task_url
stringlengths
30
116
task_name
stringlengths
2
86
task_description
stringlengths
0
14.4k
language_url
stringlengths
2
53
language_name
stringlengths
1
52
code
stringlengths
0
61.9k
response_seed
stringclasses
1 value
instruction_seed
stringlengths
27
14.4k
_source
stringclasses
1 value
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...
#C.23
C#
using System; using System.IO; using System.Collections.Generic; using System.Runtime.Serialization.Formatters.Binary;   namespace Object_serialization { [Serializable] public class Being { public bool Alive { get; set; } }   [Serializable] public class Animal: Being { public Animal() { }   public...
Give a code snippet in #C.23 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...
christopher/rosetta-code
http://rosettacode.org/wiki/DNS_query
DNS query
DNS is an internet service that maps domain names, like rosettacode.org, to IP addresses, like 66.220.0.231. Use DNS to resolve www.kame.net to both IPv4 and IPv6 addresses. Print these addresses.
#zkl
zkl
zkl: Network.TCPClientSocket.addrInfo("www.kame.net") L("orange.kame.net",L("203.178.141.194","2001:200:dff:fff1:216:3eff:feb1:44d7"))
Give a code snippet in #zkl DNS is an internet service that maps domain names, like rosettacode.org, to IP addresses, like 66.220.0.231. Use DNS to resolve www.kame.net to both IPv4 and IPv6 addresses. Print these addresses.
christopher/rosetta-code
http://rosettacode.org/wiki/Parametric_polymorphism
Parametric polymorphism
Parametric Polymorphism type variables Task Write a small example for a type declaration that is parametric over another type, together with a short bit of code (and its type signature) that uses it. A good example is a container type, let's say a binary tree, together with some function that traverses the tree, ...
#Raku
Raku
role BinaryTree[::T] { has T $.value; has BinaryTree[T] $.left; has BinaryTree[T] $.right;   method replace-all(T $value) { $!value = $value; $!left.replace-all($value) if $!left.defined; $!right.replace-all($value) if $!right.defined; } }   class IntTree does BinaryTree[Int]...
Give a code snippet in #Raku Parametric Polymorphism type variables Task Write a small example for a type declaration that is parametric over another type, together with a short bit of code (and its type signature) that uses it. A good example is a container type, let's say a binary tree, together with some func...
christopher/rosetta-code
http://rosettacode.org/wiki/Empty_program
Empty program
Task Create the simplest possible program that is still considered "correct."
#Gecho
Gecho
 
Give a code snippet in #Gecho Task Create the simplest possible program that is still considered "correct."
christopher/rosetta-code
http://rosettacode.org/wiki/Array_length
Array length
Task Determine the amount of elements in an array. As an example use an array holding the strings 'apple' and 'orange'. 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 befo...
#Jsish
Jsish
/* Array length, in jsish */ var arr = new Array('apple', 'orange'); puts(arr.length); puts(arr[1]);
Give a code snippet in #Jsish Task Determine the amount of elements in an array. As an example use an array holding the strings 'apple' and 'orange'. Other tasks related to string operations: Metrics Array length String length Copy a string Empty string  (assignment) Counting Word frequency Letter frequ...
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...
#PowerShell
PowerShell
# Calculate best possible shuffle score for a given string # (Split out into separate function so we can use it separately in our output) function Get-BestScore ( [string]$String ) { # Convert to array of characters, group identical characters, # sort by frequecy, get size of first group $MostRepeat...
Give a code snippet in #PowerShell 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 ...
christopher/rosetta-code
http://rosettacode.org/wiki/Arithmetic-geometric_mean
Arithmetic-geometric mean
This page uses content from Wikipedia. The original article was at Arithmetic-geometric mean. 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) Task Write a function to compute the arithmetic-geomet...
#Julia
Julia
function agm(x, y, e::Real = 5) (x ≤ 0 || y ≤ 0 || e ≤ 0) && throw(DomainError("x, y must be strictly positive")) g, a = minmax(x, y) while e * eps(x) < a - g a, g = (a + g) / 2, sqrt(a * g) end a end   x, y = 1.0, 1 / √2 println("# Using literal-precision float numbers:") @show agm(x, y)   ...
Give a code snippet in #Julia This page uses content from Wikipedia. The original article was at Arithmetic-geometric mean. 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) Task Write a function t...
christopher/rosetta-code
http://rosettacode.org/wiki/Snake
Snake
This page uses content from Wikipedia. The original article was at Snake_(video_game). 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) Snake is a game where the player maneuvers a line which grows i...
#Rust
Rust
/* add to file Cargo.toml: [dependencies] winsafe = "0.0.8" rand = "0.8.4" */   #![windows_subsystem = "windows"]   use rand::Rng; use std::{cell::RefCell, rc::Rc}; use winsafe::{co, gui, prelude::*, COLORREF, HBRUSH, HPEN, SIZE};   const STEP: i32 = 3; // px, motion per frame. STEP and FPS determine the smoothness and...
Give a code snippet in #Rust This page uses content from Wikipedia. The original article was at Snake_(video_game). 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) Snake is a game where the player ...
christopher/rosetta-code
http://rosettacode.org/wiki/Fibonacci_sequence
Fibonacci sequence
The Fibonacci sequence is a sequence   Fn   of natural numbers defined recursively: F0 = 0 F1 = 1 Fn = Fn-1 + Fn-2, if n>1 Task Write a function to generate the   nth   Fibonacci number. Solutions can be iterative or recursive (though recursive solutions are generally considered too slow ...
#BlitzMax
BlitzMax
local a:int = 0, b:int = 1, c:int = 1, n:int   n = int(input( "Enter n: ")) if n = 0 then print 0 end else if n = 1 print 1 end end if   while n>2 a = b b = c c = a + b n = n - 1 wend print c
Give a code snippet in #BlitzMax The Fibonacci sequence is a sequence   Fn   of natural numbers defined recursively: F0 = 0 F1 = 1 Fn = Fn-1 + Fn-2, if n>1 Task Write a function to generate the   nth   Fibonacci number. Solutions can be iterative or recursive (though recursive solutions ...
christopher/rosetta-code
http://rosettacode.org/wiki/SHA-256
SHA-256
SHA-256 is the recommended stronger alternative to SHA-1. See FIPS PUB 180-4 for implementation details. Either by using a dedicated library or implementing the algorithm in your language, show that the SHA-256 digest of the string "Rosetta code" is: 764faf5c61ac315f1497f9dfa542713965b785e5cc2f707d6468d7d1124cdfcf
#OS_X_sha256sum
OS X sha256sum
echo -n 'Rosetta code' | sha256sum
Give a code snippet in #OS_X_sha256sum SHA-256 is the recommended stronger alternative to SHA-1. See FIPS PUB 180-4 for implementation details. Either by using a dedicated library or implementing the algorithm in your language, show that the SHA-256 digest of the string "Rosetta code" is: 764faf5c61ac315f1497f9dfa542...
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 |...
#Python
Python
#!/usr/bin/env python a = input('Enter value of a: ') b = input('Enter value of b: ')   if a < b: print 'a is less than b' elif a > b: print 'a is greater than b' elif a == b: print 'a is equal to b'
Give a code snippet in #Python 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...
christopher/rosetta-code
http://rosettacode.org/wiki/Exceptions/Catch_an_exception_thrown_in_a_nested_call
Exceptions/Catch an exception thrown in a nested call
Show how to create a user-defined exception   and   show how to catch an exception raised from several nested calls away.   Create two user-defined exceptions,   U0   and   U1.   Have function   foo   call function   bar   twice.   Have function   bar   call function   baz.   Arrange for function   baz   to rais...
#Go
Go
// Outline for a try/catch-like exception mechanism in Go // // As all Go programmers should know, the Go authors are sharply critical of // the try/catch idiom and consider it bad practice in general. // See http://golang.org/doc/go_faq.html#exceptions   package main   import ( "fmt" "runtime" "strings" ) ...
Give a code snippet in #Go Show how to create a user-defined exception   and   show how to catch an exception raised from several nested calls away.   Create two user-defined exceptions,   U0   and   U1.   Have function   foo   call function   bar   twice.   Have function   bar   call function   baz.   Arrange ...
christopher/rosetta-code
http://rosettacode.org/wiki/Loops/For
Loops/For
“For”   loops are used to make some block of code be iterated a number of times, setting a variable or parameter to a monotonically increasing integer value for each execution of the block of code. Common extensions of this allow other counting patterns or iterating over abstract structures other than the integers. ...
#bc
bc
for (i = 1; i <= 5; i++) { for (j = 1; j <= i; j++) "*" " " } quit
Give a code snippet in #bc “For”   loops are used to make some block of code be iterated a number of times, setting a variable or parameter to a monotonically increasing integer value for each execution of the block of code. Common extensions of this allow other counting patterns or iterating over abstract structures...
christopher/rosetta-code
http://rosettacode.org/wiki/Law_of_cosines_-_triples
Law of cosines - triples
The Law of cosines states that for an angle γ, (gamma) of any triangle, if the sides adjacent to the angle are A and B and the side opposite is C; then the lengths of the sides are related by this formula: A2 + B2 - 2ABcos(γ) = C2 Specific angles For an angle of of   90º   this becomes the more familiar ...
#Ruby
Ruby
grouped = (1..13).to_a.repeated_permutation(3).group_by do |a,b,c| sumaabb, ab = a*a + b*b, a*b case c*c when sumaabb then 90 when sumaabb - ab then 60 when sumaabb + ab then 120 end end   grouped.delete(nil) res = grouped.transform_values{|v| v.map(&:sort).uniq }   res.each do |k,v| puts "For...
Give a code snippet in #Ruby The Law of cosines states that for an angle γ, (gamma) of any triangle, if the sides adjacent to the angle are A and B and the side opposite is C; then the lengths of the sides are related by this formula: A2 + B2 - 2ABcos(γ) = C2 Specific angles For an angle of of   90º   t...
christopher/rosetta-code
http://rosettacode.org/wiki/Leap_year
Leap year
Task Determine whether a given year is a leap year in the Gregorian calendar. See also Leap year (wiki)
#XPL0
XPL0
func LeapYear(Y); \Return 'true' if Y is a leap year int Y; [if rem(Y/100)=0 then return rem(Y/400)=0; return rem(Y/4)=0; ];
Give a code snippet in #XPL0 Task Determine whether a given year is a leap year in the Gregorian calendar. See also Leap year (wiki)
christopher/rosetta-code
http://rosettacode.org/wiki/Write_float_arrays_to_a_text_file
Write float arrays to a text file
Task Write two equal-sized numerical arrays 'x' and 'y' to a two-column text file named 'filename'. The first column of the file contains values from an 'x'-array with a given 'xprecision', the second -- values from 'y'-array with 'yprecision'. For example, considering: x = {1, 2, 3, 1e11}; y = {1, 1.41421356...
#IDL
IDL
; the data: x = [1,2,3,1e11] y=sqrt(x) xprecision=3 yprecision=5 ; NOT how one would do things in IDL, but in the spirit of the task - the output format: form = string(xprecision,yprecision,format='("(G0.",I0.0,",1x,G0.",I0.0,")")') ; file I/O: openw,unit,"datafile.txt",/get for i = 1L, n_elements(x) do printf, u...
Give a code snippet in #IDL Task Write two equal-sized numerical arrays 'x' and 'y' to a two-column text file named 'filename'. The first column of the file contains values from an 'x'-array with a given 'xprecision', the second -- values from 'y'-array with 'yprecision'. For example, considering: x = {1, 2, 3,...
christopher/rosetta-code
http://rosettacode.org/wiki/Chowla_numbers
Chowla numbers
Chowla numbers are also known as:   Chowla's function   chowla numbers   the chowla function   the chowla number   the chowla sequence The chowla number of   n   is   (as defined by Chowla's function):   the sum of the divisors of   n     excluding unity and   n   where   n   is a positive integer The s...
#Ruby
Ruby
def chowla(n) sum = 0 i = 2 while i * i <= n do if n % i == 0 then sum = sum + i j = n / i if i != j then sum = sum + j end end i = i + 1 end return sum end   def main for n in 1 .. 37 do puts "chowla...
Give a code snippet in #Ruby Chowla numbers are also known as:   Chowla's function   chowla numbers   the chowla function   the chowla number   the chowla sequence The chowla number of   n   is   (as defined by Chowla's function):   the sum of the divisors of   n     excluding unity and   n   where   n  ...
christopher/rosetta-code
http://rosettacode.org/wiki/Sort_using_a_custom_comparator
Sort using a custom comparator
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 ...
#Fortran
Fortran
module sorts_with_custom_comparator implicit none contains subroutine a_sort(a, cc) character(len=*), dimension(:), intent(inout) :: a interface integer function cc(a, b) character(len=*), intent(in) :: a, b end function cc end interface   integer :: i, j, increment charac...
Give a code snippet in #Fortran 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 ...
christopher/rosetta-code
http://rosettacode.org/wiki/Pointers_and_references
Pointers and references
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 |...
#Pascal
Pascal
program pointerDemo;   type { A new pointer data type is declared by `↑` followed by a data type name, the domain.   The domain data type may not have been declared yet, but must be declared within the current `type` section.   Most compilers do not support the reference token `↑` as specified in the ISO s...
Give a code snippet in #Pascal 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...
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...
#C.23
C#
using System; using System.Collections.Generic; using System.Numerics;   namespace PierpontPrimes { public static class Helper { private static readonly Random rand = new Random(); private static readonly List<int> primeList = new List<int>() { 2, 3, 5, 7, 11, 13, 17, 19, 23...
Give a code snippet in #C.23 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 f...
christopher/rosetta-code
http://rosettacode.org/wiki/Remove_duplicate_elements
Remove duplicate elements
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 ...
#True_BASIC
True BASIC
  OPTION BASE 1 LET max = 10 DIM dat(10), res(10) FOR i = 1 TO max READ dat(i) NEXT i   DATA 1, 2, 1, 4, 5, 2, 15, 1, 3, 4   LET res(1) = dat(1) LET count = 1 LET posic = 1 DO WHILE posic < max LET posic = posic + 1 LET esnuevo = 1 LET indice = 1 DO WHILE (indice <= count) AND esnuevo = 1 IF dat(p...
Give a code snippet in #True_BASIC 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 | Qui...
christopher/rosetta-code
http://rosettacode.org/wiki/Averages/Median
Averages/Median
Task[edit] Write a program to find the   median   value of a vector of floating-point numbers. The program need not handle the case where the vector is empty, but must handle the case where there are an even number of elements.   In that case, return the average of the two middle values. There are several approaches ...
#Factor
Factor
USING: arrays kernel locals math math.functions random sequences ; IN: median   : pivot ( seq -- pivot ) random ;   : split ( seq pivot -- {lt,eq,gt} ) [ [ < ] curry partition ] keep [ = ] curry partition 3array ;   DEFER: nth-in-order :: nth-in-order-recur ( seq ind -- elt ) seq dup pivot split dup [ length ...
Give a code snippet in #Factor Task[edit] Write a program to find the   median   value of a vector of floating-point numbers. The program need not handle the case where the vector is empty, but must handle the case where there are an even number of elements.   In that case, return the average of the two middle values...
christopher/rosetta-code
http://rosettacode.org/wiki/Quaternion_type
Quaternion type
Quaternions   are an extension of the idea of   complex numbers. A complex number has a real and complex part,   sometimes written as   a + bi, where   a   and   b   stand for real numbers, and   i   stands for the square root of minus 1. An example of a complex number might be   -3 + 2i,   wher...
#Liberty_BASIC
Liberty BASIC
    q$ = q$( 1 , 2 , 3 , 4 ) q1$ = q$( 2 , 3 , 4 , 5 ) q2$ = q$( 3 , 4 , 5 , 6 )   real = 7   print "q = "  ; q$ print "q1 = " ; q1$ print "q2 = " ; q2$   print "real = " ; real   print "length /norm q = " ; length( q$ ) ' =norm norm of q print "negative (-q1) = " ; negative$...
Give a code snippet in #Liberty_BASIC Quaternions   are an extension of the idea of   complex numbers. A complex number has a real and complex part,   sometimes written as   a + bi, where   a   and   b   stand for real numbers, and   i   stands for the square root of minus 1. An example of a complex...
christopher/rosetta-code
http://rosettacode.org/wiki/Strip_whitespace_from_a_string/Top_and_tail
Strip whitespace from a string/Top and tail
Task Demonstrate how to strip leading and trailing whitespace from a string. The solution should demonstrate how to achieve the following three results: String with leading whitespace removed String with trailing whitespace removed String with both leading and trailing whitespace removed For the purposes of thi...
#Vala
Vala
string s = " word "; string s_chug = s.chug();
Give a code snippet in #Vala Task Demonstrate how to strip leading and trailing whitespace from a string. The solution should demonstrate how to achieve the following three results: String with leading whitespace removed String with trailing whitespace removed String with both leading and trailing whitespace rem...
christopher/rosetta-code
http://rosettacode.org/wiki/Keyboard_input/Keypress_check
Keyboard input/Keypress check
Determine if a key has been pressed and store this in a variable. If no key has been pressed, the program should continue without waiting.
#AutoHotkey
AutoHotkey
; Input [, OutputVar, Options, EndKeys, MatchList] Input, KeyPressed, L1 T2 ; Length = 1, Timeout = 2 seconds
Give a code snippet in #AutoHotkey Determine if a key has been pressed and store this in a variable. If no key has been pressed, the program should continue without waiting.
christopher/rosetta-code
http://rosettacode.org/wiki/Selectively_replace_multiple_instances_of_a_character_within_a_string
Selectively replace multiple instances of a character within a string
Task This is admittedly a trivial task but I thought it would be interesting to see how succinctly (or otherwise) different languages can handle it. Given the string: "abracadabra", replace programatically: the first 'a' with 'A' the second 'a' with 'B' the fourth 'a' with 'C' the fifth 'a' with 'D' the first 'b...
#Perl
Perl
use strict; use warnings; use feature 'say';   sub transmogrify { my($str, %sub) = @_; for my $l (keys %sub) { $str =~ s/$l/$_/ for split '', $sub{$l}; $str =~ s/_/$l/g; } $str }   my $word = 'abracadabra'; say "$word -> " . transmogrify $word, 'a' => 'AB_CD', 'r' => '_F', 'b' => 'E';
Give a code snippet in #Perl Task This is admittedly a trivial task but I thought it would be interesting to see how succinctly (or otherwise) different languages can handle it. Given the string: "abracadabra", replace programatically: the first 'a' with 'A' the second 'a' with 'B' the fourth 'a' with 'C' the fi...
christopher/rosetta-code
http://rosettacode.org/wiki/Jensen%27s_Device
Jensen's Device
Jensen's Device You are encouraged to solve this task according to the task description, using any language you may know. This task is an exercise in call by name. Jensen's Device is a computer programming technique devised by Danish computer scientist Jørn Jensen after studying the ALGOL 60 Report. The following pr...
#C.23
C#
using System;   class JensensDevice { public static double Sum(ref int i, int lo, int hi, Func<double> term) { double temp = 0.0; for (i = lo; i <= hi; i++) { temp += term(); } return temp; }   static void Main() { int i = 0; Co...
Give a code snippet in #C.23 Jensen's Device You are encouraged to solve this task according to the task description, using any language you may know. This task is an exercise in call by name. Jensen's Device is a computer programming technique devised by Danish computer scientist Jørn Jensen after studying the ALGO...
christopher/rosetta-code
http://rosettacode.org/wiki/Polynomial_long_division
Polynomial long division
This page uses content from Wikipedia. The original article was at Polynomial long division. 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 algebra, polynomial long division is an algorithm for d...
#Ursala
Ursala
#import std #import flo   polydiv =   zeroid~-l~~; leql?rlX\~&NlX ^H\(@rNrNSPXlHDlS |\ :/0.) @NlX //=> ?( @lrrPX ==!| zipp0.; @x not zeroid+ ==@h->hr ~&t, (^lryPX/~&lrrl2C minus^*p/~&rrr times*lrlPD)^/div@bzPrrPlXO ~&, @r ^|\~& ~&i&& :/0.)
Give a code snippet in #Ursala This page uses content from Wikipedia. The original article was at Polynomial long division. 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 algebra, polynomial lon...
christopher/rosetta-code
http://rosettacode.org/wiki/Function_definition
Function definition
A function is a body of code that returns a value. The value returned may depend on arguments provided to the function. Task Write a definition of a function called "multiply" that takes two arguments and returns their product. (Argument types should be chosen so as not to distract from showing how functions are ...
#MAXScript
MAXScript
fn multiply a b = ( a * b )
Give a code snippet in #MAXScript A function is a body of code that returns a value. The value returned may depend on arguments provided to the function. Task Write a definition of a function called "multiply" that takes two arguments and returns their product. (Argument types should be chosen so as not to distr...
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...
#BASIC
BASIC
DECLARE FUNCTION life$ (lastGen$) DECLARE FUNCTION getNeighbors! (group$) CLS start$ = "_###_##_#_#_#_#__#__" numGens = 10 FOR i = 0 TO numGens - 1 PRINT "Generation"; i; ": "; start$ start$ = life$(start$) NEXT i   FUNCTION getNeighbors (group$) ans = 0 IF (MID$(group$, 1, 1) = "#") THEN ans = ans + 1 IF (MID$...
Give a code snippet in #BASIC 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...
christopher/rosetta-code
http://rosettacode.org/wiki/Strong_and_weak_primes
Strong and weak primes
Definitions   (as per number theory)   The   prime(p)   is the   pth   prime.   prime(1)   is   2   prime(4)   is   7   A   strong   prime   is when     prime(p)   is   >   [prime(p-1) + prime(p+1)] ÷ 2   A     weak    prime   is when     prime(p)   is   <   [prime(p-1) + prime(p+1)] ÷ 2 Note that the defin...
#Phix
Phix
with javascript_semantics sequence strong = {}, weak = {} for i=2 to get_maxprime(1e14) do -- (ie idx of primes < (sqrt(1e14)==1e7), bar 1st) integer p = get_prime(i), c = compare(p,(get_prime(i-1)+get_prime(i+1))/2) if c=+1 then strong &= p end if if c=-1 then weak &= p end if end for printf(1,"The f...
Give a code snippet in #Phix Definitions   (as per number theory)   The   prime(p)   is the   pth   prime.   prime(1)   is   2   prime(4)   is   7   A   strong   prime   is when     prime(p)   is   >   [prime(p-1) + prime(p+1)] ÷ 2   A     weak    prime   is when     prime(p)   is   <   [prime(p-1) + prime(p...
christopher/rosetta-code
http://rosettacode.org/wiki/First_perfect_square_in_base_n_with_n_unique_digits
First perfect square in base n with n unique digits
Find the first perfect square in a given base N that has at least N digits and exactly N significant unique digits when expressed in base N. E.G. In base 10, the first perfect square with at least 10 unique digits is 1026753849 (32043²). You may use analytical methods to reduce the search space, but the code must do ...
#JavaScript
JavaScript
(() => { 'use strict';   // allDigitSquare :: Int -> Int const allDigitSquare = base => { const bools = replicate(base, false); return untilSucc( allDigitsUsedAtBase(base, bools), ceil(sqrt(parseInt( '10' + '0123456789abcdef'.slice(2, base), ...
Give a code snippet in #JavaScript Find the first perfect square in a given base N that has at least N digits and exactly N significant unique digits when expressed in base N. E.G. In base 10, the first perfect square with at least 10 unique digits is 1026753849 (32043²). You may use analytical methods to reduce the...
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...
#Free_Pascal
Free Pascal
  ' FreeBASIC v1.05.0 win64 Print "a - > "; Asc("a") Print "98 -> "; Chr(98) Print Print "Press any key to exit the program" Sleep End  
Give a code snippet in #Free_Pascal 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)....
christopher/rosetta-code
http://rosettacode.org/wiki/Narcissistic_decimal_number
Narcissistic decimal number
A   Narcissistic decimal number   is a non-negative integer,   n {\displaystyle n} ,   that is equal to the sum of the   m {\displaystyle m} -th   powers of each of the digits in the decimal representation of   n {\displaystyle n} ,   where   m {\displaystyle m}   is the number of digits in...
#Wren
Wren
var narc = Fn.new { |n| var power = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9] var limit = 10 var result = [] var x = 0 while (result.count < n) { if (x >= limit) { for (i in 0..9) power[i] = power[i] * i limit = limit * 10 } var sum = 0 var xx = x ...
Give a code snippet in #Wren A   Narcissistic decimal number   is a non-negative integer,   n {\displaystyle n} ,   that is equal to the sum of the   m {\displaystyle m} -th   powers of each of the digits in the decimal representation of   n {\displaystyle n} ,   where   m {\displaystyle m} ...
christopher/rosetta-code
http://rosettacode.org/wiki/CRC-32
CRC-32
Task Demonstrate a method of deriving the Cyclic Redundancy Check from within the language. The result should be in accordance with ISO 3309, ITU-T V.42, Gzip and PNG. Algorithms are described on Computation of CRC in Wikipedia. This variant of CRC-32 uses LSB-first order, sets the initial CRC to FFFFFFFF16, and...
#Clojure
Clojure
(let [crc (new java.util.zip.CRC32) str "The quick brown fox jumps over the lazy dog"] (. crc update (. str getBytes)) (printf "CRC-32('%s') = %s\n" str (Long/toHexString (. crc getValue))))
Give a code snippet in #Clojure Task Demonstrate a method of deriving the Cyclic Redundancy Check from within the language. The result should be in accordance with ISO 3309, ITU-T V.42, Gzip and PNG. Algorithms are described on Computation of CRC in Wikipedia. This variant of CRC-32 uses LSB-first order, sets t...
christopher/rosetta-code
http://rosettacode.org/wiki/Isqrt_(integer_square_root)_of_X
Isqrt (integer square root) of X
Sometimes a function is needed to find the integer square root of   X,   where   X   can be a real non─negative number. Often   X   is actually a non─negative integer. For the purposes of this task,   X   can be an integer or a real number,   but if it simplifies things in your computer programming language,   assume...
#11l
11l
F commatize(number, step = 3, sep = ‘,’) V s = reversed(String(number)) String r = s[0] L(i) 1 .< s.len I i % step == 0 r ‘’= sep r ‘’= s[i] R reversed(r)   F isqrt(BigInt x) assert(x >= 0)   V q = BigInt(1) L q <= x q *= 4   V z = x V r = BigInt(0) L q > 1 ...
Give a code snippet in #11l Sometimes a function is needed to find the integer square root of   X,   where   X   can be a real non─negative number. Often   X   is actually a non─negative integer. For the purposes of this task,   X   can be an integer or a real number,   but if it simplifies things in your computer p...
christopher/rosetta-code
http://rosettacode.org/wiki/Ramer-Douglas-Peucker_line_simplification
Ramer-Douglas-Peucker line simplification
Ramer-Douglas-Peucker line simplification You are encouraged to solve this task according to the task description, using any language you may know. The   Ramer–Douglas–Peucker   algorithm is a line simplification algorithm for reducing the number of points used to define its shape. Task Using the   Ramer–Douglas–P...
#J
J
mp=: +/ .* NB. matrix product norm=: +/&.:*: NB. vector norm normalize=: (% norm)^:(0 < norm)   dxy=. normalize@({: - {.) pv=. -"1 {. NB.*perpDist v Calculate perpendicular distance of points from a line perpDist=: norm"1@(pv ([ -"1 mp"1~ */ ]) dxy) f.   rdp=: verb define 1 rdp y  : points=. ,:^:(2...
Give a code snippet in #J Ramer-Douglas-Peucker line simplification You are encouraged to solve this task according to the task description, using any language you may know. The   Ramer–Douglas–Peucker   algorithm is a line simplification algorithm for reducing the number of points used to define its shape. Task ...
christopher/rosetta-code
http://rosettacode.org/wiki/A%2BB
A+B
A+B   ─── a classic problem in programming contests,   it's given so contestants can gain familiarity with the online judging system being used. Task Given two integers,   A and B. Their sum needs to be calculated. Input data Two integers are written in the input stream, separated by space(s): ( − 1000 ≤...
#X86_Assembly
X86 Assembly
section .text global _start   _print: mov ebx, 1 mov eax, 4 int 0x80 ret   _get_input: mov edx, 4 mov ebx, 0 mov eax, 3 int 0x80 ret   _start: mov edx, in_val_len mov ecx, in_val_msg call _print mov ecx, a call _get_input ;make 'a' an actual number rather than a char. sub dword [a], ...
Give a code snippet in #X86_Assembly A+B   ─── a classic problem in programming contests,   it's given so contestants can gain familiarity with the online judging system being used. Task Given two integers,   A and B. Their sum needs to be calculated. Input data Two integers are written in the input stream, s...
christopher/rosetta-code
http://rosettacode.org/wiki/Read_a_specific_line_from_a_file
Read a specific line from a file
Some languages have special semantics for obtaining a known line number from a file. Task Demonstrate how to obtain the contents of a specific line within a file. For the purpose of this task demonstrate how the contents of the seventh line of a file can be obtained,   and store it in a variable or in memory   (fo...
#Action.21
Action!
BYTE FUNC ReadLine(CHAR ARRAY fname CARD index CHAR ARRAY result) CHAR ARRAY line(255) CARD curr BYTE status,dev=[1]   Close(dev) Open(dev,fname,4) curr=1 status=1 WHILE Eof(dev)=0 DO InputSD(dev,line) IF curr=index THEN SCopy(result,line) status=0 EXIT FI curr==+1 OD...
Give a code snippet in #Action.21 Some languages have special semantics for obtaining a known line number from a file. Task Demonstrate how to obtain the contents of a specific line within a file. For the purpose of this task demonstrate how the contents of the seventh line of a file can be obtained,   and store ...
christopher/rosetta-code
http://rosettacode.org/wiki/Word_search
Word search
A word search puzzle typically consists of a grid of letters in which words are hidden. There are many varieties of word search puzzles. For the task at hand we will use a rectangular grid in which the words may be placed horizontally, vertically, or diagonally. The words may also be spelled backwards. The words may ...
#Perl
Perl
#!/usr/bin/perl   use strict; # http://www.rosettacode.org/wiki/Word_search use warnings; use Path::Tiny; use List::Util qw( shuffle );   my $size = 10; my $s1 = $size + 1; $_ = <<END; .....R.... ......O... .......S.. ........E. T........T .A........ ..C....... ...O...... ....D..... .....E.... END   my @words = shuffle...
Give a code snippet in #Perl A word search puzzle typically consists of a grid of letters in which words are hidden. There are many varieties of word search puzzles. For the task at hand we will use a rectangular grid in which the words may be placed horizontally, vertically, or diagonally. The words may also be spel...
christopher/rosetta-code
http://rosettacode.org/wiki/Interactive_programming_(repl)
Interactive programming (repl)
Many language implementations come with an interactive mode. This is a command-line interpreter that reads lines from the user and evaluates these lines as statements or expressions. An interactive mode may also be known as a command mode,   a read-eval-print loop (REPL),   or a shell. Task Show how to start this...
#Jsish
Jsish
prompt$ jsish Jsish interactive: see 'help [cmd]' # function f(a:string, b:string, s:string):string { return a+s+s+b; } # f('Rosetta', 'Code', 1) warn: type mismatch for argument arg 3 's': expected "string" but got "number", in call to 'f' <1>. (at or near "Code") "Rosetta11Code" # f('Rosetta', 'Code', ':') "Roset...
Give a code snippet in #Jsish 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/Day_of_the_week
Day of the week
A company decides that whenever Xmas falls on a Sunday they will give their workers all extra paid holidays so that, together with any public holidays, workers will not have to work the following week (between the 25th of December and the first of January). Task In what years between 2008 and 2121 will the 25th of ...
#Red
Red
Red [] repeat yy 114 [ d: to-date reduce [25 12 (2007 + yy )] if 7 = d/weekday [ print d ] ;; 7 = sunday ] ;; or print "version 2"   d: to-date [25 12 2008] while [d <= 25/12/2121 ] [ if 7 = d/weekday [ print rejoin [d/day '. d/month '. d/year ] ] d/year: d/year + 1 ]  
Give a code snippet in #Red A company decides that whenever Xmas falls on a Sunday they will give their workers all extra paid holidays so that, together with any public holidays, workers will not have to work the following week (between the 25th of December and the first of January). Task In what years between 20...
christopher/rosetta-code
http://rosettacode.org/wiki/Van_der_Corput_sequence
Van der Corput sequence
When counting integers in binary, if you put a (binary) point to the righEasyLangt of the count then the column immediately to the left denotes a digit with a multiplier of 2 0 {\displaystyle 2^{0}} ; the digit in the next column to the left has a multiplier of 2 1 {\displaystyle 2^{1}} ; and so o...
#Ada
Ada
with Ada.Text_IO;   procedure Main is package Float_IO is new Ada.Text_IO.Float_IO (Float); function Van_Der_Corput (N : Natural; Base : Positive := 2) return Float is Value  : Natural  := N; Result  : Float  := 0.0; Exponent : Positive := 1; begin while Value > 0 loop Res...
Give a code snippet in #Ada When counting integers in binary, if you put a (binary) point to the righEasyLangt of the count then the column immediately to the left denotes a digit with a multiplier of 2 0 {\displaystyle 2^{0}} ; the digit in the next column to the left has a multiplier of 2 1 {\di...
christopher/rosetta-code
http://rosettacode.org/wiki/Sorting_algorithms/Counting_sort
Sorting algorithms/Counting sort
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 ...
#PowerShell
PowerShell
  function countingSort($array) { $minmax = $array | Measure-Object -Minimum -Maximum $min, $max = $minmax.Minimum, $minmax.Maximum $count = @(0) * ($max - $min + 1) foreach ($number in $array) { $count[$number - $min] = $count[$number - $min] + 1 } $z = 0 foreach ($i in $min..$max...
Give a code snippet in #PowerShell 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 | Qui...
christopher/rosetta-code
http://rosettacode.org/wiki/Hash_from_two_arrays
Hash from two arrays
Task Using two Arrays of equal length, create a Hash object where the elements from one array (the keys) are linked to the elements of the other (the values) Related task   Associative arrays/Creation
#PARI.2FGP
PARI/GP
hash(key, value)=Map(matrix(#key,2,x,y,if(y==1,key[x],value[x])));
Give a code snippet in #PARI.2FGP Task Using two Arrays of equal length, create a Hash object where the elements from one array (the keys) are linked to the elements of the other (the values) Related task   Associative arrays/Creation
christopher/rosetta-code
http://rosettacode.org/wiki/Stack_traces
Stack traces
Many programming languages allow for introspection of the current call stack environment. This can be for a variety of purposes such as enforcing security checks, debugging, or for getting access to the stack frame of callers. Task Print out (in a manner considered suitable for the platform) the current call stack....
#R
R
foo <- function() { bar <- function() { sys.calls() } bar() }   foo()
Give a code snippet in #R Many programming languages allow for introspection of the current call stack environment. This can be for a variety of purposes such as enforcing security checks, debugging, or for getting access to the stack frame of callers. Task Print out (in a manner considered suitable for the platfo...
christopher/rosetta-code
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 Stri...
#Sidef
Sidef
var days = <first second third fourth fifth sixth seventh eighth ninth tenth eleventh twelfth>;   var gifts = <<'EOT'.lines; And 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, Ni...
Give a code snippet in #Sidef 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 operation...
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...
#F.23
F#
open System.IO open System.Net open System.Net.Sockets   let service (client:TcpClient) = use stream = client.GetStream() use out = new StreamWriter(stream, AutoFlush = true) use inp = new StreamReader(stream) while not inp.EndOfStream do match inp.ReadLine() with | line -> printfn "< %s...
Give a code snippet in #F.23 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 ...
christopher/rosetta-code
http://rosettacode.org/wiki/Random_numbers
Random numbers
Task Generate a collection filled with   1000   normally distributed random (or pseudo-random) numbers with a mean of   1.0   and a   standard deviation   of   0.5 Many libraries only generate uniformly distributed random numbers. If so, you may use one of these algorithms. Related task   Standard deviation
#Racket
Racket
  #lang racket (for/list ([i 1000]) (add1 (* (sqrt (* -2 (log (random)))) (cos (* 2 pi (random))) 0.5)))  
Give a code snippet in #Racket Task Generate a collection filled with   1000   normally distributed random (or pseudo-random) numbers with a mean of   1.0   and a   standard deviation   of   0.5 Many libraries only generate uniformly distributed random numbers. If so, you may use one of these algorithms. Relate...
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 ...
#Tcl
Tcl
package require Tcl 8.6   oo::class create Flip { variable board target s constructor {size} { set s $size set target [my RandomConfiguration] set board $target while {$board eq $target} { for {set i 0} {$i < $s} {incr i} { if {rand()<.5} { my SwapRow $i } if {rand()<.5} { my SwapColu...
Give a code snippet in #Tcl 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/Execute_HQ9%2B
Execute HQ9+
Task Implement a   HQ9+   interpreter or compiler.
#Arturo
Arturo
hq9: function [source][ acc: 0 loop split source 'ch [ case [(lower ch)=] when? ["h"]-> print "Hello, world!" when? ["q"]-> print source when? ["9"]-> print "99 bottles here ..." when? ["+"]-> acc: acc+1 else []   ] return acc ]  ...
Give a code snippet in #Arturo Task Implement a   HQ9+   interpreter or compiler.
christopher/rosetta-code
http://rosettacode.org/wiki/Munchausen_numbers
Munchausen numbers
A Munchausen number is a natural number n the sum of whose digits (in base 10), each raised to the power of itself, equals n. (Munchausen is also spelled: Münchhausen.) For instance:   3435 = 33 + 44 + 33 + 55 Task Find all Munchausen numbers between   1   and   5000. Also see The OEIS entry: A046253 The ...
#Arturo
Arturo
munchausen?: function [n][ n = sum map split to :string n 'digit [ d: to :integer digit d^d ] ]   loop 1..5000 'x [ if munchausen? x -> print x ]
Give a code snippet in #Arturo A Munchausen number is a natural number n the sum of whose digits (in base 10), each raised to the power of itself, equals n. (Munchausen is also spelled: Münchhausen.) For instance:   3435 = 33 + 44 + 33 + 55 Task Find all Munchausen numbers between   1   and   5000. Also see ...
christopher/rosetta-code
http://rosettacode.org/wiki/Fibonacci_sequence
Fibonacci sequence
The Fibonacci sequence is a sequence   Fn   of natural numbers defined recursively: F0 = 0 F1 = 1 Fn = Fn-1 + Fn-2, if n>1 Task Write a function to generate the   nth   Fibonacci number. Solutions can be iterative or recursive (though recursive solutions are generally considered too slow ...
#XQuery
XQuery
declare function local:fib($n as xs:integer) as xs:integer { if($n < 2) then $n else local:fib($n - 1) + local:fib($n - 2) };
Give a code snippet in #XQuery The Fibonacci sequence is a sequence   Fn   of natural numbers defined recursively: F0 = 0 F1 = 1 Fn = Fn-1 + Fn-2, if n>1 Task Write a function to generate the   nth   Fibonacci number. Solutions can be iterative or recursive (though recursive solutions ar...
christopher/rosetta-code
http://rosettacode.org/wiki/Maximum_triangle_path_sum
Maximum triangle path sum
Starting from the top of a pyramid of numbers like this, you can walk down going one step on the right or on the left, until you reach the bottom row: 55 94 48 95 30 96 77 71 26 67 One of such walks is 55 - 94 - 30 - 26. You...
#Mathematica.2FWolfram_Language
Mathematica/Wolfram Language
nums={{55},{94,48},{95,30,96},{77,71,26,67},{97,13,76,38,45},{7,36,79,16,37,68},{48,7,9,18,70,26,6},{18,72,79,46,59,79,29,90},{20,76,87,11,32,7,7,49,18},{27,83,58,35,71,11,25,57,29,85},{14,64,36,96,27,11,58,56,92,18,55},{2,90,3,60,48,49,41,46,33,36,47,23},{92,50,48,2,36,59,42,79,72,20,82,77,42},{56,78,38,80,39,75,2,71,...
Give a code snippet in #Mathematica.2FWolfram_Language Starting from the top of a pyramid of numbers like this, you can walk down going one step on the right or on the left, until you reach the bottom row: 55 94 48 95 30 96 ...
christopher/rosetta-code
http://rosettacode.org/wiki/Pell%27s_equation
Pell's equation
Pell's equation   (also called the Pell–Fermat equation)   is a   Diophantine equation   of the form: x2   -   ny2   =   1 with integer solutions for   x   and   y,   where   n   is a given non-square positive integer. Task requirements   find the smallest solution in positive integers to Pell's equation for...
#Arturo
Arturo
solvePell: function [n][ x: to :integer sqrt n [y, z, r]: @[x, 1, shl x 1] [e1, e2]: [1, 0] [f1, f2]: [0, 1]   while [true][ y: (r * z) - y z: (n - y * y) / z r: (x + y) / z   [e1, e2]: @[e2, e1 + e2 * r] [f1, f2]: @[f2, f1 + f2 * r] [a, b]: @[e2 + f2 ...
Give a code snippet in #Arturo Pell's equation   (also called the Pell–Fermat equation)   is a   Diophantine equation   of the form: x2   -   ny2   =   1 with integer solutions for   x   and   y,   where   n   is a given non-square positive integer. Task requirements   find the smallest solution in positive...
christopher/rosetta-code
http://rosettacode.org/wiki/Lychrel_numbers
Lychrel numbers
  Take an integer n, greater than zero.   Form the next n of its series by reversing the digits of the current n and adding the result to the current n.   Stop when n becomes palindromic - i.e. the digits of n in reverse order == n. The above recurrence relation when applied to most starting numbers n = 1, 2, ... ...
#Crystal
Crystal
require "set" require "big"   def add_reverse(num, max_iter=1000) num = num.to_big_i nums = [] of BigInt (1..max_iter).each_with_object(Set.new([num])) do |_, nums| num += reverse_int(num) nums << num return nums if palindrome?(num) end end   def palindrome?(num) num == reverse_int(num) end   def ...
Give a code snippet in #Crystal   Take an integer n, greater than zero.   Form the next n of its series by reversing the digits of the current n and adding the result to the current n.   Stop when n becomes palindromic - i.e. the digits of n in reverse order == n. The above recurrence relation when applied to mos...
christopher/rosetta-code
http://rosettacode.org/wiki/Guess_the_number
Guess the number
Task Write a program where the program chooses a number between   1   and   10. A player is then prompted to enter a guess.   If the player guesses wrong,   then the prompt appears again until the guess is correct. When the player has made a successful guess the computer will issue a   "Well guessed!"   message,   a...
#Fortran
Fortran
program guess_the_number implicit none   integer :: guess real :: r integer :: i, clock, count, n integer,dimension(:),allocatable :: seed   real,parameter :: rmax = 10   !initialize random number generator: call random_seed(size=n) ...
Give a code snippet in #Fortran Task Write a program where the program chooses a number between   1   and   10. A player is then prompted to enter a guess.   If the player guesses wrong,   then the prompt appears again until the guess is correct. When the player has made a successful guess the computer will issue a...
christopher/rosetta-code
http://rosettacode.org/wiki/URL_parser
URL parser
URLs are strings with a simple syntax: scheme://[username:password@]domain[:port]/path?query_string#fragment_id Task Parse a well-formed URL to retrieve the relevant information:   scheme, domain, path, ... Note:   this task has nothing to do with URL encoding or URL decoding. According to the standards, t...
#Phix
Phix
with javascript_semantics include builtins/url.e procedure show_url_details(string uri) ?uri sequence r = parse_url(uri) for i=1 to length(r) do if r[i]!=0 then string desc = url_element_desc(i) printf(1,"%s : %v\n",{desc,r[i]}) end if end for puts(1,"\n") e...
Give a code snippet in #Phix URLs are strings with a simple syntax: scheme://[username:password@]domain[:port]/path?query_string#fragment_id Task Parse a well-formed URL to retrieve the relevant information:   scheme, domain, path, ... Note:   this task has nothing to do with URL encoding or URL decoding. ...
christopher/rosetta-code
http://rosettacode.org/wiki/Tic-tac-toe
Tic-tac-toe
Task Play a game of tic-tac-toe. Ensure that legal moves are played and that a winning position is notified. Tic-tac-toe   is also known as:   naughts and crosses   tic tac toe   tick tack toe   three in a row   tres en rayo       and   Xs  and  Os See also   MathWorld™, Tic-Tac-Toe game.   Wikipedi...
#mIRC_Scripting_Language
mIRC Scripting Language
alias ttt { if ($2 isin %ttt) || (!%ttt) { var %ttt~ = $remove($iif(%ttt,%ttt,1 2 3 4 5 6 7 8 9),$2,X,O) var %ttt~~ = $replace($iif(%ttt,%ttt,1 2 3 4 5 6 7 8 9),$2,X) set %ttt $replace(%ttt~~,$iif(($regex(%ttt~~,/(?:O . . (?:(?:. O .|O) . . (\d)|(?:. (\d) .|(\d)) . . O)|(\d) . . (?:. O .|O) . . O|. . (?:O...
Give a code snippet in #mIRC_Scripting_Language Task Play a game of tic-tac-toe. Ensure that legal moves are played and that a winning position is notified. Tic-tac-toe   is also known as:   naughts and crosses   tic tac toe   tick tack toe   three in a row   tres en rayo       and   Xs  and  Os See ...
christopher/rosetta-code
http://rosettacode.org/wiki/Rosetta_Code/Find_unimplemented_tasks
Rosetta Code/Find unimplemented tasks
Task Given the name of a language on Rosetta Code, find all tasks which are not implemented in that language. Note: Implementations should allow for fetching more data than can be returned in one request to Rosetta Code. You'll need to use the Media Wiki API, which you can find out about locally, here, or in Media...
#J
J
require 'strings web/gethttp'   findUnimpTasks=: ('Programming_Tasks' -.&getCategoryMembers ,&'/Omit') ([ #~ -.@e.) getCategoryMembers   getTagContents=: dyad define 'starttag endtag'=. x ('\' -.~ endtag&taketo)&.>@(starttag&E. <@((#starttag)&}.);.1 ]) y )   NB. RosettaCode Utilities parseTitles=: ('"title":"';'"')...
Give a code snippet in #J Task Given the name of a language on Rosetta Code, find all tasks which are not implemented in that language. Note: Implementations should allow for fetching more data than can be returned in one request to Rosetta Code. You'll need to use the Media Wiki API, which you can find out about...
christopher/rosetta-code
http://rosettacode.org/wiki/Anagrams
Anagrams
When two or more words are composed of the same characters, but in a different order, they are called anagrams. Task[edit] Using the word list at   http://wiki.puzzlers.org/pub/wordlists/unixdict.txt, find the sets of words that share the same characters that contain the most words in them. Related tasks Word plays ...
#Red
Red
Red []   m: make map! [] 25000   maxx: 0 foreach word read/lines http://wiki.puzzlers.org/pub/wordlists/unixdict.txt [ sword: sort copy word ;; sorted characters of word   either find m sword [ append m/:sword word maxx: max maxx length? m/:sword ] [ put m sword append copy [] word ] ]...
Give a code snippet in #Red When two or more words are composed of the same characters, but in a different order, they are called anagrams. Task[edit] Using the word list at   http://wiki.puzzlers.org/pub/wordlists/unixdict.txt, find the sets of words that share the same characters that contain the most words in the...
christopher/rosetta-code
http://rosettacode.org/wiki/N%27th
N'th
Write a function/method/subroutine/... that when given an integer greater than or equal to zero returns a string of the number followed by an apostrophe then the ordinal suffix. Example Returns would include 1'st 2'nd 3'rd 11'th 111'th 1001'st 1012'th Task Use your routine to show here the output for at least t...
#Red
Red
Red[]   nth: function [n][ d: n % 10 suffix: either any [d < 1 d > 4 1 = to-integer n / 10] [4] [d] rejoin [n pick ["st" "nd" "rd" "th"] suffix] ]   test: function [low high][ repeat i high - low + 1 [ prin [nth i + low - 1 ""] ] prin newline ]   test 0 25 test 250 265 test 1000 1025
Give a code snippet in #Red Write a function/method/subroutine/... that when given an integer greater than or equal to zero returns a string of the number followed by an apostrophe then the ordinal suffix. Example Returns would include 1'st 2'nd 3'rd 11'th 111'th 1001'st 1012'th Task Use your routine to show h...
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...
#OCaml
OCaml
let div_mod n d = (n / d, n mod d) let join = String.concat ", " ;;   let rec nonzero = function | _, 0 -> "" | c, n -> c ^ (spell_integer n)   and tens n = [| ""; ""; "twenty"; "thirty"; "forty"; "fifty"; "sixty"; "seventy"; "eighty"; "ninety" |].(n)   and small n = [| "zero"; "one"; "two"; "three...
Give a code snippet in #OCaml 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 posi...
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
#Tcl
Tcl
proc entropy {str} { set log2 [expr log(2)] foreach char [split $str ""] {dict incr counts $char} set entropy 0.0 foreach count [dict values $counts] { set freq [expr {$count / double([string length $str])}] set entropy [expr {$entropy - $freq * log($freq)/$log2}] } return $entropy }   puts [f...
Give a code snippet in #Tcl Task Write a computer program that computes and shows its own   entropy. Related Tasks   Fibonacci_word   Entropy
christopher/rosetta-code
http://rosettacode.org/wiki/Ramanujan%27s_constant
Ramanujan's constant
Calculate Ramanujan's constant (as described on the OEIS site) with at least 32 digits of precision, by the method of your choice. Optionally, if using the 𝑒**(π*√x) approach, show that when evaluated with the last four Heegner numbers the result is almost an integer.
#Python
Python
from mpmath import mp heegner = [19,43,67,163] mp.dps = 50 x = mp.exp(mp.pi*mp.sqrt(163)) print("calculated Ramanujan's constant: {}".format(x)) print("Heegner numbers yielding 'almost' integers:") for i in heegner: print(" for {}: {} ~ {} error: {}".format(str(i),mp.exp(mp.pi*mp.sqrt(i)),round(mp.exp(mp.pi*mp.sqrt...
Give a code snippet in #Python Calculate Ramanujan's constant (as described on the OEIS site) with at least 32 digits of precision, by the method of your choice. Optionally, if using the 𝑒**(π*√x) approach, show that when evaluated with the last four Heegner numbers the result is almost an integer.
christopher/rosetta-code
http://rosettacode.org/wiki/SOAP
SOAP
In this task, the goal is to create a SOAP client which accesses functions defined at http://example.com/soap/wsdl, and calls the functions soapFunc( ) and anotherSoapFunc( ). 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...
#Perl
Perl
use SOAP::Lite;   print SOAP::Lite -> service('http://example.com/soap/wsdl') -> soapFunc("hello"); print SOAP::Lite -> service('http://example.com/soap/wsdl') -> anotherSoapFunc(34234);
Give a code snippet in #Perl In this task, the goal is to create a SOAP client which accesses functions defined at http://example.com/soap/wsdl, and calls the functions soapFunc( ) and anotherSoapFunc( ). This task has been flagged for clarification. Code on this page in its current state may be flagged incorrect onc...
christopher/rosetta-code
http://rosettacode.org/wiki/Law_of_cosines_-_triples
Law of cosines - triples
The Law of cosines states that for an angle γ, (gamma) of any triangle, if the sides adjacent to the angle are A and B and the side opposite is C; then the lengths of the sides are related by this formula: A2 + B2 - 2ABcos(γ) = C2 Specific angles For an angle of of   90º   this becomes the more familiar ...
#REXX
REXX
/*REXX pgm finds integer sided triangles that satisfy Law of cosines for 60º, 90º, 120º.*/ parse arg os1 os2 os3 os4 . /*obtain optional arguments from the CL*/ if os1=='' | os1=="," then os1= 13; s1=abs(os1) /*Not specified? Then use the default.*/ if os2=='' | os2=="," then os2= 13; s2=abs(os2...
Give a code snippet in #REXX The Law of cosines states that for an angle γ, (gamma) of any triangle, if the sides adjacent to the angle are A and B and the side opposite is C; then the lengths of the sides are related by this formula: A2 + B2 - 2ABcos(γ) = C2 Specific angles For an angle of of   90º   t...
christopher/rosetta-code
http://rosettacode.org/wiki/Sierpinski_carpet
Sierpinski carpet
Task Produce a graphical or ASCII-art representation of a Sierpinski carpet of order   N. For example, the Sierpinski carpet of order   3   should look like this: ########################### # ## ## ## ## ## ## ## ## # ########################### ### ###### ###### ### # # # ## # # ## # # # ### ###### ...
#Java
Java
public static boolean inCarpet(long x, long y) { while (x!=0 && y!=0) { if (x % 3 == 1 && y % 3 == 1) return false; x /= 3; y /= 3; } return true; }   public static void carpet(final int n) { final double power = Math.pow(3,n); for(long i = 0; i < power; i++) { ...
Give a code snippet in #Java Task Produce a graphical or ASCII-art representation of a Sierpinski carpet of order   N. For example, the Sierpinski carpet of order   3   should look like this: ########################### # ## ## ## ## ## ## ## ## # ########################### ### ###### ###### ### # # # ## ...
christopher/rosetta-code
http://rosettacode.org/wiki/One_of_n_lines_in_a_file
One of n lines in a file
A method of choosing a line randomly from a file: Without reading the file more than once When substantial parts of the file cannot be held in memory Without knowing how many lines are in the file Is to: keep the first line of the file as a possible choice, then Read the second line of the file if possible and m...
#Eiffel
Eiffel
  class APPLICATION   create make   feature   make -- Simulates one_of_n_lines a 1000000 times. local t: INTEGER simulator: ARRAY [INTEGER] do create simulator.make_filled (0, 1, 10) create one.make across 1 |..| 1000000 as c loop t := one.one_of_n_lines (10) simulator [t] := sim...
Give a code snippet in #Eiffel A method of choosing a line randomly from a file: Without reading the file more than once When substantial parts of the file cannot be held in memory Without knowing how many lines are in the file Is to: keep the first line of the file as a possible choice, then Read the second li...
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...
#Racket
Racket
  #lang racket   (define (get-last-door a b) ; assumes a != b (vector-ref '#(- 2 1 2 - 0 1 0 -) (+ a (* 3 b))))   (define (run-game strategy) (define car-door (random 3)) (define first-choice (random 3)) (define revealed-goat (if (= car-door first-choice) ...
Give a code snippet in #Racket 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 th...
christopher/rosetta-code
http://rosettacode.org/wiki/Empty_string
Empty string
Languages may have features for dealing specifically with empty strings (those containing no characters). Task   Demonstrate how to assign an empty string to a variable.   Demonstrate how to check that a string is empty.   Demonstrate how to check that a string is not empty. Other tasks related to string oper...
#Nim
Nim
var x = ""   if x == "": echo "empty" if x != "": echo "not empty"   # Alternatively: if x.len == 0: echo "empty" if x.len > 0: echo "not empty"
Give a code snippet in #Nim Languages may have features for dealing specifically with empty strings (those containing no characters). Task   Demonstrate how to assign an empty string to a variable.   Demonstrate how to check that a string is empty.   Demonstrate how to check that a string is not empty. Other...
christopher/rosetta-code
http://rosettacode.org/wiki/Greyscale_bars/Display
Greyscale bars/Display
The task is to display a series of vertical greyscale bars (contrast bars) with a sufficient number of bars to span the entire width of the display. For the top quarter of the display, the left hand bar should be black, and we then incrementally step through six shades of grey until we have a white bar on the right ha...
#Raku
Raku
my ($width,$height) = 1280,768;   my $PGM = open "Greyscale-bars-perl6.pgm", :w orelse die "Can't create Greyscale-bars-perl6.pgm: $_";   $PGM.print: qq:to/EOH/; P2 # Greyscale-bars-perl6.pgm $width $height 65535 EOH   my ($h1,$h2,$h3,$h4) = divvy($height,4);   my @nums = ((0/7,1/7...7/7) X* 65535)»...
Give a code snippet in #Raku The task is to display a series of vertical greyscale bars (contrast bars) with a sufficient number of bars to span the entire width of the display. For the top quarter of the display, the left hand bar should be black, and we then incrementally step through six shades of grey until we ha...
christopher/rosetta-code
http://rosettacode.org/wiki/Create_an_HTML_table
Create an HTML table
Create an HTML table. The table body should have at least three rows of three columns. Each of these three columns should be labelled "X", "Y", and "Z". An extra column should be added at either the extreme left or the extreme right of the table that has no heading, but is filled with sequential row numbers. The...
#Seed7
Seed7
$ include "seed7_05.s7i";   const proc: main is func local var integer: line is 0; var integer: column is 0; begin writeln("<table style=\"text-align:center; border: 1px solid\">"); writeln("<tr><th></th><th>X</th><th>Y</th><th>Z</th></tr>"); for line range 1 to 3 do write("<tr><th>" <& li...
Give a code snippet in #Seed7 Create an HTML table. The table body should have at least three rows of three columns. Each of these three columns should be labelled "X", "Y", and "Z". An extra column should be added at either the extreme left or the extreme right of the table that has no heading, but is filled wit...
christopher/rosetta-code
http://rosettacode.org/wiki/Array_length
Array length
Task Determine the amount of elements in an array. As an example use an array holding the strings 'apple' and 'orange'. 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 befo...
#Dragon
Dragon
select "std"   a = ["apple","orange"] b = length(a)   show b  
Give a code snippet in #Dragon Task Determine the amount of elements in an array. As an example use an array holding the strings 'apple' and 'orange'. Other tasks related to string operations: Metrics Array length String length Copy a string Empty string  (assignment) Counting Word frequency Letter freq...
christopher/rosetta-code
http://rosettacode.org/wiki/Humble_numbers
Humble numbers
Humble numbers are positive integers which have   no   prime factors   >   7. Humble numbers are also called   7-smooth numbers,   and sometimes called   highly composite, although this conflicts with another meaning of   highly composite numbers. Another way to express the above is: humble = 2i × 3j × 5k...
#ALGOL_W
ALGOL W
begin % find some Humble numbers - numbers with no prime factors above 7 %  % returns the minimum of a and b  % integer procedure min ( integer value a, b ) ; if a < b then a else b;  % find and print Humble Numbers  % integer MAX_HUMB...
Give a code snippet in #ALGOL_W Humble numbers are positive integers which have   no   prime factors   >   7. Humble numbers are also called   7-smooth numbers,   and sometimes called   highly composite, although this conflicts with another meaning of   highly composite numbers. Another way to express the abo...
christopher/rosetta-code
http://rosettacode.org/wiki/Towers_of_Hanoi
Towers of Hanoi
Task Solve the   Towers of Hanoi   problem with recursion.
#Klingphix
Klingphix
include ..\Utilitys.tlhy   :moveDisc %B !B %C !C %A !A %n !n { n A C B } $n [ $n 1 - $A $B $C moveDisc ( "Move disc " $n " from pole " $A " to pole " $C ) lprint nl $n 1 - $B $C $A moveDisc ] if ;   { Move disc 3 from pole 1 to pole 3, with pole 2 as spare } 3 1 3 2 moveDisc   " " input
Give a code snippet in #Klingphix Task Solve the   Towers of Hanoi   problem with recursion.
christopher/rosetta-code
http://rosettacode.org/wiki/M%C3%B6bius_function
Möbius function
The classical Möbius function: μ(n) is an important multiplicative function in number theory and combinatorics. There are several ways to implement a Möbius function. A fairly straightforward method is to find the prime factors of a positive integer n, then define μ(n) based on the sum of the primitive factors. It ha...
#jq
jq
# Input: a non-negative integer, $n # Output: an array of size $n + 1 such that the nth-mobius number is .[$n] # i.e. $n|mobius_array[-1] # For example, the first mobius number could be evaluated by 1|mobius_array[-1]. def mobius_array: . as $n | ($n|sqrt) as $sqrt | reduce range(2; 1 + $sqrt) as $i ([range(0; $n...
Give a code snippet in #jq The classical Möbius function: μ(n) is an important multiplicative function in number theory and combinatorics. There are several ways to implement a Möbius function. A fairly straightforward method is to find the prime factors of a positive integer n, then define μ(n) based on the sum of ...
christopher/rosetta-code
http://rosettacode.org/wiki/Leonardo_numbers
Leonardo numbers
Leonardo numbers   are also known as the   Leonardo series. The   Leonardo numbers   are a sequence of numbers defined by: L(0) = 1 [1st equation] L(1) = 1 [2nd equation] L(n) = L(n-1) + L(n-2) + 1 ...
#Visual_Basic_.NET
Visual Basic .NET
Module Module1   Iterator Function Leonardo(Optional L0 = 1, Optional L1 = 1, Optional add = 1) As IEnumerable(Of Integer) While True Yield L0 Dim t = L0 + L1 + add L0 = L1 L1 = t End While End Function   Sub Main() Console.WriteLine(St...
Give a code snippet in #Visual_Basic_.NET Leonardo numbers   are also known as the   Leonardo series. The   Leonardo numbers   are a sequence of numbers defined by: L(0) = 1 [1st equation] L(1) = 1 [2nd equation] ...
christopher/rosetta-code
http://rosettacode.org/wiki/Averages/Mean_angle
Averages/Mean angle
When calculating the average or mean of an angle one has to take into account how angles wrap around so that any angle in degrees plus any integer multiple of 360 degrees is a measure of the same angle. If one wanted an average direction of the wind over two readings where the first reading was of 350 degrees and the ...
#Go
Go
package main   import ( "fmt" "math" "math/cmplx" )   func deg2rad(d float64) float64 { return d * math.Pi / 180 } func rad2deg(r float64) float64 { return r * 180 / math.Pi }   func mean_angle(deg []float64) float64 { sum := 0i for _, x := range deg { sum += cmplx.Rect(1, deg2rad(x)) } return rad2deg(cmplx.Ph...
Give a code snippet in #Go When calculating the average or mean of an angle one has to take into account how angles wrap around so that any angle in degrees plus any integer multiple of 360 degrees is a measure of the same angle. If one wanted an average direction of the wind over two readings where the first reading...
christopher/rosetta-code
http://rosettacode.org/wiki/Sorting_algorithms/Counting_sort
Sorting algorithms/Counting sort
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 ...
#zkl
zkl
fcn countingSort(array, min, max){ // modifies array count:=(max - min + 1).pump(List().write,0); // array of (max - min + 1) zeros foreach number in (array){ count[number - min] += 1; } z:=-1; foreach i in ([min .. max]){ do(count[i - min]){ array[z += 1] = i } } array }
Give a code snippet in #zkl 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...
christopher/rosetta-code
http://rosettacode.org/wiki/Subleq
Subleq
Subleq is an example of a One-Instruction Set Computer (OISC). It is named after its only instruction, which is SUbtract and Branch if Less than or EQual to zero. Task Your task is to create an interpreter which emulates a SUBLEQ machine. The machine's memory consists of an array of signed integers.   These integers...
#CLU
CLU
% Read numbers from a stream read_nums = iter (s: stream) yields (int) while true do c: char := stream$getc(s) while c~='-' & ~(c>='0' & c<='9') do c := stream$getc(s) end acc: int := 0 neg: bool if c='-' then neg := true c := strea...
Give a code snippet in #CLU Subleq is an example of a One-Instruction Set Computer (OISC). It is named after its only instruction, which is SUbtract and Branch if Less than or EQual to zero. Task Your task is to create an interpreter which emulates a SUBLEQ machine. The machine's memory consists of an array of sign...
christopher/rosetta-code
http://rosettacode.org/wiki/Split_a_character_string_based_on_change_of_character
Split a character string based on change of character
Task Split a (character) string into comma (plus a blank) delimited strings based on a change of character   (left to right). Show the output here   (use the 1st example below). Blanks should be treated as any other character   (except they are problematic to display clearly).   The same applies to commas. Fo...
#J
J
splitChars=: (1 ,~ 2 ~:/\ ]) <;.2 ] delimitChars=: ', ' joinstring splitChars
Give a code snippet in #J Task Split a (character) string into comma (plus a blank) delimited strings based on a change of character   (left to right). Show the output here   (use the 1st example below). Blanks should be treated as any other character   (except they are problematic to display clearly).   The sa...
christopher/rosetta-code
http://rosettacode.org/wiki/Integer_sequence
Integer sequence
Task Create a program that, when run, would display all integers from   1   to   ∞   (or any relevant implementation limit),   in sequence   (i.e.   1, 2, 3, 4, etc)   if given enough time. An example may not be able to reach arbitrarily-large numbers based on implementations limits.   For example, if integer...
#Fish
Fish
0>:n1+v ^o" "<
Give a code snippet in #Fish Task Create a program that, when run, would display all integers from   1   to   ∞   (or any relevant implementation limit),   in sequence   (i.e.   1, 2, 3, 4, etc)   if given enough time. An example may not be able to reach arbitrarily-large numbers based on implementations lim...
christopher/rosetta-code
http://rosettacode.org/wiki/Left_factorials
Left factorials
Left factorials,   !n,   may refer to either   subfactorials   or to   factorial sums; the same notation can be confusingly seen being used for the two different definitions. Sometimes,   subfactorials   (also known as derangements)   may use any of the notations:   !n`   !n   n¡ (It may not be vis...
#Icon_and_Unicon
Icon and Unicon
procedure main() every writes(lfact(0 | !10)," ") write() write() every write(lfact(20 to 110 by 10)) write() every writes(*lfact(1000 to 10000 by 1000)," ") write() end   procedure lfact(n) r := 0 f := 1 every (i := !n, r +:= .f, f *:= .i) return r end
Give a code snippet in #Icon_and_Unicon Left factorials,   !n,   may refer to either   subfactorials   or to   factorial sums; the same notation can be confusingly seen being used for the two different definitions. Sometimes,   subfactorials   (also known as derangements)   may use any of the notations:   !n` ...
christopher/rosetta-code
http://rosettacode.org/wiki/Rate_counter
Rate counter
Of interest is the code that performs the actual measurements. Any other code (such as job implementation or dispatching) that is required to demonstrate the rate tracking is helpful, but not the focus. Multiple approaches are allowed (even preferable), so long as they can accomplish these goals: Run N seconds worth...
#Ring
Ring
  # Project : Rate counter   see "method 1: calculate reciprocal of elapsed time:" + nl for trial = 1 to 3 start = clock() tasktomeasure() finish = clock() see "rate = " + 100 / (finish-start) + " per second" + nl next   see "method 2: count completed tasks in one second:" + nl for trial = 1 to 3 r...
Give a code snippet in #Ring Of interest is the code that performs the actual measurements. Any other code (such as job implementation or dispatching) that is required to demonstrate the rate tracking is helpful, but not the focus. Multiple approaches are allowed (even preferable), so long as they can accomplish thes...
christopher/rosetta-code
http://rosettacode.org/wiki/Jaro_similarity
Jaro similarity
The Jaro distance is a measure of edit distance between two strings; its inverse, called the Jaro similarity, is a measure of two strings' similarity: the higher the value, the more similar the strings are. The score is normalized such that   0   equates to no similarities and   1   is an exact match. Definition The...
#ARM_Assembly
ARM Assembly
    /* ARM assembly Raspberry PI */ /* program jarodist.s */     /* Constantes */ .equ BUFFERSIZE, 100 .equ STDIN, 0 @ Linux input console .equ STDOUT, 1 @ Linux output console .equ EXIT, 1 ...
Give a code snippet in #ARM_Assembly The Jaro distance is a measure of edit distance between two strings; its inverse, called the Jaro similarity, is a measure of two strings' similarity: the higher the value, the more similar the strings are. The score is normalized such that   0   equates to no similarities and   1 ...
christopher/rosetta-code
http://rosettacode.org/wiki/Feigenbaum_constant_calculation
Feigenbaum constant calculation
Task Calculate the Feigenbaum constant. See   Details in the Wikipedia article:   Feigenbaum constant.
#Swift
Swift
import Foundation   func feigenbaum(iterations: Int = 13) { var a = 0.0 var a1 = 1.0 var a2 = 0.0 var d = 0.0 var d1 = 3.2   print(" i d")   for i in 2...iterations { a = a1 + (a1 - a2) / d1   for _ in 1...10 { var x = 0.0 var y = 0.0   for _ in 1...1<<i { y = 1.0 -...
Give a code snippet in #Swift Task Calculate the Feigenbaum constant. See   Details in the Wikipedia article:   Feigenbaum constant.
christopher/rosetta-code
http://rosettacode.org/wiki/Short-circuit_evaluation
Short-circuit evaluation
Control Structures These are examples of control structures. You may also be interested in: Conditional structures Exceptions Flow-control structures Loops Assume functions   a   and   b   return boolean values,   and further, the execution of function   b   takes considerable resources without side effects, an...
#PARI.2FGP
PARI/GP
a(n)={ print(a"("n")"); a }; b(n)={ print("b("n")"); n }; or(A,B)={ a(A) || b(B) }; and(A,B)={ a(A) && b(B) };
Give a code snippet in #PARI.2FGP Control Structures These are examples of control structures. You may also be interested in: Conditional structures Exceptions Flow-control structures Loops Assume functions   a   and   b   return boolean values,   and further, the execution of function   b   takes considerable...
christopher/rosetta-code
http://rosettacode.org/wiki/Julia_set
Julia set
Task Generate and draw a Julia set. Related tasks   Mandelbrot Set
#Wren
Wren
import "graphics" for Canvas, Color import "dome" for Window   var MaxIters = 300 var Zoom = 1 var MoveX = 0 var MoveY = 0 var CX = -0.7 var CY = 0.27015   class JuliaSet { construct new(width, height) { Window.title = "Julia Set" Window.resize(width, height) Canvas.resize(width, height) ...
Give a code snippet in #Wren Task Generate and draw a Julia set. Related tasks   Mandelbrot Set
christopher/rosetta-code
http://rosettacode.org/wiki/Disarium_numbers
Disarium numbers
A Disarium number is an integer where the sum of each digit raised to the power of its position in the number, is equal to the number. E.G. 135 is a Disarium number: 11 + 32 + 53 == 1 + 9 + 125 == 135 There are a finite number of Disarium numbers. Task Find and display the first 18 Disarium numbers. Stretch...
#Julia
Julia
isdisarium(n) = sum(last(p)^first(p) for p in enumerate(reverse(digits(n)))) == n   function disariums(numberwanted) n, ret = 0, Int[] while length(ret) < numberwanted isdisarium(n) && push!(ret, n) n += 1 end return ret end   println(disariums(19)) @time disariums(19)  
Give a code snippet in #Julia A Disarium number is an integer where the sum of each digit raised to the power of its position in the number, is equal to the number. E.G. 135 is a Disarium number: 11 + 32 + 53 == 1 + 9 + 125 == 135 There are a finite number of Disarium numbers. Task Find and display the first...
christopher/rosetta-code
http://rosettacode.org/wiki/Introspection
Introspection
Task verify the version/revision of your currently running (compiler/interpreter/byte-compiler/runtime environment/whatever your language uses) and exit if it is too old. check whether the variable "bloop" exists and whether the math-function "abs()" is available and if yes compute abs(bloop). Extra credit Repor...
#TI-89_BASIC
TI-89 BASIC
() Prgm Local l, i, vers getConfg() → l For i,1,dim(l),2 If l[i] = "OS Version" or l[i] = "Version" Then l[i + 1] → vers Disp "Version: " & vers If expr(right(vers, 4)) < 2005 Then © Lousy parsing strategy Disp vers & " is too old" Stop EndIf EndIf EndFor   If ...
Give a code snippet in #TI-89_BASIC Task verify the version/revision of your currently running (compiler/interpreter/byte-compiler/runtime environment/whatever your language uses) and exit if it is too old. check whether the variable "bloop" exists and whether the math-function "abs()" is available and if yes compu...
christopher/rosetta-code
http://rosettacode.org/wiki/Extreme_floating_point_values
Extreme floating point values
The IEEE floating point specification defines certain 'extreme' floating point values such as minus zero, -0.0, a value distinct from plus zero; not a number, NaN; and plus and minus infinity. The task is to use expressions involving other 'normal' floating point values in your language to calculate these, (and maybe ...
#Oz
Oz
declare Inf = 1.0e234 * 1.0e234 MinusInf = 1.0e234 * ~1.0e234 Zero = 1.0 / Inf MinusZero = 1.0 / MinusInf NaN = 0.0 / 0.0   {System.showInfo "infinite: "#Inf} {System.showInfo "-infinite: "#MinusInf} {System.showInfo "0: "#Zero} {System.showInfo "-0: "#MinusZero} %% seems to be identical to Zero {System.showInfo "NaN:...
Give a code snippet in #Oz The IEEE floating point specification defines certain 'extreme' floating point values such as minus zero, -0.0, a value distinct from plus zero; not a number, NaN; and plus and minus infinity. The task is to use expressions involving other 'normal' floating point values in your language to ...
christopher/rosetta-code
http://rosettacode.org/wiki/Generate_Chess960_starting_position
Generate Chess960 starting position
Chess960 is a variant of chess created by world champion Bobby Fischer. Unlike other variants of the game, Chess960 does not require a different material, but instead relies on a random initial position, with a few constraints: as in the standard chess game, all eight white pawns must be placed on the second rank. W...
#Seed7
Seed7
$ include "seed7_05.s7i";   const proc: main is func local var string: start is "RKR"; var char: piece is ' '; var integer: pos is 0; begin for piece range "QNN" do pos := rand(1, succ(length(start))); start := start[.. pred(pos)] & str(piece) & start[pos ..]; end for; pos := ran...
Give a code snippet in #Seed7 Chess960 is a variant of chess created by world champion Bobby Fischer. Unlike other variants of the game, Chess960 does not require a different material, but instead relies on a random initial position, with a few constraints: as in the standard chess game, all eight white pawns must b...
christopher/rosetta-code
http://rosettacode.org/wiki/Arithmetic/Integer
Arithmetic/Integer
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 |...
#Befunge
Befunge
&&00p"=A",,:."=B ",,,00g.55+,v v,+55.+g00:,,,,"A+B="< >"=B-A",,,,:00g-.55+,v v,+55.*g00:,,,,"A*B="< >"=B/A",,,,:00g/.55+,v @,+55.%g00,,,,"A%B="<
Give a code snippet in #Befunge 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 Operation...
christopher/rosetta-code
http://rosettacode.org/wiki/Search_a_list
Search a list
Task[edit] Find the index of a string (needle) in an indexable, ordered collection of strings (haystack). Raise an exception if the needle is missing. If there is more than one occurrence then return the smallest index to the needle. Extra credit Return the largest index to a needle that has multiple occurrences in ...
#Burlesque
Burlesque
blsq ) {"Zig" "Zag" "Wally" "Bush" "Ronald" "Bush"}"Bush"Fi 3
Give a code snippet in #Burlesque Task[edit] Find the index of a string (needle) in an indexable, ordered collection of strings (haystack). Raise an exception if the needle is missing. If there is more than one occurrence then return the smallest index to the needle. Extra credit Return the largest index to a needl...
christopher/rosetta-code
http://rosettacode.org/wiki/Loops/While
Loops/While
Task Start an integer value at   1024. Loop while it is greater than zero. Print the value (with a newline) and divide it by two each time through the loop. Related tasks   Loop over multiple arrays simultaneously   Loops/Break   Loops/Continue   Loops/Do-while   Loops/Downward for   Loops/For   Loops/For...
#min
min
1024 :n (n 0 >) (n puts 2 div @n) while
Give a code snippet in #min Task Start an integer value at   1024. Loop while it is greater than zero. Print the value (with a newline) and divide it by two each time through the loop. Related tasks   Loop over multiple arrays simultaneously   Loops/Break   Loops/Continue   Loops/Do-while   Loops/Downward ...
christopher/rosetta-code
http://rosettacode.org/wiki/Web_scraping
Web scraping
Task Create a program that downloads the time from this URL:   http://tycho.usno.navy.mil/cgi-bin/timer.pl   and then prints the current UTC time by extracting just the UTC time from the web page's HTML. Alternatively, if the above url is not working, grab the first date/time off this page's talk page. If possible,...
#Microsoft_Small_Basic
Microsoft Small Basic
  'Entered by AykayayCiti -- Earl L. Montgomery url_name = "http://tycho.usno.navy.mil/cgi-bin/timer.pl" url_data = Network.GetWebPageContents(url_name) find = "UTC" ' the length from the UTC to the time is -18 so we need ' to subtract from the UTC position pos = Text.GetIndexOf(url_data,find)-18 result = Text.GetSubT...
Give a code snippet in #Microsoft_Small_Basic Task Create a program that downloads the time from this URL:   http://tycho.usno.navy.mil/cgi-bin/timer.pl   and then prints the current UTC time by extracting just the UTC time from the web page's HTML. Alternatively, if the above url is not working, grab the first date/...
christopher/rosetta-code
http://rosettacode.org/wiki/One-time_pad
One-time pad
Implement a One-time pad, for encrypting and decrypting messages. To keep it simple, we will be using letters only. Sub-Tasks Generate the data for a One-time pad (user needs to specify a filename and length) The important part is to get "true random" numbers, e.g. from /dev/random encryption / decryption ( basic...
#Julia
Julia
// version 1.2.31   import java.io.File import java.security.SecureRandom   const val CHARS_PER_LINE = 48 const val CHUNK_SIZE = 6 const val COLS = 8 const val DEMO = true // would normally be set to false   enum class FileType { OTP, ENC, DEC }   fun Char.isAlpha() = this in 'A'..'Z'   fun String.toAlpha() = this.fil...
Give a code snippet in #Julia Implement a One-time pad, for encrypting and decrypting messages. To keep it simple, we will be using letters only. Sub-Tasks Generate the data for a One-time pad (user needs to specify a filename and length) The important part is to get "true random" numbers, e.g. from /dev/random ...
christopher/rosetta-code
http://rosettacode.org/wiki/Random_numbers
Random numbers
Task Generate a collection filled with   1000   normally distributed random (or pseudo-random) numbers with a mean of   1.0   and a   standard deviation   of   0.5 Many libraries only generate uniformly distributed random numbers. If so, you may use one of these algorithms. Related task   Standard deviation
#MATLAB
MATLAB
mu = 1; sd = 0.5; x = randn(1000,1) * sd + mu;  
Give a code snippet in #MATLAB Task Generate a collection filled with   1000   normally distributed random (or pseudo-random) numbers with a mean of   1.0   and a   standard deviation   of   0.5 Many libraries only generate uniformly distributed random numbers. If so, you may use one of these algorithms. Relate...
christopher/rosetta-code
http://rosettacode.org/wiki/Sierpinski_triangle/Graphical
Sierpinski triangle/Graphical
Produce a graphical representation of a Sierpinski triangle of order N in any orientation. An example of Sierpinski's triangle (order = 8) looks like this:
#BASIC
BASIC
  SCREEN 9 H=.5 P=300 FOR I=1 TO 9^6 N=RND IF N > 2/3 THEN X=H+X*H:Y=Y*H ELSEIF N > 1/3 THEN X=H^2+X*H:Y=H+Y*H ELSE X=X*H:Y=Y*H END IF PSET(P-X*P,P-Y*P) NEXT  
Give a code snippet in #BASIC Produce a graphical representation of a Sierpinski triangle of order N in any orientation. An example of Sierpinski's triangle (order = 8) looks like this:
christopher/rosetta-code