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http://rosettacode.org/wiki/Stream_merge | Stream merge | 2-stream merge
Read two sorted streams of items from external source (e.g. disk, or network), and write one stream of sorted items to external sink.
Common algorithm: keep 1 buffered item from each source, select minimal of them, write it, fetch another item from that stream from which the written item was.
N-stream merge
The same as above, but reading from N sources.
Common algorithm: same as above, but keep buffered items and their source descriptors in a heap.
Assume streams are very big. You must not suck them whole in the memory, but read them as streams.
| #REXX | REXX | /* REXX ***************************************************************
* Merge 1.txt ... n.txt into all.txt
* 1.txt 2.txt 3.txt 4.txt
* 1 19 1999 2e3
* 17 33 2999 3000
* 8 500 3999 RC task STREAM MERGE
**********************************************************************/
done.=0 /* done.i=1 indicates file exhausted */
p.='' /* for test of sort error */
Do i=1 By 1 /* check files for existence */
f.i=i'.txt'
If lines(f.i)=0 Then Leave
Call get i /* and read first line of each*/
End
n=i-1 /* we have n input files */
done.0=n /* and all must be used */
say n 'Input files'
oid='all.txt'
If lines(oid)>0 Then Do /* output file exists */
Call lineout oid
Do Until wordpos(answer,'Y N')>0
Say 'file' oid 'exists. May it be replaced?'
Pull answer
End
If answer='Y' Then
'erase' oid
Else Do
Say 'Ok, we give up'
Exit
End
End
say oid 'is the output file' /* we'll create it now */
Do Until done.0=0
imin=0 /* index of next source */
Do i=1 To n
If done.i=0 Then Do /* file i still in use */
If imin=0 Then Do /* it's the first in this loop*/
imin=i /* next source */
min=x.i /* element to be used */
End
Else Do /* not the first */
If x.i<<min Then Do /* avoid numerical comparison */
imin=i /* next source */
min=x.i /* element to be used */
End
End
End
End
If imin<>0 Then Do /* found next source */
Call o x.imin /* use its element */
Call get imin /* get next element */
/* or set done.imin */
End
Else /* no more elements */
Call lineout oid /* close output file */
End
'type' oid
Exit
get: Procedure Expose f. x. p. done.
/*********************************************************************
* Get next element from file ii or set done.ii=1 if file is exhausted
*********************************************************************/
Parse Arg ii
If lines(f.ii)=0 Then Do /* file ii is exhausted */
done.ii=1 /* mark it as done */
done.0=done.0-1 /* reduce number of files tbd*/
End
Else Do /* there's more in file ii */
x.ii=linein(f.ii) /* get next element (line) */
If x.ii<<p.ii Then Do /* smaller than previous */
Say 'Input file' f.ii 'is not sorted ascendingly'
Say p.ii 'precedes' x.ii /* tell the user */
Exit /* and give up */
End
p.ii=x.ii /* remember the element */
End
Return
o: Return lineout(oid,arg(1)) |
http://rosettacode.org/wiki/State_name_puzzle | State name puzzle | Background
This task is inspired by Mark Nelson's DDJ Column "Wordplay" and one of the weekly puzzle challenges from Will Shortz on NPR Weekend Edition [1] and originally attributed to David Edelheit.
The challenge was to take the names of two U.S. States, mix them all together, then rearrange the letters to form the names of two different U.S. States (so that all four state names differ from one another).
What states are these?
The problem was reissued on the Unicon Discussion Web which includes several solutions with analysis. Several techniques may be helpful and you may wish to refer to Gödel numbering, equivalence relations, and equivalence classes. The basic merits of these were discussed in the Unicon Discussion Web.
A second challenge in the form of a set of fictitious new states was also presented.
Task
Write a program to solve the challenge using both the original list of states and the fictitious list.
Caveats
case and spacing aren't significant - just letters (harmonize case)
don't expect the names to be in any order - such as being sorted
don't rely on names to be unique (eliminate duplicates - meaning if Iowa appears twice you can only use it once)
Comma separated list of state names used in the original puzzle:
"Alabama", "Alaska", "Arizona", "Arkansas",
"California", "Colorado", "Connecticut", "Delaware",
"Florida", "Georgia", "Hawaii", "Idaho", "Illinois",
"Indiana", "Iowa", "Kansas", "Kentucky", "Louisiana",
"Maine", "Maryland", "Massachusetts", "Michigan",
"Minnesota", "Mississippi", "Missouri", "Montana",
"Nebraska", "Nevada", "New Hampshire", "New Jersey",
"New Mexico", "New York", "North Carolina", "North Dakota",
"Ohio", "Oklahoma", "Oregon", "Pennsylvania", "Rhode Island",
"South Carolina", "South Dakota", "Tennessee", "Texas",
"Utah", "Vermont", "Virginia",
"Washington", "West Virginia", "Wisconsin", "Wyoming"
Comma separated list of additional fictitious state names to be added to the original (Includes a duplicate):
"New Kory", "Wen Kory", "York New", "Kory New", "New Kory"
Other tasks related to string operations:
Metrics
Array length
String length
Copy a string
Empty string (assignment)
Counting
Word frequency
Letter frequency
Jewels and stones
I before E except after C
Bioinformatics/base count
Count occurrences of a substring
Count how many vowels and consonants occur in a string
Remove/replace
XXXX redacted
Conjugate a Latin verb
Remove vowels from a string
String interpolation (included)
Strip block comments
Strip comments from a string
Strip a set of characters from a string
Strip whitespace from a string -- top and tail
Strip control codes and extended characters from a string
Anagrams/Derangements/shuffling
Word wheel
ABC problem
Sattolo cycle
Knuth shuffle
Ordered words
Superpermutation minimisation
Textonyms (using a phone text pad)
Anagrams
Anagrams/Deranged anagrams
Permutations/Derangements
Find/Search/Determine
ABC words
Odd words
Word ladder
Semordnilap
Word search
Wordiff (game)
String matching
Tea cup rim text
Alternade words
Changeable words
State name puzzle
String comparison
Unique characters
Unique characters in each string
Extract file extension
Levenshtein distance
Palindrome detection
Common list elements
Longest common suffix
Longest common prefix
Compare a list of strings
Longest common substring
Find common directory path
Words from neighbour ones
Change e letters to i in words
Non-continuous subsequences
Longest common subsequence
Longest palindromic substrings
Longest increasing subsequence
Words containing "the" substring
Sum of the digits of n is substring of n
Determine if a string is numeric
Determine if a string is collapsible
Determine if a string is squeezable
Determine if a string has all unique characters
Determine if a string has all the same characters
Longest substrings without repeating characters
Find words which contains all the vowels
Find words which contains most consonants
Find words which contains more than 3 vowels
Find words which first and last three letters are equals
Find words which odd letters are consonants and even letters are vowels or vice_versa
Formatting
Substring
Rep-string
Word wrap
String case
Align columns
Literals/String
Repeat a string
Brace expansion
Brace expansion using ranges
Reverse a string
Phrase reversals
Comma quibbling
Special characters
String concatenation
Substring/Top and tail
Commatizing numbers
Reverse words in a string
Suffixation of decimal numbers
Long literals, with continuations
Numerical and alphabetical suffixes
Abbreviations, easy
Abbreviations, simple
Abbreviations, automatic
Song lyrics/poems/Mad Libs/phrases
Mad Libs
Magic 8-ball
99 Bottles of Beer
The Name Game (a song)
The Old lady swallowed a fly
The Twelve Days of Christmas
Tokenize
Text between
Tokenize a string
Word break problem
Tokenize a string with escaping
Split a character string based on change of character
Sequences
Show ASCII table
De Bruijn sequences
Self-referential sequences
Generate lower case ASCII alphabet
| #AppleScript | AppleScript | use AppleScript version "2.3.1" -- Mac OS X 10.9 (Mavericks) or later.
use sorter : script "Custom Iterative Ternary Merge Sort" -- <https://macscripter.net/viewtopic.php?pid=194430#p194430>
on stateNamePuzzle()
script o
property stateNames : {"Alabama", "Alaska", "Arizona", "Arkansas", ¬
"California", "Colorado", "Connecticut", "Delaware", ¬
"Florida", "Georgia", "Hawaii", "Idaho", "Illinois", ¬
"Indiana", "Iowa", "Kansas", "Kentucky", "Louisiana", ¬
"Maine", "Maryland", "Massachusetts", "Michigan", ¬
"Minnesota", "Mississippi", "Missouri", "Montana", ¬
"Nebraska", "Nevada", "New Hampshire", "New Jersey", ¬
"New Mexico", "New York", "North Carolina", "North Dakota", ¬
"Ohio", "Oklahoma", "Oregon", "Pennsylvania", "Rhode Island", ¬
"South Carolina", "South Dakota", "Tennessee", "Texas", ¬
"Utah", "Vermont", "Virginia", ¬
"Washington", "West Virginia", "Wisconsin", "Wyoming", ¬
"New Kory", "Wen Kory", "York New", "Kory New", "New Kory"}
property namePairs : {}
property checkList : {}
end script
ignoring case
-- Remove duplicates.
repeat with i from 1 to (count o's stateNames)
set thisName to item i of o's stateNames
if (thisName is not in o's checkList) then set end of o's checkList to thisName
end repeat
set o's stateNames to o's checkList
-- Build lists containing unique pairs of names preceded by
-- texts composed of their combined visible characters, sorted.
set stateCount to (count o's stateNames)
repeat with i from 1 to (stateCount - 1)
set name1 to item i of o's stateNames
repeat with j from (i + 1) to stateCount
set name2 to item j of o's stateNames
set chrs to characters of (name1 & name2)
tell sorter to sort(chrs, 1, -1, {})
set end of o's namePairs to {word 1 of join(chrs, ""), name1, name2}
end repeat
end repeat
-- Sort the lists on the character strings
set pairCount to (count o's namePairs)
tell sorter to sort(o's namePairs, 1, pairCount, {comparer:me})
-- Look for groups of equal character strings and match
-- associated name pairs not containing the same name(s).
set output to {}
set l to 1
repeat while (l < pairCount)
set chrs to beginning of item l of o's namePairs
set r to l
repeat while ((r < pairCount) and (beginning of item (r + 1) of o's namePairs = chrs))
set r to r + 1
end repeat
if (r > l) then
repeat with i from l to (r - 1)
set {name1, name2} to rest of item i of o's namePairs
set text1 to join(result, " and ") & " --> "
repeat with j from (i + 1) to r
set pair2 to rest of item j of o's namePairs
if (not ((name1 is in pair2) or (name2 is in pair2))) then
set end of output to text1 & join(pair2, " and ")
end if
end repeat
end repeat
end if
set l to r + 1
end repeat
end ignoring
return join(output, linefeed)
end stateNamePuzzle
-- Custom comparison handler used when the sort comparer is 'me'. Compares the first items of two lists.
on isGreater(a, b)
return (beginning of a comes after beginning of b)
end isGreater
on join(lst, delim)
set astid to AppleScript's text item delimiters
set AppleScript's text item delimiters to delim
set txt to lst as text
set AppleScript's text item delimiters to astid
return txt
end join
stateNamePuzzle() |
http://rosettacode.org/wiki/Start_from_a_main_routine | Start from a main routine |
Some languages (like Gambas and Visual Basic) support two startup modes. Applications written in these languages start with an open window that waits for events, and it is necessary to do some trickery to cause a main procedure to run instead. Data driven or event driven languages may also require similar trickery to force a startup procedure to run.
Task
Demonstrate the steps involved in causing the application to run a main procedure, rather than an event driven window at startup.
Languages that always run from main() can be omitted from this task.
| #8086_Assembly | 8086 Assembly | with Ada.Text_IO;
procedure Foo is
begin
Ada.Text_IO.Put_Line("Bar");
end Foo; |
http://rosettacode.org/wiki/Start_from_a_main_routine | Start from a main routine |
Some languages (like Gambas and Visual Basic) support two startup modes. Applications written in these languages start with an open window that waits for events, and it is necessary to do some trickery to cause a main procedure to run instead. Data driven or event driven languages may also require similar trickery to force a startup procedure to run.
Task
Demonstrate the steps involved in causing the application to run a main procedure, rather than an event driven window at startup.
Languages that always run from main() can be omitted from this task.
| #Ada | Ada | with Ada.Text_IO;
procedure Foo is
begin
Ada.Text_IO.Put_Line("Bar");
end Foo; |
http://rosettacode.org/wiki/Start_from_a_main_routine | Start from a main routine |
Some languages (like Gambas and Visual Basic) support two startup modes. Applications written in these languages start with an open window that waits for events, and it is necessary to do some trickery to cause a main procedure to run instead. Data driven or event driven languages may also require similar trickery to force a startup procedure to run.
Task
Demonstrate the steps involved in causing the application to run a main procedure, rather than an event driven window at startup.
Languages that always run from main() can be omitted from this task.
| #ALGOL_68 | ALGOL 68 | BEGIN
print( ( "Hello, World!", newline ) )
END |
http://rosettacode.org/wiki/Start_from_a_main_routine | Start from a main routine |
Some languages (like Gambas and Visual Basic) support two startup modes. Applications written in these languages start with an open window that waits for events, and it is necessary to do some trickery to cause a main procedure to run instead. Data driven or event driven languages may also require similar trickery to force a startup procedure to run.
Task
Demonstrate the steps involved in causing the application to run a main procedure, rather than an event driven window at startup.
Languages that always run from main() can be omitted from this task.
| #Arturo | Arturo | main: function [][
print "Yes, we are in main!"
]
main |
http://rosettacode.org/wiki/Straddling_checkerboard | Straddling checkerboard | Task
Implement functions to encrypt and decrypt a message using the straddling checkerboard method. The checkerboard should take a 28 character alphabet (A-Z plus a full stop and an escape character) and two different numbers representing the blanks in the first row. The output will be a series of decimal digits.
Numbers should be encrypted by inserting the escape character before each digit, then including the digit unencrypted. This should be reversed for decryption.
| #PHP | PHP | $key2val = ["A"=>"30", "B"=>"31", "C"=>"32", "D"=>"33", "E"=>"5", "F"=>"34", "G"=>"35",
"H"=>"0", "I"=>"36", "J"=>"37", "K"=>"38", "L"=>"2", "M"=>"4", "."=>"78", "N"=>"39",
"/"=>"79", "O"=>"1", "0"=>"790", "P"=>"70", "1"=>"791", "Q"=>"71", "2"=>"792",
"R"=>"8", "3"=>"793", "S"=>"6", "4"=>"794", "T"=>"9", "5"=>"795", "U"=>"72",
"6"=>"796", "V"=>"73", "7"=>"797", "W"=>"74", "8"=>"798", "X"=>"75", "9"=>"799",
"Y"=>"76", "Z"=>"77"];
$val2key = array_flip($key2val);
function encode(string $s) : string {
global $key2val;
$callback = function($c) use ($key2val) { return $key2val[$c] ?? ''; };
return implode(array_map($callback, str_split(strtoupper($s))));
}
function decode(string $s) : string {
global $val2key;
$callback = function($c) use ($val2key) { return $val2key[$c] ?? ''; };
preg_match_all('/79.|7.|3.|./', $s, $m);
return implode(array_map($callback, $m[0]));
}
function main($s) {
$encoded = encode($s);
echo $encoded;
echo "\n";
echo decode($encoded);
}
main('One night-it was on the twentieth of March, 1888-I was returning'); |
http://rosettacode.org/wiki/Stirling_numbers_of_the_first_kind | Stirling numbers of the first kind | Stirling numbers of the first kind, or Stirling cycle numbers, count permutations according to their number
of cycles (counting fixed points as cycles of length one).
They may be defined directly to be the number of permutations of n
elements with k disjoint cycles.
Stirling numbers of the first kind express coefficients of polynomial expansions of falling or rising factorials.
Depending on the application, Stirling numbers of the first kind may be "signed"
or "unsigned". Signed Stirling numbers of the first kind arise when the
polynomial expansion is expressed in terms of falling factorials; unsigned when
expressed in terms of rising factorials. The only substantial difference is that,
for signed Stirling numbers of the first kind, values of S1(n, k) are negative
when n + k is odd.
Stirling numbers of the first kind follow the simple identities:
S1(0, 0) = 1
S1(n, 0) = 0 if n > 0
S1(n, k) = 0 if k > n
S1(n, k) = S1(n - 1, k - 1) + (n - 1) * S1(n - 1, k) # For unsigned
or
S1(n, k) = S1(n - 1, k - 1) - (n - 1) * S1(n - 1, k) # For signed
Task
Write a routine (function, procedure, whatever) to find Stirling numbers of the first kind. There are several methods to generate Stirling numbers of the first kind. You are free to choose the most appropriate for your language. If your language has a built-in, or easily, publicly available library implementation, it is acceptable to use that.
Using the routine, generate and show here, on this page, a table (or triangle) showing the Stirling numbers of the first kind, S1(n, k), up to S1(12, 12). it is optional to show the row / column for n == 0 and k == 0. It is optional to show places where S1(n, k) == 0 (when k > n). You may choose to show signed or unsigned Stirling numbers of the first kind, just make a note of which was chosen.
If your language supports large integers, find and show here, on this page, the maximum value of S1(n, k) where n == 100.
See also
Wikipedia - Stirling numbers of the first kind
OEIS:A008275 - Signed Stirling numbers of the first kind
OEIS:A130534 - Unsigned Stirling numbers of the first kind
Related Tasks
Stirling numbers of the second kind
Lah numbers
| #REXX | REXX | /*REXX program to compute and display (unsigned) Stirling numbers of the first kind.*/
parse arg lim . /*obtain optional argument from the CL.*/
if lim=='' | lim=="," then lim= 12 /*Not specified? Then use the default.*/
olim= lim /*save the original value of LIM. */
lim= abs(lim) /*only use the absolute value of LIM. */
numeric digits max(9, 2*lim) /*(over) specify maximum number in grid*/
@.=; @.0.0= 1 /*define the (0, 0)th value in grid*/
do n=0 for lim+1 /* [↓] initialize some values " " */
if n>0 then @.n.0 = 0 /*assign value if N > zero. */
do k=n+1 to lim
@.n.k = 0 /*zero some values in grid if K > N. */
end /*k*/
end /*n*/
max#.= 0 /* [↓] calculate values for the grid. */
do n=1 for lim; nm= n - 1
do k=1 for lim; km= k - 1
@.n.k = @.nm.km + nm * @.nm.k /*calculate an unsigned number in grid.*/
max#.k= max(max#.k, @.n.k) /*find the maximum value " " */
max#.b= max(max#.b, @.n.k) /*find the maximum value for all rows. */
end /*k*/
end /*n*/
do k=1 for lim /*find max column width for each column*/
max#.a= max#.a + length(max#.k)
end /*k*/
/* [↓] only show the maximum value ? */
w= length(max#.b) /*calculate max width of all numbers. */
if olim<0 then do; say 'The maximum value (which has ' w " decimal digits):"
say max#.b /*display maximum number in the grid. */
exit /*stick a fork in it, we're all done. */
end
wi= max(3, length(lim+1) ) /*the maximum width of the grid's index*/
say 'row' center('columns', max(9, max#.a + lim), '═') /*display header of the grid.*/
do r=0 for lim+1; $= /* [↓] display the grid to the term. */
do c=0 for lim+1 until c>=r /*build a row of grid, 1 col at a time.*/
$= $ right(@.r.c, length(max#.c) ) /*append a column to a row of the grid.*/
end /*c*/
say right(r,wi) strip(substr($,2), 'T') /*display a single row of the grid. */
end /*r*/ /*stick a fork in it, we're all done. */ |
http://rosettacode.org/wiki/String_append | String append |
Basic Data Operation
This is a basic data operation. It represents a fundamental action on a basic data type.
You may see other such operations in the Basic Data Operations category, or:
Integer Operations
Arithmetic |
Comparison
Boolean Operations
Bitwise |
Logical
String Operations
Concatenation |
Interpolation |
Comparison |
Matching
Memory Operations
Pointers & references |
Addresses
Most languages provide a way to concatenate two string values, but some languages also provide a convenient way to append in-place to an existing string variable without referring to the variable twice.
Task
Create a string variable equal to any text value.
Append the string variable with another string literal in the most idiomatic way, without double reference if your language supports it.
Show the contents of the variable after the append operation.
| #Jsish | Jsish | /* String append, in Jsish */
var str = 'Hello';
;str += ', world';
var s2 = 'Goodbye';
;s2.concat(', World!');
/*
=!EXPECTSTART!=
str += ', world' ==> Hello, world
s2.concat(', World!') ==> Goodbye, World!
=!EXPECTEND!=
*/ |
http://rosettacode.org/wiki/String_append | String append |
Basic Data Operation
This is a basic data operation. It represents a fundamental action on a basic data type.
You may see other such operations in the Basic Data Operations category, or:
Integer Operations
Arithmetic |
Comparison
Boolean Operations
Bitwise |
Logical
String Operations
Concatenation |
Interpolation |
Comparison |
Matching
Memory Operations
Pointers & references |
Addresses
Most languages provide a way to concatenate two string values, but some languages also provide a convenient way to append in-place to an existing string variable without referring to the variable twice.
Task
Create a string variable equal to any text value.
Append the string variable with another string literal in the most idiomatic way, without double reference if your language supports it.
Show the contents of the variable after the append operation.
| #Julia | Julia | s = "Hello"
s *= ", world!" |
http://rosettacode.org/wiki/Statistics/Normal_distribution | Statistics/Normal distribution | The Normal (or Gaussian) distribution is a frequently used distribution in statistics. While most programming languages provide a uniformly distributed random number generator, one can derive normally distributed random numbers from a uniform generator.
The task
Take a uniform random number generator and create a large (you decide how large) set of numbers that follow a normal (Gaussian) distribution. Calculate the dataset's mean and standard deviation, and show a histogram of the data.
Mention any native language support for the generation of normally distributed random numbers.
Reference
You may refer to code in Statistics/Basic if available.
| #FreeBASIC | FreeBASIC | ' FB 1.05.0 Win64
Const pi As Double = 3.141592653589793
Randomize
' Generates normally distributed random numbers with mean 0 and standard deviation 1
Function randomNormal() As Double
Return Cos(2.0 * pi * Rnd) * Sqr(-2.0 * Log(Rnd))
End Function
Sub normalStats(sampleSize As Integer)
If sampleSize < 1 Then Return
Dim r(1 To sampleSize) As Double
Dim h(-1 To 10) As Integer '' all zero by default
Dim sum As Double = 0.0
Dim hSum As Integer = 0
' Generate 'sampleSize' normally distributed random numbers with mean 0.5 and standard deviation 0.25
' calculate their sum
' and in which box they will fall when drawing the histogram
For i As Integer = 1 To sampleSize
r(i) = 0.5 + randomNormal / 4.0
sum += r(i)
If r(i) < 0.0 Then
h(-1) += 1
ElseIf r(i) >= 1.0 Then
h(10) += 1
Else
h(Int(r(i) * 10)) += 1
End If
Next
For i As Integer = -1 To 10 : hSum += h(i) : Next
' adjust one of the h() values if necessary to ensure hSum = sampleSize
Dim adj As Integer = sampleSize - hSum
If adj <> 0 Then
For i As Integer = -1 To 10
h(i) += adj
If h(i) >= 0 Then Exit For
h(i) -= adj
Next
End If
Dim mean As Double = sum / sampleSize
Dim sd As Double
sum = 0.0
' Now calculate their standard deviation
For i As Integer = 1 To sampleSize
sum += (r(i) - mean) ^ 2.0
Next
sd = Sqr(sum/sampleSize)
' Draw a histogram of the data with interval 0.1
Dim numStars As Integer
' If sample size > 300 then normalize histogram to 300
Dim scale As Double = 1.0
If sampleSize > 300 Then scale = 300.0 / sampleSize
Print "Sample size "; sampleSize
Print
Print Using " Mean #.######"; mean;
Print Using " SD #.######"; sd
Print
For i As Integer = -1 To 10
If i = -1 Then
Print Using "< 0.00 : ";
ElseIf i = 10 Then
Print Using ">=1.00 : ";
Else
Print Using " #.## : "; i/10.0;
End If
Print Using "##### " ; h(i);
numStars = Int(h(i) * scale + 0.5)
Print String(numStars, "*")
Next
End Sub
normalStats 100
Print
normalStats 1000
Print
normalStats 10000
Print
normalStats 100000
Print
Print "Press any key to quit"
Sleep |
http://rosettacode.org/wiki/Stem-and-leaf_plot | Stem-and-leaf plot | Create a well-formatted stem-and-leaf plot from the following data set, where the leaves are the last digits:
12 127 28 42 39 113 42 18 44 118 44 37 113 124 37 48 127 36 29 31 125 139 131 115 105 132 104 123 35 113 122 42 117 119 58 109 23 105 63 27 44 105 99 41 128 121 116 125 32 61 37 127 29 113 121 58 114 126 53 114 96 25 109 7 31 141 46 13 27 43 117 116 27 7 68 40 31 115 124 42 128 52 71 118 117 38 27 106 33 117 116 111 40 119 47 105 57 122 109 124 115 43 120 43 27 27 18 28 48 125 107 114 34 133 45 120 30 127 31 116 146
The primary intent of this task is the presentation of information. It is acceptable to hardcode the data set or characteristics of it (such as what the stems are) in the example, insofar as it is impractical to make the example generic to any data set. For example, in a computation-less language like HTML the data set may be entirely prearranged within the example; the interesting characteristics are how the proper visual formatting is arranged.
If possible, the output should not be a bitmap image. Monospaced plain text is acceptable, but do better if you can. It may be a window, i.e. not a file.
Note: If you wish to try multiple data sets, you might try this generator.
| #C.23 | C# | using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
class Program
{
static void Main()
{
const string data =
"12 127 28 42 39 113 42 18 44 118 44 37 113 124 37 48 127 36 29 31 " +
"125 139 131 115 105 132 104 123 35 113 122 42 117 119 58 109 23 " +
"105 63 27 44 105 99 41 128 121 116 125 32 61 37 127 29 113 121 58 " +
"114 126 53 114 96 25 109 7 31 141 46 13 27 43 117 116 27 7 68 40 31 " +
"115 124 42 128 52 71 118 117 38 27 106 33 117 116 111 40 119 47 " +
"105 57 122 109 124 115 43 120 43 27 27 18 28 48 125 107 114 34 " +
"133 45 120 30 127 31 116 146";
int[] ints = data.Split(' ').Select(int.Parse).ToArray();
StemAndLeafPlot(ints);
Console.ReadKey();
}
public static void StemAndLeafPlot(int[] arr)
{
int stemMax = arr.Max() / 10;
int stemMin = arr.Min() / 10;
Array.Sort(arr);
for (int i = stemMin; i <= stemMax; i++)
{
Console.Write("{0,3} | ", i);
foreach (var t in arr)
{
if (t < 10 * i)
continue;
if (t >= 10 * (i + 1))
break;
Console.Write("{0} ", t % 10);
}
Console.WriteLine("");
}
}
} |
http://rosettacode.org/wiki/Stern-Brocot_sequence | Stern-Brocot sequence | For this task, the Stern-Brocot sequence is to be generated by an algorithm similar to that employed in generating the Fibonacci sequence.
The first and second members of the sequence are both 1:
1, 1
Start by considering the second member of the sequence
Sum the considered member of the sequence and its precedent, (1 + 1) = 2, and append it to the end of the sequence:
1, 1, 2
Append the considered member of the sequence to the end of the sequence:
1, 1, 2, 1
Consider the next member of the series, (the third member i.e. 2)
GOTO 3
─── Expanding another loop we get: ───
Sum the considered member of the sequence and its precedent, (2 + 1) = 3, and append it to the end of the sequence:
1, 1, 2, 1, 3
Append the considered member of the sequence to the end of the sequence:
1, 1, 2, 1, 3, 2
Consider the next member of the series, (the fourth member i.e. 1)
The task is to
Create a function/method/subroutine/procedure/... to generate the Stern-Brocot sequence of integers using the method outlined above.
Show the first fifteen members of the sequence. (This should be: 1, 1, 2, 1, 3, 2, 3, 1, 4, 3, 5, 2, 5, 3, 4)
Show the (1-based) index of where the numbers 1-to-10 first appears in the sequence.
Show the (1-based) index of where the number 100 first appears in the sequence.
Check that the greatest common divisor of all the two consecutive members of the series up to the 1000th member, is always one.
Show your output on this page.
Related tasks
Fusc sequence.
Continued fraction/Arithmetic
Ref
Infinite Fractions - Numberphile (Video).
Trees, Teeth, and Time: The mathematics of clock making.
A002487 The On-Line Encyclopedia of Integer Sequences.
| #AppleScript | AppleScript | use AppleScript version "2.4"
use framework "Foundation"
use scripting additions
------------------ STERN-BROCOT SEQUENCE -----------------
-- sternBrocot :: Generator [Int]
on sternBrocot()
script go
on |λ|(xs)
set x to snd(xs)
tail(xs) & {fst(xs) + x, x}
end |λ|
end script
fmapGen(my head, iterate(go, {1, 1}))
end sternBrocot
--------------------------- TEST -------------------------
on run
set sbs to take(1200, sternBrocot())
set ixSB to zip(sbs, enumFrom(1))
script low
on |λ|(x)
12 ≠ fst(x)
end |λ|
end script
script sameFst
on |λ|(a, b)
fst(a) = fst(b)
end |λ|
end script
script asList
on |λ|(x)
{fst(x), snd(x)}
end |λ|
end script
script below100
on |λ|(x)
100 ≠ fst(x)
end |λ|
end script
script fullyReduced
on |λ|(ab)
1 = gcd(|1| of ab, |2| of ab)
end |λ|
end script
unlines(map(showJSON, ¬
{take(15, sbs), ¬
take(10, map(asList, ¬
nubBy(sameFst, ¬
sortBy(comparing(fst), ¬
takeWhile(low, ixSB))))), ¬
asList's |λ|(fst(take(1, dropWhile(below100, ixSB)))), ¬
all(fullyReduced, take(1000, zip(sbs, tail(sbs))))}))
end run
--> [1,1,2,1,3,2,3,1,4,3,5,2,5,3,4]
--> [[1,32],[2,24],[3,40],[4,36],[5,44],[6,33],[7,38],[8,42],[9,35],[10,39]]
--> [100,1179]
--> true
------------------------- GENERIC ------------------------
-- Absolute value.
-- abs :: Num -> Num
on abs(x)
if 0 > x then
-x
else
x
end if
end abs
-- Applied to a predicate and a list, `all` determines if all elements
-- of the list satisfy the predicate.
-- all :: (a -> Bool) -> [a] -> Bool
on all(p, xs)
tell mReturn(p)
set lng to length of xs
repeat with i from 1 to lng
if not |λ|(item i of xs, i, xs) then return false
end repeat
true
end tell
end all
-- comparing :: (a -> b) -> (a -> a -> Ordering)
on comparing(f)
script
on |λ|(a, b)
tell mReturn(f)
set fa to |λ|(a)
set fb to |λ|(b)
if fa < fb then
-1
else if fa > fb then
1
else
0
end if
end tell
end |λ|
end script
end comparing
-- drop :: Int -> [a] -> [a]
-- drop :: Int -> String -> String
on drop(n, xs)
set c to class of xs
if c is not script then
if c is not string then
if n < length of xs then
items (1 + n) thru -1 of xs
else
{}
end if
else
if n < length of xs then
text (1 + n) thru -1 of xs
else
""
end if
end if
else
take(n, xs) -- consumed
return xs
end if
end drop
-- dropWhile :: (a -> Bool) -> [a] -> [a]
-- dropWhile :: (Char -> Bool) -> String -> String
on dropWhile(p, xs)
set lng to length of xs
set i to 1
tell mReturn(p)
repeat while i ≤ lng and |λ|(item i of xs)
set i to i + 1
end repeat
end tell
drop(i - 1, xs)
end dropWhile
-- enumFrom :: a -> [a]
on enumFrom(x)
script
property v : missing value
property blnNum : class of x is not text
on |λ|()
if missing value is not v then
if blnNum then
set v to 1 + v
else
set v to succ(v)
end if
else
set v to x
end if
return v
end |λ|
end script
end enumFrom
-- filter :: (a -> Bool) -> [a] -> [a]
on filter(f, xs)
tell mReturn(f)
set lst to {}
set lng to length of xs
repeat with i from 1 to lng
set v to item i of xs
if |λ|(v, i, xs) then set end of lst to v
end repeat
return lst
end tell
end filter
-- fmapGen <$> :: (a -> b) -> Gen [a] -> Gen [b]
on fmapGen(f, gen)
script
property g : gen
property mf : mReturn(f)'s |λ|
on |λ|()
set v to g's |λ|()
if v is missing value then
v
else
mf(v)
end if
end |λ|
end script
end fmapGen
-- fst :: (a, b) -> a
on fst(tpl)
if class of tpl is record then
|1| of tpl
else
item 1 of tpl
end if
end fst
-- gcd :: Int -> Int -> Int
on gcd(a, b)
set x to abs(a)
set y to abs(b)
repeat until y = 0
if x > y then
set x to x - y
else
set y to y - x
end if
end repeat
return x
end gcd
-- head :: [a] -> a
on head(xs)
if xs = {} then
missing value
else
item 1 of xs
end if
end head
-- iterate :: (a -> a) -> a -> Gen [a]
on iterate(f, x)
script
property v : missing value
property g : mReturn(f)'s |λ|
on |λ|()
if missing value is v then
set v to x
else
set v to g(v)
end if
return v
end |λ|
end script
end iterate
-- length :: [a] -> Int
on |length|(xs)
set c to class of xs
if list is c or string is c then
length of xs
else
(2 ^ 29 - 1) -- (maxInt - simple proxy for non-finite)
end if
end |length|
-- map :: (a -> b) -> [a] -> [b]
on map(f, xs)
tell mReturn(f)
set lng to length of xs
set lst to {}
repeat with i from 1 to lng
set end of lst to |λ|(item i of xs, i, xs)
end repeat
return lst
end tell
end map
-- min :: Ord a => a -> a -> a
on min(x, y)
if y < x then
y
else
x
end if
end min
-- Lift 2nd class handler function into 1st class script wrapper
-- mReturn :: First-class m => (a -> b) -> m (a -> b)
on mReturn(f)
if class of f is script then
f
else
script
property |λ| : f
end script
end if
end mReturn
-- nubBy :: (a -> a -> Bool) -> [a] -> [a]
on nubBy(f, xs)
set g to mReturn(f)'s |λ|
script notEq
property fEq : g
on |λ|(a)
script
on |λ|(b)
not fEq(a, b)
end |λ|
end script
end |λ|
end script
script go
on |λ|(xs)
if (length of xs) > 1 then
set x to item 1 of xs
{x} & go's |λ|(filter(notEq's |λ|(x), items 2 thru -1 of xs))
else
xs
end if
end |λ|
end script
go's |λ|(xs)
end nubBy
-- partition :: predicate -> List -> (Matches, nonMatches)
-- partition :: (a -> Bool) -> [a] -> ([a], [a])
on partition(f, xs)
tell mReturn(f)
set ys to {}
set zs to {}
repeat with x in xs
set v to contents of x
if |λ|(v) then
set end of ys to v
else
set end of zs to v
end if
end repeat
end tell
Tuple(ys, zs)
end partition
-- showJSON :: a -> String
on showJSON(x)
set c to class of x
if (c is list) or (c is record) then
set ca to current application
set {json, e} to ca's NSJSONSerialization's dataWithJSONObject:x options:0 |error|:(reference)
if json is missing value then
e's localizedDescription() as text
else
(ca's NSString's alloc()'s initWithData:json encoding:(ca's NSUTF8StringEncoding)) as text
end if
else if c is date then
"\"" & ((x - (time to GMT)) as «class isot» as string) & ".000Z" & "\""
else if c is text then
"\"" & x & "\""
else if (c is integer or c is real) then
x as text
else if c is class then
"null"
else
try
x as text
on error
("«" & c as text) & "»"
end try
end if
end showJSON
-- snd :: (a, b) -> b
on snd(tpl)
if class of tpl is record then
|2| of tpl
else
item 2 of tpl
end if
end snd
-- Enough for small scale sorts.
-- Use instead sortOn :: Ord b => (a -> b) -> [a] -> [a]
-- which is equivalent to the more flexible sortBy(comparing(f), xs)
-- and uses a much faster ObjC NSArray sort method
-- sortBy :: (a -> a -> Ordering) -> [a] -> [a]
on sortBy(f, xs)
if length of xs > 1 then
set h to item 1 of xs
set f to mReturn(f)
script
on |λ|(x)
f's |λ|(x, h) ≤ 0
end |λ|
end script
set lessMore to partition(result, rest of xs)
sortBy(f, |1| of lessMore) & {h} & ¬
sortBy(f, |2| of lessMore)
else
xs
end if
end sortBy
-- tail :: [a] -> [a]
on tail(xs)
set blnText to text is class of xs
if blnText then
set unit to ""
else
set unit to {}
end if
set lng to length of xs
if 1 > lng then
missing value
else if 2 > lng then
unit
else
if blnText then
text 2 thru -1 of xs
else
rest of xs
end if
end if
end tail
-- take :: Int -> [a] -> [a]
-- take :: Int -> String -> String
on take(n, xs)
set c to class of xs
if list is c then
if 0 < n then
items 1 thru min(n, length of xs) of xs
else
{}
end if
else if string is c then
if 0 < n then
text 1 thru min(n, length of xs) of xs
else
""
end if
else if script is c then
set ys to {}
repeat with i from 1 to n
set v to xs's |λ|()
if missing value is v then
return ys
else
set end of ys to v
end if
end repeat
return ys
else
missing value
end if
end take
-- takeWhile :: (a -> Bool) -> [a] -> [a]
-- takeWhile :: (Char -> Bool) -> String -> String
on takeWhile(p, xs)
if script is class of xs then
takeWhileGen(p, xs)
else
tell mReturn(p)
repeat with i from 1 to length of xs
if not |λ|(item i of xs) then ¬
return take(i - 1, xs)
end repeat
end tell
return xs
end if
end takeWhile
-- takeWhileGen :: (a -> Bool) -> Gen [a] -> [a]
on takeWhileGen(p, xs)
set ys to {}
set v to |λ|() of xs
tell mReturn(p)
repeat while (|λ|(v))
set end of ys to v
set v to xs's |λ|()
end repeat
end tell
return ys
end takeWhileGen
-- Tuple (,) :: a -> b -> (a, b)
on Tuple(a, b)
{type:"Tuple", |1|:a, |2|:b, length:2}
end Tuple
-- unlines :: [String] -> String
on unlines(xs)
set {dlm, my text item delimiters} to ¬
{my text item delimiters, linefeed}
set str to xs as text
set my text item delimiters to dlm
str
end unlines
-- zip :: [a] -> [b] -> [(a, b)]
on zip(xs, ys)
zipWith(Tuple, xs, ys)
end zip
-- zipWith :: (a -> b -> c) -> [a] -> [b] -> [c]
on zipWith(f, xs, ys)
set lng to min(|length|(xs), |length|(ys))
if 1 > lng then return {}
set xs_ to take(lng, xs) -- Allow for non-finite
set ys_ to take(lng, ys) -- generators like cycle etc
set lst to {}
tell mReturn(f)
repeat with i from 1 to lng
set end of lst to |λ|(item i of xs_, item i of ys_)
end repeat
return lst
end tell
end zipWith |
http://rosettacode.org/wiki/Stream_merge | Stream merge | 2-stream merge
Read two sorted streams of items from external source (e.g. disk, or network), and write one stream of sorted items to external sink.
Common algorithm: keep 1 buffered item from each source, select minimal of them, write it, fetch another item from that stream from which the written item was.
N-stream merge
The same as above, but reading from N sources.
Common algorithm: same as above, but keep buffered items and their source descriptors in a heap.
Assume streams are very big. You must not suck them whole in the memory, but read them as streams.
| #Raku | Raku | sub merge_streams ( @streams ) {
my @s = @streams.map({ hash( STREAM => $_, HEAD => .get ) })\
.grep({ .<HEAD>.defined });
return gather while @s {
my $h = @s.min: *.<HEAD>;
take $h<HEAD>;
$h<HEAD> := $h<STREAM>.get
orelse @s .= grep( { $_ !=== $h } );
}
}
say merge_streams([ @*ARGS».&open ]); |
http://rosettacode.org/wiki/State_name_puzzle | State name puzzle | Background
This task is inspired by Mark Nelson's DDJ Column "Wordplay" and one of the weekly puzzle challenges from Will Shortz on NPR Weekend Edition [1] and originally attributed to David Edelheit.
The challenge was to take the names of two U.S. States, mix them all together, then rearrange the letters to form the names of two different U.S. States (so that all four state names differ from one another).
What states are these?
The problem was reissued on the Unicon Discussion Web which includes several solutions with analysis. Several techniques may be helpful and you may wish to refer to Gödel numbering, equivalence relations, and equivalence classes. The basic merits of these were discussed in the Unicon Discussion Web.
A second challenge in the form of a set of fictitious new states was also presented.
Task
Write a program to solve the challenge using both the original list of states and the fictitious list.
Caveats
case and spacing aren't significant - just letters (harmonize case)
don't expect the names to be in any order - such as being sorted
don't rely on names to be unique (eliminate duplicates - meaning if Iowa appears twice you can only use it once)
Comma separated list of state names used in the original puzzle:
"Alabama", "Alaska", "Arizona", "Arkansas",
"California", "Colorado", "Connecticut", "Delaware",
"Florida", "Georgia", "Hawaii", "Idaho", "Illinois",
"Indiana", "Iowa", "Kansas", "Kentucky", "Louisiana",
"Maine", "Maryland", "Massachusetts", "Michigan",
"Minnesota", "Mississippi", "Missouri", "Montana",
"Nebraska", "Nevada", "New Hampshire", "New Jersey",
"New Mexico", "New York", "North Carolina", "North Dakota",
"Ohio", "Oklahoma", "Oregon", "Pennsylvania", "Rhode Island",
"South Carolina", "South Dakota", "Tennessee", "Texas",
"Utah", "Vermont", "Virginia",
"Washington", "West Virginia", "Wisconsin", "Wyoming"
Comma separated list of additional fictitious state names to be added to the original (Includes a duplicate):
"New Kory", "Wen Kory", "York New", "Kory New", "New Kory"
Other tasks related to string operations:
Metrics
Array length
String length
Copy a string
Empty string (assignment)
Counting
Word frequency
Letter frequency
Jewels and stones
I before E except after C
Bioinformatics/base count
Count occurrences of a substring
Count how many vowels and consonants occur in a string
Remove/replace
XXXX redacted
Conjugate a Latin verb
Remove vowels from a string
String interpolation (included)
Strip block comments
Strip comments from a string
Strip a set of characters from a string
Strip whitespace from a string -- top and tail
Strip control codes and extended characters from a string
Anagrams/Derangements/shuffling
Word wheel
ABC problem
Sattolo cycle
Knuth shuffle
Ordered words
Superpermutation minimisation
Textonyms (using a phone text pad)
Anagrams
Anagrams/Deranged anagrams
Permutations/Derangements
Find/Search/Determine
ABC words
Odd words
Word ladder
Semordnilap
Word search
Wordiff (game)
String matching
Tea cup rim text
Alternade words
Changeable words
State name puzzle
String comparison
Unique characters
Unique characters in each string
Extract file extension
Levenshtein distance
Palindrome detection
Common list elements
Longest common suffix
Longest common prefix
Compare a list of strings
Longest common substring
Find common directory path
Words from neighbour ones
Change e letters to i in words
Non-continuous subsequences
Longest common subsequence
Longest palindromic substrings
Longest increasing subsequence
Words containing "the" substring
Sum of the digits of n is substring of n
Determine if a string is numeric
Determine if a string is collapsible
Determine if a string is squeezable
Determine if a string has all unique characters
Determine if a string has all the same characters
Longest substrings without repeating characters
Find words which contains all the vowels
Find words which contains most consonants
Find words which contains more than 3 vowels
Find words which first and last three letters are equals
Find words which odd letters are consonants and even letters are vowels or vice_versa
Formatting
Substring
Rep-string
Word wrap
String case
Align columns
Literals/String
Repeat a string
Brace expansion
Brace expansion using ranges
Reverse a string
Phrase reversals
Comma quibbling
Special characters
String concatenation
Substring/Top and tail
Commatizing numbers
Reverse words in a string
Suffixation of decimal numbers
Long literals, with continuations
Numerical and alphabetical suffixes
Abbreviations, easy
Abbreviations, simple
Abbreviations, automatic
Song lyrics/poems/Mad Libs/phrases
Mad Libs
Magic 8-ball
99 Bottles of Beer
The Name Game (a song)
The Old lady swallowed a fly
The Twelve Days of Christmas
Tokenize
Text between
Tokenize a string
Word break problem
Tokenize a string with escaping
Split a character string based on change of character
Sequences
Show ASCII table
De Bruijn sequences
Self-referential sequences
Generate lower case ASCII alphabet
| #Bracmat | Bracmat | ( Alabama
Alaska
Arizona
Arkansas
California
Colorado
Connecticut
Delaware
Florida
Georgia
Hawaii
Idaho
Illinois
Indiana
Iowa
Kansas
Kentucky
Louisiana
Maine
Maryland
Massachusetts
Michigan
Minnesota
Mississippi
Missouri
Montana
Nebraska
Nevada
"New Hampshire"
"New Jersey"
"New Mexico"
"New York"
"North Carolina"
"North Dakota"
Ohio
Oklahoma
Oregon
Pennsylvania
"Rhode Island"
"South Carolina"
"South Dakota"
Tennessee
Texas
Utah
Vermont
Virginia
Washington
"West Virginia"
Wisconsin
Wyoming
: ?states
& "New Kory" "Wen Kory" "York New" "Kory New" "New Kory":?extrastates
& ( "State name puzzle"
= allStates State state statechars char
, A Z S1 S2 S3 S4 L1 L2 L3 L4 L12
. 0:?allStates
& whl
' ( !arg:%?State ?arg
& low$!State:?state
& 0:?statechars
& whl
' ( @(!state:? (%@:~" ":?char) ?state)
& !char+!statechars:?statechars
)
& (!State.!statechars)+!allStates:?allStates
)
& ( !allStates
: ?
+ ?*(?S1.?L1)
+ ?A
+ ?*(?S2.?L2)
+ ( ?Z
& !L1+!L2:?L12
& !A+!Z
: ?
+ ?*(?S3.?L3&!L12+-1*!L3:?L4)
+ ?
+ ?
* ( ?S4
. !L4
& out$(!S1 "+" !S2 "=" !S3 "+" !S4)
& ~
)
+ ?
)
| out$"No more solutions"
)
)
& "State name puzzle"$!states
& "State name puzzle"$(!states !extrastates)
); |
http://rosettacode.org/wiki/State_name_puzzle | State name puzzle | Background
This task is inspired by Mark Nelson's DDJ Column "Wordplay" and one of the weekly puzzle challenges from Will Shortz on NPR Weekend Edition [1] and originally attributed to David Edelheit.
The challenge was to take the names of two U.S. States, mix them all together, then rearrange the letters to form the names of two different U.S. States (so that all four state names differ from one another).
What states are these?
The problem was reissued on the Unicon Discussion Web which includes several solutions with analysis. Several techniques may be helpful and you may wish to refer to Gödel numbering, equivalence relations, and equivalence classes. The basic merits of these were discussed in the Unicon Discussion Web.
A second challenge in the form of a set of fictitious new states was also presented.
Task
Write a program to solve the challenge using both the original list of states and the fictitious list.
Caveats
case and spacing aren't significant - just letters (harmonize case)
don't expect the names to be in any order - such as being sorted
don't rely on names to be unique (eliminate duplicates - meaning if Iowa appears twice you can only use it once)
Comma separated list of state names used in the original puzzle:
"Alabama", "Alaska", "Arizona", "Arkansas",
"California", "Colorado", "Connecticut", "Delaware",
"Florida", "Georgia", "Hawaii", "Idaho", "Illinois",
"Indiana", "Iowa", "Kansas", "Kentucky", "Louisiana",
"Maine", "Maryland", "Massachusetts", "Michigan",
"Minnesota", "Mississippi", "Missouri", "Montana",
"Nebraska", "Nevada", "New Hampshire", "New Jersey",
"New Mexico", "New York", "North Carolina", "North Dakota",
"Ohio", "Oklahoma", "Oregon", "Pennsylvania", "Rhode Island",
"South Carolina", "South Dakota", "Tennessee", "Texas",
"Utah", "Vermont", "Virginia",
"Washington", "West Virginia", "Wisconsin", "Wyoming"
Comma separated list of additional fictitious state names to be added to the original (Includes a duplicate):
"New Kory", "Wen Kory", "York New", "Kory New", "New Kory"
Other tasks related to string operations:
Metrics
Array length
String length
Copy a string
Empty string (assignment)
Counting
Word frequency
Letter frequency
Jewels and stones
I before E except after C
Bioinformatics/base count
Count occurrences of a substring
Count how many vowels and consonants occur in a string
Remove/replace
XXXX redacted
Conjugate a Latin verb
Remove vowels from a string
String interpolation (included)
Strip block comments
Strip comments from a string
Strip a set of characters from a string
Strip whitespace from a string -- top and tail
Strip control codes and extended characters from a string
Anagrams/Derangements/shuffling
Word wheel
ABC problem
Sattolo cycle
Knuth shuffle
Ordered words
Superpermutation minimisation
Textonyms (using a phone text pad)
Anagrams
Anagrams/Deranged anagrams
Permutations/Derangements
Find/Search/Determine
ABC words
Odd words
Word ladder
Semordnilap
Word search
Wordiff (game)
String matching
Tea cup rim text
Alternade words
Changeable words
State name puzzle
String comparison
Unique characters
Unique characters in each string
Extract file extension
Levenshtein distance
Palindrome detection
Common list elements
Longest common suffix
Longest common prefix
Compare a list of strings
Longest common substring
Find common directory path
Words from neighbour ones
Change e letters to i in words
Non-continuous subsequences
Longest common subsequence
Longest palindromic substrings
Longest increasing subsequence
Words containing "the" substring
Sum of the digits of n is substring of n
Determine if a string is numeric
Determine if a string is collapsible
Determine if a string is squeezable
Determine if a string has all unique characters
Determine if a string has all the same characters
Longest substrings without repeating characters
Find words which contains all the vowels
Find words which contains most consonants
Find words which contains more than 3 vowels
Find words which first and last three letters are equals
Find words which odd letters are consonants and even letters are vowels or vice_versa
Formatting
Substring
Rep-string
Word wrap
String case
Align columns
Literals/String
Repeat a string
Brace expansion
Brace expansion using ranges
Reverse a string
Phrase reversals
Comma quibbling
Special characters
String concatenation
Substring/Top and tail
Commatizing numbers
Reverse words in a string
Suffixation of decimal numbers
Long literals, with continuations
Numerical and alphabetical suffixes
Abbreviations, easy
Abbreviations, simple
Abbreviations, automatic
Song lyrics/poems/Mad Libs/phrases
Mad Libs
Magic 8-ball
99 Bottles of Beer
The Name Game (a song)
The Old lady swallowed a fly
The Twelve Days of Christmas
Tokenize
Text between
Tokenize a string
Word break problem
Tokenize a string with escaping
Split a character string based on change of character
Sequences
Show ASCII table
De Bruijn sequences
Self-referential sequences
Generate lower case ASCII alphabet
| #C | C | #include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define USE_FAKES 1
const char *states[] = {
#if USE_FAKES
"New Kory", "Wen Kory", "York New", "Kory New", "New Kory",
#endif
"Alabama", "Alaska", "Arizona", "Arkansas",
"California", "Colorado", "Connecticut",
"Delaware",
"Florida", "Georgia", "Hawaii",
"Idaho", "Illinois", "Indiana", "Iowa",
"Kansas", "Kentucky", "Louisiana",
"Maine", "Maryland", "Massachusetts", "Michigan",
"Minnesota", "Mississippi", "Missouri", "Montana",
"Nebraska", "Nevada", "New Hampshire", "New Jersey",
"New Mexico", "New York", "North Carolina", "North Dakota",
"Ohio", "Oklahoma", "Oregon",
"Pennsylvania", "Rhode Island",
"South Carolina", "South Dakota", "Tennessee", "Texas",
"Utah", "Vermont", "Virginia",
"Washington", "West Virginia", "Wisconsin", "Wyoming"
};
int n_states = sizeof(states)/sizeof(*states);
typedef struct { unsigned char c[26]; const char *name[2]; } letters;
void count_letters(letters *l, const char *s)
{
int c;
if (!l->name[0]) l->name[0] = s;
else l->name[1] = s;
while ((c = *s++)) {
if (c >= 'a' && c <= 'z') l->c[c - 'a']++;
if (c >= 'A' && c <= 'Z') l->c[c - 'A']++;
}
}
int lcmp(const void *aa, const void *bb)
{
int i;
const letters *a = aa, *b = bb;
for (i = 0; i < 26; i++)
if (a->c[i] > b->c[i]) return 1;
else if (a->c[i] < b->c[i]) return -1;
return 0;
}
int scmp(const void *a, const void *b)
{
return strcmp(*(const char *const *)a, *(const char *const *)b);
}
void no_dup()
{
int i, j;
qsort(states, n_states, sizeof(const char*), scmp);
for (i = j = 0; i < n_states;) {
while (++i < n_states && !strcmp(states[i], states[j]));
if (i < n_states) states[++j] = states[i];
}
n_states = j + 1;
}
void find_mix()
{
int i, j, n;
letters *l, *p;
no_dup();
n = n_states * (n_states - 1) / 2;
p = l = calloc(n, sizeof(letters));
for (i = 0; i < n_states; i++)
for (j = i + 1; j < n_states; j++, p++) {
count_letters(p, states[i]);
count_letters(p, states[j]);
}
qsort(l, n, sizeof(letters), lcmp);
for (j = 0; j < n; j++) {
for (i = j + 1; i < n && !lcmp(l + j, l + i); i++) {
if (l[j].name[0] == l[i].name[0]
|| l[j].name[1] == l[i].name[0]
|| l[j].name[1] == l[i].name[1])
continue;
printf("%s + %s => %s + %s\n",
l[j].name[0], l[j].name[1], l[i].name[0], l[i].name[1]);
}
}
free(l);
}
int main(void)
{
find_mix();
return 0;
} |
http://rosettacode.org/wiki/Start_from_a_main_routine | Start from a main routine |
Some languages (like Gambas and Visual Basic) support two startup modes. Applications written in these languages start with an open window that waits for events, and it is necessary to do some trickery to cause a main procedure to run instead. Data driven or event driven languages may also require similar trickery to force a startup procedure to run.
Task
Demonstrate the steps involved in causing the application to run a main procedure, rather than an event driven window at startup.
Languages that always run from main() can be omitted from this task.
| #AutoHotkey | AutoHotkey | BEGIN {
# This is our main startup procedure
print "Hello World!"
} |
http://rosettacode.org/wiki/Start_from_a_main_routine | Start from a main routine |
Some languages (like Gambas and Visual Basic) support two startup modes. Applications written in these languages start with an open window that waits for events, and it is necessary to do some trickery to cause a main procedure to run instead. Data driven or event driven languages may also require similar trickery to force a startup procedure to run.
Task
Demonstrate the steps involved in causing the application to run a main procedure, rather than an event driven window at startup.
Languages that always run from main() can be omitted from this task.
| #AWK | AWK | BEGIN {
# This is our main startup procedure
print "Hello World!"
} |
http://rosettacode.org/wiki/Start_from_a_main_routine | Start from a main routine |
Some languages (like Gambas and Visual Basic) support two startup modes. Applications written in these languages start with an open window that waits for events, and it is necessary to do some trickery to cause a main procedure to run instead. Data driven or event driven languages may also require similar trickery to force a startup procedure to run.
Task
Demonstrate the steps involved in causing the application to run a main procedure, rather than an event driven window at startup.
Languages that always run from main() can be omitted from this task.
| #BASIC | BASIC | SUB main
PRINT "Hello from main!"
END SUB
main |
http://rosettacode.org/wiki/Start_from_a_main_routine | Start from a main routine |
Some languages (like Gambas and Visual Basic) support two startup modes. Applications written in these languages start with an open window that waits for events, and it is necessary to do some trickery to cause a main procedure to run instead. Data driven or event driven languages may also require similar trickery to force a startup procedure to run.
Task
Demonstrate the steps involved in causing the application to run a main procedure, rather than an event driven window at startup.
Languages that always run from main() can be omitted from this task.
| #C | C |
#include<stdio.h>
#define start main()
int start
{
printf("Hello World !");
return 0;
}
|
http://rosettacode.org/wiki/Straddling_checkerboard | Straddling checkerboard | Task
Implement functions to encrypt and decrypt a message using the straddling checkerboard method. The checkerboard should take a 28 character alphabet (A-Z plus a full stop and an escape character) and two different numbers representing the blanks in the first row. The output will be a series of decimal digits.
Numbers should be encrypted by inserting the escape character before each digit, then including the digit unencrypted. This should be reversed for decryption.
| #PicoLisp | PicoLisp | (de *Straddling
(NIL "H" "O" "L" NIL "M" "E" "S" NIL "R" "T")
("3" "A" "B" "C" "D" "F" "G" "I" "J" "K" "N")
("7" "P" "Q" "U" "V" "W" "X" "Y" "Z" "." "/")
("79" "0" "1" "2" "3" "4" "5" "6" "7" "8" "9") )
(de straddle (Str)
(pack
(mapcar
'((C)
(pick
'((L)
(and
(index C (cdr L))
(cons (car L) (dec @)) ) )
*Straddling ) )
(chop (uppc Str)) ) ) )
(de unStraddle (Str)
(pack
(make
(for (L (chop Str) L)
(let C (pop 'L)
(setq C
(if (assoc C *Straddling)
(get (cdr @) (inc (format (pop 'L))))
(get (cdar *Straddling) (inc (format C))) ) )
(link (if (= "/" C) (pop 'L) C)) ) ) ) ) ) |
http://rosettacode.org/wiki/Straddling_checkerboard | Straddling checkerboard | Task
Implement functions to encrypt and decrypt a message using the straddling checkerboard method. The checkerboard should take a 28 character alphabet (A-Z plus a full stop and an escape character) and two different numbers representing the blanks in the first row. The output will be a series of decimal digits.
Numbers should be encrypted by inserting the escape character before each digit, then including the digit unencrypted. This should be reversed for decryption.
| #PureBasic | PureBasic | Procedure.s encrypt_SC(originalText.s, alphabet.s, blank_1, blank_2)
Static notEscape.s = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ."
Protected preDigit_1.s = Str(blank_1), preDigit_2.s = Str(blank_2)
Protected i, index, curChar.s, escapeChar.s, outputText.s
Protected NewMap cipher.s()
;build cipher reference
alphabet = UCase(alphabet)
For i = 1 To 28
curChar = Mid(alphabet, i, 1)
If Not FindString(notEscape, curChar)
escapeChar = curChar
EndIf
Select i
Case 1 To 8
If index = blank_1 Or index = blank_2: index + 1: EndIf ;adjust index for blank
cipher(curChar) = Str(index)
index + 1
Case 9 To 18
cipher(curChar) = preDigit_1 + Str(i - 9)
Case 19 To 28
cipher(curChar) = preDigit_2 + Str(i - 19)
EndSelect
Next
For i = 0 To 9: cipher(Str(i)) = cipher(escapeChar) + Str(i): Next
;encrypt each character
originalText = UCase(originalText)
Protected length = Len(originalText)
For i = 1 To length
outputText + cipher(Mid(originalText, i, 1))
Next
ProcedureReturn outputText
EndProcedure
Procedure.s decrypt_SC(cipherText.s, alphabet.s, blank_1, blank_2)
Static notEscape.s = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ."
Protected preDigit_1.s = Str(blank_1), preDigit_2.s = Str(blank_2)
Protected i, index, curChar.s, escapeCipher.s, outputText.s
Protected NewMap cipher.s()
;build decipher reference
alphabet = UCase(alphabet)
For i = 1 To 28
curChar = Mid(alphabet, i, 1)
Select i
Case 1 To 8
If index = blank_1 Or index = blank_2: index + 1: EndIf ;adjust index for blank
cipher(Str(index)) = curChar
index + 1
Case 9 To 18
cipher(preDigit_1 + Str(i - 9)) = curChar
Case 19 To 28
cipher(preDigit_2 + Str(i - 19)) = curChar
EndSelect
If Not FindString(notEscape, curChar)
escapeCipher = MapKey(cipher())
EndIf
Next
For i = 0 To 9: cipher(escapeCipher + Str(i)) = Str(i): Next
;decrypt each character
Protected length = Len(cipherText)
index = 1
While index <=length
curChar = Mid(cipherText, index, 1)
If curChar = preDigit_1 Or curChar = preDigit_2
curChar = Mid(cipherText, index, 2)
If curChar = escapeCipher: curChar = Mid(cipherText, index, 3): EndIf
EndIf
outputText + cipher(curChar)
index + Len(curChar)
Wend
ProcedureReturn outputText
EndProcedure
If OpenConsole()
Define message.s = "One night-it was on the twentieth of March, 1888-I was returning"
Define cipher.s = "HOLMESRTABCDFGIJKNPQUVWXYZ./", encoded.s
PrintN("Original: " + message)
encoded = encrypt_SC(message, cipher, 3, 7)
PrintN("encoded: " + encoded)
PrintN("decoded: " + decrypt_SC(encoded, cipher, 3, 7))
Print(#CRLF$ + #CRLF$ + "Press ENTER to exit"): Input()
CloseConsole()
EndIf |
http://rosettacode.org/wiki/Stirling_numbers_of_the_first_kind | Stirling numbers of the first kind | Stirling numbers of the first kind, or Stirling cycle numbers, count permutations according to their number
of cycles (counting fixed points as cycles of length one).
They may be defined directly to be the number of permutations of n
elements with k disjoint cycles.
Stirling numbers of the first kind express coefficients of polynomial expansions of falling or rising factorials.
Depending on the application, Stirling numbers of the first kind may be "signed"
or "unsigned". Signed Stirling numbers of the first kind arise when the
polynomial expansion is expressed in terms of falling factorials; unsigned when
expressed in terms of rising factorials. The only substantial difference is that,
for signed Stirling numbers of the first kind, values of S1(n, k) are negative
when n + k is odd.
Stirling numbers of the first kind follow the simple identities:
S1(0, 0) = 1
S1(n, 0) = 0 if n > 0
S1(n, k) = 0 if k > n
S1(n, k) = S1(n - 1, k - 1) + (n - 1) * S1(n - 1, k) # For unsigned
or
S1(n, k) = S1(n - 1, k - 1) - (n - 1) * S1(n - 1, k) # For signed
Task
Write a routine (function, procedure, whatever) to find Stirling numbers of the first kind. There are several methods to generate Stirling numbers of the first kind. You are free to choose the most appropriate for your language. If your language has a built-in, or easily, publicly available library implementation, it is acceptable to use that.
Using the routine, generate and show here, on this page, a table (or triangle) showing the Stirling numbers of the first kind, S1(n, k), up to S1(12, 12). it is optional to show the row / column for n == 0 and k == 0. It is optional to show places where S1(n, k) == 0 (when k > n). You may choose to show signed or unsigned Stirling numbers of the first kind, just make a note of which was chosen.
If your language supports large integers, find and show here, on this page, the maximum value of S1(n, k) where n == 100.
See also
Wikipedia - Stirling numbers of the first kind
OEIS:A008275 - Signed Stirling numbers of the first kind
OEIS:A130534 - Unsigned Stirling numbers of the first kind
Related Tasks
Stirling numbers of the second kind
Lah numbers
| #Ruby | Ruby | $cache = {}
def sterling1(n, k)
if n == 0 and k == 0 then
return 1
end
if n > 0 and k == 0 then
return 0
end
if k > n then
return 0
end
key = [n, k]
if $cache[key] then
return $cache[key]
end
value = sterling1(n - 1, k - 1) + (n - 1) * sterling1(n - 1, k)
$cache[key] = value
return value
end
MAX = 12
def main
print "Unsigned Stirling numbers of the first kind:\n"
print "n/k"
for n in 0 .. MAX
print "%10d" % [n]
end
print "\n"
for n in 0 .. MAX
print "%-3d" % [n]
for k in 0 .. n
print "%10d" % [sterling1(n, k)]
end
print "\n"
end
print "The maximum value of S1(100, k) =\n"
previous = 0
for k in 1 .. 100
current = sterling1(100, k)
if previous < current then
previous = current
else
print previous, "\n"
print "(%d digits, k = %d)\n" % [previous.to_s.length, k - 1]
break
end
end
end
main() |
http://rosettacode.org/wiki/String_append | String append |
Basic Data Operation
This is a basic data operation. It represents a fundamental action on a basic data type.
You may see other such operations in the Basic Data Operations category, or:
Integer Operations
Arithmetic |
Comparison
Boolean Operations
Bitwise |
Logical
String Operations
Concatenation |
Interpolation |
Comparison |
Matching
Memory Operations
Pointers & references |
Addresses
Most languages provide a way to concatenate two string values, but some languages also provide a convenient way to append in-place to an existing string variable without referring to the variable twice.
Task
Create a string variable equal to any text value.
Append the string variable with another string literal in the most idiomatic way, without double reference if your language supports it.
Show the contents of the variable after the append operation.
| #Kotlin | Kotlin | fun main(args: Array<String>) {
var s = "a"
s += "b"
s += "c"
println(s)
println("a" + "b" + "c")
val a = "a"
val b = "b"
val c = "c"
println("$a$b$c")
} |
http://rosettacode.org/wiki/String_append | String append |
Basic Data Operation
This is a basic data operation. It represents a fundamental action on a basic data type.
You may see other such operations in the Basic Data Operations category, or:
Integer Operations
Arithmetic |
Comparison
Boolean Operations
Bitwise |
Logical
String Operations
Concatenation |
Interpolation |
Comparison |
Matching
Memory Operations
Pointers & references |
Addresses
Most languages provide a way to concatenate two string values, but some languages also provide a convenient way to append in-place to an existing string variable without referring to the variable twice.
Task
Create a string variable equal to any text value.
Append the string variable with another string literal in the most idiomatic way, without double reference if your language supports it.
Show the contents of the variable after the append operation.
| #Lambdatalk | Lambdatalk |
{def christian_name Albert}
-> christian_name
{def name de Jeumont-Schneidre}
-> name
{christian_name} {name}
-> Albert de Jeumont-Schneidre
|
http://rosettacode.org/wiki/String_append | String append |
Basic Data Operation
This is a basic data operation. It represents a fundamental action on a basic data type.
You may see other such operations in the Basic Data Operations category, or:
Integer Operations
Arithmetic |
Comparison
Boolean Operations
Bitwise |
Logical
String Operations
Concatenation |
Interpolation |
Comparison |
Matching
Memory Operations
Pointers & references |
Addresses
Most languages provide a way to concatenate two string values, but some languages also provide a convenient way to append in-place to an existing string variable without referring to the variable twice.
Task
Create a string variable equal to any text value.
Append the string variable with another string literal in the most idiomatic way, without double reference if your language supports it.
Show the contents of the variable after the append operation.
| #langur | langur | var .s = "no more "
.s ~= "foo bars"
writeln .s |
http://rosettacode.org/wiki/Statistics/Normal_distribution | Statistics/Normal distribution | The Normal (or Gaussian) distribution is a frequently used distribution in statistics. While most programming languages provide a uniformly distributed random number generator, one can derive normally distributed random numbers from a uniform generator.
The task
Take a uniform random number generator and create a large (you decide how large) set of numbers that follow a normal (Gaussian) distribution. Calculate the dataset's mean and standard deviation, and show a histogram of the data.
Mention any native language support for the generation of normally distributed random numbers.
Reference
You may refer to code in Statistics/Basic if available.
| #Go | Go | package main
import (
"fmt"
"math"
"math/rand"
"strings"
)
// Box-Muller
func norm2() (s, c float64) {
r := math.Sqrt(-2 * math.Log(rand.Float64()))
s, c = math.Sincos(2 * math.Pi * rand.Float64())
return s * r, c * r
}
func main() {
const (
n = 10000
bins = 12
sig = 3
scale = 100
)
var sum, sumSq float64
h := make([]int, bins)
for i, accum := 0, func(v float64) {
sum += v
sumSq += v * v
b := int((v + sig) * bins / sig / 2)
if b >= 0 && b < bins {
h[b]++
}
}; i < n/2; i++ {
v1, v2 := norm2()
accum(v1)
accum(v2)
}
m := sum / n
fmt.Println("mean:", m)
fmt.Println("stddev:", math.Sqrt(sumSq/float64(n)-m*m))
for _, p := range h {
fmt.Println(strings.Repeat("*", p/scale))
}
} |
http://rosettacode.org/wiki/Stem-and-leaf_plot | Stem-and-leaf plot | Create a well-formatted stem-and-leaf plot from the following data set, where the leaves are the last digits:
12 127 28 42 39 113 42 18 44 118 44 37 113 124 37 48 127 36 29 31 125 139 131 115 105 132 104 123 35 113 122 42 117 119 58 109 23 105 63 27 44 105 99 41 128 121 116 125 32 61 37 127 29 113 121 58 114 126 53 114 96 25 109 7 31 141 46 13 27 43 117 116 27 7 68 40 31 115 124 42 128 52 71 118 117 38 27 106 33 117 116 111 40 119 47 105 57 122 109 124 115 43 120 43 27 27 18 28 48 125 107 114 34 133 45 120 30 127 31 116 146
The primary intent of this task is the presentation of information. It is acceptable to hardcode the data set or characteristics of it (such as what the stems are) in the example, insofar as it is impractical to make the example generic to any data set. For example, in a computation-less language like HTML the data set may be entirely prearranged within the example; the interesting characteristics are how the proper visual formatting is arranged.
If possible, the output should not be a bitmap image. Monospaced plain text is acceptable, but do better if you can. It may be a window, i.e. not a file.
Note: If you wish to try multiple data sets, you might try this generator.
| #C.2B.2B | C++ | #include <algorithm>
#include <iomanip>
#include <iostream>
#include <vector>
const int dataset[] = {
12,127, 28, 42, 39,113, 42, 18, 44,118, 44, 37,113,124, 37, 48,127, 36,
29, 31,125,139,131,115,105,132,104,123, 35,113,122, 42,117,119, 58,109,
23,105, 63, 27, 44,105, 99, 41,128,121,116,125, 32, 61, 37,127, 29,113,
121, 58,114,126, 53,114, 96, 25,109, 7, 31,141, 46, 13, 27, 43,117,116,
27, 7, 68, 40, 31,115,124, 42,128, 52, 71,118,117, 38, 27,106, 33,117,
116,111, 40,119, 47,105, 57,122,109,124,115, 43,120, 43, 27, 27, 18, 28,
48,125,107,114, 34,133, 45,120, 30,127, 31,116,146
};
const int datasize = sizeof(dataset) / sizeof(dataset[0]);
int main()
{
typedef std::pair<int,int> StemLeaf;
std::vector<StemLeaf> stemplot;
for (int i = 0; i < datasize; ++i)
{
stemplot.push_back(StemLeaf(dataset[i] / 10, dataset[i] % 10));
}
std::sort(stemplot.begin(), stemplot.end()); // order stem/leaf pairs
int lo = stemplot.front().first; // minimum stem value
int hi = stemplot.back().first; // maximum stem value
for (std::vector<StemLeaf>::iterator itr = stemplot.begin(); lo <= hi; ++lo)
{
std::cout << std::setw(2) << lo << " |"; // print stem
// while (there are more stems) and (stem is equal to lo)
for ( ; itr != stemplot.end() && itr->first == lo; ++itr)
{
std::cout << " " << itr->second; // print leaf
}
std::cout << std::endl;
}
} |
http://rosettacode.org/wiki/Stern-Brocot_sequence | Stern-Brocot sequence | For this task, the Stern-Brocot sequence is to be generated by an algorithm similar to that employed in generating the Fibonacci sequence.
The first and second members of the sequence are both 1:
1, 1
Start by considering the second member of the sequence
Sum the considered member of the sequence and its precedent, (1 + 1) = 2, and append it to the end of the sequence:
1, 1, 2
Append the considered member of the sequence to the end of the sequence:
1, 1, 2, 1
Consider the next member of the series, (the third member i.e. 2)
GOTO 3
─── Expanding another loop we get: ───
Sum the considered member of the sequence and its precedent, (2 + 1) = 3, and append it to the end of the sequence:
1, 1, 2, 1, 3
Append the considered member of the sequence to the end of the sequence:
1, 1, 2, 1, 3, 2
Consider the next member of the series, (the fourth member i.e. 1)
The task is to
Create a function/method/subroutine/procedure/... to generate the Stern-Brocot sequence of integers using the method outlined above.
Show the first fifteen members of the sequence. (This should be: 1, 1, 2, 1, 3, 2, 3, 1, 4, 3, 5, 2, 5, 3, 4)
Show the (1-based) index of where the numbers 1-to-10 first appears in the sequence.
Show the (1-based) index of where the number 100 first appears in the sequence.
Check that the greatest common divisor of all the two consecutive members of the series up to the 1000th member, is always one.
Show your output on this page.
Related tasks
Fusc sequence.
Continued fraction/Arithmetic
Ref
Infinite Fractions - Numberphile (Video).
Trees, Teeth, and Time: The mathematics of clock making.
A002487 The On-Line Encyclopedia of Integer Sequences.
| #AutoHotkey | AutoHotkey | Found := FindOneToX(100), FoundList := ""
Loop, 10
FoundList .= "First " A_Index " found at " Found[A_Index] "`n"
MsgBox, 64, Stern-Brocot Sequence
, % "First 15: " FirstX(15) "`n"
. FoundList
. "First 100 found at " Found[100] "`n"
. "GCDs of all two consecutive members are " (GCDsUpToXAreOne(1000) ? "" : "not ") "one."
return
class SternBrocot
{
__New()
{
this[1] := 1
this[2] := 1
this.Consider := 2
}
InsertPair()
{
n := this.Consider
this.Push(this[n] + this[n - 1], this[n])
this.Consider++
}
}
; Show the first fifteen members of the sequence. (This should be: 1, 1, 2, 1, 3, 2, 3, 1, 4, 3,
; 5, 2, 5, 3, 4)
FirstX(x)
{
SB := new SternBrocot()
while SB.MaxIndex() < x
SB.InsertPair()
Loop, % x
Out .= SB[A_Index] ", "
return RTrim(Out, " ,")
}
; Show the (1-based) index of where the numbers 1-to-10 first appears in the sequence.
; Show the (1-based) index of where the number 100 first appears in the sequence.
FindOneToX(x)
{
SB := new SternBrocot(), xRequired := x, Found := []
while xRequired > 0 ; While the count of numbers yet to be found is > 0.
{
Loop, 2 ; Consider the second last member and then the last member.
{
n := SB[i := SB.MaxIndex() - 2 + A_Index]
; If number (n) has not been found yet, and it is less than the maximum number to
; find (x), record the index (i) and decrement the count of numbers yet to be found.
if (Found[n] = "" && n <= x)
Found[n] := i, xRequired--
}
SB.InsertPair() ; Insert the two members that will be checked next.
}
return Found
}
; Check that the greatest common divisor of all the two consecutive members of the series up to
; the 1000th member, is always one.
GCDsUpToXAreOne(x)
{
SB := new SternBrocot()
while SB.MaxIndex() < x
SB.InsertPair()
Loop, % x - 1
if GCD(SB[A_Index], SB[A_Index + 1]) > 1
return 0
return 1
}
GCD(a, b) {
while b
b := Mod(a | 0x0, a := b)
return a
} |
http://rosettacode.org/wiki/Stream_merge | Stream merge | 2-stream merge
Read two sorted streams of items from external source (e.g. disk, or network), and write one stream of sorted items to external sink.
Common algorithm: keep 1 buffered item from each source, select minimal of them, write it, fetch another item from that stream from which the written item was.
N-stream merge
The same as above, but reading from N sources.
Common algorithm: same as above, but keep buffered items and their source descriptors in a heap.
Assume streams are very big. You must not suck them whole in the memory, but read them as streams.
| #Ruby | Ruby | def stream_merge(*files)
fio = files.map{|fname| open(fname)}
merge(fio.map{|io| [io, io.gets]})
end
def merge(fdata)
until fdata.empty?
io, min = fdata.min_by{|_,data| data}
puts min
if (next_data = io.gets).nil?
io.close
fdata.delete([io, min])
else
i = fdata.index{|x,_| x == io}
fdata[i] = [io, next_data]
end
end
end
files = %w(temp1.dat temp2.dat temp3.dat)
files.each do |fname|
data = IO.read(fname).gsub("\n", " ")
puts "#{fname}: #{data}"
end
stream_merge(*files) |
http://rosettacode.org/wiki/State_name_puzzle | State name puzzle | Background
This task is inspired by Mark Nelson's DDJ Column "Wordplay" and one of the weekly puzzle challenges from Will Shortz on NPR Weekend Edition [1] and originally attributed to David Edelheit.
The challenge was to take the names of two U.S. States, mix them all together, then rearrange the letters to form the names of two different U.S. States (so that all four state names differ from one another).
What states are these?
The problem was reissued on the Unicon Discussion Web which includes several solutions with analysis. Several techniques may be helpful and you may wish to refer to Gödel numbering, equivalence relations, and equivalence classes. The basic merits of these were discussed in the Unicon Discussion Web.
A second challenge in the form of a set of fictitious new states was also presented.
Task
Write a program to solve the challenge using both the original list of states and the fictitious list.
Caveats
case and spacing aren't significant - just letters (harmonize case)
don't expect the names to be in any order - such as being sorted
don't rely on names to be unique (eliminate duplicates - meaning if Iowa appears twice you can only use it once)
Comma separated list of state names used in the original puzzle:
"Alabama", "Alaska", "Arizona", "Arkansas",
"California", "Colorado", "Connecticut", "Delaware",
"Florida", "Georgia", "Hawaii", "Idaho", "Illinois",
"Indiana", "Iowa", "Kansas", "Kentucky", "Louisiana",
"Maine", "Maryland", "Massachusetts", "Michigan",
"Minnesota", "Mississippi", "Missouri", "Montana",
"Nebraska", "Nevada", "New Hampshire", "New Jersey",
"New Mexico", "New York", "North Carolina", "North Dakota",
"Ohio", "Oklahoma", "Oregon", "Pennsylvania", "Rhode Island",
"South Carolina", "South Dakota", "Tennessee", "Texas",
"Utah", "Vermont", "Virginia",
"Washington", "West Virginia", "Wisconsin", "Wyoming"
Comma separated list of additional fictitious state names to be added to the original (Includes a duplicate):
"New Kory", "Wen Kory", "York New", "Kory New", "New Kory"
Other tasks related to string operations:
Metrics
Array length
String length
Copy a string
Empty string (assignment)
Counting
Word frequency
Letter frequency
Jewels and stones
I before E except after C
Bioinformatics/base count
Count occurrences of a substring
Count how many vowels and consonants occur in a string
Remove/replace
XXXX redacted
Conjugate a Latin verb
Remove vowels from a string
String interpolation (included)
Strip block comments
Strip comments from a string
Strip a set of characters from a string
Strip whitespace from a string -- top and tail
Strip control codes and extended characters from a string
Anagrams/Derangements/shuffling
Word wheel
ABC problem
Sattolo cycle
Knuth shuffle
Ordered words
Superpermutation minimisation
Textonyms (using a phone text pad)
Anagrams
Anagrams/Deranged anagrams
Permutations/Derangements
Find/Search/Determine
ABC words
Odd words
Word ladder
Semordnilap
Word search
Wordiff (game)
String matching
Tea cup rim text
Alternade words
Changeable words
State name puzzle
String comparison
Unique characters
Unique characters in each string
Extract file extension
Levenshtein distance
Palindrome detection
Common list elements
Longest common suffix
Longest common prefix
Compare a list of strings
Longest common substring
Find common directory path
Words from neighbour ones
Change e letters to i in words
Non-continuous subsequences
Longest common subsequence
Longest palindromic substrings
Longest increasing subsequence
Words containing "the" substring
Sum of the digits of n is substring of n
Determine if a string is numeric
Determine if a string is collapsible
Determine if a string is squeezable
Determine if a string has all unique characters
Determine if a string has all the same characters
Longest substrings without repeating characters
Find words which contains all the vowels
Find words which contains most consonants
Find words which contains more than 3 vowels
Find words which first and last three letters are equals
Find words which odd letters are consonants and even letters are vowels or vice_versa
Formatting
Substring
Rep-string
Word wrap
String case
Align columns
Literals/String
Repeat a string
Brace expansion
Brace expansion using ranges
Reverse a string
Phrase reversals
Comma quibbling
Special characters
String concatenation
Substring/Top and tail
Commatizing numbers
Reverse words in a string
Suffixation of decimal numbers
Long literals, with continuations
Numerical and alphabetical suffixes
Abbreviations, easy
Abbreviations, simple
Abbreviations, automatic
Song lyrics/poems/Mad Libs/phrases
Mad Libs
Magic 8-ball
99 Bottles of Beer
The Name Game (a song)
The Old lady swallowed a fly
The Twelve Days of Christmas
Tokenize
Text between
Tokenize a string
Word break problem
Tokenize a string with escaping
Split a character string based on change of character
Sequences
Show ASCII table
De Bruijn sequences
Self-referential sequences
Generate lower case ASCII alphabet
| #C.2B.2B | C++ | #include <algorithm>
#include <iostream>
#include <string>
#include <array>
#include <vector>
template<typename T>
T unique(T&& src)
{
T retval(std::move(src));
std::sort(retval.begin(), retval.end(), std::less<typename T::value_type>());
retval.erase(std::unique(retval.begin(), retval.end()), retval.end());
return retval;
}
#define USE_FAKES 1
auto states = unique(std::vector<std::string>({
#if USE_FAKES
"Slender Dragon", "Abalamara",
#endif
"Alabama", "Alaska", "Arizona", "Arkansas",
"California", "Colorado", "Connecticut",
"Delaware",
"Florida", "Georgia", "Hawaii",
"Idaho", "Illinois", "Indiana", "Iowa",
"Kansas", "Kentucky", "Louisiana",
"Maine", "Maryland", "Massachusetts", "Michigan",
"Minnesota", "Mississippi", "Missouri", "Montana",
"Nebraska", "Nevada", "New Hampshire", "New Jersey",
"New Mexico", "New York", "North Carolina", "North Dakota",
"Ohio", "Oklahoma", "Oregon",
"Pennsylvania", "Rhode Island",
"South Carolina", "South Dakota", "Tennessee", "Texas",
"Utah", "Vermont", "Virginia",
"Washington", "West Virginia", "Wisconsin", "Wyoming"
}));
struct counted_pair
{
std::string name;
std::array<int, 26> count{};
void count_characters(const std::string& s)
{
for (auto&& c : s) {
if (c >= 'a' && c <= 'z') count[c - 'a']++;
if (c >= 'A' && c <= 'Z') count[c - 'A']++;
}
}
counted_pair(const std::string& s1, const std::string& s2)
: name(s1 + " + " + s2)
{
count_characters(s1);
count_characters(s2);
}
};
bool operator<(const counted_pair& lhs, const counted_pair& rhs)
{
auto lhs_size = lhs.name.size();
auto rhs_size = rhs.name.size();
return lhs_size == rhs_size
? std::lexicographical_compare(lhs.count.begin(),
lhs.count.end(),
rhs.count.begin(),
rhs.count.end())
: lhs_size < rhs_size;
}
bool operator==(const counted_pair& lhs, const counted_pair& rhs)
{
return lhs.name.size() == rhs.name.size() && lhs.count == rhs.count;
}
int main()
{
const int n_states = states.size();
std::vector<counted_pair> pairs;
for (int i = 0; i < n_states; i++) {
for (int j = 0; j < i; j++) {
pairs.emplace_back(counted_pair(states[i], states[j]));
}
}
std::sort(pairs.begin(), pairs.end());
auto start = pairs.begin();
while (true) {
auto match = std::adjacent_find(start, pairs.end());
if (match == pairs.end()) {
break;
}
auto next = match + 1;
std::cout << match->name << " => " << next->name << "\n";
start = next;
}
} |
http://rosettacode.org/wiki/Start_from_a_main_routine | Start from a main routine |
Some languages (like Gambas and Visual Basic) support two startup modes. Applications written in these languages start with an open window that waits for events, and it is necessary to do some trickery to cause a main procedure to run instead. Data driven or event driven languages may also require similar trickery to force a startup procedure to run.
Task
Demonstrate the steps involved in causing the application to run a main procedure, rather than an event driven window at startup.
Languages that always run from main() can be omitted from this task.
| #Clojure | Clojure |
MODULE MainProcedure;
IMPORT StdLog;
PROCEDURE Do*;
BEGIN
StdLog.String("From Do");StdLog.Ln
END Do;
PROCEDURE Main*;
BEGIN
StdLog.String("From Main");StdLog.Ln
END Main;
END MainProcedure.
|
http://rosettacode.org/wiki/Start_from_a_main_routine | Start from a main routine |
Some languages (like Gambas and Visual Basic) support two startup modes. Applications written in these languages start with an open window that waits for events, and it is necessary to do some trickery to cause a main procedure to run instead. Data driven or event driven languages may also require similar trickery to force a startup procedure to run.
Task
Demonstrate the steps involved in causing the application to run a main procedure, rather than an event driven window at startup.
Languages that always run from main() can be omitted from this task.
| #Component_Pascal | Component Pascal |
MODULE MainProcedure;
IMPORT StdLog;
PROCEDURE Do*;
BEGIN
StdLog.String("From Do");StdLog.Ln
END Do;
PROCEDURE Main*;
BEGIN
StdLog.String("From Main");StdLog.Ln
END Main;
END MainProcedure.
|
http://rosettacode.org/wiki/Start_from_a_main_routine | Start from a main routine |
Some languages (like Gambas and Visual Basic) support two startup modes. Applications written in these languages start with an open window that waits for events, and it is necessary to do some trickery to cause a main procedure to run instead. Data driven or event driven languages may also require similar trickery to force a startup procedure to run.
Task
Demonstrate the steps involved in causing the application to run a main procedure, rather than an event driven window at startup.
Languages that always run from main() can be omitted from this task.
| #Erlang | Erlang | USE: io
IN: example
: hello ( -- ) "Hello, world!" print ;
MAIN: hello |
http://rosettacode.org/wiki/Start_from_a_main_routine | Start from a main routine |
Some languages (like Gambas and Visual Basic) support two startup modes. Applications written in these languages start with an open window that waits for events, and it is necessary to do some trickery to cause a main procedure to run instead. Data driven or event driven languages may also require similar trickery to force a startup procedure to run.
Task
Demonstrate the steps involved in causing the application to run a main procedure, rather than an event driven window at startup.
Languages that always run from main() can be omitted from this task.
| #Factor | Factor | USE: io
IN: example
: hello ( -- ) "Hello, world!" print ;
MAIN: hello |
http://rosettacode.org/wiki/Straddling_checkerboard | Straddling checkerboard | Task
Implement functions to encrypt and decrypt a message using the straddling checkerboard method. The checkerboard should take a 28 character alphabet (A-Z plus a full stop and an escape character) and two different numbers representing the blanks in the first row. The output will be a series of decimal digits.
Numbers should be encrypted by inserting the escape character before each digit, then including the digit unencrypted. This should be reversed for decryption.
| #Python | Python | T = [["79", "0", "1", "2", "3", "4", "5", "6", "7", "8", "9"],
["", "H", "O", "L", "", "M", "E", "S", "", "R", "T"],
["3", "A", "B", "C", "D", "F", "G", "I", "J", "K", "N"],
["7", "P", "Q", "U", "V", "W", "X", "Y", "Z", ".", "/"]]
def straddle(s):
return "".join(L[0]+T[0][L.index(c)] for c in s.upper() for L in T if c in L)
def unstraddle(s):
s = iter(s)
for c in s:
if c in [T[2][0], T[3][0]]:
i = [T[2][0], T[3][0]].index(c)
n = T[2 + i][T[0].index(s.next())]
yield s.next() if n == "/" else n
else:
yield T[1][T[0].index(c)]
O = "One night-it was on the twentieth of March, 1888-I was returning"
print "Encoded:", straddle(O)
print "Decoded:", "".join(unstraddle(straddle(O))) |
http://rosettacode.org/wiki/Stirling_numbers_of_the_first_kind | Stirling numbers of the first kind | Stirling numbers of the first kind, or Stirling cycle numbers, count permutations according to their number
of cycles (counting fixed points as cycles of length one).
They may be defined directly to be the number of permutations of n
elements with k disjoint cycles.
Stirling numbers of the first kind express coefficients of polynomial expansions of falling or rising factorials.
Depending on the application, Stirling numbers of the first kind may be "signed"
or "unsigned". Signed Stirling numbers of the first kind arise when the
polynomial expansion is expressed in terms of falling factorials; unsigned when
expressed in terms of rising factorials. The only substantial difference is that,
for signed Stirling numbers of the first kind, values of S1(n, k) are negative
when n + k is odd.
Stirling numbers of the first kind follow the simple identities:
S1(0, 0) = 1
S1(n, 0) = 0 if n > 0
S1(n, k) = 0 if k > n
S1(n, k) = S1(n - 1, k - 1) + (n - 1) * S1(n - 1, k) # For unsigned
or
S1(n, k) = S1(n - 1, k - 1) - (n - 1) * S1(n - 1, k) # For signed
Task
Write a routine (function, procedure, whatever) to find Stirling numbers of the first kind. There are several methods to generate Stirling numbers of the first kind. You are free to choose the most appropriate for your language. If your language has a built-in, or easily, publicly available library implementation, it is acceptable to use that.
Using the routine, generate and show here, on this page, a table (or triangle) showing the Stirling numbers of the first kind, S1(n, k), up to S1(12, 12). it is optional to show the row / column for n == 0 and k == 0. It is optional to show places where S1(n, k) == 0 (when k > n). You may choose to show signed or unsigned Stirling numbers of the first kind, just make a note of which was chosen.
If your language supports large integers, find and show here, on this page, the maximum value of S1(n, k) where n == 100.
See also
Wikipedia - Stirling numbers of the first kind
OEIS:A008275 - Signed Stirling numbers of the first kind
OEIS:A130534 - Unsigned Stirling numbers of the first kind
Related Tasks
Stirling numbers of the second kind
Lah numbers
| #Sidef | Sidef | func S1(n, k) { # unsigned Stirling numbers of the first kind
stirling(n, k).abs
}
const r = (0..12)
var triangle = r.map {|n| 0..n -> map {|k| S1(n, k) } }
var widths = r.map {|n| r.map {|k| (triangle[k][n] \\ 0).len }.max }
say ('n\k ', r.map {|n| "%*s" % (widths[n], n) }.join(' '))
r.each {|n|
var str = ('%-3s ' % n)
str += triangle[n].map_kv {|k,v| "%*s" % (widths[k], v) }.join(' ')
say str
}
with (100) {|n|
say "\nMaximum value from the S1(#{n}, *) row:"
say { S1(n, _) }.map(^n).max
} |
http://rosettacode.org/wiki/Stirling_numbers_of_the_first_kind | Stirling numbers of the first kind | Stirling numbers of the first kind, or Stirling cycle numbers, count permutations according to their number
of cycles (counting fixed points as cycles of length one).
They may be defined directly to be the number of permutations of n
elements with k disjoint cycles.
Stirling numbers of the first kind express coefficients of polynomial expansions of falling or rising factorials.
Depending on the application, Stirling numbers of the first kind may be "signed"
or "unsigned". Signed Stirling numbers of the first kind arise when the
polynomial expansion is expressed in terms of falling factorials; unsigned when
expressed in terms of rising factorials. The only substantial difference is that,
for signed Stirling numbers of the first kind, values of S1(n, k) are negative
when n + k is odd.
Stirling numbers of the first kind follow the simple identities:
S1(0, 0) = 1
S1(n, 0) = 0 if n > 0
S1(n, k) = 0 if k > n
S1(n, k) = S1(n - 1, k - 1) + (n - 1) * S1(n - 1, k) # For unsigned
or
S1(n, k) = S1(n - 1, k - 1) - (n - 1) * S1(n - 1, k) # For signed
Task
Write a routine (function, procedure, whatever) to find Stirling numbers of the first kind. There are several methods to generate Stirling numbers of the first kind. You are free to choose the most appropriate for your language. If your language has a built-in, or easily, publicly available library implementation, it is acceptable to use that.
Using the routine, generate and show here, on this page, a table (or triangle) showing the Stirling numbers of the first kind, S1(n, k), up to S1(12, 12). it is optional to show the row / column for n == 0 and k == 0. It is optional to show places where S1(n, k) == 0 (when k > n). You may choose to show signed or unsigned Stirling numbers of the first kind, just make a note of which was chosen.
If your language supports large integers, find and show here, on this page, the maximum value of S1(n, k) where n == 100.
See also
Wikipedia - Stirling numbers of the first kind
OEIS:A008275 - Signed Stirling numbers of the first kind
OEIS:A130534 - Unsigned Stirling numbers of the first kind
Related Tasks
Stirling numbers of the second kind
Lah numbers
| #Tcl | Tcl | proc US1 {n k} {
if {$k == 0} {
return [expr {$n == 0}]
}
if {$n < $k} {
return 0
}
if {$n == $k} {
return 1
}
set nk [list $n $k]
if {[info exists ::US1cache($nk)]} {
return $::US1cache($nk)
}
set n1 [expr {$n - 1}]
set k1 [expr {$k - 1}]
set r [expr {($n1 * [US1 $n1 $k]) + [US1 $n1 $k1]}]
set ::US1cache($nk) $r
}
proc main {} {
puts "Unsigned Stirling numbers of the first kind:"
set max 12 ;# last table line to print
set L 9 ;# space to use for 1 number
puts -nonewline "n\\k"
for {set n 0} {$n <= $max} {incr n} {
puts -nonewline " [format %${L}d $n]"
}
puts ""
for {set n 0} {$n <= $max} {incr n} {
puts -nonewline [format %-3d $n]
for {set k 0} {$k <= $n} {incr k} {
puts -nonewline " [format %${L}s [US1 $n $k]]"
}
puts ""
}
puts "The maximum value of US1(100, k) = "
set previous 0
for {set k 1} {$k <= 100} {incr k} {
set current [US1 100 $k]
if {$current > $previous} {
set previous $current
} else {
puts $previous
puts "([string length $previous] digits, k = [expr {$k-1}])"
break
}
}
}
main |
http://rosettacode.org/wiki/String_append | String append |
Basic Data Operation
This is a basic data operation. It represents a fundamental action on a basic data type.
You may see other such operations in the Basic Data Operations category, or:
Integer Operations
Arithmetic |
Comparison
Boolean Operations
Bitwise |
Logical
String Operations
Concatenation |
Interpolation |
Comparison |
Matching
Memory Operations
Pointers & references |
Addresses
Most languages provide a way to concatenate two string values, but some languages also provide a convenient way to append in-place to an existing string variable without referring to the variable twice.
Task
Create a string variable equal to any text value.
Append the string variable with another string literal in the most idiomatic way, without double reference if your language supports it.
Show the contents of the variable after the append operation.
| #Lasso | Lasso | local(x = 'Hello')
#x->append(', World!')
#x |
http://rosettacode.org/wiki/String_append | String append |
Basic Data Operation
This is a basic data operation. It represents a fundamental action on a basic data type.
You may see other such operations in the Basic Data Operations category, or:
Integer Operations
Arithmetic |
Comparison
Boolean Operations
Bitwise |
Logical
String Operations
Concatenation |
Interpolation |
Comparison |
Matching
Memory Operations
Pointers & references |
Addresses
Most languages provide a way to concatenate two string values, but some languages also provide a convenient way to append in-place to an existing string variable without referring to the variable twice.
Task
Create a string variable equal to any text value.
Append the string variable with another string literal in the most idiomatic way, without double reference if your language supports it.
Show the contents of the variable after the append operation.
| #Lingo | Lingo | str = "Hello"
put " world!" after str
put str
-- "Hello world!" |
http://rosettacode.org/wiki/String_append | String append |
Basic Data Operation
This is a basic data operation. It represents a fundamental action on a basic data type.
You may see other such operations in the Basic Data Operations category, or:
Integer Operations
Arithmetic |
Comparison
Boolean Operations
Bitwise |
Logical
String Operations
Concatenation |
Interpolation |
Comparison |
Matching
Memory Operations
Pointers & references |
Addresses
Most languages provide a way to concatenate two string values, but some languages also provide a convenient way to append in-place to an existing string variable without referring to the variable twice.
Task
Create a string variable equal to any text value.
Append the string variable with another string literal in the most idiomatic way, without double reference if your language supports it.
Show the contents of the variable after the append operation.
| #LiveCode | LiveCode | local str="live"
put "code" after str |
http://rosettacode.org/wiki/Statistics/Normal_distribution | Statistics/Normal distribution | The Normal (or Gaussian) distribution is a frequently used distribution in statistics. While most programming languages provide a uniformly distributed random number generator, one can derive normally distributed random numbers from a uniform generator.
The task
Take a uniform random number generator and create a large (you decide how large) set of numbers that follow a normal (Gaussian) distribution. Calculate the dataset's mean and standard deviation, and show a histogram of the data.
Mention any native language support for the generation of normally distributed random numbers.
Reference
You may refer to code in Statistics/Basic if available.
| #Haskell | Haskell | import Data.Map (Map, empty, insert, findWithDefault, toList)
import Data.Maybe (fromMaybe)
import Text.Printf (printf)
import Data.Function (on)
import Data.List (sort, maximumBy, minimumBy)
import Control.Monad.Random (RandomGen, Rand, evalRandIO, getRandomR)
import Control.Monad (replicateM)
-- Box-Muller
getNorm :: RandomGen g => Rand g Double
getNorm = do
u0 <- getRandomR (0.0, 1.0)
u1 <- getRandomR (0.0, 1.0)
let r = sqrt $ (-2.0) * log u0
theta = 2.0 * pi * u1
return $ r * sin theta
putInBin :: Double -> Map Int Int -> Double -> Map Int Int
putInBin binWidth t v =
let bin = round (v / binWidth)
count = findWithDefault 0 bin t
in insert bin (count+1) t
runTest :: Int -> IO ()
runTest n = do
rs <- evalRandIO $ replicateM n getNorm
let binWidth = 0.1
tally v (sv, sv2, t) = (sv+v, sv2 + v*v, putInBin binWidth t v)
(sum, sum2, tallies) = foldr tally (0.0, 0.0, empty) rs
tallyList = sort $ toList tallies
printStars tallies binWidth maxCount selection =
let count = findWithDefault 0 selection tallies
bin = binWidth * fromIntegral selection
maxStars = 100
starCount = if maxCount <= maxStars
then count
else maxStars * count `div` maxCount
stars = replicate starCount '*'
in printf "%5.2f: %s %d\n" bin stars count
mean = sum / fromIntegral n
stddev = sqrt (sum2/fromIntegral n - mean*mean)
printf "\n"
printf "sample count: %d\n" n
printf "mean: %9.7f\n" mean
printf "stddev: %9.7f\n" stddev
let maxCount = snd $ maximumBy (compare `on` snd) tallyList
maxBin = fst $ maximumBy (compare `on` fst) tallyList
minBin = fst $ minimumBy (compare `on` fst) tallyList
mapM_ (printStars tallies binWidth maxCount) [minBin..maxBin]
main = do
runTest 1000
runTest 2000000 |
http://rosettacode.org/wiki/Stem-and-leaf_plot | Stem-and-leaf plot | Create a well-formatted stem-and-leaf plot from the following data set, where the leaves are the last digits:
12 127 28 42 39 113 42 18 44 118 44 37 113 124 37 48 127 36 29 31 125 139 131 115 105 132 104 123 35 113 122 42 117 119 58 109 23 105 63 27 44 105 99 41 128 121 116 125 32 61 37 127 29 113 121 58 114 126 53 114 96 25 109 7 31 141 46 13 27 43 117 116 27 7 68 40 31 115 124 42 128 52 71 118 117 38 27 106 33 117 116 111 40 119 47 105 57 122 109 124 115 43 120 43 27 27 18 28 48 125 107 114 34 133 45 120 30 127 31 116 146
The primary intent of this task is the presentation of information. It is acceptable to hardcode the data set or characteristics of it (such as what the stems are) in the example, insofar as it is impractical to make the example generic to any data set. For example, in a computation-less language like HTML the data set may be entirely prearranged within the example; the interesting characteristics are how the proper visual formatting is arranged.
If possible, the output should not be a bitmap image. Monospaced plain text is acceptable, but do better if you can. It may be a window, i.e. not a file.
Note: If you wish to try multiple data sets, you might try this generator.
| #Ceylon | Ceylon | "Run the module `thestemandleafplot`."
shared void run() {
value data ="12 127 28 42 39 113 42 18 44 118 44 37 113 124 37 48 127 36 29 31 125 139 131 115 105 132 104 123 35
113 122 42 117 119 58 109 23 105 63 27 44 105 99 41 128 121 116 125 32 61 37 127 29 113 121 58 114
126 53 114 96 25 109 7 31 141 46 13 27 43 117 116 27 7 68 40 31 115 124 42 128 52 71 118 117 38 27
106 33 117 116 111 40 119 47 105 57 122 109 124 115 43 120 43 27 27 18 28 48 125 107 114 34 133 45
120 30 127 31 116 146";
value numbers = data
.split()
.map(parseInteger)
.coalesced;
value stemsToLeaves = numbers
.group((Integer element) => element / 10)
.mapItems((Integer key, [Integer+] item) => item.map((Integer element) => element % 10))
.mapItems((Integer key, {Integer+} item) => sort(item));
value lastStem = stemsToLeaves.keys.last else 0;
for(i in 0..lastStem) {
print("``formatInteger(i).padLeading(2)``| ``" ".join(stemsToLeaves[i] else [])``");
}
} |
http://rosettacode.org/wiki/Stern-Brocot_sequence | Stern-Brocot sequence | For this task, the Stern-Brocot sequence is to be generated by an algorithm similar to that employed in generating the Fibonacci sequence.
The first and second members of the sequence are both 1:
1, 1
Start by considering the second member of the sequence
Sum the considered member of the sequence and its precedent, (1 + 1) = 2, and append it to the end of the sequence:
1, 1, 2
Append the considered member of the sequence to the end of the sequence:
1, 1, 2, 1
Consider the next member of the series, (the third member i.e. 2)
GOTO 3
─── Expanding another loop we get: ───
Sum the considered member of the sequence and its precedent, (2 + 1) = 3, and append it to the end of the sequence:
1, 1, 2, 1, 3
Append the considered member of the sequence to the end of the sequence:
1, 1, 2, 1, 3, 2
Consider the next member of the series, (the fourth member i.e. 1)
The task is to
Create a function/method/subroutine/procedure/... to generate the Stern-Brocot sequence of integers using the method outlined above.
Show the first fifteen members of the sequence. (This should be: 1, 1, 2, 1, 3, 2, 3, 1, 4, 3, 5, 2, 5, 3, 4)
Show the (1-based) index of where the numbers 1-to-10 first appears in the sequence.
Show the (1-based) index of where the number 100 first appears in the sequence.
Check that the greatest common divisor of all the two consecutive members of the series up to the 1000th member, is always one.
Show your output on this page.
Related tasks
Fusc sequence.
Continued fraction/Arithmetic
Ref
Infinite Fractions - Numberphile (Video).
Trees, Teeth, and Time: The mathematics of clock making.
A002487 The On-Line Encyclopedia of Integer Sequences.
| #BASIC | BASIC | 10 DEFINT A,B,I,J,S: DIM S(1200)
20 S(1)=1: S(2)=1
30 FOR I=2 TO 600
40 S(I*2-1)=S(I)+S(I-1)
50 S(I*2)=S(I)
60 NEXT I
70 PRINT "First 15 elements: ";
80 FOR I=1 TO 15: PRINT USING"# ";S(I);: NEXT I
85 PRINT
90 FOR I=1 TO 10
100 FOR J=1 TO 1200: IF S(J)<>I THEN NEXT J
110 PRINT "First";I;"at";J
120 NEXT I
130 FOR J=1 TO 1200: IF S(J)<>100 THEN NEXT J
140 PRINT "First 100 at";J
150 FOR I=2 TO 1000
160 A=S(I): B=S(I-1)
170 J=A: A=B: B=J MOD A: IF B THEN 170
180 IF A<>1 THEN PRINT "GCD <> 1 at ";I: STOP
190 NEXT I
200 PRINT "All GCDs are 1."
210 END |
http://rosettacode.org/wiki/Stream_merge | Stream merge | 2-stream merge
Read two sorted streams of items from external source (e.g. disk, or network), and write one stream of sorted items to external sink.
Common algorithm: keep 1 buffered item from each source, select minimal of them, write it, fetch another item from that stream from which the written item was.
N-stream merge
The same as above, but reading from N sources.
Common algorithm: same as above, but keep buffered items and their source descriptors in a heap.
Assume streams are very big. You must not suck them whole in the memory, but read them as streams.
| #Scala | Scala | def mergeN[A : Ordering](is: Iterator[A]*): Iterator[A] = is.reduce((a, b) => merge2(a, b))
def merge2[A : Ordering](i1: Iterator[A], i2: Iterator[A]): Iterator[A] = {
merge2Buffered(i1.buffered, i2.buffered)
}
def merge2Buffered[A](i1: BufferedIterator[A], i2: BufferedIterator[A])(implicit ord: Ordering[A]): Iterator[A] = {
if (!i1.hasNext) {
i2
} else if (!i2.hasNext) {
i1
} else {
val nextHead = if (ord.lt(i1.head, i2.head)) {
Iterator.single(i1.next)
} else {
Iterator.single(i2.next)
}
nextHead ++ merge2Buffered(i1, i2)
}
} |
http://rosettacode.org/wiki/State_name_puzzle | State name puzzle | Background
This task is inspired by Mark Nelson's DDJ Column "Wordplay" and one of the weekly puzzle challenges from Will Shortz on NPR Weekend Edition [1] and originally attributed to David Edelheit.
The challenge was to take the names of two U.S. States, mix them all together, then rearrange the letters to form the names of two different U.S. States (so that all four state names differ from one another).
What states are these?
The problem was reissued on the Unicon Discussion Web which includes several solutions with analysis. Several techniques may be helpful and you may wish to refer to Gödel numbering, equivalence relations, and equivalence classes. The basic merits of these were discussed in the Unicon Discussion Web.
A second challenge in the form of a set of fictitious new states was also presented.
Task
Write a program to solve the challenge using both the original list of states and the fictitious list.
Caveats
case and spacing aren't significant - just letters (harmonize case)
don't expect the names to be in any order - such as being sorted
don't rely on names to be unique (eliminate duplicates - meaning if Iowa appears twice you can only use it once)
Comma separated list of state names used in the original puzzle:
"Alabama", "Alaska", "Arizona", "Arkansas",
"California", "Colorado", "Connecticut", "Delaware",
"Florida", "Georgia", "Hawaii", "Idaho", "Illinois",
"Indiana", "Iowa", "Kansas", "Kentucky", "Louisiana",
"Maine", "Maryland", "Massachusetts", "Michigan",
"Minnesota", "Mississippi", "Missouri", "Montana",
"Nebraska", "Nevada", "New Hampshire", "New Jersey",
"New Mexico", "New York", "North Carolina", "North Dakota",
"Ohio", "Oklahoma", "Oregon", "Pennsylvania", "Rhode Island",
"South Carolina", "South Dakota", "Tennessee", "Texas",
"Utah", "Vermont", "Virginia",
"Washington", "West Virginia", "Wisconsin", "Wyoming"
Comma separated list of additional fictitious state names to be added to the original (Includes a duplicate):
"New Kory", "Wen Kory", "York New", "Kory New", "New Kory"
Other tasks related to string operations:
Metrics
Array length
String length
Copy a string
Empty string (assignment)
Counting
Word frequency
Letter frequency
Jewels and stones
I before E except after C
Bioinformatics/base count
Count occurrences of a substring
Count how many vowels and consonants occur in a string
Remove/replace
XXXX redacted
Conjugate a Latin verb
Remove vowels from a string
String interpolation (included)
Strip block comments
Strip comments from a string
Strip a set of characters from a string
Strip whitespace from a string -- top and tail
Strip control codes and extended characters from a string
Anagrams/Derangements/shuffling
Word wheel
ABC problem
Sattolo cycle
Knuth shuffle
Ordered words
Superpermutation minimisation
Textonyms (using a phone text pad)
Anagrams
Anagrams/Deranged anagrams
Permutations/Derangements
Find/Search/Determine
ABC words
Odd words
Word ladder
Semordnilap
Word search
Wordiff (game)
String matching
Tea cup rim text
Alternade words
Changeable words
State name puzzle
String comparison
Unique characters
Unique characters in each string
Extract file extension
Levenshtein distance
Palindrome detection
Common list elements
Longest common suffix
Longest common prefix
Compare a list of strings
Longest common substring
Find common directory path
Words from neighbour ones
Change e letters to i in words
Non-continuous subsequences
Longest common subsequence
Longest palindromic substrings
Longest increasing subsequence
Words containing "the" substring
Sum of the digits of n is substring of n
Determine if a string is numeric
Determine if a string is collapsible
Determine if a string is squeezable
Determine if a string has all unique characters
Determine if a string has all the same characters
Longest substrings without repeating characters
Find words which contains all the vowels
Find words which contains most consonants
Find words which contains more than 3 vowels
Find words which first and last three letters are equals
Find words which odd letters are consonants and even letters are vowels or vice_versa
Formatting
Substring
Rep-string
Word wrap
String case
Align columns
Literals/String
Repeat a string
Brace expansion
Brace expansion using ranges
Reverse a string
Phrase reversals
Comma quibbling
Special characters
String concatenation
Substring/Top and tail
Commatizing numbers
Reverse words in a string
Suffixation of decimal numbers
Long literals, with continuations
Numerical and alphabetical suffixes
Abbreviations, easy
Abbreviations, simple
Abbreviations, automatic
Song lyrics/poems/Mad Libs/phrases
Mad Libs
Magic 8-ball
99 Bottles of Beer
The Name Game (a song)
The Old lady swallowed a fly
The Twelve Days of Christmas
Tokenize
Text between
Tokenize a string
Word break problem
Tokenize a string with escaping
Split a character string based on change of character
Sequences
Show ASCII table
De Bruijn sequences
Self-referential sequences
Generate lower case ASCII alphabet
| #Clojure | Clojure | (ns clojure-sandbox.statenames
(:require [clojure.data.csv :as csv]
[clojure.java.io :as io]
[clojure.string :refer [lower-case]]
[clojure.math.combinatorics :as c]
[clojure.pprint :as pprint]))
(def made-up-states ["New Kory" "Wen Kory" "York New" "Kory New" "New Kory"])
;; I saved the list of states in a local file to keep the code clean but you can copy and paste the list instead
(def real-states (with-open [in-file (io/reader (io/resource "states.csv"))]
(->> (doall
(csv/read-csv in-file))
(map first))))
(defn- state->charset [state-name]
"Convert state name into sorted list of characters with no spaces"
(->> state-name
char-array
sort
(filter (set (map char (range 97 123)))))) ;; ASCII range for lower case letters
(defn- add-charsets [states]
"Calculate sorted character list for each state and store with name"
(->> states
(map lower-case) ;; Convert all names to lower case
set ;; remove duplicates
(map
(fn [s] {:name s
:characters (state->charset s)})))) ;; add characters
(defn- pair-chars [state1 state2]
"Join the characters of two states together and sort them"
(-> state1
:characters
(concat (:characters state2))
sort))
(defn- pair [[state1 state2]]
"Record representing two state names and the total characters used in them"
{:inputs [(:name state1) (:name state2)]
:characters (pair-chars state1 state2)})
(defn- find-all-pairs [elements]
(c/combinations elements 2))
(defn- pairs-to-search [state-names]
"Create character lists for all states and return a list of all possible pairs"
(->> state-names
add-charsets
find-all-pairs
(map pair)))
(defn- pairs-have-same-letters? [[pair1 pair2]]
(= (:characters pair1) (:characters pair2)))
(defn- inputs-are-distinct? [[pair1 pair2 :as pairs]]
"Check that two pairs of states don't contain the same state"
(= 4 ;; There should be a total of 4 distinct states in the two pairs
(->> pairs
(map :inputs)
flatten
set
count)))
(defn- search [pairs]
(->> pairs
find-all-pairs ;; find pairs of pairs to search
(filter pairs-have-same-letters?) ;; Keep only those where each pair has the same characters
(filter inputs-are-distinct?))) ;; Remove pairs with duplicate states
(defn find-matches [state-names]
"Find all state pairs and return pairs of them using the same letters"
(-> state-names
pairs-to-search
search))
(defn- format-match-output [[pair1 pair2]]
"Format a pair of state pairs to print out"
(str (first (:inputs pair1))
" + "
(last (:inputs pair1))
" = "
(first (:inputs pair2))
" + "
(last (:inputs pair2))))
(defn- evaluate-and-print [states]
(->> states
find-matches
(map format-match-output)
pprint/pprint))
(defn -main [& args]
(println "Solutions for 50 real states")
(evaluate-and-print real-states)
(println "Solutions with made up states added")
(evaluate-and-print (concat real-states made-up-states)))
|
http://rosettacode.org/wiki/Start_from_a_main_routine | Start from a main routine |
Some languages (like Gambas and Visual Basic) support two startup modes. Applications written in these languages start with an open window that waits for events, and it is necessary to do some trickery to cause a main procedure to run instead. Data driven or event driven languages may also require similar trickery to force a startup procedure to run.
Task
Demonstrate the steps involved in causing the application to run a main procedure, rather than an event driven window at startup.
Languages that always run from main() can be omitted from this task.
| #Forth | Forth | include foo.fs
...
: main ... ;
main bye |
http://rosettacode.org/wiki/Start_from_a_main_routine | Start from a main routine |
Some languages (like Gambas and Visual Basic) support two startup modes. Applications written in these languages start with an open window that waits for events, and it is necessary to do some trickery to cause a main procedure to run instead. Data driven or event driven languages may also require similar trickery to force a startup procedure to run.
Task
Demonstrate the steps involved in causing the application to run a main procedure, rather than an event driven window at startup.
Languages that always run from main() can be omitted from this task.
| #FreeBASIC | FreeBASIC | ' FB 1.05.0 Win64
Sub main()
Print "Hello from main!"
End Sub
main
Sleep |
http://rosettacode.org/wiki/Start_from_a_main_routine | Start from a main routine |
Some languages (like Gambas and Visual Basic) support two startup modes. Applications written in these languages start with an open window that waits for events, and it is necessary to do some trickery to cause a main procedure to run instead. Data driven or event driven languages may also require similar trickery to force a startup procedure to run.
Task
Demonstrate the steps involved in causing the application to run a main procedure, rather than an event driven window at startup.
Languages that always run from main() can be omitted from this task.
| #Gambas | Gambas | PUBLIC SUB Main()
' This is the start of the program
END |
http://rosettacode.org/wiki/Start_from_a_main_routine | Start from a main routine |
Some languages (like Gambas and Visual Basic) support two startup modes. Applications written in these languages start with an open window that waits for events, and it is necessary to do some trickery to cause a main procedure to run instead. Data driven or event driven languages may also require similar trickery to force a startup procedure to run.
Task
Demonstrate the steps involved in causing the application to run a main procedure, rather than an event driven window at startup.
Languages that always run from main() can be omitted from this task.
| #Go | Go | package main
import "fmt"
var count = 0
func foo() {
fmt.Println("foo called")
}
func init() {
fmt.Println("first init called")
foo()
}
func init() {
fmt.Println("second init called")
main()
}
func main() {
count++
fmt.Println("main called when count is", count)
} |
http://rosettacode.org/wiki/Straddling_checkerboard | Straddling checkerboard | Task
Implement functions to encrypt and decrypt a message using the straddling checkerboard method. The checkerboard should take a 28 character alphabet (A-Z plus a full stop and an escape character) and two different numbers representing the blanks in the first row. The output will be a series of decimal digits.
Numbers should be encrypted by inserting the escape character before each digit, then including the digit unencrypted. This should be reversed for decryption.
| #Racket | Racket | #lang racket
(struct *straddling (header main original)
#:reflection-name 'straddling
#:methods gen:custom-write
[(define (write-proc board port mode)
(write-string "#<straddling " port)
(write (*straddling-original board) port)
(write-string ">" port))])
(define string->vector (compose list->vector string->list))
(define (straddling . lines)
(define header-tail (reverse
(for/fold ([rev-ret '()])
([char (in-list (string->list (car lines)))]
[i (in-naturals)])
(if (equal? char #\space)
(cons (number->string i) rev-ret)
rev-ret))))
(define main (list->vector
(map string->vector
(cons "0123456789"
(map string-upcase
lines)))))
(define temporal-board
(*straddling (list->vector (list* "?" "" header-tail)) main lines))
(define escape (straddling-encode-char #\/ temporal-board))
(*straddling (list->vector (list* escape "" header-tail)) main lines)) |
http://rosettacode.org/wiki/Straddling_checkerboard | Straddling checkerboard | Task
Implement functions to encrypt and decrypt a message using the straddling checkerboard method. The checkerboard should take a 28 character alphabet (A-Z plus a full stop and an escape character) and two different numbers representing the blanks in the first row. The output will be a series of decimal digits.
Numbers should be encrypted by inserting the escape character before each digit, then including the digit unencrypted. This should be reversed for decryption.
| #Raku | Raku | class Straddling_Checkerboard {
has @!flat_board; # 10x3 stored as 30x1
has $!plain2code; # full translation table, invertable
has @!table; # Printable layout, like Wikipedia entry
my $numeric_escape = '/';
my $exclude = /<-[A..Z0..9.]>/; # Omit the escape character
method display_table { gather { take ~ .list for @!table } };
method decode ( Str $s --> Str ) {
$s.trans($!plain2code.antipairs);
}
method encode ( Str $s, :$collapse? --> Str ) {
my $replace = $collapse ?? '' !! '.';
$s.uc.subst( $exclude, $replace, :g ).trans($!plain2code);
}
submethod BUILD ( :$alphabet, :$u where 0..9, :$v where 0..9 ) {
die if $u == $v;
die if $alphabet.comb.sort.join ne [~] flat './', 'A'..'Z';
@!flat_board = $alphabet.uc.comb;
@!flat_board.splice( $u min $v, 0, Any );
@!flat_board.splice( $u max $v, 0, Any );
@!table = [ ' ',| [ 0 .. 9] ],
[ ' ',|@!flat_board[ 0 .. 9].map: {.defined ?? $_ !! ' '} ],
[ $u, |@!flat_board[10 .. 19] ],
[ $v, |@!flat_board[20 .. 29] ];
my @order = 0..9; # This may be passed as a param in the future
my @nums = flat @order,
@order.map({ +"$u$_" }),
@order.map({ +"$v$_" });
my %c2p = @nums Z=> @!flat_board;
%c2p{$_}:delete if %c2p{$_} eqv Any for keys %c2p;
my %p2c = %c2p.invert;
%p2c{$_} = %p2c{$numeric_escape} ~ $_ for 0..9;
$!plain2code = [%p2c.keys] => [%p2c.values];
}
}
sub MAIN ( :$u = 3, :$v = 7, :$alphabet = 'HOLMESRTABCDFGIJKNPQUVWXYZ./' ) {
my Straddling_Checkerboard $sc .= new: :$u, :$v, :$alphabet;
$sc.display_table;
for 0..1 -> $collapse {
my $original = 'One night-it was on the twentieth of March, 1888-I was returning';
my $en = $sc.encode($original, :$collapse);
my $de = $sc.decode($en);
say '';
say "Original: $original";
say "Encoded: $en";
say "Decoded: $de";
}
} |
http://rosettacode.org/wiki/Stirling_numbers_of_the_first_kind | Stirling numbers of the first kind | Stirling numbers of the first kind, or Stirling cycle numbers, count permutations according to their number
of cycles (counting fixed points as cycles of length one).
They may be defined directly to be the number of permutations of n
elements with k disjoint cycles.
Stirling numbers of the first kind express coefficients of polynomial expansions of falling or rising factorials.
Depending on the application, Stirling numbers of the first kind may be "signed"
or "unsigned". Signed Stirling numbers of the first kind arise when the
polynomial expansion is expressed in terms of falling factorials; unsigned when
expressed in terms of rising factorials. The only substantial difference is that,
for signed Stirling numbers of the first kind, values of S1(n, k) are negative
when n + k is odd.
Stirling numbers of the first kind follow the simple identities:
S1(0, 0) = 1
S1(n, 0) = 0 if n > 0
S1(n, k) = 0 if k > n
S1(n, k) = S1(n - 1, k - 1) + (n - 1) * S1(n - 1, k) # For unsigned
or
S1(n, k) = S1(n - 1, k - 1) - (n - 1) * S1(n - 1, k) # For signed
Task
Write a routine (function, procedure, whatever) to find Stirling numbers of the first kind. There are several methods to generate Stirling numbers of the first kind. You are free to choose the most appropriate for your language. If your language has a built-in, or easily, publicly available library implementation, it is acceptable to use that.
Using the routine, generate and show here, on this page, a table (or triangle) showing the Stirling numbers of the first kind, S1(n, k), up to S1(12, 12). it is optional to show the row / column for n == 0 and k == 0. It is optional to show places where S1(n, k) == 0 (when k > n). You may choose to show signed or unsigned Stirling numbers of the first kind, just make a note of which was chosen.
If your language supports large integers, find and show here, on this page, the maximum value of S1(n, k) where n == 100.
See also
Wikipedia - Stirling numbers of the first kind
OEIS:A008275 - Signed Stirling numbers of the first kind
OEIS:A130534 - Unsigned Stirling numbers of the first kind
Related Tasks
Stirling numbers of the second kind
Lah numbers
| #Wren | Wren | import "/big" for BigInt
import "/fmt" for Fmt
var computed = {}
var stirling1 // recursive
stirling1 = Fn.new { |n, k|
var key = "%(n),%(k)"
if (computed.containsKey(key)) return computed[key]
if (n == 0 && k == 0) return BigInt.one
if (n > 0 && k == 0) return BigInt.zero
if (k > n) return BigInt.zero
var result = stirling1.call(n-1, k-1) + stirling1.call(n-1, k)*(n-1)
computed[key] = result
return result
}
System.print("Unsigned Stirling numbers of the first kind:")
var max = 12
System.write("n/k")
for (n in 0..max) Fmt.write("$10d", n)
System.print()
for (n in 0..max) {
Fmt.write("$-3d", n)
for (k in 0..n) Fmt.write("$10i", stirling1.call(n, k))
System.print()
}
System.print("The maximum value of S1(100, k) =")
var previous = BigInt.zero
for (k in 1..100) {
var current = stirling1.call(100, k)
if (current > previous) {
previous = current
} else {
Fmt.print("$i\n($d digits, k = $d)", previous, previous.toString.count, k - 1)
break
}
} |
http://rosettacode.org/wiki/String_append | String append |
Basic Data Operation
This is a basic data operation. It represents a fundamental action on a basic data type.
You may see other such operations in the Basic Data Operations category, or:
Integer Operations
Arithmetic |
Comparison
Boolean Operations
Bitwise |
Logical
String Operations
Concatenation |
Interpolation |
Comparison |
Matching
Memory Operations
Pointers & references |
Addresses
Most languages provide a way to concatenate two string values, but some languages also provide a convenient way to append in-place to an existing string variable without referring to the variable twice.
Task
Create a string variable equal to any text value.
Append the string variable with another string literal in the most idiomatic way, without double reference if your language supports it.
Show the contents of the variable after the append operation.
| #Lua | Lua | function string:show ()
print(self)
end
function string:append (s)
self = self .. s
end
x = "Hi "
x:show()
x:append("there!")
x:show() |
http://rosettacode.org/wiki/String_append | String append |
Basic Data Operation
This is a basic data operation. It represents a fundamental action on a basic data type.
You may see other such operations in the Basic Data Operations category, or:
Integer Operations
Arithmetic |
Comparison
Boolean Operations
Bitwise |
Logical
String Operations
Concatenation |
Interpolation |
Comparison |
Matching
Memory Operations
Pointers & references |
Addresses
Most languages provide a way to concatenate two string values, but some languages also provide a convenient way to append in-place to an existing string variable without referring to the variable twice.
Task
Create a string variable equal to any text value.
Append the string variable with another string literal in the most idiomatic way, without double reference if your language supports it.
Show the contents of the variable after the append operation.
| #M2000_Interpreter | M2000 Interpreter |
a$="ok"
a$+="(one)"
Print a$
Document b$
b$="ok"
b$="(one)"
Print b$
|
http://rosettacode.org/wiki/Statistics/Normal_distribution | Statistics/Normal distribution | The Normal (or Gaussian) distribution is a frequently used distribution in statistics. While most programming languages provide a uniformly distributed random number generator, one can derive normally distributed random numbers from a uniform generator.
The task
Take a uniform random number generator and create a large (you decide how large) set of numbers that follow a normal (Gaussian) distribution. Calculate the dataset's mean and standard deviation, and show a histogram of the data.
Mention any native language support for the generation of normally distributed random numbers.
Reference
You may refer to code in Statistics/Basic if available.
| #J | J | runif01=: ?@$ 0: NB. random uniform number generator
rnorm01=. (2 o. 2p1 * runif01) * [: %: _2 * ^.@runif01 NB. random normal number generator (Box-Muller)
mean=: +/ % # NB. mean
stddev=: (<:@# %~ +/)&.:*:@(- mean) NB. standard deviation
histogram=: <:@(#/.~)@(i.@#@[ , I.) |
http://rosettacode.org/wiki/Statistics/Normal_distribution | Statistics/Normal distribution | The Normal (or Gaussian) distribution is a frequently used distribution in statistics. While most programming languages provide a uniformly distributed random number generator, one can derive normally distributed random numbers from a uniform generator.
The task
Take a uniform random number generator and create a large (you decide how large) set of numbers that follow a normal (Gaussian) distribution. Calculate the dataset's mean and standard deviation, and show a histogram of the data.
Mention any native language support for the generation of normally distributed random numbers.
Reference
You may refer to code in Statistics/Basic if available.
| #Java | Java | import static java.lang.Math.*;
import static java.util.Arrays.stream;
import java.util.Locale;
import java.util.function.DoubleSupplier;
import static java.util.stream.Collectors.joining;
import java.util.stream.DoubleStream;
import static java.util.stream.IntStream.range;
public class Test implements DoubleSupplier {
private double mu, sigma;
private double[] state = new double[2];
private int index = state.length;
Test(double m, double s) {
mu = m;
sigma = s;
}
static double[] meanStdDev(double[] numbers) {
if (numbers.length == 0)
return new double[]{0.0, 0.0};
double sx = 0.0, sxx = 0.0;
long n = 0;
for (double x : numbers) {
sx += x;
sxx += pow(x, 2);
n++;
}
return new double[]{sx / n, pow((n * sxx - pow(sx, 2)), 0.5) / n};
}
static String replicate(int n, String s) {
return range(0, n + 1).mapToObj(i -> s).collect(joining());
}
static void showHistogram01(double[] numbers) {
final int maxWidth = 50;
long[] bins = new long[10];
for (double x : numbers)
bins[(int) (x * bins.length)]++;
double maxFreq = stream(bins).max().getAsLong();
for (int i = 0; i < bins.length; i++)
System.out.printf(" %3.1f: %s%n", i / (double) bins.length,
replicate((int) (bins[i] / maxFreq * maxWidth), "*"));
System.out.println();
}
@Override
public double getAsDouble() {
index++;
if (index >= state.length) {
double r = sqrt(-2 * log(random())) * sigma;
double x = 2 * PI * random();
state = new double[]{mu + r * sin(x), mu + r * cos(x)};
index = 0;
}
return state[index];
}
public static void main(String[] args) {
Locale.setDefault(Locale.US);
double[] data = DoubleStream.generate(new Test(0.0, 0.5)).limit(100_000)
.toArray();
double[] res = meanStdDev(data);
System.out.printf("Mean: %8.6f, SD: %8.6f%n", res[0], res[1]);
showHistogram01(stream(data).map(a -> max(0.0, min(0.9999, a / 3 + 0.5)))
.toArray());
}
} |
http://rosettacode.org/wiki/Stem-and-leaf_plot | Stem-and-leaf plot | Create a well-formatted stem-and-leaf plot from the following data set, where the leaves are the last digits:
12 127 28 42 39 113 42 18 44 118 44 37 113 124 37 48 127 36 29 31 125 139 131 115 105 132 104 123 35 113 122 42 117 119 58 109 23 105 63 27 44 105 99 41 128 121 116 125 32 61 37 127 29 113 121 58 114 126 53 114 96 25 109 7 31 141 46 13 27 43 117 116 27 7 68 40 31 115 124 42 128 52 71 118 117 38 27 106 33 117 116 111 40 119 47 105 57 122 109 124 115 43 120 43 27 27 18 28 48 125 107 114 34 133 45 120 30 127 31 116 146
The primary intent of this task is the presentation of information. It is acceptable to hardcode the data set or characteristics of it (such as what the stems are) in the example, insofar as it is impractical to make the example generic to any data set. For example, in a computation-less language like HTML the data set may be entirely prearranged within the example; the interesting characteristics are how the proper visual formatting is arranged.
If possible, the output should not be a bitmap image. Monospaced plain text is acceptable, but do better if you can. It may be a window, i.e. not a file.
Note: If you wish to try multiple data sets, you might try this generator.
| #Clojure | Clojure | (def data
[12 127 28 42 39 113 42 18 44 118 44 37 113 124 37 48 127 36 29 31 125
139 131 115 105 132 104 123 35 113 122 42 117 119 58 109 23 105 63 27
44 105 99 41 128 121 116 125 32 61 37 127 29 113 121 58 114 126 53 114
96 25 109 7 31 141 46 13 27 43 117 116 27 7 68 40 31 115 124 42 128 146
52 71 118 117 38 27 106 33 117 116 111 40 119 47 105 57 122 109 124
115 43 120 43 27 27 18 28 48 125 107 114 34 133 45 120 30 127 31 116])
(defn calc-stem [number]
(int (Math/floor (/ number 10))))
(defn calc-leaf [number]
(mod number 10))
(defn new-plant
"Returns a leafless plant, with `size` empty branches,
i.e. a hash-map with integer keys (from 0 to `size` inclusive)
mapped to empty vectors.
(new-plant 2) ;=> {0 [] 1 [] 2 []}"
[size]
(let [end (inc size)]
(->> (repeat end [])
(interleave (range end))
(apply hash-map))))
(defn sprout-leaves
[plant [stem leaf]]
(update plant stem conj leaf))
(defn stem-and-leaf [numbers]
(let [max-stem (calc-stem (reduce max numbers))
baby-plant (new-plant max-stem)
plant (->> (map (juxt calc-stem calc-leaf) numbers)
(reduce sprout-leaves baby-plant)
(sort))]
(doseq [[stem leaves] plant]
(print (format (str "%2s") stem))
(print " | ")
(println (clojure.string/join " " (sort leaves))))))
(stem-and-leaf data)
|
http://rosettacode.org/wiki/Stern-Brocot_sequence | Stern-Brocot sequence | For this task, the Stern-Brocot sequence is to be generated by an algorithm similar to that employed in generating the Fibonacci sequence.
The first and second members of the sequence are both 1:
1, 1
Start by considering the second member of the sequence
Sum the considered member of the sequence and its precedent, (1 + 1) = 2, and append it to the end of the sequence:
1, 1, 2
Append the considered member of the sequence to the end of the sequence:
1, 1, 2, 1
Consider the next member of the series, (the third member i.e. 2)
GOTO 3
─── Expanding another loop we get: ───
Sum the considered member of the sequence and its precedent, (2 + 1) = 3, and append it to the end of the sequence:
1, 1, 2, 1, 3
Append the considered member of the sequence to the end of the sequence:
1, 1, 2, 1, 3, 2
Consider the next member of the series, (the fourth member i.e. 1)
The task is to
Create a function/method/subroutine/procedure/... to generate the Stern-Brocot sequence of integers using the method outlined above.
Show the first fifteen members of the sequence. (This should be: 1, 1, 2, 1, 3, 2, 3, 1, 4, 3, 5, 2, 5, 3, 4)
Show the (1-based) index of where the numbers 1-to-10 first appears in the sequence.
Show the (1-based) index of where the number 100 first appears in the sequence.
Check that the greatest common divisor of all the two consecutive members of the series up to the 1000th member, is always one.
Show your output on this page.
Related tasks
Fusc sequence.
Continued fraction/Arithmetic
Ref
Infinite Fractions - Numberphile (Video).
Trees, Teeth, and Time: The mathematics of clock making.
A002487 The On-Line Encyclopedia of Integer Sequences.
| #BCPL | BCPL | get "libhdr"
manifest $( AMOUNT = 1200 $)
let gcd(a,b) =
a>b -> gcd(a-b, b),
a<b -> gcd(a, b-a),
a
let mkstern(s, n) be
$( s!1 := 1
s!2 := 1
for i=2 to n/2 do
$( s!(i*2-1) := s!i + s!(i-1)
s!(i*2) := s!i
$)
$)
let find(v, n, max) = valof
for i=1 to max
if v!i=n then resultis i
let findwrite(v, n, max) be
writef("%I3 at %I4*N", n, find(v, n, max))
let start() be
$( let stern = vec AMOUNT
mkstern(stern, AMOUNT)
writes("First 15 numbers: ")
for i=1 to 15 do writef("%N ", stern!i)
writes("*N*NFirst occurrence:*N")
for i=1 to 10 do findwrite(stern, i, AMOUNT)
findwrite(stern, 100, AMOUNT)
if valof
$( for i=2 to AMOUNT
unless gcd(stern!i, stern!(i-1)) = 1
resultis false
resultis true
$) then
writes("*NThe GCD of each pair of consecutive members is 1.*N")
$) |
http://rosettacode.org/wiki/Stream_merge | Stream merge | 2-stream merge
Read two sorted streams of items from external source (e.g. disk, or network), and write one stream of sorted items to external sink.
Common algorithm: keep 1 buffered item from each source, select minimal of them, write it, fetch another item from that stream from which the written item was.
N-stream merge
The same as above, but reading from N sources.
Common algorithm: same as above, but keep buffered items and their source descriptors in a heap.
Assume streams are very big. You must not suck them whole in the memory, but read them as streams.
| #Sidef | Sidef | func merge_streams(streams) {
var s = streams.map { |stream|
Pair(stream, stream.readline)
}.grep {|p| defined(p.value) }
gather {
while (s) {
var p = s.min_by { .value }
take(p.value)
p.value = (p.key.readline \\ s.delete_if { _ == p })
}
}
}
say merge_streams(ARGV.map {|f| File(f).open_r }).join("\n") |
http://rosettacode.org/wiki/Stack_traces | Stack traces | Many programming languages allow for introspection of the current call stack environment. This can be for a variety of purposes such as enforcing security checks, debugging, or for getting access to the stack frame of callers.
Task
Print out (in a manner considered suitable for the platform) the current call stack.
The amount of information printed for each frame on the call stack is not constrained, but should include at least the name of the function or method at that level of the stack frame.
You may explicitly add a call to produce the stack trace to the (example) code being instrumented for examination.
The task should allow the program to continue after generating the stack trace.
The task report here must include the trace from a sample program.
| #Ada | Ada | with Ada.Text_IO; use Ada.Text_IO;
with GNAT.Traceback;
with GNAT.Traceback.Symbolic;
procedure Test_Stack_Trace is
procedure Call_Stack is
Trace : GNAT.Traceback.Tracebacks_Array (1..1_000);
Length : Natural;
begin
GNAT.Traceback.Call_Chain (Trace, Length);
Put_Line (GNAT.Traceback.Symbolic.Symbolic_Traceback (Trace (1..Length)));
end Call_Stack;
procedure Inner (K : Integer) is
begin
Call_Stack;
end Inner;
procedure Middle (X, Y : Integer) is
begin
Inner (X * Y);
end Middle;
procedure Outer (A, B, C : Integer) is
begin
Middle (A + B, B + C);
end Outer;
begin
Outer (2,3,5);
end Test_Stack_Trace; |
http://rosettacode.org/wiki/Stair-climbing_puzzle | Stair-climbing puzzle | From Chung-Chieh Shan (LtU):
Your stair-climbing robot has a very simple low-level API: the "step" function takes no argument and attempts to climb one step as a side effect. Unfortunately, sometimes the attempt fails and the robot clumsily falls one step instead. The "step" function detects what happens and returns a boolean flag: true on success, false on failure.
Write a function "step_up" that climbs one step up [from the initial position] (by repeating "step" attempts if necessary). Assume that the robot is not already at the top of the stairs, and neither does it ever reach the bottom of the stairs. How small can you make "step_up"? Can you avoid using variables (even immutable ones) and numbers?
Here's a pseudo-code of a simple recursive solution without using variables:
func step_up()
{
if not step() {
step_up();
step_up();
}
}
Inductive proof that step_up() steps up one step, if it terminates:
Base case (if the step() call returns true): it stepped up one step. QED
Inductive case (if the step() call returns false): Assume that recursive calls to step_up() step up one step. It stepped down one step (because step() returned false), but now we step up two steps using two step_up() calls. QED
The second (tail) recursion above can be turned into an iteration, as follows:
func step_up()
{
while not step() {
step_up();
}
}
| #11l | 11l | F step_up1()
V deficit = 1
L deficit > 0
I step()
deficit--
E
deficit++ |
http://rosettacode.org/wiki/State_name_puzzle | State name puzzle | Background
This task is inspired by Mark Nelson's DDJ Column "Wordplay" and one of the weekly puzzle challenges from Will Shortz on NPR Weekend Edition [1] and originally attributed to David Edelheit.
The challenge was to take the names of two U.S. States, mix them all together, then rearrange the letters to form the names of two different U.S. States (so that all four state names differ from one another).
What states are these?
The problem was reissued on the Unicon Discussion Web which includes several solutions with analysis. Several techniques may be helpful and you may wish to refer to Gödel numbering, equivalence relations, and equivalence classes. The basic merits of these were discussed in the Unicon Discussion Web.
A second challenge in the form of a set of fictitious new states was also presented.
Task
Write a program to solve the challenge using both the original list of states and the fictitious list.
Caveats
case and spacing aren't significant - just letters (harmonize case)
don't expect the names to be in any order - such as being sorted
don't rely on names to be unique (eliminate duplicates - meaning if Iowa appears twice you can only use it once)
Comma separated list of state names used in the original puzzle:
"Alabama", "Alaska", "Arizona", "Arkansas",
"California", "Colorado", "Connecticut", "Delaware",
"Florida", "Georgia", "Hawaii", "Idaho", "Illinois",
"Indiana", "Iowa", "Kansas", "Kentucky", "Louisiana",
"Maine", "Maryland", "Massachusetts", "Michigan",
"Minnesota", "Mississippi", "Missouri", "Montana",
"Nebraska", "Nevada", "New Hampshire", "New Jersey",
"New Mexico", "New York", "North Carolina", "North Dakota",
"Ohio", "Oklahoma", "Oregon", "Pennsylvania", "Rhode Island",
"South Carolina", "South Dakota", "Tennessee", "Texas",
"Utah", "Vermont", "Virginia",
"Washington", "West Virginia", "Wisconsin", "Wyoming"
Comma separated list of additional fictitious state names to be added to the original (Includes a duplicate):
"New Kory", "Wen Kory", "York New", "Kory New", "New Kory"
Other tasks related to string operations:
Metrics
Array length
String length
Copy a string
Empty string (assignment)
Counting
Word frequency
Letter frequency
Jewels and stones
I before E except after C
Bioinformatics/base count
Count occurrences of a substring
Count how many vowels and consonants occur in a string
Remove/replace
XXXX redacted
Conjugate a Latin verb
Remove vowels from a string
String interpolation (included)
Strip block comments
Strip comments from a string
Strip a set of characters from a string
Strip whitespace from a string -- top and tail
Strip control codes and extended characters from a string
Anagrams/Derangements/shuffling
Word wheel
ABC problem
Sattolo cycle
Knuth shuffle
Ordered words
Superpermutation minimisation
Textonyms (using a phone text pad)
Anagrams
Anagrams/Deranged anagrams
Permutations/Derangements
Find/Search/Determine
ABC words
Odd words
Word ladder
Semordnilap
Word search
Wordiff (game)
String matching
Tea cup rim text
Alternade words
Changeable words
State name puzzle
String comparison
Unique characters
Unique characters in each string
Extract file extension
Levenshtein distance
Palindrome detection
Common list elements
Longest common suffix
Longest common prefix
Compare a list of strings
Longest common substring
Find common directory path
Words from neighbour ones
Change e letters to i in words
Non-continuous subsequences
Longest common subsequence
Longest palindromic substrings
Longest increasing subsequence
Words containing "the" substring
Sum of the digits of n is substring of n
Determine if a string is numeric
Determine if a string is collapsible
Determine if a string is squeezable
Determine if a string has all unique characters
Determine if a string has all the same characters
Longest substrings without repeating characters
Find words which contains all the vowels
Find words which contains most consonants
Find words which contains more than 3 vowels
Find words which first and last three letters are equals
Find words which odd letters are consonants and even letters are vowels or vice_versa
Formatting
Substring
Rep-string
Word wrap
String case
Align columns
Literals/String
Repeat a string
Brace expansion
Brace expansion using ranges
Reverse a string
Phrase reversals
Comma quibbling
Special characters
String concatenation
Substring/Top and tail
Commatizing numbers
Reverse words in a string
Suffixation of decimal numbers
Long literals, with continuations
Numerical and alphabetical suffixes
Abbreviations, easy
Abbreviations, simple
Abbreviations, automatic
Song lyrics/poems/Mad Libs/phrases
Mad Libs
Magic 8-ball
99 Bottles of Beer
The Name Game (a song)
The Old lady swallowed a fly
The Twelve Days of Christmas
Tokenize
Text between
Tokenize a string
Word break problem
Tokenize a string with escaping
Split a character string based on change of character
Sequences
Show ASCII table
De Bruijn sequences
Self-referential sequences
Generate lower case ASCII alphabet
| #D | D | import std.stdio, std.algorithm, std.string, std.exception;
auto states = ["Alabama", "Alaska", "Arizona", "Arkansas",
"California", "Colorado", "Connecticut", "Delaware", "Florida",
"Georgia", "Hawaii", "Idaho", "Illinois", "Indiana", "Iowa", "Kansas",
"Kentucky", "Louisiana", "Maine", "Maryland", "Massachusetts",
"Michigan", "Minnesota", "Mississippi", "Missouri", "Montana",
"Nebraska", "Nevada", "New Hampshire", "New Jersey", "New Mexico",
"New York", "North Carolina", "North Dakota", "Ohio", "Oklahoma",
"Oregon", "Pennsylvania", "Rhode Island", "South Carolina",
"South Dakota", "Tennessee", "Texas", "Utah", "Vermont", "Virginia",
"Washington", "West Virginia", "Wisconsin", "Wyoming",
// Uncomment the next line for the fake states.
// "New Kory", "Wen Kory", "York New", "Kory New", "New Kory"
];
void main() {
states.length -= states.sort().uniq.copy(states).length;
string[][const ubyte[]] smap;
foreach (immutable i, s1; states[0 .. $ - 1])
foreach (s2; states[i + 1 .. $])
smap[(s1 ~ s2).dup.representation.sort().release.assumeUnique]
~= s1 ~ " + " ~ s2;
writefln("%-(%-(%s = %)\n%)",
smap.values.sort().filter!q{ a.length > 1 });
} |
http://rosettacode.org/wiki/Start_from_a_main_routine | Start from a main routine |
Some languages (like Gambas and Visual Basic) support two startup modes. Applications written in these languages start with an open window that waits for events, and it is necessary to do some trickery to cause a main procedure to run instead. Data driven or event driven languages may also require similar trickery to force a startup procedure to run.
Task
Demonstrate the steps involved in causing the application to run a main procedure, rather than an event driven window at startup.
Languages that always run from main() can be omitted from this task.
| #J | J | Welcome to Kotlin version 1.1.1 (JRE 1.8.0_121-b13)
Type :help for help, :quit for quit
>>> println("Look no main!")
Look no main!
>>> :quit
|
http://rosettacode.org/wiki/Start_from_a_main_routine | Start from a main routine |
Some languages (like Gambas and Visual Basic) support two startup modes. Applications written in these languages start with an open window that waits for events, and it is necessary to do some trickery to cause a main procedure to run instead. Data driven or event driven languages may also require similar trickery to force a startup procedure to run.
Task
Demonstrate the steps involved in causing the application to run a main procedure, rather than an event driven window at startup.
Languages that always run from main() can be omitted from this task.
| #Julia | Julia | Welcome to Kotlin version 1.1.1 (JRE 1.8.0_121-b13)
Type :help for help, :quit for quit
>>> println("Look no main!")
Look no main!
>>> :quit
|
http://rosettacode.org/wiki/Start_from_a_main_routine | Start from a main routine |
Some languages (like Gambas and Visual Basic) support two startup modes. Applications written in these languages start with an open window that waits for events, and it is necessary to do some trickery to cause a main procedure to run instead. Data driven or event driven languages may also require similar trickery to force a startup procedure to run.
Task
Demonstrate the steps involved in causing the application to run a main procedure, rather than an event driven window at startup.
Languages that always run from main() can be omitted from this task.
| #Kotlin | Kotlin | Welcome to Kotlin version 1.1.1 (JRE 1.8.0_121-b13)
Type :help for help, :quit for quit
>>> println("Look no main!")
Look no main!
>>> :quit
|
http://rosettacode.org/wiki/Start_from_a_main_routine | Start from a main routine |
Some languages (like Gambas and Visual Basic) support two startup modes. Applications written in these languages start with an open window that waits for events, and it is necessary to do some trickery to cause a main procedure to run instead. Data driven or event driven languages may also require similar trickery to force a startup procedure to run.
Task
Demonstrate the steps involved in causing the application to run a main procedure, rather than an event driven window at startup.
Languages that always run from main() can be omitted from this task.
| #Logtalk | Logtalk |
:- initialization(main).
|
http://rosettacode.org/wiki/Start_from_a_main_routine | Start from a main routine |
Some languages (like Gambas and Visual Basic) support two startup modes. Applications written in these languages start with an open window that waits for events, and it is necessary to do some trickery to cause a main procedure to run instead. Data driven or event driven languages may also require similar trickery to force a startup procedure to run.
Task
Demonstrate the steps involved in causing the application to run a main procedure, rather than an event driven window at startup.
Languages that always run from main() can be omitted from this task.
| #Mathematica.2FWolfram_Language | Mathematica/Wolfram Language | proc main() =
echo "Hello World!"
main()
|
http://rosettacode.org/wiki/Start_from_a_main_routine | Start from a main routine |
Some languages (like Gambas and Visual Basic) support two startup modes. Applications written in these languages start with an open window that waits for events, and it is necessary to do some trickery to cause a main procedure to run instead. Data driven or event driven languages may also require similar trickery to force a startup procedure to run.
Task
Demonstrate the steps involved in causing the application to run a main procedure, rather than an event driven window at startup.
Languages that always run from main() can be omitted from this task.
| #Nim | Nim | proc main() =
echo "Hello World!"
main()
|
http://rosettacode.org/wiki/Start_from_a_main_routine | Start from a main routine |
Some languages (like Gambas and Visual Basic) support two startup modes. Applications written in these languages start with an open window that waits for events, and it is necessary to do some trickery to cause a main procedure to run instead. Data driven or event driven languages may also require similar trickery to force a startup procedure to run.
Task
Demonstrate the steps involved in causing the application to run a main procedure, rather than an event driven window at startup.
Languages that always run from main() can be omitted from this task.
| #Oforth | Oforth | : main(n)
"Sleeping..." println
n sleep
"Awake and leaving." println ; |
http://rosettacode.org/wiki/Straddling_checkerboard | Straddling checkerboard | Task
Implement functions to encrypt and decrypt a message using the straddling checkerboard method. The checkerboard should take a 28 character alphabet (A-Z plus a full stop and an escape character) and two different numbers representing the blanks in the first row. The output will be a series of decimal digits.
Numbers should be encrypted by inserting the escape character before each digit, then including the digit unencrypted. This should be reversed for decryption.
| #REXX | REXX | /*REXX program uses the straddling checkerboard cipher to encrypt/decrypt a message. */
parse arg msg /*obtain optional message from the C.L.*/
if msg='' then msg= 'One night-it was the twentieth of March, 1888-I was returning'
say 'plain text=' msg
call genCipher 'et aon ris', 'bcdfghjklm', 'pq/uvwxyz.' /*build the cipher (board)*/
enc= encrypt(msg); say ' encrypted=' enc /*encrypt message and show encryption. */
dec= decrypt(enc); say ' decrypted=' dec /*decrypt " " " decryption. */
exit 0 /*stick a fork in it, we're all done. */
/*──────────────────────────────────────────────────────────────────────────────────────*/
genCipher: @.=; arg @..,two,three; z= -1; @.z= @.. /*build top row of cipher.*/
_= pos(' ', @.. ) - 1; @._= two /* " 2nd " " " */
_= pos(' ', @.., _+2) - 1; @._= three /* " 3rd " " " */
do j=0 for 9; @..= @.. || @.j /*construct a table for fast searching.*/
if @.j\=='' then @.r= @.r || j
_= pos('/', @.j) /*is the escape character in this row? */
if _\==0 then @.dig= j || (_-1) /*define " " for numerals.*/
end /*j*/
@..= space(@.., 0); return /*purify the table of encryptable chars*/
/*──────────────────────────────────────────────────────────────────────────────────────*/
encrypt: procedure expose @.; arg !,,$ /*$: output (encrypted text) so far.*/
do j=1 for length(!) /*process each of the plain─text chars.*/
x= substr(!, j, 1) /*obtain a message char to be encrypted*/
if datatype(x, 'W') then do; $= $ || @.dig || x; iterate; end /*numeral?*/
if pos(x, @..)==0 then iterate /*Not one of the allowable chars? Skip*/
do k=-1 for 10; y= pos(x, @.k) /*traipse thru rows, looking for match.*/
if y==0 then iterate /*Not in this row? Then keep looking.*/
z= k; if z==-1 then z= /*construct the index of the cypher row*/
$= $ || z || (y-1); leave /*add an encrypted character to output.*/
end /*k*/
end /*j*/; return $
/*──────────────────────────────────────────────────────────────────────────────────────*/
decrypt: procedure expose @.; parse arg !,,$ /*$: output (decrypted text) so far.*/
do j=1 to length(!); rw= -1 /*process each of the encypted numbers.*/
x= substr(!,j,1) /*obtain a message char to be decrypted*/
if substr(!,j,2)[email protected] then do; j= j+2; $= $ || substr(!, j, 1); iterate; end
if pos(x, @.r)\==0 then do; j= j+1; rw=x; x=substr(!, j, 1); end
$= $ || substr(@.rw, x+1, 1) /*add a character to decrypted message.*/
end /*j*/; return $ |
http://rosettacode.org/wiki/Stirling_numbers_of_the_first_kind | Stirling numbers of the first kind | Stirling numbers of the first kind, or Stirling cycle numbers, count permutations according to their number
of cycles (counting fixed points as cycles of length one).
They may be defined directly to be the number of permutations of n
elements with k disjoint cycles.
Stirling numbers of the first kind express coefficients of polynomial expansions of falling or rising factorials.
Depending on the application, Stirling numbers of the first kind may be "signed"
or "unsigned". Signed Stirling numbers of the first kind arise when the
polynomial expansion is expressed in terms of falling factorials; unsigned when
expressed in terms of rising factorials. The only substantial difference is that,
for signed Stirling numbers of the first kind, values of S1(n, k) are negative
when n + k is odd.
Stirling numbers of the first kind follow the simple identities:
S1(0, 0) = 1
S1(n, 0) = 0 if n > 0
S1(n, k) = 0 if k > n
S1(n, k) = S1(n - 1, k - 1) + (n - 1) * S1(n - 1, k) # For unsigned
or
S1(n, k) = S1(n - 1, k - 1) - (n - 1) * S1(n - 1, k) # For signed
Task
Write a routine (function, procedure, whatever) to find Stirling numbers of the first kind. There are several methods to generate Stirling numbers of the first kind. You are free to choose the most appropriate for your language. If your language has a built-in, or easily, publicly available library implementation, it is acceptable to use that.
Using the routine, generate and show here, on this page, a table (or triangle) showing the Stirling numbers of the first kind, S1(n, k), up to S1(12, 12). it is optional to show the row / column for n == 0 and k == 0. It is optional to show places where S1(n, k) == 0 (when k > n). You may choose to show signed or unsigned Stirling numbers of the first kind, just make a note of which was chosen.
If your language supports large integers, find and show here, on this page, the maximum value of S1(n, k) where n == 100.
See also
Wikipedia - Stirling numbers of the first kind
OEIS:A008275 - Signed Stirling numbers of the first kind
OEIS:A130534 - Unsigned Stirling numbers of the first kind
Related Tasks
Stirling numbers of the second kind
Lah numbers
| #zkl | zkl | fcn stirling1(n,k){
var seen=Dictionary(); // cache for recursion
if(n==k==0) return(1);
if(n==0 or k==0) return(0);
z1,z2 := "%d,%d".fmt(n-1,k-1), "%d,%d".fmt(n-1,k);
if(Void==(s1 := seen.find(z1))){ s1 = seen[z1] = stirling1(n - 1, k - 1) }
if(Void==(s2 := seen.find(z2))){ s2 = seen[z2] = stirling1(n - 1, k) }
(n - 1)*s2 + s1; // n is first to cast to BigInt (if using BigInts)
} |
http://rosettacode.org/wiki/String_append | String append |
Basic Data Operation
This is a basic data operation. It represents a fundamental action on a basic data type.
You may see other such operations in the Basic Data Operations category, or:
Integer Operations
Arithmetic |
Comparison
Boolean Operations
Bitwise |
Logical
String Operations
Concatenation |
Interpolation |
Comparison |
Matching
Memory Operations
Pointers & references |
Addresses
Most languages provide a way to concatenate two string values, but some languages also provide a convenient way to append in-place to an existing string variable without referring to the variable twice.
Task
Create a string variable equal to any text value.
Append the string variable with another string literal in the most idiomatic way, without double reference if your language supports it.
Show the contents of the variable after the append operation.
| #Maple | Maple | a := "Hello";
b := cat(a, " World");
c := `||`(a, " World"); |
http://rosettacode.org/wiki/String_append | String append |
Basic Data Operation
This is a basic data operation. It represents a fundamental action on a basic data type.
You may see other such operations in the Basic Data Operations category, or:
Integer Operations
Arithmetic |
Comparison
Boolean Operations
Bitwise |
Logical
String Operations
Concatenation |
Interpolation |
Comparison |
Matching
Memory Operations
Pointers & references |
Addresses
Most languages provide a way to concatenate two string values, but some languages also provide a convenient way to append in-place to an existing string variable without referring to the variable twice.
Task
Create a string variable equal to any text value.
Append the string variable with another string literal in the most idiomatic way, without double reference if your language supports it.
Show the contents of the variable after the append operation.
| #Mathematica.2FWolfram_Language | Mathematica/Wolfram Language | (* mutable strings are not supported *)
s1 = "testing";
s1 = s1 <> " 123";
s1 |
http://rosettacode.org/wiki/String_append | String append |
Basic Data Operation
This is a basic data operation. It represents a fundamental action on a basic data type.
You may see other such operations in the Basic Data Operations category, or:
Integer Operations
Arithmetic |
Comparison
Boolean Operations
Bitwise |
Logical
String Operations
Concatenation |
Interpolation |
Comparison |
Matching
Memory Operations
Pointers & references |
Addresses
Most languages provide a way to concatenate two string values, but some languages also provide a convenient way to append in-place to an existing string variable without referring to the variable twice.
Task
Create a string variable equal to any text value.
Append the string variable with another string literal in the most idiomatic way, without double reference if your language supports it.
Show the contents of the variable after the append operation.
| #min | min | (quote cons "" join) :str-append
"foo" "bar" str-append puts! |
http://rosettacode.org/wiki/Statistics/Normal_distribution | Statistics/Normal distribution | The Normal (or Gaussian) distribution is a frequently used distribution in statistics. While most programming languages provide a uniformly distributed random number generator, one can derive normally distributed random numbers from a uniform generator.
The task
Take a uniform random number generator and create a large (you decide how large) set of numbers that follow a normal (Gaussian) distribution. Calculate the dataset's mean and standard deviation, and show a histogram of the data.
Mention any native language support for the generation of normally distributed random numbers.
Reference
You may refer to code in Statistics/Basic if available.
| #jq | jq | cat /dev/urandom | tr -cd '0-9' | fold -w 10 |
jq -nRr -f normal-distribution.jq
|
http://rosettacode.org/wiki/Statistics/Normal_distribution | Statistics/Normal distribution | The Normal (or Gaussian) distribution is a frequently used distribution in statistics. While most programming languages provide a uniformly distributed random number generator, one can derive normally distributed random numbers from a uniform generator.
The task
Take a uniform random number generator and create a large (you decide how large) set of numbers that follow a normal (Gaussian) distribution. Calculate the dataset's mean and standard deviation, and show a histogram of the data.
Mention any native language support for the generation of normally distributed random numbers.
Reference
You may refer to code in Statistics/Basic if available.
| #Julia | Julia | using Printf, Distributions, Gadfly
data = rand(Normal(0, 1), 1000)
@printf("N = %i\n", length(data))
@printf("μ = %2.2f\tσ = %2.2f\n", mean(data), std(data))
@printf("range = (%2.2f, %2.2f\n)", minimum(data), maximum(data))
h = plot(x=data, Geom.histogram)
draw(PNG("norm_hist.png", 10cm, 10cm), h) |
http://rosettacode.org/wiki/Stem-and-leaf_plot | Stem-and-leaf plot | Create a well-formatted stem-and-leaf plot from the following data set, where the leaves are the last digits:
12 127 28 42 39 113 42 18 44 118 44 37 113 124 37 48 127 36 29 31 125 139 131 115 105 132 104 123 35 113 122 42 117 119 58 109 23 105 63 27 44 105 99 41 128 121 116 125 32 61 37 127 29 113 121 58 114 126 53 114 96 25 109 7 31 141 46 13 27 43 117 116 27 7 68 40 31 115 124 42 128 52 71 118 117 38 27 106 33 117 116 111 40 119 47 105 57 122 109 124 115 43 120 43 27 27 18 28 48 125 107 114 34 133 45 120 30 127 31 116 146
The primary intent of this task is the presentation of information. It is acceptable to hardcode the data set or characteristics of it (such as what the stems are) in the example, insofar as it is impractical to make the example generic to any data set. For example, in a computation-less language like HTML the data set may be entirely prearranged within the example; the interesting characteristics are how the proper visual formatting is arranged.
If possible, the output should not be a bitmap image. Monospaced plain text is acceptable, but do better if you can. It may be a window, i.e. not a file.
Note: If you wish to try multiple data sets, you might try this generator.
| #D | D | import std.stdio, std.algorithm;
void main() {
enum data = [12,127,28,42,39,113,42,18,44,118,44,37,113,124,37,48,
127,36,29,31,125,139,131,115,105,132,104,123,35,113,122,42,117,
119,58,109,23,105,63,27,44,105,99,41,128,121,116,125,32,61,37,
127,29,113,121,58,114,126,53,114,96,25,109,7,31,141,46,13,27,
43,117,116,27,7,68,40,31,115,124,42,128,52,71,118,117,38,27,
106,33,117,116,111,40,119,47,105,57,122,109,124,115,43,120,43,
27,27,18,28,48,125,107,114,34,133,45,120,30,127,31,116,146];
int[][int] histo;
foreach (x; data)
histo[x / 10] ~= x % 10;
immutable loHi = data.reduce!(min, max);
foreach (i; loHi[0]/10 .. loHi[1]/10 + 1)
writefln("%2d | %(%d %) ", i, histo.get(i, []).sort());
} |
http://rosettacode.org/wiki/Stern-Brocot_sequence | Stern-Brocot sequence | For this task, the Stern-Brocot sequence is to be generated by an algorithm similar to that employed in generating the Fibonacci sequence.
The first and second members of the sequence are both 1:
1, 1
Start by considering the second member of the sequence
Sum the considered member of the sequence and its precedent, (1 + 1) = 2, and append it to the end of the sequence:
1, 1, 2
Append the considered member of the sequence to the end of the sequence:
1, 1, 2, 1
Consider the next member of the series, (the third member i.e. 2)
GOTO 3
─── Expanding another loop we get: ───
Sum the considered member of the sequence and its precedent, (2 + 1) = 3, and append it to the end of the sequence:
1, 1, 2, 1, 3
Append the considered member of the sequence to the end of the sequence:
1, 1, 2, 1, 3, 2
Consider the next member of the series, (the fourth member i.e. 1)
The task is to
Create a function/method/subroutine/procedure/... to generate the Stern-Brocot sequence of integers using the method outlined above.
Show the first fifteen members of the sequence. (This should be: 1, 1, 2, 1, 3, 2, 3, 1, 4, 3, 5, 2, 5, 3, 4)
Show the (1-based) index of where the numbers 1-to-10 first appears in the sequence.
Show the (1-based) index of where the number 100 first appears in the sequence.
Check that the greatest common divisor of all the two consecutive members of the series up to the 1000th member, is always one.
Show your output on this page.
Related tasks
Fusc sequence.
Continued fraction/Arithmetic
Ref
Infinite Fractions - Numberphile (Video).
Trees, Teeth, and Time: The mathematics of clock making.
A002487 The On-Line Encyclopedia of Integer Sequences.
| #C | C | #include <stdio.h>
typedef unsigned int uint;
/* the sequence, 0-th member is 0 */
uint f(uint n)
{
return n < 2 ? n : (n&1) ? f(n/2) + f(n/2 + 1) : f(n/2);
}
uint gcd(uint a, uint b)
{
return a ? a < b ? gcd(b%a, a) : gcd(a%b, b) : b;
}
void find(uint from, uint to)
{
do {
uint n;
for (n = 1; f(n) != from ; n++);
printf("%3u at Stern #%u.\n", from, n);
} while (++from <= to);
}
int main(void)
{
uint n;
for (n = 1; n < 16; n++) printf("%u ", f(n));
puts("are the first fifteen.");
find(1, 10);
find(100, 0);
for (n = 1; n < 1000 && gcd(f(n), f(n+1)) == 1; n++);
printf(n == 1000 ? "All GCDs are 1.\n" : "GCD of #%d and #%d is not 1", n, n+1);
return 0;
} |
http://rosettacode.org/wiki/Stream_merge | Stream merge | 2-stream merge
Read two sorted streams of items from external source (e.g. disk, or network), and write one stream of sorted items to external sink.
Common algorithm: keep 1 buffered item from each source, select minimal of them, write it, fetch another item from that stream from which the written item was.
N-stream merge
The same as above, but reading from N sources.
Common algorithm: same as above, but keep buffered items and their source descriptors in a heap.
Assume streams are very big. You must not suck them whole in the memory, but read them as streams.
| #Tcl | Tcl | #!/usr/bin/env tclsh
proc merge {args} {
set peeks {}
foreach chan $args {
if {[gets $chan peek] > 0} {
dict set peeks $chan $peek
}
}
set peeks [lsort -stride 2 -index 1 $peeks]
while {[dict size $peeks]} {
set peeks [lassign $peeks chan peek]
puts $peek
if {[gets $chan peek] > 0} {
dict set peeks $chan $peek
set peeks [lsort -stride 2 -index 1 $peeks]
}
}
}
merge {*}[lmap f $::argv {open $f r}]
|
http://rosettacode.org/wiki/Stack_traces | Stack traces | Many programming languages allow for introspection of the current call stack environment. This can be for a variety of purposes such as enforcing security checks, debugging, or for getting access to the stack frame of callers.
Task
Print out (in a manner considered suitable for the platform) the current call stack.
The amount of information printed for each frame on the call stack is not constrained, but should include at least the name of the function or method at that level of the stack frame.
You may explicitly add a call to produce the stack trace to the (example) code being instrumented for examination.
The task should allow the program to continue after generating the stack trace.
The task report here must include the trace from a sample program.
| #AutoHotkey | AutoHotkey | f()
return
f()
{
return g()
}
g()
{
ListLines
msgbox, lines recently executed
x = local to g
ListVars
msgbox, variable bindings
}
#Persistent |
http://rosettacode.org/wiki/Stack_traces | Stack traces | Many programming languages allow for introspection of the current call stack environment. This can be for a variety of purposes such as enforcing security checks, debugging, or for getting access to the stack frame of callers.
Task
Print out (in a manner considered suitable for the platform) the current call stack.
The amount of information printed for each frame on the call stack is not constrained, but should include at least the name of the function or method at that level of the stack frame.
You may explicitly add a call to produce the stack trace to the (example) code being instrumented for examination.
The task should allow the program to continue after generating the stack trace.
The task report here must include the trace from a sample program.
| #BASIC | BASIC | 100 DEF PROC callstack
110 ON ERROR GOTO 1000
120 FOR i=1 TO 100
130 POP lnum
140 LIST lnum TO lnum
150 NEXT i
190 END PROC
1000 PRINT "End of stack"
1010 STOP
|
http://rosettacode.org/wiki/Stack_traces | Stack traces | Many programming languages allow for introspection of the current call stack environment. This can be for a variety of purposes such as enforcing security checks, debugging, or for getting access to the stack frame of callers.
Task
Print out (in a manner considered suitable for the platform) the current call stack.
The amount of information printed for each frame on the call stack is not constrained, but should include at least the name of the function or method at that level of the stack frame.
You may explicitly add a call to produce the stack trace to the (example) code being instrumented for examination.
The task should allow the program to continue after generating the stack trace.
The task report here must include the trace from a sample program.
| #C | C | #include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <execinfo.h>
#define MAX_BT 200
void print_stack_trace()
{
void *buffer[MAX_BT];
int n;
n = backtrace(buffer, MAX_BT);
fprintf(stderr, "--- (depth %d) ---\n", n);
backtrace_symbols_fd(buffer, n, STDERR_FILENO);
}
void inner(int k)
{
print_stack_trace();
}
void middle(int x, int y)
{
inner(x*y);
}
void outer(int a, int b, int c)
{
middle(a+b, b+c);
}
int main()
{
outer(2,3,5);
return EXIT_SUCCESS;
} |
http://rosettacode.org/wiki/Stair-climbing_puzzle | Stair-climbing puzzle | From Chung-Chieh Shan (LtU):
Your stair-climbing robot has a very simple low-level API: the "step" function takes no argument and attempts to climb one step as a side effect. Unfortunately, sometimes the attempt fails and the robot clumsily falls one step instead. The "step" function detects what happens and returns a boolean flag: true on success, false on failure.
Write a function "step_up" that climbs one step up [from the initial position] (by repeating "step" attempts if necessary). Assume that the robot is not already at the top of the stairs, and neither does it ever reach the bottom of the stairs. How small can you make "step_up"? Can you avoid using variables (even immutable ones) and numbers?
Here's a pseudo-code of a simple recursive solution without using variables:
func step_up()
{
if not step() {
step_up();
step_up();
}
}
Inductive proof that step_up() steps up one step, if it terminates:
Base case (if the step() call returns true): it stepped up one step. QED
Inductive case (if the step() call returns false): Assume that recursive calls to step_up() step up one step. It stepped down one step (because step() returned false), but now we step up two steps using two step_up() calls. QED
The second (tail) recursion above can be turned into an iteration, as follows:
func step_up()
{
while not step() {
step_up();
}
}
| #ActionScript | ActionScript | function stepUp()
{
var i:int = 0;
while(i < 1)
if(step())i++;
else i--;
} |
http://rosettacode.org/wiki/Stair-climbing_puzzle | Stair-climbing puzzle | From Chung-Chieh Shan (LtU):
Your stair-climbing robot has a very simple low-level API: the "step" function takes no argument and attempts to climb one step as a side effect. Unfortunately, sometimes the attempt fails and the robot clumsily falls one step instead. The "step" function detects what happens and returns a boolean flag: true on success, false on failure.
Write a function "step_up" that climbs one step up [from the initial position] (by repeating "step" attempts if necessary). Assume that the robot is not already at the top of the stairs, and neither does it ever reach the bottom of the stairs. How small can you make "step_up"? Can you avoid using variables (even immutable ones) and numbers?
Here's a pseudo-code of a simple recursive solution without using variables:
func step_up()
{
if not step() {
step_up();
step_up();
}
}
Inductive proof that step_up() steps up one step, if it terminates:
Base case (if the step() call returns true): it stepped up one step. QED
Inductive case (if the step() call returns false): Assume that recursive calls to step_up() step up one step. It stepped down one step (because step() returned false), but now we step up two steps using two step_up() calls. QED
The second (tail) recursion above can be turned into an iteration, as follows:
func step_up()
{
while not step() {
step_up();
}
}
| #Ada | Ada | procedure Step_Up is
begin
while not Step loop
Step_Up;
end loop;
end Step_Up; |
http://rosettacode.org/wiki/State_name_puzzle | State name puzzle | Background
This task is inspired by Mark Nelson's DDJ Column "Wordplay" and one of the weekly puzzle challenges from Will Shortz on NPR Weekend Edition [1] and originally attributed to David Edelheit.
The challenge was to take the names of two U.S. States, mix them all together, then rearrange the letters to form the names of two different U.S. States (so that all four state names differ from one another).
What states are these?
The problem was reissued on the Unicon Discussion Web which includes several solutions with analysis. Several techniques may be helpful and you may wish to refer to Gödel numbering, equivalence relations, and equivalence classes. The basic merits of these were discussed in the Unicon Discussion Web.
A second challenge in the form of a set of fictitious new states was also presented.
Task
Write a program to solve the challenge using both the original list of states and the fictitious list.
Caveats
case and spacing aren't significant - just letters (harmonize case)
don't expect the names to be in any order - such as being sorted
don't rely on names to be unique (eliminate duplicates - meaning if Iowa appears twice you can only use it once)
Comma separated list of state names used in the original puzzle:
"Alabama", "Alaska", "Arizona", "Arkansas",
"California", "Colorado", "Connecticut", "Delaware",
"Florida", "Georgia", "Hawaii", "Idaho", "Illinois",
"Indiana", "Iowa", "Kansas", "Kentucky", "Louisiana",
"Maine", "Maryland", "Massachusetts", "Michigan",
"Minnesota", "Mississippi", "Missouri", "Montana",
"Nebraska", "Nevada", "New Hampshire", "New Jersey",
"New Mexico", "New York", "North Carolina", "North Dakota",
"Ohio", "Oklahoma", "Oregon", "Pennsylvania", "Rhode Island",
"South Carolina", "South Dakota", "Tennessee", "Texas",
"Utah", "Vermont", "Virginia",
"Washington", "West Virginia", "Wisconsin", "Wyoming"
Comma separated list of additional fictitious state names to be added to the original (Includes a duplicate):
"New Kory", "Wen Kory", "York New", "Kory New", "New Kory"
Other tasks related to string operations:
Metrics
Array length
String length
Copy a string
Empty string (assignment)
Counting
Word frequency
Letter frequency
Jewels and stones
I before E except after C
Bioinformatics/base count
Count occurrences of a substring
Count how many vowels and consonants occur in a string
Remove/replace
XXXX redacted
Conjugate a Latin verb
Remove vowels from a string
String interpolation (included)
Strip block comments
Strip comments from a string
Strip a set of characters from a string
Strip whitespace from a string -- top and tail
Strip control codes and extended characters from a string
Anagrams/Derangements/shuffling
Word wheel
ABC problem
Sattolo cycle
Knuth shuffle
Ordered words
Superpermutation minimisation
Textonyms (using a phone text pad)
Anagrams
Anagrams/Deranged anagrams
Permutations/Derangements
Find/Search/Determine
ABC words
Odd words
Word ladder
Semordnilap
Word search
Wordiff (game)
String matching
Tea cup rim text
Alternade words
Changeable words
State name puzzle
String comparison
Unique characters
Unique characters in each string
Extract file extension
Levenshtein distance
Palindrome detection
Common list elements
Longest common suffix
Longest common prefix
Compare a list of strings
Longest common substring
Find common directory path
Words from neighbour ones
Change e letters to i in words
Non-continuous subsequences
Longest common subsequence
Longest palindromic substrings
Longest increasing subsequence
Words containing "the" substring
Sum of the digits of n is substring of n
Determine if a string is numeric
Determine if a string is collapsible
Determine if a string is squeezable
Determine if a string has all unique characters
Determine if a string has all the same characters
Longest substrings without repeating characters
Find words which contains all the vowels
Find words which contains most consonants
Find words which contains more than 3 vowels
Find words which first and last three letters are equals
Find words which odd letters are consonants and even letters are vowels or vice_versa
Formatting
Substring
Rep-string
Word wrap
String case
Align columns
Literals/String
Repeat a string
Brace expansion
Brace expansion using ranges
Reverse a string
Phrase reversals
Comma quibbling
Special characters
String concatenation
Substring/Top and tail
Commatizing numbers
Reverse words in a string
Suffixation of decimal numbers
Long literals, with continuations
Numerical and alphabetical suffixes
Abbreviations, easy
Abbreviations, simple
Abbreviations, automatic
Song lyrics/poems/Mad Libs/phrases
Mad Libs
Magic 8-ball
99 Bottles of Beer
The Name Game (a song)
The Old lady swallowed a fly
The Twelve Days of Christmas
Tokenize
Text between
Tokenize a string
Word break problem
Tokenize a string with escaping
Split a character string based on change of character
Sequences
Show ASCII table
De Bruijn sequences
Self-referential sequences
Generate lower case ASCII alphabet
| #Go | Go | package main
import (
"fmt"
"unicode"
)
var states = []string{"Alabama", "Alaska", "Arizona", "Arkansas",
"California", "Colorado", "Connecticut",
"Delaware",
"Florida", "Georgia", "Hawaii",
"Idaho", "Illinois", "Indiana", "Iowa",
"Kansas", "Kentucky", "Louisiana",
"Maine", "Maryland", "Massachusetts", "Michigan",
"Minnesota", "Mississippi", "Missouri", "Montana",
"Nebraska", "Nevada", "New Hampshire", "New Jersey",
"New Mexico", "New York", "North Carolina", "North Dakota",
"Ohio", "Oklahoma", "Oregon",
"Pennsylvania", "Rhode Island",
"South Carolina", "South Dakota", "Tennessee", "Texas",
"Utah", "Vermont", "Virginia",
"Washington", "West Virginia", "Wisconsin", "Wyoming"}
func main() {
play(states)
play(append(states,
"New Kory", "Wen Kory", "York New", "Kory New", "New Kory"))
}
func play(states []string) {
fmt.Println(len(states), "states:")
// get list of unique state names
set := make(map[string]bool, len(states))
for _, s := range states {
set[s] = true
}
// make parallel arrays for unique state names and letter histograms
s := make([]string, len(set))
h := make([][26]byte, len(set))
var i int
for us := range set {
s[i] = us
for _, c := range us {
if u := uint(unicode.ToLower(c)) - 'a'; u < 26 {
h[i][u]++
}
}
i++
}
// use map to find matches. map key is sum of histograms of
// two different states. map value is indexes of the two states.
type pair struct {
i1, i2 int
}
m := make(map[string][]pair)
b := make([]byte, 26) // buffer for summing histograms
for i1, h1 := range h {
for i2 := i1 + 1; i2 < len(h); i2++ {
// sum histograms
for i := range b {
b[i] = h1[i] + h[i2][i]
}
k := string(b) // make key from buffer.
// now loop over any existing pairs with the same key,
// printing any where both states of this pair are different
// than the states of the existing pair
for _, x := range m[k] {
if i1 != x.i1 && i1 != x.i2 && i2 != x.i1 && i2 != x.i2 {
fmt.Printf("%s, %s = %s, %s\n", s[i1], s[i2],
s[x.i1], s[x.i2])
}
}
// store this pair in the map whether printed or not.
m[k] = append(m[k], pair{i1, i2})
}
}
} |
http://rosettacode.org/wiki/Start_from_a_main_routine | Start from a main routine |
Some languages (like Gambas and Visual Basic) support two startup modes. Applications written in these languages start with an open window that waits for events, and it is necessary to do some trickery to cause a main procedure to run instead. Data driven or event driven languages may also require similar trickery to force a startup procedure to run.
Task
Demonstrate the steps involved in causing the application to run a main procedure, rather than an event driven window at startup.
Languages that always run from main() can be omitted from this task.
| #PARI.2FGP | PARI/GP | BEGIN {...} # as soon as parsed
CHECK {...} # end of compile time
INIT {...} # beginning of run time
END {...} # end of run time |
http://rosettacode.org/wiki/Start_from_a_main_routine | Start from a main routine |
Some languages (like Gambas and Visual Basic) support two startup modes. Applications written in these languages start with an open window that waits for events, and it is necessary to do some trickery to cause a main procedure to run instead. Data driven or event driven languages may also require similar trickery to force a startup procedure to run.
Task
Demonstrate the steps involved in causing the application to run a main procedure, rather than an event driven window at startup.
Languages that always run from main() can be omitted from this task.
| #Pascal | Pascal | BEGIN {...} # as soon as parsed
CHECK {...} # end of compile time
INIT {...} # beginning of run time
END {...} # end of run time |
http://rosettacode.org/wiki/Start_from_a_main_routine | Start from a main routine |
Some languages (like Gambas and Visual Basic) support two startup modes. Applications written in these languages start with an open window that waits for events, and it is necessary to do some trickery to cause a main procedure to run instead. Data driven or event driven languages may also require similar trickery to force a startup procedure to run.
Task
Demonstrate the steps involved in causing the application to run a main procedure, rather than an event driven window at startup.
Languages that always run from main() can be omitted from this task.
| #Perl | Perl | BEGIN {...} # as soon as parsed
CHECK {...} # end of compile time
INIT {...} # beginning of run time
END {...} # end of run time |
http://rosettacode.org/wiki/Start_from_a_main_routine | Start from a main routine |
Some languages (like Gambas and Visual Basic) support two startup modes. Applications written in these languages start with an open window that waits for events, and it is necessary to do some trickery to cause a main procedure to run instead. Data driven or event driven languages may also require similar trickery to force a startup procedure to run.
Task
Demonstrate the steps involved in causing the application to run a main procedure, rather than an event driven window at startup.
Languages that always run from main() can be omitted from this task.
| #Phix | Phix | procedure main()
...
end procedure
main()
|
http://rosettacode.org/wiki/Start_from_a_main_routine | Start from a main routine |
Some languages (like Gambas and Visual Basic) support two startup modes. Applications written in these languages start with an open window that waits for events, and it is necessary to do some trickery to cause a main procedure to run instead. Data driven or event driven languages may also require similar trickery to force a startup procedure to run.
Task
Demonstrate the steps involved in causing the application to run a main procedure, rather than an event driven window at startup.
Languages that always run from main() can be omitted from this task.
| #PicoLisp | PicoLisp | println("hello world");
line(0, 0, width, height); |
http://rosettacode.org/wiki/Straddling_checkerboard | Straddling checkerboard | Task
Implement functions to encrypt and decrypt a message using the straddling checkerboard method. The checkerboard should take a 28 character alphabet (A-Z plus a full stop and an escape character) and two different numbers representing the blanks in the first row. The output will be a series of decimal digits.
Numbers should be encrypted by inserting the escape character before each digit, then including the digit unencrypted. This should be reversed for decryption.
| #Ruby | Ruby | class StraddlingCheckerboard
EncodableChars = "A-Z0-9."
SortedChars = " ./" + [*"A".."Z"].join
def initialize(board = nil)
if board.nil?
# create a new random board
rest = "BCDFGHJKLMPQUVWXYZ/.".chars.shuffle
@board = [" ESTONIAR".chars.shuffle, rest[0..9], rest[10..19]]
elsif board.chars.sort.join == SortedChars
@board = board.chars.each_slice(10).to_a
else
raise ArgumentError, "invalid #{self.class}: #{board}"
end
# find the indices of the first row blanks
@row_labels = @board[0].each_with_index.select {|v, i| v == " "}.map {|v,i| i}
@mapping = {}
@board[0].each_with_index {|char, idx| @mapping[char] = idx.to_s unless char == " "}
@board[1..2].each_with_index do |row, row_idx|
row.each_with_index do |char, idx|
@mapping[char] = "%d%d" % [@row_labels[row_idx], idx]
end
end
end
def encode(message)
msg = message.upcase.delete("^#{EncodableChars}")
msg.chars.inject("") do |crypt, char|
crypt << (char =~ /[0-9]/ ? @mapping["/"] + char : @mapping[char])
end
end
def decode(code)
msg = ""
tokens = code.chars
until tokens.empty?
token = tokens.shift
itoken = token.to_i
unless @row_labels.include?(itoken)
msg << @board[0][itoken]
else
token2 = tokens.shift
if @mapping["/"] == token + token2
msg << tokens.shift
else
msg << @board[1+@row_labels.index(itoken)][token2.to_i]
end
end
end
msg
end
def to_s
@board.inject("") {|res, row| res << row.join}
end
def inspect
"#<%s board=%p, row_labels=%p, mapping=%p>" % [self.class, to_s, @row_labels, @mapping]
end
end |
http://rosettacode.org/wiki/String_append | String append |
Basic Data Operation
This is a basic data operation. It represents a fundamental action on a basic data type.
You may see other such operations in the Basic Data Operations category, or:
Integer Operations
Arithmetic |
Comparison
Boolean Operations
Bitwise |
Logical
String Operations
Concatenation |
Interpolation |
Comparison |
Matching
Memory Operations
Pointers & references |
Addresses
Most languages provide a way to concatenate two string values, but some languages also provide a convenient way to append in-place to an existing string variable without referring to the variable twice.
Task
Create a string variable equal to any text value.
Append the string variable with another string literal in the most idiomatic way, without double reference if your language supports it.
Show the contents of the variable after the append operation.
| #MontiLang | MontiLang | |Hello | |world!| swap + print |
http://rosettacode.org/wiki/String_append | String append |
Basic Data Operation
This is a basic data operation. It represents a fundamental action on a basic data type.
You may see other such operations in the Basic Data Operations category, or:
Integer Operations
Arithmetic |
Comparison
Boolean Operations
Bitwise |
Logical
String Operations
Concatenation |
Interpolation |
Comparison |
Matching
Memory Operations
Pointers & references |
Addresses
Most languages provide a way to concatenate two string values, but some languages also provide a convenient way to append in-place to an existing string variable without referring to the variable twice.
Task
Create a string variable equal to any text value.
Append the string variable with another string literal in the most idiomatic way, without double reference if your language supports it.
Show the contents of the variable after the append operation.
| #Nanoquery | Nanoquery | s1 = "this is"
s1 += " a test"
println s1 |
http://rosettacode.org/wiki/String_append | String append |
Basic Data Operation
This is a basic data operation. It represents a fundamental action on a basic data type.
You may see other such operations in the Basic Data Operations category, or:
Integer Operations
Arithmetic |
Comparison
Boolean Operations
Bitwise |
Logical
String Operations
Concatenation |
Interpolation |
Comparison |
Matching
Memory Operations
Pointers & references |
Addresses
Most languages provide a way to concatenate two string values, but some languages also provide a convenient way to append in-place to an existing string variable without referring to the variable twice.
Task
Create a string variable equal to any text value.
Append the string variable with another string literal in the most idiomatic way, without double reference if your language supports it.
Show the contents of the variable after the append operation.
| #Neko | Neko | /**
<doc><p>String append in Neko</pre></doc>
**/
var str = "Hello"
str += ", world"
$print(str, "\n") |
http://rosettacode.org/wiki/Statistics/Normal_distribution | Statistics/Normal distribution | The Normal (or Gaussian) distribution is a frequently used distribution in statistics. While most programming languages provide a uniformly distributed random number generator, one can derive normally distributed random numbers from a uniform generator.
The task
Take a uniform random number generator and create a large (you decide how large) set of numbers that follow a normal (Gaussian) distribution. Calculate the dataset's mean and standard deviation, and show a histogram of the data.
Mention any native language support for the generation of normally distributed random numbers.
Reference
You may refer to code in Statistics/Basic if available.
| #Kotlin | Kotlin | // version 1.1.2
val rand = java.util.Random()
fun normalStats(sampleSize: Int) {
if (sampleSize < 1) return
val r = DoubleArray(sampleSize)
val h = IntArray(12) // all zero by default
/*
Generate 'sampleSize' normally distributed random numbers with mean 0.5 and SD 0.25
and calculate in which box they will fall when drawing the histogram
*/
for (i in 0 until sampleSize) {
r[i] = 0.5 + rand.nextGaussian() / 4.0
when {
r[i] < 0.0 -> h[0]++
r[i] >= 1.0 -> h[11]++
else -> h[1 + (r[i] * 10).toInt()]++
}
}
// adjust one of the h[] values if necessary to ensure they sum to sampleSize
val adj = sampleSize - h.sum()
if (adj != 0) {
for (i in 0..11) {
h[i] += adj
if (h[i] >= 0) break
h[i] -= adj
}
}
val mean = r.average()
val sd = Math.sqrt(r.map { (it - mean) * (it - mean) }.average())
// Draw a histogram of the data with interval 0.1
var numStars: Int
// If sample size > 300 then normalize histogram to 300
val scale = if (sampleSize <= 300) 1.0 else 300.0 / sampleSize
println("Sample size $sampleSize\n")
println(" Mean ${"%1.6f".format(mean)} SD ${"%1.6f".format(sd)}\n")
for (i in 0..11) {
when (i) {
0 -> print("< 0.00 : ")
11 -> print(">=1.00 : ")
else -> print(" %1.2f : ".format(i / 10.0))
}
print("%5d ".format(h[i]))
numStars = (h[i] * scale + 0.5).toInt()
println("*".repeat(numStars))
}
println()
}
fun main(args: Array<String>) {
val sampleSizes = intArrayOf(100, 1_000, 10_000, 100_000)
for (sampleSize in sampleSizes) normalStats(sampleSize)
} |
http://rosettacode.org/wiki/Stem-and-leaf_plot | Stem-and-leaf plot | Create a well-formatted stem-and-leaf plot from the following data set, where the leaves are the last digits:
12 127 28 42 39 113 42 18 44 118 44 37 113 124 37 48 127 36 29 31 125 139 131 115 105 132 104 123 35 113 122 42 117 119 58 109 23 105 63 27 44 105 99 41 128 121 116 125 32 61 37 127 29 113 121 58 114 126 53 114 96 25 109 7 31 141 46 13 27 43 117 116 27 7 68 40 31 115 124 42 128 52 71 118 117 38 27 106 33 117 116 111 40 119 47 105 57 122 109 124 115 43 120 43 27 27 18 28 48 125 107 114 34 133 45 120 30 127 31 116 146
The primary intent of this task is the presentation of information. It is acceptable to hardcode the data set or characteristics of it (such as what the stems are) in the example, insofar as it is impractical to make the example generic to any data set. For example, in a computation-less language like HTML the data set may be entirely prearranged within the example; the interesting characteristics are how the proper visual formatting is arranged.
If possible, the output should not be a bitmap image. Monospaced plain text is acceptable, but do better if you can. It may be a window, i.e. not a file.
Note: If you wish to try multiple data sets, you might try this generator.
| #Elixir | Elixir | defmodule Stem_and_leaf do
def plot(data, leaf_digits\\1) do
multiplier = Enum.reduce(1..leaf_digits, 1, fn _,acc -> acc*10 end)
Enum.group_by(data, fn x -> div(x, multiplier) end)
|> Map.new(fn {k,v} -> {k, Enum.map(v, &rem(&1, multiplier)) |> Enum.sort} end)
|> print(leaf_digits)
end
defp print(plot_data, leaf_digits) do
{min, max} = Map.keys(plot_data) |> Enum.min_max
stem_width = length(to_charlist(max))
fmt = "~#{stem_width}w | ~s~n"
Enum.each(min..max, fn stem ->
leaves = Enum.map_join(Map.get(plot_data, stem, []), " ", fn leaf ->
to_string(leaf) |> String.pad_leading(leaf_digits)
end)
:io.format fmt, [stem, leaves]
end)
end
end
data = ~w(12 127 28 42 39 113 42 18 44 118 44 37 113 124 37 48 127 36 29 31 125 139 131 115 105 132 104 123 35 113 122 42 117 119 58 109 23 105 63 27 44 105 99 41 128 121 116 125 32 61 37 127 29 113 121 58 114 126 53 114 96 25 109 7 31 141 46 13 27 43 117 116 27 7 68 40 31 115 124 42 128 52 71 118 117 38 27 106 33 117 116 111 40 119 47 105 57 122 109 124 115 43 120 43 27 27 18 28 48 125 107 114 34 133 45 120 30 127 31 116 146)
|> Enum.map(&String.to_integer(&1))
Stem_and_leaf.plot(data) |
http://rosettacode.org/wiki/Stern-Brocot_sequence | Stern-Brocot sequence | For this task, the Stern-Brocot sequence is to be generated by an algorithm similar to that employed in generating the Fibonacci sequence.
The first and second members of the sequence are both 1:
1, 1
Start by considering the second member of the sequence
Sum the considered member of the sequence and its precedent, (1 + 1) = 2, and append it to the end of the sequence:
1, 1, 2
Append the considered member of the sequence to the end of the sequence:
1, 1, 2, 1
Consider the next member of the series, (the third member i.e. 2)
GOTO 3
─── Expanding another loop we get: ───
Sum the considered member of the sequence and its precedent, (2 + 1) = 3, and append it to the end of the sequence:
1, 1, 2, 1, 3
Append the considered member of the sequence to the end of the sequence:
1, 1, 2, 1, 3, 2
Consider the next member of the series, (the fourth member i.e. 1)
The task is to
Create a function/method/subroutine/procedure/... to generate the Stern-Brocot sequence of integers using the method outlined above.
Show the first fifteen members of the sequence. (This should be: 1, 1, 2, 1, 3, 2, 3, 1, 4, 3, 5, 2, 5, 3, 4)
Show the (1-based) index of where the numbers 1-to-10 first appears in the sequence.
Show the (1-based) index of where the number 100 first appears in the sequence.
Check that the greatest common divisor of all the two consecutive members of the series up to the 1000th member, is always one.
Show your output on this page.
Related tasks
Fusc sequence.
Continued fraction/Arithmetic
Ref
Infinite Fractions - Numberphile (Video).
Trees, Teeth, and Time: The mathematics of clock making.
A002487 The On-Line Encyclopedia of Integer Sequences.
| #C.23 | C# | using System;
using System.Collections.Generic;
using System.Linq;
static class Program {
static List<int> l = new List<int>() { 1, 1 };
static int gcd(int a, int b) {
return a > 0 ? a < b ? gcd(b % a, a) : gcd(a % b, b) : b; }
static void Main(string[] args) {
int max = 1000; int take = 15; int i = 1;
int[] selection = new[] { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 100 };
do { l.AddRange(new List<int>() { l[i] + l[i - 1], l[i] }); i += 1; }
while (l.Count < max || l[l.Count - 2] != selection.Last());
Console.Write("The first {0} items In the Stern-Brocot sequence: ", take);
Console.WriteLine("{0}\n", string.Join(", ", l.Take(take)));
Console.WriteLine("The locations of where the selected numbers (1-to-10, & 100) first appear:");
foreach (int ii in selection) {
int j = l.FindIndex(x => x == ii) + 1; Console.WriteLine("{0,3}: {1:n0}", ii, j); }
Console.WriteLine(); bool good = true;
for (i = 1; i <= max; i++) { if (gcd(l[i], l[i - 1]) != 1) { good = false; break; } }
Console.WriteLine("The greatest common divisor of all the two consecutive items of the" +
" series up to the {0}th item is {1}always one.", max, good ? "" : "not ");
}
} |
http://rosettacode.org/wiki/Stream_merge | Stream merge | 2-stream merge
Read two sorted streams of items from external source (e.g. disk, or network), and write one stream of sorted items to external sink.
Common algorithm: keep 1 buffered item from each source, select minimal of them, write it, fetch another item from that stream from which the written item was.
N-stream merge
The same as above, but reading from N sources.
Common algorithm: same as above, but keep buffered items and their source descriptors in a heap.
Assume streams are very big. You must not suck them whole in the memory, but read them as streams.
| #UNIX_Shell | UNIX Shell | sort --merge source1 source2 sourceN > sink
|
http://rosettacode.org/wiki/Stream_merge | Stream merge | 2-stream merge
Read two sorted streams of items from external source (e.g. disk, or network), and write one stream of sorted items to external sink.
Common algorithm: keep 1 buffered item from each source, select minimal of them, write it, fetch another item from that stream from which the written item was.
N-stream merge
The same as above, but reading from N sources.
Common algorithm: same as above, but keep buffered items and their source descriptors in a heap.
Assume streams are very big. You must not suck them whole in the memory, but read them as streams.
| #Wren | Wren | import "io" for File
import "/ioutil" for FileUtil
import "/str" for Str
import "/seq" for Lst
var merge2 = Fn.new { |inputFile1, inputFile2, outputFile|
// Note that the FileUtil.readEachLine method checks the file exists and closes it
// when there are no more lines to read.
var reader1 = Fiber.new(FileUtil.readEachLine(inputFile1))
var reader2 = Fiber.new(FileUtil.readEachLine(inputFile2))
var writer = File.create(outputFile)
var line1 = reader1.call()
var line2 = reader2.call()
while (line1 && line2) {
if (Str.le(line1, line2)) {
writer.writeBytes(line1 + "\n")
line1 = reader1.call()
} else {
writer.writeBytes(line2 + "\n")
line2 = reader2.call()
}
}
while (line1) {
writer.writeBytes(line1 + "\n")
line1 = reader1.call()
}
while (line2) {
writer.writeBytes(line2 + "\n")
line2 = reader2.call()
}
writer.close()
}
var mergeN = Fn.new { |inputFiles, outputFile|
var readers = inputFiles.map { |f| Fiber.new(FileUtil.readEachLine(f)) }.toList
var writer = File.create(outputFile)
var lines = readers.map { |reader| reader.call() }.toList
while (lines.any { |line| line }) {
var line = lines.where { |line| line }.reduce() { |acc, s| Str.lt(s, acc) ? s : acc }
var index = Lst.indexOf(lines, line)
writer.writeBytes(line + "\n")
lines[index] = readers[index].call()
}
writer.close()
}
var files = ["merge1.txt", "merge2.txt", "merge3.txt", "merge4.txt"]
merge2.call(files[0], files[1], "merged2.txt")
mergeN.call(files, "mergedN.txt")
// check it worked
System.print(File.read("merged2.txt"))
System.print(File.read("mergedN.txt")) |
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