alps\", 2); // Add location with name=\"alps\" and score=2 to the system.\n\t\ttracker.get(); // Sorted locations: branford, alps, bradford.\n\t\t // Note that alps precedes bradford even though they have the same score (2).\n\t\t // This is because \"alps\" is lexicographically smaller than \"bradford\".\n\t\t // Return the 2nd best location \"alps\", as it is the 2nd time get() is called.\n\t\ttracker.add(\"orland\", 2); // Add location with name=\"orland\" and score=2 to the system.\n\t\ttracker.get(); // Sorted locations: branford, alps, bradford, orland.\n\t\t // Return \"bradford\", as it is the 3rd time get() is called.\n\t\ttracker.add(\"orlando\", 3); // Add location with name=\"orlando\" and score=3 to the system.\n\t\ttracker.get(); // Sorted locations: branford, orlando, alps, bradford, orland.\n\t\t // Return \"bradford\".\n\t\ttracker.add(\"alpine\", 2); // Add location with name=\"alpine\" and score=2 to the system.\n\t\ttracker.get(); // Sorted locations: branford, orlando, alpine, alps, bradford, orland.\n\t\t // Return \"bradford\".\n\t\ttracker.get(); // Sorted locations: branford, orlando, alpine, alps, bradford, orland.\n\t\t // Return \"orland\".\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 2210, - "question": "class Solution:\n def targetIndices(self, nums: List[int], target: int) -> List[int]:\n\t\t\"\"\"\n\t\tYou are given a 0-indexed integer array nums and a target element target.\n\t\tA target index is an index i such that nums[i] == target.\n\t\tReturn a list of the target indices of nums after sorting nums in non-decreasing order. If there are no target indices, return an empty list. The returned list must be sorted in increasing order.\n\t\tExample 1:\n\t\tInput: nums = [1,2,5,2,3], target = 2\n\t\tOutput: [1,2]\n\t\tExplanation: After sorting, nums is [1,2,2,3,5].\n\t\tThe indices where nums[i] == 2 are 1 and 2.\n\t\tExample 2:\n\t\tInput: nums = [1,2,5,2,3], target = 3\n\t\tOutput: [3]\n\t\tExplanation: After sorting, nums is [1,2,2,3,5].\n\t\tThe index where nums[i] == 3 is 3.\n\t\tExample 3:\n\t\tInput: nums = [1,2,5,2,3], target = 5\n\t\tOutput: [4]\n\t\tExplanation: After sorting, nums is [1,2,2,3,5].\n\t\tThe index where nums[i] == 5 is 4.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 2211, - "question": "class Solution:\n def getAverages(self, nums: List[int], k: int) -> List[int]:\n\t\t\"\"\"\n\t\tYou are given a 0-indexed array nums of n integers, and an integer k.\n\t\tThe k-radius average for a subarray of nums centered at some index i with the radius k is the average of all elements in nums between the indices i - k and i + k (inclusive). If there are less than k elements before or after the index i, then the k-radius average is -1.\n\t\tBuild and return an array avgs of length n where avgs[i] is the k-radius average for the subarray centered at index i.\n\t\tThe average of x elements is the sum of the x elements divided by x, using integer division. The integer division truncates toward zero, which means losing its fractional part.\n\t\t\tFor example, the average of four elements 2, 3, 1, and 5 is (2 + 3 + 1 + 5) / 4 = 11 / 4 = 2.75, which truncates to 2.\n\t\tExample 1:\n\t\tInput: nums = [7,4,3,9,1,8,5,2,6], k = 3\n\t\tOutput: [-1,-1,-1,5,4,4,-1,-1,-1]\n\t\tExplanation:\n\t\t- avg[0], avg[1], and avg[2] are -1 because there are less than k elements before each index.\n\t\t- The sum of the subarray centered at index 3 with radius 3 is: 7 + 4 + 3 + 9 + 1 + 8 + 5 = 37.\n\t\t Using integer division, avg[3] = 37 / 7 = 5.\n\t\t- For the subarray centered at index 4, avg[4] = (4 + 3 + 9 + 1 + 8 + 5 + 2) / 7 = 4.\n\t\t- For the subarray centered at index 5, avg[5] = (3 + 9 + 1 + 8 + 5 + 2 + 6) / 7 = 4.\n\t\t- avg[6], avg[7], and avg[8] are -1 because there are less than k elements after each index.\n\t\tExample 2:\n\t\tInput: nums = [100000], k = 0\n\t\tOutput: [100000]\n\t\tExplanation:\n\t\t- The sum of the subarray centered at index 0 with radius 0 is: 100000.\n\t\t avg[0] = 100000 / 1 = 100000.\n\t\tExample 3:\n\t\tInput: nums = [8], k = 100000\n\t\tOutput: [-1]\n\t\tExplanation: \n\t\t- avg[0] is -1 because there are less than k elements before and after index 0.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 2212, - "question": "class Solution:\n def minimumDeletions(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou are given a 0-indexed array of distinct integers nums.\n\t\tThere is an element in nums that has the lowest value and an element that has the highest value. We call them the minimum and maximum respectively. Your goal is to remove both these elements from the array.\n\t\tA deletion is defined as either removing an element from the front of the array or removing an element from the back of the array.\n\t\tReturn the minimum number of deletions it would take to remove both the minimum and maximum element from the array.\n\t\tExample 1:\n\t\tInput: nums = [2,10,7,5,4,1,8,6]\n\t\tOutput: 5\n\t\tExplanation: \n\t\tThe minimum element in the array is nums[5], which is 1.\n\t\tThe maximum element in the array is nums[1], which is 10.\n\t\tWe can remove both the minimum and maximum by removing 2 elements from the front and 3 elements from the back.\n\t\tThis results in 2 + 3 = 5 deletions, which is the minimum number possible.\n\t\tExample 2:\n\t\tInput: nums = [0,-4,19,1,8,-2,-3,5]\n\t\tOutput: 3\n\t\tExplanation: \n\t\tThe minimum element in the array is nums[1], which is -4.\n\t\tThe maximum element in the array is nums[2], which is 19.\n\t\tWe can remove both the minimum and maximum by removing 3 elements from the front.\n\t\tThis results in only 3 deletions, which is the minimum number possible.\n\t\tExample 3:\n\t\tInput: nums = [101]\n\t\tOutput: 1\n\t\tExplanation: \n\t\tThere is only one element in the array, which makes it both the minimum and maximum element.\n\t\tWe can remove it with 1 deletion.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 2213, - "question": "class Solution:\n def findAllPeople(self, n: int, meetings: List[List[int]], firstPerson: int) -> List[int]:\n\t\t\"\"\"\n\t\tYou are given an integer n indicating there are n people numbered from 0 to n - 1. You are also given a 0-indexed 2D integer array meetings where meetings[i] = [xi, yi, timei] indicates that person xi and person yi have a meeting at timei. A person may attend multiple meetings at the same time. Finally, you are given an integer firstPerson.\n\t\tPerson 0 has a secret and initially shares the secret with a person firstPerson at time 0. This secret is then shared every time a meeting takes place with a person that has the secret. More formally, for every meeting, if a person xi has the secret at timei, then they will share the secret with person yi, and vice versa.\n\t\tThe secrets are shared instantaneously. That is, a person may receive the secret and share it with people in other meetings within the same time frame.\n\t\tReturn a list of all the people that have the secret after all the meetings have taken place. You may return the answer in any order.\n\t\tExample 1:\n\t\tInput: n = 6, meetings = [[1,2,5],[2,3,8],[1,5,10]], firstPerson = 1\n\t\tOutput: [0,1,2,3,5]\n\t\tExplanation:\n\t\tAt time 0, person 0 shares the secret with person 1.\n\t\tAt time 5, person 1 shares the secret with person 2.\n\t\tAt time 8, person 2 shares the secret with person 3.\n\t\tAt time 10, person 1 shares the secret with person 5.\u200b\u200b\u200b\u200b\n\t\tThus, people 0, 1, 2, 3, and 5 know the secret after all the meetings.\n\t\tExample 2:\n\t\tInput: n = 4, meetings = [[3,1,3],[1,2,2],[0,3,3]], firstPerson = 3\n\t\tOutput: [0,1,3]\n\t\tExplanation:\n\t\tAt time 0, person 0 shares the secret with person 3.\n\t\tAt time 2, neither person 1 nor person 2 know the secret.\n\t\tAt time 3, person 3 shares the secret with person 0 and person 1.\n\t\tThus, people 0, 1, and 3 know the secret after all the meetings.\n\t\tExample 3:\n\t\tInput: n = 5, meetings = [[3,4,2],[1,2,1],[2,3,1]], firstPerson = 1\n\t\tOutput: [0,1,2,3,4]\n\t\tExplanation:\n\t\tAt time 0, person 0 shares the secret with person 1.\n\t\tAt time 1, person 1 shares the secret with person 2, and person 2 shares the secret with person 3.\n\t\tNote that person 2 can share the secret at the same time as receiving it.\n\t\tAt time 2, person 3 shares the secret with person 4.\n\t\tThus, people 0, 1, 2, 3, and 4 know the secret after all the meetings.\n\t\t\"\"\"\n", - "difficulty": 2 - }, - { - "number": 2215, - "question": "class Solution:\n def findEvenNumbers(self, digits: List[int]) -> List[int]:\n\t\t\"\"\"\n\t\tYou are given an integer array digits, where each element is a digit. The array may contain duplicates.\n\t\tYou need to find all the unique integers that follow the given requirements:\n\t\t\tThe integer consists of the concatenation of three elements from digits in any arbitrary order.\n\t\t\tThe integer does not have leading zeros.\n\t\t\tThe integer is even.\n\t\tFor example, if the given digits were [1, 2, 3], integers 132 and 312 follow the requirements.\n\t\tReturn a sorted array of the unique integers.\n\t\tExample 1:\n\t\tInput: digits = [2,1,3,0]\n\t\tOutput: [102,120,130,132,210,230,302,310,312,320]\n\t\tExplanation: All the possible integers that follow the requirements are in the output array. \n\t\tNotice that there are no odd integers or integers with leading zeros.\n\t\tExample 2:\n\t\tInput: digits = [2,2,8,8,2]\n\t\tOutput: [222,228,282,288,822,828,882]\n\t\tExplanation: The same digit can be used as many times as it appears in digits. \n\t\tIn this example, the digit 8 is used twice each time in 288, 828, and 882. \n\t\tExample 3:\n\t\tInput: digits = [3,7,5]\n\t\tOutput: []\n\t\tExplanation: No even integers can be formed using the given digits.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 2216, - "question": "class Solution:\n def deleteMiddle(self, head: Optional[ListNode]) -> Optional[ListNode]:\n\t\t\"\"\"\n\t\tYou are given the head of a linked list. Delete the middle node, and return the head of the modified linked list.\n\t\tThe middle node of a linked list of size n is the \u230an / 2\u230bth node from the start using 0-based indexing, where \u230ax\u230b denotes the largest integer less than or equal to x.\n\t\t\tFor n = 1, 2, 3, 4, and 5, the middle nodes are 0, 1, 1, 2, and 2, respectively.\n\t\tExample 1:\n\t\tInput: head = [1,3,4,7,1,2,6]\n\t\tOutput: [1,3,4,1,2,6]\n\t\tExplanation:\n\t\tThe above figure represents the given linked list. The indices of the nodes are written below.\n\t\tSince n = 7, node 3 with value 7 is the middle node, which is marked in red.\n\t\tWe return the new list after removing this node. \n\t\tExample 2:\n\t\tInput: head = [1,2,3,4]\n\t\tOutput: [1,2,4]\n\t\tExplanation:\n\t\tThe above figure represents the given linked list.\n\t\tFor n = 4, node 2 with value 3 is the middle node, which is marked in red.\n\t\tExample 3:\n\t\tInput: head = [2,1]\n\t\tOutput: [2]\n\t\tExplanation:\n\t\tThe above figure represents the given linked list.\n\t\tFor n = 2, node 1 with value 1 is the middle node, which is marked in red.\n\t\tNode 0 with value 2 is the only node remaining after removing node 1.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 2217, - "question": "class Solution:\n def getDirections(self, root: Optional[TreeNode], startValue: int, destValue: int) -> str:\n\t\t\"\"\"\n\t\tYou are given the root of a binary tree with n nodes. Each node is uniquely assigned a value from 1 to n. You are also given an integer startValue representing the value of the start node s, and a different integer destValue representing the value of the destination node t.\n\t\tFind the shortest path starting from node s and ending at node t. Generate step-by-step directions of such path as a string consisting of only the uppercase letters 'L', 'R', and 'U'. Each letter indicates a specific direction:\n\t\t\t'L' means to go from a node to its left child node.\n\t\t\t'R' means to go from a node to its right child node.\n\t\t\t'U' means to go from a node to its parent node.\n\t\tReturn the step-by-step directions of the shortest path from node s to node t.\n\t\tExample 1:\n\t\tInput: root = [5,1,2,3,null,6,4], startValue = 3, destValue = 6\n\t\tOutput: \"UURL\"\n\t\tExplanation: The shortest path is: 3 \u2192 1 \u2192 5 \u2192 2 \u2192 6.\n\t\tExample 2:\n\t\tInput: root = [2,1], startValue = 2, destValue = 1\n\t\tOutput: \"L\"\n\t\tExplanation: The shortest path is: 2 \u2192 1.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 2219, - "question": "class Solution:\n def mostWordsFound(self, sentences: List[str]) -> int:\n\t\t\"\"\"\n\t\tA sentence is a list of words that are separated by a single space with no leading or trailing spaces.\n\t\tYou are given an array of strings sentences, where each sentences[i] represents a single sentence.\n\t\tReturn the maximum number of words that appear in a single sentence.\n\t\tExample 1:\n\t\tInput: sentences = [\"alice and bob love leetcode\", \"i think so too\", \"this is great thanks very much\"]\n\t\tOutput: 6\n\t\tExplanation: \n\t\t- The first sentence, \"alice and bob love leetcode\", has 5 words in total.\n\t\t- The second sentence, \"i think so too\", has 4 words in total.\n\t\t- The third sentence, \"this is great thanks very much\", has 6 words in total.\n\t\tThus, the maximum number of words in a single sentence comes from the third sentence, which has 6 words.\n\t\tExample 2:\n\t\tInput: sentences = [\"please wait\", \"continue to fight\", \"continue to win\"]\n\t\tOutput: 3\n\t\tExplanation: It is possible that multiple sentences contain the same number of words. \n\t\tIn this example, the second and third sentences (underlined) have the same number of words.\n\t\t\"\"\"\n", - "difficulty": 0 - }, - { - "number": 2220, - "question": "class Solution:\n def findAllRecipes(self, recipes: List[str], ingredients: List[List[str]], supplies: List[str]) -> List[str]:\n\t\t\"\"\"\n\t\tYou have information about n different recipes. You are given a string array recipes and a 2D string array ingredients. The ith recipe has the name recipes[i], and you can create it if you have all the needed ingredients from ingredients[i]. Ingredients to a recipe may need to be created from other recipes, i.e., ingredients[i] may contain a string that is in recipes.\n\t\tYou are also given a string array supplies containing all the ingredients that you initially have, and you have an infinite supply of all of them.\n\t\tReturn a list of all the recipes that you can create. You may return the answer in any order.\n\t\tNote that two recipes may contain each other in their ingredients.\n\t\tExample 1:\n\t\tInput: recipes = [\"bread\"], ingredients = [[\"yeast\",\"flour\"]], supplies = [\"yeast\",\"flour\",\"corn\"]\n\t\tOutput: [\"bread\"]\n\t\tExplanation:\n\t\tWe can create \"bread\" since we have the ingredients \"yeast\" and \"flour\".\n\t\tExample 2:\n\t\tInput: recipes = [\"bread\",\"sandwich\"], ingredients = [[\"yeast\",\"flour\"],[\"bread\",\"meat\"]], supplies = [\"yeast\",\"flour\",\"meat\"]\n\t\tOutput: [\"bread\",\"sandwich\"]\n\t\tExplanation:\n\t\tWe can create \"bread\" since we have the ingredients \"yeast\" and \"flour\".\n\t\tWe can create \"sandwich\" since we have the ingredient \"meat\" and can create the ingredient \"bread\".\n\t\tExample 3:\n\t\tInput: recipes = [\"bread\",\"sandwich\",\"burger\"], ingredients = [[\"yeast\",\"flour\"],[\"bread\",\"meat\"],[\"sandwich\",\"meat\",\"bread\"]], supplies = [\"yeast\",\"flour\",\"meat\"]\n\t\tOutput: [\"bread\",\"sandwich\",\"burger\"]\n\t\tExplanation:\n\t\tWe can create \"bread\" since we have the ingredients \"yeast\" and \"flour\".\n\t\tWe can create \"sandwich\" since we have the ingredient \"meat\" and can create the ingredient \"bread\".\n\t\tWe can create \"burger\" since we have the ingredient \"meat\" and can create the ingredients \"bread\" and \"sandwich\".\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 2221, - "question": "class Solution:\n def canBeValid(self, s: str, locked: str) -> bool:\n\t\t\"\"\"\n\t\tA parentheses string is a non-empty string consisting only of '(' and ')'. It is valid if any of the following conditions is true:\n\t\t\tIt is ().\n\t\t\tIt can be written as AB (A concatenated with B), where A and B are valid parentheses strings.\n\t\t\tIt can be written as (A), where A is a valid parentheses string.\n\t\tYou are given a parentheses string s and a string locked, both of length n. locked is a binary string consisting only of '0's and '1's. For each index i of locked,\n\t\t\tIf locked[i] is '1', you cannot change s[i].\n\t\t\tBut if locked[i] is '0', you can change s[i] to either '(' or ')'.\n\t\tReturn true if you can make s a valid parentheses string. Otherwise, return false.\n\t\tExample 1:\n\t\tInput: s = \"))()))\", locked = \"010100\"\n\t\tOutput: true\n\t\tExplanation: locked[1] == '1' and locked[3] == '1', so we cannot change s[1] or s[3].\n\t\tWe change s[0] and s[4] to '(' while leaving s[2] and s[5] unchanged to make s valid.\n\t\tExample 2:\n\t\tInput: s = \"()()\", locked = \"0000\"\n\t\tOutput: true\n\t\tExplanation: We do not need to make any changes because s is already valid.\n\t\tExample 3:\n\t\tInput: s = \")\", locked = \"0\"\n\t\tOutput: false\n\t\tExplanation: locked permits us to change s[0]. \n\t\tChanging s[0] to either '(' or ')' will not make s valid.\n\t\t\"\"\"\n", - "difficulty": 1 - }, - { - "number": 2222, - "question": "class Solution:\n def abbreviateProduct(self, left: int, right: int) -> str:\n\t\t\"\"\"\n\t\tYou are given two positive integers left and right with left <= right. Calculate the product of all integers in the inclusive range [left, right].\n\t\tSince the product may be very large, you will abbreviate it following these steps:\n\t\t\tCount all trailing zeros in the product and remove them. Let us denote this count as C.\n\t\t\t\tFor example, there are 3 trailing zeros in 1000, and there are 0 trailing zeros in 546.\n\t\t\tDenote the remaining number of digits in the product as d. If d > 10, then express the product as 
... where 
 denotes the first 5 digits of the product, and  denotes the last 5 digits of the product after removing all trailing zeros. If d <= 10, we keep it unchanged.\n\t\t\t\tFor example, we express 1234567654321 as 12345...54321, but 1234567 is represented as 1234567.\n\t\t\tFinally, represent the product as a string \"
...eC\".\n\t\t\t\tFor example, 12345678987600000 will be represented as \"12345...89876e5\".\n\t\tReturn a string denoting the abbreviated product of all integers in the inclusive range [left, right].\n\t\tExample 1:\n\t\tInput: left = 1, right = 4\n\t\tOutput: \"24e0\"\n\t\tExplanation: The product is 1 \u00d7 2 \u00d7 3 \u00d7 4 = 24.\n\t\tThere are no trailing zeros, so 24 remains the same. The abbreviation will end with \"e0\".\n\t\tSince the number of digits is 2, which is less than 10, we do not have to abbreviate it further.\n\t\tThus, the final representation is \"24e0\".\n\t\tExample 2:\n\t\tInput: left = 2, right = 11\n\t\tOutput: \"399168e2\"\n\t\tExplanation: The product is 39916800.\n\t\tThere are 2 trailing zeros, which we remove to get 399168. The abbreviation will end with \"e2\".\n\t\tThe number of digits after removing the trailing zeros is 6, so we do not abbreviate it further.\n\t\tHence, the abbreviated product is \"399168e2\".\n\t\tExample 3:\n\t\tInput: left = 371, right = 375\n\t\tOutput: \"7219856259e3\"\n\t\tExplanation: The product is 7219856259000.\n\t\t\"\"\"\n",
-        "difficulty": 2
-    },
-    {
-        "number": 2226,
-        "question": "class Solution:\n    def countPoints(self, rings: str) -> int:\n\t\t\"\"\"\n\t\tThere are n rings and each ring is either red, green, or blue. The rings are distributed across ten rods labeled from 0 to 9.\n\t\tYou are given a string rings of length 2n that describes the n rings that are placed onto the rods. Every two characters in rings forms a color-position pair that is used to describe each ring where:\n\t\t\tThe first character of the ith pair denotes the ith ring's color ('R', 'G', 'B').\n\t\t\tThe second character of the ith pair denotes the rod that the ith ring is placed on ('0' to '9').\n\t\tFor example, \"R3G2B1\" describes n == 3 rings: a red ring placed onto the rod labeled 3, a green ring placed onto the rod labeled 2, and a blue ring placed onto the rod labeled 1.\n\t\tReturn the number of rods that have all three colors of rings on them.\n\t\tExample 1:\n\t\tInput: rings = \"B0B6G0R6R0R6G9\"\n\t\tOutput: 1\n\t\tExplanation: \n\t\t- The rod labeled 0 holds 3 rings with all colors: red, green, and blue.\n\t\t- The rod labeled 6 holds 3 rings, but it only has red and blue.\n\t\t- The rod labeled 9 holds only a green ring.\n\t\tThus, the number of rods with all three colors is 1.\n\t\tExample 2:\n\t\tInput: rings = \"B0R0G0R9R0B0G0\"\n\t\tOutput: 1\n\t\tExplanation: \n\t\t- The rod labeled 0 holds 6 rings with all colors: red, green, and blue.\n\t\t- The rod labeled 9 holds only a red ring.\n\t\tThus, the number of rods with all three colors is 1.\n\t\tExample 3:\n\t\tInput: rings = \"G4\"\n\t\tOutput: 0\n\t\tExplanation: \n\t\tOnly one ring is given. Thus, no rods have all three colors.\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 2227,
-        "question": "class Solution:\n    def subArrayRanges(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou are given an integer array nums. The range of a subarray of nums is the difference between the largest and smallest element in the subarray.\n\t\tReturn the sum of all subarray ranges of nums.\n\t\tA subarray is a contiguous non-empty sequence of elements within an array.\n\t\tExample 1:\n\t\tInput: nums = [1,2,3]\n\t\tOutput: 4\n\t\tExplanation: The 6 subarrays of nums are the following:\n\t\t[1], range = largest - smallest = 1 - 1 = 0 \n\t\t[2], range = 2 - 2 = 0\n\t\t[3], range = 3 - 3 = 0\n\t\t[1,2], range = 2 - 1 = 1\n\t\t[2,3], range = 3 - 2 = 1\n\t\t[1,2,3], range = 3 - 1 = 2\n\t\tSo the sum of all ranges is 0 + 0 + 0 + 1 + 1 + 2 = 4.\n\t\tExample 2:\n\t\tInput: nums = [1,3,3]\n\t\tOutput: 4\n\t\tExplanation: The 6 subarrays of nums are the following:\n\t\t[1], range = largest - smallest = 1 - 1 = 0\n\t\t[3], range = 3 - 3 = 0\n\t\t[3], range = 3 - 3 = 0\n\t\t[1,3], range = 3 - 1 = 2\n\t\t[3,3], range = 3 - 3 = 0\n\t\t[1,3,3], range = 3 - 1 = 2\n\t\tSo the sum of all ranges is 0 + 0 + 0 + 2 + 0 + 2 = 4.\n\t\tExample 3:\n\t\tInput: nums = [4,-2,-3,4,1]\n\t\tOutput: 59\n\t\tExplanation: The sum of all subarray ranges of nums is 59.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2228,
-        "question": "class Solution:\n    def minimumRefill(self, plants: List[int], capacityA: int, capacityB: int) -> int:\n\t\t\"\"\"\n\t\tAlice and Bob want to water n plants in their garden. The plants are arranged in a row and are labeled from 0 to n - 1 from left to right where the ith plant is located at x = i.\n\t\tEach plant needs a specific amount of water. Alice and Bob have a watering can each, initially full. They water the plants in the following way:\n\t\t\tAlice waters the plants in order from left to right, starting from the 0th plant. Bob waters the plants in order from right to left, starting from the (n - 1)th plant. They begin watering the plants simultaneously.\n\t\t\tIt takes the same amount of time to water each plant regardless of how much water it needs.\n\t\t\tAlice/Bob must water the plant if they have enough in their can to fully water it. Otherwise, they first refill their can (instantaneously) then water the plant.\n\t\t\tIn case both Alice and Bob reach the same plant, the one with more water currently in his/her watering can should water this plant. If they have the same amount of water, then Alice should water this plant.\n\t\tGiven a 0-indexed integer array plants of n integers, where plants[i] is the amount of water the ith plant needs, and two integers capacityA and capacityB representing the capacities of Alice's and Bob's watering cans respectively, return the number of times they have to refill to water all the plants.\n\t\tExample 1:\n\t\tInput: plants = [2,2,3,3], capacityA = 5, capacityB = 5\n\t\tOutput: 1\n\t\tExplanation:\n\t\t- Initially, Alice and Bob have 5 units of water each in their watering cans.\n\t\t- Alice waters plant 0, Bob waters plant 3.\n\t\t- Alice and Bob now have 3 units and 2 units of water respectively.\n\t\t- Alice has enough water for plant 1, so she waters it. Bob does not have enough water for plant 2, so he refills his can then waters it.\n\t\tSo, the total number of times they have to refill to water all the plants is 0 + 0 + 1 + 0 = 1.\n\t\tExample 2:\n\t\tInput: plants = [2,2,3,3], capacityA = 3, capacityB = 4\n\t\tOutput: 2\n\t\tExplanation:\n\t\t- Initially, Alice and Bob have 3 units and 4 units of water in their watering cans respectively.\n\t\t- Alice waters plant 0, Bob waters plant 3.\n\t\t- Alice and Bob now have 1 unit of water each, and need to water plants 1 and 2 respectively.\n\t\t- Since neither of them have enough water for their current plants, they refill their cans and then water the plants.\n\t\tSo, the total number of times they have to refill to water all the plants is 0 + 1 + 1 + 0 = 2.\n\t\tExample 3:\n\t\tInput: plants = [5], capacityA = 10, capacityB = 8\n\t\tOutput: 0\n\t\tExplanation:\n\t\t- There is only one plant.\n\t\t- Alice's watering can has 10 units of water, whereas Bob's can has 8 units. Since Alice has more water in her can, she waters this plant.\n\t\tSo, the total number of times they have to refill is 0.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2229,
-        "question": "class Solution:\n    def maxTotalFruits(self, fruits: List[List[int]], startPos: int, k: int) -> int:\n\t\t\"\"\"\n\t\tFruits are available at some positions on an infinite x-axis. You are given a 2D integer array fruits where fruits[i] = [positioni, amounti] depicts amounti fruits at the position positioni. fruits is already sorted by positioni in ascending order, and each positioni is unique.\n\t\tYou are also given an integer startPos and an integer k. Initially, you are at the position startPos. From any position, you can either walk to the left or right. It takes one step to move one unit on the x-axis, and you can walk at most k steps in total. For every position you reach, you harvest all the fruits at that position, and the fruits will disappear from that position.\n\t\tReturn the maximum total number of fruits you can harvest.\n\t\tExample 1:\n\t\tInput: fruits = [[2,8],[6,3],[8,6]], startPos = 5, k = 4\n\t\tOutput: 9\n\t\tExplanation: \n\t\tThe optimal way is to:\n\t\t- Move right to position 6 and harvest 3 fruits\n\t\t- Move right to position 8 and harvest 6 fruits\n\t\tYou moved 3 steps and harvested 3 + 6 = 9 fruits in total.\n\t\tExample 2:\n\t\tInput: fruits = [[0,9],[4,1],[5,7],[6,2],[7,4],[10,9]], startPos = 5, k = 4\n\t\tOutput: 14\n\t\tExplanation: \n\t\tYou can move at most k = 4 steps, so you cannot reach position 0 nor 10.\n\t\tThe optimal way is to:\n\t\t- Harvest the 7 fruits at the starting position 5\n\t\t- Move left to position 4 and harvest 1 fruit\n\t\t- Move right to position 6 and harvest 2 fruits\n\t\t- Move right to position 7 and harvest 4 fruits\n\t\tYou moved 1 + 3 = 4 steps and harvested 7 + 1 + 2 + 4 = 14 fruits in total.\n\t\tExample 3:\n\t\tInput: fruits = [[0,3],[6,4],[8,5]], startPos = 3, k = 2\n\t\tOutput: 0\n\t\tExplanation:\n\t\tYou can move at most k = 2 steps and cannot reach any position with fruits.\n\t\t\"\"\"\n",
-        "difficulty": 2
-    },
-    {
-        "number": 2231,
-        "question": "class Solution:\n    def firstPalindrome(self, words: List[str]) -> str:\n\t\t\"\"\"\n\t\tGiven an array of strings words, return the first palindromic string in the array. If there is no such string, return an empty string \"\".\n\t\tA string is palindromic if it reads the same forward and backward.\n\t\tExample 1:\n\t\tInput: words = [\"abc\",\"car\",\"ada\",\"racecar\",\"cool\"]\n\t\tOutput: \"ada\"\n\t\tExplanation: The first string that is palindromic is \"ada\".\n\t\tNote that \"racecar\" is also palindromic, but it is not the first.\n\t\tExample 2:\n\t\tInput: words = [\"notapalindrome\",\"racecar\"]\n\t\tOutput: \"racecar\"\n\t\tExplanation: The first and only string that is palindromic is \"racecar\".\n\t\tExample 3:\n\t\tInput: words = [\"def\",\"ghi\"]\n\t\tOutput: \"\"\n\t\tExplanation: There are no palindromic strings, so the empty string is returned.\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 2232,
-        "question": "class Solution:\n    def addSpaces(self, s: str, spaces: List[int]) -> str:\n\t\t\"\"\"\n\t\tYou are given a 0-indexed string s and a 0-indexed integer array spaces that describes the indices in the original string where spaces will be added. Each space should be inserted before the character at the given index.\n\t\t\tFor example, given s = \"EnjoyYourCoffee\" and spaces = [5, 9], we place spaces before 'Y' and 'C', which are at indices 5 and 9 respectively. Thus, we obtain \"Enjoy Your Coffee\".\n\t\tReturn the modified string after the spaces have been added.\n\t\tExample 1:\n\t\tInput: s = \"LeetcodeHelpsMeLearn\", spaces = [8,13,15]\n\t\tOutput: \"Leetcode Helps Me Learn\"\n\t\tExplanation: \n\t\tThe indices 8, 13, and 15 correspond to the underlined characters in \"LeetcodeHelpsMeLearn\".\n\t\tWe then place spaces before those characters.\n\t\tExample 2:\n\t\tInput: s = \"icodeinpython\", spaces = [1,5,7,9]\n\t\tOutput: \"i code in py thon\"\n\t\tExplanation:\n\t\tThe indices 1, 5, 7, and 9 correspond to the underlined characters in \"icodeinpython\".\n\t\tWe then place spaces before those characters.\n\t\tExample 3:\n\t\tInput: s = \"spacing\", spaces = [0,1,2,3,4,5,6]\n\t\tOutput: \" s p a c i n g\"\n\t\tExplanation:\n\t\tWe are also able to place spaces before the first character of the string.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2233,
-        "question": "class Solution:\n    def getDescentPeriods(self, prices: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou are given an integer array prices representing the daily price history of a stock, where prices[i] is the stock price on the ith day.\n\t\tA smooth descent period of a stock consists of one or more contiguous days such that the price on each day is lower than the price on the preceding day by exactly 1. The first day of the period is exempted from this rule.\n\t\tReturn the number of smooth descent periods.\n\t\tExample 1:\n\t\tInput: prices = [3,2,1,4]\n\t\tOutput: 7\n\t\tExplanation: There are 7 smooth descent periods:\n\t\t[3], [2], [1], [4], [3,2], [2,1], and [3,2,1]\n\t\tNote that a period with one day is a smooth descent period by the definition.\n\t\tExample 2:\n\t\tInput: prices = [8,6,7,7]\n\t\tOutput: 4\n\t\tExplanation: There are 4 smooth descent periods: [8], [6], [7], and [7]\n\t\tNote that [8,6] is not a smooth descent period as 8 - 6 \u2260 1.\n\t\tExample 3:\n\t\tInput: prices = [1]\n\t\tOutput: 1\n\t\tExplanation: There is 1 smooth descent period: [1]\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2234,
-        "question": "class Solution:\n    def kIncreasing(self, arr: List[int], k: int) -> int:\n\t\t\"\"\"\n\t\tYou are given a 0-indexed array arr consisting of n positive integers, and a positive integer k.\n\t\tThe array arr is called K-increasing if arr[i-k] <= arr[i] holds for every index i, where k <= i <= n-1.\n\t\t\tFor example, arr = [4, 1, 5, 2, 6, 2] is K-increasing for k = 2 because:\n\t\t\t\tarr[0] <= arr[2] (4 <= 5)\n\t\t\t\tarr[1] <= arr[3] (1 <= 2)\n\t\t\t\tarr[2] <= arr[4] (5 <= 6)\n\t\t\t\tarr[3] <= arr[5] (2 <= 2)\n\t\t\tHowever, the same arr is not K-increasing for k = 1 (because arr[0] > arr[1]) or k = 3 (because arr[0] > arr[3]).\n\t\tIn one operation, you can choose an index i and change arr[i] into any positive integer.\n\t\tReturn the minimum number of operations required to make the array K-increasing for the given k.\n\t\tExample 1:\n\t\tInput: arr = [5,4,3,2,1], k = 1\n\t\tOutput: 4\n\t\tExplanation:\n\t\tFor k = 1, the resultant array has to be non-decreasing.\n\t\tSome of the K-increasing arrays that can be formed are [5,6,7,8,9], [1,1,1,1,1], [2,2,3,4,4]. All of them require 4 operations.\n\t\tIt is suboptimal to change the array to, for example, [6,7,8,9,10] because it would take 5 operations.\n\t\tIt can be shown that we cannot make the array K-increasing in less than 4 operations.\n\t\tExample 2:\n\t\tInput: arr = [4,1,5,2,6,2], k = 2\n\t\tOutput: 0\n\t\tExplanation:\n\t\tThis is the same example as the one in the problem description.\n\t\tHere, for every index i where 2 <= i <= 5, arr[i-2] <= arr[i].\n\t\tSince the given array is already K-increasing, we do not need to perform any operations.\n\t\tExample 3:\n\t\tInput: arr = [4,1,5,2,6,2], k = 3\n\t\tOutput: 2\n\t\tExplanation:\n\t\tIndices 3 and 5 are the only ones not satisfying arr[i-3] <= arr[i] for 3 <= i <= 5.\n\t\tOne of the ways we can make the array K-increasing is by changing arr[3] to 4 and arr[5] to 5.\n\t\tThe array will now be [4,1,5,4,6,5].\n\t\tNote that there can be other ways to make the array K-increasing, but none of them require less than 2 operations.\n\t\t\"\"\"\n",
-        "difficulty": 2
-    },
-    {
-        "number": 2235,
-        "question": "class Solution:\n    def capitalizeTitle(self, title: str) -> str:\n\t\t\"\"\"\n\t\tYou are given a string title consisting of one or more words separated by a single space, where each word consists of English letters. Capitalize the string by changing the capitalization of each word such that:\n\t\t\tIf the length of the word is 1 or 2 letters, change all letters to lowercase.\n\t\t\tOtherwise, change the first letter to uppercase and the remaining letters to lowercase.\n\t\tReturn the capitalized title.\n\t\tExample 1:\n\t\tInput: title = \"capiTalIze tHe titLe\"\n\t\tOutput: \"Capitalize The Title\"\n\t\tExplanation:\n\t\tSince all the words have a length of at least 3, the first letter of each word is uppercase, and the remaining letters are lowercase.\n\t\tExample 2:\n\t\tInput: title = \"First leTTeR of EACH Word\"\n\t\tOutput: \"First Letter of Each Word\"\n\t\tExplanation:\n\t\tThe word \"of\" has length 2, so it is all lowercase.\n\t\tThe remaining words have a length of at least 3, so the first letter of each remaining word is uppercase, and the remaining letters are lowercase.\n\t\tExample 3:\n\t\tInput: title = \"i lOve leetcode\"\n\t\tOutput: \"i Love Leetcode\"\n\t\tExplanation:\n\t\tThe word \"i\" has length 1, so it is lowercase.\n\t\tThe remaining words have a length of at least 3, so the first letter of each remaining word is uppercase, and the remaining letters are lowercase.\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 2236,
-        "question": "class Solution:\n    def pairSum(self, head: Optional[ListNode]) -> int:\n\t\t\"\"\"\n\t\tIn a linked list of size n, where n is even, the ith node (0-indexed) of the linked list is known as the twin of the (n-1-i)th node, if 0 <= i <= (n / 2) - 1.\n\t\t\tFor example, if n = 4, then node 0 is the twin of node 3, and node 1 is the twin of node 2. These are the only nodes with twins for n = 4.\n\t\tThe twin sum is defined as the sum of a node and its twin.\n\t\tGiven the head of a linked list with even length, return the maximum twin sum of the linked list.\n\t\tExample 1:\n\t\tInput: head = [5,4,2,1]\n\t\tOutput: 6\n\t\tExplanation:\n\t\tNodes 0 and 1 are the twins of nodes 3 and 2, respectively. All have twin sum = 6.\n\t\tThere are no other nodes with twins in the linked list.\n\t\tThus, the maximum twin sum of the linked list is 6. \n\t\tExample 2:\n\t\tInput: head = [4,2,2,3]\n\t\tOutput: 7\n\t\tExplanation:\n\t\tThe nodes with twins present in this linked list are:\n\t\t- Node 0 is the twin of node 3 having a twin sum of 4 + 3 = 7.\n\t\t- Node 1 is the twin of node 2 having a twin sum of 2 + 2 = 4.\n\t\tThus, the maximum twin sum of the linked list is max(7, 4) = 7. \n\t\tExample 3:\n\t\tInput: head = [1,100000]\n\t\tOutput: 100001\n\t\tExplanation:\n\t\tThere is only one node with a twin in the linked list having twin sum of 1 + 100000 = 100001.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2237,
-        "question": "class Solution:\n    def longestPalindrome(self, words: List[str]) -> int:\n\t\t\"\"\"\n\t\tYou are given an array of strings words. Each element of words consists of two lowercase English letters.\n\t\tCreate the longest possible palindrome by selecting some elements from words and concatenating them in any order. Each element can be selected at most once.\n\t\tReturn the length of the longest palindrome that you can create. If it is impossible to create any palindrome, return 0.\n\t\tA palindrome is a string that reads the same forward and backward.\n\t\tExample 1:\n\t\tInput: words = [\"lc\",\"cl\",\"gg\"]\n\t\tOutput: 6\n\t\tExplanation: One longest palindrome is \"lc\" + \"gg\" + \"cl\" = \"lcggcl\", of length 6.\n\t\tNote that \"clgglc\" is another longest palindrome that can be created.\n\t\tExample 2:\n\t\tInput: words = [\"ab\",\"ty\",\"yt\",\"lc\",\"cl\",\"ab\"]\n\t\tOutput: 8\n\t\tExplanation: One longest palindrome is \"ty\" + \"lc\" + \"cl\" + \"yt\" = \"tylcclyt\", of length 8.\n\t\tNote that \"lcyttycl\" is another longest palindrome that can be created.\n\t\tExample 3:\n\t\tInput: words = [\"cc\",\"ll\",\"xx\"]\n\t\tOutput: 2\n\t\tExplanation: One longest palindrome is \"cc\", of length 2.\n\t\tNote that \"ll\" is another longest palindrome that can be created, and so is \"xx\".\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2238,
-        "question": "class Solution:\n    def isSameAfterReversals(self, num: int) -> bool:\n\t\t\"\"\"\n\t\tReversing an integer means to reverse all its digits.\n\t\t\tFor example, reversing 2021 gives 1202. Reversing 12300 gives 321 as the leading zeros are not retained.\n\t\tGiven an integer num, reverse num to get reversed1, then reverse reversed1 to get reversed2. Return true if reversed2 equals num. Otherwise return false.\n\t\tExample 1:\n\t\tInput: num = 526\n\t\tOutput: true\n\t\tExplanation: Reverse num to get 625, then reverse 625 to get 526, which equals num.\n\t\tExample 2:\n\t\tInput: num = 1800\n\t\tOutput: false\n\t\tExplanation: Reverse num to get 81, then reverse 81 to get 18, which does not equal num.\n\t\tExample 3:\n\t\tInput: num = 0\n\t\tOutput: true\n\t\tExplanation: Reverse num to get 0, then reverse 0 to get 0, which equals num.\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 2239,
-        "question": "class Solution:\n    def executeInstructions(self, n: int, startPos: List[int], s: str) -> List[int]:\n\t\t\"\"\"\n\t\tThere is an n x n grid, with the top-left cell at (0, 0) and the bottom-right cell at (n - 1, n - 1). You are given the integer n and an integer array startPos where startPos = [startrow, startcol] indicates that a robot is initially at cell (startrow, startcol).\n\t\tYou are also given a 0-indexed string s of length m where s[i] is the ith instruction for the robot: 'L' (move left), 'R' (move right), 'U' (move up), and 'D' (move down).\n\t\tThe robot can begin executing from any ith instruction in s. It executes the instructions one by one towards the end of s but it stops if either of these conditions is met:\n\t\t\tThe next instruction will move the robot off the grid.\n\t\t\tThere are no more instructions left to execute.\n\t\tReturn an array answer of length m where answer[i] is the number of instructions the robot can execute if the robot begins executing from the ith instruction in s.\n\t\tExample 1:\n\t\tInput: n = 3, startPos = [0,1], s = \"RRDDLU\"\n\t\tOutput: [1,5,4,3,1,0]\n\t\tExplanation: Starting from startPos and beginning execution from the ith instruction:\n\t\t- 0th: \"RRDDLU\". Only one instruction \"R\" can be executed before it moves off the grid.\n\t\t- 1st:  \"RDDLU\". All five instructions can be executed while it stays in the grid and ends at (1, 1).\n\t\t- 2nd:   \"DDLU\". All four instructions can be executed while it stays in the grid and ends at (1, 0).\n\t\t- 3rd:    \"DLU\". All three instructions can be executed while it stays in the grid and ends at (0, 0).\n\t\t- 4th:     \"LU\". Only one instruction \"L\" can be executed before it moves off the grid.\n\t\t- 5th:      \"U\". If moving up, it would move off the grid.\n\t\tExample 2:\n\t\tInput: n = 2, startPos = [1,1], s = \"LURD\"\n\t\tOutput: [4,1,0,0]\n\t\tExplanation:\n\t\t- 0th: \"LURD\".\n\t\t- 1st:  \"URD\".\n\t\t- 2nd:   \"RD\".\n\t\t- 3rd:    \"D\".\n\t\tExample 3:\n\t\tInput: n = 1, startPos = [0,0], s = \"LRUD\"\n\t\tOutput: [0,0,0,0]\n\t\tExplanation: No matter which instruction the robot begins execution from, it would move off the grid.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2240,
-        "question": "class Solution:\n    def getDistances(self, arr: List[int]) -> List[int]:\n\t\t\"\"\"\n\t\tYou are given a 0-indexed array of n integers arr.\n\t\tThe interval between two elements in arr is defined as the absolute difference between their indices. More formally, the interval between arr[i] and arr[j] is |i - j|.\n\t\tReturn an array intervals of length n where intervals[i] is the sum of intervals between arr[i] and each element in arr with the same value as arr[i].\n\t\tNote: |x| is the absolute value of x.\n\t\tExample 1:\n\t\tInput: arr = [2,1,3,1,2,3,3]\n\t\tOutput: [4,2,7,2,4,4,5]\n\t\tExplanation:\n\t\t- Index 0: Another 2 is found at index 4. |0 - 4| = 4\n\t\t- Index 1: Another 1 is found at index 3. |1 - 3| = 2\n\t\t- Index 2: Two more 3s are found at indices 5 and 6. |2 - 5| + |2 - 6| = 7\n\t\t- Index 3: Another 1 is found at index 1. |3 - 1| = 2\n\t\t- Index 4: Another 2 is found at index 0. |4 - 0| = 4\n\t\t- Index 5: Two more 3s are found at indices 2 and 6. |5 - 2| + |5 - 6| = 4\n\t\t- Index 6: Two more 3s are found at indices 2 and 5. |6 - 2| + |6 - 5| = 5\n\t\tExample 2:\n\t\tInput: arr = [10,5,10,10]\n\t\tOutput: [5,0,3,4]\n\t\tExplanation:\n\t\t- Index 0: Two more 10s are found at indices 2 and 3. |0 - 2| + |0 - 3| = 5\n\t\t- Index 1: There is only one 5 in the array, so its sum of intervals to identical elements is 0.\n\t\t- Index 2: Two more 10s are found at indices 0 and 3. |2 - 0| + |2 - 3| = 3\n\t\t- Index 3: Two more 10s are found at indices 0 and 2. |3 - 0| + |3 - 2| = 4\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2241,
-        "question": "class Solution:\n    def recoverArray(self, nums: List[int]) -> List[int]:\n\t\t\"\"\"\n\t\tAlice had a 0-indexed array arr consisting of n positive integers. She chose an arbitrary positive integer k and created two new 0-indexed integer arrays lower and higher in the following manner:\n\t\t\tlower[i] = arr[i] - k, for every index i where 0 <= i < n\n\t\t\thigher[i] = arr[i] + k, for every index i where 0 <= i < n\n\t\tUnfortunately, Alice lost all three arrays. However, she remembers the integers that were present in the arrays lower and higher, but not the array each integer belonged to. Help Alice and recover the original array.\n\t\tGiven an array nums consisting of 2n integers, where exactly n of the integers were present in lower and the remaining in higher, return the original array arr. In case the answer is not unique, return any valid array.\n\t\tNote: The test cases are generated such that there exists at least one valid array arr.\n\t\tExample 1:\n\t\tInput: nums = [2,10,6,4,8,12]\n\t\tOutput: [3,7,11]\n\t\tExplanation:\n\t\tIf arr = [3,7,11] and k = 1, we get lower = [2,6,10] and higher = [4,8,12].\n\t\tCombining lower and higher gives us [2,6,10,4,8,12], which is a permutation of nums.\n\t\tAnother valid possibility is that arr = [5,7,9] and k = 3. In that case, lower = [2,4,6] and higher = [8,10,12]. \n\t\tExample 2:\n\t\tInput: nums = [1,1,3,3]\n\t\tOutput: [2,2]\n\t\tExplanation:\n\t\tIf arr = [2,2] and k = 1, we get lower = [1,1] and higher = [3,3].\n\t\tCombining lower and higher gives us [1,1,3,3], which is equal to nums.\n\t\tNote that arr cannot be [1,3] because in that case, the only possible way to obtain [1,1,3,3] is with k = 0.\n\t\tThis is invalid since k must be positive.\n\t\tExample 3:\n\t\tInput: nums = [5,435]\n\t\tOutput: [220]\n\t\tExplanation:\n\t\tThe only possible combination is arr = [220] and k = 215. Using them, we get lower = [5] and higher = [435].\n\t\t\"\"\"\n",
-        "difficulty": 2
-    },
-    {
-        "number": 2243,
-        "question": "class Solution:\n    def checkString(self, s: str) -> bool:\n\t\t\"\"\"\n\t\tGiven a string s consisting of only the characters 'a' and 'b', return true if every 'a' appears before every 'b' in the string. Otherwise, return false.\n\t\tExample 1:\n\t\tInput: s = \"aaabbb\"\n\t\tOutput: true\n\t\tExplanation:\n\t\tThe 'a's are at indices 0, 1, and 2, while the 'b's are at indices 3, 4, and 5.\n\t\tHence, every 'a' appears before every 'b' and we return true.\n\t\tExample 2:\n\t\tInput: s = \"abab\"\n\t\tOutput: false\n\t\tExplanation:\n\t\tThere is an 'a' at index 2 and a 'b' at index 1.\n\t\tHence, not every 'a' appears before every 'b' and we return false.\n\t\tExample 3:\n\t\tInput: s = \"bbb\"\n\t\tOutput: true\n\t\tExplanation:\n\t\tThere are no 'a's, hence, every 'a' appears before every 'b' and we return true.\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 2244,
-        "question": "class Solution:\n    def numberOfBeams(self, bank: List[str]) -> int:\n\t\t\"\"\"\n\t\tAnti-theft security devices are activated inside a bank. You are given a 0-indexed binary string array bank representing the floor plan of the bank, which is an m x n 2D matrix. bank[i] represents the ith row, consisting of '0's and '1's. '0' means the cell is empty, while'1' means the cell has a security device.\n\t\tThere is one laser beam between any two security devices if both conditions are met:\n\t\t\tThe two devices are located on two different rows: r1 and r2, where r1 < r2.\n\t\t\tFor each row i where r1 < i < r2, there are no security devices in the ith row.\n\t\tLaser beams are independent, i.e., one beam does not interfere nor join with another.\n\t\tReturn the total number of laser beams in the bank.\n\t\tExample 1:\n\t\tInput: bank = [\"011001\",\"000000\",\"010100\",\"001000\"]\n\t\tOutput: 8\n\t\tExplanation: Between each of the following device pairs, there is one beam. In total, there are 8 beams:\n\t\t * bank[0][1] -- bank[2][1]\n\t\t * bank[0][1] -- bank[2][3]\n\t\t * bank[0][2] -- bank[2][1]\n\t\t * bank[0][2] -- bank[2][3]\n\t\t * bank[0][5] -- bank[2][1]\n\t\t * bank[0][5] -- bank[2][3]\n\t\t * bank[2][1] -- bank[3][2]\n\t\t * bank[2][3] -- bank[3][2]\n\t\tNote that there is no beam between any device on the 0th row with any on the 3rd row.\n\t\tThis is because the 2nd row contains security devices, which breaks the second condition.\n\t\tExample 2:\n\t\tInput: bank = [\"000\",\"111\",\"000\"]\n\t\tOutput: 0\n\t\tExplanation: There does not exist two devices located on two different rows.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2245,
-        "question": "class Solution:\n    def asteroidsDestroyed(self, mass: int, asteroids: List[int]) -> bool:\n\t\t\"\"\"\n\t\tYou are given an integer mass, which represents the original mass of a planet. You are further given an integer array asteroids, where asteroids[i] is the mass of the ith asteroid.\n\t\tYou can arrange for the planet to collide with the asteroids in any arbitrary order. If the mass of the planet is greater than or equal to the mass of the asteroid, the asteroid is destroyed and the planet gains the mass of the asteroid. Otherwise, the planet is destroyed.\n\t\tReturn true if all asteroids can be destroyed. Otherwise, return false.\n\t\tExample 1:\n\t\tInput: mass = 10, asteroids = [3,9,19,5,21]\n\t\tOutput: true\n\t\tExplanation: One way to order the asteroids is [9,19,5,3,21]:\n\t\t- The planet collides with the asteroid with a mass of 9. New planet mass: 10 + 9 = 19\n\t\t- The planet collides with the asteroid with a mass of 19. New planet mass: 19 + 19 = 38\n\t\t- The planet collides with the asteroid with a mass of 5. New planet mass: 38 + 5 = 43\n\t\t- The planet collides with the asteroid with a mass of 3. New planet mass: 43 + 3 = 46\n\t\t- The planet collides with the asteroid with a mass of 21. New planet mass: 46 + 21 = 67\n\t\tAll asteroids are destroyed.\n\t\tExample 2:\n\t\tInput: mass = 5, asteroids = [4,9,23,4]\n\t\tOutput: false\n\t\tExplanation: \n\t\tThe planet cannot ever gain enough mass to destroy the asteroid with a mass of 23.\n\t\tAfter the planet destroys the other asteroids, it will have a mass of 5 + 4 + 9 + 4 = 22.\n\t\tThis is less than 23, so a collision would not destroy the last asteroid.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2246,
-        "question": "class Solution:\n    def maximumInvitations(self, favorite: List[int]) -> int:\n\t\t\"\"\"\n\t\tA company is organizing a meeting and has a list of n employees, waiting to be invited. They have arranged for a large circular table, capable of seating any number of employees.\n\t\tThe employees are numbered from 0 to n - 1. Each employee has a favorite person and they will attend the meeting only if they can sit next to their favorite person at the table. The favorite person of an employee is not themself.\n\t\tGiven a 0-indexed integer array favorite, where favorite[i] denotes the favorite person of the ith employee, return the maximum number of employees that can be invited to the meeting.\n\t\tExample 1:\n\t\tInput: favorite = [2,2,1,2]\n\t\tOutput: 3\n\t\tExplanation:\n\t\tThe above figure shows how the company can invite employees 0, 1, and 2, and seat them at the round table.\n\t\tAll employees cannot be invited because employee 2 cannot sit beside employees 0, 1, and 3, simultaneously.\n\t\tNote that the company can also invite employees 1, 2, and 3, and give them their desired seats.\n\t\tThe maximum number of employees that can be invited to the meeting is 3. \n\t\tExample 2:\n\t\tInput: favorite = [1,2,0]\n\t\tOutput: 3\n\t\tExplanation: \n\t\tEach employee is the favorite person of at least one other employee, and the only way the company can invite them is if they invite every employee.\n\t\tThe seating arrangement will be the same as that in the figure given in example 1:\n\t\t- Employee 0 will sit between employees 2 and 1.\n\t\t- Employee 1 will sit between employees 0 and 2.\n\t\t- Employee 2 will sit between employees 1 and 0.\n\t\tThe maximum number of employees that can be invited to the meeting is 3.\n\t\tExample 3:\n\t\tInput: favorite = [3,0,1,4,1]\n\t\tOutput: 4\n\t\tExplanation:\n\t\tThe above figure shows how the company will invite employees 0, 1, 3, and 4, and seat them at the round table.\n\t\tEmployee 2 cannot be invited because the two spots next to their favorite employee 1 are taken.\n\t\tSo the company leaves them out of the meeting.\n\t\tThe maximum number of employees that can be invited to the meeting is 4.\n\t\t\"\"\"\n",
-        "difficulty": 2
-    },
-    {
-        "number": 2248,
-        "question": "class Solution:\n    def minimumCost(self, cost: List[int]) -> int:\n\t\t\"\"\"\n\t\tA shop is selling candies at a discount. For every two candies sold, the shop gives a third candy for free.\n\t\tThe customer can choose any candy to take away for free as long as the cost of the chosen candy is less than or equal to the minimum cost of the two candies bought.\n\t\t\tFor example, if there are 4 candies with costs 1, 2, 3, and 4, and the customer buys candies with costs 2 and 3, they can take the candy with cost 1 for free, but not the candy with cost 4.\n\t\tGiven a 0-indexed integer array cost, where cost[i] denotes the cost of the ith candy, return the minimum cost of buying all the candies.\n\t\tExample 1:\n\t\tInput: cost = [1,2,3]\n\t\tOutput: 5\n\t\tExplanation: We buy the candies with costs 2 and 3, and take the candy with cost 1 for free.\n\t\tThe total cost of buying all candies is 2 + 3 = 5. This is the only way we can buy the candies.\n\t\tNote that we cannot buy candies with costs 1 and 3, and then take the candy with cost 2 for free.\n\t\tThe cost of the free candy has to be less than or equal to the minimum cost of the purchased candies.\n\t\tExample 2:\n\t\tInput: cost = [6,5,7,9,2,2]\n\t\tOutput: 23\n\t\tExplanation: The way in which we can get the minimum cost is described below:\n\t\t- Buy candies with costs 9 and 7\n\t\t- Take the candy with cost 6 for free\n\t\t- We buy candies with costs 5 and 2\n\t\t- Take the last remaining candy with cost 2 for free\n\t\tHence, the minimum cost to buy all candies is 9 + 7 + 5 + 2 = 23.\n\t\tExample 3:\n\t\tInput: cost = [5,5]\n\t\tOutput: 10\n\t\tExplanation: Since there are only 2 candies, we buy both of them. There is not a third candy we can take for free.\n\t\tHence, the minimum cost to buy all candies is 5 + 5 = 10.\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 2249,
-        "question": "class Solution:\n    def numberOfArrays(self, differences: List[int], lower: int, upper: int) -> int:\n\t\t\"\"\"\n\t\tYou are given a 0-indexed array of n integers differences, which describes the differences between each pair of consecutive integers of a hidden sequence of length (n + 1). More formally, call the hidden sequence hidden, then we have that differences[i] = hidden[i + 1] - hidden[i].\n\t\tYou are further given two integers lower and upper that describe the inclusive range of values [lower, upper] that the hidden sequence can contain.\n\t\t\tFor example, given differences = [1, -3, 4], lower = 1, upper = 6, the hidden sequence is a sequence of length 4 whose elements are in between 1 and 6 (inclusive).\n\t\t\t\t[3, 4, 1, 5] and [4, 5, 2, 6] are possible hidden sequences.\n\t\t\t\t[5, 6, 3, 7] is not possible since it contains an element greater than 6.\n\t\t\t\t[1, 2, 3, 4] is not possible since the differences are not correct.\n\t\tReturn the number of possible hidden sequences there are. If there are no possible sequences, return 0.\n\t\tExample 1:\n\t\tInput: differences = [1,-3,4], lower = 1, upper = 6\n\t\tOutput: 2\n\t\tExplanation: The possible hidden sequences are:\n\t\t- [3, 4, 1, 5]\n\t\t- [4, 5, 2, 6]\n\t\tThus, we return 2.\n\t\tExample 2:\n\t\tInput: differences = [3,-4,5,1,-2], lower = -4, upper = 5\n\t\tOutput: 4\n\t\tExplanation: The possible hidden sequences are:\n\t\t- [-3, 0, -4, 1, 2, 0]\n\t\t- [-2, 1, -3, 2, 3, 1]\n\t\t- [-1, 2, -2, 3, 4, 2]\n\t\t- [0, 3, -1, 4, 5, 3]\n\t\tThus, we return 4.\n\t\tExample 3:\n\t\tInput: differences = [4,-7,2], lower = 3, upper = 6\n\t\tOutput: 0\n\t\tExplanation: There are no possible hidden sequences. Thus, we return 0.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2250,
-        "question": "class Solution:\n    def highestRankedKItems(self, grid: List[List[int]], pricing: List[int], start: List[int], k: int) -> List[List[int]]:\n\t\t\"\"\"\n\t\tYou are given a 0-indexed 2D integer array grid of size m x n that represents a map of the items in a shop. The integers in the grid represent the following:\n\t\t\t0 represents a wall that you cannot pass through.\n\t\t\t1 represents an empty cell that you can freely move to and from.\n\t\t\tAll other positive integers represent the price of an item in that cell. You may also freely move to and from these item cells.\n\t\tIt takes 1 step to travel between adjacent grid cells.\n\t\tYou are also given integer arrays pricing and start where pricing = [low, high] and start = [row, col] indicates that you start at the position (row, col) and are interested only in items with a price in the range of [low, high] (inclusive). You are further given an integer k.\n\t\tYou are interested in the positions of the k highest-ranked items whose prices are within the given price range. The rank is determined by the first of these criteria that is different:\n\t\t\tDistance, defined as the length of the shortest path from the start (shorter distance has a higher rank).\n\t\t\tPrice (lower price has a higher rank, but it must be in the price range).\n\t\t\tThe row number (smaller row number has a higher rank).\n\t\t\tThe column number (smaller column number has a higher rank).\n\t\tReturn the k highest-ranked items within the price range sorted by their rank (highest to lowest). If there are fewer than k reachable items within the price range, return all of them.\n\t\tExample 1:\n\t\tInput: grid = [[1,2,0,1],[1,3,0,1],[0,2,5,1]], pricing = [2,5], start = [0,0], k = 3\n\t\tOutput: [[0,1],[1,1],[2,1]]\n\t\tExplanation: You start at (0,0).\n\t\tWith a price range of [2,5], we can take items from (0,1), (1,1), (2,1) and (2,2).\n\t\tThe ranks of these items are:\n\t\t- (0,1) with distance 1\n\t\t- (1,1) with distance 2\n\t\t- (2,1) with distance 3\n\t\t- (2,2) with distance 4\n\t\tThus, the 3 highest ranked items in the price range are (0,1), (1,1), and (2,1).\n\t\tExample 2:\n\t\tInput: grid = [[1,2,0,1],[1,3,3,1],[0,2,5,1]], pricing = [2,3], start = [2,3], k = 2\n\t\tOutput: [[2,1],[1,2]]\n\t\tExplanation: You start at (2,3).\n\t\tWith a price range of [2,3], we can take items from (0,1), (1,1), (1,2) and (2,1).\n\t\tThe ranks of these items are:\n\t\t- (2,1) with distance 2, price 2\n\t\t- (1,2) with distance 2, price 3\n\t\t- (1,1) with distance 3\n\t\t- (0,1) with distance 4\n\t\tThus, the 2 highest ranked items in the price range are (2,1) and (1,2).\n\t\tExample 3:\n\t\tInput: grid = [[1,1,1],[0,0,1],[2,3,4]], pricing = [2,3], start = [0,0], k = 3\n\t\tOutput: [[2,1],[2,0]]\n\t\tExplanation: You start at (0,0).\n\t\tWith a price range of [2,3], we can take items from (2,0) and (2,1). \n\t\tThe ranks of these items are: \n\t\t- (2,1) with distance 5\n\t\t- (2,0) with distance 6\n\t\tThus, the 2 highest ranked items in the price range are (2,1) and (2,0). \n\t\tNote that k = 3 but there are only 2 reachable items within the price range.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2251,
-        "question": "class Solution:\n    def numberOfWays(self, corridor: str) -> int:\n\t\t\"\"\"\n\t\tAlong a long library corridor, there is a line of seats and decorative plants. You are given a 0-indexed string corridor of length n consisting of letters 'S' and 'P' where each 'S' represents a seat and each 'P' represents a plant.\n\t\tOne room divider has already been installed to the left of index 0, and another to the right of index n - 1. Additional room dividers can be installed. For each position between indices i - 1 and i (1 <= i <= n - 1), at most one divider can be installed.\n\t\tDivide the corridor into non-overlapping sections, where each section has exactly two seats with any number of plants. There may be multiple ways to perform the division. Two ways are different if there is a position with a room divider installed in the first way but not in the second way.\n\t\tReturn the number of ways to divide the corridor. Since the answer may be very large, return it modulo 109 + 7. If there is no way, return 0.\n\t\tExample 1:\n\t\tInput: corridor = \"SSPPSPS\"\n\t\tOutput: 3\n\t\tExplanation: There are 3 different ways to divide the corridor.\n\t\tThe black bars in the above image indicate the two room dividers already installed.\n\t\tNote that in each of the ways, each section has exactly two seats.\n\t\tExample 2:\n\t\tInput: corridor = \"PPSPSP\"\n\t\tOutput: 1\n\t\tExplanation: There is only 1 way to divide the corridor, by not installing any additional dividers.\n\t\tInstalling any would create some section that does not have exactly two seats.\n\t\tExample 3:\n\t\tInput: corridor = \"S\"\n\t\tOutput: 0\n\t\tExplanation: There is no way to divide the corridor because there will always be a section that does not have exactly two seats.\n\t\t\"\"\"\n",
-        "difficulty": 2
-    },
-    {
-        "number": 2254,
-        "question": "class Solution:\n    def checkValid(self, matrix: List[List[int]]) -> bool:\n\t\t\"\"\"\n\t\tAn n x n matrix is valid if every row and every column contains all the integers from 1 to n (inclusive).\n\t\tGiven an n x n integer matrix matrix, return true if the matrix is valid. Otherwise, return false.\n\t\tExample 1:\n\t\tInput: matrix = [[1,2,3],[3,1,2],[2,3,1]]\n\t\tOutput: true\n\t\tExplanation: In this case, n = 3, and every row and column contains the numbers 1, 2, and 3.\n\t\tHence, we return true.\n\t\tExample 2:\n\t\tInput: matrix = [[1,1,1],[1,2,3],[1,2,3]]\n\t\tOutput: false\n\t\tExplanation: In this case, n = 3, but the first row and the first column do not contain the numbers 2 or 3.\n\t\tHence, we return false.\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 2255,
-        "question": "class Solution:\n    def minSwaps(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tA swap is defined as taking two distinct positions in an array and swapping the values in them.\n\t\tA circular array is defined as an array where we consider the first element and the last element to be adjacent.\n\t\tGiven a binary circular array nums, return the minimum number of swaps required to group all 1's present in the array together at any location.\n\t\tExample 1:\n\t\tInput: nums = [0,1,0,1,1,0,0]\n\t\tOutput: 1\n\t\tExplanation: Here are a few of the ways to group all the 1's together:\n\t\t[0,0,1,1,1,0,0] using 1 swap.\n\t\t[0,1,1,1,0,0,0] using 1 swap.\n\t\t[1,1,0,0,0,0,1] using 2 swaps (using the circular property of the array).\n\t\tThere is no way to group all 1's together with 0 swaps.\n\t\tThus, the minimum number of swaps required is 1.\n\t\tExample 2:\n\t\tInput: nums = [0,1,1,1,0,0,1,1,0]\n\t\tOutput: 2\n\t\tExplanation: Here are a few of the ways to group all the 1's together:\n\t\t[1,1,1,0,0,0,0,1,1] using 2 swaps (using the circular property of the array).\n\t\t[1,1,1,1,1,0,0,0,0] using 2 swaps.\n\t\tThere is no way to group all 1's together with 0 or 1 swaps.\n\t\tThus, the minimum number of swaps required is 2.\n\t\tExample 3:\n\t\tInput: nums = [1,1,0,0,1]\n\t\tOutput: 0\n\t\tExplanation: All the 1's are already grouped together due to the circular property of the array.\n\t\tThus, the minimum number of swaps required is 0.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2256,
-        "question": "class Solution:\n    def wordCount(self, startWords: List[str], targetWords: List[str]) -> int:\n\t\t\"\"\"\n\t\tYou are given two 0-indexed arrays of strings startWords and targetWords. Each string consists of lowercase English letters only.\n\t\tFor each string in targetWords, check if it is possible to choose a string from startWords and perform a conversion operation on it to be equal to that from targetWords.\n\t\tThe conversion operation is described in the following two steps:\n\t\t\tAppend any lowercase letter that is not present in the string to its end.\n\t\t\t\tFor example, if the string is \"abc\", the letters 'd', 'e', or 'y' can be added to it, but not 'a'. If 'd' is added, the resulting string will be \"abcd\".\n\t\t\tRearrange the letters of the new string in any arbitrary order.\n\t\t\t\tFor example, \"abcd\" can be rearranged to \"acbd\", \"bacd\", \"cbda\", and so on. Note that it can also be rearranged to \"abcd\" itself.\n\t\tReturn the number of strings in targetWords that can be obtained by performing the operations on any string of startWords.\n\t\tNote that you will only be verifying if the string in targetWords can be obtained from a string in startWords by performing the operations. The strings in startWords do not actually change during this process.\n\t\tExample 1:\n\t\tInput: startWords = [\"ant\",\"act\",\"tack\"], targetWords = [\"tack\",\"act\",\"acti\"]\n\t\tOutput: 2\n\t\tExplanation:\n\t\t- In order to form targetWords[0] = \"tack\", we use startWords[1] = \"act\", append 'k' to it, and rearrange \"actk\" to \"tack\".\n\t\t- There is no string in startWords that can be used to obtain targetWords[1] = \"act\".\n\t\t  Note that \"act\" does exist in startWords, but we must append one letter to the string before rearranging it.\n\t\t- In order to form targetWords[2] = \"acti\", we use startWords[1] = \"act\", append 'i' to it, and rearrange \"acti\" to \"acti\" itself.\n\t\tExample 2:\n\t\tInput: startWords = [\"ab\",\"a\"], targetWords = [\"abc\",\"abcd\"]\n\t\tOutput: 1\n\t\tExplanation:\n\t\t- In order to form targetWords[0] = \"abc\", we use startWords[0] = \"ab\", add 'c' to it, and rearrange it to \"abc\".\n\t\t- There is no string in startWords that can be used to obtain targetWords[1] = \"abcd\".\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2257,
-        "question": "class Solution:\n    def earliestFullBloom(self, plantTime: List[int], growTime: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou have n flower seeds. Every seed must be planted first before it can begin to grow, then bloom. Planting a seed takes time and so does the growth of a seed. You are given two 0-indexed integer arrays plantTime and growTime, of length n each:\n\t\t\tplantTime[i] is the number of full days it takes you to plant the ith seed. Every day, you can work on planting exactly one seed. You do not have to work on planting the same seed on consecutive days, but the planting of a seed is not complete until you have worked plantTime[i] days on planting it in total.\n\t\t\tgrowTime[i] is the number of full days it takes the ith seed to grow after being completely planted. After the last day of its growth, the flower blooms and stays bloomed forever.\n\t\tFrom the beginning of day 0, you can plant the seeds in any order.\n\t\tReturn the earliest possible day where all seeds are blooming.\n\t\tExample 1:\n\t\tInput: plantTime = [1,4,3], growTime = [2,3,1]\n\t\tOutput: 9\n\t\tExplanation: The grayed out pots represent planting days, colored pots represent growing days, and the flower represents the day it blooms.\n\t\tOne optimal way is:\n\t\tOn day 0, plant the 0th seed. The seed grows for 2 full days and blooms on day 3.\n\t\tOn days 1, 2, 3, and 4, plant the 1st seed. The seed grows for 3 full days and blooms on day 8.\n\t\tOn days 5, 6, and 7, plant the 2nd seed. The seed grows for 1 full day and blooms on day 9.\n\t\tThus, on day 9, all the seeds are blooming.\n\t\tExample 2:\n\t\tInput: plantTime = [1,2,3,2], growTime = [2,1,2,1]\n\t\tOutput: 9\n\t\tExplanation: The grayed out pots represent planting days, colored pots represent growing days, and the flower represents the day it blooms.\n\t\tOne optimal way is:\n\t\tOn day 1, plant the 0th seed. The seed grows for 2 full days and blooms on day 4.\n\t\tOn days 0 and 3, plant the 1st seed. The seed grows for 1 full day and blooms on day 5.\n\t\tOn days 2, 4, and 5, plant the 2nd seed. The seed grows for 2 full days and blooms on day 8.\n\t\tOn days 6 and 7, plant the 3rd seed. The seed grows for 1 full day and blooms on day 9.\n\t\tThus, on day 9, all the seeds are blooming.\n\t\tExample 3:\n\t\tInput: plantTime = [1], growTime = [1]\n\t\tOutput: 2\n\t\tExplanation: On day 0, plant the 0th seed. The seed grows for 1 full day and blooms on day 2.\n\t\tThus, on day 2, all the seeds are blooming.\n\t\t\"\"\"\n",
-        "difficulty": 2
-    },
-    {
-        "number": 2260,
-        "question": "class Solution:\n    def divideString(self, s: str, k: int, fill: str) -> List[str]:\n\t\t\"\"\"\n\t\tA string s can be partitioned into groups of size k using the following procedure:\n\t\t\tThe first group consists of the first k characters of the string, the second group consists of the next k characters of the string, and so on. Each character can be a part of exactly one group.\n\t\t\tFor the last group, if the string does not have k characters remaining, a character fill is used to complete the group.\n\t\tNote that the partition is done so that after removing the fill character from the last group (if it exists) and concatenating all the groups in order, the resultant string should be s.\n\t\tGiven the string s, the size of each group k and the character fill, return a string array denoting the composition of every group s has been divided into, using the above procedure.\n\t\tExample 1:\n\t\tInput: s = \"abcdefghi\", k = 3, fill = \"x\"\n\t\tOutput: [\"abc\",\"def\",\"ghi\"]\n\t\tExplanation:\n\t\tThe first 3 characters \"abc\" form the first group.\n\t\tThe next 3 characters \"def\" form the second group.\n\t\tThe last 3 characters \"ghi\" form the third group.\n\t\tSince all groups can be completely filled by characters from the string, we do not need to use fill.\n\t\tThus, the groups formed are \"abc\", \"def\", and \"ghi\".\n\t\tExample 2:\n\t\tInput: s = \"abcdefghij\", k = 3, fill = \"x\"\n\t\tOutput: [\"abc\",\"def\",\"ghi\",\"jxx\"]\n\t\tExplanation:\n\t\tSimilar to the previous example, we are forming the first three groups \"abc\", \"def\", and \"ghi\".\n\t\tFor the last group, we can only use the character 'j' from the string. To complete this group, we add 'x' twice.\n\t\tThus, the 4 groups formed are \"abc\", \"def\", \"ghi\", and \"jxx\".\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 2261,
-        "question": "class Solution:\n    def maxScoreIndices(self, nums: List[int]) -> List[int]:\n\t\t\"\"\"\n\t\tYou are given a 0-indexed binary array nums of length n. nums can be divided at index i (where 0 <= i <= n) into two arrays (possibly empty) numsleft and numsright:\n\t\t\tnumsleft has all the elements of nums between index 0 and i - 1 (inclusive), while numsright has all the elements of nums between index i and n - 1 (inclusive).\n\t\t\tIf i == 0, numsleft is empty, while numsright has all the elements of nums.\n\t\t\tIf i == n, numsleft has all the elements of nums, while numsright is empty.\n\t\tThe division score of an index i is the sum of the number of 0's in numsleft and the number of 1's in numsright.\n\t\tReturn all distinct indices that have the highest possible division score. You may return the answer in any order.\n\t\tExample 1:\n\t\tInput: nums = [0,0,1,0]\n\t\tOutput: [2,4]\n\t\tExplanation: Division at index\n\t\t- 0: numsleft is []. numsright is [0,0,1,0]. The score is 0 + 1 = 1.\n\t\t- 1: numsleft is [0]. numsright is [0,1,0]. The score is 1 + 1 = 2.\n\t\t- 2: numsleft is [0,0]. numsright is [1,0]. The score is 2 + 1 = 3.\n\t\t- 3: numsleft is [0,0,1]. numsright is [0]. The score is 2 + 0 = 2.\n\t\t- 4: numsleft is [0,0,1,0]. numsright is []. The score is 3 + 0 = 3.\n\t\tIndices 2 and 4 both have the highest possible division score 3.\n\t\tNote the answer [4,2] would also be accepted.\n\t\tExample 2:\n\t\tInput: nums = [0,0,0]\n\t\tOutput: [3]\n\t\tExplanation: Division at index\n\t\t- 0: numsleft is []. numsright is [0,0,0]. The score is 0 + 0 = 0.\n\t\t- 1: numsleft is [0]. numsright is [0,0]. The score is 1 + 0 = 1.\n\t\t- 2: numsleft is [0,0]. numsright is [0]. The score is 2 + 0 = 2.\n\t\t- 3: numsleft is [0,0,0]. numsright is []. The score is 3 + 0 = 3.\n\t\tOnly index 3 has the highest possible division score 3.\n\t\tExample 3:\n\t\tInput: nums = [1,1]\n\t\tOutput: [0]\n\t\tExplanation: Division at index\n\t\t- 0: numsleft is []. numsright is [1,1]. The score is 0 + 2 = 2.\n\t\t- 1: numsleft is [1]. numsright is [1]. The score is 0 + 1 = 1.\n\t\t- 2: numsleft is [1,1]. numsright is []. The score is 0 + 0 = 0.\n\t\tOnly index 0 has the highest possible division score 2.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2262,
-        "question": "class Solution:\n    def mostPoints(self, questions: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tYou are given a 0-indexed 2D integer array questions where questions[i] = [pointsi, brainpoweri].\n\t\tThe array describes the questions of an exam, where you have to process the questions in order (i.e., starting from question 0) and make a decision whether to solve or skip each question. Solving question i will earn you pointsi points but you will be unable to solve each of the next brainpoweri questions. If you skip question i, you get to make the decision on the next question.\n\t\t\tFor example, given questions = [[3, 2], [4, 3], [4, 4], [2, 5]]:\n\t\t\t\tIf question 0 is solved, you will earn 3 points but you will be unable to solve questions 1 and 2.\n\t\t\t\tIf instead, question 0 is skipped and question 1 is solved, you will earn 4 points but you will be unable to solve questions 2 and 3.\n\t\tReturn the maximum points you can earn for the exam.\n\t\tExample 1:\n\t\tInput: questions = [[3,2],[4,3],[4,4],[2,5]]\n\t\tOutput: 5\n\t\tExplanation: The maximum points can be earned by solving questions 0 and 3.\n\t\t- Solve question 0: Earn 3 points, will be unable to solve the next 2 questions\n\t\t- Unable to solve questions 1 and 2\n\t\t- Solve question 3: Earn 2 points\n\t\tTotal points earned: 3 + 2 = 5. There is no other way to earn 5 or more points.\n\t\tExample 2:\n\t\tInput: questions = [[1,1],[2,2],[3,3],[4,4],[5,5]]\n\t\tOutput: 7\n\t\tExplanation: The maximum points can be earned by solving questions 1 and 4.\n\t\t- Skip question 0\n\t\t- Solve question 1: Earn 2 points, will be unable to solve the next 2 questions\n\t\t- Unable to solve questions 2 and 3\n\t\t- Solve question 4: Earn 5 points\n\t\tTotal points earned: 2 + 5 = 7. There is no other way to earn 7 or more points.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2263,
-        "question": "class Solution:\n    def maxRunTime(self, n: int, batteries: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou have n computers. You are given the integer n and a 0-indexed integer array batteries where the ith battery can run a computer for batteries[i] minutes. You are interested in running all n computers simultaneously using the given batteries.\n\t\tInitially, you can insert at most one battery into each computer. After that and at any integer time moment, you can remove a battery from a computer and insert another battery any number of times. The inserted battery can be a totally new battery or a battery from another computer. You may assume that the removing and inserting processes take no time.\n\t\tNote that the batteries cannot be recharged.\n\t\tReturn the maximum number of minutes you can run all the n computers simultaneously.\n\t\tExample 1:\n\t\tInput: n = 2, batteries = [3,3,3]\n\t\tOutput: 4\n\t\tExplanation: \n\t\tInitially, insert battery 0 into the first computer and battery 1 into the second computer.\n\t\tAfter two minutes, remove battery 1 from the second computer and insert battery 2 instead. Note that battery 1 can still run for one minute.\n\t\tAt the end of the third minute, battery 0 is drained, and you need to remove it from the first computer and insert battery 1 instead.\n\t\tBy the end of the fourth minute, battery 1 is also drained, and the first computer is no longer running.\n\t\tWe can run the two computers simultaneously for at most 4 minutes, so we return 4.\n\t\tExample 2:\n\t\tInput: n = 2, batteries = [1,1,1,1]\n\t\tOutput: 2\n\t\tExplanation: \n\t\tInitially, insert battery 0 into the first computer and battery 2 into the second computer. \n\t\tAfter one minute, battery 0 and battery 2 are drained so you need to remove them and insert battery 1 into the first computer and battery 3 into the second computer. \n\t\tAfter another minute, battery 1 and battery 3 are also drained so the first and second computers are no longer running.\n\t\tWe can run the two computers simultaneously for at most 2 minutes, so we return 2.\n\t\t\"\"\"\n",
-        "difficulty": 2
-    },
-    {
-        "number": 2264,
-        "question": "class Solution:\n    def minimumSum(self, num: int) -> int:\n\t\t\"\"\"\n\t\tYou are given a positive integer num consisting of exactly four digits. Split num into two new integers new1 and new2 by using the digits found in num. Leading zeros are allowed in new1 and new2, and all the digits found in num must be used.\n\t\t\tFor example, given num = 2932, you have the following digits: two 2's, one 9 and one 3. Some of the possible pairs [new1, new2] are [22, 93], [23, 92], [223, 9] and [2, 329].\n\t\tReturn the minimum possible sum of new1 and new2.\n\t\tExample 1:\n\t\tInput: num = 2932\n\t\tOutput: 52\n\t\tExplanation: Some possible pairs [new1, new2] are [29, 23], [223, 9], etc.\n\t\tThe minimum sum can be obtained by the pair [29, 23]: 29 + 23 = 52.\n\t\tExample 2:\n\t\tInput: num = 4009\n\t\tOutput: 13\n\t\tExplanation: Some possible pairs [new1, new2] are [0, 49], [490, 0], etc. \n\t\tThe minimum sum can be obtained by the pair [4, 9]: 4 + 9 = 13.\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 2265,
-        "question": "class Solution:\n    def pivotArray(self, nums: List[int], pivot: int) -> List[int]:\n\t\t\"\"\"\n\t\tYou are given a 0-indexed integer array nums and an integer pivot. Rearrange nums such that the following conditions are satisfied:\n\t\t\tEvery element less than pivot appears before every element greater than pivot.\n\t\t\tEvery element equal to pivot appears in between the elements less than and greater than pivot.\n\t\t\tThe relative order of the elements less than pivot and the elements greater than pivot is maintained.\n\t\t\t\tMore formally, consider every pi, pj where pi is the new position of the ith element and pj is the new position of the jth element. For elements less than pivot, if i < j and nums[i] < pivot and nums[j] < pivot, then pi < pj. Similarly for elements greater than pivot, if i < j and nums[i] > pivot and nums[j] > pivot, then pi < pj.\n\t\tReturn nums after the rearrangement.\n\t\tExample 1:\n\t\tInput: nums = [9,12,5,10,14,3,10], pivot = 10\n\t\tOutput: [9,5,3,10,10,12,14]\n\t\tExplanation: \n\t\tThe elements 9, 5, and 3 are less than the pivot so they are on the left side of the array.\n\t\tThe elements 12 and 14 are greater than the pivot so they are on the right side of the array.\n\t\tThe relative ordering of the elements less than and greater than pivot is also maintained. [9, 5, 3] and [12, 14] are the respective orderings.\n\t\tExample 2:\n\t\tInput: nums = [-3,4,3,2], pivot = 2\n\t\tOutput: [-3,2,4,3]\n\t\tExplanation: \n\t\tThe element -3 is less than the pivot so it is on the left side of the array.\n\t\tThe elements 4 and 3 are greater than the pivot so they are on the right side of the array.\n\t\tThe relative ordering of the elements less than and greater than pivot is also maintained. [-3] and [4, 3] are the respective orderings.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2266,
-        "question": "class Solution:\n    def minCostSetTime(self, startAt: int, moveCost: int, pushCost: int, targetSeconds: int) -> int:\n\t\t\"\"\"\n\t\tA generic microwave supports cooking times for:\n\t\t\tat least 1 second.\n\t\t\tat most 99 minutes and 99 seconds.\n\t\tTo set the cooking time, you push at most four digits. The microwave normalizes what you push as four digits by prepending zeroes. It interprets the first two digits as the minutes and the last two digits as the seconds. It then adds them up as the cooking time. For example,\n\t\t\tYou push 9 5 4 (three digits). It is normalized as 0954 and interpreted as 9 minutes and 54 seconds.\n\t\t\tYou push 0 0 0 8 (four digits). It is interpreted as 0 minutes and 8 seconds.\n\t\t\tYou push 8 0 9 0. It is interpreted as 80 minutes and 90 seconds.\n\t\t\tYou push 8 1 3 0. It is interpreted as 81 minutes and 30 seconds.\n\t\tYou are given integers startAt, moveCost, pushCost, and targetSeconds. Initially, your finger is on the digit startAt. Moving the finger above any specific digit costs moveCost units of fatigue. Pushing the digit below the finger once costs pushCost units of fatigue.\n\t\tThere can be multiple ways to set the microwave to cook for targetSeconds seconds but you are interested in the way with the minimum cost.\n\t\tReturn the minimum cost to set targetSeconds seconds of cooking time.\n\t\tRemember that one minute consists of 60 seconds.\n\t\tExample 1:\n\t\tInput: startAt = 1, moveCost = 2, pushCost = 1, targetSeconds = 600\n\t\tOutput: 6\n\t\tExplanation: The following are the possible ways to set the cooking time.\n\t\t- 1 0 0 0, interpreted as 10 minutes and 0 seconds.\n\t\t  The finger is already on digit 1, pushes 1 (with cost 1), moves to 0 (with cost 2), pushes 0 (with cost 1), pushes 0 (with cost 1), and pushes 0 (with cost 1).\n\t\t  The cost is: 1 + 2 + 1 + 1 + 1 = 6. This is the minimum cost.\n\t\t- 0 9 6 0, interpreted as 9 minutes and 60 seconds. That is also 600 seconds.\n\t\t  The finger moves to 0 (with cost 2), pushes 0 (with cost 1), moves to 9 (with cost 2), pushes 9 (with cost 1), moves to 6 (with cost 2), pushes 6 (with cost 1), moves to 0 (with cost 2), and pushes 0 (with cost 1).\n\t\t  The cost is: 2 + 1 + 2 + 1 + 2 + 1 + 2 + 1 = 12.\n\t\t- 9 6 0, normalized as 0960 and interpreted as 9 minutes and 60 seconds.\n\t\t  The finger moves to 9 (with cost 2), pushes 9 (with cost 1), moves to 6 (with cost 2), pushes 6 (with cost 1), moves to 0 (with cost 2), and pushes 0 (with cost 1).\n\t\t  The cost is: 2 + 1 + 2 + 1 + 2 + 1 = 9.\n\t\tExample 2:\n\t\tInput: startAt = 0, moveCost = 1, pushCost = 2, targetSeconds = 76\n\t\tOutput: 6\n\t\tExplanation: The optimal way is to push two digits: 7 6, interpreted as 76 seconds.\n\t\tThe finger moves to 7 (with cost 1), pushes 7 (with cost 2), moves to 6 (with cost 1), and pushes 6 (with cost 2). The total cost is: 1 + 2 + 1 + 2 = 6\n\t\tNote other possible ways are 0076, 076, 0116, and 116, but none of them produces the minimum cost.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2267,
-        "question": "class Solution:\n    def minimumDifference(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou are given a 0-indexed integer array nums consisting of 3 * n elements.\n\t\tYou are allowed to remove any subsequence of elements of size exactly n from nums. The remaining 2 * n elements will be divided into two equal parts:\n\t\t\tThe first n elements belonging to the first part and their sum is sumfirst.\n\t\t\tThe next n elements belonging to the second part and their sum is sumsecond.\n\t\tThe difference in sums of the two parts is denoted as sumfirst - sumsecond.\n\t\t\tFor example, if sumfirst = 3 and sumsecond = 2, their difference is 1.\n\t\t\tSimilarly, if sumfirst = 2 and sumsecond = 3, their difference is -1.\n\t\tReturn the minimum difference possible between the sums of the two parts after the removal of n elements.\n\t\tExample 1:\n\t\tInput: nums = [3,1,2]\n\t\tOutput: -1\n\t\tExplanation: Here, nums has 3 elements, so n = 1. \n\t\tThus we have to remove 1 element from nums and divide the array into two equal parts.\n\t\t- If we remove nums[0] = 3, the array will be [1,2]. The difference in sums of the two parts will be 1 - 2 = -1.\n\t\t- If we remove nums[1] = 1, the array will be [3,2]. The difference in sums of the two parts will be 3 - 2 = 1.\n\t\t- If we remove nums[2] = 2, the array will be [3,1]. The difference in sums of the two parts will be 3 - 1 = 2.\n\t\tThe minimum difference between sums of the two parts is min(-1,1,2) = -1. \n\t\tExample 2:\n\t\tInput: nums = [7,9,5,8,1,3]\n\t\tOutput: 1\n\t\tExplanation: Here n = 2. So we must remove 2 elements and divide the remaining array into two parts containing two elements each.\n\t\tIf we remove nums[2] = 5 and nums[3] = 8, the resultant array will be [7,9,1,3]. The difference in sums will be (7+9) - (1+3) = 12.\n\t\tTo obtain the minimum difference, we should remove nums[1] = 9 and nums[4] = 1. The resultant array becomes [7,5,8,3]. The difference in sums of the two parts is (7+5) - (8+3) = 1.\n\t\tIt can be shown that it is not possible to obtain a difference smaller than 1.\n\t\t\"\"\"\n",
-        "difficulty": 2
-    },
-    {
-        "number": 2269,
-        "question": "class Solution:\n    def countElements(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tGiven an integer array nums, return the number of elements that have both a strictly smaller and a strictly greater element appear in nums.\n\t\tExample 1:\n\t\tInput: nums = [11,7,2,15]\n\t\tOutput: 2\n\t\tExplanation: The element 7 has the element 2 strictly smaller than it and the element 11 strictly greater than it.\n\t\tElement 11 has element 7 strictly smaller than it and element 15 strictly greater than it.\n\t\tIn total there are 2 elements having both a strictly smaller and a strictly greater element appear in nums.\n\t\tExample 2:\n\t\tInput: nums = [-3,3,3,90]\n\t\tOutput: 2\n\t\tExplanation: The element 3 has the element -3 strictly smaller than it and the element 90 strictly greater than it.\n\t\tSince there are two elements with the value 3, in total there are 2 elements having both a strictly smaller and a strictly greater element appear in nums.\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 2270,
-        "question": "class Solution:\n    def findLonely(self, nums: List[int]) -> List[int]:\n\t\t\"\"\"\n\t\tYou are given an integer array nums. A number x is lonely when it appears only once, and no adjacent numbers (i.e. x + 1 and x - 1) appear in the array.\n\t\tReturn all lonely numbers in nums. You may return the answer in any order.\n\t\tExample 1:\n\t\tInput: nums = [10,6,5,8]\n\t\tOutput: [10,8]\n\t\tExplanation: \n\t\t- 10 is a lonely number since it appears exactly once and 9 and 11 does not appear in nums.\n\t\t- 8 is a lonely number since it appears exactly once and 7 and 9 does not appear in nums.\n\t\t- 5 is not a lonely number since 6 appears in nums and vice versa.\n\t\tHence, the lonely numbers in nums are [10, 8].\n\t\tNote that [8, 10] may also be returned.\n\t\tExample 2:\n\t\tInput: nums = [1,3,5,3]\n\t\tOutput: [1,5]\n\t\tExplanation: \n\t\t- 1 is a lonely number since it appears exactly once and 0 and 2 does not appear in nums.\n\t\t- 5 is a lonely number since it appears exactly once and 4 and 6 does not appear in nums.\n\t\t- 3 is not a lonely number since it appears twice.\n\t\tHence, the lonely numbers in nums are [1, 5].\n\t\tNote that [5, 1] may also be returned.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2271,
-        "question": "class Solution:\n    def rearrangeArray(self, nums: List[int]) -> List[int]:\n\t\t\"\"\"\n\t\tYou are given a 0-indexed integer array nums of even length consisting of an equal number of positive and negative integers.\n\t\tYou should rearrange the elements of nums such that the modified array follows the given conditions:\n\t\t\tEvery consecutive pair of integers have opposite signs.\n\t\t\tFor all integers with the same sign, the order in which they were present in nums is preserved.\n\t\t\tThe rearranged array begins with a positive integer.\n\t\tReturn the modified array after rearranging the elements to satisfy the aforementioned conditions.\n\t\tExample 1:\n\t\tInput: nums = [3,1,-2,-5,2,-4]\n\t\tOutput: [3,-2,1,-5,2,-4]\n\t\tExplanation:\n\t\tThe positive integers in nums are [3,1,2]. The negative integers are [-2,-5,-4].\n\t\tThe only possible way to rearrange them such that they satisfy all conditions is [3,-2,1,-5,2,-4].\n\t\tOther ways such as [1,-2,2,-5,3,-4], [3,1,2,-2,-5,-4], [-2,3,-5,1,-4,2] are incorrect because they do not satisfy one or more conditions.  \n\t\tExample 2:\n\t\tInput: nums = [-1,1]\n\t\tOutput: [1,-1]\n\t\tExplanation:\n\t\t1 is the only positive integer and -1 the only negative integer in nums.\n\t\tSo nums is rearranged to [1,-1].\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2272,
-        "question": "class Solution:\n    def maximumGood(self, statements: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tThere are two types of persons:\n\t\t\tThe good person: The person who always tells the truth.\n\t\t\tThe bad person: The person who might tell the truth and might lie.\n\t\tYou are given a 0-indexed 2D integer array statements of size n x n that represents the statements made by n people about each other. More specifically, statements[i][j] could be one of the following:\n\t\t\t0 which represents a statement made by person i that person j is a bad person.\n\t\t\t1 which represents a statement made by person i that person j is a good person.\n\t\t\t2 represents that no statement is made by person i about person j.\n\t\tAdditionally, no person ever makes a statement about themselves. Formally, we have that statements[i][i] = 2 for all 0 <= i < n.\n\t\tReturn the maximum number of people who can be good based on the statements made by the n people.\n\t\tExample 1:\n\t\tInput: statements = [[2,1,2],[1,2,2],[2,0,2]]\n\t\tOutput: 2\n\t\tExplanation: Each person makes a single statement.\n\t\t- Person 0 states that person 1 is good.\n\t\t- Person 1 states that person 0 is good.\n\t\t- Person 2 states that person 1 is bad.\n\t\tLet's take person 2 as the key.\n\t\t- Assuming that person 2 is a good person:\n\t\t    - Based on the statement made by person 2, person 1 is a bad person.\n\t\t    - Now we know for sure that person 1 is bad and person 2 is good.\n\t\t    - Based on the statement made by person 1, and since person 1 is bad, they could be:\n\t\t        - telling the truth. There will be a contradiction in this case and this assumption is invalid.\n\t\t        - lying. In this case, person 0 is also a bad person and lied in their statement.\n\t\t    - Following that person 2 is a good person, there will be only one good person in the group.\n\t\t- Assuming that person 2 is a bad person:\n\t\t    - Based on the statement made by person 2, and since person 2 is bad, they could be:\n\t\t        - telling the truth. Following this scenario, person 0 and 1 are both bad as explained before.\n\t\t            - Following that person 2 is bad but told the truth, there will be no good persons in the group.\n\t\t        - lying. In this case person 1 is a good person.\n\t\t            - Since person 1 is a good person, person 0 is also a good person.\n\t\t            - Following that person 2 is bad and lied, there will be two good persons in the group.\n\t\tWe can see that at most 2 persons are good in the best case, so we return 2.\n\t\tNote that there is more than one way to arrive at this conclusion.\n\t\tExample 2:\n\t\tInput: statements = [[2,0],[0,2]]\n\t\tOutput: 1\n\t\tExplanation: Each person makes a single statement.\n\t\t- Person 0 states that person 1 is bad.\n\t\t- Person 1 states that person 0 is bad.\n\t\tLet's take person 0 as the key.\n\t\t- Assuming that person 0 is a good person:\n\t\t    - Based on the statement made by person 0, person 1 is a bad person and was lying.\n\t\t    - Following that person 0 is a good person, there will be only one good person in the group.\n\t\t- Assuming that person 0 is a bad person:\n\t\t    - Based on the statement made by person 0, and since person 0 is bad, they could be:\n\t\t        - telling the truth. Following this scenario, person 0 and 1 are both bad.\n\t\t            - Following that person 0 is bad but told the truth, there will be no good persons in the group.\n\t\t        - lying. In this case person 1 is a good person.\n\t\t            - Following that person 0 is bad and lied, there will be only one good person in the group.\n\t\tWe can see that at most, one person is good in the best case, so we return 1.\n\t\tNote that there is more than one way to arrive at this conclusion.\n\t\t\"\"\"\n",
-        "difficulty": 2
-    },
-    {
-        "number": 2274,
-        "question": "class Solution:\n    def findFinalValue(self, nums: List[int], original: int) -> int:\n\t\t\"\"\"\n\t\tYou are given an array of integers nums. You are also given an integer original which is the first number that needs to be searched for in nums.\n\t\tYou then do the following steps:\n\t\t\tIf original is found in nums, multiply it by two (i.e., set original = 2 * original).\n\t\t\tOtherwise, stop the process.\n\t\t\tRepeat this process with the new number as long as you keep finding the number.\n\t\tReturn the final value of original.\n\t\tExample 1:\n\t\tInput: nums = [5,3,6,1,12], original = 3\n\t\tOutput: 24\n\t\tExplanation: \n\t\t- 3 is found in nums. 3 is multiplied by 2 to obtain 6.\n\t\t- 6 is found in nums. 6 is multiplied by 2 to obtain 12.\n\t\t- 12 is found in nums. 12 is multiplied by 2 to obtain 24.\n\t\t- 24 is not found in nums. Thus, 24 is returned.\n\t\tExample 2:\n\t\tInput: nums = [2,7,9], original = 4\n\t\tOutput: 4\n\t\tExplanation:\n\t\t- 4 is not found in nums. Thus, 4 is returned.\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 2275,
-        "question": "class Solution:\n    def subStrHash(self, s: str, power: int, modulo: int, k: int, hashValue: int) -> str:\n\t\t\"\"\"\n\t\tThe hash of a 0-indexed string s of length k, given integers p and m, is computed using the following function:\n\t\t\thash(s, p, m) = (val(s[0]) * p0 + val(s[1]) * p1 + ... + val(s[k-1]) * pk-1) mod m.\n\t\tWhere val(s[i]) represents the index of s[i] in the alphabet from val('a') = 1 to val('z') = 26.\n\t\tYou are given a string s and the integers power, modulo, k, and hashValue. Return sub, the first substring of s of length k such that hash(sub, power, modulo) == hashValue.\n\t\tThe test cases will be generated such that an answer always exists.\n\t\tA substring is a contiguous non-empty sequence of characters within a string.\n\t\tExample 1:\n\t\tInput: s = \"leetcode\", power = 7, modulo = 20, k = 2, hashValue = 0\n\t\tOutput: \"ee\"\n\t\tExplanation: The hash of \"ee\" can be computed to be hash(\"ee\", 7, 20) = (5 * 1 + 5 * 7) mod 20 = 40 mod 20 = 0. \n\t\t\"ee\" is the first substring of length 2 with hashValue 0. Hence, we return \"ee\".\n\t\tExample 2:\n\t\tInput: s = \"fbxzaad\", power = 31, modulo = 100, k = 3, hashValue = 32\n\t\tOutput: \"fbx\"\n\t\tExplanation: The hash of \"fbx\" can be computed to be hash(\"fbx\", 31, 100) = (6 * 1 + 2 * 31 + 24 * 312) mod 100 = 23132 mod 100 = 32. \n\t\tThe hash of \"bxz\" can be computed to be hash(\"bxz\", 31, 100) = (2 * 1 + 24 * 31 + 26 * 312) mod 100 = 25732 mod 100 = 32. \n\t\t\"fbx\" is the first substring of length 3 with hashValue 32. Hence, we return \"fbx\".\n\t\tNote that \"bxz\" also has a hash of 32 but it appears later than \"fbx\".\n\t\t\"\"\"\n",
-        "difficulty": 2
-    },
-    {
-        "number": 2276,
-        "question": "class Solution:\n    def groupStrings(self, words: List[str]) -> List[int]:\n\t\t\"\"\"\n\t\tYou are given a 0-indexed array of strings words. Each string consists of lowercase English letters only. No letter occurs more than once in any string of words.\n\t\tTwo strings s1 and s2 are said to be connected if the set of letters of s2 can be obtained from the set of letters of s1 by any one of the following operations:\n\t\t\tAdding exactly one letter to the set of the letters of s1.\n\t\t\tDeleting exactly one letter from the set of the letters of s1.\n\t\t\tReplacing exactly one letter from the set of the letters of s1 with any letter, including itself.\n\t\tThe array words can be divided into one or more non-intersecting groups. A string belongs to a group if any one of the following is true:\n\t\t\tIt is connected to at least one other string of the group.\n\t\t\tIt is the only string present in the group.\n\t\tNote that the strings in words should be grouped in such a manner that a string belonging to a group cannot be connected to a string present in any other group. It can be proved that such an arrangement is always unique.\n\t\tReturn an array ans of size 2 where:\n\t\t\tans[0] is the maximum number of groups words can be divided into, and\n\t\t\tans[1] is the size of the largest group.\n\t\tExample 1:\n\t\tInput: words = [\"a\",\"b\",\"ab\",\"cde\"]\n\t\tOutput: [2,3]\n\t\tExplanation:\n\t\t- words[0] can be used to obtain words[1] (by replacing 'a' with 'b'), and words[2] (by adding 'b'). So words[0] is connected to words[1] and words[2].\n\t\t- words[1] can be used to obtain words[0] (by replacing 'b' with 'a'), and words[2] (by adding 'a'). So words[1] is connected to words[0] and words[2].\n\t\t- words[2] can be used to obtain words[0] (by deleting 'b'), and words[1] (by deleting 'a'). So words[2] is connected to words[0] and words[1].\n\t\t- words[3] is not connected to any string in words.\n\t\tThus, words can be divided into 2 groups [\"a\",\"b\",\"ab\"] and [\"cde\"]. The size of the largest group is 3.  \n\t\tExample 2:\n\t\tInput: words = [\"a\",\"ab\",\"abc\"]\n\t\tOutput: [1,3]\n\t\tExplanation:\n\t\t- words[0] is connected to words[1].\n\t\t- words[1] is connected to words[0] and words[2].\n\t\t- words[2] is connected to words[1].\n\t\tSince all strings are connected to each other, they should be grouped together.\n\t\tThus, the size of the largest group is 3.\n\t\t\"\"\"\n",
-        "difficulty": 2
-    },
-    {
-        "number": 2277,
-        "question": "class Solution:\n    def countPairs(self, nums: List[int], k: int) -> int:\n\t\t\"\"\"\n\t\tGiven a 0-indexed integer array nums of length n and an integer k, return the number of pairs (i, j) where 0 <= i < j < n, such that nums[i] == nums[j] and (i * j) is divisible by k.\n\t\tExample 1:\n\t\tInput: nums = [3,1,2,2,2,1,3], k = 2\n\t\tOutput: 4\n\t\tExplanation:\n\t\tThere are 4 pairs that meet all the requirements:\n\t\t- nums[0] == nums[6], and 0 * 6 == 0, which is divisible by 2.\n\t\t- nums[2] == nums[3], and 2 * 3 == 6, which is divisible by 2.\n\t\t- nums[2] == nums[4], and 2 * 4 == 8, which is divisible by 2.\n\t\t- nums[3] == nums[4], and 3 * 4 == 12, which is divisible by 2.\n\t\tExample 2:\n\t\tInput: nums = [1,2,3,4], k = 1\n\t\tOutput: 0\n\t\tExplanation: Since no value in nums is repeated, there are no pairs (i,j) that meet all the requirements.\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 2278,
-        "question": "class Solution:\n    def sumOfThree(self, num: int) -> List[int]:\n\t\t\"\"\"\n\t\tGiven an integer num, return three consecutive integers (as a sorted array) that sum to num. If num cannot be expressed as the sum of three consecutive integers, return an empty array.\n\t\tExample 1:\n\t\tInput: num = 33\n\t\tOutput: [10,11,12]\n\t\tExplanation: 33 can be expressed as 10 + 11 + 12 = 33.\n\t\t10, 11, 12 are 3 consecutive integers, so we return [10, 11, 12].\n\t\tExample 2:\n\t\tInput: num = 4\n\t\tOutput: []\n\t\tExplanation: There is no way to express 4 as the sum of 3 consecutive integers.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2279,
-        "question": "class Solution:\n    def maximumEvenSplit(self, finalSum: int) -> List[int]:\n\t\t\"\"\"\n\t\tYou are given an integer finalSum. Split it into a sum of a maximum number of unique positive even integers.\n\t\t\tFor example, given finalSum = 12, the following splits are valid (unique positive even integers summing up to finalSum): (12), (2 + 10), (2 + 4 + 6), and (4 + 8). Among them, (2 + 4 + 6) contains the maximum number of integers. Note that finalSum cannot be split into (2 + 2 + 4 + 4) as all the numbers should be unique.\n\t\tReturn a list of integers that represent a valid split containing a maximum number of integers. If no valid split exists for finalSum, return an empty list. You may return the integers in any order.\n\t\tExample 1:\n\t\tInput: finalSum = 12\n\t\tOutput: [2,4,6]\n\t\tExplanation: The following are valid splits: (12), (2 + 10), (2 + 4 + 6), and (4 + 8).\n\t\t(2 + 4 + 6) has the maximum number of integers, which is 3. Thus, we return [2,4,6].\n\t\tNote that [2,6,4], [6,2,4], etc. are also accepted.\n\t\tExample 2:\n\t\tInput: finalSum = 7\n\t\tOutput: []\n\t\tExplanation: There are no valid splits for the given finalSum.\n\t\tThus, we return an empty array.\n\t\tExample 3:\n\t\tInput: finalSum = 28\n\t\tOutput: [6,8,2,12]\n\t\tExplanation: The following are valid splits: (2 + 26), (6 + 8 + 2 + 12), and (4 + 24). \n\t\t(6 + 8 + 2 + 12) has the maximum number of integers, which is 4. Thus, we return [6,8,2,12].\n\t\tNote that [10,2,4,12], [6,2,4,16], etc. are also accepted.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2280,
-        "question": "class Solution:\n    def goodTriplets(self, nums1: List[int], nums2: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou are given two 0-indexed arrays nums1 and nums2 of length n, both of which are permutations of [0, 1, ..., n - 1].\n\t\tA good triplet is a set of 3 distinct values which are present in increasing order by position both in nums1 and nums2. In other words, if we consider pos1v as the index of the value v in nums1 and pos2v as the index of the value v in nums2, then a good triplet will be a set (x, y, z) where 0 <= x, y, z <= n - 1, such that pos1x < pos1y < pos1z and pos2x < pos2y < pos2z.\n\t\tReturn the total number of good triplets.\n\t\tExample 1:\n\t\tInput: nums1 = [2,0,1,3], nums2 = [0,1,2,3]\n\t\tOutput: 1\n\t\tExplanation: \n\t\tThere are 4 triplets (x,y,z) such that pos1x < pos1y < pos1z. They are (2,0,1), (2,0,3), (2,1,3), and (0,1,3). \n\t\tOut of those triplets, only the triplet (0,1,3) satisfies pos2x < pos2y < pos2z. Hence, there is only 1 good triplet.\n\t\tExample 2:\n\t\tInput: nums1 = [4,0,1,3,2], nums2 = [4,1,0,2,3]\n\t\tOutput: 4\n\t\tExplanation: The 4 good triplets are (4,0,3), (4,0,2), (4,1,3), and (4,1,2).\n\t\t\"\"\"\n",
-        "difficulty": 2
-    },
-    {
-        "number": 2283,
-        "question": "class Solution:\n    def sortEvenOdd(self, nums: List[int]) -> List[int]:\n\t\t\"\"\"\n\t\tYou are given a 0-indexed integer array nums. Rearrange the values of nums according to the following rules:\n\t\t\tSort the values at odd indices of nums in non-increasing order.\n\t\t\t\tFor example, if nums = [4,1,2,3] before this step, it becomes [4,3,2,1] after. The values at odd indices 1 and 3 are sorted in non-increasing order.\n\t\t\tSort the values at even indices of nums in non-decreasing order.\n\t\t\t\tFor example, if nums = [4,1,2,3] before this step, it becomes [2,1,4,3] after. The values at even indices 0 and 2 are sorted in non-decreasing order.\n\t\tReturn the array formed after rearranging the values of nums.\n\t\tExample 1:\n\t\tInput: nums = [4,1,2,3]\n\t\tOutput: [2,3,4,1]\n\t\tExplanation: \n\t\tFirst, we sort the values present at odd indices (1 and 3) in non-increasing order.\n\t\tSo, nums changes from [4,1,2,3] to [4,3,2,1].\n\t\tNext, we sort the values present at even indices (0 and 2) in non-decreasing order.\n\t\tSo, nums changes from [4,1,2,3] to [2,3,4,1].\n\t\tThus, the array formed after rearranging the values is [2,3,4,1].\n\t\tExample 2:\n\t\tInput: nums = [2,1]\n\t\tOutput: [2,1]\n\t\tExplanation: \n\t\tSince there is exactly one odd index and one even index, no rearrangement of values takes place.\n\t\tThe resultant array formed is [2,1], which is the same as the initial array. \n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 2284,
-        "question": "class Solution:\n    def smallestNumber(self, num: int) -> int:\n\t\t\"\"\"\n\t\tYou are given an integer num. Rearrange the digits of num such that its value is minimized and it does not contain any leading zeros.\n\t\tReturn the rearranged number with minimal value.\n\t\tNote that the sign of the number does not change after rearranging the digits.\n\t\tExample 1:\n\t\tInput: num = 310\n\t\tOutput: 103\n\t\tExplanation: The possible arrangements for the digits of 310 are 013, 031, 103, 130, 301, 310. \n\t\tThe arrangement with the smallest value that does not contain any leading zeros is 103.\n\t\tExample 2:\n\t\tInput: num = -7605\n\t\tOutput: -7650\n\t\tExplanation: Some possible arrangements for the digits of -7605 are -7650, -6705, -5076, -0567.\n\t\tThe arrangement with the smallest value that does not contain any leading zeros is -7650.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2285,
-        "question": "class Bitset:\n    def __init__(self, size: int):\n    def fix(self, idx: int) -> None:\n    def unfix(self, idx: int) -> None:\n    def flip(self) -> None:\n    def all(self) -> bool:\n    def one(self) -> bool:\n    def count(self) -> int:\n    def toString(self) -> str:\n\t\t\"\"\"\n\t\tA Bitset is a data structure that compactly stores bits.\n\t\tImplement the Bitset class:\n\t\t\tBitset(int size) Initializes the Bitset with size bits, all of which are 0.\n\t\t\tvoid fix(int idx) Updates the value of the bit at the index idx to 1. If the value was already 1, no change occurs.\n\t\t\tvoid unfix(int idx) Updates the value of the bit at the index idx to 0. If the value was already 0, no change occurs.\n\t\t\tvoid flip() Flips the values of each bit in the Bitset. In other words, all bits with value 0 will now have value 1 and vice versa.\n\t\t\tboolean all() Checks if the value of each bit in the Bitset is 1. Returns true if it satisfies the condition, false otherwise.\n\t\t\tboolean one() Checks if there is at least one bit in the Bitset with value 1. Returns true if it satisfies the condition, false otherwise.\n\t\t\tint count() Returns the total number of bits in the Bitset which have value 1.\n\t\t\tString toString() Returns the current composition of the Bitset. Note that in the resultant string, the character at the ith index should coincide with the value at the ith bit of the Bitset.\n\t\tExample 1:\n\t\tInput\n\t\t[\"Bitset\", \"fix\", \"fix\", \"flip\", \"all\", \"unfix\", \"flip\", \"one\", \"unfix\", \"count\", \"toString\"]\n\t\t[[5], [3], [1], [], [], [0], [], [], [0], [], []]\n\t\tOutput\n\t\t[null, null, null, null, false, null, null, true, null, 2, \"01010\"]\n\t\tExplanation\n\t\tBitset bs = new Bitset(5); // bitset = \"00000\".\n\t\tbs.fix(3);     // the value at idx = 3 is updated to 1, so bitset = \"00010\".\n\t\tbs.fix(1);     // the value at idx = 1 is updated to 1, so bitset = \"01010\". \n\t\tbs.flip();     // the value of each bit is flipped, so bitset = \"10101\". \n\t\tbs.all();      // return False, as not all values of the bitset are 1.\n\t\tbs.unfix(0);   // the value at idx = 0 is updated to 0, so bitset = \"00101\".\n\t\tbs.flip();     // the value of each bit is flipped, so bitset = \"11010\". \n\t\tbs.one();      // return True, as there is at least 1 index with value 1.\n\t\tbs.unfix(0);   // the value at idx = 0 is updated to 0, so bitset = \"01010\".\n\t\tbs.count();    // return 2, as there are 2 bits with value 1.\n\t\tbs.toString(); // return \"01010\", which is the composition of bitset.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2286,
-        "question": "class Solution:\n    def minimumTime(self, s: str) -> int:\n\t\t\"\"\"\n\t\tYou are given a 0-indexed binary string s which represents a sequence of train cars. s[i] = '0' denotes that the ith car does not contain illegal goods and s[i] = '1' denotes that the ith car does contain illegal goods.\n\t\tAs the train conductor, you would like to get rid of all the cars containing illegal goods. You can do any of the following three operations any number of times:\n\t\t\tRemove a train car from the left end (i.e., remove s[0]) which takes 1 unit of time.\n\t\t\tRemove a train car from the right end (i.e., remove s[s.length - 1]) which takes 1 unit of time.\n\t\t\tRemove a train car from anywhere in the sequence which takes 2 units of time.\n\t\tReturn the minimum time to remove all the cars containing illegal goods.\n\t\tNote that an empty sequence of cars is considered to have no cars containing illegal goods.\n\t\tExample 1:\n\t\tInput: s = \"1100101\"\n\t\tOutput: 5\n\t\tExplanation: \n\t\tOne way to remove all the cars containing illegal goods from the sequence is to\n\t\t- remove a car from the left end 2 times. Time taken is 2 * 1 = 2.\n\t\t- remove a car from the right end. Time taken is 1.\n\t\t- remove the car containing illegal goods found in the middle. Time taken is 2.\n\t\tThis obtains a total time of 2 + 1 + 2 = 5. \n\t\tAn alternative way is to\n\t\t- remove a car from the left end 2 times. Time taken is 2 * 1 = 2.\n\t\t- remove a car from the right end 3 times. Time taken is 3 * 1 = 3.\n\t\tThis also obtains a total time of 2 + 3 = 5.\n\t\t5 is the minimum time taken to remove all the cars containing illegal goods. \n\t\tThere are no other ways to remove them with less time.\n\t\tExample 2:\n\t\tInput: s = \"0010\"\n\t\tOutput: 2\n\t\tExplanation:\n\t\tOne way to remove all the cars containing illegal goods from the sequence is to\n\t\t- remove a car from the left end 3 times. Time taken is 3 * 1 = 3.\n\t\tThis obtains a total time of 3.\n\t\tAnother way to remove all the cars containing illegal goods from the sequence is to\n\t\t- remove the car containing illegal goods found in the middle. Time taken is 2.\n\t\tThis obtains a total time of 2.\n\t\tAnother way to remove all the cars containing illegal goods from the sequence is to \n\t\t- remove a car from the right end 2 times. Time taken is 2 * 1 = 2. \n\t\tThis obtains a total time of 2.\n\t\t2 is the minimum time taken to remove all the cars containing illegal goods. \n\t\tThere are no other ways to remove them with less time.\n\t\t\"\"\"\n",
-        "difficulty": 2
-    },
-    {
-        "number": 2288,
-        "question": "class Solution:\n    def countOperations(self, num1: int, num2: int) -> int:\n\t\t\"\"\"\n\t\tYou are given two non-negative integers num1 and num2.\n\t\tIn one operation, if num1 >= num2, you must subtract num2 from num1, otherwise subtract num1 from num2.\n\t\t\tFor example, if num1 = 5 and num2 = 4, subtract num2 from num1, thus obtaining num1 = 1 and num2 = 4. However, if num1 = 4 and num2 = 5, after one operation, num1 = 4 and num2 = 1.\n\t\tReturn the number of operations required to make either num1 = 0 or num2 = 0.\n\t\tExample 1:\n\t\tInput: num1 = 2, num2 = 3\n\t\tOutput: 3\n\t\tExplanation: \n\t\t- Operation 1: num1 = 2, num2 = 3. Since num1 < num2, we subtract num1 from num2 and get num1 = 2, num2 = 3 - 2 = 1.\n\t\t- Operation 2: num1 = 2, num2 = 1. Since num1 > num2, we subtract num2 from num1.\n\t\t- Operation 3: num1 = 1, num2 = 1. Since num1 == num2, we subtract num2 from num1.\n\t\tNow num1 = 0 and num2 = 1. Since num1 == 0, we do not need to perform any further operations.\n\t\tSo the total number of operations required is 3.\n\t\tExample 2:\n\t\tInput: num1 = 10, num2 = 10\n\t\tOutput: 1\n\t\tExplanation: \n\t\t- Operation 1: num1 = 10, num2 = 10. Since num1 == num2, we subtract num2 from num1 and get num1 = 10 - 10 = 0.\n\t\tNow num1 = 0 and num2 = 10. Since num1 == 0, we are done.\n\t\tSo the total number of operations required is 1.\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 2289,
-        "question": "class Solution:\n    def minimumOperations(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou are given a 0-indexed array nums consisting of n positive integers.\n\t\tThe array nums is called alternating if:\n\t\t\tnums[i - 2] == nums[i], where 2 <= i <= n - 1.\n\t\t\tnums[i - 1] != nums[i], where 1 <= i <= n - 1.\n\t\tIn one operation, you can choose an index i and change nums[i] into any positive integer.\n\t\tReturn the minimum number of operations required to make the array alternating.\n\t\tExample 1:\n\t\tInput: nums = [3,1,3,2,4,3]\n\t\tOutput: 3\n\t\tExplanation:\n\t\tOne way to make the array alternating is by converting it to [3,1,3,1,3,1].\n\t\tThe number of operations required in this case is 3.\n\t\tIt can be proven that it is not possible to make the array alternating in less than 3 operations. \n\t\tExample 2:\n\t\tInput: nums = [1,2,2,2,2]\n\t\tOutput: 2\n\t\tExplanation:\n\t\tOne way to make the array alternating is by converting it to [1,2,1,2,1].\n\t\tThe number of operations required in this case is 2.\n\t\tNote that the array cannot be converted to [2,2,2,2,2] because in this case nums[0] == nums[1] which violates the conditions of an alternating array.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2290,
-        "question": "class Solution:\n    def minimumRemoval(self, beans: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou are given an array of positive integers beans, where each integer represents the number of magic beans found in a particular magic bag.\n\t\tRemove any number of beans (possibly none) from each bag such that the number of beans in each remaining non-empty bag (still containing at least one bean) is equal. Once a bean has been removed from a bag, you are not allowed to return it to any of the bags.\n\t\tReturn the minimum number of magic beans that you have to remove.\n\t\tExample 1:\n\t\tInput: beans = [4,1,6,5]\n\t\tOutput: 4\n\t\tExplanation: \n\t\t- We remove 1 bean from the bag with only 1 bean.\n\t\t  This results in the remaining bags: [4,0,6,5]\n\t\t- Then we remove 2 beans from the bag with 6 beans.\n\t\t  This results in the remaining bags: [4,0,4,5]\n\t\t- Then we remove 1 bean from the bag with 5 beans.\n\t\t  This results in the remaining bags: [4,0,4,4]\n\t\tWe removed a total of 1 + 2 + 1 = 4 beans to make the remaining non-empty bags have an equal number of beans.\n\t\tThere are no other solutions that remove 4 beans or fewer.\n\t\tExample 2:\n\t\tInput: beans = [2,10,3,2]\n\t\tOutput: 7\n\t\tExplanation:\n\t\t- We remove 2 beans from one of the bags with 2 beans.\n\t\t  This results in the remaining bags: [0,10,3,2]\n\t\t- Then we remove 2 beans from the other bag with 2 beans.\n\t\t  This results in the remaining bags: [0,10,3,0]\n\t\t- Then we remove 3 beans from the bag with 3 beans. \n\t\t  This results in the remaining bags: [0,10,0,0]\n\t\tWe removed a total of 2 + 2 + 3 = 7 beans to make the remaining non-empty bags have an equal number of beans.\n\t\tThere are no other solutions that removes 7 beans or fewer.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2291,
-        "question": "class Solution:\n    def maximumANDSum(self, nums: List[int], numSlots: int) -> int:\n\t\t\"\"\"\n\t\tYou are given an integer array nums of length n and an integer numSlots such that 2 * numSlots >= n. There are numSlots slots numbered from 1 to numSlots.\n\t\tYou have to place all n integers into the slots such that each slot contains at most two numbers. The AND sum of a given placement is the sum of the bitwise AND of every number with its respective slot number.\n\t\t\tFor example, the AND sum of placing the numbers [1, 3] into slot 1 and [4, 6] into slot 2 is equal to (1 AND 1) + (3 AND 1) + (4 AND 2) + (6 AND 2) = 1 + 1 + 0 + 2 = 4.\n\t\tReturn the maximum possible AND sum of nums given numSlots slots.\n\t\tExample 1:\n\t\tInput: nums = [1,2,3,4,5,6], numSlots = 3\n\t\tOutput: 9\n\t\tExplanation: One possible placement is [1, 4] into slot 1, [2, 6] into slot 2, and [3, 5] into slot 3. \n\t\tThis gives the maximum AND sum of (1 AND 1) + (4 AND 1) + (2 AND 2) + (6 AND 2) + (3 AND 3) + (5 AND 3) = 1 + 0 + 2 + 2 + 3 + 1 = 9.\n\t\tExample 2:\n\t\tInput: nums = [1,3,10,4,7,1], numSlots = 9\n\t\tOutput: 24\n\t\tExplanation: One possible placement is [1, 1] into slot 1, [3] into slot 3, [4] into slot 4, [7] into slot 7, and [10] into slot 9.\n\t\tThis gives the maximum AND sum of (1 AND 1) + (1 AND 1) + (3 AND 3) + (4 AND 4) + (7 AND 7) + (10 AND 9) = 1 + 1 + 3 + 4 + 7 + 8 = 24.\n\t\tNote that slots 2, 5, 6, and 8 are empty which is permitted.\n\t\t\"\"\"\n",
-        "difficulty": 2
-    },
-    {
-        "number": 2292,
-        "question": "class Solution:\n    def prefixCount(self, words: List[str], pref: str) -> int:\n\t\t\"\"\"\n\t\tYou are given an array of strings words and a string pref.\n\t\tReturn the number of strings in words that contain pref as a prefix.\n\t\tA prefix of a string s is any leading contiguous substring of s.\n\t\tExample 1:\n\t\tInput: words = [\"pay\",\"attention\",\"practice\",\"attend\"], pref = \"at\"\n\t\tOutput: 2\n\t\tExplanation: The 2 strings that contain \"at\" as a prefix are: \"attention\" and \"attend\".\n\t\tExample 2:\n\t\tInput: words = [\"leetcode\",\"win\",\"loops\",\"success\"], pref = \"code\"\n\t\tOutput: 0\n\t\tExplanation: There are no strings that contain \"code\" as a prefix.\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 2293,
-        "question": "class Solution:\n    def minSteps(self, s: str, t: str) -> int:\n\t\t\"\"\"\n\t\tYou are given two strings s and t. In one step, you can append any character to either s or t.\n\t\tReturn the minimum number of steps to make s and t anagrams of each other.\n\t\tAn anagram of a string is a string that contains the same characters with a different (or the same) ordering.\n\t\tExample 1:\n\t\tInput: s = \"leetcode\", t = \"coats\"\n\t\tOutput: 7\n\t\tExplanation: \n\t\t- In 2 steps, we can append the letters in \"as\" onto s = \"leetcode\", forming s = \"leetcodeas\".\n\t\t- In 5 steps, we can append the letters in \"leede\" onto t = \"coats\", forming t = \"coatsleede\".\n\t\t\"leetcodeas\" and \"coatsleede\" are now anagrams of each other.\n\t\tWe used a total of 2 + 5 = 7 steps.\n\t\tIt can be shown that there is no way to make them anagrams of each other with less than 7 steps.\n\t\tExample 2:\n\t\tInput: s = \"night\", t = \"thing\"\n\t\tOutput: 0\n\t\tExplanation: The given strings are already anagrams of each other. Thus, we do not need any further steps.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2294,
-        "question": "class Solution:\n    def minimumTime(self, time: List[int], totalTrips: int) -> int:\n\t\t\"\"\"\n\t\tYou are given an array time where time[i] denotes the time taken by the ith bus to complete one trip.\n\t\tEach bus can make multiple trips successively; that is, the next trip can start immediately after completing the current trip. Also, each bus operates independently; that is, the trips of one bus do not influence the trips of any other bus.\n\t\tYou are also given an integer totalTrips, which denotes the number of trips all buses should make in total. Return the minimum time required for all buses to complete at least totalTrips trips.\n\t\tExample 1:\n\t\tInput: time = [1,2,3], totalTrips = 5\n\t\tOutput: 3\n\t\tExplanation:\n\t\t- At time t = 1, the number of trips completed by each bus are [1,0,0]. \n\t\t  The total number of trips completed is 1 + 0 + 0 = 1.\n\t\t- At time t = 2, the number of trips completed by each bus are [2,1,0]. \n\t\t  The total number of trips completed is 2 + 1 + 0 = 3.\n\t\t- At time t = 3, the number of trips completed by each bus are [3,1,1]. \n\t\t  The total number of trips completed is 3 + 1 + 1 = 5.\n\t\tSo the minimum time needed for all buses to complete at least 5 trips is 3.\n\t\tExample 2:\n\t\tInput: time = [2], totalTrips = 1\n\t\tOutput: 2\n\t\tExplanation:\n\t\tThere is only one bus, and it will complete its first trip at t = 2.\n\t\tSo the minimum time needed to complete 1 trip is 2.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2295,
-        "question": "class Solution:\n    def minimumFinishTime(self, tires: List[List[int]], changeTime: int, numLaps: int) -> int:\n\t\t\"\"\"\n\t\tYou are given a 0-indexed 2D integer array tires where tires[i] = [fi, ri] indicates that the ith tire can finish its xth successive lap in fi * ri(x-1) seconds.\n\t\t\tFor example, if fi = 3 and ri = 2, then the tire would finish its 1st lap in 3 seconds, its 2nd lap in 3 * 2 = 6 seconds, its 3rd lap in 3 * 22 = 12 seconds, etc.\n\t\tYou are also given an integer changeTime and an integer numLaps.\n\t\tThe race consists of numLaps laps and you may start the race with any tire. You have an unlimited supply of each tire and after every lap, you may change to any given tire (including the current tire type) if you wait changeTime seconds.\n\t\tReturn the minimum time to finish the race.\n\t\tExample 1:\n\t\tInput: tires = [[2,3],[3,4]], changeTime = 5, numLaps = 4\n\t\tOutput: 21\n\t\tExplanation: \n\t\tLap 1: Start with tire 0 and finish the lap in 2 seconds.\n\t\tLap 2: Continue with tire 0 and finish the lap in 2 * 3 = 6 seconds.\n\t\tLap 3: Change tires to a new tire 0 for 5 seconds and then finish the lap in another 2 seconds.\n\t\tLap 4: Continue with tire 0 and finish the lap in 2 * 3 = 6 seconds.\n\t\tTotal time = 2 + 6 + 5 + 2 + 6 = 21 seconds.\n\t\tThe minimum time to complete the race is 21 seconds.\n\t\tExample 2:\n\t\tInput: tires = [[1,10],[2,2],[3,4]], changeTime = 6, numLaps = 5\n\t\tOutput: 25\n\t\tExplanation: \n\t\tLap 1: Start with tire 1 and finish the lap in 2 seconds.\n\t\tLap 2: Continue with tire 1 and finish the lap in 2 * 2 = 4 seconds.\n\t\tLap 3: Change tires to a new tire 1 for 6 seconds and then finish the lap in another 2 seconds.\n\t\tLap 4: Continue with tire 1 and finish the lap in 2 * 2 = 4 seconds.\n\t\tLap 5: Change tires to tire 0 for 6 seconds then finish the lap in another 1 second.\n\t\tTotal time = 2 + 4 + 6 + 2 + 4 + 6 + 1 = 25 seconds.\n\t\tThe minimum time to complete the race is 25 seconds. \n\t\t\"\"\"\n",
-        "difficulty": 2
-    },
-    {
-        "number": 2298,
-        "question": "class Solution:\n    def countEven(self, num: int) -> int:\n\t\t\"\"\"\n\t\tGiven a positive integer num, return the number of positive integers less than or equal to num whose digit sums are even.\n\t\tThe digit sum of a positive integer is the sum of all its digits.\n\t\tExample 1:\n\t\tInput: num = 4\n\t\tOutput: 2\n\t\tExplanation:\n\t\tThe only integers less than or equal to 4 whose digit sums are even are 2 and 4.    \n\t\tExample 2:\n\t\tInput: num = 30\n\t\tOutput: 14\n\t\tExplanation:\n\t\tThe 14 integers less than or equal to 30 whose digit sums are even are\n\t\t2, 4, 6, 8, 11, 13, 15, 17, 19, 20, 22, 24, 26, and 28.\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 2299,
-        "question": "class Solution:\n    def mergeNodes(self, head: Optional[ListNode]) -> Optional[ListNode]:\n\t\t\"\"\"\n\t\tYou are given the head of a linked list, which contains a series of integers separated by 0's. The beginning and end of the linked list will have Node.val == 0.\n\t\tFor every two consecutive 0's, merge all the nodes lying in between them into a single node whose value is the sum of all the merged nodes. The modified list should not contain any 0's.\n\t\tReturn the head of the modified linked list.\n\t\tExample 1:\n\t\tInput: head = [0,3,1,0,4,5,2,0]\n\t\tOutput: [4,11]\n\t\tExplanation: \n\t\tThe above figure represents the given linked list. The modified list contains\n\t\t- The sum of the nodes marked in green: 3 + 1 = 4.\n\t\t- The sum of the nodes marked in red: 4 + 5 + 2 = 11.\n\t\tExample 2:\n\t\tInput: head = [0,1,0,3,0,2,2,0]\n\t\tOutput: [1,3,4]\n\t\tExplanation: \n\t\tThe above figure represents the given linked list. The modified list contains\n\t\t- The sum of the nodes marked in green: 1 = 1.\n\t\t- The sum of the nodes marked in red: 3 = 3.\n\t\t- The sum of the nodes marked in yellow: 2 + 2 = 4.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2300,
-        "question": "class Solution:\n    def repeatLimitedString(self, s: str, repeatLimit: int) -> str:\n\t\t\"\"\"\n\t\tYou are given a string s and an integer repeatLimit. Construct a new string repeatLimitedString using the characters of s such that no letter appears more than repeatLimit times in a row. You do not have to use all characters from s.\n\t\tReturn the lexicographically largest repeatLimitedString possible.\n\t\tA string a is lexicographically larger than a string b if in the first position where a and b differ, string a has a letter that appears later in the alphabet than the corresponding letter in b. If the first min(a.length, b.length) characters do not differ, then the longer string is the lexicographically larger one.\n\t\tExample 1:\n\t\tInput: s = \"cczazcc\", repeatLimit = 3\n\t\tOutput: \"zzcccac\"\n\t\tExplanation: We use all of the characters from s to construct the repeatLimitedString \"zzcccac\".\n\t\tThe letter 'a' appears at most 1 time in a row.\n\t\tThe letter 'c' appears at most 3 times in a row.\n\t\tThe letter 'z' appears at most 2 times in a row.\n\t\tHence, no letter appears more than repeatLimit times in a row and the string is a valid repeatLimitedString.\n\t\tThe string is the lexicographically largest repeatLimitedString possible so we return \"zzcccac\".\n\t\tNote that the string \"zzcccca\" is lexicographically larger but the letter 'c' appears more than 3 times in a row, so it is not a valid repeatLimitedString.\n\t\tExample 2:\n\t\tInput: s = \"aababab\", repeatLimit = 2\n\t\tOutput: \"bbabaa\"\n\t\tExplanation: We use only some of the characters from s to construct the repeatLimitedString \"bbabaa\". \n\t\tThe letter 'a' appears at most 2 times in a row.\n\t\tThe letter 'b' appears at most 2 times in a row.\n\t\tHence, no letter appears more than repeatLimit times in a row and the string is a valid repeatLimitedString.\n\t\tThe string is the lexicographically largest repeatLimitedString possible so we return \"bbabaa\".\n\t\tNote that the string \"bbabaaa\" is lexicographically larger but the letter 'a' appears more than 2 times in a row, so it is not a valid repeatLimitedString.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2301,
-        "question": "class Solution:\n    def countPairs(self, nums: List[int], k: int) -> int:\n\t\t\"\"\"\n\t\tGiven a 0-indexed integer array nums of length n and an integer k, return the number of pairs (i, j) such that:\n\t\t\t0 <= i < j <= n - 1 and\n\t\t\tnums[i] * nums[j] is divisible by k.\n\t\tExample 1:\n\t\tInput: nums = [1,2,3,4,5], k = 2\n\t\tOutput: 7\n\t\tExplanation: \n\t\tThe 7 pairs of indices whose corresponding products are divisible by 2 are\n\t\t(0, 1), (0, 3), (1, 2), (1, 3), (1, 4), (2, 3), and (3, 4).\n\t\tTheir products are 2, 4, 6, 8, 10, 12, and 20 respectively.\n\t\tOther pairs such as (0, 2) and (2, 4) have products 3 and 15 respectively, which are not divisible by 2.    \n\t\tExample 2:\n\t\tInput: nums = [1,2,3,4], k = 5\n\t\tOutput: 0\n\t\tExplanation: There does not exist any pair of indices whose corresponding product is divisible by 5.\n\t\t\"\"\"\n",
-        "difficulty": 2
-    },
-    {
-        "number": 2304,
-        "question": "class Solution:\n    def cellsInRange(self, s: str) -> List[str]:\n\t\t\"\"\"\n\t\tA cell (r, c) of an excel sheet is represented as a string \"\" where:\n\t\t\t denotes the column number c of the cell. It is represented by alphabetical letters.\n\t\t\t\tFor example, the 1st column is denoted by 'A', the 2nd by 'B', the 3rd by 'C', and so on.\n\t\t\t is the row number r of the cell. The rth row is represented by the integer r.\n\t\tYou are given a string s in the format \":\", where  represents the column c1,  represents the row r1,  represents the column c2, and  represents the row r2, such that r1 <= r2 and c1 <= c2.\n\t\tReturn the list of cells (x, y) such that r1 <= x <= r2 and c1 <= y <= c2. The cells should be represented as strings in the format mentioned above and be sorted in non-decreasing order first by columns and then by rows.\n\t\tExample 1:\n\t\tInput: s = \"K1:L2\"\n\t\tOutput: [\"K1\",\"K2\",\"L1\",\"L2\"]\n\t\tExplanation:\n\t\tThe above diagram shows the cells which should be present in the list.\n\t\tThe red arrows denote the order in which the cells should be presented.\n\t\tExample 2:\n\t\tInput: s = \"A1:F1\"\n\t\tOutput: [\"A1\",\"B1\",\"C1\",\"D1\",\"E1\",\"F1\"]\n\t\tExplanation:\n\t\tThe above diagram shows the cells which should be present in the list.\n\t\tThe red arrow denotes the order in which the cells should be presented.\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 2305,
-        "question": "class Solution:\n    def minimalKSum(self, nums: List[int], k: int) -> int:\n\t\t\"\"\"\n\t\tYou are given an integer array nums and an integer k. Append k unique positive integers that do not appear in nums to nums such that the resulting total sum is minimum.\n\t\tReturn the sum of the k integers appended to nums.\n\t\tExample 1:\n\t\tInput: nums = [1,4,25,10,25], k = 2\n\t\tOutput: 5\n\t\tExplanation: The two unique positive integers that do not appear in nums which we append are 2 and 3.\n\t\tThe resulting sum of nums is 1 + 4 + 25 + 10 + 25 + 2 + 3 = 70, which is the minimum.\n\t\tThe sum of the two integers appended is 2 + 3 = 5, so we return 5.\n\t\tExample 2:\n\t\tInput: nums = [5,6], k = 6\n\t\tOutput: 25\n\t\tExplanation: The six unique positive integers that do not appear in nums which we append are 1, 2, 3, 4, 7, and 8.\n\t\tThe resulting sum of nums is 5 + 6 + 1 + 2 + 3 + 4 + 7 + 8 = 36, which is the minimum. \n\t\tThe sum of the six integers appended is 1 + 2 + 3 + 4 + 7 + 8 = 25, so we return 25.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2306,
-        "question": "class Solution:\n    def createBinaryTree(self, descriptions: List[List[int]]) -> Optional[TreeNode]:\n\t\t\"\"\"\n\t\tYou are given a 2D integer array descriptions where descriptions[i] = [parenti, childi, isLefti] indicates that parenti is the parent of childi in a binary tree of unique values. Furthermore,\n\t\t\tIf isLefti == 1, then childi is the left child of parenti.\n\t\t\tIf isLefti == 0, then childi is the right child of parenti.\n\t\tConstruct the binary tree described by descriptions and return its root.\n\t\tThe test cases will be generated such that the binary tree is valid.\n\t\tExample 1:\n\t\tInput: descriptions = [[20,15,1],[20,17,0],[50,20,1],[50,80,0],[80,19,1]]\n\t\tOutput: [50,20,80,15,17,19]\n\t\tExplanation: The root node is the node with value 50 since it has no parent.\n\t\tThe resulting binary tree is shown in the diagram.\n\t\tExample 2:\n\t\tInput: descriptions = [[1,2,1],[2,3,0],[3,4,1]]\n\t\tOutput: [1,2,null,null,3,4]\n\t\tExplanation: The root node is the node with value 1 since it has no parent.\n\t\tThe resulting binary tree is shown in the diagram.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2307,
-        "question": "class Solution:\n    def replaceNonCoprimes(self, nums: List[int]) -> List[int]:\n\t\t\"\"\"\n\t\tYou are given an array of integers nums. Perform the following steps:\n\t\t\tFind any two adjacent numbers in nums that are non-coprime.\n\t\t\tIf no such numbers are found, stop the process.\n\t\t\tOtherwise, delete the two numbers and replace them with their LCM (Least Common Multiple).\n\t\t\tRepeat this process as long as you keep finding two adjacent non-coprime numbers.\n\t\tReturn the final modified array. It can be shown that replacing adjacent non-coprime numbers in any arbitrary order will lead to the same result.\n\t\tThe test cases are generated such that the values in the final array are less than or equal to 108.\n\t\tTwo values x and y are non-coprime if GCD(x, y) > 1 where GCD(x, y) is the Greatest Common Divisor of x and y.\n\t\tExample 1:\n\t\tInput: nums = [6,4,3,2,7,6,2]\n\t\tOutput: [12,7,6]\n\t\tExplanation: \n\t\t- (6, 4) are non-coprime with LCM(6, 4) = 12. Now, nums = [12,3,2,7,6,2].\n\t\t- (12, 3) are non-coprime with LCM(12, 3) = 12. Now, nums = [12,2,7,6,2].\n\t\t- (12, 2) are non-coprime with LCM(12, 2) = 12. Now, nums = [12,7,6,2].\n\t\t- (6, 2) are non-coprime with LCM(6, 2) = 6. Now, nums = [12,7,6].\n\t\tThere are no more adjacent non-coprime numbers in nums.\n\t\tThus, the final modified array is [12,7,6].\n\t\tNote that there are other ways to obtain the same resultant array.\n\t\tExample 2:\n\t\tInput: nums = [2,2,1,1,3,3,3]\n\t\tOutput: [2,1,1,3]\n\t\tExplanation: \n\t\t- (3, 3) are non-coprime with LCM(3, 3) = 3. Now, nums = [2,2,1,1,3,3].\n\t\t- (3, 3) are non-coprime with LCM(3, 3) = 3. Now, nums = [2,2,1,1,3].\n\t\t- (2, 2) are non-coprime with LCM(2, 2) = 2. Now, nums = [2,1,1,3].\n\t\tThere are no more adjacent non-coprime numbers in nums.\n\t\tThus, the final modified array is [2,1,1,3].\n\t\tNote that there are other ways to obtain the same resultant array.\n\t\t\"\"\"\n",
-        "difficulty": 2
-    },
-    {
-        "number": 2308,
-        "question": "class Solution:\n    def divideArray(self, nums: List[int]) -> bool:\n\t\t\"\"\"\n\t\tYou are given an integer array nums consisting of 2 * n integers.\n\t\tYou need to divide nums into n pairs such that:\n\t\t\tEach element belongs to exactly one pair.\n\t\t\tThe elements present in a pair are equal.\n\t\tReturn true if nums can be divided into n pairs, otherwise return false.\n\t\tExample 1:\n\t\tInput: nums = [3,2,3,2,2,2]\n\t\tOutput: true\n\t\tExplanation: \n\t\tThere are 6 elements in nums, so they should be divided into 6 / 2 = 3 pairs.\n\t\tIf nums is divided into the pairs (2, 2), (3, 3), and (2, 2), it will satisfy all the conditions.\n\t\tExample 2:\n\t\tInput: nums = [1,2,3,4]\n\t\tOutput: false\n\t\tExplanation: \n\t\tThere is no way to divide nums into 4 / 2 = 2 pairs such that the pairs satisfy every condition.\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 2309,
-        "question": "class Solution:\n    def maximumSubsequenceCount(self, text: str, pattern: str) -> int:\n\t\t\"\"\"\n\t\tYou are given a 0-indexed string text and another 0-indexed string pattern of length 2, both of which consist of only lowercase English letters.\n\t\tYou can add either pattern[0] or pattern[1] anywhere in text exactly once. Note that the character can be added even at the beginning or at the end of text.\n\t\tReturn the maximum number of times pattern can occur as a subsequence of the modified text.\n\t\tA subsequence is a string that can be derived from another string by deleting some or no characters without changing the order of the remaining characters.\n\t\tExample 1:\n\t\tInput: text = \"abdcdbc\", pattern = \"ac\"\n\t\tOutput: 4\n\t\tExplanation:\n\t\tIf we add pattern[0] = 'a' in between text[1] and text[2], we get \"abadcdbc\". Now, the number of times \"ac\" occurs as a subsequence is 4.\n\t\tSome other strings which have 4 subsequences \"ac\" after adding a character to text are \"aabdcdbc\" and \"abdacdbc\".\n\t\tHowever, strings such as \"abdcadbc\", \"abdccdbc\", and \"abdcdbcc\", although obtainable, have only 3 subsequences \"ac\" and are thus suboptimal.\n\t\tIt can be shown that it is not possible to get more than 4 subsequences \"ac\" by adding only one character.\n\t\tExample 2:\n\t\tInput: text = \"aabb\", pattern = \"ab\"\n\t\tOutput: 6\n\t\tExplanation:\n\t\tSome of the strings which can be obtained from text and have 6 subsequences \"ab\" are \"aaabb\", \"aaabb\", and \"aabbb\".\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2310,
-        "question": "class Solution:\n    def halveArray(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou are given an array nums of positive integers. In one operation, you can choose any number from nums and reduce it to exactly half the number. (Note that you may choose this reduced number in future operations.)\n\t\tReturn the minimum number of operations to reduce the sum of nums by at least half.\n\t\tExample 1:\n\t\tInput: nums = [5,19,8,1]\n\t\tOutput: 3\n\t\tExplanation: The initial sum of nums is equal to 5 + 19 + 8 + 1 = 33.\n\t\tThe following is one of the ways to reduce the sum by at least half:\n\t\tPick the number 19 and reduce it to 9.5.\n\t\tPick the number 9.5 and reduce it to 4.75.\n\t\tPick the number 8 and reduce it to 4.\n\t\tThe final array is [5, 4.75, 4, 1] with a total sum of 5 + 4.75 + 4 + 1 = 14.75. \n\t\tThe sum of nums has been reduced by 33 - 14.75 = 18.25, which is at least half of the initial sum, 18.25 >= 33/2 = 16.5.\n\t\tOverall, 3 operations were used so we return 3.\n\t\tIt can be shown that we cannot reduce the sum by at least half in less than 3 operations.\n\t\tExample 2:\n\t\tInput: nums = [3,8,20]\n\t\tOutput: 3\n\t\tExplanation: The initial sum of nums is equal to 3 + 8 + 20 = 31.\n\t\tThe following is one of the ways to reduce the sum by at least half:\n\t\tPick the number 20 and reduce it to 10.\n\t\tPick the number 10 and reduce it to 5.\n\t\tPick the number 3 and reduce it to 1.5.\n\t\tThe final array is [1.5, 8, 5] with a total sum of 1.5 + 8 + 5 = 14.5. \n\t\tThe sum of nums has been reduced by 31 - 14.5 = 16.5, which is at least half of the initial sum, 16.5 >= 31/2 = 15.5.\n\t\tOverall, 3 operations were used so we return 3.\n\t\tIt can be shown that we cannot reduce the sum by at least half in less than 3 operations.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2311,
-        "question": "class Solution:\n    def minimumWhiteTiles(self, floor: str, numCarpets: int, carpetLen: int) -> int:\n\t\t\"\"\"\n\t\tYou are given a 0-indexed binary string floor, which represents the colors of tiles on a floor:\n\t\t\tfloor[i] = '0' denotes that the ith tile of the floor is colored black.\n\t\t\tOn the other hand, floor[i] = '1' denotes that the ith tile of the floor is colored white.\n\t\tYou are also given numCarpets and carpetLen. You have numCarpets black carpets, each of length carpetLen tiles. Cover the tiles with the given carpets such that the number of white tiles still visible is minimum. Carpets may overlap one another.\n\t\tReturn the minimum number of white tiles still visible.\n\t\tExample 1:\n\t\tInput: floor = \"10110101\", numCarpets = 2, carpetLen = 2\n\t\tOutput: 2\n\t\tExplanation: \n\t\tThe figure above shows one way of covering the tiles with the carpets such that only 2 white tiles are visible.\n\t\tNo other way of covering the tiles with the carpets can leave less than 2 white tiles visible.\n\t\tExample 2:\n\t\tInput: floor = \"11111\", numCarpets = 2, carpetLen = 3\n\t\tOutput: 0\n\t\tExplanation: \n\t\tThe figure above shows one way of covering the tiles with the carpets such that no white tiles are visible.\n\t\tNote that the carpets are able to overlap one another.\n\t\t\"\"\"\n",
-        "difficulty": 2
-    },
-    {
-        "number": 2312,
-        "question": "class Solution:\n    def mostFrequent(self, nums: List[int], key: int) -> int:\n\t\t\"\"\"\n\t\tYou are given a 0-indexed integer array nums. You are also given an integer key, which is present in nums.\n\t\tFor every unique integer target in nums, count the number of times target immediately follows an occurrence of key in nums. In other words, count the number of indices i such that:\n\t\t\t0 <= i <= nums.length - 2,\n\t\t\tnums[i] == key and,\n\t\t\tnums[i + 1] == target.\n\t\tReturn the target with the maximum count. The test cases will be generated such that the target with maximum count is unique.\n\t\tExample 1:\n\t\tInput: nums = [1,100,200,1,100], key = 1\n\t\tOutput: 100\n\t\tExplanation: For target = 100, there are 2 occurrences at indices 1 and 4 which follow an occurrence of key.\n\t\tNo other integers follow an occurrence of key, so we return 100.\n\t\tExample 2:\n\t\tInput: nums = [2,2,2,2,3], key = 2\n\t\tOutput: 2\n\t\tExplanation: For target = 2, there are 3 occurrences at indices 1, 2, and 3 which follow an occurrence of key.\n\t\tFor target = 3, there is only one occurrence at index 4 which follows an occurrence of key.\n\t\ttarget = 2 has the maximum number of occurrences following an occurrence of key, so we return 2.\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 2316,
-        "question": "class Solution:\n    def countHillValley(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou are given a 0-indexed integer array nums. An index i is part of a hill in nums if the closest non-equal neighbors of i are smaller than nums[i]. Similarly, an index i is part of a valley in nums if the closest non-equal neighbors of i are larger than nums[i]. Adjacent indices i and j are part of the same hill or valley if nums[i] == nums[j].\n\t\tNote that for an index to be part of a hill or valley, it must have a non-equal neighbor on both the left and right of the index.\n\t\tReturn the number of hills and valleys in nums.\n\t\tExample 1:\n\t\tInput: nums = [2,4,1,1,6,5]\n\t\tOutput: 3\n\t\tExplanation:\n\t\tAt index 0: There is no non-equal neighbor of 2 on the left, so index 0 is neither a hill nor a valley.\n\t\tAt index 1: The closest non-equal neighbors of 4 are 2 and 1. Since 4 > 2 and 4 > 1, index 1 is a hill. \n\t\tAt index 2: The closest non-equal neighbors of 1 are 4 and 6. Since 1 < 4 and 1 < 6, index 2 is a valley.\n\t\tAt index 3: The closest non-equal neighbors of 1 are 4 and 6. Since 1 < 4 and 1 < 6, index 3 is a valley, but note that it is part of the same valley as index 2.\n\t\tAt index 4: The closest non-equal neighbors of 6 are 1 and 5. Since 6 > 1 and 6 > 5, index 4 is a hill.\n\t\tAt index 5: There is no non-equal neighbor of 5 on the right, so index 5 is neither a hill nor a valley. \n\t\tThere are 3 hills and valleys so we return 3.\n\t\tExample 2:\n\t\tInput: nums = [6,6,5,5,4,1]\n\t\tOutput: 0\n\t\tExplanation:\n\t\tAt index 0: There is no non-equal neighbor of 6 on the left, so index 0 is neither a hill nor a valley.\n\t\tAt index 1: There is no non-equal neighbor of 6 on the left, so index 1 is neither a hill nor a valley.\n\t\tAt index 2: The closest non-equal neighbors of 5 are 6 and 4. Since 5 < 6 and 5 > 4, index 2 is neither a hill nor a valley.\n\t\tAt index 3: The closest non-equal neighbors of 5 are 6 and 4. Since 5 < 6 and 5 > 4, index 3 is neither a hill nor a valley.\n\t\tAt index 4: The closest non-equal neighbors of 4 are 5 and 1. Since 4 < 5 and 4 > 1, index 4 is neither a hill nor a valley.\n\t\tAt index 5: There is no non-equal neighbor of 1 on the right, so index 5 is neither a hill nor a valley.\n\t\tThere are 0 hills and valleys so we return 0.\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 2317,
-        "question": "class Solution:\n    def countCollisions(self, directions: str) -> int:\n\t\t\"\"\"\n\t\tThere are n cars on an infinitely long road. The cars are numbered from 0 to n - 1 from left to right and each car is present at a unique point.\n\t\tYou are given a 0-indexed string directions of length n. directions[i] can be either 'L', 'R', or 'S' denoting whether the ith car is moving towards the left, towards the right, or staying at its current point respectively. Each moving car has the same speed.\n\t\tThe number of collisions can be calculated as follows:\n\t\t\tWhen two cars moving in opposite directions collide with each other, the number of collisions increases by 2.\n\t\t\tWhen a moving car collides with a stationary car, the number of collisions increases by 1.\n\t\tAfter a collision, the cars involved can no longer move and will stay at the point where they collided. Other than that, cars cannot change their state or direction of motion.\n\t\tReturn the total number of collisions that will happen on the road.\n\t\tExample 1:\n\t\tInput: directions = \"RLRSLL\"\n\t\tOutput: 5\n\t\tExplanation:\n\t\tThe collisions that will happen on the road are:\n\t\t- Cars 0 and 1 will collide with each other. Since they are moving in opposite directions, the number of collisions becomes 0 + 2 = 2.\n\t\t- Cars 2 and 3 will collide with each other. Since car 3 is stationary, the number of collisions becomes 2 + 1 = 3.\n\t\t- Cars 3 and 4 will collide with each other. Since car 3 is stationary, the number of collisions becomes 3 + 1 = 4.\n\t\t- Cars 4 and 5 will collide with each other. After car 4 collides with car 3, it will stay at the point of collision and get hit by car 5. The number of collisions becomes 4 + 1 = 5.\n\t\tThus, the total number of collisions that will happen on the road is 5. \n\t\tExample 2:\n\t\tInput: directions = \"LLRR\"\n\t\tOutput: 0\n\t\tExplanation:\n\t\tNo cars will collide with each other. Thus, the total number of collisions that will happen on the road is 0.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2318,
-        "question": "class Solution:\n    def maximumBobPoints(self, numArrows: int, aliceArrows: List[int]) -> List[int]:\n\t\t\"\"\"\n\t\tAlice and Bob are opponents in an archery competition. The competition has set the following rules:\n\t\t\tAlice first shoots numArrows arrows and then Bob shoots numArrows arrows.\n\t\t\tThe points are then calculated as follows:\n\t\t\t\tThe target has integer scoring sections ranging from 0 to 11 inclusive.\n\t\t\t\tFor each section of the target with score k (in between 0 to 11), say Alice and Bob have shot ak and bk arrows on that section respectively. If ak >= bk, then Alice takes k points. If ak < bk, then Bob takes k points.\n\t\t\t\tHowever, if ak == bk == 0, then nobody takes k points.\n\t\t\tFor example, if Alice and Bob both shot 2 arrows on the section with score 11, then Alice takes 11 points. On the other hand, if Alice shot 0 arrows on the section with score 11 and Bob shot 2 arrows on that same section, then Bob takes 11 points.\n\t\tYou are given the integer numArrows and an integer array aliceArrows of size 12, which represents the number of arrows Alice shot on each scoring section from 0 to 11. Now, Bob wants to maximize the total number of points he can obtain.\n\t\tReturn the array bobArrows which represents the number of arrows Bob shot on each scoring section from 0 to 11. The sum of the values in bobArrows should equal numArrows.\n\t\tIf there are multiple ways for Bob to earn the maximum total points, return any one of them.\n\t\tExample 1:\n\t\tInput: numArrows = 9, aliceArrows = [1,1,0,1,0,0,2,1,0,1,2,0]\n\t\tOutput: [0,0,0,0,1,1,0,0,1,2,3,1]\n\t\tExplanation: The table above shows how the competition is scored. \n\t\tBob earns a total point of 4 + 5 + 8 + 9 + 10 + 11 = 47.\n\t\tIt can be shown that Bob cannot obtain a score higher than 47 points.\n\t\tExample 2:\n\t\tInput: numArrows = 3, aliceArrows = [0,0,1,0,0,0,0,0,0,0,0,2]\n\t\tOutput: [0,0,0,0,0,0,0,0,1,1,1,0]\n\t\tExplanation: The table above shows how the competition is scored.\n\t\tBob earns a total point of 8 + 9 + 10 = 27.\n\t\tIt can be shown that Bob cannot obtain a score higher than 27 points.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2319,
-        "question": "class Solution:\n    def longestRepeating(self, s: str, queryCharacters: str, queryIndices: List[int]) -> List[int]:\n\t\t\"\"\"\n\t\tYou are given a 0-indexed string s. You are also given a 0-indexed string queryCharacters of length k and a 0-indexed array of integer indices queryIndices of length k, both of which are used to describe k queries.\n\t\tThe ith query updates the character in s at index queryIndices[i] to the character queryCharacters[i].\n\t\tReturn an array lengths of length k where lengths[i] is the length of the longest substring of s consisting of only one repeating character after the ith query is performed.\n\t\tExample 1:\n\t\tInput: s = \"babacc\", queryCharacters = \"bcb\", queryIndices = [1,3,3]\n\t\tOutput: [3,3,4]\n\t\tExplanation: \n\t\t- 1st query updates s = \"bbbacc\". The longest substring consisting of one repeating character is \"bbb\" with length 3.\n\t\t- 2nd query updates s = \"bbbccc\". \n\t\t  The longest substring consisting of one repeating character can be \"bbb\" or \"ccc\" with length 3.\n\t\t- 3rd query updates s = \"bbbbcc\". The longest substring consisting of one repeating character is \"bbbb\" with length 4.\n\t\tThus, we return [3,3,4].\n\t\tExample 2:\n\t\tInput: s = \"abyzz\", queryCharacters = \"aa\", queryIndices = [2,1]\n\t\tOutput: [2,3]\n\t\tExplanation:\n\t\t- 1st query updates s = \"abazz\". The longest substring consisting of one repeating character is \"zz\" with length 2.\n\t\t- 2nd query updates s = \"aaazz\". The longest substring consisting of one repeating character is \"aaa\" with length 3.\n\t\tThus, we return [2,3].\n\t\t\"\"\"\n",
-        "difficulty": 2
-    },
-    {
-        "number": 2320,
-        "question": "class Solution:\n    def findKDistantIndices(self, nums: List[int], key: int, k: int) -> List[int]:\n\t\t\"\"\"\n\t\tYou are given a 0-indexed integer array nums and two integers key and k. A k-distant index is an index i of nums for which there exists at least one index j such that |i - j| <= k and nums[j] == key.\n\t\tReturn a list of all k-distant indices sorted in increasing order.\n\t\tExample 1:\n\t\tInput: nums = [3,4,9,1,3,9,5], key = 9, k = 1\n\t\tOutput: [1,2,3,4,5,6]\n\t\tExplanation: Here, nums[2] == key and nums[5] == key.\n\t\t- For index 0, |0 - 2| > k and |0 - 5| > k, so there is no j where |0 - j| <= k and nums[j] == key. Thus, 0 is not a k-distant index.\n\t\t- For index 1, |1 - 2| <= k and nums[2] == key, so 1 is a k-distant index.\n\t\t- For index 2, |2 - 2| <= k and nums[2] == key, so 2 is a k-distant index.\n\t\t- For index 3, |3 - 2| <= k and nums[2] == key, so 3 is a k-distant index.\n\t\t- For index 4, |4 - 5| <= k and nums[5] == key, so 4 is a k-distant index.\n\t\t- For index 5, |5 - 5| <= k and nums[5] == key, so 5 is a k-distant index.\n\t\t- For index 6, |6 - 5| <= k and nums[5] == key, so 6 is a k-distant index.\n\t\tThus, we return [1,2,3,4,5,6] which is sorted in increasing order. \n\t\tExample 2:\n\t\tInput: nums = [2,2,2,2,2], key = 2, k = 2\n\t\tOutput: [0,1,2,3,4]\n\t\tExplanation: For all indices i in nums, there exists some index j such that |i - j| <= k and nums[j] == key, so every index is a k-distant index. \n\t\tHence, we return [0,1,2,3,4].\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 2321,
-        "question": "class Solution:\n    def minimumWeight(self, n: int, edges: List[List[int]], src1: int, src2: int, dest: int) -> int:\n\t\t\"\"\"\n\t\tYou are given an integer n denoting the number of nodes of a weighted directed graph. The nodes are numbered from 0 to n - 1.\n\t\tYou are also given a 2D integer array edges where edges[i] = [fromi, toi, weighti] denotes that there exists a directed edge from fromi to toi with weight weighti.\n\t\tLastly, you are given three distinct integers src1, src2, and dest denoting three distinct nodes of the graph.\n\t\tReturn the minimum weight of a subgraph of the graph such that it is possible to reach dest from both src1 and src2 via a set of edges of this subgraph. In case such a subgraph does not exist, return -1.\n\t\tA subgraph is a graph whose vertices and edges are subsets of the original graph. The weight of a subgraph is the sum of weights of its constituent edges.\n\t\tExample 1:\n\t\tInput: n = 6, edges = [[0,2,2],[0,5,6],[1,0,3],[1,4,5],[2,1,1],[2,3,3],[2,3,4],[3,4,2],[4,5,1]], src1 = 0, src2 = 1, dest = 5\n\t\tOutput: 9\n\t\tExplanation:\n\t\tThe above figure represents the input graph.\n\t\tThe blue edges represent one of the subgraphs that yield the optimal answer.\n\t\tNote that the subgraph [[1,0,3],[0,5,6]] also yields the optimal answer. It is not possible to get a subgraph with less weight satisfying all the constraints.\n\t\tExample 2:\n\t\tInput: n = 3, edges = [[0,1,1],[2,1,1]], src1 = 0, src2 = 1, dest = 2\n\t\tOutput: -1\n\t\tExplanation:\n\t\tThe above figure represents the input graph.\n\t\tIt can be seen that there does not exist any path from node 1 to node 2, hence there are no subgraphs satisfying all the constraints.\n\t\t\"\"\"\n",
-        "difficulty": 2
-    },
-    {
-        "number": 2323,
-        "question": "class Solution:\n    def minBitFlips(self, start: int, goal: int) -> int:\n\t\t\"\"\"\n\t\tA bit flip of a number x is choosing a bit in the binary representation of x and flipping it from either 0 to 1 or 1 to 0.\n\t\t\tFor example, for x = 7, the binary representation is 111 and we may choose any bit (including any leading zeros not shown) and flip it. We can flip the first bit from the right to get 110, flip the second bit from the right to get 101, flip the fifth bit from the right (a leading zero) to get 10111, etc.\n\t\tGiven two integers start and goal, return the minimum number of bit flips to convert start to goal.\n\t\tExample 1:\n\t\tInput: start = 10, goal = 7\n\t\tOutput: 3\n\t\tExplanation: The binary representation of 10 and 7 are 1010 and 0111 respectively. We can convert 10 to 7 in 3 steps:\n\t\t- Flip the first bit from the right: 1010 -> 1011.\n\t\t- Flip the third bit from the right: 1011 -> 1111.\n\t\t- Flip the fourth bit from the right: 1111 -> 0111.\n\t\tIt can be shown we cannot convert 10 to 7 in less than 3 steps. Hence, we return 3.\n\t\tExample 2:\n\t\tInput: start = 3, goal = 4\n\t\tOutput: 3\n\t\tExplanation: The binary representation of 3 and 4 are 011 and 100 respectively. We can convert 3 to 4 in 3 steps:\n\t\t- Flip the first bit from the right: 011 -> 010.\n\t\t- Flip the second bit from the right: 010 -> 000.\n\t\t- Flip the third bit from the right: 000 -> 100.\n\t\tIt can be shown we cannot convert 3 to 4 in less than 3 steps. Hence, we return 3.\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 2324,
-        "question": "class Solution:\n    def triangularSum(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou are given a 0-indexed integer array nums, where nums[i] is a digit between 0 and 9 (inclusive).\n\t\tThe triangular sum of nums is the value of the only element present in nums after the following process terminates:\n\t\t\tLet nums comprise of n elements. If n == 1, end the process. Otherwise, create a new 0-indexed integer array newNums of length n - 1.\n\t\t\tFor each index i, where 0 <= i < n - 1, assign the value of newNums[i] as (nums[i] + nums[i+1]) % 10, where % denotes modulo operator.\n\t\t\tReplace the array nums with newNums.\n\t\t\tRepeat the entire process starting from step 1.\n\t\tReturn the triangular sum of nums.\n\t\tExample 1:\n\t\tInput: nums = [1,2,3,4,5]\n\t\tOutput: 8\n\t\tExplanation:\n\t\tThe above diagram depicts the process from which we obtain the triangular sum of the array.\n\t\tExample 2:\n\t\tInput: nums = [5]\n\t\tOutput: 5\n\t\tExplanation:\n\t\tSince there is only one element in nums, the triangular sum is the value of that element itself.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2325,
-        "question": "class Solution:\n    def numberOfWays(self, s: str) -> int:\n\t\t\"\"\"\n\t\tYou are given a 0-indexed binary string s which represents the types of buildings along a street where:\n\t\t\ts[i] = '0' denotes that the ith building is an office and\n\t\t\ts[i] = '1' denotes that the ith building is a restaurant.\n\t\tAs a city official, you would like to select 3 buildings for random inspection. However, to ensure variety, no two consecutive buildings out of the selected buildings can be of the same type.\n\t\t\tFor example, given s = \"001101\", we cannot select the 1st, 3rd, and 5th buildings as that would form \"011\" which is not allowed due to having two consecutive buildings of the same type.\n\t\tReturn the number of valid ways to select 3 buildings.\n\t\tExample 1:\n\t\tInput: s = \"001101\"\n\t\tOutput: 6\n\t\tExplanation: \n\t\tThe following sets of indices selected are valid:\n\t\t- [0,2,4] from \"001101\" forms \"010\"\n\t\t- [0,3,4] from \"001101\" forms \"010\"\n\t\t- [1,2,4] from \"001101\" forms \"010\"\n\t\t- [1,3,4] from \"001101\" forms \"010\"\n\t\t- [2,4,5] from \"001101\" forms \"101\"\n\t\t- [3,4,5] from \"001101\" forms \"101\"\n\t\tNo other selection is valid. Thus, there are 6 total ways.\n\t\tExample 2:\n\t\tInput: s = \"11100\"\n\t\tOutput: 0\n\t\tExplanation: It can be shown that there are no valid selections.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2326,
-        "question": "class Solution:\n    def sumScores(self, s: str) -> int:\n\t\t\"\"\"\n\t\tYou are building a string s of length n one character at a time, prepending each new character to the front of the string. The strings are labeled from 1 to n, where the string with length i is labeled si.\n\t\t\tFor example, for s = \"abaca\", s1 == \"a\", s2 == \"ca\", s3 == \"aca\", etc.\n\t\tThe score of si is the length of the longest common prefix between si and sn (Note that s == sn).\n\t\tGiven the final string s, return the sum of the score of every si.\n\t\tExample 1:\n\t\tInput: s = \"babab\"\n\t\tOutput: 9\n\t\tExplanation:\n\t\tFor s1 == \"b\", the longest common prefix is \"b\" which has a score of 1.\n\t\tFor s2 == \"ab\", there is no common prefix so the score is 0.\n\t\tFor s3 == \"bab\", the longest common prefix is \"bab\" which has a score of 3.\n\t\tFor s4 == \"abab\", there is no common prefix so the score is 0.\n\t\tFor s5 == \"babab\", the longest common prefix is \"babab\" which has a score of 5.\n\t\tThe sum of the scores is 1 + 0 + 3 + 0 + 5 = 9, so we return 9.\n\t\tExample 2:\n\t\tInput: s = \"azbazbzaz\"\n\t\tOutput: 14\n\t\tExplanation: \n\t\tFor s2 == \"az\", the longest common prefix is \"az\" which has a score of 2.\n\t\tFor s6 == \"azbzaz\", the longest common prefix is \"azb\" which has a score of 3.\n\t\tFor s9 == \"azbazbzaz\", the longest common prefix is \"azbazbzaz\" which has a score of 9.\n\t\tFor all other si, the score is 0.\n\t\tThe sum of the scores is 2 + 3 + 9 = 14, so we return 14.\n\t\t\"\"\"\n",
-        "difficulty": 2
-    },
-    {
-        "number": 2327,
-        "question": "class Solution:\n    def largestInteger(self, num: int) -> int:\n\t\t\"\"\"\n\t\tYou are given a positive integer num. You may swap any two digits of num that have the same parity (i.e. both odd digits or both even digits).\n\t\tReturn the largest possible value of num after any number of swaps.\n\t\tExample 1:\n\t\tInput: num = 1234\n\t\tOutput: 3412\n\t\tExplanation: Swap the digit 3 with the digit 1, this results in the number 3214.\n\t\tSwap the digit 2 with the digit 4, this results in the number 3412.\n\t\tNote that there may be other sequences of swaps but it can be shown that 3412 is the largest possible number.\n\t\tAlso note that we may not swap the digit 4 with the digit 1 since they are of different parities.\n\t\tExample 2:\n\t\tInput: num = 65875\n\t\tOutput: 87655\n\t\tExplanation: Swap the digit 8 with the digit 6, this results in the number 85675.\n\t\tSwap the first digit 5 with the digit 7, this results in the number 87655.\n\t\tNote that there may be other sequences of swaps but it can be shown that 87655 is the largest possible number.\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 2328,
-        "question": "class Solution:\n    def minimizeResult(self, expression: str) -> str:\n\t\t\"\"\"\n\t\tYou are given a 0-indexed string expression of the form \"+\" where  and  represent positive integers.\n\t\tAdd a pair of parentheses to expression such that after the addition of parentheses, expression is a valid mathematical expression and evaluates to the smallest possible value. The left parenthesis must be added to the left of '+' and the right parenthesis must be added to the right of '+'.\n\t\tReturn expression after adding a pair of parentheses such that expression evaluates to the smallest possible value. If there are multiple answers that yield the same result, return any of them.\n\t\tThe input has been generated such that the original value of expression, and the value of expression after adding any pair of parentheses that meets the requirements fits within a signed 32-bit integer.\n\t\tExample 1:\n\t\tInput: expression = \"247+38\"\n\t\tOutput: \"2(47+38)\"\n\t\tExplanation: The expression evaluates to 2 * (47 + 38) = 2 * 85 = 170.\n\t\tNote that \"2(4)7+38\" is invalid because the right parenthesis must be to the right of the '+'.\n\t\tIt can be shown that 170 is the smallest possible value.\n\t\tExample 2:\n\t\tInput: expression = \"12+34\"\n\t\tOutput: \"1(2+3)4\"\n\t\tExplanation: The expression evaluates to 1 * (2 + 3) * 4 = 1 * 5 * 4 = 20.\n\t\tExample 3:\n\t\tInput: expression = \"999+999\"\n\t\tOutput: \"(999+999)\"\n\t\tExplanation: The expression evaluates to 999 + 999 = 1998.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2329,
-        "question": "class Solution:\n    def maximumProduct(self, nums: List[int], k: int) -> int:\n\t\t\"\"\"\n\t\tYou are given an array of non-negative integers nums and an integer k. In one operation, you may choose any element from nums and increment it by 1.\n\t\tReturn the maximum product of nums after at most k operations. Since the answer may be very large, return it modulo 109 + 7. Note that you should maximize the product before taking the modulo. \n\t\tExample 1:\n\t\tInput: nums = [0,4], k = 5\n\t\tOutput: 20\n\t\tExplanation: Increment the first number 5 times.\n\t\tNow nums = [5, 4], with a product of 5 * 4 = 20.\n\t\tIt can be shown that 20 is maximum product possible, so we return 20.\n\t\tNote that there may be other ways to increment nums to have the maximum product.\n\t\tExample 2:\n\t\tInput: nums = [6,3,3,2], k = 2\n\t\tOutput: 216\n\t\tExplanation: Increment the second number 1 time and increment the fourth number 1 time.\n\t\tNow nums = [6, 4, 3, 3], with a product of 6 * 4 * 3 * 3 = 216.\n\t\tIt can be shown that 216 is maximum product possible, so we return 216.\n\t\tNote that there may be other ways to increment nums to have the maximum product.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2330,
-        "question": "class Solution:\n    def maximumBeauty(self, flowers: List[int], newFlowers: int, target: int, full: int, partial: int) -> int:\n\t\t\"\"\"\n\t\tAlice is a caretaker of n gardens and she wants to plant flowers to maximize the total beauty of all her gardens.\n\t\tYou are given a 0-indexed integer array flowers of size n, where flowers[i] is the number of flowers already planted in the ith garden. Flowers that are already planted cannot be removed. You are then given another integer newFlowers, which is the maximum number of flowers that Alice can additionally plant. You are also given the integers target, full, and partial.\n\t\tA garden is considered complete if it has at least target flowers. The total beauty of the gardens is then determined as the sum of the following:\n\t\t\tThe number of complete gardens multiplied by full.\n\t\t\tThe minimum number of flowers in any of the incomplete gardens multiplied by partial. If there are no incomplete gardens, then this value will be 0.\n\t\tReturn the maximum total beauty that Alice can obtain after planting at most newFlowers flowers.\n\t\tExample 1:\n\t\tInput: flowers = [1,3,1,1], newFlowers = 7, target = 6, full = 12, partial = 1\n\t\tOutput: 14\n\t\tExplanation: Alice can plant\n\t\t- 2 flowers in the 0th garden\n\t\t- 3 flowers in the 1st garden\n\t\t- 1 flower in the 2nd garden\n\t\t- 1 flower in the 3rd garden\n\t\tThe gardens will then be [3,6,2,2]. She planted a total of 2 + 3 + 1 + 1 = 7 flowers.\n\t\tThere is 1 garden that is complete.\n\t\tThe minimum number of flowers in the incomplete gardens is 2.\n\t\tThus, the total beauty is 1 * 12 + 2 * 1 = 12 + 2 = 14.\n\t\tNo other way of planting flowers can obtain a total beauty higher than 14.\n\t\tExample 2:\n\t\tInput: flowers = [2,4,5,3], newFlowers = 10, target = 5, full = 2, partial = 6\n\t\tOutput: 30\n\t\tExplanation: Alice can plant\n\t\t- 3 flowers in the 0th garden\n\t\t- 0 flowers in the 1st garden\n\t\t- 0 flowers in the 2nd garden\n\t\t- 2 flowers in the 3rd garden\n\t\tThe gardens will then be [5,4,5,5]. She planted a total of 3 + 0 + 0 + 2 = 5 flowers.\n\t\tThere are 3 gardens that are complete.\n\t\tThe minimum number of flowers in the incomplete gardens is 4.\n\t\tThus, the total beauty is 3 * 2 + 4 * 6 = 6 + 24 = 30.\n\t\tNo other way of planting flowers can obtain a total beauty higher than 30.\n\t\tNote that Alice could make all the gardens complete but in this case, she would obtain a lower total beauty.\n\t\t\"\"\"\n",
-        "difficulty": 2
-    },
-    {
-        "number": 2331,
-        "question": "class Solution:\n    def intersection(self, nums: List[List[int]]) -> List[int]:\n\t\t\"\"\"\n\t\tGiven a 2D integer array nums where nums[i] is a non-empty array of distinct positive integers, return the list of integers that are present in each array of nums sorted in ascending order.\n\t\tExample 1:\n\t\tInput: nums = [[3,1,2,4,5],[1,2,3,4],[3,4,5,6]]\n\t\tOutput: [3,4]\n\t\tExplanation: \n\t\tThe only integers present in each of nums[0] = [3,1,2,4,5], nums[1] = [1,2,3,4], and nums[2] = [3,4,5,6] are 3 and 4, so we return [3,4].\n\t\tExample 2:\n\t\tInput: nums = [[1,2,3],[4,5,6]]\n\t\tOutput: []\n\t\tExplanation: \n\t\tThere does not exist any integer present both in nums[0] and nums[1], so we return an empty list [].\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 2332,
-        "question": "class Solution:\n    def countLatticePoints(self, circles: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tGiven a 2D integer array circles where circles[i] = [xi, yi, ri] represents the center (xi, yi) and radius ri of the ith circle drawn on a grid, return the number of lattice points that are present inside at least one circle.\n\t\tNote:\n\t\t\tA lattice point is a point with integer coordinates.\n\t\t\tPoints that lie on the circumference of a circle are also considered to be inside it.\n\t\tExample 1:\n\t\tInput: circles = [[2,2,1]]\n\t\tOutput: 5\n\t\tExplanation:\n\t\tThe figure above shows the given circle.\n\t\tThe lattice points present inside the circle are (1, 2), (2, 1), (2, 2), (2, 3), and (3, 2) and are shown in green.\n\t\tOther points such as (1, 1) and (1, 3), which are shown in red, are not considered inside the circle.\n\t\tHence, the number of lattice points present inside at least one circle is 5.\n\t\tExample 2:\n\t\tInput: circles = [[2,2,2],[3,4,1]]\n\t\tOutput: 16\n\t\tExplanation:\n\t\tThe figure above shows the given circles.\n\t\tThere are exactly 16 lattice points which are present inside at least one circle. \n\t\tSome of them are (0, 2), (2, 0), (2, 4), (3, 2), and (4, 4).\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2333,
-        "question": "class Solution:\n    def countRectangles(self, rectangles: List[List[int]], points: List[List[int]]) -> List[int]:\n\t\t\"\"\"\n\t\tYou are given a 2D integer array rectangles where rectangles[i] = [li, hi] indicates that ith rectangle has a length of li and a height of hi. You are also given a 2D integer array points where points[j] = [xj, yj] is a point with coordinates (xj, yj).\n\t\tThe ith rectangle has its bottom-left corner point at the coordinates (0, 0) and its top-right corner point at (li, hi).\n\t\tReturn an integer array count of length points.length where count[j] is the number of rectangles that contain the jth point.\n\t\tThe ith rectangle contains the jth point if 0 <= xj <= li and 0 <= yj <= hi. Note that points that lie on the edges of a rectangle are also considered to be contained by that rectangle.\n\t\tExample 1:\n\t\tInput: rectangles = [[1,2],[2,3],[2,5]], points = [[2,1],[1,4]]\n\t\tOutput: [2,1]\n\t\tExplanation: \n\t\tThe first rectangle contains no points.\n\t\tThe second rectangle contains only the point (2, 1).\n\t\tThe third rectangle contains the points (2, 1) and (1, 4).\n\t\tThe number of rectangles that contain the point (2, 1) is 2.\n\t\tThe number of rectangles that contain the point (1, 4) is 1.\n\t\tTherefore, we return [2, 1].\n\t\tExample 2:\n\t\tInput: rectangles = [[1,1],[2,2],[3,3]], points = [[1,3],[1,1]]\n\t\tOutput: [1,3]\n\t\tExplanation:\n\t\tThe first rectangle contains only the point (1, 1).\n\t\tThe second rectangle contains only the point (1, 1).\n\t\tThe third rectangle contains the points (1, 3) and (1, 1).\n\t\tThe number of rectangles that contain the point (1, 3) is 1.\n\t\tThe number of rectangles that contain the point (1, 1) is 3.\n\t\tTherefore, we return [1, 3].\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2334,
-        "question": "class Solution:\n    def fullBloomFlowers(self, flowers: List[List[int]], persons: List[int]) -> List[int]:\n\t\t\"\"\"\n\t\tYou are given a 0-indexed 2D integer array flowers, where flowers[i] = [starti, endi] means the ith flower will be in full bloom from starti to endi (inclusive). You are also given a 0-indexed integer array persons of size n, where persons[i] is the time that the ith person will arrive to see the flowers.\n\t\tReturn an integer array answer of size n, where answer[i] is the number of flowers that are in full bloom when the ith person arrives.\n\t\tExample 1:\n\t\tInput: flowers = [[1,6],[3,7],[9,12],[4,13]], persons = [2,3,7,11]\n\t\tOutput: [1,2,2,2]\n\t\tExplanation: The figure above shows the times when the flowers are in full bloom and when the people arrive.\n\t\tFor each person, we return the number of flowers in full bloom during their arrival.\n\t\tExample 2:\n\t\tInput: flowers = [[1,10],[3,3]], persons = [3,3,2]\n\t\tOutput: [2,2,1]\n\t\tExplanation: The figure above shows the times when the flowers are in full bloom and when the people arrive.\n\t\tFor each person, we return the number of flowers in full bloom during their arrival.\n\t\t\"\"\"\n",
-        "difficulty": 2
-    },
-    {
-        "number": 2337,
-        "question": "class Solution:\n    def removeDigit(self, number: str, digit: str) -> str:\n\t\t\"\"\"\n\t\tYou are given a string number representing a positive integer and a character digit.\n\t\tReturn the resulting string after removing exactly one occurrence of digit from number such that the value of the resulting string in decimal form is maximized. The test cases are generated such that digit occurs at least once in number.\n\t\tExample 1:\n\t\tInput: number = \"123\", digit = \"3\"\n\t\tOutput: \"12\"\n\t\tExplanation: There is only one '3' in \"123\". After removing '3', the result is \"12\".\n\t\tExample 2:\n\t\tInput: number = \"1231\", digit = \"1\"\n\t\tOutput: \"231\"\n\t\tExplanation: We can remove the first '1' to get \"231\" or remove the second '1' to get \"123\".\n\t\tSince 231 > 123, we return \"231\".\n\t\tExample 3:\n\t\tInput: number = \"551\", digit = \"5\"\n\t\tOutput: \"51\"\n\t\tExplanation: We can remove either the first or second '5' from \"551\".\n\t\tBoth result in the string \"51\".\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 2338,
-        "question": "class Solution:\n    def minimumCardPickup(self, cards: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou are given an integer array cards where cards[i] represents the value of the ith card. A pair of cards are matching if the cards have the same value.\n\t\tReturn the minimum number of consecutive cards you have to pick up to have a pair of matching cards among the picked cards. If it is impossible to have matching cards, return -1.\n\t\tExample 1:\n\t\tInput: cards = [3,4,2,3,4,7]\n\t\tOutput: 4\n\t\tExplanation: We can pick up the cards [3,4,2,3] which contain a matching pair of cards with value 3. Note that picking up the cards [4,2,3,4] is also optimal.\n\t\tExample 2:\n\t\tInput: cards = [1,0,5,3]\n\t\tOutput: -1\n\t\tExplanation: There is no way to pick up a set of consecutive cards that contain a pair of matching cards.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2339,
-        "question": "class Solution:\n    def countDistinct(self, nums: List[int], k: int, p: int) -> int:\n\t\t\"\"\"\n\t\tGiven an integer array nums and two integers k and p, return the number of distinct subarrays which have at most k elements divisible by p.\n\t\tTwo arrays nums1 and nums2 are said to be distinct if:\n\t\t\tThey are of different lengths, or\n\t\t\tThere exists at least one index i where nums1[i] != nums2[i].\n\t\tA subarray is defined as a non-empty contiguous sequence of elements in an array.\n\t\tExample 1:\n\t\tInput: nums = [2,3,3,2,2], k = 2, p = 2\n\t\tOutput: 11\n\t\tExplanation:\n\t\tThe elements at indices 0, 3, and 4 are divisible by p = 2.\n\t\tThe 11 distinct subarrays which have at most k = 2 elements divisible by 2 are:\n\t\t[2], [2,3], [2,3,3], [2,3,3,2], [3], [3,3], [3,3,2], [3,3,2,2], [3,2], [3,2,2], and [2,2].\n\t\tNote that the subarrays [2] and [3] occur more than once in nums, but they should each be counted only once.\n\t\tThe subarray [2,3,3,2,2] should not be counted because it has 3 elements that are divisible by 2.\n\t\tExample 2:\n\t\tInput: nums = [1,2,3,4], k = 4, p = 1\n\t\tOutput: 10\n\t\tExplanation:\n\t\tAll element of nums are divisible by p = 1.\n\t\tAlso, every subarray of nums will have at most 4 elements that are divisible by 1.\n\t\tSince all subarrays are distinct, the total number of subarrays satisfying all the constraints is 10.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2340,
-        "question": "class Solution:\n    def appealSum(self, s: str) -> int:\n\t\t\"\"\"\n\t\tThe appeal of a string is the number of distinct characters found in the string.\n\t\t\tFor example, the appeal of \"abbca\" is 3 because it has 3 distinct characters: 'a', 'b', and 'c'.\n\t\tGiven a string s, return the total appeal of all of its substrings.\n\t\tA substring is a contiguous sequence of characters within a string.\n\t\tExample 1:\n\t\tInput: s = \"abbca\"\n\t\tOutput: 28\n\t\tExplanation: The following are the substrings of \"abbca\":\n\t\t- Substrings of length 1: \"a\", \"b\", \"b\", \"c\", \"a\" have an appeal of 1, 1, 1, 1, and 1 respectively. The sum is 5.\n\t\t- Substrings of length 2: \"ab\", \"bb\", \"bc\", \"ca\" have an appeal of 2, 1, 2, and 2 respectively. The sum is 7.\n\t\t- Substrings of length 3: \"abb\", \"bbc\", \"bca\" have an appeal of 2, 2, and 3 respectively. The sum is 7.\n\t\t- Substrings of length 4: \"abbc\", \"bbca\" have an appeal of 3 and 3 respectively. The sum is 6.\n\t\t- Substrings of length 5: \"abbca\" has an appeal of 3. The sum is 3.\n\t\tThe total sum is 5 + 7 + 7 + 6 + 3 = 28.\n\t\tExample 2:\n\t\tInput: s = \"code\"\n\t\tOutput: 20\n\t\tExplanation: The following are the substrings of \"code\":\n\t\t- Substrings of length 1: \"c\", \"o\", \"d\", \"e\" have an appeal of 1, 1, 1, and 1 respectively. The sum is 4.\n\t\t- Substrings of length 2: \"co\", \"od\", \"de\" have an appeal of 2, 2, and 2 respectively. The sum is 6.\n\t\t- Substrings of length 3: \"cod\", \"ode\" have an appeal of 3 and 3 respectively. The sum is 6.\n\t\t- Substrings of length 4: \"code\" has an appeal of 4. The sum is 4.\n\t\tThe total sum is 4 + 6 + 6 + 4 = 20.\n\t\t\"\"\"\n",
-        "difficulty": 2
-    },
-    {
-        "number": 2341,
-        "question": "class Solution:\n    def countPrefixes(self, words: List[str], s: str) -> int:\n\t\t\"\"\"\n\t\tYou are given a string array words and a string s, where words[i] and s comprise only of lowercase English letters.\n\t\tReturn the number of strings in words that are a prefix of s.\n\t\tA prefix of a string is a substring that occurs at the beginning of the string. A substring is a contiguous sequence of characters within a string.\n\t\tExample 1:\n\t\tInput: words = [\"a\",\"b\",\"c\",\"ab\",\"bc\",\"abc\"], s = \"abc\"\n\t\tOutput: 3\n\t\tExplanation:\n\t\tThe strings in words which are a prefix of s = \"abc\" are:\n\t\t\"a\", \"ab\", and \"abc\".\n\t\tThus the number of strings in words which are a prefix of s is 3.\n\t\tExample 2:\n\t\tInput: words = [\"a\",\"a\"], s = \"aa\"\n\t\tOutput: 2\n\t\tExplanation:\n\t\tBoth of the strings are a prefix of s. \n\t\tNote that the same string can occur multiple times in words, and it should be counted each time.\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 2342,
-        "question": "class Solution:\n    def minimumAverageDifference(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou are given a 0-indexed integer array nums of length n.\n\t\tThe average difference of the index i is the absolute difference between the average of the first i + 1 elements of nums and the average of the last n - i - 1 elements. Both averages should be rounded down to the nearest integer.\n\t\tReturn the index with the minimum average difference. If there are multiple such indices, return the smallest one.\n\t\tNote:\n\t\t\tThe absolute difference of two numbers is the absolute value of their difference.\n\t\t\tThe average of n elements is the sum of the n elements divided (integer division) by n.\n\t\t\tThe average of 0 elements is considered to be 0.\n\t\tExample 1:\n\t\tInput: nums = [2,5,3,9,5,3]\n\t\tOutput: 3\n\t\tExplanation:\n\t\t- The average difference of index 0 is: |2 / 1 - (5 + 3 + 9 + 5 + 3) / 5| = |2 / 1 - 25 / 5| = |2 - 5| = 3.\n\t\t- The average difference of index 1 is: |(2 + 5) / 2 - (3 + 9 + 5 + 3) / 4| = |7 / 2 - 20 / 4| = |3 - 5| = 2.\n\t\t- The average difference of index 2 is: |(2 + 5 + 3) / 3 - (9 + 5 + 3) / 3| = |10 / 3 - 17 / 3| = |3 - 5| = 2.\n\t\t- The average difference of index 3 is: |(2 + 5 + 3 + 9) / 4 - (5 + 3) / 2| = |19 / 4 - 8 / 2| = |4 - 4| = 0.\n\t\t- The average difference of index 4 is: |(2 + 5 + 3 + 9 + 5) / 5 - 3 / 1| = |24 / 5 - 3 / 1| = |4 - 3| = 1.\n\t\t- The average difference of index 5 is: |(2 + 5 + 3 + 9 + 5 + 3) / 6 - 0| = |27 / 6 - 0| = |4 - 0| = 4.\n\t\tThe average difference of index 3 is the minimum average difference so return 3.\n\t\tExample 2:\n\t\tInput: nums = [0]\n\t\tOutput: 0\n\t\tExplanation:\n\t\tThe only index is 0 so return 0.\n\t\tThe average difference of index 0 is: |0 / 1 - 0| = |0 - 0| = 0.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2343,
-        "question": "class Solution:\n    def countUnguarded(self, m: int, n: int, guards: List[List[int]], walls: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tYou are given two integers m and n representing a 0-indexed m x n grid. You are also given two 2D integer arrays guards and walls where guards[i] = [rowi, coli] and walls[j] = [rowj, colj] represent the positions of the ith guard and jth wall respectively.\n\t\tA guard can see every cell in the four cardinal directions (north, east, south, or west) starting from their position unless obstructed by a wall or another guard. A cell is guarded if there is at least one guard that can see it.\n\t\tReturn the number of unoccupied cells that are not guarded.\n\t\tExample 1:\n\t\tInput: m = 4, n = 6, guards = [[0,0],[1,1],[2,3]], walls = [[0,1],[2,2],[1,4]]\n\t\tOutput: 7\n\t\tExplanation: The guarded and unguarded cells are shown in red and green respectively in the above diagram.\n\t\tThere are a total of 7 unguarded cells, so we return 7.\n\t\tExample 2:\n\t\tInput: m = 3, n = 3, guards = [[1,1]], walls = [[0,1],[1,0],[2,1],[1,2]]\n\t\tOutput: 4\n\t\tExplanation: The unguarded cells are shown in green in the above diagram.\n\t\tThere are a total of 4 unguarded cells, so we return 4.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2344,
-        "question": "class Solution:\n    def maximumMinutes(self, grid: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tYou are given a 0-indexed 2D integer array grid of size m x n which represents a field. Each cell has one of three values:\n\t\t\t0 represents grass,\n\t\t\t1 represents fire,\n\t\t\t2 represents a wall that you and fire cannot pass through.\n\t\tYou are situated in the top-left cell, (0, 0), and you want to travel to the safehouse at the bottom-right cell, (m - 1, n - 1). Every minute, you may move to an adjacent grass cell. After your move, every fire cell will spread to all adjacent cells that are not walls.\n\t\tReturn the maximum number of minutes that you can stay in your initial position before moving while still safely reaching the safehouse. If this is impossible, return -1. If you can always reach the safehouse regardless of the minutes stayed, return 109.\n\t\tNote that even if the fire spreads to the safehouse immediately after you have reached it, it will be counted as safely reaching the safehouse.\n\t\tA cell is adjacent to another cell if the former is directly north, east, south, or west of the latter (i.e., their sides are touching).\n\t\tExample 1:\n\t\tInput: grid = [[0,2,0,0,0,0,0],[0,0,0,2,2,1,0],[0,2,0,0,1,2,0],[0,0,2,2,2,0,2],[0,0,0,0,0,0,0]]\n\t\tOutput: 3\n\t\tExplanation: The figure above shows the scenario where you stay in the initial position for 3 minutes.\n\t\tYou will still be able to safely reach the safehouse.\n\t\tStaying for more than 3 minutes will not allow you to safely reach the safehouse.\n\t\tExample 2:\n\t\tInput: grid = [[0,0,0,0],[0,1,2,0],[0,2,0,0]]\n\t\tOutput: -1\n\t\tExplanation: The figure above shows the scenario where you immediately move towards the safehouse.\n\t\tFire will spread to any cell you move towards and it is impossible to safely reach the safehouse.\n\t\tThus, -1 is returned.\n\t\tExample 3:\n\t\tInput: grid = [[0,0,0],[2,2,0],[1,2,0]]\n\t\tOutput: 1000000000\n\t\tExplanation: The figure above shows the initial grid.\n\t\tNotice that the fire is contained by walls and you will always be able to safely reach the safehouse.\n\t\tThus, 109 is returned.\n\t\t\"\"\"\n",
-        "difficulty": 2
-    },
-    {
-        "number": 2345,
-        "question": "class Solution:\n    def convertTime(self, current: str, correct: str) -> int:\n\t\t\"\"\"\n\t\tYou are given two strings current and correct representing two 24-hour times.\n\t\t24-hour times are formatted as \"HH:MM\", where HH is between 00 and 23, and MM is between 00 and 59. The earliest 24-hour time is 00:00, and the latest is 23:59.\n\t\tIn one operation you can increase the time current by 1, 5, 15, or 60 minutes. You can perform this operation any number of times.\n\t\tReturn the minimum number of operations needed to convert current to correct.\n\t\tExample 1:\n\t\tInput: current = \"02:30\", correct = \"04:35\"\n\t\tOutput: 3\n\t\tExplanation:\n\t\tWe can convert current to correct in 3 operations as follows:\n\t\t- Add 60 minutes to current. current becomes \"03:30\".\n\t\t- Add 60 minutes to current. current becomes \"04:30\".\n\t\t- Add 5 minutes to current. current becomes \"04:35\".\n\t\tIt can be proven that it is not possible to convert current to correct in fewer than 3 operations.\n\t\tExample 2:\n\t\tInput: current = \"11:00\", correct = \"11:01\"\n\t\tOutput: 1\n\t\tExplanation: We only have to add one minute to current, so the minimum number of operations needed is 1.\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 2346,
-        "question": "class Solution:\n    def largestGoodInteger(self, num: str) -> str:\n\t\t\"\"\"\n\t\tYou are given a string num representing a large integer. An integer is good if it meets the following conditions:\n\t\t\tIt is a substring of num with length 3.\n\t\t\tIt consists of only one unique digit.\n\t\tReturn the maximum good integer as a string or an empty string \"\" if no such integer exists.\n\t\tNote:\n\t\t\tA substring is a contiguous sequence of characters within a string.\n\t\t\tThere may be leading zeroes in num or a good integer.\n\t\tExample 1:\n\t\tInput: num = \"6777133339\"\n\t\tOutput: \"777\"\n\t\tExplanation: There are two distinct good integers: \"777\" and \"333\".\n\t\t\"777\" is the largest, so we return \"777\".\n\t\tExample 2:\n\t\tInput: num = \"2300019\"\n\t\tOutput: \"000\"\n\t\tExplanation: \"000\" is the only good integer.\n\t\tExample 3:\n\t\tInput: num = \"42352338\"\n\t\tOutput: \"\"\n\t\tExplanation: No substring of length 3 consists of only one unique digit. Therefore, there are no good integers.\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 2347,
-        "question": "class Solution:\n    def averageOfSubtree(self, root: Optional[TreeNode]) -> int:\n\t\t\"\"\"\n\t\tGiven the root of a binary tree, return the number of nodes where the value of the node is equal to the average of the values in its subtree.\n\t\tNote:\n\t\t\tThe average of n elements is the sum of the n elements divided by n and rounded down to the nearest integer.\n\t\t\tA subtree of root is a tree consisting of root and all of its descendants.\n\t\tExample 1:\n\t\tInput: root = [4,8,5,0,1,null,6]\n\t\tOutput: 5\n\t\tExplanation: \n\t\tFor the node with value 4: The average of its subtree is (4 + 8 + 5 + 0 + 1 + 6) / 6 = 24 / 6 = 4.\n\t\tFor the node with value 5: The average of its subtree is (5 + 6) / 2 = 11 / 2 = 5.\n\t\tFor the node with value 0: The average of its subtree is 0 / 1 = 0.\n\t\tFor the node with value 1: The average of its subtree is 1 / 1 = 1.\n\t\tFor the node with value 6: The average of its subtree is 6 / 1 = 6.\n\t\tExample 2:\n\t\tInput: root = [1]\n\t\tOutput: 1\n\t\tExplanation: For the node with value 1: The average of its subtree is 1 / 1 = 1.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2348,
-        "question": "class Solution:\n    def countTexts(self, pressedKeys: str) -> int:\n\t\t\"\"\"\n\t\tAlice is texting Bob using her phone. The mapping of digits to letters is shown in the figure below.\n\t\tIn order to add a letter, Alice has to press the key of the corresponding digit i times, where i is the position of the letter in the key.\n\t\t\tFor example, to add the letter 's', Alice has to press '7' four times. Similarly, to add the letter 'k', Alice has to press '5' twice.\n\t\t\tNote that the digits '0' and '1' do not map to any letters, so Alice does not use them.\n\t\tHowever, due to an error in transmission, Bob did not receive Alice's text message but received a string of pressed keys instead.\n\t\t\tFor example, when Alice sent the message \"bob\", Bob received the string \"2266622\".\n\t\tGiven a string pressedKeys representing the string received by Bob, return the total number of possible text messages Alice could have sent.\n\t\tSince the answer may be very large, return it modulo 109 + 7.\n\t\tExample 1:\n\t\tInput: pressedKeys = \"22233\"\n\t\tOutput: 8\n\t\tExplanation:\n\t\tThe possible text messages Alice could have sent are:\n\t\t\"aaadd\", \"abdd\", \"badd\", \"cdd\", \"aaae\", \"abe\", \"bae\", and \"ce\".\n\t\tSince there are 8 possible messages, we return 8.\n\t\tExample 2:\n\t\tInput: pressedKeys = \"222222222222222222222222222222222222\"\n\t\tOutput: 82876089\n\t\tExplanation:\n\t\tThere are 2082876103 possible text messages Alice could have sent.\n\t\tSince we need to return the answer modulo 109 + 7, we return 2082876103 % (109 + 7) = 82876089.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2349,
-        "question": "class Solution:\n    def hasValidPath(self, grid: List[List[str]]) -> bool:\n\t\t\"\"\"\n\t\tA parentheses string is a non-empty string consisting only of '(' and ')'. It is valid if any of the following conditions is true:\n\t\t\tIt is ().\n\t\t\tIt can be written as AB (A concatenated with B), where A and B are valid parentheses strings.\n\t\t\tIt can be written as (A), where A is a valid parentheses string.\n\t\tYou are given an m x n matrix of parentheses grid. A valid parentheses string path in the grid is a path satisfying all of the following conditions:\n\t\t\tThe path starts from the upper left cell (0, 0).\n\t\t\tThe path ends at the bottom-right cell (m - 1, n - 1).\n\t\t\tThe path only ever moves down or right.\n\t\t\tThe resulting parentheses string formed by the path is valid.\n\t\tReturn true if there exists a valid parentheses string path in the grid. Otherwise, return false.\n\t\tExample 1:\n\t\tInput: grid = [[\"(\",\"(\",\"(\"],[\")\",\"(\",\")\"],[\"(\",\"(\",\")\"],[\"(\",\"(\",\")\"]]\n\t\tOutput: true\n\t\tExplanation: The above diagram shows two possible paths that form valid parentheses strings.\n\t\tThe first path shown results in the valid parentheses string \"()(())\".\n\t\tThe second path shown results in the valid parentheses string \"((()))\".\n\t\tNote that there may be other valid parentheses string paths.\n\t\tExample 2:\n\t\tInput: grid = [[\")\",\")\"],[\"(\",\"(\"]]\n\t\tOutput: false\n\t\tExplanation: The two possible paths form the parentheses strings \"))(\" and \")((\". Since neither of them are valid parentheses strings, we return false.\n\t\t\"\"\"\n",
-        "difficulty": 2
-    },
-    {
-        "number": 2350,
-        "question": "class Solution:\n    def findClosestNumber(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tGiven an integer array nums of size n, return the number with the value closest to 0 in nums. If there are multiple answers, return the number with the largest value.\n\t\tExample 1:\n\t\tInput: nums = [-4,-2,1,4,8]\n\t\tOutput: 1\n\t\tExplanation:\n\t\tThe distance from -4 to 0 is |-4| = 4.\n\t\tThe distance from -2 to 0 is |-2| = 2.\n\t\tThe distance from 1 to 0 is |1| = 1.\n\t\tThe distance from 4 to 0 is |4| = 4.\n\t\tThe distance from 8 to 0 is |8| = 8.\n\t\tThus, the closest number to 0 in the array is 1.\n\t\tExample 2:\n\t\tInput: nums = [2,-1,1]\n\t\tOutput: 1\n\t\tExplanation: 1 and -1 are both the closest numbers to 0, so 1 being larger is returned.\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 2351,
-        "question": "class Solution:\n    def waysToBuyPensPencils(self, total: int, cost1: int, cost2: int) -> int:\n\t\t\"\"\"\n\t\tYou are given an integer total indicating the amount of money you have. You are also given two integers cost1 and cost2 indicating the price of a pen and pencil respectively. You can spend part or all of your money to buy multiple quantities (or none) of each kind of writing utensil.\n\t\tReturn the number of distinct ways you can buy some number of pens and pencils.\n\t\tExample 1:\n\t\tInput: total = 20, cost1 = 10, cost2 = 5\n\t\tOutput: 9\n\t\tExplanation: The price of a pen is 10 and the price of a pencil is 5.\n\t\t- If you buy 0 pens, you can buy 0, 1, 2, 3, or 4 pencils.\n\t\t- If you buy 1 pen, you can buy 0, 1, or 2 pencils.\n\t\t- If you buy 2 pens, you cannot buy any pencils.\n\t\tThe total number of ways to buy pens and pencils is 5 + 3 + 1 = 9.\n\t\tExample 2:\n\t\tInput: total = 5, cost1 = 10, cost2 = 10\n\t\tOutput: 1\n\t\tExplanation: The price of both pens and pencils are 10, which cost more than total, so you cannot buy any writing utensils. Therefore, there is only 1 way: buy 0 pens and 0 pencils.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2352,
-        "question": "class ATM:\n    def __init__(self):\n    def deposit(self, banknotesCount: List[int]) -> None:\n    def withdraw(self, amount: int) -> List[int]:\n\t\t\"\"\"\n\t\tThere is an ATM machine that stores banknotes of 5 denominations: 20, 50, 100, 200, and 500 dollars. Initially the ATM is empty. The user can use the machine to deposit or withdraw any amount of money.\n\t\tWhen withdrawing, the machine prioritizes using banknotes of larger values.\n\t\t\tFor example, if you want to withdraw $300 and there are 2 $50 banknotes, 1 $100 banknote, and 1 $200 banknote, then the machine will use the $100 and $200 banknotes.\n\t\t\tHowever, if you try to withdraw $600 and there are 3 $200 banknotes and 1 $500 banknote, then the withdraw request will be rejected because the machine will first try to use the $500 banknote and then be unable to use banknotes to complete the remaining $100. Note that the machine is not allowed to use the $200 banknotes instead of the $500 banknote.\n\t\tImplement the ATM class:\n\t\t\tATM() Initializes the ATM object.\n\t\t\tvoid deposit(int[] banknotesCount) Deposits new banknotes in the order $20, $50, $100, $200, and $500.\n\t\t\tint[] withdraw(int amount) Returns an array of length 5 of the number of banknotes that will be handed to the user in the order $20, $50, $100, $200, and $500, and update the number of banknotes in the ATM after withdrawing. Returns [-1] if it is not possible (do not withdraw any banknotes in this case).\n\t\tExample 1:\n\t\tInput\n\t\t[\"ATM\", \"deposit\", \"withdraw\", \"deposit\", \"withdraw\", \"withdraw\"]\n\t\t[[], [[0,0,1,2,1]], [600], [[0,1,0,1,1]], [600], [550]]\n\t\tOutput\n\t\t[null, null, [0,0,1,0,1], null, [-1], [0,1,0,0,1]]\n\t\tExplanation\n\t\tATM atm = new ATM();\n\t\tatm.deposit([0,0,1,2,1]); // Deposits 1 $100 banknote, 2 $200 banknotes,\n\t\t                          // and 1 $500 banknote.\n\t\tatm.withdraw(600);        // Returns [0,0,1,0,1]. The machine uses 1 $100 banknote\n\t\t                          // and 1 $500 banknote. The banknotes left over in the\n\t\t                          // machine are [0,0,0,2,0].\n\t\tatm.deposit([0,1,0,1,1]); // Deposits 1 $50, $200, and $500 banknote.\n\t\t                          // The banknotes in the machine are now [0,1,0,3,1].\n\t\tatm.withdraw(600);        // Returns [-1]. The machine will try to use a $500 banknote\n\t\t                          // and then be unable to complete the remaining $100,\n\t\t                          // so the withdraw request will be rejected.\n\t\t                          // Since the request is rejected, the number of banknotes\n\t\t                          // in the machine is not modified.\n\t\tatm.withdraw(550);        // Returns [0,1,0,0,1]. The machine uses 1 $50 banknote\n\t\t                          // and 1 $500 banknote.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2353,
-        "question": "class Solution:\n    def maximumScore(self, scores: List[int], edges: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tThere is an undirected graph with n nodes, numbered from 0 to n - 1.\n\t\tYou are given a 0-indexed integer array scores of length n where scores[i] denotes the score of node i. You are also given a 2D integer array edges where edges[i] = [ai, bi] denotes that there exists an undirected edge connecting nodes ai and bi.\n\t\tA node sequence is valid if it meets the following conditions:\n\t\t\tThere is an edge connecting every pair of adjacent nodes in the sequence.\n\t\t\tNo node appears more than once in the sequence.\n\t\tThe score of a node sequence is defined as the sum of the scores of the nodes in the sequence.\n\t\tReturn the maximum score of a valid node sequence with a length of 4. If no such sequence exists, return -1.\n\t\tExample 1:\n\t\tInput: scores = [5,2,9,8,4], edges = [[0,1],[1,2],[2,3],[0,2],[1,3],[2,4]]\n\t\tOutput: 24\n\t\tExplanation: The figure above shows the graph and the chosen node sequence [0,1,2,3].\n\t\tThe score of the node sequence is 5 + 2 + 9 + 8 = 24.\n\t\tIt can be shown that no other node sequence has a score of more than 24.\n\t\tNote that the sequences [3,1,2,0] and [1,0,2,3] are also valid and have a score of 24.\n\t\tThe sequence [0,3,2,4] is not valid since no edge connects nodes 0 and 3.\n\t\tExample 2:\n\t\tInput: scores = [9,20,6,4,11,12], edges = [[0,3],[5,3],[2,4],[1,3]]\n\t\tOutput: -1\n\t\tExplanation: The figure above shows the graph.\n\t\tThere are no valid node sequences of length 4, so we return -1.\n\t\t\"\"\"\n",
-        "difficulty": 2
-    },
-    {
-        "number": 2355,
-        "question": "class Solution:\n    def maxConsecutive(self, bottom: int, top: int, special: List[int]) -> int:\n\t\t\"\"\"\n\t\tAlice manages a company and has rented some floors of a building as office space. Alice has decided some of these floors should be special floors, used for relaxation only.\n\t\tYou are given two integers bottom and top, which denote that Alice has rented all the floors from bottom to top (inclusive). You are also given the integer array special, where special[i] denotes a special floor that Alice has designated for relaxation.\n\t\tReturn the maximum number of consecutive floors without a special floor.\n\t\tExample 1:\n\t\tInput: bottom = 2, top = 9, special = [4,6]\n\t\tOutput: 3\n\t\tExplanation: The following are the ranges (inclusive) of consecutive floors without a special floor:\n\t\t- (2, 3) with a total amount of 2 floors.\n\t\t- (5, 5) with a total amount of 1 floor.\n\t\t- (7, 9) with a total amount of 3 floors.\n\t\tTherefore, we return the maximum number which is 3 floors.\n\t\tExample 2:\n\t\tInput: bottom = 6, top = 8, special = [7,6,8]\n\t\tOutput: 0\n\t\tExplanation: Every floor rented is a special floor, so we return 0.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2356,
-        "question": "class Solution:\n    def largestCombination(self, candidates: List[int]) -> int:\n\t\t\"\"\"\n\t\tThe bitwise AND of an array nums is the bitwise AND of all integers in nums.\n\t\t\tFor example, for nums = [1, 5, 3], the bitwise AND is equal to 1 & 5 & 3 = 1.\n\t\t\tAlso, for nums = [7], the bitwise AND is 7.\n\t\tYou are given an array of positive integers candidates. Evaluate the bitwise AND of every combination of numbers of candidates. Each number in candidates may only be used once in each combination.\n\t\tReturn the size of the largest combination of candidates with a bitwise AND greater than 0.\n\t\tExample 1:\n\t\tInput: candidates = [16,17,71,62,12,24,14]\n\t\tOutput: 4\n\t\tExplanation: The combination [16,17,62,24] has a bitwise AND of 16 & 17 & 62 & 24 = 16 > 0.\n\t\tThe size of the combination is 4.\n\t\tIt can be shown that no combination with a size greater than 4 has a bitwise AND greater than 0.\n\t\tNote that more than one combination may have the largest size.\n\t\tFor example, the combination [62,12,24,14] has a bitwise AND of 62 & 12 & 24 & 14 = 8 > 0.\n\t\tExample 2:\n\t\tInput: candidates = [8,8]\n\t\tOutput: 2\n\t\tExplanation: The largest combination [8,8] has a bitwise AND of 8 & 8 = 8 > 0.\n\t\tThe size of the combination is 2, so we return 2.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2357,
-        "question": "class CountIntervals:\n    def __init__(self):\n    def add(self, left: int, right: int) -> None:\n    def count(self) -> int:\n\t\t\"\"\"\n\t\tGiven an empty set of intervals, implement a data structure that can:\n\t\t\tAdd an interval to the set of intervals.\n\t\t\tCount the number of integers that are present in at least one interval.\n\t\tImplement the CountIntervals class:\n\t\t\tCountIntervals() Initializes the object with an empty set of intervals.\n\t\t\tvoid add(int left, int right) Adds the interval [left, right] to the set of intervals.\n\t\t\tint count() Returns the number of integers that are present in at least one interval.\n\t\tNote that an interval [left, right] denotes all the integers x where left <= x <= right.\n\t\tExample 1:\n\t\tInput\n\t\t[\"CountIntervals\", \"add\", \"add\", \"count\", \"add\", \"count\"]\n\t\t[[], [2, 3], [7, 10], [], [5, 8], []]\n\t\tOutput\n\t\t[null, null, null, 6, null, 8]\n\t\tExplanation\n\t\tCountIntervals countIntervals = new CountIntervals(); // initialize the object with an empty set of intervals. \n\t\tcountIntervals.add(2, 3);  // add [2, 3] to the set of intervals.\n\t\tcountIntervals.add(7, 10); // add [7, 10] to the set of intervals.\n\t\tcountIntervals.count();    // return 6\n\t\t                           // the integers 2 and 3 are present in the interval [2, 3].\n\t\t                           // the integers 7, 8, 9, and 10 are present in the interval [7, 10].\n\t\tcountIntervals.add(5, 8);  // add [5, 8] to the set of intervals.\n\t\tcountIntervals.count();    // return 8\n\t\t                           // the integers 2 and 3 are present in the interval [2, 3].\n\t\t                           // the integers 5 and 6 are present in the interval [5, 8].\n\t\t                           // the integers 7 and 8 are present in the intervals [5, 8] and [7, 10].\n\t\t                           // the integers 9 and 10 are present in the interval [7, 10].\n\t\t\"\"\"\n",
-        "difficulty": 2
-    },
-    {
-        "number": 2358,
-        "question": "class Solution:\n    def waysToSplitArray(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou are given a 0-indexed integer array nums of length n.\n\t\tnums contains a valid split at index i if the following are true:\n\t\t\tThe sum of the first i + 1 elements is greater than or equal to the sum of the last n - i - 1 elements.\n\t\t\tThere is at least one element to the right of i. That is, 0 <= i < n - 1.\n\t\tReturn the number of valid splits in nums.\n\t\tExample 1:\n\t\tInput: nums = [10,4,-8,7]\n\t\tOutput: 2\n\t\tExplanation: \n\t\tThere are three ways of splitting nums into two non-empty parts:\n\t\t- Split nums at index 0. Then, the first part is [10], and its sum is 10. The second part is [4,-8,7], and its sum is 3. Since 10 >= 3, i = 0 is a valid split.\n\t\t- Split nums at index 1. Then, the first part is [10,4], and its sum is 14. The second part is [-8,7], and its sum is -1. Since 14 >= -1, i = 1 is a valid split.\n\t\t- Split nums at index 2. Then, the first part is [10,4,-8], and its sum is 6. The second part is [7], and its sum is 7. Since 6 < 7, i = 2 is not a valid split.\n\t\tThus, the number of valid splits in nums is 2.\n\t\tExample 2:\n\t\tInput: nums = [2,3,1,0]\n\t\tOutput: 2\n\t\tExplanation: \n\t\tThere are two valid splits in nums:\n\t\t- Split nums at index 1. Then, the first part is [2,3], and its sum is 5. The second part is [1,0], and its sum is 1. Since 5 >= 1, i = 1 is a valid split. \n\t\t- Split nums at index 2. Then, the first part is [2,3,1], and its sum is 6. The second part is [0], and its sum is 0. Since 6 >= 0, i = 2 is a valid split.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2359,
-        "question": "class Solution:\n    def maximumWhiteTiles(self, tiles: List[List[int]], carpetLen: int) -> int:\n\t\t\"\"\"\n\t\tYou are given a 2D integer array tiles where tiles[i] = [li, ri] represents that every tile j in the range li <= j <= ri is colored white.\n\t\tYou are also given an integer carpetLen, the length of a single carpet that can be placed anywhere.\n\t\tReturn the maximum number of white tiles that can be covered by the carpet.\n\t\tExample 1:\n\t\tInput: tiles = [[1,5],[10,11],[12,18],[20,25],[30,32]], carpetLen = 10\n\t\tOutput: 9\n\t\tExplanation: Place the carpet starting on tile 10. \n\t\tIt covers 9 white tiles, so we return 9.\n\t\tNote that there may be other places where the carpet covers 9 white tiles.\n\t\tIt can be shown that the carpet cannot cover more than 9 white tiles.\n\t\tExample 2:\n\t\tInput: tiles = [[10,11],[1,1]], carpetLen = 2\n\t\tOutput: 2\n\t\tExplanation: Place the carpet starting on tile 10. \n\t\tIt covers 2 white tiles, so we return 2.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2360,
-        "question": "class Solution:\n    def largestVariance(self, s: str) -> int:\n\t\t\"\"\"\n\t\tThe variance of a string is defined as the largest difference between the number of occurrences of any 2 characters present in the string. Note the two characters may or may not be the same.\n\t\tGiven a string s consisting of lowercase English letters only, return the largest variance possible among all substrings of s.\n\t\tA substring is a contiguous sequence of characters within a string.\n\t\tExample 1:\n\t\tInput: s = \"aababbb\"\n\t\tOutput: 3\n\t\tExplanation:\n\t\tAll possible variances along with their respective substrings are listed below:\n\t\t- Variance 0 for substrings \"a\", \"aa\", \"ab\", \"abab\", \"aababb\", \"ba\", \"b\", \"bb\", and \"bbb\".\n\t\t- Variance 1 for substrings \"aab\", \"aba\", \"abb\", \"aabab\", \"ababb\", \"aababbb\", and \"bab\".\n\t\t- Variance 2 for substrings \"aaba\", \"ababbb\", \"abbb\", and \"babb\".\n\t\t- Variance 3 for substring \"babbb\".\n\t\tSince the largest possible variance is 3, we return it.\n\t\tExample 2:\n\t\tInput: s = \"abcde\"\n\t\tOutput: 0\n\t\tExplanation:\n\t\tNo letter occurs more than once in s, so the variance of every substring is 0.\n\t\t\"\"\"\n",
-        "difficulty": 2
-    },
-    {
-        "number": 2361,
-        "question": "class Solution:\n    def digitSum(self, s: str, k: int) -> str:\n\t\t\"\"\"\n\t\tYou are given a string s consisting of digits and an integer k.\n\t\tA round can be completed if the length of s is greater than k. In one round, do the following:\n\t\t\tDivide s into consecutive groups of size k such that the first k characters are in the first group, the next k characters are in the second group, and so on. Note that the size of the last group can be smaller than k.\n\t\t\tReplace each group of s with a string representing the sum of all its digits. For example, \"346\" is replaced with \"13\" because 3 + 4 + 6 = 13.\n\t\t\tMerge consecutive groups together to form a new string. If the length of the string is greater than k, repeat from step 1.\n\t\tReturn s after all rounds have been completed.\n\t\tExample 1:\n\t\tInput: s = \"11111222223\", k = 3\n\t\tOutput: \"135\"\n\t\tExplanation: \n\t\t- For the first round, we divide s into groups of size 3: \"111\", \"112\", \"222\", and \"23\".\n\t\t  \u200b\u200b\u200b\u200b\u200bThen we calculate the digit sum of each group: 1 + 1 + 1 = 3, 1 + 1 + 2 = 4, 2 + 2 + 2 = 6, and 2 + 3 = 5. \n\t\t  So, s becomes \"3\" + \"4\" + \"6\" + \"5\" = \"3465\" after the first round.\n\t\t- For the second round, we divide s into \"346\" and \"5\".\n\t\t  Then we calculate the digit sum of each group: 3 + 4 + 6 = 13, 5 = 5. \n\t\t  So, s becomes \"13\" + \"5\" = \"135\" after second round. \n\t\tNow, s.length <= k, so we return \"135\" as the answer.\n\t\tExample 2:\n\t\tInput: s = \"00000000\", k = 3\n\t\tOutput: \"000\"\n\t\tExplanation: \n\t\tWe divide s into \"000\", \"000\", and \"00\".\n\t\tThen we calculate the digit sum of each group: 0 + 0 + 0 = 0, 0 + 0 + 0 = 0, and 0 + 0 = 0. \n\t\ts becomes \"0\" + \"0\" + \"0\" = \"000\", whose length is equal to k, so we return \"000\".\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 2362,
-        "question": "class Solution:\n    def minimumRounds(self, tasks: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou are given a 0-indexed integer array tasks, where tasks[i] represents the difficulty level of a task. In each round, you can complete either 2 or 3 tasks of the same difficulty level.\n\t\tReturn the minimum rounds required to complete all the tasks, or -1 if it is not possible to complete all the tasks.\n\t\tExample 1:\n\t\tInput: tasks = [2,2,3,3,2,4,4,4,4,4]\n\t\tOutput: 4\n\t\tExplanation: To complete all the tasks, a possible plan is:\n\t\t- In the first round, you complete 3 tasks of difficulty level 2. \n\t\t- In the second round, you complete 2 tasks of difficulty level 3. \n\t\t- In the third round, you complete 3 tasks of difficulty level 4. \n\t\t- In the fourth round, you complete 2 tasks of difficulty level 4.  \n\t\tIt can be shown that all the tasks cannot be completed in fewer than 4 rounds, so the answer is 4.\n\t\tExample 2:\n\t\tInput: tasks = [2,3,3]\n\t\tOutput: -1\n\t\tExplanation: There is only 1 task of difficulty level 2, but in each round, you can only complete either 2 or 3 tasks of the same difficulty level. Hence, you cannot complete all the tasks, and the answer is -1.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2363,
-        "question": "class Solution:\n    def maxTrailingZeros(self, grid: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tYou are given a 2D integer array grid of size m x n, where each cell contains a positive integer.\n\t\tA cornered path is defined as a set of adjacent cells with at most one turn. More specifically, the path should exclusively move either horizontally or vertically up to the turn (if there is one), without returning to a previously visited cell. After the turn, the path will then move exclusively in the alternate direction: move vertically if it moved horizontally, and vice versa, also without returning to a previously visited cell.\n\t\tThe product of a path is defined as the product of all the values in the path.\n\t\tReturn the maximum number of trailing zeros in the product of a cornered path found in grid.\n\t\tNote:\n\t\t\tHorizontal movement means moving in either the left or right direction.\n\t\t\tVertical movement means moving in either the up or down direction.\n\t\tExample 1:\n\t\tInput: grid = [[23,17,15,3,20],[8,1,20,27,11],[9,4,6,2,21],[40,9,1,10,6],[22,7,4,5,3]]\n\t\tOutput: 3\n\t\tExplanation: The grid on the left shows a valid cornered path.\n\t\tIt has a product of 15 * 20 * 6 * 1 * 10 = 18000 which has 3 trailing zeros.\n\t\tIt can be shown that this is the maximum trailing zeros in the product of a cornered path.\n\t\tThe grid in the middle is not a cornered path as it has more than one turn.\n\t\tThe grid on the right is not a cornered path as it requires a return to a previously visited cell.\n\t\tExample 2:\n\t\tInput: grid = [[4,3,2],[7,6,1],[8,8,8]]\n\t\tOutput: 0\n\t\tExplanation: The grid is shown in the figure above.\n\t\tThere are no cornered paths in the grid that result in a product with a trailing zero.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2364,
-        "question": "class Solution:\n    def longestPath(self, parent: List[int], s: str) -> int:\n\t\t\"\"\"\n\t\tYou are given a tree (i.e. a connected, undirected graph that has no cycles) rooted at node 0 consisting of n nodes numbered from 0 to n - 1. The tree is represented by a 0-indexed array parent of size n, where parent[i] is the parent of node i. Since node 0 is the root, parent[0] == -1.\n\t\tYou are also given a string s of length n, where s[i] is the character assigned to node i.\n\t\tReturn the length of the longest path in the tree such that no pair of adjacent nodes on the path have the same character assigned to them.\n\t\tExample 1:\n\t\tInput: parent = [-1,0,0,1,1,2], s = \"abacbe\"\n\t\tOutput: 3\n\t\tExplanation: The longest path where each two adjacent nodes have different characters in the tree is the path: 0 -> 1 -> 3. The length of this path is 3, so 3 is returned.\n\t\tIt can be proven that there is no longer path that satisfies the conditions. \n\t\tExample 2:\n\t\tInput: parent = [-1,0,0,0], s = \"aabc\"\n\t\tOutput: 3\n\t\tExplanation: The longest path where each two adjacent nodes have different characters is the path: 2 -> 0 -> 3. The length of this path is 3, so 3 is returned.\n\t\t\"\"\"\n",
-        "difficulty": 2
-    },
-    {
-        "number": 2365,
-        "question": "class Solution:\n    def percentageLetter(self, s: str, letter: str) -> int:\n\t\t\"\"\"\n\t\tGiven a string s and a character letter, return the percentage of characters in s that equal letter rounded down to the nearest whole percent.\n\t\tExample 1:\n\t\tInput: s = \"foobar\", letter = \"o\"\n\t\tOutput: 33\n\t\tExplanation:\n\t\tThe percentage of characters in s that equal the letter 'o' is 2 / 6 * 100% = 33% when rounded down, so we return 33.\n\t\tExample 2:\n\t\tInput: s = \"jjjj\", letter = \"k\"\n\t\tOutput: 0\n\t\tExplanation:\n\t\tThe percentage of characters in s that equal the letter 'k' is 0%, so we return 0.\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 2366,
-        "question": "class Solution:\n    def maximumBags(self, capacity: List[int], rocks: List[int], additionalRocks: int) -> int:\n\t\t\"\"\"\n\t\tYou have n bags numbered from 0 to n - 1. You are given two 0-indexed integer arrays capacity and rocks. The ith bag can hold a maximum of capacity[i] rocks and currently contains rocks[i] rocks. You are also given an integer additionalRocks, the number of additional rocks you can place in any of the bags.\n\t\tReturn the maximum number of bags that could have full capacity after placing the additional rocks in some bags.\n\t\tExample 1:\n\t\tInput: capacity = [2,3,4,5], rocks = [1,2,4,4], additionalRocks = 2\n\t\tOutput: 3\n\t\tExplanation:\n\t\tPlace 1 rock in bag 0 and 1 rock in bag 1.\n\t\tThe number of rocks in each bag are now [2,3,4,4].\n\t\tBags 0, 1, and 2 have full capacity.\n\t\tThere are 3 bags at full capacity, so we return 3.\n\t\tIt can be shown that it is not possible to have more than 3 bags at full capacity.\n\t\tNote that there may be other ways of placing the rocks that result in an answer of 3.\n\t\tExample 2:\n\t\tInput: capacity = [10,2,2], rocks = [2,2,0], additionalRocks = 100\n\t\tOutput: 3\n\t\tExplanation:\n\t\tPlace 8 rocks in bag 0 and 2 rocks in bag 2.\n\t\tThe number of rocks in each bag are now [10,2,2].\n\t\tBags 0, 1, and 2 have full capacity.\n\t\tThere are 3 bags at full capacity, so we return 3.\n\t\tIt can be shown that it is not possible to have more than 3 bags at full capacity.\n\t\tNote that we did not use all of the additional rocks.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2367,
-        "question": "class Solution:\n    def minimumLines(self, stockPrices: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tYou are given a 2D integer array stockPrices where stockPrices[i] = [dayi, pricei] indicates the price of the stock on day dayi is pricei. A line chart is created from the array by plotting the points on an XY plane with the X-axis representing the day and the Y-axis representing the price and connecting adjacent points. One such example is shown below:\n\t\tReturn the minimum number of lines needed to represent the line chart.\n\t\tExample 1:\n\t\tInput: stockPrices = [[1,7],[2,6],[3,5],[4,4],[5,4],[6,3],[7,2],[8,1]]\n\t\tOutput: 3\n\t\tExplanation:\n\t\tThe diagram above represents the input, with the X-axis representing the day and Y-axis representing the price.\n\t\tThe following 3 lines can be drawn to represent the line chart:\n\t\t- Line 1 (in red) from (1,7) to (4,4) passing through (1,7), (2,6), (3,5), and (4,4).\n\t\t- Line 2 (in blue) from (4,4) to (5,4).\n\t\t- Line 3 (in green) from (5,4) to (8,1) passing through (5,4), (6,3), (7,2), and (8,1).\n\t\tIt can be shown that it is not possible to represent the line chart using less than 3 lines.\n\t\tExample 2:\n\t\tInput: stockPrices = [[3,4],[1,2],[7,8],[2,3]]\n\t\tOutput: 1\n\t\tExplanation:\n\t\tAs shown in the diagram above, the line chart can be represented with a single line.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2368,
-        "question": "class Solution:\n    def totalStrength(self, strength: List[int]) -> int:\n\t\t\"\"\"\n\t\tAs the ruler of a kingdom, you have an army of wizards at your command.\n\t\tYou are given a 0-indexed integer array strength, where strength[i] denotes the strength of the ith wizard. For a contiguous group of wizards (i.e. the wizards' strengths form a subarray of strength), the total strength is defined as the product of the following two values:\n\t\t\tThe strength of the weakest wizard in the group.\n\t\t\tThe total of all the individual strengths of the wizards in the group.\n\t\tReturn the sum of the total strengths of all contiguous groups of wizards. Since the answer may be very large, return it modulo 109 + 7.\n\t\tA subarray is a contiguous non-empty sequence of elements within an array.\n\t\tExample 1:\n\t\tInput: strength = [1,3,1,2]\n\t\tOutput: 44\n\t\tExplanation: The following are all the contiguous groups of wizards:\n\t\t- [1] from [1,3,1,2] has a total strength of min([1]) * sum([1]) = 1 * 1 = 1\n\t\t- [3] from [1,3,1,2] has a total strength of min([3]) * sum([3]) = 3 * 3 = 9\n\t\t- [1] from [1,3,1,2] has a total strength of min([1]) * sum([1]) = 1 * 1 = 1\n\t\t- [2] from [1,3,1,2] has a total strength of min([2]) * sum([2]) = 2 * 2 = 4\n\t\t- [1,3] from [1,3,1,2] has a total strength of min([1,3]) * sum([1,3]) = 1 * 4 = 4\n\t\t- [3,1] from [1,3,1,2] has a total strength of min([3,1]) * sum([3,1]) = 1 * 4 = 4\n\t\t- [1,2] from [1,3,1,2] has a total strength of min([1,2]) * sum([1,2]) = 1 * 3 = 3\n\t\t- [1,3,1] from [1,3,1,2] has a total strength of min([1,3,1]) * sum([1,3,1]) = 1 * 5 = 5\n\t\t- [3,1,2] from [1,3,1,2] has a total strength of min([3,1,2]) * sum([3,1,2]) = 1 * 6 = 6\n\t\t- [1,3,1,2] from [1,3,1,2] has a total strength of min([1,3,1,2]) * sum([1,3,1,2]) = 1 * 7 = 7\n\t\tThe sum of all the total strengths is 1 + 9 + 1 + 4 + 4 + 4 + 3 + 5 + 6 + 7 = 44.\n\t\tExample 2:\n\t\tInput: strength = [5,4,6]\n\t\tOutput: 213\n\t\tExplanation: The following are all the contiguous groups of wizards: \n\t\t- [5] from [5,4,6] has a total strength of min([5]) * sum([5]) = 5 * 5 = 25\n\t\t- [4] from [5,4,6] has a total strength of min([4]) * sum([4]) = 4 * 4 = 16\n\t\t- [6] from [5,4,6] has a total strength of min([6]) * sum([6]) = 6 * 6 = 36\n\t\t- [5,4] from [5,4,6] has a total strength of min([5,4]) * sum([5,4]) = 4 * 9 = 36\n\t\t- [4,6] from [5,4,6] has a total strength of min([4,6]) * sum([4,6]) = 4 * 10 = 40\n\t\t- [5,4,6] from [5,4,6] has a total strength of min([5,4,6]) * sum([5,4,6]) = 4 * 15 = 60\n\t\tThe sum of all the total strengths is 25 + 16 + 36 + 36 + 40 + 60 = 213.\n\t\t\"\"\"\n",
-        "difficulty": 2
-    },
-    {
-        "number": 2372,
-        "question": "class Solution:\n    def rearrangeCharacters(self, s: str, target: str) -> int:\n\t\t\"\"\"\n\t\tYou are given two 0-indexed strings s and target. You can take some letters from s and rearrange them to form new strings.\n\t\tReturn the maximum number of copies of target that can be formed by taking letters from s and rearranging them.\n\t\tExample 1:\n\t\tInput: s = \"ilovecodingonleetcode\", target = \"code\"\n\t\tOutput: 2\n\t\tExplanation:\n\t\tFor the first copy of \"code\", take the letters at indices 4, 5, 6, and 7.\n\t\tFor the second copy of \"code\", take the letters at indices 17, 18, 19, and 20.\n\t\tThe strings that are formed are \"ecod\" and \"code\" which can both be rearranged into \"code\".\n\t\tWe can make at most two copies of \"code\", so we return 2.\n\t\tExample 2:\n\t\tInput: s = \"abcba\", target = \"abc\"\n\t\tOutput: 1\n\t\tExplanation:\n\t\tWe can make one copy of \"abc\" by taking the letters at indices 0, 1, and 2.\n\t\tWe can make at most one copy of \"abc\", so we return 1.\n\t\tNote that while there is an extra 'a' and 'b' at indices 3 and 4, we cannot reuse the letter 'c' at index 2, so we cannot make a second copy of \"abc\".\n\t\tExample 3:\n\t\tInput: s = \"abbaccaddaeea\", target = \"aaaaa\"\n\t\tOutput: 1\n\t\tExplanation:\n\t\tWe can make one copy of \"aaaaa\" by taking the letters at indices 0, 3, 6, 9, and 12.\n\t\tWe can make at most one copy of \"aaaaa\", so we return 1.\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 2373,
-        "question": "class Solution:\n    def discountPrices(self, sentence: str, discount: int) -> str:\n\t\t\"\"\"\n\t\tA sentence is a string of single-space separated words where each word can contain digits, lowercase letters, and the dollar sign '$'. A word represents a price if it is a sequence of digits preceded by a dollar sign.\n\t\t\tFor example, \"$100\", \"$23\", and \"$6\" represent prices while \"100\", \"$\", and \"$1e5\" do not.\n\t\tYou are given a string sentence representing a sentence and an integer discount. For each word representing a price, apply a discount of discount% on the price and update the word in the sentence. All updated prices should be represented with exactly two decimal places.\n\t\tReturn a string representing the modified sentence.\n\t\tNote that all prices will contain at most 10 digits.\n\t\tExample 1:\n\t\tInput: sentence = \"there are $1 $2 and 5$ candies in the shop\", discount = 50\n\t\tOutput: \"there are $0.50 $1.00 and 5$ candies in the shop\"\n\t\tExplanation: \n\t\tThe words which represent prices are \"$1\" and \"$2\". \n\t\t- A 50% discount on \"$1\" yields \"$0.50\", so \"$1\" is replaced by \"$0.50\".\n\t\t- A 50% discount on \"$2\" yields \"$1\". Since we need to have exactly 2 decimal places after a price, we replace \"$2\" with \"$1.00\".\n\t\tExample 2:\n\t\tInput: sentence = \"1 2 $3 4 $5 $6 7 8$ $9 $10$\", discount = 100\n\t\tOutput: \"1 2 $0.00 4 $0.00 $0.00 7 8$ $0.00 $10$\"\n\t\tExplanation: \n\t\tApplying a 100% discount on any price will result in 0.\n\t\tThe words representing prices are \"$3\", \"$5\", \"$6\", and \"$9\".\n\t\tEach of them is replaced by \"$0.00\".\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2374,
-        "question": "class Solution:\n    def totalSteps(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou are given a 0-indexed integer array nums. In one step, remove all elements nums[i] where nums[i - 1] > nums[i] for all 0 < i < nums.length.\n\t\tReturn the number of steps performed until nums becomes a non-decreasing array.\n\t\tExample 1:\n\t\tInput: nums = [5,3,4,4,7,3,6,11,8,5,11]\n\t\tOutput: 3\n\t\tExplanation: The following are the steps performed:\n\t\t- Step 1: [5,3,4,4,7,3,6,11,8,5,11] becomes [5,4,4,7,6,11,11]\n\t\t- Step 2: [5,4,4,7,6,11,11] becomes [5,4,7,11,11]\n\t\t- Step 3: [5,4,7,11,11] becomes [5,7,11,11]\n\t\t[5,7,11,11] is a non-decreasing array. Therefore, we return 3.\n\t\tExample 2:\n\t\tInput: nums = [4,5,7,7,13]\n\t\tOutput: 0\n\t\tExplanation: nums is already a non-decreasing array. Therefore, we return 0.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2375,
-        "question": "class Solution:\n    def minimumObstacles(self, grid: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tYou are given a 0-indexed 2D integer array grid of size m x n. Each cell has one of two values:\n\t\t\t0 represents an empty cell,\n\t\t\t1 represents an obstacle that may be removed.\n\t\tYou can move up, down, left, or right from and to an empty cell.\n\t\tReturn the minimum number of obstacles to remove so you can move from the upper left corner (0, 0) to the lower right corner (m - 1, n - 1).\n\t\tExample 1:\n\t\tInput: grid = [[0,1,1],[1,1,0],[1,1,0]]\n\t\tOutput: 2\n\t\tExplanation: We can remove the obstacles at (0, 1) and (0, 2) to create a path from (0, 0) to (2, 2).\n\t\tIt can be shown that we need to remove at least 2 obstacles, so we return 2.\n\t\tNote that there may be other ways to remove 2 obstacles to create a path.\n\t\tExample 2:\n\t\tInput: grid = [[0,1,0,0,0],[0,1,0,1,0],[0,0,0,1,0]]\n\t\tOutput: 0\n\t\tExplanation: We can move from (0, 0) to (2, 4) without removing any obstacles, so we return 0.\n\t\t\"\"\"\n",
-        "difficulty": 2
-    },
-    {
-        "number": 2377,
-        "question": "class Solution:\n    def digitCount(self, num: str) -> bool:\n\t\t\"\"\"\n\t\tYou are given a 0-indexed string num of length n consisting of digits.\n\t\tReturn true if for every index i in the range 0 <= i < n, the digit i occurs num[i] times in num, otherwise return false.\n\t\tExample 1:\n\t\tInput: num = \"1210\"\n\t\tOutput: true\n\t\tExplanation:\n\t\tnum[0] = '1'. The digit 0 occurs once in num.\n\t\tnum[1] = '2'. The digit 1 occurs twice in num.\n\t\tnum[2] = '1'. The digit 2 occurs once in num.\n\t\tnum[3] = '0'. The digit 3 occurs zero times in num.\n\t\tThe condition holds true for every index in \"1210\", so return true.\n\t\tExample 2:\n\t\tInput: num = \"030\"\n\t\tOutput: false\n\t\tExplanation:\n\t\tnum[0] = '0'. The digit 0 should occur zero times, but actually occurs twice in num.\n\t\tnum[1] = '3'. The digit 1 should occur three times, but actually occurs zero times in num.\n\t\tnum[2] = '0'. The digit 2 occurs zero times in num.\n\t\tThe indices 0 and 1 both violate the condition, so return false.\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 2378,
-        "question": "class Solution:\n    def largestWordCount(self, messages: List[str], senders: List[str]) -> str:\n\t\t\"\"\"\n\t\tYou have a chat log of n messages. You are given two string arrays messages and senders where messages[i] is a message sent by senders[i].\n\t\tA message is list of words that are separated by a single space with no leading or trailing spaces. The word count of a sender is the total number of words sent by the sender. Note that a sender may send more than one message.\n\t\tReturn the sender with the largest word count. If there is more than one sender with the largest word count, return the one with the lexicographically largest name.\n\t\tNote:\n\t\t\tUppercase letters come before lowercase letters in lexicographical order.\n\t\t\t\"Alice\" and \"alice\" are distinct.\n\t\tExample 1:\n\t\tInput: messages = [\"Hello userTwooo\",\"Hi userThree\",\"Wonderful day Alice\",\"Nice day userThree\"], senders = [\"Alice\",\"userTwo\",\"userThree\",\"Alice\"]\n\t\tOutput: \"Alice\"\n\t\tExplanation: Alice sends a total of 2 + 3 = 5 words.\n\t\tuserTwo sends a total of 2 words.\n\t\tuserThree sends a total of 3 words.\n\t\tSince Alice has the largest word count, we return \"Alice\".\n\t\tExample 2:\n\t\tInput: messages = [\"How is leetcode for everyone\",\"Leetcode is useful for practice\"], senders = [\"Bob\",\"Charlie\"]\n\t\tOutput: \"Charlie\"\n\t\tExplanation: Bob sends a total of 5 words.\n\t\tCharlie sends a total of 5 words.\n\t\tSince there is a tie for the largest word count, we return the sender with the lexicographically larger name, Charlie.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2379,
-        "question": "class Solution:\n    def maximumImportance(self, n: int, roads: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tYou are given an integer n denoting the number of cities in a country. The cities are numbered from 0 to n - 1.\n\t\tYou are also given a 2D integer array roads where roads[i] = [ai, bi] denotes that there exists a bidirectional road connecting cities ai and bi.\n\t\tYou need to assign each city with an integer value from 1 to n, where each value can only be used once. The importance of a road is then defined as the sum of the values of the two cities it connects.\n\t\tReturn the maximum total importance of all roads possible after assigning the values optimally.\n\t\tExample 1:\n\t\tInput: n = 5, roads = [[0,1],[1,2],[2,3],[0,2],[1,3],[2,4]]\n\t\tOutput: 43\n\t\tExplanation: The figure above shows the country and the assigned values of [2,4,5,3,1].\n\t\t- The road (0,1) has an importance of 2 + 4 = 6.\n\t\t- The road (1,2) has an importance of 4 + 5 = 9.\n\t\t- The road (2,3) has an importance of 5 + 3 = 8.\n\t\t- The road (0,2) has an importance of 2 + 5 = 7.\n\t\t- The road (1,3) has an importance of 4 + 3 = 7.\n\t\t- The road (2,4) has an importance of 5 + 1 = 6.\n\t\tThe total importance of all roads is 6 + 9 + 8 + 7 + 7 + 6 = 43.\n\t\tIt can be shown that we cannot obtain a greater total importance than 43.\n\t\tExample 2:\n\t\tInput: n = 5, roads = [[0,3],[2,4],[1,3]]\n\t\tOutput: 20\n\t\tExplanation: The figure above shows the country and the assigned values of [4,3,2,5,1].\n\t\t- The road (0,3) has an importance of 4 + 5 = 9.\n\t\t- The road (2,4) has an importance of 2 + 1 = 3.\n\t\t- The road (1,3) has an importance of 3 + 5 = 8.\n\t\tThe total importance of all roads is 9 + 3 + 8 = 20.\n\t\tIt can be shown that we cannot obtain a greater total importance than 20.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2380,
-        "question": "class BookMyShow:\n    def __init__(self, n: int, m: int):\n    def gather(self, k: int, maxRow: int) -> List[int]:\n    def scatter(self, k: int, maxRow: int) -> bool:\n\t\t\"\"\"\n\t\tA concert hall has n rows numbered from 0 to n - 1, each with m seats, numbered from 0 to m - 1. You need to design a ticketing system that can allocate seats in the following cases:\n\t\t\tIf a group of k spectators can sit together in a row.\n\t\t\tIf every member of a group of k spectators can get a seat. They may or may not sit together.\n\t\tNote that the spectators are very picky. Hence:\n\t\t\tThey will book seats only if each member of their group can get a seat with row number less than or equal to maxRow. maxRow can vary from group to group.\n\t\t\tIn case there are multiple rows to choose from, the row with the smallest number is chosen. If there are multiple seats to choose in the same row, the seat with the smallest number is chosen.\n\t\tImplement the BookMyShow class:\n\t\t\tBookMyShow(int n, int m) Initializes the object with n as number of rows and m as number of seats per row.\n\t\t\tint[] gather(int k, int maxRow) Returns an array of length 2 denoting the row and seat number (respectively) of the first seat being allocated to the k members of the group, who must sit together. In other words, it returns the smallest possible r and c such that all [c, c + k - 1] seats are valid and empty in row r, and r <= maxRow. Returns [] in case it is not possible to allocate seats to the group.\n\t\t\tboolean scatter(int k, int maxRow) Returns true if all k members of the group can be allocated seats in rows 0 to maxRow, who may or may not sit together. If the seats can be allocated, it allocates k seats to the group with the smallest row numbers, and the smallest possible seat numbers in each row. Otherwise, returns false.\n\t\tExample 1:\n\t\tInput\n\t\t[\"BookMyShow\", \"gather\", \"gather\", \"scatter\", \"scatter\"]\n\t\t[[2, 5], [4, 0], [2, 0], [5, 1], [5, 1]]\n\t\tOutput\n\t\t[null, [0, 0], [], true, false]\n\t\tExplanation\n\t\tBookMyShow bms = new BookMyShow(2, 5); // There are 2 rows with 5 seats each \n\t\tbms.gather(4, 0); // return [0, 0]\n\t\t                  // The group books seats [0, 3] of row 0. \n\t\tbms.gather(2, 0); // return []\n\t\t                  // There is only 1 seat left in row 0,\n\t\t                  // so it is not possible to book 2 consecutive seats. \n\t\tbms.scatter(5, 1); // return True\n\t\t                   // The group books seat 4 of row 0 and seats [0, 3] of row 1. \n\t\tbms.scatter(5, 1); // return False\n\t\t                   // There is only one seat left in the hall.\n\t\t\"\"\"\n",
-        "difficulty": 2
-    },
-    {
-        "number": 2383,
-        "question": "class Solution:\n    def sum(self, num1: int, num2: int) -> int:\n\t\t\"\"\"\n\t\tGiven two integers num1 and num2, return the sum of the two integers.\n\t\tExample 1:\n\t\tInput: num1 = 12, num2 = 5\n\t\tOutput: 17\n\t\tExplanation: num1 is 12, num2 is 5, and their sum is 12 + 5 = 17, so 17 is returned.\n\t\tExample 2:\n\t\tInput: num1 = -10, num2 = 4\n\t\tOutput: -6\n\t\tExplanation: num1 + num2 = -6, so -6 is returned.\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 2384,
-        "question": "class Solution:\n    def checkTree(self, root: Optional[TreeNode]) -> bool:\n\t\t\"\"\"\n\t\tYou are given the root of a binary tree that consists of exactly 3 nodes: the root, its left child, and its right child.\n\t\tReturn true if the value of the root is equal to the sum of the values of its two children, or false otherwise.\n\t\tExample 1:\n\t\tInput: root = [10,4,6]\n\t\tOutput: true\n\t\tExplanation: The values of the root, its left child, and its right child are 10, 4, and 6, respectively.\n\t\t10 is equal to 4 + 6, so we return true.\n\t\tExample 2:\n\t\tInput: root = [5,3,1]\n\t\tOutput: false\n\t\tExplanation: The values of the root, its left child, and its right child are 5, 3, and 1, respectively.\n\t\t5 is not equal to 3 + 1, so we return false.\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 2386,
-        "question": "class Solution:\n    def minMaxGame(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou are given a 0-indexed integer array nums whose length is a power of 2.\n\t\tApply the following algorithm on nums:\n\t\t\tLet n be the length of nums. If n == 1, end the process. Otherwise, create a new 0-indexed integer array newNums of length n / 2.\n\t\t\tFor every even index i where 0 <= i < n / 2, assign the value of newNums[i] as min(nums[2 * i], nums[2 * i + 1]).\n\t\t\tFor every odd index i where 0 <= i < n / 2, assign the value of newNums[i] as max(nums[2 * i], nums[2 * i + 1]).\n\t\t\tReplace the array nums with newNums.\n\t\t\tRepeat the entire process starting from step 1.\n\t\tReturn the last number that remains in nums after applying the algorithm.\n\t\tExample 1:\n\t\tInput: nums = [1,3,5,2,4,8,2,2]\n\t\tOutput: 1\n\t\tExplanation: The following arrays are the results of applying the algorithm repeatedly.\n\t\tFirst: nums = [1,5,4,2]\n\t\tSecond: nums = [1,4]\n\t\tThird: nums = [1]\n\t\t1 is the last remaining number, so we return 1.\n\t\tExample 2:\n\t\tInput: nums = [3]\n\t\tOutput: 3\n\t\tExplanation: 3 is already the last remaining number, so we return 3.\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 2387,
-        "question": "class Solution:\n    def partitionArray(self, nums: List[int], k: int) -> int:\n\t\t\"\"\"\n\t\tYou are given an integer array nums and an integer k. You may partition nums into one or more subsequences such that each element in nums appears in exactly one of the subsequences.\n\t\tReturn the minimum number of subsequences needed such that the difference between the maximum and minimum values in each subsequence is at most k.\n\t\tA subsequence is a sequence that can be derived from another sequence by deleting some or no elements without changing the order of the remaining elements.\n\t\tExample 1:\n\t\tInput: nums = [3,6,1,2,5], k = 2\n\t\tOutput: 2\n\t\tExplanation:\n\t\tWe can partition nums into the two subsequences [3,1,2] and [6,5].\n\t\tThe difference between the maximum and minimum value in the first subsequence is 3 - 1 = 2.\n\t\tThe difference between the maximum and minimum value in the second subsequence is 6 - 5 = 1.\n\t\tSince two subsequences were created, we return 2. It can be shown that 2 is the minimum number of subsequences needed.\n\t\tExample 2:\n\t\tInput: nums = [1,2,3], k = 1\n\t\tOutput: 2\n\t\tExplanation:\n\t\tWe can partition nums into the two subsequences [1,2] and [3].\n\t\tThe difference between the maximum and minimum value in the first subsequence is 2 - 1 = 1.\n\t\tThe difference between the maximum and minimum value in the second subsequence is 3 - 3 = 0.\n\t\tSince two subsequences were created, we return 2. Note that another optimal solution is to partition nums into the two subsequences [1] and [2,3].\n\t\tExample 3:\n\t\tInput: nums = [2,2,4,5], k = 0\n\t\tOutput: 3\n\t\tExplanation:\n\t\tWe can partition nums into the three subsequences [2,2], [4], and [5].\n\t\tThe difference between the maximum and minimum value in the first subsequences is 2 - 2 = 0.\n\t\tThe difference between the maximum and minimum value in the second subsequences is 4 - 4 = 0.\n\t\tThe difference between the maximum and minimum value in the third subsequences is 5 - 5 = 0.\n\t\tSince three subsequences were created, we return 3. It can be shown that 3 is the minimum number of subsequences needed.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2388,
-        "question": "class Solution:\n    def arrayChange(self, nums: List[int], operations: List[List[int]]) -> List[int]:\n\t\t\"\"\"\n\t\tYou are given a 0-indexed array nums that consists of n distinct positive integers. Apply m operations to this array, where in the ith operation you replace the number operations[i][0] with operations[i][1].\n\t\tIt is guaranteed that in the ith operation:\n\t\t\toperations[i][0] exists in nums.\n\t\t\toperations[i][1] does not exist in nums.\n\t\tReturn the array obtained after applying all the operations.\n\t\tExample 1:\n\t\tInput: nums = [1,2,4,6], operations = [[1,3],[4,7],[6,1]]\n\t\tOutput: [3,2,7,1]\n\t\tExplanation: We perform the following operations on nums:\n\t\t- Replace the number 1 with 3. nums becomes [3,2,4,6].\n\t\t- Replace the number 4 with 7. nums becomes [3,2,7,6].\n\t\t- Replace the number 6 with 1. nums becomes [3,2,7,1].\n\t\tWe return the final array [3,2,7,1].\n\t\tExample 2:\n\t\tInput: nums = [1,2], operations = [[1,3],[2,1],[3,2]]\n\t\tOutput: [2,1]\n\t\tExplanation: We perform the following operations to nums:\n\t\t- Replace the number 1 with 3. nums becomes [3,2].\n\t\t- Replace the number 2 with 1. nums becomes [3,1].\n\t\t- Replace the number 3 with 2. nums becomes [2,1].\n\t\tWe return the array [2,1].\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2389,
-        "question": "class TextEditor:\n    def __init__(self):\n    def addText(self, text: str) -> None:\n    def deleteText(self, k: int) -> int:\n    def cursorLeft(self, k: int) -> str:\n    def cursorRight(self, k: int) -> str:\n\t\t\"\"\"\n\t\tDesign a text editor with a cursor that can do the following:\n\t\t\tAdd text to where the cursor is.\n\t\t\tDelete text from where the cursor is (simulating the backspace key).\n\t\t\tMove the cursor either left or right.\n\t\tWhen deleting text, only characters to the left of the cursor will be deleted. The cursor will also remain within the actual text and cannot be moved beyond it. More formally, we have that 0 <= cursor.position <= currentText.length always holds.\n\t\tImplement the TextEditor class:\n\t\t\tTextEditor() Initializes the object with empty text.\n\t\t\tvoid addText(string text) Appends text to where the cursor is. The cursor ends to the right of text.\n\t\t\tint deleteText(int k) Deletes k characters to the left of the cursor. Returns the number of characters actually deleted.\n\t\t\tstring cursorLeft(int k) Moves the cursor to the left k times. Returns the last min(10, len) characters to the left of the cursor, where len is the number of characters to the left of the cursor.\n\t\t\tstring cursorRight(int k) Moves the cursor to the right k times. Returns the last min(10, len) characters to the left of the cursor, where len is the number of characters to the left of the cursor.\n\t\tExample 1:\n\t\tInput\n\t\t[\"TextEditor\", \"addText\", \"deleteText\", \"addText\", \"cursorRight\", \"cursorLeft\", \"deleteText\", \"cursorLeft\", \"cursorRight\"]\n\t\t[[], [\"leetcode\"], [4], [\"practice\"], [3], [8], [10], [2], [6]]\n\t\tOutput\n\t\t[null, null, 4, null, \"etpractice\", \"leet\", 4, \"\", \"practi\"]\n\t\tExplanation\n\t\tTextEditor textEditor = new TextEditor(); // The current text is \"|\". (The '|' character represents the cursor)\n\t\ttextEditor.addText(\"leetcode\"); // The current text is \"leetcode|\".\n\t\ttextEditor.deleteText(4); // return 4\n\t\t                          // The current text is \"leet|\". \n\t\t                          // 4 characters were deleted.\n\t\ttextEditor.addText(\"practice\"); // The current text is \"leetpractice|\". \n\t\ttextEditor.cursorRight(3); // return \"etpractice\"\n\t\t                           // The current text is \"leetpractice|\". \n\t\t                           // The cursor cannot be moved beyond the actual text and thus did not move.\n\t\t                           // \"etpractice\" is the last 10 characters to the left of the cursor.\n\t\ttextEditor.cursorLeft(8); // return \"leet\"\n\t\t                          // The current text is \"leet|practice\".\n\t\t                          // \"leet\" is the last min(10, 4) = 4 characters to the left of the cursor.\n\t\ttextEditor.deleteText(10); // return 4\n\t\t                           // The current text is \"|practice\".\n\t\t                           // Only 4 characters were deleted.\n\t\ttextEditor.cursorLeft(2); // return \"\"\n\t\t                          // The current text is \"|practice\".\n\t\t                          // The cursor cannot be moved beyond the actual text and thus did not move. \n\t\t                          // \"\" is the last min(10, 0) = 0 characters to the left of the cursor.\n\t\ttextEditor.cursorRight(6); // return \"practi\"\n\t\t                           // The current text is \"practi|ce\".\n\t\t                           // \"practi\" is the last min(10, 6) = 6 characters to the left of the cursor.\n\t\t\"\"\"\n",
-        "difficulty": 2
-    },
-    {
-        "number": 2390,
-        "question": "class Solution:\n    def distinctNames(self, ideas: List[str]) -> int:\n\t\t\"\"\"\n\t\tYou are given an array of strings ideas that represents a list of names to be used in the process of naming a company. The process of naming a company is as follows:\n\t\t\tChoose 2 distinct names from ideas, call them ideaA and ideaB.\n\t\t\tSwap the first letters of ideaA and ideaB with each other.\n\t\t\tIf both of the new names are not found in the original ideas, then the name ideaA ideaB (the concatenation of ideaA and ideaB, separated by a space) is a valid company name.\n\t\t\tOtherwise, it is not a valid name.\n\t\tReturn the number of distinct valid names for the company.\n\t\tExample 1:\n\t\tInput: ideas = [\"coffee\",\"donuts\",\"time\",\"toffee\"]\n\t\tOutput: 6\n\t\tExplanation: The following selections are valid:\n\t\t- (\"coffee\", \"donuts\"): The company name created is \"doffee conuts\".\n\t\t- (\"donuts\", \"coffee\"): The company name created is \"conuts doffee\".\n\t\t- (\"donuts\", \"time\"): The company name created is \"tonuts dime\".\n\t\t- (\"donuts\", \"toffee\"): The company name created is \"tonuts doffee\".\n\t\t- (\"time\", \"donuts\"): The company name created is \"dime tonuts\".\n\t\t- (\"toffee\", \"donuts\"): The company name created is \"doffee tonuts\".\n\t\tTherefore, there are a total of 6 distinct company names.\n\t\tThe following are some examples of invalid selections:\n\t\t- (\"coffee\", \"time\"): The name \"toffee\" formed after swapping already exists in the original array.\n\t\t- (\"time\", \"toffee\"): Both names are still the same after swapping and exist in the original array.\n\t\t- (\"coffee\", \"toffee\"): Both names formed after swapping already exist in the original array.\n\t\tExample 2:\n\t\tInput: ideas = [\"lack\",\"back\"]\n\t\tOutput: 0\n\t\tExplanation: There are no valid selections. Therefore, 0 is returned.\n\t\t\"\"\"\n",
-        "difficulty": 2
-    },
-    {
-        "number": 2391,
-        "question": "class Solution:\n    def strongPasswordCheckerII(self, password: str) -> bool:\n\t\t\"\"\"\n\t\tA password is said to be strong if it satisfies all the following criteria:\n\t\t\tIt has at least 8 characters.\n\t\t\tIt contains at least one lowercase letter.\n\t\t\tIt contains at least one uppercase letter.\n\t\t\tIt contains at least one digit.\n\t\t\tIt contains at least one special character. The special characters are the characters in the following string: \"!@#$%^&*()-+\".\n\t\t\tIt does not contain 2 of the same character in adjacent positions (i.e., \"aab\" violates this condition, but \"aba\" does not).\n\t\tGiven a string password, return true if it is a strong password. Otherwise, return false.\n\t\tExample 1:\n\t\tInput: password = \"IloveLe3tcode!\"\n\t\tOutput: true\n\t\tExplanation: The password meets all the requirements. Therefore, we return true.\n\t\tExample 2:\n\t\tInput: password = \"Me+You--IsMyDream\"\n\t\tOutput: false\n\t\tExplanation: The password does not contain a digit and also contains 2 of the same character in adjacent positions. Therefore, we return false.\n\t\tExample 3:\n\t\tInput: password = \"1aB!\"\n\t\tOutput: false\n\t\tExplanation: The password does not meet the length requirement. Therefore, we return false.\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 2392,
-        "question": "class Solution:\n    def successfulPairs(self, spells: List[int], potions: List[int], success: int) -> List[int]:\n\t\t\"\"\"\n\t\tYou are given two positive integer arrays spells and potions, of length n and m respectively, where spells[i] represents the strength of the ith spell and potions[j] represents the strength of the jth potion.\n\t\tYou are also given an integer success. A spell and potion pair is considered successful if the product of their strengths is at least success.\n\t\tReturn an integer array pairs of length n where pairs[i] is the number of potions that will form a successful pair with the ith spell.\n\t\tExample 1:\n\t\tInput: spells = [5,1,3], potions = [1,2,3,4,5], success = 7\n\t\tOutput: [4,0,3]\n\t\tExplanation:\n\t\t- 0th spell: 5 * [1,2,3,4,5] = [5,10,15,20,25]. 4 pairs are successful.\n\t\t- 1st spell: 1 * [1,2,3,4,5] = [1,2,3,4,5]. 0 pairs are successful.\n\t\t- 2nd spell: 3 * [1,2,3,4,5] = [3,6,9,12,15]. 3 pairs are successful.\n\t\tThus, [4,0,3] is returned.\n\t\tExample 2:\n\t\tInput: spells = [3,1,2], potions = [8,5,8], success = 16\n\t\tOutput: [2,0,2]\n\t\tExplanation:\n\t\t- 0th spell: 3 * [8,5,8] = [24,15,24]. 2 pairs are successful.\n\t\t- 1st spell: 1 * [8,5,8] = [8,5,8]. 0 pairs are successful. \n\t\t- 2nd spell: 2 * [8,5,8] = [16,10,16]. 2 pairs are successful. \n\t\tThus, [2,0,2] is returned.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2393,
-        "question": "class Solution:\n    def matchReplacement(self, s: str, sub: str, mappings: List[List[str]]) -> bool:\n\t\t\"\"\"\n\t\tYou are given two strings s and sub. You are also given a 2D character array mappings where mappings[i] = [oldi, newi] indicates that you may perform the following operation any number of times:\n\t\t\tReplace a character oldi of sub with newi.\n\t\tEach character in sub cannot be replaced more than once.\n\t\tReturn true if it is possible to make sub a substring of s by replacing zero or more characters according to mappings. Otherwise, return false.\n\t\tA substring is a contiguous non-empty sequence of characters within a string.\n\t\tExample 1:\n\t\tInput: s = \"fool3e7bar\", sub = \"leet\", mappings = [[\"e\",\"3\"],[\"t\",\"7\"],[\"t\",\"8\"]]\n\t\tOutput: true\n\t\tExplanation: Replace the first 'e' in sub with '3' and 't' in sub with '7'.\n\t\tNow sub = \"l3e7\" is a substring of s, so we return true.\n\t\tExample 2:\n\t\tInput: s = \"fooleetbar\", sub = \"f00l\", mappings = [[\"o\",\"0\"]]\n\t\tOutput: false\n\t\tExplanation: The string \"f00l\" is not a substring of s and no replacements can be made.\n\t\tNote that we cannot replace '0' with 'o'.\n\t\tExample 3:\n\t\tInput: s = \"Fool33tbaR\", sub = \"leetd\", mappings = [[\"e\",\"3\"],[\"t\",\"7\"],[\"t\",\"8\"],[\"d\",\"b\"],[\"p\",\"b\"]]\n\t\tOutput: true\n\t\tExplanation: Replace the first and second 'e' in sub with '3' and 'd' in sub with 'b'.\n\t\tNow sub = \"l33tb\" is a substring of s, so we return true.\n\t\t\"\"\"\n",
-        "difficulty": 2
-    },
-    {
-        "number": 2394,
-        "question": "class Solution:\n    def countSubarrays(self, nums: List[int], k: int) -> int:\n\t\t\"\"\"\n\t\tThe score of an array is defined as the product of its sum and its length.\n\t\t\tFor example, the score of [1, 2, 3, 4, 5] is (1 + 2 + 3 + 4 + 5) * 5 = 75.\n\t\tGiven a positive integer array nums and an integer k, return the number of non-empty subarrays of nums whose score is strictly less than k.\n\t\tA subarray is a contiguous sequence of elements within an array.\n\t\tExample 1:\n\t\tInput: nums = [2,1,4,3,5], k = 10\n\t\tOutput: 6\n\t\tExplanation:\n\t\tThe 6 subarrays having scores less than 10 are:\n\t\t- [2] with score 2 * 1 = 2.\n\t\t- [1] with score 1 * 1 = 1.\n\t\t- [4] with score 4 * 1 = 4.\n\t\t- [3] with score 3 * 1 = 3. \n\t\t- [5] with score 5 * 1 = 5.\n\t\t- [2,1] with score (2 + 1) * 2 = 6.\n\t\tNote that subarrays such as [1,4] and [4,3,5] are not considered because their scores are 10 and 36 respectively, while we need scores strictly less than 10.\n\t\tExample 2:\n\t\tInput: nums = [1,1,1], k = 5\n\t\tOutput: 5\n\t\tExplanation:\n\t\tEvery subarray except [1,1,1] has a score less than 5.\n\t\t[1,1,1] has a score (1 + 1 + 1) * 3 = 9, which is greater than 5.\n\t\tThus, there are 5 subarrays having scores less than 5.\n\t\t\"\"\"\n",
-        "difficulty": 2
-    },
-    {
-        "number": 2395,
-        "question": "class Solution:\n    def longestSubsequence(self, s: str, k: int) -> int:\n\t\t\"\"\"\n\t\tYou are given a binary string s and a positive integer k.\n\t\tReturn the length of the longest subsequence of s that makes up a binary number less than or equal to k.\n\t\tNote:\n\t\t\tThe subsequence can contain leading zeroes.\n\t\t\tThe empty string is considered to be equal to 0.\n\t\t\tA subsequence is a string that can be derived from another string by deleting some or no characters without changing the order of the remaining characters.\n\t\tExample 1:\n\t\tInput: s = \"1001010\", k = 5\n\t\tOutput: 5\n\t\tExplanation: The longest subsequence of s that makes up a binary number less than or equal to 5 is \"00010\", as this number is equal to 2 in decimal.\n\t\tNote that \"00100\" and \"00101\" are also possible, which are equal to 4 and 5 in decimal, respectively.\n\t\tThe length of this subsequence is 5, so 5 is returned.\n\t\tExample 2:\n\t\tInput: s = \"00101001\", k = 1\n\t\tOutput: 6\n\t\tExplanation: \"000001\" is the longest subsequence of s that makes up a binary number less than or equal to 1, as this number is equal to 1 in decimal.\n\t\tThe length of this subsequence is 6, so 6 is returned.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2397,
-        "question": "class Solution:\n    def countHousePlacements(self, n: int) -> int:\n\t\t\"\"\"\n\t\tThere is a street with n * 2 plots, where there are n plots on each side of the street. The plots on each side are numbered from 1 to n. On each plot, a house can be placed.\n\t\tReturn the number of ways houses can be placed such that no two houses are adjacent to each other on the same side of the street. Since the answer may be very large, return it modulo 109 + 7.\n\t\tNote that if a house is placed on the ith plot on one side of the street, a house can also be placed on the ith plot on the other side of the street.\n\t\tExample 1:\n\t\tInput: n = 1\n\t\tOutput: 4\n\t\tExplanation: \n\t\tPossible arrangements:\n\t\t1. All plots are empty.\n\t\t2. A house is placed on one side of the street.\n\t\t3. A house is placed on the other side of the street.\n\t\t4. Two houses are placed, one on each side of the street.\n\t\tExample 2:\n\t\tInput: n = 2\n\t\tOutput: 9\n\t\tExplanation: The 9 possible arrangements are shown in the diagram above.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2398,
-        "question": "class Solution:\n    def checkXMatrix(self, grid: List[List[int]]) -> bool:\n\t\t\"\"\"\n\t\tA square matrix is said to be an X-Matrix if both of the following conditions hold:\n\t\t\tAll the elements in the diagonals of the matrix are non-zero.\n\t\t\tAll other elements are 0.\n\t\tGiven a 2D integer array grid of size n x n representing a square matrix, return true if grid is an X-Matrix. Otherwise, return false.\n\t\tExample 1:\n\t\tInput: grid = [[2,0,0,1],[0,3,1,0],[0,5,2,0],[4,0,0,2]]\n\t\tOutput: true\n\t\tExplanation: Refer to the diagram above. \n\t\tAn X-Matrix should have the green elements (diagonals) be non-zero and the red elements be 0.\n\t\tThus, grid is an X-Matrix.\n\t\tExample 2:\n\t\tInput: grid = [[5,7,0],[0,3,1],[0,5,0]]\n\t\tOutput: false\n\t\tExplanation: Refer to the diagram above.\n\t\tAn X-Matrix should have the green elements (diagonals) be non-zero and the red elements be 0.\n\t\tThus, grid is not an X-Matrix.\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 2400,
-        "question": "class Solution:\n    def minimumScore(self, nums: List[int], edges: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tThere is an undirected connected tree with n nodes labeled from 0 to n - 1 and n - 1 edges.\n\t\tYou are given a 0-indexed integer array nums of length n where nums[i] represents the value of the ith node. You are also given a 2D integer array edges of length n - 1 where edges[i] = [ai, bi] indicates that there is an edge between nodes ai and bi in the tree.\n\t\tRemove two distinct edges of the tree to form three connected components. For a pair of removed edges, the following steps are defined:\n\t\t\tGet the XOR of all the values of the nodes for each of the three components respectively.\n\t\t\tThe difference between the largest XOR value and the smallest XOR value is the score of the pair.\n\t\t\tFor example, say the three components have the node values: [4,5,7], [1,9], and [3,3,3]. The three XOR values are 4 ^ 5 ^ 7 = 6, 1 ^ 9 = 8, and 3 ^ 3 ^ 3 = 3. The largest XOR value is 8 and the smallest XOR value is 3. The score is then 8 - 3 = 5.\n\t\tReturn the minimum score of any possible pair of edge removals on the given tree.\n\t\tExample 1:\n\t\tInput: nums = [1,5,5,4,11], edges = [[0,1],[1,2],[1,3],[3,4]]\n\t\tOutput: 9\n\t\tExplanation: The diagram above shows a way to make a pair of removals.\n\t\t- The 1st component has nodes [1,3,4] with values [5,4,11]. Its XOR value is 5 ^ 4 ^ 11 = 10.\n\t\t- The 2nd component has node [0] with value [1]. Its XOR value is 1 = 1.\n\t\t- The 3rd component has node [2] with value [5]. Its XOR value is 5 = 5.\n\t\tThe score is the difference between the largest and smallest XOR value which is 10 - 1 = 9.\n\t\tIt can be shown that no other pair of removals will obtain a smaller score than 9.\n\t\tExample 2:\n\t\tInput: nums = [5,5,2,4,4,2], edges = [[0,1],[1,2],[5,2],[4,3],[1,3]]\n\t\tOutput: 0\n\t\tExplanation: The diagram above shows a way to make a pair of removals.\n\t\t- The 1st component has nodes [3,4] with values [4,4]. Its XOR value is 4 ^ 4 = 0.\n\t\t- The 2nd component has nodes [1,0] with values [5,5]. Its XOR value is 5 ^ 5 = 0.\n\t\t- The 3rd component has nodes [2,5] with values [2,2]. Its XOR value is 2 ^ 2 = 0.\n\t\tThe score is the difference between the largest and smallest XOR value which is 0 - 0 = 0.\n\t\tWe cannot obtain a smaller score than 0.\n\t\t\"\"\"\n",
-        "difficulty": 2
-    },
-    {
-        "number": 2401,
-        "question": "class Solution:\n    def countAsterisks(self, s: str) -> int:\n\t\t\"\"\"\n\t\tYou are given a string s, where every two consecutive vertical bars '|' are grouped into a pair. In other words, the 1st and 2nd '|' make a pair, the 3rd and 4th '|' make a pair, and so forth.\n\t\tReturn the number of '*' in s, excluding the '*' between each pair of '|'.\n\t\tNote that each '|' will belong to exactly one pair.\n\t\tExample 1:\n\t\tInput: s = \"l|*e*et|c**o|*de|\"\n\t\tOutput: 2\n\t\tExplanation: The considered characters are underlined: \"l|*e*et|c**o|*de|\".\n\t\tThe characters between the first and second '|' are excluded from the answer.\n\t\tAlso, the characters between the third and fourth '|' are excluded from the answer.\n\t\tThere are 2 asterisks considered. Therefore, we return 2.\n\t\tExample 2:\n\t\tInput: s = \"iamprogrammer\"\n\t\tOutput: 0\n\t\tExplanation: In this example, there are no asterisks in s. Therefore, we return 0.\n\t\tExample 3:\n\t\tInput: s = \"yo|uar|e**|b|e***au|tifu|l\"\n\t\tOutput: 5\n\t\tExplanation: The considered characters are underlined: \"yo|uar|e**|b|e***au|tifu|l\". There are 5 asterisks considered. Therefore, we return 5.\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 2402,
-        "question": "class Solution:\n    def maximumXOR(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou are given a 0-indexed integer array nums. In one operation, select any non-negative integer x and an index i, then update nums[i] to be equal to nums[i] AND (nums[i] XOR x).\n\t\tNote that AND is the bitwise AND operation and XOR is the bitwise XOR operation.\n\t\tReturn the maximum possible bitwise XOR of all elements of nums after applying the operation any number of times.\n\t\tExample 1:\n\t\tInput: nums = [3,2,4,6]\n\t\tOutput: 7\n\t\tExplanation: Apply the operation with x = 4 and i = 3, num[3] = 6 AND (6 XOR 4) = 6 AND 2 = 2.\n\t\tNow, nums = [3, 2, 4, 2] and the bitwise XOR of all the elements = 3 XOR 2 XOR 4 XOR 2 = 7.\n\t\tIt can be shown that 7 is the maximum possible bitwise XOR.\n\t\tNote that other operations may be used to achieve a bitwise XOR of 7.\n\t\tExample 2:\n\t\tInput: nums = [1,2,3,9,2]\n\t\tOutput: 11\n\t\tExplanation: Apply the operation zero times.\n\t\tThe bitwise XOR of all the elements = 1 XOR 2 XOR 3 XOR 9 XOR 2 = 11.\n\t\tIt can be shown that 11 is the maximum possible bitwise XOR.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2403,
-        "question": "class Solution:\n    def countPairs(self, n: int, edges: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tYou are given an integer n. There is an undirected graph with n nodes, numbered from 0 to n - 1. You are given a 2D integer array edges where edges[i] = [ai, bi] denotes that there exists an undirected edge connecting nodes ai and bi.\n\t\tReturn the number of pairs of different nodes that are unreachable from each other.\n\t\tExample 1:\n\t\tInput: n = 3, edges = [[0,1],[0,2],[1,2]]\n\t\tOutput: 0\n\t\tExplanation: There are no pairs of nodes that are unreachable from each other. Therefore, we return 0.\n\t\tExample 2:\n\t\tInput: n = 7, edges = [[0,2],[0,5],[2,4],[1,6],[5,4]]\n\t\tOutput: 14\n\t\tExplanation: There are 14 pairs of nodes that are unreachable from each other:\n\t\t[[0,1],[0,3],[0,6],[1,2],[1,3],[1,4],[1,5],[2,3],[2,6],[3,4],[3,5],[3,6],[4,6],[5,6]].\n\t\tTherefore, we return 14.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2404,
-        "question": "class Solution:\n    def distinctSequences(self, n: int) -> int:\n\t\t\"\"\"\n\t\tYou are given an integer n. You roll a fair 6-sided dice n times. Determine the total number of distinct sequences of rolls possible such that the following conditions are satisfied:\n\t\t\tThe greatest common divisor of any adjacent values in the sequence is equal to 1.\n\t\t\tThere is at least a gap of 2 rolls between equal valued rolls. More formally, if the value of the ith roll is equal to the value of the jth roll, then abs(i - j) > 2.\n\t\tReturn the total number of distinct sequences possible. Since the answer may be very large, return it modulo 109 + 7.\n\t\tTwo sequences are considered distinct if at least one element is different.\n\t\tExample 1:\n\t\tInput: n = 4\n\t\tOutput: 184\n\t\tExplanation: Some of the possible sequences are (1, 2, 3, 4), (6, 1, 2, 3), (1, 2, 3, 1), etc.\n\t\tSome invalid sequences are (1, 2, 1, 3), (1, 2, 3, 6).\n\t\t(1, 2, 1, 3) is invalid since the first and third roll have an equal value and abs(1 - 3) = 2 (i and j are 1-indexed).\n\t\t(1, 2, 3, 6) is invalid since the greatest common divisor of 3 and 6 = 3.\n\t\tThere are a total of 184 distinct sequences possible, so we return 184.\n\t\tExample 2:\n\t\tInput: n = 2\n\t\tOutput: 22\n\t\tExplanation: Some of the possible sequences are (1, 2), (2, 1), (3, 2).\n\t\tSome invalid sequences are (3, 6), (2, 4) since the greatest common divisor is not equal to 1.\n\t\tThere are a total of 22 distinct sequences possible, so we return 22.\n\t\t\"\"\"\n",
-        "difficulty": 2
-    },
-    {
-        "number": 2406,
-        "question": "class Solution:\n    def decodeMessage(self, key: str, message: str) -> str:\n\t\t\"\"\"\n\t\tYou are given the strings key and message, which represent a cipher key and a secret message, respectively. The steps to decode message are as follows:\n\t\t\tUse the first appearance of all 26 lowercase English letters in key as the order of the substitution table.\n\t\t\tAlign the substitution table with the regular English alphabet.\n\t\t\tEach letter in message is then substituted using the table.\n\t\t\tSpaces ' ' are transformed to themselves.\n\t\t\tFor example, given key = \"happy boy\" (actual key would have at least one instance of each letter in the alphabet), we have the partial substitution table of ('h' -> 'a', 'a' -> 'b', 'p' -> 'c', 'y' -> 'd', 'b' -> 'e', 'o' -> 'f').\n\t\tReturn the decoded message.\n\t\tExample 1:\n\t\tInput: key = \"the quick brown fox jumps over the lazy dog\", message = \"vkbs bs t suepuv\"\n\t\tOutput: \"this is a secret\"\n\t\tExplanation: The diagram above shows the substitution table.\n\t\tIt is obtained by taking the first appearance of each letter in \"the quick brown fox jumps over the lazy dog\".\n\t\tExample 2:\n\t\tInput: key = \"eljuxhpwnyrdgtqkviszcfmabo\", message = \"zwx hnfx lqantp mnoeius ycgk vcnjrdb\"\n\t\tOutput: \"the five boxing wizards jump quickly\"\n\t\tExplanation: The diagram above shows the substitution table.\n\t\tIt is obtained by taking the first appearance of each letter in \"eljuxhpwnyrdgtqkviszcfmabo\".\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 2408,
-        "question": "class Solution:\n    def peopleAwareOfSecret(self, n: int, delay: int, forget: int) -> int:\n\t\t\"\"\"\n\t\tOn day 1, one person discovers a secret.\n\t\tYou are given an integer delay, which means that each person will share the secret with a new person every day, starting from delay days after discovering the secret. You are also given an integer forget, which means that each person will forget the secret forget days after discovering it. A person cannot share the secret on the same day they forgot it, or on any day afterwards.\n\t\tGiven an integer n, return the number of people who know the secret at the end of day n. Since the answer may be very large, return it modulo 109 + 7.\n\t\tExample 1:\n\t\tInput: n = 6, delay = 2, forget = 4\n\t\tOutput: 5\n\t\tExplanation:\n\t\tDay 1: Suppose the first person is named A. (1 person)\n\t\tDay 2: A is the only person who knows the secret. (1 person)\n\t\tDay 3: A shares the secret with a new person, B. (2 people)\n\t\tDay 4: A shares the secret with a new person, C. (3 people)\n\t\tDay 5: A forgets the secret, and B shares the secret with a new person, D. (3 people)\n\t\tDay 6: B shares the secret with E, and C shares the secret with F. (5 people)\n\t\tExample 2:\n\t\tInput: n = 4, delay = 1, forget = 3\n\t\tOutput: 6\n\t\tExplanation:\n\t\tDay 1: The first person is named A. (1 person)\n\t\tDay 2: A shares the secret with B. (2 people)\n\t\tDay 3: A and B share the secret with 2 new people, C and D. (4 people)\n\t\tDay 4: A forgets the secret. B, C, and D share the secret with 3 new people. (6 people)\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2409,
-        "question": "class Solution:\n    def countPaths(self, grid: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tYou are given an m x n integer matrix grid, where you can move from a cell to any adjacent cell in all 4 directions.\n\t\tReturn the number of strictly increasing paths in the grid such that you can start from any cell and end at any cell. Since the answer may be very large, return it modulo 109 + 7.\n\t\tTwo paths are considered different if they do not have exactly the same sequence of visited cells.\n\t\tExample 1:\n\t\tInput: grid = [[1,1],[3,4]]\n\t\tOutput: 8\n\t\tExplanation: The strictly increasing paths are:\n\t\t- Paths with length 1: [1], [1], [3], [4].\n\t\t- Paths with length 2: [1 -> 3], [1 -> 4], [3 -> 4].\n\t\t- Paths with length 3: [1 -> 3 -> 4].\n\t\tThe total number of paths is 4 + 3 + 1 = 8.\n\t\tExample 2:\n\t\tInput: grid = [[1],[2]]\n\t\tOutput: 3\n\t\tExplanation: The strictly increasing paths are:\n\t\t- Paths with length 1: [1], [2].\n\t\t- Paths with length 2: [1 -> 2].\n\t\tThe total number of paths is 2 + 1 = 3.\n\t\t\"\"\"\n",
-        "difficulty": 2
-    },
-    {
-        "number": 2411,
-        "question": "class Solution:\n    def spiralMatrix(self, m: int, n: int, head: Optional[ListNode]) -> List[List[int]]:\n\t\t\"\"\"\n\t\tYou are given two integers m and n, which represent the dimensions of a matrix.\n\t\tYou are also given the head of a linked list of integers.\n\t\tGenerate an m x n matrix that contains the integers in the linked list presented in spiral order (clockwise), starting from the top-left of the matrix. If there are remaining empty spaces, fill them with -1.\n\t\tReturn the generated matrix.\n\t\tExample 1:\n\t\tInput: m = 3, n = 5, head = [3,0,2,6,8,1,7,9,4,2,5,5,0]\n\t\tOutput: [[3,0,2,6,8],[5,0,-1,-1,1],[5,2,4,9,7]]\n\t\tExplanation: The diagram above shows how the values are printed in the matrix.\n\t\tNote that the remaining spaces in the matrix are filled with -1.\n\t\tExample 2:\n\t\tInput: m = 1, n = 4, head = [0,1,2]\n\t\tOutput: [[0,1,2,-1]]\n\t\tExplanation: The diagram above shows how the values are printed from left to right in the matrix.\n\t\tThe last space in the matrix is set to -1.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2412,
-        "question": "class Solution:\n    def fillCups(self, amount: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou have a water dispenser that can dispense cold, warm, and hot water. Every second, you can either fill up 2 cups with different types of water, or 1 cup of any type of water.\n\t\tYou are given a 0-indexed integer array amount of length 3 where amount[0], amount[1], and amount[2] denote the number of cold, warm, and hot water cups you need to fill respectively. Return the minimum number of seconds needed to fill up all the cups.\n\t\tExample 1:\n\t\tInput: amount = [1,4,2]\n\t\tOutput: 4\n\t\tExplanation: One way to fill up the cups is:\n\t\tSecond 1: Fill up a cold cup and a warm cup.\n\t\tSecond 2: Fill up a warm cup and a hot cup.\n\t\tSecond 3: Fill up a warm cup and a hot cup.\n\t\tSecond 4: Fill up a warm cup.\n\t\tIt can be proven that 4 is the minimum number of seconds needed.\n\t\tExample 2:\n\t\tInput: amount = [5,4,4]\n\t\tOutput: 7\n\t\tExplanation: One way to fill up the cups is:\n\t\tSecond 1: Fill up a cold cup, and a hot cup.\n\t\tSecond 2: Fill up a cold cup, and a warm cup.\n\t\tSecond 3: Fill up a cold cup, and a warm cup.\n\t\tSecond 4: Fill up a warm cup, and a hot cup.\n\t\tSecond 5: Fill up a cold cup, and a hot cup.\n\t\tSecond 6: Fill up a cold cup, and a warm cup.\n\t\tSecond 7: Fill up a hot cup.\n\t\tExample 3:\n\t\tInput: amount = [5,0,0]\n\t\tOutput: 5\n\t\tExplanation: Every second, we fill up a cold cup.\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 2413,
-        "question": "class SmallestInfiniteSet:\n    def __init__(self):\n    def popSmallest(self) -> int:\n    def addBack(self, num: int) -> None:\n\t\t\"\"\"\n\t\tYou have a set which contains all positive integers [1, 2, 3, 4, 5, ...].\n\t\tImplement the SmallestInfiniteSet class:\n\t\t\tSmallestInfiniteSet() Initializes the SmallestInfiniteSet object to contain all positive integers.\n\t\t\tint popSmallest() Removes and returns the smallest integer contained in the infinite set.\n\t\t\tvoid addBack(int num) Adds a positive integer num back into the infinite set, if it is not already in the infinite set.\n\t\tExample 1:\n\t\tInput\n\t\t[\"SmallestInfiniteSet\", \"addBack\", \"popSmallest\", \"popSmallest\", \"popSmallest\", \"addBack\", \"popSmallest\", \"popSmallest\", \"popSmallest\"]\n\t\t[[], [2], [], [], [], [1], [], [], []]\n\t\tOutput\n\t\t[null, null, 1, 2, 3, null, 1, 4, 5]\n\t\tExplanation\n\t\tSmallestInfiniteSet smallestInfiniteSet = new SmallestInfiniteSet();\n\t\tsmallestInfiniteSet.addBack(2);    // 2 is already in the set, so no change is made.\n\t\tsmallestInfiniteSet.popSmallest(); // return 1, since 1 is the smallest number, and remove it from the set.\n\t\tsmallestInfiniteSet.popSmallest(); // return 2, and remove it from the set.\n\t\tsmallestInfiniteSet.popSmallest(); // return 3, and remove it from the set.\n\t\tsmallestInfiniteSet.addBack(1);    // 1 is added back to the set.\n\t\tsmallestInfiniteSet.popSmallest(); // return 1, since 1 was added back to the set and\n\t\t                                   // is the smallest number, and remove it from the set.\n\t\tsmallestInfiniteSet.popSmallest(); // return 4, and remove it from the set.\n\t\tsmallestInfiniteSet.popSmallest(); // return 5, and remove it from the set.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2414,
-        "question": "class Solution:\n    def canChange(self, start: str, target: str) -> bool:\n\t\t\"\"\"\n\t\tYou are given two strings start and target, both of length n. Each string consists only of the characters 'L', 'R', and '_' where:\n\t\t\tThe characters 'L' and 'R' represent pieces, where a piece 'L' can move to the left only if there is a blank space directly to its left, and a piece 'R' can move to the right only if there is a blank space directly to its right.\n\t\t\tThe character '_' represents a blank space that can be occupied by any of the 'L' or 'R' pieces.\n\t\tReturn true if it is possible to obtain the string target by moving the pieces of the string start any number of times. Otherwise, return false.\n\t\tExample 1:\n\t\tInput: start = \"_L__R__R_\", target = \"L______RR\"\n\t\tOutput: true\n\t\tExplanation: We can obtain the string target from start by doing the following moves:\n\t\t- Move the first piece one step to the left, start becomes equal to \"L___R__R_\".\n\t\t- Move the last piece one step to the right, start becomes equal to \"L___R___R\".\n\t\t- Move the second piece three steps to the right, start becomes equal to \"L______RR\".\n\t\tSince it is possible to get the string target from start, we return true.\n\t\tExample 2:\n\t\tInput: start = \"R_L_\", target = \"__LR\"\n\t\tOutput: false\n\t\tExplanation: The 'R' piece in the string start can move one step to the right to obtain \"_RL_\".\n\t\tAfter that, no pieces can move anymore, so it is impossible to obtain the string target from start.\n\t\tExample 3:\n\t\tInput: start = \"_R\", target = \"R_\"\n\t\tOutput: false\n\t\tExplanation: The piece in the string start can move only to the right, so it is impossible to obtain the string target from start.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2415,
-        "question": "class Solution:\n    def idealArrays(self, n: int, maxValue: int) -> int:\n\t\t\"\"\"\n\t\tYou are given two integers n and maxValue, which are used to describe an ideal array.\n\t\tA 0-indexed integer array arr of length n is considered ideal if the following conditions hold:\n\t\t\tEvery arr[i] is a value from 1 to maxValue, for 0 <= i < n.\n\t\t\tEvery arr[i] is divisible by arr[i - 1], for 0 < i < n.\n\t\tReturn the number of distinct ideal arrays of length n. Since the answer may be very large, return it modulo 109 + 7.\n\t\tExample 1:\n\t\tInput: n = 2, maxValue = 5\n\t\tOutput: 10\n\t\tExplanation: The following are the possible ideal arrays:\n\t\t- Arrays starting with the value 1 (5 arrays): [1,1], [1,2], [1,3], [1,4], [1,5]\n\t\t- Arrays starting with the value 2 (2 arrays): [2,2], [2,4]\n\t\t- Arrays starting with the value 3 (1 array): [3,3]\n\t\t- Arrays starting with the value 4 (1 array): [4,4]\n\t\t- Arrays starting with the value 5 (1 array): [5,5]\n\t\tThere are a total of 5 + 2 + 1 + 1 + 1 = 10 distinct ideal arrays.\n\t\tExample 2:\n\t\tInput: n = 5, maxValue = 3\n\t\tOutput: 11\n\t\tExplanation: The following are the possible ideal arrays:\n\t\t- Arrays starting with the value 1 (9 arrays): \n\t\t   - With no other distinct values (1 array): [1,1,1,1,1] \n\t\t   - With 2nd distinct value 2 (4 arrays): [1,1,1,1,2], [1,1,1,2,2], [1,1,2,2,2], [1,2,2,2,2]\n\t\t   - With 2nd distinct value 3 (4 arrays): [1,1,1,1,3], [1,1,1,3,3], [1,1,3,3,3], [1,3,3,3,3]\n\t\t- Arrays starting with the value 2 (1 array): [2,2,2,2,2]\n\t\t- Arrays starting with the value 3 (1 array): [3,3,3,3,3]\n\t\tThere are a total of 9 + 1 + 1 = 11 distinct ideal arrays.\n\t\t\"\"\"\n",
-        "difficulty": 2
-    },
-    {
-        "number": 2416,
-        "question": "class Solution:\n    def evaluateTree(self, root: Optional[TreeNode]) -> bool:\n\t\t\"\"\"\n\t\tYou are given the root of a full binary tree with the following properties:\n\t\t\tLeaf nodes have either the value 0 or 1, where 0 represents False and 1 represents True.\n\t\t\tNon-leaf nodes have either the value 2 or 3, where 2 represents the boolean OR and 3 represents the boolean AND.\n\t\tThe evaluation of a node is as follows:\n\t\t\tIf the node is a leaf node, the evaluation is the value of the node, i.e. True or False.\n\t\t\tOtherwise, evaluate the node's two children and apply the boolean operation of its value with the children's evaluations.\n\t\tReturn the boolean result of evaluating the root node.\n\t\tA full binary tree is a binary tree where each node has either 0 or 2 children.\n\t\tA leaf node is a node that has zero children.\n\t\tExample 1:\n\t\tInput: root = [2,1,3,null,null,0,1]\n\t\tOutput: true\n\t\tExplanation: The above diagram illustrates the evaluation process.\n\t\tThe AND node evaluates to False AND True = False.\n\t\tThe OR node evaluates to True OR False = True.\n\t\tThe root node evaluates to True, so we return true.\n\t\tExample 2:\n\t\tInput: root = [0]\n\t\tOutput: false\n\t\tExplanation: The root node is a leaf node and it evaluates to false, so we return false.\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 2417,
-        "question": "class Solution:\n    def latestTimeCatchTheBus(self, buses: List[int], passengers: List[int], capacity: int) -> int:\n\t\t\"\"\"\n\t\tYou are given a 0-indexed integer array buses of length n, where buses[i] represents the departure time of the ith bus. You are also given a 0-indexed integer array passengers of length m, where passengers[j] represents the arrival time of the jth passenger. All bus departure times are unique. All passenger arrival times are unique.\n\t\tYou are given an integer capacity, which represents the maximum number of passengers that can get on each bus.\n\t\tWhen a passenger arrives, they will wait in line for the next available bus. You can get on a bus that departs at x minutes if you arrive at y minutes where y <= x, and the bus is not full. Passengers with the earliest arrival times get on the bus first.\n\t\tMore formally when a bus arrives, either:\n\t\t\tIf capacity or fewer passengers are waiting for a bus, they will all get on the bus, or\n\t\t\tThe capacity passengers with the earliest arrival times will get on the bus.\n\t\tReturn the latest time you may arrive at the bus station to catch a bus. You cannot arrive at the same time as another passenger.\n\t\tNote: The arrays buses and passengers are not necessarily sorted.\n\t\tExample 1:\n\t\tInput: buses = [10,20], passengers = [2,17,18,19], capacity = 2\n\t\tOutput: 16\n\t\tExplanation: Suppose you arrive at time 16.\n\t\tAt time 10, the first bus departs with the 0th passenger. \n\t\tAt time 20, the second bus departs with you and the 1st passenger.\n\t\tNote that you may not arrive at the same time as another passenger, which is why you must arrive before the 1st passenger to catch the bus.\n\t\tExample 2:\n\t\tInput: buses = [20,30,10], passengers = [19,13,26,4,25,11,21], capacity = 2\n\t\tOutput: 20\n\t\tExplanation: Suppose you arrive at time 20.\n\t\tAt time 10, the first bus departs with the 3rd passenger. \n\t\tAt time 20, the second bus departs with the 5th and 1st passengers.\n\t\tAt time 30, the third bus departs with the 0th passenger and you.\n\t\tNotice if you had arrived any later, then the 6th passenger would have taken your seat on the third bus.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2418,
-        "question": "class Solution:\n    def minSumSquareDiff(self, nums1: List[int], nums2: List[int], k1: int, k2: int) -> int:\n\t\t\"\"\"\n\t\tYou are given two positive 0-indexed integer arrays nums1 and nums2, both of length n.\n\t\tThe sum of squared difference of arrays nums1 and nums2 is defined as the sum of (nums1[i] - nums2[i])2 for each 0 <= i < n.\n\t\tYou are also given two positive integers k1 and k2. You can modify any of the elements of nums1 by +1 or -1 at most k1 times. Similarly, you can modify any of the elements of nums2 by +1 or -1 at most k2 times.\n\t\tReturn the minimum sum of squared difference after modifying array nums1 at most k1 times and modifying array nums2 at most k2 times.\n\t\tNote: You are allowed to modify the array elements to become negative integers.\n\t\tExample 1:\n\t\tInput: nums1 = [1,2,3,4], nums2 = [2,10,20,19], k1 = 0, k2 = 0\n\t\tOutput: 579\n\t\tExplanation: The elements in nums1 and nums2 cannot be modified because k1 = 0 and k2 = 0. \n\t\tThe sum of square difference will be: (1 - 2)2 + (2 - 10)2 + (3 - 20)2 + (4 - 19)2 = 579.\n\t\tExample 2:\n\t\tInput: nums1 = [1,4,10,12], nums2 = [5,8,6,9], k1 = 1, k2 = 1\n\t\tOutput: 43\n\t\tExplanation: One way to obtain the minimum sum of square difference is: \n\t\t- Increase nums1[0] once.\n\t\t- Increase nums2[2] once.\n\t\tThe minimum of the sum of square difference will be: \n\t\t(2 - 5)2 + (4 - 8)2 + (10 - 7)2 + (12 - 9)2 = 43.\n\t\tNote that, there are other ways to obtain the minimum of the sum of square difference, but there is no way to obtain a sum smaller than 43.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2419,
-        "question": "class Solution:\n    def validSubarraySize(self, nums: List[int], threshold: int) -> int:\n\t\t\"\"\"\n\t\tYou are given an integer array nums and an integer threshold.\n\t\tFind any subarray of nums of length k such that every element in the subarray is greater than threshold / k.\n\t\tReturn the size of any such subarray. If there is no such subarray, return -1.\n\t\tA subarray is a contiguous non-empty sequence of elements within an array.\n\t\tExample 1:\n\t\tInput: nums = [1,3,4,3,1], threshold = 6\n\t\tOutput: 3\n\t\tExplanation: The subarray [3,4,3] has a size of 3, and every element is greater than 6 / 3 = 2.\n\t\tNote that this is the only valid subarray.\n\t\tExample 2:\n\t\tInput: nums = [6,5,6,5,8], threshold = 7\n\t\tOutput: 1\n\t\tExplanation: The subarray [8] has a size of 1, and 8 > 7 / 1 = 7. So 1 is returned.\n\t\tNote that the subarray [6,5] has a size of 2, and every element is greater than 7 / 2 = 3.5. \n\t\tSimilarly, the subarrays [6,5,6], [6,5,6,5], [6,5,6,5,8] also satisfy the given conditions.\n\t\tTherefore, 2, 3, 4, or 5 may also be returned.\n\t\t\"\"\"\n",
-        "difficulty": 2
-    },
-    {
-        "number": 2421,
-        "question": "class Solution:\n    def numberOfPairs(self, nums: List[int]) -> List[int]:\n\t\t\"\"\"\n\t\tYou are given a 0-indexed integer array nums. In one operation, you may do the following:\n\t\t\tChoose two integers in nums that are equal.\n\t\t\tRemove both integers from nums, forming a pair.\n\t\tThe operation is done on nums as many times as possible.\n\t\tReturn a 0-indexed integer array answer of size 2 where answer[0] is the number of pairs that are formed and answer[1] is the number of leftover integers in nums after doing the operation as many times as possible.\n\t\tExample 1:\n\t\tInput: nums = [1,3,2,1,3,2,2]\n\t\tOutput: [3,1]\n\t\tExplanation:\n\t\tForm a pair with nums[0] and nums[3] and remove them from nums. Now, nums = [3,2,3,2,2].\n\t\tForm a pair with nums[0] and nums[2] and remove them from nums. Now, nums = [2,2,2].\n\t\tForm a pair with nums[0] and nums[1] and remove them from nums. Now, nums = [2].\n\t\tNo more pairs can be formed. A total of 3 pairs have been formed, and there is 1 number leftover in nums.\n\t\tExample 2:\n\t\tInput: nums = [1,1]\n\t\tOutput: [1,0]\n\t\tExplanation: Form a pair with nums[0] and nums[1] and remove them from nums. Now, nums = [].\n\t\tNo more pairs can be formed. A total of 1 pair has been formed, and there are 0 numbers leftover in nums.\n\t\tExample 3:\n\t\tInput: nums = [0]\n\t\tOutput: [0,1]\n\t\tExplanation: No pairs can be formed, and there is 1 number leftover in nums.\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 2422,
-        "question": "class Solution:\n    def smallestTrimmedNumbers(self, nums: List[str], queries: List[List[int]]) -> List[int]:\n\t\t\"\"\"\n\t\tYou are given a 0-indexed array of strings nums, where each string is of equal length and consists of only digits.\n\t\tYou are also given a 0-indexed 2D integer array queries where queries[i] = [ki, trimi]. For each queries[i], you need to:\n\t\t\tTrim each number in nums to its rightmost trimi digits.\n\t\t\tDetermine the index of the kith smallest trimmed number in nums. If two trimmed numbers are equal, the number with the lower index is considered to be smaller.\n\t\t\tReset each number in nums to its original length.\n\t\tReturn an array answer of the same length as queries, where answer[i] is the answer to the ith query.\n\t\tNote:\n\t\t\tTo trim to the rightmost x digits means to keep removing the leftmost digit, until only x digits remain.\n\t\t\tStrings in nums may contain leading zeros.\n\t\tExample 1:\n\t\tInput: nums = [\"102\",\"473\",\"251\",\"814\"], queries = [[1,1],[2,3],[4,2],[1,2]]\n\t\tOutput: [2,2,1,0]\n\t\tExplanation:\n\t\t1. After trimming to the last digit, nums = [\"2\",\"3\",\"1\",\"4\"]. The smallest number is 1 at index 2.\n\t\t2. Trimmed to the last 3 digits, nums is unchanged. The 2nd smallest number is 251 at index 2.\n\t\t3. Trimmed to the last 2 digits, nums = [\"02\",\"73\",\"51\",\"14\"]. The 4th smallest number is 73.\n\t\t4. Trimmed to the last 2 digits, the smallest number is 2 at index 0.\n\t\t   Note that the trimmed number \"02\" is evaluated as 2.\n\t\tExample 2:\n\t\tInput: nums = [\"24\",\"37\",\"96\",\"04\"], queries = [[2,1],[2,2]]\n\t\tOutput: [3,0]\n\t\tExplanation:\n\t\t1. Trimmed to the last digit, nums = [\"4\",\"7\",\"6\",\"4\"]. The 2nd smallest number is 4 at index 3.\n\t\t   There are two occurrences of 4, but the one at index 0 is considered smaller than the one at index 3.\n\t\t2. Trimmed to the last 2 digits, nums is unchanged. The 2nd smallest number is 24.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2423,
-        "question": "class Solution:\n    def minOperations(self, nums: List[int], numsDivide: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou are given two positive integer arrays nums and numsDivide. You can delete any number of elements from nums.\n\t\tReturn the minimum number of deletions such that the smallest element in nums divides all the elements of numsDivide. If this is not possible, return -1.\n\t\tNote that an integer x divides y if y % x == 0.\n\t\tExample 1:\n\t\tInput: nums = [2,3,2,4,3], numsDivide = [9,6,9,3,15]\n\t\tOutput: 2\n\t\tExplanation: \n\t\tThe smallest element in [2,3,2,4,3] is 2, which does not divide all the elements of numsDivide.\n\t\tWe use 2 deletions to delete the elements in nums that are equal to 2 which makes nums = [3,4,3].\n\t\tThe smallest element in [3,4,3] is 3, which divides all the elements of numsDivide.\n\t\tIt can be shown that 2 is the minimum number of deletions needed.\n\t\tExample 2:\n\t\tInput: nums = [4,3,6], numsDivide = [8,2,6,10]\n\t\tOutput: -1\n\t\tExplanation: \n\t\tWe want the smallest element in nums to divide all the elements of numsDivide.\n\t\tThere is no way to delete elements from nums to allow this.\n\t\t\"\"\"\n",
-        "difficulty": 2
-    },
-    {
-        "number": 2427,
-        "question": "class Solution:\n    def repeatedCharacter(self, s: str) -> str:\n\t\t\"\"\"\n\t\tGiven a string s consisting of lowercase English letters, return the first letter to appear twice.\n\t\tNote:\n\t\t\tA letter a appears twice before another letter b if the second occurrence of a is before the second occurrence of b.\n\t\t\ts will contain at least one letter that appears twice.\n\t\tExample 1:\n\t\tInput: s = \"abccbaacz\"\n\t\tOutput: \"c\"\n\t\tExplanation:\n\t\tThe letter 'a' appears on the indexes 0, 5 and 6.\n\t\tThe letter 'b' appears on the indexes 1 and 4.\n\t\tThe letter 'c' appears on the indexes 2, 3 and 7.\n\t\tThe letter 'z' appears on the index 8.\n\t\tThe letter 'c' is the first letter to appear twice, because out of all the letters the index of its second occurrence is the smallest.\n\t\tExample 2:\n\t\tInput: s = \"abcdd\"\n\t\tOutput: \"d\"\n\t\tExplanation:\n\t\tThe only letter that appears twice is 'd' so we return 'd'.\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 2428,
-        "question": "class Solution:\n    def equalPairs(self, grid: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tGiven a 0-indexed n x n integer matrix grid, return the number of pairs (ri, cj) such that row ri and column cj are equal.\n\t\tA row and column pair is considered equal if they contain the same elements in the same order (i.e., an equal array).\n\t\tExample 1:\n\t\tInput: grid = [[3,2,1],[1,7,6],[2,7,7]]\n\t\tOutput: 1\n\t\tExplanation: There is 1 equal row and column pair:\n\t\t- (Row 2, Column 1): [2,7,7]\n\t\tExample 2:\n\t\tInput: grid = [[3,1,2,2],[1,4,4,5],[2,4,2,2],[2,4,2,2]]\n\t\tOutput: 3\n\t\tExplanation: There are 3 equal row and column pairs:\n\t\t- (Row 0, Column 0): [3,1,2,2]\n\t\t- (Row 2, Column 2): [2,4,2,2]\n\t\t- (Row 3, Column 2): [2,4,2,2]\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2429,
-        "question": "class FoodRatings:\n    def __init__(self, foods: List[str], cuisines: List[str], ratings: List[int]):\n    def changeRating(self, food: str, newRating: int) -> None:\n    def highestRated(self, cuisine: str) -> str:\n\t\t\"\"\"\n\t\tDesign a food rating system that can do the following:\n\t\t\tModify the rating of a food item listed in the system.\n\t\t\tReturn the highest-rated food item for a type of cuisine in the system.\n\t\tImplement the FoodRatings class:\n\t\t\tFoodRatings(String[] foods, String[] cuisines, int[] ratings) Initializes the system. The food items are described by foods, cuisines and ratings, all of which have a length of n.\n\t\t\t\tfoods[i] is the name of the ith food,\n\t\t\t\tcuisines[i] is the type of cuisine of the ith food, and\n\t\t\t\tratings[i] is the initial rating of the ith food.\n\t\t\tvoid changeRating(String food, int newRating) Changes the rating of the food item with the name food.\n\t\t\tString highestRated(String cuisine) Returns the name of the food item that has the highest rating for the given type of cuisine. If there is a tie, return the item with the lexicographically smaller name.\n\t\tNote that a string x is lexicographically smaller than string y if x comes before y in dictionary order, that is, either x is a prefix of y, or if i is the first position such that x[i] != y[i], then x[i] comes before y[i] in alphabetic order.\n\t\tExample 1:\n\t\tInput\n\t\t[\"FoodRatings\", \"highestRated\", \"highestRated\", \"changeRating\", \"highestRated\", \"changeRating\", \"highestRated\"]\n\t\t[[[\"kimchi\", \"miso\", \"sushi\", \"moussaka\", \"ramen\", \"bulgogi\"], [\"korean\", \"japanese\", \"japanese\", \"greek\", \"japanese\", \"korean\"], [9, 12, 8, 15, 14, 7]], [\"korean\"], [\"japanese\"], [\"sushi\", 16], [\"japanese\"], [\"ramen\", 16], [\"japanese\"]]\n\t\tOutput\n\t\t[null, \"kimchi\", \"ramen\", null, \"sushi\", null, \"ramen\"]\n\t\tExplanation\n\t\tFoodRatings foodRatings = new FoodRatings([\"kimchi\", \"miso\", \"sushi\", \"moussaka\", \"ramen\", \"bulgogi\"], [\"korean\", \"japanese\", \"japanese\", \"greek\", \"japanese\", \"korean\"], [9, 12, 8, 15, 14, 7]);\n\t\tfoodRatings.highestRated(\"korean\"); // return \"kimchi\"\n\t\t                                    // \"kimchi\" is the highest rated korean food with a rating of 9.\n\t\tfoodRatings.highestRated(\"japanese\"); // return \"ramen\"\n\t\t                                      // \"ramen\" is the highest rated japanese food with a rating of 14.\n\t\tfoodRatings.changeRating(\"sushi\", 16); // \"sushi\" now has a rating of 16.\n\t\tfoodRatings.highestRated(\"japanese\"); // return \"sushi\"\n\t\t                                      // \"sushi\" is the highest rated japanese food with a rating of 16.\n\t\tfoodRatings.changeRating(\"ramen\", 16); // \"ramen\" now has a rating of 16.\n\t\tfoodRatings.highestRated(\"japanese\"); // return \"ramen\"\n\t\t                                      // Both \"sushi\" and \"ramen\" have a rating of 16.\n\t\t                                      // However, \"ramen\" is lexicographically smaller than \"sushi\".\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2430,
-        "question": "class Solution:\n    def countExcellentPairs(self, nums: List[int], k: int) -> int:\n\t\t\"\"\"\n\t\tYou are given a 0-indexed positive integer array nums and a positive integer k.\n\t\tA pair of numbers (num1, num2) is called excellent if the following conditions are satisfied:\n\t\t\tBoth the numbers num1 and num2 exist in the array nums.\n\t\t\tThe sum of the number of set bits in num1 OR num2 and num1 AND num2 is greater than or equal to k, where OR is the bitwise OR operation and AND is the bitwise AND operation.\n\t\tReturn the number of distinct excellent pairs.\n\t\tTwo pairs (a, b) and (c, d) are considered distinct if either a != c or b != d. For example, (1, 2) and (2, 1) are distinct.\n\t\tNote that a pair (num1, num2) such that num1 == num2 can also be excellent if you have at least one occurrence of num1 in the array.\n\t\tExample 1:\n\t\tInput: nums = [1,2,3,1], k = 3\n\t\tOutput: 5\n\t\tExplanation: The excellent pairs are the following:\n\t\t- (3, 3). (3 AND 3) and (3 OR 3) are both equal to (11) in binary. The total number of set bits is 2 + 2 = 4, which is greater than or equal to k = 3.\n\t\t- (2, 3) and (3, 2). (2 AND 3) is equal to (10) in binary, and (2 OR 3) is equal to (11) in binary. The total number of set bits is 1 + 2 = 3.\n\t\t- (1, 3) and (3, 1). (1 AND 3) is equal to (01) in binary, and (1 OR 3) is equal to (11) in binary. The total number of set bits is 1 + 2 = 3.\n\t\tSo the number of excellent pairs is 5.\n\t\tExample 2:\n\t\tInput: nums = [5,1,1], k = 10\n\t\tOutput: 0\n\t\tExplanation: There are no excellent pairs for this array.\n\t\t\"\"\"\n",
-        "difficulty": 2
-    },
-    {
-        "number": 2432,
-        "question": "class Solution:\n    def zeroFilledSubarray(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tGiven an integer array nums, return the number of subarrays filled with 0.\n\t\tA subarray is a contiguous non-empty sequence of elements within an array.\n\t\tExample 1:\n\t\tInput: nums = [1,3,0,0,2,0,0,4]\n\t\tOutput: 6\n\t\tExplanation: \n\t\tThere are 4 occurrences of [0] as a subarray.\n\t\tThere are 2 occurrences of [0,0] as a subarray.\n\t\tThere is no occurrence of a subarray with a size more than 2 filled with 0. Therefore, we return 6.\n\t\tExample 2:\n\t\tInput: nums = [0,0,0,2,0,0]\n\t\tOutput: 9\n\t\tExplanation:\n\t\tThere are 5 occurrences of [0] as a subarray.\n\t\tThere are 3 occurrences of [0,0] as a subarray.\n\t\tThere is 1 occurrence of [0,0,0] as a subarray.\n\t\tThere is no occurrence of a subarray with a size more than 3 filled with 0. Therefore, we return 9.\n\t\tExample 3:\n\t\tInput: nums = [2,10,2019]\n\t\tOutput: 0\n\t\tExplanation: There is no subarray filled with 0. Therefore, we return 0.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2433,
-        "question": "class Solution:\n    def bestHand(self, ranks: List[int], suits: List[str]) -> str:\n\t\t\"\"\"\n\t\tYou are given an integer array ranks and a character array suits. You have 5 cards where the ith card has a rank of ranks[i] and a suit of suits[i].\n\t\tThe following are the types of poker hands you can make from best to worst:\n\t\t\t\"Flush\": Five cards of the same suit.\n\t\t\t\"Three of a Kind\": Three cards of the same rank.\n\t\t\t\"Pair\": Two cards of the same rank.\n\t\t\t\"High Card\": Any single card.\n\t\tReturn a string representing the best type of poker hand you can make with the given cards.\n\t\tNote that the return values are case-sensitive.\n\t\tExample 1:\n\t\tInput: ranks = [13,2,3,1,9], suits = [\"a\",\"a\",\"a\",\"a\",\"a\"]\n\t\tOutput: \"Flush\"\n\t\tExplanation: The hand with all the cards consists of 5 cards with the same suit, so we have a \"Flush\".\n\t\tExample 2:\n\t\tInput: ranks = [4,4,2,4,4], suits = [\"d\",\"a\",\"a\",\"b\",\"c\"]\n\t\tOutput: \"Three of a Kind\"\n\t\tExplanation: The hand with the first, second, and fourth card consists of 3 cards with the same rank, so we have a \"Three of a Kind\".\n\t\tNote that we could also make a \"Pair\" hand but \"Three of a Kind\" is a better hand.\n\t\tAlso note that other cards could be used to make the \"Three of a Kind\" hand.\n\t\tExample 3:\n\t\tInput: ranks = [10,10,2,12,9], suits = [\"a\",\"b\",\"c\",\"a\",\"d\"]\n\t\tOutput: \"Pair\"\n\t\tExplanation: The hand with the first and second card consists of 2 cards with the same rank, so we have a \"Pair\".\n\t\tNote that we cannot make a \"Flush\" or a \"Three of a Kind\".\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 2434,
-        "question": "class NumberContainers:\n    def __init__(self):\n    def change(self, index: int, number: int) -> None:\n    def find(self, number: int) -> int:\n\t\t\"\"\"\n\t\tDesign a number container system that can do the following:\n\t\t\tInsert or Replace a number at the given index in the system.\n\t\t\tReturn the smallest index for the given number in the system.\n\t\tImplement the NumberContainers class:\n\t\t\tNumberContainers() Initializes the number container system.\n\t\t\tvoid change(int index, int number) Fills the container at index with the number. If there is already a number at that index, replace it.\n\t\t\tint find(int number) Returns the smallest index for the given number, or -1 if there is no index that is filled by number in the system.\n\t\tExample 1:\n\t\tInput\n\t\t[\"NumberContainers\", \"find\", \"change\", \"change\", \"change\", \"change\", \"find\", \"change\", \"find\"]\n\t\t[[], [10], [2, 10], [1, 10], [3, 10], [5, 10], [10], [1, 20], [10]]\n\t\tOutput\n\t\t[null, -1, null, null, null, null, 1, null, 2]\n\t\tExplanation\n\t\tNumberContainers nc = new NumberContainers();\n\t\tnc.find(10); // There is no index that is filled with number 10. Therefore, we return -1.\n\t\tnc.change(2, 10); // Your container at index 2 will be filled with number 10.\n\t\tnc.change(1, 10); // Your container at index 1 will be filled with number 10.\n\t\tnc.change(3, 10); // Your container at index 3 will be filled with number 10.\n\t\tnc.change(5, 10); // Your container at index 5 will be filled with number 10.\n\t\tnc.find(10); // Number 10 is at the indices 1, 2, 3, and 5. Since the smallest index that is filled with 10 is 1, we return 1.\n\t\tnc.change(1, 20); // Your container at index 1 will be filled with number 20. Note that index 1 was filled with 10 and then replaced with 20. \n\t\tnc.find(10); // Number 10 is at the indices 2, 3, and 5. The smallest index that is filled with 10 is 2. Therefore, we return 2.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2435,
-        "question": "class Solution:\n    def shortestSequence(self, rolls: List[int], k: int) -> int:\n\t\t\"\"\"\n\t\tYou are given an integer array rolls of length n and an integer k. You roll a k sided dice numbered from 1 to k, n times, where the result of the ith roll is rolls[i].\n\t\tReturn the length of the shortest sequence of rolls that cannot be taken from rolls.\n\t\tA sequence of rolls of length len is the result of rolling a k sided dice len times.\n\t\tNote that the sequence taken does not have to be consecutive as long as it is in order.\n\t\tExample 1:\n\t\tInput: rolls = [4,2,1,2,3,3,2,4,1], k = 4\n\t\tOutput: 3\n\t\tExplanation: Every sequence of rolls of length 1, [1], [2], [3], [4], can be taken from rolls.\n\t\tEvery sequence of rolls of length 2, [1, 1], [1, 2], ..., [4, 4], can be taken from rolls.\n\t\tThe sequence [1, 4, 2] cannot be taken from rolls, so we return 3.\n\t\tNote that there are other sequences that cannot be taken from rolls.\n\t\tExample 2:\n\t\tInput: rolls = [1,1,2,2], k = 2\n\t\tOutput: 2\n\t\tExplanation: Every sequence of rolls of length 1, [1], [2], can be taken from rolls.\n\t\tThe sequence [2, 1] cannot be taken from rolls, so we return 2.\n\t\tNote that there are other sequences that cannot be taken from rolls but [2, 1] is the shortest.\n\t\tExample 3:\n\t\tInput: rolls = [1,1,3,2,2,2,3,3], k = 4\n\t\tOutput: 1\n\t\tExplanation: The sequence [4] cannot be taken from rolls, so we return 1.\n\t\tNote that there are other sequences that cannot be taken from rolls but [4] is the shortest.\n\t\t\"\"\"\n",
-        "difficulty": 2
-    },
-    {
-        "number": 2436,
-        "question": "class Solution:\n    def minimumOperations(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou are given a non-negative integer array nums. In one operation, you must:\n\t\t\tChoose a positive integer x such that x is less than or equal to the smallest non-zero element in nums.\n\t\t\tSubtract x from every positive element in nums.\n\t\tReturn the minimum number of operations to make every element in nums equal to 0.\n\t\tExample 1:\n\t\tInput: nums = [1,5,0,3,5]\n\t\tOutput: 3\n\t\tExplanation:\n\t\tIn the first operation, choose x = 1. Now, nums = [0,4,0,2,4].\n\t\tIn the second operation, choose x = 2. Now, nums = [0,2,0,0,2].\n\t\tIn the third operation, choose x = 2. Now, nums = [0,0,0,0,0].\n\t\tExample 2:\n\t\tInput: nums = [0]\n\t\tOutput: 0\n\t\tExplanation: Each element in nums is already 0 so no operations are needed.\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 2437,
-        "question": "class Solution:\n    def maximumGroups(self, grades: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou are given a positive integer array grades which represents the grades of students in a university. You would like to enter all these students into a competition in ordered non-empty groups, such that the ordering meets the following conditions:\n\t\t\tThe sum of the grades of students in the ith group is less than the sum of the grades of students in the (i + 1)th group, for all groups (except the last).\n\t\t\tThe total number of students in the ith group is less than the total number of students in the (i + 1)th group, for all groups (except the last).\n\t\tReturn the maximum number of groups that can be formed.\n\t\tExample 1:\n\t\tInput: grades = [10,6,12,7,3,5]\n\t\tOutput: 3\n\t\tExplanation: The following is a possible way to form 3 groups of students:\n\t\t- 1st group has the students with grades = [12]. Sum of grades: 12. Student count: 1\n\t\t- 2nd group has the students with grades = [6,7]. Sum of grades: 6 + 7 = 13. Student count: 2\n\t\t- 3rd group has the students with grades = [10,3,5]. Sum of grades: 10 + 3 + 5 = 18. Student count: 3\n\t\tIt can be shown that it is not possible to form more than 3 groups.\n\t\tExample 2:\n\t\tInput: grades = [8,8]\n\t\tOutput: 1\n\t\tExplanation: We can only form 1 group, since forming 2 groups would lead to an equal number of students in both groups.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2438,
-        "question": "class Solution:\n    def closestMeetingNode(self, edges: List[int], node1: int, node2: int) -> int:\n\t\t\"\"\"\n\t\tYou are given a directed graph of n nodes numbered from 0 to n - 1, where each node has at most one outgoing edge.\n\t\tThe graph is represented with a given 0-indexed array edges of size n, indicating that there is a directed edge from node i to node edges[i]. If there is no outgoing edge from i, then edges[i] == -1.\n\t\tYou are also given two integers node1 and node2.\n\t\tReturn the index of the node that can be reached from both node1 and node2, such that the maximum between the distance from node1 to that node, and from node2 to that node is minimized. If there are multiple answers, return the node with the smallest index, and if no possible answer exists, return -1.\n\t\tNote that edges may contain cycles.\n\t\tExample 1:\n\t\tInput: edges = [2,2,3,-1], node1 = 0, node2 = 1\n\t\tOutput: 2\n\t\tExplanation: The distance from node 0 to node 2 is 1, and the distance from node 1 to node 2 is 1.\n\t\tThe maximum of those two distances is 1. It can be proven that we cannot get a node with a smaller maximum distance than 1, so we return node 2.\n\t\tExample 2:\n\t\tInput: edges = [1,2,-1], node1 = 0, node2 = 2\n\t\tOutput: 2\n\t\tExplanation: The distance from node 0 to node 2 is 2, and the distance from node 2 to itself is 0.\n\t\tThe maximum of those two distances is 2. It can be proven that we cannot get a node with a smaller maximum distance than 2, so we return node 2.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2439,
-        "question": "class Solution:\n    def longestCycle(self, edges: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou are given a directed graph of n nodes numbered from 0 to n - 1, where each node has at most one outgoing edge.\n\t\tThe graph is represented with a given 0-indexed array edges of size n, indicating that there is a directed edge from node i to node edges[i]. If there is no outgoing edge from node i, then edges[i] == -1.\n\t\tReturn the length of the longest cycle in the graph. If no cycle exists, return -1.\n\t\tA cycle is a path that starts and ends at the same node.\n\t\tExample 1:\n\t\tInput: edges = [3,3,4,2,3]\n\t\tOutput: 3\n\t\tExplanation: The longest cycle in the graph is the cycle: 2 -> 4 -> 3 -> 2.\n\t\tThe length of this cycle is 3, so 3 is returned.\n\t\tExample 2:\n\t\tInput: edges = [2,-1,3,1]\n\t\tOutput: -1\n\t\tExplanation: There are no cycles in this graph.\n\t\t\"\"\"\n",
-        "difficulty": 2
-    },
-    {
-        "number": 2442,
-        "question": "class Solution:\n    def arithmeticTriplets(self, nums: List[int], diff: int) -> int:\n\t\t\"\"\"\n\t\tYou are given a 0-indexed, strictly increasing integer array nums and a positive integer diff. A triplet (i, j, k) is an arithmetic triplet if the following conditions are met:\n\t\t\ti < j < k,\n\t\t\tnums[j] - nums[i] == diff, and\n\t\t\tnums[k] - nums[j] == diff.\n\t\tReturn the number of unique arithmetic triplets.\n\t\tExample 1:\n\t\tInput: nums = [0,1,4,6,7,10], diff = 3\n\t\tOutput: 2\n\t\tExplanation:\n\t\t(1, 2, 4) is an arithmetic triplet because both 7 - 4 == 3 and 4 - 1 == 3.\n\t\t(2, 4, 5) is an arithmetic triplet because both 10 - 7 == 3 and 7 - 4 == 3. \n\t\tExample 2:\n\t\tInput: nums = [4,5,6,7,8,9], diff = 2\n\t\tOutput: 2\n\t\tExplanation:\n\t\t(0, 2, 4) is an arithmetic triplet because both 8 - 6 == 2 and 6 - 4 == 2.\n\t\t(1, 3, 5) is an arithmetic triplet because both 9 - 7 == 2 and 7 - 5 == 2.\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 2443,
-        "question": "class Solution:\n    def validPartition(self, nums: List[int]) -> bool:\n\t\t\"\"\"\n\t\tYou are given a 0-indexed integer array nums. You have to partition the array into one or more contiguous subarrays.\n\t\tWe call a partition of the array valid if each of the obtained subarrays satisfies one of the following conditions:\n\t\t\tThe subarray consists of exactly 2 equal elements. For example, the subarray [2,2] is good.\n\t\t\tThe subarray consists of exactly 3 equal elements. For example, the subarray [4,4,4] is good.\n\t\t\tThe subarray consists of exactly 3 consecutive increasing elements, that is, the difference between adjacent elements is 1. For example, the subarray [3,4,5] is good, but the subarray [1,3,5] is not.\n\t\tReturn true if the array has at least one valid partition. Otherwise, return false.\n\t\tExample 1:\n\t\tInput: nums = [4,4,4,5,6]\n\t\tOutput: true\n\t\tExplanation: The array can be partitioned into the subarrays [4,4] and [4,5,6].\n\t\tThis partition is valid, so we return true.\n\t\tExample 2:\n\t\tInput: nums = [1,1,1,2]\n\t\tOutput: false\n\t\tExplanation: There is no valid partition for this array.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2444,
-        "question": "class Solution:\n    def longestIdealString(self, s: str, k: int) -> int:\n\t\t\"\"\"\n\t\tYou are given a string s consisting of lowercase letters and an integer k. We call a string t ideal if the following conditions are satisfied:\n\t\t\tt is a subsequence of the string s.\n\t\t\tThe absolute difference in the alphabet order of every two adjacent letters in t is less than or equal to k.\n\t\tReturn the length of the longest ideal string.\n\t\tA subsequence is a string that can be derived from another string by deleting some or no characters without changing the order of the remaining characters.\n\t\tNote that the alphabet order is not cyclic. For example, the absolute difference in the alphabet order of 'a' and 'z' is 25, not 1.\n\t\tExample 1:\n\t\tInput: s = \"acfgbd\", k = 2\n\t\tOutput: 4\n\t\tExplanation: The longest ideal string is \"acbd\". The length of this string is 4, so 4 is returned.\n\t\tNote that \"acfgbd\" is not ideal because 'c' and 'f' have a difference of 3 in alphabet order.\n\t\tExample 2:\n\t\tInput: s = \"abcd\", k = 3\n\t\tOutput: 4\n\t\tExplanation: The longest ideal string is \"abcd\". The length of this string is 4, so 4 is returned.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2445,
-        "question": "class Solution:\n    def reachableNodes(self, n: int, edges: List[List[int]], restricted: List[int]) -> int:\n\t\t\"\"\"\n\t\tThere is an undirected tree with n nodes labeled from 0 to n - 1 and n - 1 edges.\n\t\tYou are given a 2D integer array edges of length n - 1 where edges[i] = [ai, bi] indicates that there is an edge between nodes ai and bi in the tree. You are also given an integer array restricted which represents restricted nodes.\n\t\tReturn the maximum number of nodes you can reach from node 0 without visiting a restricted node.\n\t\tNote that node 0 will not be a restricted node.\n\t\tExample 1:\n\t\tInput: n = 7, edges = [[0,1],[1,2],[3,1],[4,0],[0,5],[5,6]], restricted = [4,5]\n\t\tOutput: 4\n\t\tExplanation: The diagram above shows the tree.\n\t\tWe have that [0,1,2,3] are the only nodes that can be reached from node 0 without visiting a restricted node.\n\t\tExample 2:\n\t\tInput: n = 7, edges = [[0,1],[0,2],[0,5],[0,4],[3,2],[6,5]], restricted = [4,2,1]\n\t\tOutput: 3\n\t\tExplanation: The diagram above shows the tree.\n\t\tWe have that [0,5,6] are the only nodes that can be reached from node 0 without visiting a restricted node.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2447,
-        "question": "class Solution:\n    def mergeSimilarItems(self, items1: List[List[int]], items2: List[List[int]]) -> List[List[int]]:\n\t\t\"\"\"\n\t\tYou are given two 2D integer arrays, items1 and items2, representing two sets of items. Each array items has the following properties:\n\t\t\titems[i] = [valuei, weighti] where valuei represents the value and weighti represents the weight of the ith item.\n\t\t\tThe value of each item in items is unique.\n\t\tReturn a 2D integer array ret where ret[i] = [valuei, weighti], with weighti being the sum of weights of all items with value valuei.\n\t\tNote: ret should be returned in ascending order by value.\n\t\tExample 1:\n\t\tInput: items1 = [[1,1],[4,5],[3,8]], items2 = [[3,1],[1,5]]\n\t\tOutput: [[1,6],[3,9],[4,5]]\n\t\tExplanation: \n\t\tThe item with value = 1 occurs in items1 with weight = 1 and in items2 with weight = 5, total weight = 1 + 5 = 6.\n\t\tThe item with value = 3 occurs in items1 with weight = 8 and in items2 with weight = 1, total weight = 8 + 1 = 9.\n\t\tThe item with value = 4 occurs in items1 with weight = 5, total weight = 5.  \n\t\tTherefore, we return [[1,6],[3,9],[4,5]].\n\t\tExample 2:\n\t\tInput: items1 = [[1,1],[3,2],[2,3]], items2 = [[2,1],[3,2],[1,3]]\n\t\tOutput: [[1,4],[2,4],[3,4]]\n\t\tExplanation: \n\t\tThe item with value = 1 occurs in items1 with weight = 1 and in items2 with weight = 3, total weight = 1 + 3 = 4.\n\t\tThe item with value = 2 occurs in items1 with weight = 3 and in items2 with weight = 1, total weight = 3 + 1 = 4.\n\t\tThe item with value = 3 occurs in items1 with weight = 2 and in items2 with weight = 2, total weight = 2 + 2 = 4.\n\t\tTherefore, we return [[1,4],[2,4],[3,4]].\n\t\tExample 3:\n\t\tInput: items1 = [[1,3],[2,2]], items2 = [[7,1],[2,2],[1,4]]\n\t\tOutput: [[1,7],[2,4],[7,1]]\n\t\tExplanation:\n\t\tThe item with value = 1 occurs in items1 with weight = 3 and in items2 with weight = 4, total weight = 3 + 4 = 7. \n\t\tThe item with value = 2 occurs in items1 with weight = 2 and in items2 with weight = 2, total weight = 2 + 2 = 4. \n\t\tThe item with value = 7 occurs in items2 with weight = 1, total weight = 1.\n\t\tTherefore, we return [[1,7],[2,4],[7,1]].\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 2448,
-        "question": "class Solution:\n    def countBadPairs(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou are given a 0-indexed integer array nums. A pair of indices (i, j) is a bad pair if i < j and j - i != nums[j] - nums[i].\n\t\tReturn the total number of bad pairs in nums.\n\t\tExample 1:\n\t\tInput: nums = [4,1,3,3]\n\t\tOutput: 5\n\t\tExplanation: The pair (0, 1) is a bad pair since 1 - 0 != 1 - 4.\n\t\tThe pair (0, 2) is a bad pair since 2 - 0 != 3 - 4, 2 != -1.\n\t\tThe pair (0, 3) is a bad pair since 3 - 0 != 3 - 4, 3 != -1.\n\t\tThe pair (1, 2) is a bad pair since 2 - 1 != 3 - 1, 1 != 2.\n\t\tThe pair (2, 3) is a bad pair since 3 - 2 != 3 - 3, 1 != 0.\n\t\tThere are a total of 5 bad pairs, so we return 5.\n\t\tExample 2:\n\t\tInput: nums = [1,2,3,4,5]\n\t\tOutput: 0\n\t\tExplanation: There are no bad pairs.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2449,
-        "question": "class Solution:\n    def maximumRobots(self, chargeTimes: List[int], runningCosts: List[int], budget: int) -> int:\n\t\t\"\"\"\n\t\tYou have n robots. You are given two 0-indexed integer arrays, chargeTimes and runningCosts, both of length n. The ith robot costs chargeTimes[i] units to charge and costs runningCosts[i] units to run. You are also given an integer budget.\n\t\tThe total cost of running k chosen robots is equal to max(chargeTimes) + k * sum(runningCosts), where max(chargeTimes) is the largest charge cost among the k robots and sum(runningCosts) is the sum of running costs among the k robots.\n\t\tReturn the maximum number of consecutive robots you can run such that the total cost does not exceed budget.\n\t\tExample 1:\n\t\tInput: chargeTimes = [3,6,1,3,4], runningCosts = [2,1,3,4,5], budget = 25\n\t\tOutput: 3\n\t\tExplanation: \n\t\tIt is possible to run all individual and consecutive pairs of robots within budget.\n\t\tTo obtain answer 3, consider the first 3 robots. The total cost will be max(3,6,1) + 3 * sum(2,1,3) = 6 + 3 * 6 = 24 which is less than 25.\n\t\tIt can be shown that it is not possible to run more than 3 consecutive robots within budget, so we return 3.\n\t\tExample 2:\n\t\tInput: chargeTimes = [11,12,19], runningCosts = [10,8,7], budget = 19\n\t\tOutput: 0\n\t\tExplanation: No robot can be run that does not exceed the budget, so we return 0.\n\t\t\"\"\"\n",
-        "difficulty": 2
-    },
-    {
-        "number": 2450,
-        "question": "class Solution:\n    def minimumReplacement(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou are given a 0-indexed integer array nums. In one operation you can replace any element of the array with any two elements that sum to it.\n\t\t\tFor example, consider nums = [5,6,7]. In one operation, we can replace nums[1] with 2 and 4 and convert nums to [5,2,4,7].\n\t\tReturn the minimum number of operations to make an array that is sorted in non-decreasing order.\n\t\tExample 1:\n\t\tInput: nums = [3,9,3]\n\t\tOutput: 2\n\t\tExplanation: Here are the steps to sort the array in non-decreasing order:\n\t\t- From [3,9,3], replace the 9 with 3 and 6 so the array becomes [3,3,6,3]\n\t\t- From [3,3,6,3], replace the 6 with 3 and 3 so the array becomes [3,3,3,3,3]\n\t\tThere are 2 steps to sort the array in non-decreasing order. Therefore, we return 2.\n\t\tExample 2:\n\t\tInput: nums = [1,2,3,4,5]\n\t\tOutput: 0\n\t\tExplanation: The array is already in non-decreasing order. Therefore, we return 0. \n\t\t\"\"\"\n",
-        "difficulty": 2
-    },
-    {
-        "number": 2454,
-        "question": "class Solution:\n    def largestLocal(self, grid: List[List[int]]) -> List[List[int]]:\n\t\t\"\"\"\n\t\tYou are given an n x n integer matrix grid.\n\t\tGenerate an integer matrix maxLocal of size (n - 2) x (n - 2) such that:\n\t\t\tmaxLocal[i][j] is equal to the largest value of the 3 x 3 matrix in grid centered around row i + 1 and column j + 1.\n\t\tIn other words, we want to find the largest value in every contiguous 3 x 3 matrix in grid.\n\t\tReturn the generated matrix.\n\t\tExample 1:\n\t\tInput: grid = [[9,9,8,1],[5,6,2,6],[8,2,6,4],[6,2,2,2]]\n\t\tOutput: [[9,9],[8,6]]\n\t\tExplanation: The diagram above shows the original matrix and the generated matrix.\n\t\tNotice that each value in the generated matrix corresponds to the largest value of a contiguous 3 x 3 matrix in grid.\n\t\tExample 2:\n\t\tInput: grid = [[1,1,1,1,1],[1,1,1,1,1],[1,1,2,1,1],[1,1,1,1,1],[1,1,1,1,1]]\n\t\tOutput: [[2,2,2],[2,2,2],[2,2,2]]\n\t\tExplanation: Notice that the 2 is contained within every contiguous 3 x 3 matrix in grid.\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 2455,
-        "question": "class Solution:\n    def edgeScore(self, edges: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou are given a directed graph with n nodes labeled from 0 to n - 1, where each node has exactly one outgoing edge.\n\t\tThe graph is represented by a given 0-indexed integer array edges of length n, where edges[i] indicates that there is a directed edge from node i to node edges[i].\n\t\tThe edge score of a node i is defined as the sum of the labels of all the nodes that have an edge pointing to i.\n\t\tReturn the node with the highest edge score. If multiple nodes have the same edge score, return the node with the smallest index.\n\t\tExample 1:\n\t\tInput: edges = [1,0,0,0,0,7,7,5]\n\t\tOutput: 7\n\t\tExplanation:\n\t\t- The nodes 1, 2, 3 and 4 have an edge pointing to node 0. The edge score of node 0 is 1 + 2 + 3 + 4 = 10.\n\t\t- The node 0 has an edge pointing to node 1. The edge score of node 1 is 0.\n\t\t- The node 7 has an edge pointing to node 5. The edge score of node 5 is 7.\n\t\t- The nodes 5 and 6 have an edge pointing to node 7. The edge score of node 7 is 5 + 6 = 11.\n\t\tNode 7 has the highest edge score so return 7.\n\t\tExample 2:\n\t\tInput: edges = [2,0,0,2]\n\t\tOutput: 0\n\t\tExplanation:\n\t\t- The nodes 1 and 2 have an edge pointing to node 0. The edge score of node 0 is 1 + 2 = 3.\n\t\t- The nodes 0 and 3 have an edge pointing to node 2. The edge score of node 2 is 0 + 3 = 3.\n\t\tNodes 0 and 2 both have an edge score of 3. Since node 0 has a smaller index, we return 0.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2456,
-        "question": "class Solution:\n    def smallestNumber(self, pattern: str) -> str:\n\t\t\"\"\"\n\t\tYou are given a 0-indexed string pattern of length n consisting of the characters 'I' meaning increasing and 'D' meaning decreasing.\n\t\tA 0-indexed string num of length n + 1 is created using the following conditions:\n\t\t\tnum consists of the digits '1' to '9', where each digit is used at most once.\n\t\t\tIf pattern[i] == 'I', then num[i] < num[i + 1].\n\t\t\tIf pattern[i] == 'D', then num[i] > num[i + 1].\n\t\tReturn the lexicographically smallest possible string num that meets the conditions.\n\t\tExample 1:\n\t\tInput: pattern = \"IIIDIDDD\"\n\t\tOutput: \"123549876\"\n\t\tExplanation:\n\t\tAt indices 0, 1, 2, and 4 we must have that num[i] < num[i+1].\n\t\tAt indices 3, 5, 6, and 7 we must have that num[i] > num[i+1].\n\t\tSome possible values of num are \"245639871\", \"135749862\", and \"123849765\".\n\t\tIt can be proven that \"123549876\" is the smallest possible num that meets the conditions.\n\t\tNote that \"123414321\" is not possible because the digit '1' is used more than once.\n\t\tExample 2:\n\t\tInput: pattern = \"DDD\"\n\t\tOutput: \"4321\"\n\t\tExplanation:\n\t\tSome possible values of num are \"9876\", \"7321\", and \"8742\".\n\t\tIt can be proven that \"4321\" is the smallest possible num that meets the conditions.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2457,
-        "question": "class Solution:\n    def countSpecialNumbers(self, n: int) -> int:\n\t\t\"\"\"\n\t\tWe call a positive integer special if all of its digits are distinct.\n\t\tGiven a positive integer n, return the number of special integers that belong to the interval [1, n].\n\t\tExample 1:\n\t\tInput: n = 20\n\t\tOutput: 19\n\t\tExplanation: All the integers from 1 to 20, except 11, are special. Thus, there are 19 special integers.\n\t\tExample 2:\n\t\tInput: n = 5\n\t\tOutput: 5\n\t\tExplanation: All the integers from 1 to 5 are special.\n\t\tExample 3:\n\t\tInput: n = 135\n\t\tOutput: 110\n\t\tExplanation: There are 110 integers from 1 to 135 that are special.\n\t\tSome of the integers that are not special are: 22, 114, and 131.\n\t\t\"\"\"\n",
-        "difficulty": 2
-    },
-    {
-        "number": 2459,
-        "question": "class Solution:\n    def minNumberOfHours(self, initialEnergy: int, initialExperience: int, energy: List[int], experience: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou are entering a competition, and are given two positive integers initialEnergy and initialExperience denoting your initial energy and initial experience respectively.\n\t\tYou are also given two 0-indexed integer arrays energy and experience, both of length n.\n\t\tYou will face n opponents in order. The energy and experience of the ith opponent is denoted by energy[i] and experience[i] respectively. When you face an opponent, you need to have both strictly greater experience and energy to defeat them and move to the next opponent if available.\n\t\tDefeating the ith opponent increases your experience by experience[i], but decreases your energy by energy[i].\n\t\tBefore starting the competition, you can train for some number of hours. After each hour of training, you can either choose to increase your initial experience by one, or increase your initial energy by one.\n\t\tReturn the minimum number of training hours required to defeat all n opponents.\n\t\tExample 1:\n\t\tInput: initialEnergy = 5, initialExperience = 3, energy = [1,4,3,2], experience = [2,6,3,1]\n\t\tOutput: 8\n\t\tExplanation: You can increase your energy to 11 after 6 hours of training, and your experience to 5 after 2 hours of training.\n\t\tYou face the opponents in the following order:\n\t\t- You have more energy and experience than the 0th opponent so you win.\n\t\t  Your energy becomes 11 - 1 = 10, and your experience becomes 5 + 2 = 7.\n\t\t- You have more energy and experience than the 1st opponent so you win.\n\t\t  Your energy becomes 10 - 4 = 6, and your experience becomes 7 + 6 = 13.\n\t\t- You have more energy and experience than the 2nd opponent so you win.\n\t\t  Your energy becomes 6 - 3 = 3, and your experience becomes 13 + 3 = 16.\n\t\t- You have more energy and experience than the 3rd opponent so you win.\n\t\t  Your energy becomes 3 - 2 = 1, and your experience becomes 16 + 1 = 17.\n\t\tYou did a total of 6 + 2 = 8 hours of training before the competition, so we return 8.\n\t\tIt can be proven that no smaller answer exists.\n\t\tExample 2:\n\t\tInput: initialEnergy = 2, initialExperience = 4, energy = [1], experience = [3]\n\t\tOutput: 0\n\t\tExplanation: You do not need any additional energy or experience to win the competition, so we return 0.\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 2461,
-        "question": "class Solution:\n    def amountOfTime(self, root: Optional[TreeNode], start: int) -> int:\n\t\t\"\"\"\n\t\tYou are given the root of a binary tree with unique values, and an integer start. At minute 0, an infection starts from the node with value start.\n\t\tEach minute, a node becomes infected if:\n\t\t\tThe node is currently uninfected.\n\t\t\tThe node is adjacent to an infected node.\n\t\tReturn the number of minutes needed for the entire tree to be infected.\n\t\tExample 1:\n\t\tInput: root = [1,5,3,null,4,10,6,9,2], start = 3\n\t\tOutput: 4\n\t\tExplanation: The following nodes are infected during:\n\t\t- Minute 0: Node 3\n\t\t- Minute 1: Nodes 1, 10 and 6\n\t\t- Minute 2: Node 5\n\t\t- Minute 3: Node 4\n\t\t- Minute 4: Nodes 9 and 2\n\t\tIt takes 4 minutes for the whole tree to be infected so we return 4.\n\t\tExample 2:\n\t\tInput: root = [1], start = 1\n\t\tOutput: 0\n\t\tExplanation: At minute 0, the only node in the tree is infected so we return 0.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2462,
-        "question": "class Solution:\n    def kSum(self, nums: List[int], k: int) -> int:\n\t\t\"\"\"\n\t\tYou are given an integer array nums and a positive integer k. You can choose any subsequence of the array and sum all of its elements together.\n\t\tWe define the K-Sum of the array as the kth largest subsequence sum that can be obtained (not necessarily distinct).\n\t\tReturn the K-Sum of the array.\n\t\tA subsequence is an array that can be derived from another array by deleting some or no elements without changing the order of the remaining elements.\n\t\tNote that the empty subsequence is considered to have a sum of 0.\n\t\tExample 1:\n\t\tInput: nums = [2,4,-2], k = 5\n\t\tOutput: 2\n\t\tExplanation: All the possible subsequence sums that we can obtain are the following sorted in decreasing order:\n\t\t- 6, 4, 4, 2, 2, 0, 0, -2.\n\t\tThe 5-Sum of the array is 2.\n\t\tExample 2:\n\t\tInput: nums = [1,-2,3,4,-10,12], k = 16\n\t\tOutput: 10\n\t\tExplanation: The 16-Sum of the array is 10.\n\t\t\"\"\"\n",
-        "difficulty": 2
-    },
-    {
-        "number": 2463,
-        "question": "class Solution:\n    def minimumRecolors(self, blocks: str, k: int) -> int:\n\t\t\"\"\"\n\t\tYou are given a 0-indexed string blocks of length n, where blocks[i] is either 'W' or 'B', representing the color of the ith block. The characters 'W' and 'B' denote the colors white and black, respectively.\n\t\tYou are also given an integer k, which is the desired number of consecutive black blocks.\n\t\tIn one operation, you can recolor a white block such that it becomes a black block.\n\t\tReturn the minimum number of operations needed such that there is at least one occurrence of k consecutive black blocks.\n\t\tExample 1:\n\t\tInput: blocks = \"WBBWWBBWBW\", k = 7\n\t\tOutput: 3\n\t\tExplanation:\n\t\tOne way to achieve 7 consecutive black blocks is to recolor the 0th, 3rd, and 4th blocks\n\t\tso that blocks = \"BBBBBBBWBW\". \n\t\tIt can be shown that there is no way to achieve 7 consecutive black blocks in less than 3 operations.\n\t\tTherefore, we return 3.\n\t\tExample 2:\n\t\tInput: blocks = \"WBWBBBW\", k = 2\n\t\tOutput: 0\n\t\tExplanation:\n\t\tNo changes need to be made, since 2 consecutive black blocks already exist.\n\t\tTherefore, we return 0.\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 2464,
-        "question": "class Solution:\n    def secondsToRemoveOccurrences(self, s: str) -> int:\n\t\t\"\"\"\n\t\tYou are given a binary string s. In one second, all occurrences of \"01\" are simultaneously replaced with \"10\". This process repeats until no occurrences of \"01\" exist.\n\t\tReturn the number of seconds needed to complete this process.\n\t\tExample 1:\n\t\tInput: s = \"0110101\"\n\t\tOutput: 4\n\t\tExplanation: \n\t\tAfter one second, s becomes \"1011010\".\n\t\tAfter another second, s becomes \"1101100\".\n\t\tAfter the third second, s becomes \"1110100\".\n\t\tAfter the fourth second, s becomes \"1111000\".\n\t\tNo occurrence of \"01\" exists any longer, and the process needed 4 seconds to complete,\n\t\tso we return 4.\n\t\tExample 2:\n\t\tInput: s = \"11100\"\n\t\tOutput: 0\n\t\tExplanation:\n\t\tNo occurrence of \"01\" exists in s, and the processes needed 0 seconds to complete,\n\t\tso we return 0.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2465,
-        "question": "class Solution:\n    def shiftingLetters(self, s: str, shifts: List[List[int]]) -> str:\n\t\t\"\"\"\n\t\tYou are given a string s of lowercase English letters and a 2D integer array shifts where shifts[i] = [starti, endi, directioni]. For every i, shift the characters in s from the index starti to the index endi (inclusive) forward if directioni = 1, or shift the characters backward if directioni = 0.\n\t\tShifting a character forward means replacing it with the next letter in the alphabet (wrapping around so that 'z' becomes 'a'). Similarly, shifting a character backward means replacing it with the previous letter in the alphabet (wrapping around so that 'a' becomes 'z').\n\t\tReturn the final string after all such shifts to s are applied.\n\t\tExample 1:\n\t\tInput: s = \"abc\", shifts = [[0,1,0],[1,2,1],[0,2,1]]\n\t\tOutput: \"ace\"\n\t\tExplanation: Firstly, shift the characters from index 0 to index 1 backward. Now s = \"zac\".\n\t\tSecondly, shift the characters from index 1 to index 2 forward. Now s = \"zbd\".\n\t\tFinally, shift the characters from index 0 to index 2 forward. Now s = \"ace\".\n\t\tExample 2:\n\t\tInput: s = \"dztz\", shifts = [[0,0,0],[1,1,1]]\n\t\tOutput: \"catz\"\n\t\tExplanation: Firstly, shift the characters from index 0 to index 0 backward. Now s = \"cztz\".\n\t\tFinally, shift the characters from index 1 to index 1 forward. Now s = \"catz\".\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2466,
-        "question": "class Solution:\n    def maximumSegmentSum(self, nums: List[int], removeQueries: List[int]) -> List[int]:\n\t\t\"\"\"\n\t\tYou are given two 0-indexed integer arrays nums and removeQueries, both of length n. For the ith query, the element in nums at the index removeQueries[i] is removed, splitting nums into different segments.\n\t\tA segment is a contiguous sequence of positive integers in nums. A segment sum is the sum of every element in a segment.\n\t\tReturn an integer array answer, of length n, where answer[i] is the maximum segment sum after applying the ith removal.\n\t\tNote: The same index will not be removed more than once.\n\t\tExample 1:\n\t\tInput: nums = [1,2,5,6,1], removeQueries = [0,3,2,4,1]\n\t\tOutput: [14,7,2,2,0]\n\t\tExplanation: Using 0 to indicate a removed element, the answer is as follows:\n\t\tQuery 1: Remove the 0th element, nums becomes [0,2,5,6,1] and the maximum segment sum is 14 for segment [2,5,6,1].\n\t\tQuery 2: Remove the 3rd element, nums becomes [0,2,5,0,1] and the maximum segment sum is 7 for segment [2,5].\n\t\tQuery 3: Remove the 2nd element, nums becomes [0,2,0,0,1] and the maximum segment sum is 2 for segment [2]. \n\t\tQuery 4: Remove the 4th element, nums becomes [0,2,0,0,0] and the maximum segment sum is 2 for segment [2]. \n\t\tQuery 5: Remove the 1st element, nums becomes [0,0,0,0,0] and the maximum segment sum is 0, since there are no segments.\n\t\tFinally, we return [14,7,2,2,0].\n\t\tExample 2:\n\t\tInput: nums = [3,2,11,1], removeQueries = [3,2,1,0]\n\t\tOutput: [16,5,3,0]\n\t\tExplanation: Using 0 to indicate a removed element, the answer is as follows:\n\t\tQuery 1: Remove the 3rd element, nums becomes [3,2,11,0] and the maximum segment sum is 16 for segment [3,2,11].\n\t\tQuery 2: Remove the 2nd element, nums becomes [3,2,0,0] and the maximum segment sum is 5 for segment [3,2].\n\t\tQuery 3: Remove the 1st element, nums becomes [3,0,0,0] and the maximum segment sum is 3 for segment [3].\n\t\tQuery 4: Remove the 0th element, nums becomes [0,0,0,0] and the maximum segment sum is 0, since there are no segments.\n\t\tFinally, we return [16,5,3,0].\n\t\t\"\"\"\n",
-        "difficulty": 2
-    },
-    {
-        "number": 2469,
-        "question": "class Solution:\n    def answerQueries(self, nums: List[int], queries: List[int]) -> List[int]:\n\t\t\"\"\"\n\t\tYou are given an integer array nums of length n, and an integer array queries of length m.\n\t\tReturn an array answer of length m where answer[i] is the maximum size of a subsequence that you can take from nums such that the sum of its elements is less than or equal to queries[i].\n\t\tA subsequence is an array that can be derived from another array by deleting some or no elements without changing the order of the remaining elements.\n\t\tExample 1:\n\t\tInput: nums = [4,5,2,1], queries = [3,10,21]\n\t\tOutput: [2,3,4]\n\t\tExplanation: We answer the queries as follows:\n\t\t- The subsequence [2,1] has a sum less than or equal to 3. It can be proven that 2 is the maximum size of such a subsequence, so answer[0] = 2.\n\t\t- The subsequence [4,5,1] has a sum less than or equal to 10. It can be proven that 3 is the maximum size of such a subsequence, so answer[1] = 3.\n\t\t- The subsequence [4,5,2,1] has a sum less than or equal to 21. It can be proven that 4 is the maximum size of such a subsequence, so answer[2] = 4.\n\t\tExample 2:\n\t\tInput: nums = [2,3,4,5], queries = [1]\n\t\tOutput: [0]\n\t\tExplanation: The empty subsequence is the only subsequence that has a sum less than or equal to 1, so answer[0] = 0.\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 2470,
-        "question": "class Solution:\n    def removeStars(self, s: str) -> str:\n\t\t\"\"\"\n\t\tYou are given a string s, which contains stars *.\n\t\tIn one operation, you can:\n\t\t\tChoose a star in s.\n\t\t\tRemove the closest non-star character to its left, as well as remove the star itself.\n\t\tReturn the string after all stars have been removed.\n\t\tNote:\n\t\t\tThe input will be generated such that the operation is always possible.\n\t\t\tIt can be shown that the resulting string will always be unique.\n\t\tExample 1:\n\t\tInput: s = \"leet**cod*e\"\n\t\tOutput: \"lecoe\"\n\t\tExplanation: Performing the removals from left to right:\n\t\t- The closest character to the 1st star is 't' in \"leet**cod*e\". s becomes \"lee*cod*e\".\n\t\t- The closest character to the 2nd star is 'e' in \"lee*cod*e\". s becomes \"lecod*e\".\n\t\t- The closest character to the 3rd star is 'd' in \"lecod*e\". s becomes \"lecoe\".\n\t\tThere are no more stars, so we return \"lecoe\".\n\t\tExample 2:\n\t\tInput: s = \"erase*****\"\n\t\tOutput: \"\"\n\t\tExplanation: The entire string is removed, so we return an empty string.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2471,
-        "question": "class Solution:\n    def garbageCollection(self, garbage: List[str], travel: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou are given a 0-indexed array of strings garbage where garbage[i] represents the assortment of garbage at the ith house. garbage[i] consists only of the characters 'M', 'P' and 'G' representing one unit of metal, paper and glass garbage respectively. Picking up one unit of any type of garbage takes 1 minute.\n\t\tYou are also given a 0-indexed integer array travel where travel[i] is the number of minutes needed to go from house i to house i + 1.\n\t\tThere are three garbage trucks in the city, each responsible for picking up one type of garbage. Each garbage truck starts at house 0 and must visit each house in order; however, they do not need to visit every house.\n\t\tOnly one garbage truck may be used at any given moment. While one truck is driving or picking up garbage, the other two trucks cannot do anything.\n\t\tReturn the minimum number of minutes needed to pick up all the garbage.\n\t\tExample 1:\n\t\tInput: garbage = [\"G\",\"P\",\"GP\",\"GG\"], travel = [2,4,3]\n\t\tOutput: 21\n\t\tExplanation:\n\t\tThe paper garbage truck:\n\t\t1. Travels from house 0 to house 1\n\t\t2. Collects the paper garbage at house 1\n\t\t3. Travels from house 1 to house 2\n\t\t4. Collects the paper garbage at house 2\n\t\tAltogether, it takes 8 minutes to pick up all the paper garbage.\n\t\tThe glass garbage truck:\n\t\t1. Collects the glass garbage at house 0\n\t\t2. Travels from house 0 to house 1\n\t\t3. Travels from house 1 to house 2\n\t\t4. Collects the glass garbage at house 2\n\t\t5. Travels from house 2 to house 3\n\t\t6. Collects the glass garbage at house 3\n\t\tAltogether, it takes 13 minutes to pick up all the glass garbage.\n\t\tSince there is no metal garbage, we do not need to consider the metal garbage truck.\n\t\tTherefore, it takes a total of 8 + 13 = 21 minutes to collect all the garbage.\n\t\tExample 2:\n\t\tInput: garbage = [\"MMM\",\"PGM\",\"GP\"], travel = [3,10]\n\t\tOutput: 37\n\t\tExplanation:\n\t\tThe metal garbage truck takes 7 minutes to pick up all the metal garbage.\n\t\tThe paper garbage truck takes 15 minutes to pick up all the paper garbage.\n\t\tThe glass garbage truck takes 15 minutes to pick up all the glass garbage.\n\t\tIt takes a total of 7 + 15 + 15 = 37 minutes to collect all the garbage.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2472,
-        "question": "class Solution:\n    def buildMatrix(self, k: int, rowConditions: List[List[int]], colConditions: List[List[int]]) -> List[List[int]]:\n\t\t\"\"\"\n\t\tYou are given a positive integer k. You are also given:\n\t\t\ta 2D integer array rowConditions of size n where rowConditions[i] = [abovei, belowi], and\n\t\t\ta 2D integer array colConditions of size m where colConditions[i] = [lefti, righti].\n\t\tThe two arrays contain integers from 1 to k.\n\t\tYou have to build a k x k matrix that contains each of the numbers from 1 to k exactly once. The remaining cells should have the value 0.\n\t\tThe matrix should also satisfy the following conditions:\n\t\t\tThe number abovei should appear in a row that is strictly above the row at which the number belowi appears for all i from 0 to n - 1.\n\t\t\tThe number lefti should appear in a column that is strictly left of the column at which the number righti appears for all i from 0 to m - 1.\n\t\tReturn any matrix that satisfies the conditions. If no answer exists, return an empty matrix.\n\t\tExample 1:\n\t\tInput: k = 3, rowConditions = [[1,2],[3,2]], colConditions = [[2,1],[3,2]]\n\t\tOutput: [[3,0,0],[0,0,1],[0,2,0]]\n\t\tExplanation: The diagram above shows a valid example of a matrix that satisfies all the conditions.\n\t\tThe row conditions are the following:\n\t\t- Number 1 is in row 1, and number 2 is in row 2, so 1 is above 2 in the matrix.\n\t\t- Number 3 is in row 0, and number 2 is in row 2, so 3 is above 2 in the matrix.\n\t\tThe column conditions are the following:\n\t\t- Number 2 is in column 1, and number 1 is in column 2, so 2 is left of 1 in the matrix.\n\t\t- Number 3 is in column 0, and number 2 is in column 1, so 3 is left of 2 in the matrix.\n\t\tNote that there may be multiple correct answers.\n\t\tExample 2:\n\t\tInput: k = 3, rowConditions = [[1,2],[2,3],[3,1],[2,3]], colConditions = [[2,1]]\n\t\tOutput: []\n\t\tExplanation: From the first two conditions, 3 has to be below 1 but the third conditions needs 3 to be above 1 to be satisfied.\n\t\tNo matrix can satisfy all the conditions, so we return the empty matrix.\n\t\t\"\"\"\n",
-        "difficulty": 2
-    },
-    {
-        "number": 2473,
-        "question": "class Solution:\n    def maximumSum(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou are given a 0-indexed array nums consisting of positive integers. You can choose two indices i and j, such that i != j, and the sum of digits of the number nums[i] is equal to that of nums[j].\n\t\tReturn the maximum value of nums[i] + nums[j] that you can obtain over all possible indices i and j that satisfy the conditions.\n\t\tExample 1:\n\t\tInput: nums = [18,43,36,13,7]\n\t\tOutput: 54\n\t\tExplanation: The pairs (i, j) that satisfy the conditions are:\n\t\t- (0, 2), both numbers have a sum of digits equal to 9, and their sum is 18 + 36 = 54.\n\t\t- (1, 4), both numbers have a sum of digits equal to 7, and their sum is 43 + 7 = 50.\n\t\tSo the maximum sum that we can obtain is 54.\n\t\tExample 2:\n\t\tInput: nums = [10,12,19,14]\n\t\tOutput: -1\n\t\tExplanation: There are no two numbers that satisfy the conditions, so we return -1.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2475,
-        "question": "class Solution:\n    def largestPalindromic(self, num: str) -> str:\n\t\t\"\"\"\n\t\tYou are given a string num consisting of digits only.\n\t\tReturn the largest palindromic integer (in the form of a string) that can be formed using digits taken from num. It should not contain leading zeroes.\n\t\tNotes:\n\t\t\tYou do not need to use all the digits of num, but you must use at least one digit.\n\t\t\tThe digits can be reordered.\n\t\tExample 1:\n\t\tInput: num = \"444947137\"\n\t\tOutput: \"7449447\"\n\t\tExplanation: \n\t\tUse the digits \"4449477\" from \"444947137\" to form the palindromic integer \"7449447\".\n\t\tIt can be shown that \"7449447\" is the largest palindromic integer that can be formed.\n\t\tExample 2:\n\t\tInput: num = \"00009\"\n\t\tOutput: \"9\"\n\t\tExplanation: \n\t\tIt can be shown that \"9\" is the largest palindromic integer that can be formed.\n\t\tNote that the integer returned should not contain leading zeroes.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2476,
-        "question": "class Solution:\n    def checkDistances(self, s: str, distance: List[int]) -> bool:\n\t\t\"\"\"\n\t\tYou are given a 0-indexed string s consisting of only lowercase English letters, where each letter in s appears exactly twice. You are also given a 0-indexed integer array distance of length 26.\n\t\tEach letter in the alphabet is numbered from 0 to 25 (i.e. 'a' -> 0, 'b' -> 1, 'c' -> 2, ... , 'z' -> 25).\n\t\tIn a well-spaced string, the number of letters between the two occurrences of the ith letter is distance[i]. If the ith letter does not appear in s, then distance[i] can be ignored.\n\t\tReturn true if s is a well-spaced string, otherwise return false.\n\t\tExample 1:\n\t\tInput: s = \"abaccb\", distance = [1,3,0,5,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0]\n\t\tOutput: true\n\t\tExplanation:\n\t\t- 'a' appears at indices 0 and 2 so it satisfies distance[0] = 1.\n\t\t- 'b' appears at indices 1 and 5 so it satisfies distance[1] = 3.\n\t\t- 'c' appears at indices 3 and 4 so it satisfies distance[2] = 0.\n\t\tNote that distance[3] = 5, but since 'd' does not appear in s, it can be ignored.\n\t\tReturn true because s is a well-spaced string.\n\t\tExample 2:\n\t\tInput: s = \"aa\", distance = [1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0]\n\t\tOutput: false\n\t\tExplanation:\n\t\t- 'a' appears at indices 0 and 1 so there are zero letters between them.\n\t\tBecause distance[0] = 1, s is not a well-spaced string.\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 2477,
-        "question": "class Solution:\n    def numberOfWays(self, startPos: int, endPos: int, k: int) -> int:\n\t\t\"\"\"\n\t\tYou are given two positive integers startPos and endPos. Initially, you are standing at position startPos on an infinite number line. With one step, you can move either one position to the left, or one position to the right.\n\t\tGiven a positive integer k, return the number of different ways to reach the position endPos starting from startPos, such that you perform exactly k steps. Since the answer may be very large, return it modulo 109 + 7.\n\t\tTwo ways are considered different if the order of the steps made is not exactly the same.\n\t\tNote that the number line includes negative integers.\n\t\tExample 1:\n\t\tInput: startPos = 1, endPos = 2, k = 3\n\t\tOutput: 3\n\t\tExplanation: We can reach position 2 from 1 in exactly 3 steps in three ways:\n\t\t- 1 -> 2 -> 3 -> 2.\n\t\t- 1 -> 2 -> 1 -> 2.\n\t\t- 1 -> 0 -> 1 -> 2.\n\t\tIt can be proven that no other way is possible, so we return 3.\n\t\tExample 2:\n\t\tInput: startPos = 2, endPos = 5, k = 10\n\t\tOutput: 0\n\t\tExplanation: It is impossible to reach position 5 from position 2 in exactly 10 steps.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2478,
-        "question": "class Solution:\n    def longestNiceSubarray(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou are given an array nums consisting of positive integers.\n\t\tWe call a subarray of nums nice if the bitwise AND of every pair of elements that are in different positions in the subarray is equal to 0.\n\t\tReturn the length of the longest nice subarray.\n\t\tA subarray is a contiguous part of an array.\n\t\tNote that subarrays of length 1 are always considered nice.\n\t\tExample 1:\n\t\tInput: nums = [1,3,8,48,10]\n\t\tOutput: 3\n\t\tExplanation: The longest nice subarray is [3,8,48]. This subarray satisfies the conditions:\n\t\t- 3 AND 8 = 0.\n\t\t- 3 AND 48 = 0.\n\t\t- 8 AND 48 = 0.\n\t\tIt can be proven that no longer nice subarray can be obtained, so we return 3.\n\t\tExample 2:\n\t\tInput: nums = [3,1,5,11,13]\n\t\tOutput: 1\n\t\tExplanation: The length of the longest nice subarray is 1. Any subarray of length 1 can be chosen.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2479,
-        "question": "class Solution:\n    def mostBooked(self, n: int, meetings: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tYou are given an integer n. There are n rooms numbered from 0 to n - 1.\n\t\tYou are given a 2D integer array meetings where meetings[i] = [starti, endi] means that a meeting will be held during the half-closed time interval [starti, endi). All the values of starti are unique.\n\t\tMeetings are allocated to rooms in the following manner:\n\t\t\tEach meeting will take place in the unused room with the lowest number.\n\t\t\tIf there are no available rooms, the meeting will be delayed until a room becomes free. The delayed meeting should have the same duration as the original meeting.\n\t\t\tWhen a room becomes unused, meetings that have an earlier original start time should be given the room.\n\t\tReturn the number of the room that held the most meetings. If there are multiple rooms, return the room with the lowest number.\n\t\tA half-closed interval [a, b) is the interval between a and b including a and not including b.\n\t\tExample 1:\n\t\tInput: n = 2, meetings = [[0,10],[1,5],[2,7],[3,4]]\n\t\tOutput: 0\n\t\tExplanation:\n\t\t- At time 0, both rooms are not being used. The first meeting starts in room 0.\n\t\t- At time 1, only room 1 is not being used. The second meeting starts in room 1.\n\t\t- At time 2, both rooms are being used. The third meeting is delayed.\n\t\t- At time 3, both rooms are being used. The fourth meeting is delayed.\n\t\t- At time 5, the meeting in room 1 finishes. The third meeting starts in room 1 for the time period [5,10).\n\t\t- At time 10, the meetings in both rooms finish. The fourth meeting starts in room 0 for the time period [10,11).\n\t\tBoth rooms 0 and 1 held 2 meetings, so we return 0. \n\t\tExample 2:\n\t\tInput: n = 3, meetings = [[1,20],[2,10],[3,5],[4,9],[6,8]]\n\t\tOutput: 1\n\t\tExplanation:\n\t\t- At time 1, all three rooms are not being used. The first meeting starts in room 0.\n\t\t- At time 2, rooms 1 and 2 are not being used. The second meeting starts in room 1.\n\t\t- At time 3, only room 2 is not being used. The third meeting starts in room 2.\n\t\t- At time 4, all three rooms are being used. The fourth meeting is delayed.\n\t\t- At time 5, the meeting in room 2 finishes. The fourth meeting starts in room 2 for the time period [5,10).\n\t\t- At time 6, all three rooms are being used. The fifth meeting is delayed.\n\t\t- At time 10, the meetings in rooms 1 and 2 finish. The fifth meeting starts in room 1 for the time period [10,12).\n\t\tRoom 0 held 1 meeting while rooms 1 and 2 each held 2 meetings, so we return 1. \n\t\t\"\"\"\n",
-        "difficulty": 2
-    },
-    {
-        "number": 2480,
-        "question": "class Solution:\n    def findSubarrays(self, nums: List[int]) -> bool:\n\t\t\"\"\"\n\t\tGiven a 0-indexed integer array nums, determine whether there exist two subarrays of length 2 with equal sum. Note that the two subarrays must begin at different indices.\n\t\tReturn true if these subarrays exist, and false otherwise.\n\t\tA subarray is a contiguous non-empty sequence of elements within an array.\n\t\tExample 1:\n\t\tInput: nums = [4,2,4]\n\t\tOutput: true\n\t\tExplanation: The subarrays with elements [4,2] and [2,4] have the same sum of 6.\n\t\tExample 2:\n\t\tInput: nums = [1,2,3,4,5]\n\t\tOutput: false\n\t\tExplanation: No two subarrays of size 2 have the same sum.\n\t\tExample 3:\n\t\tInput: nums = [0,0,0]\n\t\tOutput: true\n\t\tExplanation: The subarrays [nums[0],nums[1]] and [nums[1],nums[2]] have the same sum of 0. \n\t\tNote that even though the subarrays have the same content, the two subarrays are considered different because they are in different positions in the original array.\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 2481,
-        "question": "class Solution:\n    def isStrictlyPalindromic(self, n: int) -> bool:\n\t\t\"\"\"\n\t\tAn integer n is strictly palindromic if, for every base b between 2 and n - 2 (inclusive), the string representation of the integer n in base b is palindromic.\n\t\tGiven an integer n, return true if n is strictly palindromic and false otherwise.\n\t\tA string is palindromic if it reads the same forward and backward.\n\t\tExample 1:\n\t\tInput: n = 9\n\t\tOutput: false\n\t\tExplanation: In base 2: 9 = 1001 (base 2), which is palindromic.\n\t\tIn base 3: 9 = 100 (base 3), which is not palindromic.\n\t\tTherefore, 9 is not strictly palindromic so we return false.\n\t\tNote that in bases 4, 5, 6, and 7, n = 9 is also not palindromic.\n\t\tExample 2:\n\t\tInput: n = 4\n\t\tOutput: false\n\t\tExplanation: We only consider base 2: 4 = 100 (base 2), which is not palindromic.\n\t\tTherefore, we return false.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2482,
-        "question": "class Solution:\n    def maximumRows(self, matrix: List[List[int]], numSelect: int) -> int:\n\t\t\"\"\"\n\t\tYou are given a 0-indexed m x n binary matrix matrix and an integer numSelect, which denotes the number of distinct columns you must select from matrix.\n\t\tLet us consider s = {c1, c2, ...., cnumSelect} as the set of columns selected by you. A row row is covered by s if:\n\t\t\tFor each cell matrix[row][col] (0 <= col <= n - 1) where matrix[row][col] == 1, col is present in s or,\n\t\t\tNo cell in row has a value of 1.\n\t\tYou need to choose numSelect columns such that the number of rows that are covered is maximized.\n\t\tReturn the maximum number of rows that can be covered by a set of numSelect columns.\n\t\tExample 1:\n\t\tInput: matrix = [[0,0,0],[1,0,1],[0,1,1],[0,0,1]], numSelect = 2\n\t\tOutput: 3\n\t\tExplanation: One possible way to cover 3 rows is shown in the diagram above.\n\t\tWe choose s = {0, 2}.\n\t\t- Row 0 is covered because it has no occurrences of 1.\n\t\t- Row 1 is covered because the columns with value 1, i.e. 0 and 2 are present in s.\n\t\t- Row 2 is not covered because matrix[2][1] == 1 but 1 is not present in s.\n\t\t- Row 3 is covered because matrix[2][2] == 1 and 2 is present in s.\n\t\tThus, we can cover three rows.\n\t\tNote that s = {1, 2} will also cover 3 rows, but it can be shown that no more than three rows can be covered.\n\t\tExample 2:\n\t\tInput: matrix = [[1],[0]], numSelect = 1\n\t\tOutput: 2\n\t\tExplanation: Selecting the only column will result in both rows being covered since the entire matrix is selected.\n\t\tTherefore, we return 2.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2483,
-        "question": "class Solution:\n    def taskSchedulerII(self, tasks: List[int], space: int) -> int:\n\t\t\"\"\"\n\t\tYou are given a 0-indexed array of positive integers tasks, representing tasks that need to be completed in order, where tasks[i] represents the type of the ith task.\n\t\tYou are also given a positive integer space, which represents the minimum number of days that must pass after the completion of a task before another task of the same type can be performed.\n\t\tEach day, until all tasks have been completed, you must either:\n\t\t\tComplete the next task from tasks, or\n\t\t\tTake a break.\n\t\tReturn the minimum number of days needed to complete all tasks.\n\t\tExample 1:\n\t\tInput: tasks = [1,2,1,2,3,1], space = 3\n\t\tOutput: 9\n\t\tExplanation:\n\t\tOne way to complete all tasks in 9 days is as follows:\n\t\tDay 1: Complete the 0th task.\n\t\tDay 2: Complete the 1st task.\n\t\tDay 3: Take a break.\n\t\tDay 4: Take a break.\n\t\tDay 5: Complete the 2nd task.\n\t\tDay 6: Complete the 3rd task.\n\t\tDay 7: Take a break.\n\t\tDay 8: Complete the 4th task.\n\t\tDay 9: Complete the 5th task.\n\t\tIt can be shown that the tasks cannot be completed in less than 9 days.\n\t\tExample 2:\n\t\tInput: tasks = [5,8,8,5], space = 2\n\t\tOutput: 6\n\t\tExplanation:\n\t\tOne way to complete all tasks in 6 days is as follows:\n\t\tDay 1: Complete the 0th task.\n\t\tDay 2: Complete the 1st task.\n\t\tDay 3: Take a break.\n\t\tDay 4: Take a break.\n\t\tDay 5: Complete the 2nd task.\n\t\tDay 6: Complete the 3rd task.\n\t\tIt can be shown that the tasks cannot be completed in less than 6 days.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2486,
-        "question": "class Solution:\n    def mostFrequentEven(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tGiven an integer array nums, return the most frequent even element.\n\t\tIf there is a tie, return the smallest one. If there is no such element, return -1.\n\t\tExample 1:\n\t\tInput: nums = [0,1,2,2,4,4,1]\n\t\tOutput: 2\n\t\tExplanation:\n\t\tThe even elements are 0, 2, and 4. Of these, 2 and 4 appear the most.\n\t\tWe return the smallest one, which is 2.\n\t\tExample 2:\n\t\tInput: nums = [4,4,4,9,2,4]\n\t\tOutput: 4\n\t\tExplanation: 4 is the even element appears the most.\n\t\tExample 3:\n\t\tInput: nums = [29,47,21,41,13,37,25,7]\n\t\tOutput: -1\n\t\tExplanation: There is no even element.\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 2487,
-        "question": "class Solution:\n    def partitionString(self, s: str) -> int:\n\t\t\"\"\"\n\t\tGiven a string s, partition the string into one or more substrings such that the characters in each substring are unique. That is, no letter appears in a single substring more than once.\n\t\tReturn the minimum number of substrings in such a partition.\n\t\tNote that each character should belong to exactly one substring in a partition.\n\t\tExample 1:\n\t\tInput: s = \"abacaba\"\n\t\tOutput: 4\n\t\tExplanation:\n\t\tTwo possible partitions are (\"a\",\"ba\",\"cab\",\"a\") and (\"ab\",\"a\",\"ca\",\"ba\").\n\t\tIt can be shown that 4 is the minimum number of substrings needed.\n\t\tExample 2:\n\t\tInput: s = \"ssssss\"\n\t\tOutput: 6\n\t\tExplanation:\n\t\tThe only valid partition is (\"s\",\"s\",\"s\",\"s\",\"s\",\"s\").\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2488,
-        "question": "class Solution:\n    def minGroups(self, intervals: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tYou are given a 2D integer array intervals where intervals[i] = [lefti, righti] represents the inclusive interval [lefti, righti].\n\t\tYou have to divide the intervals into one or more groups such that each interval is in exactly one group, and no two intervals that are in the same group intersect each other.\n\t\tReturn the minimum number of groups you need to make.\n\t\tTwo intervals intersect if there is at least one common number between them. For example, the intervals [1, 5] and [5, 8] intersect.\n\t\tExample 1:\n\t\tInput: intervals = [[5,10],[6,8],[1,5],[2,3],[1,10]]\n\t\tOutput: 3\n\t\tExplanation: We can divide the intervals into the following groups:\n\t\t- Group 1: [1, 5], [6, 8].\n\t\t- Group 2: [2, 3], [5, 10].\n\t\t- Group 3: [1, 10].\n\t\tIt can be proven that it is not possible to divide the intervals into fewer than 3 groups.\n\t\tExample 2:\n\t\tInput: intervals = [[1,3],[5,6],[8,10],[11,13]]\n\t\tOutput: 1\n\t\tExplanation: None of the intervals overlap, so we can put all of them in one group.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2491,
-        "question": "class Solution:\n    def smallestEvenMultiple(self, n: int) -> int:\n\t\t\"\"\"\n\t\tGiven a positive integer n, return the smallest positive integer that is a multiple of both 2 and n.\n\t\tExample 1:\n\t\tInput: n = 5\n\t\tOutput: 10\n\t\tExplanation: The smallest multiple of both 5 and 2 is 10.\n\t\tExample 2:\n\t\tInput: n = 6\n\t\tOutput: 6\n\t\tExplanation: The smallest multiple of both 6 and 2 is 6. Note that a number is a multiple of itself.\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 2492,
-        "question": "class Solution:\n    def longestContinuousSubstring(self, s: str) -> int:\n\t\t\"\"\"\n\t\tAn alphabetical continuous string is a string consisting of consecutive letters in the alphabet. In other words, it is any substring of the string \"abcdefghijklmnopqrstuvwxyz\".\n\t\t\tFor example, \"abc\" is an alphabetical continuous string, while \"acb\" and \"za\" are not.\n\t\tGiven a string s consisting of lowercase letters only, return the length of the longest alphabetical continuous substring.\n\t\tExample 1:\n\t\tInput: s = \"abacaba\"\n\t\tOutput: 2\n\t\tExplanation: There are 4 distinct continuous substrings: \"a\", \"b\", \"c\" and \"ab\".\n\t\t\"ab\" is the longest continuous substring.\n\t\tExample 2:\n\t\tInput: s = \"abcde\"\n\t\tOutput: 5\n\t\tExplanation: \"abcde\" is the longest continuous substring.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2493,
-        "question": "class Solution:\n    def reverseOddLevels(self, root: Optional[TreeNode]) -> Optional[TreeNode]:\n\t\t\"\"\"\n\t\tGiven the root of a perfect binary tree, reverse the node values at each odd level of the tree.\n\t\t\tFor example, suppose the node values at level 3 are [2,1,3,4,7,11,29,18], then it should become [18,29,11,7,4,3,1,2].\n\t\tReturn the root of the reversed tree.\n\t\tA binary tree is perfect if all parent nodes have two children and all leaves are on the same level.\n\t\tThe level of a node is the number of edges along the path between it and the root node.\n\t\tExample 1:\n\t\tInput: root = [2,3,5,8,13,21,34]\n\t\tOutput: [2,5,3,8,13,21,34]\n\t\tExplanation: \n\t\tThe tree has only one odd level.\n\t\tThe nodes at level 1 are 3, 5 respectively, which are reversed and become 5, 3.\n\t\tExample 2:\n\t\tInput: root = [7,13,11]\n\t\tOutput: [7,11,13]\n\t\tExplanation: \n\t\tThe nodes at level 1 are 13, 11, which are reversed and become 11, 13.\n\t\tExample 3:\n\t\tInput: root = [0,1,2,0,0,0,0,1,1,1,1,2,2,2,2]\n\t\tOutput: [0,2,1,0,0,0,0,2,2,2,2,1,1,1,1]\n\t\tExplanation: \n\t\tThe odd levels have non-zero values.\n\t\tThe nodes at level 1 were 1, 2, and are 2, 1 after the reversal.\n\t\tThe nodes at level 3 were 1, 1, 1, 1, 2, 2, 2, 2, and are 2, 2, 2, 2, 1, 1, 1, 1 after the reversal.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2494,
-        "question": "class Solution:\n    def sumPrefixScores(self, words: List[str]) -> List[int]:\n\t\t\"\"\"\n\t\tYou are given an array words of size n consisting of non-empty strings.\n\t\tWe define the score of a string word as the number of strings words[i] such that word is a prefix of words[i].\n\t\t\tFor example, if words = [\"a\", \"ab\", \"abc\", \"cab\"], then the score of \"ab\" is 2, since \"ab\" is a prefix of both \"ab\" and \"abc\".\n\t\tReturn an array answer of size n where answer[i] is the sum of scores of every non-empty prefix of words[i].\n\t\tNote that a string is considered as a prefix of itself.\n\t\tExample 1:\n\t\tInput: words = [\"abc\",\"ab\",\"bc\",\"b\"]\n\t\tOutput: [5,4,3,2]\n\t\tExplanation: The answer for each string is the following:\n\t\t- \"abc\" has 3 prefixes: \"a\", \"ab\", and \"abc\".\n\t\t- There are 2 strings with the prefix \"a\", 2 strings with the prefix \"ab\", and 1 string with the prefix \"abc\".\n\t\tThe total is answer[0] = 2 + 2 + 1 = 5.\n\t\t- \"ab\" has 2 prefixes: \"a\" and \"ab\".\n\t\t- There are 2 strings with the prefix \"a\", and 2 strings with the prefix \"ab\".\n\t\tThe total is answer[1] = 2 + 2 = 4.\n\t\t- \"bc\" has 2 prefixes: \"b\" and \"bc\".\n\t\t- There are 2 strings with the prefix \"b\", and 1 string with the prefix \"bc\".\n\t\tThe total is answer[2] = 2 + 1 = 3.\n\t\t- \"b\" has 1 prefix: \"b\".\n\t\t- There are 2 strings with the prefix \"b\".\n\t\tThe total is answer[3] = 2.\n\t\tExample 2:\n\t\tInput: words = [\"abcd\"]\n\t\tOutput: [4]\n\t\tExplanation:\n\t\t\"abcd\" has 4 prefixes: \"a\", \"ab\", \"abc\", and \"abcd\".\n\t\tEach prefix has a score of one, so the total is answer[0] = 1 + 1 + 1 + 1 = 4.\n\t\t\"\"\"\n",
-        "difficulty": 2
-    },
-    {
-        "number": 2496,
-        "question": "class Solution:\n    def countDaysTogether(self, arriveAlice: str, leaveAlice: str, arriveBob: str, leaveBob: str) -> int:\n\t\t\"\"\"\n\t\tAlice and Bob are traveling to Rome for separate business meetings.\n\t\tYou are given 4 strings arriveAlice, leaveAlice, arriveBob, and leaveBob. Alice will be in the city from the dates arriveAlice to leaveAlice (inclusive), while Bob will be in the city from the dates arriveBob to leaveBob (inclusive). Each will be a 5-character string in the format \"MM-DD\", corresponding to the month and day of the date.\n\t\tReturn the total number of days that Alice and Bob are in Rome together.\n\t\tYou can assume that all dates occur in the same calendar year, which is not a leap year. Note that the number of days per month can be represented as: [31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31].\n\t\tExample 1:\n\t\tInput: arriveAlice = \"08-15\", leaveAlice = \"08-18\", arriveBob = \"08-16\", leaveBob = \"08-19\"\n\t\tOutput: 3\n\t\tExplanation: Alice will be in Rome from August 15 to August 18. Bob will be in Rome from August 16 to August 19. They are both in Rome together on August 16th, 17th, and 18th, so the answer is 3.\n\t\tExample 2:\n\t\tInput: arriveAlice = \"10-01\", leaveAlice = \"10-31\", arriveBob = \"11-01\", leaveBob = \"12-31\"\n\t\tOutput: 0\n\t\tExplanation: There is no day when Alice and Bob are in Rome together, so we return 0.\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 2497,
-        "question": "class Solution:\n    def matchPlayersAndTrainers(self, players: List[int], trainers: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou are given a 0-indexed integer array players, where players[i] represents the ability of the ith player. You are also given a 0-indexed integer array trainers, where trainers[j] represents the training capacity of the jth trainer.\n\t\tThe ith player can match with the jth trainer if the player's ability is less than or equal to the trainer's training capacity. Additionally, the ith player can be matched with at most one trainer, and the jth trainer can be matched with at most one player.\n\t\tReturn the maximum number of matchings between players and trainers that satisfy these conditions.\n\t\tExample 1:\n\t\tInput: players = [4,7,9], trainers = [8,2,5,8]\n\t\tOutput: 2\n\t\tExplanation:\n\t\tOne of the ways we can form two matchings is as follows:\n\t\t- players[0] can be matched with trainers[0] since 4 <= 8.\n\t\t- players[1] can be matched with trainers[3] since 7 <= 8.\n\t\tIt can be proven that 2 is the maximum number of matchings that can be formed.\n\t\tExample 2:\n\t\tInput: players = [1,1,1], trainers = [10]\n\t\tOutput: 1\n\t\tExplanation:\n\t\tThe trainer can be matched with any of the 3 players.\n\t\tEach player can only be matched with one trainer, so the maximum answer is 1.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2498,
-        "question": "class Solution:\n    def smallestSubarrays(self, nums: List[int]) -> List[int]:\n\t\t\"\"\"\n\t\tYou are given a 0-indexed array nums of length n, consisting of non-negative integers. For each index i from 0 to n - 1, you must determine the size of the minimum sized non-empty subarray of nums starting at i (inclusive) that has the maximum possible bitwise OR.\n\t\t\tIn other words, let Bij be the bitwise OR of the subarray nums[i...j]. You need to find the smallest subarray starting at i, such that bitwise OR of this subarray is equal to max(Bik) where i <= k <= n - 1.\n\t\tThe bitwise OR of an array is the bitwise OR of all the numbers in it.\n\t\tReturn an integer array answer of size n where answer[i] is the length of the minimum sized subarray starting at i with maximum bitwise OR.\n\t\tA subarray is a contiguous non-empty sequence of elements within an array.\n\t\tExample 1:\n\t\tInput: nums = [1,0,2,1,3]\n\t\tOutput: [3,3,2,2,1]\n\t\tExplanation:\n\t\tThe maximum possible bitwise OR starting at any index is 3. \n\t\t- Starting at index 0, the shortest subarray that yields it is [1,0,2].\n\t\t- Starting at index 1, the shortest subarray that yields the maximum bitwise OR is [0,2,1].\n\t\t- Starting at index 2, the shortest subarray that yields the maximum bitwise OR is [2,1].\n\t\t- Starting at index 3, the shortest subarray that yields the maximum bitwise OR is [1,3].\n\t\t- Starting at index 4, the shortest subarray that yields the maximum bitwise OR is [3].\n\t\tTherefore, we return [3,3,2,2,1]. \n\t\tExample 2:\n\t\tInput: nums = [1,2]\n\t\tOutput: [2,1]\n\t\tExplanation:\n\t\tStarting at index 0, the shortest subarray that yields the maximum bitwise OR is of length 2.\n\t\tStarting at index 1, the shortest subarray that yields the maximum bitwise OR is of length 1.\n\t\tTherefore, we return [2,1].\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2499,
-        "question": "class Solution:\n    def minimumMoney(self, transactions: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tYou are given a 0-indexed 2D integer array transactions, where transactions[i] = [costi, cashbacki].\n\t\tThe array describes transactions, where each transaction must be completed exactly once in some order. At any given moment, you have a certain amount of money. In order to complete transaction i, money >= costi must hold true. After performing a transaction, money becomes money - costi + cashbacki.\n\t\tReturn the minimum amount of money required before any transaction so that all of the transactions can be completed regardless of the order of the transactions.\n\t\tExample 1:\n\t\tInput: transactions = [[2,1],[5,0],[4,2]]\n\t\tOutput: 10\n\t\tExplanation:\n\t\tStarting with money = 10, the transactions can be performed in any order.\n\t\tIt can be shown that starting with money < 10 will fail to complete all transactions in some order.\n\t\tExample 2:\n\t\tInput: transactions = [[3,0],[0,3]]\n\t\tOutput: 3\n\t\tExplanation:\n\t\t- If transactions are in the order [[3,0],[0,3]], the minimum money required to complete the transactions is 3.\n\t\t- If transactions are in the order [[0,3],[3,0]], the minimum money required to complete the transactions is 0.\n\t\tThus, starting with money = 3, the transactions can be performed in any order.\n\t\t\"\"\"\n",
-        "difficulty": 2
-    },
-    {
-        "number": 2502,
-        "question": "class Solution:\n    def sortPeople(self, names: List[str], heights: List[int]) -> List[str]:\n\t\t\"\"\"\n\t\tYou are given an array of strings names, and an array heights that consists of distinct positive integers. Both arrays are of length n.\n\t\tFor each index i, names[i] and heights[i] denote the name and height of the ith person.\n\t\tReturn names sorted in descending order by the people's heights.\n\t\tExample 1:\n\t\tInput: names = [\"Mary\",\"John\",\"Emma\"], heights = [180,165,170]\n\t\tOutput: [\"Mary\",\"Emma\",\"John\"]\n\t\tExplanation: Mary is the tallest, followed by Emma and John.\n\t\tExample 2:\n\t\tInput: names = [\"Alice\",\"Bob\",\"Bob\"], heights = [155,185,150]\n\t\tOutput: [\"Bob\",\"Alice\",\"Bob\"]\n\t\tExplanation: The first Bob is the tallest, followed by Alice and the second Bob.\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 2503,
-        "question": "class Solution:\n    def longestSubarray(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou are given an integer array nums of size n.\n\t\tConsider a non-empty subarray from nums that has the maximum possible bitwise AND.\n\t\t\tIn other words, let k be the maximum value of the bitwise AND of any subarray of nums. Then, only subarrays with a bitwise AND equal to k should be considered.\n\t\tReturn the length of the longest such subarray.\n\t\tThe bitwise AND of an array is the bitwise AND of all the numbers in it.\n\t\tA subarray is a contiguous sequence of elements within an array.\n\t\tExample 1:\n\t\tInput: nums = [1,2,3,3,2,2]\n\t\tOutput: 2\n\t\tExplanation:\n\t\tThe maximum possible bitwise AND of a subarray is 3.\n\t\tThe longest subarray with that value is [3,3], so we return 2.\n\t\tExample 2:\n\t\tInput: nums = [1,2,3,4]\n\t\tOutput: 1\n\t\tExplanation:\n\t\tThe maximum possible bitwise AND of a subarray is 4.\n\t\tThe longest subarray with that value is [4], so we return 1.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2504,
-        "question": "class Solution:\n    def goodIndices(self, nums: List[int], k: int) -> List[int]:\n\t\t\"\"\"\n\t\tYou are given a 0-indexed integer array nums of size n and a positive integer k.\n\t\tWe call an index i in the range k <= i < n - k good if the following conditions are satisfied:\n\t\t\tThe k elements that are just before the index i are in non-increasing order.\n\t\t\tThe k elements that are just after the index i are in non-decreasing order.\n\t\tReturn an array of all good indices sorted in increasing order.\n\t\tExample 1:\n\t\tInput: nums = [2,1,1,1,3,4,1], k = 2\n\t\tOutput: [2,3]\n\t\tExplanation: There are two good indices in the array:\n\t\t- Index 2. The subarray [2,1] is in non-increasing order, and the subarray [1,3] is in non-decreasing order.\n\t\t- Index 3. The subarray [1,1] is in non-increasing order, and the subarray [3,4] is in non-decreasing order.\n\t\tNote that the index 4 is not good because [4,1] is not non-decreasing.\n\t\tExample 2:\n\t\tInput: nums = [2,1,1,2], k = 2\n\t\tOutput: []\n\t\tExplanation: There are no good indices in this array.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2505,
-        "question": "class Solution:\n    def numberOfGoodPaths(self, vals: List[int], edges: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tThere is a tree (i.e. a connected, undirected graph with no cycles) consisting of n nodes numbered from 0 to n - 1 and exactly n - 1 edges.\n\t\tYou are given a 0-indexed integer array vals of length n where vals[i] denotes the value of the ith node. You are also given a 2D integer array edges where edges[i] = [ai, bi] denotes that there exists an undirected edge connecting nodes ai and bi.\n\t\tA good path is a simple path that satisfies the following conditions:\n\t\t\tThe starting node and the ending node have the same value.\n\t\t\tAll nodes between the starting node and the ending node have values less than or equal to the starting node (i.e. the starting node's value should be the maximum value along the path).\n\t\tReturn the number of distinct good paths.\n\t\tNote that a path and its reverse are counted as the same path. For example, 0 -> 1 is considered to be the same as 1 -> 0. A single node is also considered as a valid path.\n\t\tExample 1:\n\t\tInput: vals = [1,3,2,1,3], edges = [[0,1],[0,2],[2,3],[2,4]]\n\t\tOutput: 6\n\t\tExplanation: There are 5 good paths consisting of a single node.\n\t\tThere is 1 additional good path: 1 -> 0 -> 2 -> 4.\n\t\t(The reverse path 4 -> 2 -> 0 -> 1 is treated as the same as 1 -> 0 -> 2 -> 4.)\n\t\tNote that 0 -> 2 -> 3 is not a good path because vals[2] > vals[0].\n\t\tExample 2:\n\t\tInput: vals = [1,1,2,2,3], edges = [[0,1],[1,2],[2,3],[2,4]]\n\t\tOutput: 7\n\t\tExplanation: There are 5 good paths consisting of a single node.\n\t\tThere are 2 additional good paths: 0 -> 1 and 2 -> 3.\n\t\tExample 3:\n\t\tInput: vals = [1], edges = []\n\t\tOutput: 1\n\t\tExplanation: The tree consists of only one node, so there is one good path.\n\t\t\"\"\"\n",
-        "difficulty": 2
-    },
-    {
-        "number": 2507,
-        "question": "class Solution:\n    def commonFactors(self, a: int, b: int) -> int:\n\t\t\"\"\"\n\t\tGiven two positive integers a and b, return the number of common factors of a and b.\n\t\tAn integer x is a common factor of a and b if x divides both a and b.\n\t\tExample 1:\n\t\tInput: a = 12, b = 6\n\t\tOutput: 4\n\t\tExplanation: The common factors of 12 and 6 are 1, 2, 3, 6.\n\t\tExample 2:\n\t\tInput: a = 25, b = 30\n\t\tOutput: 2\n\t\tExplanation: The common factors of 25 and 30 are 1, 5.\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 2508,
-        "question": "class Solution:\n    def maxSum(self, grid: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tYou are given an m x n integer matrix grid.\n\t\tWe define an hourglass as a part of the matrix with the following form:\n\t\tReturn the maximum sum of the elements of an hourglass.\n\t\tNote that an hourglass cannot be rotated and must be entirely contained within the matrix.\n\t\tExample 1:\n\t\tInput: grid = [[6,2,1,3],[4,2,1,5],[9,2,8,7],[4,1,2,9]]\n\t\tOutput: 30\n\t\tExplanation: The cells shown above represent the hourglass with the maximum sum: 6 + 2 + 1 + 2 + 9 + 2 + 8 = 30.\n\t\tExample 2:\n\t\tInput: grid = [[1,2,3],[4,5,6],[7,8,9]]\n\t\tOutput: 35\n\t\tExplanation: There is only one hourglass in the matrix, with the sum: 1 + 2 + 3 + 5 + 7 + 8 + 9 = 35.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2509,
-        "question": "class Solution:\n    def minimizeXor(self, num1: int, num2: int) -> int:\n\t\t\"\"\"\n\t\tGiven two positive integers num1 and num2, find the positive integer x such that:\n\t\t\tx has the same number of set bits as num2, and\n\t\t\tThe value x XOR num1 is minimal.\n\t\tNote that XOR is the bitwise XOR operation.\n\t\tReturn the integer x. The test cases are generated such that x is uniquely determined.\n\t\tThe number of set bits of an integer is the number of 1's in its binary representation.\n\t\tExample 1:\n\t\tInput: num1 = 3, num2 = 5\n\t\tOutput: 3\n\t\tExplanation:\n\t\tThe binary representations of num1 and num2 are 0011 and 0101, respectively.\n\t\tThe integer 3 has the same number of set bits as num2, and the value 3 XOR 3 = 0 is minimal.\n\t\tExample 2:\n\t\tInput: num1 = 1, num2 = 12\n\t\tOutput: 3\n\t\tExplanation:\n\t\tThe binary representations of num1 and num2 are 0001 and 1100, respectively.\n\t\tThe integer 3 has the same number of set bits as num2, and the value 3 XOR 1 = 2 is minimal.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2510,
-        "question": "class Solution:\n    def deleteString(self, s: str) -> int:\n\t\t\"\"\"\n\t\tYou are given a string s consisting of only lowercase English letters. In one operation, you can:\n\t\t\tDelete the entire string s, or\n\t\t\tDelete the first i letters of s if the first i letters of s are equal to the following i letters in s, for any i in the range 1 <= i <= s.length / 2.\n\t\tFor example, if s = \"ababc\", then in one operation, you could delete the first two letters of s to get \"abc\", since the first two letters of s and the following two letters of s are both equal to \"ab\".\n\t\tReturn the maximum number of operations needed to delete all of s.\n\t\tExample 1:\n\t\tInput: s = \"abcabcdabc\"\n\t\tOutput: 2\n\t\tExplanation:\n\t\t- Delete the first 3 letters (\"abc\") since the next 3 letters are equal. Now, s = \"abcdabc\".\n\t\t- Delete all the letters.\n\t\tWe used 2 operations so return 2. It can be proven that 2 is the maximum number of operations needed.\n\t\tNote that in the second operation we cannot delete \"abc\" again because the next occurrence of \"abc\" does not happen in the next 3 letters.\n\t\tExample 2:\n\t\tInput: s = \"aaabaab\"\n\t\tOutput: 4\n\t\tExplanation:\n\t\t- Delete the first letter (\"a\") since the next letter is equal. Now, s = \"aabaab\".\n\t\t- Delete the first 3 letters (\"aab\") since the next 3 letters are equal. Now, s = \"aab\".\n\t\t- Delete the first letter (\"a\") since the next letter is equal. Now, s = \"ab\".\n\t\t- Delete all the letters.\n\t\tWe used 4 operations so return 4. It can be proven that 4 is the maximum number of operations needed.\n\t\tExample 3:\n\t\tInput: s = \"aaaaa\"\n\t\tOutput: 5\n\t\tExplanation: In each operation, we can delete the first letter of s.\n\t\t\"\"\"\n",
-        "difficulty": 2
-    },
-    {
-        "number": 2511,
-        "question": "class Solution:\n    def minimumPartition(self, s: str, k: int) -> int:\n\t\t\"\"\"\n\t\tYou are given a string s consisting of digits from 1 to 9 and an integer k.\n\t\tA partition of a string s is called good if:\n\t\t\tEach digit of s is part of exactly one substring.\n\t\t\tThe value of each substring is less than or equal to k.\n\t\tReturn the minimum number of substrings in a good partition of s. If no good partition of s exists, return -1.\n\t\tNote that:\n\t\t\tThe value of a string is its result when interpreted as an integer. For example, the value of \"123\" is 123 and the value of \"1\" is 1.\n\t\t\tA substring is a contiguous sequence of characters within a string.\n\t\tExample 1:\n\t\tInput: s = \"165462\", k = 60\n\t\tOutput: 4\n\t\tExplanation: We can partition the string into substrings \"16\", \"54\", \"6\", and \"2\". Each substring has a value less than or equal to k = 60.\n\t\tIt can be shown that we cannot partition the string into less than 4 substrings.\n\t\tExample 2:\n\t\tInput: s = \"238182\", k = 5\n\t\tOutput: -1\n\t\tExplanation: There is no good partition for this string.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2512,
-        "question": "class LUPrefix:\n    def __init__(self, n: int):\n    def upload(self, video: int) -> None:\n    def longest(self) -> int:\n\t\t\"\"\"\n\t\tYou are given a stream of n videos, each represented by a distinct number from 1 to n that you need to \"upload\" to a server. You need to implement a data structure that calculates the length of the longest uploaded prefix at various points in the upload process.\n\t\tWe consider i to be an uploaded prefix if all videos in the range 1 to i (inclusive) have been uploaded to the server. The longest uploaded prefix is the maximum value of i that satisfies this definition.\n\t\tImplement the LUPrefix class:\n\t\t\tLUPrefix(int n) Initializes the object for a stream of n videos.\n\t\t\tvoid upload(int video) Uploads video to the server.\n\t\t\tint longest() Returns the length of the longest uploaded prefix defined above.\n\t\tExample 1:\n\t\tInput\n\t\t[\"LUPrefix\", \"upload\", \"longest\", \"upload\", \"longest\", \"upload\", \"longest\"]\n\t\t[[4], [3], [], [1], [], [2], []]\n\t\tOutput\n\t\t[null, null, 0, null, 1, null, 3]\n\t\tExplanation\n\t\tLUPrefix server = new LUPrefix(4);   // Initialize a stream of 4 videos.\n\t\tserver.upload(3);                    // Upload video 3.\n\t\tserver.longest();                    // Since video 1 has not been uploaded yet, there is no prefix.\n\t\t                                     // So, we return 0.\n\t\tserver.upload(1);                    // Upload video 1.\n\t\tserver.longest();                    // The prefix [1] is the longest uploaded prefix, so we return 1.\n\t\tserver.upload(2);                    // Upload video 2.\n\t\tserver.longest();                    // The prefix [1,2,3] is the longest uploaded prefix, so we return 3.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2513,
-        "question": "class Solution:\n    def numberOfPairs(self, nums1: List[int], nums2: List[int], diff: int) -> int:\n\t\t\"\"\"\n\t\tYou are given two 0-indexed integer arrays nums1 and nums2, each of size n, and an integer diff. Find the number of pairs (i, j) such that:\n\t\t\t0 <= i < j <= n - 1 and\n\t\t\tnums1[i] - nums1[j] <= nums2[i] - nums2[j] + diff.\n\t\tReturn the number of pairs that satisfy the conditions.\n\t\tExample 1:\n\t\tInput: nums1 = [3,2,5], nums2 = [2,2,1], diff = 1\n\t\tOutput: 3\n\t\tExplanation:\n\t\tThere are 3 pairs that satisfy the conditions:\n\t\t1. i = 0, j = 1: 3 - 2 <= 2 - 2 + 1. Since i < j and 1 <= 1, this pair satisfies the conditions.\n\t\t2. i = 0, j = 2: 3 - 5 <= 2 - 1 + 1. Since i < j and -2 <= 2, this pair satisfies the conditions.\n\t\t3. i = 1, j = 2: 2 - 5 <= 2 - 1 + 1. Since i < j and -3 <= 2, this pair satisfies the conditions.\n\t\tTherefore, we return 3.\n\t\tExample 2:\n\t\tInput: nums1 = [3,-1], nums2 = [-2,2], diff = -1\n\t\tOutput: 0\n\t\tExplanation:\n\t\tSince there does not exist any pair that satisfies the conditions, we return 0.\n\t\t\"\"\"\n",
-        "difficulty": 2
-    },
-    {
-        "number": 2518,
-        "question": "class Solution:\n    def hardestWorker(self, n: int, logs: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tThere are n employees, each with a unique id from 0 to n - 1.\n\t\tYou are given a 2D integer array logs where logs[i] = [idi, leaveTimei] where:\n\t\t\tidi is the id of the employee that worked on the ith task, and\n\t\t\tleaveTimei is the time at which the employee finished the ith task. All the values leaveTimei are unique.\n\t\tNote that the ith task starts the moment right after the (i - 1)th task ends, and the 0th task starts at time 0.\n\t\tReturn the id of the employee that worked the task with the longest time. If there is a tie between two or more employees, return the smallest id among them.\n\t\tExample 1:\n\t\tInput: n = 10, logs = [[0,3],[2,5],[0,9],[1,15]]\n\t\tOutput: 1\n\t\tExplanation: \n\t\tTask 0 started at 0 and ended at 3 with 3 units of times.\n\t\tTask 1 started at 3 and ended at 5 with 2 units of times.\n\t\tTask 2 started at 5 and ended at 9 with 4 units of times.\n\t\tTask 3 started at 9 and ended at 15 with 6 units of times.\n\t\tThe task with the longest time is task 3 and the employee with id 1 is the one that worked on it, so we return 1.\n\t\tExample 2:\n\t\tInput: n = 26, logs = [[1,1],[3,7],[2,12],[7,17]]\n\t\tOutput: 3\n\t\tExplanation: \n\t\tTask 0 started at 0 and ended at 1 with 1 unit of times.\n\t\tTask 1 started at 1 and ended at 7 with 6 units of times.\n\t\tTask 2 started at 7 and ended at 12 with 5 units of times.\n\t\tTask 3 started at 12 and ended at 17 with 5 units of times.\n\t\tThe tasks with the longest time is task 1. The employees that worked on it is 3, so we return 3.\n\t\tExample 3:\n\t\tInput: n = 2, logs = [[0,10],[1,20]]\n\t\tOutput: 0\n\t\tExplanation: \n\t\tTask 0 started at 0 and ended at 10 with 10 units of times.\n\t\tTask 1 started at 10 and ended at 20 with 10 units of times.\n\t\tThe tasks with the longest time are tasks 0 and 1. The employees that worked on them are 0 and 1, so we return the smallest id 0.\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 2519,
-        "question": "class Solution:\n    def findArray(self, pref: List[int]) -> List[int]:\n\t\t\"\"\"\n\t\tYou are given an integer array pref of size n. Find and return the array arr of size n that satisfies:\n\t\t\tpref[i] = arr[0] ^ arr[1] ^ ... ^ arr[i].\n\t\tNote that ^ denotes the bitwise-xor operation.\n\t\tIt can be proven that the answer is unique.\n\t\tExample 1:\n\t\tInput: pref = [5,2,0,3,1]\n\t\tOutput: [5,7,2,3,2]\n\t\tExplanation: From the array [5,7,2,3,2] we have the following:\n\t\t- pref[0] = 5.\n\t\t- pref[1] = 5 ^ 7 = 2.\n\t\t- pref[2] = 5 ^ 7 ^ 2 = 0.\n\t\t- pref[3] = 5 ^ 7 ^ 2 ^ 3 = 3.\n\t\t- pref[4] = 5 ^ 7 ^ 2 ^ 3 ^ 2 = 1.\n\t\tExample 2:\n\t\tInput: pref = [13]\n\t\tOutput: [13]\n\t\tExplanation: We have pref[0] = arr[0] = 13.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2520,
-        "question": "class Solution:\n    def robotWithString(self, s: str) -> str:\n\t\t\"\"\"\n\t\tYou are given a string s and a robot that currently holds an empty string t. Apply one of the following operations until s and t are both empty:\n\t\t\tRemove the first character of a string s and give it to the robot. The robot will append this character to the string t.\n\t\t\tRemove the last character of a string t and give it to the robot. The robot will write this character on paper.\n\t\tReturn the lexicographically smallest string that can be written on the paper.\n\t\tExample 1:\n\t\tInput: s = \"zza\"\n\t\tOutput: \"azz\"\n\t\tExplanation: Let p denote the written string.\n\t\tInitially p=\"\", s=\"zza\", t=\"\".\n\t\tPerform first operation three times p=\"\", s=\"\", t=\"zza\".\n\t\tPerform second operation three times p=\"azz\", s=\"\", t=\"\".\n\t\tExample 2:\n\t\tInput: s = \"bac\"\n\t\tOutput: \"abc\"\n\t\tExplanation: Let p denote the written string.\n\t\tPerform first operation twice p=\"\", s=\"c\", t=\"ba\". \n\t\tPerform second operation twice p=\"ab\", s=\"c\", t=\"\". \n\t\tPerform first operation p=\"ab\", s=\"\", t=\"c\". \n\t\tPerform second operation p=\"abc\", s=\"\", t=\"\".\n\t\tExample 3:\n\t\tInput: s = \"bdda\"\n\t\tOutput: \"addb\"\n\t\tExplanation: Let p denote the written string.\n\t\tInitially p=\"\", s=\"bdda\", t=\"\".\n\t\tPerform first operation four times p=\"\", s=\"\", t=\"bdda\".\n\t\tPerform second operation four times p=\"addb\", s=\"\", t=\"\".\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2521,
-        "question": "class Solution:\n    def numberOfPaths(self, grid: List[List[int]], k: int) -> int:\n\t\t\"\"\"\n\t\tYou are given a 0-indexed m x n integer matrix grid and an integer k. You are currently at position (0, 0) and you want to reach position (m - 1, n - 1) moving only down or right.\n\t\tReturn the number of paths where the sum of the elements on the path is divisible by k. Since the answer may be very large, return it modulo 109 + 7.\n\t\tExample 1:\n\t\tInput: grid = [[5,2,4],[3,0,5],[0,7,2]], k = 3\n\t\tOutput: 2\n\t\tExplanation: There are two paths where the sum of the elements on the path is divisible by k.\n\t\tThe first path highlighted in red has a sum of 5 + 2 + 4 + 5 + 2 = 18 which is divisible by 3.\n\t\tThe second path highlighted in blue has a sum of 5 + 3 + 0 + 5 + 2 = 15 which is divisible by 3.\n\t\tExample 2:\n\t\tInput: grid = [[0,0]], k = 5\n\t\tOutput: 1\n\t\tExplanation: The path highlighted in red has a sum of 0 + 0 = 0 which is divisible by 5.\n\t\tExample 3:\n\t\tInput: grid = [[7,3,4,9],[2,3,6,2],[2,3,7,0]], k = 1\n\t\tOutput: 10\n\t\tExplanation: Every integer is divisible by 1 so the sum of the elements on every possible path is divisible by k.\n\t\t\"\"\"\n",
-        "difficulty": 2
-    },
-    {
-        "number": 2524,
-        "question": "class Solution:\n    def findMaxK(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tGiven an integer array nums that does not contain any zeros, find the largest positive integer k such that -k also exists in the array.\n\t\tReturn the positive integer k. If there is no such integer, return -1.\n\t\tExample 1:\n\t\tInput: nums = [-1,2,-3,3]\n\t\tOutput: 3\n\t\tExplanation: 3 is the only valid k we can find in the array.\n\t\tExample 2:\n\t\tInput: nums = [-1,10,6,7,-7,1]\n\t\tOutput: 7\n\t\tExplanation: Both 1 and 7 have their corresponding negative values in the array. 7 has a larger value.\n\t\tExample 3:\n\t\tInput: nums = [-10,8,6,7,-2,-3]\n\t\tOutput: -1\n\t\tExplanation: There is no a single valid k, we return -1.\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 2525,
-        "question": "class Solution:\n    def countDistinctIntegers(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou are given an array nums consisting of positive integers.\n\t\tYou have to take each integer in the array, reverse its digits, and add it to the end of the array. You should apply this operation to the original integers in nums.\n\t\tReturn the number of distinct integers in the final array.\n\t\tExample 1:\n\t\tInput: nums = [1,13,10,12,31]\n\t\tOutput: 6\n\t\tExplanation: After including the reverse of each number, the resulting array is [1,13,10,12,31,1,31,1,21,13].\n\t\tThe reversed integers that were added to the end of the array are underlined. Note that for the integer 10, after reversing it, it becomes 01 which is just 1.\n\t\tThe number of distinct integers in this array is 6 (The numbers 1, 10, 12, 13, 21, and 31).\n\t\tExample 2:\n\t\tInput: nums = [2,2,2]\n\t\tOutput: 1\n\t\tExplanation: After including the reverse of each number, the resulting array is [2,2,2,2,2,2].\n\t\tThe number of distinct integers in this array is 1 (The number 2).\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2526,
-        "question": "class Solution:\n    def lengthOfLIS(self, nums: List[int], k: int) -> int:\n\t\t\"\"\"\n\t\tYou are given an integer array nums and an integer k.\n\t\tFind the longest subsequence of nums that meets the following requirements:\n\t\t\tThe subsequence is strictly increasing and\n\t\t\tThe difference between adjacent elements in the subsequence is at most k.\n\t\tReturn the length of the longest subsequence that meets the requirements.\n\t\tA subsequence is an array that can be derived from another array by deleting some or no elements without changing the order of the remaining elements.\n\t\tExample 1:\n\t\tInput: nums = [4,2,1,4,3,4,5,8,15], k = 3\n\t\tOutput: 5\n\t\tExplanation:\n\t\tThe longest subsequence that meets the requirements is [1,3,4,5,8].\n\t\tThe subsequence has a length of 5, so we return 5.\n\t\tNote that the subsequence [1,3,4,5,8,15] does not meet the requirements because 15 - 8 = 7 is larger than 3.\n\t\tExample 2:\n\t\tInput: nums = [7,4,5,1,8,12,4,7], k = 5\n\t\tOutput: 4\n\t\tExplanation:\n\t\tThe longest subsequence that meets the requirements is [4,5,8,12].\n\t\tThe subsequence has a length of 4, so we return 4.\n\t\tExample 3:\n\t\tInput: nums = [1,5], k = 1\n\t\tOutput: 1\n\t\tExplanation:\n\t\tThe longest subsequence that meets the requirements is [1].\n\t\tThe subsequence has a length of 1, so we return 1.\n\t\t\"\"\"\n",
-        "difficulty": 2
-    },
-    {
-        "number": 2527,
-        "question": "class Solution:\n    def countSubarrays(self, nums: List[int], minK: int, maxK: int) -> int:\n\t\t\"\"\"\n\t\tYou are given an integer array nums and two integers minK and maxK.\n\t\tA fixed-bound subarray of nums is a subarray that satisfies the following conditions:\n\t\t\tThe minimum value in the subarray is equal to minK.\n\t\t\tThe maximum value in the subarray is equal to maxK.\n\t\tReturn the number of fixed-bound subarrays.\n\t\tA subarray is a contiguous part of an array.\n\t\tExample 1:\n\t\tInput: nums = [1,3,5,2,7,5], minK = 1, maxK = 5\n\t\tOutput: 2\n\t\tExplanation: The fixed-bound subarrays are [1,3,5] and [1,3,5,2].\n\t\tExample 2:\n\t\tInput: nums = [1,1,1,1], minK = 1, maxK = 1\n\t\tOutput: 10\n\t\tExplanation: Every subarray of nums is a fixed-bound subarray. There are 10 possible subarrays.\n\t\t\"\"\"\n",
-        "difficulty": 2
-    },
-    {
-        "number": 2528,
-        "question": "class Solution:\n    def countTime(self, time: str) -> int:\n\t\t\"\"\"\n\t\tYou are given a string of length 5 called time, representing the current time on a digital clock in the format \"hh:mm\". The earliest possible time is \"00:00\" and the latest possible time is \"23:59\".\n\t\tIn the string time, the digits represented by the ? symbol are unknown, and must be replaced with a digit from 0 to 9.\n\t\tReturn an integer answer, the number of valid clock times that can be created by replacing every ? with a digit from 0 to 9.\n\t\tExample 1:\n\t\tInput: time = \"?5:00\"\n\t\tOutput: 2\n\t\tExplanation: We can replace the ? with either a 0 or 1, producing \"05:00\" or \"15:00\". Note that we cannot replace it with a 2, since the time \"25:00\" is invalid. In total, we have two choices.\n\t\tExample 2:\n\t\tInput: time = \"0?:0?\"\n\t\tOutput: 100\n\t\tExplanation: Each ? can be replaced by any digit from 0 to 9, so we have 100 total choices.\n\t\tExample 3:\n\t\tInput: time = \"??:??\"\n\t\tOutput: 1440\n\t\tExplanation: There are 24 possible choices for the hours, and 60 possible choices for the minutes. In total, we have 24 * 60 = 1440 choices.\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 2529,
-        "question": "class Solution:\n    def productQueries(self, n: int, queries: List[List[int]]) -> List[int]:\n\t\t\"\"\"\n\t\tGiven a positive integer n, there exists a 0-indexed array called powers, composed of the minimum number of powers of 2 that sum to n. The array is sorted in non-decreasing order, and there is only one way to form the array.\n\t\tYou are also given a 0-indexed 2D integer array queries, where queries[i] = [lefti, righti]. Each queries[i] represents a query where you have to find the product of all powers[j] with lefti <= j <= righti.\n\t\tReturn an array answers, equal in length to queries, where answers[i] is the answer to the ith query. Since the answer to the ith query may be too large, each answers[i] should be returned modulo 109 + 7.\n\t\tExample 1:\n\t\tInput: n = 15, queries = [[0,1],[2,2],[0,3]]\n\t\tOutput: [2,4,64]\n\t\tExplanation:\n\t\tFor n = 15, powers = [1,2,4,8]. It can be shown that powers cannot be a smaller size.\n\t\tAnswer to 1st query: powers[0] * powers[1] = 1 * 2 = 2.\n\t\tAnswer to 2nd query: powers[2] = 4.\n\t\tAnswer to 3rd query: powers[0] * powers[1] * powers[2] * powers[3] = 1 * 2 * 4 * 8 = 64.\n\t\tEach answer modulo 109 + 7 yields the same answer, so [2,4,64] is returned.\n\t\tExample 2:\n\t\tInput: n = 2, queries = [[0,0]]\n\t\tOutput: [2]\n\t\tExplanation:\n\t\tFor n = 2, powers = [2].\n\t\tThe answer to the only query is powers[0] = 2. The answer modulo 109 + 7 is the same, so [2] is returned.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2530,
-        "question": "class Solution:\n    def minimizeArrayValue(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou are given a 0-indexed array nums comprising of n non-negative integers.\n\t\tIn one operation, you must:\n\t\t\tChoose an integer i such that 1 <= i < n and nums[i] > 0.\n\t\t\tDecrease nums[i] by 1.\n\t\t\tIncrease nums[i - 1] by 1.\n\t\tReturn the minimum possible value of the maximum integer of nums after performing any number of operations.\n\t\tExample 1:\n\t\tInput: nums = [3,7,1,6]\n\t\tOutput: 5\n\t\tExplanation:\n\t\tOne set of optimal operations is as follows:\n\t\t1. Choose i = 1, and nums becomes [4,6,1,6].\n\t\t2. Choose i = 3, and nums becomes [4,6,2,5].\n\t\t3. Choose i = 1, and nums becomes [5,5,2,5].\n\t\tThe maximum integer of nums is 5. It can be shown that the maximum number cannot be less than 5.\n\t\tTherefore, we return 5.\n\t\tExample 2:\n\t\tInput: nums = [10,1]\n\t\tOutput: 10\n\t\tExplanation:\n\t\tIt is optimal to leave nums as is, and since 10 is the maximum value, we return 10.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2531,
-        "question": "class Solution:\n    def componentValue(self, nums: List[int], edges: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tThere is an undirected tree with n nodes labeled from 0 to n - 1.\n\t\tYou are given a 0-indexed integer array nums of length n where nums[i] represents the value of the ith node. You are also given a 2D integer array edges of length n - 1 where edges[i] = [ai, bi] indicates that there is an edge between nodes ai and bi in the tree.\n\t\tYou are allowed to delete some edges, splitting the tree into multiple connected components. Let the value of a component be the sum of all nums[i] for which node i is in the component.\n\t\tReturn the maximum number of edges you can delete, such that every connected component in the tree has the same value.\n\t\tExample 1:\n\t\tInput: nums = [6,2,2,2,6], edges = [[0,1],[1,2],[1,3],[3,4]] \n\t\tOutput: 2 \n\t\tExplanation: The above figure shows how we can delete the edges [0,1] and [3,4]. The created components are nodes [0], [1,2,3] and [4]. The sum of the values in each component equals 6. It can be proven that no better deletion exists, so the answer is 2.\n\t\tExample 2:\n\t\tInput: nums = [2], edges = []\n\t\tOutput: 0\n\t\tExplanation: There are no edges to be deleted.\n\t\t\"\"\"\n",
-        "difficulty": 2
-    },
-    {
-        "number": 2532,
-        "question": "class Solution:\n    def equalFrequency(self, word: str) -> bool:\n\t\t\"\"\"\n\t\tYou are given a 0-indexed string word, consisting of lowercase English letters. You need to select one index and remove the letter at that index from word so that the frequency of every letter present in word is equal.\n\t\tReturn true if it is possible to remove one letter so that the frequency of all letters in word are equal, and false otherwise.\n\t\tNote:\n\t\t\tThe frequency of a letter x is the number of times it occurs in the string.\n\t\t\tYou must remove exactly one letter and cannot chose to do nothing.\n\t\tExample 1:\n\t\tInput: word = \"abcc\"\n\t\tOutput: true\n\t\tExplanation: Select index 3 and delete it: word becomes \"abc\" and each character has a frequency of 1.\n\t\tExample 2:\n\t\tInput: word = \"aazz\"\n\t\tOutput: false\n\t\tExplanation: We must delete a character, so either the frequency of \"a\" is 1 and the frequency of \"z\" is 2, or vice versa. It is impossible to make all present letters have equal frequency.\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 2533,
-        "question": "class Solution:\n    def xorAllNums(self, nums1: List[int], nums2: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou are given two 0-indexed arrays, nums1 and nums2, consisting of non-negative integers. There exists another array, nums3, which contains the bitwise XOR of all pairings of integers between nums1 and nums2 (every integer in nums1 is paired with every integer in nums2 exactly once).\n\t\tReturn the bitwise XOR of all integers in nums3.\n\t\tExample 1:\n\t\tInput: nums1 = [2,1,3], nums2 = [10,2,5,0]\n\t\tOutput: 13\n\t\tExplanation:\n\t\tA possible nums3 array is [8,0,7,2,11,3,4,1,9,1,6,3].\n\t\tThe bitwise XOR of all these numbers is 13, so we return 13.\n\t\tExample 2:\n\t\tInput: nums1 = [1,2], nums2 = [3,4]\n\t\tOutput: 0\n\t\tExplanation:\n\t\tAll possible pairs of bitwise XORs are nums1[0] ^ nums2[0], nums1[0] ^ nums2[1], nums1[1] ^ nums2[0],\n\t\tand nums1[1] ^ nums2[1].\n\t\tThus, one possible nums3 array is [2,5,1,6].\n\t\t2 ^ 5 ^ 1 ^ 6 = 0, so we return 0.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2536,
-        "question": "class Solution:\n    def haveConflict(self, event1: List[str], event2: List[str]) -> bool:\n\t\t\"\"\"\n\t\tYou are given two arrays of strings that represent two inclusive events that happened on the same day, event1 and event2, where:\n\t\t\tevent1 = [startTime1, endTime1] and\n\t\t\tevent2 = [startTime2, endTime2].\n\t\tEvent times are valid 24 hours format in the form of HH:MM.\n\t\tA conflict happens when two events have some non-empty intersection (i.e., some moment is common to both events).\n\t\tReturn true if there is a conflict between two events. Otherwise, return false.\n\t\tExample 1:\n\t\tInput: event1 = [\"01:15\",\"02:00\"], event2 = [\"02:00\",\"03:00\"]\n\t\tOutput: true\n\t\tExplanation: The two events intersect at time 2:00.\n\t\tExample 2:\n\t\tInput: event1 = [\"01:00\",\"02:00\"], event2 = [\"01:20\",\"03:00\"]\n\t\tOutput: true\n\t\tExplanation: The two events intersect starting from 01:20 to 02:00.\n\t\tExample 3:\n\t\tInput: event1 = [\"10:00\",\"11:00\"], event2 = [\"14:00\",\"15:00\"]\n\t\tOutput: false\n\t\tExplanation: The two events do not intersect.\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 2538,
-        "question": "class Solution:\n    def minCost(self, nums: List[int], cost: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou are given two 0-indexed arrays nums and cost consisting each of n positive integers.\n\t\tYou can do the following operation any number of times:\n\t\t\tIncrease or decrease any element of the array nums by 1.\n\t\tThe cost of doing one operation on the ith element is cost[i].\n\t\tReturn the minimum total cost such that all the elements of the array nums become equal.\n\t\tExample 1:\n\t\tInput: nums = [1,3,5,2], cost = [2,3,1,14]\n\t\tOutput: 8\n\t\tExplanation: We can make all the elements equal to 2 in the following way:\n\t\t- Increase the 0th element one time. The cost is 2.\n\t\t- Decrease the 1st element one time. The cost is 3.\n\t\t- Decrease the 2nd element three times. The cost is 1 + 1 + 1 = 3.\n\t\tThe total cost is 2 + 3 + 3 = 8.\n\t\tIt can be shown that we cannot make the array equal with a smaller cost.\n\t\tExample 2:\n\t\tInput: nums = [2,2,2,2,2], cost = [4,2,8,1,3]\n\t\tOutput: 0\n\t\tExplanation: All the elements are already equal, so no operations are needed.\n\t\t\"\"\"\n",
-        "difficulty": 2
-    },
-    {
-        "number": 2539,
-        "question": "class Solution:\n    def makeSimilar(self, nums: List[int], target: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou are given two positive integer arrays nums and target, of the same length.\n\t\tIn one operation, you can choose any two distinct indices i and j where 0 <= i, j < nums.length and:\n\t\t\tset nums[i] = nums[i] + 2 and\n\t\t\tset nums[j] = nums[j] - 2.\n\t\tTwo arrays are considered to be similar if the frequency of each element is the same.\n\t\tReturn the minimum number of operations required to make nums similar to target. The test cases are generated such that nums can always be similar to target.\n\t\tExample 1:\n\t\tInput: nums = [8,12,6], target = [2,14,10]\n\t\tOutput: 2\n\t\tExplanation: It is possible to make nums similar to target in two operations:\n\t\t- Choose i = 0 and j = 2, nums = [10,12,4].\n\t\t- Choose i = 1 and j = 2, nums = [10,14,2].\n\t\tIt can be shown that 2 is the minimum number of operations needed.\n\t\tExample 2:\n\t\tInput: nums = [1,2,5], target = [4,1,3]\n\t\tOutput: 1\n\t\tExplanation: We can make nums similar to target in one operation:\n\t\t- Choose i = 1 and j = 2, nums = [1,4,3].\n\t\tExample 3:\n\t\tInput: nums = [1,1,1,1,1], target = [1,1,1,1,1]\n\t\tOutput: 0\n\t\tExplanation: The array nums is already similiar to target.\n\t\t\"\"\"\n",
-        "difficulty": 2
-    },
-    {
-        "number": 2541,
-        "question": "class Solution:\n    def sumOfNumberAndReverse(self, num: int) -> bool:\n\t\t\"\"\"\n\t\tGiven a non-negative integer num, return true if num can be expressed as the sum of any non-negative integer and its reverse, or false otherwise.\n\t\tExample 1:\n\t\tInput: num = 443\n\t\tOutput: true\n\t\tExplanation: 172 + 271 = 443 so we return true.\n\t\tExample 2:\n\t\tInput: num = 63\n\t\tOutput: false\n\t\tExplanation: 63 cannot be expressed as the sum of a non-negative integer and its reverse so we return false.\n\t\tExample 3:\n\t\tInput: num = 181\n\t\tOutput: true\n\t\tExplanation: 140 + 041 = 181 so we return true. Note that when a number is reversed, there may be leading zeros.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2542,
-        "question": "class Solution:\n    def averageValue(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tGiven an integer array nums of positive integers, return the average value of all even integers that are divisible by 3.\n\t\tNote that the average of n elements is the sum of the n elements divided by n and rounded down to the nearest integer.\n\t\tExample 1:\n\t\tInput: nums = [1,3,6,10,12,15]\n\t\tOutput: 9\n\t\tExplanation: 6 and 12 are even numbers that are divisible by 3. (6 + 12) / 2 = 9.\n\t\tExample 2:\n\t\tInput: nums = [1,2,4,7,10]\n\t\tOutput: 0\n\t\tExplanation: There is no single number that satisfies the requirement, so return 0.\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 2543,
-        "question": "class Solution:\n    def mostPopularCreator(self, creators: List[str], ids: List[str], views: List[int]) -> List[List[str]]:\n\t\t\"\"\"\n\t\tYou are given two string arrays creators and ids, and an integer array views, all of length n. The ith video on a platform was created by creator[i], has an id of ids[i], and has views[i] views.\n\t\tThe popularity of a creator is the sum of the number of views on all of the creator's videos. Find the creator with the highest popularity and the id of their most viewed video.\n\t\t\tIf multiple creators have the highest popularity, find all of them.\n\t\t\tIf multiple videos have the highest view count for a creator, find the lexicographically smallest id.\n\t\tReturn a 2D array of strings answer where answer[i] = [creatori, idi] means that creatori has the highest popularity and idi is the id of their most popular video. The answer can be returned in any order.\n\t\tExample 1:\n\t\tInput: creators = [\"alice\",\"bob\",\"alice\",\"chris\"], ids = [\"one\",\"two\",\"three\",\"four\"], views = [5,10,5,4]\n\t\tOutput: [[\"alice\",\"one\"],[\"bob\",\"two\"]]\n\t\tExplanation:\n\t\tThe popularity of alice is 5 + 5 = 10.\n\t\tThe popularity of bob is 10.\n\t\tThe popularity of chris is 4.\n\t\talice and bob are the most popular creators.\n\t\tFor bob, the video with the highest view count is \"two\".\n\t\tFor alice, the videos with the highest view count are \"one\" and \"three\". Since \"one\" is lexicographically smaller than \"three\", it is included in the answer.\n\t\tExample 2:\n\t\tInput: creators = [\"alice\",\"alice\",\"alice\"], ids = [\"a\",\"b\",\"c\"], views = [1,2,2]\n\t\tOutput: [[\"alice\",\"b\"]]\n\t\tExplanation:\n\t\tThe videos with id \"b\" and \"c\" have the highest view count.\n\t\tSince \"b\" is lexicographically smaller than \"c\", it is included in the answer.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2544,
-        "question": "class Solution:\n    def makeIntegerBeautiful(self, n: int, target: int) -> int:\n\t\t\"\"\"\n\t\tYou are given two positive integers n and target.\n\t\tAn integer is considered beautiful if the sum of its digits is less than or equal to target.\n\t\tReturn the minimum non-negative integer x such that n + x is beautiful. The input will be generated such that it is always possible to make n beautiful.\n\t\tExample 1:\n\t\tInput: n = 16, target = 6\n\t\tOutput: 4\n\t\tExplanation: Initially n is 16 and its digit sum is 1 + 6 = 7. After adding 4, n becomes 20 and digit sum becomes 2 + 0 = 2. It can be shown that we can not make n beautiful with adding non-negative integer less than 4.\n\t\tExample 2:\n\t\tInput: n = 467, target = 6\n\t\tOutput: 33\n\t\tExplanation: Initially n is 467 and its digit sum is 4 + 6 + 7 = 17. After adding 33, n becomes 500 and digit sum becomes 5 + 0 + 0 = 5. It can be shown that we can not make n beautiful with adding non-negative integer less than 33.\n\t\tExample 3:\n\t\tInput: n = 1, target = 1\n\t\tOutput: 0\n\t\tExplanation: Initially n is 1 and its digit sum is 1, which is already smaller than or equal to target.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2545,
-        "question": "class Solution:\n    def treeQueries(self, root: Optional[TreeNode], queries: List[int]) -> List[int]:\n\t\t\"\"\"\n\t\tYou are given the root of a binary tree with n nodes. Each node is assigned a unique value from 1 to n. You are also given an array queries of size m.\n\t\tYou have to perform m independent queries on the tree where in the ith query you do the following:\n\t\t\tRemove the subtree rooted at the node with the value queries[i] from the tree. It is guaranteed that queries[i] will not be equal to the value of the root.\n\t\tReturn an array answer of size m where answer[i] is the height of the tree after performing the ith query.\n\t\tNote:\n\t\t\tThe queries are independent, so the tree returns to its initial state after each query.\n\t\t\tThe height of a tree is the number of edges in the longest simple path from the root to some node in the tree.\n\t\tExample 1:\n\t\tInput: root = [1,3,4,2,null,6,5,null,null,null,null,null,7], queries = [4]\n\t\tOutput: [2]\n\t\tExplanation: The diagram above shows the tree after removing the subtree rooted at node with value 4.\n\t\tThe height of the tree is 2 (The path 1 -> 3 -> 2).\n\t\tExample 2:\n\t\tInput: root = [5,8,9,2,1,3,7,4,6], queries = [3,2,4,8]\n\t\tOutput: [3,2,3,2]\n\t\tExplanation: We have the following queries:\n\t\t- Removing the subtree rooted at node with value 3. The height of the tree becomes 3 (The path 5 -> 8 -> 2 -> 4).\n\t\t- Removing the subtree rooted at node with value 2. The height of the tree becomes 2 (The path 5 -> 8 -> 1).\n\t\t- Removing the subtree rooted at node with value 4. The height of the tree becomes 3 (The path 5 -> 8 -> 2 -> 6).\n\t\t- Removing the subtree rooted at node with value 8. The height of the tree becomes 2 (The path 5 -> 9 -> 3).\n\t\t\"\"\"\n",
-        "difficulty": 2
-    },
-    {
-        "number": 2546,
-        "question": "class Solution:\n    def subarrayGCD(self, nums: List[int], k: int) -> int:\n\t\t\"\"\"\n\t\tGiven an integer array nums and an integer k, return the number of subarrays of nums where the greatest common divisor of the subarray's elements is k.\n\t\tA subarray is a contiguous non-empty sequence of elements within an array.\n\t\tThe greatest common divisor of an array is the largest integer that evenly divides all the array elements.\n\t\tExample 1:\n\t\tInput: nums = [9,3,1,2,6,3], k = 3\n\t\tOutput: 4\n\t\tExplanation: The subarrays of nums where 3 is the greatest common divisor of all the subarray's elements are:\n\t\t- [9,3,1,2,6,3]\n\t\t- [9,3,1,2,6,3]\n\t\t- [9,3,1,2,6,3]\n\t\t- [9,3,1,2,6,3]\n\t\tExample 2:\n\t\tInput: nums = [4], k = 7\n\t\tOutput: 0\n\t\tExplanation: There are no subarrays of nums where 7 is the greatest common divisor of all the subarray's elements.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2547,
-        "question": "class Solution:\n    def oddString(self, words: List[str]) -> str:\n\t\t\"\"\"\n\t\tYou are given an array of equal-length strings words. Assume that the length of each string is n.\n\t\tEach string words[i] can be converted into a difference integer array difference[i] of length n - 1 where difference[i][j] = words[i][j+1] - words[i][j] where 0 <= j <= n - 2. Note that the difference between two letters is the difference between their positions in the alphabet i.e. the position of 'a' is 0, 'b' is 1, and 'z' is 25.\n\t\t\tFor example, for the string \"acb\", the difference integer array is [2 - 0, 1 - 2] = [2, -1].\n\t\tAll the strings in words have the same difference integer array, except one. You should find that string.\n\t\tReturn the string in words that has different difference integer array.\n\t\tExample 1:\n\t\tInput: words = [\"adc\",\"wzy\",\"abc\"]\n\t\tOutput: \"abc\"\n\t\tExplanation: \n\t\t- The difference integer array of \"adc\" is [3 - 0, 2 - 3] = [3, -1].\n\t\t- The difference integer array of \"wzy\" is [25 - 22, 24 - 25]= [3, -1].\n\t\t- The difference integer array of \"abc\" is [1 - 0, 2 - 1] = [1, 1]. \n\t\tThe odd array out is [1, 1], so we return the corresponding string, \"abc\".\n\t\tExample 2:\n\t\tInput: words = [\"aaa\",\"bob\",\"ccc\",\"ddd\"]\n\t\tOutput: \"bob\"\n\t\tExplanation: All the integer arrays are [0, 0] except for \"bob\", which corresponds to [13, -13].\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 2548,
-        "question": "class Solution:\n    def destroyTargets(self, nums: List[int], space: int) -> int:\n\t\t\"\"\"\n\t\tYou are given a 0-indexed array nums consisting of positive integers, representing targets on a number line. You are also given an integer space.\n\t\tYou have a machine which can destroy targets. Seeding the machine with some nums[i] allows it to destroy all targets with values that can be represented as nums[i] + c * space, where c is any non-negative integer. You want to destroy the maximum number of targets in nums.\n\t\tReturn the minimum value of nums[i] you can seed the machine with to destroy the maximum number of targets.\n\t\tExample 1:\n\t\tInput: nums = [3,7,8,1,1,5], space = 2\n\t\tOutput: 1\n\t\tExplanation: If we seed the machine with nums[3], then we destroy all targets equal to 1,3,5,7,9,... \n\t\tIn this case, we would destroy 5 total targets (all except for nums[2]). \n\t\tIt is impossible to destroy more than 5 targets, so we return nums[3].\n\t\tExample 2:\n\t\tInput: nums = [1,3,5,2,4,6], space = 2\n\t\tOutput: 1\n\t\tExplanation: Seeding the machine with nums[0], or nums[3] destroys 3 targets. \n\t\tIt is not possible to destroy more than 3 targets.\n\t\tSince nums[0] is the minimal integer that can destroy 3 targets, we return 1.\n\t\tExample 3:\n\t\tInput: nums = [6,2,5], space = 100\n\t\tOutput: 2\n\t\tExplanation: Whatever initial seed we select, we can only destroy 1 target. The minimal seed is nums[1].\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2549,
-        "question": "class Solution:\n    def secondGreaterElement(self, nums: List[int]) -> List[int]:\n\t\t\"\"\"\n\t\tYou are given a 0-indexed array of non-negative integers nums. For each integer in nums, you must find its respective second greater integer.\n\t\tThe second greater integer of nums[i] is nums[j] such that:\n\t\t\tj > i\n\t\t\tnums[j] > nums[i]\n\t\t\tThere exists exactly one index k such that nums[k] > nums[i] and i < k < j.\n\t\tIf there is no such nums[j], the second greater integer is considered to be -1.\n\t\t\tFor example, in the array [1, 2, 4, 3], the second greater integer of 1 is 4, 2 is 3, and that of 3 and 4 is -1.\n\t\tReturn an integer array answer, where answer[i] is the second greater integer of nums[i].\n\t\tExample 1:\n\t\tInput: nums = [2,4,0,9,6]\n\t\tOutput: [9,6,6,-1,-1]\n\t\tExplanation:\n\t\t0th index: 4 is the first integer greater than 2, and 9 is the second integer greater than 2, to the right of 2.\n\t\t1st index: 9 is the first, and 6 is the second integer greater than 4, to the right of 4.\n\t\t2nd index: 9 is the first, and 6 is the second integer greater than 0, to the right of 0.\n\t\t3rd index: There is no integer greater than 9 to its right, so the second greater integer is considered to be -1.\n\t\t4th index: There is no integer greater than 6 to its right, so the second greater integer is considered to be -1.\n\t\tThus, we return [9,6,6,-1,-1].\n\t\tExample 2:\n\t\tInput: nums = [3,3]\n\t\tOutput: [-1,-1]\n\t\tExplanation:\n\t\tWe return [-1,-1] since neither integer has any integer greater than it.\n\t\t\"\"\"\n",
-        "difficulty": 2
-    },
-    {
-        "number": 2550,
-        "question": "class Solution:\n    def twoEditWords(self, queries: List[str], dictionary: List[str]) -> List[str]:\n\t\t\"\"\"\n\t\tYou are given two string arrays, queries and dictionary. All words in each array comprise of lowercase English letters and have the same length.\n\t\tIn one edit you can take a word from queries, and change any letter in it to any other letter. Find all words from queries that, after a maximum of two edits, equal some word from dictionary.\n\t\tReturn a list of all words from queries, that match with some word from dictionary after a maximum of two edits. Return the words in the same order they appear in queries.\n\t\tExample 1:\n\t\tInput: queries = [\"word\",\"note\",\"ants\",\"wood\"], dictionary = [\"wood\",\"joke\",\"moat\"]\n\t\tOutput: [\"word\",\"note\",\"wood\"]\n\t\tExplanation:\n\t\t- Changing the 'r' in \"word\" to 'o' allows it to equal the dictionary word \"wood\".\n\t\t- Changing the 'n' to 'j' and the 't' to 'k' in \"note\" changes it to \"joke\".\n\t\t- It would take more than 2 edits for \"ants\" to equal a dictionary word.\n\t\t- \"wood\" can remain unchanged (0 edits) and match the corresponding dictionary word.\n\t\tThus, we return [\"word\",\"note\",\"wood\"].\n\t\tExample 2:\n\t\tInput: queries = [\"yes\"], dictionary = [\"not\"]\n\t\tOutput: []\n\t\tExplanation:\n\t\tApplying any two edits to \"yes\" cannot make it equal to \"not\". Thus, we return an empty array.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2551,
-        "question": "class Solution:\n    def applyOperations(self, nums: List[int]) -> List[int]:\n\t\t\"\"\"\n\t\tYou are given a 0-indexed array nums of size n consisting of non-negative integers.\n\t\tYou need to apply n - 1 operations to this array where, in the ith operation (0-indexed), you will apply the following on the ith element of nums:\n\t\t\tIf nums[i] == nums[i + 1], then multiply nums[i] by 2 and set nums[i + 1] to 0. Otherwise, you skip this operation.\n\t\tAfter performing all the operations, shift all the 0's to the end of the array.\n\t\t\tFor example, the array [1,0,2,0,0,1] after shifting all its 0's to the end, is [1,2,1,0,0,0].\n\t\tReturn the resulting array.\n\t\tNote that the operations are applied sequentially, not all at once.\n\t\tExample 1:\n\t\tInput: nums = [1,2,2,1,1,0]\n\t\tOutput: [1,4,2,0,0,0]\n\t\tExplanation: We do the following operations:\n\t\t- i = 0: nums[0] and nums[1] are not equal, so we skip this operation.\n\t\t- i = 1: nums[1] and nums[2] are equal, we multiply nums[1] by 2 and change nums[2] to 0. The array becomes [1,4,0,1,1,0].\n\t\t- i = 2: nums[2] and nums[3] are not equal, so we skip this operation.\n\t\t- i = 3: nums[3] and nums[4] are equal, we multiply nums[3] by 2 and change nums[4] to 0. The array becomes [1,4,0,2,0,0].\n\t\t- i = 4: nums[4] and nums[5] are equal, we multiply nums[4] by 2 and change nums[5] to 0. The array becomes [1,4,0,2,0,0].\n\t\tAfter that, we shift the 0's to the end, which gives the array [1,4,2,0,0,0].\n\t\tExample 2:\n\t\tInput: nums = [0,1]\n\t\tOutput: [1,0]\n\t\tExplanation: No operation can be applied, we just shift the 0 to the end.\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 2552,
-        "question": "class Solution:\n    def maximumSubarraySum(self, nums: List[int], k: int) -> int:\n\t\t\"\"\"\n\t\tYou are given an integer array nums and an integer k. Find the maximum subarray sum of all the subarrays of nums that meet the following conditions:\n\t\t\tThe length of the subarray is k, and\n\t\t\tAll the elements of the subarray are distinct.\n\t\tReturn the maximum subarray sum of all the subarrays that meet the conditions. If no subarray meets the conditions, return 0.\n\t\tA subarray is a contiguous non-empty sequence of elements within an array.\n\t\tExample 1:\n\t\tInput: nums = [1,5,4,2,9,9,9], k = 3\n\t\tOutput: 15\n\t\tExplanation: The subarrays of nums with length 3 are:\n\t\t- [1,5,4] which meets the requirements and has a sum of 10.\n\t\t- [5,4,2] which meets the requirements and has a sum of 11.\n\t\t- [4,2,9] which meets the requirements and has a sum of 15.\n\t\t- [2,9,9] which does not meet the requirements because the element 9 is repeated.\n\t\t- [9,9,9] which does not meet the requirements because the element 9 is repeated.\n\t\tWe return 15 because it is the maximum subarray sum of all the subarrays that meet the conditions\n\t\tExample 2:\n\t\tInput: nums = [4,4,4], k = 3\n\t\tOutput: 0\n\t\tExplanation: The subarrays of nums with length 3 are:\n\t\t- [4,4,4] which does not meet the requirements because the element 4 is repeated.\n\t\tWe return 0 because no subarrays meet the conditions.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2553,
-        "question": "class Solution:\n    def totalCost(self, costs: List[int], k: int, candidates: int) -> int:\n\t\t\"\"\"\n\t\tYou are given a 0-indexed integer array costs where costs[i] is the cost of hiring the ith worker.\n\t\tYou are also given two integers k and candidates. We want to hire exactly k workers according to the following rules:\n\t\t\tYou will run k sessions and hire exactly one worker in each session.\n\t\t\tIn each hiring session, choose the worker with the lowest cost from either the first candidates workers or the last candidates workers. Break the tie by the smallest index.\n\t\t\t\tFor example, if costs = [3,2,7,7,1,2] and candidates = 2, then in the first hiring session, we will choose the 4th worker because they have the lowest cost [3,2,7,7,1,2].\n\t\t\t\tIn the second hiring session, we will choose 1st worker because they have the same lowest cost as 4th worker but they have the smallest index [3,2,7,7,2]. Please note that the indexing may be changed in the process.\n\t\t\tIf there are fewer than candidates workers remaining, choose the worker with the lowest cost among them. Break the tie by the smallest index.\n\t\t\tA worker can only be chosen once.\n\t\tReturn the total cost to hire exactly k workers.\n\t\tExample 1:\n\t\tInput: costs = [17,12,10,2,7,2,11,20,8], k = 3, candidates = 4\n\t\tOutput: 11\n\t\tExplanation: We hire 3 workers in total. The total cost is initially 0.\n\t\t- In the first hiring round we choose the worker from [17,12,10,2,7,2,11,20,8]. The lowest cost is 2, and we break the tie by the smallest index, which is 3. The total cost = 0 + 2 = 2.\n\t\t- In the second hiring round we choose the worker from [17,12,10,7,2,11,20,8]. The lowest cost is 2 (index 4). The total cost = 2 + 2 = 4.\n\t\t- In the third hiring round we choose the worker from [17,12,10,7,11,20,8]. The lowest cost is 7 (index 3). The total cost = 4 + 7 = 11. Notice that the worker with index 3 was common in the first and last four workers.\n\t\tThe total hiring cost is 11.\n\t\tExample 2:\n\t\tInput: costs = [1,2,4,1], k = 3, candidates = 3\n\t\tOutput: 4\n\t\tExplanation: We hire 3 workers in total. The total cost is initially 0.\n\t\t- In the first hiring round we choose the worker from [1,2,4,1]. The lowest cost is 1, and we break the tie by the smallest index, which is 0. The total cost = 0 + 1 = 1. Notice that workers with index 1 and 2 are common in the first and last 3 workers.\n\t\t- In the second hiring round we choose the worker from [2,4,1]. The lowest cost is 1 (index 2). The total cost = 1 + 1 = 2.\n\t\t- In the third hiring round there are less than three candidates. We choose the worker from the remaining workers [2,4]. The lowest cost is 2 (index 0). The total cost = 2 + 2 = 4.\n\t\tThe total hiring cost is 4.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2554,
-        "question": "class Solution:\n    def minimumTotalDistance(self, robot: List[int], factory: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tThere are some robots and factories on the X-axis. You are given an integer array robot where robot[i] is the position of the ith robot. You are also given a 2D integer array factory where factory[j] = [positionj, limitj] indicates that positionj is the position of the jth factory and that the jth factory can repair at most limitj robots.\n\t\tThe positions of each robot are unique. The positions of each factory are also unique. Note that a robot can be in the same position as a factory initially.\n\t\tAll the robots are initially broken; they keep moving in one direction. The direction could be the negative or the positive direction of the X-axis. When a robot reaches a factory that did not reach its limit, the factory repairs the robot, and it stops moving.\n\t\tAt any moment, you can set the initial direction of moving for some robot. Your target is to minimize the total distance traveled by all the robots.\n\t\tReturn the minimum total distance traveled by all the robots. The test cases are generated such that all the robots can be repaired.\n\t\tNote that\n\t\t\tAll robots move at the same speed.\n\t\t\tIf two robots move in the same direction, they will never collide.\n\t\t\tIf two robots move in opposite directions and they meet at some point, they do not collide. They cross each other.\n\t\t\tIf a robot passes by a factory that reached its limits, it crosses it as if it does not exist.\n\t\t\tIf the robot moved from a position x to a position y, the distance it moved is |y - x|.\n\t\tExample 1:\n\t\tInput: robot = [0,4,6], factory = [[2,2],[6,2]]\n\t\tOutput: 4\n\t\tExplanation: As shown in the figure:\n\t\t- The first robot at position 0 moves in the positive direction. It will be repaired at the first factory.\n\t\t- The second robot at position 4 moves in the negative direction. It will be repaired at the first factory.\n\t\t- The third robot at position 6 will be repaired at the second factory. It does not need to move.\n\t\tThe limit of the first factory is 2, and it fixed 2 robots.\n\t\tThe limit of the second factory is 2, and it fixed 1 robot.\n\t\tThe total distance is |2 - 0| + |2 - 4| + |6 - 6| = 4. It can be shown that we cannot achieve a better total distance than 4.\n\t\tExample 2:\n\t\tInput: robot = [1,-1], factory = [[-2,1],[2,1]]\n\t\tOutput: 2\n\t\tExplanation: As shown in the figure:\n\t\t- The first robot at position 1 moves in the positive direction. It will be repaired at the second factory.\n\t\t- The second robot at position -1 moves in the negative direction. It will be repaired at the first factory.\n\t\tThe limit of the first factory is 1, and it fixed 1 robot.\n\t\tThe limit of the second factory is 1, and it fixed 1 robot.\n\t\tThe total distance is |2 - 1| + |(-2) - (-1)| = 2. It can be shown that we cannot achieve a better total distance than 2.\n\t\t\"\"\"\n",
-        "difficulty": 2
-    },
-    {
-        "number": 2556,
-        "question": "class Solution:\n    def convertTemperature(self, celsius: float) -> List[float]:\n\t\t\"\"\"\n\t\tYou are given a non-negative floating point number rounded to two decimal places celsius, that denotes the temperature in Celsius.\n\t\tYou should convert Celsius into Kelvin and Fahrenheit and return it as an array ans = [kelvin, fahrenheit].\n\t\tReturn the array ans. Answers within 10-5 of the actual answer will be accepted.\n\t\tNote that:\n\t\t\tKelvin = Celsius + 273.15\n\t\t\tFahrenheit = Celsius * 1.80 + 32.00\n\t\tExample 1:\n\t\tInput: celsius = 36.50\n\t\tOutput: [309.65000,97.70000]\n\t\tExplanation: Temperature at 36.50 Celsius converted in Kelvin is 309.65 and converted in Fahrenheit is 97.70.\n\t\tExample 2:\n\t\tInput: celsius = 122.11\n\t\tOutput: [395.26000,251.79800]\n\t\tExplanation: Temperature at 122.11 Celsius converted in Kelvin is 395.26 and converted in Fahrenheit is 251.798.\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 2557,
-        "question": "class Solution:\n    def subarrayLCM(self, nums: List[int], k: int) -> int:\n\t\t\"\"\"\n\t\tGiven an integer array nums and an integer k, return the number of subarrays of nums where the least common multiple of the subarray's elements is k.\n\t\tA subarray is a contiguous non-empty sequence of elements within an array.\n\t\tThe least common multiple of an array is the smallest positive integer that is divisible by all the array elements.\n\t\tExample 1:\n\t\tInput: nums = [3,6,2,7,1], k = 6\n\t\tOutput: 4\n\t\tExplanation: The subarrays of nums where 6 is the least common multiple of all the subarray's elements are:\n\t\t- [3,6,2,7,1]\n\t\t- [3,6,2,7,1]\n\t\t- [3,6,2,7,1]\n\t\t- [3,6,2,7,1]\n\t\tExample 2:\n\t\tInput: nums = [3], k = 2\n\t\tOutput: 0\n\t\tExplanation: There are no subarrays of nums where 2 is the least common multiple of all the subarray's elements.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2558,
-        "question": "class Solution:\n    def minimumOperations(self, root: Optional[TreeNode]) -> int:\n\t\t\"\"\"\n\t\tYou are given the root of a binary tree with unique values.\n\t\tIn one operation, you can choose any two nodes at the same level and swap their values.\n\t\tReturn the minimum number of operations needed to make the values at each level sorted in a strictly increasing order.\n\t\tThe level of a node is the number of edges along the path between it and the root node.\n\t\tExample 1:\n\t\tInput: root = [1,4,3,7,6,8,5,null,null,null,null,9,null,10]\n\t\tOutput: 3\n\t\tExplanation:\n\t\t- Swap 4 and 3. The 2nd level becomes [3,4].\n\t\t- Swap 7 and 5. The 3rd level becomes [5,6,8,7].\n\t\t- Swap 8 and 7. The 3rd level becomes [5,6,7,8].\n\t\tWe used 3 operations so return 3.\n\t\tIt can be proven that 3 is the minimum number of operations needed.\n\t\tExample 2:\n\t\tInput: root = [1,3,2,7,6,5,4]\n\t\tOutput: 3\n\t\tExplanation:\n\t\t- Swap 3 and 2. The 2nd level becomes [2,3].\n\t\t- Swap 7 and 4. The 3rd level becomes [4,6,5,7].\n\t\t- Swap 6 and 5. The 3rd level becomes [4,5,6,7].\n\t\tWe used 3 operations so return 3.\n\t\tIt can be proven that 3 is the minimum number of operations needed.\n\t\tExample 3:\n\t\tInput: root = [1,2,3,4,5,6]\n\t\tOutput: 0\n\t\tExplanation: Each level is already sorted in increasing order so return 0.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2559,
-        "question": "class Solution:\n    def maxPalindromes(self, s: str, k: int) -> int:\n\t\t\"\"\"\n\t\tYou are given a string s and a positive integer k.\n\t\tSelect a set of non-overlapping substrings from the string s that satisfy the following conditions:\n\t\t\tThe length of each substring is at least k.\n\t\t\tEach substring is a palindrome.\n\t\tReturn the maximum number of substrings in an optimal selection.\n\t\tA substring is a contiguous sequence of characters within a string.\n\t\tExample 1:\n\t\tInput: s = \"abaccdbbd\", k = 3\n\t\tOutput: 2\n\t\tExplanation: We can select the substrings underlined in s = \"abaccdbbd\". Both \"aba\" and \"dbbd\" are palindromes and have a length of at least k = 3.\n\t\tIt can be shown that we cannot find a selection with more than two valid substrings.\n\t\tExample 2:\n\t\tInput: s = \"adbcda\", k = 2\n\t\tOutput: 0\n\t\tExplanation: There is no palindrome substring of length at least 2 in the string.\n\t\t\"\"\"\n",
-        "difficulty": 2
-    },
-    {
-        "number": 2561,
-        "question": "class Solution:\n    def distinctAverages(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou are given a 0-indexed integer array nums of even length.\n\t\tAs long as nums is not empty, you must repetitively:\n\t\t\tFind the minimum number in nums and remove it.\n\t\t\tFind the maximum number in nums and remove it.\n\t\t\tCalculate the average of the two removed numbers.\n\t\tThe average of two numbers a and b is (a + b) / 2.\n\t\t\tFor example, the average of 2 and 3 is (2 + 3) / 2 = 2.5.\n\t\tReturn the number of distinct averages calculated using the above process.\n\t\tNote that when there is a tie for a minimum or maximum number, any can be removed.\n\t\tExample 1:\n\t\tInput: nums = [4,1,4,0,3,5]\n\t\tOutput: 2\n\t\tExplanation:\n\t\t1. Remove 0 and 5, and the average is (0 + 5) / 2 = 2.5. Now, nums = [4,1,4,3].\n\t\t2. Remove 1 and 4. The average is (1 + 4) / 2 = 2.5, and nums = [4,3].\n\t\t3. Remove 3 and 4, and the average is (3 + 4) / 2 = 3.5.\n\t\tSince there are 2 distinct numbers among 2.5, 2.5, and 3.5, we return 2.\n\t\tExample 2:\n\t\tInput: nums = [1,100]\n\t\tOutput: 1\n\t\tExplanation:\n\t\tThere is only one average to be calculated after removing 1 and 100, so we return 1.\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 2562,
-        "question": "class Solution:\n    def countGoodStrings(self, low: int, high: int, zero: int, one: int) -> int:\n\t\t\"\"\"\n\t\tGiven the integers zero, one, low, and high, we can construct a string by starting with an empty string, and then at each step perform either of the following:\n\t\t\tAppend the character '0' zero times.\n\t\t\tAppend the character '1' one times.\n\t\tThis can be performed any number of times.\n\t\tA good string is a string constructed by the above process having a length between low and high (inclusive).\n\t\tReturn the number of different good strings that can be constructed satisfying these properties. Since the answer can be large, return it modulo 109 + 7.\n\t\tExample 1:\n\t\tInput: low = 3, high = 3, zero = 1, one = 1\n\t\tOutput: 8\n\t\tExplanation: \n\t\tOne possible valid good string is \"011\". \n\t\tIt can be constructed as follows: \"\" -> \"0\" -> \"01\" -> \"011\". \n\t\tAll binary strings from \"000\" to \"111\" are good strings in this example.\n\t\tExample 2:\n\t\tInput: low = 2, high = 3, zero = 1, one = 2\n\t\tOutput: 5\n\t\tExplanation: The good strings are \"00\", \"11\", \"000\", \"110\", and \"011\".\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2563,
-        "question": "class Solution:\n    def splitMessage(self, message: str, limit: int) -> List[str]:\n\t\t\"\"\"\n\t\tYou are given a string, message, and a positive integer, limit.\n\t\tYou must split message into one or more parts based on limit. Each resulting part should have the suffix \"\", where \"b\" is to be replaced with the total number of parts and \"a\" is to be replaced with the index of the part, starting from 1 and going up to b. Additionally, the length of each resulting part (including its suffix) should be equal to limit, except for the last part whose length can be at most limit.\n\t\tThe resulting parts should be formed such that when their suffixes are removed and they are all concatenated in order, they should be equal to message. Also, the result should contain as few parts as possible.\n\t\tReturn the parts message would be split into as an array of strings. If it is impossible to split message as required, return an empty array.\n\t\tExample 1:\n\t\tInput: message = \"this is really a very awesome message\", limit = 9\n\t\tOutput: [\"thi<1/14>\",\"s i<2/14>\",\"s r<3/14>\",\"eal<4/14>\",\"ly <5/14>\",\"a v<6/14>\",\"ery<7/14>\",\" aw<8/14>\",\"eso<9/14>\",\"me<10/14>\",\" m<11/14>\",\"es<12/14>\",\"sa<13/14>\",\"ge<14/14>\"]\n\t\tExplanation:\n\t\tThe first 9 parts take 3 characters each from the beginning of message.\n\t\tThe next 5 parts take 2 characters each to finish splitting message. \n\t\tIn this example, each part, including the last, has length 9. \n\t\tIt can be shown it is not possible to split message into less than 14 parts.\n\t\tExample 2:\n\t\tInput: message = \"short message\", limit = 15\n\t\tOutput: [\"short mess<1/2>\",\"age<2/2>\"]\n\t\tExplanation:\n\t\tUnder the given constraints, the string can be split into two parts: \n\t\t- The first part comprises of the first 10 characters, and has a length 15.\n\t\t- The next part comprises of the last 3 characters, and has a length 8.\n\t\t\"\"\"\n",
-        "difficulty": 2
-    },
-    {
-        "number": 2564,
-        "question": "class Solution:\n    def mostProfitablePath(self, edges: List[List[int]], bob: int, amount: List[int]) -> int:\n\t\t\"\"\"\n\t\tThere is an undirected tree with n nodes labeled from 0 to n - 1, rooted at node 0. You are given a 2D integer array edges of length n - 1 where edges[i] = [ai, bi] indicates that there is an edge between nodes ai and bi in the tree.\n\t\tAt every node i, there is a gate. You are also given an array of even integers amount, where amount[i] represents:\n\t\t\tthe price needed to open the gate at node i, if amount[i] is negative, or,\n\t\t\tthe cash reward obtained on opening the gate at node i, otherwise.\n\t\tThe game goes on as follows:\n\t\t\tInitially, Alice is at node 0 and Bob is at node bob.\n\t\t\tAt every second, Alice and Bob each move to an adjacent node. Alice moves towards some leaf node, while Bob moves towards node 0.\n\t\t\tFor every node along their path, Alice and Bob either spend money to open the gate at that node, or accept the reward. Note that:\n\t\t\t\tIf the gate is already open, no price will be required, nor will there be any cash reward.\n\t\t\t\tIf Alice and Bob reach the node simultaneously, they share the price/reward for opening the gate there. In other words, if the price to open the gate is c, then both Alice and Bob pay c / 2 each. Similarly, if the reward at the gate is c, both of them receive c / 2 each.\n\t\t\tIf Alice reaches a leaf node, she stops moving. Similarly, if Bob reaches node 0, he stops moving. Note that these events are independent of each other.\n\t\tReturn the maximum net income Alice can have if she travels towards the optimal leaf node.\n\t\tExample 1:\n\t\tInput: edges = [[0,1],[1,2],[1,3],[3,4]], bob = 3, amount = [-2,4,2,-4,6]\n\t\tOutput: 6\n\t\tExplanation: \n\t\tThe above diagram represents the given tree. The game goes as follows:\n\t\t- Alice is initially on node 0, Bob on node 3. They open the gates of their respective nodes.\n\t\t  Alice's net income is now -2.\n\t\t- Both Alice and Bob move to node 1. \n\t\t  Since they reach here simultaneously, they open the gate together and share the reward.\n\t\t  Alice's net income becomes -2 + (4 / 2) = 0.\n\t\t- Alice moves on to node 3. Since Bob already opened its gate, Alice's income remains unchanged.\n\t\t  Bob moves on to node 0, and stops moving.\n\t\t- Alice moves on to node 4 and opens the gate there. Her net income becomes 0 + 6 = 6.\n\t\tNow, neither Alice nor Bob can make any further moves, and the game ends.\n\t\tIt is not possible for Alice to get a higher net income.\n\t\tExample 2:\n\t\tInput: edges = [[0,1]], bob = 1, amount = [-7280,2350]\n\t\tOutput: -7280\n\t\tExplanation: \n\t\tAlice follows the path 0->1 whereas Bob follows the path 1->0.\n\t\tThus, Alice opens the gate at node 0 only. Hence, her net income is -7280. \n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2566,
-        "question": "class Solution:\n    def unequalTriplets(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou are given a 0-indexed array of positive integers nums. Find the number of triplets (i, j, k) that meet the following conditions:\n\t\t\t0 <= i < j < k < nums.length\n\t\t\tnums[i], nums[j], and nums[k] are pairwise distinct.\n\t\t\t\tIn other words, nums[i] != nums[j], nums[i] != nums[k], and nums[j] != nums[k].\n\t\tReturn the number of triplets that meet the conditions.\n\t\tExample 1:\n\t\tInput: nums = [4,4,2,4,3]\n\t\tOutput: 3\n\t\tExplanation: The following triplets meet the conditions:\n\t\t- (0, 2, 4) because 4 != 2 != 3\n\t\t- (1, 2, 4) because 4 != 2 != 3\n\t\t- (2, 3, 4) because 2 != 4 != 3\n\t\tSince there are 3 triplets, we return 3.\n\t\tNote that (2, 0, 4) is not a valid triplet because 2 > 0.\n\t\tExample 2:\n\t\tInput: nums = [1,1,1,1,1]\n\t\tOutput: 0\n\t\tExplanation: No triplets meet the conditions so we return 0.\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 2567,
-        "question": "class Solution:\n    def closestNodes(self, root: Optional[TreeNode], queries: List[int]) -> List[List[int]]:\n\t\t\"\"\"\n\t\tYou are given the root of a binary search tree and an array queries of size n consisting of positive integers.\n\t\tFind a 2D array answer of size n where answer[i] = [mini, maxi]:\n\t\t\tmini is the largest value in the tree that is smaller than or equal to queries[i]. If a such value does not exist, add -1 instead.\n\t\t\tmaxi is the smallest value in the tree that is greater than or equal to queries[i]. If a such value does not exist, add -1 instead.\n\t\tReturn the array answer.\n\t\tExample 1:\n\t\tInput: root = [6,2,13,1,4,9,15,null,null,null,null,null,null,14], queries = [2,5,16]\n\t\tOutput: [[2,2],[4,6],[15,-1]]\n\t\tExplanation: We answer the queries in the following way:\n\t\t- The largest number that is smaller or equal than 2 in the tree is 2, and the smallest number that is greater or equal than 2 is still 2. So the answer for the first query is [2,2].\n\t\t- The largest number that is smaller or equal than 5 in the tree is 4, and the smallest number that is greater or equal than 5 is 6. So the answer for the second query is [4,6].\n\t\t- The largest number that is smaller or equal than 16 in the tree is 15, and the smallest number that is greater or equal than 16 does not exist. So the answer for the third query is [15,-1].\n\t\tExample 2:\n\t\tInput: root = [4,null,9], queries = [3]\n\t\tOutput: [[-1,4]]\n\t\tExplanation: The largest number that is smaller or equal to 3 in the tree does not exist, and the smallest number that is greater or equal to 3 is 4. So the answer for the query is [-1,4].\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2568,
-        "question": "class Solution:\n    def minimumFuelCost(self, roads: List[List[int]], seats: int) -> int:\n\t\t\"\"\"\n\t\tThere is a tree (i.e., a connected, undirected graph with no cycles) structure country network consisting of n cities numbered from 0 to n - 1 and exactly n - 1 roads. The capital city is city 0. You are given a 2D integer array roads where roads[i] = [ai, bi] denotes that there exists a bidirectional road connecting cities ai and bi.\n\t\tThere is a meeting for the representatives of each city. The meeting is in the capital city.\n\t\tThere is a car in each city. You are given an integer seats that indicates the number of seats in each car.\n\t\tA representative can use the car in their city to travel or change the car and ride with another representative. The cost of traveling between two cities is one liter of fuel.\n\t\tReturn the minimum number of liters of fuel to reach the capital city.\n\t\tExample 1:\n\t\tInput: roads = [[0,1],[0,2],[0,3]], seats = 5\n\t\tOutput: 3\n\t\tExplanation: \n\t\t- Representative1 goes directly to the capital with 1 liter of fuel.\n\t\t- Representative2 goes directly to the capital with 1 liter of fuel.\n\t\t- Representative3 goes directly to the capital with 1 liter of fuel.\n\t\tIt costs 3 liters of fuel at minimum. \n\t\tIt can be proven that 3 is the minimum number of liters of fuel needed.\n\t\tExample 2:\n\t\tInput: roads = [[3,1],[3,2],[1,0],[0,4],[0,5],[4,6]], seats = 2\n\t\tOutput: 7\n\t\tExplanation: \n\t\t- Representative2 goes directly to city 3 with 1 liter of fuel.\n\t\t- Representative2 and representative3 go together to city 1 with 1 liter of fuel.\n\t\t- Representative2 and representative3 go together to the capital with 1 liter of fuel.\n\t\t- Representative1 goes directly to the capital with 1 liter of fuel.\n\t\t- Representative5 goes directly to the capital with 1 liter of fuel.\n\t\t- Representative6 goes directly to city 4 with 1 liter of fuel.\n\t\t- Representative4 and representative6 go together to the capital with 1 liter of fuel.\n\t\tIt costs 7 liters of fuel at minimum. \n\t\tIt can be proven that 7 is the minimum number of liters of fuel needed.\n\t\tExample 3:\n\t\tInput: roads = [], seats = 1\n\t\tOutput: 0\n\t\tExplanation: No representatives need to travel to the capital city.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2569,
-        "question": "class Solution:\n    def beautifulPartitions(self, s: str, k: int, minLength: int) -> int:\n\t\t\"\"\"\n\t\tYou are given a string s that consists of the digits '1' to '9' and two integers k and minLength.\n\t\tA partition of s is called beautiful if:\n\t\t\ts is partitioned into k non-intersecting substrings.\n\t\t\tEach substring has a length of at least minLength.\n\t\t\tEach substring starts with a prime digit and ends with a non-prime digit. Prime digits are '2', '3', '5', and '7', and the rest of the digits are non-prime.\n\t\tReturn the number of beautiful partitions of s. Since the answer may be very large, return it modulo 109 + 7.\n\t\tA substring is a contiguous sequence of characters within a string.\n\t\tExample 1:\n\t\tInput: s = \"23542185131\", k = 3, minLength = 2\n\t\tOutput: 3\n\t\tExplanation: There exists three ways to create a beautiful partition:\n\t\t\"2354 | 218 | 5131\"\n\t\t\"2354 | 21851 | 31\"\n\t\t\"2354218 | 51 | 31\"\n\t\tExample 2:\n\t\tInput: s = \"23542185131\", k = 3, minLength = 3\n\t\tOutput: 1\n\t\tExplanation: There exists one way to create a beautiful partition: \"2354 | 218 | 5131\".\n\t\tExample 3:\n\t\tInput: s = \"3312958\", k = 3, minLength = 1\n\t\tOutput: 1\n\t\tExplanation: There exists one way to create a beautiful partition: \"331 | 29 | 58\".\n\t\t\"\"\"\n",
-        "difficulty": 2
-    },
-    {
-        "number": 2571,
-        "question": "class Solution:\n    def pivotInteger(self, n: int) -> int:\n\t\t\"\"\"\n\t\tGiven a positive integer n, find the pivot integer x such that:\n\t\t\tThe sum of all elements between 1 and x inclusively equals the sum of all elements between x and n inclusively.\n\t\tReturn the pivot integer x. If no such integer exists, return -1. It is guaranteed that there will be at most one pivot index for the given input.\n\t\tExample 1:\n\t\tInput: n = 8\n\t\tOutput: 6\n\t\tExplanation: 6 is the pivot integer since: 1 + 2 + 3 + 4 + 5 + 6 = 6 + 7 + 8 = 21.\n\t\tExample 2:\n\t\tInput: n = 1\n\t\tOutput: 1\n\t\tExplanation: 1 is the pivot integer since: 1 = 1.\n\t\tExample 3:\n\t\tInput: n = 4\n\t\tOutput: -1\n\t\tExplanation: It can be proved that no such integer exist.\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 2572,
-        "question": "class Solution:\n    def appendCharacters(self, s: str, t: str) -> int:\n\t\t\"\"\"\n\t\tYou are given two strings s and t consisting of only lowercase English letters.\n\t\tReturn the minimum number of characters that need to be appended to the end of s so that t becomes a subsequence of s.\n\t\tA subsequence is a string that can be derived from another string by deleting some or no characters without changing the order of the remaining characters.\n\t\tExample 1:\n\t\tInput: s = \"coaching\", t = \"coding\"\n\t\tOutput: 4\n\t\tExplanation: Append the characters \"ding\" to the end of s so that s = \"coachingding\".\n\t\tNow, t is a subsequence of s (\"coachingding\").\n\t\tIt can be shown that appending any 3 characters to the end of s will never make t a subsequence.\n\t\tExample 2:\n\t\tInput: s = \"abcde\", t = \"a\"\n\t\tOutput: 0\n\t\tExplanation: t is already a subsequence of s (\"abcde\").\n\t\tExample 3:\n\t\tInput: s = \"z\", t = \"abcde\"\n\t\tOutput: 5\n\t\tExplanation: Append the characters \"abcde\" to the end of s so that s = \"zabcde\".\n\t\tNow, t is a subsequence of s (\"zabcde\").\n\t\tIt can be shown that appending any 4 characters to the end of s will never make t a subsequence.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2573,
-        "question": "class Solution:\n    def removeNodes(self, head: Optional[ListNode]) -> Optional[ListNode]:\n\t\t\"\"\"\n\t\tYou are given the head of a linked list.\n\t\tRemove every node which has a node with a strictly greater value anywhere to the right side of it.\n\t\tReturn the head of the modified linked list.\n\t\tExample 1:\n\t\tInput: head = [5,2,13,3,8]\n\t\tOutput: [13,8]\n\t\tExplanation: The nodes that should be removed are 5, 2 and 3.\n\t\t- Node 13 is to the right of node 5.\n\t\t- Node 13 is to the right of node 2.\n\t\t- Node 8 is to the right of node 3.\n\t\tExample 2:\n\t\tInput: head = [1,1,1,1]\n\t\tOutput: [1,1,1,1]\n\t\tExplanation: Every node has value 1, so no nodes are removed.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2574,
-        "question": "class Solution:\n    def countSubarrays(self, nums: List[int], k: int) -> int:\n\t\t\"\"\"\n\t\tYou are given an array nums of size n consisting of distinct integers from 1 to n and a positive integer k.\n\t\tReturn the number of non-empty subarrays in nums that have a median equal to k.\n\t\tNote:\n\t\t\tThe median of an array is the middle element after sorting the array in ascending order. If the array is of even length, the median is the left middle element.\n\t\t\t\tFor example, the median of [2,3,1,4] is 2, and the median of [8,4,3,5,1] is 4.\n\t\t\tA subarray is a contiguous part of an array.\n\t\tExample 1:\n\t\tInput: nums = [3,2,1,4,5], k = 4\n\t\tOutput: 3\n\t\tExplanation: The subarrays that have a median equal to 4 are: [4], [4,5] and [1,4,5].\n\t\tExample 2:\n\t\tInput: nums = [2,3,1], k = 3\n\t\tOutput: 1\n\t\tExplanation: [3] is the only subarray that has a median equal to 3.\n\t\t\"\"\"\n",
-        "difficulty": 2
-    },
-    {
-        "number": 2575,
-        "question": "class Solution:\n    def numberOfCuts(self, n: int) -> int:\n\t\t\"\"\"\n\t\tA valid cut in a circle can be:\n\t\t\tA cut that is represented by a straight line that touches two points on the edge of the circle and passes through its center, or\n\t\t\tA cut that is represented by a straight line that touches one point on the edge of the circle and its center.\n\t\tSome valid and invalid cuts are shown in the figures below.\n\t\tGiven the integer n, return the minimum number of cuts needed to divide a circle into n equal slices.\n\t\tExample 1:\n\t\tInput: n = 4\n\t\tOutput: 2\n\t\tExplanation: \n\t\tThe above figure shows how cutting the circle twice through the middle divides it into 4 equal slices.\n\t\tExample 2:\n\t\tInput: n = 3\n\t\tOutput: 3\n\t\tExplanation:\n\t\tAt least 3 cuts are needed to divide the circle into 3 equal slices. \n\t\tIt can be shown that less than 3 cuts cannot result in 3 slices of equal size and shape.\n\t\tAlso note that the first cut will not divide the circle into distinct parts.\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 2576,
-        "question": "class Solution:\n    def bestClosingTime(self, customers: str) -> int:\n\t\t\"\"\"\n\t\tYou are given the customer visit log of a shop represented by a 0-indexed string customers consisting only of characters 'N' and 'Y':\n\t\t\tif the ith character is 'Y', it means that customers come at the ith hour\n\t\t\twhereas 'N' indicates that no customers come at the ith hour.\n\t\tIf the shop closes at the jth hour (0 <= j <= n), the penalty is calculated as follows:\n\t\t\tFor every hour when the shop is open and no customers come, the penalty increases by 1.\n\t\t\tFor every hour when the shop is closed and customers come, the penalty increases by 1.\n\t\tReturn the earliest hour at which the shop must be closed to incur a minimum penalty.\n\t\tNote that if a shop closes at the jth hour, it means the shop is closed at the hour j.\n\t\tExample 1:\n\t\tInput: customers = \"YYNY\"\n\t\tOutput: 2\n\t\tExplanation: \n\t\t- Closing the shop at the 0th hour incurs in 1+1+0+1 = 3 penalty.\n\t\t- Closing the shop at the 1st hour incurs in 0+1+0+1 = 2 penalty.\n\t\t- Closing the shop at the 2nd hour incurs in 0+0+0+1 = 1 penalty.\n\t\t- Closing the shop at the 3rd hour incurs in 0+0+1+1 = 2 penalty.\n\t\t- Closing the shop at the 4th hour incurs in 0+0+1+0 = 1 penalty.\n\t\tClosing the shop at 2nd or 4th hour gives a minimum penalty. Since 2 is earlier, the optimal closing time is 2.\n\t\tExample 2:\n\t\tInput: customers = \"NNNNN\"\n\t\tOutput: 0\n\t\tExplanation: It is best to close the shop at the 0th hour as no customers arrive.\n\t\tExample 3:\n\t\tInput: customers = \"YYYY\"\n\t\tOutput: 4\n\t\tExplanation: It is best to close the shop at the 4th hour as customers arrive at each hour.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2577,
-        "question": "class Solution:\n    def countPalindromes(self, s: str) -> int:\n\t\t\"\"\"\n\t\tGiven a string of digits s, return the number of palindromic subsequences of s having length 5. Since the answer may be very large, return it modulo 109 + 7.\n\t\tNote:\n\t\t\tA string is palindromic if it reads the same forward and backward.\n\t\t\tA subsequence is a string that can be derived from another string by deleting some or no characters without changing the order of the remaining characters.\n\t\tExample 1:\n\t\tInput: s = \"103301\"\n\t\tOutput: 2\n\t\tExplanation: \n\t\tThere are 6 possible subsequences of length 5: \"10330\",\"10331\",\"10301\",\"10301\",\"13301\",\"03301\". \n\t\tTwo of them (both equal to \"10301\") are palindromic.\n\t\tExample 2:\n\t\tInput: s = \"0000000\"\n\t\tOutput: 21\n\t\tExplanation: All 21 subsequences are \"00000\", which is palindromic.\n\t\tExample 3:\n\t\tInput: s = \"9999900000\"\n\t\tOutput: 2\n\t\tExplanation: The only two palindromic subsequences are \"99999\" and \"00000\".\n\t\t\"\"\"\n",
-        "difficulty": 2
-    },
-    {
-        "number": 2580,
-        "question": "class Solution:\n    def isCircularSentence(self, sentence: str) -> bool:\n\t\t\"\"\"\n\t\tA sentence is a list of words that are separated by a single space with no leading or trailing spaces.\n\t\t\tFor example, \"Hello World\", \"HELLO\", \"hello world hello world\" are all sentences.\n\t\tWords consist of only uppercase and lowercase English letters. Uppercase and lowercase English letters are considered different.\n\t\tA sentence is circular if:\n\t\t\tThe last character of a word is equal to the first character of the next word.\n\t\t\tThe last character of the last word is equal to the first character of the first word.\n\t\tFor example, \"leetcode exercises sound delightful\", \"eetcode\", \"leetcode eats soul\" are all circular sentences. However, \"Leetcode is cool\", \"happy Leetcode\", \"Leetcode\" and \"I like Leetcode\" are not circular sentences.\n\t\tGiven a string sentence, return true if it is circular. Otherwise, return false.\n\t\tExample 1:\n\t\tInput: sentence = \"leetcode exercises sound delightful\"\n\t\tOutput: true\n\t\tExplanation: The words in sentence are [\"leetcode\", \"exercises\", \"sound\", \"delightful\"].\n\t\t- leetcode's last character is equal to exercises's first character.\n\t\t- exercises's last character is equal to sound's first character.\n\t\t- sound's last character is equal to delightful's first character.\n\t\t- delightful's last character is equal to leetcode's first character.\n\t\tThe sentence is circular.\n\t\tExample 2:\n\t\tInput: sentence = \"eetcode\"\n\t\tOutput: true\n\t\tExplanation: The words in sentence are [\"eetcode\"].\n\t\t- eetcode's last character is equal to eetcode's first character.\n\t\tThe sentence is circular.\n\t\tExample 3:\n\t\tInput: sentence = \"Leetcode is cool\"\n\t\tOutput: false\n\t\tExplanation: The words in sentence are [\"Leetcode\", \"is\", \"cool\"].\n\t\t- Leetcode's last character is not equal to is's first character.\n\t\tThe sentence is not circular.\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 2581,
-        "question": "class Solution:\n    def dividePlayers(self, skill: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou are given a positive integer array skill of even length n where skill[i] denotes the skill of the ith player. Divide the players into n / 2 teams of size 2 such that the total skill of each team is equal.\n\t\tThe chemistry of a team is equal to the product of the skills of the players on that team.\n\t\tReturn the sum of the chemistry of all the teams, or return -1 if there is no way to divide the players into teams such that the total skill of each team is equal.\n\t\tExample 1:\n\t\tInput: skill = [3,2,5,1,3,4]\n\t\tOutput: 22\n\t\tExplanation: \n\t\tDivide the players into the following teams: (1, 5), (2, 4), (3, 3), where each team has a total skill of 6.\n\t\tThe sum of the chemistry of all the teams is: 1 * 5 + 2 * 4 + 3 * 3 = 5 + 8 + 9 = 22.\n\t\tExample 2:\n\t\tInput: skill = [3,4]\n\t\tOutput: 12\n\t\tExplanation: \n\t\tThe two players form a team with a total skill of 7.\n\t\tThe chemistry of the team is 3 * 4 = 12.\n\t\tExample 3:\n\t\tInput: skill = [1,1,2,3]\n\t\tOutput: -1\n\t\tExplanation: \n\t\tThere is no way to divide the players into teams such that the total skill of each team is equal.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2582,
-        "question": "class Solution:\n    def minScore(self, n: int, roads: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tYou are given a positive integer n representing n cities numbered from 1 to n. You are also given a 2D array roads where roads[i] = [ai, bi, distancei] indicates that there is a bidirectional road between cities ai and bi with a distance equal to distancei. The cities graph is not necessarily connected.\n\t\tThe score of a path between two cities is defined as the minimum distance of a road in this path.\n\t\tReturn the minimum possible score of a path between cities 1 and n.\n\t\tNote:\n\t\t\tA path is a sequence of roads between two cities.\n\t\t\tIt is allowed for a path to contain the same road multiple times, and you can visit cities 1 and n multiple times along the path.\n\t\t\tThe test cases are generated such that there is at least one path between 1 and n.\n\t\tExample 1:\n\t\tInput: n = 4, roads = [[1,2,9],[2,3,6],[2,4,5],[1,4,7]]\n\t\tOutput: 5\n\t\tExplanation: The path from city 1 to 4 with the minimum score is: 1 -> 2 -> 4. The score of this path is min(9,5) = 5.\n\t\tIt can be shown that no other path has less score.\n\t\tExample 2:\n\t\tInput: n = 4, roads = [[1,2,2],[1,3,4],[3,4,7]]\n\t\tOutput: 2\n\t\tExplanation: The path from city 1 to 4 with the minimum score is: 1 -> 2 -> 1 -> 3 -> 4. The score of this path is min(2,2,4,7) = 2.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2583,
-        "question": "class Solution:\n    def magnificentSets(self, n: int, edges: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tYou are given a positive integer n representing the number of nodes in an undirected graph. The nodes are labeled from 1 to n.\n\t\tYou are also given a 2D integer array edges, where edges[i] = [ai, bi] indicates that there is a bidirectional edge between nodes ai and bi. Notice that the given graph may be disconnected.\n\t\tDivide the nodes of the graph into m groups (1-indexed) such that:\n\t\t\tEach node in the graph belongs to exactly one group.\n\t\t\tFor every pair of nodes in the graph that are connected by an edge [ai, bi], if ai belongs to the group with index x, and bi belongs to the group with index y, then |y - x| = 1.\n\t\tReturn the maximum number of groups (i.e., maximum m) into which you can divide the nodes. Return -1 if it is impossible to group the nodes with the given conditions.\n\t\tExample 1:\n\t\tInput: n = 6, edges = [[1,2],[1,4],[1,5],[2,6],[2,3],[4,6]]\n\t\tOutput: 4\n\t\tExplanation: As shown in the image we:\n\t\t- Add node 5 to the first group.\n\t\t- Add node 1 to the second group.\n\t\t- Add nodes 2 and 4 to the third group.\n\t\t- Add nodes 3 and 6 to the fourth group.\n\t\tWe can see that every edge is satisfied.\n\t\tIt can be shown that that if we create a fifth group and move any node from the third or fourth group to it, at least on of the edges will not be satisfied.\n\t\tExample 2:\n\t\tInput: n = 3, edges = [[1,2],[2,3],[3,1]]\n\t\tOutput: -1\n\t\tExplanation: If we add node 1 to the first group, node 2 to the second group, and node 3 to the third group to satisfy the first two edges, we can see that the third edge will not be satisfied.\n\t\tIt can be shown that no grouping is possible.\n\t\t\"\"\"\n",
-        "difficulty": 2
-    },
-    {
-        "number": 2585,
-        "question": "class Solution:\n    def deleteGreatestValue(self, grid: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tYou are given an m x n matrix grid consisting of positive integers.\n\t\tPerform the following operation until grid becomes empty:\n\t\t\tDelete the element with the greatest value from each row. If multiple such elements exist, delete any of them.\n\t\t\tAdd the maximum of deleted elements to the answer.\n\t\tNote that the number of columns decreases by one after each operation.\n\t\tReturn the answer after performing the operations described above.\n\t\tExample 1:\n\t\tInput: grid = [[1,2,4],[3,3,1]]\n\t\tOutput: 8\n\t\tExplanation: The diagram above shows the removed values in each step.\n\t\t- In the first operation, we remove 4 from the first row and 3 from the second row (notice that, there are two cells with value 3 and we can remove any of them). We add 4 to the answer.\n\t\t- In the second operation, we remove 2 from the first row and 3 from the second row. We add 3 to the answer.\n\t\t- In the third operation, we remove 1 from the first row and 1 from the second row. We add 1 to the answer.\n\t\tThe final answer = 4 + 3 + 1 = 8.\n\t\tExample 2:\n\t\tInput: grid = [[10]]\n\t\tOutput: 10\n\t\tExplanation: The diagram above shows the removed values in each step.\n\t\t- In the first operation, we remove 10 from the first row. We add 10 to the answer.\n\t\tThe final answer = 10.\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 2586,
-        "question": "class Solution:\n    def longestSquareStreak(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou are given an integer array nums. A subsequence of nums is called a square streak if:\n\t\t\tThe length of the subsequence is at least 2, and\n\t\t\tafter sorting the subsequence, each element (except the first element) is the square of the previous number.\n\t\tReturn the length of the longest square streak in nums, or return -1 if there is no square streak.\n\t\tA subsequence is an array that can be derived from another array by deleting some or no elements without changing the order of the remaining elements.\n\t\tExample 1:\n\t\tInput: nums = [4,3,6,16,8,2]\n\t\tOutput: 3\n\t\tExplanation: Choose the subsequence [4,16,2]. After sorting it, it becomes [2,4,16].\n\t\t- 4 = 2 * 2.\n\t\t- 16 = 4 * 4.\n\t\tTherefore, [4,16,2] is a square streak.\n\t\tIt can be shown that every subsequence of length 4 is not a square streak.\n\t\tExample 2:\n\t\tInput: nums = [2,3,5,6,7]\n\t\tOutput: -1\n\t\tExplanation: There is no square streak in nums so return -1.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2587,
-        "question": "class Allocator:\n    def __init__(self, n: int):\n    def allocate(self, size: int, mID: int) -> int:\n    def free(self, mID: int) -> int:\n\t\t\"\"\"\n\t\tYou are given an integer n representing the size of a 0-indexed memory array. All memory units are initially free.\n\t\tYou have a memory allocator with the following functionalities:\n\t\t\tAllocate a block of size consecutive free memory units and assign it the id mID.\n\t\t\tFree all memory units with the given id mID.\n\t\tNote that:\n\t\t\tMultiple blocks can be allocated to the same mID.\n\t\t\tYou should free all the memory units with mID, even if they were allocated in different blocks.\n\t\tImplement the Allocator class:\n\t\t\tAllocator(int n) Initializes an Allocator object with a memory array of size n.\n\t\t\tint allocate(int size, int mID) Find the leftmost block of size consecutive free memory units and allocate it with the id mID. Return the block's first index. If such a block does not exist, return -1.\n\t\t\tint free(int mID) Free all memory units with the id mID. Return the number of memory units you have freed.\n\t\tExample 1:\n\t\tInput\n\t\t[\"Allocator\", \"allocate\", \"allocate\", \"allocate\", \"free\", \"allocate\", \"allocate\", \"allocate\", \"free\", \"allocate\", \"free\"]\n\t\t[[10], [1, 1], [1, 2], [1, 3], [2], [3, 4], [1, 1], [1, 1], [1], [10, 2], [7]]\n\t\tOutput\n\t\t[null, 0, 1, 2, 1, 3, 1, 6, 3, -1, 0]\n\t\tExplanation\n\t\tAllocator loc = new Allocator(10); // Initialize a memory array of size 10. All memory units are initially free.\n\t\tloc.allocate(1, 1); // The leftmost block's first index is 0. The memory array becomes [1,_,_,_,_,_,_,_,_,_]. We return 0.\n\t\tloc.allocate(1, 2); // The leftmost block's first index is 1. The memory array becomes [1,2,_,_,_,_,_,_,_,_]. We return 1.\n\t\tloc.allocate(1, 3); // The leftmost block's first index is 2. The memory array becomes [1,2,3,_,_,_,_,_,_,_]. We return 2.\n\t\tloc.free(2); // Free all memory units with mID 2. The memory array becomes [1,_, 3,_,_,_,_,_,_,_]. We return 1 since there is only 1 unit with mID 2.\n\t\tloc.allocate(3, 4); // The leftmost block's first index is 3. The memory array becomes [1,_,3,4,4,4,_,_,_,_]. We return 3.\n\t\tloc.allocate(1, 1); // The leftmost block's first index is 1. The memory array becomes [1,1,3,4,4,4,_,_,_,_]. We return 1.\n\t\tloc.allocate(1, 1); // The leftmost block's first index is 6. The memory array becomes [1,1,3,4,4,4,1,_,_,_]. We return 6.\n\t\tloc.free(1); // Free all memory units with mID 1. The memory array becomes [_,_,3,4,4,4,_,_,_,_]. We return 3 since there are 3 units with mID 1.\n\t\tloc.allocate(10, 2); // We can not find any free block with 10 consecutive free memory units, so we return -1.\n\t\tloc.free(7); // Free all memory units with mID 7. The memory array remains the same since there is no memory unit with mID 7. We return 0.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2588,
-        "question": "class Solution:\n    def maxPoints(self, grid: List[List[int]], queries: List[int]) -> List[int]:\n\t\t\"\"\"\n\t\tYou are given an m x n integer matrix grid and an array queries of size k.\n\t\tFind an array answer of size k such that for each integer queries[i] you start in the top left cell of the matrix and repeat the following process:\n\t\t\tIf queries[i] is strictly greater than the value of the current cell that you are in, then you get one point if it is your first time visiting this cell, and you can move to any adjacent cell in all 4 directions: up, down, left, and right.\n\t\t\tOtherwise, you do not get any points, and you end this process.\n\t\tAfter the process, answer[i] is the maximum number of points you can get. Note that for each query you are allowed to visit the same cell multiple times.\n\t\tReturn the resulting array answer.\n\t\tExample 1:\n\t\tInput: grid = [[1,2,3],[2,5,7],[3,5,1]], queries = [5,6,2]\n\t\tOutput: [5,8,1]\n\t\tExplanation: The diagrams above show which cells we visit to get points for each query.\n\t\tExample 2:\n\t\tInput: grid = [[5,2,1],[1,1,2]], queries = [3]\n\t\tOutput: [0]\n\t\tExplanation: We can not get any points because the value of the top left cell is already greater than or equal to 3.\n\t\t\"\"\"\n",
-        "difficulty": 2
-    },
-    {
-        "number": 2589,
-        "question": "class Solution:\n    def maximumValue(self, strs: List[str]) -> int:\n\t\t\"\"\"\n\t\tThe value of an alphanumeric string can be defined as:\n\t\t\tThe numeric representation of the string in base 10, if it comprises of digits only.\n\t\t\tThe length of the string, otherwise.\n\t\tGiven an array strs of alphanumeric strings, return the maximum value of any string in strs.\n\t\tExample 1:\n\t\tInput: strs = [\"alic3\",\"bob\",\"3\",\"4\",\"00000\"]\n\t\tOutput: 5\n\t\tExplanation: \n\t\t- \"alic3\" consists of both letters and digits, so its value is its length, i.e. 5.\n\t\t- \"bob\" consists only of letters, so its value is also its length, i.e. 3.\n\t\t- \"3\" consists only of digits, so its value is its numeric equivalent, i.e. 3.\n\t\t- \"4\" also consists only of digits, so its value is 4.\n\t\t- \"00000\" consists only of digits, so its value is 0.\n\t\tHence, the maximum value is 5, of \"alic3\".\n\t\tExample 2:\n\t\tInput: strs = [\"1\",\"01\",\"001\",\"0001\"]\n\t\tOutput: 1\n\t\tExplanation: \n\t\tEach string in the array has value 1. Hence, we return 1.\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 2590,
-        "question": "class Solution:\n    def maxStarSum(self, vals: List[int], edges: List[List[int]], k: int) -> int:\n\t\t\"\"\"\n\t\tThere is an undirected graph consisting of n nodes numbered from 0 to n - 1. You are given a 0-indexed integer array vals of length n where vals[i] denotes the value of the ith node.\n\t\tYou are also given a 2D integer array edges where edges[i] = [ai, bi] denotes that there exists an undirected edge connecting nodes ai and bi.\n\t\tA star graph is a subgraph of the given graph having a center node containing 0 or more neighbors. In other words, it is a subset of edges of the given graph such that there exists a common node for all edges.\n\t\tThe image below shows star graphs with 3 and 4 neighbors respectively, centered at the blue node.\n\t\tThe star sum is the sum of the values of all the nodes present in the star graph.\n\t\tGiven an integer k, return the maximum star sum of a star graph containing at most k edges.\n\t\tExample 1:\n\t\tInput: vals = [1,2,3,4,10,-10,-20], edges = [[0,1],[1,2],[1,3],[3,4],[3,5],[3,6]], k = 2\n\t\tOutput: 16\n\t\tExplanation: The above diagram represents the input graph.\n\t\tThe star graph with the maximum star sum is denoted by blue. It is centered at 3 and includes its neighbors 1 and 4.\n\t\tIt can be shown it is not possible to get a star graph with a sum greater than 16.\n\t\tExample 2:\n\t\tInput: vals = [-5], edges = [], k = 0\n\t\tOutput: -5\n\t\tExplanation: There is only one possible star graph, which is node 0 itself.\n\t\tHence, we return -5.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2591,
-        "question": "class Solution:\n    def maxJump(self, stones: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou are given a 0-indexed integer array stones sorted in strictly increasing order representing the positions of stones in a river.\n\t\tA frog, initially on the first stone, wants to travel to the last stone and then return to the first stone. However, it can jump to any stone at most once.\n\t\tThe length of a jump is the absolute difference between the position of the stone the frog is currently on and the position of the stone to which the frog jumps.\n\t\t\tMore formally, if the frog is at stones[i] and is jumping to stones[j], the length of the jump is |stones[i] - stones[j]|.\n\t\tThe cost of a path is the maximum length of a jump among all jumps in the path.\n\t\tReturn the minimum cost of a path for the frog.\n\t\tExample 1:\n\t\tInput: stones = [0,2,5,6,7]\n\t\tOutput: 5\n\t\tExplanation: The above figure represents one of the optimal paths the frog can take.\n\t\tThe cost of this path is 5, which is the maximum length of a jump.\n\t\tSince it is not possible to achieve a cost of less than 5, we return it.\n\t\tExample 2:\n\t\tInput: stones = [0,3,9]\n\t\tOutput: 9\n\t\tExplanation: \n\t\tThe frog can jump directly to the last stone and come back to the first stone. \n\t\tIn this case, the length of each jump will be 9. The cost for the path will be max(9, 9) = 9.\n\t\tIt can be shown that this is the minimum achievable cost.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2592,
-        "question": "class Solution:\n    def minimumTotalCost(self, nums1: List[int], nums2: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou are given two 0-indexed integer arrays nums1 and nums2, of equal length n.\n\t\tIn one operation, you can swap the values of any two indices of nums1. The cost of this operation is the sum of the indices.\n\t\tFind the minimum total cost of performing the given operation any number of times such that nums1[i] != nums2[i] for all 0 <= i <= n - 1 after performing all the operations.\n\t\tReturn the minimum total cost such that nums1 and nums2 satisfy the above condition. In case it is not possible, return -1.\n\t\tExample 1:\n\t\tInput: nums1 = [1,2,3,4,5], nums2 = [1,2,3,4,5]\n\t\tOutput: 10\n\t\tExplanation: \n\t\tOne of the ways we can perform the operations is:\n\t\t- Swap values at indices 0 and 3, incurring cost = 0 + 3 = 3. Now, nums1 = [4,2,3,1,5]\n\t\t- Swap values at indices 1 and 2, incurring cost = 1 + 2 = 3. Now, nums1 = [4,3,2,1,5].\n\t\t- Swap values at indices 0 and 4, incurring cost = 0 + 4 = 4. Now, nums1 =[5,3,2,1,4].\n\t\tWe can see that for each index i, nums1[i] != nums2[i]. The cost required here is 10.\n\t\tNote that there are other ways to swap values, but it can be proven that it is not possible to obtain a cost less than 10.\n\t\tExample 2:\n\t\tInput: nums1 = [2,2,2,1,3], nums2 = [1,2,2,3,3]\n\t\tOutput: 10\n\t\tExplanation: \n\t\tOne of the ways we can perform the operations is:\n\t\t- Swap values at indices 2 and 3, incurring cost = 2 + 3 = 5. Now, nums1 = [2,2,1,2,3].\n\t\t- Swap values at indices 1 and 4, incurring cost = 1 + 4 = 5. Now, nums1 = [2,3,1,2,2].\n\t\tThe total cost needed here is 10, which is the minimum possible.\n\t\tExample 3:\n\t\tInput: nums1 = [1,2,2], nums2 = [1,2,2]\n\t\tOutput: -1\n\t\tExplanation: \n\t\tIt can be shown that it is not possible to satisfy the given conditions irrespective of the number of operations we perform.\n\t\tHence, we return -1.\n\t\t\"\"\"\n",
-        "difficulty": 2
-    },
-    {
-        "number": 2594,
-        "question": "class Solution:\n    def similarPairs(self, words: List[str]) -> int:\n\t\t\"\"\"\n\t\tYou are given a 0-indexed string array words.\n\t\tTwo strings are similar if they consist of the same characters.\n\t\t\tFor example, \"abca\" and \"cba\" are similar since both consist of characters 'a', 'b', and 'c'.\n\t\t\tHowever, \"abacba\" and \"bcfd\" are not similar since they do not consist of the same characters.\n\t\tReturn the number of pairs (i, j) such that 0 <= i < j <= word.length - 1 and the two strings words[i] and words[j] are similar.\n\t\tExample 1:\n\t\tInput: words = [\"aba\",\"aabb\",\"abcd\",\"bac\",\"aabc\"]\n\t\tOutput: 2\n\t\tExplanation: There are 2 pairs that satisfy the conditions:\n\t\t- i = 0 and j = 1 : both words[0] and words[1] only consist of characters 'a' and 'b'. \n\t\t- i = 3 and j = 4 : both words[3] and words[4] only consist of characters 'a', 'b', and 'c'. \n\t\tExample 2:\n\t\tInput: words = [\"aabb\",\"ab\",\"ba\"]\n\t\tOutput: 3\n\t\tExplanation: There are 3 pairs that satisfy the conditions:\n\t\t- i = 0 and j = 1 : both words[0] and words[1] only consist of characters 'a' and 'b'. \n\t\t- i = 0 and j = 2 : both words[0] and words[2] only consist of characters 'a' and 'b'.\n\t\t- i = 1 and j = 2 : both words[1] and words[2] only consist of characters 'a' and 'b'.\n\t\tExample 3:\n\t\tInput: words = [\"nba\",\"cba\",\"dba\"]\n\t\tOutput: 0\n\t\tExplanation: Since there does not exist any pair that satisfies the conditions, we return 0.\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 2595,
-        "question": "class Solution:\n    def smallestValue(self, n: int) -> int:\n\t\t\"\"\"\n\t\tYou are given a positive integer n.\n\t\tContinuously replace n with the sum of its prime factors.\n\t\t\tNote that if a prime factor divides n multiple times, it should be included in the sum as many times as it divides n.\n\t\tReturn the smallest value n will take on.\n\t\tExample 1:\n\t\tInput: n = 15\n\t\tOutput: 5\n\t\tExplanation: Initially, n = 15.\n\t\t15 = 3 * 5, so replace n with 3 + 5 = 8.\n\t\t8 = 2 * 2 * 2, so replace n with 2 + 2 + 2 = 6.\n\t\t6 = 2 * 3, so replace n with 2 + 3 = 5.\n\t\t5 is the smallest value n will take on.\n\t\tExample 2:\n\t\tInput: n = 3\n\t\tOutput: 3\n\t\tExplanation: Initially, n = 3.\n\t\t3 is the smallest value n will take on.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2596,
-        "question": "class Solution:\n    def isPossible(self, n: int, edges: List[List[int]]) -> bool:\n\t\t\"\"\"\n\t\tThere is an undirected graph consisting of n nodes numbered from 1 to n. You are given the integer n and a 2D array edges where edges[i] = [ai, bi] indicates that there is an edge between nodes ai and bi. The graph can be disconnected.\n\t\tYou can add at most two additional edges (possibly none) to this graph so that there are no repeated edges and no self-loops.\n\t\tReturn true if it is possible to make the degree of each node in the graph even, otherwise return false.\n\t\tThe degree of a node is the number of edges connected to it.\n\t\tExample 1:\n\t\tInput: n = 5, edges = [[1,2],[2,3],[3,4],[4,2],[1,4],[2,5]]\n\t\tOutput: true\n\t\tExplanation: The above diagram shows a valid way of adding an edge.\n\t\tEvery node in the resulting graph is connected to an even number of edges.\n\t\tExample 2:\n\t\tInput: n = 4, edges = [[1,2],[3,4]]\n\t\tOutput: true\n\t\tExplanation: The above diagram shows a valid way of adding two edges.\n\t\tExample 3:\n\t\tInput: n = 4, edges = [[1,2],[1,3],[1,4]]\n\t\tOutput: false\n\t\tExplanation: It is not possible to obtain a valid graph with adding at most 2 edges.\n\t\t\"\"\"\n",
-        "difficulty": 2
-    },
-    {
-        "number": 2597,
-        "question": "class Solution:\n    def cycleLengthQueries(self, n: int, queries: List[List[int]]) -> List[int]:\n\t\t\"\"\"\n\t\tYou are given an integer n. There is a complete binary tree with 2n - 1 nodes. The root of that tree is the node with the value 1, and every node with a value val in the range [1, 2n - 1 - 1] has two children where:\n\t\t\tThe left node has the value 2 * val, and\n\t\t\tThe right node has the value 2 * val + 1.\n\t\tYou are also given a 2D integer array queries of length m, where queries[i] = [ai, bi]. For each query, solve the following problem:\n\t\t\tAdd an edge between the nodes with values ai and bi.\n\t\t\tFind the length of the cycle in the graph.\n\t\t\tRemove the added edge between nodes with values ai and bi.\n\t\tNote that:\n\t\t\tA cycle is a path that starts and ends at the same node, and each edge in the path is visited only once.\n\t\t\tThe length of a cycle is the number of edges visited in the cycle.\n\t\t\tThere could be multiple edges between two nodes in the tree after adding the edge of the query.\n\t\tReturn an array answer of length m where answer[i] is the answer to the ith query.\n\t\tExample 1:\n\t\tInput: n = 3, queries = [[5,3],[4,7],[2,3]]\n\t\tOutput: [4,5,3]\n\t\tExplanation: The diagrams above show the tree of 23 - 1 nodes. Nodes colored in red describe the nodes in the cycle after adding the edge.\n\t\t- After adding the edge between nodes 3 and 5, the graph contains a cycle of nodes [5,2,1,3]. Thus answer to the first query is 4. We delete the added edge and process the next query.\n\t\t- After adding the edge between nodes 4 and 7, the graph contains a cycle of nodes [4,2,1,3,7]. Thus answer to the second query is 5. We delete the added edge and process the next query.\n\t\t- After adding the edge between nodes 2 and 3, the graph contains a cycle of nodes [2,1,3]. Thus answer to the third query is 3. We delete the added edge.\n\t\tExample 2:\n\t\tInput: n = 2, queries = [[1,2]]\n\t\tOutput: [2]\n\t\tExplanation: The diagram above shows the tree of 22 - 1 nodes. Nodes colored in red describe the nodes in the cycle after adding the edge.\n\t\t- After adding the edge between nodes 1 and 2, the graph contains a cycle of nodes [2,1]. Thus answer for the first query is 2. We delete the added edge.\n\t\t\"\"\"\n",
-        "difficulty": 2
-    },
-    {
-        "number": 2598,
-        "question": "class Solution:\n    def closetTarget(self, words: List[str], target: str, startIndex: int) -> int:\n\t\t\"\"\"\n\t\tYou are given a 0-indexed circular string array words and a string target. A circular array means that the array's end connects to the array's beginning.\n\t\t\tFormally, the next element of words[i] is words[(i + 1) % n] and the previous element of words[i] is words[(i - 1 + n) % n], where n is the length of words.\n\t\tStarting from startIndex, you can move to either the next word or the previous word with 1 step at a time.\n\t\tReturn the shortest distance needed to reach the string target. If the string target does not exist in words, return -1.\n\t\tExample 1:\n\t\tInput: words = [\"hello\",\"i\",\"am\",\"leetcode\",\"hello\"], target = \"hello\", startIndex = 1\n\t\tOutput: 1\n\t\tExplanation: We start from index 1 and can reach \"hello\" by\n\t\t- moving 3 units to the right to reach index 4.\n\t\t- moving 2 units to the left to reach index 4.\n\t\t- moving 4 units to the right to reach index 0.\n\t\t- moving 1 unit to the left to reach index 0.\n\t\tThe shortest distance to reach \"hello\" is 1.\n\t\tExample 2:\n\t\tInput: words = [\"a\",\"b\",\"leetcode\"], target = \"leetcode\", startIndex = 0\n\t\tOutput: 1\n\t\tExplanation: We start from index 0 and can reach \"leetcode\" by\n\t\t- moving 2 units to the right to reach index 3.\n\t\t- moving 1 unit to the left to reach index 3.\n\t\tThe shortest distance to reach \"leetcode\" is 1.\n\t\tExample 3:\n\t\tInput: words = [\"i\",\"eat\",\"leetcode\"], target = \"ate\", startIndex = 0\n\t\tOutput: -1\n\t\tExplanation: Since \"ate\" does not exist in words, we return -1.\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 2599,
-        "question": "class Solution:\n    def takeCharacters(self, s: str, k: int) -> int:\n\t\t\"\"\"\n\t\tYou are given a string s consisting of the characters 'a', 'b', and 'c' and a non-negative integer k. Each minute, you may take either the leftmost character of s, or the rightmost character of s.\n\t\tReturn the minimum number of minutes needed for you to take at least k of each character, or return -1 if it is not possible to take k of each character.\n\t\tExample 1:\n\t\tInput: s = \"aabaaaacaabc\", k = 2\n\t\tOutput: 8\n\t\tExplanation: \n\t\tTake three characters from the left of s. You now have two 'a' characters, and one 'b' character.\n\t\tTake five characters from the right of s. You now have four 'a' characters, two 'b' characters, and two 'c' characters.\n\t\tA total of 3 + 5 = 8 minutes is needed.\n\t\tIt can be proven that 8 is the minimum number of minutes needed.\n\t\tExample 2:\n\t\tInput: s = \"a\", k = 1\n\t\tOutput: -1\n\t\tExplanation: It is not possible to take one 'b' or 'c' so return -1.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2600,
-        "question": "class Solution:\n    def maximumTastiness(self, price: List[int], k: int) -> int:\n\t\t\"\"\"\n\t\tYou are given an array of positive integers price where price[i] denotes the price of the ith candy and a positive integer k.\n\t\tThe store sells baskets of k distinct candies. The tastiness of a candy basket is the smallest absolute difference of the prices of any two candies in the basket.\n\t\tReturn the maximum tastiness of a candy basket.\n\t\tExample 1:\n\t\tInput: price = [13,5,1,8,21,2], k = 3\n\t\tOutput: 8\n\t\tExplanation: Choose the candies with the prices [13,5,21].\n\t\tThe tastiness of the candy basket is: min(|13 - 5|, |13 - 21|, |5 - 21|) = min(8, 8, 16) = 8.\n\t\tIt can be proven that 8 is the maximum tastiness that can be achieved.\n\t\tExample 2:\n\t\tInput: price = [1,3,1], k = 2\n\t\tOutput: 2\n\t\tExplanation: Choose the candies with the prices [1,3].\n\t\tThe tastiness of the candy basket is: min(|1 - 3|) = min(2) = 2.\n\t\tIt can be proven that 2 is the maximum tastiness that can be achieved.\n\t\tExample 3:\n\t\tInput: price = [7,7,7,7], k = 2\n\t\tOutput: 0\n\t\tExplanation: Choosing any two distinct candies from the candies we have will result in a tastiness of 0.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2601,
-        "question": "class Solution:\n    def countPartitions(self, nums: List[int], k: int) -> int:\n\t\t\"\"\"\n\t\tYou are given an array nums consisting of positive integers and an integer k.\n\t\tPartition the array into two ordered groups such that each element is in exactly one group. A partition is called great if the sum of elements of each group is greater than or equal to k.\n\t\tReturn the number of distinct great partitions. Since the answer may be too large, return it modulo 109 + 7.\n\t\tTwo partitions are considered distinct if some element nums[i] is in different groups in the two partitions.\n\t\tExample 1:\n\t\tInput: nums = [1,2,3,4], k = 4\n\t\tOutput: 6\n\t\tExplanation: The great partitions are: ([1,2,3], [4]), ([1,3], [2,4]), ([1,4], [2,3]), ([2,3], [1,4]), ([2,4], [1,3]) and ([4], [1,2,3]).\n\t\tExample 2:\n\t\tInput: nums = [3,3,3], k = 4\n\t\tOutput: 0\n\t\tExplanation: There are no great partitions for this array.\n\t\tExample 3:\n\t\tInput: nums = [6,6], k = 2\n\t\tOutput: 2\n\t\tExplanation: We can either put nums[0] in the first partition or in the second partition.\n\t\tThe great partitions will be ([6], [6]) and ([6], [6]).\n\t\t\"\"\"\n",
-        "difficulty": 2
-    },
-    {
-        "number": 2602,
-        "question": "class Solution:\n    def captureForts(self, forts: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou are given a 0-indexed integer array forts of length n representing the positions of several forts. forts[i] can be -1, 0, or 1 where:\n\t\t\t-1 represents there is no fort at the ith position.\n\t\t\t0 indicates there is an enemy fort at the ith position.\n\t\t\t1 indicates the fort at the ith the position is under your command.\n\t\tNow you have decided to move your army from one of your forts at position i to an empty position j such that:\n\t\t\t0 <= i, j <= n - 1\n\t\t\tThe army travels over enemy forts only. Formally, for all k where min(i,j) < k < max(i,j), forts[k] == 0.\n\t\tWhile moving the army, all the enemy forts that come in the way are captured.\n\t\tReturn the maximum number of enemy forts that can be captured. In case it is impossible to move your army, or you do not have any fort under your command, return 0.\n\t\tExample 1:\n\t\tInput: forts = [1,0,0,-1,0,0,0,0,1]\n\t\tOutput: 4\n\t\tExplanation:\n\t\t- Moving the army from position 0 to position 3 captures 2 enemy forts, at 1 and 2.\n\t\t- Moving the army from position 8 to position 3 captures 4 enemy forts.\n\t\tSince 4 is the maximum number of enemy forts that can be captured, we return 4.\n\t\tExample 2:\n\t\tInput: forts = [0,0,1,-1]\n\t\tOutput: 0\n\t\tExplanation: Since no enemy fort can be captured, 0 is returned.\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 2603,
-        "question": "class Solution:\n    def topStudents(self, positive_feedback: List[str], negative_feedback: List[str], report: List[str], student_id: List[int], k: int) -> List[int]:\n\t\t\"\"\"\n\t\tYou are given two string arrays positive_feedback and negative_feedback, containing the words denoting positive and negative feedback, respectively. Note that no word is both positive and negative.\n\t\tInitially every student has 0 points. Each positive word in a feedback report increases the points of a student by 3, whereas each negative word decreases the points by 1.\n\t\tYou are given n feedback reports, represented by a 0-indexed string array report and a 0-indexed integer array student_id, where student_id[i] represents the ID of the student who has received the feedback report report[i]. The ID of each student is unique.\n\t\tGiven an integer k, return the top k students after ranking them in non-increasing order by their points. In case more than one student has the same points, the one with the lower ID ranks higher.\n\t\tExample 1:\n\t\tInput: positive_feedback = [\"smart\",\"brilliant\",\"studious\"], negative_feedback = [\"not\"], report = [\"this student is studious\",\"the student is smart\"], student_id = [1,2], k = 2\n\t\tOutput: [1,2]\n\t\tExplanation: \n\t\tBoth the students have 1 positive feedback and 3 points but since student 1 has a lower ID he ranks higher.\n\t\tExample 2:\n\t\tInput: positive_feedback = [\"smart\",\"brilliant\",\"studious\"], negative_feedback = [\"not\"], report = [\"this student is not studious\",\"the student is smart\"], student_id = [1,2], k = 2\n\t\tOutput: [2,1]\n\t\tExplanation: \n\t\t- The student with ID 1 has 1 positive feedback and 1 negative feedback, so he has 3-1=2 points. \n\t\t- The student with ID 2 has 1 positive feedback, so he has 3 points. \n\t\tSince student 2 has more points, [2,1] is returned.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2604,
-        "question": "class Solution:\n    def minOperations(self, nums1: List[int], nums2: List[int], k: int) -> int:\n\t\t\"\"\"\n\t\tYou are given two integer arrays nums1 and nums2 of equal length n and an integer k. You can perform the following operation on nums1:\n\t\t\tChoose two indexes i and j and increment nums1[i] by k and decrement nums1[j] by k. In other words, nums1[i] = nums1[i] + k and nums1[j] = nums1[j] - k.\n\t\tnums1 is said to be equal to nums2 if for all indices i such that 0 <= i < n, nums1[i] == nums2[i].\n\t\tReturn the minimum number of operations required to make nums1 equal to nums2. If it is impossible to make them equal, return -1.\n\t\tExample 1:\n\t\tInput: nums1 = [4,3,1,4], nums2 = [1,3,7,1], k = 3\n\t\tOutput: 2\n\t\tExplanation: In 2 operations, we can transform nums1 to nums2.\n\t\t1st operation: i = 2, j = 0. After applying the operation, nums1 = [1,3,4,4].\n\t\t2nd operation: i = 2, j = 3. After applying the operation, nums1 = [1,3,7,1].\n\t\tOne can prove that it is impossible to make arrays equal in fewer operations.\n\t\tExample 2:\n\t\tInput: nums1 = [3,8,5,2], nums2 = [2,4,1,6], k = 1\n\t\tOutput: -1\n\t\tExplanation: It can be proved that it is impossible to make the two arrays equal.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2605,
-        "question": "class Solution:\n    def countAnagrams(self, s: str) -> int:\n\t\t\"\"\"\n\t\tYou are given a string s containing one or more words. Every consecutive pair of words is separated by a single space ' '.\n\t\tA string t is an anagram of string s if the ith word of t is a permutation of the ith word of s.\n\t\t\tFor example, \"acb dfe\" is an anagram of \"abc def\", but \"def cab\" and \"adc bef\" are not.\n\t\tReturn the number of distinct anagrams of s. Since the answer may be very large, return it modulo 109 + 7.\n\t\tExample 1:\n\t\tInput: s = \"too hot\"\n\t\tOutput: 18\n\t\tExplanation: Some of the anagrams of the given string are \"too hot\", \"oot hot\", \"oto toh\", \"too toh\", and \"too oht\".\n\t\tExample 2:\n\t\tInput: s = \"aa\"\n\t\tOutput: 1\n\t\tExplanation: There is only one anagram possible for the given string.\n\t\t\"\"\"\n",
-        "difficulty": 2
-    },
-    {
-        "number": 2606,
-        "question": "class Solution:\n    def onesMinusZeros(self, grid: List[List[int]]) -> List[List[int]]:\n\t\t\"\"\"\n\t\tYou are given a 0-indexed m x n binary matrix grid.\n\t\tA 0-indexed m x n difference matrix diff is created with the following procedure:\n\t\t\tLet the number of ones in the ith row be onesRowi.\n\t\t\tLet the number of ones in the jth column be onesColj.\n\t\t\tLet the number of zeros in the ith row be zerosRowi.\n\t\t\tLet the number of zeros in the jth column be zerosColj.\n\t\t\tdiff[i][j] = onesRowi + onesColj - zerosRowi - zerosColj\n\t\tReturn the difference matrix diff.\n\t\tExample 1:\n\t\tInput: grid = [[0,1,1],[1,0,1],[0,0,1]]\n\t\tOutput: [[0,0,4],[0,0,4],[-2,-2,2]]\n\t\tExplanation:\n\t\t- diff[0][0] = onesRow0 + onesCol0 - zerosRow0 - zerosCol0 = 2 + 1 - 1 - 2 = 0 \n\t\t- diff[0][1] = onesRow0 + onesCol1 - zerosRow0 - zerosCol1 = 2 + 1 - 1 - 2 = 0 \n\t\t- diff[0][2] = onesRow0 + onesCol2 - zerosRow0 - zerosCol2 = 2 + 3 - 1 - 0 = 4 \n\t\t- diff[1][0] = onesRow1 + onesCol0 - zerosRow1 - zerosCol0 = 2 + 1 - 1 - 2 = 0 \n\t\t- diff[1][1] = onesRow1 + onesCol1 - zerosRow1 - zerosCol1 = 2 + 1 - 1 - 2 = 0 \n\t\t- diff[1][2] = onesRow1 + onesCol2 - zerosRow1 - zerosCol2 = 2 + 3 - 1 - 0 = 4 \n\t\t- diff[2][0] = onesRow2 + onesCol0 - zerosRow2 - zerosCol0 = 1 + 1 - 2 - 2 = -2\n\t\t- diff[2][1] = onesRow2 + onesCol1 - zerosRow2 - zerosCol1 = 1 + 1 - 2 - 2 = -2\n\t\t- diff[2][2] = onesRow2 + onesCol2 - zerosRow2 - zerosCol2 = 1 + 3 - 2 - 0 = 2\n\t\tExample 2:\n\t\tInput: grid = [[1,1,1],[1,1,1]]\n\t\tOutput: [[5,5,5],[5,5,5]]\n\t\tExplanation:\n\t\t- diff[0][0] = onesRow0 + onesCol0 - zerosRow0 - zerosCol0 = 3 + 2 - 0 - 0 = 5\n\t\t- diff[0][1] = onesRow0 + onesCol1 - zerosRow0 - zerosCol1 = 3 + 2 - 0 - 0 = 5\n\t\t- diff[0][2] = onesRow0 + onesCol2 - zerosRow0 - zerosCol2 = 3 + 2 - 0 - 0 = 5\n\t\t- diff[1][0] = onesRow1 + onesCol0 - zerosRow1 - zerosCol0 = 3 + 2 - 0 - 0 = 5\n\t\t- diff[1][1] = onesRow1 + onesCol1 - zerosRow1 - zerosCol1 = 3 + 2 - 0 - 0 = 5\n\t\t- diff[1][2] = onesRow1 + onesCol2 - zerosRow1 - zerosCol2 = 3 + 2 - 0 - 0 = 5\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2608,
-        "question": "class Solution:\n    def countDigits(self, num: int) -> int:\n\t\t\"\"\"\n\t\tGiven an integer num, return the number of digits in num that divide num.\n\t\tAn integer val divides nums if nums % val == 0.\n\t\tExample 1:\n\t\tInput: num = 7\n\t\tOutput: 1\n\t\tExplanation: 7 divides itself, hence the answer is 1.\n\t\tExample 2:\n\t\tInput: num = 121\n\t\tOutput: 2\n\t\tExplanation: 121 is divisible by 1, but not 2. Since 1 occurs twice as a digit, we return 2.\n\t\tExample 3:\n\t\tInput: num = 1248\n\t\tOutput: 4\n\t\tExplanation: 1248 is divisible by all of its digits, hence the answer is 4.\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 2609,
-        "question": "class Solution:\n    def distinctPrimeFactors(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tGiven an array of positive integers nums, return the number of distinct prime factors in the product of the elements of nums.\n\t\tNote that:\n\t\t\tA number greater than 1 is called prime if it is divisible by only 1 and itself.\n\t\t\tAn integer val1 is a factor of another integer val2 if val2 / val1 is an integer.\n\t\tExample 1:\n\t\tInput: nums = [2,4,3,7,10,6]\n\t\tOutput: 4\n\t\tExplanation:\n\t\tThe product of all the elements in nums is: 2 * 4 * 3 * 7 * 10 * 6 = 10080 = 25 * 32 * 5 * 7.\n\t\tThere are 4 distinct prime factors so we return 4.\n\t\tExample 2:\n\t\tInput: nums = [2,4,8,16]\n\t\tOutput: 1\n\t\tExplanation:\n\t\tThe product of all the elements in nums is: 2 * 4 * 8 * 16 = 1024 = 210.\n\t\tThere is 1 distinct prime factor so we return 1.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2610,
-        "question": "class Solution:\n    def closestPrimes(self, left: int, right: int) -> List[int]:\n\t\t\"\"\"\n\t\tGiven two positive integers left and right, find the two integers num1 and num2 such that:\n\t\t\tleft <= nums1 < nums2 <= right .\n\t\t\tnums1 and nums2 are both prime numbers.\n\t\t\tnums2 - nums1 is the minimum amongst all other pairs satisfying the above conditions.\n\t\tReturn the positive integer array ans = [nums1, nums2]. If there are multiple pairs satisfying these conditions, return the one with the minimum nums1 value or [-1, -1] if such numbers do not exist.\n\t\tA number greater than 1 is called prime if it is only divisible by 1 and itself.\n\t\tExample 1:\n\t\tInput: left = 10, right = 19\n\t\tOutput: [11,13]\n\t\tExplanation: The prime numbers between 10 and 19 are 11, 13, 17, and 19.\n\t\tThe closest gap between any pair is 2, which can be achieved by [11,13] or [17,19].\n\t\tSince 11 is smaller than 17, we return the first pair.\n\t\tExample 2:\n\t\tInput: left = 4, right = 6\n\t\tOutput: [-1,-1]\n\t\tExplanation: There exists only one prime number in the given range, so the conditions cannot be satisfied.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2614,
-        "question": "class Solution:\n    def maximumCount(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tGiven an array nums sorted in non-decreasing order, return the maximum between the number of positive integers and the number of negative integers.\n\t\t\tIn other words, if the number of positive integers in nums is pos and the number of negative integers is neg, then return the maximum of pos and neg.\n\t\tNote that 0 is neither positive nor negative.\n\t\tExample 1:\n\t\tInput: nums = [-2,-1,-1,1,2,3]\n\t\tOutput: 3\n\t\tExplanation: There are 3 positive integers and 3 negative integers. The maximum count among them is 3.\n\t\tExample 2:\n\t\tInput: nums = [-3,-2,-1,0,0,1,2]\n\t\tOutput: 3\n\t\tExplanation: There are 2 positive integers and 3 negative integers. The maximum count among them is 3.\n\t\tExample 3:\n\t\tInput: nums = [5,20,66,1314]\n\t\tOutput: 4\n\t\tExplanation: There are 4 positive integers and 0 negative integers. The maximum count among them is 4.\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 2615,
-        "question": "class Solution:\n    def isItPossible(self, word1: str, word2: str) -> bool:\n\t\t\"\"\"\n\t\tYou are given two 0-indexed strings word1 and word2.\n\t\tA move consists of choosing two indices i and j such that 0 <= i < word1.length and 0 <= j < word2.length and swapping word1[i] with word2[j].\n\t\tReturn true if it is possible to get the number of distinct characters in word1 and word2 to be equal with exactly one move. Return false otherwise.\n\t\tExample 1:\n\t\tInput: word1 = \"ac\", word2 = \"b\"\n\t\tOutput: false\n\t\tExplanation: Any pair of swaps would yield two distinct characters in the first string, and one in the second string.\n\t\tExample 2:\n\t\tInput: word1 = \"abcc\", word2 = \"aab\"\n\t\tOutput: true\n\t\tExplanation: We swap index 2 of the first string with index 0 of the second string. The resulting strings are word1 = \"abac\" and word2 = \"cab\", which both have 3 distinct characters.\n\t\tExample 3:\n\t\tInput: word1 = \"abcde\", word2 = \"fghij\"\n\t\tOutput: true\n\t\tExplanation: Both resulting strings will have 5 distinct characters, regardless of which indices we swap.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2616,
-        "question": "class Solution:\n    def maxKelements(self, nums: List[int], k: int) -> int:\n\t\t\"\"\"\n\t\tYou are given a 0-indexed integer array nums and an integer k. You have a starting score of 0.\n\t\tIn one operation:\n\t\t\tchoose an index i such that 0 <= i < nums.length,\n\t\t\tincrease your score by nums[i], and\n\t\t\treplace nums[i] with ceil(nums[i] / 3).\n\t\tReturn the maximum possible score you can attain after applying exactly k operations.\n\t\tThe ceiling function ceil(val) is the least integer greater than or equal to val.\n\t\tExample 1:\n\t\tInput: nums = [10,10,10,10,10], k = 5\n\t\tOutput: 50\n\t\tExplanation: Apply the operation to each array element exactly once. The final score is 10 + 10 + 10 + 10 + 10 = 50.\n\t\tExample 2:\n\t\tInput: nums = [1,10,3,3,3], k = 3\n\t\tOutput: 17\n\t\tExplanation: You can do the following operations:\n\t\tOperation 1: Select i = 1, so nums becomes [1,4,3,3,3]. Your score increases by 10.\n\t\tOperation 2: Select i = 1, so nums becomes [1,2,3,3,3]. Your score increases by 4.\n\t\tOperation 3: Select i = 2, so nums becomes [1,1,1,3,3]. Your score increases by 3.\n\t\tThe final score is 10 + 4 + 3 = 17.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2618,
-        "question": "class Solution:\n    def maxPower(self, stations: List[int], r: int, k: int) -> int:\n\t\t\"\"\"\n\t\tYou are given a 0-indexed integer array stations of length n, where stations[i] represents the number of power stations in the ith city.\n\t\tEach power station can provide power to every city in a fixed range. In other words, if the range is denoted by r, then a power station at city i can provide power to all cities j such that |i - j| <= r and 0 <= i, j <= n - 1.\n\t\t\tNote that |x| denotes absolute value. For example, |7 - 5| = 2 and |3 - 10| = 7.\n\t\tThe power of a city is the total number of power stations it is being provided power from.\n\t\tThe government has sanctioned building k more power stations, each of which can be built in any city, and have the same range as the pre-existing ones.\n\t\tGiven the two integers r and k, return the maximum possible minimum power of a city, if the additional power stations are built optimally.\n\t\tNote that you can build the k power stations in multiple cities.\n\t\tExample 1:\n\t\tInput: stations = [1,2,4,5,0], r = 1, k = 2\n\t\tOutput: 5\n\t\tExplanation: \n\t\tOne of the optimal ways is to install both the power stations at city 1. \n\t\tSo stations will become [1,4,4,5,0].\n\t\t- City 0 is provided by 1 + 4 = 5 power stations.\n\t\t- City 1 is provided by 1 + 4 + 4 = 9 power stations.\n\t\t- City 2 is provided by 4 + 4 + 5 = 13 power stations.\n\t\t- City 3 is provided by 5 + 4 = 9 power stations.\n\t\t- City 4 is provided by 5 + 0 = 5 power stations.\n\t\tSo the minimum power of a city is 5.\n\t\tSince it is not possible to obtain a larger power, we return 5.\n\t\tExample 2:\n\t\tInput: stations = [4,4,4,4], r = 0, k = 3\n\t\tOutput: 4\n\t\tExplanation: \n\t\tIt can be proved that we cannot make the minimum power of a city greater than 4.\n\t\t\"\"\"\n",
-        "difficulty": 2
-    },
-    {
-        "number": 2619,
-        "question": "class Solution:\n    def categorizeBox(self, length: int, width: int, height: int, mass: int) -> str:\n\t\t\"\"\"\n\t\tGiven four integers length, width, height, and mass, representing the dimensions and mass of a box, respectively, return a string representing the category of the box.\n\t\t\tThe box is \"Bulky\" if:\n\t\t\t\tAny of the dimensions of the box is greater or equal to 104.\n\t\t\t\tOr, the volume of the box is greater or equal to 109.\n\t\t\tIf the mass of the box is greater or equal to 100, it is \"Heavy\".\n\t\t\tIf the box is both \"Bulky\" and \"Heavy\", then its category is \"Both\".\n\t\t\tIf the box is neither \"Bulky\" nor \"Heavy\", then its category is \"Neither\".\n\t\t\tIf the box is \"Bulky\" but not \"Heavy\", then its category is \"Bulky\".\n\t\t\tIf the box is \"Heavy\" but not \"Bulky\", then its category is \"Heavy\".\n\t\tNote that the volume of the box is the product of its length, width and height.\n\t\tExample 1:\n\t\tInput: length = 1000, width = 35, height = 700, mass = 300\n\t\tOutput: \"Heavy\"\n\t\tExplanation: \n\t\tNone of the dimensions of the box is greater or equal to 104. \n\t\tIts volume = 24500000 <= 109. So it cannot be categorized as \"Bulky\".\n\t\tHowever mass >= 100, so the box is \"Heavy\".\n\t\tSince the box is not \"Bulky\" but \"Heavy\", we return \"Heavy\".\n\t\tExample 2:\n\t\tInput: length = 200, width = 50, height = 800, mass = 50\n\t\tOutput: \"Neither\"\n\t\tExplanation: \n\t\tNone of the dimensions of the box is greater or equal to 104.\n\t\tIts volume = 8 * 106 <= 109. So it cannot be categorized as \"Bulky\".\n\t\tIts mass is also less than 100, so it cannot be categorized as \"Heavy\" either. \n\t\tSince its neither of the two above categories, we return \"Neither\".\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 2620,
-        "question": "class DataStream:\n    def __init__(self, value: int, k: int):\n    def consec(self, num: int) -> bool:\n\t\t\"\"\"\n\t\tFor a stream of integers, implement a data structure that checks if the last k integers parsed in the stream are equal to value.\n\t\tImplement the DataStream class:\n\t\t\tDataStream(int value, int k) Initializes the object with an empty integer stream and the two integers value and k.\n\t\t\tboolean consec(int num) Adds num to the stream of integers. Returns true if the last k integers are equal to value, and false otherwise. If there are less than k integers, the condition does not hold true, so returns false.\n\t\tExample 1:\n\t\tInput\n\t\t[\"DataStream\", \"consec\", \"consec\", \"consec\", \"consec\"]\n\t\t[[4, 3], [4], [4], [4], [3]]\n\t\tOutput\n\t\t[null, false, false, true, false]\n\t\tExplanation\n\t\tDataStream dataStream = new DataStream(4, 3); //value = 4, k = 3 \n\t\tdataStream.consec(4); // Only 1 integer is parsed, so returns False. \n\t\tdataStream.consec(4); // Only 2 integers are parsed.\n\t\t                      // Since 2 is less than k, returns False. \n\t\tdataStream.consec(4); // The 3 integers parsed are all equal to value, so returns True. \n\t\tdataStream.consec(3); // The last k integers parsed in the stream are [4,4,3].\n\t\t                      // Since 3 is not equal to value, it returns False.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2621,
-        "question": "class Solution:\n    def xorBeauty(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou are given a 0-indexed integer array nums.\n\t\tThe effective value of three indices i, j, and k is defined as ((nums[i] | nums[j]) & nums[k]).\n\t\tThe xor-beauty of the array is the XORing of the effective values of all the possible triplets of indices (i, j, k) where 0 <= i, j, k < n.\n\t\tReturn the xor-beauty of nums.\n\t\tNote that:\n\t\t\tval1 | val2 is bitwise OR of val1 and val2.\n\t\t\tval1 & val2 is bitwise AND of val1 and val2.\n\t\tExample 1:\n\t\tInput: nums = [1,4]\n\t\tOutput: 5\n\t\tExplanation: \n\t\tThe triplets and their corresponding effective values are listed below:\n\t\t- (0,0,0) with effective value ((1 | 1) & 1) = 1\n\t\t- (0,0,1) with effective value ((1 | 1) & 4) = 0\n\t\t- (0,1,0) with effective value ((1 | 4) & 1) = 1\n\t\t- (0,1,1) with effective value ((1 | 4) & 4) = 4\n\t\t- (1,0,0) with effective value ((4 | 1) & 1) = 1\n\t\t- (1,0,1) with effective value ((4 | 1) & 4) = 4\n\t\t- (1,1,0) with effective value ((4 | 4) & 1) = 0\n\t\t- (1,1,1) with effective value ((4 | 4) & 4) = 4 \n\t\tXor-beauty of array will be bitwise XOR of all beauties = 1 ^ 0 ^ 1 ^ 4 ^ 1 ^ 4 ^ 0 ^ 4 = 5.\n\t\tExample 2:\n\t\tInput: nums = [15,45,20,2,34,35,5,44,32,30]\n\t\tOutput: 34\n\t\tExplanation: The xor-beauty of the given array is 34.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2624,
-        "question": "class Solution:\n    def differenceOfSum(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou are given a positive integer array nums.\n\t\t\tThe element sum is the sum of all the elements in nums.\n\t\t\tThe digit sum is the sum of all the digits (not necessarily distinct) that appear in nums.\n\t\tReturn the absolute difference between the element sum and digit sum of nums.\n\t\tNote that the absolute difference between two integers x and y is defined as |x - y|.\n\t\tExample 1:\n\t\tInput: nums = [1,15,6,3]\n\t\tOutput: 9\n\t\tExplanation: \n\t\tThe element sum of nums is 1 + 15 + 6 + 3 = 25.\n\t\tThe digit sum of nums is 1 + 1 + 5 + 6 + 3 = 16.\n\t\tThe absolute difference between the element sum and digit sum is |25 - 16| = 9.\n\t\tExample 2:\n\t\tInput: nums = [1,2,3,4]\n\t\tOutput: 0\n\t\tExplanation:\n\t\tThe element sum of nums is 1 + 2 + 3 + 4 = 10.\n\t\tThe digit sum of nums is 1 + 2 + 3 + 4 = 10.\n\t\tThe absolute difference between the element sum and digit sum is |10 - 10| = 0.\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 2625,
-        "question": "class Solution:\n    def rangeAddQueries(self, n: int, queries: List[List[int]]) -> List[List[int]]:\n\t\t\"\"\"\n\t\tYou are given a positive integer n, indicating that we initially have an n x n 0-indexed integer matrix mat filled with zeroes.\n\t\tYou are also given a 2D integer array query. For each query[i] = [row1i, col1i, row2i, col2i], you should do the following operation:\n\t\t\tAdd 1 to every element in the submatrix with the top left corner (row1i, col1i) and the bottom right corner (row2i, col2i). That is, add 1 to mat[x][y] for all row1i <= x <= row2i and col1i <= y <= col2i.\n\t\tReturn the matrix mat after performing every query.\n\t\tExample 1:\n\t\tInput: n = 3, queries = [[1,1,2,2],[0,0,1,1]]\n\t\tOutput: [[1,1,0],[1,2,1],[0,1,1]]\n\t\tExplanation: The diagram above shows the initial matrix, the matrix after the first query, and the matrix after the second query.\n\t\t- In the first query, we add 1 to every element in the submatrix with the top left corner (1, 1) and bottom right corner (2, 2).\n\t\t- In the second query, we add 1 to every element in the submatrix with the top left corner (0, 0) and bottom right corner (1, 1).\n\t\tExample 2:\n\t\tInput: n = 2, queries = [[0,0,1,1]]\n\t\tOutput: [[1,1],[1,1]]\n\t\tExplanation: The diagram above shows the initial matrix and the matrix after the first query.\n\t\t- In the first query we add 1 to every element in the matrix.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2626,
-        "question": "class Solution:\n    def countGood(self, nums: List[int], k: int) -> int:\n\t\t\"\"\"\n\t\tGiven an integer array nums and an integer k, return the number of good subarrays of nums.\n\t\tA subarray arr is good if it there are at least k pairs of indices (i, j) such that i < j and arr[i] == arr[j].\n\t\tA subarray is a contiguous non-empty sequence of elements within an array.\n\t\tExample 1:\n\t\tInput: nums = [1,1,1,1,1], k = 10\n\t\tOutput: 1\n\t\tExplanation: The only good subarray is the array nums itself.\n\t\tExample 2:\n\t\tInput: nums = [3,1,4,3,2,2,4], k = 2\n\t\tOutput: 4\n\t\tExplanation: There are 4 different good subarrays:\n\t\t- [3,1,4,3,2,2] that has 2 pairs.\n\t\t- [3,1,4,3,2,2,4] that has 3 pairs.\n\t\t- [1,4,3,2,2,4] that has 2 pairs.\n\t\t- [4,3,2,2,4] that has 2 pairs.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2627,
-        "question": "class Solution:\n    def maxOutput(self, n: int, edges: List[List[int]], price: List[int]) -> int:\n\t\t\"\"\"\n\t\tThere exists an undirected and initially unrooted tree with n nodes indexed from 0 to n - 1. You are given the integer n and a 2D integer array edges of length n - 1, where edges[i] = [ai, bi] indicates that there is an edge between nodes ai and bi in the tree.\n\t\tEach node has an associated price. You are given an integer array price, where price[i] is the price of the ith node.\n\t\tThe price sum of a given path is the sum of the prices of all nodes lying on that path.\n\t\tThe tree can be rooted at any node root of your choice. The incurred cost after choosing root is the difference between the maximum and minimum price sum amongst all paths starting at root.\n\t\tReturn the maximum possible cost amongst all possible root choices.\n\t\tExample 1:\n\t\tInput: n = 6, edges = [[0,1],[1,2],[1,3],[3,4],[3,5]], price = [9,8,7,6,10,5]\n\t\tOutput: 24\n\t\tExplanation: The diagram above denotes the tree after rooting it at node 2. The first part (colored in red) shows the path with the maximum price sum. The second part (colored in blue) shows the path with the minimum price sum.\n\t\t- The first path contains nodes [2,1,3,4]: the prices are [7,8,6,10], and the sum of the prices is 31.\n\t\t- The second path contains the node [2] with the price [7].\n\t\tThe difference between the maximum and minimum price sum is 24. It can be proved that 24 is the maximum cost.\n\t\tExample 2:\n\t\tInput: n = 3, edges = [[0,1],[1,2]], price = [1,1,1]\n\t\tOutput: 2\n\t\tExplanation: The diagram above denotes the tree after rooting it at node 0. The first part (colored in red) shows the path with the maximum price sum. The second part (colored in blue) shows the path with the minimum price sum.\n\t\t- The first path contains nodes [0,1,2]: the prices are [1,1,1], and the sum of the prices is 3.\n\t\t- The second path contains node [0] with a price [1].\n\t\tThe difference between the maximum and minimum price sum is 2. It can be proved that 2 is the maximum cost.\n\t\t\"\"\"\n",
-        "difficulty": 2
-    },
-    {
-        "number": 2628,
-        "question": "class Solution:\n    def minimizeSet(self, divisor1: int, divisor2: int, uniqueCnt1: int, uniqueCnt2: int) -> int:\n\t\t\"\"\"\n\t\tWe have two arrays arr1 and arr2 which are initially empty. You need to add positive integers to them such that they satisfy all the following conditions:\n\t\t\tarr1 contains uniqueCnt1 distinct positive integers, each of which is not divisible by divisor1.\n\t\t\tarr2 contains uniqueCnt2 distinct positive integers, each of which is not divisible by divisor2.\n\t\t\tNo integer is present in both arr1 and arr2.\n\t\tGiven divisor1, divisor2, uniqueCnt1, and uniqueCnt2, return the minimum possible maximum integer that can be present in either array.\n\t\tExample 1:\n\t\tInput: divisor1 = 2, divisor2 = 7, uniqueCnt1 = 1, uniqueCnt2 = 3\n\t\tOutput: 4\n\t\tExplanation: \n\t\tWe can distribute the first 4 natural numbers into arr1 and arr2.\n\t\tarr1 = [1] and arr2 = [2,3,4].\n\t\tWe can see that both arrays satisfy all the conditions.\n\t\tSince the maximum value is 4, we return it.\n\t\tExample 2:\n\t\tInput: divisor1 = 3, divisor2 = 5, uniqueCnt1 = 2, uniqueCnt2 = 1\n\t\tOutput: 3\n\t\tExplanation: \n\t\tHere arr1 = [1,2], and arr2 = [3] satisfy all conditions.\n\t\tSince the maximum value is 3, we return it.\n\t\tExample 3:\n\t\tInput: divisor1 = 2, divisor2 = 4, uniqueCnt1 = 8, uniqueCnt2 = 2\n\t\tOutput: 15\n\t\tExplanation: \n\t\tHere, the final possible arrays can be arr1 = [1,3,5,7,9,11,13,15], and arr2 = [2,6].\n\t\tIt can be shown that it is not possible to obtain a lower maximum satisfying all conditions. \n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2630,
-        "question": "class Solution:\n    def alternateDigitSum(self, n: int) -> int:\n\t\t\"\"\"\n\t\tYou are given a positive integer n. Each digit of n has a sign according to the following rules:\n\t\t\tThe most significant digit is assigned a positive sign.\n\t\t\tEach other digit has an opposite sign to its adjacent digits.\n\t\tReturn the sum of all digits with their corresponding sign.\n\t\tExample 1:\n\t\tInput: n = 521\n\t\tOutput: 4\n\t\tExplanation: (+5) + (-2) + (+1) = 4.\n\t\tExample 2:\n\t\tInput: n = 111\n\t\tOutput: 1\n\t\tExplanation: (+1) + (-1) + (+1) = 1.\n\t\tExample 3:\n\t\tInput: n = 886996\n\t\tOutput: 0\n\t\tExplanation: (+8) + (-8) + (+6) + (-9) + (+9) + (-6) = 0.\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 2631,
-        "question": "class Solution:\n    def sortTheStudents(self, score: List[List[int]], k: int) -> List[List[int]]:\n\t\t\"\"\"\n\t\tThere is a class with m students and n exams. You are given a 0-indexed m x n integer matrix score, where each row represents one student and score[i][j] denotes the score the ith student got in the jth exam. The matrix score contains distinct integers only.\n\t\tYou are also given an integer k. Sort the students (i.e., the rows of the matrix) by their scores in the kth (0-indexed) exam from the highest to the lowest.\n\t\tReturn the matrix after sorting it.\n\t\tExample 1:\n\t\tInput: score = [[10,6,9,1],[7,5,11,2],[4,8,3,15]], k = 2\n\t\tOutput: [[7,5,11,2],[10,6,9,1],[4,8,3,15]]\n\t\tExplanation: In the above diagram, S denotes the student, while E denotes the exam.\n\t\t- The student with index 1 scored 11 in exam 2, which is the highest score, so they got first place.\n\t\t- The student with index 0 scored 9 in exam 2, which is the second highest score, so they got second place.\n\t\t- The student with index 2 scored 3 in exam 2, which is the lowest score, so they got third place.\n\t\tExample 2:\n\t\tInput: score = [[3,4],[5,6]], k = 0\n\t\tOutput: [[5,6],[3,4]]\n\t\tExplanation: In the above diagram, S denotes the student, while E denotes the exam.\n\t\t- The student with index 1 scored 5 in exam 0, which is the highest score, so they got first place.\n\t\t- The student with index 0 scored 3 in exam 0, which is the lowest score, so they got second place.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2632,
-        "question": "class Solution:\n    def makeStringsEqual(self, s: str, target: str) -> bool:\n\t\t\"\"\"\n\t\tYou are given two 0-indexed binary strings s and target of the same length n. You can do the following operation on s any number of times:\n\t\t\tChoose two different indices i and j where 0 <= i, j < n.\n\t\t\tSimultaneously, replace s[i] with (s[i] OR s[j]) and s[j] with (s[i] XOR s[j]).\n\t\tFor example, if s = \"0110\", you can choose i = 0 and j = 2, then simultaneously replace s[0] with (s[0] OR s[2] = 0 OR 1 = 1), and s[2] with (s[0] XOR s[2] = 0 XOR 1 = 1), so we will have s = \"1110\".\n\t\tReturn true if you can make the string s equal to target, or false otherwise.\n\t\tExample 1:\n\t\tInput: s = \"1010\", target = \"0110\"\n\t\tOutput: true\n\t\tExplanation: We can do the following operations:\n\t\t- Choose i = 2 and j = 0. We have now s = \"0010\".\n\t\t- Choose i = 2 and j = 1. We have now s = \"0110\".\n\t\tSince we can make s equal to target, we return true.\n\t\tExample 2:\n\t\tInput: s = \"11\", target = \"00\"\n\t\tOutput: false\n\t\tExplanation: It is not possible to make s equal to target with any number of operations.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2633,
-        "question": "class Solution:\n    def minCost(self, nums: List[int], k: int) -> int:\n\t\t\"\"\"\n\t\tYou are given an integer array nums and an integer k.\n\t\tSplit the array into some number of non-empty subarrays. The cost of a split is the sum of the importance value of each subarray in the split.\n\t\tLet trimmed(subarray) be the version of the subarray where all numbers which appear only once are removed.\n\t\t\tFor example, trimmed([3,1,2,4,3,4]) = [3,4,3,4].\n\t\tThe importance value of a subarray is k + trimmed(subarray).length.\n\t\t\tFor example, if a subarray is [1,2,3,3,3,4,4], then trimmed([1,2,3,3,3,4,4]) = [3,3,3,4,4].The importance value of this subarray will be k + 5.\n\t\tReturn the minimum possible cost of a split of nums.\n\t\tA subarray is a contiguous non-empty sequence of elements within an array.\n\t\tExample 1:\n\t\tInput: nums = [1,2,1,2,1,3,3], k = 2\n\t\tOutput: 8\n\t\tExplanation: We split nums to have two subarrays: [1,2], [1,2,1,3,3].\n\t\tThe importance value of [1,2] is 2 + (0) = 2.\n\t\tThe importance value of [1,2,1,3,3] is 2 + (2 + 2) = 6.\n\t\tThe cost of the split is 2 + 6 = 8. It can be shown that this is the minimum possible cost among all the possible splits.\n\t\tExample 2:\n\t\tInput: nums = [1,2,1,2,1], k = 2\n\t\tOutput: 6\n\t\tExplanation: We split nums to have two subarrays: [1,2], [1,2,1].\n\t\tThe importance value of [1,2] is 2 + (0) = 2.\n\t\tThe importance value of [1,2,1] is 2 + (2) = 4.\n\t\tThe cost of the split is 2 + 4 = 6. It can be shown that this is the minimum possible cost among all the possible splits.\n\t\tExample 3:\n\t\tInput: nums = [1,2,1,2,1], k = 5\n\t\tOutput: 10\n\t\tExplanation: We split nums to have one subarray: [1,2,1,2,1].\n\t\tThe importance value of [1,2,1,2,1] is 5 + (3 + 2) = 10.\n\t\tThe cost of the split is 10. It can be shown that this is the minimum possible cost among all the possible splits.\n\t\t\"\"\"\n",
-        "difficulty": 2
-    },
-    {
-        "number": 2634,
-        "question": "class Solution:\n    def getCommon(self, nums1: List[int], nums2: List[int]) -> int:\n\t\t\"\"\"\n\t\tGiven two integer arrays nums1 and nums2, sorted in non-decreasing order, return the minimum integer common to both arrays. If there is no common integer amongst nums1 and nums2, return -1.\n\t\tNote that an integer is said to be common to nums1 and nums2 if both arrays have at least one occurrence of that integer.\n\t\tExample 1:\n\t\tInput: nums1 = [1,2,3], nums2 = [2,4]\n\t\tOutput: 2\n\t\tExplanation: The smallest element common to both arrays is 2, so we return 2.\n\t\tExample 2:\n\t\tInput: nums1 = [1,2,3,6], nums2 = [2,3,4,5]\n\t\tOutput: 2\n\t\tExplanation: There are two common elements in the array 2 and 3 out of which 2 is the smallest, so 2 is returned.\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 2635,
-        "question": "class Solution:\n    def isReachable(self, targetX: int, targetY: int) -> bool:\n\t\t\"\"\"\n\t\tThere exists an infinitely large grid. You are currently at point (1, 1), and you need to reach the point (targetX, targetY) using a finite number of steps.\n\t\tIn one step, you can move from point (x, y) to any one of the following points:\n\t\t\t(x, y - x)\n\t\t\t(x - y, y)\n\t\t\t(2 * x, y)\n\t\t\t(x, 2 * y)\n\t\tGiven two integers targetX and targetY representing the X-coordinate and Y-coordinate of your final position, return true if you can reach the point from (1, 1) using some number of steps, and false otherwise.\n\t\tExample 1:\n\t\tInput: targetX = 6, targetY = 9\n\t\tOutput: false\n\t\tExplanation: It is impossible to reach (6,9) from (1,1) using any sequence of moves, so false is returned.\n\t\tExample 2:\n\t\tInput: targetX = 4, targetY = 7\n\t\tOutput: true\n\t\tExplanation: You can follow the path (1,1) -> (1,2) -> (1,4) -> (1,8) -> (1,7) -> (2,7) -> (4,7).\n\t\t\"\"\"\n",
-        "difficulty": 2
-    },
-    {
-        "number": 2636,
-        "question": "class Solution:\n    def maxScore(self, nums1: List[int], nums2: List[int], k: int) -> int:\n\t\t\"\"\"\n\t\tYou are given two 0-indexed integer arrays nums1 and nums2 of equal length n and a positive integer k. You must choose a subsequence of indices from nums1 of length k.\n\t\tFor chosen indices i0, i1, ..., ik - 1, your score is defined as:\n\t\t\tThe sum of the selected elements from nums1 multiplied with the minimum of the selected elements from nums2.\n\t\t\tIt can defined simply as: (nums1[i0] + nums1[i1] +...+ nums1[ik - 1]) * min(nums2[i0] , nums2[i1], ... ,nums2[ik - 1]).\n\t\tReturn the maximum possible score.\n\t\tA subsequence of indices of an array is a set that can be derived from the set {0, 1, ..., n-1} by deleting some or no elements.\n\t\tExample 1:\n\t\tInput: nums1 = [1,3,3,2], nums2 = [2,1,3,4], k = 3\n\t\tOutput: 12\n\t\tExplanation: \n\t\tThe four possible subsequence scores are:\n\t\t- We choose the indices 0, 1, and 2 with score = (1+3+3) * min(2,1,3) = 7.\n\t\t- We choose the indices 0, 1, and 3 with score = (1+3+2) * min(2,1,4) = 6. \n\t\t- We choose the indices 0, 2, and 3 with score = (1+3+2) * min(2,3,4) = 12. \n\t\t- We choose the indices 1, 2, and 3 with score = (3+3+2) * min(1,3,4) = 8.\n\t\tTherefore, we return the max score, which is 12.\n\t\tExample 2:\n\t\tInput: nums1 = [4,2,3,1,1], nums2 = [7,5,10,9,6], k = 1\n\t\tOutput: 30\n\t\tExplanation: \n\t\tChoosing index 2 is optimal: nums1[2] * nums2[2] = 3 * 10 = 30 is the maximum possible score.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2639,
-        "question": "class Solution:\n    def separateDigits(self, nums: List[int]) -> List[int]:\n\t\t\"\"\"\n\t\tGiven an array of positive integers nums, return an array answer that consists of the digits of each integer in nums after separating them in the same order they appear in nums.\n\t\tTo separate the digits of an integer is to get all the digits it has in the same order.\n\t\t\tFor example, for the integer 10921, the separation of its digits is [1,0,9,2,1].\n\t\tExample 1:\n\t\tInput: nums = [13,25,83,77]\n\t\tOutput: [1,3,2,5,8,3,7,7]\n\t\tExplanation: \n\t\t- The separation of 13 is [1,3].\n\t\t- The separation of 25 is [2,5].\n\t\t- The separation of 83 is [8,3].\n\t\t- The separation of 77 is [7,7].\n\t\tanswer = [1,3,2,5,8,3,7,7]. Note that answer contains the separations in the same order.\n\t\tExample 2:\n\t\tInput: nums = [7,1,3,9]\n\t\tOutput: [7,1,3,9]\n\t\tExplanation: The separation of each integer in nums is itself.\n\t\tanswer = [7,1,3,9].\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 2640,
-        "question": "class Solution:\n    def maxCount(self, banned: List[int], n: int, maxSum: int) -> int:\n\t\t\"\"\"\n\t\tYou are given an integer array banned and two integers n and maxSum. You are choosing some number of integers following the below rules:\n\t\t\tThe chosen integers have to be in the range [1, n].\n\t\t\tEach integer can be chosen at most once.\n\t\t\tThe chosen integers should not be in the array banned.\n\t\t\tThe sum of the chosen integers should not exceed maxSum.\n\t\tReturn the maximum number of integers you can choose following the mentioned rules.\n\t\tExample 1:\n\t\tInput: banned = [1,6,5], n = 5, maxSum = 6\n\t\tOutput: 2\n\t\tExplanation: You can choose the integers 2 and 4.\n\t\t2 and 4 are from the range [1, 5], both did not appear in banned, and their sum is 6, which did not exceed maxSum.\n\t\tExample 2:\n\t\tInput: banned = [1,2,3,4,5,6,7], n = 8, maxSum = 1\n\t\tOutput: 0\n\t\tExplanation: You cannot choose any integer while following the mentioned conditions.\n\t\tExample 3:\n\t\tInput: banned = [11], n = 7, maxSum = 50\n\t\tOutput: 7\n\t\tExplanation: You can choose the integers 1, 2, 3, 4, 5, 6, and 7.\n\t\tThey are from the range [1, 7], all did not appear in banned, and their sum is 28, which did not exceed maxSum.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2641,
-        "question": "class Solution:\n    def isPossibleToCutPath(self, grid: List[List[int]]) -> bool:\n\t\t\"\"\"\n\t\tYou are given a 0-indexed m x n binary matrix grid. You can move from a cell (row, col) to any of the cells (row + 1, col) or (row, col + 1) that has the value 1. The matrix is disconnected if there is no path from (0, 0) to (m - 1, n - 1).\n\t\tYou can flip the value of at most one (possibly none) cell. You cannot flip the cells (0, 0) and (m - 1, n - 1).\n\t\tReturn true if it is possible to make the matrix disconnect or false otherwise.\n\t\tNote that flipping a cell changes its value from 0 to 1 or from 1 to 0.\n\t\tExample 1:\n\t\tInput: grid = [[1,1,1],[1,0,0],[1,1,1]]\n\t\tOutput: true\n\t\tExplanation: We can change the cell shown in the diagram above. There is no path from (0, 0) to (2, 2) in the resulting grid.\n\t\tExample 2:\n\t\tInput: grid = [[1,1,1],[1,0,1],[1,1,1]]\n\t\tOutput: false\n\t\tExplanation: It is not possible to change at most one cell such that there is not path from (0, 0) to (2, 2).\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2642,
-        "question": "class Solution:\n    def findCrossingTime(self, n: int, k: int, time: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tThere are k workers who want to move n boxes from an old warehouse to a new one. You are given the two integers n and k, and a 2D integer array time of size k x 4 where time[i] = [leftToRighti, pickOldi, rightToLefti, putNewi].\n\t\tThe warehouses are separated by a river and connected by a bridge. The old warehouse is on the right bank of the river, and the new warehouse is on the left bank of the river. Initially, all k workers are waiting on the left side of the bridge. To move the boxes, the ith worker (0-indexed) can :\n\t\t\tCross the bridge from the left bank (new warehouse) to the right bank (old warehouse) in leftToRighti minutes.\n\t\t\tPick a box from the old warehouse and return to the bridge in pickOldi minutes. Different workers can pick up their boxes simultaneously.\n\t\t\tCross the bridge from the right bank (old warehouse) to the left bank (new warehouse) in rightToLefti minutes.\n\t\t\tPut the box in the new warehouse and return to the bridge in putNewi minutes. Different workers can put their boxes simultaneously.\n\t\tA worker i is less efficient than a worker j if either condition is met:\n\t\t\tleftToRighti + rightToLefti > leftToRightj + rightToLeftj\n\t\t\tleftToRighti + rightToLefti == leftToRightj + rightToLeftj and i > j\n\t\tThe following rules regulate the movement of the workers through the bridge :\n\t\t\tIf a worker x reaches the bridge while another worker y is crossing the bridge, x waits at their side of the bridge.\n\t\t\tIf the bridge is free, the worker waiting on the right side of the bridge gets to cross the bridge. If more than one worker is waiting on the right side, the one with the lowest efficiency crosses first.\n\t\t\tIf the bridge is free and no worker is waiting on the right side, and at least one box remains at the old warehouse, the worker on the left side of the river gets to cross the bridge. If more than one worker is waiting on the left side, the one with the lowest efficiency crosses first.\n\t\tReturn the instance of time at which the last worker reaches the left bank of the river after all n boxes have been put in the new warehouse.\n\t\tExample 1:\n\t\tInput: n = 1, k = 3, time = [[1,1,2,1],[1,1,3,1],[1,1,4,1]]\n\t\tOutput: 6\n\t\tExplanation: \n\t\tFrom 0 to 1: worker 2 crosses the bridge from the left bank to the right bank.\n\t\tFrom 1 to 2: worker 2 picks up a box from the old warehouse.\n\t\tFrom 2 to 6: worker 2 crosses the bridge from the right bank to the left bank.\n\t\tFrom 6 to 7: worker 2 puts a box at the new warehouse.\n\t\tThe whole process ends after 7 minutes. We return 6 because the problem asks for the instance of time at which the last worker reaches the left bank.\n\t\tExample 2:\n\t\tInput: n = 3, k = 2, time = [[1,9,1,8],[10,10,10,10]]\n\t\tOutput: 50\n\t\tExplanation: \n\t\tFrom 0  to 10: worker 1 crosses the bridge from the left bank to the right bank.\n\t\tFrom 10 to 20: worker 1 picks up a box from the old warehouse.\n\t\tFrom 10 to 11: worker 0 crosses the bridge from the left bank to the right bank.\n\t\tFrom 11 to 20: worker 0 picks up a box from the old warehouse.\n\t\tFrom 20 to 30: worker 1 crosses the bridge from the right bank to the left bank.\n\t\tFrom 30 to 40: worker 1 puts a box at the new warehouse.\n\t\tFrom 30 to 31: worker 0 crosses the bridge from the right bank to the left bank.\n\t\tFrom 31 to 39: worker 0 puts a box at the new warehouse.\n\t\tFrom 39 to 40: worker 0 crosses the bridge from the left bank to the right bank.\n\t\tFrom 40 to 49: worker 0 picks up a box from the old warehouse.\n\t\tFrom 49 to 50: worker 0 crosses the bridge from the right bank to the left bank.\n\t\tFrom 50 to 58: worker 0 puts a box at the new warehouse.\n\t\tThe whole process ends after 58 minutes. We return 50 because the problem asks for the instance of time at which the last worker reaches the left bank.\n\t\t\"\"\"\n",
-        "difficulty": 2
-    },
-    {
-        "number": 2645,
-        "question": "class Solution:\n    def passThePillow(self, n: int, time: int) -> int:\n\t\t\"\"\"\n\t\tThere are n people standing in a line labeled from 1 to n. The first person in the line is holding a pillow initially. Every second, the person holding the pillow passes it to the next person standing in the line. Once the pillow reaches the end of the line, the direction changes, and people continue passing the pillow in the opposite direction.\n\t\t\tFor example, once the pillow reaches the nth person they pass it to the n - 1th person, then to the n - 2th person and so on.\n\t\tGiven the two positive integers n and time, return the index of the person holding the pillow after time seconds.\n\t\tExample 1:\n\t\tInput: n = 4, time = 5\n\t\tOutput: 2\n\t\tExplanation: People pass the pillow in the following way: 1 -> 2 -> 3 -> 4 -> 3 -> 2.\n\t\tAfer five seconds, the pillow is given to the 2nd person.\n\t\tExample 2:\n\t\tInput: n = 3, time = 2\n\t\tOutput: 3\n\t\tExplanation: People pass the pillow in the following way: 1 -> 2 -> 3.\n\t\tAfer two seconds, the pillow is given to the 3rd person.\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 2646,
-        "question": "class Solution:\n    def kthLargestLevelSum(self, root: Optional[TreeNode], k: int) -> int:\n\t\t\"\"\"\n\t\tYou are given the root of a binary tree and a positive integer k.\n\t\tThe level sum in the tree is the sum of the values of the nodes that are on the same level.\n\t\tReturn the kth largest level sum in the tree (not necessarily distinct). If there are fewer than k levels in the tree, return -1.\n\t\tNote that two nodes are on the same level if they have the same distance from the root.\n\t\tExample 1:\n\t\tInput: root = [5,8,9,2,1,3,7,4,6], k = 2\n\t\tOutput: 13\n\t\tExplanation: The level sums are the following:\n\t\t- Level 1: 5.\n\t\t- Level 2: 8 + 9 = 17.\n\t\t- Level 3: 2 + 1 + 3 + 7 = 13.\n\t\t- Level 4: 4 + 6 = 10.\n\t\tThe 2nd largest level sum is 13.\n\t\tExample 2:\n\t\tInput: root = [1,2,null,3], k = 1\n\t\tOutput: 3\n\t\tExplanation: The largest level sum is 3.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2647,
-        "question": "class Solution:\n    def findValidSplit(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou are given a 0-indexed integer array nums of length n.\n\t\tA split at an index i where 0 <= i <= n - 2 is called valid if the product of the first i + 1 elements and the product of the remaining elements are coprime.\n\t\t\tFor example, if nums = [2, 3, 3], then a split at the index i = 0 is valid because 2 and 9 are coprime, while a split at the index i = 1 is not valid because 6 and 3 are not coprime. A split at the index i = 2 is not valid because i == n - 1.\n\t\tReturn the smallest index i at which the array can be split validly or -1 if there is no such split.\n\t\tTwo values val1 and val2 are coprime if gcd(val1, val2) == 1 where gcd(val1, val2) is the greatest common divisor of val1 and val2.\n\t\tExample 1:\n\t\tInput: nums = [4,7,8,15,3,5]\n\t\tOutput: 2\n\t\tExplanation: The table above shows the values of the product of the first i + 1 elements, the remaining elements, and their gcd at each index i.\n\t\tThe only valid split is at index 2.\n\t\tExample 2:\n\t\tInput: nums = [4,7,15,8,3,5]\n\t\tOutput: -1\n\t\tExplanation: The table above shows the values of the product of the first i + 1 elements, the remaining elements, and their gcd at each index i.\n\t\tThere is no valid split.\n\t\t\"\"\"\n",
-        "difficulty": 2
-    },
-    {
-        "number": 2648,
-        "question": "class Solution:\n    def waysToReachTarget(self, target: int, types: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tThere is a test that has n types of questions. You are given an integer target and a 0-indexed 2D integer array types where types[i] = [counti, marksi] indicates that there are counti questions of the ith type, and each one of them is worth marksi points.\n\t\tReturn the number of ways you can earn exactly target points in the exam. Since the answer may be too large, return it modulo 109 + 7.\n\t\tNote that questions of the same type are indistinguishable.\n\t\t\tFor example, if there are 3 questions of the same type, then solving the 1st and 2nd questions is the same as solving the 1st and 3rd questions, or the 2nd and 3rd questions.\n\t\tExample 1:\n\t\tInput: target = 6, types = [[6,1],[3,2],[2,3]]\n\t\tOutput: 7\n\t\tExplanation: You can earn 6 points in one of the seven ways:\n\t\t- Solve 6 questions of the 0th type: 1 + 1 + 1 + 1 + 1 + 1 = 6\n\t\t- Solve 4 questions of the 0th type and 1 question of the 1st type: 1 + 1 + 1 + 1 + 2 = 6\n\t\t- Solve 2 questions of the 0th type and 2 questions of the 1st type: 1 + 1 + 2 + 2 = 6\n\t\t- Solve 3 questions of the 0th type and 1 question of the 2nd type: 1 + 1 + 1 + 3 = 6\n\t\t- Solve 1 question of the 0th type, 1 question of the 1st type and 1 question of the 2nd type: 1 + 2 + 3 = 6\n\t\t- Solve 3 questions of the 1st type: 2 + 2 + 2 = 6\n\t\t- Solve 2 questions of the 2nd type: 3 + 3 = 6\n\t\tExample 2:\n\t\tInput: target = 5, types = [[50,1],[50,2],[50,5]]\n\t\tOutput: 4\n\t\tExplanation: You can earn 5 points in one of the four ways:\n\t\t- Solve 5 questions of the 0th type: 1 + 1 + 1 + 1 + 1 = 5\n\t\t- Solve 3 questions of the 0th type and 1 question of the 1st type: 1 + 1 + 1 + 2 = 5\n\t\t- Solve 1 questions of the 0th type and 2 questions of the 1st type: 1 + 2 + 2 = 5\n\t\t- Solve 1 question of the 2nd type: 5\n\t\tExample 3:\n\t\tInput: target = 18, types = [[6,1],[3,2],[2,3]]\n\t\tOutput: 1\n\t\tExplanation: You can only earn 18 points by answering all questions.\n\t\t\"\"\"\n",
-        "difficulty": 2
-    },
-    {
-        "number": 2649,
-        "question": "class Solution:\n    def coloredCells(self, n: int) -> int:\n\t\t\"\"\"\n\t\tThere exists an infinitely large two-dimensional grid of uncolored unit cells. You are given a positive integer n, indicating that you must do the following routine for n minutes:\n\t\t\tAt the first minute, color any arbitrary unit cell blue.\n\t\t\tEvery minute thereafter, color blue every uncolored cell that touches a blue cell.\n\t\tBelow is a pictorial representation of the state of the grid after minutes 1, 2, and 3.\n\t\tReturn the number of colored cells at the end of n minutes.\n\t\tExample 1:\n\t\tInput: n = 1\n\t\tOutput: 1\n\t\tExplanation: After 1 minute, there is only 1 blue cell, so we return 1.\n\t\tExample 2:\n\t\tInput: n = 2\n\t\tOutput: 5\n\t\tExplanation: After 2 minutes, there are 4 colored cells on the boundary and 1 in the center, so we return 5. \n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2650,
-        "question": "class Solution:\n    def splitNum(self, num: int) -> int:\n\t\t\"\"\"\n\t\tGiven a positive integer num, split it into two non-negative integers num1 and num2 such that:\n\t\t\tThe concatenation of num1 and num2 is a permutation of num.\n\t\t\t\tIn other words, the sum of the number of occurrences of each digit in num1 and num2 is equal to the number of occurrences of that digit in num.\n\t\t\tnum1 and num2 can contain leading zeros.\n\t\tReturn the minimum possible sum of num1 and num2.\n\t\tNotes:\n\t\t\tIt is guaranteed that num does not contain any leading zeros.\n\t\t\tThe order of occurrence of the digits in num1 and num2 may differ from the order of occurrence of num.\n\t\tExample 1:\n\t\tInput: num = 4325\n\t\tOutput: 59\n\t\tExplanation: We can split 4325 so that num1 is 24 and num2 is 35, giving a sum of 59. We can prove that 59 is indeed the minimal possible sum.\n\t\tExample 2:\n\t\tInput: num = 687\n\t\tOutput: 75\n\t\tExplanation: We can split 687 so that num1 is 68 and num2 is 7, which would give an optimal sum of 75.\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 2651,
-        "question": "class Solution:\n    def countWays(self, ranges: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tYou are given a 2D integer array ranges where ranges[i] = [starti, endi] denotes that all integers between starti and endi (both inclusive) are contained in the ith range.\n\t\tYou are to split ranges into two (possibly empty) groups such that:\n\t\t\tEach range belongs to exactly one group.\n\t\t\tAny two overlapping ranges must belong to the same group.\n\t\tTwo ranges are said to be overlapping if there exists at least one integer that is present in both ranges.\n\t\t\tFor example, [1, 3] and [2, 5] are overlapping because 2 and 3 occur in both ranges.\n\t\tReturn the total number of ways to split ranges into two groups. Since the answer may be very large, return it modulo 109 + 7.\n\t\tExample 1:\n\t\tInput: ranges = [[6,10],[5,15]]\n\t\tOutput: 2\n\t\tExplanation: \n\t\tThe two ranges are overlapping, so they must be in the same group.\n\t\tThus, there are two possible ways:\n\t\t- Put both the ranges together in group 1.\n\t\t- Put both the ranges together in group 2.\n\t\tExample 2:\n\t\tInput: ranges = [[1,3],[10,20],[2,5],[4,8]]\n\t\tOutput: 4\n\t\tExplanation: \n\t\tRanges [1,3], and [2,5] are overlapping. So, they must be in the same group.\n\t\tAgain, ranges [2,5] and [4,8] are also overlapping. So, they must also be in the same group. \n\t\tThus, there are four possible ways to group them:\n\t\t- All the ranges in group 1.\n\t\t- All the ranges in group 2.\n\t\t- Ranges [1,3], [2,5], and [4,8] in group 1 and [10,20] in group 2.\n\t\t- Ranges [1,3], [2,5], and [4,8] in group 2 and [10,20] in group 1.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2652,
-        "question": "class Solution:\n    def rootCount(self, edges: List[List[int]], guesses: List[List[int]], k: int) -> int:\n\t\t\"\"\"\n\t\tAlice has an undirected tree with n nodes labeled from 0 to n - 1. The tree is represented as a 2D integer array edges of length n - 1 where edges[i] = [ai, bi] indicates that there is an edge between nodes ai and bi in the tree.\n\t\tAlice wants Bob to find the root of the tree. She allows Bob to make several guesses about her tree. In one guess, he does the following:\n\t\t\tChooses two distinct integers u and v such that there exists an edge [u, v] in the tree.\n\t\t\tHe tells Alice that u is the parent of v in the tree.\n\t\tBob's guesses are represented by a 2D integer array guesses where guesses[j] = [uj, vj] indicates Bob guessed uj to be the parent of vj.\n\t\tAlice being lazy, does not reply to each of Bob's guesses, but just says that at least k of his guesses are true.\n\t\tGiven the 2D integer arrays edges, guesses and the integer k, return the number of possible nodes that can be the root of Alice's tree. If there is no such tree, return 0.\n\t\tExample 1:\n\t\tInput: edges = [[0,1],[1,2],[1,3],[4,2]], guesses = [[1,3],[0,1],[1,0],[2,4]], k = 3\n\t\tOutput: 3\n\t\tExplanation: \n\t\tRoot = 0, correct guesses = [1,3], [0,1], [2,4]\n\t\tRoot = 1, correct guesses = [1,3], [1,0], [2,4]\n\t\tRoot = 2, correct guesses = [1,3], [1,0], [2,4]\n\t\tRoot = 3, correct guesses = [1,0], [2,4]\n\t\tRoot = 4, correct guesses = [1,3], [1,0]\n\t\tConsidering 0, 1, or 2 as root node leads to 3 correct guesses.\n\t\tExample 2:\n\t\tInput: edges = [[0,1],[1,2],[2,3],[3,4]], guesses = [[1,0],[3,4],[2,1],[3,2]], k = 1\n\t\tOutput: 5\n\t\tExplanation: \n\t\tRoot = 0, correct guesses = [3,4]\n\t\tRoot = 1, correct guesses = [1,0], [3,4]\n\t\tRoot = 2, correct guesses = [1,0], [2,1], [3,4]\n\t\tRoot = 3, correct guesses = [1,0], [2,1], [3,2], [3,4]\n\t\tRoot = 4, correct guesses = [1,0], [2,1], [3,2]\n\t\tConsidering any node as root will give at least 1 correct guess. \n\t\t\"\"\"\n",
-        "difficulty": 2
-    },
-    {
-        "number": 2673,
-        "question": "class Solution:\n    def maximizeWin(self, prizePositions: List[int], k: int) -> int:\n\t\t\"\"\"\n\t\tThere are some prizes on the X-axis. You are given an integer array prizePositions that is sorted in non-decreasing order, where prizePositions[i] is the position of the ith prize. There could be different prizes at the same position on the line. You are also given an integer k.\n\t\tYou are allowed to select two segments with integer endpoints. The length of each segment must be k. You will collect all prizes whose position falls within at least one of the two selected segments (including the endpoints of the segments). The two selected segments may intersect.\n\t\t\tFor example if k = 2, you can choose segments [1, 3] and [2, 4], and you will win any prize i that satisfies 1 <= prizePositions[i] <= 3 or 2 <= prizePositions[i] <= 4.\n\t\tReturn the maximum number of prizes you can win if you choose the two segments optimally.\n\t\tExample 1:\n\t\tInput: prizePositions = [1,1,2,2,3,3,5], k = 2\n\t\tOutput: 7\n\t\tExplanation: In this example, you can win all 7 prizes by selecting two segments [1, 3] and [3, 5].\n\t\tExample 2:\n\t\tInput: prizePositions = [1,2,3,4], k = 0\n\t\tOutput: 2\n\t\tExplanation: For this example, one choice for the segments is [3, 3] and [4, 4], and you will be able to get 2 prizes. \n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2679,
-        "question": "class Solution:\n    def distinctIntegers(self, n: int) -> int:\n\t\t\"\"\"\n\t\tYou are given a positive integer n, that is initially placed on a board. Every day, for 109 days, you perform the following procedure:\n\t\t\tFor each number x present on the board, find all numbers 1 <= i <= n such that x % i == 1.\n\t\t\tThen, place those numbers on the board.\n\t\tReturn the number of distinct integers present on the board after 109 days have elapsed.\n\t\tNote:\n\t\t\tOnce a number is placed on the board, it will remain on it until the end.\n\t\t\t% stands for the modulo operation. For example, 14 % 3 is 2.\n\t\tExample 1:\n\t\tInput: n = 5\n\t\tOutput: 4\n\t\tExplanation: Initially, 5 is present on the board. \n\t\tThe next day, 2 and 4 will be added since 5 % 2 == 1 and 5 % 4 == 1. \n\t\tAfter that day, 3 will be added to the board because 4 % 3 == 1. \n\t\tAt the end of a billion days, the distinct numbers on the board will be 2, 3, 4, and 5. \n\t\tExample 2:\n\t\tInput: n = 3\n\t\tOutput: 2\n\t\tExplanation: \n\t\tSince 3 % 2 == 1, 2 will be added to the board. \n\t\tAfter a billion days, the only two distinct numbers on the board are 2 and 3. \n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 2680,
-        "question": "class Solution:\n    def monkeyMove(self, n: int) -> int:\n\t\t\"\"\"\n\t\tThere is a regular convex polygon with n vertices. The vertices are labeled from 0 to n - 1 in a clockwise direction, and each vertex has exactly one monkey. The following figure shows a convex polygon of 6 vertices.\n\t\tEach monkey moves simultaneously to a neighboring vertex. A neighboring vertex for a vertex i can be:\n\t\t\tthe vertex (i + 1) % n in the clockwise direction, or\n\t\t\tthe vertex (i - 1 + n) % n in the counter-clockwise direction.\n\t\tA collision happens if at least two monkeys reside on the same vertex after the movement or intersect on an edge.\n\t\tReturn the number of ways the monkeys can move so that at least one collision  happens. Since the answer may be very large, return it modulo 109 + 7.\n\t\tNote that each monkey can only move once.\n\t\tExample 1:\n\t\tInput: n = 3\n\t\tOutput: 6\n\t\tExplanation: There are 8 total possible movements.\n\t\tTwo ways such that they collide at some point are:\n\t\t- Monkey 1 moves in a clockwise direction; monkey 2 moves in an anticlockwise direction; monkey 3 moves in a clockwise direction. Monkeys 1 and 2 collide.\n\t\t- Monkey 1 moves in an anticlockwise direction; monkey 2 moves in an anticlockwise direction; monkey 3 moves in a clockwise direction. Monkeys 1 and 3 collide.\n\t\tIt can be shown 6 total movements result in a collision.\n\t\tExample 2:\n\t\tInput: n = 4\n\t\tOutput: 14\n\t\tExplanation: It can be shown that there are 14 ways for the monkeys to collide.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2681,
-        "question": "class Solution:\n    def putMarbles(self, weights: List[int], k: int) -> int:\n\t\t\"\"\"\n\t\tYou have k bags. You are given a 0-indexed integer array weights where weights[i] is the weight of the ith marble. You are also given the integer k.\n\t\tDivide the marbles into the k bags according to the following rules:\n\t\t\tNo bag is empty.\n\t\t\tIf the ith marble and jth marble are in a bag, then all marbles with an index between the ith and jth indices should also be in that same bag.\n\t\t\tIf a bag consists of all the marbles with an index from i to j inclusively, then the cost of the bag is weights[i] + weights[j].\n\t\tThe score after distributing the marbles is the sum of the costs of all the k bags.\n\t\tReturn the difference between the maximum and minimum scores among marble distributions.\n\t\tExample 1:\n\t\tInput: weights = [1,3,5,1], k = 2\n\t\tOutput: 4\n\t\tExplanation: \n\t\tThe distribution [1],[3,5,1] results in the minimal score of (1+1) + (3+1) = 6. \n\t\tThe distribution [1,3],[5,1], results in the maximal score of (1+3) + (5+1) = 10. \n\t\tThus, we return their difference 10 - 6 = 4.\n\t\tExample 2:\n\t\tInput: weights = [1, 3], k = 2\n\t\tOutput: 0\n\t\tExplanation: The only distribution possible is [1],[3]. \n\t\tSince both the maximal and minimal score are the same, we return 0.\n\t\t\"\"\"\n",
-        "difficulty": 2
-    },
-    {
-        "number": 2682,
-        "question": "class Solution:\n    def countQuadruplets(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tGiven a 0-indexed integer array nums of size n containing all numbers from 1 to n, return the number of increasing quadruplets.\n\t\tA quadruplet (i, j, k, l) is increasing if:\n\t\t\t0 <= i < j < k < l < n, and\n\t\t\tnums[i] < nums[k] < nums[j] < nums[l].\n\t\tExample 1:\n\t\tInput: nums = [1,3,2,4,5]\n\t\tOutput: 2\n\t\tExplanation: \n\t\t- When i = 0, j = 1, k = 2, and l = 3, nums[i] < nums[k] < nums[j] < nums[l].\n\t\t- When i = 0, j = 1, k = 2, and l = 4, nums[i] < nums[k] < nums[j] < nums[l]. \n\t\tThere are no other quadruplets, so we return 2.\n\t\tExample 2:\n\t\tInput: nums = [1,2,3,4]\n\t\tOutput: 0\n\t\tExplanation: There exists only one quadruplet with i = 0, j = 1, k = 2, l = 3, but since nums[j] < nums[k], we return 0.\n\t\t\"\"\"\n",
-        "difficulty": 2
-    },
-    {
-        "number": 2689,
-        "question": "class Solution:\n    def minCost(self, basket1: List[int], basket2: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou have two fruit baskets containing n fruits each. You are given two 0-indexed integer arrays basket1 and basket2 representing the cost of fruit in each basket. You want to make both baskets equal. To do so, you can use the following operation as many times as you want:\n\t\t\tChose two indices i and j, and swap the ith fruit of basket1 with the jth fruit of basket2.\n\t\t\tThe cost of the swap is min(basket1[i],basket2[j]).\n\t\tTwo baskets are considered equal if sorting them according to the fruit cost makes them exactly the same baskets.\n\t\tReturn the minimum cost to make both the baskets equal or -1 if impossible.\n\t\tExample 1:\n\t\tInput: basket1 = [4,2,2,2], basket2 = [1,4,1,2]\n\t\tOutput: 1\n\t\tExplanation: Swap index 1 of basket1 with index 0 of basket2, which has cost 1. Now basket1 = [4,1,2,2] and basket2 = [2,4,1,2]. Rearranging both the arrays makes them equal.\n\t\tExample 2:\n\t\tInput: basket1 = [2,3,4,1], basket2 = [3,2,5,1]\n\t\tOutput: -1\n\t\tExplanation: It can be shown that it is impossible to make both the baskets equal.\n\t\t\"\"\"\n",
-        "difficulty": 2
-    },
-    {
-        "number": 2690,
-        "question": "class Solution:\n    def minCapability(self, nums: List[int], k: int) -> int:\n\t\t\"\"\"\n\t\tThere are several consecutive houses along a street, each of which has some money inside. There is also a robber, who wants to steal money from the homes, but he refuses to steal from adjacent homes.\n\t\tThe capability of the robber is the maximum amount of money he steals from one house of all the houses he robbed.\n\t\tYou are given an integer array nums representing how much money is stashed in each house. More formally, the ith house from the left has nums[i] dollars.\n\t\tYou are also given an integer k, representing the minimum number of houses the robber will steal from. It is always possible to steal at least k houses.\n\t\tReturn the minimum capability of the robber out of all the possible ways to steal at least k houses.\n\t\tExample 1:\n\t\tInput: nums = [2,3,5,9], k = 2\n\t\tOutput: 5\n\t\tExplanation: \n\t\tThere are three ways to rob at least 2 houses:\n\t\t- Rob the houses at indices 0 and 2. Capability is max(nums[0], nums[2]) = 5.\n\t\t- Rob the houses at indices 0 and 3. Capability is max(nums[0], nums[3]) = 9.\n\t\t- Rob the houses at indices 1 and 3. Capability is max(nums[1], nums[3]) = 9.\n\t\tTherefore, we return min(5, 9, 9) = 5.\n\t\tExample 2:\n\t\tInput: nums = [2,7,9,3,1], k = 2\n\t\tOutput: 2\n\t\tExplanation: There are 7 ways to rob the houses. The way which leads to minimum capability is to rob the house at index 0 and 4. Return max(nums[0], nums[4]) = 2.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2691,
-        "question": "class Solution:\n    def vowelStrings(self, words: List[str], queries: List[List[int]]) -> List[int]:\n\t\t\"\"\"\n\t\tYou are given a 0-indexed array of strings words and a 2D array of integers queries.\n\t\tEach query queries[i] = [li, ri] asks us to find the number of strings present in the range li to ri (both inclusive) of words that start and end with a vowel.\n\t\tReturn an array ans of size queries.length, where ans[i] is the answer to the ith query.\n\t\tNote that the vowel letters are 'a', 'e', 'i', 'o', and 'u'.\n\t\tExample 1:\n\t\tInput: words = [\"aba\",\"bcb\",\"ece\",\"aa\",\"e\"], queries = [[0,2],[1,4],[1,1]]\n\t\tOutput: [2,3,0]\n\t\tExplanation: The strings starting and ending with a vowel are \"aba\", \"ece\", \"aa\" and \"e\".\n\t\tThe answer to the query [0,2] is 2 (strings \"aba\" and \"ece\").\n\t\tto query [1,4] is 3 (strings \"ece\", \"aa\", \"e\").\n\t\tto query [1,1] is 0.\n\t\tWe return [2,3,0].\n\t\tExample 2:\n\t\tInput: words = [\"a\",\"e\",\"i\"], queries = [[0,2],[0,1],[2,2]]\n\t\tOutput: [3,2,1]\n\t\tExplanation: Every string satisfies the conditions, so we return [3,2,1].\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2692,
-        "question": "class Solution:\n    def pickGifts(self, gifts: List[int], k: int) -> int:\n\t\t\"\"\"\n\t\tYou are given an integer array gifts denoting the number of gifts in various piles. Every second, you do the following:\n\t\t\tChoose the pile with the maximum number of gifts.\n\t\t\tIf there is more than one pile with the maximum number of gifts, choose any.\n\t\t\tLeave behind the floor of the square root of the number of gifts in the pile. Take the rest of the gifts.\n\t\tReturn the number of gifts remaining after k seconds.\n\t\tExample 1:\n\t\tInput: gifts = [25,64,9,4,100], k = 4\n\t\tOutput: 29\n\t\tExplanation: \n\t\tThe gifts are taken in the following way:\n\t\t- In the first second, the last pile is chosen and 10 gifts are left behind.\n\t\t- Then the second pile is chosen and 8 gifts are left behind.\n\t\t- After that the first pile is chosen and 5 gifts are left behind.\n\t\t- Finally, the last pile is chosen again and 3 gifts are left behind.\n\t\tThe final remaining gifts are [5,8,9,4,3], so the total number of gifts remaining is 29.\n\t\tExample 2:\n\t\tInput: gifts = [1,1,1,1], k = 4\n\t\tOutput: 4\n\t\tExplanation: \n\t\tIn this case, regardless which pile you choose, you have to leave behind 1 gift in each pile. \n\t\tThat is, you can't take any pile with you. \n\t\tSo, the total gifts remaining are 4.\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 2698,
-        "question": "class Solution:\n    def findTheArrayConcVal(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou are given a 0-indexed integer array nums.\n\t\tThe concatenation of two numbers is the number formed by concatenating their numerals.\n\t\t\tFor example, the concatenation of 15, 49 is 1549.\n\t\tThe concatenation value of nums is initially equal to 0. Perform this operation until nums becomes empty:\n\t\t\tIf there exists more than one number in nums, pick the first element and last element in nums respectively and add the value of their concatenation to the concatenation value of nums, then delete the first and last element from nums.\n\t\t\tIf one element exists, add its value to the concatenation value of nums, then delete it.\n\t\tReturn the concatenation value of the nums.\n\t\tExample 1:\n\t\tInput: nums = [7,52,2,4]\n\t\tOutput: 596\n\t\tExplanation: Before performing any operation, nums is [7,52,2,4] and concatenation value is 0.\n\t\t - In the first operation:\n\t\tWe pick the first element, 7, and the last element, 4.\n\t\tTheir concatenation is 74, and we add it to the concatenation value, so it becomes equal to 74.\n\t\tThen we delete them from nums, so nums becomes equal to [52,2].\n\t\t - In the second operation:\n\t\tWe pick the first element, 52, and the last element, 2.\n\t\tTheir concatenation is 522, and we add it to the concatenation value, so it becomes equal to 596.\n\t\tThen we delete them from the nums, so nums becomes empty.\n\t\tSince the concatenation value is 596 so the answer is 596.\n\t\tExample 2:\n\t\tInput: nums = [5,14,13,8,12]\n\t\tOutput: 673\n\t\tExplanation: Before performing any operation, nums is [5,14,13,8,12] and concatenation value is 0.\n\t\t - In the first operation:\n\t\tWe pick the first element, 5, and the last element, 12.\n\t\tTheir concatenation is 512, and we add it to the concatenation value, so it becomes equal to 512.\n\t\tThen we delete them from the nums, so nums becomes equal to [14,13,8].\n\t\t - In the second operation:\n\t\tWe pick the first element, 14, and the last element, 8.\n\t\tTheir concatenation is 148, and we add it to the concatenation value, so it becomes equal to 660.\n\t\tThen we delete them from the nums, so nums becomes equal to [13].\n\t\t - In the third operation:\n\t\tnums has only one element, so we pick 13 and add it to the concatenation value, so it becomes equal to 673.\n\t\tThen we delete it from nums, so nums become empty.\n\t\tSince the concatenation value is 673 so the answer is 673.\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 2699,
-        "question": "class Solution:\n    def countFairPairs(self, nums: List[int], lower: int, upper: int) -> int:\n\t\t\"\"\"\n\t\tGiven a 0-indexed integer array nums of size n and two integers lower and upper, return the number of fair pairs.\n\t\tA pair (i, j) is fair if:\n\t\t\t0 <= i < j < n, and\n\t\t\tlower <= nums[i] + nums[j] <= upper\n\t\tExample 1:\n\t\tInput: nums = [0,1,7,4,4,5], lower = 3, upper = 6\n\t\tOutput: 6\n\t\tExplanation: There are 6 fair pairs: (0,3), (0,4), (0,5), (1,3), (1,4), and (1,5).\n\t\tExample 2:\n\t\tInput: nums = [1,7,9,2,5], lower = 11, upper = 11\n\t\tOutput: 1\n\t\tExplanation: There is a single fair pair: (2,3).\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2700,
-        "question": "class Solution:\n    def substringXorQueries(self, s: str, queries: List[List[int]]) -> List[List[int]]:\n\t\t\"\"\"\n\t\tYou are given a binary string s, and a 2D integer array queries where queries[i] = [firsti, secondi].\n\t\tFor the ith query, find the shortest substring of s whose decimal value, val, yields secondi when bitwise XORed with firsti. In other words, val ^ firsti == secondi.\n\t\tThe answer to the ith query is the endpoints (0-indexed) of the substring [lefti, righti] or [-1, -1] if no such substring exists. If there are multiple answers, choose the one with the minimum lefti.\n\t\tReturn an array ans where ans[i] = [lefti, righti] is the answer to the ith query.\n\t\tA substring is a contiguous non-empty sequence of characters within a string.\n\t\tExample 1:\n\t\tInput: s = \"101101\", queries = [[0,5],[1,2]]\n\t\tOutput: [[0,2],[2,3]]\n\t\tExplanation: For the first query the substring in range [0,2] is \"101\" which has a decimal value of 5, and 5 ^ 0 = 5, hence the answer to the first query is [0,2]. In the second query, the substring in range [2,3] is \"11\", and has a decimal value of 3, and 3 ^ 1 = 2. So, [2,3] is returned for the second query. \n\t\tExample 2:\n\t\tInput: s = \"0101\", queries = [[12,8]]\n\t\tOutput: [[-1,-1]]\n\t\tExplanation: In this example there is no substring that answers the query, hence [-1,-1] is returned.\n\t\tExample 3:\n\t\tInput: s = \"1\", queries = [[4,5]]\n\t\tOutput: [[0,0]]\n\t\tExplanation: For this example, the substring in range [0,0] has a decimal value of 1, and 1 ^ 4 = 5. So, the answer is [0,0].\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2701,
-        "question": "class Solution:\n    def minimumScore(self, s: str, t: str) -> int:\n\t\t\"\"\"\n\t\tYou are given two strings s and t.\n\t\tYou are allowed to remove any number of characters from the string t.\n\t\tThe score of the string is 0 if no characters are removed from the string t, otherwise:\n\t\t\tLet left be the minimum index among all removed characters.\n\t\t\tLet right be the maximum index among all removed characters.\n\t\tThen the score of the string is right - left + 1.\n\t\tReturn the minimum possible score to make t a subsequence of s.\n\t\tA subsequence of a string is a new string that is formed from the original string by deleting some (can be none) of the characters without disturbing the relative positions of the remaining characters. (i.e., \"ace\" is a subsequence of \"abcde\" while \"aec\" is not).\n\t\tExample 1:\n\t\tInput: s = \"abacaba\", t = \"bzaa\"\n\t\tOutput: 1\n\t\tExplanation: In this example, we remove the character \"z\" at index 1 (0-indexed).\n\t\tThe string t becomes \"baa\" which is a subsequence of the string \"abacaba\" and the score is 1 - 1 + 1 = 1.\n\t\tIt can be proven that 1 is the minimum score that we can achieve.\n\t\tExample 2:\n\t\tInput: s = \"cde\", t = \"xyz\"\n\t\tOutput: 3\n\t\tExplanation: In this example, we remove characters \"x\", \"y\" and \"z\" at indices 0, 1, and 2 (0-indexed).\n\t\tThe string t becomes \"\" which is a subsequence of the string \"cde\" and the score is 2 - 0 + 1 = 3.\n\t\tIt can be proven that 3 is the minimum score that we can achieve.\n\t\t\"\"\"\n",
-        "difficulty": 2
-    },
-    {
-        "number": 2703,
-        "question": "class Solution:\n    def handleQuery(self, nums1: List[int], nums2: List[int], queries: List[List[int]]) -> List[int]:\n\t\t\"\"\"\n\t\tYou are given two 0-indexed arrays nums1 and nums2 and a 2D array queries of queries. There are three types of queries:\n\t\t\tFor a query of type 1, queries[i] = [1, l, r]. Flip the values from 0 to 1 and from 1 to 0 in nums1 from index l to index r. Both l and r are 0-indexed.\n\t\t\tFor a query of type 2, queries[i] = [2, p, 0]. For every index 0 <= i < n, set nums2[i] = nums2[i] + nums1[i] * p.\n\t\t\tFor a query of type 3, queries[i] = [3, 0, 0]. Find the sum of the elements in nums2.\n\t\tReturn an array containing all the answers to the third type queries.\n\t\tExample 1:\n\t\tInput: nums1 = [1,0,1], nums2 = [0,0,0], queries = [[1,1,1],[2,1,0],[3,0,0]]\n\t\tOutput: [3]\n\t\tExplanation: After the first query nums1 becomes [1,1,1]. After the second query, nums2 becomes [1,1,1], so the answer to the third query is 3. Thus, [3] is returned.\n\t\tExample 2:\n\t\tInput: nums1 = [1], nums2 = [5], queries = [[2,0,0],[3,0,0]]\n\t\tOutput: [5]\n\t\tExplanation: After the first query, nums2 remains [5], so the answer to the second query is 5. Thus, [5] is returned.\n\t\t\"\"\"\n",
-        "difficulty": 2
-    },
-    {
-        "number": 2704,
-        "question": "class Solution:\n    def minMaxDifference(self, num: int) -> int:\n\t\t\"\"\"\n\t\tYou are given an integer num. You know that Danny Mittal will sneakily remap one of the 10 possible digits (0 to 9) to another digit.\n\t\tReturn the difference between the maximum and minimum values Danny can make by remapping exactly one digit in num.\n\t\tNotes:\n\t\t\tWhen Danny remaps a digit d1 to another digit d2, Danny replaces all occurrences of d1 in num with d2.\n\t\t\tDanny can remap a digit to itself, in which case num does not change.\n\t\t\tDanny can remap different digits for obtaining minimum and maximum values respectively.\n\t\t\tThe resulting number after remapping can contain leading zeroes.\n\t\t\tWe mentioned \"Danny Mittal\" to congratulate him on being in the top 10 in Weekly Contest 326.\n\t\tExample 1:\n\t\tInput: num = 11891\n\t\tOutput: 99009\n\t\tExplanation: \n\t\tTo achieve the maximum value, Danny can remap the digit 1 to the digit 9 to yield 99899.\n\t\tTo achieve the minimum value, Danny can remap the digit 1 to the digit 0, yielding 890.\n\t\tThe difference between these two numbers is 99009.\n\t\tExample 2:\n\t\tInput: num = 90\n\t\tOutput: 99\n\t\tExplanation:\n\t\tThe maximum value that can be returned by the function is 99 (if 0 is replaced by 9) and the minimum value that can be returned by the function is 0 (if 9 is replaced by 0).\n\t\tThus, we return 99.\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 2705,
-        "question": "class Solution:\n    def minImpossibleOR(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou are given a 0-indexed integer array nums.\n\t\tWe say that an integer x is expressible from nums if there exist some integers 0 <= index1 < index2 < ... < indexk < nums.length for which nums[index1] | nums[index2] | ... | nums[indexk] = x. In other words, an integer is expressible if it can be written as the bitwise OR of some subsequence of nums.\n\t\tReturn the minimum positive non-zero integer that is not expressible from nums.\n\t\tExample 1:\n\t\tInput: nums = [2,1]\n\t\tOutput: 4\n\t\tExplanation: 1 and 2 are already present in the array. We know that 3 is expressible, since nums[0] | nums[1] = 2 | 1 = 3. Since 4 is not expressible, we return 4.\n\t\tExample 2:\n\t\tInput: nums = [5,3,2]\n\t\tOutput: 1\n\t\tExplanation: We can show that 1 is the smallest number that is not expressible.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2706,
-        "question": "class Solution:\n    def minimizeSum(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou are given a 0-indexed integer array nums.\n\t\t\tThe low score of nums is the minimum value of |nums[i] - nums[j]| over all 0 <= i < j < nums.length.\n\t\t\tThe high score of nums is the maximum value of |nums[i] - nums[j]| over all 0 <= i < j < nums.length.\n\t\t\tThe score of nums is the sum of the high and low scores of nums.\n\t\tTo minimize the score of nums, we can change the value of at most two elements of nums.\n\t\tReturn the minimum possible score after changing the value of at most two elements of nums.\n\t\tNote that |x| denotes the absolute value of x.\n\t\tExample 1:\n\t\tInput: nums = [1,4,3]\n\t\tOutput: 0\n\t\tExplanation: Change value of nums[1] and nums[2] to 1 so that nums becomes [1,1,1]. Now, the value of |nums[i] - nums[j]| is always equal to 0, so we return 0 + 0 = 0.\n\t\tExample 2:\n\t\tInput: nums = [1,4,7,8,5]\n\t\tOutput: 3\n\t\tExplanation: Change nums[0] and nums[1] to be 6. Now nums becomes [6,6,7,8,5].\n\t\tOur low score is achieved when i = 0 and j = 1, in which case |nums[i] - nums[j]| = |6 - 6| = 0.\n\t\tOur high score is achieved when i = 3 and j = 4, in which case |nums[i] - nums[j]| = |8 - 5| = 3.\n\t\tThe sum of our high and low score is 3, which we can prove to be minimal.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2707,
-        "question": "class Solution:\n    def mergeArrays(self, nums1: List[List[int]], nums2: List[List[int]]) -> List[List[int]]:\n\t\t\"\"\"\n\t\tYou are given two 2D integer arrays nums1 and nums2.\n\t\t\tnums1[i] = [idi, vali] indicate that the number with the id idi has a value equal to vali.\n\t\t\tnums2[i] = [idi, vali] indicate that the number with the id idi has a value equal to vali.\n\t\tEach array contains unique ids and is sorted in ascending order by id.\n\t\tMerge the two arrays into one array that is sorted in ascending order by id, respecting the following conditions:\n\t\t\tOnly ids that appear in at least one of the two arrays should be included in the resulting array.\n\t\t\tEach id should be included only once and its value should be the sum of the values of this id in the two arrays. If the id does not exist in one of the two arrays then its value in that array is considered to be 0.\n\t\tReturn the resulting array. The returned array must be sorted in ascending order by id.\n\t\tExample 1:\n\t\tInput: nums1 = [[1,2],[2,3],[4,5]], nums2 = [[1,4],[3,2],[4,1]]\n\t\tOutput: [[1,6],[2,3],[3,2],[4,6]]\n\t\tExplanation: The resulting array contains the following:\n\t\t- id = 1, the value of this id is 2 + 4 = 6.\n\t\t- id = 2, the value of this id is 3.\n\t\t- id = 3, the value of this id is 2.\n\t\t- id = 4, the value of this id is 5 + 1 = 6.\n\t\tExample 2:\n\t\tInput: nums1 = [[2,4],[3,6],[5,5]], nums2 = [[1,3],[4,3]]\n\t\tOutput: [[1,3],[2,4],[3,6],[4,3],[5,5]]\n\t\tExplanation: There are no common ids, so we just include each id with its value in the resulting list.\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 2708,
-        "question": "class Solution:\n    def findTheString(self, lcp: List[List[int]]) -> str:\n\t\t\"\"\"\n\t\tWe define the lcp matrix of any 0-indexed string word of n lowercase English letters as an n x n grid such that:\n\t\t\tlcp[i][j] is equal to the length of the longest common prefix between the substrings word[i,n-1] and word[j,n-1].\n\t\tGiven an n x n matrix lcp, return the alphabetically smallest string word that corresponds to lcp. If there is no such string, return an empty string.\n\t\tA string a is lexicographically smaller than a string b (of the same length) if in the first position where a and b differ, string a has a letter that appears earlier in the alphabet than the corresponding letter in b. For example, \"aabd\" is lexicographically smaller than \"aaca\" because the first position they differ is at the third letter, and 'b' comes before 'c'.\n\t\tExample 1:\n\t\tInput: lcp = [[4,0,2,0],[0,3,0,1],[2,0,2,0],[0,1,0,1]]\n\t\tOutput: \"abab\"\n\t\tExplanation: lcp corresponds to any 4 letter string with two alternating letters. The lexicographically smallest of them is \"abab\".\n\t\tExample 2:\n\t\tInput: lcp = [[4,3,2,1],[3,3,2,1],[2,2,2,1],[1,1,1,1]]\n\t\tOutput: \"aaaa\"\n\t\tExplanation: lcp corresponds to any 4 letter string with a single distinct letter. The lexicographically smallest of them is \"aaaa\". \n\t\tExample 3:\n\t\tInput: lcp = [[4,3,2,1],[3,3,2,1],[2,2,2,1],[1,1,1,3]]\n\t\tOutput: \"\"\n\t\tExplanation: lcp[3][3] cannot be equal to 3 since word[3,...,3] consists of only a single letter; Thus, no answer exists.\n\t\t\"\"\"\n",
-        "difficulty": 2
-    },
-    {
-        "number": 2709,
-        "question": "class Solution:\n    def squareFreeSubsets(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou are given a positive integer 0-indexed array nums.\n\t\tA subset of the array nums is square-free if the product of its elements is a square-free integer.\n\t\tA square-free integer is an integer that is divisible by no square number other than 1.\n\t\tReturn the number of square-free non-empty subsets of the array nums. Since the answer may be too large, return it modulo 109 + 7.\n\t\tA non-empty subset of nums is an array that can be obtained by deleting some (possibly none but not all) elements from nums. Two subsets are different if and only if the chosen indices to delete are different.\n\t\tExample 1:\n\t\tInput: nums = [3,4,4,5]\n\t\tOutput: 3\n\t\tExplanation: There are 3 square-free subsets in this example:\n\t\t- The subset consisting of the 0th element [3]. The product of its elements is 3, which is a square-free integer.\n\t\t- The subset consisting of the 3rd element [5]. The product of its elements is 5, which is a square-free integer.\n\t\t- The subset consisting of 0th and 3rd elements [3,5]. The product of its elements is 15, which is a square-free integer.\n\t\tIt can be proven that there are no more than 3 square-free subsets in the given array.\n\t\tExample 2:\n\t\tInput: nums = [1]\n\t\tOutput: 1\n\t\tExplanation: There is 1 square-free subset in this example:\n\t\t- The subset consisting of the 0th element [1]. The product of its elements is 1, which is a square-free integer.\n\t\tIt can be proven that there is no more than 1 square-free subset in the given array.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2710,
-        "question": "class Solution:\n    def minOperations(self, n: int) -> int:\n\t\t\"\"\"\n\t\tYou are given a positive integer n, you can do the following operation any number of times:\n\t\t\tAdd or subtract a power of 2 from n.\n\t\tReturn the minimum number of operations to make n equal to 0.\n\t\tA number x is power of 2 if x == 2i where i >= 0.\n\t\tExample 1:\n\t\tInput: n = 39\n\t\tOutput: 3\n\t\tExplanation: We can do the following operations:\n\t\t- Add 20 = 1 to n, so now n = 40.\n\t\t- Subtract 23 = 8 from n, so now n = 32.\n\t\t- Subtract 25 = 32 from n, so now n = 0.\n\t\tIt can be shown that 3 is the minimum number of operations we need to make n equal to 0.\n\t\tExample 2:\n\t\tInput: n = 54\n\t\tOutput: 3\n\t\tExplanation: We can do the following operations:\n\t\t- Add 21 = 2 to n, so now n = 56.\n\t\t- Add 23 = 8 to n, so now n = 64.\n\t\t- Subtract 26 = 64 from n, so now n = 0.\n\t\tSo the minimum number of operations is 3.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2711,
-        "question": "class Solution:\n    def minimumTime(self, grid: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tYou are given a m x n matrix grid consisting of non-negative integers where grid[row][col] represents the minimum time required to be able to visit the cell (row, col), which means you can visit the cell (row, col) only when the time you visit it is greater than or equal to grid[row][col].\n\t\tYou are standing in the top-left cell of the matrix in the 0th second, and you must move to any adjacent cell in the four directions: up, down, left, and right. Each move you make takes 1 second.\n\t\tReturn the minimum time required in which you can visit the bottom-right cell of the matrix. If you cannot visit the bottom-right cell, then return -1.\n\t\tExample 1:\n\t\tInput: grid = [[0,1,3,2],[5,1,2,5],[4,3,8,6]]\n\t\tOutput: 7\n\t\tExplanation: One of the paths that we can take is the following:\n\t\t- at t = 0, we are on the cell (0,0).\n\t\t- at t = 1, we move to the cell (0,1). It is possible because grid[0][1] <= 1.\n\t\t- at t = 2, we move to the cell (1,1). It is possible because grid[1][1] <= 2.\n\t\t- at t = 3, we move to the cell (1,2). It is possible because grid[1][2] <= 3.\n\t\t- at t = 4, we move to the cell (1,1). It is possible because grid[1][1] <= 4.\n\t\t- at t = 5, we move to the cell (1,2). It is possible because grid[1][2] <= 5.\n\t\t- at t = 6, we move to the cell (1,3). It is possible because grid[1][3] <= 6.\n\t\t- at t = 7, we move to the cell (2,3). It is possible because grid[1][3] <= 7.\n\t\tThe final time is 7. It can be shown that it is the minimum time possible.\n\t\tExample 2:\n\t\tInput: grid = [[0,2,4],[3,2,1],[1,0,4]]\n\t\tOutput: -1\n\t\tExplanation: There is no path from the top left to the bottom-right cell.\n\t\t\"\"\"\n",
-        "difficulty": 2
-    },
-    {
-        "number": 2712,
-        "question": "class Solution:\n    def maxNumOfMarkedIndices(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou are given a 0-indexed integer array nums.\n\t\tInitially, all of the indices are unmarked. You are allowed to make this operation any number of times:\n\t\t\tPick two different unmarked indices i and j such that 2 * nums[i] <= nums[j], then mark i and j.\n\t\tReturn the maximum possible number of marked indices in nums using the above operation any number of times.\n\t\tExample 1:\n\t\tInput: nums = [3,5,2,4]\n\t\tOutput: 2\n\t\tExplanation: In the first operation: pick i = 2 and j = 1, the operation is allowed because 2 * nums[2] <= nums[1]. Then mark index 2 and 1.\n\t\tIt can be shown that there's no other valid operation so the answer is 2.\n\t\tExample 2:\n\t\tInput: nums = [9,2,5,4]\n\t\tOutput: 4\n\t\tExplanation: In the first operation: pick i = 3 and j = 0, the operation is allowed because 2 * nums[3] <= nums[0]. Then mark index 3 and 0.\n\t\tIn the second operation: pick i = 1 and j = 2, the operation is allowed because 2 * nums[1] <= nums[2]. Then mark index 1 and 2.\n\t\tSince there is no other operation, the answer is 4.\n\t\tExample 3:\n\t\tInput: nums = [7,6,8]\n\t\tOutput: 0\n\t\tExplanation: There is no valid operation to do, so the answer is 0.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2713,
-        "question": "class Solution:\n    def divisibilityArray(self, word: str, m: int) -> List[int]:\n\t\t\"\"\"\n\t\tYou are given a 0-indexed string word of length n consisting of digits, and a positive integer m.\n\t\tThe divisibility array div of word is an integer array of length n such that:\n\t\t\tdiv[i] = 1 if the numeric value of word[0,...,i] is divisible by m, or\n\t\t\tdiv[i] = 0 otherwise.\n\t\tReturn the divisibility array of word.\n\t\tExample 1:\n\t\tInput: word = \"998244353\", m = 3\n\t\tOutput: [1,1,0,0,0,1,1,0,0]\n\t\tExplanation: There are only 4 prefixes that are divisible by 3: \"9\", \"99\", \"998244\", and \"9982443\".\n\t\tExample 2:\n\t\tInput: word = \"1010\", m = 10\n\t\tOutput: [0,1,0,1]\n\t\tExplanation: There are only 2 prefixes that are divisible by 10: \"10\", and \"1010\".\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 2714,
-        "question": "class Solution:\n    def leftRigthDifference(self, nums: List[int]) -> List[int]:\n\t\t\"\"\"\n\t\tGiven a 0-indexed integer array nums, find a 0-indexed integer array answer where:\n\t\t    answer.length == nums.length.\n\t\t    answer[i] = |leftSum[i] - rightSum[i]|.\n\t\tWhere:\n\t\t    leftSum[i] is the sum of elements to the left of the index i in the array nums. If there is no such element, leftSum[i] = 0.\n\t\t    rightSum[i] is the sum of elements to the right of the index i in the array nums. If there is no such element, rightSum[i] = 0.\n\t\tReturn the array answer.\n\t\tExample 1:\n\t\tInput: nums = [10,4,8,3]\n\t\tOutput: [15,1,11,22]\n\t\tExplanation: The array leftSum is [0,10,14,22] and the array rightSum is [15,11,3,0].\n\t\tThe array answer is [|0 - 15|,|10 - 11|,|14 - 3|,|22 - 0|] = [15,1,11,22].\n\t\tExample 2:\n\t\tInput: nums = [1]\n\t\tOutput: [0]\n\t\tExplanation: The array leftSum is [0] and the array rightSum is [0].\n\t\tThe array answer is [|0 - 0|] = [0].\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 100092,
-        "question": "class Solution:\n    def fraction(self, cont: List[int]) -> List[int]:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\r\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 100093,
-        "question": "class Solution:\n    def domino(self, n: int, m: int, broken: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\r\n\t\t\"\"\"\n",
-        "difficulty": 2
-    },
-    {
-        "number": 100094,
-        "question": "class Solution:\n    def bonus(self, n: int, leadership: List[List[int]], operations: List[List[int]]) -> List[int]:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\r\n\t\t\"\"\"\n",
-        "difficulty": 2
-    },
-    {
-        "number": 100096,
-        "question": "class Solution:\n    def robot(self, command: str, obstacles: List[List[int]], x: int, y: int) -> bool:\n\t\t\"\"\"\n\t\tEnglish description is not available. Please switch to Chinese.\r\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 100107,
-        "question": "class Solution:\n    def game(self, guess: List[int], answer: List[int]) -> int:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\r\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 100158,
-        "question": "class Solution:\n    def isUnique(self, astr: str) -> bool:\n\t\t\"\"\"\n\t\tImplement an algorithm to determine if a string has all unique characters. What if you cannot use additional data structures?\r\n\t\tExample 1:\r\n\t\tInput: s = \"leetcode\"\r\n\t\tOutput: false\r\n\t\tExample 2:\r\n\t\tInput: s = \"abc\"\r\n\t\tOutput: true\r\n\t\tNote:\r\n\t\t\t0 <= len(s) <= 100 \r\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 100159,
-        "question": "class Solution:\n    def CheckPermutation(self, s1: str, s2: str) -> bool:\n\t\t\"\"\"\n\t\tGiven two strings,write a method to decide if one is a permutation of the other.\r\n\t\tExample 1:\r\n\t\tInput: s1 = \"abc\", s2 = \"bca\"\r\n\t\tOutput: true\r\n\t\tExample 2:\r\n\t\tInput: s1 = \"abc\", s2 = \"bad\"\r\n\t\tOutput: false\r\n\t\tNote:\r\n\t\t\t0 <= len(s1) <= 100 \r\n\t\t\t0 <= len(s2) <= 100\r\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 100160,
-        "question": "class Solution:\n    def replaceSpaces(self, S: str, length: int) -> str:\n\t\t\"\"\"\n\t\tWrite a method to replace all spaces in a string with '%20'. You may assume that the string has sufficient space at the end to hold the additional characters,and that you are given the \"true\" length of the string. (Note: If implementing in Java,please use a character array so that you can perform this operation in place.)\r\n\t\tExample 1:\r\n\t\tInput: \"Mr John Smith \", 13\r\n\t\tOutput: \"Mr%20John%20Smith\"\r\n\t\tExample 2:\r\n\t\tInput: \"               \", 5\r\n\t\tOutput: \"%20%20%20%20%20\"\r\n\t\tNote:\r\n\t\t\t0 <= S.length <= 500000\r\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 100161,
-        "question": "class Solution:\n    def compressString(self, S: str) -> str:\n\t\t\"\"\"\n\t\tImplement a method to perform basic string compression using the counts of repeated characters. For example, the string aabcccccaaa would become a2blc5a3. If the \"compressed\" string would not become smaller than the original string, your method should return the original string. You can assume the string has only uppercase and lowercase letters (a - z).\r\n\t\tExample 1:\r\n\t\tInput: \"aabcccccaaa\"\r\n\t\tOutput: \"a2b1c5a3\"\r\n\t\tExample 2:\r\n\t\tInput: \"abbccd\"\r\n\t\tOutput: \"abbccd\"\r\n\t\tExplanation: \r\n\t\tThe compressed string is \"a1b2c2d1\", which is longer than the original string.\r\n\t\tNote:\r\n\t\t\t0 <= S.length <= 50000\r\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 100162,
-        "question": "class Solution:\n    def isFlipedString(self, s1: str, s2: str) -> bool:\n\t\t\"\"\"\n\t\tGiven two strings, s1 and s2, write code to check if s2 is a rotation of s1 (e.g.,\"waterbottle\" is a rotation of\"erbottlewat\"). Can you use only one call to the method that checks if one word is a substring of another?\r\n\t\tExample 1:\r\n\t\tInput: s1 = \"waterbottle\", s2 = \"erbottlewat\"\r\n\t\tOutput: True\r\n\t\tExample 2:\r\n\t\tInput: s1 = \"aa\", s2 = \"aba\"\r\n\t\tOutput: False\r\n\t\tNote:\r\n\t\t\t0 <= s1.length, s2.length <= 100000\r\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 100163,
-        "question": "class Solution:\n    def removeDuplicateNodes(self, head: ListNode) -> ListNode:\n\t\t\"\"\"\n\t\tWrite code to remove duplicates from an unsorted linked list.\r\n\t\tExample1:\r\n\t\t Input: [1, 2, 3, 3, 2, 1]\r\n\t\t Output: [1, 2, 3]\r\n\t\tExample2:\r\n\t\t Input: [1, 1, 1, 1, 2]\r\n\t\t Output: [1, 2]\r\n\t\tNote: \r\n\t\t\tThe length of the list is within the range[0, 20000].\r\n\t\t\tThe values of the list elements are within the range [0, 20000].\r\n\t\tFollow Up: \r\n\t\tHow would you solve this problem if a temporary buffer is not allowed?\r\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 100164,
-        "question": "class Solution:\n    def isPalindrome(self, head: ListNode) -> bool:\n\t\t\"\"\"\n\t\tImplement a function to check if a linked list is a palindrome.\r\n\t\tExample 1: \r\n\t\tInput:  1->2\r\n\t\tOutput:  false \r\n\t\tExample 2: \r\n\t\tInput:  1->2->2->1\r\n\t\tOutput:  true \r\n\t\tFollow up:\r\n\t\tCould you do it in O(n) time and O(1) space?\r\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 100167,
-        "question": "class Solution:\n    def getIntersectionNode(self, headA: ListNode, headB: ListNode) -> ListNode:\n\t\t\"\"\"\n\t\tGiven two (singly) linked lists, determine if the two lists intersect. Return the inter\u00ad secting node. Note that the intersection is defined based on reference, not value. That is, if the kth node of the first linked list is the exact same node (by reference) as the jth node of the second linked list, then they are intersecting.\r\n\t\tExample 1: \r\n\t\tInput: intersectVal = 8, listA = [4,1,8,4,5], listB = [5,0,1,8,4,5], skipA = 2, skipB = 3\r\n\t\tOutput: Reference of the node with value = 8\r\n\t\tInput Explanation: The intersected node's value is 8 (note that this must not be 0 if the two lists intersect). From the head of A, it reads as [4,1,8,4,5]. From the head of B, it reads as [5,0,1,8,4,5]. There are 2 nodes before the intersected node in A; There are 3 nodes before the intersected node in B.\r\n\t\tExample 2: \r\n\t\tInput: intersectVal = 2, listA = [0,9,1,2,4], listB = [3,2,4], skipA = 3, skipB = 1\r\n\t\tOutput: Reference of the node with value = 2\r\n\t\tInput Explanation: The intersected node's value is 2 (note that this must not be 0 if the two lists intersect). From the head of A, it reads as [0,9,1,2,4]. From the head of B, it reads as [3,2,4]. There are 3 nodes before the intersected node in A; There are 1 node before the intersected node in B.\r\n\t\tExample 3: \r\n\t\tInput: intersectVal = 0, listA = [2,6,4], listB = [1,5], skipA = 3, skipB = 2\r\n\t\tOutput: null\r\n\t\tInput Explanation: From the head of A, it reads as [2,6,4]. From the head of B, it reads as [1,5]. Since the two lists do not intersect, intersectVal must be 0, while skipA and skipB can be arbitrary values.\r\n\t\tExplanation: The two lists do not intersect, so return null.\r\n\t\tNotes:\r\n\t\t\tIf the two linked lists have no intersection at all, return null.\r\n\t\t\tThe linked lists must retain their original structure after the function returns.\r\n\t\t\tYou may assume there are no cycles anywhere in the entire linked structure.\r\n\t\t\tYour code should preferably run in O(n) time and use only O(1) memory.\r\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 100168,
-        "question": "class Solution:\n    def detectCycle(self, head: ListNode) -> ListNode:\n\t\t\"\"\"\n\t\tGiven a circular linked list, implement an algorithm that returns the node at the beginning of the loop.\r\n\t\tCircular linked list: A (corrupt) linked list in which a node's next pointer points to an earlier node, so as to make a loop in the linked list.\r\n\t\tExample 1: \r\n\t\tInput: head = [3,2,0,-4], pos = 1\r\n\t\tOutput: tail connects to node index 1\r\n\t\tExample 2: \r\n\t\tInput: head = [1,2], pos = 0\r\n\t\tOutput: tail connects to node index 0\r\n\t\tExample 3: \r\n\t\tInput: head = [1], pos = -1\r\n\t\tOutput: no cycle\r\n\t\tFollow Up: \r\n\t\tCan you solve it without using additional space?\r\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 100169,
-        "question": "class MinStack:\n    def __init__(self):\n\t\t\"\"\"\n        initialize your data structure here.\n\t\tHow would you design a stack which, in addition to push and pop, has a function min which returns the minimum element? Push, pop and min should all operate in 0(1) time.\r\n\t\tExample: \r\n\t\tMinStack minStack = new MinStack();\r\n\t\tminStack.push(-2);\r\n\t\tminStack.push(0);\r\n\t\tminStack.push(-3);\r\n\t\tminStack.getMin();   --> return -3.\r\n\t\tminStack.pop();\r\n\t\tminStack.top();      --> return 0.\r\n\t\tminStack.getMin();   --> return -2.\r\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 100170,
-        "question": "class MyQueue:\n    def __init__(self):\n\t\t\"\"\"\n        Initialize your data structure here.\n\t\tImplement a MyQueue class which implements a queue using two stacks.\r\n\t\tExample: \r\n\t\tMyQueue queue = new MyQueue();\r\n\t\tqueue.push(1);\r\n\t\tqueue.push(2);\r\n\t\tqueue.peek();  // return 1\r\n\t\tqueue.pop();   // return 1\r\n\t\tqueue.empty(); // return false\r\n\t\tNotes:\r\n\t\t\tYou must use only standard operations of a stack -- which means only push to top, peek/pop from top, size, and is empty operations are valid.\r\n\t\t\tDepending on your language, stack may not be supported natively. You may simulate a stack by using a list or deque (double-ended queue), as long as you use only standard operations of a stack.\r\n\t\t\tYou may assume that all operations are valid (for example, no pop or peek operations will be called on an empty queue).\r\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 100171,
-        "question": "class Solution:\n    def findWhetherExistsPath(self, n: int, graph: List[List[int]], start: int, target: int) -> bool:\n\t\t\"\"\"\n\t\tGiven a directed graph, design an algorithm to find out whether there is a route between two nodes.\r\n\t\tExample1:\r\n\t\t Input: n = 3, graph = [[0, 1], [0, 2], [1, 2], [1, 2]], start = 0, target = 2\r\n\t\t Output: true\r\n\t\tExample2:\r\n\t\t Input: n = 5, graph = [[0, 1], [0, 2], [0, 4], [0, 4], [0, 1], [1, 3], [1, 4], [1, 3], [2, 3], [3, 4]], start = 0, target = 4\r\n\t\t Output true\r\n\t\tNote: \r\n\t\t\t0 <= n <= 100000\r\n\t\t\tAll node numbers are within the range [0, n].\r\n\t\t\tThere might be self cycles and duplicated edges.\r\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 100172,
-        "question": "class TripleInOne:\n    def __init__(self, stackSize: int):\n    def push(self, stackNum: int, value: int) -> None:\n    def pop(self, stackNum: int) -> int:\n    def peek(self, stackNum: int) -> int:\n    def isEmpty(self, stackNum: int) -> bool:\n\t\t\"\"\"\n\t\tDescribe how you could use a single array to implement three stacks.\r\n\t\tYou should implement push(stackNum, value)\u3001pop(stackNum)\u3001isEmpty(stackNum)\u3001peek(stackNum) methods. stackNum is the index of the stack. value is the value that pushed to the stack.\r\n\t\tThe constructor requires a stackSize parameter, which represents the size of each stack.\r\n\t\tExample1:\r\n\t\t Input: \r\n\t\t[\"TripleInOne\", \"push\", \"push\", \"pop\", \"pop\", \"pop\", \"isEmpty\"]\r\n\t\t[[1], [0, 1], [0, 2], [0], [0], [0], [0]]\r\n\t\t Output: \r\n\t\t[null, null, null, 1, -1, -1, true]\r\n\t\tExplanation: When the stack is empty, `pop, peek` return -1. When the stack is full, `push` does nothing.\r\n\t\tExample2:\r\n\t\t Input: \r\n\t\t[\"TripleInOne\", \"push\", \"push\", \"push\", \"pop\", \"pop\", \"pop\", \"peek\"]\r\n\t\t[[2], [0, 1], [0, 2], [0, 3], [0], [0], [0], [0]]\r\n\t\t Output: \r\n\t\t[null, null, null, null, 2, 1, -1, -1]\r\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 100173,
-        "question": "class SortedStack:\n    def __init__(self):\n    def push(self, val: int) -> None:\n    def pop(self) -> None:\n    def peek(self) -> int:\n    def isEmpty(self) -> bool:\n\t\t\"\"\"\n\t\tWrite a program to sort a stack such that the smallest items are on the top. You can use an additional temporary stack, but you may not copy the elements into any other data structure (such as an array). The stack supports the following operations: push, pop, peek, and isEmpty. When the stack is empty, peek should return -1.\r\n\t\tExample1:\r\n\t\t Input: \r\n\t\t[\"SortedStack\", \"push\", \"push\", \"peek\", \"pop\", \"peek\"]\r\n\t\t[[], [1], [2], [], [], []]\r\n\t\t Output: \r\n\t\t[null,null,null,1,null,2]\r\n\t\tExample2:\r\n\t\t Input:  \r\n\t\t[\"SortedStack\", \"pop\", \"pop\", \"push\", \"pop\", \"isEmpty\"]\r\n\t\t[[], [], [], [1], [], []]\r\n\t\t Output: \r\n\t\t[null,null,null,null,null,true]\r\n\t\tNote:\r\n\t\t\tThe total number of elements in the stack is within the range [0, 5000].\r\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 100174,
-        "question": "class Solution:\n    def sortedArrayToBST(self, nums: List[int]) -> TreeNode:\n\t\t\"\"\"\n\t\tGiven a sorted (increasing order) array with unique integer elements, write an algo\u00adrithm to create a binary search tree with minimal height.\r\n\t\tExample:\r\n\t\tGiven sorted array: [-10,-3,0,5,9],\r\n\t\tOne possible answer is: [0,-3,9,-10,null,5]\uff0cwhich represents the following tree: \r\n\t\t          0 \r\n\t\t         / \\ \r\n\t\t       -3   9 \r\n\t\t       /   / \r\n\t\t     -10  5 \r\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 100175,
-        "question": "class Solution:\n    def listOfDepth(self, tree: TreeNode) -> List[ListNode]:\n\t\t\"\"\"\n\t\tGiven a binary tree, design an algorithm which creates a linked list of all the nodes at each depth (e.g., if you have a tree with depth D, you'll have D linked lists). Return a array containing all the linked lists.\r\n\t\tExample: \r\n\t\tInput: [1,2,3,4,5,null,7,8]\r\n\t\t        1\r\n\t\t       /  \\ \r\n\t\t      2    3\r\n\t\t     / \\    \\ \r\n\t\t    4   5    7\r\n\t\t   /\r\n\t\t  8\r\n\t\tOutput: [[1],[2,3],[4,5,7],[8]]\r\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 100176,
-        "question": "class Solution:\n    def isBalanced(self, root: TreeNode) -> bool:\n\t\t\"\"\"\n\t\tImplement a function to check if a binary tree is balanced. For the purposes of this question, a balanced tree is defined to be a tree such that the heights of the two subtrees of any node never differ by more than one.\r\n\t\tExample 1:\r\n\t\tGiven tree [3,9,20,null,null,15,7]\r\n\t\t    3\r\n\t\t   / \\\r\n\t\t  9  20\r\n\t\t    /  \\\r\n\t\t   15   7\r\n\t\treturn true.\r\n\t\tExample 2:\r\n\t\tGiven [1,2,2,3,3,null,null,4,4]\r\n\t\t      1\r\n\t\t     / \\\r\n\t\t    2   2\r\n\t\t   / \\\r\n\t\t  3   3\r\n\t\t / \\\r\n\t\t4   4\r\n\t\treturn false.\r\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 100177,
-        "question": "class Solution:\n    def isValidBST(self, root: TreeNode) -> bool:\n\t\t\"\"\"\n\t\tImplement a function to check if a binary tree is a binary search tree.\r\n\t\tExample 1:\r\n\t\tInput:\r\n\t\t    2\r\n\t\t   / \\\r\n\t\t  1   3\r\n\t\tOutput: true\r\n\t\tExample 2:\r\n\t\tInput:\r\n\t\t    5\r\n\t\t   / \\\r\n\t\t  1   4\r\n\t\t     / \\\r\n\t\t    3   6\r\n\t\tOutput: false\r\n\t\tExplanation: Input: [5,1,4,null,null,3,6].\r\n\t\t     the value of root node is 5, but its right child has value 4.\r\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 100178,
-        "question": "class Solution:\n    def inorderSuccessor(self, root: TreeNode, p: TreeNode) -> TreeNode:\n\t\t\"\"\"\n\t\tWrite an algorithm to find the \"next\" node (i.e., in-order successor) of a given node in a binary search tree.\r\n\t\tReturn null if there's no \"next\" node for the given node.\r\n\t\tExample 1:\r\n\t\tInput: root = [2,1,3], p = 1\r\n\t\t  2\r\n\t\t / \\\r\n\t\t1   3\r\n\t\tOutput: 2\r\n\t\tExample 2:\r\n\t\tInput: root = [5,3,6,2,4,null,null,1], p = 6\r\n\t\t      5\r\n\t\t     / \\\r\n\t\t    3   6\r\n\t\t   / \\\r\n\t\t  2   4\r\n\t\t /   \r\n\t\t1\r\n\t\tOutput: null\r\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 100179,
-        "question": "class Solution:\n    def lowestCommonAncestor(self, root: TreeNode, p: TreeNode, q: TreeNode) -> TreeNode:\n\t\t\"\"\"\n\t\tDesign an algorithm and write code to find the first common ancestor of two nodes in a binary tree. Avoid storing additional nodes in a data structure. NOTE: This is not necessarily a binary search tree.\r\n\t\tFor example, Given the following tree: root = [3,5,1,6,2,0,8,null,null,7,4]\r\n\t\t    3\r\n\t\t   / \\\r\n\t\t  5   1\r\n\t\t / \\ / \\\r\n\t\t6  2 0  8\r\n\t\t  / \\\r\n\t\t 7   4\r\n\t\tExample 1:\r\n\t\tInput: root = [3,5,1,6,2,0,8,null,null,7,4], p = 5, q = 1\r\n\t\tInput: 3\r\n\t\tExplanation: The first common ancestor of node 5 and node 1 is node 3.\r\n\t\tExample 2:\r\n\t\tInput: root = [3,5,1,6,2,0,8,null,null,7,4], p = 5, q = 4\r\n\t\tOutput: 5\r\n\t\tExplanation: The first common ancestor of node 5 and node 4 is node 5.\r\n\t\tNotes:\r\n\t\t\tAll node values are pairwise distinct.\r\n\t\t\tp, q are different node and both can be found in the given tree.\r\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 100180,
-        "question": "class Solution:\n    def insertBits(self, N: int, M: int, i: int, j: int) -> int:\n\t\t\"\"\"\n\t\tYou are given two 32-bit numbers, N and M, and two bit positions, i and j. Write a method to insert M into N such that M starts at bit j and ends at bit i. You can assume that the bits j through i have enough space to fit all of M. That is, if M = 10011, you can assume that there are at least 5 bits between j and i. You would not, for example, have j = 3 and i = 2, because M could not fully fit between bit 3 and bit 2.\r\n\t\tExample1:\r\n\t\t Input: N = 10000000000, M = 10011, i = 2, j = 6\r\n\t\t Output: N = 10001001100\r\n\t\tExample2:\r\n\t\t Input:  N = 0, M = 11111, i = 0, j = 4\r\n\t\t Output: N = 11111\r\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 100181,
-        "question": "class Solution:\n    def convertInteger(self, A: int, B: int) -> int:\n\t\t\"\"\"\n\t\tWrite a function to determine the number of bits you would need to flip to convert integer A to integer B.\r\n\t\tExample1:\r\n\t\t Input: A = 29 (0b11101), B = 15 (0b01111)\r\n\t\t Output: 2\r\n\t\tExample2:\r\n\t\t Input: A = 1\uff0cB = 2\r\n\t\t Output: 2\r\n\t\tNote:\r\n\t\t\t-2147483648 <= A, B <= 2147483647\r\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 100182,
-        "question": "class Solution:\n    def exchangeBits(self, num: int) -> int:\n\t\t\"\"\"\n\t\tWrite a program to swap odd and even bits in an integer with as few instructions as possible (e.g., bit 0 and bit 1 are swapped, bit 2 and bit 3 are swapped, and so on).\r\n\t\tExample1:\r\n\t\t Input: num = 2\uff080b10\uff09\r\n\t\t Output 1 (0b01)\r\n\t\tExample2:\r\n\t\t Input: num = 3\r\n\t\t Output: 3\r\n\t\tNote:\r\n\t\t\t0 <= num <= 2^30 - 1\r\n\t\t\tThe result integer fits into 32-bit integer.\r\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 100183,
-        "question": "class Solution:\n    def findClosedNumbers(self, num: int) -> List[int]:\n\t\t\"\"\"\n\t\tGiven a positive integer, print the next smallest and the next largest number that have the same number of 1 bits in their binary representation.\r\n\t\tExample1:\r\n\t\t Input: num = 2 (0b10)\r\n\t\t Output: [4, 1] ([0b100, 0b1])\r\n\t\tExample2:\r\n\t\t Input: num = 1\r\n\t\t Output: [2, -1]\r\n\t\tNote:\r\n\t\t\t1 <= num <= 2147483647\r\n\t\t\tIf there is no next smallest or next largest number, output -1.\r\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 100184,
-        "question": "class Solution:\n    def canPermutePalindrome(self, s: str) -> bool:\n\t\t\"\"\"\n\t\tGiven a string, write a function to check if it is a permutation of a palindrome. A palindrome is a word or phrase that is the same forwards and backwards. A permutation is a rearrangement of letters. The palindrome does not need to be limited to just dictionary words.\r\n\t\tExample1: \r\n\t\tInput: \"tactcoa\"\r\n\t\tOutput: true\uff08permutations: \"tacocat\"\u3001\"atcocta\", etc.\uff09\r\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 100185,
-        "question": "class Solution:\n    def rotate(self, matrix: List[List[int]]) -> None:\n\t\t\"\"\"\n        Do not return anything, modify matrix in-place instead.\n\t\tGiven an image represented by an N x N matrix, where each pixel in the image is 4 bytes, write a method to rotate the image by 90 degrees. Can you do this in place?\r\n\t\tExample 1:\r\n\t\tGiven matrix = \r\n\t\t[\r\n\t\t  [1,2,3],\r\n\t\t  [4,5,6],\r\n\t\t  [7,8,9]\r\n\t\t],\r\n\t\tRotate the matrix in place. It becomes:\r\n\t\t[\r\n\t\t  [7,4,1],\r\n\t\t  [8,5,2],\r\n\t\t  [9,6,3]\r\n\t\t]\r\n\t\tExample 2:\r\n\t\tGiven matrix =\r\n\t\t[\r\n\t\t  [ 5, 1, 9,11],\r\n\t\t  [ 2, 4, 8,10],\r\n\t\t  [13, 3, 6, 7],\r\n\t\t  [15,14,12,16]\r\n\t\t], \r\n\t\tRotate the matrix in place. It becomes:\r\n\t\t[\r\n\t\t  [15,13, 2, 5],\r\n\t\t  [14, 3, 4, 1],\r\n\t\t  [12, 6, 8, 9],\r\n\t\t  [16, 7,10,11]\r\n\t\t]\r\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 100186,
-        "question": "class Solution:\n    def setZeroes(self, matrix: List[List[int]]) -> None:\n\t\t\"\"\"\n        Do not return anything, modify matrix in-place instead.\n\t\tWrite an algorithm such that if an element in an MxN matrix is 0, its entire row and column are set to 0.\r\n\t\tExample 1: \r\n\t\tInput: \r\n\t\t[\r\n\t\t  [1,1,1],\r\n\t\t  [1,0,1],\r\n\t\t  [1,1,1]\r\n\t\t]\r\n\t\tOutput: \r\n\t\t[\r\n\t\t  [1,0,1],\r\n\t\t  [0,0,0],\r\n\t\t  [1,0,1]\r\n\t\t]\r\n\t\tExample 2: \r\n\t\tInput: \r\n\t\t[\r\n\t\t  [0,1,2,0],\r\n\t\t  [3,4,5,2],\r\n\t\t  [1,3,1,5]\r\n\t\t]\r\n\t\tOutput: \r\n\t\t[\r\n\t\t  [0,0,0,0],\r\n\t\t  [0,4,5,0],\r\n\t\t  [0,3,1,0]\r\n\t\t]\r\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 100187,
-        "question": "class Solution:\n    def deleteNode(self, node):\n\t\t\"\"\"\n        :type node: ListNode\n        :rtype: void Do not return anything, modify node in-place instead.\n\t\tImplement an algorithm to delete a node in the middle (i.e., any node but the first and last node, not necessarily the exact middle) of a singly linked list, given only access to that node.\r\n\t\tExample: \r\n\t\tInput: the node c from the linked list a->b->c->d->e->f\r\n\t\tOutput: nothing is returned, but the new linked list looks like a->b->d->e->f\r\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 100188,
-        "question": "class Solution:\n    def addTwoNumbers(self, l1: ListNode, l2: ListNode) -> ListNode:\n\t\t\"\"\"\n\t\tYou have two numbers represented by a linked list, where each node contains a single digit. The digits are stored in reverse order, such that the 1's digit is at the head of the list. Write a function that adds the two numbers and returns the sum as a linked list.\r\n\t\tExample: \r\n\t\tInput: (7 -> 1 -> 6) + (5 -> 9 -> 2). That is, 617 + 295.\r\n\t\tOutput: 2 -> 1 -> 9. That is, 912.\r\n\t\tFollow Up: Suppose the digits are stored in forward order. Repeat the above problem.\r\n\t\tExample: \r\n\t\tInput: (6 -> 1 -> 7) + (2 -> 9 -> 5). That is, 617 + 295.\r\n\t\tOutput: 9 -> 1 -> 2. That is, 912.\r\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 100195,
-        "question": "class StackOfPlates:\n    def __init__(self, cap: int):\n    def push(self, val: int) -> None:\n    def pop(self) -> int:\n    def popAt(self, index: int) -> int:\n\t\t\"\"\"\n\t\tImagine a (literal) stack of plates. If the stack gets too high, it might topple. Therefore, in real life, we would likely start a new stack when the previous stack exceeds some threshold. Implement a data structure SetOfStacks that mimics this. SetOfStacks should be composed of several stacks and should create a new stack once the previous one exceeds capacity. SetOfStacks.push() and SetOfStacks.pop() should behave identically to a single stack (that is, pop() should return the same values as it would if there were just a single stack). Follow Up: Implement a function popAt(int index) which performs a pop operation on a specific sub-stack.\r\n\t\tYou should delete the sub-stack when it becomes empty. pop, popAt should return -1 when there's no element to pop.\r\n\t\tExample1:\r\n\t\t Input: \r\n\t\t[\"StackOfPlates\", \"push\", \"push\", \"popAt\", \"pop\", \"pop\"]\r\n\t\t[[1], [1], [2], [1], [], []]\r\n\t\t Output: \r\n\t\t[null, null, null, 2, 1, -1]\r\n\t\t Explanation: \r\n\t\tExample2:\r\n\t\t Input: \r\n\t\t[\"StackOfPlates\", \"push\", \"push\", \"push\", \"popAt\", \"popAt\", \"popAt\"]\r\n\t\t[[2], [1], [2], [3], [0], [0], [0]]\r\n\t\t Output: \r\n\t\t[null, null, null, null, 2, 1, 3]\r\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 100196,
-        "question": "class Solution:\n    def drawLine(self, length: int, w: int, x1: int, x2: int, y: int) -> List[int]:\n\t\t\"\"\"\n\t\tA monochrome screen is stored as a single array of int, allowing 32 consecutive pixels to be stored in one int. The screen has width w, where w is divisible by 32 (that is, no byte will be split across rows). The height of the screen, of course, can be derived from the length of the array and the width. Implement a function that draws a horizontal line from (x1, y) to (x2, y).\r\n\t\tGiven the length of the array, the width of the array (in bit), start position x1 (in bit) of the line, end position x2 (in bit) of the line and the row number y of the line, return the array after drawing.\r\n\t\tExample1:\r\n\t\t Input: length = 1, w = 32, x1 = 30, x2 = 31, y = 0\r\n\t\t Output: [3]\r\n\t\t Explanation: After drawing a line from (30, 0) to (31, 0), the screen becomes [0b000000000000000000000000000000011].\r\n\t\tExample2:\r\n\t\t Input: length = 3, w = 96, x1 = 0, x2 = 95, y = 0\r\n\t\t Output: [-1, -1, -1]\r\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 100197,
-        "question": "class Solution:\n    def waysToStep(self, n: int) -> int:\n\t\t\"\"\"\n\t\tA child is running up a staircase with n steps and can hop either 1 step, 2 steps, or 3 steps at a time. Implement a method to count how many possible ways the child can run up the stairs. The result may be large, so return it modulo 1000000007.\r\n\t\tExample1:\r\n\t\t Input: n = 3 \r\n\t\t Output: 4\r\n\t\tExample2:\r\n\t\t Input: n = 5\r\n\t\t Output: 13\r\n\t\tNote:\r\n\t\t\t1 <= n <= 1000000\r\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 100198,
-        "question": "class Solution:\n    def subsets(self, nums: List[int]) -> List[List[int]]:\n\t\t\"\"\"\n\t\tWrite a method to return all subsets of a set. The elements in a set are pairwise distinct.\r\n\t\tNote: The result set should not contain duplicated subsets.\r\n\t\tExample:\r\n\t\t Input:  nums = [1,2,3]\r\n\t\t Output: \r\n\t\t[\r\n\t\t  [3],\r\n\t\t  [1],\r\n\t\t  [2],\r\n\t\t  [1,2,3],\r\n\t\t  [1,3],\r\n\t\t  [2,3],\r\n\t\t  [1,2],\r\n\t\t  []\r\n\t\t]\r\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 100199,
-        "question": "class Solution:\n    def multiply(self, A: int, B: int) -> int:\n\t\t\"\"\"\n\t\tWrite a recursive function to multiply two positive integers without using the * operator. You can use addition, subtraction, and bit shifting, but you should minimize the number of those operations.\r\n\t\tExample 1:\r\n\t\t Input: A = 1, B = 10\r\n\t\t Output: 10\r\n\t\tExample 2:\r\n\t\t Input: A = 3, B = 4\r\n\t\t Output: 12\r\n\t\tNote:\r\n\t\t\tThe result will not overflow.\r\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 100200,
-        "question": "class Solution:\n    def generateParenthesis(self, n: int) -> List[str]:\n\t\t\"\"\"\n\t\tImplement an algorithm to print all valid (e.g., properly opened and closed) combinations of n pairs of parentheses.\r\n\t\tNote: The result set should not contain duplicated subsets.\r\n\t\tFor example, given n = 3, the result should be:\r\n\t\t[\r\n\t\t  \"((()))\",\r\n\t\t  \"(()())\",\r\n\t\t  \"(())()\",\r\n\t\t  \"()(())\",\r\n\t\t  \"()()()\"\r\n\t\t]\r\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 100201,
-        "question": "class Solution:\n    def floodFill(self, image: List[List[int]], sr: int, sc: int, newColor: int) -> List[List[int]]:\n\t\t\"\"\"\n\t\tImplement the \"paint fill\" function that one might see on many image editing programs. That is, given a screen (represented by a two-dimensional array of colors), a point, and a new color, fill in the surrounding area until the color changes from the original color.\r\n\t\tExample1:\r\n\t\tInput: \r\n\t\timage = [[1,1,1],[1,1,0],[1,0,1]] \r\n\t\tsr = 1, sc = 1, newColor = 2\r\n\t\tOutput: [[2,2,2],[2,2,0],[2,0,1]]\r\n\t\tExplanation: \r\n\t\tFrom the center of the image (with position (sr, sc) = (1, 1)), all pixels connected \r\n\t\tby a path of the same color as the starting pixel are colored with the new color.\r\n\t\tNote the bottom corner is not colored 2, because it is not 4-directionally connected\r\n\t\tto the starting pixel.\r\n\t\tNote:\r\n\t\t\tThe length of image and image[0] will be in the range [1, 50].\r\n\t\t\tThe given starting pixel will satisfy 0 <= sr < image.length and 0 <= sc < image[0].length.\r\n\t\t\tThe value of each color in image[i][j] and newColor will be an integer in [0, 65535].\r\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 100202,
-        "question": "class Solution:\n    def pileBox(self, box: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tYou have a stack of n boxes, with widths wi, depths di, and heights hi. The boxes cannot be rotated and can only be stacked on top of one another if each box in the stack is strictly larger than the box above it in width, height, and depth. Implement a method to compute the height of the tallest possible stack. The height of a stack is the sum of the heights of each box.\r\n\t\tThe input use [wi, di, hi] to represents each box.\r\n\t\tExample1:\r\n\t\t Input: box = [[1, 1, 1], [2, 2, 2], [3, 3, 3]]\r\n\t\t Output: 6\r\n\t\tExample2:\r\n\t\t Input: box = [[1, 1, 1], [2, 3, 4], [2, 6, 7], [3, 4, 5]]\r\n\t\t Output: 10\r\n\t\tNote:\r\n\t\t\tbox.length <= 3000\r\n\t\t\"\"\"\n",
-        "difficulty": 2
-    },
-    {
-        "number": 100203,
-        "question": "class Solution:\n    def printBin(self, num: float) -> str:\n\t\t\"\"\"\n\t\tGiven a real number between 0 and 1 (e.g., 0.72) that is passed in as a double, print the binary representation. If the number cannot be represented accurately in binary with at most 32 characters, print \"ERROR\".\r\n\t\tExample1:\r\n\t\t Input: 0.625\r\n\t\t Output: \"0.101\"\r\n\t\tExample2:\r\n\t\t Input: 0.1\r\n\t\t Output: \"ERROR\"\r\n\t\t Note: 0.1 cannot be represented accurately in binary.\r\n\t\tNote: \r\n\t\t\tThis two charaters \"0.\" should be counted into 32 characters.\r\n\t\t\tThe number of decimal places for num is at most 6 digits\r\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 100228,
-        "question": "class AnimalShelf:\n    def __init__(self):\n    def enqueue(self, animal: List[int]) -> None:\n    def dequeueAny(self) -> List[int]:\n    def dequeueDog(self) -> List[int]:\n    def dequeueCat(self) -> List[int]:\n\t\t\"\"\"\n\t\tAn animal shelter, which holds only dogs and cats, operates on a strictly\"first in, first out\" basis. People must adopt either the\"oldest\" (based on arrival time) of all animals at the shelter, or they can select whether they would prefer a dog or a cat (and will receive the oldest animal of that type). They cannot select which specific animal they would like. Create the data structures to maintain this system and implement operations such as enqueue, dequeueAny, dequeueDog, and dequeueCat. You may use the built-in Linked list data structure.\r\n\t\tenqueue method has a animal parameter, animal[0] represents the number of the animal, animal[1] represents the type of the animal, 0 for cat and 1 for dog.\r\n\t\tdequeue* method returns [animal number, animal type], if there's no animal that can be adopted, return [-1, -1].\r\n\t\tExample1:\r\n\t\t Input: \r\n\t\t[\"AnimalShelf\", \"enqueue\", \"enqueue\", \"dequeueCat\", \"dequeueDog\", \"dequeueAny\"]\r\n\t\t[[], [[0, 0]], [[1, 0]], [], [], []]\r\n\t\t Output: \r\n\t\t[null,null,null,[0,0],[-1,-1],[1,0]]\r\n\t\tExample2:\r\n\t\t Input: \r\n\t\t[\"AnimalShelf\", \"enqueue\", \"enqueue\", \"enqueue\", \"dequeueDog\", \"dequeueCat\", \"dequeueAny\"]\r\n\t\t[[], [[0, 0]], [[1, 0]], [[2, 1]], [], [], []]\r\n\t\t Output: \r\n\t\t[null,null,null,null,[2,1],[0,0],[1,0]]\r\n\t\tNote:\r\n\t\t\tThe number of animals in the shelter will not exceed 20000.\r\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 100229,
-        "question": "class Solution:\n    def checkSubTree(self, t1: TreeNode, t2: TreeNode) -> bool:\n\t\t\"\"\"\n\t\tT1 and T2 are two very large binary trees. Create an algorithm to determine if T2 is a subtree of T1.\r\n\t\tA tree T2 is a subtree of T1 if there exists a node n in T1 such that the subtree of n is identical to T2. That is, if you cut off the tree at node n, the two trees would be identical.\r\n\t\tNote: This problem is slightly different from the original problem.\r\n\t\tExample1:\r\n\t\t Input: t1 = [1, 2, 3], t2 = [2]\r\n\t\t Output: true\r\n\t\tExample2:\r\n\t\t Input: t1 = [1, null, 2, 4], t2 = [3, 2]\r\n\t\t Output: false\r\n\t\tNote: \r\n\t\t\tThe node numbers of both tree are in [0, 20000].\r\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 100230,
-        "question": "class Solution:\n    def reverseBits(self, num: int) -> int:\n\t\t\"\"\"\n\t\tYou have an integer and you can flip exactly one bit from a 0 to a 1. Write code to find the length of the longest sequence of 1s you could create.\r\n\t\tExample 1: \r\n\t\tInput: num = 1775(110111011112)\r\n\t\tOutput: 8\r\n\t\tExample 2: \r\n\t\tInput: num = 7(01112)\r\n\t\tOutput: 4\r\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 100231,
-        "question": "class Solution:\n    def waysToChange(self, n: int) -> int:\n\t\t\"\"\"\n\t\tGiven an infinite number of quarters (25 cents), dimes (10 cents), nickels (5 cents), and pennies (1 cent), write code to calculate the number of ways of representing n cents. (The result may be large, so you should return it modulo 1000000007)\r\n\t\tExample1:\r\n\t\t Input: n = 5\r\n\t\t Output: 2\r\n\t\t Explanation: There are two ways:\r\n\t\t5=5\r\n\t\t5=1+1+1+1+1\r\n\t\tExample2:\r\n\t\t Input: n = 10\r\n\t\t Output: 4\r\n\t\t Explanation: There are four ways:\r\n\t\t10=10\r\n\t\t10=5+5\r\n\t\t10=5+1+1+1+1+1\r\n\t\t10=1+1+1+1+1+1+1+1+1+1\r\n\t\tNotes: \r\n\t\tYou can assume:\r\n\t\t\t0 <= n <= 1000000\r\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 100232,
-        "question": "class Solution:\n    def search(self, arr: List[int], target: int) -> int:\n\t\t\"\"\"\n\t\tGiven a sorted array of n integers that has been rotated an unknown number of times, write code to find an element in the array. You may assume that the array was originally sorted in increasing order. If there are more than one target elements in the array, return the smallest index.\r\n\t\tExample1:\r\n\t\t Input: arr = [15, 16, 19, 20, 25, 1, 3, 4, 5, 7, 10, 14], target = 5\r\n\t\t Output: 8 (the index of 5 in the array)\r\n\t\tExample2:\r\n\t\t Input: arr = [15, 16, 19, 20, 25, 1, 3, 4, 5, 7, 10, 14], target = 11\r\n\t\t Output: -1 (not found)\r\n\t\tNote:\r\n\t\t\t1 <= arr.length <= 1000000\r\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 100233,
-        "question": "class Solution:\n    def solveNQueens(self, n: int) -> List[List[str]]:\n\t\t\"\"\"\n\t\tWrite an algorithm to print all ways of arranging n queens on an n x n chess board so that none of them share the same row, column, or diagonal. In this case, \"diagonal\" means all diagonals, not just the two that bisect the board.\r\n\t\tNotes: This problem is a generalization of the original one in the book.\r\n\t\tExample:\r\n\t\t Input: 4\r\n\t\t Output: [[\".Q..\",\"...Q\",\"Q...\",\"..Q.\"],[\"..Q.\",\"Q...\",\"...Q\",\".Q..\"]]\r\n\t\t Explanation: 4 queens has following two solutions\r\n\t\t[\r\n\t\t [\".Q..\",  // solution 1\r\n\t\t  \"...Q\",\r\n\t\t  \"Q...\",\r\n\t\t  \"..Q.\"],\r\n\t\t [\"..Q.\",  // solution 2\r\n\t\t  \"Q...\",\r\n\t\t  \"...Q\",\r\n\t\t  \".Q..\"]\r\n\t\t]\r\n\t\t\"\"\"\n",
-        "difficulty": 2
-    },
-    {
-        "number": 100240,
-        "question": "class Solution:\n    def findMagicIndex(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tA magic index in an array A[0...n-1] is defined to be an index such that A[i] = i. Given a sorted array of integers, write a method to find a magic index, if one exists, in array A. If not, return -1. If there are more than one magic index, return the smallest one.\r\n\t\tExample1:\r\n\t\t Input: nums = [0, 2, 3, 4, 5]\r\n\t\t Output: 0\r\n\t\tExample2:\r\n\t\t Input: nums = [1, 1, 1]\r\n\t\t Output: 1\r\n\t\tNote:\r\n\t\t\t1 <= nums.length <= 1000000\r\n\t\t\tThis problem is the follow-up of the original problem in the book, i.e. the values are not distinct.\r\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 100241,
-        "question": "class Solution:\n    def permutation(self, S: str) -> List[str]:\n\t\t\"\"\"\n\t\tWrite a method to compute all permutations of a string of unique characters.\r\n\t\tExample1:\r\n\t\t Input: S = \"qwe\"\r\n\t\t Output: [\"qwe\", \"qew\", \"wqe\", \"weq\", \"ewq\", \"eqw\"]\r\n\t\tExample2:\r\n\t\t Input: S = \"ab\"\r\n\t\t Output: [\"ab\", \"ba\"]\r\n\t\tNote:\r\n\t\t\tAll charaters are English letters.\r\n\t\t\t1 <= S.length <= 9\r\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 100242,
-        "question": "class Solution:\n    def findString(self, words: List[str], s: str) -> int:\n\t\t\"\"\"\n\t\tGiven a sorted array of strings that is interspersed with empty strings, write a method to find the location of a given string.\r\n\t\tExample1:\r\n\t\t Input: words = [\"at\", \"\", \"\", \"\", \"ball\", \"\", \"\", \"car\", \"\", \"\",\"dad\", \"\", \"\"], s = \"ta\"\r\n\t\t Output: -1\r\n\t\t Explanation: Return -1 if s is not in words.\r\n\t\tExample2:\r\n\t\t Input: words = [\"at\", \"\", \"\", \"\", \"ball\", \"\", \"\", \"car\", \"\", \"\",\"dad\", \"\", \"\"], s = \"ball\"\r\n\t\t Output: 4\r\n\t\tNote:\r\n\t\t\t1 <= words.length <= 1000000\r\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 100258,
-        "question": "class Solution:\n    def swapNumbers(self, numbers: List[int]) -> List[int]:\n\t\t\"\"\"\n\t\tWrite a function to swap a number in place (that is, without temporary variables).\r\n\t\tExample: \r\n\t\tInput: numbers = [1,2]\r\n\t\tOutput: [2,1]\r\n\t\tNote: \r\n\t\t\tnumbers.length == 2\r\n\t\t\t-2147483647 <= numbers[i] <= 2147483647\r\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 100259,
-        "question": "class WordsFrequency:\n    def __init__(self, book: List[str]):\n    def get(self, word: str) -> int:\n\t\t\"\"\"\n\t\tDesign a method to find the frequency of occurrences of any given word in a book. What if we were running this algorithm multiple times?\r\n\t\tYou should implement following methods:\r\n\t\t\tWordsFrequency(book) constructor, parameter is a array of strings, representing the book.\r\n\t\t\tget(word) get the frequency of word in the book. \r\n\t\tExample: \r\n\t\tWordsFrequency wordsFrequency = new WordsFrequency({\"i\", \"have\", \"an\", \"apple\", \"he\", \"have\", \"a\", \"pen\"});\r\n\t\twordsFrequency.get(\"you\"); //returns 0\uff0c\"you\" is not in the book\r\n\t\twordsFrequency.get(\"have\"); //returns 2\uff0c\"have\" occurs twice in the book\r\n\t\twordsFrequency.get(\"an\"); //returns 1\r\n\t\twordsFrequency.get(\"apple\"); //returns 1\r\n\t\twordsFrequency.get(\"pen\"); //returns 1\r\n\t\tNote: \r\n\t\t\tThere are only lowercase letters in book[i].\r\n\t\t\t1 <= book.length <= 100000\r\n\t\t\t1 <= book[i].length <= 10\r\n\t\t\tget function will not be called more than 100000 times.\r\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 100260,
-        "question": "class Solution:\n    def intersection(self, start1: List[int], end1: List[int], start2: List[int], end2: List[int]) -> List[float]:\n\t\t\"\"\"\n\t\tGiven two straight line segments (represented as a start point and an end point), compute the point of intersection, if any. If there's no intersection, return an empty array.\r\n\t\tThe absolute error should not exceed 10^-6. If there are more than one intersections, return the one with smallest X axis value. If there are more than one intersections that have same X axis value, return the one with smallest Y axis value.\r\n\t\tExample 1: \r\n\t\tInput: \r\n\t\tline1 = {0, 0}, {1, 0}\r\n\t\tline2 = {1, 1}, {0, -1}\r\n\t\tOutput:  {0.5, 0}\r\n\t\tExample 2: \r\n\t\tInput: \r\n\t\tline1 = {0, 0}, {3, 3}\r\n\t\tline2 = {1, 1}, {2, 2}\r\n\t\tOutput:  {1, 1}\r\n\t\tExample 3: \r\n\t\tInput: \r\n\t\tline1 = {0, 0}, {1, 1}\r\n\t\tline2 = {1, 0}, {2, 1}\r\n\t\tOutput:  {}  (no intersection)\r\n\t\tNote: \r\n\t\t\tThe absolute value of coordinate value will not exceed 2^7.\r\n\t\t\tAll coordinates are valid 2D coordinates.\r\n\t\t\"\"\"\n",
-        "difficulty": 2
-    },
-    {
-        "number": 100261,
-        "question": "class Solution:\n    def tictactoe(self, board: List[str]) -> str:\n\t\t\"\"\"\n\t\tDesign an algorithm to figure out if someone has won a game of tic-tac-toe. Input is a string array of size N x N, including characters \" \", \"X\" and \"O\", where \" \" represents a empty grid.\r\n\t\tThe rules of tic-tac-toe are as follows:\r\n\t\t\tPlayers place characters into an empty grid(\" \") in turn.\r\n\t\t\tThe first player always place character \"O\", and the second one place \"X\".\r\n\t\t\tPlayers are only allowed to place characters in empty grid. Replacing a character is not allowed.\r\n\t\t\tIf there is any row, column or diagonal filled with N same characters, the game ends. The player who place the last charater wins.\r\n\t\t\tWhen there is no empty grid, the game ends.\r\n\t\t\tIf the game ends, players cannot place any character further.\r\n\t\tIf there is any winner, return the character that the winner used. If there's a draw, return \"Draw\". If the game doesn't end and there is no winner, return \"Pending\".\r\n\t\tExample 1: \r\n\t\tInput:  board = [\"O X\",\" XO\",\"X O\"]\r\n\t\tOutput:  \"X\"\r\n\t\tExample 2: \r\n\t\tInput:  board = [\"OOX\",\"XXO\",\"OXO\"]\r\n\t\tOutput:  \"Draw\"\r\n\t\tExplanation:  no player wins and no empty grid left\r\n\t\tExample 3: \r\n\t\tInput:  board = [\"OOX\",\"XXO\",\"OX \"]\r\n\t\tOutput:  \"Pending\"\r\n\t\tExplanation:  no player wins but there is still a empty grid\r\n\t\tNote: \r\n\t\t\t1 <= board.length == board[i].length <= 100\r\n\t\t\tInput follows the rules.\r\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 100262,
-        "question": "class Solution:\n    def smallestDifference(self, a: List[int], b: List[int]) -> int:\n\t\t\"\"\"\n\t\tGiven two arrays of integers, compute the pair of values (one value in each array) with the smallest (non-negative) difference. Return the difference.\r\n\t\tExample: \r\n\t\tInput: {1, 3, 15, 11, 2}, {23, 127, 235, 19, 8}\r\n\t\tOutput:  3, the pair (11, 8)\r\n\t\tNote: \r\n\t\t\t1 <= a.length, b.length <= 100000\r\n\t\t\t-2147483648 <= a[i], b[i] <= 2147483647\r\n\t\t\tThe result is in the range [0, 2147483647]\r\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 100273,
-        "question": "class CQueue:\n    def __init__(self):\n    def appendTail(self, value: int) -> None:\n    def deleteHead(self) -> int:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 100274,
-        "question": "class Solution:\n    def fib(self, n: int) -> int:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 100275,
-        "question": "class Solution:\n    def findRepeatNumber(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\r\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 100276,
-        "question": "class Solution:\n    def findNumberIn2DArray(self, matrix: List[List[int]], target: int) -> bool:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\r\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 100277,
-        "question": "class Solution:\n    def numWays(self, n: int) -> int:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 100278,
-        "question": "class Solution:\n    def minArray(self, numbers: List[int]) -> int:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 100279,
-        "question": "class Solution:\n    def exist(self, board: List[List[str]], word: str) -> bool:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 100280,
-        "question": "class Solution:\n    def replaceSpace(self, s: str) -> str:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\r\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 100281,
-        "question": "class Solution:\n    def movingCount(self, m: int, n: int, k: int) -> int:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 100282,
-        "question": "class Solution:\n    def reversePrint(self, head: ListNode) -> List[int]:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 100283,
-        "question": "class Solution:\n    def buildTree(self, preorder: List[int], inorder: List[int]) -> TreeNode:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 100284,
-        "question": "class Solution:\n    def cuttingRope(self, n: int) -> int:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 100285,
-        "question": "class Solution:\n    def cuttingRope(self, n: int) -> int:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 100286,
-        "question": "class Solution:\n    def mergeTwoLists(self, l1: ListNode, l2: ListNode) -> ListNode:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 100287,
-        "question": "class Solution:\n    def isSubStructure(self, A: TreeNode, B: TreeNode) -> bool:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 100288,
-        "question": "class Solution:\n    def mirrorTree(self, root: TreeNode) -> TreeNode:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 100289,
-        "question": "class Solution:\n    def isSymmetric(self, root: TreeNode) -> bool:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 100290,
-        "question": "class Solution:\n    def isNumber(self, s: str) -> bool:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\r\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 100291,
-        "question": "class Solution:\n    def exchange(self, nums: List[int]) -> List[int]:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\r\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 100292,
-        "question": "class Solution:\n    def hammingWeight(self, n: int) -> int:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 100293,
-        "question": "class Solution:\n    def spiralOrder(self, matrix: List[List[int]]) -> List[int]:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 100294,
-        "question": "class Solution:\n    def getKthFromEnd(self, head: ListNode, k: int) -> ListNode:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 100295,
-        "question": "class Solution:\n    def myPow(self, x: float, n: int) -> float:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 100296,
-        "question": "class Solution:\n    def printNumbers(self, n: int) -> List[int]:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 100297,
-        "question": "class Solution:\n    def isMatch(self, s: str, p: str) -> bool:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 2
-    },
-    {
-        "number": 100298,
-        "question": "class Solution:\n    def reverseList(self, head: ListNode) -> ListNode:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\r\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 100299,
-        "question": "class Solution:\n    def deleteNode(self, head: ListNode, val: int) -> ListNode:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 100300,
-        "question": "\n\t\t\"\"\"\nclass Node:\n    def __init__(self, x: int, next: 'Node' = None, random: 'Node' = None):\n        self.val = int(x)\n        self.next = next\n        self.random = random\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 100301,
-        "question": "class Solution:\n    def getLeastNumbers(self, arr: List[int], k: int) -> List[int]:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 100302,
-        "question": "class MinStack:\n    def __init__(self):\n\t\t\"\"\"\n        initialize your data structure here.\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 100303,
-        "question": "class MedianFinder:\n    def __init__(self):\n\t\t\"\"\"\n        initialize your data structure here.\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 2
-    },
-    {
-        "number": 100304,
-        "question": "class Solution:\n    def maxSubArray(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 100305,
-        "question": "\n\t\t\"\"\"\nclass Node:\n    def __init__(self, val, left=None, right=None):\n        self.val = val\n        self.left = left\n        self.right = right\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 100306,
-        "question": "class Solution:\n    def validateStackSequences(self, pushed: List[int], popped: List[int]) -> bool:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 100307,
-        "question": "class Codec:\n    def serialize(self, root):\n\t\t\"\"\"Encodes a tree to a single string.\n        :type root: TreeNode\n        :rtype: str\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 2
-    },
-    {
-        "number": 100308,
-        "question": "class Solution:\n    def permutation(self, s: str) -> List[str]:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 100309,
-        "question": "class Solution:\n    def countDigitOne(self, n: int) -> int:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 2
-    },
-    {
-        "number": 100310,
-        "question": "class Solution:\n    def majorityElement(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 100311,
-        "question": "class Solution:\n    def levelOrder(self, root: TreeNode) -> List[int]:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 100312,
-        "question": "class Solution:\n    def levelOrder(self, root: TreeNode) -> List[List[int]]:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 100313,
-        "question": "class Solution:\n    def findNthDigit(self, n: int) -> int:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 100314,
-        "question": "class Solution:\n    def levelOrder(self, root: TreeNode) -> List[List[int]]:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 100315,
-        "question": "class Solution:\n    def verifyPostorder(self, postorder: List[int]) -> bool:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 100316,
-        "question": "class Solution:\n    def firstUniqChar(self, s: str) -> str:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 100317,
-        "question": "class Solution:\n    def pathSum(self, root: TreeNode, target: int) -> List[List[int]]:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 100318,
-        "question": "class Solution:\n    def reversePairs(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 2
-    },
-    {
-        "number": 100319,
-        "question": "class Solution:\n    def maxDepth(self, root: TreeNode) -> int:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\r\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 100320,
-        "question": "class Solution:\n    def singleNumbers(self, nums: List[int]) -> List[int]:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\r\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 100321,
-        "question": "class Solution:\n    def singleNumber(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\r\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 100322,
-        "question": "class Solution:\n    def twoSum(self, nums: List[int], target: int) -> List[int]:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\r\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 100323,
-        "question": "class Solution:\n    def minNumber(self, nums: List[int]) -> str:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 100324,
-        "question": "class Solution:\n    def findContinuousSequence(self, target: int) -> List[List[int]]:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\r\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 100325,
-        "question": "class Solution:\n    def translateNum(self, num: int) -> int:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 100326,
-        "question": "class Solution:\n    def getIntersectionNode(self, headA: ListNode, headB: ListNode) -> ListNode:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 100327,
-        "question": "class Solution:\n    def maxValue(self, grid: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 100328,
-        "question": "class Solution:\n    def reverseWords(self, s: str) -> str:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 100329,
-        "question": "class Solution:\n    def search(self, nums: List[int], target: int) -> int:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 100330,
-        "question": "class Solution:\n    def reverseLeftWords(self, s: str, n: int) -> str:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\r\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 100331,
-        "question": "class Solution:\n    def missingNumber(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 100332,
-        "question": "class Solution:\n    def lengthOfLongestSubstring(self, s: str) -> int:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 100333,
-        "question": "class Solution:\n    def kthLargest(self, root: TreeNode, k: int) -> int:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 100334,
-        "question": "class Solution:\n    def nthUglyNumber(self, n: int) -> int:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 100335,
-        "question": "class Solution:\n    def add(self, a: int, b: int) -> int:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 100336,
-        "question": "class Solution:\n    def maxSlidingWindow(self, nums: List[int], k: int) -> List[int]:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\r\n\t\t\"\"\"\n",
-        "difficulty": 2
-    },
-    {
-        "number": 100337,
-        "question": "class MaxQueue:\n    def __init__(self):\n    def max_value(self) -> int:\n    def push_back(self, value: int) -> None:\n    def pop_front(self) -> int:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\r\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 100338,
-        "question": "class Solution:\n    def constructArr(self, a: List[int]) -> List[int]:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 100339,
-        "question": "class Solution:\n    def dicesProbability(self, n: int) -> List[float]:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 100340,
-        "question": "class Solution:\n    def strToInt(self, str: str) -> int:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 100341,
-        "question": "class Solution:\n    def isStraight(self, nums: List[int]) -> bool:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 100342,
-        "question": "class Solution:\n    def isBalanced(self, root: TreeNode) -> bool:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 100343,
-        "question": "class Solution:\n    def lastRemaining(self, n: int, m: int) -> int:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\r\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 100344,
-        "question": "class Solution:\n    def maxProfit(self, prices: List[int]) -> int:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 100345,
-        "question": "class Solution:\n    def sumNums(self, n: int) -> int:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\r\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 100346,
-        "question": "class Solution:\n    def lowestCommonAncestor(self, root: 'TreeNode', p: 'TreeNode', q: 'TreeNode') -> 'TreeNode':\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\r\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 100347,
-        "question": "class Solution:\n    def lowestCommonAncestor(self, root: TreeNode, p: TreeNode, q: TreeNode) -> TreeNode:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\r\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 100348,
-        "question": "class Solution:\n    def permutation(self, S: str) -> List[str]:\n\t\t\"\"\"\n\t\tWrite a method to compute all permutations of a string whose characters are not necessarily unique. The list of permutations should not have duplicates.\r\n\t\tExample1:\r\n\t\t Input: S = \"qqe\"\r\n\t\t Output: [\"eqq\",\"qeq\",\"qqe\"]\r\n\t\tExample2:\r\n\t\t Input: S = \"ab\"\r\n\t\t Output: [\"ab\", \"ba\"]\r\n\t\tNote:\r\n\t\t\tAll characters are English letters.\r\n\t\t\t1 <= S.length <= 9\r\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 100349,
-        "question": "class Solution:\n    def maximum(self, a: int, b: int) -> int:\n\t\t\"\"\"\n\t\tWrite a method that finds the maximum of two numbers. You should not use if-else or any other comparison operator.\r\n\t\tExample: \r\n\t\tInput:  a = 1, b = 2\r\n\t\tOutput:  2\r\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 100350,
-        "question": "class Operations:\n    def __init__(self):\n    def minus(self, a: int, b: int) -> int:\n    def multiply(self, a: int, b: int) -> int:\n    def divide(self, a: int, b: int) -> int:\n\t\t\"\"\"\n\t\tWrite methods to implement the multiply, subtract, and divide operations for integers. The results of all of these are integers. Use only the add operator.\r\n\t\tYou should implement following methods:\r\n\t\t\tOperations()  constructor\r\n\t\t\tminus(a, b)  Subtraction, returns a - b\r\n\t\t\tmultiply(a, b)  Multiplication, returns a * b\r\n\t\t\tdivide(a, b)  Division, returns a / b\r\n\t\tExample: \r\n\t\tOperations operations = new Operations();\r\n\t\toperations.minus(1, 2); //returns -1\r\n\t\toperations.multiply(3, 4); //returns 12\r\n\t\toperations.divide(5, -2); //returns -2\r\n\t\tNote: \r\n\t\t\tYou can assume inputs are always valid, that is, e.g., denominator will not be 0 in division.\r\n\t\t\tThe number of calls will not exceed 1000.\r\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 100351,
-        "question": "class Solution:\n    def maxAliveYear(self, birth: List[int], death: List[int]) -> int:\n\t\t\"\"\"\n\t\tGiven a list of people with their birth and death years, implement a method to compute the year with the most number of people alive. You may assume that all people were born between 1900 and 2000 (inclusive). If a person was alive during any portion of that year, they should be included in that year's count. For example, Person (birth= 1908, death= 1909) is included in the counts for both 1908 and 1909.\r\n\t\tIf there are more than one years that have the most number of people alive, return the smallest one.\r\n\t\tExample: \r\n\t\tInput: \r\n\t\tbirth = [1900, 1901, 1950]\r\n\t\tdeath = [1948, 1951, 2000]\r\n\t\tOutput:  1901\r\n\t\tNote: \r\n\t\t\t0 < birth.length == death.length <= 10000\r\n\t\t\tbirth[i] <= death[i]\r\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 100352,
-        "question": "class Solution:\n    def divingBoard(self, shorter: int, longer: int, k: int) -> List[int]:\n\t\t\"\"\"\n\t\tYou are building a diving board by placing a bunch of planks of wood end-to-end. There are two types of planks, one of length shorter and one of length longer. You must use exactly K planks of wood. Write a method to generate all possible lengths for the diving board.\r\n\t\treturn all lengths in non-decreasing order.\r\n\t\tExample: \r\n\t\tInput: \r\n\t\tshorter = 1\r\n\t\tlonger = 2\r\n\t\tk = 3\r\n\t\tOutput:  {3,4,5,6}\r\n\t\tNote: \r\n\t\t\t0 < shorter <= longer\r\n\t\t\t0 <= k <= 100000\r\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 100353,
-        "question": "class Solution:\n    def cutSquares(self, square1: List[int], square2: List[int]) -> List[float]:\n\t\t\"\"\"\n\t\tGiven two squares on a two-dimensional plane, find a line that would cut these two squares in half. Assume that the top and the bottom sides of the square run parallel to the x-axis.\r\n\t\tEach square consists of three values, the coordinate of bottom left corner [X,Y] = [square[0],square[1]], and the side length of the square square[2]. The line will intersect to the two squares in four points. Return the coordinates of two intersection points [X1,Y1] and [X2,Y2] that the forming segment covers the other two intersection points in format of {X1,Y1,X2,Y2}. If X1 != X2, there should be X1 < X2, otherwise there should be Y1 <= Y2.\r\n\t\tIf there are more than one line that can cut these two squares in half, return the one that has biggest slope (slope of a line parallel to the y-axis is considered as infinity).\r\n\t\tExample: \r\n\t\tInput: \r\n\t\tsquare1 = {-1, -1, 2}\r\n\t\tsquare2 = {0, -1, 2}\r\n\t\tOutput: {-1,0,2,0}\r\n\t\tExplanation: y = 0 is the line that can cut these two squares in half.\r\n\t\tNote: \r\n\t\t\tsquare.length == 3\r\n\t\t\tsquare[2] > 0\r\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 100354,
-        "question": "class Solution:\n    def bestLine(self, points: List[List[int]]) -> List[int]:\n\t\t\"\"\"\n\t\tGiven a two-dimensional graph with points on it, find a line which passes the most number of points.\r\n\t\tAssume all the points that passed by the line are stored in list S sorted by their number. You need to return [S[0], S[1]], that is , two points that have smallest number. If there are more than one line that passes the most number of points, choose the one that has the smallest S[0]. If there are more that one line that has the same S[0], choose the one that has smallest S[1].\r\n\t\tExample: \r\n\t\tInput:  [[0,0],[1,1],[1,0],[2,0]]\r\n\t\tOutput:  [0,2]\r\n\t\tExplanation:  The numbers of points passed by the line are [0,2,3].\r\n\t\tNote: \r\n\t\t\t2 <= len(Points) <= 300\r\n\t\t\tlen(Points[i]) = 2\r\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 100355,
-        "question": "class Solution:\n    def masterMind(self, solution: str, guess: str) -> List[int]:\n\t\t\"\"\"\n\t\tThe Game of Master Mind is played as follows:\r\n\t\tThe computer has four slots, and each slot will contain a ball that is red (R). yellow (Y). green (G) or blue (B). For example, the computer might have RGGB (Slot #1 is red, Slots #2 and #3 are green, Slot #4 is blue).\r\n\t\tYou, the user, are trying to guess the solution. You might, for example, guess YRGB.\r\n\t\tWhen you guess the correct color for the correct slot, you get a \"hit:' If you guess a color that exists but is in the wrong slot, you get a \"pseudo-hit:' Note that a slot that is a hit can never count as a pseudo-hit.\r\n\t\tFor example, if the actual solution is RGBY and you guess GGRR, you have one hit and one pseudo-hit. Write a method that, given a guess and a solution, returns the number of hits and pseudo-hits.\r\n\t\tGiven a sequence of colors solution, and a guess, write a method that return the number of hits and pseudo-hit answer, where answer[0] is the number of hits and answer[1] is the number of pseudo-hit.\r\n\t\tExample: \r\n\t\tInput:  solution=\"RGBY\",guess=\"GGRR\"\r\n\t\tOutput:  [1,1]\r\n\t\tExplanation:  hit once, pseudo-hit once.\r\n\t\tNote: \r\n\t\t\tlen(solution) = len(guess) = 4\r\n\t\t\tThere are only \"R\",\"G\",\"B\",\"Y\" in solution and guess.\r\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 100356,
-        "question": "class Solution:\n    def subSort(self, array: List[int]) -> List[int]:\n\t\t\"\"\"\n\t\tGiven an array of integers, write a method to find indices m and n such that if you sorted elements m through n, the entire array would be sorted. Minimize n - m (that is, find the smallest such sequence).\r\n\t\tReturn [m,n]. If there are no such m and n (e.g. the array is already sorted), return [-1, -1].\r\n\t\tExample: \r\n\t\tInput:  [1,2,4,7,10,11,7,12,6,7,16,18,19]\r\n\t\tOutput:  [3,9]\r\n\t\tNote: \r\n\t\t\t0 <= len(array) <= 1000000\r\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 1000003,
-        "question": "class Solution:\n    def maxSubArray(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tYou are given an array of integers (both positive and negative). Find the contiguous sequence with the largest sum. Return the sum.\r\n\t\tExample: \r\n\t\tInput:  [-2,1,-3,4,-1,2,1,-5,4]\r\n\t\tOutput:  6\r\n\t\tExplanation:  [4,-1,2,1] has the largest sum 6.\r\n\t\tFollow Up: \r\n\t\tIf you have figured out the O(n) solution, try coding another solution using the divide and conquer approach, which is more subtle.\r\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 1000004,
-        "question": "class Solution:\n    def patternMatching(self, pattern: str, value: str) -> bool:\n\t\t\"\"\"\n\t\tYou are given two strings, pattern and value. The pattern string consists of just the letters a and b, describing a pattern within a string. For example, the string catcatgocatgo matches the pattern aabab (where cat is a and go is b). It also matches patterns like a, ab, and b. Write a method to determine if value matches pattern. a and b cannot be the same string.\r\n\t\tExample 1: \r\n\t\tInput:  pattern = \"abba\", value = \"dogcatcatdog\"\r\n\t\tOutput:  true\r\n\t\tExample 2: \r\n\t\tInput:  pattern = \"abba\", value = \"dogcatcatfish\"\r\n\t\tOutput:  false\r\n\t\tExample 3: \r\n\t\tInput:  pattern = \"aaaa\", value = \"dogcatcatdog\"\r\n\t\tOutput:  false\r\n\t\tExample 4: \r\n\t\tInput:  pattern = \"abba\", value = \"dogdogdogdog\"\r\n\t\tOutput:  true\r\n\t\tExplanation:  \"a\"=\"dogdog\",b=\"\"\uff0cvice versa.\r\n\t\tNote: \r\n\t\t\t0 <= len(pattern) <= 1000\r\n\t\t\t0 <= len(value) <= 1000\r\n\t\t\tpattern only contains \"a\" and \"b\", value only contains lowercase letters.\r\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 1000005,
-        "question": "class Solution:\n    def pondSizes(self, land: List[List[int]]) -> List[int]:\n\t\t\"\"\"\n\t\tYou have an integer matrix representing a plot of land, where the value at that loca\u00adtion represents the height above sea level. A value of zero indicates water. A pond is a region of water connected vertically, horizontally, or diagonally. The size of the pond is the total number of connected water cells. Write a method to compute the sizes of all ponds in the matrix.\r\n\t\tExample: \r\n\t\tInput: \r\n\t\t[\r\n\t\t  [0,2,1,0],\r\n\t\t  [0,1,0,1],\r\n\t\t  [1,1,0,1],\r\n\t\t  [0,1,0,1]\r\n\t\t]\r\n\t\tOutput:  [1,2,4]\r\n\t\tNote: \r\n\t\t\t0 < len(land) <= 1000\r\n\t\t\t0 < len(land[i]) <= 1000\r\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 1000006,
-        "question": "class Solution:\n    def oneEditAway(self, first: str, second: str) -> bool:\n\t\t\"\"\"\n\t\tThere are three types of edits that can be performed on strings: insert a character, remove a character, or replace a character. Given two strings, write a function to check if they are one edit (or zero edits) away.\r\n\t\tExample 1:\r\n\t\tInput: \r\n\t\tfirst = \"pale\"\r\n\t\tsecond = \"ple\"\r\n\t\tOutput: True\r\n\t\tExample 2:\r\n\t\tInput: \r\n\t\tfirst = \"pales\"\r\n\t\tsecond = \"pal\"\r\n\t\tOutput: False\r\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 1000007,
-        "question": "class Solution:\n    def kthToLast(self, head: ListNode, k: int) -> int:\n\t\t\"\"\"\n\t\tImplement an algorithm to find the kth to last element of a singly linked list. Return the value of the element.\r\n\t\tNote: This problem is slightly different from the original one in the book.\r\n\t\tExample: \r\n\t\tInput:  1->2->3->4->5 \u548c k = 2\r\n\t\tOutput:  4\r\n\t\tNote: \r\n\t\tk is always valid.\r\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 1000008,
-        "question": "class Solution:\n    def partition(self, head: ListNode, x: int) -> ListNode:\n\t\t\"\"\"\n\t\tWrite code to partition a linked list around a value x, such that all nodes less than x come before all nodes greater than or equal to x. If x is contained within the list, the values of x only need to be after the elements less than x (see below). The partition element x can appear anywhere in the \"right partition\"; it does not need to appear between the left and right partitions.\r\n\t\tExample:\r\n\t\tInput: head = 3->5->8->5->10->2->1, x = 5\r\n\t\tOutput: 3->1->2->10->5->5->8\r\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 1000009,
-        "question": "class Solution:\n    def pathSum(self, root: TreeNode, sum: int) -> int:\n\t\t\"\"\"\n\t\tYou are given a binary tree in which each node contains an integer value (which might be positive or negative). Design an algorithm to count the number of paths that sum to a given value. The path does not need to start or end at the root or a leaf, but it must go downwards (traveling only from parent nodes to child nodes).\r\n\t\tExample:\r\n\t\tGiven the following tree and  sum = 22,\r\n\t\t              5\r\n\t\t             / \\\r\n\t\t            4   8\r\n\t\t           /   / \\\r\n\t\t          11  13  4\r\n\t\t         /  \\    / \\\r\n\t\t        7    2  5   1\r\n\t\tOutput:\r\n\t\t3\r\n\t\tExplanation: Paths that have sum 22 are: [5,4,11,2], [5,8,4,5], [4,11,7]\r\n\t\tNote:\r\n\t\t\tnode number <= 10000\r\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 1000010,
-        "question": "class Solution:\n    def BSTSequences(self, root: TreeNode) -> List[List[int]]:\n\t\t\"\"\"\n\t\tA binary search tree was created by traversing through an array from left to right and inserting each element. Given a binary search tree with distinct elements, print all possible arrays that could have led to this tree.\r\n\t\tExample:\r\n\t\tGiven the following tree:\r\n\t\t        2\r\n\t\t       / \\\r\n\t\t      1   3\r\n\t\tOutput:\r\n\t\t[\r\n\t\t   [2,1,3],\r\n\t\t   [2,3,1]\r\n\t\t]\r\n\t\t\"\"\"\n",
-        "difficulty": 2
-    },
-    {
-        "number": 1000011,
-        "question": "class Solution:\n    def pathWithObstacles(self, obstacleGrid: List[List[int]]) -> List[List[int]]:\n\t\t\"\"\"\n\t\tImagine a robot sitting on the upper left corner of grid with r rows and c columns. The robot can only move in two directions, right and down, but certain cells are \"off limits\" such that the robot cannot step on them. Design an algorithm to find a path for the robot from the top left to the bottom right.\r\n\t\t\"off limits\" and empty grid are represented by 1 and 0 respectively.\r\n\t\tReturn a valid path, consisting of row number and column number of grids in the path.\r\n\t\tExample 1:\r\n\t\tInput:\r\n\t\t[\r\n\t\t  [0,0,0],\r\n\t\t  [0,1,0],\r\n\t\t  [0,0,0]\r\n\t\t]\r\n\t\tOutput: [[0,0],[0,1],[0,2],[1,2],[2,2]]\r\n\t\tNote: \r\n\t\t\tr, c <= 100\r\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 1000012,
-        "question": "class Solution:\n    def merge(self, A: List[int], m: int, B: List[int], n: int) -> None:\n\t\t\"\"\"\n        Do not return anything, modify A in-place instead.\n\t\tYou are given two sorted arrays, A and B, where A has a large enough buffer at the end to hold B. Write a method to merge B into A in sorted order.\r\n\t\tInitially the number of elements in A and B are m and n respectively.\r\n\t\tExample:\r\n\t\tInput:\r\n\t\tA = [1,2,3,0,0,0], m = 3\r\n\t\tB = [2,5,6],       n = 3\r\n\t\tOutput: [1,2,2,3,5,6]\r\n\t\tNote:\r\n\t\t\tA.length == n + m\r\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 1000013,
-        "question": "class Solution:\n    def wiggleSort(self, nums: List[int]) -> None:\n\t\t\"\"\"\n        Do not return anything, modify nums in-place instead.\n\t\tIn an array of integers, a \"peak\" is an element which is greater than or equal to the adjacent integers and a \"valley\" is an element which is less than or equal to the adjacent inte\u00adgers. For example, in the array {5, 8, 4, 2, 3, 4, 6}, {8, 6} are peaks and {5, 2} are valleys. Given an array of integers, sort the array into an alternating sequence of peaks and valleys.\r\n\t\tExample:\r\n\t\tInput: [5, 3, 1, 2, 3]\r\n\t\tOutput: [5, 1, 3, 2, 3]\r\n\t\tNote: \r\n\t\t\tnums.length <= 10000\r\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 1000015,
-        "question": "class Solution:\n    def hanota(self, A: List[int], B: List[int], C: List[int]) -> None:\n\t\t\"\"\"\n        Do not return anything, modify C in-place instead.\n\t\tIn the classic problem of the Towers of Hanoi, you have 3 towers and N disks of different sizes which can slide onto any tower. The puzzle starts with disks sorted in ascending order of size from top to bottom (i.e., each disk sits on top of an even larger one). You have the following constraints:\r\n\t\t(1) Only one disk can be moved at a time.\r\n\t\t(2) A disk is slid off the top of one tower onto another tower.\r\n\t\t(3) A disk cannot be placed on top of a smaller disk.\r\n\t\tWrite a program to move the disks from the first tower to the last using stacks.\r\n\t\tExample1:\r\n\t\t Input: A = [2, 1, 0], B = [], C = []\r\n\t\t Output: C = [2, 1, 0]\r\n\t\tExample2:\r\n\t\t Input: A = [1, 0], B = [], C = []\r\n\t\t Output: C = [1, 0]\r\n\t\tNote:\r\n\t\t\tA.length <= 14\r\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 1000016,
-        "question": "class Solution:\n    def searchMatrix(self, matrix: List[List[int]], target: int) -> bool:\n\t\t\"\"\"\n\t\tGiven an M x N matrix in which each row and each column is sorted in ascending order, write a method to find an element.\r\n\t\tExample:\r\n\t\tGiven matrix:\r\n\t\t[\r\n\t\t  [1,   4,  7, 11, 15],\r\n\t\t  [2,   5,  8, 12, 19],\r\n\t\t  [3,   6,  9, 16, 22],\r\n\t\t  [10, 13, 14, 17, 24],\r\n\t\t  [18, 21, 23, 26, 30]\r\n\t\t]\r\n\t\tGiven target = 5, return true.\r\n\t\tGiven target = 20, return false.\r\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 1000017,
-        "question": "class Solution:\n    def trailingZeroes(self, n: int) -> int:\n\t\t\"\"\"\n\t\tWrite an algorithm which computes the number of trailing zeros in n factorial.\r\n\t\tExample 1:\r\n\t\tInput: 3\r\n\t\tOutput: 0\r\n\t\tExplanation: 3! = 6, no trailing zero.\r\n\t\tExample 2:\r\n\t\tInput: 5\r\n\t\tOutput: 1\r\n\t\tExplanation: 5! = 120, one trailing zero.\r\n\t\tNote: Your solution should be in logarithmic time complexity.\r\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 1000018,
-        "question": "class Solution:\n    def numberToWords(self, num: int) -> str:\n\t\t\"\"\"\n\t\tGiven any integer, print an English phrase that describes the integer (e.g., \"One Thousand Two Hundred Thirty Four\").\r\n\t\tExample 1:\r\n\t\tInput: 123\r\n\t\tOutput: \"One Hundred Twenty Three\"\r\n\t\tExample 2:\r\n\t\tInput: 12345\r\n\t\tOutput: \"Twelve Thousand Three Hundred Forty Five\"\r\n\t\tExample 3:\r\n\t\tInput: 1234567\r\n\t\tOutput: \"One Million Two Hundred Thirty Four Thousand Five Hundred Sixty Seven\"\r\n\t\tExample 4:\r\n\t\tInput: 1234567891\r\n\t\tOutput: \"One Billion Two Hundred Thirty Four Million Five Hundred Sixty Seven Thousand Eight Hundred Ninety One\"\r\n\t\t\"\"\"\n",
-        "difficulty": 2
-    },
-    {
-        "number": 1000019,
-        "question": "class Solution:\n    def convertBiNode(self, root: TreeNode) -> TreeNode:\n\t\t\"\"\"\n\t\tThe data structure TreeNode is used for binary tree, but it can also used to represent a single linked list (where left is null, and right is the next node in the list). Implement a method to convert a binary search tree (implemented with TreeNode) into a single linked list. The values should be kept in order and the operation should be performed in place (that is, on the original data structure).\r\n\t\tReturn the head node of the linked list after converting.\r\n\t\tNote: This problem is slightly different from the original one in the book.\r\n\t\tExample: \r\n\t\tInput:  [4,2,5,1,3,null,6,0]\r\n\t\tOutput:  [0,null,1,null,2,null,3,null,4,null,5,null,6]\r\n\t\tNote: \r\n\t\t\tThe number of nodes will not exceed 100000.\r\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 1000020,
-        "question": "class Solution:\n    def respace(self, dictionary: List[str], sentence: str) -> int:\n\t\t\"\"\"\n\t\tOh, no! You have accidentally removed all spaces, punctuation, and capitalization in a lengthy document. A sentence like \"I reset the computer. It still didn't boot!\" became \"iresetthecomputeritstilldidntboot''. You'll deal with the punctuation and capi\u00adtalization later; right now you need to re-insert the spaces. Most of the words are in a dictionary but a few are not. Given a dictionary (a list of strings) and the document (a string), design an algorithm to unconcatenate the document in a way that minimizes the number of unrecognized characters. Return the number of unrecognized characters.\r\n\t\tNote: This problem is slightly different from the original one in the book.\r\n\t\tExample: \r\n\t\tInput: \r\n\t\tdictionary = [\"looked\",\"just\",\"like\",\"her\",\"brother\"]\r\n\t\tsentence = \"jesslookedjustliketimherbrother\"\r\n\t\tOutput:  7\r\n\t\tExplanation:  After unconcatenating, we got \"jess looked just like tim her brother\", which containing 7 unrecognized characters.\r\n\t\tNote: \r\n\t\t\t0 <= len(sentence) <= 1000\r\n\t\t\tThe total number of characters in dictionary is less than or equal to 150000.\r\n\t\t\tThere are only lowercase letters in dictionary and sentence.\r\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 1000021,
-        "question": "class Solution:\n    def smallestK(self, arr: List[int], k: int) -> List[int]:\n\t\t\"\"\"\n\t\tDesign an algorithm to find the smallest K numbers in an array.\r\n\t\tExample: \r\n\t\tInput:  arr = [1,3,5,7,2,4,6,8], k = 4\r\n\t\tOutput:  [1,2,3,4]\r\n\t\tNote: \r\n\t\t\t0 <= len(arr) <= 100000\r\n\t\t\t0 <= k <= min(100000, len(arr))\r\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 1000022,
-        "question": "class Solution:\n    def longestWord(self, words: List[str]) -> str:\n\t\t\"\"\"\n\t\tGiven a list of words, write a program to find the longest word made of other words in the list. If there are more than one answer, return the one that has smallest lexicographic order. If no answer, return an empty string.\r\n\t\tExample: \r\n\t\tInput:  [\"cat\",\"banana\",\"dog\",\"nana\",\"walk\",\"walker\",\"dogwalker\"]\r\n\t\tOutput:  \"dogwalker\"\r\n\t\tExplanation:  \"dogwalker\" can be made of \"dog\" and \"walker\".\r\n\t\tNote: \r\n\t\t\t0 <= len(words) <= 200\r\n\t\t\t1 <= len(words[i]) <= 100\r\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 1000023,
-        "question": "class Solution:\n    def massage(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tA popular masseuse receives a sequence of back-to-back appointment requests and is debating which ones to accept. She needs a break between appointments and therefore she cannot accept any adjacent requests. Given a sequence of back-to-back appoint\u00ad ment requests, find the optimal (highest total booked minutes) set the masseuse can honor. Return the number of minutes.\r\n\t\tNote: This problem is slightly different from the original one in the book.\r\n\t\tExample 1: \r\n\t\tInput:  [1,2,3,1]\r\n\t\tOutput:  4\r\n\t\tExplanation:  Accept request 1 and 3, total minutes = 1 + 3 = 4\r\n\t\tExample 2: \r\n\t\tInput:  [2,7,9,3,1]\r\n\t\tOutput:  12\r\n\t\tExplanation:  Accept request 1, 3 and 5, total minutes = 2 + 9 + 1 = 12\r\n\t\tExample 3: \r\n\t\tInput:  [2,1,4,5,3,1,1,3]\r\n\t\tOutput:  12\r\n\t\tExplanation:  Accept request 1, 3, 5 and 8, total minutes = 2 + 4 + 3 + 3 = 12\r\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 1000024,
-        "question": "class Solution:\n    def multiSearch(self, big: str, smalls: List[str]) -> List[List[int]]:\n\t\t\"\"\"\n\t\tGiven a string band an array of smaller strings T, design a method to search b for each small string in T. Output positions of all strings in smalls that appear in big, where positions[i] is all positions of smalls[i].\r\n\t\tExample: \r\n\t\tInput: \r\n\t\tbig = \"mississippi\"\r\n\t\tsmalls = [\"is\",\"ppi\",\"hi\",\"sis\",\"i\",\"ssippi\"]\r\n\t\tOutput:  [[1,4],[8],[],[3],[1,4,7,10],[5]]\r\n\t\tNote: \r\n\t\t\t0 <= len(big) <= 1000\r\n\t\t\t0 <= len(smalls[i]) <= 1000\r\n\t\t\tThe total number of characters in smalls will not exceed 100000.\r\n\t\t\tNo duplicated strings in smalls.\r\n\t\t\tAll characters are lowercase letters.\r\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 1000025,
-        "question": "class Solution:\n    def add(self, a: int, b: int) -> int:\n\t\t\"\"\"\n\t\tWrite a function that adds two numbers. You should not use + or any arithmetic operators.\r\n\t\tExample:\r\n\t\tInput: a = 1, b = 1\r\n\t\tOutput: 2\r\n\t\tNote: \r\n\t\t\ta and b may be 0 or negative.\r\n\t\t\tThe result fits in 32-bit integer.\r\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 1000026,
-        "question": "class LRUCache:\n    def __init__(self, capacity: int):\n    def get(self, key: int) -> int:\n    def put(self, key: int, value: int) -> None:\n\t\t\"\"\"\n\t\tDesign and build a \"least recently used\" cache, which evicts the least recently used item. The cache should map from keys to values (allowing you to insert and retrieve a value associ\u00adated with a particular key) and be initialized with a max size. When it is full, it should evict the least recently used item.\r\n\t\tYou should implement following operations:  get and put.\r\n\t\tGet a value by key: get(key) - If key is in the cache, return the value, otherwise return -1.\r\n\t\tWrite a key-value pair to the cache: put(key, value) - If the key is not in the cache, then write its value to the cache. Evict the least recently used item before writing if necessary.\r\n\t\tExample:\r\n\t\tLRUCache cache = new LRUCache( 2 /* capacity */ );\r\n\t\tcache.put(1, 1);\r\n\t\tcache.put(2, 2);\r\n\t\tcache.get(1);       // returns 1\r\n\t\tcache.put(3, 3);    // evicts key 2\r\n\t\tcache.get(2);       // returns -1 (not found)\r\n\t\tcache.put(4, 4);    // evicts key 1\r\n\t\tcache.get(1);       // returns -1 (not found)\r\n\t\tcache.get(3);       // returns 3\r\n\t\tcache.get(4);       // returns 4\r\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 1000027,
-        "question": "class Solution:\n    def calculate(self, s: str) -> int:\n\t\t\"\"\"\n\t\tGiven an arithmetic equation consisting of positive integers, +, -, * and / (no paren\u00adtheses), compute the result.\r\n\t\tThe expression string contains only non-negative integers, +, -, *, / operators and empty spaces . The integer division should truncate toward zero.\r\n\t\tExample 1:\r\n\t\tInput: \"3+2*2\"\r\n\t\tOutput: 7\r\n\t\tExample 2:\r\n\t\tInput: \" 3/2 \"\r\n\t\tOutput: 1\r\n\t\tExample 3:\r\n\t\tInput: \" 3+5 / 2 \"\r\n\t\tOutput: 5\r\n\t\tNote:\r\n\t\t\tYou may assume that the given expression is always valid.\r\n\t\t\tDo not use the eval built-in library function.\r\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 1000028,
-        "question": "class MedianFinder:\n    def __init__(self):\n\t\t\"\"\"\n        initialize your data structure here.\n\t\tNumbers are randomly generated and passed to a method. Write a program to find and maintain the median value as new values are generated.\r\n\t\tMedian is the middle value in an ordered integer list. If the size of the list is even, there is no middle value. So the median is the mean of the two middle value.\r\n\t\tFor example,\r\n\t\t[2,3,4], the median is 3\r\n\t\t[2,3], the median is (2 + 3) / 2 = 2.5\r\n\t\tDesign a data structure that supports the following two operations:\r\n\t\t\tvoid addNum(int num) - Add a integer number from the data stream to the data structure.\r\n\t\t\tdouble findMedian() - Return the median of all elements so far.\r\n\t\tExample: \r\n\t\taddNum(1)\r\n\t\taddNum(2)\r\n\t\tfindMedian() -> 1.5\r\n\t\taddNum(3) \r\n\t\tfindMedian() -> 2\r\n\t\t\"\"\"\n",
-        "difficulty": 2
-    },
-    {
-        "number": 1000029,
-        "question": "class Solution:\n    def trap(self, height: List[int]) -> int:\n\t\t\"\"\"\n\t\tImagine a histogram (bar graph). Design an algorithm to compute the volume of water it could hold if someone poured water across the top. You can assume that each histogram bar has width 1.\r\n\t\tThe above elevation map is represented by array [0,1,0,2,1,0,1,3,2,1,2,1]. In this case, 6 units of water (blue section) are being trapped. Thanks Marcos for contributing this image!\r\n\t\tExample:\r\n\t\tInput: [0,1,0,2,1,0,1,3,2,1,2,1]\r\n\t\tOutput: 6\r\n\t\t\"\"\"\n",
-        "difficulty": 2
-    },
-    {
-        "number": 1000030,
-        "question": "class Solution:\n    def findLadders(self, beginWord: str, endWord: str, wordList: List[str]) -> List[str]:\n\t\t\"\"\"\n\t\tGiven two words of equal length that are in a dictionary, write a method to transform one word into another word by changing only one letter at a time. The new word you get in each step must be in the dictionary.\r\n\t\tWrite code to return a possible transforming sequence. If there is more than one sequence, return any of them.\r\n\t\tExample 1:\r\n\t\tInput:\r\n\t\tbeginWord = \"hit\",\r\n\t\tendWord = \"cog\",\r\n\t\twordList = [\"hot\",\"dot\",\"dog\",\"lot\",\"log\",\"cog\"]\r\n\t\tOutput:\r\n\t\t[\"hit\",\"hot\",\"dot\",\"lot\",\"log\",\"cog\"]\r\n\t\tExample 2:\r\n\t\tInput:\r\n\t\tbeginWord = \"hit\"\r\n\t\tendWord = \"cog\"\r\n\t\twordList = [\"hot\",\"dot\",\"dog\",\"lot\",\"log\"]\r\n\t\tOutput: []\r\n\t\tExplanation: endWord \"cog\" is not in the dictionary, so there's no possible transforming sequence.\r\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 1000031,
-        "question": "class Solution:\n    def countEval(self, s: str, result: int) -> int:\n\t\t\"\"\"\n\t\tGiven a boolean expression consisting of the symbols 0 (false), 1 (true), & (AND), | (OR), and ^ (XOR), and a desired boolean result value result, implement a function to count the number of ways of parenthesizing the expression such that it evaluates to result.\r\n\t\tExample 1:\r\n\t\tInput: s = \"1^0|0|1\", result = 0\r\n\t\tOutput: 2\r\n\t\tExplanation: Two possible parenthesizing ways are:\r\n\t\t1^(0|(0|1))\r\n\t\t1^((0|0)|1)\r\n\t\tExample 2:\r\n\t\tInput: s = \"0&0&0&1^1|0\", result = 1\r\n\t\tOutput: 10\r\n\t\tNote: \r\n\t\t\tThere are no more than 19 operators in s.\r\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 1000032,
-        "question": "class Solution:\n    def missingNumber(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tAn array contains all the integers from 0 to n, except for one number which is missing.  Write code to find the missing integer. Can you do it in O(n) time?\r\n\t\tNote: This problem is slightly different from the original one the book.\r\n\t\tExample 1: \r\n\t\tInput: [3,0,1]\r\n\t\tOutput: 2\r\n\t\tExample 2: \r\n\t\tInput: [9,6,4,2,3,5,7,0,1]\r\n\t\tOutput: 8\r\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 1000033,
-        "question": "class Solution:\n    def findLongestSubarray(self, array: List[str]) -> List[str]:\n\t\t\"\"\"\n\t\tGiven an array filled with letters and numbers, find the longest subarray with an equal number of letters and numbers.\r\n\t\tReturn the subarray. If there are more than one answer, return the one which has the smallest index of its left endpoint. If there is no answer, return an empty arrary.\r\n\t\tExample 1:\r\n\t\tInput: [\"A\",\"1\",\"B\",\"C\",\"D\",\"2\",\"3\",\"4\",\"E\",\"5\",\"F\",\"G\",\"6\",\"7\",\"H\",\"I\",\"J\",\"K\",\"L\",\"M\"]\r\n\t\tOutput: [\"A\",\"1\",\"B\",\"C\",\"D\",\"2\",\"3\",\"4\",\"E\",\"5\",\"F\",\"G\",\"6\",\"7\"]\r\n\t\tExample 2:\r\n\t\tInput: [\"A\",\"A\"]\r\n\t\tOutput: []\r\n\t\tNote: \r\n\t\t\tarray.length <= 100000\r\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 1000034,
-        "question": "class Solution:\n    def numberOf2sInRange(self, n: int) -> int:\n\t\t\"\"\"\n\t\tWrite a method to count the number of 2s that appear in all the numbers between 0 and n (inclusive).\r\n\t\tExample:\r\n\t\tInput: 25\r\n\t\tOutput: 9\r\n\t\tExplanation: (2, 12, 20, 21, 22, 23, 24, 25)(Note that 22 counts for two 2s.)\r\n\t\tNote:\r\n\t\t\tn <= 10^9\r\n\t\t\"\"\"\n",
-        "difficulty": 2
-    },
-    {
-        "number": 1000035,
-        "question": "class Solution:\n    def trulyMostPopular(self, names: List[str], synonyms: List[str]) -> List[str]:\n\t\t\"\"\"\n\t\tEach year, the government releases a list of the 10000 most common baby names and their frequencies (the number of babies with that name). The only problem with this is that some names have multiple spellings. For example,\"John\" and ''Jon\" are essentially the same name but would be listed separately in the list. Given two lists, one of names/frequencies and the other of pairs of equivalent names, write an algorithm to print a new list of the true frequency of each name. Note that if John and Jon are synonyms, and Jon and Johnny are synonyms, then John and Johnny are synonyms. (It is both transitive and symmetric.) In the final list, choose the name that are lexicographically smallest as the \"real\" name.\r\n\t\tExample: \r\n\t\tInput: names = [\"John(15)\",\"Jon(12)\",\"Chris(13)\",\"Kris(4)\",\"Christopher(19)\"], synonyms = [\"(Jon,John)\",\"(John,Johnny)\",\"(Chris,Kris)\",\"(Chris,Christopher)\"]\r\n\t\tOutput: [\"John(27)\",\"Chris(36)\"]\r\n\t\tNote:\r\n\t\t\tnames.length <= 100000\r\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 1000036,
-        "question": "class Solution:\n    def bestSeqAtIndex(self, height: List[int], weight: List[int]) -> int:\n\t\t\"\"\"\n\t\tA circus is designing a tower routine consisting of people standing atop one anoth\u00ader's shoulders. For practical and aesthetic reasons, each person must be both shorter and lighter than the person below him or her. Given the heights and weights of each person in the circus, write a method to compute the largest possible number of people in such a tower.\r\n\t\tExample: \r\n\t\tInput: height = [65,70,56,75,60,68] weight = [100,150,90,190,95,110]\r\n\t\tOutput: 6\r\n\t\tExplanation: The longest tower is length 6 and includes from top to bottom: (56,90), (60,95), (65,100), (68,110), (70,150), (75,190)\r\n\t\tNote:\r\n\t\t\theight.length == weight.length <= 10000\r\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 1000037,
-        "question": "class Solution:\n    def getKthMagicNumber(self, k: int) -> int:\n\t\t\"\"\"\n\t\tDesign an algorithm to find the kth number such that the only prime factors are 3, 5, and 7. Note that 3, 5, and 7 do not have to be factors, but it should not have any other prime factors. For example, the first several multiples would be (in order) 1, 3, 5, 7, 9, 15, 21.\r\n\t\tExample 1:\r\n\t\tInput: k = 5\r\n\t\tOutput: 9\r\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 1000038,
-        "question": "class Solution:\n    def majorityElement(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tA majority element is an element that makes up more than half of the items in an array. Given a integers array, find the majority element. If there is no majority element, return -1. Do this in O(N) time and O(1) space.\r\n\t\tExample 1: \r\n\t\tInput: [1,2,5,9,5,9,5,5,5]\r\n\t\tOutput: 5\r\n\t\tExample 2: \r\n\t\tInput: [3,2]\r\n\t\tOutput: -1\r\n\t\tExample 3: \r\n\t\tInput: [2,2,1,1,1,2,2]\r\n\t\tOutput: 2\r\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 1000039,
-        "question": "class Solution:\n    def findClosest(self, words: List[str], word1: str, word2: str) -> int:\n\t\t\"\"\"\n\t\tYou have a large text file containing words. Given any two different words, find the shortest distance (in terms of number of words) between them in the file. If the operation will be repeated many times for the same file (but different pairs of words), can you optimize your solution?\r\n\t\tExample: \r\n\t\tInput: words = [\"I\",\"am\",\"a\",\"student\",\"from\",\"a\",\"university\",\"in\",\"a\",\"city\"], word1 = \"a\", word2 = \"student\"\r\n\t\tOutput: 1\r\n\t\tNote:\r\n\t\t\twords.length <= 100000\r\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 1000040,
-        "question": "class Solution:\n    def groupAnagrams(self, strs: List[str]) -> List[List[str]]:\n\t\t\"\"\"\n\t\tWrite a method to sort an array of strings so that all the anagrams are in the same group.\r\n\t\tNote: This problem is slightly different from the original one the book.\r\n\t\tExample:\r\n\t\tInput: [\"eat\", \"tea\", \"tan\", \"ate\", \"nat\", \"bat\"],\r\n\t\tOutput:\r\n\t\t[\r\n\t\t  [\"ate\",\"eat\",\"tea\"],\r\n\t\t  [\"nat\",\"tan\"],\r\n\t\t  [\"bat\"]\r\n\t\t]\r\n\t\tNotes: \r\n\t\t\tAll inputs will be in lowercase.\r\n\t\t\tThe order of your output does not matter.\r\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 1000041,
-        "question": "class StreamRank:\n    def __init__(self):\n    def track(self, x: int) -> None:\n    def getRankOfNumber(self, x: int) -> int:\n\t\t\"\"\"\n\t\tImagine you are reading in a stream of integers. Periodically, you wish to be able to look up the rank of a number x (the number of values less than or equal to x). lmplement the data structures and algorithms to support these operations. That is, implement the method track (int x), which is called when each number is generated, and the method getRankOfNumber(int x), which returns the number of values less than or equal to x.\r\n\t\tNote: This problem is slightly different from the original one in the book.\r\n\t\tExample:\r\n\t\tInput:\r\n\t\t[\"StreamRank\", \"getRankOfNumber\", \"track\", \"getRankOfNumber\"]\r\n\t\t[[], [1], [0], [0]]\r\n\t\tOutput:\r\n\t\t[null,0,null,1]\r\n\t\tNote: \r\n\t\t\tx <= 50000\r\n\t\t\tThe number of calls of both track and getRankOfNumber methods are less than or equal to 2000.\r\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 1000042,
-        "question": "class Solution:\n    def pairSums(self, nums: List[int], target: int) -> List[List[int]]:\n\t\t\"\"\"\n\t\tDesign an algorithm to find all pairs of integers within an array which sum to a specified value.\r\n\t\tExample 1:\r\n\t\tInput: nums = [5,6,5], target = 11\r\n\t\tOutput: [[5,6]]\r\n\t\tExample 2:\r\n\t\tInput: nums = [5,6,5,6], target = 11\r\n\t\tOutput: [[5,6],[5,6]]\r\n\t\tNote: \r\n\t\t\tnums.length <= 100000\r\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 1000043,
-        "question": "class Solution:\n    def shortestSeq(self, big: List[int], small: List[int]) -> List[int]:\n\t\t\"\"\"\n\t\tYou are given two arrays, one shorter (with all distinct elements) and one longer. Find the shortest subarray in the longer array that contains all the elements in the shorter array. The items can appear in any order.\r\n\t\tReturn the indexes of the leftmost and the rightmost elements of the array. If there are more than one answer, return the one that has the smallest left index. If there is no answer, return an empty array.\r\n\t\tExample 1:\r\n\t\tInput:\r\n\t\tbig = [7,5,9,0,2,1,3,5,7,9,1,1,5,8,8,9,7]\r\n\t\tsmall = [1,5,9]\r\n\t\tOutput: [7,10]\r\n\t\tExample 2:\r\n\t\tInput:\r\n\t\tbig = [1,2,3]\r\n\t\tsmall = [4]\r\n\t\tOutput: []\r\n\t\tNote: \r\n\t\t\tbig.length <= 100000\r\n\t\t\t1 <= small.length <= 100000\r\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 1000044,
-        "question": "class Solution:\n    def missingTwo(self, nums: List[int]) -> List[int]:\n\t\t\"\"\"\n\t\tYou are given an array with all the numbers from 1 to N appearing exactly once, except for two number that is missing. How can you find the missing number in O(N) time and 0(1) space?\r\n\t\tYou can return the missing numbers in any order.\r\n\t\tExample 1:\r\n\t\tInput: [1]\r\n\t\tOutput: [2,3]\r\n\t\tExample 2:\r\n\t\tInput: [2,3]\r\n\t\tOutput: [1,4]\r\n\t\tNote: \r\n\t\t\tnums.length <= 30000\r\n\t\t\"\"\"\n",
-        "difficulty": 2
-    },
-    {
-        "number": 1000045,
-        "question": "class Solution:\n    def findSquare(self, matrix: List[List[int]]) -> List[int]:\n\t\t\"\"\"\n\t\tImagine you have a square matrix, where each cell (pixel) is either black or white Design an algorithm to find the maximum subsquare such that all four borders are filled with black pixels.\r\n\t\tReturn an array [r, c, size], where r, c are the row number and the column number of the subsquare's upper left corner respectively, and size is the side length of the subsquare. If there are more than one answers, return the one that has smallest r. If there are more than one answers that have the same r, return the one that has smallest c. If there's no answer, return an empty array.\r\n\t\tExample 1:\r\n\t\tInput:\r\n\t\t[\r\n\t\t   [1,0,1],\r\n\t\t   [0,0,1],\r\n\t\t   [0,0,1]\r\n\t\t]\r\n\t\tOutput: [1,0,2]\r\n\t\tExplanation: 0 represents black, and 1 represents white, bold elements in the input is the answer.\r\n\t\tExample 2:\r\n\t\tInput:\r\n\t\t[\r\n\t\t   [0,1,1],\r\n\t\t   [1,0,1],\r\n\t\t   [1,1,0]\r\n\t\t]\r\n\t\tOutput: [0,0,1]\r\n\t\tNote: \r\n\t\t\tmatrix.length == matrix[0].length <= 200\r\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 1000046,
-        "question": "class Solution:\n    def getMaxMatrix(self, matrix: List[List[int]]) -> List[int]:\n\t\t\"\"\"\n\t\tGiven an NxM matrix of positive and negative integers, write code to find the submatrix with the largest possible sum.\r\n\t\tReturn an array [r1, c1, r2, c2], where r1, c1 are the row number and the column number of the submatrix's upper left corner respectively, and r2, c2 are the row number of and the column number of lower right corner. If there are more than one answers, return any one of them.\r\n\t\tNote: This problem is slightly different from the original one in the book.\r\n\t\tExample:\r\n\t\tInput:\r\n\t\t[\r\n\t\t   [-1,0],\r\n\t\t   [0,-1]\r\n\t\t]\r\n\t\tOutput: [0,1,0,1]\r\n\t\tNote: \r\n\t\t\t1 <= matrix.length, matrix[0].length <= 200\r\n\t\t\"\"\"\n",
-        "difficulty": 2
-    },
-    {
-        "number": 1000047,
-        "question": "class Solution:\n    def getValidT9Words(self, num: str, words: List[str]) -> List[str]:\n\t\t\"\"\"\n\t\tOn old cell phones, users typed on a numeric keypad and the phone would provide a list of words that matched these numbers. Each digit mapped to a set of 0 - 4 letters. Implement an algo\u00adrithm to return a list of matching words, given a sequence of digits. You are provided a list of valid words. The mapping is shown in the diagram below:\r\n\t\tExample 1:\r\n\t\tInput: num = \"8733\", words = [\"tree\", \"used\"]\r\n\t\tOutput: [\"tree\", \"used\"]\r\n\t\tExample 2:\r\n\t\tInput: num = \"2\", words = [\"a\", \"b\", \"c\", \"d\"]\r\n\t\tOutput: [\"a\", \"b\", \"c\"]\r\n\t\tNote:\r\n\t\t\tnum.length <= 1000\r\n\t\t\twords.length <= 500\r\n\t\t\twords[i].length == num.length\r\n\t\t\tThere are no number 0 and 1 in num.\r\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 1000048,
-        "question": "class Solution:\n    def findSwapValues(self, array1: List[int], array2: List[int]) -> List[int]:\n\t\t\"\"\"\n\t\tGiven two arrays of integers, find a pair of values (one value from each array) that you can swap to give the two arrays the same sum.\r\n\t\tReturn an array, where the first element is the element in the first array that will be swapped, and the second element is another one in the second array. If there are more than one answers, return any one of them. If there is no answer, return an empty array.\r\n\t\tExample:\r\n\t\tInput: array1 = [4, 1, 2, 1, 1, 2], array2 = [3, 6, 3, 3]\r\n\t\tOutput: [1, 3]\r\n\t\tExample:\r\n\t\tInput: array1 = [1, 2, 3], array2 = [4, 5, 6]\r\n\t\tOutput: []\r\n\t\tNote: \r\n\t\t\t1 <= array1.length, array2.length <= 100000\r\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 1000049,
-        "question": "class Solution:\n    def maxRectangle(self, words: List[str]) -> List[str]:\n\t\t\"\"\"\n\t\tGiven a list of millions of words, design an algorithm to create the largest possible rectangle of letters such that every row forms a word (reading left to right) and every column forms a word (reading top to bottom). The words need not be chosen consecutively from the list but all rows must be the same length and all columns must be the same height.\r\n\t\tIf there are more than one answer, return any one of them. A word can be used more than once.\r\n\t\tExample 1:\r\n\t\tInput: [\"this\", \"real\", \"hard\", \"trh\", \"hea\", \"iar\", \"sld\"]\r\n\t\tOutput:\r\n\t\t[\r\n\t\t   \"this\",\r\n\t\t   \"real\",\r\n\t\t   \"hard\"\r\n\t\t]\r\n\t\tExample 2:\r\n\t\tInput: [\"aa\"]\r\n\t\tOutput: [\"aa\",\"aa\"]\r\n\t\tNotes: \r\n\t\t\twords.length <= 1000\r\n\t\t\twords[i].length <= 100\r\n\t\t\tIt's guaranteed that all the words are randomly generated.\r\n\t\t\"\"\"\n",
-        "difficulty": 2
-    },
-    {
-        "number": 1000050,
-        "question": "class Solution:\n    def printKMoves(self, K: int) -> List[str]:\n\t\t\"\"\"\n\t\tAn ant is sitting on an infinite grid of white and black squares. It initially faces right. All squares are white initially.\r\n\t\tAt each step, it does the following:\r\n\t\t(1) At a white square, flip the color of the square, turn 90 degrees right (clockwise), and move forward one unit.\r\n\t\t(2) At a black square, flip the color of the square, turn 90 degrees left (counter-clockwise), and move forward one unit.\r\n\t\tWrite a program to simulate the first K moves that the ant makes and print the final board as a grid.\r\n\t\tThe grid should be represented as an array of strings, where each element represents one row in the grid. The black square is represented as 'X', and the white square is represented as '_', the square which is occupied by the ant is represented as 'L', 'U', 'R', 'D', which means the left, up, right and down orientations respectively. You only need to return the minimum matrix that is able to contain all squares that are passed through by the ant.\r\n\t\tExample 1:\r\n\t\tInput: 0\r\n\t\tOutput: [\"R\"]\r\n\t\tExample 2:\r\n\t\tInput: 2\r\n\t\tOutput:\r\n\t\t[\r\n\t\t  \"_X\",\r\n\t\t  \"LX\"\r\n\t\t]\r\n\t\tExample 3:\r\n\t\tInput: 5\r\n\t\tOutput:\r\n\t\t[\r\n\t\t  \"_U\",\r\n\t\t  \"X_\",\r\n\t\t  \"XX\"\r\n\t\t]\r\n\t\tNote: \r\n\t\t\tK <= 100000\r\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 1000051,
-        "question": "class Solution:\n    def computeSimilarities(self, docs: List[List[int]]) -> List[str]:\n\t\t\"\"\"\n\t\tThe similarity of two documents (each with distinct words) is defined to be the size of the intersection divided by the size of the union. For example, if the documents consist of integers, the similarity of {1, 5, 3} and {1, 7, 2, 3} is 0.4, because the intersection has size 2 and the union has size 5. We have a long list of documents (with distinct values and each with an associated ID) where the similarity is believed to be \"sparse\". That is, any two arbitrarily selected documents are very likely to have similarity 0. Design an algorithm that returns a list of pairs of document IDs and the associated similarity.\r\n\t\tInput is a 2D array docs, where docs[i] is the document with id i. Return an array of strings, where each string represents a pair of documents with similarity greater than 0. The string should be formatted as  {id1},{id2}: {similarity}, where id1 is the smaller id in the two documents, and similarity is the similarity rounded to four decimal places. You can return the array in any order.\r\n\t\tExample:\r\n\t\tInput: \r\n\t\t[\r\n\t\t  [14, 15, 100, 9, 3],\r\n\t\t  [32, 1, 9, 3, 5],\r\n\t\t  [15, 29, 2, 6, 8, 7],\r\n\t\t  [7, 10]\r\n\t\t]\r\n\t\tOutput:\r\n\t\t[\r\n\t\t  \"0,1: 0.2500\",\r\n\t\t  \"0,2: 0.1000\",\r\n\t\t  \"2,3: 0.1429\"\r\n\t\t]\r\n\t\tNote: \r\n\t\t\tdocs.length <= 500\r\n\t\t\tdocs[i].length <= 500\r\n\t\t\tThe number of document pairs with similarity greater than 0 will not exceed 1000.\r\n\t\t\"\"\"\n",
-        "difficulty": 2
-    },
-    {
-        "number": 1000228,
-        "question": "class Solution:\n    def divide(self, a: int, b: int) -> int:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 1000229,
-        "question": "class Solution:\n    def combinationSum(self, candidates: List[int], target: int) -> List[List[int]]:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 1000230,
-        "question": "class Solution:\n    def countBits(self, n: int) -> List[int]:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 1000231,
-        "question": "class Solution:\n    def addBinary(self, a: str, b: str) -> str:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 1000232,
-        "question": "class Solution:\n    def combinationSum2(self, candidates: List[int], target: int) -> List[List[int]]:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 1000233,
-        "question": "class Solution:\n    def singleNumber(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 1000234,
-        "question": "class Solution:\n    def permute(self, nums: List[int]) -> List[List[int]]:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 1000235,
-        "question": "class Solution:\n    def permuteUnique(self, nums: List[int]) -> List[List[int]]:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 1000236,
-        "question": "class Solution:\n    def maxProduct(self, words: List[str]) -> int:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 1000237,
-        "question": "class Solution:\n    def twoSum(self, numbers: List[int], target: int) -> List[int]:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 1000238,
-        "question": "class Solution:\n    def generateParenthesis(self, n: int) -> List[str]:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 1000239,
-        "question": "class Solution:\n    def threeSum(self, nums: List[int]) -> List[List[int]]:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 1000240,
-        "question": "class Solution:\n    def partition(self, s: str) -> List[List[str]]:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 1000241,
-        "question": "class Solution:\n    def restoreIpAddresses(self, s: str) -> List[str]:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 1000242,
-        "question": "class Solution:\n    def minSubArrayLen(self, target: int, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 1000243,
-        "question": "class Solution:\n    def minCostClimbingStairs(self, cost: List[int]) -> int:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 1000244,
-        "question": "class Solution:\n    def numSubarrayProductLessThanK(self, nums: List[int], k: int) -> int:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 1000245,
-        "question": "class Solution:\n    def rob(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 1000246,
-        "question": "class Solution:\n    def subarraySum(self, nums: List[int], k: int) -> int:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 1000247,
-        "question": "class Solution:\n    def findMaxLength(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 1000248,
-        "question": "class Solution:\n    def pivotIndex(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 1000249,
-        "question": "class NumMatrix:\n    def __init__(self, matrix: List[List[int]]):\n    def sumRegion(self, row1: int, col1: int, row2: int, col2: int) -> int:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 1000250,
-        "question": "class Solution:\n    def checkInclusion(self, s1: str, s2: str) -> bool:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 1000251,
-        "question": "class Solution:\n    def findAnagrams(self, s: str, p: str) -> List[int]:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 1000252,
-        "question": "class Solution:\n    def lengthOfLongestSubstring(self, s: str) -> int:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 1000253,
-        "question": "class Solution:\n    def minWindow(self, s: str, t: str) -> str:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 2
-    },
-    {
-        "number": 1000254,
-        "question": "class Solution:\n    def isPalindrome(self, s: str) -> bool:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 1000255,
-        "question": "class Solution:\n    def validPalindrome(self, s: str) -> bool:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 1000256,
-        "question": "class Solution:\n    def countSubstrings(self, s: str) -> int:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 1000257,
-        "question": "class Solution:\n    def removeNthFromEnd(self, head: ListNode, n: int) -> ListNode:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 1000258,
-        "question": "class Solution:\n    def detectCycle(self, head: ListNode) -> ListNode:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 1000259,
-        "question": "class Solution:\n    def getIntersectionNode(self, headA: ListNode, headB: ListNode) -> ListNode:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 1000260,
-        "question": "class Solution:\n    def reverseList(self, head: ListNode) -> ListNode:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 1000261,
-        "question": "class Solution:\n    def addTwoNumbers(self, l1: ListNode, l2: ListNode) -> ListNode:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 1000262,
-        "question": "class Solution:\n    def reorderList(self, head: ListNode) -> None:\n\t\t\"\"\"\n        Do not return anything, modify head in-place instead.\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 1000263,
-        "question": "class Solution:\n    def isPalindrome(self, head: ListNode) -> bool:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 1000264,
-        "question": "\n\t\t\"\"\"\nclass Node:\n    def __init__(self, val, prev, next, child):\n        self.val = val\n        self.prev = prev\n        self.next = next\n        self.child = child\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 1000265,
-        "question": "\n\t\t\"\"\"\nclass Node:\n    def __init__(self, val=None, next=None):\n        self.val = val\n        self.next = next\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 1000266,
-        "question": "class Solution:\n    def rob(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 1000267,
-        "question": "class RandomizedSet:\n    def __init__(self):\n\t\t\"\"\"\n        Initialize your data structure here.\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 1000268,
-        "question": "class Solution:\n    def minCost(self, costs: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 1000269,
-        "question": "class Solution:\n    def minFlipsMonoIncr(self, s: str) -> int:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 1000270,
-        "question": "class LRUCache:\n    def __init__(self, capacity: int):\n    def get(self, key: int) -> int:\n    def put(self, key: int, value: int) -> None:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 1000271,
-        "question": "class Solution:\n    def lenLongestFibSubseq(self, arr: List[int]) -> int:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 1000272,
-        "question": "class Solution:\n    def minCut(self, s: str) -> int:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 2
-    },
-    {
-        "number": 1000273,
-        "question": "class Solution:\n    def isAnagram(self, s: str, t: str) -> bool:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 1000274,
-        "question": "class Solution:\n    def longestCommonSubsequence(self, text1: str, text2: str) -> int:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 1000275,
-        "question": "class Solution:\n    def groupAnagrams(self, strs: List[str]) -> List[List[str]]:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 1000276,
-        "question": "class Solution:\n    def isAlienSorted(self, words: List[str], order: str) -> bool:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 1000277,
-        "question": "class Solution:\n    def isInterleave(self, s1: str, s2: str, s3: str) -> bool:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 1000278,
-        "question": "class Solution:\n    def findMinDifference(self, timePoints: List[str]) -> int:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 1000279,
-        "question": "class Solution:\n    def evalRPN(self, tokens: List[str]) -> int:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 1000280,
-        "question": "class Solution:\n    def numDistinct(self, s: str, t: str) -> int:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 2
-    },
-    {
-        "number": 1000281,
-        "question": "class Solution:\n    def asteroidCollision(self, asteroids: List[int]) -> List[int]:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 1000282,
-        "question": "class Solution:\n    def dailyTemperatures(self, temperatures: List[int]) -> List[int]:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 1000283,
-        "question": "class Solution:\n    def largestRectangleArea(self, heights: List[int]) -> int:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 2
-    },
-    {
-        "number": 1000284,
-        "question": "class Solution:\n    def maximalRectangle(self, matrix: List[str]) -> int:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 2
-    },
-    {
-        "number": 1000285,
-        "question": "class Solution:\n    def minPathSum(self, grid: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 1000286,
-        "question": "class Solution:\n    def minimumTotal(self, triangle: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 1000287,
-        "question": "class Solution:\n    def canPartition(self, nums: List[int]) -> bool:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 1000288,
-        "question": "class Solution:\n    def findTargetSumWays(self, nums: List[int], target: int) -> int:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 1000289,
-        "question": "class Solution:\n    def coinChange(self, coins: List[int], amount: int) -> int:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 1000290,
-        "question": "class Solution:\n    def combinationSum4(self, nums: List[int], target: int) -> int:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 1000291,
-        "question": "class Solution:\n    def maxAreaOfIsland(self, grid: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 1000292,
-        "question": "class MovingAverage:\n    def __init__(self, size: int):\n\t\t\"\"\"\n        Initialize your data structure here.\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 1000293,
-        "question": "class RecentCounter:\n    def __init__(self):\n    def ping(self, t: int) -> int:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 1000294,
-        "question": "class Solution:\n    def isBipartite(self, graph: List[List[int]]) -> bool:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 1000295,
-        "question": "class CBTInserter:\n    def __init__(self, root: TreeNode):\n    def insert(self, v: int) -> int:\n    def get_root(self) -> TreeNode:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 1000296,
-        "question": "class Solution:\n    def updateMatrix(self, mat: List[List[int]]) -> List[List[int]]:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 1000297,
-        "question": "class Solution:\n    def largestValues(self, root: TreeNode) -> List[int]:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 1000298,
-        "question": "class Solution:\n    def findBottomLeftValue(self, root: TreeNode) -> int:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 1000299,
-        "question": "class Solution:\n    def rightSideView(self, root: TreeNode) -> List[int]:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 1000300,
-        "question": "class Solution:\n    def ladderLength(self, beginWord: str, endWord: str, wordList: List[str]) -> int:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 2
-    },
-    {
-        "number": 1000301,
-        "question": "class Solution:\n    def pruneTree(self, root: TreeNode) -> TreeNode:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 1000302,
-        "question": "class Solution:\n    def openLock(self, deadends: List[str], target: str) -> int:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 1000303,
-        "question": "class Solution:\n    def allPathsSourceTarget(self, graph: List[List[int]]) -> List[List[int]]:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 1000304,
-        "question": "class Codec:\n    def serialize(self, root):\n\t\t\"\"\"Encodes a tree to a single string.\n        :type root: TreeNode\n        :rtype: str\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 2
-    },
-    {
-        "number": 1000305,
-        "question": "class Solution:\n    def calcEquation(self, equations: List[List[str]], values: List[float], queries: List[List[str]]) -> List[float]:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 1000306,
-        "question": "class Solution:\n    def sumNumbers(self, root: TreeNode) -> int:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 1000307,
-        "question": "class Solution:\n    def pathSum(self, root: TreeNode, targetSum: int) -> int:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 1000308,
-        "question": "class Solution:\n    def longestIncreasingPath(self, matrix: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 2
-    },
-    {
-        "number": 1000309,
-        "question": "class Solution:\n    def maxPathSum(self, root: TreeNode) -> int:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 2
-    },
-    {
-        "number": 1000310,
-        "question": "class Solution:\n    def findOrder(self, numCourses: int, prerequisites: List[List[int]]) -> List[int]:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 1000311,
-        "question": "class Solution:\n    def increasingBST(self, root: TreeNode) -> TreeNode:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 1000312,
-        "question": "class Solution:\n    def alienOrder(self, words: List[str]) -> str:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 2
-    },
-    {
-        "number": 1000313,
-        "question": "class Solution:\n    def inorderSuccessor(self, root: 'TreeNode', p: 'TreeNode') -> 'TreeNode':\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 1000314,
-        "question": "class Solution:\n    def sequenceReconstruction(self, nums: List[int], sequences: List[List[int]]) -> bool:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 1000315,
-        "question": "class Solution:\n    def convertBST(self, root: TreeNode) -> TreeNode:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 1000316,
-        "question": "class BSTIterator:\n    def __init__(self, root: TreeNode):\n    def next(self) -> int:\n    def hasNext(self) -> bool:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 1000317,
-        "question": "class Solution:\n    def numSimilarGroups(self, strs: List[str]) -> int:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 2
-    },
-    {
-        "number": 1000318,
-        "question": "class Solution:\n    def findRedundantConnection(self, edges: List[List[int]]) -> List[int]:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 1000319,
-        "question": "class Solution:\n    def findTarget(self, root: TreeNode, k: int) -> bool:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 1000320,
-        "question": "class Solution:\n    def longestConsecutive(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 1000321,
-        "question": "class Solution:\n    def containsNearbyAlmostDuplicate(self, nums: List[int], k: int, t: int) -> bool:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 1000322,
-        "question": "class MyCalendar:\n    def __init__(self):\n    def book(self, start: int, end: int) -> bool:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 1000323,
-        "question": "class KthLargest:\n    def __init__(self, k: int, nums: List[int]):\n    def add(self, val: int) -> int:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 1000324,
-        "question": "class Solution:\n    def topKFrequent(self, nums: List[int], k: int) -> List[int]:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 1000325,
-        "question": "class Trie:\n    def __init__(self):\n\t\t\"\"\"\n        Initialize your data structure here.\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 1000326,
-        "question": "class Solution:\n    def kSmallestPairs(self, nums1: List[int], nums2: List[int], k: int) -> List[List[int]]:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 1000327,
-        "question": "class Solution:\n    def replaceWords(self, dictionary: List[str], sentence: str) -> str:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 1000328,
-        "question": "class MagicDictionary:\n    def __init__(self):\n\t\t\"\"\"\n        Initialize your data structure here.\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 1000329,
-        "question": "class Solution:\n    def minimumLengthEncoding(self, words: List[str]) -> int:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 1000330,
-        "question": "class MapSum:\n    def __init__(self):\n\t\t\"\"\"\n        Initialize your data structure here.\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 1000331,
-        "question": "class Solution:\n    def findMaximumXOR(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 1000332,
-        "question": "class Solution:\n    def searchInsert(self, nums: List[int], target: int) -> int:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 1000333,
-        "question": "class Solution:\n    def peakIndexInMountainArray(self, arr: List[int]) -> int:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 1000334,
-        "question": "class Solution:\n    def singleNonDuplicate(self, nums: List[int]) -> int:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 1000335,
-        "question": "class Solution:\n    def __init__(self, w: List[int]):\n    def pickIndex(self) -> int:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 1000336,
-        "question": "class Solution:\n    def mySqrt(self, x: int) -> int:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 1000337,
-        "question": "class Solution:\n    def minEatingSpeed(self, piles: List[int], h: int) -> int:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 1000338,
-        "question": "class Solution:\n    def merge(self, intervals: List[List[int]]) -> List[List[int]]:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 1000339,
-        "question": "class Solution:\n    def relativeSortArray(self, arr1: List[int], arr2: List[int]) -> List[int]:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 0
-    },
-    {
-        "number": 1000340,
-        "question": "class Solution:\n    def findKthLargest(self, nums: List[int], k: int) -> int:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 1000341,
-        "question": "class Solution:\n    def sortList(self, head: ListNode) -> ListNode:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 1000342,
-        "question": "class Solution:\n    def mergeKLists(self, lists: List[ListNode]) -> ListNode:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 2
-    },
-    {
-        "number": 1000343,
-        "question": "class Solution:\n    def subsets(self, nums: List[int]) -> List[List[int]]:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 1000344,
-        "question": "class Solution:\n    def combine(self, n: int, k: int) -> List[List[int]]:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 1000345,
-        "question": "class Solution:\n    def uniquePaths(self, m: int, n: int) -> int:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    },
-    {
-        "number": 1000346,
-        "question": "class Solution:\n    def findCircleNum(self, isConnected: List[List[int]]) -> int:\n\t\t\"\"\"\n\t\tEnglish description is not available for the problem. Please switch to Chinese.\n\t\t\"\"\"\n",
-        "difficulty": 1
-    }
-]
\ No newline at end of file