task_url stringlengths 30 116 | task_name stringlengths 2 86 | task_description stringlengths 0 14.4k | language_url stringlengths 2 53 | language_name stringlengths 1 52 | code stringlengths 0 61.9k | response_seed stringclasses 1
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http://rosettacode.org/wiki/Loops/Foreach | Loops/Foreach | Loop through and print each element in a collection in order.
Use your language's "for each" loop if it has one, otherwise iterate through the collection in order with some other loop.
Related tasks
Loop over multiple arrays simultaneously
Loops/Break
Loops/Continue
Loops/Do-while
Loops/Downward for... | #Emacs_Lisp | Emacs Lisp | (dolist (x '(1 2 3 4))
(message "x=%d" x)) | Give a code snippet in #Emacs_Lisp
Loop through and print each element in a collection in order.
Use your language's "for each" loop if it has one, otherwise iterate through the collection in order with some other loop.
Related tasks
Loop over multiple arrays simultaneously
Loops/Break
Loops/Continue
... | 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... | #Modula-2 | Modula-2 |
MODULE RomanNumeralsEncode;
FROM Strings IMPORT
Append;
FROM STextIO IMPORT
WriteString, WriteLn;
CONST
MaxChars = 15;
(* 3888 or MMMDCCCLXXXVIII (15 chars) is the longest string properly encoded
with these symbols. *)
TYPE
TRomanNumeral = ARRAY [0 .. MaxChars - 1] OF CHAR;
PROCEDURE ToRoman(AV... | Give a code snippet in #Modula-2
Task
Create a function taking a positive integer as its parameter and returning a string containing the Roman numeral representation of that integer. Modern Roman numerals are written by expressing each digit separately, starting with the left most digit and skipping any digit with a ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Grayscale_image | Grayscale image | Many image processing algorithms are defined for grayscale (or else monochromatic) images.
Task
Extend the data storage type defined on this page to support grayscale images.
Define two operations, one to convert a color image to a grayscale image and one for the backward conversion.
To get luminance of a color u... | #Perl | Perl | #! /usr/bin/perl
use strict;
use Image::Imlib2;
sub tograyscale
{
my $img = shift;
my $gimg = Image::Imlib2->new($img->width, $img->height);
for ( my $x = 0; $x < $gimg->width; $x++ ) {
for ( my $y = 0; $y < $gimg->height; $y++ ) {
my ( $r, $g, $b, $a ) = $img->query_pixel($x, $y);
my $gray =... | Give a code snippet in #Perl
Many image processing algorithms are defined for grayscale (or else monochromatic) images.
Task
Extend the data storage type defined on this page to support grayscale images.
Define two operations, one to convert a color image to a grayscale image and one for the backward conversion.
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Fibonacci_word | Fibonacci word | The Fibonacci Word may be created in a manner analogous to the Fibonacci Sequence as described here:
Define F_Word1 as 1
Define F_Word2 as 0
Form F_Word3 as F_Word2 concatenated with F_Word1 i.e.: 01
Form F_Wordn as F_Wordn-1 concatenated with F_wordn-... | #CLU | CLU | % NOTE: when compiling with Portable CLU,
% this program needs to be merged with 'useful.lib' to get log()
%
% pclu -merge $CLUHOME/lib/useful.lib -compile fib_words.clu
% Yield pairs of (zeroes, ones) for each Fibonacci word
% We don't generate the whole words, as that would take too much
% memory.
fib_words = iter... | Give a code snippet in #CLU
The Fibonacci Word may be created in a manner analogous to the Fibonacci Sequence as described here:
Define F_Word1 as 1
Define F_Word2 as 0
Form F_Word3 as F_Word2 concatenated with F_Word1 i.e.: 01
Form F_Wordn as F_Wordn-1 ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Koch_curve | Koch curve | Draw a Koch curve. See details: Koch curve
| #Python | Python | '''Koch curve'''
from math import cos, pi, sin
from operator import add, sub
from itertools import chain
# kochSnowflake :: Int -> (Float, Float) -> (Float, Float) -> [(Float, Float)]
def kochSnowflake(n, a, b):
'''List of points on a Koch snowflake of order n, derived
from an equilateral triangle with... | Give a code snippet in #Python
Draw a Koch curve. See details: Koch curve
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Generic_swap | Generic swap | Task
Write a generic swap function or operator which exchanges the values of two variables (or, more generally, any two storage places that can be assigned), regardless of their types.
If your solution language is statically typed please describe the way your language provides genericity.
If variables are typed in t... | #Swift | Swift | func swap<T>(inout a: T, inout b: T) {
(a, b) = (b, a)
} | Give a code snippet in #Swift
Task
Write a generic swap function or operator which exchanges the values of two variables (or, more generally, any two storage places that can be assigned), regardless of their types.
If your solution language is statically typed please describe the way your language provides genericit... | christopher/rosetta-code | |
http://rosettacode.org/wiki/State_name_puzzle | State name puzzle | Background
This task is inspired by Mark Nelson's DDJ Column "Wordplay" and one of the weekly puzzle challenges from Will Shortz on NPR Weekend Edition [1] and originally attributed to David Edelheit.
The challenge was to take the names of two U.S. States, mix them all together, then rearrange the letters to form the... | #Bracmat | Bracmat | ( Alabama
Alaska
Arizona
Arkansas
California
Colorado
Connecticut
Delaware
Florida
Georgia
Hawaii
Idaho
Illinois
Indiana
Iowa
Kansas
Kentucky
Louisiana
Maine
Maryland
Massachusetts
Michigan
... | Give a code snippet in #Bracmat
Background
This task is inspired by Mark Nelson's DDJ Column "Wordplay" and one of the weekly puzzle challenges from Will Shortz on NPR Weekend Edition [1] and originally attributed to David Edelheit.
The challenge was to take the names of two U.S. States, mix them all together, then ... | 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 ... | #Swift | Swift | import Foundation
// Allow for easy character checking
extension String {
subscript (i: Int) -> String {
return String(Array(self)[i])
}
}
func isPalindrome(str:String) -> Bool {
if (count(str) == 0 || count(str) == 1) {
return true
}
let removeRange = Range<String.Index>(start: ... | Give a code snippet in #Swift
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... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Colour_pinstripe/Display | Colour pinstripe/Display | The task is to create 1 pixel wide coloured vertical pinstripes with a sufficient number of pinstripes to span the entire width of the graphics display.
The pinstripes should either follow the system palette sequence, or a sequence that includes:
black, red, green, blue, magenta, cyan, yellow, and ... | #Plain_English | Plain English | To run:
Start up.
Clear the screen.
Imagine a box with the screen's left and the screen's top and the screen's right and the screen's bottom divided by 4.
Make a color pinstripe given 1 pixel and the box.
Draw the color pinstripe.
Draw the next color pinstripe given the color pinstripe.
Draw the next color pinstripe gi... | Give a code snippet in #Plain_English
The task is to create 1 pixel wide coloured vertical pinstripes with a sufficient number of pinstripes to span the entire width of the graphics display.
The pinstripes should either follow the system palette sequence, or a sequence that includes:
black, red, green, blu... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sort_an_outline_at_every_level | Sort an outline at every level | Task
Write and test a function over an indented plain text outline which either:
Returns a copy of the outline in which the sub-lists at every level of indentation are sorted, or
reports that the indentation characters or widths are not consistent enough to make the outline structure clear.
Your code should detec... | #Wren | Wren | import "/sort" for Sort
import "/fmt" for Fmt
var sortedOutline = Fn.new { |originalOutline, ascending|
var outline = originalOutline.toList // make copy in case we mutate it
var indent = ""
var del = "\x7f"
var sep = "\0"
var messages = []
if (outline[0].trimStart(" \t") != outline[0]) {
... | Give a code snippet in #Wren
Task
Write and test a function over an indented plain text outline which either:
Returns a copy of the outline in which the sub-lists at every level of indentation are sorted, or
reports that the indentation characters or widths are not consistent enough to make the outline structure c... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Dot_product | Dot product | Task
Create a function/use an in-built function, to compute the dot product, also known as the scalar product of two vectors.
If possible, make the vectors of arbitrary length.
As an example, compute the dot product of the vectors:
[1, 3, -5] and
[4, -2, -1]
If implementing the dot ... | #TI-89_BASIC | TI-89 BASIC | dotP([1, 3, –5], [4, –2, –1]) | Give a code snippet in #TI-89_BASIC
Task
Create a function/use an in-built function, to compute the dot product, also known as the scalar product of two vectors.
If possible, make the vectors of arbitrary length.
As an example, compute the dot product of the vectors:
[1, 3, -5] and
[4, ... | 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... | #Phix | Phix | function toRoman(integer v)
constant roman = {"M", "CM", "D","CD", "C","XC","L","XL","X","IX","V","IV","I"},
decml = {1000, 900, 500, 400, 100, 90, 50, 40, 10, 9, 5, 4, 1 }
string res = ""
integer val = v
for i=1 to length(roman) do
while val>=decml[i] do
res &=... | Give a code snippet in #Phix
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 valu... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Matrix_multiplication | Matrix multiplication | Task
Multiply two matrices together.
They can be of any dimensions, so long as the number of columns of the first matrix is equal to the number of rows of the second matrix.
| #Maxima | Maxima | a: matrix([1, 2],
[3, 4],
[5, 6],
[7, 8])$
b: matrix([1, 2, 3],
[4, 5, 6])$
a . b;
/* matrix([ 9, 12, 15],
[19, 26, 33],
[29, 40, 51],
[39, 54, 69]) */ | Give a code snippet in #Maxima
Task
Multiply two matrices together.
They can be of any dimensions, so long as the number of columns of the first matrix is equal to the number of rows of the second matrix.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Sailors,_coconuts_and_a_monkey_problem | Sailors, coconuts and a monkey problem | Five sailors are shipwrecked on an island and collect a large pile of coconuts during the day.
That night the first sailor wakes up and decides to take his first share early so tries to divide the pile of coconuts equally into five piles but finds that there is one coconut left over, so he tosses it to a monkey and th... | #Objeck | Objeck |
class Program {
function : Total(n : Int, nuts : Int) ~ Int {
k := 0;
for(nuts *= n; k < n; k++;) {
if(nuts % (n-1) <> 0) { return 0; };
nuts += nuts / (n-1) + 1;
};
return nuts;
}
function : Main(args : String[]) ~ Nil {
for(n := 2; n < 10; n++;) {
x := 0; t := 0;
... | Give a code snippet in #Objeck
Five sailors are shipwrecked on an island and collect a large pile of coconuts during the day.
That night the first sailor wakes up and decides to take his first share early so tries to divide the pile of coconuts equally into five piles but finds that there is one coconut left over, so... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Casting_out_nines | Casting out nines | Task (in three parts)
Part 1
Write a procedure (say
c
o
9
(
x
)
{\displaystyle {\mathit {co9}}(x)}
) which implements Casting Out Nines as described by returning the checksum for
x
{\displaystyle x}
. Demonstrate the procedure using the examples given there, or others you may consider lucky.
Par... | #Haskell | Haskell | co9 n
| n <= 8 = n
| otherwise = co9 $ sum $ filter (/= 9) $ digits 10 n
task2 = filter (\n -> co9 n == co9 (n ^ 2)) [1 .. 100]
task3 k = filter (\n -> n `mod` k == n ^ 2 `mod` k) [1 .. 100] | Give a code snippet in #Haskell
Task (in three parts)
Part 1
Write a procedure (say
c
o
9
(
x
)
{\displaystyle {\mathit {co9}}(x)}
) which implements Casting Out Nines as described by returning the checksum for
x
{\displaystyle x}
. Demonstrate the procedure using the examples given there, or ot... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Levenshtein_distance | Levenshtein distance |
This page uses content from Wikipedia. The original article was at Levenshtein distance. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance)
In information theory and computer science, the Levenshtein ... | #SenseTalk | SenseTalk |
put textDifference("kitten", "sitting") // --> 3
put textDifference("rosettacode", "raisethysword") // --> 8
| Give a code snippet in #SenseTalk
This page uses content from Wikipedia. The original article was at Levenshtein distance. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance)
In information theory and... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Increment_a_numerical_string | Increment a numerical string | Task
Increment a numerical string.
| #Modula-2 | Modula-2 | MODULE addstr;
IMPORT InOut, NumConv, Strings;
VAR str1, str2 : Strings.String;
num : CARDINAL;
ok : BOOLEAN;
BEGIN
str1 := "12345";
InOut.Write ('"'); InOut.WriteString (str1); InOut.WriteString ('" + 1 = ');
NumConv.Str2Num (num, 10, str1, ok);
... | Give a code snippet in #Modula-2
Task
Increment a numerical string.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Self-describing_numbers | Self-describing numbers | Self-describing numbers
You are encouraged to solve this task according to the task description, using any language you may know.
There are several so-called "self-describing" or "self-descriptive" integers.
An integer is said to be "self-describing" if it has the property that, when digit positions are labeled 0 to ... | #Pascal | Pascal | Program SelfDescribingNumber;
uses
SysUtils;
function check(number: longint): boolean;
var
i, d: integer;
a: string;
count, w : array [0..9] of integer;
begin
a := intToStr(number);
for i := 0 to 9 do
begin
count[i] := 0;
w[i] := 0;
end;
for i := 1 to length(a) do... | Give a code snippet in #Pascal
Self-describing numbers
You are encouraged to solve this task according to the task description, using any language you may know.
There are several so-called "self-describing" or "self-descriptive" integers.
An integer is said to be "self-describing" if it has the property that, when d... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Munching_squares | Munching squares | Render a graphical pattern where each pixel is colored by the value of 'x xor y' from an arbitrary color table.
| #XPL0 | XPL0 | include c:\cxpl\codes; \intrinsic 'code' declarations
int X, Y;
[SetVid($101); \set 640x480 graphics with 8-bit color
port($3C8):= 0; \set color registers with beautiful shades
for X:= 0 to 256-1 do
[port($3C9):= X>>1; \red
port($3C9):= X>>3; \green
... | Give a code snippet in #XPL0
Render a graphical pattern where each pixel is colored by the value of 'x xor y' from an arbitrary color table.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Null_object | Null object |
Null (or nil) is the computer science concept of an undefined or unbound object.
Some languages have an explicit way to access the null object, and some don't.
Some languages distinguish the null object from undefined values, and some don't.
Task
Show how to access null in your language by checking to see if an ob... | #Latitude | Latitude | foo := Nil.
if { foo nil?. } then {
putln: "Foo is nil".
} else {
putln: "Foo is not nil".
}. | Give a code snippet in #Latitude
Null (or nil) is the computer science concept of an undefined or unbound object.
Some languages have an explicit way to access the null object, and some don't.
Some languages distinguish the null object from undefined values, and some don't.
Task
Show how to access null in your la... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Harshad_or_Niven_series | Harshad or Niven series | The Harshad or Niven numbers are positive integers ≥ 1 that are divisible by the sum of their digits.
For example, 42 is a Harshad number as 42 is divisible by (4 + 2) without remainder.
Assume that the series is defined as the numbers in increasing order.
Task
The task is to create a function/method/... | #PowerShell | PowerShell |
1..1000 | Where { $_ % ( [int[]][string[]][char[]][string]$_ | Measure -Sum ).Sum -eq 0 } | Select -First 20
1001..2000 | Where { $_ % ( [int[]][string[]][char[]][string]$_ | Measure -Sum ).Sum -eq 0 } | Select -First 1
| Give a code snippet in #PowerShell
The Harshad or Niven numbers are positive integers ≥ 1 that are divisible by the sum of their digits.
For example, 42 is a Harshad number as 42 is divisible by (4 + 2) without remainder.
Assume that the series is defined as the numbers in increasing order.
Task
The ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Roots_of_unity | Roots of unity | The purpose of this task is to explore working with complex numbers.
Task
Given n, find the nth roots of unity.
| #Sidef | Sidef | func roots_of_unity(n) {
n.of { |j|
exp(2i * Num.pi / n * j)
}
}
roots_of_unity(5).each { |c|
printf("%+.5f%+.5fi\n", c.reals)
} | Give a code snippet in #Sidef
The purpose of this task is to explore working with complex numbers.
Task
Given n, find the nth roots of unity.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Least_common_multiple | Least common multiple | Least common multiple
You are encouraged to solve this task according to the task description, using any language you may know.
Task
Compute the least common multiple (LCM) of two integers.
Given m and n, the least common multiple is the smallest positive integer that has both m and n as factor... | #Objeck | Objeck |
class LCM {
function : Main(args : String[]) ~ Nil {
IO.Console->Print("lcm(35, 21) = ")->PrintLine(lcm(21,35));
}
function : lcm(m : Int, n : Int) ~ Int {
return m / gcd(m, n) * n;
}
function : gcd(m : Int, n : Int) ~ Int {
tmp : Int;
while(m <> 0) { tmp := m; m := n % m; n := tmp; };
... | Give a code snippet in #Objeck
Least common multiple
You are encouraged to solve this task according to the task description, using any language you may know.
Task
Compute the least common multiple (LCM) of two integers.
Given m and n, the least common multiple is the smallest positive integer that ha... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Null_object | Null object |
Null (or nil) is the computer science concept of an undefined or unbound object.
Some languages have an explicit way to access the null object, and some don't.
Some languages distinguish the null object from undefined values, and some don't.
Task
Show how to access null in your language by checking to see if an ob... | #AutoHotkey | AutoHotkey | If (object == null)
MsgBox, object is null | Give a code snippet in #AutoHotkey
Null (or nil) is the computer science concept of an undefined or unbound object.
Some languages have an explicit way to access the null object, and some don't.
Some languages distinguish the null object from undefined values, and some don't.
Task
Show how to access null in your ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Undefined_values | Undefined values | #PowerShell | PowerShell |
if (Get-Variable -Name noSuchVariable -ErrorAction SilentlyContinue)
{
$true
}
else
{
$false
}
| Give a code snippet in #PowerShell
| christopher/rosetta-code | ||
http://rosettacode.org/wiki/MD4 | MD4 | Find the MD4 message digest of a string of octets.
Use the ASCII encoded string “Rosetta Code” (without quotes).
You may either call an MD4 library, or implement MD4 in your language.
MD4 is an obsolete hash function that computes a 128-bit message digest that sometimes appears in obsolete protocols.
RFC 1320 specifi... | #AutoHotkey | AutoHotkey | str := "Rosetta Code"
MsgBox, % "String:`n" (str) "`n`nMD4:`n" MD4(str)
; MD4 ===============================================================================
MD4(string, encoding = "utf-8")
{
return CalcStringHash(string, 0x8002, encoding)
}
; CalcAddrHash ===================================================... | Give a code snippet in #AutoHotkey
Find the MD4 message digest of a string of octets.
Use the ASCII encoded string “Rosetta Code” (without quotes).
You may either call an MD4 library, or implement MD4 in your language.
MD4 is an obsolete hash function that computes a 128-bit message digest that sometimes appears in o... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Hailstone_sequence | Hailstone sequence | The Hailstone sequence of numbers can be generated from a starting positive integer, n by:
If n is 1 then the sequence ends.
If n is even then the next n of the sequence = n/2
If n is odd then the next n of the sequence = (3 * n) + 1
The (unproven) Collatz conje... | #APL | APL |
⍝ recursive dfn:
dfnHailstone←{
c←⊃⌽⍵ ⍝ last element
1=c:1 ⍝ if it is 1, stop.
⍵,∇(1+2|c)⊃(c÷2)(1+3×c) ⍝ otherwise pick the next step, and append the result of the recursive call
}
⍝ tradfn version:
∇seq←hailstone n;next
⍝ Returns the hailstone sequence for a given number
seq←n ⍝ Ini... | Give a code snippet in #APL
The Hailstone sequence of numbers can be generated from a starting positive integer, n by:
If n is 1 then the sequence ends.
If n is even then the next n of the sequence = n/2
If n is odd then the next n of the sequence = (3 * n) + 1
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/100_doors | 100 doors | There are 100 doors in a row that are all initially closed.
You make 100 passes by the doors.
The first time through, visit every door and toggle the door (if the door is closed, open it; if it is open, close it).
The second time, only visit every 2nd door (door #2, #4, #6, ...), and toggle it.
The third... | #X86_Assembly | X86 Assembly |
.NOLIST
; The task can be completed in 48 and "half" steps:
; On the first pass ALL doors are opened.
; On the second pass every EVEN door is closed.
; So, instead of all closed, the doors can initially be:
; Every odd door open, every even door closed and start at pass 3.
; On 51st and all the next passes, onl... | Give a code snippet in #X86_Assembly
There are 100 doors in a row that are all initially closed.
You make 100 passes by the doors.
The first time through, visit every door and toggle the door (if the door is closed, open it; if it is open, close it).
The second time, only visit every 2nd door (door #2, #4,... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Create_an_HTML_table | Create an HTML table | Create an HTML table.
The table body should have at least three rows of three columns.
Each of these three columns should be labelled "X", "Y", and "Z".
An extra column should be added at either the extreme left or the extreme right of the table that has no heading, but is filled with sequential row numbers.
The... | #Retro | Retro | needs casket::html'
with casket::html'
: rnd ( -$ ) random 1000 mod toString ;
[ [ [ ] td [ "x" ] td [ "y" ] td [ "z" ] td ] tr
[ [ "1" ] td [ rnd ] td [ rnd ] td [ rnd ] td ] tr
[ [ "2" ] td [ rnd ] td [ rnd ] td [ rnd ] td ] tr
[ [ "3" ] td [ rnd ] td [ rnd ] td [ rnd ] td ] tr
[ [ "4" ] td [ rnd ] td... | Give a code snippet in #Retro
Create an HTML table.
The table body should have at least three rows of three columns.
Each of these three columns should be labelled "X", "Y", and "Z".
An extra column should be added at either the extreme left or the extreme right of the table that has no heading, but is filled wit... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Variables | Variables | Task
Demonstrate a language's methods of:
variable declaration
initialization
assignment
datatypes
scope
referencing, and
other variable related facilities
| #Lambdatalk | Lambdatalk |
1) working in a global scope
{def A 3}
-> A // A is in the global scope
{def B 4}
-> B // B is in the global scopel
{def MUL {lambda {:x :y} {* :x :y}}}
-> MUL // MUL is a global function
{MUL {A} {B}} ... | Give a code snippet in #Lambdatalk
Task
Demonstrate a language's methods of:
variable declaration
initialization
assignment
datatypes
scope
referencing, and
other variable related facilities
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Boolean_values | Boolean values | Task
Show how to represent the boolean states "true" and "false" in a language.
If other objects represent "true" or "false" in conditionals, note it.
Related tasks
Logical operations
| #Oz | Oz | my $x = 0.0;
my $true_or_false = $x ? 'true' : 'false'; # false | Give a code snippet in #Oz
Task
Show how to represent the boolean states "true" and "false" in a language.
If other objects represent "true" or "false" in conditionals, note it.
Related tasks
Logical operations
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Arithmetic/Complex | Arithmetic/Complex | A complex number is a number which can be written as:
a
+
b
×
i
{\displaystyle a+b\times i}
(sometimes shown as:
b
+
a
×
i
{\displaystyle b+a\times i}
where
a
{\displaystyle a}
and
b
{\displaystyle b}
are real numbers, and
i
{\displaystyle i}
is √ -1
Typica... | #Haskell | Haskell | import Data.Complex
main = do
let a = 1.0 :+ 2.0 -- complex number 1+2i
let b = 4 -- complex number 4+0i
-- 'b' is inferred to be complex because it's used in
-- arithmetic with 'a' below.
putStrLn $ "Add: " ++ show (a + b)
putStrLn $ "Subtract: " ++ show (a - b)
putStrLn $ "Multipl... | Give a code snippet in #Haskell
A complex number is a number which can be written as:
a
+
b
×
i
{\displaystyle a+b\times i}
(sometimes shown as:
b
+
a
×
i
{\displaystyle b+a\times i}
where
a
{\displaystyle a}
and
b
{\displaystyle b}
are real numbers, and
i
{\display... | 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 ... | #Ada | Ada | integer f;
text s, t;
f = 36;
s = "integer f;
text s, t;
f = 36;
s = \"\";
o_text(cut(s, 0, f));
o_text(cut(s, 0, f - 1));
o_etext(cut(s, f - 1, 2));
o_text(cut(s, f + 1, 8888 - f));
o_text(cut(s, f, 8888 - f));
";
o_text(cut(s, 0, f));
o_text(cut(s, 0, f - 1));
o_etext(cut(s, f - 1, 2));
o_text(cut(s, f + 1, 8... | Give a code snippet in #Ada
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
s... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Generate_lower_case_ASCII_alphabet | Generate lower case ASCII alphabet | Task
Generate an array, list, lazy sequence, or even an indexable string of all the lower case ASCII characters, from a to z. If the standard library contains such a sequence, show how to access it, but don't fail to show how to generate a similar sequence.
For this basic task use a reliable style of coding, a sty... | #8086_Assembly | 8086 Assembly | bits 16
cpu 8086
org 100h
section .text
jmp demo
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;; Store the lowercase alphabet starting at [ES:DI]
;;; Destroys AX, CX, DI
alph: mov cx,13 ; 2*13 words = 26 bytes
mov ax,'ab' ; Do two bytes at once
.loop: stosw ; Store AX at ES:DI and add 2 t... | Give a code snippet in #8086_Assembly
Task
Generate an array, list, lazy sequence, or even an indexable string of all the lower case ASCII characters, from a to z. If the standard library contains such a sequence, show how to access it, but don't fail to show how to generate a similar sequence.
For this basic tas... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Deming%27s_Funnel | Deming's Funnel | W Edwards Deming was an American statistician and management guru who used physical demonstrations to illuminate his teachings. In one demonstration Deming repeatedly dropped marbles through a funnel at a target, marking where they landed, and observing the resulting pattern. He applied a sequence of "rules" to try to ... | #Perl | Perl | @dx = qw<
-0.533 0.270 0.859 -0.043 -0.205 -0.127 -0.071 0.275
1.251 -0.231 -0.401 0.269 0.491 0.951 1.150 0.001
-0.382 0.161 0.915 2.080 -2.337 0.034 -0.126 0.014
0.709 0.129 -1.093 -0.483 -1.193 0.020 -0.051 0.047
-0.095 0.695 0.340 -0.182 0.287 0.213 -0.423 -0.021
-0.134... | Give a code snippet in #Perl
W Edwards Deming was an American statistician and management guru who used physical demonstrations to illuminate his teachings. In one demonstration Deming repeatedly dropped marbles through a funnel at a target, marking where they landed, and observing the resulting pattern. He applied a ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/4-rings_or_4-squares_puzzle | 4-rings or 4-squares puzzle | 4-rings or 4-squares puzzle
You are encouraged to solve this task according to the task description, using any language you may know.
Task
Replace a, b, c, d, e, f, and
g with the decimal
digits LOW ───► HIGH
such that the sum of the letters inside of each of the four large squares add up to
t... | #Perl | Perl | use ntheory qw/forperm/;
use Set::CrossProduct;
sub four_sq_permute {
my($list) = @_;
my @solutions;
forperm {
@c = @$list[@_];
push @solutions, [@c] if check(@c);
} @$list;
print +@solutions . " unique solutions found using: " . join(', ', @$list) . "\n";
return @solutions;
}
... | Give a code snippet in #Perl
4-rings or 4-squares puzzle
You are encouraged to solve this task according to the task description, using any language you may know.
Task
Replace a, b, c, d, e, f, and
g with the decimal
digits LOW ───► HIGH
such that the sum of the letters inside of each of the ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Filter | Filter | Task
Select certain elements from an Array into a new Array in a generic way.
To demonstrate, select all even numbers from an Array.
As an option, give a second solution which filters destructively,
by modifying the original Array rather than creating a new Array.
| #Kotlin | Kotlin | // version 1.0.5-2
fun main(args: Array<String>) {
val array = arrayOf(1, 2, 3, 4, 5, 6, 7, 8, 9)
println(array.joinToString(" "))
val filteredArray = array.filter{ it % 2 == 0 }
println(filteredArray.joinToString(" "))
val mutableList = array.toMutableList()
mutableList.retainAll { it % 2... | Give a code snippet in #Kotlin
Task
Select certain elements from an Array into a new Array in a generic way.
To demonstrate, select all even numbers from an Array.
As an option, give a second solution which filters destructively,
by modifying the original Array rather than creating a new Array.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/P-Adic_square_roots | P-Adic square roots |
Task.
Convert rational a/b to its approximate p-adic square root. To check the result,
square the root and construct rational m/n to compare with radicand a/b.
For rational reconstruction Lagrange's lattice basis reduction algorithm is used.
Recipe: find root x1 modulo p and build a sequence of solutions
f(xk) ≡ 0 ... | #Haskell | Haskell | {-# LANGUAGE KindSignatures, DataKinds #-}
import Data.Ratio
import Data.List (find)
import GHC.TypeLits
import Padic
pSqrt :: KnownNat p => Rational -> Padic p
pSqrt r = res
where
res = maybe Null mkUnit series
(a, b) = (numerator r, denominator r)
series = case modulo res of
2 | eqMod 4 a... | Give a code snippet in #Haskell
Task.
Convert rational a/b to its approximate p-adic square root. To check the result,
square the root and construct rational m/n to compare with radicand a/b.
For rational reconstruction Lagrange's lattice basis reduction algorithm is used.
Recipe: find root x1 modulo p and build a... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Semordnilap | Semordnilap | A semordnilap is a word (or phrase) that spells a different word (or phrase) backward. "Semordnilap" is a word that itself is a semordnilap.
Example: lager and regal
Task
This task does not consider semordnilap phrases, only single words.
Using only words from this list, report the total number of unique semordnilap ... | #PureBasic | PureBasic | If OpenConsole("")=0 : End 1 : EndIf
If ReadFile(0,"./Data/unixdict.txt")=0 : End 2 : EndIf
NewList dict$()
While Eof(0)=0 : AddElement(dict$()) : dict$()=Trim(ReadString(0)) : Wend : CloseFile(0)
While FirstElement(dict$())
buf$=dict$() : DeleteElement(dict$())
If buf$="" : Continue : EndIf
xbuf$=ReverseSt... | Give a code snippet in #PureBasic
A semordnilap is a word (or phrase) that spells a different word (or phrase) backward. "Semordnilap" is a word that itself is a semordnilap.
Example: lager and regal
Task
This task does not consider semordnilap phrases, only single words.
Using only words from this list, report the ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Date_manipulation | Date manipulation | Task
Given the date string "March 7 2009 7:30pm EST",
output the time 12 hours later in any human-readable format.
As extra credit, display the resulting time in a time zone different from your own.
| #Sidef | Sidef | var dt = frequire('DateTime::Format::Strptime')
var input = 'March 7 2009 7:30pm EST'
input.sub!('EST', 'America/New_York')
say dt.strptime('%b %d %Y %I:%M%p %O', input) \
.add(hours => 12) \
.set_time_zone('America/Edmonton') \
.format_cldr('MMMM d yyyy h:mma zzz... | Give a code snippet in #Sidef
Task
Given the date string "March 7 2009 7:30pm EST",
output the time 12 hours later in any human-readable format.
As extra credit, display the resulting time in a time zone different from your own.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Delete_a_file | Delete a file | Task
Delete a file called "input.txt" and delete a directory called "docs".
This should be done twice: once "here", i.e. in the current working directory and once in the filesystem root.
| #NewLISP | NewLISP | (delete-file "input.txt")
(delete-file "/input.txt")
(remove-dir "docs")
(remove-dir "/docs") | Give a code snippet in #NewLISP
Task
Delete a file called "input.txt" and delete a 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/Delete_a_file | Delete a file | Task
Delete a file called "input.txt" and delete a directory called "docs".
This should be done twice: once "here", i.e. in the current working directory and once in the filesystem root.
| #Maple | Maple | FileTools:-Remove("input.txt");
FileTools:-RemoveDirectory("docs");
FileTools:-Remove("/input.txt");
FileTools:-RemoveDirectory("/docs");
| Give a code snippet in #Maple
Task
Delete a file called "input.txt" and delete a 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/Digital_root/Multiplicative_digital_root | Digital root/Multiplicative digital root | The multiplicative digital root (MDR) and multiplicative persistence (MP) of a number,
n
{\displaystyle n}
, is calculated rather like the Digital root except digits are multiplied instead of being added:
Set
m
{\displaystyle m}
to
n
{\displaystyle n}
and
i
{\displaystyle i}
to
0
... | #11l | 11l | F mdroot(n)
V count = 0
V mdr = n
L mdr > 9
V m = mdr
V digits_mul = 1
L m != 0
digits_mul *= m % 10
m = m I/ 10
mdr = digits_mul
count++
R (count, mdr)
print(‘Number: (MP, MDR)’)
print(‘====== =========’)
L(n) (123321, 7739, 893, 899998)
print(‘#6: ’.fo... | Give a code snippet in #11l
The multiplicative digital root (MDR) and multiplicative persistence (MP) of a number,
n
{\displaystyle n}
, is calculated rather like the Digital root except digits are multiplied instead of being added:
Set
m
{\displaystyle m}
to
n
{\displaystyle n}
and
i
{\... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Bitmap/Flood_fill | Bitmap/Flood fill | Implement a flood fill.
A flood fill is a way of filling an area using color banks to define the contained area or a target color which "determines" the area (the valley that can be flooded; Wikipedia uses the term target color). It works almost like a water flooding from a point towards the banks (or: inside the vall... | #Scala | Scala | import java.awt.Color
import scala.collection.mutable
object Flood {
def floodFillStack(bm:RgbBitmap, x: Int, y: Int, targetColor: Color): Unit = {
// validate
if (bm.getPixel(x,y) == targetColor) return
// vars
val oldColor = bm.getPixel(x,y)
val pixels = new mutable.Stack[(Int,Int)]
//... | Give a code snippet in #Scala
Implement a flood fill.
A flood fill is a way of filling an area using color banks to define the contained area or a target color which "determines" the area (the valley that can be flooded; Wikipedia uses the term target color). It works almost like a water flooding from a point towards... | christopher/rosetta-code | |
http://rosettacode.org/wiki/First-class_functions | First-class functions | A language has first-class functions if it can do each of the following without recursively invoking a compiler or interpreter or otherwise metaprogramming:
Create new functions from preexisting functions at run-time
Store functions in collections
Use functions as arguments to other functions
Use functions as retu... | #Rust | Rust | #![feature(conservative_impl_trait)]
fn main() {
let cube = |x: f64| x.powi(3);
let cube_root = |x: f64| x.powf(1.0 / 3.0);
let flist : [&Fn(f64) -> f64; 3] = [&cube , &f64::sin , &f64::cos ];
let invlist: [&Fn(f64) -> f64; 3] = [&cube_root, &f64::asin, &f64::acos];
let result = flist.... | Give a code snippet in #Rust
A language has first-class functions if it can do each of the following without recursively invoking a compiler or interpreter or otherwise metaprogramming:
Create new functions from preexisting functions at run-time
Store functions in collections
Use functions as arguments to other fu... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sum_of_squares | Sum of squares | Task
Write a program to find the sum of squares of a numeric vector.
The program should work on a zero-length vector (with an answer of 0).
Related task
Mean
| #Mathematica.2FWolfram_Language | Mathematica/Wolfram Language | SumOfSquares[x_]:=Total[x^2]
SumOfSquares[{1,2,3,4,5}] | Give a code snippet in #Mathematica.2FWolfram_Language
Task
Write a program to find the sum of squares of a numeric vector.
The program should work on a zero-length vector (with an answer of 0).
Related task
Mean
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Chinese_zodiac | Chinese zodiac | Traditionally, the Chinese have counted years using two simultaneous cycles, one of length 10 (the "celestial stems") and one of length 12 (the "terrestrial branches"); the combination results in a repeating 60-year pattern. Mapping the branches to twelve traditional animal deities results in the well-known "Chinese zo... | #360_Assembly | 360 Assembly | * Chinese zodiac 10/03/2019
CHINEZOD CSECT
USING CHINEZOD,R13 base register
B 72(R15) skip savearea
DC 17F'0' savearea
SAVE (14,12) save previous context
ST R13,4(R15) link backward
ST... | Give a code snippet in #360_Assembly
Traditionally, the Chinese have counted years using two simultaneous cycles, one of length 10 (the "celestial stems") and one of length 12 (the "terrestrial branches"); the combination results in a repeating 60-year pattern. Mapping the branches to twelve traditional animal deities... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Luhn_test_of_credit_card_numbers | Luhn test of credit card numbers | The Luhn test is used by some credit card companies to distinguish valid credit card numbers from what could be a random selection of digits.
Those companies using credit card numbers that can be validated by the Luhn test have numbers that pass the following test:
Reverse the order of the digits in the number.
Tak... | #EchoLisp | EchoLisp |
;; value for 'even' numbers
(define (even-val n) (if (> n 4) (+ n n -9) (+ n n)))
;;Luhn test
;; input : a string of decimal digits
;; output #t or #f
(define (valid nums (odd #f ))
(let ((nums (map string->number (reverse (string->list nums)))))
(= 0 (modulo
(for/sum ((n nums)) (set! odd (not odd)... | Give a code snippet in #EchoLisp
The Luhn test is used by some credit card companies to distinguish valid credit card numbers from what could be a random selection of digits.
Those companies using credit card numbers that can be validated by the Luhn test have numbers that pass the following test:
Reverse the order... | christopher/rosetta-code | |
http://rosettacode.org/wiki/ASCII_art_diagram_converter | ASCII art diagram converter | Given the RFC 1035 message diagram from Section 4.1.1 (Header section format) as a string:
http://www.ietf.org/rfc/rfc1035.txt
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
| ID |
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
|QR| Opcode |AA|TC|RD|RA| Z | RC... | #AArch64_Assembly | AArch64 Assembly |
/* ARM assembly AARCH64 Raspberry PI 3B or android 64 bits */
/* program asciiDiagram64.s */
/*******************************************/
/* Constantes file */
/*******************************************/
/* for this file see task include a file in language AArch64 assembly*/
.include ... | Give a code snippet in #AArch64_Assembly
Given the RFC 1035 message diagram from Section 4.1.1 (Header section format) as a string:
http://www.ietf.org/rfc/rfc1035.txt
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
| ID |
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Special_characters | Special characters | Special characters are symbols (single characters or sequences of characters) that have a "special" built-in meaning in the language and typically cannot be used in identifiers.
Escape sequences are methods that the language uses to remove the special meaning from the symbol, enabling it to be used as a normal charact... | #C.2B.2B | C++ | Trigraph Replacement letter
??( [
??) ]
??< {
??> }
??/ \
??= #
??' ^
??! |
??- ~
| Give a code snippet in #C.2B.2B
Special characters are symbols (single characters or sequences of characters) that have a "special" built-in meaning in the language and typically cannot be used in identifiers.
Escape sequences are methods that the language uses to remove the special meaning from the symbol, enabling ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Middle_three_digits | Middle three digits | Task
Write a function/procedure/subroutine that is called with an integer value and returns the middle three digits of the integer if possible or a clear indication of an error if this is not possible.
Note: The order of the middle digits should be preserved.
Your function should be tested with the following values;... | #D | D | import std.stdio, std.traits, std.conv;
string middleThreeDigits(T)(in T n) pure nothrow if (isIntegral!T) {
auto s = n < 0 ? n.text[1 .. $] : n.text;
auto len = s.length;
if (len < 3 || len % 2 == 0)
return "Need odd and >= 3 digits";
auto mid = len / 2;
return s[mid - 1 .. mid + 2];
}
... | Give a code snippet in #D
Task
Write a function/procedure/subroutine that is called with an integer value and returns the middle three digits of the integer if possible or a clear indication of an error if this is not possible.
Note: The order of the middle digits should be preserved.
Your function should be tested... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Tokenize_a_string_with_escaping | Tokenize a string with escaping | Task[edit]
Write a function or program that can split a string at each non-escaped occurrence of a separator character.
It should accept three input parameters:
The string
The separator character
The escape character
It should output a list of strings.
Details
Rules for splitting:
The fields that were s... | #AppleScript | AppleScript | ------------------ TOKENIZE WITH ESCAPING ----------------
-- tokenize :: String -> Character -> Character -> [String]
on tokenize(str, delimChar, chrEsc)
script charParse
-- Record: {esc:Bool, token:String, tokens:[String]}
-- charParse :: Record -> Character -> Record
on |λ|(a, x)
... | Give a code snippet in #AppleScript
Task[edit]
Write a function or program that can split a string at each non-escaped occurrence of a separator character.
It should accept three input parameters:
The string
The separator character
The escape character
It should output a list of strings.
Details
Rules fo... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Truncate_a_file | Truncate a file | Task
Truncate a file to a specific length. This should be implemented as a routine that takes two parameters: the filename and the required file length (in bytes).
Truncation can be achieved using system or library calls intended for such a task, if such methods exist, or by creating a temporary file of a reduced... | #PureBasic | PureBasic | Procedure SetFileSize(File$, length.q)
Protected fh, pos, i
If FileSize(File$) < length
Debug "File to small, is a directory or does not exist."
ProcedureReturn #False
Else
fh = OpenFile(#PB_Any, File$)
FileSeek(fh, length)
TruncateFile(fh)
CloseFile(fh)
EndIf
ProcedureReturn #True
En... | Give a code snippet in #PureBasic
Task
Truncate a file to a specific length. This should be implemented as a routine that takes two parameters: the filename and the required file length (in bytes).
Truncation can be achieved using system or library calls intended for such a task, if such methods exist, or by cre... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Exponentiation_operator | Exponentiation operator | Most programming languages have a built-in implementation of exponentiation.
Task
Re-implement integer exponentiation for both intint and floatint as both a procedure, and an operator (if your language supports operator definition).
If the language supports operator (or procedure) overloading, then an ov... | #Retro | Retro | : pow ( bp-n ) 1 swap [ over * ] times nip ; | Give a code snippet in #Retro
Most programming languages have a built-in implementation of exponentiation.
Task
Re-implement integer exponentiation for both intint and floatint as both a procedure, and an operator (if your language supports operator definition).
If the language supports operator (or pro... | 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... | #6502_Assembly | 6502 Assembly |
\ 99 bottles of beer on the wall:
: allout "no more bottles" ;
: just-one "1 bottle" ;
: yeah! dup . " bottles" ;
[
' allout ,
' just-one ,
' yeah! ,
] var, bottles
: .bottles dup 2 n:min bottles @ swap caseof ;
: .beer .bottles . " of beer" . ;
: .wall .beer " on the wall" . ;
: .take " Take o... | Give a code snippet in #6502_Assembly
Task
Display the complete lyrics for the song: 99 Bottles of Beer on the Wall.
The beer song
The lyrics follow this form:
99 bottles of beer on the wall
99 bottles of beer
Take one down, pass it around
98 bottles of beer on the wall
98 bottles of beer on the w... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Run-length_encoding | Run-length encoding | Run-length encoding
You are encouraged to solve this task according to the task description, using any language you may know.
Task
Given a string containing uppercase characters (A-Z), compress repeated 'runs' of the same character by storing the length of that run, and provide a function to reverse the compression... | #Prolog | Prolog | % the test
run_length :-
L = "WWWWWWWWWWWWBWWWWWWWWWWWWBBBWWWWWWWWWWWWWWWWWWWWWWWWBWWWWWWWWWWWWWW",
writef('encode %s\n', [L]),
encode(L, R),
writeln(R), nl,
writef('decode %w\n', [R]),
decode(R, L1),
writeln(L1).
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
% encode
%
% trans... | Give a code snippet in #Prolog
Run-length encoding
You are encouraged to solve this task according to the task description, using any language you may know.
Task
Given a string containing uppercase characters (A-Z), compress repeated 'runs' of the same character by storing the length of that run, and provide a fun... | 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.
... | #Objective-C | Objective-C | NSString *dir = @"/foo/bar";
// Pre-OS X 10.5
NSArray *contents = [[NSFileManager defaultManager] directoryContentsAtPath:dir];
// OS X 10.5+
NSArray *contents = [[NSFileManager defaultManager] contentsOfDirectoryAtPath:dir error:NULL];
for (NSString *file in contents)
if ([[file pathExtension] isEqualToString:@"... | Give a code snippet in #Objective-C
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/Sierpinski_triangle/Graphical | Sierpinski triangle/Graphical | Produce a graphical representation of a Sierpinski triangle of order N in any orientation.
An example of Sierpinski's triangle (order = 8) looks like this:
| #Nim | Nim | import imageman
const
Black = ColorRGBU [byte 0, 0, 0] # For background.
Red = ColorRGBU [byte 255, 0, 0] # For triangle.
proc drawSierpinski(img: var Image; txy: array[1..6, float]; levelsYet: Natural) =
var nxy: array[1..6, float]
if levelsYet > 0:
for i in 1..6:
let pos = if i < 5: i + 2 else... | Give a code snippet in #Nim
Produce a graphical representation of a Sierpinski triangle of order N in any orientation.
An example of Sierpinski's triangle (order = 8) looks like this:
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Loop_over_multiple_arrays_simultaneously | Loop over multiple arrays simultaneously | Task
Loop over multiple arrays (or lists or tuples or whatever they're called in
your language) and display the i th element of each.
Use your language's "for each" loop if it has one, otherwise iterate
through the collection in order with some other loop.
For this example, loop over the arrays:
... | #C.2B.2B | C++ | #include <iostream>
#include <vector>
int main(int argc, char* argv[])
{
std::vector<char> ls(3); ls[0] = 'a'; ls[1] = 'b'; ls[2] = 'c';
std::vector<char> us(3); us[0] = 'A'; us[1] = 'B'; us[2] = 'C';
std::vector<int> ns(3); ns[0] = 1; ns[1] = 2; ns[2] = 3;
std::vector<char>::const_iterator lIt = l... | Give a code snippet in #C.2B.2B
Task
Loop over multiple arrays (or lists or tuples or whatever they're called in
your language) and display the i th element of each.
Use your language's "for each" loop if it has one, otherwise iterate
through the collection in order with some other loop.
For this ex... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Hello_world/Newline_omission | Hello world/Newline omission | Some languages automatically insert a newline after outputting a string, unless measures are taken to prevent its output.
Task
Display the string Goodbye, World! without a trailing newline.
Related tasks
Hello world/Graphical
Hello world/Line Printer
Hello world/Standard error
Hello world/Text
| #Io | Io |
write("Goodbye, World!")
| Give a code snippet in #Io
Some languages automatically insert a newline after outputting a string, unless measures are taken to prevent its output.
Task
Display the string Goodbye, World! without a trailing newline.
Related tasks
Hello world/Graphical
Hello world/Line Printer
Hello world/Standard... | 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... | #AutoHotkey | AutoHotkey | MsgBox % stor(444)
stor(value)
{
romans = M,CM,D,CD,C,XC,L,XL,X,IX,V,IV,I
M := 1000
CM := 900
D := 500
CD := 400
C := 100
XC := 90
L := 50
XL := 40
X := 10
IX := 9
V := 5
IV := 4
I := 1
Loop, Parse, romans, `,
{
While, value >= %A_LoopField%
{
result .= A_LoopField
... | Give a code snippet in #AutoHotkey
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 ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Number_reversal_game | Number reversal game | Task
Given a jumbled list of the numbers 1 to 9 that are definitely not in
ascending order.
Show the list, and then ask the player how many digits from the
left to reverse.
Reverse those digits, then ask again, until all the digits end up in ascending order.
The score is the count of the reversa... | #FOCAL | FOCAL | 01.10 D 3;S T=0
01.20 F X=1,9;T %1,D(X)
01.30 T !;A "HOW MANY",R
01.40 I (R-1)1.3;I (9-R)1.3
01.50 D 5;S T=T+1
01.60 D 4;I (A-9)1.2
01.70 D 1.2;T !"CORRECT! ATTEMPTS",%4,T,!
01.80 Q
02.10 S A=10*FRAN();S A=A-FITR(A)
03.10 F X=1,9;S D(X)=X
03.20 F X=1,8;D 2;S Y=X+FITR((10-X)*A);S A=D(X);S D(X)=D(Y);S D(Y)=A
03.30 D ... | Give a code snippet in #FOCAL
Task
Given a jumbled list of the numbers 1 to 9 that are definitely not in
ascending order.
Show the list, and then ask the player how many digits from the
left to reverse.
Reverse those digits, then ask again, until all the digits end up in ascending order.
The sc... | 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
| #Go | Go | package main
import (
"fmt"
"math/rand"
"strings"
"time"
)
func main() {
rand.Seed(time.Now().UnixNano())
p := newPuzzle()
p.play()
}
type board [16]cell
type cell uint8
type move uint8
const (
up move = iota
down
right
left
)
func randMove() move { return move(rand.Intn(4)) }
var solvedBoard = b... | Give a code snippet in #Go
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/Record_sound | Record sound | Record a monophonic 16-bit PCM sound into either memory space, a file or array.
(This task neglects to specify the sample rate, and whether to use signed samples.
The programs in this page might use signed 16-bit or unsigned 16-bit samples, at 8000 Hz, 44100 Hz, or any other sample rate.
Therefore, these programs migh... | #GUISS | GUISS | Start,Programs,Accessories,Sound Recorder,Button:Record | Give a code snippet in #GUISS
Record a monophonic 16-bit PCM sound into either memory space, a file or array.
(This task neglects to specify the sample rate, and whether to use signed samples.
The programs in this page might use signed 16-bit or unsigned 16-bit samples, at 8000 Hz, 44100 Hz, or any other sample rate.... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sequence_of_primes_by_trial_division | Sequence of primes by trial division | Sequence of primes by trial division
You are encouraged to solve this task according to the task description, using any language you may know.
Task
Generate a sequence of primes by means of trial division.
Trial division is an algorithm where a candidate number is tested for being a prime by trying to divide it by... | #FileMaker | FileMaker |
#May 10th., 2018.
Set Error Capture [On]
Allow User Abort [Off]
# Set default number of minutes
Set Variable [$maxduration; Value:1]
# Ask user for a desired duration of the test
Show Custom Dialog [ "Setup";
"Enter the number of minutes (0,1-15, 6s increments) you would like this test to run.¶" &
"Hit an... | Give a code snippet in #FileMaker
Sequence of primes by trial division
You are encouraged to solve this task according to the task description, using any language you may know.
Task
Generate a sequence of primes by means of trial division.
Trial division is an algorithm where a candidate number is tested for bein... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Substring | Substring |
Basic Data Operation
This is a basic data operation. It represents a fundamental action on a basic data type.
You may see other such operations in the Basic Data Operations category, or:
Integer Operations
Arithmetic |
Comparison
Boolean Operations
Bitwise |
Logical
String Operations
Concatenation |
Interpolation |... | #QB64 | QB64 |
DefStr S
DefInt I
string1 = "abcdefghijklmnopqrstuvwxyz"
substring = "klm"
Dim Achar As String * 1
Istart = 6
Ilength = 10
Achar = "c"
' starting from n characters in and of m length;
Print Mid$(string1, Istart, Ilength)
' starting from n characters in, up to the end of the string;
Print Mid$(string... | Give a code snippet in #QB64
Basic Data Operation
This is a basic data operation. It represents a fundamental action on a basic data type.
You may see other such operations in the Basic Data Operations category, or:
Integer Operations
Arithmetic |
Comparison
Boolean Operations
Bitwise |
Logical
String Operations
C... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Gamma_function | Gamma function | Task
Implement one algorithm (or more) to compute the Gamma (
Γ
{\displaystyle \Gamma }
) function (in the real field only).
If your language has the function as built-in or you know a library which has it, compare your implementation's results with the results of the built-in/library function.
The Gamma funct... | #C | C | #include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include <gsl/gsl_sf_gamma.h>
#ifndef M_PI
#define M_PI 3.14159265358979323846
#endif
/* very simple approximation */
double st_gamma(double x)
{
return sqrt(2.0*M_PI/x)*pow(x/M_E, x);
}
#define A 12
double sp_gamma(double z)
{
const int a = A;
static d... | Give a code snippet in #C
Task
Implement one algorithm (or more) to compute the Gamma (
Γ
{\displaystyle \Gamma }
) function (in the real field only).
If your language has the function as built-in or you know a library which has it, compare your implementation's results with the results of the built-in/library... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Zero_to_the_zero_power | Zero to the zero power | Some computer programming languages are not exactly consistent (with other computer programming languages)
when raising zero to the zeroth power: 00
Task
Show the results of raising zero to the zeroth power.
If your computer language objects to 0**0 or 0^0 at compile time, ... | #ColdFusion | ColdFusion |
<cfset zeroPowerTag = 0^0>
<cfoutput>"#zeroPowerTag#"</cfoutput>
| Give a code snippet in #ColdFusion
Some computer programming languages are not exactly consistent (with other computer programming languages)
when raising zero to the zeroth power: 00
Task
Show the results of raising zero to the zeroth power.
If your computer language objects to 0**0 ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Date_format | Date format | This task has been clarified. Its programming examples are in need of review to ensure that they still fit the requirements of the task.
Task
Display the current date in the formats of:
2007-11-23 and
Friday, November 23, 2007
| #MUMPS | MUMPS | DTZ
WRITE !,"Date format 3: ",$ZDATE($H,3)
WRITE !,"Or ",$ZDATE($H,12),", ",$ZDATE($H,9)
QUIT | Give a code snippet in #MUMPS
This task has been clarified. Its programming examples are in need of review to ensure that they still fit the requirements of the task.
Task
Display the current date in the formats of:
2007-11-23 and
Friday, November 23, 2007
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Rosetta_Code/Count_examples | Rosetta Code/Count examples | task
Essentially, count the number of occurrences of =={{header| on each task page.
Output:
100 doors: 20 examples.
99 Bottles of Beer: 29 examples.
Abstract type: 10 examples.
Total: X examples.
For a full output, updated periodically, see Rosetta Code/Count examples/Full list.
You'll need to use the Media Wiki AP... | #Factor | Factor | USING: arrays assocs concurrency.combinators
concurrency.semaphores formatting hashtables http.client io
json.reader kernel math math.parser sequences splitting
urls.encoding ;
IN: rosetta-code.count-examples
CONSTANT: list-url "http://rosettacode.org/mw/api.php?action=query&list=categorymembers&cmtitle=Category:Prog... | Give a code snippet in #Factor
task
Essentially, count the number of occurrences of =={{header| on each task page.
Output:
100 doors: 20 examples.
99 Bottles of Beer: 29 examples.
Abstract type: 10 examples.
Total: X examples.
For a full output, updated periodically, see Rosetta Code/Count examples/Full list.
You'... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Secure_temporary_file | Secure temporary file | Task
Create a temporary file, securely and exclusively (opening it such that there are no possible race conditions).
It's fine assuming local filesystem semantics (NFS or other networking filesystems can have signficantly more complicated semantics for satisfying the "no race conditions" criteria).
The function shou... | #BBC_BASIC | BBC BASIC | file% = FNopentempfile
IF file% = 0 ERROR 100, "Failed to open temp file"
PRINT #file%, "Hello world!"
PTR#file% = 0
INPUT #file%, message$
CLOSE #file%
PRINT message$
END
DEF FNopentempfile
LOCAL pname%, hfile%, chan%
OPEN_EXISTING = 3
FILE_FLAG... | Give a code snippet in #BBC_BASIC
Task
Create a temporary file, securely and exclusively (opening it such that there are no possible race conditions).
It's fine assuming local filesystem semantics (NFS or other networking filesystems can have signficantly more complicated semantics for satisfying the "no race condit... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Angles_(geometric),_normalization_and_conversion | Angles (geometric), normalization and conversion | This task is about the normalization and/or conversion of (geometric) angles using
some common scales.
The angular scales that will be used in this task are:
degree
gradian
mil
radian
Definitions
The angular scales used or referenced here:
turn is a full turn or 360 degrees, also shown as 360º
... | #Racket | Racket | #lang racket
(define (rem n m)
(let* ((m (abs m)) (-m (- m)))
(let recur ((n n))
(cond [(< n -m) (recur (+ n m))]
[(>= n m) (recur (- n m))]
[else n]))))
(define 2.pi (* 2 pi))
(define (deg->deg a) (rem a 360))
(define (grad->grad a) (rem a 400))
(define (mil->mil a) (rem a 640... | Give a code snippet in #Racket
This task is about the normalization and/or conversion of (geometric) angles using
some common scales.
The angular scales that will be used in this task are:
degree
gradian
mil
radian
Definitions
The angular scales used or referenced here:
turn is a full turn or ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Brace_expansion | Brace expansion | Brace expansion is a type of parameter expansion made popular by Unix shells, where it allows users to specify multiple similar string parameters without having to type them all out. E.g. the parameter enable_{audio,video} would be interpreted as if both enable_audio and enable_video had been specified.
Task[edit]
W... | #J | J |
NB. legit { , and } do not follow a legit backslash:
legit=: 1,_1}.4>(3;(_2[\"1".;._2]0 :0);('\';a.);0 _1 0 1)&;:&.(' '&,)
2 1 1 1 NB. result 0 or 1: initial state
2 2 1 2 NB. result 2 or 3: after receiving a non backslash
1 2 1 2 NB. result 4 or 5: after receiving a backslash
)
expand=:3 :0
Ch=. u:inv y... | Give a code snippet in #J
Brace expansion is a type of parameter expansion made popular by Unix shells, where it allows users to specify multiple similar string parameters without having to type them all out. E.g. the parameter enable_{audio,video} would be interpreted as if both enable_audio and enable_video had been... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Balanced_brackets | Balanced brackets | Task:
Generate a string with N opening brackets [ and with N closing brackets ], in some arbitrary order.
Determine whether the generated string is balanced; that is, whether it consists entirely of pairs of opening/closing brackets (in that order), none of which mis-nest.
Examples
(empty) ... | #Pascal | Pascal | sub generate {
my $n = shift;
my $str = '[' x $n;
substr($str, rand($n + $_), 0) = ']' for 1..$n;
return $str;
}
sub balanced {
shift =~ /^ (\[ (?1)* \])* $/x;
}
for (0..8) {
my $input = generate($_);
print balanced($input) ? " ok:" : "bad:", " '$input'\n";
} | Give a code snippet in #Pascal
Task:
Generate a string with N opening brackets [ and with N closing brackets ], in some arbitrary order.
Determine whether the generated string is balanced; that is, whether it consists entirely of pairs of opening/closing brackets (in that order), none of which mis-... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Kernighans_large_earthquake_problem | Kernighans large earthquake problem | Brian Kernighan, in a lecture at the University of Nottingham, described a problem on which this task is based.
Problem
You are given a a data file of thousands of lines; each of three `whitespace` separated fields: a date, a one word name and the magnitude of the event.
Example lines from the file would be lines li... | #COBOL | COBOL |
*>
*> Kernighan large earthquake problem
*> Tectonics: cobc -xj kernighan-earth-quakes.cob
*> quakes.txt with the 3 sample lines
*> ./kernighan-earth-quakes
*>
>>SOURCE FORMAT IS FREE
identification division.
program-id. quakes.
e... | Give a code snippet in #COBOL
Brian Kernighan, in a lecture at the University of Nottingham, described a problem on which this task is based.
Problem
You are given a a data file of thousands of lines; each of three `whitespace` separated fields: a date, a one word name and the magnitude of the event.
Example lines ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/CRC-32 | CRC-32 |
Task
Demonstrate a method of deriving the Cyclic Redundancy Check from within the language.
The result should be in accordance with ISO 3309, ITU-T V.42, Gzip and PNG.
Algorithms are described on Computation of CRC in Wikipedia.
This variant of CRC-32 uses LSB-first order, sets the initial CRC to FFFFFFFF16, and... | #J | J | ((i.32) e. 32 26 23 22 16 12 11 10 8 7 5 4 2 1 0) 128!:3 'The quick brown fox jumps over the lazy dog'
_3199229127 | Give a code snippet in #J
Task
Demonstrate a method of deriving the Cyclic Redundancy Check from within the language.
The result should be in accordance with ISO 3309, ITU-T V.42, Gzip and PNG.
Algorithms are described on Computation of CRC in Wikipedia.
This variant of CRC-32 uses LSB-first order, sets the ini... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Knapsack_problem/Bounded | Knapsack problem/Bounded | 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 some items during the trip. Food, clothing, etc. He has a good knapsack for carrying the things, but he knows that he can carry only 4 kg weight in his knapsack, because th... | #Nim | Nim | # Knapsack. Recursive solution.
import strformat
import tables
# Description of an item.
type Item = tuple[name: string; weight, value, pieces: int]
# List of available items.
const Items: seq[Item] = @[("map", 9, 150, 1),
("compass", 13, 35, 1),
("water", 153... | Give a code snippet in #Nim
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 some items during the trip. Food, clothing, etc. He has a good knapsack for carrying the things, but he knows that he can carry only 4 kg weigh... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Execute_HQ9%2B | Execute HQ9+ | Task
Implement a HQ9+ interpreter or compiler.
| #Applesoft_BASIC | Applesoft BASIC | 100 INPUT "HQ9+ : "; I$
110 LET J$ = I$ + CHR$(13)
120 LET H$ = "HELLO, WORLD!"
130 LET B$ = "BOTTLES OF BEER"
140 LET W$ = " ON THE WALL"
150 LET W$ = W$ + CHR$(13)
160 FOR I = 1 TO LEN(I$)
170 LET C$ = MID$(J$, I, 1)
180 IF C$ = "H" THEN PRINT H$
190 IF C$ = "Q" THEN PRINT I$
200 LET A = A + (C$ = "+"... | Give a code snippet in #Applesoft_BASIC
Task
Implement a HQ9+ interpreter or compiler.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Read_entire_file | Read entire file | Task
Load the entire contents of some text file as a single string variable.
If applicable, discuss: encoding selection, the possibility of memory-mapping.
Of course, in practice one should avoid reading an entire file at once
if the file is large and the task can be accomplished incrementally instead
(in which case... | #FreeBASIC | FreeBASIC | ' FB 1.05.0 Win64
Open "input.txt" For Input Encoding "ascii" As #1
Dim fileLen As LongInt = Lof(1) '' get file length in bytes
Dim buffer As String = Space(fileLen) '' allocate a string of size 'fileLen' bytes
Get #1, 1, buffer '' read all data from start of file into the buffer
Print buffer '' print to console
buf... | Give a code snippet in #FreeBASIC
Task
Load the entire contents of some text file as a single string variable.
If applicable, discuss: encoding selection, the possibility of memory-mapping.
Of course, in practice one should avoid reading an entire file at once
if the file is large and the task can be accomplished i... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Loops/Break | Loops/Break | Task
Show a loop which prints random numbers (each number newly generated each loop) from 0 to 19 (inclusive).
If a number is 10, stop the loop after printing it, and do not generate any further numbers.
Otherwise, generate and print a second random number before restarting the loop.
If the number 10 is never gener... | #FutureBasic | FutureBasic | include "NSLog.incl"
long num
do
num = rnd(20) - 1
NSLog(@"%ld",num)
until ( num == 10 )
HandleEvents | Give a code snippet in #FutureBasic
Task
Show a loop which prints random numbers (each number newly generated each loop) from 0 to 19 (inclusive).
If a number is 10, stop the loop after printing it, and do not generate any further numbers.
Otherwise, generate and print a second random number before restarting the l... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Text_processing/Max_licenses_in_use | Text processing/Max licenses in use | A company currently pays a fixed sum for the use of a particular licensed software package. In determining if it has a good deal it decides to calculate its maximum use of the software from its license management log file.
Assume the software's licensing daemon faithfully records a checkout event when a copy of the ... | #Oz | Oz | declare
fun {MaxLicenses Filename ?Times}
InUse = {NewCell 0}
MaxInUse = {NewCell 0}
MaxTimes = {NewCell nil}
in
for Job in {ReadLines Filename} do
case {List.take Job 11} of "License OUT" then
InUse := @InUse + 1
if @InUse > @MaxInUse then
MaxInUse := @InUse
Ma... | Give a code snippet in #Oz
A company currently pays a fixed sum for the use of a particular licensed software package. In determining if it has a good deal it decides to calculate its maximum use of the software from its license management log file.
Assume the software's licensing daemon faithfully records a checko... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Associative_array/Iteration | Associative array/Iteration | Show how to iterate over the key-value pairs of an associative array, and print each pair out.
Also show how to iterate just over the keys, or the values, if there is a separate way to do that in your language.
See also
Array
Associative array: Creation, Iteration
Collections
Compound data type
Doubly-linked ... | #PowerShell | PowerShell | $h = @{ 'a' = 1; 'b' = 2; 'c' = 3 } | Give a code snippet in #PowerShell
Show how to iterate over the key-value pairs of an associative array, and print each pair out.
Also show how to iterate just over the keys, or the values, if there is a separate way to do that in your language.
See also
Array
Associative array: Creation, Iteration
Collections... | christopher/rosetta-code | |
http://rosettacode.org/wiki/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:
*
* *
* *
* * * *
* *
* * * *
... | #Ruby | Ruby | ruby -le'16.times{|y|print" "*(15-y),*(0..y).map{|x|~y&x>0?" ":" *"}}' | Give a code snippet in #Ruby
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/String_prepend | String prepend |
Basic Data Operation
This is a basic data operation. It represents a fundamental action on a basic data type.
You may see other such operations in the Basic Data Operations category, or:
Integer Operations
Arithmetic |
Comparison
Boolean Operations
Bitwise |
Logical
String Operations
Concatenation |
Interpolation |... | #Raku | Raku | # explicit concatentation
$_ = 'byte';
$_ = 'kilo' ~ $_;
.say;
# interpolation as concatenation
$_ = 'buck';
$_ = "mega$_";
.say;
# lvalue substr
$_ = 'bit';
substr-rw($_,0,0) = 'nano';
.say;
# regex substitution
$_ = 'fortnight';
s[^] = 'micro';
.say;
# reversed append assignment
$_ = 'cooper';
$_ [R~]= 'mini... | Give a code snippet in #Raku
Basic Data Operation
This is a basic data operation. It represents a fundamental action on a basic data type.
You may see other such operations in the Basic Data Operations category, or:
Integer Operations
Arithmetic |
Comparison
Boolean Operations
Bitwise |
Logical
String Operations
C... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Hailstone_sequence | Hailstone sequence | The Hailstone sequence of numbers can be generated from a starting positive integer, n by:
If n is 1 then the sequence ends.
If n is even then the next n of the sequence = n/2
If n is odd then the next n of the sequence = (3 * n) + 1
The (unproven) Collatz conje... | #Logo | Logo | to hail.next :n
output ifelse equal? 0 modulo :n 2 [:n/2] [3*:n + 1]
end
to hail.seq :n
if :n = 1 [output [1]]
output fput :n hail.seq hail.next :n
end
show hail.seq 27
show count hail.seq 27
to max.hail :n
localmake "max.n 0
localmake "max.length 0
repeat :n [if greater? count hail.seq repcount :max... | Give a code snippet in #Logo
The Hailstone sequence of numbers can be generated from a starting positive integer, n by:
If n is 1 then the sequence ends.
If n is even then the next n of the sequence = n/2
If n is odd then the next n of the sequence = (3 * n) + 1
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Terminal_control/Dimensions | Terminal control/Dimensions | Determine the height and width of the terminal, and store this information into variables for subsequent use.
| #Forth | Forth | variable term-width
variable term-height
s" gforth" environment? [if]
2drop form ( height width )
[else] \ SwiftForth
get-size ( width height ) swap
[then]
term-width ! term-height ! | Give a code snippet in #Forth
Determine the height and width of the terminal, and store this information into variables for subsequent use.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Sleep | Sleep | Task
Write a program that does the following in this order:
Input an amount of time to sleep in whatever units are most natural for your language (milliseconds, seconds, ticks, etc.). This unit should be noted in comments or in a description.
Print "Sleeping..."
Sleep the main thread for the given amount of time.
... | #E | E | def sleep(milliseconds :int, nextThing) {
stdout.println("Sleeping...")
timer.whenPast(timer.now() + milliseconds, fn {
stdout.println("Awake!")
nextThing()
})
} | Give a code snippet in #E
Task
Write a program that does the following in this order:
Input an amount of time to sleep in whatever units are most natural for your language (milliseconds, seconds, ticks, etc.). This unit should be noted in comments or in a description.
Print "Sleeping..."
Sleep the main thread for... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Nonogram_solver | Nonogram solver | A nonogram is a puzzle that provides
numeric clues used to fill in a grid of cells,
establishing for each cell whether it is filled or not.
The puzzle solution is typically a picture of some kind.
Each row and column of a rectangular grid is annotated with the lengths
of its distinct runs of occupied cells.
Using only... | #Perl | Perl | use strict;
use warnings;
my $file = 'nonogram_problems.txt';
open my $fd, '<', $file or die "$! opening $file";
while(my $row = <$fd> )
{
$row =~ /\S/ or next;
my $column = <$fd>;
my @rpats = makepatterns($row);
my @cpats = makepatterns($column);
my @rows = ( '.' x @cpats ) x @rpats;
for( my $prev = ... | Give a code snippet in #Perl
A nonogram is a puzzle that provides
numeric clues used to fill in a grid of cells,
establishing for each cell whether it is filled or not.
The puzzle solution is typically a picture of some kind.
Each row and column of a rectangular grid is annotated with the lengths
of its distinct runs... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Almost_prime | Almost prime | A k-Almost-prime is a natural number
n
{\displaystyle n}
that is the product of
k
{\displaystyle k}
(possibly identical) primes.
Example
1-almost-primes, where
k
=
1
{\displaystyle k=1}
, are the prime numbers themselves.
2-almost-primes, where
k
=
2
{\displaystyl... | #ALGOL_68 | ALGOL 68 | BEGIN
INT examples=10, classes=5;
MODE SEMIPRIME = STRUCT ([examples]INT data, INT count);
[classes]SEMIPRIME semi primes;
PROC num facs = (INT n) INT :
COMMENT
Return number of not necessarily distinct prime factors of n.
Not very efficient for large n ...
COMMENT
BEGIN
INT tf := 2, residue ... | Give a code snippet in #ALGOL_68
A k-Almost-prime is a natural number
n
{\displaystyle n}
that is the product of
k
{\displaystyle k}
(possibly identical) primes.
Example
1-almost-primes, where
k
=
1
{\displaystyle k=1}
, are the prime numbers themselves.
2-almost-primes, ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Playfair_cipher | Playfair cipher | Playfair cipher
You are encouraged to solve this task according to the task description, using any language you may know.
Task
Implement a Playfair cipher for encryption and decryption.
The user must be able to choose J = I or no Q in the alphabet.
The output of the encrypted and decrypted message ... | #Sidef | Sidef | func playfair(key, from = 'J', to = (from == 'J' ? 'I' : '')) {
func canon(str) {
str.gsub(/[^[:alpha:]]/, '').uc.gsub(from, to)
}
var m = canon(key + ('A'..'Z' -> join)).chars.uniq.slices(5)
var :ENC = gather {
m.each { |r|
for i,j in (^r ~X ^r) {
i == ... | Give a code snippet in #Sidef
Playfair cipher
You are encouraged to solve this task according to the task description, using any language you may know.
Task
Implement a Playfair cipher for encryption and decryption.
The user must be able to choose J = I or no Q in the alphabet.
The output of the e... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Remove_duplicate_elements | Remove duplicate elements |
Sorting Algorithm
This is a sorting algorithm. It may be applied to a set of data in order to sort it.
For comparing various sorts, see compare sorts.
For other sorting algorithms, see sorting algorithms, or:
O(n logn) sorts
Heap sort |
Merge sort |
Patience sort |
Quick sort
O(n log2n) sorts
Shell Sort
... | #8080_Assembly | 8080 Assembly | org 100h
jmp test
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; Given an array of bytes starting at HL with length BC,
;; remove all duplicates in the array. The new end of the array
;; is returned in HL. A page of memory (256 bytes) is required
;; to mark which bytes have been seen.
... | Give a code snippet in #8080_Assembly
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 |
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Special_variables | Special variables | Special variables have a predefined meaning within a computer programming language.
Task
List the special variables used within the language.
| #C | C | #include <iostream>
struct SpecialVariables
{
int i = 0;
SpecialVariables& operator++()
{
// 'this' is a special variable that is a pointer to the current
// class instance. It can optionally be used to refer to elements
// of the class.
this->i++; // has the same meani... | Give a code snippet in #C
Special variables have a predefined meaning within a computer programming language.
Task
List the special variables used within the language.
| 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
| #Icon_and_Unicon | Icon and Unicon | procedure main()
write( "Hello world!" )
end | Give a code snippet in #Icon_and_Unicon
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/Standa... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Roots_of_a_quadratic_function | Roots of a quadratic function | This task has been clarified. Its programming examples are in need of review to ensure that they still fit the requirements of the task.
Write a program to find the roots of a quadratic equation, i.e., solve the equation
a
x
2
+
b
x
+
c
=
0
{\displaystyle ax^{2}+bx+c=0}
.
Your program must correctly handle n... | #Clojure | Clojure | (defn quadratic
"Compute the roots of a quadratic in the form ax^2 + bx + c = 1.
Returns any of nil, a float, or a vector."
[a b c]
(let [sq-d (Math/sqrt (- (* b b) (* 4 a c)))
f #(/ (% b sq-d) (* 2 a))]
(cond
(neg? sq-d) nil
(zero? sq-d) (f +)
(pos? sq-d) [(f +) (f -)]
... | Give a code snippet in #Clojure
This task has been clarified. Its programming examples are in need of review to ensure that they still fit the requirements of the task.
Write a program to find the roots of a quadratic equation, i.e., solve the equation
a
x
2
+
b
x
+
c
=
0
{\displaystyle ax^{2}+bx+c=0}
.
You... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Averages/Pythagorean_means | Averages/Pythagorean means | Task[edit]
Compute all three of the Pythagorean means of the set of integers 1 through 10 (inclusive).
Show that
A
(
x
1
,
…
,
x
n
)
≥
G
(
x
1
,
…
,
x
n
)
≥
H
(
x
1
,
…
,
x
n
)
{\displaystyle A(x_{1},\ldots ,x_{n})\geq G(x_{1},\ldots ,x_{n})\geq H(x_{1},\ldots ,x_{n})}
for this set of p... | #ERRE | ERRE |
PROGRAM MEANS
DIM A[9]
PROCEDURE ARITHMETIC_MEAN(A[]->M)
LOCAL S,I%
NEL%=UBOUND(A,1)
S=0
FOR I%=0 TO NEL% DO
S+=A[I%]
END FOR
M=S/(NEL%+1)
END PROCEDURE
PROCEDURE GEOMETRIC_MEAN(A[]->M)
LOCAL S,I%
NEL%=UBOUND(A,1)
S=1
FOR I%=0 TO NEL% DO
... | Give a code snippet in #ERRE
Task[edit]
Compute all three of the Pythagorean means of the set of integers 1 through 10 (inclusive).
Show that
A
(
x
1
,
…
,
x
n
)
≥
G
(
x
1
,
…
,
x
n
)
≥
H
(
x
1
,
…
,
x
n
)
{\displaystyle A(x_{1},\ldots ,x_{n})\geq G(x_{1},\ldots ,x_{n})\geq H(x_{1},\ldot... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Arithmetic/Integer | Arithmetic/Integer |
Basic Data Operation
This is a basic data operation. It represents a fundamental action on a basic data type.
You may see other such operations in the Basic Data Operations category, or:
Integer Operations
Arithmetic |
Comparison
Boolean Operations
Bitwise |
Logical
String Operations
Concatenation |
Interpolation |... | #Dyalect | Dyalect | let a = 6
let b = 4
print("sum = \(a+b)")
print("difference = \(a-b)")
print("product = \(a*b)")
print("Integer quotient = \(a/b)")
print("Remainder = \(a%b)") | Give a code snippet in #Dyalect
Basic Data Operation
This is a basic data operation. It represents a fundamental action on a basic data type.
You may see other such operations in the Basic Data Operations category, or:
Integer Operations
Arithmetic |
Comparison
Boolean Operations
Bitwise |
Logical
String Operation... | christopher/rosetta-code | |
http://rosettacode.org/wiki/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... | #Scheme | Scheme | (define (next-generation left petri-dish right)
(if (null? petri-dish)
(list)
(cons (if (= (+ left
(car petri-dish)
(if (null? (cdr petri-dish))
right
(cadr petri-dish)))
2)
1... | Give a code snippet in #Scheme
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 curren... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Pi | Pi |
Create a program to continually calculate and output the next decimal digit of
π
{\displaystyle \pi }
(pi).
The program should continue forever (until it is aborted by the user) calculating and outputting each decimal digit in succession.
The output should be a decimal sequence beginning 3.14159265 ...... | #Groovy | Groovy | BigInteger q = 1, r = 0, t = 1, k = 1, n = 3, l = 3
String nn
boolean first = true
while (true) {
(nn, first, q, r, t, k, n, l) = (4*q + r - t < n*t) \
? ["${n}${first?'.':''}", false, 10*q, 10*(r - n*t), t , k , 10*(3*q + r)/t - 10*n , l ] \
: ['' , first, q*k , (2*q +... | Give a code snippet in #Groovy
Create a program to continually calculate and output the next decimal digit of
π
{\displaystyle \pi }
(pi).
The program should continue forever (until it is aborted by the user) calculating and outputting each decimal digit in succession.
The output should be a decimal seq... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Soundex | Soundex | Soundex is an algorithm for creating indices for words based on their pronunciation.
Task
The goal is for homophones to be encoded to the same representation so that they can be matched despite minor differences in spelling (from the soundex Wikipedia article).
Caution
There is a major issue in many of the ... | #Ruby | Ruby | class String
SoundexChars = 'BFPVCGJKQSXZDTLMNR'
SoundexNums = '111122222222334556'
SoundexCharsEx = '^' + SoundexChars
SoundexCharsDel = '^A-Z'
# desc: http://en.wikipedia.org/wiki/Soundex
def soundex(census = true)
str = self.upcase.delete(SoundexCharsDel)
str[0,1] + str[1..-1].delete(Soundex... | Give a code snippet in #Ruby
Soundex is an algorithm for creating indices for words based on their pronunciation.
Task
The goal is for homophones to be encoded to the same representation so that they can be matched despite minor differences in spelling (from the soundex Wikipedia article).
Caution
There is... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Exceptions/Catch_an_exception_thrown_in_a_nested_call | Exceptions/Catch an exception thrown in a nested call | Show how to create a user-defined exception and show how to catch an exception raised from several nested calls away.
Create two user-defined exceptions, U0 and U1.
Have function foo call function bar twice.
Have function bar call function baz.
Arrange for function baz to rais... | #Io | Io | U0 := Exception clone
U1 := Exception clone
foo := method(
for(i,1,2,
try(
bar(i)
)catch( U0,
"foo caught U0" print
)pass
)
)
bar := method(n,
baz(n)
)
baz := method(n,
if(n == 1,U0,U1) raise("baz with n = #{n}" interpolate)
)
foo | Give a code snippet in #Io
Show how to create a user-defined exception and show how to catch an exception raised from several nested calls away.
Create two user-defined exceptions, U0 and U1.
Have function foo call function bar twice.
Have function bar call function baz.
Arrange ... | christopher/rosetta-code |
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