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http://rosettacode.org/wiki/Accumulator_factory
Accumulator factory
A problem posed by Paul Graham is that of creating a function that takes a single (numeric) argument and which returns another function that is an accumulator. The returned accumulator function in turn also takes a single numeric argument, and returns the sum of all the numeric values passed in so far to that accumulat...
#Icon_and_Unicon
Icon and Unicon
procedure main() a := genAcc(3) b := genAcc(5)   write(" " ,center("a",5), " ", center("b", 5)) write("genAcc: ", right(a(4),5), " ", right(b(4), 5)) write("genAcc: ", right(a(2),5), " ", right(b(3),5)) write("genAcc: ", right(a(4.5),5)," ", right(b(1.3),5)) end   procedure genAcc(n) ...
Give a code snippet in #Icon_and_Unicon A problem posed by Paul Graham is that of creating a function that takes a single (numeric) argument and which returns another function that is an accumulator. The returned accumulator function in turn also takes a single numeric argument, and returns the sum of all the numeric ...
christopher/rosetta-code
http://rosettacode.org/wiki/Hamming_numbers
Hamming numbers
Hamming numbers are numbers of the form   H = 2i × 3j × 5k where i, j, k ≥ 0 Hamming numbers   are also known as   ugly numbers   and also   5-smooth numbers   (numbers whose prime divisors are less or equal to 5). Task Generate the sequence of Hamming numbers, in increasing order.   In ...
#FreeBASIC
FreeBASIC
' FB 1.05.0 Win64   ' The biggest integer which FB supports natively is 8 bytes so unable ' to calculate 1 millionth Hamming number without using an external ' "bigint" library such as GMP   Function min(x As Integer, y As Integer) As Integer Return IIf(x < y, x, y) End Function   Function hamming(n As Integer) As I...
Give a code snippet in #FreeBASIC Hamming numbers are numbers of the form   H = 2i × 3j × 5k where i, j, k ≥ 0 Hamming numbers   are also known as   ugly numbers   and also   5-smooth numbers   (numbers whose prime divisors are less or equal to 5). Task Generate the sequence of Hamming ...
christopher/rosetta-code
http://rosettacode.org/wiki/String_length
String length
Task Find the character and byte length of a string. This means encodings like UTF-8 need to be handled properly, as there is not necessarily a one-to-one relationship between bytes and characters. By character, we mean an individual Unicode code point, not a user-visible grapheme containing combining characters. F...
#AutoHotkey
AutoHotkey
Msgbox % StrLen("Hello World")
Give a code snippet in #AutoHotkey Task Find the character and byte length of a string. This means encodings like UTF-8 need to be handled properly, as there is not necessarily a one-to-one relationship between bytes and characters. By character, we mean an individual Unicode code point, not a user-visible grapheme...
christopher/rosetta-code
http://rosettacode.org/wiki/Palindrome_detection
Palindrome detection
A palindrome is a phrase which reads the same backward and forward. Task[edit] Write a function or program that checks whether a given sequence of characters (or, if you prefer, bytes) is a palindrome. For extra credit: Support Unicode characters. Write a second function (possibly as a wrapper to the first) which ...
#MAXScript
MAXScript
fn isPalindrome s = ( local reversed = "" for i in s.count to 1 by -1 do reversed += s[i] return reversed == s )
Give a code snippet in #MAXScript A palindrome is a phrase which reads the same backward and forward. Task[edit] Write a function or program that checks whether a given sequence of characters (or, if you prefer, bytes) is a palindrome. For extra credit: Support Unicode characters. Write a second function (possibl...
christopher/rosetta-code
http://rosettacode.org/wiki/GUI_enabling/disabling_of_controls
GUI enabling/disabling of controls
In addition to fundamental GUI component interaction, an application should dynamically enable and disable GUI components, to give some guidance to the user, and prohibit (inter)actions which are inappropriate in the current state of the application. Task Similar to the task GUI component interaction, write a progr...
#Fantom
Fantom
using fwt using gfx   class Main { public static Void main () { Window { textField := Text { text = "0" } incButton := Button { text = "increment" onAction.add |Event e| { if (textField.text != "") { try ...
Give a code snippet in #Fantom In addition to fundamental GUI component interaction, an application should dynamically enable and disable GUI components, to give some guidance to the user, and prohibit (inter)actions which are inappropriate in the current state of the application. Task Similar to the task GUI comp...
christopher/rosetta-code
http://rosettacode.org/wiki/Cramer%27s_rule
Cramer's rule
linear algebra Cramer's rule system of linear equations Given { a 1 x + b 1 y + c 1 z = d 1 a 2 x + b 2 y + c 2 z = d 2 a 3 x + b 3 y + c 3 z = d 3 {\displaystyle \left\{{\begin{matrix}a_{1}x+b_{1}y+c_{1}z&={\color {red}d_{1...
#Sidef
Sidef
func cramers_rule(A, terms) { gather { for i in ^A { var Ai = A.map{.map{_}} for j in ^terms { Ai[j][i] = terms[j] } take(Ai.det) } } »/» A.det }   var matrix = [ [2, -1, 5, 1], [3, 2, 2, -6], [1, 3, 3, -1], [5...
Give a code snippet in #Sidef linear algebra Cramer's rule system of linear equations Given { a 1 x + b 1 y + c 1 z = d 1 a 2 x + b 2 y + c 2 z = d 2 a 3 x + b 3 y + c 3 z = d 3 {\displaystyle \left\{{\begin{matrix}a_{1}x+b...
christopher/rosetta-code
http://rosettacode.org/wiki/Gamma_function
Gamma function
Task Implement one algorithm (or more) to compute the Gamma ( Γ {\displaystyle \Gamma } ) function (in the real field only). If your language has the function as built-in or you know a library which has it, compare your implementation's results with the results of the built-in/library function. The Gamma funct...
#Scilab
Scilab
function x=gammal(z) // Lanczos' lz=[ 1.000000000190015 .. 76.18009172947146 -86.50532032941677 24.01409824083091 .. -1.231739572450155 1.208650973866179e-3 -5.395239384953129e-6 ] if z < 0.5 then x=%pi/sin(%pi*z)-gammal(1-z) else z=z-1.0 b=z+5.5 ...
Give a code snippet in #Scilab Task Implement one algorithm (or more) to compute the Gamma ( Γ {\displaystyle \Gamma } ) function (in the real field only). If your language has the function as built-in or you know a library which has it, compare your implementation's results with the results of the built-in/li...
christopher/rosetta-code
http://rosettacode.org/wiki/Extend_your_language
Extend your language
Control Structures These are examples of control structures. You may also be interested in: Conditional structures Exceptions Flow-control structures Loops Some programming languages allow you to extend the language. While this can be done to a certain degree in most languages (e.g. by using macros), other langua...
#Clay
Clay
alias if2(cond1:Bool, cond2:Bool, both, first, second, neither) { var res1 = cond1; var res2 = cond2;   if (res1 and res2) return both; if (res1) return first; if (res2) return second; return neither; }  
Give a code snippet in #Clay Control Structures These are examples of control structures. You may also be interested in: Conditional structures Exceptions Flow-control structures Loops Some programming languages allow you to extend the language. While this can be done to a certain degree in most languages (e.g. ...
christopher/rosetta-code
http://rosettacode.org/wiki/Last_Friday_of_each_month
Last Friday of each month
Task Write a program or a script that returns the date of the last Fridays of each month of a given year. The year may be given through any simple input method in your language (command line, std in, etc). Example of an expected output: ./last_fridays 2012 2012-01-27 2012-02-24 2012-03-30 2012-04-27 2012-05-25 20...
#J
J
require 'dates' last_fridays=: 12 {. [: ({:/.~ }:"1)@(#~ 5 = weekday)@todate (i.366) + todayno@,&1 1
Give a code snippet in #J Task Write a program or a script that returns the date of the last Fridays of each month of a given year. The year may be given through any simple input method in your language (command line, std in, etc). Example of an expected output: ./last_fridays 2012 2012-01-27 2012-02-24 2012-03-...
christopher/rosetta-code
http://rosettacode.org/wiki/Fork
Fork
Task Spawn a new process which can run simultaneously with, and independently of, the original parent process.
#R
R
  p <- parallel::mcparallel({ Sys.sleep(1) cat("\tChild pid: ", Sys.getpid(), "\n") TRUE }) cat("Main pid: ", Sys.getpid(), "\n") parallel::mccollect(p)   p <- parallel:::mcfork() if (inherits(p, "masterProcess")) { Sys.sleep(1) cat("\tChild pid: ", Sys.getpid(), "\n") pa...
Give a code snippet in #R Task Spawn a new process which can run simultaneously with, and independently of, the original parent process.
christopher/rosetta-code
http://rosettacode.org/wiki/Price_fraction
Price fraction
A friend of mine runs a pharmacy.   He has a specialized function in his Dispensary application which receives a decimal value of currency and replaces it to a standard value.   This value is regulated by a government department. Task Given a floating point value between   0.00   and   1.00,   rescale according to ...
#Seed7
Seed7
$ include "seed7_05.s7i"; include "float.s7i";   const func float: computePrice (in float: x) is func result var float: price is 0.0; begin if x >= 0.0 and x < 0.06 then price := 0.10; elsif x < 0.11 then price := 0.18; elsif x < 0.36 then price := flt(((trunc(x * 100.0) - 11) di...
Give a code snippet in #Seed7 A friend of mine runs a pharmacy.   He has a specialized function in his Dispensary application which receives a decimal value of currency and replaces it to a standard value.   This value is regulated by a government department. Task Given a floating point value between   0.00   and ...
christopher/rosetta-code
http://rosettacode.org/wiki/24_game/Solve
24 game/Solve
task Write a program that takes four digits, either from user input or by random generation, and computes arithmetic expressions following the rules of the 24 game. Show examples of solutions generated by the program. Related task   Arithmetic Evaluator
#Racket
Racket
  (define (in-variants n1 o1 n2 o2 n3 o3 n4) (let ([o1n (object-name o1)] [o2n (object-name o2)] [o3n (object-name o3)]) (with-handlers ((exn:fail:contract:divide-by-zero? (λ (_) empty-sequence))) (in-parallel (list (o1 (o2 (o3 n1 n2) n3) n4) (o1 (o2 n1 (o3 n2 n3)) n4...
Give a code snippet in #Racket task Write a program that takes four digits, either from user input or by random generation, and computes arithmetic expressions following the rules of the 24 game. Show examples of solutions generated by the program. Related task   Arithmetic Evaluator
christopher/rosetta-code
http://rosettacode.org/wiki/Letter_frequency
Letter frequency
Task Open a text file and count the occurrences of each letter. Some of these programs count all characters (including punctuation), but some only count letters A to Z. Other tasks related to string operations: Metrics Array length String length Copy a string Empty string  (assignment) Counting Word frequen...
#AppleScript
AppleScript
use AppleScript version "2.4" -- OS X 10.10 (Yosemite) or later use framework "Foundation" use scripting additions   on letterFrequencyinFile(theFile) -- Read the file as an NSString, letting the system guess the encoding. set fileText to current application's class "NSString"'s stringWithContentsOfFile:(POSIX ...
Give a code snippet in #AppleScript Task Open a text file and count the occurrences of each letter. Some of these programs count all characters (including punctuation), but some only count letters A to Z. Other tasks related to string operations: Metrics Array length String length Copy a string Empty string...
christopher/rosetta-code
http://rosettacode.org/wiki/Evaluate_binomial_coefficients
Evaluate binomial coefficients
This programming task, is to calculate ANY binomial coefficient. However, it has to be able to output   ( 5 3 ) {\displaystyle {\binom {5}{3}}} ,   which is   10. This formula is recommended: ( n k ) = n ! ( n − k ) ! k ! = n ( n − 1 ) ( n − 2 ) … ( n − k + 1 ) k ( k − 1...
#Python
Python
def binomialCoeff(n, k): result = 1 for i in range(1, k+1): result = result * (n-i+1) / i return result   if __name__ == "__main__": print(binomialCoeff(5, 3))
Give a code snippet in #Python This programming task, is to calculate ANY binomial coefficient. However, it has to be able to output   ( 5 3 ) {\displaystyle {\binom {5}{3}}} ,   which is   10. This formula is recommended: ( n k ) = n ! ( n − k ) ! k ! = n ( n − 1 ) ( n −...
christopher/rosetta-code
http://rosettacode.org/wiki/Hailstone_sequence
Hailstone sequence
The Hailstone sequence of numbers can be generated from a starting positive integer,   n   by:   If   n   is     1     then the sequence ends.   If   n   is   even then the next   n   of the sequence   = n/2   If   n   is   odd   then the next   n   of the sequence   = (3 * n) + 1 The (unproven) Collatz conje...
#Oz
Oz
declare fun {HailstoneSeq N} N > 0 = true %% assert if N == 1 then [1] elseif {IsEven N} then N|{HailstoneSeq N div 2} else N|{HailstoneSeq 3*N+1} end end   HSeq27 = {HailstoneSeq 27} {Length HSeq27} = 112 {List.take HSeq27 4} = [27 82 41 124] {List.drop HS...
Give a code snippet in #Oz The Hailstone sequence of numbers can be generated from a starting positive integer,   n   by:   If   n   is     1     then the sequence ends.   If   n   is   even then the next   n   of the sequence   = n/2   If   n   is   odd   then the next   n   of the sequence   = (3 * n) + 1 ...
christopher/rosetta-code
http://rosettacode.org/wiki/Morse_code
Morse code
Morse code It has been in use for more than 175 years — longer than any other electronic encoding system. Task Send a string as audible Morse code to an audio device   (e.g., the PC speaker). As the standard Morse code does not contain all possible characters, you may either ignore unknown characters in the file...
#Nim
Nim
import os, strutils, tables   const Morse = {'A': ".-", 'B': "-...", 'C': "-.-.", 'D': "-..", 'E': ".", 'F': "..-.", 'G': "--.", 'H': "....", 'I': "..", 'J': ".---", 'K': "-.-", 'L': ".-..", 'M': "--", 'N': "-.", 'O': "---", 'P': ".--.",...
Give a code snippet in #Nim Morse code It has been in use for more than 175 years — longer than any other electronic encoding system. Task Send a string as audible Morse code to an audio device   (e.g., the PC speaker). As the standard Morse code does not contain all possible characters, you may either ignore u...
christopher/rosetta-code
http://rosettacode.org/wiki/Metronome
Metronome
The task is to implement a   metronome. The metronome should be capable of producing high and low audio beats, accompanied by a visual beat indicator, and the beat pattern and tempo should be configurable. For the purpose of this task, it is acceptable to play sound files for production of the beat notes, and an ext...
#Phix
Phix
-- -- demo\rosetta\virtunome.exw -- -- Originally by ghaberek -- Translated from win32lib by Pete Lomax -- -- I will note that accuracy drops sharply above 5 beats per second. -- with javascript_semantics -- needs some work though, usual sizing stuff [DEV] -- NB: don't break Morse_code....
Give a code snippet in #Phix The task is to implement a   metronome. The metronome should be capable of producing high and low audio beats, accompanied by a visual beat indicator, and the beat pattern and tempo should be configurable. For the purpose of this task, it is acceptable to play sound files for production...
christopher/rosetta-code
http://rosettacode.org/wiki/Multi-dimensional_array
Multi-dimensional array
For the purposes of this task, the actual memory layout or access method of this data structure is not mandated. It is enough to: State the number and extent of each index to the array. Provide specific, ordered, integer indices for all dimensions of the array together with a new value to update the indexed value. ...
#X86-64_Assembly
X86-64 Assembly
  option casemap:none   printf proto :qword, :vararg exit proto :dword   ROW_LEN equ (4*4) MEM_SIZE equ 4   .data ;; A 2d array - 2 rows, 4 columns ;; int twodimen[2][4] = { {0,1,2,3}, ;; {4,5,6,7}}; twodimen db 48 dup (0) tpl db "%d",13,10,0   .code main proc l...
Give a code snippet in #X86-64_Assembly For the purposes of this task, the actual memory layout or access method of this data structure is not mandated. It is enough to: State the number and extent of each index to the array. Provide specific, ordered, integer indices for all dimensions of the array together with ...
christopher/rosetta-code
http://rosettacode.org/wiki/MD5
MD5
Task Encode a string using an MD5 algorithm.   The algorithm can be found on   Wikipedia. Optionally, validate your implementation by running all of the test values in   IETF RFC (1321)   for MD5. Additionally,   RFC 1321   provides more precise information on the algorithm than the Wikipedia article. Warning:...
#Nim
Nim
import md5   echo toMD5("The quick brown fox jumped over the lazy dog's back")
Give a code snippet in #Nim Task Encode a string using an MD5 algorithm.   The algorithm can be found on   Wikipedia. Optionally, validate your implementation by running all of the test values in   IETF RFC (1321)   for MD5. Additionally,   RFC 1321   provides more precise information on the algorithm than the Wi...
christopher/rosetta-code
http://rosettacode.org/wiki/Quine
Quine
A quine is a self-referential program that can, without any external access, output its own source. A   quine   (named after Willard Van Orman Quine)   is also known as:   self-reproducing automata   (1972)   self-replicating program         or   self-replicating computer program   self-reproducing program      ...
#bash
bash
#!/bin/bash mapfile < $0 printf "%s" "${MAPFILE[@]}"
Give a code snippet in #bash A quine is a self-referential program that can, without any external access, output its own source. A   quine   (named after Willard Van Orman Quine)   is also known as:   self-reproducing automata   (1972)   self-replicating program         or   self-replicating computer program   ...
christopher/rosetta-code
http://rosettacode.org/wiki/Pythagorean_triples
Pythagorean triples
A Pythagorean triple is defined as three positive integers ( a , b , c ) {\displaystyle (a,b,c)} where a < b < c {\displaystyle a<b<c} , and a 2 + b 2 = c 2 . {\displaystyle a^{2}+b^{2}=c^{2}.} They are called primitive triples if a , b , c {\displaystyle a,b,c} are co-prime,...
#Phix
Phix
with javascript_semantics atom total, prim, maxPeri = 10 procedure tri(atom s0, s1, s2) atom p = s0 + s1 + s2 if p<=maxPeri then prim += 1 total += floor(maxPeri/p) tri( s0+2*(-s1+s2), 2*( s0+s2)-s1, 2*( s0-s1+s2)+s2); tri( s0+2*( s1+s2), 2*( s0+s2)+s1, 2*( s0+s1+s2)+s2); t...
Give a code snippet in #Phix A Pythagorean triple is defined as three positive integers ( a , b , c ) {\displaystyle (a,b,c)} where a < b < c {\displaystyle a<b<c} , and a 2 + b 2 = c 2 . {\displaystyle a^{2}+b^{2}=c^{2}.} They are called primitive triples if a , b , c {\displ...
christopher/rosetta-code
http://rosettacode.org/wiki/Collections
Collections
This task has been clarified. Its programming examples are in need of review to ensure that they still fit the requirements of the task. Collections are abstractions to represent sets of values. In statically-typed languages, the values are typically of a common data type. Task Create a collection, and add a fe...
#D
D
int[3] array; array[0] = 5; // array.length = 4; // compile-time error
Give a code snippet in #D This task has been clarified. Its programming examples are in need of review to ensure that they still fit the requirements of the task. Collections are abstractions to represent sets of values. In statically-typed languages, the values are typically of a common data type. Task Create...
christopher/rosetta-code
http://rosettacode.org/wiki/Flipping_bits_game
Flipping bits game
The game Given an   N×N   square array of zeroes or ones in an initial configuration,   and a target configuration of zeroes and ones. The game is to transform one to the other in as few moves as possible by inverting whole numbered rows or whole lettered columns at once   (as one move). In an inversion.   any  1 ...
#Perl
Perl
#!perl use strict; use warnings qw(FATAL all);   my $n = shift(@ARGV) || 4; if( $n < 2 or $n > 26 ) { die "You can't play a size $n game\n"; }   my $n2 = $n*$n;   my (@rows, @cols); for my $i ( 0 .. $n-1 ) { my $row = my $col = "\x00" x $n2; vec($row, $i * $n + $_, 8) ^= 1 for 0 .. $n-1; vec($col, $i + $_ * $n, 8) ...
Give a code snippet in #Perl The game Given an   N×N   square array of zeroes or ones in an initial configuration,   and a target configuration of zeroes and ones. The game is to transform one to the other in as few moves as possible by inverting whole numbered rows or whole lettered columns at once   (as one move...
christopher/rosetta-code
http://rosettacode.org/wiki/Playing_cards
Playing cards
Task Create a data structure and the associated methods to define and manipulate a deck of   playing cards. The deck should contain 52 unique cards. The methods must include the ability to:   make a new deck   shuffle (randomize) the deck   deal from the deck   print the current contents of a deck Each card mu...
#Java
Java
public enum Pip { Two, Three, Four, Five, Six, Seven, Eight, Nine, Ten, Jack, Queen, King, Ace }
Give a code snippet in #Java Task Create a data structure and the associated methods to define and manipulate a deck of   playing cards. The deck should contain 52 unique cards. The methods must include the ability to:   make a new deck   shuffle (randomize) the deck   deal from the deck   print the current co...
christopher/rosetta-code
http://rosettacode.org/wiki/Draw_a_sphere
Draw a sphere
Task Draw a sphere. The sphere can be represented graphically, or in ASCII art, depending on the language capabilities. Either static or rotational projection is acceptable for this task. Related tasks draw a cuboid draw a rotating cube write language name in 3D ASCII draw a Deathstar
#ATS
ATS
  (* ** Solution to Draw_a_sphere.dats *)   (* ****** ****** *) // #include "share/atspre_define.hats" // defines some names #include "share/atspre_staload.hats" // for targeting C #include "share/HATS/atspre_staload_libats_ML.hats" // for ... #include "share/HATS/atslib_staload_libats_libc.hats" // for libc // (* ****...
Give a code snippet in #ATS Task Draw a sphere. The sphere can be represented graphically, or in ASCII art, depending on the language capabilities. Either static or rotational projection is acceptable for this task. Related tasks draw a cuboid draw a rotating cube write language name in 3D ASCII draw a Deat...
christopher/rosetta-code
http://rosettacode.org/wiki/Percentage_difference_between_images
Percentage difference between images
basic bitmap storage Useful for comparing two JPEG images saved with a different compression ratios. You can use these pictures for testing (use the full-size version of each): 50% quality JPEG 100% quality JPEG link to full size 50% image link to full size 100% image The expected difference for these two...
#REBOL
REBOL
rebol [ Title: "Percent Image Difference" URL: http://rosettacode.org/wiki/Percentage_of_difference_between_2_images ]   ; Load from local storage. Un/comment as preferred. ; a: load-image %lenna50.jpg ; b: load-image %lenna100.jpg   ; Download from rosettacode.org. a: load-image http://rosettacode.org/mw/images/3/3c...
Give a code snippet in #REBOL basic bitmap storage Useful for comparing two JPEG images saved with a different compression ratios. You can use these pictures for testing (use the full-size version of each): 50% quality JPEG 100% quality JPEG link to full size 50% image link to full size 100% image The ex...
christopher/rosetta-code
http://rosettacode.org/wiki/FizzBuzz
FizzBuzz
Task Write a program that prints the integers from   1   to   100   (inclusive). But:   for multiples of three,   print   Fizz     (instead of the number)   for multiples of five,   print   Buzz     (instead of the number)   for multiples of both three and five,   print   FizzBuzz     (instead of the number) ...
#Nix
Nix
with (import <nixpkgs> { }).lib; with builtins; let fizzbuzz = { x ? 1 }: '' ${if (mod x 15 == 0) then "FizzBuzz" else if (mod x 3 == 0) then "Fizz" else if (mod x 5 == 0) then "Buzz" else (toString x)} '' + (if (x < 100) then fizzbuzz { x = x + 1;...
Give a code snippet in #Nix Task Write a program that prints the integers from   1   to   100   (inclusive). But:   for multiples of three,   print   Fizz     (instead of the number)   for multiples of five,   print   Buzz     (instead of the number)   for multiples of both three and five,   print   FizzBuzz  ...
christopher/rosetta-code
http://rosettacode.org/wiki/Binary_search
Binary search
A binary search divides a range of values into halves, and continues to narrow down the field of search until the unknown value is found. It is the classic example of a "divide and conquer" algorithm. As an analogy, consider the children's game "guess a number." The scorer has a secret number, and will only tell the p...
#Simula
Simula
BEGIN     INTEGER PROCEDURE BINARYSEARCHREC(A, LVALUE); INTEGER ARRAY A; INTEGER LVALUE; ! VALUE IS A KEY WORD ; BEGIN   INTEGER PROCEDURE SEARCH(LOW, HIGH); INTEGER LOW, HIGH; BEGIN INTEGER MID;  ! INVARIANTS: VALUE > A[I] FOR ALL I < LOW ...
Give a code snippet in #Simula A binary search divides a range of values into halves, and continues to narrow down the field of search until the unknown value is found. It is the classic example of a "divide and conquer" algorithm. As an analogy, consider the children's game "guess a number." The scorer has a secret ...
christopher/rosetta-code
http://rosettacode.org/wiki/Add_a_variable_to_a_class_instance_at_runtime
Add a variable to a class instance at runtime
Demonstrate how to dynamically add variables to an object (a class instance) at runtime. This is useful when the methods/variables of an instance are based on a data file that isn't available until runtime. Hal Fulton gives an example of creating an OO CSV parser at An Exercise in Metaprogramming with Ruby. This is re...
#Morfa
Morfa
  import morfa.base;   template <T> public struct Dynamic { var data: Dict<text, T>; }   // convenience to create new Dynamic instances template <T> public property dynamic(): Dynamic<T> { return Dynamic<T>(new Dict<text,T>()); }   // introduce replacement operator for . - a quoting ` operator public operator `...
Give a code snippet in #Morfa Demonstrate how to dynamically add variables to an object (a class instance) at runtime. This is useful when the methods/variables of an instance are based on a data file that isn't available until runtime. Hal Fulton gives an example of creating an OO CSV parser at An Exercise in Metapr...
christopher/rosetta-code
http://rosettacode.org/wiki/McNuggets_problem
McNuggets problem
Wikipedia The McNuggets version of the coin problem was introduced by Henri Picciotto, who included it in his algebra textbook co-authored with Anita Wah. Picciotto thought of the application in the 1980s while dining with his son at McDonald's, working the problem out on a napkin. A McNugget number is the total number...
#Dyalect
Dyalect
func mcnugget(limit) { var sv = Array.Empty(limit + 1, false) for s in 0^6..limit { for n in s^9..limit { for t in n^20..limit { sv[t] = true } } } for i in limit^-1..0 { if !sv[i] { print("Maximum non-McNuggets number is \(i)")...
Give a code snippet in #Dyalect Wikipedia The McNuggets version of the coin problem was introduced by Henri Picciotto, who included it in his algebra textbook co-authored with Anita Wah. Picciotto thought of the application in the 1980s while dining with his son at McDonald's, working the problem out on a napkin. A Mc...
christopher/rosetta-code
http://rosettacode.org/wiki/Four_bit_adder
Four bit adder
Task "Simulate" a four-bit adder. This design can be realized using four 1-bit full adders. Each of these 1-bit full adders can be built with two half adders and an   or   gate. ; Finally a half adder can be made using an   xor   gate and an   and   gate. The   xor   gate can be made using two   nots,   two   ands ...
#Perl
Perl
sub dec2bin { sprintf "%04b", shift } sub bin2dec { oct "0b".shift } sub bin2bits { reverse split(//, substr(shift,0,shift)); } sub bits2bin { join "", map { 0+$_ } reverse @_ }   sub bxor { my($a, $b) = @_; (!$a & $b) | ($a & !$b); }   sub half_adder { my($a, $b) = @_; ( bxor($a,$b), $a & $b ); }   sub full_ad...
Give a code snippet in #Perl Task "Simulate" a four-bit adder. This design can be realized using four 1-bit full adders. Each of these 1-bit full adders can be built with two half adders and an   or   gate. ; Finally a half adder can be made using an   xor   gate and an   and   gate. The   xor   gate can be made u...
christopher/rosetta-code
http://rosettacode.org/wiki/Knuth_shuffle
Knuth shuffle
The   Knuth shuffle   (a.k.a. the Fisher-Yates shuffle)   is an algorithm for randomly shuffling the elements of an array. Task Implement the Knuth shuffle for an integer array (or, if possible, an array of any type). Specification Given an array items with indices ranging from 0 to last, the algorithm can be d...
#AppleScript
AppleScript
set n to 25   set array to {} repeat with i from 1 to n set end of array to i end repeat copy {array, array} to {unshuffled, shuffled} repeat with i from n to 1 by -1 set j to (((random number) * (i - 1)) as integer) + 1 set shuffled's item i to array's item j if j ≠ i's contents then set array's item j to array's ...
Give a code snippet in #AppleScript The   Knuth shuffle   (a.k.a. the Fisher-Yates shuffle)   is an algorithm for randomly shuffling the elements of an array. Task Implement the Knuth shuffle for an integer array (or, if possible, an array of any type). Specification Given an array items with indices ranging f...
christopher/rosetta-code
http://rosettacode.org/wiki/Copy_a_string
Copy a string
This task is about copying a string. Task Where it is relevant, distinguish between copying the contents of a string versus making an additional reference to an existing string. Other tasks related to string operations: Metrics Array length String length Copy a string Empty string  (assignment) Counting W...
#Euphoria
Euphoria
sequence first = "ABC" sequence newOne = first
Give a code snippet in #Euphoria This task is about copying a string. Task Where it is relevant, distinguish between copying the contents of a string versus making an additional reference to an existing string. Other tasks related to string operations: Metrics Array length String length Copy a string Empt...
christopher/rosetta-code
http://rosettacode.org/wiki/Number_names
Number names
Task Show how to spell out a number in English. You can use a preexisting implementation or roll your own, but you should support inputs up to at least one million (or the maximum value of your language's default bounded integer type, if that's less). Support for inputs other than positive integers (like zero, negat...
#Inform_7
Inform 7
say 32767 in words;
Give a code snippet in #Inform_7 Task Show how to spell out a number in English. You can use a preexisting implementation or roll your own, but you should support inputs up to at least one million (or the maximum value of your language's default bounded integer type, if that's less). Support for inputs other than p...
christopher/rosetta-code
http://rosettacode.org/wiki/Show_ASCII_table
Show ASCII table
Task Show  the ASCII character set  from values   32   to   127   (decimal)   in a table format. 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 Bioin...
#Ada
Ada
with Ada.Text_IO; use Ada.Text_IO; with Ada.Integer_Text_IO; use Ada.Integer_Text_IO;   procedure Ascii_Table is N : Integer; begin for R in 0 .. 15 loop for C in 0 .. 5 loop N := 32 + 16 * C + R; Put (N, 3); Put (" : "); case N is when 32 => ...
Give a code snippet in #Ada Task Show  the ASCII character set  from values   32   to   127   (decimal)   in a table format. 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 b...
christopher/rosetta-code
http://rosettacode.org/wiki/I_before_E_except_after_C
I before E except after C
The phrase     "I before E, except after C"     is a widely known mnemonic which is supposed to help when spelling English words. Task Using the word list from   http://wiki.puzzlers.org/pub/wordlists/unixdict.txt, check if the two sub-clauses of the phrase are plausible individually:   "I before E when not pre...
#UNIX_Shell
UNIX Shell
#!/bin/sh   matched() { grep -Poe "$1" unixdict.txt | wc -l }   check() { local num_for="$(matched "$3")" local num_against="$(matched "$2")" if [ "$num_for" -le "$(expr 2 \* "$num_against")" ]; then echo "Clause $1 not plausible ($num_for examples; $num_against counterexamples)" return 1 else ech...
Give a code snippet in #UNIX_Shell The phrase     "I before E, except after C"     is a widely known mnemonic which is supposed to help when spelling English words. Task Using the word list from   http://wiki.puzzlers.org/pub/wordlists/unixdict.txt, check if the two sub-clauses of the phrase are plausible indivi...
christopher/rosetta-code
http://rosettacode.org/wiki/24_game
24 game
The 24 Game tests one's mental arithmetic. Task Write a program that randomly chooses and displays four digits, each from 1 ──► 9 (inclusive) with repetitions allowed. The program should prompt for the player to enter an arithmetic expression using just those, and all of those four digits, used exactly once each. T...
#HicEst
HicEst
DIMENSION digits(4), input_digits(100), difference(4) CHARACTER expression*100, prompt*100, answers='Wrong,Correct,', protocol='24 game.txt'   1 digits = CEILING( RAN(9) ) 2 DLG(Edit=expression, Text=digits, TItle=prompt)   READ(Text=expression, ItemS=n) input_digits IF(n == 4) THEN ALIAS(input_digits,1, ...
Give a code snippet in #HicEst The 24 Game tests one's mental arithmetic. Task Write a program that randomly chooses and displays four digits, each from 1 ──► 9 (inclusive) with repetitions allowed. The program should prompt for the player to enter an arithmetic expression using just those, and all of those four d...
christopher/rosetta-code
http://rosettacode.org/wiki/Object_serialization
Object serialization
Create a set of data types based upon inheritance. Each data type or class should have a print command that displays the contents of an instance of that class to standard output. Create instances of each class in your inheritance hierarchy and display them to standard output. Write each of the objects to a file named o...
#OCaml
OCaml
type entity = { name : string }   let create_entity () = { name = "Entity" } let print_entity x = print_endline x.name let create_person () = { name = "Cletus" }   let instance1 = create_person () let instance2 = create_entity ()   (* Serialize *) let out_chan = open_out_bin "objects.dat";; output_value out_chan instan...
Give a code snippet in #OCaml Create a set of data types based upon inheritance. Each data type or class should have a print command that displays the contents of an instance of that class to standard output. Create instances of each class in your inheritance hierarchy and display them to standard output. Write each o...
christopher/rosetta-code
http://rosettacode.org/wiki/Quine
Quine
A quine is a self-referential program that can, without any external access, output its own source. A   quine   (named after Willard Van Orman Quine)   is also known as:   self-reproducing automata   (1972)   self-replicating program         or   self-replicating computer program   self-reproducing program      ...
#ABAP
ABAP
REPORT R NO STANDARD PAGE HEADING LINE-SIZE 67. DATA:A(440),B,C,N(3) TYPE N,I TYPE I,S. A+000 = 'REPORT R NO STANDARD PAGE HEADING LINE-SIZE 6\7.1DATA:A'. A+055 = '(440),B,C,N(\3) TYPE N,I TYPE I,S.?1DO 440 TIMES.3C = A'. A+110 = '+I.3IF B = S.5IF C CA `\\\?\1\3\5\7`.7B = C.5ELSEIF C ='. A+165 = ' `\``.7WRITE ```` NO-G...
Give a code snippet in #ABAP A quine is a self-referential program that can, without any external access, output its own source. A   quine   (named after Willard Van Orman Quine)   is also known as:   self-reproducing automata   (1972)   self-replicating program         or   self-replicating computer program   ...
christopher/rosetta-code
http://rosettacode.org/wiki/Sleep
Sleep
Task Write a program that does the following in this order: Input an amount of time to sleep in whatever units are most natural for your language (milliseconds, seconds, ticks, etc.). This unit should be noted in comments or in a description. Print "Sleeping..." Sleep the main thread for the given amount of time. ...
#Axe
Axe
Disp "TIME:" input→A 0→T length(A)→L For(I,1,L) If {A}<'0' or {A}>'9' Disp "NOT A NUMBER",i Return End T*10+{A}-'0'→T A++ End Disp "SLEEPING...",i Pause T Disp "AWAKE",i
Give a code snippet in #Axe Task Write a program that does the following in this order: Input an amount of time to sleep in whatever units are most natural for your language (milliseconds, seconds, ticks, etc.). This unit should be noted in comments or in a description. Print "Sleeping..." Sleep the main thread f...
christopher/rosetta-code
http://rosettacode.org/wiki/N-queens_problem
N-queens problem
Solve the eight queens puzzle. You can extend the problem to solve the puzzle with a board of size   NxN. For the number of solutions for small values of   N,   see   OEIS: A000170. Related tasks A* search algorithm Solve a Hidato puzzle Solve a Holy Knight's tour Knight's tour Peaceful chess queen armie...
#XPL0
XPL0
def N=8; \board size (NxN) int R, C; \row and column of board char B(N,N); \board include c:\cxpl\codes;   proc Try; \Try adding a queen to the board int R; \row, for each level of recursion   func Okay; \Returns 'true' if no row, column, or diagonal from square R,C has a queen ...
Give a code snippet in #XPL0 Solve the eight queens puzzle. You can extend the problem to solve the puzzle with a board of size   NxN. For the number of solutions for small values of   N,   see   OEIS: A000170. Related tasks A* search algorithm Solve a Hidato puzzle Solve a Holy Knight's tour Knight's to...
christopher/rosetta-code
http://rosettacode.org/wiki/One-dimensional_cellular_automata
One-dimensional cellular automata
Assume an array of cells with an initial distribution of live and dead cells, and imaginary cells off the end of the array having fixed values. Cells in the next generation of the array are calculated based on the value of the cell and its left and right nearest neighbours in the current generation. If, in the follow...
#Yabasic
Yabasic
10 n=10:READ w:DIM x(w+1),x2(w+1):FOR i=1 to w:READ x(i):NEXT 20 FOR k=1 TO n 30 FOR j=1 TO w 40 IF x(j) THEN PRINT "#"; ELSE PRINT "_"; END IF 50 IF x(j-1)+x(j)+x(j+1)=2 THEN x2(j)=1 ELSE x2(j)=0 END IF 60 NEXT:PRINT 70 FOR j=1 TO w:x(j)=x2(j):NEXT 80 NEXT 90 DATA 20,0,1,1,1,0,1,1,0,1,0,1,0,1,0,1,0,0,1,0,0
Give a code snippet in #Yabasic Assume an array of cells with an initial distribution of live and dead cells, and imaginary cells off the end of the array having fixed values. Cells in the next generation of the array are calculated based on the value of the cell and its left and right nearest neighbours in the curre...
christopher/rosetta-code
http://rosettacode.org/wiki/String_case
String case
Task Take the string     alphaBETA     and demonstrate how to convert it to:   upper-case     and   lower-case Use the default encoding of a string literal or plain ASCII if there is no string literal in your language. Note: In some languages alphabets toLower and toUpper is not reversable. Show any additional...
#Jsish
Jsish
var msg = "alphaBETA"; ;msg; ;msg.toUpperCase(); ;msg.toLowerCase();   ;msg.toTitle(); ;msg.toLocaleUpperCase(); ;msg.toLocaleLowerCase();
Give a code snippet in #Jsish Task Take the string     alphaBETA     and demonstrate how to convert it to:   upper-case     and   lower-case Use the default encoding of a string literal or plain ASCII if there is no string literal in your language. Note: In some languages alphabets toLower and toUpper is not r...
christopher/rosetta-code
http://rosettacode.org/wiki/HTTPS/Authenticated
HTTPS/Authenticated
The goal of this task is to demonstrate HTTPS requests with authentication. Implementations of this task should not use client certificates for this: that is the subject of another task.
#Kotlin
Kotlin
// version 1.2.0   import java.net.Authenticator import java.net.PasswordAuthentication import javax.net.ssl.HttpsURLConnection import java.net.URL import java.io.InputStreamReader import java.io.BufferedReader   object PasswordAuthenticator : Authenticator() { override fun getPasswordAuthentication() = Pas...
Give a code snippet in #Kotlin The goal of this task is to demonstrate HTTPS requests with authentication. Implementations of this task should not use client certificates for this: that is the subject of another task.
christopher/rosetta-code
http://rosettacode.org/wiki/Execute_SNUSP
Execute SNUSP
Execute SNUSP is an implementation of SNUSP. Other implementations of SNUSP. RCSNUSP SNUSP An implementation need only properly implement the Core SNUSP instructions ('$', '\', '/', '+', '-', '<', '>', ',', '.', '!', and '?'). Modular SNUSP ('#', '@') and Bloated SNUSP (':', ';', '%', and '&') are also allowed, but not...
#Ruby
Ruby
$ include "seed7_05.s7i";   const proc: snusp (in string: sourceCode, in integer: memSize, inout file: input, inout file: output) is func local var array string: instructions is 0 times ""; var array char: memory is 0 times ' '; var integer: dataPointer is 1; var integer: instrPtrRow is 0; var int...
Give a code snippet in #Ruby Execute SNUSP is an implementation of SNUSP. Other implementations of SNUSP. RCSNUSP SNUSP An implementation need only properly implement the Core SNUSP instructions ('$', '\', '/', '+', '-', '<', '>', ',', '.', '!', and '?'). Modular SNUSP ('#', '@') and Bloated SNUSP (':', ';', '%', and ...
christopher/rosetta-code
http://rosettacode.org/wiki/Ranking_methods
Ranking methods
Sorting Algorithm This is a sorting algorithm.   It may be applied to a set of data in order to sort it.     For comparing various sorts, see compare sorts.   For other sorting algorithms,   see sorting algorithms,   or: O(n logn) sorts Heap sort | Merge sort | Patience sort | Quick sort O(n log2n) sorts Shell Sort ...
#J
J
competitors=:<;._1;._2]0 :0 44 Solomon 42 Jason 42 Errol 41 Garry 41 Bernard 41 Barry 39 Stephen )   scores=: {."1   standard=: 1+i.~ modified=: 1+i:~ dense=: #/.~ # #\@~. ordinal=: #\ fractional=: #/.~ # ] (+/%#)/. #\   rank=:1 :'<"0@u@:scores,.]'
Give a code snippet in #J Sorting Algorithm This is a sorting algorithm.   It may be applied to a set of data in order to sort it.     For comparing various sorts, see compare sorts.   For other sorting algorithms,   see sorting algorithms,   or: O(n logn) sorts Heap sort | Merge sort | Patience sort | Quick sort O...
christopher/rosetta-code
http://rosettacode.org/wiki/Perfect_numbers
Perfect numbers
Write a function which says whether a number is perfect. A perfect number is a positive integer that is the sum of its proper positive divisors excluding the number itself. Equivalently, a perfect number is a number that is half the sum of all of its positive divisors (including itself). Note:   The faster   Luca...
#Vlang
Vlang
fn compute_perfect(n i64) bool { mut sum := i64(0) for i := i64(1); i < n; i++ { if n%i == 0 { sum += i } } return sum == n }   // following fntion satisfies the task, returning true for all // perfect numbers representable in the argument type fn is_perfect(n i64) bool { ...
Give a code snippet in #Vlang Write a function which says whether a number is perfect. A perfect number is a positive integer that is the sum of its proper positive divisors excluding the number itself. Equivalently, a perfect number is a number that is half the sum of all of its positive divisors (including itself...
christopher/rosetta-code
http://rosettacode.org/wiki/Nim_game
Nim game
Nim game You are encouraged to solve this task according to the task description, using any language you may know. Nim is a simple game where the second player ─── if they know the trick ─── will always win. The game has only 3 rules:   start with   12   tokens   each player takes   1,  2,  or  3   tokens in tur...
#AsciiDots
AsciiDots
  %$LMRTX .-$"Nim Dots"-$""-   /$_"Number must be "\ T /----~------\ | *M /---+-*-[o] | | R [-]\ .>#3-+[>][<]-1#<.| | ...
Give a code snippet in #AsciiDots Nim game You are encouraged to solve this task according to the task description, using any language you may know. Nim is a simple game where the second player ─── if they know the trick ─── will always win. The game has only 3 rules:   start with   12   tokens   each player ta...
christopher/rosetta-code
http://rosettacode.org/wiki/Hello_world/Standard_error
Hello world/Standard error
Hello world/Standard error is part of Short Circuit's Console Program Basics selection. A common practice in computing is to send error messages to a different output stream than normal text console messages. The normal messages print to what is called "standard output" or "standard out". The error messages print to ...
#Aime
Aime
v_text("Goodbye, World!\n");
Give a code snippet in #Aime Hello world/Standard error is part of Short Circuit's Console Program Basics selection. A common practice in computing is to send error messages to a different output stream than normal text console messages. The normal messages print to what is called "standard output" or "standard out"....
christopher/rosetta-code
http://rosettacode.org/wiki/Recaman%27s_sequence
Recaman's sequence
The Recamán's sequence generates Natural numbers. Starting from a(0)=0, the n'th term a(n), where n>0, is the previous term minus n i.e a(n) = a(n-1) - n but only if this is both positive and has not been previousely generated. If the conditions don't hold then a(n) = a(n-1) + n. Task Generate and show here the...
#ALGOL_W
ALGOL W
begin  % calculate Recaman's sequence values  %    % a hash table element - holds n, A(n) and a link to the next element with the  %  % same hash value  % record AValue ( integer eN, eAn ; referen...
Give a code snippet in #ALGOL_W The Recamán's sequence generates Natural numbers. Starting from a(0)=0, the n'th term a(n), where n>0, is the previous term minus n i.e a(n) = a(n-1) - n but only if this is both positive and has not been previousely generated. If the conditions don't hold then a(n) = a(n-1) + n. ...
christopher/rosetta-code
http://rosettacode.org/wiki/Repeat_a_string
Repeat a string
Take a string and repeat it some number of times. Example: repeat("ha", 5)   =>   "hahahahaha" If there is a simpler/more efficient way to repeat a single “character” (i.e. creating a string filled with a certain character), you might want to show that as well (i.e. repeat-char("*", 5) => "*****"). Other tasks re...
#ReScript
ReScript
Js.log(Js.String2.repeat("ha", 5))
Give a code snippet in #ReScript Take a string and repeat it some number of times. Example: repeat("ha", 5)   =>   "hahahahaha" If there is a simpler/more efficient way to repeat a single “character” (i.e. creating a string filled with a certain character), you might want to show that as well (i.e. repeat-char("*", ...
christopher/rosetta-code
http://rosettacode.org/wiki/Man_or_boy_test
Man or boy test
Man or boy test You are encouraged to solve this task according to the task description, using any language you may know. Background: The man or boy test was proposed by computer scientist Donald Knuth as a means of evaluating implementations of the ALGOL 60 programming language. The aim of the test was to distinguis...
#PicoLisp
PicoLisp
(de a (K X1 X2 X3 X4 X5) (let (@K (cons K) B (cons)) # Explicit frame (set B (curry (@K B X1 X2 X3 X4) () (a (dec @K) (car B) X1 X2 X3 X4) ) ) (if (gt0 (car @K)) ((car B)) (+ (X4) (X5))) ) )   (a 10 '(() 1) '(() -1) '(() -1) '(() 1) '(() 0))
Give a code snippet in #PicoLisp Man or boy test You are encouraged to solve this task according to the task description, using any language you may know. Background: The man or boy test was proposed by computer scientist Donald Knuth as a means of evaluating implementations of the ALGOL 60 programming language. The...
christopher/rosetta-code
http://rosettacode.org/wiki/Factors_of_a_Mersenne_number
Factors of a Mersenne number
A Mersenne number is a number in the form of 2P-1. If P is prime, the Mersenne number may be a Mersenne prime (if P is not prime, the Mersenne number is also not prime). In the search for Mersenne prime numbers it is advantageous to eliminate exponents by finding a small factor before starting a, potentially lengthy,...
#FreeBASIC
FreeBASIC
' FB 1.05.0 Win64   Function isPrime(n As Integer) As Boolean If n Mod 2 = 0 Then Return n = 2 If n Mod 3 = 0 Then Return n = 3 Dim d As Integer = 5 While d * d <= n If n Mod d = 0 Then Return False d += 2 If n Mod d = 0 Then Return False d += 4 Wend Return True End Function   ' test 929 plu...
Give a code snippet in #FreeBASIC A Mersenne number is a number in the form of 2P-1. If P is prime, the Mersenne number may be a Mersenne prime (if P is not prime, the Mersenne number is also not prime). In the search for Mersenne prime numbers it is advantageous to eliminate exponents by finding a small factor befo...
christopher/rosetta-code
http://rosettacode.org/wiki/Integer_comparison
Integer comparison
Basic Data Operation This is a basic data operation. It represents a fundamental action on a basic data type. You may see other such operations in the Basic Data Operations category, or: Integer Operations Arithmetic | Comparison Boolean Operations Bitwise | Logical String Operations Concatenation | Interpolation |...
#R
R
print("insert number a") a <- scan(what=numeric(0), nmax=1) print("insert number b") b <- scan(what=numeric(0), nmax=1) if ( a < b ) { print("a is less than b") } else if ( a > b ) { print("a is greater than b") } else if ( a == b ) { # could be simply else of course... print("a and b are the same") }
Give a code snippet in #R Basic Data Operation This is a basic data operation. It represents a fundamental action on a basic data type. You may see other such operations in the Basic Data Operations category, or: Integer Operations Arithmetic | Comparison Boolean Operations Bitwise | Logical String Operations Conc...
christopher/rosetta-code
http://rosettacode.org/wiki/Echo_server
Echo server
Create a network service that sits on TCP port 12321, which accepts connections on that port, and which echoes complete lines (using a carriage-return/line-feed sequence as line separator) back to clients. No error handling is required. For the purposes of testing, it is only necessary to support connections from local...
#X86_Assembly
X86 Assembly
    ; x86_64 Linux NASM   global _start   %define af_inet 2 %define sock_stream 1 %define default_proto 0 %define sol_sock 1 %define reuse_addr 2 %define reuse_port 15 %define server_port 9001 %define addr_any 0 %define family_offset 0 %define port_offset 2 %define addr_offset 4 %define unused_offset 8 %define addr_len...
Give a code snippet in #X86_Assembly Create a network service that sits on TCP port 12321, which accepts connections on that port, and which echoes complete lines (using a carriage-return/line-feed sequence as line separator) back to clients. No error handling is required. For the purposes of testing, it is only neces...
christopher/rosetta-code
http://rosettacode.org/wiki/String_case
String case
Task Take the string     alphaBETA     and demonstrate how to convert it to:   upper-case     and   lower-case Use the default encoding of a string literal or plain ASCII if there is no string literal in your language. Note: In some languages alphabets toLower and toUpper is not reversable. Show any additional...
#Raven
Raven
'alphaBETA' upper 'alhpaBETA' lower
Give a code snippet in #Raven Task Take the string     alphaBETA     and demonstrate how to convert it to:   upper-case     and   lower-case Use the default encoding of a string literal or plain ASCII if there is no string literal in your language. Note: In some languages alphabets toLower and toUpper is not r...
christopher/rosetta-code
http://rosettacode.org/wiki/Bitmap/Histogram
Bitmap/Histogram
Extend the basic bitmap storage defined on this page to support dealing with image histograms. The image histogram contains for each luminance the count of image pixels having this luminance. Choosing a histogram representation take care about the data type used for the counts. It must have range of at least 0..NxM, wh...
#Kotlin
Kotlin
// version 1.2.10   import java.io.File import java.awt.image.BufferedImage import javax.imageio.ImageIO   const val BLACK = 0xff000000.toInt() const val WHITE = 0xffffffff.toInt()   fun luminance(argb: Int): Int { val red = (argb shr 16) and 0xFF val green = (argb shr 8) and 0xFF val blue = argb and 0...
Give a code snippet in #Kotlin Extend the basic bitmap storage defined on this page to support dealing with image histograms. The image histogram contains for each luminance the count of image pixels having this luminance. Choosing a histogram representation take care about the data type used for the counts. It must h...
christopher/rosetta-code
http://rosettacode.org/wiki/Program_termination
Program termination
Task Show the syntax for a complete stoppage of a program inside a   conditional. This includes all threads/processes which are part of your program. Explain the cleanup (or lack thereof) caused by the termination (allocated memory, database connections, open files, object finalizers/destructors, run-on-exit hooks...
#Go
Go
func main() { if problem { return } }
Give a code snippet in #Go Task Show the syntax for a complete stoppage of a program inside a   conditional. This includes all threads/processes which are part of your program. Explain the cleanup (or lack thereof) caused by the termination (allocated memory, database connections, open files, object finalizers/de...
christopher/rosetta-code
http://rosettacode.org/wiki/Monty_Hall_problem
Monty Hall problem
Suppose you're on a game show and you're given the choice of three doors. Behind one door is a car; behind the others, goats. The car and the goats were placed randomly behind the doors before the show. Rules of the game After you have chosen a door, the door remains closed for the time being. The game show hos...
#Dyalect
Dyalect
var switchWins = 0 var stayWins = 0   for plays in 0..1000000 { var doors = [0 ,0, 0] var winner = rnd(max: 3) doors[winner] = 1 var choice = rnd(max: 3) var shown = rnd(max: 3)   while doors[shown] == 1 || shown == choice { shown = rnd(max: 3) }   stayWins += doors[choice] s...
Give a code snippet in #Dyalect Suppose you're on a game show and you're given the choice of three doors. Behind one door is a car; behind the others, goats. The car and the goats were placed randomly behind the doors before the show. Rules of the game After you have chosen a door, the door remains closed for t...
christopher/rosetta-code
http://rosettacode.org/wiki/Rhonda_numbers
Rhonda numbers
A positive integer n is said to be a Rhonda number to base b if the product of the base b digits of n is equal to b times the sum of n's prime factors. These numbers were named by Kevin Brown after an acquaintance of his whose residence number was 25662, a member of the base 10 numbers with this property. 25662 is ...
#C.2B.2B
C++
#include <algorithm> #include <cassert> #include <iomanip> #include <iostream>   int digit_product(int base, int n) { int product = 1; for (; n != 0; n /= base) product *= n % base; return product; }   int prime_factor_sum(int n) { int sum = 0; for (; (n & 1) == 0; n >>= 1) sum += 2;...
Give a code snippet in #C.2B.2B A positive integer n is said to be a Rhonda number to base b if the product of the base b digits of n is equal to b times the sum of n's prime factors. These numbers were named by Kevin Brown after an acquaintance of his whose residence number was 25662, a member of the base 10 number...
christopher/rosetta-code
http://rosettacode.org/wiki/Yahoo!_search_interface
Yahoo! search interface
Create a class for searching Yahoo! results. It must implement a Next Page method, and read URL, Title and Content from results.
#Ruby
Ruby
require 'open-uri' require 'hpricot'   SearchResult = Struct.new(:url, :title, :content)   class SearchYahoo @@urlinfo = [nil, 'ca.search.yahoo.com', 80, '/search', nil, nil]   def initialize(term) @term = term @page = 1 @results = nil @url = URI::HTTP.build(@@urlinfo) end   def next_result ...
Give a code snippet in #Ruby Create a class for searching Yahoo! results. It must implement a Next Page method, and read URL, Title and Content from results.
christopher/rosetta-code
http://rosettacode.org/wiki/Pierpont_primes
Pierpont primes
A Pierpont prime is a prime number of the form: 2u3v + 1 for some non-negative integers u and v . A Pierpont prime of the second kind is a prime number of the form: 2u3v - 1 for some non-negative integers u and v . The term "Pierpont primes" is generally understood to mean the first definition, but will be c...
#M2000_Interpreter
M2000 Interpreter
Module Pierpoint_Primes { Form 80 Set Fast ! const NPP=50 dim pier(1 to 2, 1 to NPP), np(1 to 2) = 0 def long x = 1, j while np(1)<=NPP or np(2)<=NPP x++ j = @is_pierpont(x) if j>0 Else Continue if j mod 2 = 1 then np(1)++ :if np(1) <= NPP then...
Give a code snippet in #M2000_Interpreter A Pierpont prime is a prime number of the form: 2u3v + 1 for some non-negative integers u and v . A Pierpont prime of the second kind is a prime number of the form: 2u3v - 1 for some non-negative integers u and v . The term "Pierpont primes" is generally understood ...
christopher/rosetta-code
http://rosettacode.org/wiki/Horner%27s_rule_for_polynomial_evaluation
Horner's rule for polynomial evaluation
A fast scheme for evaluating a polynomial such as: − 19 + 7 x − 4 x 2 + 6 x 3 {\displaystyle -19+7x-4x^{2}+6x^{3}\,} when x = 3 {\displaystyle x=3\;} . is to arrange the computation as follows: ( ( ( ( 0 ) x + 6 ) x + ( − 4 ) ) x + 7 ) x + ( − 19 ) {\displaystyle ((((0)x+6)x+(-4))x...
#ERRE
ERRE
  PROGRAM HORNER   ! 2 3 ! polynomial is -19+7x-4x +6x !   DIM C[3]   PROCEDURE HORNER(C[],X->RES) LOCAL I%,V FOR I%=UBOUND(C,1) TO 0 STEP -1 DO V=V*X+C[I%] END FOR RES=V END PROCEDURE   BEGIN C[]=(-19,7,-4,6) HORNER(C[],3->RES) PRINT(RES) END PROGRAM  
Give a code snippet in #ERRE A fast scheme for evaluating a polynomial such as: − 19 + 7 x − 4 x 2 + 6 x 3 {\displaystyle -19+7x-4x^{2}+6x^{3}\,} when x = 3 {\displaystyle x=3\;} . is to arrange the computation as follows: ( ( ( ( 0 ) x + 6 ) x + ( − 4 ) ) x + 7 ) x + ( − 19 ) {\d...
christopher/rosetta-code
http://rosettacode.org/wiki/Discordian_date
Discordian date
Task Convert a given date from the   Gregorian calendar   to the   Discordian calendar.
#BASIC
BASIC
#INCLUDE "datetime.bi"   DECLARE FUNCTION julian(AS DOUBLE) AS INTEGER   SeasonNames: DATA "Chaos", "Discord", "Confusion", "Bureaucracy", "The Aftermath" Weekdays: DATA "Setting Orange", "Sweetmorn", "Boomtime", "Pungenday", "Prickle-Prickle" DaysPreceding1stOfMonth: ' jan feb mar apr may jun jul aug sep oct n...
Give a code snippet in #BASIC Task Convert a given date from the   Gregorian calendar   to the   Discordian calendar.
christopher/rosetta-code
http://rosettacode.org/wiki/Animation
Animation
Animation is integral to many parts of GUIs, including both the fancy effects when things change used in window managers, and of course games.   The core of any animation system is a scheme for periodically changing the display while still remaining responsive to the user.   This task demonstrates this. Task Creat...
#Lua
Lua
function love.load() text = "Hello World! " length = string.len(text)     update_time = 0.3 timer = 0 right_direction = true     local width, height = love.graphics.getDimensions( )   local size = 100 local font = love.graphics.setNewFont( size ) local twidth = font:getWidth( text ) local theight = font:getHe...
Give a code snippet in #Lua Animation is integral to many parts of GUIs, including both the fancy effects when things change used in window managers, and of course games.   The core of any animation system is a scheme for periodically changing the display while still remaining responsive to the user.   This task demo...
christopher/rosetta-code
http://rosettacode.org/wiki/Case-sensitivity_of_identifiers
Case-sensitivity of identifiers
Three dogs (Are there three dogs or one dog?) is a code snippet used to illustrate the lettercase sensitivity of the programming language. For a case-sensitive language, the identifiers dog, Dog and DOG are all different and we should get the output: The three dogs are named Benjamin, Samba and Bernie. For a language...
#D.C3.A9j.C3.A0_Vu
Déjà Vu
local :dog "Benjamin" local :Dog "Samba" local :DOG "Bernie"   !print( "There are three dogs named " dog ", " Dog " and " DOG "." )
Give a code snippet in #D.C3.A9j.C3.A0_Vu Three dogs (Are there three dogs or one dog?) is a code snippet used to illustrate the lettercase sensitivity of the programming language. For a case-sensitive language, the identifiers dog, Dog and DOG are all different and we should get the output: The three dogs are named ...
christopher/rosetta-code
http://rosettacode.org/wiki/Ackermann_function
Ackermann function
The Ackermann function is a classic example of a recursive function, notable especially because it is not a primitive recursive function. It grows very quickly in value, as does the size of its call tree. The Ackermann function is usually defined as follows: A ( m , n ) = { n + 1 if  m = 0 A ( m ...
#Babel
Babel
main: {((0 0) (0 1) (0 2) (0 3) (0 4) (1 0) (1 1) (1 2) (1 3) (1 4) (2 0) (2 1) (2 2) (2 3) (3 0) (3 1) (3 2) (4 0))   { dup "A(" << { %d " " . << } ... ") = " << reverse give ack  %d cr << } ... }   ack!: { dup zero? { <-> dup ...
Give a code snippet in #Babel The Ackermann function is a classic example of a recursive function, notable especially because it is not a primitive recursive function. It grows very quickly in value, as does the size of its call tree. The Ackermann function is usually defined as follows: A ( m , n ) = { ...
christopher/rosetta-code
http://rosettacode.org/wiki/Formatted_numeric_output
Formatted numeric output
Task Express a number in decimal as a fixed-length string with leading zeros. For example, the number   7.125   could be expressed as   00007.125.
#Factor
Factor
USE: formatting 7.125 "%09.3f\n" printf
Give a code snippet in #Factor Task Express a number in decimal as a fixed-length string with leading zeros. For example, the number   7.125   could be expressed as   00007.125.
christopher/rosetta-code
http://rosettacode.org/wiki/XML/XPath
XML/XPath
Perform the following three XPath queries on the XML Document below: //item[1]: Retrieve the first "item" element //price/text(): Perform an action on each "price" element (print it out) //name: Get an array of all the "name" elements XML Document: <inventory title="OmniCorp Store #45x10^3"> <section name="heal...
#JavaScript
JavaScript
//create XMLDocument object from file var xhr = new XMLHttpRequest(); xhr.open('GET', 'file.xml', false); xhr.send(null); var doc = xhr.responseXML;   //get first <item> element var firstItem = doc.evaluate( '//item[1]', doc, null, XPathResult.FIRST_ORDERED_NODE_TYPE, null ).singleNodeValue; alert( firstItem.textConten...
Give a code snippet in #JavaScript Perform the following three XPath queries on the XML Document below: //item[1]: Retrieve the first "item" element //price/text(): Perform an action on each "price" element (print it out) //name: Get an array of all the "name" elements XML Document: <inventory title="OmniCorp St...
christopher/rosetta-code
http://rosettacode.org/wiki/Constrained_genericity
Constrained genericity
Constrained genericity or bounded quantification means that a parametrized type or function (see parametric polymorphism) can only be instantiated on types fulfilling some conditions, even if those conditions are not used in that function. Say a type is called "eatable" if you can call the function eat on it. Write a ...
#Common_Lisp
Common Lisp
(defclass food () ())   (defclass inedible-food (food) ())   (defclass edible-food (food) ())   (defgeneric eat (foodstuff) (:documentation "Eat the foodstuff."))   (defmethod eat ((foodstuff edible-food)) "A specialized method for eating edible-food." (format nil "Eating ~w." foodstuff))   (defun eatable-p (thin...
Give a code snippet in #Common_Lisp Constrained genericity or bounded quantification means that a parametrized type or function (see parametric polymorphism) can only be instantiated on types fulfilling some conditions, even if those conditions are not used in that function. Say a type is called "eatable" if you can ...
christopher/rosetta-code
http://rosettacode.org/wiki/Reflection/Get_source
Reflection/Get source
Task The goal is to get the source code or file path and line number where a programming object (e.g. module, class, function, method) is defined.
#6502_Assembly
6502 Assembly
LDA #<foo sta $00 LDA #>foo sta $01 jsr PrintBytecode   foo: ;do stuff rts   PrintBytecode: ldy #0   lda $01  ;high byte of starting address of the source jsr PrintHex ;unimplemented routine that separates the "nibbles" of the accumulator, ; adds $30 or $37 to each depending on if it's 0-9 or A-F respectively, which...
Give a code snippet in #6502_Assembly Task The goal is to get the source code or file path and line number where a programming object (e.g. module, class, function, method) is defined.
christopher/rosetta-code
http://rosettacode.org/wiki/File_size
File size
Verify the size of a file called     input.txt     for a file in the current working directory, and another one in the file system root.
#Frink
Frink
println[newJava["java.io.File", "input.txt"].length[]] println[newJava["java.io.File", "/input.txt"].length[]]
Give a code snippet in #Frink Verify the size of a file called     input.txt     for a file in the current working directory, and another one in the file system root.
christopher/rosetta-code
http://rosettacode.org/wiki/Jewels_and_stones
Jewels and stones
Jewels and stones You are encouraged to solve this task according to the task description, using any language you may know. Task Create a function which takes two string parameters: 'stones' and 'jewels' and returns an integer. Both strings can contain any number of upper or lower case letters. However, in the case ...
#R
R
J_n_S <- function(stones ="aAAbbbb", jewels = "aA") { stones <- unlist(strsplit(stones, split = "")) # obtain a character vector jewels <- unlist(strsplit(jewels, split = "")) count <- sum(stones %in% jewels) }   print(J_n_S("aAAbbbb", "aA")) print(J_n_S("ZZ", "z")) print(J_n_S("lgGKJGljglghGLGHlhglghoIPOgfdtrdD...
Give a code snippet in #R Jewels and stones You are encouraged to solve this task according to the task description, using any language you may know. Task Create a function which takes two string parameters: 'stones' and 'jewels' and returns an integer. Both strings can contain any number of upper or lower case let...
christopher/rosetta-code
http://rosettacode.org/wiki/Call_a_function_in_a_shared_library
Call a function in a shared library
Show how to call a function in a shared library (without dynamically linking to it at compile-time). In particular, show how to call the shared library function if the library is available, otherwise use an internal equivalent function. This is a special case of calling a foreign language function where the focus is c...
#zkl
zkl
var BN=Import("zklBigNum"); BN(1)+2 //--> BN(3)
Give a code snippet in #zkl Show how to call a function in a shared library (without dynamically linking to it at compile-time). In particular, show how to call the shared library function if the library is available, otherwise use an internal equivalent function. This is a special case of calling a foreign language ...
christopher/rosetta-code
http://rosettacode.org/wiki/Convert_seconds_to_compound_duration
Convert seconds to compound duration
Task Write a function or program which:   takes a positive integer representing a duration in seconds as input (e.g., 100), and   returns a string which shows the same duration decomposed into:   weeks,   days,   hours,   minutes,   and   seconds. This is detailed below (e.g., "2 hr, 59 sec"). Demonstrat...
#XPL0
XPL0
char Str(80); func Duration(Sec); \Convert seconds to compound duration int Sec, Amt, Unit, DoComma, I, Quot; [Amt:= [7*24*60*60, 24*60*60, 60*60, 60, 1]; Unit:= [" wk", " d", " hr", " min", " sec"]; DoComma:= false; for I:= 0 to 4 do [Quot:= Sec/Amt(I); Sec:= rem(0); if Quot # 0 then [if DoComma t...
Give a code snippet in #XPL0 Task Write a function or program which:   takes a positive integer representing a duration in seconds as input (e.g., 100), and   returns a string which shows the same duration decomposed into:   weeks,   days,   hours,   minutes,   and   seconds. This is detailed below (e.g., ...
christopher/rosetta-code
http://rosettacode.org/wiki/Random_number_generator_(included)
Random number generator (included)
The task is to: State the type of random number generator algorithm used in a language's built-in random number generator. If the language or its immediate libraries don't provide a random number generator, skip this task. If possible, give a link to a wider explanation of the algorithm used. Note: the task is not t...
#FreeBASIC
FreeBASIC
randomInteger = rnd(expr)
Give a code snippet in #FreeBASIC The task is to: State the type of random number generator algorithm used in a language's built-in random number generator. If the language or its immediate libraries don't provide a random number generator, skip this task. If possible, give a link to a wider explanation of the algo...
christopher/rosetta-code
http://rosettacode.org/wiki/Return_multiple_values
Return multiple values
Task Show how to return more than one value from a function.
#Pike
Pike
array(int) addsub(int x, int y) { return ({ x+y, x-y }); }   [int z, int w] = addsub(5,4);
Give a code snippet in #Pike Task Show how to return more than one value from a function.
christopher/rosetta-code
http://rosettacode.org/wiki/Constrained_random_points_on_a_circle
Constrained random points on a circle
Task Generate 100 <x,y> coordinate pairs such that x and y are integers sampled from the uniform distribution with the condition that 10 ≤ x 2 + y 2 ≤ 15 {\displaystyle 10\leq {\sqrt {x^{2}+y^{2}}}\leq 15} . Then display/plot them. The outcome should be a "fuzzy" circle. The actual number of point...
#Delphi
Delphi
  unit Main;   interface   uses Winapi.Windows, System.SysUtils, System.Classes, Vcl.Graphics, Vcl.Controls, Vcl.Forms, Vcl.ExtCtrls;   type TForm1 = class(TForm) procedure FormCreate(Sender: TObject); procedure FormPaint(Sender: TObject); end;   var Form1: TForm1; Points: TArray<TPoint>;   implementa...
Give a code snippet in #Delphi Task Generate 100 <x,y> coordinate pairs such that x and y are integers sampled from the uniform distribution with the condition that 10 ≤ x 2 + y 2 ≤ 15 {\displaystyle 10\leq {\sqrt {x^{2}+y^{2}}}\leq 15} . Then display/plot them. The outcome should be a "fuzzy" ci...
christopher/rosetta-code
http://rosettacode.org/wiki/Entropy/Narcissist
Entropy/Narcissist
Task Write a computer program that computes and shows its own   entropy. Related Tasks   Fibonacci_word   Entropy
#Java
Java
  import java.io.BufferedReader; import java.io.File; import java.io.FileReader; import java.io.IOException; import java.util.HashMap; import java.util.Map;   public class EntropyNarcissist {   private static final String FILE_NAME = "src/EntropyNarcissist.java";   public static void main(String[] args) { ...
Give a code snippet in #Java Task Write a computer program that computes and shows its own   entropy. Related Tasks   Fibonacci_word   Entropy
christopher/rosetta-code
http://rosettacode.org/wiki/Index_finite_lists_of_positive_integers
Index finite lists of positive integers
It is known that the set of finite lists of positive integers is   countable. This means that there exists a subset of natural integers which can be mapped to the set of finite lists of positive integers. Task Implement such a mapping:   write a function     rank     which assigns an integer to any finite, arbi...
#Quackery
Quackery
[ $ "" swap witheach [ number$ char A join join ] 11 base put $->n drop base release ] is rank ( [ --> n )   [ 11 base put number$ base release [] $ "" rot witheach [ dup char A = iff [ drop $->n drop join $ "" ] ...
Give a code snippet in #Quackery It is known that the set of finite lists of positive integers is   countable. This means that there exists a subset of natural integers which can be mapped to the set of finite lists of positive integers. Task Implement such a mapping:   write a function     rank     which assi...
christopher/rosetta-code
http://rosettacode.org/wiki/Best_shuffle
Best shuffle
Task Shuffle the characters of a string in such a way that as many of the character values are in a different position as possible. A shuffle that produces a randomized result among the best choices is to be preferred. A deterministic approach that produces the same sequence every time is acceptable as an alternative...
#Action.21
Action!
PROC BestShuffle(CHAR ARRAY orig,res) BYTE i,j,len CHAR tmp   len=orig(0) SCopy(res,orig) FOR i=1 TO len DO FOR j=1 TO len DO IF i#j AND orig(i)#res(j) AND orig(j)#res(i) THEN tmp=res(i) res(i)=res(j) res(j)=tmp FI OD OD RETURN   PROC Test(CHAR ARRAY orig) CHAR ARRAY res(...
Give a code snippet in #Action.21 Task Shuffle the characters of a string in such a way that as many of the character values are in a different position as possible. A shuffle that produces a randomized result among the best choices is to be preferred. A deterministic approach that produces the same sequence every t...
christopher/rosetta-code
http://rosettacode.org/wiki/Sort_a_list_of_object_identifiers
Sort a list of object identifiers
Sorting Algorithm This is a sorting algorithm.   It may be applied to a set of data in order to sort it.     For comparing various sorts, see compare sorts.   For other sorting algorithms,   see sorting algorithms,   or: O(n logn) sorts Heap sort | Merge sort | Patience sort | Quick sort O(n log2n) sorts Shell Sort ...
#Mathematica_.2F_Wolfram_Language
Mathematica / Wolfram Language
in = {"1.3.6.1.4.1.11.2.17.19.3.4.0.10", "1.3.6.1.4.1.11.2.17.5.2.0.79", "1.3.6.1.4.1.11.2.17.19.3.4.0.4", "1.3.6.1.4.1.11150.3.4.0.1", "1.3.6.1.4.1.11.2.17.19.3.4.0.1", "1.3.6.1.4.1.11150.3.4.0"}; in = StringSplit[#, "."] & /@ in; in = Map[ToExpression, in, {2}]; Column[StringRiffle[ToString /@ #, "."] & /...
Give a code snippet in #Mathematica_.2F_Wolfram_Language Sorting Algorithm This is a sorting algorithm.   It may be applied to a set of data in order to sort it.     For comparing various sorts, see compare sorts.   For other sorting algorithms,   see sorting algorithms,   or: O(n logn) sorts Heap sort | Merge sort...
christopher/rosetta-code
http://rosettacode.org/wiki/Chat_server
Chat server
Task Write a server for a minimal text based chat. People should be able to connect via ‘telnet’, sign on with a nickname, and type messages which will then be seen by all other connected users. Arrivals and departures of chat members should generate appropriate notification messages.
#Ada
Ada
with Ada.Containers.Vectors; with Ada.Command_Line; use Ada.Command_Line; with Ada.Exceptions; use Ada.Exceptions; with Ada.Text_IO; use Ada.Text_IO; with Ada.Strings.Unbounded; use Ada.Strings.Unbounded; with Sockets; use Sockets;   procedure Chat_Server is   package Client_Vectors is new Ada.Contai...
Give a code snippet in #Ada Task Write a server for a minimal text based chat. People should be able to connect via ‘telnet’, sign on with a nickname, and type messages which will then be seen by all other connected users. Arrivals and departures of chat members should generate appropriate notification messages.
christopher/rosetta-code
http://rosettacode.org/wiki/Last_Friday_of_each_month
Last Friday of each month
Task Write a program or a script that returns the date of the last Fridays of each month of a given year. The year may be given through any simple input method in your language (command line, std in, etc). Example of an expected output: ./last_fridays 2012 2012-01-27 2012-02-24 2012-03-30 2012-04-27 2012-05-25 20...
#Ada
Ada
with Ada.Text_IO, GNAT.Calendar.Time_IO, Ada.Command_Line, Ada.Calendar.Formatting, Ada.Calendar.Arithmetic;   procedure Last_Weekday_In_Month is   procedure Put_Line(T: Ada.Calendar.Time) is use GNAT.Calendar.Time_IO; begin Ada.Text_IO.Put_Line(Image(Date => T, Picture => ISO_Date)); end Put_Lin...
Give a code snippet in #Ada Task Write a program or a script that returns the date of the last Fridays of each month of a given year. The year may be given through any simple input method in your language (command line, std in, etc). Example of an expected output: ./last_fridays 2012 2012-01-27 2012-02-24 2012-0...
christopher/rosetta-code
http://rosettacode.org/wiki/Numeric_error_propagation
Numeric error propagation
If   f,   a,   and   b   are values with uncertainties   σf,   σa,   and   σb,   and   c   is a constant; then if   f   is derived from   a,   b,   and   c   in the following ways, then   σf   can be calculated as follows: Addition/Subtraction If   f = a ± c,   or   f = c ± a   then   σf = σa If   f = a ± b   then...
#Wren
Wren
class Approx { construct new(nu, sigma) { _nu = nu _sigma = sigma }   static new(a) { if (a is Approx) return Approx.new(a.nu, a.sigma) if (a is Num) return Approx.new(a, 0) }   nu { _nu } sigma { _sigma }   +(a) { if (a is Approx) return Approx...
Give a code snippet in #Wren If   f,   a,   and   b   are values with uncertainties   σf,   σa,   and   σb,   and   c   is a constant; then if   f   is derived from   a,   b,   and   c   in the following ways, then   σf   can be calculated as follows: Addition/Subtraction If   f = a ± c,   or   f = c ± a   then   ...
christopher/rosetta-code
http://rosettacode.org/wiki/Create_a_file_on_magnetic_tape
Create a file on magnetic tape
The task is to create a new file called "TAPE.FILE" of any size on Magnetic Tape.
#TUSCRIPT
TUSCRIPT
$$ MODE TUSCRIPT STATUS = CREATE ("tape.file",tape-o,-std-) PRINT STATUS
Give a code snippet in #TUSCRIPT The task is to create a new file called "TAPE.FILE" of any size on Magnetic Tape.
christopher/rosetta-code
http://rosettacode.org/wiki/Pythagoras_tree
Pythagoras tree
The Pythagoras tree is a fractal tree constructed from squares. It is named after Pythagoras because each triple of touching squares encloses a right triangle, in a configuration traditionally used to represent the Pythagorean theorem. Task Construct a Pythagoras tree of order 7 using only vectors (no rotation or ...
#Raku
Raku
class Square { has Complex ($.position, $.edge); method size { $!edge.abs } method svg-polygon { qq[<polygon points="{join ' ', map { ($!position + $_ * $!edge).reals.join(',') }, 0, 1, 1+1i, 1i}" style="fill:lime;stroke=black" />] } method left-child { self.new: position => $!position + i*$!ed...
Give a code snippet in #Raku The Pythagoras tree is a fractal tree constructed from squares. It is named after Pythagoras because each triple of touching squares encloses a right triangle, in a configuration traditionally used to represent the Pythagorean theorem. Task Construct a Pythagoras tree of order 7 using...
christopher/rosetta-code
http://rosettacode.org/wiki/Compare_length_of_two_strings
Compare length of two strings
Basic Data Operation This is a basic data operation. It represents a fundamental action on a basic data type. You may see other such operations in the Basic Data Operations category, or: Integer Operations Arithmetic | Comparison Boolean Operations Bitwise | Logical String Operations Concatenation | Interpolation |...
#Lua
Lua
function test(list) table.sort(list, function(a,b) return #a > #b end) for _,s in ipairs(list) do print(#s, s) end end test{"abcd", "123456789", "abcdef", "1234567"}
Give a code snippet in #Lua Basic Data Operation This is a basic data operation. It represents a fundamental action on a basic data type. You may see other such operations in the Basic Data Operations category, or: Integer Operations Arithmetic | Comparison Boolean Operations Bitwise | Logical String Operations Co...
christopher/rosetta-code
http://rosettacode.org/wiki/File_modification_time
File modification time
Task Get and set the modification time of a file.
#Standard_ML
Standard ML
val mtime = OS.FileSys.modTime filename; (* returns a Time.time data structure *)   (* unfortunately it seems like you have to set modification & access times together *) OS.FileSys.setTime (filename, NONE); (* sets modification & access time to now *) (* equivalent to: *) OS.FileSys.setTime (filename, SOME (Time.now (...
Give a code snippet in #Standard_ML Task Get and set the modification time of a file.
christopher/rosetta-code
http://rosettacode.org/wiki/McNuggets_problem
McNuggets problem
Wikipedia The McNuggets version of the coin problem was introduced by Henri Picciotto, who included it in his algebra textbook co-authored with Anita Wah. Picciotto thought of the application in the 1980s while dining with his son at McDonald's, working the problem out on a napkin. A McNugget number is the total number...
#CLU
CLU
% Recursive nugget iterator. % This yields all the nugget numbers of the given box sizes from start to max. gen_nuggets = iter (start, max: int, sizes: sequence[int]) yields (int) si = sequence[int] if si$empty(sizes) then yield(start) else for i: int in int$from_to_by(start, max, si$botto...
Give a code snippet in #CLU Wikipedia The McNuggets version of the coin problem was introduced by Henri Picciotto, who included it in his algebra textbook co-authored with Anita Wah. Picciotto thought of the application in the 1980s while dining with his son at McDonald's, working the problem out on a napkin. A McNugg...
christopher/rosetta-code
http://rosettacode.org/wiki/Interactive_programming_(repl)
Interactive programming (repl)
Many language implementations come with an interactive mode. This is a command-line interpreter that reads lines from the user and evaluates these lines as statements or expressions. An interactive mode may also be known as a command mode,   a read-eval-print loop (REPL),   or a shell. Task Show how to start this...
#F.23
F#
Microsoft F# Interactive, (c) Microsoft Corporation, All Rights Reserved F# Version 1.9.6.2, compiling for .NET Framework Version v2.0.50727   Please send bug reports to fsbugs@microsoft.com For help type #help;;   > let f a b sep = String.concat sep [a; ""; b] ;;   val f : string -> string -> string -> string   > f "R...
Give a code snippet in #F.23 Many language implementations come with an interactive mode. This is a command-line interpreter that reads lines from the user and evaluates these lines as statements or expressions. An interactive mode may also be known as a command mode,   a read-eval-print loop (REPL),   or a shell. ...
christopher/rosetta-code
http://rosettacode.org/wiki/Base64_decode_data
Base64 decode data
See Base64 encode data. Now write a program that takes the output of the Base64 encode data task as input and regenerate the original file. When working on the VBA implementation I found several 'solutions' on the net, including one from the software maker himself, that showed output with incorrect padding. Obviously...
#Phix
Phix
with javascript_semantics include builtins\base64.e string s = "Rosetta Code Base64 decode data task" string e = encode_base64(s) ?e ?decode_base64(e)
Give a code snippet in #Phix See Base64 encode data. Now write a program that takes the output of the Base64 encode data task as input and regenerate the original file. When working on the VBA implementation I found several 'solutions' on the net, including one from the software maker himself, that showed output wit...
christopher/rosetta-code
http://rosettacode.org/wiki/Character_codes
Character codes
Task Given a character value in your language, print its code   (could be ASCII code, Unicode code, or whatever your language uses). Example The character   'a'   (lowercase letter A)   has a code of 97 in ASCII   (as well as Unicode, as ASCII forms the beginning of Unicode). Conversely, given a code, print out...
#Python
Python
print ord('a') # prints "97" print chr(97) # prints "a"
Give a code snippet in #Python Task Given a character value in your language, print its code   (could be ASCII code, Unicode code, or whatever your language uses). Example The character   'a'   (lowercase letter A)   has a code of 97 in ASCII   (as well as Unicode, as ASCII forms the beginning of Unicode). Con...
christopher/rosetta-code
http://rosettacode.org/wiki/Documentation
Documentation
See also Related task: Comments Related task: Here_document
#Elixir
Elixir
  def project do [app: :repo version: "0.1.0-dev", name: "REPO", source_url: "https://github.com/USER/REPO", homepage_url: "http://YOUR_PROJECT_HOMEPAGE" deps: deps] end  
Give a code snippet in #Elixir See also Related task: Comments Related task: Here_document
christopher/rosetta-code
http://rosettacode.org/wiki/Variables
Variables
Task Demonstrate a language's methods of:   variable declaration   initialization   assignment   datatypes   scope   referencing,     and   other variable related facilities
#Arturo
Arturo
num: 10 str: "hello world"   arrA: [1 2 3] arrB: ["one" "two" "three"] arrC: [1 "two" [3 4 5]] arrD: ["one" true [ print "something" ]]   dict: [ name: "john" surname: "doe" function: $[][ print "do sth" ] ]   inspect symbols
Give a code snippet in #Arturo Task Demonstrate a language's methods of:   variable declaration   initialization   assignment   datatypes   scope   referencing,     and   other variable related facilities
christopher/rosetta-code
http://rosettacode.org/wiki/String_comparison
String comparison
Basic Data Operation This is a basic data operation. It represents a fundamental action on a basic data type. You may see other such operations in the Basic Data Operations category, or: Integer Operations Arithmetic | Comparison Boolean Operations Bitwise | Logical String Operations Concatenation | Interpolation |...
#Quackery
Quackery
/O> ( compare two strings for equality ) ... $ "abc" $ "xyz" = ... echo ( 0 = false, 1 = true ) ... 0 Stack empty. /O> ( compare two strings for inequality ) ... $ "abc" $ "xyz" != ... echo ( 0 = false, 1 = true ) ... 1 Stack empty. //O> ( compare two strings to see if one is lexically ordered before the other ) .....
Give a code snippet in #Quackery Basic Data Operation This is a basic data operation. It represents a fundamental action on a basic data type. You may see other such operations in the Basic Data Operations category, or: Integer Operations Arithmetic | Comparison Boolean Operations Bitwise | Logical String Operatio...
christopher/rosetta-code
http://rosettacode.org/wiki/Color_wheel
Color wheel
Task Write a function to draw a HSV color wheel completely with code. This is strictly for learning purposes only. It's highly recommended that you use an image in an actual application to actually draw the color wheel   (as procedurally drawing is super slow). This does help you understand how color wheels work and ...
#AppleScript
AppleScript
  choose color default color {0, 0, 0, 0}  
Give a code snippet in #AppleScript Task Write a function to draw a HSV color wheel completely with code. This is strictly for learning purposes only. It's highly recommended that you use an image in an actual application to actually draw the color wheel   (as procedurally drawing is super slow). This does help you ...
christopher/rosetta-code
http://rosettacode.org/wiki/Evaluate_binomial_coefficients
Evaluate binomial coefficients
This programming task, is to calculate ANY binomial coefficient. However, it has to be able to output   ( 5 3 ) {\displaystyle {\binom {5}{3}}} ,   which is   10. This formula is recommended: ( n k ) = n ! ( n − k ) ! k ! = n ( n − 1 ) ( n − 2 ) … ( n − k + 1 ) k ( k − 1...
#Swift
Swift
func factorial<T: BinaryInteger>(_ n: T) -> T { guard n != 0 else { return 1 }   return stride(from: n, to: 0, by: -1).reduce(1, *) }   func binomial<T: BinaryInteger>(_ x: (n: T, k: T)) -> T { let nFac = factorial(x.n) let kFac = factorial(x.k)   return nFac / (factorial(x.n - x.k) * kFac) }   print("b...
Give a code snippet in #Swift This programming task, is to calculate ANY binomial coefficient. However, it has to be able to output   ( 5 3 ) {\displaystyle {\binom {5}{3}}} ,   which is   10. This formula is recommended: ( n k ) = n ! ( n − k ) ! k ! = n ( n − 1 ) ( n − ...
christopher/rosetta-code
http://rosettacode.org/wiki/Keyboard_input/Obtain_a_Y_or_N_response
Keyboard input/Obtain a Y or N response
Task Obtain a valid   Y   or   N   response from the keyboard. The keyboard should be flushed, so that any outstanding key-presses are removed, preventing any existing   Y   or   N   key-press from being evaluated. The response should be obtained as soon as   Y   or   N   are pressed, and there should be no need t...
#PL.2FI
PL/I
yn: Proc Options(main): Dcl sysin stream input; Dcl sysprint stream output; Dcl c Char(1); Put Skip List('Please enter Y or N'); Get Edit(c)(a(1)); Select(c); When('Y','y','J','j') Put Skip List('YES'); When('N','n') Put Skip List('NO'); Otherwise Put Skip List('Undecided?'); End; End...
Give a code snippet in #PL.2FI Task Obtain a valid   Y   or   N   response from the keyboard. The keyboard should be flushed, so that any outstanding key-presses are removed, preventing any existing   Y   or   N   key-press from being evaluated. The response should be obtained as soon as   Y   or   N   are presse...
christopher/rosetta-code
http://rosettacode.org/wiki/Smith_numbers
Smith numbers
Smith numbers are numbers such that the sum of the decimal digits of the integers that make up that number is the same as the sum of the decimal digits of its prime factors excluding 1. By definition, all primes are excluded as they (naturally) satisfy this condition! Smith numbers are also known as   joke   numbers....
#PicoLisp
PicoLisp
(de factor (N) (make (let (D 2 L (1 2 2 . (4 2 4 2 4 6 2 6 .)) M (sqrt N)) (while (>= M D) (if (=0 (% N D)) (setq M (sqrt (setq N (/ N (link D))))) (inc 'D (pop 'L)) ) ) (link N) ) ) ) (de sumdigits (N) (sum format (chop N)) ) (de smith (X) (m...
Give a code snippet in #PicoLisp Smith numbers are numbers such that the sum of the decimal digits of the integers that make up that number is the same as the sum of the decimal digits of its prime factors excluding 1. By definition, all primes are excluded as they (naturally) satisfy this condition! Smith numbers a...
christopher/rosetta-code