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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)
#ActionScript
ActionScript
public function isLeapYear(year:int):Boolean { if (year % 100 == 0) { return (year % 400 == 0); } return (year % 4 == 0); }
Give a code snippet in #ActionScript 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/Check_Machin-like_formulas
Check Machin-like formulas
Machin-like formulas   are useful for efficiently computing numerical approximations for π {\displaystyle \pi } Task Verify the following Machin-like formulas are correct by calculating the value of tan   (right hand side) for each equation using exact arithmetic and showing they equal 1: π 4 = ar...
#Mathematica_.2F_Wolfram_Language
Mathematica / Wolfram Language
Tan[ArcTan[1/2] + ArcTan[1/3]] == 1 Tan[2 ArcTan[1/3] + ArcTan[1/7]] == 1 Tan[4 ArcTan[1/5] - ArcTan[1/239]] == 1 Tan[5 ArcTan[1/7] + 2 ArcTan[3/79]] == 1 Tan[5 ArcTan[29/278] + 7 ArcTan[3/79]] == 1 Tan[ArcTan[1/2] + ArcTan[1/5] + ArcTan[1/8]] == 1 Tan[4 ArcTan[1/5] - ArcTan[1/70] + ArcTan[1/99]] == 1 Tan[5 ArcTan[1/7]...
Give a code snippet in #Mathematica_.2F_Wolfram_Language Machin-like formulas   are useful for efficiently computing numerical approximations for π {\displaystyle \pi } Task Verify the following Machin-like formulas are correct by calculating the value of tan   (right hand side) for each equation using exa...
christopher/rosetta-code
http://rosettacode.org/wiki/Ordered_words
Ordered words
An   ordered word   is a word in which the letters appear in alphabetic order. Examples include   abbey   and   dirt. Task[edit] Find and display all the ordered words in the dictionary   unixdict.txt   that have the longest word length. (Examples that access the dictionary file locally assume that you have download...
#Nim
Nim
import strutils   const DictFile = "unixdict.txt"   func isSorted(s: string): bool = var last = char.low for c in s: if c < last: return false last = c result = true   var mx = 0 words: seq[string]   for word in DictFile.lines: if word.len >= mx and word.isSorted: if word.len > mx: words.s...
Give a code snippet in #Nim An   ordered word   is a word in which the letters appear in alphabetic order. Examples include   abbey   and   dirt. Task[edit] Find and display all the ordered words in the dictionary   unixdict.txt   that have the longest word length. (Examples that access the dictionary file locally ...
christopher/rosetta-code
http://rosettacode.org/wiki/Balanced_ternary
Balanced ternary
Balanced ternary is a way of representing numbers. Unlike the prevailing binary representation, a balanced ternary integer is in base 3, and each digit can have the values 1, 0, or −1. Examples Decimal 11 = 32 + 31 − 30, thus it can be written as "++−" Decimal 6 = 32 − 31 + 0 × 30, thus it can be written as "+−0" ...
#Python
Python
class BalancedTernary: # Represented as a list of 0, 1 or -1s, with least significant digit first.   str2dig = {'+': 1, '-': -1, '0': 0} # immutable dig2str = {1: '+', -1: '-', 0: '0'} # immutable table = ((0, -1), (1, -1), (-1, 0), (0, 0), (1, 0), (-1, 1), (0, 1)) # immutable   def __init__(self, i...
Give a code snippet in #Python Balanced ternary is a way of representing numbers. Unlike the prevailing binary representation, a balanced ternary integer is in base 3, and each digit can have the values 1, 0, or −1. Examples Decimal 11 = 32 + 31 − 30, thus it can be written as "++−" Decimal 6 = 32 − 31 + 0 × 30, ...
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...
#Ada
Ada
with Ada.Text_IO; use Ada.Text_IO;   procedure Roman_Numeral_Test is function To_Roman (Number : Positive) return String is subtype Digit is Integer range 0..9; function Roman (Figure : Digit; I, V, X : Character) return String is begin case Figure is when 0 => return ""; ...
Give a code snippet in #Ada 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...
christopher/rosetta-code
http://rosettacode.org/wiki/Doubly-linked_list/Element_definition
Doubly-linked list/Element definition
Task Define the data structure for a doubly-linked list element. The element should include a data member to hold its value and pointers to both the next element in the list and the previous element in the list. The pointers should be mutable. See also Array Associative array: Creation, Iteration Collections ...
#Julia
Julia
abstract type AbstractNode{T} end   struct EmptyNode{T} <: AbstractNode{T} end mutable struct Node{T} <: AbstractNode{T} value::T pred::AbstractNode{T} succ::AbstractNode{T} end
Give a code snippet in #Julia Task Define the data structure for a doubly-linked list element. The element should include a data member to hold its value and pointers to both the next element in the list and the previous element in the list. The pointers should be mutable. See also Array Associative array: Cr...
christopher/rosetta-code
http://rosettacode.org/wiki/Constrained_random_points_on_a_circle
Constrained random points on a circle
Task Generate 100 <x,y> coordinate pairs such that x and y are integers sampled from the uniform distribution with the condition that 10 ≤ x 2 + y 2 ≤ 15 {\displaystyle 10\leq {\sqrt {x^{2}+y^{2}}}\leq 15} . Then display/plot them. The outcome should be a "fuzzy" circle. The actual number of point...
#Common_Lisp
Common Lisp
(flet ((good-p (x y) (<= 100 (+ (* x x) (* y y)) 255))) (loop with x with y with cnt = 0 with scr = (loop repeat 31 collect (loop repeat 31 collect " ")) while (< cnt 100) do (when (good-p (- (setf x (random 31)) 15) (- (setf y (random 31)) 15)) (setf (elt (elt scr y) x) "@ ") (incf cnt)) finally...
Give a code snippet in #Common_Lisp Task Generate 100 <x,y> coordinate pairs such that x and y are integers sampled from the uniform distribution with the condition that 10 ≤ x 2 + y 2 ≤ 15 {\displaystyle 10\leq {\sqrt {x^{2}+y^{2}}}\leq 15} . Then display/plot them. The outcome should be a "fuzz...
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...
#Fortran
Fortran
program writefloats implicit none   real, dimension(10) :: a, sqrta integer :: i integer, parameter :: unit = 40   a = (/ (i, i=1,10) /) sqrta = sqrt(a)   open(unit, file="xydata.txt", status="new", action="write") call writexy(unit, a, sqrta) close(unit)   contains   subroutine writexy(u, x, y) ...
Give a code snippet in #Fortran 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...
christopher/rosetta-code
http://rosettacode.org/wiki/Conditional_structures
Conditional structures
Control Structures These are examples of control structures. You may also be interested in: Conditional structures Exceptions Flow-control structures Loops Task List the conditional structures offered by a programming language. See Wikipedia: conditionals for descriptions. Common conditional structures include ...
#Aikido
Aikido
  var x = loggedin ? sessionid : -1    
Give a code snippet in #Aikido Control Structures These are examples of control structures. You may also be interested in: Conditional structures Exceptions Flow-control structures Loops Task List the conditional structures offered by a programming language. See Wikipedia: conditionals for descriptions. Common...
christopher/rosetta-code
http://rosettacode.org/wiki/Plasma_effect
Plasma effect
The plasma effect is a visual effect created by applying various functions, notably sine and cosine, to the color values of screen pixels. When animated (not a task requirement) the effect may give the impression of a colorful flowing liquid. Task Create a plasma effect. See also Computer Graphics Tutorial (lod...
#Java
Java
import java.awt.*; import java.awt.event.*; import java.awt.image.*; import static java.awt.image.BufferedImage.*; import static java.lang.Math.*; import javax.swing.*;   public class PlasmaEffect extends JPanel { float[][] plasma; float hueShift = 0; BufferedImage img;   public PlasmaEffect() { ...
Give a code snippet in #Java The plasma effect is a visual effect created by applying various functions, notably sine and cosine, to the color values of screen pixels. When animated (not a task requirement) the effect may give the impression of a colorful flowing liquid. Task Create a plasma effect. See also C...
christopher/rosetta-code
http://rosettacode.org/wiki/Conway%27s_Game_of_Life
Conway's Game of Life
The Game of Life is a   cellular automaton   devised by the British mathematician   John Horton Conway   in 1970.   It is the best-known example of a cellular automaton. Conway's game of life is described   here: A cell   C   is represented by a   1   when alive,   or   0   when dead,   in an   m-by-m   (or m×m)   sq...
#REXX
REXX
/*REXX program runs and displays the Conway's game of life, it stops after N repeats. */ signal on halt /*handle a cell growth interruptus. */ parse arg peeps '(' rows cols empty life! clearScreen repeats generations . rows = p(rows 3) /*the ...
Give a code snippet in #REXX The Game of Life is a   cellular automaton   devised by the British mathematician   John Horton Conway   in 1970.   It is the best-known example of a cellular automaton. Conway's game of life is described   here: A cell   C   is represented by a   1   when alive,   or   0   when dead,   ...
christopher/rosetta-code
http://rosettacode.org/wiki/Sorting_algorithms/Bubble_sort
Sorting algorithms/Bubble 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 ...
#Phix
Phix
with javascript_semantics function bubble_sort(sequence s) s = deep_copy(s) for j=length(s) to 1 by -1 do integer changed = 0 for i=1 to j-1 do object si = s[i], sn = s[i+1] if si>sn then s[i] = sn s[i+1] = si ...
Give a code snippet in #Phix 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 sor...
christopher/rosetta-code
http://rosettacode.org/wiki/Pascal%27s_triangle
Pascal's triangle
Pascal's triangle is an arithmetic and geometric figure often associated with the name of Blaise Pascal, but also studied centuries earlier in India, Persia, China and elsewhere. Its first few rows look like this: 1 1 1 1 2 1 1 3 3 1 where each element of each row is either 1 or the sum of the two elemen...
#Ada
Ada
package Pascal is   type Row is array (Natural range <>) of Natural;   function Length(R: Row) return Positive;   function First_Row(Max_Length: Positive) return Row;   function Next_Row(R: Row) return Row;   end Pascal;
Give a code snippet in #Ada Pascal's triangle is an arithmetic and geometric figure often associated with the name of Blaise Pascal, but also studied centuries earlier in India, Persia, China and elsewhere. Its first few rows look like this: 1 1 1 1 2 1 1 3 3 1 where each element of each row is either 1...
christopher/rosetta-code
http://rosettacode.org/wiki/Variable_size/Get
Variable size/Get
Demonstrate how to get the size of a variable. See also: Host introspection
#Kotlin
Kotlin
// version 1.1.2   fun main(args: Array<String>) { /* sizes for variables of the primitive types (except Boolean which is JVM dependent) */ println("A Byte variable occupies: ${java.lang.Byte.SIZE / 8} byte") println("A Short variable occupies: ${java.lang.Short.SIZE / 8} bytes") println("An Int v...
Give a code snippet in #Kotlin Demonstrate how to get the size of a variable. See also: Host introspection
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
#Blast
Blast
# This will display a goodbye message on the terminal screen .begin display "Hello world!" return # This is the end of the script.
Give a code snippet in #Blast 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/Create_a_file
Create a file
In this task, the job is to create a new empty file called "output.txt" of size 0 bytes and an empty directory called "docs". This should be done twice: once "here", i.e. in the current working directory and once in the filesystem root.
#MAXScript
MAXScript
-- Here f = createFile "output.txt" close f makeDir (sysInfo.currentDir + "\docs") -- System root f = createFile "\output.txt" close f makeDir ("c:\docs")
Give a code snippet in #MAXScript In this task, the job is to create a new empty file called "output.txt" of size 0 bytes and an empty directory called "docs". This should be done twice: once "here", i.e. in the current working directory and once in the filesystem root.
christopher/rosetta-code
http://rosettacode.org/wiki/Ultra_useful_primes
Ultra useful primes
An ultra-useful prime is a member of the sequence where each a(n) is the smallest positive integer k such that 2(2n) - k is prime. k must always be an odd number since 2 to any power is always even. Task Find and show here, on this page, the first 10 elements of the sequence. Stretch Find and show the next sev...
#Raku
Raku
sub useful ($n) { (|$n).map: { my $p = 1 +< ( 1 +< $_ ); ^$p .first: ($p - *).is-prime } }   put useful 1..10;   put useful 11..13;
Give a code snippet in #Raku An ultra-useful prime is a member of the sequence where each a(n) is the smallest positive integer k such that 2(2n) - k is prime. k must always be an odd number since 2 to any power is always even. Task Find and show here, on this page, the first 10 elements of the sequence. Stretc...
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...
#Kotlin
Kotlin
// version 1.1.0   fun isNarcissistic(n: Int): Boolean { if (n < 0) throw IllegalArgumentException("Argument must be non-negative") var nn = n val digits = mutableListOf<Int>() val powers = IntArray(10) { 1 } while (nn > 0) { digits.add(nn % 10) for (i in 1..9) powers[i] *= i // no ne...
Give a code snippet in #Kotlin 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/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...
#Brat
Brat
  p ["apple", "orange"].length  
Give a code snippet in #Brat 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 freque...
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...
#Elixir
Elixir
defmodule Bottles do def run do Enum.each 99..1, fn idx -> IO.puts "#{idx} bottle#{plural(idx)} of beer on the wall" IO.puts "#{idx} bottle#{plural(idx)} of beer" IO.puts "Take one down, pass it around" IO.puts "#{idx - 1} bottle#{plural(idx-1)} of beer on the wall" IO.puts "" en...
Give a code snippet in #Elixir 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 9...
christopher/rosetta-code
http://rosettacode.org/wiki/Binary_search
Binary search
A binary search divides a range of values into halves, and continues to narrow down the field of search until the unknown value is found. It is the classic example of a "divide and conquer" algorithm. As an analogy, consider the children's game "guess a number." The scorer has a secret number, and will only tell the p...
#Octave
Octave
function i = binsearch_r(array, val, low, high) if ( high < low ) i = 0; else mid = floor((low + high) / 2); if ( array(mid) > val ) i = binsearch_r(array, val, low, mid-1); elseif ( array(mid) < val ) i = binsearch_r(array, val, mid+1, high); else i = mid; endif endif e...
Give a code snippet in #Octave A binary search divides a range of values into halves, and continues to narrow down the field of search until the unknown value is found. It is the classic example of a "divide and conquer" algorithm. As an analogy, consider the children's game "guess a number." The scorer has a secret ...
christopher/rosetta-code
http://rosettacode.org/wiki/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 ...
#F.C5.8Drmul.C3.A6
Fōrmulæ
for y = 2008 to 2121 if (parseDate["$y-12-25"] -> ### u ###) == "7" println[y]
Give a code snippet in #F.C5.8Drmul.C3.A6 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 ye...
christopher/rosetta-code
http://rosettacode.org/wiki/Menu
Menu
Task Given a prompt and a list containing a number of strings of which one is to be selected, create a function that: prints a textual menu formatted as an index value followed by its corresponding string for each item in the list; prompts the user to enter a number; returns the string corresponding to the selecte...
#Batch_File
Batch File
@echo off & setlocal enabledelayedexpansion   set "menuChoices="fee fie","huff and puff","mirror mirror","tick tock""   call :menu   pause>nul & exit     :menu if defined menuChoices ( set "counter=0" & for %%a in (%menuChoices%) do ( set /a "counter+=1" set "currentMenuChoice=%%a" set option[!counter!]=!cu...
Give a code snippet in #Batch_File Task Given a prompt and a list containing a number of strings of which one is to be selected, create a function that: prints a textual menu formatted as an index value followed by its corresponding string for each item in the list; prompts the user to enter a number; returns the...
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...
#Lambdatalk
Lambdatalk
  {A.length {A.new 1 2 3}} -> 3  
Give a code snippet in #Lambdatalk 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 ...
christopher/rosetta-code
http://rosettacode.org/wiki/Check_that_file_exists
Check that file exists
Task Verify that a file called     input.txt     and   a directory called     docs     exist. This should be done twice:     once for the current working directory,   and   once for a file and a directory in the filesystem root. Optional criteria (May 2015):   verify it works with:   zero-length files   an ...
#AppleScript
AppleScript
use framework "Foundation" -- YOSEMITE OS X onwards use scripting additions   on run setCurrentDirectory("~/Desktop")   ap({doesFileExist, doesDirectoryExist}, ¬ {"input.txt", "/input.txt", "docs", "/docs"})   --> {true, true, true, true, false, false, true, true}   -- The first four booleans ar...
Give a code snippet in #AppleScript Task Verify that a file called     input.txt     and   a directory called     docs     exist. This should be done twice:     once for the current working directory,   and   once for a file and a directory in the filesystem root. Optional criteria (May 2015):   verify it wor...
christopher/rosetta-code
http://rosettacode.org/wiki/GUI_component_interaction
GUI component interaction
Almost every application needs to communicate with the user in some way. Therefore, a substantial part of the code deals with the interaction of program logic with GUI components. Typically, the following is needed: put values into input fields under program control read and check input from the user pop up dial...
#Fantom
Fantom
  using fwt using gfx   class GuiComponent { public static Void main () { Window { title = "Rosetta Code: Gui component" size = Size(350, 200) textField := Text { onModify.add |Event e| { Text thisText := e.widget if (thisText.text != "") // if no...
Give a code snippet in #Fantom Almost every application needs to communicate with the user in some way. Therefore, a substantial part of the code deals with the interaction of program logic with GUI components. Typically, the following is needed: put values into input fields under program control read and check ...
christopher/rosetta-code
http://rosettacode.org/wiki/Longest_common_subsequence
Longest common subsequence
Introduction Define a subsequence to be any output string obtained by deleting zero or more symbols from an input string. The Longest Common Subsequence (LCS) is a subsequence of maximum length common to two or more strings. Let A ≡ A[0]… A[m - 1] and B ≡ B[0]… B[n - 1], m < n be strings drawn from an alphabet Σ of ...
#Arturo
Arturo
lcs: function [a,b][ ls: new array.of: @[inc size a, inc size b] 0   loop.with:'i a 'x [ loop.with:'j b 'y [ ls\[i+1]\[j+1]: (x=y)? -> ls\[i]\[j] + 1 -> max @[ls\[i+1]\[j], ls\[i]\[j+1]] ] ] [result, x, y]: @[new "", size a, size b]   wh...
Give a code snippet in #Arturo Introduction Define a subsequence to be any output string obtained by deleting zero or more symbols from an input string. The Longest Common Subsequence (LCS) is a subsequence of maximum length common to two or more strings. Let A ≡ A[0]… A[m - 1] and B ≡ B[0]… B[n - 1], m < n be stri...
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...
#EGL
EGL
program TestProgram type BasicProgram {}   function main() for (count int from 99 to 1 decrement by 1) SysLib.writeStdout( bottleStr( count ) :: " of beer on the wall." ); SysLib.writeStdout( bottleStr( count ) :: " of beer." ); SysLib.writeStdout( "Take one down, pass it...
Give a code snippet in #EGL 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 b...
christopher/rosetta-code
http://rosettacode.org/wiki/Forward_difference
Forward difference
Task Provide code that produces a list of numbers which is the   nth  order forward difference, given a non-negative integer (specifying the order) and a list of numbers. The first-order forward difference of a list of numbers   A   is a new list   B,   where   Bn = An+1 - An. List   B   should have one fewer elem...
#Ursala
Ursala
#import std #import nat #import flo   nth_diff "n" = rep"n" minus*typ
Give a code snippet in #Ursala Task Provide code that produces a list of numbers which is the   nth  order forward difference, given a non-negative integer (specifying the order) and a list of numbers. The first-order forward difference of a list of numbers   A   is a new list   B,   where   Bn = An+1 - An. List ...
christopher/rosetta-code
http://rosettacode.org/wiki/Thue-Morse
Thue-Morse
Task Create a Thue-Morse sequence. See also   YouTube entry: The Fairest Sharing Sequence Ever   YouTube entry: Math and OCD - My story with the Thue-Morse sequence   Task: Fairshare between two and more
#J
J
(, -.)@]^:[&0]9 0 1 1 0 1 0 0 1 1 0 0 1 0 1 1 0 1 0 0 1 0 1 1 0 0 1 1 0 1 0 0 1 1 0 0 1 0 1 1 0 0 1 1 0 1 0 0 1 0 1 1 0 1 0 0 1 1 0 0 1 0 1 1 0 1 0 0 1 0 1 1 0 0 1 1 0 1 0 0 1 0 1 1 0 1 0 0 1 1 0 0 1 0 1 1 0 0 1 1 0 1 0 0 1 1 0 0 1 0 1 1 0 1 0 0 1 0 1 1 0 0 1 1 0 1 0 0 1 ...
Give a code snippet in #J Task Create a Thue-Morse sequence. See also   YouTube entry: The Fairest Sharing Sequence Ever   YouTube entry: Math and OCD - My story with the Thue-Morse sequence   Task: Fairshare between two and more
christopher/rosetta-code
http://rosettacode.org/wiki/Greatest_element_of_a_list
Greatest element of a list
Task Create a function that returns the maximum value in a provided set of values, where the number of values may not be known until run-time.
#Python
Python
max(values)
Give a code snippet in #Python Task Create a function that returns the maximum value in a provided set of values, where the number of values may not be known until run-time.
christopher/rosetta-code
http://rosettacode.org/wiki/Averages/Arithmetic_mean
Averages/Arithmetic mean
Task[edit] Write a program to find the mean (arithmetic average) of a numeric vector. In case of a zero-length input, since the mean of an empty set of numbers is ill-defined, the program may choose to behave in any way it deems appropriate, though if the programming language has an established convention for conveyin...
#ALGOL_68
ALGOL 68
PROC mean = (REF[]REAL p)REAL: # Calculates the mean of qty REALs beginning at p. # IF LWB p > UPB p THEN 0.0 ELSE REAL total := 0.0; FOR i FROM LWB p TO UPB p DO total +:= p[i] OD; total / (UPB p - LWB p + 1) FI;   main:( [6]REAL test := (1.0, 2.0, 5.0, -5.0, 9.5, 3.14159); print((mean(test),new...
Give a code snippet in #ALGOL_68 Task[edit] Write a program to find the mean (arithmetic average) of a numeric vector. In case of a zero-length input, since the mean of an empty set of numbers is ill-defined, the program may choose to behave in any way it deems appropriate, though if the programming language has an e...
christopher/rosetta-code
http://rosettacode.org/wiki/Quine
Quine
A quine is a self-referential program that can, without any external access, output its own source. A   quine   (named after Willard Van Orman Quine)   is also known as:   self-reproducing automata   (1972)   self-replicating program         or   self-replicating computer program   self-reproducing program      ...
#Go
Go
package main   import "fmt"   func main() { a := "package main\n\nimport \"fmt\"\n\nfunc main() {\n\ta := %q\n\tfmt.Printf(a, a)\n}\n" fmt.Printf(a, a) }
Give a code snippet in #Go A quine is a self-referential program that can, without any external access, output its own source. A   quine   (named after Willard Van Orman Quine)   is also known as:   self-reproducing automata   (1972)   self-replicating program         or   self-replicating computer program   se...
christopher/rosetta-code
http://rosettacode.org/wiki/Associative_array/Creation
Associative array/Creation
Task The goal is to create an associative array (also known as a dictionary, map, or hash). Related tasks: Associative arrays/Iteration Hash from two arrays See also Array Associative array: Creation, Iteration Collections Compound data type Doubly-linked list: Definition, Element definition, Element ins...
#Racket
Racket
  #lang racket   ;; a-lists (define a-list '((a . 5) (b . 10))) (assoc a-list 'a) ; => '(a . 5)   ;; hash tables (define table #hash((a . 5) (b . 10))) (hash-ref table 'a) ; => 5   ;; dictionary interface (dict-ref a-list 'a) ; => 5 (dict-ref table 'a)  ; => 5  
Give a code snippet in #Racket Task The goal is to create an associative array (also known as a dictionary, map, or hash). Related tasks: Associative arrays/Iteration Hash from two arrays See also Array Associative array: Creation, Iteration Collections Compound data type Doubly-linked list: Definition,...
christopher/rosetta-code
http://rosettacode.org/wiki/15_puzzle_game
15 puzzle game
Task Implement the Fifteen Puzzle Game. The   15-puzzle   is also known as:   Fifteen Puzzle   Gem Puzzle   Boss Puzzle   Game of Fifteen   Mystic Square   14-15 Puzzle   and some others. Related Tasks   15 Puzzle Solver   16 Puzzle Game
#Ada
Ada
generic Rows, Cols: Positive; with function Name(N: Natural) return String; -- with Pre => (N < Rows*Cols); -- Name(0) shall return the name for the empty tile package Generic_Puzzle is   subtype Row_Type is Positive range 1 .. Rows; subtype Col_Type is Positive range 1 .. Cols; type Moves is (Up, Dow...
Give a code snippet in #Ada Task Implement the Fifteen Puzzle Game. The   15-puzzle   is also known as:   Fifteen Puzzle   Gem Puzzle   Boss Puzzle   Game of Fifteen   Mystic Square   14-15 Puzzle   and some others. Related Tasks   15 Puzzle Solver   16 Puzzle Game
christopher/rosetta-code
http://rosettacode.org/wiki/Yin_and_yang
Yin and yang
One well-known symbol of the philosophy of duality known as yin and yang is the taijitu. Task   Create a function that, given a parameter representing size, generates such a symbol scaled to the requested size.   Generate and display the symbol for two different (small) sizes.
#Icon_and_Unicon
Icon and Unicon
link graphics   procedure main() YinYang(100) YinYang(40,"blue","yellow","white") WDone() # quit on Q/q end   procedure YinYang(R,lhs,rhs,bg) # draw YinYang with radius of R pixels and ... /lhs := "white" # left hand side /rhs := "black" # right hand side /bg := "grey" ...
Give a code snippet in #Icon_and_Unicon One well-known symbol of the philosophy of duality known as yin and yang is the taijitu. Task   Create a function that, given a parameter representing size, generates such a symbol scaled to the requested size.   Generate and display the symbol for two different (small) si...
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 ...
#R
R
# 0 and -0 are recognized but are both printed as simply 0. 1/c(0, -0, Inf, -Inf, NaN) # Inf -Inf 0 0 NaN
Give a code snippet in #R 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 c...
christopher/rosetta-code
http://rosettacode.org/wiki/QR_decomposition
QR decomposition
Any rectangular m × n {\displaystyle m\times n} matrix A {\displaystyle {\mathit {A}}} can be decomposed to a product of an orthogonal matrix Q {\displaystyle {\mathit {Q}}} and an upper (right) triangular matrix R {\displaystyle {\mathit {R}}} , as described in QR decompositi...
#PowerShell
PowerShell
  function qr([double[][]]$A) { $m,$n = $A.count, $A[0].count $pm,$pn = ($m-1), ($n-1) [double[][]]$Q = 0..($m-1) | foreach{$row = @(0) * $m; $row[$_] = 1; ,$row} [double[][]]$R = $A | foreach{$row = $_; ,@(0..$pn | foreach{$row[$_]})} foreach ($h in 0..$pn) { [double[]]$u = $R[$h..$pm] | ...
Give a code snippet in #PowerShell Any rectangular m × n {\displaystyle m\times n} matrix A {\displaystyle {\mathit {A}}} can be decomposed to a product of an orthogonal matrix Q {\displaystyle {\mathit {Q}}} and an upper (right) triangular matrix R {\displaystyle {\mathit {R}...
christopher/rosetta-code
http://rosettacode.org/wiki/Egyptian_division
Egyptian division
Egyptian division is a method of dividing integers using addition and doubling that is similar to the algorithm of Ethiopian multiplication Algorithm: Given two numbers where the dividend is to be divided by the divisor: Start the construction of a table of two columns: powers_of_2, and doublings; by a first row of...
#Modula-2
Modula-2
MODULE EgyptianDivision; FROM FormatString IMPORT FormatString; FROM Terminal IMPORT WriteString,ReadChar;   PROCEDURE EgyptianDivision(dividend,divisor : LONGCARD; VAR remainder : LONGCARD) : LONGCARD; CONST SZ = 64; VAR powers,doublings : ARRAY[0..SZ] OF LONGCARD; answer,accumulator : LONGCARD; i : IN...
Give a code snippet in #Modula-2 Egyptian division is a method of dividing integers using addition and doubling that is similar to the algorithm of Ethiopian multiplication Algorithm: Given two numbers where the dividend is to be divided by the divisor: Start the construction of a table of two columns: powers_of_2...
christopher/rosetta-code
http://rosettacode.org/wiki/Mertens_function
Mertens function
The Mertens function M(x) is the count of square-free integers up to x that have an even number of prime factors, minus the count of those that have an odd number. It is an extension of the Möbius function. Given the Möbius function μ(n), the Mertens function M(x) is the sum of the Möbius numbers from n == 1 through n...
#Prolog
Prolog
:- dynamic mertens_number_cache/2.   mertens_number(1, 1):- !. mertens_number(N, M):- mertens_number_cache(N, M), !. mertens_number(N, M):- N >= 2, mertens_number(N, 2, M, 0), assertz(mertens_number_cache(N, M)).   mertens_number(N, N, M, M):- !. mertens_number(N, K, M, S):- N1 is N // K, me...
Give a code snippet in #Prolog The Mertens function M(x) is the count of square-free integers up to x that have an even number of prime factors, minus the count of those that have an odd number. It is an extension of the Möbius function. Given the Möbius function μ(n), the Mertens function M(x) is the sum of the Möbi...
christopher/rosetta-code
http://rosettacode.org/wiki/Literals/Floating_point
Literals/Floating point
Programming languages have different ways of expressing floating-point literals. Task Show how floating-point literals can be expressed in your language: decimal or other bases, exponential notation, and any other special features. You may want to include a regular expression or BNF/ABNF/EBNF defining allowable fo...
#C.2B.2B
C++
#include <iostream>   int main() { // a numeric literal with decimal point is a double auto double1 = 2.5;   // an 'f' of 'F' suffix means the literal is a flaot auto float1 = 2.5f;   // an 'l' or 'L' suffix means a long double auto longdouble1 = 2.5l;   // a number after an 'e' or 'E' is the base 10 exp...
Give a code snippet in #C.2B.2B Programming languages have different ways of expressing floating-point literals. Task Show how floating-point literals can be expressed in your language: decimal or other bases, exponential notation, and any other special features. You may want to include a regular expression or BN...
christopher/rosetta-code
http://rosettacode.org/wiki/Tokenize_a_string
Tokenize a string
Separate the string "Hello,How,Are,You,Today" by commas into an array (or list) so that each element of it stores a different word. Display the words to the 'user', in the simplest manner possible, separated by a period. To simplify, you may display a trailing period. Other tasks related to string operations: Me...
#Arturo
Arturo
str: "Hello,How,Are,You,Today"   print join.with:"." split.by:"," str
Give a code snippet in #Arturo Separate the string "Hello,How,Are,You,Today" by commas into an array (or list) so that each element of it stores a different word. Display the words to the 'user', in the simplest manner possible, separated by a period. To simplify, you may display a trailing period. Other tasks r...
christopher/rosetta-code
http://rosettacode.org/wiki/Bernoulli_numbers
Bernoulli numbers
Bernoulli numbers are used in some series expansions of several functions   (trigonometric, hyperbolic, gamma, etc.),   and are extremely important in number theory and analysis. Note that there are two definitions of Bernoulli numbers;   this task will be using the modern usage   (as per   The National Institute of S...
#Nim
Nim
import bignum import strformat   const Lim = 60   #---------------------------------------------------------------------------------------------------   proc bernoulli(n: Natural): Rat = ## Compute a Bernoulli number using Akiyama–Tanigawa algorithm.   var a = newSeq[Rat](n + 1) for m in 0..n: a[m] = newRat(1...
Give a code snippet in #Nim Bernoulli numbers are used in some series expansions of several functions   (trigonometric, hyperbolic, gamma, etc.),   and are extremely important in number theory and analysis. Note that there are two definitions of Bernoulli numbers;   this task will be using the modern usage   (as per ...
christopher/rosetta-code
http://rosettacode.org/wiki/Determine_if_a_string_has_all_the_same_characters
Determine if a string has all the same characters
Task Given a character string   (which may be empty, or have a length of zero characters):   create a function/procedure/routine to:   determine if all the characters in the string are the same   indicate if or which character is different from the previous character   display each string and its length   (as the...
#Julia
Julia
firstdifferent(s) = isempty(s) ? nothing : findfirst(x -> x != s[1], s)   function testfunction(strings) println("String | Length | All Same | First Different(Hex) | Position\n" * "-----------------------------------------------------------------------------") for s in strings ...
Give a code snippet in #Julia Task Given a character string   (which may be empty, or have a length of zero characters):   create a function/procedure/routine to:   determine if all the characters in the string are the same   indicate if or which character is different from the previous character   display each ...
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...
#Java
Java
import java.util.ArrayList; import java.util.List;   public class ListRootedTrees { private static final List<Long> TREE_LIST = new ArrayList<>();   private static final List<Integer> OFFSET = new ArrayList<>();   static { for (int i = 0; i < 32; i++) { if (i == 1) { OFFS...
Give a code snippet in #Java 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...
christopher/rosetta-code
http://rosettacode.org/wiki/Chaos_game
Chaos game
The Chaos Game is a method of generating the attractor of an iterated function system (IFS). One of the best-known and simplest examples creates a fractal, using a polygon and an initial point selected at random. Task Play the Chaos Game using the corners of an equilateral triangle as the reference points.   Add a ...
#zkl
zkl
w,h:=640,640; bitmap:=PPM(w,h,0xFF|FF|FF); // White background colors:=T(0xFF|00|00,0x00|FF|00,0x00|00|FF); // red,green,blue   margin,size:=60, w - 2*margin; points:=T(T(w/2, margin), T(margin,size), T(margin + size,size) ); N,done:=Atomic.Int(0),Atomic.Bool(False);   Thread.HeartBeat('wrap(hb){ // a thread var...
Give a code snippet in #zkl The Chaos Game is a method of generating the attractor of an iterated function system (IFS). One of the best-known and simplest examples creates a fractal, using a polygon and an initial point selected at random. Task Play the Chaos Game using the corners of an equilateral triangle as t...
christopher/rosetta-code
http://rosettacode.org/wiki/Terminal_control/Coloured_text
Terminal control/Coloured text
Task Display a word in various colours on the terminal. The system palette, or colours such as Red, Green, Blue, Magenta, Cyan, and Yellow can be used. Optionally demonstrate: How the system should determine if the terminal supports colour Setting of the background colour How to cause blinking or flashing (if ...
#Kotlin
Kotlin
// version 1.1.2   const val ESC = "\u001B" const val NORMAL = ESC + "[0" const val BOLD = ESC + "[1" const val BLINK = ESC + "[5" // not working on my machine const val BLACK = ESC + "[0;40m" // black background const val WHITE = ESC + "[0;37m" // normal white foreground   fun main(args: Array<String>) { ...
Give a code snippet in #Kotlin Task Display a word in various colours on the terminal. The system palette, or colours such as Red, Green, Blue, Magenta, Cyan, and Yellow can be used. Optionally demonstrate: How the system should determine if the terminal supports colour Setting of the background colour How to...
christopher/rosetta-code
http://rosettacode.org/wiki/Rename_a_file
Rename a file
Task Rename:   a file called     input.txt     into     output.txt     and   a directory called     docs     into     mydocs. This should be done twice:   once "here", i.e. in the current working directory and once in the filesystem root. It can be assumed that the user has the rights to do so. (In unix-type s...
#FreeBASIC
FreeBASIC
' FB 1.05.0 Win64   Dim result As Long result = Name("input.txt", "output.txt") If result <> 0 Then Print "Renaming file failed" End If   result = Name("docs", "mydocs") If result <> 0 Then Print "Renaming directory failed" End If   Sleep
Give a code snippet in #FreeBASIC Task Rename:   a file called     input.txt     into     output.txt     and   a directory called     docs     into     mydocs. This should be done twice:   once "here", i.e. in the current working directory and once in the filesystem root. It can be assumed that the user has th...
christopher/rosetta-code
http://rosettacode.org/wiki/First_power_of_2_that_has_leading_decimal_digits_of_12
First power of 2 that has leading decimal digits of 12
(This task is taken from a   Project Euler   problem.) (All numbers herein are expressed in base ten.) 27   =   128   and   7   is the first power of   2   whose leading decimal digits are   12. The next power of   2   whose leading decimal digits are   12   is   80, 280   =   1208925819614629174706176. Define ...
#Ruby
Ruby
def p(l, n) test = 0 logv = Math.log(2.0) / Math.log(10.0) factor = 1 loopv = l while loopv > 10 do factor = factor * 10 loopv = loopv / 10 end while n > 0 do test = test + 1 val = (factor * (10.0 ** ((test * logv).modulo(1.0)))).floor if val == l then...
Give a code snippet in #Ruby (This task is taken from a   Project Euler   problem.) (All numbers herein are expressed in base ten.) 27   =   128   and   7   is the first power of   2   whose leading decimal digits are   12. The next power of   2   whose leading decimal digits are   12   is   80, 280   =   1208925...
christopher/rosetta-code
http://rosettacode.org/wiki/Knapsack_problem/0-1
Knapsack problem/0-1
A tourist wants to make a good trip at the weekend with his friends. They will go to the mountains to see the wonders of nature, so he needs to pack well for the trip. He has a good knapsack for carrying things, but knows that he can carry a maximum of only 4kg in it,   and it will have to last the whole day. He cre...
#C.23
C#
using System; using System.Collections.Generic;   namespace Tests_With_Framework_4 {   class Bag : IEnumerable<Bag.Item> { List<Item> items; const int MaxWeightAllowed = 400;   public Bag() { items = new List<Item>(); }   vo...
Give a code snippet in #C.23 A tourist wants to make a good trip at the weekend with his friends. They will go to the mountains to see the wonders of nature, so he needs to pack well for the trip. He has a good knapsack for carrying things, but knows that he can carry a maximum of only 4kg in it,   and it will have ...
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...
#PL.2FI
PL/I
  Fridays: procedure (year) options (main); /* 8 January 2013 */ declare year character (4) varying; declare start fixed binary (31); declare months fixed decimal (2) initial (0); declare (current_month, month_one_week_hence) character (2);   put list ('Last Fridays in each month for the year ' || year |...
Give a code snippet in #PL.2FI 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/Palindrome_detection
Palindrome detection
A palindrome is a phrase which reads the same backward and forward. Task[edit] Write a function or program that checks whether a given sequence of characters (or, if you prefer, bytes) is a palindrome. For extra credit: Support Unicode characters. Write a second function (possibly as a wrapper to the first) which ...
#PL.2FM
PL/M
100H:   /* CHECK EXACT PALINDROME ASSUMING $-TERMINATED STRING */ PALINDROME: PROCEDURE(PTR) BYTE; DECLARE (PTR, FRONT, BACK) ADDRESS, STR BASED PTR BYTE;   /* FIND END */ FRONT, BACK = 0; DO WHILE STR(BACK) <> '$'; BACK = BACK + 1; END; BACK = BACK - 1;   /* CHECK MATCH */ DO WH...
Give a code snippet in #PL.2FM A palindrome is a phrase which reads the same backward and forward. Task[edit] Write a function or program that checks whether a given sequence of characters (or, if you prefer, bytes) is a palindrome. For extra credit: Support Unicode characters. Write a second function (possibly a...
christopher/rosetta-code
http://rosettacode.org/wiki/Last_letter-first_letter
Last letter-first letter
A certain children's game involves starting with a word in a particular category.   Each participant in turn says a word, but that word must begin with the final letter of the previous word.   Once a word has been given, it cannot be repeated.   If an opponent cannot give a word in the category, they fall out of the ga...
#jq
jq
# convert a list of unique words to a dictionary def dictionary: reduce .[] as $word ({}; .[$word[0:1]] += [$word]) ;   # remove "word" from the input dictionary assuming the key is already there: def remove(word): .[word[0:1]] -= [word];
Give a code snippet in #jq A certain children's game involves starting with a word in a particular category.   Each participant in turn says a word, but that word must begin with the final letter of the previous word.   Once a word has been given, it cannot be repeated.   If an opponent cannot give a word in the categ...
christopher/rosetta-code
http://rosettacode.org/wiki/Algebraic_data_types
Algebraic data types
Some languages offer direct support for algebraic data types and pattern matching on them. While this of course can always be simulated with manual tagging and conditionals, it allows for terse code which is easy to read, and can represent the algorithm directly. Task As an example, implement insertion in a red-bla...
#C.2B.2B
C++
enum Color { R, B }; template<Color, class, auto, class> struct T; struct E;   template<Color col, class a, auto x, class b> struct balance { using type = T<col, a, x, b>; }; template<class a, auto x, class b, auto y, class c, auto z, class d> struct balance<B, T<R, T<R, a, x, b>, y, c>, z, d> { using type = T<...
Give a code snippet in #C.2B.2B Some languages offer direct support for algebraic data types and pattern matching on them. While this of course can always be simulated with manual tagging and conditionals, it allows for terse code which is easy to read, and can represent the algorithm directly. Task As an example,...
christopher/rosetta-code
http://rosettacode.org/wiki/Guess_the_number/With_feedback
Guess the number/With feedback
Task Write a game (computer program) that follows the following rules: The computer chooses a number between given set limits. The player is asked for repeated guesses until the the target number is guessed correctly At each guess, the computer responds with whether the guess is: higher than the target, equal to...
#Mathematica_.2F_Wolfram_Language
Mathematica / Wolfram Language
guessnumber[min_, max_] := Module[{number = RandomInteger[{min, max}], guess}, While[guess =!= number, guess = Input[ If[guess > number, "Too high.Guess again.", "Too low.Guess again.", "Guess a number between " <> ToString@min <> " and " <> ToString@max <> "."]]]; CreateDialog[{"...
Give a code snippet in #Mathematica_.2F_Wolfram_Language Task Write a game (computer program) that follows the following rules: The computer chooses a number between given set limits. The player is asked for repeated guesses until the the target number is guessed correctly At each guess, the computer responds wit...
christopher/rosetta-code
http://rosettacode.org/wiki/Table_creation/Postal_addresses
Table creation/Postal addresses
Task Create a table to store addresses. You may assume that all the addresses to be stored will be located in the USA.   As such, you will need (in addition to a field holding a unique identifier) a field holding the street address, a field holding the city, a field holding the state code, and a field holding the zip...
#PowerShell.2BSQLite
PowerShell+SQLite
  Import-Module -Name PSSQLite     ## Create a database and a table $dataSource = ".\Addresses.db" $query = "CREATE TABLE SSADDRESS (Id INTEGER PRIMARY KEY AUTOINCREMENT, LastName TEXT NOT NULL, FirstName TEXT NOT NULL, ...
Give a code snippet in #PowerShell.2BSQLite Task Create a table to store addresses. You may assume that all the addresses to be stored will be located in the USA.   As such, you will need (in addition to a field holding a unique identifier) a field holding the street address, a field holding the city, a field holdin...
christopher/rosetta-code
http://rosettacode.org/wiki/Towers_of_Hanoi
Towers of Hanoi
Task Solve the   Towers of Hanoi   problem with recursion.
#Nim
Nim
proc hanoi(disks: int; fromTower, toTower, viaTower: string) = if disks != 0: hanoi(disks - 1, fromTower, viaTower, toTower) echo("Move disk ", disks, " from ", fromTower, " to ", toTower) hanoi(disks - 1, viaTower, toTower, fromTower)   hanoi(4, "1", "2", "3")
Give a code snippet in #Nim Task Solve the   Towers of Hanoi   problem with recursion.
christopher/rosetta-code
http://rosettacode.org/wiki/Ordered_words
Ordered words
An   ordered word   is a word in which the letters appear in alphabetic order. Examples include   abbey   and   dirt. Task[edit] Find and display all the ordered words in the dictionary   unixdict.txt   that have the longest word length. (Examples that access the dictionary file locally assume that you have download...
#COBOL
COBOL
IDENTIFICATION DIVISION. PROGRAM-ID. ABC-WORDS.   ENVIRONMENT DIVISION. INPUT-OUTPUT SECTION. FILE-CONTROL. SELECT DICT ASSIGN TO DISK ORGANIZATION LINE SEQUENTIAL.   DATA DIVISION. FILE SECTION. FD DICT LABEL RECORD STANDARD ...
Give a code snippet in #COBOL An   ordered word   is a word in which the letters appear in alphabetic order. Examples include   abbey   and   dirt. Task[edit] Find and display all the ordered words in the dictionary   unixdict.txt   that have the longest word length. (Examples that access the dictionary file locall...
christopher/rosetta-code
http://rosettacode.org/wiki/CSV_to_HTML_translation
CSV to HTML translation
Consider a simplified CSV format where all rows are separated by a newline and all columns are separated by commas. No commas are allowed as field data, but the data may contain other characters and character sequences that would normally be   escaped   when converted to HTML Task Create a function that takes a st...
#Mathematica_.2F_Wolfram_Language
Mathematica / Wolfram Language
a="Character,Speech The multitude,The messiah! Show us the messiah! Brians mother,<angry>Now you listen here! He's not the messiah;he's a very naughty boy! Now go away!</angry> The multitude,Who are you? Brians mother,I'm his mother;that's who! The multitude,Behold his mother! Behold his mother!"; (*Naive*) StringJoin[...
Give a code snippet in #Mathematica_.2F_Wolfram_Language Consider a simplified CSV format where all rows are separated by a newline and all columns are separated by commas. No commas are allowed as field data, but the data may contain other characters and character sequences that would normally be   escaped   when co...
christopher/rosetta-code
http://rosettacode.org/wiki/Stem-and-leaf_plot
Stem-and-leaf plot
Create a well-formatted stem-and-leaf plot from the following data set, where the leaves are the last digits: 12 127 28 42 39 113 42 18 44 118 44 37 113 124 37 48 127 36 29 31 125 139 131 115 105 132 104 123 35 113 122 42 117 119 58 109 23 105 63 27 44 105 99 41 128 121 116 125 32 61 37 127 29 113 121 58 114 126 53 11...
#Kotlin
Kotlin
// version 1.1.2   fun leafPlot(x: IntArray) { x.sort() var i = x[0] / 10 - 1 for (j in 0 until x.size) { val d = x[j] / 10 while (d > i) print("%s%3d |".format(if (j != 0) "\n" else "", ++i)) print(" ${x[j] % 10}") } println() }   fun main(args: Array<String>) { val data...
Give a code snippet in #Kotlin Create a well-formatted stem-and-leaf plot from the following data set, where the leaves are the last digits: 12 127 28 42 39 113 42 18 44 118 44 37 113 124 37 48 127 36 29 31 125 139 131 115 105 132 104 123 35 113 122 42 117 119 58 109 23 105 63 27 44 105 99 41 128 121 116 125 32 61 37...
christopher/rosetta-code
http://rosettacode.org/wiki/Empty_directory
Empty directory
Starting with a path to some directory, determine whether the directory is empty. An empty directory contains no files nor subdirectories. With Unix or Windows systems, every directory contains an entry for “.” and almost every directory contains “..” (except for a root directory); an empty directory contains no other...
#VBA
VBA
Sub Main() Debug.Print IsEmptyDirectory("C:\Temp") Debug.Print IsEmptyDirectory("C:\Temp\") End Sub   Private Function IsEmptyDirectory(D As String) As Boolean Dim Sep As String Sep = Application.PathSeparator D = IIf(Right(D, 1) <> Sep, D & Sep, D) IsEmptyDirectory = (Dir(D & "*.*") = "") End Funct...
Give a code snippet in #VBA Starting with a path to some directory, determine whether the directory is empty. An empty directory contains no files nor subdirectories. With Unix or Windows systems, every directory contains an entry for “.” and almost every directory contains “..” (except for a root directory); an empt...
christopher/rosetta-code
http://rosettacode.org/wiki/Long_literals,_with_continuations
Long literals, with continuations
This task is about writing a computer program that has long literals   (character literals that may require specifying the words/tokens on more than one (source) line,   either with continuations or some other method, such as abutments or concatenations   (or some other mechanisms). The literal is to be in the form ...
#68000_Assembly
68000 Assembly
HelloString: DC.B "Hello World" ;no null terminator GoodbyeString: DC.B "Goodbye World!",0 EVEN   PrintString HelloString ;unimplemented macro.
Give a code snippet in #68000_Assembly This task is about writing a computer program that has long literals   (character literals that may require specifying the words/tokens on more than one (source) line,   either with continuations or some other method, such as abutments or concatenations   (or some other mechanism...
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...
#Forth
Forth
: init ( bits count -- ) 0 do dup 1 and c, 2/ loop drop ;   20 constant size create state $2556e size init 0 c,   : .state cr size 0 do state i + c@ if ." #" else space then loop ;   : ctable create does> + c@ ; ctable rules $68 8 init   : gen state c@ ( window ) size 0 do 2* state i + 1+ c@ or 7 an...
Give a code snippet in #Forth 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/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. ...
#AppleScript
AppleScript
tell application "Finder" to return name of every item in (startup disk) --> EXAMPLE RESULT: {"Applications", "Developer", "Library", "System", "Users"}
Give a code snippet in #AppleScript 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 direc...
christopher/rosetta-code
http://rosettacode.org/wiki/Sum_and_product_of_an_array
Sum and product of an array
Task Compute the sum and product of an array of integers.
#SAS
SAS
data _null_; array a{*} a1-a100; do i=1 to 100; a{i}=i*i; end; b=sum(of a{*}); put b c; run;
Give a code snippet in #SAS Task Compute the sum and product of an array of integers.
christopher/rosetta-code
http://rosettacode.org/wiki/Haversine_formula
Haversine formula
This page uses content from Wikipedia. The original article was at Haversine formula. 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) The haversine formula is an equation important in navigation, g...
#ALGOL_W
ALGOL W
begin % compute the distance between places using the Haversine formula % real procedure arcsin( real value x ) ; arctan( x / sqrt( 1 - ( x * x ) ) ); real procedure distance ( real value th1Deg, ph1Deg, th2Deg, ph2Deg ) ; begin real ph1, th1, th2, toRad, dz, dx, dy; toRad := pi / 180; ...
Give a code snippet in #ALGOL_W This page uses content from Wikipedia. The original article was at Haversine formula. 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) The haversine formula is an eq...
christopher/rosetta-code
http://rosettacode.org/wiki/Text_processing/1
Text processing/1
This task has been flagged for clarification. Code on this page in its current state may be flagged incorrect once this task has been clarified. See this page's Talk page for discussion. Often data is produced by one program, in the wrong format for later use by another program or person. In these situations another pr...
#Wren
Wren
import "io" for File import "/pattern" for Pattern import "/fmt" for Fmt   var p = Pattern.new("+1/s") var fileName = "readings.txt" var lines = File.read(fileName).trimEnd().split("\r\n") var f = "Line: $s Reject: $2d Accept: $2d Line_tot: $8.3f Line_avg: $7.3f" var grandTotal = 0 var readings = 0 var date = "" v...
Give a code snippet in #Wren This task has been flagged for clarification. Code on this page in its current state may be flagged incorrect once this task has been clarified. See this page's Talk page for discussion. Often data is produced by one program, in the wrong format for later use by another program or person. ...
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 ...
#jq
jq
  ["a","b","c"] | index("b") # => 1   ["a","b","c","b"] | index("b") # => 1   ["a","b","c","b"] | index("x") // error("element not found") # => jq: error: element not found   # Extra task - the last element of an array can be retrieved # using `rindex/` or by using -1 as an index into the array produced by `indices/1...
Give a code snippet in #jq 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 ...
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" /...
#Lasso
Lasso
// makes extracting attribute values easier define xml_attrmap(in::xml_namedNodeMap_attr) => { local(out = map) with attr in #in do #out->insert(#attr->name = #attr->value) return #out }   local( text = '<Students> <Student Name="April" Gender="F" DateOfBirth="1989-01-02" /> <Student Name="Bob" Gender="M" Da...
Give a code snippet in #Lasso 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/Dragon_curve
Dragon curve
Create and display a dragon curve fractal. (You may either display the curve directly or write it to an image file.) Algorithms Here are some brief notes the algorithms used and how they might suit various languages. Recursively a right curling dragon is a right dragon followed by a left dragon, at 90-degree an...
#C
C
#include <stdio.h> #include <stdlib.h> #include <string.h> #include <math.h>   /* x, y: coordinates of current point; dx, dy: direction of movement. * Think turtle graphics. They are divided by scale, so as to keep * very small coords/increments without losing precission. clen is * the path length travelled, which ...
Give a code snippet in #C Create and display a dragon curve fractal. (You may either display the curve directly or write it to an image file.) Algorithms Here are some brief notes the algorithms used and how they might suit various languages. Recursively a right curling dragon is a right dragon followed by a l...
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)
#VBScript
VBScript
  Function IsLeapYear(yr) IsLeapYear = False If yr Mod 4 = 0 And (yr Mod 400 = 0 Or yr Mod 100 <> 0) Then IsLeapYear = True End If End Function   'Testing the function. arr_yr = Array(1900,1972,1997,2000,2001,2004)   For Each yr In arr_yr If IsLeapYear(yr) Then WScript.StdOut.WriteLine yr & " is leap year." El...
Give a code snippet in #VBScript 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/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...
#Haskell
Haskell
  module Main where   import System.Random import Data.List (intercalate, find, minimumBy) import System.Environment (getArgs) import Data.Char (digitToInt) import Data.Maybe (listToMaybe, mapMaybe) import Control.Monad (guard) import Data.Ord (comparing)   -- check if there is a horizontal, vertical or diagonal line o...
Give a code snippet in #Haskell 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   MathWorl...
christopher/rosetta-code
http://rosettacode.org/wiki/Resistor_mesh
Resistor mesh
Task Given   10×10   grid nodes   (as shown in the image)   interconnected by   1Ω   resistors as shown, find the resistance between points   A   and   B. See also   (humor, nerd sniping)   xkcd.com cartoon
#Modula-2
Modula-2
MODULE ResistorMesh; FROM RConversions IMPORT RealToStringFixed; FROM Terminal IMPORT WriteString,WriteLn,ReadChar;   CONST S = 10;   TYPE Node = RECORD v : LONGREAL; fixed : INTEGER; END;   PROCEDURE SetBoundary(VAR m : ARRAY OF ARRAY OF Node); BEGIN m[1][1].v := 1.0; m[1][1].fixed := 1;   m[6][7]....
Give a code snippet in #Modula-2 Task Given   10×10   grid nodes   (as shown in the image)   interconnected by   1Ω   resistors as shown, find the resistance between points   A   and   B. See also   (humor, nerd sniping)   xkcd.com cartoon
christopher/rosetta-code
http://rosettacode.org/wiki/Pseudo-random_numbers/Splitmix64
Pseudo-random numbers/Splitmix64
Splitmix64 is the default pseudo-random number generator algorithm in Java and is included / available in many other languages. It uses a fairly simple algorithm that, though it is considered to be poor for cryptographic purposes, is very fast to calculate, and is "good enough" for many random number needs. It passes s...
#Mathematica.2FWolfram_Language
Mathematica/Wolfram Language
ClearAll[BitShiftLevelUint, MultiplyUint, GenerateRandomNumbers] BitShiftLevelUint[z_, n_] := BitShiftRight[z, n] MultiplyUint[z_, n_] := Mod[z n, 2^64] GenerateRandomNumbers[st_, n_] := Module[{state = st}, Table[ state += 16^^9e3779b97f4a7c15; state = Mod[state, 2^64]; z = state; z = MultiplyUint[BitXor...
Give a code snippet in #Mathematica.2FWolfram_Language Splitmix64 is the default pseudo-random number generator algorithm in Java and is included / available in many other languages. It uses a fairly simple algorithm that, though it is considered to be poor for cryptographic purposes, is very fast to calculate, and is...
christopher/rosetta-code
http://rosettacode.org/wiki/Animate_a_pendulum
Animate a pendulum
One good way of making an animation is by simulating a physical system and illustrating the variables in that system using a dynamically changing graphical display. The classic such physical system is a simple gravity pendulum. Task Create a simple physical model of a pendulum and animate it.
#Raku
Raku
use SDL2::Raw; use Cairo;   my $width = 1000; my $height = 400;   SDL_Init(VIDEO);   my $window = SDL_CreateWindow( 'Pendulum - Raku', SDL_WINDOWPOS_CENTERED_MASK, SDL_WINDOWPOS_CENTERED_MASK, $width, $height, RESIZABLE );   my $render = SDL_CreateRenderer($window, -1, ACCELERATED +| PRESENTVSYNC);   my...
Give a code snippet in #Raku One good way of making an animation is by simulating a physical system and illustrating the variables in that system using a dynamically changing graphical display. The classic such physical system is a simple gravity pendulum. Task Create a simple physical model of a pendulum and an...
christopher/rosetta-code
http://rosettacode.org/wiki/Count_in_factors
Count in factors
Task Write a program which counts up from   1,   displaying each number as the multiplication of its prime factors. For the purpose of this task,   1   (unity)   may be shown as itself. Example       2   is prime,   so it would be shown as itself.       6   is not prime;   it would be shown as   2 × 3 {\di...
#BBC_BASIC
BBC BASIC
FOR i% = 1 TO 20 PRINT i% " = " FNfactors(i%) NEXT END   DEF FNfactors(N%) LOCAL P%, f$ IF N% = 1 THEN = "1" P% = 2 WHILE P% <= N% IF (N% MOD P%) = 0 THEN f$ += STR$(P%) + " x " N% DIV= P% ELSE P% += 1 ENDIF ...
Give a code snippet in #BBC_BASIC Task Write a program which counts up from   1,   displaying each number as the multiplication of its prime factors. For the purpose of this task,   1   (unity)   may be shown as itself. Example       2   is prime,   so it would be shown as itself.       6   is not prime;   it w...
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...
#J
J
Farey=: x:@/:~@(0 , ~.)@(#~ <:&1)@:,@(%/~@(1 + i.)) NB. calculates Farey sequence displayFarey=: ('r/' charsub '0r' , ,&'r1')@": NB. format character representation of Farey sequence according to task requirements order=: ': ' ,~ ": NB. decorate order of Farey sequen...
Give a code snippet in #J 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   Far...
christopher/rosetta-code
http://rosettacode.org/wiki/Loops/Downward_for
Loops/Downward for
Task Write a   for   loop which writes a countdown from   10   to   0. Related tasks   Loop over multiple arrays simultaneously   Loops/Break   Loops/Continue   Loops/Do-while   Loops/Downward for   Loops/For   Loops/For with a specified step   Loops/Foreach   Loops/Increment loop index within loop body...
#EGL
EGL
for ( i int from 10 to 0 decrement by 1 ) SysLib.writeStdout( i ); end
Give a code snippet in #EGL Task Write a   for   loop which writes a countdown from   10   to   0. Related tasks   Loop over multiple arrays simultaneously   Loops/Break   Loops/Continue   Loops/Do-while   Loops/Downward for   Loops/For   Loops/For with a specified step   Loops/Foreach   Loops/Incremen...
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)
#UNIX_Shell
UNIX Shell
leap() { if expr $1 % 4 >/dev/null; then return 1; fi if expr $1 % 100 >/dev/null; then return 0; fi if expr $1 % 400 >/dev/null; then return 1; fi return 0; }
Give a code snippet in #UNIX_Shell 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/Loops/Wrong_ranges
Loops/Wrong ranges
Loops/Wrong ranges You are encouraged to solve this task according to the task description, using any language you may know. Some languages have syntax or function(s) to generate a range of numeric values from a start value, a stop value, and an increment. The purpose of this task is to select the range syntax/functi...
#Phix
Phix
procedure test(integer start, stop, step, string legend, bool bFor) sequence res = {} if bFor then try for i=start to stop by step do res &= i if length(res)>9 then exit end if end for res = sprint(res) catch e res =...
Give a code snippet in #Phix Loops/Wrong ranges You are encouraged to solve this task according to the task description, using any language you may know. Some languages have syntax or function(s) to generate a range of numeric values from a start value, a stop value, and an increment. The purpose of this task is to ...
christopher/rosetta-code
http://rosettacode.org/wiki/9_billion_names_of_God_the_integer
9 billion names of God the integer
This task is a variation of the short story by Arthur C. Clarke. (Solvers should be aware of the consequences of completing this task.) In detail, to specify what is meant by a   “name”: The integer 1 has 1 name     “1”. The integer 2 has 2 names   “1+1”,   and   “2”. The integer 3 has 3 names   “1+1+1”,   “2+1”,   ...
#ARM_Assembly
ARM Assembly
  /* ARM assembly Raspberry PI */ /* program integerName.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 f...
Give a code snippet in #ARM_Assembly This task is a variation of the short story by Arthur C. Clarke. (Solvers should be aware of the consequences of completing this task.) In detail, to specify what is meant by a   “name”: The integer 1 has 1 name     “1”. The integer 2 has 2 names   “1+1”,   and   “2”. The intege...
christopher/rosetta-code
http://rosettacode.org/wiki/Last_letter-first_letter
Last letter-first letter
A certain children's game involves starting with a word in a particular category.   Each participant in turn says a word, but that word must begin with the final letter of the previous word.   Once a word has been given, it cannot be repeated.   If an opponent cannot give a word in the category, they fall out of the ga...
#Yabasic
Yabasic
all$ = "audino bagon baltoy banette bidoof braviary bronzor carracosta charmeleon " all$ = all$ + "cresselia croagunk darmanitan deino emboar emolga exeggcute gabite " all$ = all$ + "girafarig gulpin haxorus heatmor heatran ivysaur jellicent jumpluff kangaskhan " all$ = all$ + "kricketune landorus ledyba loudred lumine...
Give a code snippet in #Yabasic A certain children's game involves starting with a word in a particular category.   Each participant in turn says a word, but that word must begin with the final letter of the previous word.   Once a word has been given, it cannot be repeated.   If an opponent cannot give a word in the ...
christopher/rosetta-code
http://rosettacode.org/wiki/9_billion_names_of_God_the_integer
9 billion names of God the integer
This task is a variation of the short story by Arthur C. Clarke. (Solvers should be aware of the consequences of completing this task.) In detail, to specify what is meant by a   “name”: The integer 1 has 1 name     “1”. The integer 2 has 2 names   “1+1”,   and   “2”. The integer 3 has 3 names   “1+1+1”,   “2+1”,   ...
#Ada
Ada
with Ada.Text_IO; with Ada.Numerics.Big_Numbers.Big_Integers;   procedure Names_Of_God is   NN  : constant := 100_000; Row_Count  : constant := 25; Max_Column : constant := 79;   package Triangle is procedure Print; end Triangle;   package Row_Summer is procedure Calc (N : Integer);...
Give a code snippet in #Ada This task is a variation of the short story by Arthur C. Clarke. (Solvers should be aware of the consequences of completing this task.) In detail, to specify what is meant by a   “name”: The integer 1 has 1 name     “1”. The integer 2 has 2 names   “1+1”,   and   “2”. The integer 3 has 3...
christopher/rosetta-code
http://rosettacode.org/wiki/Image_convolution
Image convolution
One class of image digital filters is described by a rectangular matrix of real coefficients called kernel convoluted in a sliding window of image pixels. Usually the kernel is square K k l {\displaystyle K_{kl}} , where k, l are in the range -R,-R+1,..,R-1,R. W=2R+1 is the kernel width. The filter determine...
#Common_Lisp
Common Lisp
(load "rgb-pixel-buffer") (load "ppm-file-io")   (defpackage #:convolve (:use #:common-lisp #:rgb-pixel-buffer #:ppm-file-io))   (in-package #:convolve) (defconstant +row-offsets+ '(-1 -1 -1 0 0 0 1 1 1)) (defconstant +col-offsets+ '(-1 0 1 -1 0 1 -1 0 1)) (defstruct cnv-record descr width kernel divisor offset) (def...
Give a code snippet in #Common_Lisp One class of image digital filters is described by a rectangular matrix of real coefficients called kernel convoluted in a sliding window of image pixels. Usually the kernel is square K k l {\displaystyle K_{kl}} , where k, l are in the range -R,-R+1,..,R-1,R. W=2R+1 is t...
christopher/rosetta-code
http://rosettacode.org/wiki/Sierpinski_triangle
Sierpinski triangle
Task Produce an ASCII representation of a Sierpinski triangle of order   N. Example The Sierpinski triangle of order   4   should look like this: * * * * * * * * * * * * * * * ...
#PicoLisp
PicoLisp
(de sierpinski (N) (let (D '("*") S " ") (do N (setq D (conc (mapcar '((X) (pack S X S)) D) (mapcar '((X) (pack X " " X)) D) ) S (pack S S) ) ) D ) )   (mapc prinl (sierpinski 4))
Give a code snippet in #PicoLisp Task Produce an ASCII representation of a Sierpinski triangle of order   N. Example The Sierpinski triangle of order   4   should look like this: * * * * * * * * * * * ...
christopher/rosetta-code
http://rosettacode.org/wiki/Exceptions
Exceptions
Control Structures These are examples of control structures. You may also be interested in: Conditional structures Exceptions Flow-control structures Loops This task is to give an example of an exception handling routine and to "throw" a new exception. Related task   Exceptions Through Nested Calls
#Quackery
Quackery
<flag on stack indicating if condition detected> if [ $ "It all went pear shaped in 'a'." message put bail ]
Give a code snippet in #Quackery Control Structures These are examples of control structures. You may also be interested in: Conditional structures Exceptions Flow-control structures Loops This task is to give an example of an exception handling routine and to "throw" a new exception. Related task   Excepti...
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. ...
#Lingo
Lingo
-- Usage: printFiles("C:\scripts", ".ls") on printFiles (dir, fileType) i = 1 sub = fileType.length -1 repeat while TRUE fn = getNthFileNameInFolder(dir, i) if fn = EMPTY then exit repeat i = i+1 if fn.length<fileType.length then next repeat if fn.char[fn.length-sub..fn.length]=fileType then ...
Give a code snippet in #Lingo 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, ...
christopher/rosetta-code
http://rosettacode.org/wiki/Even_or_odd
Even or odd
Task Test whether an integer is even or odd. There is more than one way to solve this task: Use the even and odd predicates, if the language provides them. Check the least significant digit. With binary integers, i bitwise-and 1 equals 0 iff i is even, or equals 1 iff i is odd. Divide i by 2. The remainder equals...
#Icon_and_Unicon
Icon and Unicon
procedure isEven(n) return n%2 = 0 end
Give a code snippet in #Icon_and_Unicon Task Test whether an integer is even or odd. There is more than one way to solve this task: Use the even and odd predicates, if the language provides them. Check the least significant digit. With binary integers, i bitwise-and 1 equals 0 iff i is even, or equals 1 iff i is ...
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 , . . . , ...
#C.2B.2B
C++
#include <array> #include <iostream>   void require(bool condition, const std::string &message) { if (condition) { return; } throw std::runtime_error(message); }   template<typename T, size_t N> std::ostream &operator<<(std::ostream &os, const std::array<T, N> &a) { auto it = a.cbegin(); aut...
Give a code snippet in #C.2B.2B Task Given a set of data vectors in the following format: y = { y 1 , y 2 , . . ...
christopher/rosetta-code
http://rosettacode.org/wiki/Strip_comments_from_a_string
Strip comments from a string
Strip comments from a string You are encouraged to solve this task according to the task description, using any language you may know. The task is to remove text that follow any of a set of comment markers, (in these examples either a hash or a semicolon) from a string or input line. Whitespace debacle:   There is s...
#Inform_7
Inform 7
Home is a room.   When play begins: strip comments from "apples, pears # and bananas"; strip comments from "apples, pears ; and bananas"; end the story.   To strip comments from (T - indexed text): say "[T] -> "; replace the regular expression "<#;>.*$" in T with ""; say "[T][line break]".
Give a code snippet in #Inform_7 Strip comments from a string You are encouraged to solve this task according to the task description, using any language you may know. The task is to remove text that follow any of a set of comment markers, (in these examples either a hash or a semicolon) from a string or input line. ...
christopher/rosetta-code
http://rosettacode.org/wiki/Yin_and_yang
Yin and yang
One well-known symbol of the philosophy of duality known as yin and yang is the taijitu. Task   Create a function that, given a parameter representing size, generates such a symbol scaled to the requested size.   Generate and display the symbol for two different (small) sizes.
#Logo
Logo
to taijitu :r  ; Draw a classic Taoist taijitu of the given radius centered on the current  ; turtle position. The "eyes" are placed along the turtle's heading, the  ; filled one in front, the open one behind.    ; don't bother doing anything if the pen is not down if not pendown? [stop]    ; useful derivative ...
Give a code snippet in #Logo One well-known symbol of the philosophy of duality known as yin and yang is the taijitu. Task   Create a function that, given a parameter representing size, generates such a symbol scaled to the requested size.   Generate and display the symbol for two different (small) sizes.
christopher/rosetta-code
http://rosettacode.org/wiki/Plot_coordinate_pairs
Plot coordinate pairs
Task Plot a function represented as    x,  y    numerical arrays. Post the resulting image for the following input arrays (taken from Python's Example section on Time a function): x = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9}; y = {2.7, 2.8, 31.4, 38.1, 58.0, 76.2, 100.5, 130.0, 149....
#C
C
#include <stdio.h> #include <stdlib.h> #include <math.h> #include <plot.h>   #define NP 10 double x[NP] = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9}; double y[NP] = {2.7, 2.8, 31.4, 38.1, 58.0, 76.2, 100.5, 130.0, 149.3, 180.0};   void minmax(double *x, double *y, double *minx, double *maxx, double *miny, double *maxy, ...
Give a code snippet in #C Task Plot a function represented as    x,  y    numerical arrays. Post the resulting image for the following input arrays (taken from Python's Example section on Time a function): x = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9}; y = {2.7, 2.8, 31.4, 38.1, 58....
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...
#Sparkling
Sparkling
let lines = split("---------- Ice and Fire ------------   fire, in end will world the say Some ice. in say Some desire of tasted I've what From fire. favor who those with hold I   ... elided paragraph last ...   Frost Robert -----------------------", "\n");   foreach(lines, function(idx, line) { let words = split(line...
Give a code snippet in #Sparkling 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 ...
christopher/rosetta-code
http://rosettacode.org/wiki/Conway%27s_Game_of_Life
Conway's Game of Life
The Game of Life is a   cellular automaton   devised by the British mathematician   John Horton Conway   in 1970.   It is the best-known example of a cellular automaton. Conway's game of life is described   here: A cell   C   is represented by a   1   when alive,   or   0   when dead,   in an   m-by-m   (or m×m)   sq...
#Perl
Perl
life.pl numrows numcols numiterations life.pl 5 10 15
Give a code snippet in #Perl The Game of Life is a   cellular automaton   devised by the British mathematician   John Horton Conway   in 1970.   It is the best-known example of a cellular automaton. Conway's game of life is described   here: A cell   C   is represented by a   1   when alive,   or   0   when dead,   ...
christopher/rosetta-code
http://rosettacode.org/wiki/Elementary_cellular_automaton/Infinite_length
Elementary cellular automaton/Infinite length
The purpose of this task is to create a version of an Elementary cellular automaton whose number of cells is only limited by the memory size of the computer. To be precise, consider the state of the automaton to be made of an infinite number of cells, but with a bounded support. In other words, to describe the state o...
#11l
11l
F step(cells, rule) V result = ‘’ L(i) 0 .< cells.len - 2 V bin = 0 V b = 2 L(n) i .< i + 3 bin += Int(cells[n] == ‘*’) << b b >>= 1 V a = I (rule [&] (1 << bin)) != 0 {‘*’} E ‘.’ result ‘’= a R result   F addNoCells(&cells) V left = I cells[0] == ‘*’ {‘.’}...
Give a code snippet in #11l The purpose of this task is to create a version of an Elementary cellular automaton whose number of cells is only limited by the memory size of the computer. To be precise, consider the state of the automaton to be made of an infinite number of cells, but with a bounded support. In other w...
christopher/rosetta-code
http://rosettacode.org/wiki/JSON
JSON
Load a JSON string into a data structure. Also, create a new data structure and serialize it into JSON. Use objects and arrays (as appropriate for your language) and make sure your JSON is valid (https://jsonformatter.org).
#M2000_Interpreter
M2000 Interpreter
  MODULE A { \\ Process data in json format   \\ We can load from external file with Inline "libName" \\ or multiple files Inline "file1" && "file2" \\ but here we have the library in a module Inline Code Lib1 \\ So now we make a Parser object (a group type in M2000) Parser=Par...
Give a code snippet in #M2000_Interpreter Load a JSON string into a data structure. Also, create a new data structure and serialize it into JSON. Use objects and arrays (as appropriate for your language) and make sure your JSON is valid (https://jsonformatter.org).
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...
#Dyalect
Dyalect
func happy(n) { var m = [] while n > 1 { m.Add(n) var x = n n = 0 while x > 0 { var d = x % 10 n += d * d x /= 10 } if m.IndexOf(n) != -1 { return false } } return true }   var (n, found) = (1, 0) whi...
Give a code snippet in #Dyalect 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 endlessl...
christopher/rosetta-code
http://rosettacode.org/wiki/Ordered_words
Ordered words
An   ordered word   is a word in which the letters appear in alphabetic order. Examples include   abbey   and   dirt. Task[edit] Find and display all the ordered words in the dictionary   unixdict.txt   that have the longest word length. (Examples that access the dictionary file locally assume that you have download...
#CoffeeScript
CoffeeScript
  ordered_word = (word) -> for i in [0...word.length - 1] return false unless word[i] <= word[i+1] true   show_longest_ordered_words = (candidates, dict_file_name) -> words = [''] for word in candidates continue if word.length < words[0].length if ordered_word word words = [] if word.length > ...
Give a code snippet in #CoffeeScript An   ordered word   is a word in which the letters appear in alphabetic order. Examples include   abbey   and   dirt. Task[edit] Find and display all the ordered words in the dictionary   unixdict.txt   that have the longest word length. (Examples that access the dictionary file...
christopher/rosetta-code
http://rosettacode.org/wiki/Mandelbrot_set
Mandelbrot set
Mandelbrot set You are encouraged to solve this task according to the task description, using any language you may know. Task Generate and draw the Mandelbrot set. Note that there are many algorithms to draw Mandelbrot set and there are many functions which generate it .
#Sass.2FSCSS
Sass/SCSS
  $canvasWidth: 200; $canvasHeight: 200; $iterations: 20; $xCorner: -2; $yCorner: -1.5; $zoom: 3; $data: ()!global; @mixin plot ($x,$y,$count){ $index: ($y * $canvasWidth + $x) * 4; $r: $count * -12 + 255; $g: $count * -12 + 255; $b: $count * -12 + 255; $data: append($data, $x + px $y + px 0 rgb($r,$g,$b), co...
Give a code snippet in #Sass.2FSCSS Mandelbrot set You are encouraged to solve this task according to the task description, using any language you may know. Task Generate and draw the Mandelbrot set. Note that there are many algorithms to draw Mandelbrot set and there are many functions which generate it .
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, ... ...
#Swift
Swift
import BigInt   public struct Lychrel<T: ReversibleNumeric & CustomStringConvertible>: Sequence, IteratorProtocol { @usableFromInline let seed: T   @usableFromInline var done = false   @usableFromInline var n: T   @usableFromInline var iterations: T   @inlinable public init(seed: T, iterations: T = ...
Give a code snippet in #Swift   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 ...
christopher/rosetta-code