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http://rosettacode.org/wiki/Terminal_control/Clear_the_screen
Terminal control/Clear the screen
Task Clear the terminal window.
#Nanoquery
Nanoquery
cls
http://rosettacode.org/wiki/Terminal_control/Clear_the_screen
Terminal control/Clear the screen
Task Clear the terminal window.
#Nemerle
Nemerle
Console.Clear();
http://rosettacode.org/wiki/Terminal_control/Clear_the_screen
Terminal control/Clear the screen
Task Clear the terminal window.
#NewLISP
NewLISP
  (! "clear")  
http://rosettacode.org/wiki/Ternary_logic
Ternary logic
This page uses content from Wikipedia. The original article was at Ternary logic. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance) In logic, a three-valued logic (also trivalent, ternary, or trinary logic, sometimes abbreviated 3VL) is any of several many-valued logic systems in which there are three truth values indicating true, false and some indeterminate third value. This is contrasted with the more commonly known bivalent logics (such as classical sentential or boolean logic) which provide only for true and false. Conceptual form and basic ideas were initially created by Łukasiewicz, Lewis and Sulski. These were then re-formulated by Grigore Moisil in an axiomatic algebraic form, and also extended to n-valued logics in 1945. Example Ternary Logic Operators in Truth Tables: not a ¬ True False Maybe Maybe False True a and b ∧ True Maybe False True True Maybe False Maybe Maybe Maybe False False False False False a or b ∨ True Maybe False True True True True Maybe True Maybe Maybe False True Maybe False if a then b ⊃ True Maybe False True True Maybe False Maybe True Maybe Maybe False True True True a is equivalent to b ≡ True Maybe False True True Maybe False Maybe Maybe Maybe Maybe False False Maybe True Task Define a new type that emulates ternary logic by storing data trits. Given all the binary logic operators of the original programming language, reimplement these operators for the new Ternary logic type trit. Generate a sampling of results using trit variables. Kudos for actually thinking up a test case algorithm where ternary logic is intrinsically useful, optimises the test case algorithm and is preferable to binary logic. Note:   Setun   (Сетунь) was a   balanced ternary   computer developed in 1958 at   Moscow State University.   The device was built under the lead of   Sergei Sobolev   and   Nikolay Brusentsov.   It was the only modern   ternary computer,   using three-valued ternary logic
#langur
langur
# borrowing null for "maybe" val .trSet = [false, null, true]   val .and = f given .a, .b { case true, null: case null, true: case null: null default: .a and .b }   val .or = f given .a, .b { case false, null: case null, false: case null: null default: .a or .b }   val .imply = f if(.a nor .b: not? .a; .b)   # formatting function for the result values # replacing null with "maybe" # using left alignment of 5 code points val .F = f $"\{nn [.r, "maybe"]:-5}"   writeln "a not a" for .a in .trSet { writeln $"\.a:.F; \(not? .a:.F)" }   writeln "\na b a and b" for .a in .trSet { for .b in .trSet { writeln $"\.a:.F; \.b:.F; \.and(.a, .b):.F;" } }   writeln "\na b a or b" for .a in .trSet { for .b in .trSet { writeln $"\.a:.F; \.b:.F; \.or(.a, .b):.F;" } }   writeln "\na b a implies b" for .a in .trSet { for .b in .trSet { writeln $"\.a:.F; \.b:.F; \.imply(.a, .b):.F;" } }   writeln "\na b a eq b" for .a in .trSet { for .b in .trSet { writeln $"\.a:.F; \.b:.F; \.a ==? .b:.F;" } }
http://rosettacode.org/wiki/Ternary_logic
Ternary logic
This page uses content from Wikipedia. The original article was at Ternary logic. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance) In logic, a three-valued logic (also trivalent, ternary, or trinary logic, sometimes abbreviated 3VL) is any of several many-valued logic systems in which there are three truth values indicating true, false and some indeterminate third value. This is contrasted with the more commonly known bivalent logics (such as classical sentential or boolean logic) which provide only for true and false. Conceptual form and basic ideas were initially created by Łukasiewicz, Lewis and Sulski. These were then re-formulated by Grigore Moisil in an axiomatic algebraic form, and also extended to n-valued logics in 1945. Example Ternary Logic Operators in Truth Tables: not a ¬ True False Maybe Maybe False True a and b ∧ True Maybe False True True Maybe False Maybe Maybe Maybe False False False False False a or b ∨ True Maybe False True True True True Maybe True Maybe Maybe False True Maybe False if a then b ⊃ True Maybe False True True Maybe False Maybe True Maybe Maybe False True True True a is equivalent to b ≡ True Maybe False True True Maybe False Maybe Maybe Maybe Maybe False False Maybe True Task Define a new type that emulates ternary logic by storing data trits. Given all the binary logic operators of the original programming language, reimplement these operators for the new Ternary logic type trit. Generate a sampling of results using trit variables. Kudos for actually thinking up a test case algorithm where ternary logic is intrinsically useful, optimises the test case algorithm and is preferable to binary logic. Note:   Setun   (Сетунь) was a   balanced ternary   computer developed in 1958 at   Moscow State University.   The device was built under the lead of   Sergei Sobolev   and   Nikolay Brusentsov.   It was the only modern   ternary computer,   using three-valued ternary logic
#Liberty_BASIC
Liberty BASIC
  'ternary logic '0 1 2 'F ? T 'False Don't know True 'LB has NOT AND OR XOR, so we implement them. 'LB has no EQ, but XOR could be expressed via EQ. In 'normal' boolean at least.   global tFalse, tDontKnow, tTrue tFalse = 0 tDontKnow = 1 tTrue = 2   print "Short and long names for ternary logic values" for i = tFalse to tTrue print shortName3$(i);" ";longName3$(i) next print   print "Single parameter functions" print "x";" ";"=x";" ";"not(x)" for i = tFalse to tTrue print shortName3$(i);" ";shortName3$(i);" ";shortName3$(not3(i)) next print   print "Double parameter fuctions" print "x";" ";"y";" ";"x AND y";" ";"x OR y";" ";"x EQ y";" ";"x XOR y" for a = tFalse to tTrue for b = tFalse to tTrue print shortName3$(a);" ";shortName3$(b);" "; _ shortName3$(and3(a,b));" "; shortName3$(or3(a,b));" "; _ shortName3$(eq3(a,b));" "; shortName3$(xor3(a,b)) next next   function and3(a,b) and3 = min(a,b) end function   function or3(a,b) or3 = max(a,b) end function   function eq3(a,b) select case case a=tDontKnow or b=tDontKnow eq3 = tDontKnow case a=b eq3 = tTrue case else eq3 = tFalse end select end function   function xor3(a,b) xor3 = not3(eq3(a,b)) end function   function not3(b) not3 = 2-b end function   '------------------------------------------------ function shortName3$(i) shortName3$ = word$("F ? T", i+1) end function   function longName3$(i) longName3$ = word$("False,Don't know,True", i+1, ",") end function  
http://rosettacode.org/wiki/Text_processing/1
Text processing/1
This task has been flagged for clarification. Code on this page in its current state may be flagged incorrect once this task has been clarified. See this page's Talk page for discussion. Often data is produced by one program, in the wrong format for later use by another program or person. In these situations another program can be written to parse and transform the original data into a format useful to the other. The term "Data Munging" is often used in programming circles for this task. A request on the comp.lang.awk newsgroup led to a typical data munging task: I have to analyse data files that have the following format: Each row corresponds to 1 day and the field logic is: $1 is the date, followed by 24 value/flag pairs, representing measurements at 01:00, 02:00 ... 24:00 of the respective day. In short: <date> <val1> <flag1> <val2> <flag2> ... <val24> <flag24> Some test data is available at: ... (nolonger available at original location) I have to sum up the values (per day and only valid data, i.e. with flag>0) in order to calculate the mean. That's not too difficult. However, I also need to know what the "maximum data gap" is, i.e. the longest period with successive invalid measurements (i.e values with flag<=0) The data is free to download and use and is of this format: Data is no longer available at that link. Zipped mirror available here (offsite mirror). 1991-03-30 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 1991-03-31 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 20.000 1 20.000 1 20.000 1 35.000 1 50.000 1 60.000 1 40.000 1 30.000 1 30.000 1 30.000 1 25.000 1 20.000 1 20.000 1 20.000 1 20.000 1 20.000 1 35.000 1 1991-03-31 40.000 1 0.000 -2 0.000 -2 0.000 -2 0.000 -2 0.000 -2 0.000 -2 0.000 -2 0.000 -2 0.000 -2 0.000 -2 0.000 -2 0.000 -2 0.000 -2 0.000 -2 0.000 -2 0.000 -2 0.000 -2 0.000 -2 0.000 -2 0.000 -2 0.000 -2 0.000 -2 0.000 -2 1991-04-01 0.000 -2 13.000 1 16.000 1 21.000 1 24.000 1 22.000 1 20.000 1 18.000 1 29.000 1 44.000 1 50.000 1 43.000 1 38.000 1 27.000 1 27.000 1 24.000 1 23.000 1 18.000 1 12.000 1 13.000 1 14.000 1 15.000 1 13.000 1 10.000 1 1991-04-02 8.000 1 9.000 1 11.000 1 12.000 1 12.000 1 12.000 1 27.000 1 26.000 1 27.000 1 33.000 1 32.000 1 31.000 1 29.000 1 31.000 1 25.000 1 25.000 1 24.000 1 21.000 1 17.000 1 14.000 1 15.000 1 12.000 1 12.000 1 10.000 1 1991-04-03 10.000 1 9.000 1 10.000 1 10.000 1 9.000 1 10.000 1 15.000 1 24.000 1 28.000 1 24.000 1 18.000 1 14.000 1 12.000 1 13.000 1 14.000 1 15.000 1 14.000 1 15.000 1 13.000 1 13.000 1 13.000 1 12.000 1 10.000 1 10.000 1 Only a sample of the data showing its format is given above. The full example file may be downloaded here. Structure your program to show statistics for each line of the file, (similar to the original Python, Perl, and AWK examples below), followed by summary statistics for the file. When showing example output just show a few line statistics and the full end summary.
#Picat
Picat
go => File = "readings.txt", Total = new_map([num_readings=0,num_good_readings=0,sum_readings=0.0]), InvalidCount = 0, MaxInvalidCount = 0, InvalidRunEnd = "",   Id = 0, foreach(Line in read_file_lines(File)) Id := Id + 1, NumReadings = 0, NumGoodReadings = 0, SumReadings = 0,   Fields = Line.split, Rec = Fields.tail.map(to_float), foreach([Reading,Flag] in chunks_of(Rec,2)) NumReadings := NumReadings + 1, if Flag > 0 then NumGoodReadings := NumGoodReadings + 1, SumReadings := SumReadings + Reading, InvalidCount := 0 else InvalidCount := InvalidCount + 1, if InvalidCount > MaxInvalidCount then MaxInvalidCount := InvalidCount, InvalidRunEnd := Fields[1] end end end,   Total.put(num_readings,Total.get(num_readings) + NumReadings), Total.put(num_good_readings,Total.get(num_good_readings) + NumGoodReadings), Total.put(sum_readings,Total.get(sum_readings) + SumReadings), if Id <= 3 then printf("date:%w accept:%w reject:%w sum:%w\n", Fields[1],NumGoodReadings, NumReadings-NumGoodReadings, SumReadings) end end, nl, printf("readings: %d good readings: %d sum: %0.3f avg: %0.3f\n",Total.get(num_readings), Total.get(num_good_readings), Total.get(sum_readings), Total.get(sum_readings) / Total.get(num_good_readings)), nl, println(maxInvalidCount=MaxInvalidCount), println(invalidRunEnd=InvalidRunEnd),   nl.
http://rosettacode.org/wiki/The_Twelve_Days_of_Christmas
The Twelve Days of Christmas
Task Write a program that outputs the lyrics of the Christmas carol The Twelve Days of Christmas. The lyrics can be found here. (You must reproduce the words in the correct order, but case, format, and punctuation are left to your discretion.) 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
#Julia
Julia
# v0.6.0   function printlyrics() const gifts = split(""" A partridge in a pear tree. Two turtle doves Three french hens Four calling birds Five golden rings Six geese a-laying Seven swans a-swimming Eight maids a-milking Nine ladies dancing Ten lords a-leaping Eleven pipers piping Twelve drummers drumming """, '\n') const days = split(""" first second third fourth fifth sixth seventh eighth ninth tenth eleventh twelfth""") for (n, day) in enumerate(days) g = gifts[n:-1:1] print("\nOn the $day day of Christmas\nMy true love gave to me:\n") if n == 1 print(join(g[1:end], '\n'), '\n') else print(join(g[1:end-1], '\n'), " and\n", g[end], '\n') end end end   printlyrics()
http://rosettacode.org/wiki/The_Twelve_Days_of_Christmas
The Twelve Days of Christmas
Task Write a program that outputs the lyrics of the Christmas carol The Twelve Days of Christmas. The lyrics can be found here. (You must reproduce the words in the correct order, but case, format, and punctuation are left to your discretion.) 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
#Kotlin
Kotlin
enum class Day { first, second, third, fourth, fifth, sixth, seventh, eighth, ninth, tenth, eleventh, twelfth; val header = "On the " + this + " day of Christmas, my true love sent to me\n\t" }   fun main(x: Array<String>) { val gifts = listOf("A partridge in a pear tree", "Two turtle doves and", "Three french hens", "Four calling birds", "Five golden rings", "Six geese a-laying", "Seven swans a-swimming", "Eight maids a-milking", "Nine ladies dancing", "Ten lords a-leaping", "Eleven pipers piping", "Twelve drummers drumming")   Day.values().forEachIndexed { i, d -> println(d.header + gifts.slice(0..i).asReversed().joinToString("\n\t")) } }
http://rosettacode.org/wiki/Terminal_control/Coloured_text
Terminal control/Coloured text
Task Display a word in various colours on the terminal. The system palette, or colours such as Red, Green, Blue, Magenta, Cyan, and Yellow can be used. Optionally demonstrate: How the system should determine if the terminal supports colour Setting of the background colour How to cause blinking or flashing (if supported by the terminal)
#REXX
REXX
/*REXX program to display sixteen lines, each of a different color. */ parse arg !; if !all() then exit /*exit if documentation specified*/ if \!dos & \!os2 then exit /*if this isn't DOS, then exit. */ if \!pcrexx then exit /*if this isn't PC/REXX, exit. */   color.0 = 'black' /*┌─────────────────────────────┐*/ color.1 = 'dark blue' /*│ Normally, all programs issue│*/ color.2 = 'dark green' /*│ the (above) error messages │*/ color.3 = 'dark cyan/turquois' /*│ through another REXX program│*/ color.4 = 'dark red' /*│ ($ERR) which has more │*/ color.5 = 'dark pink/magenta' /*│ verbiage and explanations, │*/ color.6 = 'dark yellow (orange)' /*│ and issues the error text in│*/ color.7 = 'dark white' /*│ red (if color is available).│*/ color.8 = 'brite black (grey/gray)' /*└─────────────────────────────┘*/ color.9 = 'bright blue' color.10 = 'bright green' color.11 = 'bright cyan/turquois' color.12 = 'bright red' color.13 = 'bright pink/magenta' color.14 = 'bright yellow' color.15 = 'bright white'   do j=0 to 15 /*show all sixteen color codes. */ call scrwrite ,,'color code=['right(j,2)"]" color.j,,,j; say end /*j*/ /*the "SAY" forces a NEWLINE. */ exit /*stick a fork in it, we're done.*/ /*══════════════════════════════════general 1-line subs═════════════════*/ !all:!!=!;!=space(!);upper !;call !fid;!nt=right(!var('OS'),2)=='NT';!cls=word('CLS VMFCLEAR CLRSCREEN',1+!cms+!tso*2);if arg(1)\==1 then return 0;if wordpos(!,'? ?SAMPLES ?AUTHOR ?FLOW')==0 then return 0;!call=']$H';call '$H' !fn !;!call=;return 1 !cal:if symbol('!CALL')\=="VAR" then !call=;return !call !env:!env='ENVIRONMENT';if !sys=='MSDOS'|!brexx|!r4|!roo then !env='SYSTEM';if !os2 then !env='OS2'!env;!ebcdic=1=='f0'x;return !fid:parse upper source !sys !fun !fid . 1 . . !fn !ft !fm .;call !sys;if !dos then do;_=lastpos('\',!fn);!fm=left(!fn,_);!fn=substr(!fn,_+1);parse var !fn !fn '.' !ft;end;return word(0 !fn !ft !fm,1+('0'arg(1))) !rex:parse upper version !ver !vernum !verdate .;!brexx='BY'==!vernum;!kexx='KEXX'==!ver;!pcrexx='REXX/PERSONAL'==!ver|'REXX/PC'==!ver;!r4='REXX-R4'==!ver;!regina='REXX-REGINA'==left(!ver,11);!roo='REXX-ROO'==!ver;call !env;return !sys:!cms=!sys=='CMS';!os2=!sys=='OS2';!tso=!sys=='TSO'|!sys=='MVS';!vse=!sys=='VSE';!dos=pos('DOS',!sys)\==0|pos('WIN',!sys)\==0|!sys=='CMD';call !rex;return !var:call !fid;if !kexx then return space(dosenv(arg(1)));return space(value(arg(1),,!env))
http://rosettacode.org/wiki/Synchronous_concurrency
Synchronous concurrency
The goal of this task is to create two concurrent activities ("Threads" or "Tasks", not processes.) that share data synchronously. Your language may provide syntax or libraries to perform concurrency. Different languages provide different implementations of concurrency, often with different names. Some languages use the term threads, others use the term tasks, while others use co-processes. This task should not be implemented using fork, spawn, or the Linux/UNIX/Win32 pipe command, as communication should be between threads, not processes. One of the concurrent units will read from a file named "input.txt" and send the contents of that file, one line at a time, to the other concurrent unit, which will print the line it receives to standard output. The printing unit must count the number of lines it prints. After the concurrent unit reading the file sends its last line to the printing unit, the reading unit will request the number of lines printed by the printing unit. The reading unit will then print the number of lines printed by the printing unit. This task requires two-way communication between the concurrent units. All concurrent units must cleanly terminate at the end of the program.
#E
E
def printer := { var count := 0 def printer { to run(item) { count += 1 println(item) } to getCount() { return count } } }   def sender(lines) { switch (lines) { match [] { when (def count := printer <- getCount()) -> { println(`$count lines were printed.`) } } match [line] + rest { when (printer <- run(line)) -> { sender(rest) } } } }   # Stream IO in E is not finished yet, so this example just uses a list. sender(<file:input.txt>.getText().split("\n"))
http://rosettacode.org/wiki/Synchronous_concurrency
Synchronous concurrency
The goal of this task is to create two concurrent activities ("Threads" or "Tasks", not processes.) that share data synchronously. Your language may provide syntax or libraries to perform concurrency. Different languages provide different implementations of concurrency, often with different names. Some languages use the term threads, others use the term tasks, while others use co-processes. This task should not be implemented using fork, spawn, or the Linux/UNIX/Win32 pipe command, as communication should be between threads, not processes. One of the concurrent units will read from a file named "input.txt" and send the contents of that file, one line at a time, to the other concurrent unit, which will print the line it receives to standard output. The printing unit must count the number of lines it prints. After the concurrent unit reading the file sends its last line to the printing unit, the reading unit will request the number of lines printed by the printing unit. The reading unit will then print the number of lines printed by the printing unit. This task requires two-way communication between the concurrent units. All concurrent units must cleanly terminate at the end of the program.
#EchoLisp
EchoLisp
  (require 'sequences) (require 'tasks)   ;; inter-tasks message : (op-code . data) (define (is-message? op message) (and message (equal? op (first message))))   ;; reader task (define (reader infile ) (wait S) (define message (semaphore-pop S)) (when (is-message? 'count message ) (writeln 'reader-> message) (task-stop-all))   (if (first infile) ;; not EOF (set! message (cons 'write (next infile))) (set! message (list 'reader-count-please)))   (semaphore-push S message) (signal S) infile)   (define (writer count) (wait S) (define message (semaphore-pop S)) (when (is-message? 'write message ) (writeln (rest message)) (set! count (1+ count)) (set! message (cons 'ack count)))   (when (is-message? 'reader-count-please message ) (set! message (cons 'count count))) (semaphore-push S message) (signal S) count)    
http://rosettacode.org/wiki/Table_creation/Postal_addresses
Table creation/Postal addresses
Task Create a table to store addresses. You may assume that all the addresses to be stored will be located in the USA.   As such, you will need (in addition to a field holding a unique identifier) a field holding the street address, a field holding the city, a field holding the state code, and a field holding the zipcode.   Choose appropriate types for each field. For non-database languages, show how you would open a connection to a database (your choice of which) and create an address table in it. You should follow the existing models here for how you would structure the table.
#PostgreSQL
PostgreSQL
CREATE SEQUENCE address_seq START 100; CREATE TABLE address ( addrID int4 PRIMARY KEY DEFAULT NEXTVAL('address_seq'), street VARCHAR(50) NOT NULL, city VARCHAR(25) NOT NULL, state VARCHAR(2) NOT NULL, zip VARCHAR(20) NOT NULL );
http://rosettacode.org/wiki/Table_creation/Postal_addresses
Table creation/Postal addresses
Task Create a table to store addresses. You may assume that all the addresses to be stored will be located in the USA.   As such, you will need (in addition to a field holding a unique identifier) a field holding the street address, a field holding the city, a field holding the state code, and a field holding the zipcode.   Choose appropriate types for each field. For non-database languages, show how you would open a connection to a database (your choice of which) and create an address table in it. You should follow the existing models here for how you would structure the table.
#PowerShell.2BSQLite
PowerShell+SQLite
  Import-Module -Name PSSQLite     ## Create a database and a table $dataSource = ".\Addresses.db" $query = "CREATE TABLE SSADDRESS (Id INTEGER PRIMARY KEY AUTOINCREMENT, LastName TEXT NOT NULL, FirstName TEXT NOT NULL, Address TEXT NOT NULL, City TEXT NOT NULL, State CHAR(2) NOT NULL, Zip CHAR(5) NOT NULL )"   Invoke-SqliteQuery -Query $Query -DataSource $DataSource     ## Insert some data $query = "INSERT INTO SSADDRESS ( FirstName, LastName, Address, City, State, Zip) VALUES (@FirstName, @LastName, @Address, @City, @State, @Zip)"   Invoke-SqliteQuery -DataSource $DataSource -Query $query -SqlParameters @{ LastName = "Monster" FirstName = "Cookie" Address = "666 Sesame St" City = "Holywood" State = "CA" Zip = "90013" }     ## View the data Invoke-SqliteQuery -DataSource $DataSource -Query "SELECT * FROM SSADDRESS" | FormatTable -AutoSize  
http://rosettacode.org/wiki/Table_creation/Postal_addresses
Table creation/Postal addresses
Task Create a table to store addresses. You may assume that all the addresses to be stored will be located in the USA.   As such, you will need (in addition to a field holding a unique identifier) a field holding the street address, a field holding the city, a field holding the state code, and a field holding the zipcode.   Choose appropriate types for each field. For non-database languages, show how you would open a connection to a database (your choice of which) and create an address table in it. You should follow the existing models here for how you would structure the table.
#PureBasic.2BSQLite
PureBasic+SQLite
  UseSQLiteDatabase() Procedure CheckDatabaseUpdate(Database, Query$) Result = DatabaseUpdate(Database, Query$) If Result = 0 Print(DatabaseError()) EndIf ProcedureReturn Result EndProcedure openconsole() DatabaseFile$ = GetCurrentDirectory()+"/rosettadb.sdb" If CreateFile(0, DatabaseFile$) CloseFile(0) If OpenDatabase(0, DatabaseFile$, "", "") CheckDatabaseUpdate(0,"CREATE TABLE address ( addrID INTEGER PRIMARY KEY AUTOINCREMENT, addrStreet TEXT Not NULL, addrCity TEXT Not NULL, addrState TEXT Not NULL, addrZIP TEXT Not NULL)") CloseDatabase(0) Else print("Can't open database !") EndIf Else print("Can't create the database file !") EndIf closeconsole()  
http://rosettacode.org/wiki/Sutherland-Hodgman_polygon_clipping
Sutherland-Hodgman polygon clipping
The   Sutherland-Hodgman clipping algorithm   finds the polygon that is the intersection between an arbitrary polygon (the “subject polygon”) and a convex polygon (the “clip polygon”). It is used in computer graphics (especially 2D graphics) to reduce the complexity of a scene being displayed by eliminating parts of a polygon that do not need to be displayed. Task Take the closed polygon defined by the points: [ ( 50 , 150 ) , ( 200 , 50 ) , ( 350 , 150 ) , ( 350 , 300 ) , ( 250 , 300 ) , ( 200 , 250 ) , ( 150 , 350 ) , ( 100 , 250 ) , ( 100 , 200 ) ] {\displaystyle [(50,150),(200,50),(350,150),(350,300),(250,300),(200,250),(150,350),(100,250),(100,200)]} and clip it by the rectangle defined by the points: [ ( 100 , 100 ) , ( 300 , 100 ) , ( 300 , 300 ) , ( 100 , 300 ) ] {\displaystyle [(100,100),(300,100),(300,300),(100,300)]} Print the sequence of points that define the resulting clipped polygon. Extra credit Display all three polygons on a graphical surface, using a different color for each polygon and filling the resulting polygon. (When displaying you may use either a north-west or a south-west origin, whichever is more convenient for your display mechanism.)
#C.23
C#
using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Windows;   namespace Sutherland { public static class SutherlandHodgman { #region Class: Edge   /// <summary> /// This represents a line segment /// </summary> private class Edge { public Edge(Point from, Point to) { this.From = from; this.To = to; }   public readonly Point From; public readonly Point To; }   #endregion   /// <summary> /// This clips the subject polygon against the clip polygon (gets the intersection of the two polygons) /// </summary> /// <remarks> /// Based on the psuedocode from: /// http://en.wikipedia.org/wiki/Sutherland%E2%80%93Hodgman /// </remarks> /// <param name="subjectPoly">Can be concave or convex</param> /// <param name="clipPoly">Must be convex</param> /// <returns>The intersection of the two polygons (or null)</returns> public static Point[] GetIntersectedPolygon(Point[] subjectPoly, Point[] clipPoly) { if (subjectPoly.Length < 3 || clipPoly.Length < 3) { throw new ArgumentException(string.Format("The polygons passed in must have at least 3 points: subject={0}, clip={1}", subjectPoly.Length.ToString(), clipPoly.Length.ToString())); }   List<Point> outputList = subjectPoly.ToList();   // Make sure it's clockwise if (!IsClockwise(subjectPoly)) { outputList.Reverse(); }   // Walk around the clip polygon clockwise foreach (Edge clipEdge in IterateEdgesClockwise(clipPoly)) { List<Point> inputList = outputList.ToList(); // clone it outputList.Clear();   if (inputList.Count == 0) { // Sometimes when the polygons don't intersect, this list goes to zero. Jump out to avoid an index out of range exception break; }   Point S = inputList[inputList.Count - 1];   foreach (Point E in inputList) { if (IsInside(clipEdge, E)) { if (!IsInside(clipEdge, S)) { Point? point = GetIntersect(S, E, clipEdge.From, clipEdge.To); if (point == null) { throw new ApplicationException("Line segments don't intersect"); // may be colinear, or may be a bug } else { outputList.Add(point.Value); } }   outputList.Add(E); } else if (IsInside(clipEdge, S)) { Point? point = GetIntersect(S, E, clipEdge.From, clipEdge.To); if (point == null) { throw new ApplicationException("Line segments don't intersect"); // may be colinear, or may be a bug } else { outputList.Add(point.Value); } }   S = E; } }   // Exit Function return outputList.ToArray(); }   #region Private Methods   /// <summary> /// This iterates through the edges of the polygon, always clockwise /// </summary> private static IEnumerable<Edge> IterateEdgesClockwise(Point[] polygon) { if (IsClockwise(polygon)) { #region Already clockwise   for (int cntr = 0; cntr < polygon.Length - 1; cntr++) { yield return new Edge(polygon[cntr], polygon[cntr + 1]); }   yield return new Edge(polygon[polygon.Length - 1], polygon[0]);   #endregion } else { #region Reverse   for (int cntr = polygon.Length - 1; cntr > 0; cntr--) { yield return new Edge(polygon[cntr], polygon[cntr - 1]); }   yield return new Edge(polygon[0], polygon[polygon.Length - 1]);   #endregion } }   /// <summary> /// Returns the intersection of the two lines (line segments are passed in, but they are treated like infinite lines) /// </summary> /// <remarks> /// Got this here: /// http://stackoverflow.com/questions/14480124/how-do-i-detect-triangle-and-rectangle-intersection /// </remarks> private static Point? GetIntersect(Point line1From, Point line1To, Point line2From, Point line2To) { Vector direction1 = line1To - line1From; Vector direction2 = line2To - line2From; double dotPerp = (direction1.X * direction2.Y) - (direction1.Y * direction2.X);   // If it's 0, it means the lines are parallel so have infinite intersection points if (IsNearZero(dotPerp)) { return null; }   Vector c = line2From - line1From; double t = (c.X * direction2.Y - c.Y * direction2.X) / dotPerp; //if (t < 0 || t > 1) //{ // return null; // lies outside the line segment //}   //double u = (c.X * direction1.Y - c.Y * direction1.X) / dotPerp; //if (u < 0 || u > 1) //{ // return null; // lies outside the line segment //}   // Return the intersection point return line1From + (t * direction1); }   private static bool IsInside(Edge edge, Point test) { bool? isLeft = IsLeftOf(edge, test); if (isLeft == null) { // Colinear points should be considered inside return true; }   return !isLeft.Value; } private static bool IsClockwise(Point[] polygon) { for (int cntr = 2; cntr < polygon.Length; cntr++) { bool? isLeft = IsLeftOf(new Edge(polygon[0], polygon[1]), polygon[cntr]); if (isLeft != null) // some of the points may be colinear. That's ok as long as the overall is a polygon { return !isLeft.Value; } }   throw new ArgumentException("All the points in the polygon are colinear"); }   /// <summary> /// Tells if the test point lies on the left side of the edge line /// </summary> private static bool? IsLeftOf(Edge edge, Point test) { Vector tmp1 = edge.To - edge.From; Vector tmp2 = test - edge.To;   double x = (tmp1.X * tmp2.Y) - (tmp1.Y * tmp2.X); // dot product of perpendicular?   if (x < 0) { return false; } else if (x > 0) { return true; } else { // Colinear points; return null; } }   private static bool IsNearZero(double testValue) { return Math.Abs(testValue) <= .000000001d; }   #endregion } }
http://rosettacode.org/wiki/Symmetric_difference
Symmetric difference
Task Given two sets A and B, compute ( A ∖ B ) ∪ ( B ∖ A ) . {\displaystyle (A\setminus B)\cup (B\setminus A).} That is, enumerate the items that are in A or B but not both. This set is called the symmetric difference of A and B. In other words: ( A ∪ B ) ∖ ( A ∩ B ) {\displaystyle (A\cup B)\setminus (A\cap B)} (the set of items that are in at least one of A or B minus the set of items that are in both A and B). Optionally, give the individual differences ( A ∖ B {\displaystyle A\setminus B} and B ∖ A {\displaystyle B\setminus A} ) as well. Test cases A = {John, Bob, Mary, Serena} B = {Jim, Mary, John, Bob} Notes If your code uses lists of items to represent sets then ensure duplicate items in lists are correctly handled. For example two lists representing sets of a = ["John", "Serena", "Bob", "Mary", "Serena"] and b = ["Jim", "Mary", "John", "Jim", "Bob"] should produce the result of just two strings: ["Serena", "Jim"], in any order. In the mathematical notation above A \ B gives the set of items in A that are not in B; A ∪ B gives the set of items in both A and B, (their union); and A ∩ B gives the set of items that are in both A and B (their intersection).
#Apex
Apex
Set<String> setA = new Set<String>{'John', 'Bob', 'Mary', 'Serena'}; Set<String> setB = new Set<String>{'Jim', 'Mary', 'John', 'Bob'};   // Option 1 Set<String> notInSetA = setB.clone(); notInSetA.removeAll(setA);   Set<String> notInSetB = setA.clone(); notInSetB.removeAll(setB);   Set<String> symmetricDifference = new Set<String>(); symmetricDifference.addAll(notInSetA); symmetricDifference.addAll(notInSetB);   // Option 2 Set<String> union = setA.clone(); union.addAll(setB);   Set<String> intersection = setA.clone(); intersection.retainAll(setB);   Set<String> symmetricDifference2 = union.clone(); symmetricDifference2.removeAll(intersection);   System.debug('Not in set A: ' + notInSetA); System.debug('Not in set B: ' + notInSetB); System.debug('Symmetric Difference: ' + symmetricDifference); System.debug('Symmetric Difference 2: ' + symmetricDifference2);
http://rosettacode.org/wiki/Super-d_numbers
Super-d numbers
A super-d number is a positive, decimal (base ten) integer   n   such that   d × nd   has at least   d   consecutive digits   d   where 2 ≤ d ≤ 9 For instance, 753 is a super-3 number because 3 × 7533 = 1280873331. Super-d   numbers are also shown on   MathWorld™   as   super-d   or   super-d. Task Write a function/procedure/routine to find super-d numbers. For   d=2   through   d=6,   use the routine to show the first   10   super-d numbers. Extra credit Show the first   10   super-7, super-8, and/or super-9 numbers   (optional). See also   Wolfram MathWorld - Super-d Number.   OEIS: A014569 - Super-3 Numbers.
#Clojure
Clojure
(defn super [d] (let [run (apply str (repeat d (str d)))] (filter #(clojure.string/includes? (str (* d (Math/pow % d ))) run) (range))))   (doseq [d (range 2 9)] (println (str d ": ") (take 10 (super d))))
http://rosettacode.org/wiki/Super-d_numbers
Super-d numbers
A super-d number is a positive, decimal (base ten) integer   n   such that   d × nd   has at least   d   consecutive digits   d   where 2 ≤ d ≤ 9 For instance, 753 is a super-3 number because 3 × 7533 = 1280873331. Super-d   numbers are also shown on   MathWorld™   as   super-d   or   super-d. Task Write a function/procedure/routine to find super-d numbers. For   d=2   through   d=6,   use the routine to show the first   10   super-d numbers. Extra credit Show the first   10   super-7, super-8, and/or super-9 numbers   (optional). See also   Wolfram MathWorld - Super-d Number.   OEIS: A014569 - Super-3 Numbers.
#D
D
import std.bigint; import std.conv; import std.stdio; import std.string;   void main() { auto rd = ["22", "333", "4444", "55555", "666666", "7777777", "88888888", "999999999"]; BigInt one = 1; BigInt nine = 9;   for (int ii = 2; ii <= 9; ii++) { writefln("First 10 super-%d numbers:", ii); auto count = 0;   inner: for (BigInt j = 3; ; j++) { auto k = ii * j ^^ ii; auto ix = k.to!string.indexOf(rd[ii-2]); if (ix >= 0) { count++; write(j, ' '); if (count == 10) { writeln(); writeln(); break inner; } } } } }
http://rosettacode.org/wiki/Take_notes_on_the_command_line
Take notes on the command line
Take notes on the command line is part of Short Circuit's Console Program Basics selection. Invoking NOTES without commandline arguments displays the current contents of the local NOTES.TXT if it exists. If NOTES has arguments, the current date and time are appended to the local NOTES.TXT followed by a newline. Then all the arguments, joined with spaces, prepended with a tab, and appended with a trailing newline, are written to NOTES.TXT. If NOTES.TXT doesn't already exist in the current directory then a new NOTES.TXT file should be created.
#E
E
#!/usr/bin/env rune   def f := <file:notes.txt> def date := makeCommand("date")   switch (interp.getArgs()) { match [] { if (f.exists()) { for line in f { print(line) } } } match noteArgs { def w := f.textWriter(true) w.print(date()[0], "\t", " ".rjoin(noteArgs), "\n") w.close() } }
http://rosettacode.org/wiki/Take_notes_on_the_command_line
Take notes on the command line
Take notes on the command line is part of Short Circuit's Console Program Basics selection. Invoking NOTES without commandline arguments displays the current contents of the local NOTES.TXT if it exists. If NOTES has arguments, the current date and time are appended to the local NOTES.TXT followed by a newline. Then all the arguments, joined with spaces, prepended with a tab, and appended with a trailing newline, are written to NOTES.TXT. If NOTES.TXT doesn't already exist in the current directory then a new NOTES.TXT file should be created.
#Elixir
Elixir
defmodule Take_notes do @filename "NOTES.TXT"   def main( [] ), do: display_notes def main( arguments ), do: save_notes( arguments )   def display_notes, do: IO.puts File.read!(@filename)   def save_notes( arguments ) do notes = "#{inspect :calendar.local_time}\n\t" <> Enum.join(arguments, " ") File.open!(@filename, [:append], fn(file) -> IO.puts(file, notes) end) end end   Take_notes.main(System.argv)
http://rosettacode.org/wiki/Superellipse
Superellipse
A superellipse is a geometric figure defined as the set of all points (x, y) with | x a | n + | y b | n = 1 , {\displaystyle \left|{\frac {x}{a}}\right|^{n}\!+\left|{\frac {y}{b}}\right|^{n}\!=1,} where n, a, and b are positive numbers. Task Draw a superellipse with n = 2.5, and a = b = 200
#C
C
  #include<graphics.h> #include<stdio.h> #include<math.h>   #define pi M_PI   int main(){   double a,b,n,i,incr = 0.0001;   printf("Enter major and minor axes of the SuperEllipse : "); scanf("%lf%lf",&a,&b);   printf("Enter n : "); scanf("%lf",&n);   initwindow(500,500,"Superellipse");   for(i=0;i<2*pi;i+=incr){ putpixel(250 + a*pow(fabs(cos(i)),2/n)*(pi/2<i && i<3*pi/2?-1:1),250 + b*pow(fabs(sin(i)),2/n)*(pi<i && i<2*pi?-1:1),15); }   printf("Done. %lf",i);   getch();   closegraph(); }
http://rosettacode.org/wiki/Sylvester%27s_sequence
Sylvester's sequence
This page uses content from Wikipedia. The original article was at Sylvester's sequence. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance) In number theory, Sylvester's sequence is an integer sequence in which each term of the sequence is the product of the previous terms, plus one. Its values grow doubly exponentially, and the sum of its reciprocals forms a series of unit fractions that converges to 1 more rapidly than any other series of unit fractions with the same number of terms. Further, the sum of the first k terms of the infinite series of reciprocals provides the closest possible underestimate of 1 by any k-term Egyptian fraction. Task Write a routine (function, procedure, generator, whatever) to calculate Sylvester's sequence. Use that routine to show the values of the first 10 elements in the sequence. Show the sum of the reciprocals of the first 10 elements on the sequence, ideally as an exact fraction. Related tasks Egyptian fractions Harmonic series See also OEIS A000058 - Sylvester's sequence
#jq
jq
# Generate the sylvester integers: def sylvester: foreach range(0; infinite) as $i ({prev: 1, product: 1}; .product *= .prev | .prev = .product + 1; .prev);
http://rosettacode.org/wiki/Sylvester%27s_sequence
Sylvester's sequence
This page uses content from Wikipedia. The original article was at Sylvester's sequence. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance) In number theory, Sylvester's sequence is an integer sequence in which each term of the sequence is the product of the previous terms, plus one. Its values grow doubly exponentially, and the sum of its reciprocals forms a series of unit fractions that converges to 1 more rapidly than any other series of unit fractions with the same number of terms. Further, the sum of the first k terms of the infinite series of reciprocals provides the closest possible underestimate of 1 by any k-term Egyptian fraction. Task Write a routine (function, procedure, generator, whatever) to calculate Sylvester's sequence. Use that routine to show the values of the first 10 elements in the sequence. Show the sum of the reciprocals of the first 10 elements on the sequence, ideally as an exact fraction. Related tasks Egyptian fractions Harmonic series See also OEIS A000058 - Sylvester's sequence
#Julia
Julia
sylvester(n) = (n == 1) ? big"2" : prod(sylvester, 1:n-1) + big"1"   foreach(n -> println(rpad(n, 3), " => ", sylvester(n)), 1:10)   println("Sum of reciprocals of first 10: ", sum(big"1.0" / sylvester(n) for n in 1:10))  
http://rosettacode.org/wiki/Sylvester%27s_sequence
Sylvester's sequence
This page uses content from Wikipedia. The original article was at Sylvester's sequence. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance) In number theory, Sylvester's sequence is an integer sequence in which each term of the sequence is the product of the previous terms, plus one. Its values grow doubly exponentially, and the sum of its reciprocals forms a series of unit fractions that converges to 1 more rapidly than any other series of unit fractions with the same number of terms. Further, the sum of the first k terms of the infinite series of reciprocals provides the closest possible underestimate of 1 by any k-term Egyptian fraction. Task Write a routine (function, procedure, generator, whatever) to calculate Sylvester's sequence. Use that routine to show the values of the first 10 elements in the sequence. Show the sum of the reciprocals of the first 10 elements on the sequence, ideally as an exact fraction. Related tasks Egyptian fractions Harmonic series See also OEIS A000058 - Sylvester's sequence
#Mathematica.2FWolfram_Language
Mathematica/Wolfram Language
Rest[Nest[Append[#, (Times @@ #) + 1] &, {1}, 10]] N[Total[1/%], 250]
http://rosettacode.org/wiki/Sylvester%27s_sequence
Sylvester's sequence
This page uses content from Wikipedia. The original article was at Sylvester's sequence. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance) In number theory, Sylvester's sequence is an integer sequence in which each term of the sequence is the product of the previous terms, plus one. Its values grow doubly exponentially, and the sum of its reciprocals forms a series of unit fractions that converges to 1 more rapidly than any other series of unit fractions with the same number of terms. Further, the sum of the first k terms of the infinite series of reciprocals provides the closest possible underestimate of 1 by any k-term Egyptian fraction. Task Write a routine (function, procedure, generator, whatever) to calculate Sylvester's sequence. Use that routine to show the values of the first 10 elements in the sequence. Show the sum of the reciprocals of the first 10 elements on the sequence, ideally as an exact fraction. Related tasks Egyptian fractions Harmonic series See also OEIS A000058 - Sylvester's sequence
#Nim
Nim
import sequtils import bignum   proc sylverster(lim: Positive): seq[Int] = result.add(newInt(2)) for _ in 2..lim: result.add result.foldl(a * b) + 1   let list = sylverster(10) echo "First 10 terms of the Sylvester sequence:" for item in list: echo item   var sum = newRat() for item in list: sum += newRat(1, item) echo "\nSum of the reciprocals of the first 10 terms: ", sum.toFloat
http://rosettacode.org/wiki/Sylvester%27s_sequence
Sylvester's sequence
This page uses content from Wikipedia. The original article was at Sylvester's sequence. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance) In number theory, Sylvester's sequence is an integer sequence in which each term of the sequence is the product of the previous terms, plus one. Its values grow doubly exponentially, and the sum of its reciprocals forms a series of unit fractions that converges to 1 more rapidly than any other series of unit fractions with the same number of terms. Further, the sum of the first k terms of the infinite series of reciprocals provides the closest possible underestimate of 1 by any k-term Egyptian fraction. Task Write a routine (function, procedure, generator, whatever) to calculate Sylvester's sequence. Use that routine to show the values of the first 10 elements in the sequence. Show the sum of the reciprocals of the first 10 elements on the sequence, ideally as an exact fraction. Related tasks Egyptian fractions Harmonic series See also OEIS A000058 - Sylvester's sequence
#PARI.2FGP
PARI/GP
  S=vector(10) S[1]=2 for(i=2, 10, S[i]=prod(n=1,i-1,S[n])+1) print(S) print(sum(i=1,10,1/S[i]))
http://rosettacode.org/wiki/Taxicab_numbers
Taxicab numbers
A   taxicab number   (the definition that is being used here)   is a positive integer that can be expressed as the sum of two positive cubes in more than one way. The first taxicab number is   1729,   which is: 13   +   123       and also 93   +   103. Taxicab numbers are also known as:   taxi numbers   taxi-cab numbers   taxi cab numbers   Hardy-Ramanujan numbers Task Compute and display the lowest 25 taxicab numbers (in numeric order, and in a human-readable format). For each of the taxicab numbers, show the number as well as it's constituent cubes. Extra credit Show the 2,000th taxicab number, and a half dozen more See also A001235: taxicab numbers on The On-Line Encyclopedia of Integer Sequences. Hardy-Ramanujan Number on MathWorld. taxicab number on MathWorld. taxicab number on Wikipedia   (includes the story on how taxi-cab numbers came to be called).
#Java
Java
import java.util.PriorityQueue; import java.util.ArrayList; import java.util.List; import java.util.Iterator;   class CubeSum implements Comparable<CubeSum> { public long x, y, value;   public CubeSum(long x, long y) { this.x = x; this.y = y; this.value = x*x*x + y*y*y; }   public String toString() { return String.format("%4d^3 + %4d^3", x, y); }   public int compareTo(CubeSum that) { return value < that.value ? -1 : value > that.value ? 1 : 0; } }   class SumIterator implements Iterator<CubeSum> { PriorityQueue<CubeSum> pq = new PriorityQueue<CubeSum>(); long n = 0;   public boolean hasNext() { return true; } public CubeSum next() { while (pq.size() == 0 || pq.peek().value >= n*n*n) pq.add(new CubeSum(++n, 1));   CubeSum s = pq.remove(); if (s.x > s.y + 1) pq.add(new CubeSum(s.x, s.y+1));   return s; } }   class TaxiIterator implements Iterator<List<CubeSum>> { Iterator<CubeSum> sumIterator = new SumIterator(); CubeSum last = sumIterator.next();   public boolean hasNext() { return true; } public List<CubeSum> next() { CubeSum s; List<CubeSum> train = new ArrayList<CubeSum>();   while ((s = sumIterator.next()).value != last.value) last = s;   train.add(last);   do { train.add(s); } while ((s = sumIterator.next()).value == last.value); last = s;   return train; } }   public class Taxi { public static final void main(String[] args) { Iterator<List<CubeSum>> taxi = new TaxiIterator();   for (int i = 1; i <= 2006; i++) { List<CubeSum> t = taxi.next(); if (i > 25 && i < 2000) continue;   System.out.printf("%4d: %10d", i, t.get(0).value); for (CubeSum s: t) System.out.print(" = " + s); System.out.println(); } } }
http://rosettacode.org/wiki/Superpermutation_minimisation
Superpermutation minimisation
A superpermutation of N different characters is a string consisting of an arrangement of multiple copies of those N different characters in which every permutation of those characters can be found as a substring. For example, representing the characters as A..Z, using N=2 we choose to use the first two characters 'AB'. The permutations of 'AB' are the two, (i.e. two-factorial), strings: 'AB' and 'BA'. A too obvious method of generating a superpermutation is to just join all the permutations together forming 'ABBA'. A little thought will produce the shorter (in fact the shortest) superpermutation of 'ABA' - it contains 'AB' at the beginning and contains 'BA' from the middle to the end. The "too obvious" method of creation generates a string of length N!*N. Using this as a yardstick, the task is to investigate other methods of generating superpermutations of N from 1-to-7 characters, that never generate larger superpermutations. Show descriptions and comparisons of algorithms used here, and select the "Best" algorithm as being the one generating shorter superpermutations. The problem of generating the shortest superpermutation for each N might be NP complete, although the minimal strings for small values of N have been found by brute -force searches. 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 Reference The Minimal Superpermutation Problem. by Nathaniel Johnston. oeis A180632 gives 0-5 as 0, 1, 3, 9, 33, 153. 6 is thought to be 872. Superpermutations - Numberphile. A video Superpermutations: the maths problem solved by 4chan - Standupmaths. A video of recent (2018) mathematical progress. New Superpermutations Discovered! Standupmaths & Numberphile.
#Go
Go
package main   import "fmt"   const max = 12   var ( super []byte pos int cnt [max]int )   // 1! + 2! + ... + n! func factSum(n int) int { s := 0 for x, f := 0, 1; x < n; { x++ f *= x s += f } return s }   func r(n int) bool { if n == 0 { return false } c := super[pos-n] cnt[n]-- if cnt[n] == 0 { cnt[n] = n if !r(n - 1) { return false } } super[pos] = c pos++ return true }   func superperm(n int) { pos = n le := factSum(n) super = make([]byte, le) for i := 0; i <= n; i++ { cnt[i] = i } for i := 1; i <= n; i++ { super[i-1] = byte(i) + '0' }   for r(n) { } }   func main() { for n := 0; n < max; n++ { fmt.Printf("superperm(%2d) ", n) superperm(n) fmt.Printf("len = %d\n", len(super)) } }
http://rosettacode.org/wiki/Tau_number
Tau number
A Tau number is a positive integer divisible by the count of its positive divisors. Task Show the first   100   Tau numbers. The numbers shall be generated during run-time (i.e. the code may not contain string literals, sets/arrays of integers, or alike). Related task  Tau function
#Python
Python
def tau(n): assert(isinstance(n, int) and 0 < n) ans, i, j = 0, 1, 1 while i*i <= n: if 0 == n%i: ans += 1 j = n//i if j != i: ans += 1 i += 1 return ans   def is_tau_number(n): assert(isinstance(n, int)) if n <= 0: return False return 0 == n%tau(n)   if __name__ == "__main__": n = 1 ans = [] while len(ans) < 100: if is_tau_number(n): ans.append(n) n += 1 print(ans)
http://rosettacode.org/wiki/Tau_number
Tau number
A Tau number is a positive integer divisible by the count of its positive divisors. Task Show the first   100   Tau numbers. The numbers shall be generated during run-time (i.e. the code may not contain string literals, sets/arrays of integers, or alike). Related task  Tau function
#Quackery
Quackery
[ dup factors size mod 0 = ] is taunumber ( n --> b )   [] 0 [ 1+ dup taunumber if [ tuck join swap ] over size 100 = until ] drop [] swap witheach [ number$ nested join ] 80 wrap$
http://rosettacode.org/wiki/Teacup_rim_text
Teacup rim text
On a set of coasters we have, there's a picture of a teacup.   On the rim of the teacup the word   TEA   appears a number of times separated by bullet characters   (•). It occurred to me that if the bullet were removed and the words run together,   you could start at any letter and still end up with a meaningful three-letter word. So start at the   T   and read   TEA.   Start at the   E   and read   EAT,   or start at the   A   and read   ATE. That got me thinking that maybe there are other words that could be used rather that   TEA.   And that's just English.   What about Italian or Greek or ... um ... Telugu. For English, we will use the unixdict (now) located at:   unixdict.txt. (This will maintain continuity with other Rosetta Code tasks that also use it.) Task Search for a set of words that could be printed around the edge of a teacup.   The words in each set are to be of the same length, that length being greater than two (thus precluding   AH   and   HA,   for example.) Having listed a set, for example   [ate tea eat],   refrain from displaying permutations of that set, e.g.:   [eat tea ate]   etc. The words should also be made of more than one letter   (thus precluding   III   and   OOO   etc.) The relationship between these words is (using ATE as an example) that the first letter of the first becomes the last letter of the second.   The first letter of the second becomes the last letter of the third.   So   ATE   becomes   TEA   and   TEA   becomes   EAT. All of the possible permutations, using this particular permutation technique, must be words in the list. The set you generate for   ATE   will never included the word   ETA   as that cannot be reached via the first-to-last movement method. Display one line for each set of teacup rim words. 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
#Wren
Wren
import "io" for File import "/str" for Str import "/sort" for Find   var readWords = Fn.new { |fileName| var dict = File.read(fileName).split("\n") return dict.where { |w| w.count >= 3 }.toList }   var dicts = ["mit10000.txt", "unixdict.txt"] for (dict in dicts) { System.print("Using %(dict):\n") var words = readWords.call(dict) var n = words.count var used = {} for (word in words) { var outer = false var variants = [word] var word2 = word for (i in 0...word.count-1) { word2 = Str.lshift(word2) if (word == word2 || used[word2]) { outer = true break } var ix = Find.first(words, word2) if (ix == n || words[ix] != word2) { outer = true break } variants.add(word2) } if (!outer) { for (variant in variants) used[variant] = true System.print(variants) } } System.print() }
http://rosettacode.org/wiki/Temperature_conversion
Temperature conversion
There are quite a number of temperature scales. For this task we will concentrate on four of the perhaps best-known ones: Kelvin, Celsius, Fahrenheit, and Rankine. The Celsius and Kelvin scales have the same magnitude, but different null points. 0 degrees Celsius corresponds to 273.15 kelvin. 0 kelvin is absolute zero. The Fahrenheit and Rankine scales also have the same magnitude, but different null points. 0 degrees Fahrenheit corresponds to 459.67 degrees Rankine. 0 degrees Rankine is absolute zero. The Celsius/Kelvin and Fahrenheit/Rankine scales have a ratio of 5 : 9. Task Write code that accepts a value of kelvin, converts it to values of the three other scales, and prints the result. Example K 21.00 C -252.15 F -421.87 R 37.80
#Befunge
Befunge
0000>0p~>"."-:!#v_2-::0\`\9`+!#v_$1>/\:3`#v_\>\:3 \`#v_v 1#<<^0 /2++g001!<1 \+g00\+*+55\< ^+55\-1< ^*+55\+1<v_ "K"\-+**"!Y]"9:\"C"\--\**"^CIT"/5*9:\"F"\/5*9:\"R"\0\0<v v/+55\+*86%+55: /+55\+*86%+55: \0/+55+5*-\1*2 p00:`\0:,< >"."\>:55+% 68*v >:#,_$55+,\:!#@_^ $_^#!:/+55\+< ^\" :"_<g00*95
http://rosettacode.org/wiki/Tau_function
Tau function
Given a positive integer, count the number of its positive divisors. Task Show the result for the first   100   positive integers. Related task  Tau number
#jq
jq
def count(s): reduce s as $x (0; .+1);   # For pretty-printing def nwise($n): def n: if length <= $n then . else .[0:$n] , (.[$n:] | n) end; n;   def lpad($len): tostring | ($len - length) as $l | (" " * $l)[:$l] + .;
http://rosettacode.org/wiki/Tau_function
Tau function
Given a positive integer, count the number of its positive divisors. Task Show the result for the first   100   positive integers. Related task  Tau number
#Julia
Julia
using Primes   function numfactors(n) f = [one(n)] for (p, e) in factor(n) f = reduce(vcat, [f * p^j for j in 1:e], init = f) end length(f) end   for i in 1:100 print(rpad(numfactors(i), 3), i % 25 == 0 ? " \n" : " ") end  
http://rosettacode.org/wiki/Tau_function
Tau function
Given a positive integer, count the number of its positive divisors. Task Show the result for the first   100   positive integers. Related task  Tau number
#Lua
Lua
function divisorCount(n) local total = 1 -- Deal with powers of 2 first while (n & 1) == 0 do total = total + 1 n = math.floor(n / 2) end -- Odd prime factors up tot eh square root local p = 3 while p * p <= n do local count = 1 while n % p == 0 do count = count + 1 n = n / p end total = total * count p = p + 2 end -- If n > 1 then it's prime if n > 1 then total = total * 2 end return total end   limit = 100 print("Count of divisors for the first " .. limit .. " positive integers:") for n=1,limit do io.write(string.format("%3d", divisorCount(n))) if n % 20 == 0 then print() end end
http://rosettacode.org/wiki/Terminal_control/Clear_the_screen
Terminal control/Clear the screen
Task Clear the terminal window.
#Nim
Nim
  import terminal   eraseScreen() #puts cursor at down setCursorPos(0, 0)  
http://rosettacode.org/wiki/Terminal_control/Clear_the_screen
Terminal control/Clear the screen
Task Clear the terminal window.
#NS-HUBASIC
NS-HUBASIC
10 CLS
http://rosettacode.org/wiki/Terminal_control/Clear_the_screen
Terminal control/Clear the screen
Task Clear the terminal window.
#OCaml
OCaml
#load "unix.cma" #directory "+ANSITerminal" #load "ANSITerminal.cma" open ANSITerminal   let () = erase Screen
http://rosettacode.org/wiki/Ternary_logic
Ternary logic
This page uses content from Wikipedia. The original article was at Ternary logic. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance) In logic, a three-valued logic (also trivalent, ternary, or trinary logic, sometimes abbreviated 3VL) is any of several many-valued logic systems in which there are three truth values indicating true, false and some indeterminate third value. This is contrasted with the more commonly known bivalent logics (such as classical sentential or boolean logic) which provide only for true and false. Conceptual form and basic ideas were initially created by Łukasiewicz, Lewis and Sulski. These were then re-formulated by Grigore Moisil in an axiomatic algebraic form, and also extended to n-valued logics in 1945. Example Ternary Logic Operators in Truth Tables: not a ¬ True False Maybe Maybe False True a and b ∧ True Maybe False True True Maybe False Maybe Maybe Maybe False False False False False a or b ∨ True Maybe False True True True True Maybe True Maybe Maybe False True Maybe False if a then b ⊃ True Maybe False True True Maybe False Maybe True Maybe Maybe False True True True a is equivalent to b ≡ True Maybe False True True Maybe False Maybe Maybe Maybe Maybe False False Maybe True Task Define a new type that emulates ternary logic by storing data trits. Given all the binary logic operators of the original programming language, reimplement these operators for the new Ternary logic type trit. Generate a sampling of results using trit variables. Kudos for actually thinking up a test case algorithm where ternary logic is intrinsically useful, optimises the test case algorithm and is preferable to binary logic. Note:   Setun   (Сетунь) was a   balanced ternary   computer developed in 1958 at   Moscow State University.   The device was built under the lead of   Sergei Sobolev   and   Nikolay Brusentsov.   It was the only modern   ternary computer,   using three-valued ternary logic
#Maple
Maple
tv := [true, false, FAIL]; NotTable  := Array(1..3, i->not tv[i] ); AndTable  := Array(1..3, 1..3, (i,j)->tv[i] and tv[j] ); OrTable  := Array(1..3, 1..3, (i,j)->tv[i] or tv[j] ); XorTable  := Array(1..3, 1..3, (i,j)->tv[i] xor tv[j] ); ImpliesTable := Array(1..3, 1..3, (i,j)->tv[i] implies tv[j] );
http://rosettacode.org/wiki/Text_processing/1
Text processing/1
This task has been flagged for clarification. Code on this page in its current state may be flagged incorrect once this task has been clarified. See this page's Talk page for discussion. Often data is produced by one program, in the wrong format for later use by another program or person. In these situations another program can be written to parse and transform the original data into a format useful to the other. The term "Data Munging" is often used in programming circles for this task. A request on the comp.lang.awk newsgroup led to a typical data munging task: I have to analyse data files that have the following format: Each row corresponds to 1 day and the field logic is: $1 is the date, followed by 24 value/flag pairs, representing measurements at 01:00, 02:00 ... 24:00 of the respective day. In short: <date> <val1> <flag1> <val2> <flag2> ... <val24> <flag24> Some test data is available at: ... (nolonger available at original location) I have to sum up the values (per day and only valid data, i.e. with flag>0) in order to calculate the mean. That's not too difficult. However, I also need to know what the "maximum data gap" is, i.e. the longest period with successive invalid measurements (i.e values with flag<=0) The data is free to download and use and is of this format: Data is no longer available at that link. Zipped mirror available here (offsite mirror). 1991-03-30 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 1991-03-31 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 20.000 1 20.000 1 20.000 1 35.000 1 50.000 1 60.000 1 40.000 1 30.000 1 30.000 1 30.000 1 25.000 1 20.000 1 20.000 1 20.000 1 20.000 1 20.000 1 35.000 1 1991-03-31 40.000 1 0.000 -2 0.000 -2 0.000 -2 0.000 -2 0.000 -2 0.000 -2 0.000 -2 0.000 -2 0.000 -2 0.000 -2 0.000 -2 0.000 -2 0.000 -2 0.000 -2 0.000 -2 0.000 -2 0.000 -2 0.000 -2 0.000 -2 0.000 -2 0.000 -2 0.000 -2 0.000 -2 1991-04-01 0.000 -2 13.000 1 16.000 1 21.000 1 24.000 1 22.000 1 20.000 1 18.000 1 29.000 1 44.000 1 50.000 1 43.000 1 38.000 1 27.000 1 27.000 1 24.000 1 23.000 1 18.000 1 12.000 1 13.000 1 14.000 1 15.000 1 13.000 1 10.000 1 1991-04-02 8.000 1 9.000 1 11.000 1 12.000 1 12.000 1 12.000 1 27.000 1 26.000 1 27.000 1 33.000 1 32.000 1 31.000 1 29.000 1 31.000 1 25.000 1 25.000 1 24.000 1 21.000 1 17.000 1 14.000 1 15.000 1 12.000 1 12.000 1 10.000 1 1991-04-03 10.000 1 9.000 1 10.000 1 10.000 1 9.000 1 10.000 1 15.000 1 24.000 1 28.000 1 24.000 1 18.000 1 14.000 1 12.000 1 13.000 1 14.000 1 15.000 1 14.000 1 15.000 1 13.000 1 13.000 1 13.000 1 12.000 1 10.000 1 10.000 1 Only a sample of the data showing its format is given above. The full example file may be downloaded here. Structure your program to show statistics for each line of the file, (similar to the original Python, Perl, and AWK examples below), followed by summary statistics for the file. When showing example output just show a few line statistics and the full end summary.
#PicoLisp
PicoLisp
#!/usr/bin/picolisp /usr/lib/picolisp/lib.l   (let (NoData 0 NoDataMax -1 NoDataMaxline "!" TotFile 0 NumFile 0) (let InFiles (glue "," (mapcar '((File) (in File (while (split (line) "^I") (let (Len (length @) Date (car @) TotLine 0 NumLine 0) (for (L (cdr @) L (cddr L)) (if (> 1 (format (cadr L))) (inc 'NoData) (when (gt0 NoData) (when (= NoDataMax NoData) (setq NoDataMaxline (pack NoDataMaxline ", " Date)) ) (when (> NoData NoDataMax) (setq NoDataMax NoData NoDataMaxline Date) ) ) (zero NoData) (inc 'TotLine (format (car L) 3)) (inc 'NumLine) ) ) (inc 'TotFile TotLine) (inc 'NumFile NumLine) (tab (-7 -12 -7 3 -9 3 -11 11 -11 11) "Line:" Date "Reject:" (- (/ (dec Len) 2) NumLine) " Accept:" NumLine " Line_tot:" (format TotLine 3) " Line_avg:" (and (gt0 NumLine) (format (*/ TotLine @) 3)) ) ) ) ) File ) (argv) ) ) (prinl) (prinl "File(s) = " InFiles) (prinl "Total = " (format TotFile 3)) (prinl "Readings = " NumFile) (prinl "Average = " (format (*/ TotFile NumFile) 3)) (prinl) (prinl "Maximum run(s) of " NoDataMax " consecutive false readings ends at line starting with date(s): " NoDataMaxline ) ) )   (bye)
http://rosettacode.org/wiki/The_Twelve_Days_of_Christmas
The Twelve Days of Christmas
Task Write a program that outputs the lyrics of the Christmas carol The Twelve Days of Christmas. The lyrics can be found here. (You must reproduce the words in the correct order, but case, format, and punctuation are left to your discretion.) 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
#Lambdatalk
Lambdatalk
  {def days first second third fourth fifth sixth seventh eight ninth tenth eleventh twelfth} -> days   {def texts {quote A partridge in a pear tree.} {quote Two turtle doves and} {quote Three french hens} {quote Four calling birds} {quote Five golden rings} {quote Six geese a-laying} {quote Seven swans a-swimming} {quote Eight maids a-milking} {quote Nine ladies dancing} {quote Ten lords a-leaping} {quote Eleven pipers piping} {quote Twelve drummers drumming}} -> texts   {S.map {lambda {:i} {hr}On the {S.get :i {days}} day of Christmas {br}My true love gave to me {S.map {lambda {:i} {br}{S.get :i {texts}}} {S.serie :i 0 -1}} } {S.serie 0 {- {S.length {days}} 1}}} -> On the first day of Christmas My true love gave to me A partridge in a pear tree.   On the second day of Christmas My true love gave to me Two turtle doves and A partridge in a pear tree.   ...   On the twelfth day of Christmas My true love gave to me Twelve drummers drumming Eleven pipers piping Ten lords a-leaping Nine ladies dancing Eight maids a-milking Seven swans a-swimming Six geese a-laying Five golden rings Four calling birds Three french hens Two turtle doves and A partridge in a pear tree.  
http://rosettacode.org/wiki/Terminal_control/Coloured_text
Terminal control/Coloured text
Task Display a word in various colours on the terminal. The system palette, or colours such as Red, Green, Blue, Magenta, Cyan, and Yellow can be used. Optionally demonstrate: How the system should determine if the terminal supports colour Setting of the background colour How to cause blinking or flashing (if supported by the terminal)
#Ring
Ring
  # Project : Terminal control/Coloured text   load "consolecolors.ring"   forecolors = [CC_FG_BLACK,CC_FG_RED,CC_FG_GREEN,CC_FG_YELLOW, CC_FG_BLUE,CC_FG_MAGENTA,CC_FG_CYAN,CC_FG_GRAY,CC_BG_WHITE]   for n = 1 to len(forecolors) forecolor = forecolors[n] cc_print(forecolor | CC_BG_WHITE, "Rosetta Code" + nl) next  
http://rosettacode.org/wiki/Terminal_control/Coloured_text
Terminal control/Coloured text
Task Display a word in various colours on the terminal. The system palette, or colours such as Red, Green, Blue, Magenta, Cyan, and Yellow can be used. Optionally demonstrate: How the system should determine if the terminal supports colour Setting of the background colour How to cause blinking or flashing (if supported by the terminal)
#Ruby
Ruby
#!/usr/bin/ruby -w require 'rubygems' require 'colored'   print 'Colors are'.bold print ' black'.black print ' blue'.blue print ' cyan'.cyan print ' green'.green print ' magenta'.magenta print ' red'.red print ' white '.white print 'and'.underline, ' yellow'.yellow, "\n" puts 'black on blue'.black_on_blue puts 'black on cyan'.black_on_cyan puts 'black on green'.black_on_green puts 'black on magenta'.black_on_magenta puts 'black on red'.black_on_red puts 'white on black'.white_on_black puts 'white on blue'.white_on_blue puts 'white on cyan'.white_on_cyan puts 'white on green'.white_on_green puts 'white on magenta'.white_on_magenta puts 'white on red'.white_on_red
http://rosettacode.org/wiki/Synchronous_concurrency
Synchronous concurrency
The goal of this task is to create two concurrent activities ("Threads" or "Tasks", not processes.) that share data synchronously. Your language may provide syntax or libraries to perform concurrency. Different languages provide different implementations of concurrency, often with different names. Some languages use the term threads, others use the term tasks, while others use co-processes. This task should not be implemented using fork, spawn, or the Linux/UNIX/Win32 pipe command, as communication should be between threads, not processes. One of the concurrent units will read from a file named "input.txt" and send the contents of that file, one line at a time, to the other concurrent unit, which will print the line it receives to standard output. The printing unit must count the number of lines it prints. After the concurrent unit reading the file sends its last line to the printing unit, the reading unit will request the number of lines printed by the printing unit. The reading unit will then print the number of lines printed by the printing unit. This task requires two-way communication between the concurrent units. All concurrent units must cleanly terminate at the end of the program.
#Elixir
Elixir
defmodule RC do def start do my_pid = self pid = spawn( fn -> reader(my_pid, 0) end ) File.open( "input.txt", [:read], fn io -> process( IO.gets(io, ""), io, pid ) end ) end   defp process( :eof, _io, pid ) do send( pid, :count ) receive do i -> IO.puts "Count:#{i}" end end defp process( any, io, pid ) do send( pid, any ) process( IO.gets(io, ""), io, pid ) end   defp reader( pid, c ) do receive do  :count -> send( pid, c ) any -> IO.write any reader( pid, c+1 ) end end end   RC.start
http://rosettacode.org/wiki/Synchronous_concurrency
Synchronous concurrency
The goal of this task is to create two concurrent activities ("Threads" or "Tasks", not processes.) that share data synchronously. Your language may provide syntax or libraries to perform concurrency. Different languages provide different implementations of concurrency, often with different names. Some languages use the term threads, others use the term tasks, while others use co-processes. This task should not be implemented using fork, spawn, or the Linux/UNIX/Win32 pipe command, as communication should be between threads, not processes. One of the concurrent units will read from a file named "input.txt" and send the contents of that file, one line at a time, to the other concurrent unit, which will print the line it receives to standard output. The printing unit must count the number of lines it prints. After the concurrent unit reading the file sends its last line to the printing unit, the reading unit will request the number of lines printed by the printing unit. The reading unit will then print the number of lines printed by the printing unit. This task requires two-way communication between the concurrent units. All concurrent units must cleanly terminate at the end of the program.
#Erlang
Erlang
-module(cc).   -export([start/0]).   start() -> My_pid = erlang:self(), Pid = erlang:spawn( fun() -> reader(My_pid, 0) end ), {ok, IO } = file:open( "input.txt", [read] ), process( io:get_line(IO, ""), IO, Pid ), file:close( IO ).   process( eof, _IO, Pid ) -> Pid ! count, receive I -> io:fwrite("Count:~p~n", [I]) end; process( Any, IO, Pid ) -> Pid ! Any, process( io:get_line(IO, ""), IO, Pid ).   reader(Pid, C) -> receive count -> Pid ! C; Any -> io:fwrite("~s", [Any]), reader(Pid, C+1) end.
http://rosettacode.org/wiki/Table_creation/Postal_addresses
Table creation/Postal addresses
Task Create a table to store addresses. You may assume that all the addresses to be stored will be located in the USA.   As such, you will need (in addition to a field holding a unique identifier) a field holding the street address, a field holding the city, a field holding the state code, and a field holding the zipcode.   Choose appropriate types for each field. For non-database languages, show how you would open a connection to a database (your choice of which) and create an address table in it. You should follow the existing models here for how you would structure the table.
#Python.2BSQLite
Python+SQLite
>>> import sqlite3 >>> conn = sqlite3.connect(':memory:') >>> conn.execute('''CREATE TABLE address ( addrID INTEGER PRIMARY KEY AUTOINCREMENT, addrStreet TEXT NOT NULL, addrCity TEXT NOT NULL, addrState TEXT NOT NULL, addrZIP TEXT NOT NULL )''') <sqlite3.Cursor object at 0x013265C0> >>>
http://rosettacode.org/wiki/Table_creation/Postal_addresses
Table creation/Postal addresses
Task Create a table to store addresses. You may assume that all the addresses to be stored will be located in the USA.   As such, you will need (in addition to a field holding a unique identifier) a field holding the street address, a field holding the city, a field holding the state code, and a field holding the zipcode.   Choose appropriate types for each field. For non-database languages, show how you would open a connection to a database (your choice of which) and create an address table in it. You should follow the existing models here for how you would structure the table.
#Racket
Racket
  #lang at-exp racket   (require db) (define postal (sqlite3-connect #:database "/tmp/postal.db" #:mode 'create))   (define (add! name street city state zip) (query-exec postal @~a{INSERT INTO addresses (name, street, city, state, zip) VALUES (?, ?, ?, ?, ?)} name street city state zip))   (unless (table-exists? postal "addresses") (query-exec postal @~a{CREATE TABLE addresses( id INTEGER PRIMARY KEY, name TEXT NOT NULL, street TEXT NOT NULL, city TEXT NOT NULL, state TEXT NOT NULL, zip TEXT NOT NULL)}))   (add! "FSF Inc." "51 Franklin St" "Boston" "MA" "02110-1301") (add! "The White House" "1600 Pennsylvania Avenue NW" "Washington" "DC" "20500") (add! "National Security Council" "1700 Pennsylvania Avenue NW" "Washington" "DC" "20500")   (printf "Addresses:\n") (for ([r (query-rows postal "SELECT * FROM addresses")]) (printf " ~a.\n" (string-join (cdr (vector->list r)) ", "))) (newline)   (printf "By State+ZIP:\n") (for ([z (query-rows postal "SELECT * FROM addresses" #:group #("state" "zip"))]) (printf " ~a, ~a:\n" (vector-ref z 0) (vector-ref z 1)) (for ([r (vector-ref z 2)]) (printf " ~a.\n" (string-join (cdr (vector->list r)) ", "))))   (disconnect postal)  
http://rosettacode.org/wiki/Table_creation/Postal_addresses
Table creation/Postal addresses
Task Create a table to store addresses. You may assume that all the addresses to be stored will be located in the USA.   As such, you will need (in addition to a field holding a unique identifier) a field holding the street address, a field holding the city, a field holding the state code, and a field holding the zipcode.   Choose appropriate types for each field. For non-database languages, show how you would open a connection to a database (your choice of which) and create an address table in it. You should follow the existing models here for how you would structure the table.
#Raku
Raku
use DBIish;   my $dbh = DBIish.connect('SQLite', :database<addresses.sqlite3>);   my $sth = $dbh.do(q:to/STATEMENT/); DROP TABLE IF EXISTS Address; CREATE TABLE Address ( addrID INTEGER PRIMARY KEY AUTOINCREMENT, addrStreet TEXT NOT NULL, addrCity TEXT NOT NULL, addrState TEXT NOT NULL, addrZIP TEXT NOT NULL ) STATEMENT
http://rosettacode.org/wiki/System_time
System time
Task Output the system time   (any units will do as long as they are noted) either by a system command or one built into the language. The system time can be used for debugging, network information, random number seeds, or something as simple as program performance. Related task   Date format See also   Retrieving system time (wiki)
#11l
11l
print(Time())
http://rosettacode.org/wiki/Summarize_and_say_sequence
Summarize and say sequence
There are several ways to generate a self-referential sequence. One very common one (the Look-and-say sequence) is to start with a positive integer, then generate the next term by concatenating enumerated groups of adjacent alike digits: 0, 10, 1110, 3110, 132110, 1113122110, 311311222110 ... The terms generated grow in length geometrically and never converge. Another way to generate a self-referential sequence is to summarize the previous term. Count how many of each alike digit there is, then concatenate the sum and digit for each of the sorted enumerated digits. Note that the first five terms are the same as for the previous sequence. 0, 10, 1110, 3110, 132110, 13123110, 23124110 ... Sort the digits largest to smallest. Do not include counts of digits that do not appear in the previous term. Depending on the seed value, series generated this way always either converge to a stable value or to a short cyclical pattern. (For our purposes, I'll use converge to mean an element matches a previously seen element.) The sequence shown, with a seed value of 0, converges to a stable value of 1433223110 after 11 iterations. The seed value that converges most quickly is 22. It goes stable after the first element. (The next element is 22, which has been seen before.) Task Find all the positive integer seed values under 1000000, for the above convergent self-referential sequence, that takes the largest number of iterations before converging. Then print out the number of iterations and the sequence they return. Note that different permutations of the digits of the seed will yield the same sequence. For this task, assume leading zeros are not permitted. Seed Value(s): 9009 9090 9900 Iterations: 21 Sequence: (same for all three seeds except for first element) 9009 2920 192210 19222110 19323110 1923123110 1923224110 191413323110 191433125110 19151423125110 19251413226110 1916151413325110 1916251423127110 191716151413326110 191726151423128110 19181716151413327110 19182716151423129110 29181716151413328110 19281716151423228110 19281716151413427110 19182716152413228110 Related tasks   Fours is the number of letters in the ...   Look-and-say sequence   Number names   Self-describing numbers   Spelling of ordinal numbers 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 Also see   The On-Line Encyclopedia of Integer Sequences.
#11l
11l
[String] result V longest = 0   F make_sequence(n) -> N DefaultDict[Char, Int] map L(c) n map[c]++   V z = ‘’ L(k) sorted(map.keys(), reverse' 1B) z ‘’= Char(code' map[k] + ‘0’.code) z ‘’= k   I :longest <= z.len  :longest = z.len I z !C :result  :result [+]= z make_sequence(z)   L(test) [‘9900’, ‘9090’, ‘9009’] result.clear() longest = 0 make_sequence(test) print(‘[#.] Iterations: #.’.format(test, result.len + 1)) print(result.join("\n")) print("\n")
http://rosettacode.org/wiki/Summarize_primes
Summarize primes
Task Considering in order of length, n, all sequences of consecutive primes, p, from 2 onwards, where p < 1000 and n>0, select those sequences whose sum is prime, and for these display the length of the sequence, the last item in the sequence, and the sum.
#11l
11l
F is_prime(a) I a == 2 R 1B I a < 2 | a % 2 == 0 R 0B L(i) (3 .. Int(sqrt(a))).step(2) I a % i == 0 R 0B R 1B   print(‘index prime prime sum’) V s = 0 V idx = 0 L(n) 2..999 I is_prime(n) idx++ s += n I is_prime(s) print(f:‘{idx:3} {n:5} {s:7}’)
http://rosettacode.org/wiki/Sutherland-Hodgman_polygon_clipping
Sutherland-Hodgman polygon clipping
The   Sutherland-Hodgman clipping algorithm   finds the polygon that is the intersection between an arbitrary polygon (the “subject polygon”) and a convex polygon (the “clip polygon”). It is used in computer graphics (especially 2D graphics) to reduce the complexity of a scene being displayed by eliminating parts of a polygon that do not need to be displayed. Task Take the closed polygon defined by the points: [ ( 50 , 150 ) , ( 200 , 50 ) , ( 350 , 150 ) , ( 350 , 300 ) , ( 250 , 300 ) , ( 200 , 250 ) , ( 150 , 350 ) , ( 100 , 250 ) , ( 100 , 200 ) ] {\displaystyle [(50,150),(200,50),(350,150),(350,300),(250,300),(200,250),(150,350),(100,250),(100,200)]} and clip it by the rectangle defined by the points: [ ( 100 , 100 ) , ( 300 , 100 ) , ( 300 , 300 ) , ( 100 , 300 ) ] {\displaystyle [(100,100),(300,100),(300,300),(100,300)]} Print the sequence of points that define the resulting clipped polygon. Extra credit Display all three polygons on a graphical surface, using a different color for each polygon and filling the resulting polygon. (When displaying you may use either a north-west or a south-west origin, whichever is more convenient for your display mechanism.)
#C.2B.2B
C++
#include <iostream>   using namespace std;   struct point2D { float x, y; };   const int N = 99; // clipped (new) polygon size   // check if a point is on the LEFT side of an edge bool inside(point2D p, point2D p1, point2D p2) { return (p2.y - p1.y) * p.x + (p1.x - p2.x) * p.y + (p2.x * p1.y - p1.x * p2.y) < 0; }   // calculate intersection point point2D intersection(point2D cp1, point2D cp2, point2D s, point2D e) { point2D dc = { cp1.x - cp2.x, cp1.y - cp2.y }; point2D dp = { s.x - e.x, s.y - e.y };   float n1 = cp1.x * cp2.y - cp1.y * cp2.x; float n2 = s.x * e.y - s.y * e.x; float n3 = 1.0 / (dc.x * dp.y - dc.y * dp.x);   return { (n1 * dp.x - n2 * dc.x) * n3, (n1 * dp.y - n2 * dc.y) * n3 }; }   // Sutherland-Hodgman clipping void SutherlandHodgman(point2D *subjectPolygon, int &subjectPolygonSize, point2D *clipPolygon, int &clipPolygonSize, point2D (&newPolygon)[N], int &newPolygonSize) { point2D cp1, cp2, s, e, inputPolygon[N];   // copy subject polygon to new polygon and set its size for(int i = 0; i < subjectPolygonSize; i++) newPolygon[i] = subjectPolygon[i];   newPolygonSize = subjectPolygonSize;   for(int j = 0; j < clipPolygonSize; j++) { // copy new polygon to input polygon & set counter to 0 for(int k = 0; k < newPolygonSize; k++){ inputPolygon[k] = newPolygon[k]; } int counter = 0;   // get clipping polygon edge cp1 = clipPolygon[j]; cp2 = clipPolygon[(j + 1) % clipPolygonSize];   for(int i = 0; i < newPolygonSize; i++) { // get subject polygon edge s = inputPolygon[i]; e = inputPolygon[(i + 1) % newPolygonSize];   // Case 1: Both vertices are inside: // Only the second vertex is added to the output list if(inside(s, cp1, cp2) && inside(e, cp1, cp2)) newPolygon[counter++] = e;   // Case 2: First vertex is outside while second one is inside: // Both the point of intersection of the edge with the clip boundary // and the second vertex are added to the output list else if(!inside(s, cp1, cp2) && inside(e, cp1, cp2)) { newPolygon[counter++] = intersection(cp1, cp2, s, e); newPolygon[counter++] = e; }   // Case 3: First vertex is inside while second one is outside: // Only the point of intersection of the edge with the clip boundary // is added to the output list else if(inside(s, cp1, cp2) && !inside(e, cp1, cp2)) newPolygon[counter++] = intersection(cp1, cp2, s, e);   // Case 4: Both vertices are outside else if(!inside(s, cp1, cp2) && !inside(e, cp1, cp2)) { // No vertices are added to the output list } } // set new polygon size newPolygonSize = counter; } }   int main(int argc, char** argv) { // subject polygon point2D subjectPolygon[] = { {50,150}, {200,50}, {350,150}, {350,300},{250,300},{200,250}, {150,350},{100,250},{100,200} }; int subjectPolygonSize = sizeof(subjectPolygon) / sizeof(subjectPolygon[0]);   // clipping polygon point2D clipPolygon[] = { {100,100}, {300,100}, {300,300}, {100,300} }; int clipPolygonSize = sizeof(clipPolygon) / sizeof(clipPolygon[0]);   // define the new clipped polygon (empty) int newPolygonSize = 0; point2D newPolygon[N] = { 0 };   // apply clipping SutherlandHodgman(subjectPolygon, subjectPolygonSize, clipPolygon, clipPolygonSize, newPolygon, newPolygonSize);   // print clipped polygon points cout << "Clipped polygon points:" << endl; for(int i = 0; i < newPolygonSize; i++) cout << "(" << newPolygon[i].x << ", " << newPolygon[i].y << ")" << endl;   return 0; }  
http://rosettacode.org/wiki/Symmetric_difference
Symmetric difference
Task Given two sets A and B, compute ( A ∖ B ) ∪ ( B ∖ A ) . {\displaystyle (A\setminus B)\cup (B\setminus A).} That is, enumerate the items that are in A or B but not both. This set is called the symmetric difference of A and B. In other words: ( A ∪ B ) ∖ ( A ∩ B ) {\displaystyle (A\cup B)\setminus (A\cap B)} (the set of items that are in at least one of A or B minus the set of items that are in both A and B). Optionally, give the individual differences ( A ∖ B {\displaystyle A\setminus B} and B ∖ A {\displaystyle B\setminus A} ) as well. Test cases A = {John, Bob, Mary, Serena} B = {Jim, Mary, John, Bob} Notes If your code uses lists of items to represent sets then ensure duplicate items in lists are correctly handled. For example two lists representing sets of a = ["John", "Serena", "Bob", "Mary", "Serena"] and b = ["Jim", "Mary", "John", "Jim", "Bob"] should produce the result of just two strings: ["Serena", "Jim"], in any order. In the mathematical notation above A \ B gives the set of items in A that are not in B; A ∪ B gives the set of items in both A and B, (their union); and A ∩ B gives the set of items that are in both A and B (their intersection).
#APL
APL
symdiff ← ∪~∩
http://rosettacode.org/wiki/Symmetric_difference
Symmetric difference
Task Given two sets A and B, compute ( A ∖ B ) ∪ ( B ∖ A ) . {\displaystyle (A\setminus B)\cup (B\setminus A).} That is, enumerate the items that are in A or B but not both. This set is called the symmetric difference of A and B. In other words: ( A ∪ B ) ∖ ( A ∩ B ) {\displaystyle (A\cup B)\setminus (A\cap B)} (the set of items that are in at least one of A or B minus the set of items that are in both A and B). Optionally, give the individual differences ( A ∖ B {\displaystyle A\setminus B} and B ∖ A {\displaystyle B\setminus A} ) as well. Test cases A = {John, Bob, Mary, Serena} B = {Jim, Mary, John, Bob} Notes If your code uses lists of items to represent sets then ensure duplicate items in lists are correctly handled. For example two lists representing sets of a = ["John", "Serena", "Bob", "Mary", "Serena"] and b = ["Jim", "Mary", "John", "Jim", "Bob"] should produce the result of just two strings: ["Serena", "Jim"], in any order. In the mathematical notation above A \ B gives the set of items in A that are not in B; A ∪ B gives the set of items in both A and B, (their union); and A ∩ B gives the set of items that are in both A and B (their intersection).
#AppleScript
AppleScript
-- SYMMETRIC DIFFERENCE -------------------------------------------   -- symmetricDifference :: [a] -> [a] -> [a] on symmetricDifference(xs, ys) union(difference(xs, ys), difference(ys, xs)) end symmetricDifference   -- TEST ----------------------------------------------------------- on run set a to ["John", "Serena", "Bob", "Mary", "Serena"] set b to ["Jim", "Mary", "John", "Jim", "Bob"]   symmetricDifference(a, b)   --> {"Serena", "Jim"} end run     -- GENERIC FUNCTIONS ----------------------------------------------   -- delete :: Eq a => a -> [a] -> [a] on |delete|(x, xs) set mbIndex to elemIndex(x, xs) set lng to length of xs   if mbIndex is not missing value then if lng > 1 then if mbIndex = 1 then items 2 thru -1 of xs else if mbIndex = lng then items 1 thru -2 of xs else tell xs to items 1 thru (mbIndex - 1) & ¬ items (mbIndex + 1) thru -1 end if else {} end if else xs end if end |delete|   -- difference :: [a] -> [a] -> [a] on difference(xs, ys) script on |λ|(a, y) if a contains y then my |delete|(y, a) else a end if end |λ| end script   foldl(result, xs, ys) end difference   -- elemIndex :: a -> [a] -> Maybe Int on elemIndex(x, xs) set lng to length of xs repeat with i from 1 to lng if x = (item i of xs) then return i end repeat return missing value end elemIndex   -- foldl :: (a -> b -> a) -> a -> [b] -> a on foldl(f, startValue, xs) tell mReturn(f) set v to startValue set lng to length of xs repeat with i from 1 to lng set v to |λ|(v, item i of xs, i, xs) end repeat return v end tell end foldl   -- Lift 2nd class handler function into 1st class script wrapper -- mReturn :: Handler -> Script on mReturn(f) if class of f is script then f else script property |λ| : f end script end if end mReturn   -- nub :: [a] -> [a] on nub(xs) if (length of xs) > 1 then set x to item 1 of xs [x] & nub(|delete|(x, items 2 thru -1 of xs)) else xs end if end nub   -- union :: [a] -> [a] -> [a] on union(xs, ys) script flipDelete on |λ|(xs, x) my |delete|(x, xs) end |λ| end script   set sx to nub(xs) sx & foldl(flipDelete, nub(ys), sx) end union
http://rosettacode.org/wiki/Super-d_numbers
Super-d numbers
A super-d number is a positive, decimal (base ten) integer   n   such that   d × nd   has at least   d   consecutive digits   d   where 2 ≤ d ≤ 9 For instance, 753 is a super-3 number because 3 × 7533 = 1280873331. Super-d   numbers are also shown on   MathWorld™   as   super-d   or   super-d. Task Write a function/procedure/routine to find super-d numbers. For   d=2   through   d=6,   use the routine to show the first   10   super-d numbers. Extra credit Show the first   10   super-7, super-8, and/or super-9 numbers   (optional). See also   Wolfram MathWorld - Super-d Number.   OEIS: A014569 - Super-3 Numbers.
#F.23
F#
  // Generate Super-N numbers. Nigel Galloway: October 12th., 2019 let superD N= let I=bigint(pown 10 N) let G=bigint N let E=G*(111111111I%I) let rec fL n=match (E-n%I).IsZero with true->true |_->if (E*10I)<n then false else fL (n/10I) seq{1I..999999999999999999I}|>Seq.choose(fun n->if fL (G*n**N) then Some n else None)  
http://rosettacode.org/wiki/Super-d_numbers
Super-d numbers
A super-d number is a positive, decimal (base ten) integer   n   such that   d × nd   has at least   d   consecutive digits   d   where 2 ≤ d ≤ 9 For instance, 753 is a super-3 number because 3 × 7533 = 1280873331. Super-d   numbers are also shown on   MathWorld™   as   super-d   or   super-d. Task Write a function/procedure/routine to find super-d numbers. For   d=2   through   d=6,   use the routine to show the first   10   super-d numbers. Extra credit Show the first   10   super-7, super-8, and/or super-9 numbers   (optional). See also   Wolfram MathWorld - Super-d Number.   OEIS: A014569 - Super-3 Numbers.
#Factor
Factor
USING: arrays formatting io kernel lists lists.lazy math math.functions math.ranges math.text.utils prettyprint sequences ; IN: rosetta-code.super-d   : super-d? ( seq n d -- ? ) tuck ^ * 1 digit-groups subseq? ;   : super-d ( d -- list ) [ dup <array> ] [ drop 1 lfrom ] [ ] tri [ super-d? ] curry with lfilter ;   : super-d-demo ( -- ) 10 2 6 [a,b] [ dup "First 10 super-%d numbers:\n" printf super-d ltake list>array [ pprint bl ] each nl nl ] with each ;   MAIN: super-d-demo
http://rosettacode.org/wiki/Super-d_numbers
Super-d numbers
A super-d number is a positive, decimal (base ten) integer   n   such that   d × nd   has at least   d   consecutive digits   d   where 2 ≤ d ≤ 9 For instance, 753 is a super-3 number because 3 × 7533 = 1280873331. Super-d   numbers are also shown on   MathWorld™   as   super-d   or   super-d. Task Write a function/procedure/routine to find super-d numbers. For   d=2   through   d=6,   use the routine to show the first   10   super-d numbers. Extra credit Show the first   10   super-7, super-8, and/or super-9 numbers   (optional). See also   Wolfram MathWorld - Super-d Number.   OEIS: A014569 - Super-3 Numbers.
#F.C5.8Drmul.C3.A6
Fōrmulæ
package main   import ( "fmt" "math/big" "strings" "time" )   func main() { start := time.Now() rd := []string{"22", "333", "4444", "55555", "666666", "7777777", "88888888", "999999999"} one := big.NewInt(1) nine := big.NewInt(9) for i := big.NewInt(2); i.Cmp(nine) <= 0; i.Add(i, one) { fmt.Printf("First 10 super-%d numbers:\n", i) ii := i.Uint64() k := new(big.Int) count := 0 inner: for j := big.NewInt(3); ; j.Add(j, one) { k.Exp(j, i, nil) k.Mul(i, k) ix := strings.Index(k.String(), rd[ii-2]) if ix >= 0 { count++ fmt.Printf("%d ", j) if count == 10 { fmt.Printf("\nfound in %d ms\n\n", time.Since(start).Milliseconds()) break inner } } } } }
http://rosettacode.org/wiki/Take_notes_on_the_command_line
Take notes on the command line
Take notes on the command line is part of Short Circuit's Console Program Basics selection. Invoking NOTES without commandline arguments displays the current contents of the local NOTES.TXT if it exists. If NOTES has arguments, the current date and time are appended to the local NOTES.TXT followed by a newline. Then all the arguments, joined with spaces, prepended with a tab, and appended with a trailing newline, are written to NOTES.TXT. If NOTES.TXT doesn't already exist in the current directory then a new NOTES.TXT file should be created.
#Erlang
Erlang
  #! /usr/bin/env escript   main( Arguments ) -> display_notes( Arguments ), save_notes( Arguments ).       display_notes( [] ) -> io:fwrite( "~s", [erlang:binary_to_list(file_contents())] ); display_notes( _Arguments ) -> ok.   file() -> "NOTES.TXT".   file_contents() -> file_contents( file:read_file(file()) ).   file_contents( {ok, Binary} ) -> Binary; file_contents( {error, _Error} ) -> <<>>.   save_notes( [] ) -> ok; save_notes( Arguments ) -> Date = io_lib:format( "~p~n", [calendar:local_time()] ), Notes = [Date ++ "\t" | [io_lib:format( "~s ", [X]) || X <- Arguments]], Existing_contents = file_contents(), file:write_file( file(), [Existing_contents, Notes, "\n"] ).  
http://rosettacode.org/wiki/Superellipse
Superellipse
A superellipse is a geometric figure defined as the set of all points (x, y) with | x a | n + | y b | n = 1 , {\displaystyle \left|{\frac {x}{a}}\right|^{n}\!+\left|{\frac {y}{b}}\right|^{n}\!=1,} where n, a, and b are positive numbers. Task Draw a superellipse with n = 2.5, and a = b = 200
#EchoLisp
EchoLisp
  (lib 'plot) (define (eaxpt x n) (expt (abs x) n)) (define (Ellie x y) (+ (eaxpt (// x 200) 2.5) (eaxpt (// y 200) 2.5) -1))   (plot-xy Ellie -400 -400) → (("x:auto" -400 400) ("y:auto" -400 400))  
http://rosettacode.org/wiki/Sylvester%27s_sequence
Sylvester's sequence
This page uses content from Wikipedia. The original article was at Sylvester's sequence. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance) In number theory, Sylvester's sequence is an integer sequence in which each term of the sequence is the product of the previous terms, plus one. Its values grow doubly exponentially, and the sum of its reciprocals forms a series of unit fractions that converges to 1 more rapidly than any other series of unit fractions with the same number of terms. Further, the sum of the first k terms of the infinite series of reciprocals provides the closest possible underestimate of 1 by any k-term Egyptian fraction. Task Write a routine (function, procedure, generator, whatever) to calculate Sylvester's sequence. Use that routine to show the values of the first 10 elements in the sequence. Show the sum of the reciprocals of the first 10 elements on the sequence, ideally as an exact fraction. Related tasks Egyptian fractions Harmonic series See also OEIS A000058 - Sylvester's sequence
#Perl
Perl
use strict; use warnings; use feature 'say'; use List::Util 'reduce'; use Math::AnyNum ':overload'; local $Math::AnyNum::PREC = 845;   my(@S,$sum); push @S, 1 + reduce { $a * $b } @S for 0..10; shift @S; $sum += 1/$_ for @S;   say "First 10 elements of Sylvester's sequence: @S"; say "\nSum of the reciprocals of first 10 elements: " . float $sum;
http://rosettacode.org/wiki/Sylvester%27s_sequence
Sylvester's sequence
This page uses content from Wikipedia. The original article was at Sylvester's sequence. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance) In number theory, Sylvester's sequence is an integer sequence in which each term of the sequence is the product of the previous terms, plus one. Its values grow doubly exponentially, and the sum of its reciprocals forms a series of unit fractions that converges to 1 more rapidly than any other series of unit fractions with the same number of terms. Further, the sum of the first k terms of the infinite series of reciprocals provides the closest possible underestimate of 1 by any k-term Egyptian fraction. Task Write a routine (function, procedure, generator, whatever) to calculate Sylvester's sequence. Use that routine to show the values of the first 10 elements in the sequence. Show the sum of the reciprocals of the first 10 elements on the sequence, ideally as an exact fraction. Related tasks Egyptian fractions Harmonic series See also OEIS A000058 - Sylvester's sequence
#Phix
Phix
atom n, rn = 0, lim = power(2,iff(machine_bits()=32?53:64)) for i=1 to 10 do n = iff(i=1?2:n*n-n+1) printf(1,iff(n<=lim?"%d: %d\n":"%d: %g\n"),{i,n}) rn += 1/n end for printf(1,"sum of reciprocals: %g\n",{rn})
http://rosettacode.org/wiki/Taxicab_numbers
Taxicab numbers
A   taxicab number   (the definition that is being used here)   is a positive integer that can be expressed as the sum of two positive cubes in more than one way. The first taxicab number is   1729,   which is: 13   +   123       and also 93   +   103. Taxicab numbers are also known as:   taxi numbers   taxi-cab numbers   taxi cab numbers   Hardy-Ramanujan numbers Task Compute and display the lowest 25 taxicab numbers (in numeric order, and in a human-readable format). For each of the taxicab numbers, show the number as well as it's constituent cubes. Extra credit Show the 2,000th taxicab number, and a half dozen more See also A001235: taxicab numbers on The On-Line Encyclopedia of Integer Sequences. Hardy-Ramanujan Number on MathWorld. taxicab number on MathWorld. taxicab number on Wikipedia   (includes the story on how taxi-cab numbers came to be called).
#JavaScript
JavaScript
var n3s = [], s3s = {} for (var n = 1, e = 1200; n < e; n += 1) n3s[n] = n * n * n for (var a = 1; a < e - 1; a += 1) { var a3 = n3s[a] for (var b = a; b < e; b += 1) { var b3 = n3s[b] var s3 = a3 + b3, abs = s3s[s3] if (!abs) s3s[s3] = abs = [] abs.push([a, b]) } }   var i = 0 for (var s3 in s3s) { var abs = s3s[s3] if (abs.length < 2) continue i += 1 if (abs.length == 2 && i > 25 && i < 2000) continue if (i > 2006) break document.write(i, ': ', s3) for (var ab of abs) { document.write(' = ', ab[0], '<sup>3</sup>+', ab[1], '<sup>3</sup>') } document.write('<br>') }
http://rosettacode.org/wiki/Superpermutation_minimisation
Superpermutation minimisation
A superpermutation of N different characters is a string consisting of an arrangement of multiple copies of those N different characters in which every permutation of those characters can be found as a substring. For example, representing the characters as A..Z, using N=2 we choose to use the first two characters 'AB'. The permutations of 'AB' are the two, (i.e. two-factorial), strings: 'AB' and 'BA'. A too obvious method of generating a superpermutation is to just join all the permutations together forming 'ABBA'. A little thought will produce the shorter (in fact the shortest) superpermutation of 'ABA' - it contains 'AB' at the beginning and contains 'BA' from the middle to the end. The "too obvious" method of creation generates a string of length N!*N. Using this as a yardstick, the task is to investigate other methods of generating superpermutations of N from 1-to-7 characters, that never generate larger superpermutations. Show descriptions and comparisons of algorithms used here, and select the "Best" algorithm as being the one generating shorter superpermutations. The problem of generating the shortest superpermutation for each N might be NP complete, although the minimal strings for small values of N have been found by brute -force searches. 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 Reference The Minimal Superpermutation Problem. by Nathaniel Johnston. oeis A180632 gives 0-5 as 0, 1, 3, 9, 33, 153. 6 is thought to be 872. Superpermutations - Numberphile. A video Superpermutations: the maths problem solved by 4chan - Standupmaths. A video of recent (2018) mathematical progress. New Superpermutations Discovered! Standupmaths & Numberphile.
#Groovy
Groovy
import static java.util.stream.IntStream.rangeClosed   class Superpermutation { final static int nMax = 12   static char[] superperm static int pos static int[] count = new int[nMax]   static int factSum(int n) { return rangeClosed(1, n) .map({ m -> rangeClosed(1, m).reduce(1, { a, b -> a * b }) }).sum() }   static boolean r(int n) { if (n == 0) { return false }   char c = superperm[pos - n] if (--count[n] == 0) { count[n] = n if (!r(n - 1)) { return false } } superperm[pos++] = c return true }   static void superPerm(int n) { String chars = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ"   pos = n superperm = new char[factSum(n)]   for (int i = 0; i < n + 1; i++) { count[i] = i } for (int i = 1; i < n + 1; i++) { superperm[i - 1] = chars.charAt(i) }   while (r(n)) { } }   static void main(String[] args) { for (int n = 0; n < nMax; n++) { superPerm(n) printf("superPerm(%2d) len = %d", n, superperm.length) println() } } }
http://rosettacode.org/wiki/Tau_number
Tau number
A Tau number is a positive integer divisible by the count of its positive divisors. Task Show the first   100   Tau numbers. The numbers shall be generated during run-time (i.e. the code may not contain string literals, sets/arrays of integers, or alike). Related task  Tau function
#R
R
tau <- function(t) { results <- integer(0) resultsCount <- 0 n <- 1 while(resultsCount != t) { condition <- function(n) (n %% length(c(Filter(function(x) n %% x == 0, seq_len(n %/% 2)), n))) == 0 if(condition(n)) { resultsCount <- resultsCount + 1 results[resultsCount] <- n } n <- n + 1 } results } tau(100)
http://rosettacode.org/wiki/Tau_number
Tau number
A Tau number is a positive integer divisible by the count of its positive divisors. Task Show the first   100   Tau numbers. The numbers shall be generated during run-time (i.e. the code may not contain string literals, sets/arrays of integers, or alike). Related task  Tau function
#Raku
Raku
use Prime::Factor:ver<0.3.0+>; use Lingua::EN::Numbers;   say "\nTau function - first 100:\n", # ID (1..*).map({ +.&divisors })[^100]\ # the task .batch(20)».fmt("%3d").join("\n"); # display formatting   say "\nTau numbers - first 100:\n", # ID (1..*).grep({ $_ %% +.&divisors })[^100]\ # the task .batch(10)».&comma».fmt("%5s").join("\n"); # display formatting   say "\nDivisor sums - first 100:\n", # ID (1..*).map({ [+] .&divisors })[^100]\ # the task .batch(20)».fmt("%4d").join("\n"); # display formatting   say "\nDivisor products - first 100:\n", # ID (1..*).map({ [×] .&divisors })[^100]\ # the task .batch(5)».&comma».fmt("%16s").join("\n"); # display formatting
http://rosettacode.org/wiki/Teacup_rim_text
Teacup rim text
On a set of coasters we have, there's a picture of a teacup.   On the rim of the teacup the word   TEA   appears a number of times separated by bullet characters   (•). It occurred to me that if the bullet were removed and the words run together,   you could start at any letter and still end up with a meaningful three-letter word. So start at the   T   and read   TEA.   Start at the   E   and read   EAT,   or start at the   A   and read   ATE. That got me thinking that maybe there are other words that could be used rather that   TEA.   And that's just English.   What about Italian or Greek or ... um ... Telugu. For English, we will use the unixdict (now) located at:   unixdict.txt. (This will maintain continuity with other Rosetta Code tasks that also use it.) Task Search for a set of words that could be printed around the edge of a teacup.   The words in each set are to be of the same length, that length being greater than two (thus precluding   AH   and   HA,   for example.) Having listed a set, for example   [ate tea eat],   refrain from displaying permutations of that set, e.g.:   [eat tea ate]   etc. The words should also be made of more than one letter   (thus precluding   III   and   OOO   etc.) The relationship between these words is (using ATE as an example) that the first letter of the first becomes the last letter of the second.   The first letter of the second becomes the last letter of the third.   So   ATE   becomes   TEA   and   TEA   becomes   EAT. All of the possible permutations, using this particular permutation technique, must be words in the list. The set you generate for   ATE   will never included the word   ETA   as that cannot be reached via the first-to-last movement method. Display one line for each set of teacup rim words. 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
#zkl
zkl
// Limited to ASCII // This is limited to the max items a Dictionary can hold fcn teacut(wordFile){ words:=File(wordFile).pump(Dictionary().add.fp1(True),"strip"); seen :=Dictionary(); foreach word in (words.keys){ rots,w,sz := List(), word, word.len(); if(sz>2 and word.unique().len()>2 and not seen.holds(word)){ do(sz-1){ w=String(w[-1],w[0,-1]); // rotate one character if(not words.holds(w)) continue(2); // not a word, skip these rots.append(w); // I'd like to see all the rotations } println(rots.append(word).sort().concat(" ")); rots.pump(seen.add.fp1(True)); // we've seen these rotations } } }
http://rosettacode.org/wiki/Temperature_conversion
Temperature conversion
There are quite a number of temperature scales. For this task we will concentrate on four of the perhaps best-known ones: Kelvin, Celsius, Fahrenheit, and Rankine. The Celsius and Kelvin scales have the same magnitude, but different null points. 0 degrees Celsius corresponds to 273.15 kelvin. 0 kelvin is absolute zero. The Fahrenheit and Rankine scales also have the same magnitude, but different null points. 0 degrees Fahrenheit corresponds to 459.67 degrees Rankine. 0 degrees Rankine is absolute zero. The Celsius/Kelvin and Fahrenheit/Rankine scales have a ratio of 5 : 9. Task Write code that accepts a value of kelvin, converts it to values of the three other scales, and prints the result. Example K 21.00 C -252.15 F -421.87 R 37.80
#Bracmat
Bracmat
( ( rational2fixedpoint = minus fixedpointnumber number decimals .  !arg:(#?number.~<0:~/#?decimals) & ( !number:0&"0.0" | ( !number:>0& | -1*!number:?number&"-" )  : ?minus & !number+1/2*10^(-1*!decimals):?number & !minus div$(!number.1) ".":?fixedpointnumber & whl ' ( !decimals+-1:~<0:?decimals &  !fixedpointnumber div$(mod$(!number.1)*10:?number.1)  : ?fixedpointnumber ) & str$!fixedpointnumber ) ) & ( fixedpoint2rational = integerpart fractionalpart decimals . @( !arg  : #?integerpart ( "." ?fractionalpart | &0:?fractionalpart ) ) & @(!fractionalpart:? #?fractionalpart [?decimals) &  !integerpart + (!integerpart:<0&-1|1) * 10^(-1*!decimals) * !fractionalpart ) & whl ' ( put$"Enter Kelvin temperature:" & fixedpoint2rational$(get'(,STR)):?kelvin & !kelvin+-27315/100:?celcius & (degree=.str$(chu$(x2d$b0) !arg)) & out$(rational2fixedpoint$(!kelvin.2) K) & out$(rational2fixedpoint$(!celcius.2) degree$C) & out$(rational2fixedpoint$(!celcius*9/5+32.2) degree$F) & out$(rational2fixedpoint$(!kelvin*9/5.2) degree$Ra) & out$(rational2fixedpoint$(!celcius*4/5.2) degree$Ré) ) & done! )
http://rosettacode.org/wiki/Tau_function
Tau function
Given a positive integer, count the number of its positive divisors. Task Show the result for the first   100   positive integers. Related task  Tau number
#Mathematica.2FWolfram_Language
Mathematica/Wolfram Language
DivisorSum[#, 1 &] & /@ Range[100]
http://rosettacode.org/wiki/Tau_function
Tau function
Given a positive integer, count the number of its positive divisors. Task Show the result for the first   100   positive integers. Related task  Tau number
#Modula-2
Modula-2
MODULE TauFunc; FROM InOut IMPORT WriteCard, WriteLn;   VAR i: CARDINAL;   PROCEDURE tau(n: CARDINAL): CARDINAL; VAR total, count, p: CARDINAL; BEGIN total := 1; WHILE n MOD 2 = 0 DO n := n DIV 2; total := total + 1 END; p := 3; WHILE p*p <= n DO count := 1; WHILE n MOD p = 0 DO n := n DIV p; count := count + 1 END; total := total * count; p := p + 2 END; IF n>1 THEN total := total * 2 END; RETURN total; END tau;   BEGIN FOR i := 1 TO 100 DO WriteCard(tau(i), 3); IF i MOD 20 = 0 THEN WriteLn END END END TauFunc.
http://rosettacode.org/wiki/Terminal_control/Clear_the_screen
Terminal control/Clear the screen
Task Clear the terminal window.
#Octave
Octave
system clear;
http://rosettacode.org/wiki/Terminal_control/Clear_the_screen
Terminal control/Clear the screen
Task Clear the terminal window.
#Pascal
Pascal
clrscr;
http://rosettacode.org/wiki/Terminal_control/Clear_the_screen
Terminal control/Clear the screen
Task Clear the terminal window.
#Perl
Perl
system('clear')
http://rosettacode.org/wiki/Ternary_logic
Ternary logic
This page uses content from Wikipedia. The original article was at Ternary logic. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance) In logic, a three-valued logic (also trivalent, ternary, or trinary logic, sometimes abbreviated 3VL) is any of several many-valued logic systems in which there are three truth values indicating true, false and some indeterminate third value. This is contrasted with the more commonly known bivalent logics (such as classical sentential or boolean logic) which provide only for true and false. Conceptual form and basic ideas were initially created by Łukasiewicz, Lewis and Sulski. These were then re-formulated by Grigore Moisil in an axiomatic algebraic form, and also extended to n-valued logics in 1945. Example Ternary Logic Operators in Truth Tables: not a ¬ True False Maybe Maybe False True a and b ∧ True Maybe False True True Maybe False Maybe Maybe Maybe False False False False False a or b ∨ True Maybe False True True True True Maybe True Maybe Maybe False True Maybe False if a then b ⊃ True Maybe False True True Maybe False Maybe True Maybe Maybe False True True True a is equivalent to b ≡ True Maybe False True True Maybe False Maybe Maybe Maybe Maybe False False Maybe True Task Define a new type that emulates ternary logic by storing data trits. Given all the binary logic operators of the original programming language, reimplement these operators for the new Ternary logic type trit. Generate a sampling of results using trit variables. Kudos for actually thinking up a test case algorithm where ternary logic is intrinsically useful, optimises the test case algorithm and is preferable to binary logic. Note:   Setun   (Сетунь) was a   balanced ternary   computer developed in 1958 at   Moscow State University.   The device was built under the lead of   Sergei Sobolev   and   Nikolay Brusentsov.   It was the only modern   ternary computer,   using three-valued ternary logic
#Mathematica.2FWolfram_Language
Mathematica/Wolfram Language
Maybe /: ! Maybe = Maybe; Maybe /: (And | Or | Nand | Nor | Xor | Xnor | Implies | Equivalent)[Maybe, Maybe] = Maybe;
http://rosettacode.org/wiki/Ternary_logic
Ternary logic
This page uses content from Wikipedia. The original article was at Ternary logic. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance) In logic, a three-valued logic (also trivalent, ternary, or trinary logic, sometimes abbreviated 3VL) is any of several many-valued logic systems in which there are three truth values indicating true, false and some indeterminate third value. This is contrasted with the more commonly known bivalent logics (such as classical sentential or boolean logic) which provide only for true and false. Conceptual form and basic ideas were initially created by Łukasiewicz, Lewis and Sulski. These were then re-formulated by Grigore Moisil in an axiomatic algebraic form, and also extended to n-valued logics in 1945. Example Ternary Logic Operators in Truth Tables: not a ¬ True False Maybe Maybe False True a and b ∧ True Maybe False True True Maybe False Maybe Maybe Maybe False False False False False a or b ∨ True Maybe False True True True True Maybe True Maybe Maybe False True Maybe False if a then b ⊃ True Maybe False True True Maybe False Maybe True Maybe Maybe False True True True a is equivalent to b ≡ True Maybe False True True Maybe False Maybe Maybe Maybe Maybe False False Maybe True Task Define a new type that emulates ternary logic by storing data trits. Given all the binary logic operators of the original programming language, reimplement these operators for the new Ternary logic type trit. Generate a sampling of results using trit variables. Kudos for actually thinking up a test case algorithm where ternary logic is intrinsically useful, optimises the test case algorithm and is preferable to binary logic. Note:   Setun   (Сетунь) was a   balanced ternary   computer developed in 1958 at   Moscow State University.   The device was built under the lead of   Sergei Sobolev   and   Nikolay Brusentsov.   It was the only modern   ternary computer,   using three-valued ternary logic
#.D0.9C.D0.9A-61.2F52
МК-61/52
П0 Сx С/П ^ 1 + 3 * + 1 + 3 x^y ИП0 <-> / [x] ^ ^ 3 / [x] 3 * - 1 - С/П 1 5 6 3 3 БП 00 1 9 5 6 9 БП 00 1 5 9 2 9 БП 00 1 5 6 6 5 БП 00 /-/ ЗН С/П
http://rosettacode.org/wiki/Text_processing/1
Text processing/1
This task has been flagged for clarification. Code on this page in its current state may be flagged incorrect once this task has been clarified. See this page's Talk page for discussion. Often data is produced by one program, in the wrong format for later use by another program or person. In these situations another program can be written to parse and transform the original data into a format useful to the other. The term "Data Munging" is often used in programming circles for this task. A request on the comp.lang.awk newsgroup led to a typical data munging task: I have to analyse data files that have the following format: Each row corresponds to 1 day and the field logic is: $1 is the date, followed by 24 value/flag pairs, representing measurements at 01:00, 02:00 ... 24:00 of the respective day. In short: <date> <val1> <flag1> <val2> <flag2> ... <val24> <flag24> Some test data is available at: ... (nolonger available at original location) I have to sum up the values (per day and only valid data, i.e. with flag>0) in order to calculate the mean. That's not too difficult. However, I also need to know what the "maximum data gap" is, i.e. the longest period with successive invalid measurements (i.e values with flag<=0) The data is free to download and use and is of this format: Data is no longer available at that link. Zipped mirror available here (offsite mirror). 1991-03-30 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 1991-03-31 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 20.000 1 20.000 1 20.000 1 35.000 1 50.000 1 60.000 1 40.000 1 30.000 1 30.000 1 30.000 1 25.000 1 20.000 1 20.000 1 20.000 1 20.000 1 20.000 1 35.000 1 1991-03-31 40.000 1 0.000 -2 0.000 -2 0.000 -2 0.000 -2 0.000 -2 0.000 -2 0.000 -2 0.000 -2 0.000 -2 0.000 -2 0.000 -2 0.000 -2 0.000 -2 0.000 -2 0.000 -2 0.000 -2 0.000 -2 0.000 -2 0.000 -2 0.000 -2 0.000 -2 0.000 -2 0.000 -2 1991-04-01 0.000 -2 13.000 1 16.000 1 21.000 1 24.000 1 22.000 1 20.000 1 18.000 1 29.000 1 44.000 1 50.000 1 43.000 1 38.000 1 27.000 1 27.000 1 24.000 1 23.000 1 18.000 1 12.000 1 13.000 1 14.000 1 15.000 1 13.000 1 10.000 1 1991-04-02 8.000 1 9.000 1 11.000 1 12.000 1 12.000 1 12.000 1 27.000 1 26.000 1 27.000 1 33.000 1 32.000 1 31.000 1 29.000 1 31.000 1 25.000 1 25.000 1 24.000 1 21.000 1 17.000 1 14.000 1 15.000 1 12.000 1 12.000 1 10.000 1 1991-04-03 10.000 1 9.000 1 10.000 1 10.000 1 9.000 1 10.000 1 15.000 1 24.000 1 28.000 1 24.000 1 18.000 1 14.000 1 12.000 1 13.000 1 14.000 1 15.000 1 14.000 1 15.000 1 13.000 1 13.000 1 13.000 1 12.000 1 10.000 1 10.000 1 Only a sample of the data showing its format is given above. The full example file may be downloaded here. Structure your program to show statistics for each line of the file, (similar to the original Python, Perl, and AWK examples below), followed by summary statistics for the file. When showing example output just show a few line statistics and the full end summary.
#PL.2FI
PL/I
text1: procedure options (main); /* 13 May 2010 */   declare line character (2000) varying; declare 1 pairs(24), 2 value fixed (10,4), 2 flag fixed; declare date character (12) varying; declare no_items fixed decimal (10); declare (nv, sum, line_no, ndud_values, max_ndud_values) fixed; declare (i, k) fixed binary; declare in file input;   open file (in) title ('/TEXT1.DAT,TYPE(TEXT),RECSIZE(2000)' );   on endfile (in) go to finish_up;   line_no = 0; loop: do forever; get file (in) edit (line) (L); /* put skip list (line); */ line = translate(line, ' ', '09'x); line_no = line_no + 1; line = trim(line); no_items = tally(line, ' ') - tally(line, ' ') + 1; if no_items ^= 49 then do; put skip list ('There are not 49 items on this line'); iterate loop; end; k = index(line, ' '); /* Find the first blank in the line. */ date = substr(line, 1, k); line = substr(line, k) || ' '; on conversion go to loop; get string (line) list (pairs); sum, nv, ndud_values, max_ndud_values = 0; do i = 1 to 24; if flag(i) > 0 then do; sum = sum + value(i); nv = nv + 1; ndud_values = 0; /* reset the counter of dud values */ end; else do; /* we have a dud reading. */ ndud_values = ndud_values + 1; if ndud_values > max_ndud_values then max_ndud_values = ndud_values; end; end; if nv = 0 then iterate; put skip list ('Line ' || trim(line_no) || ' average=', divide(sum, nv, 10,4) ); if max_ndud_values > 0 then put skip list ('Maximum run of dud readings =', max_ndud_values); end;   finish_up:   end text1;
http://rosettacode.org/wiki/The_Twelve_Days_of_Christmas
The Twelve Days of Christmas
Task Write a program that outputs the lyrics of the Christmas carol The Twelve Days of Christmas. The lyrics can be found here. (You must reproduce the words in the correct order, but case, format, and punctuation are left to your discretion.) 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
#Logo
Logo
make "numbers [first second third fourth fifth sixth seventh eighth ninth tenth eleventh twelfth] make "gifts [[And a partridge in a pear tree] [Two turtle doves] [Three French hens] [Four calling birds] [Five gold rings] [Six geese a-laying] [Seven swans a-swimming] [Eight maids a-miling] [Nine ladies dancing] [Ten lords a-leaping] [Eleven pipers piping] [Twelve drummers drumming]]   to nth :n print (sentence [On the] (item :n :numbers) [day of Christmas, my true love sent to me]) end   nth 1 print [A partridge in a pear tree]   for [d 2 12] [ print [] nth :d for [g :d 1] [ print item :g gifts ] ] bye
http://rosettacode.org/wiki/The_Twelve_Days_of_Christmas
The Twelve Days of Christmas
Task Write a program that outputs the lyrics of the Christmas carol The Twelve Days of Christmas. The lyrics can be found here. (You must reproduce the words in the correct order, but case, format, and punctuation are left to your discretion.) 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
#LOLCODE
LOLCODE
CAN HAS STDIO? HAI 1.2   I HAS A Dayz ITZ A BUKKIT Dayz HAS A SRS 1 ITZ "first" Dayz HAS A SRS 2 ITZ "second" Dayz HAS A SRS 3 ITZ "third" Dayz HAS A SRS 4 ITZ "fourth" Dayz HAS A SRS 5 ITZ "fifth" Dayz HAS A SRS 6 ITZ "sixth" Dayz HAS A SRS 7 ITZ "seventh" Dayz HAS A SRS 8 ITZ "eighth" Dayz HAS A SRS 9 ITZ "ninth" Dayz HAS A SRS 10 ITZ "tenth" Dayz HAS A SRS 11 ITZ "eleventh" Dayz HAS A SRS 12 ITZ "twelfth"   I HAS A Prezents ITZ A BUKKIT Prezents HAS A SRS 1 ITZ "A partridge in a pear tree" Prezents HAS A SRS 2 ITZ "Two turtle doves" Prezents HAS A SRS 3 ITZ "Three French hens" Prezents HAS A SRS 4 ITZ "Four calling birds" Prezents HAS A SRS 5 ITZ "Five gold rings" Prezents HAS A SRS 6 ITZ "Six geese a-laying" Prezents HAS A SRS 7 ITZ "Seven swans a-swimming" Prezents HAS A SRS 8 ITZ "Eight maids a-milking" Prezents HAS A SRS 9 ITZ "Nine ladies dancing" Prezents HAS A SRS 10 ITZ "Ten lords a-leaping" Prezents HAS A SRS 11 ITZ "Eleven pipers piping" Prezents HAS A SRS 12 ITZ "Twelve drummers drumming"   IM IN YR Outer UPPIN YR i WILE DIFFRINT i AN 12 I HAS A Day ITZ SUM OF i AN 1 VISIBLE "On the " ! VISIBLE Dayz'Z SRS Day ! VISIBLE " day of Christmas, my true love sent to me" IM IN YR Inner UPPIN YR j WILE DIFFRINT j AN Day I HAS A Count ITZ DIFFERENCE OF Day AN j VISIBLE Prezents'Z SRS Count IM OUTTA YR Inner BOTH SAEM i AN 0 O RLY? YA RLY Prezents'Z SRS 1 R "And a partridge in a pear tree" OIC DIFFRINT i AN 11 O RLY? YA RLY VISIBLE "" OIC IM OUTTA YR Outer   KTHXBYE
http://rosettacode.org/wiki/Terminal_control/Coloured_text
Terminal control/Coloured text
Task Display a word in various colours on the terminal. The system palette, or colours such as Red, Green, Blue, Magenta, Cyan, and Yellow can be used. Optionally demonstrate: How the system should determine if the terminal supports colour Setting of the background colour How to cause blinking or flashing (if supported by the terminal)
#Rust
Rust
const ESC: &str = "\x1B["; const RESET: &str = "\x1B[0m";   fn main() { println!("Foreground¦Background--------------------------------------------------------------"); print!(" ¦"); for i in 40..48 { print!(" ESC[{}m ", i); } println!("\n----------¦------------------------------------------------------------------------"); for i in 30..38 { print!("{}ESC[{}m ¦{}{1}m", RESET, i, ESC); for j in 40..48 { print!("{}{}m Rosetta ", ESC, j); } println!("{}", RESET); print!("{}ESC[{};1m ¦{}{1};1m", RESET, i, ESC); for j in 40..48 { print!("{}{}m Rosetta ", ESC, j); } println!("{}", RESET); } }
http://rosettacode.org/wiki/Terminal_control/Coloured_text
Terminal control/Coloured text
Task Display a word in various colours on the terminal. The system palette, or colours such as Red, Green, Blue, Magenta, Cyan, and Yellow can be used. Optionally demonstrate: How the system should determine if the terminal supports colour Setting of the background colour How to cause blinking or flashing (if supported by the terminal)
#Scala
Scala
object ColouredText extends App { val ESC = "\u001B" val (normal, bold, blink, black, white) = (ESC + "[0", ESC + "[1" , ESC + "[5" // not working on my machine , ESC + "[0;40m" // black background , ESC + "[0;37m" // normal white foreground )   print(s"${ESC}c") // clear terminal first print(black) // set background color to black def foreColors = Map( ";31m" -> "red", ";32m" -> "green", ";33m" -> "yellow", ";34m" -> "blue", ";35m" -> "magenta", ";36m" -> "cyan", ";37m" -> "white")   Seq(normal, bold, blink).flatMap(attr => foreColors.map(color => (attr, color))) .foreach { case (attr, (seq, text)) => println(s"$attr${seq}${text}") } println(white) // set foreground color to normal white }  
http://rosettacode.org/wiki/Synchronous_concurrency
Synchronous concurrency
The goal of this task is to create two concurrent activities ("Threads" or "Tasks", not processes.) that share data synchronously. Your language may provide syntax or libraries to perform concurrency. Different languages provide different implementations of concurrency, often with different names. Some languages use the term threads, others use the term tasks, while others use co-processes. This task should not be implemented using fork, spawn, or the Linux/UNIX/Win32 pipe command, as communication should be between threads, not processes. One of the concurrent units will read from a file named "input.txt" and send the contents of that file, one line at a time, to the other concurrent unit, which will print the line it receives to standard output. The printing unit must count the number of lines it prints. After the concurrent unit reading the file sends its last line to the printing unit, the reading unit will request the number of lines printed by the printing unit. The reading unit will then print the number of lines printed by the printing unit. This task requires two-way communication between the concurrent units. All concurrent units must cleanly terminate at the end of the program.
#Euphoria
Euphoria
sequence lines sequence count lines = {} count = {}   procedure read(integer fn) object line while 1 do line = gets(fn) if atom(line) then exit else lines = append(lines, line) task_yield() end if end while   lines = append(lines,0) while length(count) = 0 do task_yield() end while   printf(1,"Count: %d\n",count[1]) end procedure   procedure write(integer fn) integer n object line n = 0 while 1 do while length(lines) = 0 do task_yield() end while   line = lines[1] lines = lines[2..$] if atom(line) then exit else puts(fn,line) n += 1 end if end while count = append(count,n) end procedure   integer fn atom reader, writer constant stdout = 1 fn = open("input.txt","r") reader = task_create(routine_id("read"),{fn}) writer = task_create(routine_id("write"),{stdout}) task_schedule(writer,1) task_schedule(reader,1)   while length(task_list()) > 1 do task_yield() end while
http://rosettacode.org/wiki/Table_creation/Postal_addresses
Table creation/Postal addresses
Task Create a table to store addresses. You may assume that all the addresses to be stored will be located in the USA.   As such, you will need (in addition to a field holding a unique identifier) a field holding the street address, a field holding the city, a field holding the state code, and a field holding the zipcode.   Choose appropriate types for each field. For non-database languages, show how you would open a connection to a database (your choice of which) and create an address table in it. You should follow the existing models here for how you would structure the table.
#REXX
REXX
╔════════╤════════════════════════════════════════════════════════════════════════╤══════╗ ╟────────┘ Format of an entry in the USA address/city/state/zip code structure: └──────╢ ║ ║ ║ The structure name can be any variable name, but here it'll be shortened to make these║ ║ comments and program easier to read; its name will be: @USA or @usa (or both).║ ║ ║ ║ Each of the variable names beginning with an underscore (_) aren't to be used elsewhere║ ║ in the program. Other possibilities are to have a trailing underscore (or both) or ║ ║ some other special eye─catching character such as:  ! @ # $  ? ║ ║ ║ ║ Any field not specified will have a value of a null (which has a length of zero). ║ ║ ║ ║ Any field may contain any number of characters, this can be limited by the ║ ║ restrictions imposed by the standards or the USA legal definitions. ║ ║ Any number of fields could be added (with testing for invalid fields). ║ ╟────────────────────────────────────────────────────────────────────────────────────────╢ ║ @USA.0 the number of entries in the @USA stemmed array. ║ ║ ║ ║ nnn is some positive integer of any length (no leading zeros). ║ ╟────────────────────────────────────────────────────────────────────────────────────────╢ ║ @USA.nnn._name is the name of person, business, or a lot description. ║ ╟────────────────────────────────────────────────────────────────────────────────────────╢ ║ @USA.nnn._addr1 is the 1st street address ║ ║ @USA.nnn._addr2 is the 2nd street address ║ ║ @USA.nnn._addr3 is the 3rd street address ║ ║ @USA.nnn._addrNN ··· (any number, but in sequential order). ║ ╟────────────────────────────────────────────────────────────────────────────────────────╢ ║ @USA.nnn._state is the USA postal code for the state, territory, etc. ║ ╟────────────────────────────────────────────────────────────────────────────────────────╢ ║ @USA.nnn._city is the official city name, it may include any character. ║ ╟────────────────────────────────────────────────────────────────────────────────────────╢ ║ @USA.nnn._zip is the USA postal zip code (five or ten digit format). ║ ╟────────────────────────────────────────────────────────────────────────────────────────╢ ║ @USA.nnn._upHist is the update history: userID who did the update; date, timestamp.║ ╚════════════════════════════════════════════════════════════════════════════════════════╝
http://rosettacode.org/wiki/Table_creation/Postal_addresses
Table creation/Postal addresses
Task Create a table to store addresses. You may assume that all the addresses to be stored will be located in the USA.   As such, you will need (in addition to a field holding a unique identifier) a field holding the street address, a field holding the city, a field holding the state code, and a field holding the zipcode.   Choose appropriate types for each field. For non-database languages, show how you would open a connection to a database (your choice of which) and create an address table in it. You should follow the existing models here for how you would structure the table.
#Ring
Ring
  # Project : Table creation/Postal addresses   load "stdlib.ring" oSQLite = sqlite_init()   sqlite_open(oSQLite,"mytest.db")   sql = "CREATE TABLE ADDRESS (" + "addrID INT NOT NULL," + "street CHAR(50) NOT NULL," + "city CHAR(25) NOT NULL," + "state CHAR(2), NOT NULL" + "zip CHAR(20) NOT NULL);"   sqlite_execute(oSQLite,sql)  
http://rosettacode.org/wiki/Table_creation/Postal_addresses
Table creation/Postal addresses
Task Create a table to store addresses. You may assume that all the addresses to be stored will be located in the USA.   As such, you will need (in addition to a field holding a unique identifier) a field holding the street address, a field holding the city, a field holding the state code, and a field holding the zipcode.   Choose appropriate types for each field. For non-database languages, show how you would open a connection to a database (your choice of which) and create an address table in it. You should follow the existing models here for how you would structure the table.
#Ruby
Ruby
require 'pstore' require 'set'   Address = Struct.new :id, :street, :city, :state, :zip   db = PStore.new("addresses.pstore") db.transaction do db[:next] ||= 0 # Next available Address#id db[:ids] ||= Set[] # Set of all ids in db end
http://rosettacode.org/wiki/System_time
System time
Task Output the system time   (any units will do as long as they are noted) either by a system command or one built into the language. The system time can be used for debugging, network information, random number seeds, or something as simple as program performance. Related task   Date format See also   Retrieving system time (wiki)
#AArch64_Assembly
AArch64 Assembly
  /* ARM assembly AARCH64 Raspberry PI 3B */ /* program sysTime64.s */   /*******************************************/ /* Constantes file */ /*******************************************/ /* for this file see task include a file in language AArch64 assembly*/ .include "../includeConstantesARM64.inc"   .equ GETTIME, 169 // call system linux gettimeofday   /*******************************************/ /* Structures */ /********************************************/ /* example structure time */ .struct 0 timeval_sec: // .struct timeval_sec + 8 timeval_usec: // .struct timeval_usec + 8 timeval_end: .struct 0 timezone_min: // .struct timezone_min + 8 timezone_dsttime: // .struct timezone_dsttime + 8 timezone_end:   /*********************************/ /* Initialized data */ /*********************************/ .data szMessEmpty: .asciz "Empty queue. \n" szMessNotEmpty: .asciz "Not empty queue. \n" szMessError: .asciz "Error detected !!!!. \n" szMessResult: .asciz "GMT: @/@/@ @:@:@ @ms\n" // message result   szCarriageReturn: .asciz "\n" .align 4 tbDayMonthYear: .quad 0, 31, 60, 91, 121, 152, 182, 213, 244, 274, 305, 335 .quad 366, 397, 425, 456, 486, 517, 547, 578, 609, 639, 670, 700 .quad 731, 762, 790, 821, 851, 882, 912, 943, 974,1004,1035,1065 .quad 1096,1127,1155,1186,1216,1247,1277,1308,1339,1369,1400,1430 /*********************************/ /* UnInitialized data */ /*********************************/ .bss .align 4 stTVal: .skip timeval_end stTZone: .skip timezone_end sZoneConv: .skip 100 /*********************************/ /* code section */ /*********************************/ .text .global main main: // entry of program ldr x0,qAdrstTVal // time zones ldr x1,qAdrstTZone mov x8,GETTIME // call system svc 0 cmp x0,-1 // error ? beq 99f ldr x1,qAdrstTVal ldr x0,[x1,timeval_sec] // timestamp in second bl convTimeStamp //ldr x0,qTStest1 //bl convTimeStamp //ldr x0,qTStest2 //bl convTimeStamp //ldr x0,qTStest3 //bl convTimeStamp b 100f 99: ldr x0,qAdrszMessError bl affichageMess 100: // standard end of the program mov x0,0 // return code mov x8,EXIT // request to exit program svc 0 // perform the system call   qAdrszMessError: .quad szMessError qAdrstTVal: .quad stTVal qAdrstTZone: .quad stTZone qAdrszMessResult: .quad szMessResult qAdrszCarriageReturn: .quad szCarriageReturn qTStest1: .quad 1609508339 // 01/01/2021 qTStest2: .quad 1657805939 // 14/07/2022 qTStest3: .quad 1767221999 // 31/12/2025 /******************************************************************/ /* conversion timestamp to date */ /******************************************************************/ /* x0 contains the value of timestamp */ convTimeStamp: stp x1,lr,[sp,-16]! // save registers ldr x2,qSecJan2020 sub x3,x0,x2 // total secondes to 01/01/2020 mov x4,60 udiv x5,x3,x4 msub x6,x5,x4,x3 // compute secondes udiv x3,x5,x4 msub x7,x3,x4,x5 // compute minutes mov x4,24 udiv x5,x3,x4 msub x8,x5,x4,x3 // compute hours mov x4,(365 * 4 + 1) udiv x9,x5,x4 lsl x9,x9,2 // multiply by 4 = year1 udiv x12,x5,x4 msub x10,x12,x4,x5 ldr x11,qAdrtbDayMonthYear mov x12,3 mov x13,12 1: mul x14,x13,x12 ldr x15,[x11,x14,lsl 3] // load days by year cmp x10,x15 bge 2f sub x12,x12,1 cmp x12,0 cbnz x12,1b 2: // x12 = year2 mov x16,11 mul x15,x13,x12 lsl x15,x15,3 // * par 8 add x14,x15,x11 3: ldr x15,[x14,x16,lsl 3] // load days by month cmp x10,x15 bge 4f sub x16,x16,1 cmp x16,0 cbnz x16,3b 4: // x16 = month - 1 mul x15,x13,x12 add x15,x15,x16 ldr x1,qAdrtbDayMonthYear ldr x3,[x1,x15,lsl 3] sub x0,x10,x3 add x0,x0,1 // final compute day ldr x1,qAdrsZoneConv bl conversion10 ldr x0,qAdrszMessResult ldr x1,qAdrsZoneConv bl strInsertAtCharInc // insert result at first @ character mov x2,x0 add x0,x16,1 // final compute month ldr x1,qAdrsZoneConv bl conversion10 mov x0,x2 ldr x1,qAdrsZoneConv bl strInsertAtCharInc // insert result at next @ character mov x2,x0 add x0,x9,2020 add x0,x0,x12 // final compute year = 2020 + year1 + year2 ldr x1,qAdrsZoneConv bl conversion10 mov x0,x2 ldr x1,qAdrsZoneConv bl strInsertAtCharInc // insert result at next @ character mov x2,x0 mov x0,x8 // hours ldr x1,qAdrsZoneConv bl conversion10 mov x0,x2 ldr x1,qAdrsZoneConv bl strInsertAtCharInc // insert result at next @ character mov x2,x0 mov x0,x7 // minutes ldr x1,qAdrsZoneConv bl conversion10 mov x0,x2 ldr x1,qAdrsZoneConv bl strInsertAtCharInc // insert result at next @ character mov x2,x0 mov x0,x6 // secondes ldr x1,qAdrsZoneConv bl conversion10 mov x0,x2 ldr x1,qAdrsZoneConv bl strInsertAtCharInc // insert result at next @ character mov x2,x0 ldr x1,qAdrstTVal ldr x0,[x1,timeval_usec] // millisecondes ldr x1,qAdrsZoneConv bl conversion10 mov x0,x2 ldr x1,qAdrsZoneConv bl strInsertAtCharInc // insert result at next @ character bl affichageMess b 100f 99: ldr x0,qAdrszMessError bl affichageMess 100: ldp x1,lr,[sp],16 // restaur 2 registers ret // return to address lr x30 qAdrsZoneConv: .quad sZoneConv qSecJan2020: .quad 1577836800 qAdrtbDayMonthYear: .quad tbDayMonthYear /********************************************************/ /* File Include fonctions */ /********************************************************/ /* for this file see task include a file in language AArch64 assembly */ .include "../includeARM64.inc"  
http://rosettacode.org/wiki/System_time
System time
Task Output the system time   (any units will do as long as they are noted) either by a system command or one built into the language. The system time can be used for debugging, network information, random number seeds, or something as simple as program performance. Related task   Date format See also   Retrieving system time (wiki)
#ABAP
ABAP
REPORT system_time.   WRITE: sy-uzeit.
http://rosettacode.org/wiki/Summarize_and_say_sequence
Summarize and say sequence
There are several ways to generate a self-referential sequence. One very common one (the Look-and-say sequence) is to start with a positive integer, then generate the next term by concatenating enumerated groups of adjacent alike digits: 0, 10, 1110, 3110, 132110, 1113122110, 311311222110 ... The terms generated grow in length geometrically and never converge. Another way to generate a self-referential sequence is to summarize the previous term. Count how many of each alike digit there is, then concatenate the sum and digit for each of the sorted enumerated digits. Note that the first five terms are the same as for the previous sequence. 0, 10, 1110, 3110, 132110, 13123110, 23124110 ... Sort the digits largest to smallest. Do not include counts of digits that do not appear in the previous term. Depending on the seed value, series generated this way always either converge to a stable value or to a short cyclical pattern. (For our purposes, I'll use converge to mean an element matches a previously seen element.) The sequence shown, with a seed value of 0, converges to a stable value of 1433223110 after 11 iterations. The seed value that converges most quickly is 22. It goes stable after the first element. (The next element is 22, which has been seen before.) Task Find all the positive integer seed values under 1000000, for the above convergent self-referential sequence, that takes the largest number of iterations before converging. Then print out the number of iterations and the sequence they return. Note that different permutations of the digits of the seed will yield the same sequence. For this task, assume leading zeros are not permitted. Seed Value(s): 9009 9090 9900 Iterations: 21 Sequence: (same for all three seeds except for first element) 9009 2920 192210 19222110 19323110 1923123110 1923224110 191413323110 191433125110 19151423125110 19251413226110 1916151413325110 1916251423127110 191716151413326110 191726151423128110 19181716151413327110 19182716151423129110 29181716151413328110 19281716151423228110 19281716151413427110 19182716152413228110 Related tasks   Fours is the number of letters in the ...   Look-and-say sequence   Number names   Self-describing numbers   Spelling of ordinal numbers 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 Also see   The On-Line Encyclopedia of Integer Sequences.
#Ada
Ada
with Ada.Text_IO; use Ada.Text_IO; with Ada.Containers.Vectors; procedure SelfRef is subtype Seed is Natural range 0 .. 1_000_000; subtype Num is Natural range 0 .. 10; type NumList is array (0 .. 10) of Num; package IO is new Ada.Text_IO.Integer_IO (Natural); package DVect is new Ada.Containers.Vectors (Positive, NumList);   function Init (innum : Seed) return NumList is list : NumList := (others => 0); number : Seed := innum; d : Num; begin loop d := Num (number mod 10); list (d) := list (d) + 1; number := number / 10; exit when number = 0; end loop; return list; end Init;   procedure Next (inoutlist : in out NumList) is list : NumList := (others => 0); begin for i in list'Range loop if inoutlist (i) /= 0 then list (i) := list (i) + 1; list (inoutlist (i)) := list (inoutlist (i)) + 1; end if; end loop; inoutlist := list; end Next;   procedure Show (list : NumList) is begin for i in reverse list'Range loop if list (i) > 0 then IO.Put (list (i), Width => 1); IO.Put (i, Width => 1); end if; end loop; New_Line; end Show;   function Iterate (theseed : Seed; p : Boolean) return Natural is list : NumList := Init (theseed); vect : DVect.Vector; begin vect.Append (list); loop if p then Show (list); end if; Next (list); exit when vect.Contains (list); vect.Append (list); end loop; return Integer (DVect.Length (vect)) + 1; end Iterate;   mseed : Seed; len, maxlen : Natural := 0; begin for i in Seed'Range loop len := Iterate (i, False); if len > maxlen then mseed := i; maxlen := len; end if; end loop; IO.Put (maxlen, Width => 1); Put_Line (" Iterations:"); IO.Put (mseed, Width => 1); New_Line; len := Iterate (mseed, True); end SelfRef;
http://rosettacode.org/wiki/Summarize_primes
Summarize primes
Task Considering in order of length, n, all sequences of consecutive primes, p, from 2 onwards, where p < 1000 and n>0, select those sequences whose sum is prime, and for these display the length of the sequence, the last item in the sequence, and the sum.
#ALGOL_68
ALGOL 68
BEGIN # sum the primes below n and report the sums that are prime # # sieve the primes to 999 # PR read "primes.incl.a68" PR []BOOL prime = PRIMESIEVE 999; # sum the primes and test the sum # INT prime sum := 0; INT prime count := 0; INT prime sum count := 0; print( ( "prime prime", newline ) ); print( ( "count prime sum", newline ) ); FOR i TO UPB prime DO IF prime[ i ] THEN # have another prime # prime count +:= 1; prime sum +:= i; # check whether the prime sum is prime or not # BOOL is prime := TRUE; FOR p TO i OVER 2 WHILE is prime DO IF prime[ p ] THEN is prime := prime sum MOD p /= 0 FI OD; IF is prime THEN # the prime sum is also prime # prime sum count +:= 1; print( ( whole( prime count, -5 ) , " " , whole( i, -6 ) , " " , whole( prime sum, -6 ) , newline ) ) FI FI OD; print( ( newline , "Found " , whole( prime sum count, 0 ) , " prime sums of primes below " , whole( UPB prime + 1, 0 ) , newline ) ) END
http://rosettacode.org/wiki/Summarize_primes
Summarize primes
Task Considering in order of length, n, all sequences of consecutive primes, p, from 2 onwards, where p < 1000 and n>0, select those sequences whose sum is prime, and for these display the length of the sequence, the last item in the sequence, and the sum.
#ALGOL_W
ALGOL W
begin % sum the primes below n and report the sums that are prime  % integer MAX_NUMBER; MAX_NUMBER := 999; begin logical array prime( 1 :: MAX_NUMBER ); integer primeCount, primeSum, primeSumCount;  % sieve the primes to MAX_NUMBER  % prime( 1 ) := false; prime( 2 ) := true; for i := 3 step 2 until MAX_NUMBER do prime( i ) := true; for i := 4 step 2 until MAX_NUMBER do prime( i ) := false; for i := 3 step 2 until truncate( sqrt( MAX_NUMBER ) ) do begin integer ii; ii := i + i; if prime( i ) then begin for p := i * i step ii until MAX_NUMBER do prime( p ) := false end if_prime_i end for_i ;  % find the prime sums that are prime  % primeCount := primeSum := primeSumCount := 0; write( "prime prime" ); write( "count sum" ); for i := 1 until MAX_NUMBER do begin if prime( i ) then begin  % have another prime  % logical isPrime; primeSum  := primeSum + i; primeCount := primeCount + 1;  % check whether the prime sum is also prime  % isPrime := true; for p := 1 until i div 2 do begin if prime( p ) then begin isPrime := primeSum rem p not = 0; if not isPrime then goto endPrimeCheck end if_prime_p end for_p ; endPrimeCheck: if isPrime then begin  % the prime sum is also prime  % primeSumCount := primeSumCount + 1; write( i_w := 5, s_w := 0 , primeCount , " " , i_w := 6 , primeSum ) end if_isPrime end if_prime_i end for_i ; write(); write( i_w := 1, s_w := 0 , "Found " , primeSumCount , " prime sums of primes below " , MAX_NUMBER + 1 ) end end.
http://rosettacode.org/wiki/Sutherland-Hodgman_polygon_clipping
Sutherland-Hodgman polygon clipping
The   Sutherland-Hodgman clipping algorithm   finds the polygon that is the intersection between an arbitrary polygon (the “subject polygon”) and a convex polygon (the “clip polygon”). It is used in computer graphics (especially 2D graphics) to reduce the complexity of a scene being displayed by eliminating parts of a polygon that do not need to be displayed. Task Take the closed polygon defined by the points: [ ( 50 , 150 ) , ( 200 , 50 ) , ( 350 , 150 ) , ( 350 , 300 ) , ( 250 , 300 ) , ( 200 , 250 ) , ( 150 , 350 ) , ( 100 , 250 ) , ( 100 , 200 ) ] {\displaystyle [(50,150),(200,50),(350,150),(350,300),(250,300),(200,250),(150,350),(100,250),(100,200)]} and clip it by the rectangle defined by the points: [ ( 100 , 100 ) , ( 300 , 100 ) , ( 300 , 300 ) , ( 100 , 300 ) ] {\displaystyle [(100,100),(300,100),(300,300),(100,300)]} Print the sequence of points that define the resulting clipped polygon. Extra credit Display all three polygons on a graphical surface, using a different color for each polygon and filling the resulting polygon. (When displaying you may use either a north-west or a south-west origin, whichever is more convenient for your display mechanism.)
#D
D
import std.stdio, std.array, std.range, std.typecons, std.algorithm;   struct Vec2 { // To be replaced with Phobos code. double x, y;   Vec2 opBinary(string op="-")(in Vec2 other) const pure nothrow @safe @nogc { return Vec2(this.x - other.x, this.y - other.y); }   typeof(x) cross(in Vec2 other) const pure nothrow @safe @nogc { return this.x * other.y - this.y * other.x; } }   immutable(Vec2)[] clip(in Vec2[] subjectPolygon, in Vec2[] clipPolygon) pure /*nothrow*/ @safe in { assert(subjectPolygon.length > 1); assert(clipPolygon.length > 1); // Probably clipPolygon needs to be convex and probably // its vertices need to be listed in a direction. } out(result) { assert(result.length > 1); } body { alias Edge = Tuple!(Vec2,"p", Vec2,"q");   static enum isInside = (in Vec2 p, in Edge cle) pure nothrow @safe @nogc => (cle.q.x - cle.p.x) * (p.y - cle.p.y) > (cle.q.y - cle.p.y) * (p.x - cle.p.x);   static Vec2 intersection(in Edge se, in Edge cle) pure nothrow @safe @nogc { immutable dc = cle.p - cle.q; immutable dp = se.p - se.q; immutable n1 = cle.p.cross(cle.q); immutable n2 = se.p.cross(se.q); immutable n3 = 1.0 / dc.cross(dp); return Vec2((n1 * dp.x - n2 * dc.x) * n3, (n1 * dp.y - n2 * dc.y) * n3); }   // How much slower is this compared to lower-level code? static enum edges = (in Vec2[] poly) pure nothrow @safe @nogc => // poly[$ - 1 .. $].chain(poly).zip!Edge(poly); poly[$ - 1 .. $].chain(poly).zip(poly).map!Edge;   immutable(Vec2)[] result = subjectPolygon.idup; // Not nothrow.   foreach (immutable clipEdge; edges(clipPolygon)) { immutable inputList = result; result.destroy; foreach (immutable inEdge; edges(inputList)) { if (isInside(inEdge.q, clipEdge)) { if (!isInside(inEdge.p, clipEdge)) result ~= intersection(inEdge, clipEdge); result ~= inEdge.q; } else if (isInside(inEdge.p, clipEdge)) result ~= intersection(inEdge, clipEdge); } }   return result; }   // Code adapted from the C version. void saveEPSImage(in string fileName, in Vec2[] subjPoly, in Vec2[] clipPoly, in Vec2[] clipped) in { assert(!fileName.empty); assert(subjPoly.length > 1); assert(clipPoly.length > 1); assert(clipped.length > 1); } body { auto eps = File(fileName, "w");   // The image bounding box is hard-coded, not computed. eps.writeln( "%%!PS-Adobe-3.0 %%%%BoundingBox: 40 40 360 360 /l {lineto} def /m {moveto} def /s {setrgbcolor} def /c {closepath} def /gs {fill grestore stroke} def ");   eps.writef("0 setlinewidth %g %g m ", clipPoly[0].tupleof); foreach (immutable cl; clipPoly[1 .. $]) eps.writef("%g %g l ", cl.tupleof); eps.writefln("c 0.5 0 0 s gsave 1 0.7 0.7 s gs");   eps.writef("%g %g m ", subjPoly[0].tupleof); foreach (immutable s; subjPoly[1 .. $]) eps.writef("%g %g l ", s.tupleof); eps.writefln("c 0 0.2 0.5 s gsave 0.4 0.7 1 s gs");   eps.writef("2 setlinewidth [10 8] 0 setdash %g %g m ", clipped[0].tupleof); foreach (immutable c; clipped[1 .. $]) eps.writef("%g %g l ", c.tupleof); eps.writefln("c 0.5 0 0.5 s gsave 0.7 0.3 0.8 s gs");   eps.writefln("%%%%EOF"); eps.close; writeln(fileName, " written."); }   void main() { alias V = Vec2; immutable subjectPolygon = [V(50, 150), V(200, 50), V(350, 150), V(350, 300), V(250, 300), V(200, 250), V(150, 350), V(100, 250), V(100, 200)]; immutable clippingPolygon = [V(100, 100), V(300, 100), V(300, 300), V(100, 300)]; immutable clipped = subjectPolygon.clip(clippingPolygon); writefln("%(%s\n%)", clipped); saveEPSImage("sutherland_hodgman_clipping_out.eps", subjectPolygon, clippingPolygon, clipped); }
http://rosettacode.org/wiki/Symmetric_difference
Symmetric difference
Task Given two sets A and B, compute ( A ∖ B ) ∪ ( B ∖ A ) . {\displaystyle (A\setminus B)\cup (B\setminus A).} That is, enumerate the items that are in A or B but not both. This set is called the symmetric difference of A and B. In other words: ( A ∪ B ) ∖ ( A ∩ B ) {\displaystyle (A\cup B)\setminus (A\cap B)} (the set of items that are in at least one of A or B minus the set of items that are in both A and B). Optionally, give the individual differences ( A ∖ B {\displaystyle A\setminus B} and B ∖ A {\displaystyle B\setminus A} ) as well. Test cases A = {John, Bob, Mary, Serena} B = {Jim, Mary, John, Bob} Notes If your code uses lists of items to represent sets then ensure duplicate items in lists are correctly handled. For example two lists representing sets of a = ["John", "Serena", "Bob", "Mary", "Serena"] and b = ["Jim", "Mary", "John", "Jim", "Bob"] should produce the result of just two strings: ["Serena", "Jim"], in any order. In the mathematical notation above A \ B gives the set of items in A that are not in B; A ∪ B gives the set of items in both A and B, (their union); and A ∩ B gives the set of items that are in both A and B (their intersection).
#Arturo
Arturo
a: ["John" "Bob" "Mary" "Serena"] b: ["Jim" "Mary" "John" "Bob"]   print difference.symmetric a b
http://rosettacode.org/wiki/Symmetric_difference
Symmetric difference
Task Given two sets A and B, compute ( A ∖ B ) ∪ ( B ∖ A ) . {\displaystyle (A\setminus B)\cup (B\setminus A).} That is, enumerate the items that are in A or B but not both. This set is called the symmetric difference of A and B. In other words: ( A ∪ B ) ∖ ( A ∩ B ) {\displaystyle (A\cup B)\setminus (A\cap B)} (the set of items that are in at least one of A or B minus the set of items that are in both A and B). Optionally, give the individual differences ( A ∖ B {\displaystyle A\setminus B} and B ∖ A {\displaystyle B\setminus A} ) as well. Test cases A = {John, Bob, Mary, Serena} B = {Jim, Mary, John, Bob} Notes If your code uses lists of items to represent sets then ensure duplicate items in lists are correctly handled. For example two lists representing sets of a = ["John", "Serena", "Bob", "Mary", "Serena"] and b = ["Jim", "Mary", "John", "Jim", "Bob"] should produce the result of just two strings: ["Serena", "Jim"], in any order. In the mathematical notation above A \ B gives the set of items in A that are not in B; A ∪ B gives the set of items in both A and B, (their union); and A ∩ B gives the set of items that are in both A and B (their intersection).
#AutoHotkey
AutoHotkey
setA = John, Bob, Mary, Serena setB = Jim, Mary, John, Bob MsgBox,, Singles, % SymmetricDifference(setA, setB)   setA = John, Serena, Bob, Mary, Serena setB = Jim, Mary, John, Jim, Bob MsgBox,, Duplicates, % SymmetricDifference(setA, setB)   ;--------------------------------------------------------------------------- SymmetricDifference(A, B) { ; returns the symmetric difference of A and B ;--------------------------------------------------------------------------- StringSplit, A_, A, `,, %A_Space% Loop, %A_0% If Not InStr(B, A_%A_Index%) And Not InStr(Result, A_%A_Index%) Result .= A_%A_Index% ", " StringSplit, B_, B, `,, %A_Space% Loop, %B_0% If Not InStr(A, B_%A_Index%) And Not InStr(Result, B_%A_Index%) Result .= B_%A_Index% ", " Return, SubStr(Result, 1, -2) }
http://rosettacode.org/wiki/Super-d_numbers
Super-d numbers
A super-d number is a positive, decimal (base ten) integer   n   such that   d × nd   has at least   d   consecutive digits   d   where 2 ≤ d ≤ 9 For instance, 753 is a super-3 number because 3 × 7533 = 1280873331. Super-d   numbers are also shown on   MathWorld™   as   super-d   or   super-d. Task Write a function/procedure/routine to find super-d numbers. For   d=2   through   d=6,   use the routine to show the first   10   super-d numbers. Extra credit Show the first   10   super-7, super-8, and/or super-9 numbers   (optional). See also   Wolfram MathWorld - Super-d Number.   OEIS: A014569 - Super-3 Numbers.
#Go
Go
package main   import ( "fmt" "math/big" "strings" "time" )   func main() { start := time.Now() rd := []string{"22", "333", "4444", "55555", "666666", "7777777", "88888888", "999999999"} one := big.NewInt(1) nine := big.NewInt(9) for i := big.NewInt(2); i.Cmp(nine) <= 0; i.Add(i, one) { fmt.Printf("First 10 super-%d numbers:\n", i) ii := i.Uint64() k := new(big.Int) count := 0 inner: for j := big.NewInt(3); ; j.Add(j, one) { k.Exp(j, i, nil) k.Mul(i, k) ix := strings.Index(k.String(), rd[ii-2]) if ix >= 0 { count++ fmt.Printf("%d ", j) if count == 10 { fmt.Printf("\nfound in %d ms\n\n", time.Since(start).Milliseconds()) break inner } } } } }
http://rosettacode.org/wiki/Super-d_numbers
Super-d numbers
A super-d number is a positive, decimal (base ten) integer   n   such that   d × nd   has at least   d   consecutive digits   d   where 2 ≤ d ≤ 9 For instance, 753 is a super-3 number because 3 × 7533 = 1280873331. Super-d   numbers are also shown on   MathWorld™   as   super-d   or   super-d. Task Write a function/procedure/routine to find super-d numbers. For   d=2   through   d=6,   use the routine to show the first   10   super-d numbers. Extra credit Show the first   10   super-7, super-8, and/or super-9 numbers   (optional). See also   Wolfram MathWorld - Super-d Number.   OEIS: A014569 - Super-3 Numbers.
#Haskell
Haskell
import Data.List (isInfixOf) import Data.Char (intToDigit)   isSuperd :: (Show a, Integral a) => a -> a -> Bool isSuperd p n = (replicate <*> intToDigit) (fromIntegral p) `isInfixOf` show (p * n ^ p)   findSuperd :: (Show a, Integral a) => a -> [a] findSuperd p = filter (isSuperd p) [1 ..]   main :: IO () main = mapM_ (putStrLn . ("First 10 super-" ++) . ((++) . show <*> ((" : " ++) . show . take 10 . findSuperd))) [2 .. 6]
http://rosettacode.org/wiki/Take_notes_on_the_command_line
Take notes on the command line
Take notes on the command line is part of Short Circuit's Console Program Basics selection. Invoking NOTES without commandline arguments displays the current contents of the local NOTES.TXT if it exists. If NOTES has arguments, the current date and time are appended to the local NOTES.TXT followed by a newline. Then all the arguments, joined with spaces, prepended with a tab, and appended with a trailing newline, are written to NOTES.TXT. If NOTES.TXT doesn't already exist in the current directory then a new NOTES.TXT file should be created.
#Euphoria
Euphoria
constant cmd = command_line() constant filename = "notes.txt" integer fn object line sequence date_time   if length(cmd) < 3 then fn = open(filename,"r") if fn != -1 then while 1 do line = gets(fn) if atom(line) then exit end if puts(1,line) end while close(fn) end if else fn = open(filename,"a") -- if such file doesn't exist it will be created date_time = date() date_time = date_time[1..6] date_time[1] += 1900 printf(fn,"%d-%02d-%02d %d:%02d:%02d\n",date_time) line = "\t" for n = 3 to length(cmd) do line &= cmd[n] & ' ' end for line[$] = '\n' puts(fn,line) close(fn) end if
http://rosettacode.org/wiki/Take_notes_on_the_command_line
Take notes on the command line
Take notes on the command line is part of Short Circuit's Console Program Basics selection. Invoking NOTES without commandline arguments displays the current contents of the local NOTES.TXT if it exists. If NOTES has arguments, the current date and time are appended to the local NOTES.TXT followed by a newline. Then all the arguments, joined with spaces, prepended with a tab, and appended with a trailing newline, are written to NOTES.TXT. If NOTES.TXT doesn't already exist in the current directory then a new NOTES.TXT file should be created.
#F.23
F#
open System;; open System.IO;;   let file_path = "notes.txt";;   let show_notes () = try printfn "%s" <| File.ReadAllText(file_path) with _ -> printfn "Take some notes first!";;   let take_note (note : string) = let now = DateTime.Now.ToString() in let note = sprintf "%s\n\t%s" now note in use file_stream = File.AppendText file_path in (* 'use' closes file_stream automatically when control leaves the scope *) file_stream.WriteLine note;;   [<EntryPoint>] let main args = match Array.length args with | 0 -> show_notes() | _ -> take_note <| String.concat " " args; 0;;
http://rosettacode.org/wiki/Superellipse
Superellipse
A superellipse is a geometric figure defined as the set of all points (x, y) with | x a | n + | y b | n = 1 , {\displaystyle \left|{\frac {x}{a}}\right|^{n}\!+\left|{\frac {y}{b}}\right|^{n}\!=1,} where n, a, and b are positive numbers. Task Draw a superellipse with n = 2.5, and a = b = 200
#FreeBASIC
FreeBASIC
' version 23-10-2016 ' compile with: fbc -s console   Const scr_x = 800 ' screen 800 x 800 Const scr_y = 600 Const m_x = scr_x \ 2 ' middle of screen Const m_y = scr_y \ 2     Sub superellipse(a As Long, b As Long, n As Double)   ReDim As Long y(0 To a) Dim As Long x   y(0) = b ' value for x = 0 y(a) = 0 ' value for x = a   '(0,0) is in upper left corner   PSet (m_x, m_y - y(0)) ' set starting point   For x = 1 To a-1 y(x) = Int( Exp( Log(1 - ((x / a) ^ n)) / n ) * b ) Line - ((m_x + x), (m_y - y(x))) Next   For x = a To 0 Step -1 Line - ((m_x + x), (m_y + y(x))) Next   For x = 0 To a Line - ((m_x - x), (m_y + y(x))) Next   For x = a To 0 Step -1 Line - ((m_x - x), (m_y - y(x))) Next   End Sub   ' ------=< MAIN >=------   ScreenRes scr_x, scr_y, 32   Dim As Long a = 200 Dim As Long b = 150 Dim As Double n = 2.5   superellipse(a, b, n)   ' empty keyboard buffer While Inkey <> "" : Wend Print : Print "hit any key to end program" Sleep End
http://rosettacode.org/wiki/Sylvester%27s_sequence
Sylvester's sequence
This page uses content from Wikipedia. The original article was at Sylvester's sequence. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance) In number theory, Sylvester's sequence is an integer sequence in which each term of the sequence is the product of the previous terms, plus one. Its values grow doubly exponentially, and the sum of its reciprocals forms a series of unit fractions that converges to 1 more rapidly than any other series of unit fractions with the same number of terms. Further, the sum of the first k terms of the infinite series of reciprocals provides the closest possible underestimate of 1 by any k-term Egyptian fraction. Task Write a routine (function, procedure, generator, whatever) to calculate Sylvester's sequence. Use that routine to show the values of the first 10 elements in the sequence. Show the sum of the reciprocals of the first 10 elements on the sequence, ideally as an exact fraction. Related tasks Egyptian fractions Harmonic series See also OEIS A000058 - Sylvester's sequence
#PL.2FM
PL/M
100H: /* CALCULATE ELEMENTS OF SYLVESTOR'S SEQUENCE */   BDOS: PROCEDURE( FN, ARG ); /* CP/M BDOS SYSTEM CALL */ DECLARE FN BYTE, ARG ADDRESS; GOTO 5; END BDOS; PRINT$CHAR: PROCEDURE( C ); DECLARE C BYTE; CALL BDOS( 2, C ); END; PRINT$STRING: PROCEDURE( S ); DECLARE S ADDRESS; CALL BDOS( 9, S ); END; DECLARE PRINT$NL LITERALLY 'PRINT$STRING( .( 0DH, 0AH, ''$'' ) )';   DECLARE LONG$INTEGER LITERALLY '(201)BYTE'; DECLARE DIGIT$BASE LITERALLY '10';   /* PRINTS A LONG INTEGER */ PRINT$LONG$INTEGER: PROCEDURE( N$PTR ); DECLARE N$PTR ADDRESS; DECLARE N BASED N$PTR LONG$INTEGER; DECLARE ( D, F ) BYTE; F = N( 0 ); DO D = 1 TO N( 0 ); CALL PRINT$CHAR( N( F ) + '0' ); F = F - 1; END; END PRINT$LONG$INTEGER; /* IMPLEMENTS LONG MULTIPLICATION, C IS SET TO A * B */ /* C CAN BE THE SAME LONG$INTEGER AS A OR B */ LONG$MULTIPLY: PROCEDURE( A$PTR, B$PTR, C$PTR ); DECLARE ( A$PTR, B$PTR, C$PTR ) ADDRESS; DECLARE ( A BASED A$PTR, B BASED B$PTR, C BASED C$PTR ) LONG$INTEGER; DECLARE MRESULT LONG$INTEGER; DECLARE RPOS BYTE;   /* MULTIPLIES THE LONG INTEGER IN B BY THE INTEGER A, THE RESULT */ /* IS ADDED TO C, STARTING FROM DIGIT START */ /* OVERFLOW IS IGNORED */ MULTIPLY$ELEMENT: PROCEDURE( A, B$PTR, C$PTR, START ); DECLARE ( B$PTR, C$PTR ) ADDRESS; DECLARE ( A, START ) BYTE; DECLARE ( B BASED B$PTR, C BASED C$PTR ) LONG$INTEGER; DECLARE ( CDIGIT, D$CARRY, BPOS, CPOS ) BYTE; D$CARRY = 0; CPOS = START; DO BPOS = 1 TO B( 0 ); CDIGIT = C( CPOS ) + ( A * B( BPOS ) ) + D$CARRY; IF CDIGIT < DIGIT$BASE THEN D$CARRY = 0; ELSE DO; /* HAVE DIGITS TO CARRY */ D$CARRY = CDIGIT / DIGIT$BASE; CDIGIT = CDIGIT MOD DIGIT$BASE; END; C( CPOS ) = CDIGIT; CPOS = CPOS + 1; END; C( CPOS ) = D$CARRY; /* REMOVE LEADING ZEROS BUT IF THE NUMBER IS 0, KEEP THE FINAL 0 */ DO WHILE( CPOS > 1 AND C( CPOS ) = 0 ); CPOS = CPOS - 1; END; C( 0 ) = CPOS; END MULTIPLY$ELEMENT ;   /* THE RESULT WILL BE COMPUTED IN MRESULT, ALLOWING A OR B TO BE C */ DO RPOS = 1 TO LAST( MRESULT ); MRESULT( RPOS ) = 0; END; /* MULTIPLY BY EACH DIGIT AND ADD TO THE RESULT */ DO RPOS = 1 TO A( 0 ); IF A( RPOS ) <> 0 THEN DO; CALL MULTIPLY$ELEMENT( A( RPOS ), B$PTR, .MRESULT, RPOS ); END; END; /* RETURN THE RESULT IN C */ DO RPOS = 0 TO MRESULT( 0 ); C( RPOS ) = MRESULT( RPOS ); END; END; /* ADDS THE INTEGER A TO THE LONG$INTEGER N */ ADD$BYTE$TO$LONG$INTEGER: PROCEDURE( A, N$PTR ); DECLARE A BYTE, N$PTR ADDRESS; DECLARE N BASED N$PTR LONG$INTEGER; DECLARE ( D, D$CARRY, DIGIT ) BYTE; D = 1; D$CARRY = A; DO WHILE( D$CARRY > 0 ); DIGIT = N( D ) + D$CARRY; IF DIGIT < DIGIT$BASE THEN DO; N( D ) = DIGIT; D$CARRY = 0; END; ELSE DO; D$CARRY = DIGIT / DIGIT$BASE; N( D ) = DIGIT MOD DIGIT$BASE; D = D + 1; IF D > N( 0 ) THEN DO; /* THE NUMBER NOW HAS AN EXTRA DIGIT */ N( 0 ) = D; N( D ) = D$CARRY; D$CARRY = 0; END; END; END; END ADD$BYTE$TO$LONG$INTEGER; /* FIND THE FIRST 10 ELEMENTS OF SYLVESTOR'S SEQUENCE */ DECLARE ( SEQ$ELEMENT, PRODUCT ) LONG$INTEGER; DECLARE ( I, D ) BYTE; DO D = 2 TO LAST( PRODUCT ); PRODUCT( D ) = 0; END; DO D = 2 TO LAST( SEQ$ELEMENT ); SEQ$ELEMENT( D ) = 0; END; SEQ$ELEMENT( 0 ) = 1; /* THE FIRST SEQUENCE ELEMENT HAS 1 DIGIT... */ SEQ$ELEMENT( 1 ) = 2; /* WHICH IS 2 */ PRODUCT( 0 ) = 1; PRODUCT( 1 ) = 2; CALL PRINT$LONG$INTEGER( .SEQ$ELEMENT ); /* SHOW ELEMENT 1 */ CALL PRINT$NL; DO I = 2 TO 9; DO D = 0 TO PRODUCT( 0 ); SEQ$ELEMENT( D ) = PRODUCT( D ); END; CALL ADD$BYTE$TO$LONG$INTEGER( 1, .SEQ$ELEMENT ); CALL PRINT$LONG$INTEGER( .SEQ$ELEMENT ); CALL LONG$MULTIPLY( .SEQ$ELEMENT, .PRODUCT, .PRODUCT ); CALL PRINT$NL; END; /* THE FINAL ELEMENT IS THE PRODUCT PLUS 1 */ CALL ADD$BYTE$TO$LONG$INTEGER( 1, .PRODUCT ); CALL PRINT$LONG$INTEGER( .PRODUCT ); CALL PRINT$NL; EOF
http://rosettacode.org/wiki/Sylvester%27s_sequence
Sylvester's sequence
This page uses content from Wikipedia. The original article was at Sylvester's sequence. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance) In number theory, Sylvester's sequence is an integer sequence in which each term of the sequence is the product of the previous terms, plus one. Its values grow doubly exponentially, and the sum of its reciprocals forms a series of unit fractions that converges to 1 more rapidly than any other series of unit fractions with the same number of terms. Further, the sum of the first k terms of the infinite series of reciprocals provides the closest possible underestimate of 1 by any k-term Egyptian fraction. Task Write a routine (function, procedure, generator, whatever) to calculate Sylvester's sequence. Use that routine to show the values of the first 10 elements in the sequence. Show the sum of the reciprocals of the first 10 elements on the sequence, ideally as an exact fraction. Related tasks Egyptian fractions Harmonic series See also OEIS A000058 - Sylvester's sequence
#Prolog
Prolog
sylvesters_sequence(N, S, R):- sylvesters_sequence(N, S, 2, R, 0).   sylvesters_sequence(0, [X], X, R, S):- !, R is S + 1 rdiv X. sylvesters_sequence(N, [X|Xs], X, R, S):- Y is X * X - X + 1, M is N - 1, T is S + 1 rdiv X, sylvesters_sequence(M, Xs, Y, R, T).   main:- sylvesters_sequence(9, Sequence, Sum), writeln('First 10 elements in Sylvester\'s sequence:'), forall(member(S, Sequence), writef('%t\n', [S])), N is numerator(Sum), D is denominator(Sum), writef('\nSum of reciprocals: %t / %t\n', [N, D]).
http://rosettacode.org/wiki/Sylvester%27s_sequence
Sylvester's sequence
This page uses content from Wikipedia. The original article was at Sylvester's sequence. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance) In number theory, Sylvester's sequence is an integer sequence in which each term of the sequence is the product of the previous terms, plus one. Its values grow doubly exponentially, and the sum of its reciprocals forms a series of unit fractions that converges to 1 more rapidly than any other series of unit fractions with the same number of terms. Further, the sum of the first k terms of the infinite series of reciprocals provides the closest possible underestimate of 1 by any k-term Egyptian fraction. Task Write a routine (function, procedure, generator, whatever) to calculate Sylvester's sequence. Use that routine to show the values of the first 10 elements in the sequence. Show the sum of the reciprocals of the first 10 elements on the sequence, ideally as an exact fraction. Related tasks Egyptian fractions Harmonic series See also OEIS A000058 - Sylvester's sequence
#Python
Python
'''Sylvester's sequence'''   from functools import reduce from itertools import count, islice     # sylvester :: [Int] def sylvester(): '''Non-finite stream of the terms of Sylvester's sequence. (OEIS A000058) ''' def go(n): return 1 + reduce( lambda a, x: a * go(x), range(0, n), 1 ) if 0 != n else 2   return map(go, count(0))     # ------------------------- TEST ------------------------- # main :: IO () def main(): '''First terms, and sum of reciprocals.'''   print("First 10 terms of OEIS A000058:") xs = list(islice(sylvester(), 10)) print('\n'.join([ str(x) for x in xs ]))   print("\nSum of the reciprocals of the first 10 terms:") print( reduce(lambda a, x: a + 1 / x, xs, 0) )     # MAIN --- if __name__ == '__main__': main()
http://rosettacode.org/wiki/Taxicab_numbers
Taxicab numbers
A   taxicab number   (the definition that is being used here)   is a positive integer that can be expressed as the sum of two positive cubes in more than one way. The first taxicab number is   1729,   which is: 13   +   123       and also 93   +   103. Taxicab numbers are also known as:   taxi numbers   taxi-cab numbers   taxi cab numbers   Hardy-Ramanujan numbers Task Compute and display the lowest 25 taxicab numbers (in numeric order, and in a human-readable format). For each of the taxicab numbers, show the number as well as it's constituent cubes. Extra credit Show the 2,000th taxicab number, and a half dozen more See also A001235: taxicab numbers on The On-Line Encyclopedia of Integer Sequences. Hardy-Ramanujan Number on MathWorld. taxicab number on MathWorld. taxicab number on Wikipedia   (includes the story on how taxi-cab numbers came to be called).
#jq
jq
# Output: an array of the form [i^3 + j^3, [i, j]] sorted by the sum. # Only cubes of 1 to ($in-1) are considered; the listing is therefore truncated # as it might not capture taxicab numbers greater than $in ^ 3. def sum_of_two_cubes: def cubed: .*.*.; . as $in | (cubed + 1) as $limit | [range(1;$in) as $i | range($i;$in) as $j   | [ ($i|cubed) + ($j|cubed), [$i, $j] ] ] | sort | map( select( .[0] < $limit ) );   # Output a stream of triples [t, d1, d2], in order of t, # where t is a taxicab number, and d1 and d2 are distinct # decompositions [i,j] with i^3 + j^3 == t. # The stream includes each taxicab number once only. # def taxicabs0: sum_of_two_cubes as $sums | range(1;$sums|length) as $i | if $sums[$i][0] == $sums[$i-1][0] and ($i==1 or $sums[$i][0] != $sums[$i-2][0]) then [$sums[$i][0], $sums[$i-1][1], $sums[$i][1]] else empty end;   # Output a stream of $n taxicab triples: [t, d1, d2] as described above, # without repeating t. def taxicabs: # If your jq includes until/2 then the following definition # can be omitted: def until(cond; next): def _until: if cond then . else (next|_until) end; _until; . as $n | [10, ($n / 10 | floor)] | max as $increment | [20, ($n / 2 | floor)] | max | [ ., [taxicabs0] ] | until( .[1] | length >= $m; (.[0] + $increment) | [., [taxicabs0]] ) | .[1][0:$n] ;