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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...
#XBS
XBS
const Range:{Min:number,Max:number} = { Min:number=1, Max:number=10, };   while(true){ set RandomNumber:number = math.random(Range.Min,Range.Max); set Response:string = window->prompt("Enter a number from "+tostring(Range.Min)+" to "+tostring(Range.Max)); if (toint(Response)==RandomNumber){ log("Well guessed!");...
Give a code snippet in #XBS 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/Find_limit_of_recursion
Find limit of recursion
Find limit of recursion is part of Short Circuit's Console Program Basics selection. Task Find the limit of recursion.
#Java
Java
  public class RecursionTest {   private static void recurse(int i) { try { recurse(i+1); } catch (StackOverflowError e) { System.out.print("Recursion depth on this system is " + i + "."); } }   public static void main(String[] args) { recurse(0); } }  
Give a code snippet in #Java Find limit of recursion is part of Short Circuit's Console Program Basics selection. Task Find the limit of recursion.
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 ...
#360_Assembly
360 Assembly
* Day of the week 06/07/2016 DOW CSECT USING DOW,R15 base register LA R6,2008 year=2008 LOOP C R6,=F'2121' do year=2008 to 2121 BH ELOOP . LR R7,R6 y=year LA R8,12 ...
Give a code snippet in #360_Assembly 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 b...
christopher/rosetta-code
http://rosettacode.org/wiki/Combinations_with_repetitions
Combinations with repetitions
The set of combinations with repetitions is computed from a set, S {\displaystyle S} (of cardinality n {\displaystyle n} ), and a size of resulting selection, k {\displaystyle k} , by reporting the sets of cardinality k {\displaystyle k} where each member of those sets is chosen from S...
#Ruby
Ruby
possible_doughnuts = ['iced', 'jam', 'plain'].repeated_combination(2) puts "There are #{possible_doughnuts.count} possible doughnuts:" possible_doughnuts.each{|doughnut_combi| puts doughnut_combi.join(' and ')}   # Extra credit possible_doughnuts = [*1..1000].repeated_combination(30) # size returns the size of the enum...
Give a code snippet in #Ruby The set of combinations with repetitions is computed from a set, S {\displaystyle S} (of cardinality n {\displaystyle n} ), and a size of resulting selection, k {\displaystyle k} , by reporting the sets of cardinality k {\displaystyle k} where each member of t...
christopher/rosetta-code
http://rosettacode.org/wiki/Assertions
Assertions
Assertions are a way of breaking out of code when there is an error or an unexpected input. Some languages throw exceptions and some treat it as a break point. Task Show an assertion in your language by asserting that an integer variable is equal to 42.
#SPARK
SPARK
-# check X = 42;
Give a code snippet in #SPARK Assertions are a way of breaking out of code when there is an error or an unexpected input. Some languages throw exceptions and some treat it as a break point. Task Show an assertion in your language by asserting that an integer variable is equal to 42.
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
#ooRexx
ooRexx
array1 = .array~of("Rick", "Mike", "David") array2 = .array~of("555-9862", "555-5309", "555-6666")   -- if the index items are constrained to string objects, this can -- be a directory too. hash = .table~new   loop i = 1 to array1~size hash[array1[i]] = array2[i] end Say 'Enter a name' Parse Pull name Say name '->'...
Give a code snippet in #ooRexx 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/Factorial
Factorial
Definitions   The factorial of   0   (zero)   is defined as being   1   (unity).   The   Factorial Function   of a positive integer,   n,   is defined as the product of the sequence: n,   n-1,   n-2,   ...   1 Task Write a function to return the factorial of a number. Solutions can be iterat...
#Arendelle
Arendelle
< n > { @n = 0 , ( return , 1 ) , ( return , @n * !factorial( @n - ! ) ) }
Give a code snippet in #Arendelle Definitions   The factorial of   0   (zero)   is defined as being   1   (unity).   The   Factorial Function   of a positive integer,   n,   is defined as the product of the sequence: n,   n-1,   n-2,   ...   1 Task Write a function to return the factorial of...
christopher/rosetta-code
http://rosettacode.org/wiki/Matrix-exponentiation_operator
Matrix-exponentiation operator
Most programming languages have a built-in implementation of exponentiation for integers and reals only. Task Demonstrate how to implement matrix exponentiation as an operator.
#FreeBASIC
FreeBASIC
#include once "matmult.bas" #include once "rowech.bas" #include once "matinv.bas"   operator ^ (byval M as Matrix, byval n as integer ) as Matrix dim as uinteger i, j, k = ubound( M.m, 1 ) if n < 0 then return matinv(M) ^ (-n) if n = 0 then return M * matinv(M) return (M ^ (n-1)) * M end operator   dim ...
Give a code snippet in #FreeBASIC Most programming languages have a built-in implementation of exponentiation for integers and reals only. Task Demonstrate how to implement matrix exponentiation as an operator.
christopher/rosetta-code
http://rosettacode.org/wiki/Farey_sequence
Farey sequence
The   Farey sequence   Fn   of order   n   is the sequence of completely reduced fractions between   0   and   1   which, when in lowest terms, have denominators less than or equal to   n,   arranged in order of increasing size. The   Farey sequence   is sometimes incorrectly called a   Farey series. Each Farey se...
#C.2B.2B
C++
#include <iostream>   struct fraction { fraction(int n, int d) : numerator(n), denominator(d) {} int numerator; int denominator; };   std::ostream& operator<<(std::ostream& out, const fraction& f) { out << f.numerator << '/' << f.denominator; return out; }   class farey_sequence { public: explic...
Give a code snippet in #C.2B.2B The   Farey sequence   Fn   of order   n   is the sequence of completely reduced fractions between   0   and   1   which, when in lowest terms, have denominators less than or equal to   n,   arranged in order of increasing size. The   Farey sequence   is sometimes incorrectly called a...
christopher/rosetta-code
http://rosettacode.org/wiki/Copy_stdin_to_stdout
Copy stdin to stdout
Create an executable file that copies stdin to stdout, or else a script that does so through the invocation of an interpreter at the command line.
#Julia
Julia
while !eof(stdin) write(stdout, read(stdin, UInt8)) end
Give a code snippet in #Julia Create an executable file that copies stdin to stdout, or else a script that does so through the invocation of an interpreter at the command line.
christopher/rosetta-code
http://rosettacode.org/wiki/Truncatable_primes
Truncatable primes
A truncatable prime is a prime number that when you successively remove digits from one end of the prime, you are left with a new prime number. Examples The number 997 is called a left-truncatable prime as the numbers 997, 97, and 7 are all prime. The number 7393 is a right-truncatable prime as the numbers 7393, 7...
#Forth
Forth
: prime? ( n -- ? ) here + c@ 0= ; : notprime! ( n -- ) here + 1 swap c! ;   : sieve ( n -- ) here over erase 0 notprime! 1 notprime! 2 begin 2dup dup * > while dup prime? if 2dup dup * do i notprime! dup +loop then 1+ repeat 2drop ;   : left_truncatable_prime? ( n --...
Give a code snippet in #Forth A truncatable prime is a prime number that when you successively remove digits from one end of the prime, you are left with a new prime number. Examples The number 997 is called a left-truncatable prime as the numbers 997, 97, and 7 are all prime. The number 7393 is a right-truncatab...
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:
#Phix
Phix
-- demo\rosetta\SierpinskyTriangle.exw include pGUI.e Ihandle dlg, canvas cdCanvas cddbuffer, cdcanvas procedure SierpinskyTriangle(integer level, atom x, atom y, atom w, atom h) atom w2 = w/2, w4 = w/4, h2 = h/2 if level=1 then cdCanvasBegin(cddbuffer,CD_CLOSED_LINES) cdCanvasVertex(cddbuff...
Give a code snippet in #Phix 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
http://rosettacode.org/wiki/Walk_a_directory/Non-recursively
Walk a directory/Non-recursively
Task Walk a given directory and print the names of files matching a given pattern. (How is "pattern" defined? substring match? DOS pattern? BASH pattern? ZSH pattern? Perl regular expression?) Note: This task is for non-recursive methods.   These tasks should read a single directory, not an entire directory tree. ...
#E
E
def walkDirectory(directory, pattern) { for name => file ? (name =~ rx`.*$pattern.*`) in directory { println(name) } }
Give a code snippet in #E Task Walk a given directory and print the names of files matching a given pattern. (How is "pattern" defined? substring match? DOS pattern? BASH pattern? ZSH pattern? Perl regular expression?) Note: This task is for non-recursive methods.   These tasks should read a single directory, not ...
christopher/rosetta-code
http://rosettacode.org/wiki/Josephus_problem
Josephus problem
Josephus problem is a math puzzle with a grim description: n {\displaystyle n} prisoners are standing on a circle, sequentially numbered from 0 {\displaystyle 0} to n − 1 {\displaystyle n-1} . An executioner walks along the circle, starting from prisoner 0 {\displaystyle 0} , removing eve...
#Fortran
Fortran
program josephus implicit none integer :: n, i, k, p integer, allocatable :: next(:) read *, n, k allocate(next(0:n - 1)) do i = 0, n - 2 next(i) = i + 1 end do next(n - 1) = 0 p = 0 do while(next(p) /= p) do i = 1, k - 2 p = next(p) end do print *, "Kill",...
Give a code snippet in #Fortran Josephus problem is a math puzzle with a grim description: n {\displaystyle n} prisoners are standing on a circle, sequentially numbered from 0 {\displaystyle 0} to n − 1 {\displaystyle n-1} . An executioner walks along the circle, starting from prisoner 0 ...
christopher/rosetta-code
http://rosettacode.org/wiki/Happy_numbers
Happy numbers
From Wikipedia, the free encyclopedia: A happy number is defined by the following process: Starting with any positive integer, replace the number by the sum of the squares of its digits, and repeat the process until the number equals   1   (where it will stay),   or it loops endlessly in a cycle which does not inclu...
#MAD
MAD
NORMAL MODE IS INTEGER BOOLEAN CYCLE DIMENSION CYCLE(200) VECTOR VALUES OUTFMT = $I2*$   SEEN = 0 I = 0   NEXNUM THROUGH ZERO, FOR K=0, 1, K.G.200 ZERO CYCLE(K) = 0B I = I + 1 SUMSQR = I CHKLP N = SUMSQR ...
Give a code snippet in #MAD From Wikipedia, the free encyclopedia: A happy number is defined by the following process: Starting with any positive integer, replace the number by the sum of the squares of its digits, and repeat the process until the number equals   1   (where it will stay),   or it loops endlessly in...
christopher/rosetta-code
http://rosettacode.org/wiki/Hello_world/Web_server
Hello world/Web server
The browser is the new GUI ! Task Serve our standard text   Goodbye, World!   to   http://localhost:8080/   so that it can be viewed with a web browser. The provided solution must start or implement a server that accepts multiple client connections and serves text as requested. Note that starting a web browser or...
#Fantom
Fantom
using web using wisp   const class HelloMod : WebMod // provides the content { override Void onGet () { res.headers["Content-Type"] = "text/plain; charset=utf-8" res.out.print ("Goodbye, World!") } }   class HelloWeb { Void main () { WispService // creates the web service { port = 8080 ...
Give a code snippet in #Fantom The browser is the new GUI ! Task Serve our standard text   Goodbye, World!   to   http://localhost:8080/   so that it can be viewed with a web browser. The provided solution must start or implement a server that accepts multiple client connections and serves text as requested. Not...
christopher/rosetta-code
http://rosettacode.org/wiki/Rot-13
Rot-13
Task Implement a   rot-13   function   (or procedure, class, subroutine, or other "callable" object as appropriate to your programming environment). Optionally wrap this function in a utility program   (like tr,   which acts like a common UNIX utility, performing a line-by-line rot-13 encoding of every line of inpu...
#D.C3.A9j.C3.A0_Vu
Déjà Vu
rot-13: ) for ch in chars swap: ord ch if <= 65 dup: if >= 90 dup: + 13 - swap 65 + 65 % swap 26 if <= 97 dup: if >= 122 dup: + 13 - swap 97 + 97 % swap 26 chr concat(   !print rot-13 "Snape kills Frodo with Rosebud."
Give a code snippet in #D.C3.A9j.C3.A0_Vu Task Implement a   rot-13   function   (or procedure, class, subroutine, or other "callable" object as appropriate to your programming environment). Optionally wrap this function in a utility program   (like tr,   which acts like a common UNIX utility, performing a line-by...
christopher/rosetta-code
http://rosettacode.org/wiki/Last_Friday_of_each_month
Last Friday of each month
Task Write a program or a script that returns the date of the last Fridays of each month of a given year. The year may be given through any simple input method in your language (command line, std in, etc). Example of an expected output: ./last_fridays 2012 2012-01-27 2012-02-24 2012-03-30 2012-04-27 2012-05-25 20...
#Action.21
Action!
;https://en.wikipedia.org/wiki/Determination_of_the_day_of_the_week#Sakamoto.27s_methods BYTE FUNC DayOfWeek(INT y BYTE m,d) ;1<=m<=12, y>1752 BYTE ARRAY t=[0 3 2 5 0 3 5 1 4 6 2 4] BYTE res   IF m<3 THEN y==-1 FI res=(y+y/4-y/100+y/400+t(m-1)+d) MOD 7 RETURN (res)   BYTE FUNC IsLeapYear(INT y) IF y MOD...
Give a code snippet in #Action.21 Task Write a program or a script that returns the date of the last Fridays of each month of a given year. The year may be given through any simple input method in your language (command line, std in, etc). Example of an expected output: ./last_fridays 2012 2012-01-27 2012-02-24 ...
christopher/rosetta-code
http://rosettacode.org/wiki/Repeat
Repeat
Task Write a procedure which accepts as arguments another procedure and a positive integer. The latter procedure is executed a number of times equal to the accepted integer.
#PARI.2FGP
PARI/GP
repeat(f, n)=for(i=1,n,f()); repeat( ()->print("Hi!"), 2);
Give a code snippet in #PARI.2FGP Task Write a procedure which accepts as arguments another procedure and a positive integer. The latter procedure is executed a number of times equal to the accepted integer.
christopher/rosetta-code
http://rosettacode.org/wiki/String_interpolation_(included)
String interpolation (included)
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 |...
#Fantom
Fantom
  fansh> x := "little" little fansh> echo ("Mary had a $x lamb") Mary had a little lamb  
Give a code snippet in #Fantom 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/Check_output_device_is_a_terminal
Check output device is a terminal
Task Demonstrate how to check whether the output device is a terminal or not. Related task   Check input device is a terminal
#Factor
Factor
  IN: scratchpad USE: unix.ffi IN: scratchpad 1 isatty   --- Data stack: 1  
Give a code snippet in #Factor Task Demonstrate how to check whether the output device is a terminal or not. Related task   Check input device is a terminal
christopher/rosetta-code
http://rosettacode.org/wiki/Loops/Break
Loops/Break
Task Show a loop which prints random numbers (each number newly generated each loop) from 0 to 19 (inclusive). If a number is 10, stop the loop after printing it, and do not generate any further numbers. Otherwise, generate and print a second random number before restarting the loop. If the number 10 is never gener...
#Euphoria
Euphoria
integer i while 1 do i = rand(20) - 1 printf(1, "%g ", {i}) if i = 10 then exit end if printf(1, "%g ", {rand(20)-1}) end while
Give a code snippet in #Euphoria Task Show a loop which prints random numbers (each number newly generated each loop) from 0 to 19 (inclusive). If a number is 10, stop the loop after printing it, and do not generate any further numbers. Otherwise, generate and print a second random number before restarting the loop...
christopher/rosetta-code
http://rosettacode.org/wiki/Almost_prime
Almost prime
A   k-Almost-prime   is a natural number   n {\displaystyle n}   that is the product of   k {\displaystyle k}   (possibly identical) primes. Example 1-almost-primes,   where   k = 1 {\displaystyle k=1} ,   are the prime numbers themselves. 2-almost-primes,   where   k = 2 {\displaystyl...
#Java
Java
public class AlmostPrime { public static void main(String[] args) { for (int k = 1; k <= 5; k++) { System.out.print("k = " + k + ":");   for (int i = 2, c = 0; c < 10; i++) { if (kprime(i, k)) { System.out.print(" " + i); c++; ...
Give a code snippet in #Java A   k-Almost-prime   is a natural number   n {\displaystyle n}   that is the product of   k {\displaystyle k}   (possibly identical) primes. Example 1-almost-primes,   where   k = 1 {\displaystyle k=1} ,   are the prime numbers themselves. 2-almost-primes,   whe...
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...
#Plorth
Plorth
["apple", "orange"] length println
Give a code snippet in #Plorth 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/Multiple_regression
Multiple regression
Task Given a set of data vectors in the following format: y = { y 1 , y 2 , . . . , ...
#Emacs_Lisp
Emacs Lisp
(let ((x1 '(0 1 2 3 4 5 6 7 8 9 10)) (x2 '(0 1 1 3 3 7 6 7 3 9 8)) (y '(1 6 17 34 57 86 121 162 209 262 321))) (apply #'calc-eval "fit(a*X1+b*X2+c,[X1,X2],[a,b,c],[$1 $2 $3])" nil (mapcar (lambda (items) (cons 'vec items)) (list x1 x2 y))))
Give a code snippet in #Emacs_Lisp Task Given a set of data vectors in the following format: y = { y 1 , y 2 , . . ...
christopher/rosetta-code
http://rosettacode.org/wiki/Zig-zag_matrix
Zig-zag matrix
Task Produce a zig-zag array. A   zig-zag   array is a square arrangement of the first   N2   natural numbers,   where the numbers increase sequentially as you zig-zag along the array's   anti-diagonals. For a graphical representation, see   JPG zigzag   (JPG uses such arrays to encode images). For example, gi...
#Prolog
Prolog
zig_zag(N) :- zig_zag(N, N).   % compute zig_zag for a matrix of Lig lines of Col columns zig_zag(Lig, Col) :- length(M, Lig), maplist(init(Col), M), fill(M, 0, 0, 0, Lig, Col, up), % display the matrix maplist(print_line, M).     fill(M, Cur, L, C, NL, NC, _) :- L is NL - 1, C is NC - 1, nth0(L, M, Line), nt...
Give a code snippet in #Prolog Task Produce a zig-zag array. A   zig-zag   array is a square arrangement of the first   N2   natural numbers,   where the numbers increase sequentially as you zig-zag along the array's   anti-diagonals. For a graphical representation, see   JPG zigzag   (JPG uses such arrays to en...
christopher/rosetta-code
http://rosettacode.org/wiki/Find_largest_left_truncatable_prime_in_a_given_base
Find largest left truncatable prime in a given base
A truncatable prime is one where all non-empty substrings that finish at the end of the number (right-substrings) are also primes when understood as numbers in a particular base. The largest such prime in a given (integer) base is therefore computable, provided the base is larger than 2. Let's consider what happens in...
#Swift
Swift
import BigInt   func largestLeftTruncatablePrime(_ base: Int) -> BigInt { var radix = 0 var candidates = [BigInt(0)]   while true { let multiplier = BigInt(base).power(radix) var newCandidates = [BigInt]()   for i in 1..<BigInt(base) { newCandidates += candidates.map({ ($0+i*multiplier, ($0+i*mu...
Give a code snippet in #Swift A truncatable prime is one where all non-empty substrings that finish at the end of the number (right-substrings) are also primes when understood as numbers in a particular base. The largest such prime in a given (integer) base is therefore computable, provided the base is larger than 2. ...
christopher/rosetta-code
http://rosettacode.org/wiki/Magic_squares_of_odd_order
Magic squares of odd order
A magic square is an   NxN   square matrix whose numbers (usually integers) consist of consecutive numbers arranged so that the sum of each row and column,   and   both long (main) diagonals are equal to the same sum (which is called the   magic number   or   magic constant). The numbers are usually (but not always) t...
#Perl
Perl
 
Give a code snippet in #Perl A magic square is an   NxN   square matrix whose numbers (usually integers) consist of consecutive numbers arranged so that the sum of each row and column,   and   both long (main) diagonals are equal to the same sum (which is called the   magic number   or   magic constant). The numbers ...
christopher/rosetta-code
http://rosettacode.org/wiki/Terminal_control/Cursor_positioning
Terminal control/Cursor positioning
Task Move the cursor to column   3,   row   6,   and display the word   "Hello"   (without the quotes),   so that the letter   H   is in column   3   on row   6.
#Logo
Logo
setcursor [2 5] type "Hello
Give a code snippet in #Logo Task Move the cursor to column   3,   row   6,   and display the word   "Hello"   (without the quotes),   so that the letter   H   is in column   3   on row   6.
christopher/rosetta-code
http://rosettacode.org/wiki/Sort_an_integer_array
Sort an integer array
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 ...
#LiveCode
LiveCode
put "3,2,5,4,1" into X sort items of X numeric put X -- outputs "1,2,3,4,5"
Give a code snippet in #LiveCode 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/UTF-8_encode_and_decode
UTF-8 encode and decode
As described in UTF-8 and in Wikipedia, UTF-8 is a popular encoding of (multi-byte) Unicode code-points into eight-bit octets. The goal of this task is to write a encoder that takes a unicode code-point (an integer representing a unicode character) and returns a sequence of 1-4 bytes representing that character in the...
#Ada
Ada
with Ada.Strings.Fixed; use Ada.Strings.Fixed; with Ada.Strings.UTF_Encoding.Wide_Wide_Strings; with Ada.Integer_Text_IO; with Ada.Text_IO; with Ada.Wide_Wide_Text_IO;   procedure UTF8_Encode_And_Decode is package TIO renames Ada.Text_IO; package WWTIO renames Ada.Wide_Wide_Text_IO; package WWS renames Ada.Str...
Give a code snippet in #Ada As described in UTF-8 and in Wikipedia, UTF-8 is a popular encoding of (multi-byte) Unicode code-points into eight-bit octets. The goal of this task is to write a encoder that takes a unicode code-point (an integer representing a unicode character) and returns a sequence of 1-4 bytes repre...
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...
#Elixir
Elixir
defmodule Chess960 do @pieces ~w(♔ ♕ ♘ ♘ ♗ ♗ ♖ ♖) # ~w(K Q N N B B R R) @regexes [~r/♗(..)*♗/, ~r/♖.*♔.*♖/] # [~r/B(..)*B/, ~r/R.*K.*R/]   def shuffle do row = Enum.shuffle(@pieces) |> Enum.join if Enum.all?(@regexes, &Regex.match?(&1, row)), do: row, else: shuffle end end   Enum.e...
Give a code snippet in #Elixir 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 ...
christopher/rosetta-code
http://rosettacode.org/wiki/Visualize_a_tree
Visualize a tree
A tree structure   (i.e. a rooted, connected acyclic graph)   is often used in programming. It's often helpful to visually examine such a structure. There are many ways to represent trees to a reader, such as:   indented text   (à la unix tree command)   nested HTML tables   hierarchical GUI widgets   2D   or ...
#Tcl
Tcl
package require struct::tree   proc visualize_tree {tree {nameattr name}} { set path {} $tree walk [$tree rootname] -order both {mode node} { if {$mode eq "enter"} { set s "" foreach p $path { append s [expr {[$tree next $p] eq "" ? " " : "\u2502 "}] } lappend path $node append s [e...
Give a code snippet in #Tcl A tree structure   (i.e. a rooted, connected acyclic graph)   is often used in programming. It's often helpful to visually examine such a structure. There are many ways to represent trees to a reader, such as:   indented text   (à la unix tree command)   nested HTML tables   hierarc...
christopher/rosetta-code
http://rosettacode.org/wiki/Trabb_Pardo%E2%80%93Knuth_algorithm
Trabb Pardo–Knuth algorithm
The TPK algorithm is an early example of a programming chrestomathy. It was used in Donald Knuth and Luis Trabb Pardo's Stanford tech report The Early Development of Programming Languages. The report traces the early history of work in developing computer languages in the 1940s and 1950s, giving several translations of...
#PL.2FM
PL/M
TPK: DO; /* external I/O and real mathematical routines */ WRITE$STRING: PROCEDURE( S ) EXTERNAL; DECLARE S POINTER; END; WRITE$REAL: PROCEDURE( R ) EXTERNAL; DECLARE R REAL; END; WRITE$NL: PROCEDURE EXTERNAL; END; READ$REAL: PROCEDURE( R ) REAL EXT...
Give a code snippet in #PL.2FM The TPK algorithm is an early example of a programming chrestomathy. It was used in Donald Knuth and Luis Trabb Pardo's Stanford tech report The Early Development of Programming Languages. The report traces the early history of work in developing computer languages in the 1940s and 1950s...
christopher/rosetta-code
http://rosettacode.org/wiki/Empty_program
Empty program
Task Create the simplest possible program that is still considered "correct."
#Huginn
Huginn
main(){}
Give a code snippet in #Huginn Task Create the simplest possible program that is still considered "correct."
christopher/rosetta-code
http://rosettacode.org/wiki/Sequence_of_non-squares
Sequence of non-squares
Task Show that the following remarkable formula gives the sequence of non-square natural numbers: n + floor(1/2 + sqrt(n)) Print out the values for   n   in the range   1   to   22 Show that no squares occur for   n   less than one million This is sequence   A000037   in the OEIS database.
#Forth
Forth
: u>f 0 d>f ; : f>u f>d drop ;   : fn ( n -- n ) dup u>f fsqrt fround f>u + ; : test ( n -- ) 1 do i fn . loop ; 23 test \ 2 3 5 6 7 8 10 11 12 13 14 15 17 18 19 20 21 22 23 24 26 27 ok   : square? ( n -- ? ) u>f fsqrt fdup fround f- f0= ; : test ( n -- ) 1 do i fn square? if cr i . ." fn was square" then loop ...
Give a code snippet in #Forth Task Show that the following remarkable formula gives the sequence of non-square natural numbers: n + floor(1/2 + sqrt(n)) Print out the values for   n   in the range   1   to   22 Show that no squares occur for   n   less than one million This is sequence   A00003...
christopher/rosetta-code
http://rosettacode.org/wiki/Pancake_numbers
Pancake numbers
Adrian Monk has problems and an assistant, Sharona Fleming. Sharona can deal with most of Adrian's problems except his lack of punctuality paying her remuneration. 2 pay checks down and she prepares him pancakes for breakfast. Knowing that he will be unable to eat them unless they are stacked in ascending order of size...
#Nim
Nim
import strformat, strutils   func pancake(n: int): int = var gap, sumGaps = 2 pg = 1 adj = -1 while sumGaps < n: inc adj inc pg, gap swap pg, gap inc sumGaps, gap result = n + adj   var line = "" for n in 1..20: line.addSep(" ") line.add &"p({n:>2}) = {pancake(n):>2}" if n mod ...
Give a code snippet in #Nim Adrian Monk has problems and an assistant, Sharona Fleming. Sharona can deal with most of Adrian's problems except his lack of punctuality paying her remuneration. 2 pay checks down and she prepares him pancakes for breakfast. Knowing that he will be unable to eat them unless they are stack...
christopher/rosetta-code
http://rosettacode.org/wiki/Carmichael_3_strong_pseudoprimes
Carmichael 3 strong pseudoprimes
A lot of composite numbers can be separated from primes by Fermat's Little Theorem, but there are some that completely confound it. The   Miller Rabin Test   uses a combination of Fermat's Little Theorem and Chinese Division Theorem to overcome this. The purpose of this task is to investigate such numbers using a met...
#Wren
Wren
import "/fmt" for Fmt import "/math" for Int   var mod = Fn.new { |n, m| ((n%m) + m) % m }   var carmichael = Fn.new { |p1| for (h3 in 2...p1) { for (d in 1...h3 + p1) { if ((h3 + p1) * (p1 - 1) % d == 0 && mod.call(-p1 * p1, h3) == d % h3) { var p2 = 1 + ((p1 - 1) * (h3 + p1) / ...
Give a code snippet in #Wren A lot of composite numbers can be separated from primes by Fermat's Little Theorem, but there are some that completely confound it. The   Miller Rabin Test   uses a combination of Fermat's Little Theorem and Chinese Division Theorem to overcome this. The purpose of this task is to invest...
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...
#VBA
VBA
Private Function ordinals() As Variant ordinals = [{"th","st","nd","rd"}] End Function   Private Function Nth(n As Variant, Optional apostrophe As Boolean = False) As String Dim mod10 As Integer: mod10 = n Mod 10 + 1 If mod10 > 4 Or n Mod 100 = mod10 + 9 Then mod10 = 1 Nth = CStr(n) & String$(Val(-apost...
Give a code snippet in #VBA 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/4-rings_or_4-squares_puzzle
4-rings or 4-squares puzzle
4-rings or 4-squares puzzle You are encouraged to solve this task according to the task description, using any language you may know. Task Replace       a, b, c, d, e, f,   and   g       with the decimal digits   LOW   ───►   HIGH such that the sum of the letters inside of each of the four large squares add up to t...
#Simula
Simula
BEGIN   INTEGER PROCEDURE GETCOMBS(LOW, HIGH, UNIQUE, COMBS); INTEGER LOW, HIGH; INTEGER ARRAY COMBS; BOOLEAN UNIQUE; BEGIN INTEGER A, B, C, D, E, F, G; INTEGER NUM;   BOOLEAN PROCEDURE ISUNIQUE(A, B, C, D, E, F, G); INTEGER A, B, C, D, E, F, G; ...
Give a code snippet in #Simula 4-rings or 4-squares puzzle You are encouraged to solve this task according to the task description, using any language you may know. Task Replace       a, b, c, d, e, f,   and   g       with the decimal digits   LOW   ───►   HIGH such that the sum of the letters inside of each of th...
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 |...
#C.23
C#
  static void Main(string[] args) { int p;   p = 1; Console.WriteLine("Ref Before: " + p); Value(ref p); Console.WriteLine("Ref After : " + p);   p = 1; Console.WriteLine("Val Before: " + p); Value(p); Console.WriteLine("Val After : " + p);   Console.ReadLine(); }   private static void Value(ref int Value) { ...
Give a code snippet in #C.23 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 C...
christopher/rosetta-code
http://rosettacode.org/wiki/Random_number_generator_(included)
Random number generator (included)
The task is to: State the type of random number generator algorithm used in a language's built-in random number generator. If the language or its immediate libraries don't provide a random number generator, skip this task. If possible, give a link to a wider explanation of the algorithm used. Note: the task is not t...
#Inform_7
Inform 7
setrand(3) random(6)+1 \\ chosen by fair dice roll. \\ guaranteed to the random.
Give a code snippet in #Inform_7 The task is to: State the type of random number generator algorithm used in a language's built-in random number generator. If the language or its immediate libraries don't provide a random number generator, skip this task. If possible, give a link to a wider explanation of the algor...
christopher/rosetta-code
http://rosettacode.org/wiki/Sieve_of_Eratosthenes
Sieve of Eratosthenes
This task has been clarified. Its programming examples are in need of review to ensure that they still fit the requirements of the task. The Sieve of Eratosthenes is a simple algorithm that finds the prime numbers up to a given integer. Task Implement the   Sieve of Eratosthenes   algorithm, with the only allowed...
#J
J
10|13 3
Give a code snippet in #J This task has been clarified. Its programming examples are in need of review to ensure that they still fit the requirements of the task. The Sieve of Eratosthenes is a simple algorithm that finds the prime numbers up to a given integer. Task Implement the   Sieve of Eratosthenes   algor...
christopher/rosetta-code
http://rosettacode.org/wiki/Bitwise_operations
Bitwise operations
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 |...
#Maxima
Maxima
load(functs)$   a: 3661$ b: 2541$   logor(a, b); /* 4077 */   logand(a, b); /* 2125 */   logxor(a, b); /* 1952 */   /* NOT(x) is simply -x - 1 -a - 1; /* -3662 */   logor(a, -a - 1); /* -1 */   logand(a, -a - 1); /* 0 */
Give a code snippet in #Maxima 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/Show_ASCII_table
Show ASCII table
Task Show  the ASCII character set  from values   32   to   127   (decimal)   in a table format. Other tasks related to string operations: Metrics Array length String length Copy a string Empty string  (assignment) Counting Word frequency Letter frequency Jewels and stones I before E except after C Bioin...
#REXX
REXX
/*REXX program displays an ASCII table of characters (within a 16x16 indexed grid).*/ parse upper version !ver . /*some REXXes can't display '1b'x glyph*/ !pcRexx= 'REXX/PERSONAL'==!ver | "REXX/PC"==!ver /*is this PC/REXX or REXX/Personal? */ func= ' nul soh stx etx eot enq ack ...
Give a code snippet in #REXX Task Show  the ASCII character set  from values   32   to   127   (decimal)   in a table format. Other tasks related to string operations: Metrics Array length String length Copy a string Empty string  (assignment) Counting Word frequency Letter frequency Jewels and stones I ...
christopher/rosetta-code
http://rosettacode.org/wiki/Roots_of_unity
Roots of unity
The purpose of this task is to explore working with   complex numbers. Task Given   n,   find the   nth   roots of unity.
#Kotlin
Kotlin
import java.lang.Math.*   data class Complex(val r: Double, val i: Double) { override fun toString() = when { i == 0.0 -> r.toString() r == 0.0 -> i.toString() + 'i' else -> "$r + ${i}i" } }   fun unity_roots(n: Number) = (1..n.toInt() - 1).map { val a = it * 2 * PI / n.toDouble() ...
Give a code snippet in #Kotlin The purpose of this task is to explore working with   complex numbers. Task Given   n,   find the   nth   roots of unity.
christopher/rosetta-code
http://rosettacode.org/wiki/Command-line_arguments
Command-line arguments
Command-line arguments is part of Short Circuit's Console Program Basics selection. Scripted main See also Program name. For parsing command line arguments intelligently, see Parsing command-line arguments. Example command line: myprogram -c "alpha beta" -h "gamma"
#Mercury
Mercury
  :- module cmd_line_args. :- interface.   :- import_module io. :- pred main(io::di, io::uo) is det.   :- implementation. :- import_module int, list, string.   main(!IO) :- io.progname("", ProgName, !IO), io.format("This program is named %s.\n", [s(ProgName)], !IO), io.command_line_arguments(Args, !IO), ...
Give a code snippet in #Mercury Command-line arguments is part of Short Circuit's Console Program Basics selection. Scripted main See also Program name. For parsing command line arguments intelligently, see Parsing command-line arguments. Example command line: myprogram -c "alpha beta" -h "gamma"
christopher/rosetta-code
http://rosettacode.org/wiki/Lucas-Lehmer_test
Lucas-Lehmer test
Lucas-Lehmer Test: for p {\displaystyle p} an odd prime, the Mersenne number 2 p − 1 {\displaystyle 2^{p}-1} is prime if and only if 2 p − 1 {\displaystyle 2^{p}-1} divides S ( p − 1 ) {\displaystyle S(p-1)} where S ( n + 1 ) = ( S ( n ) ) 2 − 2 {\displaystyle S(n+1)=(...
#F.23
F#
let rec s mp n = if n = 1 then 4I % mp else ((s mp (n - 1)) ** 2 - 2I) % mp   [ for p in 2..47 do if p = 2 || s ((1I <<< p) - 1I) (p - 1) = 0I then yield p ]
Give a code snippet in #F.23 Lucas-Lehmer Test: for p {\displaystyle p} an odd prime, the Mersenne number 2 p − 1 {\displaystyle 2^{p}-1} is prime if and only if 2 p − 1 {\displaystyle 2^{p}-1} divides S ( p − 1 ) {\displaystyle S(p-1)} where S ( n + 1 ) = ( S ( n ) ) 2 ...
christopher/rosetta-code
http://rosettacode.org/wiki/Heronian_triangles
Heronian triangles
Hero's formula for the area of a triangle given the length of its three sides   a,   b,   and   c   is given by: A = s ( s − a ) ( s − b ) ( s − c ) , {\displaystyle A={\sqrt {s(s-a)(s-b)(s-c)}},} where   s   is half the perimeter of the triangle; that is, s = a + b + c 2 . {\displaystyle s...
#Lua
Lua
-- Returns the details of the Heronian Triangle with sides a, b, c or nil if it isn't one local function tryHt( a, b, c ) local result local s = ( a + b + c ) / 2; local areaSquared = s * ( s - a ) * ( s - b ) * ( s - c ); if areaSquared > 0 then -- a, b, c does form a triangle local are...
Give a code snippet in #Lua Hero's formula for the area of a triangle given the length of its three sides   a,   b,   and   c   is given by: A = s ( s − a ) ( s − b ) ( s − c ) , {\displaystyle A={\sqrt {s(s-a)(s-b)(s-c)}},} where   s   is half the perimeter of the triangle; that is, s = a + b ...
christopher/rosetta-code
http://rosettacode.org/wiki/Metaprogramming
Metaprogramming
Name and briefly demonstrate any support your language has for metaprogramming. Your demonstration may take the form of cross-references to other tasks on Rosetta Code. When possible, provide links to relevant documentation. For the purposes of this task, "support for metaprogramming" means any way the user can effect...
#Sidef
Sidef
class Number { method ⊕(arg) { self + arg } }   say (21 ⊕ 42)
Give a code snippet in #Sidef Name and briefly demonstrate any support your language has for metaprogramming. Your demonstration may take the form of cross-references to other tasks on Rosetta Code. When possible, provide links to relevant documentation. For the purposes of this task, "support for metaprogramming" me...
christopher/rosetta-code
http://rosettacode.org/wiki/Hello_world/Text
Hello world/Text
Hello world/Text is part of Short Circuit's Console Program Basics selection. Task Display the string Hello world! on a text console. Related tasks   Hello world/Graphical   Hello world/Line Printer   Hello world/Newbie   Hello world/Newline omission   Hello world/Standard error   Hello world/Web server
#Inko
Inko
import std::stdio::stdout   stdout.print('Hello, world!')
Give a code snippet in #Inko Hello world/Text is part of Short Circuit's Console Program Basics selection. Task Display the string Hello world! on a text console. Related tasks   Hello world/Graphical   Hello world/Line Printer   Hello world/Newbie   Hello world/Newline omission   Hello world/Standard error  ...
christopher/rosetta-code
http://rosettacode.org/wiki/Permutation_test
Permutation test
Permutation test You are encouraged to solve this task according to the task description, using any language you may know. A new medical treatment was tested on a population of n + m {\displaystyle n+m} volunteers, with each volunteer randomly assigned either to a group of n {\displaystyle n} treatment...
#GAP
GAP
a := [85, 88, 75, 66, 25, 29, 83, 39, 97]; b := [68, 41, 10, 49, 16, 65, 32, 92, 28, 98];   # Compute a decimal approximation of a rational Approx := function(x, d) local neg, a, b, n, m, s; if x < 0 then x := -x; neg := true; else neg := false; fi; a := NumeratorRat(x); b := DenominatorRat(x); n := QuoInt...
Give a code snippet in #GAP Permutation test You are encouraged to solve this task according to the task description, using any language you may know. A new medical treatment was tested on a population of n + m {\displaystyle n+m} volunteers, with each volunteer randomly assigned either to a group of n ...
christopher/rosetta-code
http://rosettacode.org/wiki/Munching_squares
Munching squares
Render a graphical pattern where each pixel is colored by the value of 'x xor y' from an arbitrary color table.
#PL.2FI
PL/I
munch: procedure options (main); /* 21 May 2014 */   declare screen (0:255, 0:255) bit(24) aligned; declare b bit(8) aligned; declare (x, y) unsigned fixed binary (8);   do x = 0 upthru hbound(screen,2); do y = 0 upthru hbound(screen,1); b = unspec(x) ^ unspec(y); screen(x,y) = b; ...
Give a code snippet in #PL.2FI Render a graphical pattern where each pixel is colored by the value of 'x xor y' from an arbitrary color table.
christopher/rosetta-code
http://rosettacode.org/wiki/Almost_prime
Almost prime
A   k-Almost-prime   is a natural number   n {\displaystyle n}   that is the product of   k {\displaystyle k}   (possibly identical) primes. Example 1-almost-primes,   where   k = 1 {\displaystyle k=1} ,   are the prime numbers themselves. 2-almost-primes,   where   k = 2 {\displaystyl...
#Prolog
Prolog
% almostPrime(K, +Take, List) succeeds if List can be unified with the % first Take K-almost-primes. % Notice that K need not be specified. % To avoid having to cache or recompute the first Take primes, we define % almostPrime/3 in terms of almostPrime/4 as follows: % almostPrime(K, Take, List) :- % Compute the list ...
Give a code snippet in #Prolog A   k-Almost-prime   is a natural number   n {\displaystyle n}   that is the product of   k {\displaystyle k}   (possibly identical) primes. Example 1-almost-primes,   where   k = 1 {\displaystyle k=1} ,   are the prime numbers themselves. 2-almost-primes,   w...
christopher/rosetta-code
http://rosettacode.org/wiki/Sum_of_a_series
Sum of a series
Compute the   nth   term of a series,   i.e. the sum of the   n   first terms of the corresponding sequence. Informally this value, or its limit when   n   tends to infinity, is also called the sum of the series, thus the title of this task. For this task, use: S n = ∑ k = 1 n 1 k 2 {\displa...
#Racket
Racket
  #lang typed/racket   (: S : Natural -> Real) (define (S n) (for/sum: : Real ([k : Natural (in-range 1 (+ n 1))]) (/ 1.0 (* k k))))  
Give a code snippet in #Racket Compute the   nth   term of a series,   i.e. the sum of the   n   first terms of the corresponding sequence. Informally this value, or its limit when   n   tends to infinity, is also called the sum of the series, thus the title of this task. For this task, use: S n = ∑ k = ...
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 |...
#Pike
Pike
int main(int argc, array(int) argv){ if(argc != 3){ write("usage: `pike compare-two-ints.pike <x> <y>` where x and y are integers.\n"); return 0; }   int a = argv[1]; int b = argv[2];   if(a > b) { write(a + " is greater than " + b + "\n"); } else if (a < b) { write(a + " is le...
Give a code snippet in #Pike 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 C...
christopher/rosetta-code
http://rosettacode.org/wiki/Tokenize_a_string_with_escaping
Tokenize a string with escaping
Task[edit] Write a function or program that can split a string at each non-escaped occurrence of a separator character. It should accept three input parameters:   The string   The separator character   The escape character It should output a list of strings. Details Rules for splitting: The fields that were s...
#J
J
  tokenize1=: tokenize =: '^|'&$: :(4 : 0) 'ESC SEP' =. x STATE =. 0 RESULT =. 0 $ a: TOKEN =. '' for_C. y do. if. STATE do. TOKEN =. TOKEN , C STATE =. 0 else. if. C = ESC do. STATE =. 1 elseif. C = SEP do. RESULT =. RESULT , < TOKEN TOKEN =. '' elseif. do. TOKEN =. TOKEN , C ...
Give a code snippet in #J Task[edit] Write a function or program that can split a string at each non-escaped occurrence of a separator character. It should accept three input parameters:   The string   The separator character   The escape character It should output a list of strings. Details Rules for splittin...
christopher/rosetta-code
http://rosettacode.org/wiki/Create_a_two-dimensional_array_at_runtime
Create a two-dimensional array at runtime
Data Structure This illustrates a data structure, a means of storing data within a program. You may see other such structures in the Data Structures category. Get two integers from the user, then create a two-dimensional array where the two dimensions have the sizes given by those numbers, and which can be accessed ...
#Objeck
Objeck
  use IO;   bundle Default { class TwoDee { function : Main(args : System.String[]) ~ Nil { DoIt(); }   function : native : DoIt() ~ Nil { Console->GetInstance()->Print("Enter x: "); x := Console->GetInstance()->ReadString()->ToInt();   Console->GetInstance()->Print("Enter y: "); ...
Give a code snippet in #Objeck Data Structure This illustrates a data structure, a means of storing data within a program. You may see other such structures in the Data Structures category. Get two integers from the user, then create a two-dimensional array where the two dimensions have the sizes given by those num...
christopher/rosetta-code
http://rosettacode.org/wiki/Power_set
Power set
A   set   is a collection (container) of certain values, without any particular order, and no repeated values. It corresponds with a finite set in mathematics. A set can be implemented as an associative array (partial mapping) in which the value of each key-value pair is ignored. Given a set S, the power set (or pow...
#FunL
FunL
def powerset( s ) = s.subsets().toSet()
Give a code snippet in #FunL A   set   is a collection (container) of certain values, without any particular order, and no repeated values. It corresponds with a finite set in mathematics. A set can be implemented as an associative array (partial mapping) in which the value of each key-value pair is ignored. Given ...
christopher/rosetta-code
http://rosettacode.org/wiki/Function_composition
Function composition
Task Create a function, compose,   whose two arguments   f   and   g,   are both functions with one argument. The result of compose is to be a function of one argument, (lets call the argument   x),   which works like applying function   f   to the result of applying function   g   to   x. Example compose...
#Smalltalk
Smalltalk
| composer fg | composer := [ :f :g | [ :x | f value: (g value: x) ] ]. fg := composer value: [ :x | x + 1 ] value: [ :x | x * x ].   (fg value:3) displayNl.
Give a code snippet in #Smalltalk Task Create a function, compose,   whose two arguments   f   and   g,   are both functions with one argument. The result of compose is to be a function of one argument, (lets call the argument   x),   which works like applying function   f   to the result of applying function   ...
christopher/rosetta-code
http://rosettacode.org/wiki/Simple_windowed_application
Simple windowed application
Task Create a window that has:   a label that says   "There have been no clicks yet"   a button that says   "click me" Upon clicking the button with the mouse, the label should change and show the number of times the button has been clicked.
#XPL0
XPL0
include c:\cxpl\stdlib; \standard library provides mouse routines, etc. def Ww=40, Wh=12, Wx=(80-Ww)/2, Wy=(25-Wh)/2; \window width, etc. def Bw=11, Bh=4, Bx=Wx+(Ww-Bw)/2, By=Wy+3*(Wh-Bh)/4; \button size & position int Clicks, Mx, My; \number of clicks and mouse coordinates   [ShowCurso...
Give a code snippet in #XPL0 Task Create a window that has:   a label that says   "There have been no clicks yet"   a button that says   "click me" Upon clicking the button with the mouse, the label should change and show the number of times the button has been clicked.
christopher/rosetta-code
http://rosettacode.org/wiki/Draw_a_sphere
Draw a sphere
Task Draw a sphere. The sphere can be represented graphically, or in ASCII art, depending on the language capabilities. Either static or rotational projection is acceptable for this task. Related tasks draw a cuboid draw a rotating cube write language name in 3D ASCII draw a Deathstar
#C.23
C#
using System;   namespace Sphere { internal class Program { private const string Shades = ".:!*oe%&#@"; private static readonly double[] Light = {30, 30, -50};   private static void Normalize(double[] v) { double len = Math.Sqrt(v[0]*v[0] + v[1]*v[1] + v[2]*v[2]); v[0...
Give a code snippet in #C.23 Task Draw a sphere. The sphere can be represented graphically, or in ASCII art, depending on the language capabilities. Either static or rotational projection is acceptable for this task. Related tasks draw a cuboid draw a rotating cube write language name in 3D ASCII draw a Dea...
christopher/rosetta-code
http://rosettacode.org/wiki/Count_occurrences_of_a_substring
Count occurrences of a substring
Task Create a function,   or show a built-in function,   to count the number of non-overlapping occurrences of a substring inside a string. The function should take two arguments:   the first argument being the string to search,   and   the second a substring to be searched for. It should return an integer cou...
#Elixir
Elixir
countSubstring = fn(_, "") -> 0 (str, sub) -> length(String.split(str, sub)) - 1 end   data = [ {"the three truths", "th"}, {"ababababab", "abab"}, {"abaabba*bbaba*bbab", "a*b"}, {"abaabba*bbaba*bbab", "a"}, {"abaabba*bbaba*bbab", " "}, {"abaabba*bbaba*bba...
Give a code snippet in #Elixir Task Create a function,   or show a built-in function,   to count the number of non-overlapping occurrences of a substring inside a string. The function should take two arguments:   the first argument being the string to search,   and   the second a substring to be searched for. ...
christopher/rosetta-code
http://rosettacode.org/wiki/XML/Input
XML/Input
Given the following XML fragment, extract the list of student names using whatever means desired. If the only viable method is to use XPath, refer the reader to the task XML and XPath. <Students> <Student Name="April" Gender="F" DateOfBirth="1989-01-02" /> <Student Name="Bob" Gender="M" DateOfBirth="1990-03-04" /...
#Forth
Forth
include ffl/est.fs include ffl/str.fs include ffl/xis.fs   \ Build input string str-create xmlstr : x+ xmlstr str-append-string ;   s\" <Students>\n" x+ s\" <Student Name=\"April\" Gender=\"F\" DateOfBirth=\"1989-01-02\" />\n" x+ s\" <Student Name=\"Bob\" Gender=\"M\" DateOfBirth=\"1990-03-04\" />\n" x+ s\" <Stude...
Give a code snippet in #Forth Given the following XML fragment, extract the list of student names using whatever means desired. If the only viable method is to use XPath, refer the reader to the task XML and XPath. <Students> <Student Name="April" Gender="F" DateOfBirth="1989-01-02" /> <Student Name="Bob" Gender=...
christopher/rosetta-code
http://rosettacode.org/wiki/Ray-casting_algorithm
Ray-casting algorithm
This page uses content from Wikipedia. The original article was at Point_in_polygon. 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) Given a point and a polygon, check if the point is inside or out...
#AutoHotkey
AutoHotkey
Points :=[{x: 5.0, y: 5.0} , {x: 5.0, y: 8.0} , {x:-10.0, y: 5.0} , {x: 0.0, y: 5.0} , {x: 10.0, y: 5.0} , {x: 8.0, y: 5.0} , {x: 10.0, y:10.0}] Square :=[{x: 0.0, y: 0.0}, {x:10.0, y: 0.0} , {x:10.0, y: 0.0}, {x:10.0, y:10.0} , {x:10.0, y:10.0}, {x: 0.0, y:10.0} , {x: 0.0, y:10.0}, {x: 0.0, y: 0....
Give a code snippet in #AutoHotkey This page uses content from Wikipedia. The original article was at Point_in_polygon. 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) Given a point and a polygon,...
christopher/rosetta-code
http://rosettacode.org/wiki/Associative_array/Iteration
Associative array/Iteration
Show how to iterate over the key-value pairs of an associative array, and print each pair out. Also show how to iterate just over the keys, or the values, if there is a separate way to do that in your language. See also Array Associative array: Creation, Iteration Collections Compound data type Doubly-linked ...
#MiniScript
MiniScript
d = { 3: "test", "foo": 3 }   for keyVal in d print keyVal // produces results like: { "key": 3, "value": "test" } end for   for key in d.indexes print key end for   for val in d.values print val end for
Give a code snippet in #MiniScript Show how to iterate over the key-value pairs of an associative array, and print each pair out. Also show how to iterate just over the keys, or the values, if there is a separate way to do that in your language. See also Array Associative array: Creation, Iteration Collections...
christopher/rosetta-code
http://rosettacode.org/wiki/Brace_expansion
Brace expansion
Brace expansion is a type of parameter expansion made popular by Unix shells, where it allows users to specify multiple similar string parameters without having to type them all out. E.g. the parameter enable_{audio,video} would be interpreted as if both enable_audio and enable_video had been specified. Task[edit] W...
#C
C
#include <stdbool.h> #include <stdio.h> #include <stdlib.h> #include <string.h>   #define BUFFER_SIZE 128   typedef unsigned char character; typedef character *string;   typedef struct node_t node; struct node_t { enum tag_t { NODE_LEAF, NODE_TREE, NODE_SEQ, } tag;   union { ...
Give a code snippet in #C Brace expansion is a type of parameter expansion made popular by Unix shells, where it allows users to specify multiple similar string parameters without having to type them all out. E.g. the parameter enable_{audio,video} would be interpreted as if both enable_audio and enable_video had been...
christopher/rosetta-code
http://rosettacode.org/wiki/Kronecker_product_based_fractals
Kronecker product based fractals
This task is based on   Kronecker product   of two matrices. If your language has no a built-in function for such product then you need to implement it first. The essence of fractals is self-replication (at least, self-similar replications). So, using   n   times self-product of the matrix   (filled with 0/1)   we ...
#F.C5.8Drmul.C3.A6
Fōrmulæ
package main   import "fmt"   type matrix [][]int   func (m1 matrix) kroneckerProduct(m2 matrix) matrix { m := len(m1) n := len(m1[0]) p := len(m2) q := len(m2[0]) rtn := m * p ctn := n * q r := make(matrix, rtn) for i := range r { r[i] = make([]int, ctn) // all elements zero by ...
Give a code snippet in #F.C5.8Drmul.C3.A6 This task is based on   Kronecker product   of two matrices. If your language has no a built-in function for such product then you need to implement it first. The essence of fractals is self-replication (at least, self-similar replications). So, using   n   times self-prod...
christopher/rosetta-code
http://rosettacode.org/wiki/Roman_numerals/Decode
Roman numerals/Decode
Task Create a function that takes a Roman numeral as its argument and returns its value as a numeric decimal integer. You don't need to validate the form of the Roman numeral. Modern Roman numerals are written by expressing each decimal digit of the number to be encoded separately, starting with the leftmost decima...
#FALSE
FALSE
[ 32| {get value of Roman digit on stack} $'m= $[\% 1000\]? ~[ $'d= $[\% 500\]? ~[ $'c= $[\% 100\]? ~[ $'l= $[\% 50\]? ~[ $'x= $[\% 10\]? ~[ $'v= $[\% 5\]? ~[ $'i= $[\% 1\]? ~[  % 0 ]?]?]?]?]?]?]? ]r:   0 {accumulator} ^r;! {read first Roman digit} [^r;!$][ {read another, and as l...
Give a code snippet in #FALSE Task Create a function that takes a Roman numeral as its argument and returns its value as a numeric decimal integer. You don't need to validate the form of the Roman numeral. Modern Roman numerals are written by expressing each decimal digit of the number to be encoded separately, st...
christopher/rosetta-code
http://rosettacode.org/wiki/Straddling_checkerboard
Straddling checkerboard
Task Implement functions to encrypt and decrypt a message using the straddling checkerboard method. The checkerboard should take a 28 character alphabet (A-Z plus a full stop and an escape character) and two different numbers representing the blanks in the first row. The output will be a series of decimal digits. Num...
#C
C
#include <stdio.h> #include <stdlib.h> #include <string.h> #include <stdbool.h> #include <ctype.h> #include <glib.h>   #define ROWS 4 #define COLS 10 #define NPRX "/"   /* wikipedia table const char *table[ROWS][COLS] = { { "0", "1", "2", "3", "4", "5", "6", "7", "8", "9" }, { "E", "T", NULL, "A", "O", "N", N...
Give a code snippet in #C Task Implement functions to encrypt and decrypt a message using the straddling checkerboard method. The checkerboard should take a 28 character alphabet (A-Z plus a full stop and an escape character) and two different numbers representing the blanks in the first row. The output will be a ser...
christopher/rosetta-code
http://rosettacode.org/wiki/Population_count
Population count
Population count You are encouraged to solve this task according to the task description, using any language you may know. The   population count   is the number of   1s   (ones)   in the binary representation of a non-negative integer. Population count   is also known as:   pop count   popcount   sideways sum ...
#zkl
zkl
n:=1; do(30){ print(n.num1s,","); n*=3 } println();   println("evil: ",[0..].filter(30,fcn(n){ n.num1s.isEven }).concat(","));   // now, as an iterator aka lazy: println("odious: ",(0).walker(*).tweak( // 0,1,2,3,4... iterator fcn(n){ if(n.num1s.isEven) Void.Skip else n }).walk(30).concat(","));
Give a code snippet in #zkl Population count You are encouraged to solve this task according to the task description, using any language you may know. The   population count   is the number of   1s   (ones)   in the binary representation of a non-negative integer. Population count   is also known as:   pop count ...
christopher/rosetta-code
http://rosettacode.org/wiki/Evaluate_binomial_coefficients
Evaluate binomial coefficients
This programming task, is to calculate ANY binomial coefficient. However, it has to be able to output   ( 5 3 ) {\displaystyle {\binom {5}{3}}} ,   which is   10. This formula is recommended: ( n k ) = n ! ( n − k ) ! k ! = n ( n − 1 ) ( n − 2 ) … ( n − k + 1 ) k ( k − 1...
#F.23
F#
  let choose n k = List.fold (fun s i -> s * (n-i+1)/i ) 1 [1..k]  
Give a code snippet in #F.23 This programming task, is to calculate ANY binomial coefficient. However, it has to be able to output   ( 5 3 ) {\displaystyle {\binom {5}{3}}} ,   which is   10. This formula is recommended: ( n k ) = n ! ( n − k ) ! k ! = n ( n − 1 ) ( n − 2...
christopher/rosetta-code
http://rosettacode.org/wiki/Runge-Kutta_method
Runge-Kutta method
Given the example Differential equation: y ′ ( t ) = t × y ( t ) {\displaystyle y'(t)=t\times {\sqrt {y(t)}}} With initial condition: t 0 = 0 {\displaystyle t_{0}=0} and y 0 = y ( t 0 ) = y ( 0 ) = 1 {\displaystyle y_{0}=y(t_{0})=y(0)=1} This equation has an exact solution: ...
#Fortran
Fortran
program rungekutta implicit none integer, parameter :: dp = kind(1d0) real(dp) :: t, dt, tstart, tstop real(dp) :: y, k1, k2, k3, k4   tstart = 0.0d0 tstop = 10.0d0 dt = 0.1d0 y = 1.0d0 t = tstart write (6, '(a,f4.1,a,f12.8,a,es13.6)') 'y(', t, ') = ', y, ' error = ', & a...
Give a code snippet in #Fortran Given the example Differential equation: y ′ ( t ) = t × y ( t ) {\displaystyle y'(t)=t\times {\sqrt {y(t)}}} With initial condition: t 0 = 0 {\displaystyle t_{0}=0} and y 0 = y ( t 0 ) = y ( 0 ) = 1 {\displaystyle y_{0}=y(t_{0})=y(0)=1} This ...
christopher/rosetta-code
http://rosettacode.org/wiki/Particle_fountain
Particle fountain
Implement a particle fountain. Emulate a fountain of water droplets in a gravitational field being sprayed up and then falling back down. The particle fountain should be generally ordered but individually chaotic; the particles should be going mostly in the same direction, but should have slightly different vectors. ...
#Wren
Wren
import "dome" for Window, Platform, Process import "graphics" for Canvas, Color import "math" for Math, Point import "random" for Random import "input" for Keyboard import "./dynamic" for Struct   var Start = Platform.time var Rand = Random.new()   var fields = [ "particleNum", "positions", "velocities",...
Give a code snippet in #Wren Implement a particle fountain. Emulate a fountain of water droplets in a gravitational field being sprayed up and then falling back down. The particle fountain should be generally ordered but individually chaotic; the particles should be going mostly in the same direction, but should hav...
christopher/rosetta-code
http://rosettacode.org/wiki/RSA_code
RSA code
Given an RSA key (n,e,d), construct a program to encrypt and decrypt plaintext messages strings. Background RSA code is used to encode secret messages. It is named after Ron Rivest, Adi Shamir, and Leonard Adleman who published it at MIT in 1977. The advantage of this type of encryption is that you can distribute the...
#zkl
zkl
var BN=Import.lib("zklBigNum");   n:=BN("9516311845790656153499716760847001433441357"); e:=BN("65537"); d:=BN("5617843187844953170308463622230283376298685");   const plaintext="Rossetta Code"; pt:=BN(Data(Int,0,plaintext)); // convert string (as stream of bytes) to big int if(pt>n) throw(Exception.ValueError("Message ...
Give a code snippet in #zkl Given an RSA key (n,e,d), construct a program to encrypt and decrypt plaintext messages strings. Background RSA code is used to encode secret messages. It is named after Ron Rivest, Adi Shamir, and Leonard Adleman who published it at MIT in 1977. The advantage of this type of encryption i...
christopher/rosetta-code
http://rosettacode.org/wiki/Fractran
Fractran
FRACTRAN is a Turing-complete esoteric programming language invented by the mathematician John Horton Conway. A FRACTRAN program is an ordered list of positive fractions P = ( f 1 , f 2 , … , f m ) {\displaystyle P=(f_{1},f_{2},\ldots ,f_{m})} , together with an initial positive integer input n ...
#REXX
REXX
/*REXX program runs FRACTRAN for a given set of fractions and from a specified N. */ numeric digits 2000 /*be able to handle larger numbers. */ parse arg N terms fracs /*obtain optional arguments from the CL*/ if N=='' | N=="," then N= 2 ...
Give a code snippet in #REXX FRACTRAN is a Turing-complete esoteric programming language invented by the mathematician John Horton Conway. A FRACTRAN program is an ordered list of positive fractions P = ( f 1 , f 2 , … , f m ) {\displaystyle P=(f_{1},f_{2},\ldots ,f_{m})} , together with an initial...
christopher/rosetta-code
http://rosettacode.org/wiki/Assertions
Assertions
Assertions are a way of breaking out of code when there is an error or an unexpected input. Some languages throw exceptions and some treat it as a break point. Task Show an assertion in your language by asserting that an integer variable is equal to 42.
#Maple
Maple
a := 5: ASSERT( a = 42 ); ASSERT( a = 42, "a is not the answer to life, the universe, and everything" );
Give a code snippet in #Maple Assertions are a way of breaking out of code when there is an error or an unexpected input. Some languages throw exceptions and some treat it as a break point. Task Show an assertion in your language by asserting that an integer variable is equal to 42.
christopher/rosetta-code
http://rosettacode.org/wiki/Greatest_common_divisor
Greatest common divisor
Greatest common divisor You are encouraged to solve this task according to the task description, using any language you may know. Task Find the greatest common divisor   (GCD)   of two integers. Greatest common divisor   is also known as   greatest common factor (gcf)   and   greatest common measure. Related tas...
#Logo
Logo
to gcd :a :b if :b = 0 [output :a] output gcd :b modulo :a :b end
Give a code snippet in #Logo Greatest common divisor You are encouraged to solve this task according to the task description, using any language you may know. Task Find the greatest common divisor   (GCD)   of two integers. Greatest common divisor   is also known as   greatest common factor (gcf)   and   greatest ...
christopher/rosetta-code
http://rosettacode.org/wiki/Anagrams/Deranged_anagrams
Anagrams/Deranged anagrams
Two or more words are said to be anagrams if they have the same characters, but in a different order. By analogy with derangements we define a deranged anagram as two words with the same characters, but in which the same character does not appear in the same position in both words. Task[edit] Use the word list at uni...
#ARM_Assembly
ARM Assembly
  /* ARM assembly Raspberry PI */ /* program anaderan.s */   /* REMARK 1 : this program use routines in a include file see task Include a file language arm assembly for the routine affichageMess conversion10 see at end of this program the instruction include */ /* for constantes see task include a file...
Give a code snippet in #ARM_Assembly Two or more words are said to be anagrams if they have the same characters, but in a different order. By analogy with derangements we define a deranged anagram as two words with the same characters, but in which the same character does not appear in the same position in both words...
christopher/rosetta-code
http://rosettacode.org/wiki/Unbias_a_random_generator
Unbias a random generator
P 1 {\displaystyle P_{1}} P 0 {\displaystyle P_{0}} P 1 {\displaystyle P_{1}} P 0 {\displaystyle P_{0}} P 0 {\displaystyle P_{0}} P 1 {\displaystyle P_{1}} Task details Use your language's random number generator to create a function/method/sub...
#Perl
Perl
sub randn { my $n = shift; return int(rand($n) / ($n - 1)); }   for my $n (3 .. 6) { print "Bias $n: "; my (@raw, @fixed); for (1 .. 10000) { my $x = randn($n); $raw[$x]++; $fixed[$x]++ if randn($n) != $x } print ...
Give a code snippet in #Perl P 1 {\displaystyle P_{1}} P 0 {\displaystyle P_{0}} P 1 {\displaystyle P_{1}} P 0 {\displaystyle P_{0}} P 0 {\displaystyle P_{0}} P 1 {\displaystyle P_{1}} Task details Use your language's random number generator t...
christopher/rosetta-code
http://rosettacode.org/wiki/Last_Friday_of_each_month
Last Friday of each month
Task Write a program or a script that returns the date of the last Fridays of each month of a given year. The year may be given through any simple input method in your language (command line, std in, etc). Example of an expected output: ./last_fridays 2012 2012-01-27 2012-02-24 2012-03-30 2012-04-27 2012-05-25 20...
#Arturo
Arturo
lastFridayForMonth: function [m][ ensure -> in? m 1..12   daysOfMonth: [0 31 27 31 30 31 30 31 31 30 31 30 31] loop range get daysOfMonth m 1 [d][ dt: to :date.format:"yyyy-M-dd" ~"2012-|m|-|d|" if dt\Day = "Friday" -> return dt ] ]   loop 1..12 'month [ print to :string.format:"yyyy...
Give a code snippet in #Arturo Task Write a program or a script that returns the date of the last Fridays of each month of a given year. The year may be given through any simple input method in your language (command line, std in, etc). Example of an expected output: ./last_fridays 2012 2012-01-27 2012-02-24 201...
christopher/rosetta-code
http://rosettacode.org/wiki/Named_parameters
Named parameters
Create a function which takes in a number of arguments which are specified by name rather than (necessarily) position, and show how to call the function. If the language supports reordering the arguments or optionally omitting some of them, note this. Note: Named parameters relies on being able to use the names give...
#JavaScript
JavaScript
function example(options) { // assign some defaults where the user's has not provided a value opts = {} opts.foo = options.foo || 0; opts.bar = options.bar || 1; opts.grill = options.grill || 'pork chops'   alert("foo is " + opts.foo + ", bar is " + opts.bar + ", and grill is " + opts.grill); }   example({g...
Give a code snippet in #JavaScript Create a function which takes in a number of arguments which are specified by name rather than (necessarily) position, and show how to call the function. If the language supports reordering the arguments or optionally omitting some of them, note this. Note: Named parameters relies...
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...
#Component_Pascal
Component Pascal
  MODULE EmptyString; IMPORT StdLog;   PROCEDURE Do*; VAR s: ARRAY 64 OF CHAR; (* s := "" <=> s[0] := 0X => s isEmpty*) BEGIN s := ""; StdLog.String("Is 's' empty?:> ");StdLog.Bool(s = "");StdLog.Ln; StdLog.String("Is not 's' empty?:> ");StdLog.Bool(s # "");StdLog.Ln; StdLog.Ln; (* Or *) s := 0X; StdLog.Strin...
Give a code snippet in #Component_Pascal 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 em...
christopher/rosetta-code
http://rosettacode.org/wiki/Named_parameters
Named parameters
Create a function which takes in a number of arguments which are specified by name rather than (necessarily) position, and show how to call the function. If the language supports reordering the arguments or optionally omitting some of them, note this. Note: Named parameters relies on being able to use the names give...
#jq
jq
  def formatName(obj): ({ "name": "?"} + obj) as $obj # the default default value is null | ($obj|.name) as $name | ($obj|.first) as $first | if ($first == null) then $name else $name + ", " + $first end;  
Give a code snippet in #jq Create a function which takes in a number of arguments which are specified by name rather than (necessarily) position, and show how to call the function. If the language supports reordering the arguments or optionally omitting some of them, note this. Note: Named parameters relies on bein...
christopher/rosetta-code
http://rosettacode.org/wiki/Reverse_words_in_a_string
Reverse words in a string
Task Reverse the order of all tokens in each of a number of strings and display the result;   the order of characters within a token should not be modified. Example Hey you, Bub!   would be shown reversed as:   Bub! you, Hey Tokens are any non-space characters separated by spaces (formally, white-space);   t...
#F.23
F#
  //Reverse words in a string. Nigel Galloway: July 14th., 2021 [" ---------- Ice and Fire ------------ "; " "; " fire, in end will world the say Some "; " ice. in say Some "; " desire of tasted I've what From "; " fire. favour who tho...
Give a code snippet in #F.23 Task Reverse the order of all tokens in each of a number of strings and display the result;   the order of characters within a token should not be modified. Example Hey you, Bub!   would be shown reversed as:   Bub! you, Hey Tokens are any non-space characters separated by space...
christopher/rosetta-code
http://rosettacode.org/wiki/Averages/Pythagorean_means
Averages/Pythagorean means
Task[edit] Compute all three of the Pythagorean means of the set of integers 1 through 10 (inclusive). Show that A ( x 1 , … , x n ) ≥ G ( x 1 , … , x n ) ≥ H ( x 1 , … , x n ) {\displaystyle A(x_{1},\ldots ,x_{n})\geq G(x_{1},\ldots ,x_{n})\geq H(x_{1},\ldots ,x_{n})} for this set of p...
#K
K
  am:{(+/x)%#x} gm:{(*/x)^(%#x)} hm:{(#x)%+/%:'x}   {(am x;gm x;hm x)} 1+!10 5.5 4.528729 3.414172  
Give a code snippet in #K Task[edit] Compute all three of the Pythagorean means of the set of integers 1 through 10 (inclusive). Show that A ( x 1 , … , x n ) ≥ G ( x 1 , … , x n ) ≥ H ( x 1 , … , x n ) {\displaystyle A(x_{1},\ldots ,x_{n})\geq G(x_{1},\ldots ,x_{n})\geq H(x_{1},\ldots ,...
christopher/rosetta-code
http://rosettacode.org/wiki/LZW_compression
LZW compression
The Lempel-Ziv-Welch (LZW) algorithm provides loss-less data compression. You can read a complete description of it in the   Wikipedia article   on the subject.   It was patented, but it entered the public domain in 2004.
#BBC_BASIC
BBC BASIC
plaintext$ = "TOBEORNOTTOBEORTOBEORNOT" encodeLZW$ = FNencodeLZW(plaintext$) FOR i% = 1 TO LEN(encodeLZW$) STEP 2 PRINT ; ASCMID$(encodeLZW$,i%) + 256*ASCMID$(encodeLZW$,i%+1) " " ; NEXT PRINT ' FNdecodeLZW(encodeLZW$) END   DEF FNencodeLZW(i$) LOCAL c%, d%, i%, l...
Give a code snippet in #BBC_BASIC The Lempel-Ziv-Welch (LZW) algorithm provides loss-less data compression. You can read a complete description of it in the   Wikipedia article   on the subject.   It was patented, but it entered the public domain in 2004.
christopher/rosetta-code
http://rosettacode.org/wiki/99_bottles_of_beer
99 bottles of beer
Task Display the complete lyrics for the song:     99 Bottles of Beer on the Wall. The beer song The lyrics follow this form: 99 bottles of beer on the wall 99 bottles of beer Take one down, pass it around 98 bottles of beer on the wall 98 bottles of beer on the wall 98 bottles of beer Take one dow...
#MIPS_Assembly
MIPS Assembly
  ################################## # 99 bottles of beer on the wall # # MIPS Assembly targeting MARS # # By Keith Stellyes # # August 24, 2016 # ##################################   #It is simple, a loop that goes as follows:   #if accumulator is not 1: #PRINT INTEGER: accumulator #PRINT...
Give a code snippet in #MIPS_Assembly Task Display the complete lyrics for the song:     99 Bottles of Beer on the Wall. The beer song The lyrics follow this form: 99 bottles of beer on the wall 99 bottles of beer Take one down, pass it around 98 bottles of beer on the wall 98 bottles of beer on the w...
christopher/rosetta-code
http://rosettacode.org/wiki/Roman_numerals/Encode
Roman numerals/Encode
Task Create a function taking a positive integer as its parameter and returning a string containing the Roman numeral representation of that integer. Modern Roman numerals are written by expressing each digit separately, starting with the left most digit and skipping any digit with a value of zero. In Roman numeral...
#Euphoria
Euphoria
constant arabic = {1000, 900, 500, 400, 100, 90, 50, 40, 10, 9, 5, 4, 1 } constant roman = {"M", "CM", "D","CD", "C","XC","L","XL","X","IX","V","IV","I"}   function toRoman(integer val) sequence result result = "" for i = 1 to 13 do while val >= arabic[i] do result &= roman[i] ...
Give a code snippet in #Euphoria Task Create a function taking a positive integer as its parameter and returning a string containing the Roman numeral representation of that integer. Modern Roman numerals are written by expressing each digit separately, starting with the left most digit and skipping any digit with a ...
christopher/rosetta-code
http://rosettacode.org/wiki/Filter
Filter
Task Select certain elements from an Array into a new Array in a generic way. To demonstrate, select all even numbers from an Array. As an option, give a second solution which filters destructively, by modifying the original Array rather than creating a new Array.
#Haskell
Haskell
ary = [1..10] evens = [x | x <- ary, even x]
Give a code snippet in #Haskell Task Select certain elements from an Array into a new Array in a generic way. To demonstrate, select all even numbers from an Array. As an option, give a second solution which filters destructively, by modifying the original Array rather than creating a new Array.
christopher/rosetta-code
http://rosettacode.org/wiki/Amb
Amb
Define and give an example of the Amb operator. The Amb operator (short for "ambiguous") expresses nondeterminism. This doesn't refer to randomness (as in "nondeterministic universe") but is closely related to the term as it is used in automata theory ("non-deterministic finite automaton"). The Amb operator takes a v...
#Haskell
Haskell
import Control.Monad   amb = id   joins left right = last left == head right   example = do w1 <- amb ["the", "that", "a"] w2 <- amb ["frog", "elephant", "thing"] w3 <- amb ["walked", "treaded", "grows"] w4 <- amb ["slowly", "quickly"] guard (w1 `joins` w2) guard (w2 `joins` w3) guard (w3 `joins` w4) pu...
Give a code snippet in #Haskell Define and give an example of the Amb operator. The Amb operator (short for "ambiguous") expresses nondeterminism. This doesn't refer to randomness (as in "nondeterministic universe") but is closely related to the term as it is used in automata theory ("non-deterministic finite automat...
christopher/rosetta-code
http://rosettacode.org/wiki/Descending_primes
Descending primes
Generate and show all primes with strictly descending decimal digits. See also OEIS:A052014 - Primes with distinct digits in descending order Related Ascending primes
#Go
Go
package main   import ( "fmt" "rcu" "sort" "strconv" )   func combinations(a []int, k int) [][]int { n := len(a) c := make([]int, k) var combs [][]int var combine func(start, end, index int) combine = func(start, end, index int) { if index == k { t := make([]int, ...
Give a code snippet in #Go Generate and show all primes with strictly descending decimal digits. See also OEIS:A052014 - Primes with distinct digits in descending order Related Ascending primes
christopher/rosetta-code
http://rosettacode.org/wiki/Higher-order_functions
Higher-order functions
Task Pass a function     as an argument     to another function. Related task   First-class functions
#Metafont
Metafont
def calcit(expr v, s) = scantokens(s & decimal v) enddef;   t := calcit(100.4, "sind"); show t; end
Give a code snippet in #Metafont Task Pass a function     as an argument     to another function. Related task   First-class functions
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. ...
#Panoramic
Panoramic
  dim x,y   for x=1 to 5   for y=1 to x   print "*";   next y   print   next x  
Give a code snippet in #Panoramic “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 str...
christopher/rosetta-code
http://rosettacode.org/wiki/Null_object
Null object
Null (or nil) is the computer science concept of an undefined or unbound object. Some languages have an explicit way to access the null object, and some don't. Some languages distinguish the null object from undefined values, and some don't. Task Show how to access null in your language by checking to see if an ob...
#Pike
Pike
> mapping bar; > bar; Result: 0 > bar = ([ "foo":0 ]); > bar->foo; Result 0; > zero_type(bar->foo); Result: 0 > bar->baz; Result: 0 > zero_type(bar->baz); Result: 1
Give a code snippet in #Pike Null (or nil) is the computer science concept of an undefined or unbound object. Some languages have an explicit way to access the null object, and some don't. Some languages distinguish the null object from undefined values, and some don't. Task Show how to access null in your langua...
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...
#Arturo
Arturo
disarium?: function [x][ j: 0 psum: sum map digits x 'dig [ j: j + 1 dig ^ j ] return psum = x ]   cnt: 0 i: 0 while [cnt < 18][ if disarium? i [ print i cnt: cnt + 1 ] i: i + 1 ]
Give a code snippet in #Arturo 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 firs...
christopher/rosetta-code
http://rosettacode.org/wiki/List_rooted_trees
List rooted trees
You came back from grocery shopping.   After putting away all the goods, you are left with a pile of plastic bags, which you want to save for later use, so you take one bag and stuff all the others into it, and throw it under the sink.   In doing so, you realize that there are various ways of nesting the bags, with all...
#Julia
Julia
bags(n,cache="") = n < 1 ? [(0, "")] : [(c + 1, "(" * s * ")") for (c, s) in bagchain((0, ""), n - 1, n < 2 ? [] : reduce(append!, [bags(x) for x in n-1:-1:1]))]   bagchain(x, n, bb, start=1) = n < 1 ? [x] : reduce(append!, [bagchain((x[1] + bb[i][1], x[2] * bb[i][2]), n - bb[i][1], bb, i) fo...
Give a code snippet in #Julia You came back from grocery shopping.   After putting away all the goods, you are left with a pile of plastic bags, which you want to save for later use, so you take one bag and stuff all the others into it, and throw it under the sink.   In doing so, you realize that there are various way...
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...
#Plain_TeX
Plain TeX
\newcount\rosetta \rosetta=1024 \loop \the\rosetta\endgraf \divide\rosetta by 2 \ifnum\rosetta > 0 \repeat \end
Give a code snippet in #Plain_TeX 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/Dow...
christopher/rosetta-code
http://rosettacode.org/wiki/Partition_an_integer_x_into_n_primes
Partition an integer x into n primes
Task Partition a positive integer   X   into   N   distinct primes. Or, to put it in another way: Find   N   unique primes such that they add up to   X. Show in the output section the sum   X   and the   N   primes in ascending order separated by plus (+) signs: •   partition 99809 with 1 prime. ...
#11l
11l
F is_prime(a) R !(a < 2 | any((2 .. Int(a ^ 0.5)).map(x -> @a % x == 0)))   F generate_primes(n) V r = [2] V i = 3 L I is_prime(i) r.append(i) I r.len == n L.break i += 2 R r   V primes = generate_primes(50'000)   F find_combo(k, x, m, n, &combo) I k >= m ...
Give a code snippet in #11l Task Partition a positive integer   X   into   N   distinct primes. Or, to put it in another way: Find   N   unique primes such that they add up to   X. Show in the output section the sum   X   and the   N   primes in ascending order separated by plus (+) signs: •   partition...
christopher/rosetta-code
http://rosettacode.org/wiki/Fibonacci_word/fractal
Fibonacci word/fractal
The Fibonacci word may be represented as a fractal as described here: (Clicking on the above website   (hal.archives-ouvertes.fr)   will leave a cookie.) For F_wordm start with F_wordCharn=1 Draw a segment forward If current F_wordChar is 0 Turn left if n is even Turn right if n is odd next n and iterate until e...
#FreeBASIC
FreeBASIC
' version 23-06-2015 ' compile with: fbc -s console "filename".bas   Dim As String fw1, fw2, fw3 Dim As Integer a, b, d , i, n , x, y, w, h Dim As Any Ptr img_ptr, scr_ptr   ' data for screen/buffer size Data 1, 2, 3, 2, 2, 2, 2, 2, 7, 10, 8, 14 Dim As Integer s(38,2) For i = 3 To 9 Read s(i,1) : Read s(i,2) Next F...
Give a code snippet in #FreeBASIC The Fibonacci word may be represented as a fractal as described here: (Clicking on the above website   (hal.archives-ouvertes.fr)   will leave a cookie.) For F_wordm start with F_wordCharn=1 Draw a segment forward If current F_wordChar is 0 Turn left if n is even Turn right if ...
christopher/rosetta-code