task_url stringlengths 30 116 | task_name stringlengths 2 86 | task_description stringlengths 0 14.4k | language_url stringlengths 2 53 | language_name stringlengths 1 52 | code stringlengths 0 61.9k | response_seed stringclasses 1
value | instruction_seed stringlengths 27 14.4k | _source stringclasses 1
value |
|---|---|---|---|---|---|---|---|---|
http://rosettacode.org/wiki/Loops/Infinite | Loops/Infinite | Task
Print out SPAM followed by a newline in an infinite loop.
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 l... | #Microsoft_Small_Basic | Microsoft Small Basic |
While "True"
TextWindow.WriteLine("SPAM")
EndWhile
| Give a code snippet in #Microsoft_Small_Basic
Task
Print out SPAM followed by a newline in an infinite loop.
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... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Lah_numbers | Lah numbers | Lah numbers, sometimes referred to as Stirling numbers of the third kind, are coefficients of polynomial expansions expressing rising factorials in terms of falling factorials.
Unsigned Lah numbers count the number of ways a set of n elements can be partitioned into k non-empty linearly ordered subsets.
Lah numbers a... | #FreeBASIC | FreeBASIC | function factorial( n as uinteger ) as ulongint
if n = 0 then return 1
return n*factorial(n-1)
end function
function s_Lah( n as uinteger, k as uinteger ) as ulongint
if n = k then return 1
if n = 0 orelse k = 0 then return 0
if k = 1 then return factorial(n)
return ((-1)^n)*(factorial(n)*fact... | Give a code snippet in #FreeBASIC
Lah numbers, sometimes referred to as Stirling numbers of the third kind, are coefficients of polynomial expansions expressing rising factorials in terms of falling factorials.
Unsigned Lah numbers count the number of ways a set of n elements can be partitioned into k non-empty linea... | christopher/rosetta-code | |
http://rosettacode.org/wiki/RPG_attributes_generator | RPG attributes generator | RPG = Role Playing Game.
You're running a tabletop RPG, and your players are creating characters.
Each character has six core attributes: strength, dexterity, constitution, intelligence, wisdom, and charisma.
One way of generating values for these attributes is to roll four, 6-sided dice (d6) and sum the three... | #zkl | zkl | reg attrs=List(), S,N;
do{
attrs.clear();
do(6){
abcd:=(4).pump(List,(0).random.fp(1,7)); // list of 4 [1..6] randoms
attrs.append(abcd.sum(0) - (0).min(abcd)); // sum and substract min
}
}while((S=attrs.sum(0))<75 or (N=attrs.filter('>=(15)).len())<2);
println("Random numbers: %s\nSums to %d, wi... | Give a code snippet in #zkl
RPG = Role Playing Game.
You're running a tabletop RPG, and your players are creating characters.
Each character has six core attributes: strength, dexterity, constitution, intelligence, wisdom, and charisma.
One way of generating values for these attributes is to roll four, 6-side... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Averages/Simple_moving_average | Averages/Simple moving average | Computing the simple moving average of a series of numbers.
Task[edit]
Create a stateful function/class/instance that takes a period and returns a routine that takes a number as argument and returns a simple moving average of its arguments so far.
Description
A simple moving average is a method for computing an avera... | #TI-83_BASIC | TI-83 BASIC | :1->C
:While 1
:Prompt I
:C->dim(L1)
:I->L1(C)
:Disp mean(L1)
:1+C->C
:End | Give a code snippet in #TI-83_BASIC
Computing the simple moving average of a series of numbers.
Task[edit]
Create a stateful function/class/instance that takes a period and returns a routine that takes a number as argument and returns a simple moving average of its arguments so far.
Description
A simple moving avera... | 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... | #F.C5.8Drmul.C3.A6 | Fōrmulæ | Dim As Integer ancho = 143, alto = 188, x, y, p, red, green, blue, luminancia
Dim As String imagen = "Mona_Lisa.bmp"
Screenres ancho,alto,32
Bload imagen
For x = 0 To ancho-1
For y = 0 To alto-1
p = Point(x,y)
red = p Mod 256
p = p \ 256
green = p Mod 256
p = p \ 256
... | Give a code snippet in #F.C5.8Drmul.C3.A6
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... | 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
| #Shiny | Shiny | say 'Hello world!' | Give a code snippet in #Shiny
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/Remove_lines_from_a_file | Remove lines from a file | Task
Remove a specific line or a number of lines from a file.
This should be implemented as a routine that takes three parameters (filename, starting line, and the number of lines to be removed).
For the purpose of this task, line numbers and the number of lines start at one, so to remove the first two lines from th... | #Scala | Scala | object RemoveLinesFromAFile extends App {
args match {
case Array(filename, start, num) =>
import java.nio.file.{Files,Paths}
val lines = scala.io.Source.fromFile(filename).getLines
val keep = start.toInt - 1
val top = lines.take(keep).toList
val drop = lines.take(num.toInt).toList... | Give a code snippet in #Scala
Task
Remove a specific line or a number of lines from a file.
This should be implemented as a routine that takes three parameters (filename, starting line, and the number of lines to be removed).
For the purpose of this task, line numbers and the number of lines start at one, so to rem... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Five_weekends | Five weekends | The month of October in 2010 has five Fridays, five Saturdays, and five Sundays.
Task
Write a program to show all months that have this same characteristic of five full weekends from the year 1900 through 2100 (Gregorian calendar).
Show the number of months with this property (there should be 201).
Show at leas... | #Ceylon | Ceylon |
module rosetta.fiveweekends "1.0.0" {
import ceylon.time "1.2.2";
}
| Give a code snippet in #Ceylon
The month of October in 2010 has five Fridays, five Saturdays, and five Sundays.
Task
Write a program to show all months that have this same characteristic of five full weekends from the year 1900 through 2100 (Gregorian calendar).
Show the number of months with this property (the... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Compound_data_type | Compound data type |
Data Structure
This illustrates a data structure, a means of storing data within a program.
You may see other such structures in the Data Structures category.
Task
Create a compound data type:
Point(x,y)
A compound data type is one that holds multiple independent values.
Related task
Enumeration
S... | #REXX | REXX | x= -4.9
y= 1.7
point=x y | Give a code snippet in #REXX
Data Structure
This illustrates a data structure, a means of storing data within a program.
You may see other such structures in the Data Structures category.
Task
Create a compound data type:
Point(x,y)
A compound data type is one that holds multiple independent values.
Re... | 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... | #FreeBASIC | FreeBASIC | -- comment here until end of line
{- comment here -} | Give a code snippet in #FreeBASIC
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, enablin... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Yellowstone_sequence | Yellowstone sequence | The Yellowstone sequence, also called the Yellowstone permutation, is defined as:
For n <= 3,
a(n) = n
For n >= 4,
a(n) = the smallest number not already in sequence such that a(n) is relatively prime to a(n-1) and
is not relatively prime to a(n-2).
The sequence is a permutation of the natural n... | #Quackery | Quackery | [ stack ] is seqbits ( --> s )
[ bit
seqbits take |
seqbits put ] is seqadd ( n --> )
[ bit
seqbits share & not ] is notinseq ( n --> b )
[ temp put
' [ 1 2 3 ]
7 seqbits put
4
[ dip
[ dup -1 peek
over -2 peek ]
dup... | Give a code snippet in #Quackery
The Yellowstone sequence, also called the Yellowstone permutation, is defined as:
For n <= 3,
a(n) = n
For n >= 4,
a(n) = the smallest number not already in sequence such that a(n) is relatively prime to a(n-1) and
is not relatively prime to a(n-2).
The sequence... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Empty_program | Empty program | Task
Create the simplest possible program that is still considered "correct."
| #Vim_Script | Vim Script | Sub Main()
End Sub | Give a code snippet in #Vim_Script
Task
Create the simplest possible program that is still considered "correct."
| christopher/rosetta-code | |
http://rosettacode.org/wiki/N%27th | N'th | Write a function/method/subroutine/... that when given an integer greater than or equal to zero returns a string of the number followed by an apostrophe then the ordinal suffix.
Example
Returns would include 1'st 2'nd 3'rd 11'th 111'th 1001'st 1012'th
Task
Use your routine to show here the output for at least t... | #Tcl | Tcl | proc ordinal {n} {
if {$n%100<10 || $n%100>20} {
set suff [lindex {th st nd rd th th th th th th} [expr {$n % 10}]]
} else {
set suff th
}
return "$n'$suff"
}
foreach start {0 250 1000} {
for {set n $start; set l {}} {$n<=$start+25} {incr n} {
lappend l [ordinal $n]
}
puts $l
} | Give a code snippet in #Tcl
Write a function/method/subroutine/... that when given an integer greater than or equal to zero returns a string of the number followed by an apostrophe then the ordinal suffix.
Example
Returns would include 1'st 2'nd 3'rd 11'th 111'th 1001'st 1012'th
Task
Use your routine to show h... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sort_stability | Sort stability |
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
... | #Sidef | Sidef | var table = [
<UK London>,
<US New\ York>,
<US Birmingham>,
<UK Birmingham>,
];
table.sort {|a,b| a[0] <=> b[0]}.each { |col|
say "#{col[0]} #{col[1]}"
} | Give a code snippet in #Sidef
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 so... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Flipping_bits_game | Flipping bits game | The game
Given an N×N square array of zeroes or ones in an initial configuration, and a target configuration of zeroes and ones.
The game is to transform one to the other in as few moves as possible by inverting whole numbered rows or whole lettered
columns at once (as one move).
In an inversion. any 1 ... | #Java | Java | import java.awt.*;
import java.awt.event.*;
import java.util.*;
import javax.swing.*;
public class FlippingBitsGame extends JPanel {
final int maxLevel = 7;
final int minLevel = 3;
private Random rand = new Random();
private int[][] grid, target;
private Rectangle box;
private int n = maxLev... | Give a code snippet in #Java
The game
Given an N×N square array of zeroes or ones in an initial configuration, and a target configuration of zeroes and ones.
The game is to transform one to the other in as few moves as possible by inverting whole numbered rows or whole lettered
columns at once (as one move... | christopher/rosetta-code | |
http://rosettacode.org/wiki/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... | #AWK | AWK | #!/usr/bin/awk -f
BEGIN {
A[1] = 49927398716;
A[2] = 49927398717;
A[3] = 1234567812345678;
A[4] = 1234567812345670;
A[5] = "01234567897";
A[6] = "01234567890";
A[7] = "00000000000";
for (k in A) print "isLuhn("A[k]"): ",isLuhn(A[k]);
}
function isLuhn(cardno) {
s = 0;
m = "024... | Give a code snippet in #AWK
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 t... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Execute_HQ9%2B | Execute HQ9+ | Task
Implement a HQ9+ interpreter or compiler.
| #D | D | import std.stdio, std.string;
void main(in string[] args) {
if (args.length != 2 ||
args[1].length != args[1].countchars("hHqQ9+")) {
writeln("Not valid HQ9+ code.");
return;
}
ulong accumulator;
foreach (immutable c; args[1]) {
final switch(c) {
case 'Q',... | Give a code snippet in #D
Task
Implement a HQ9+ interpreter or compiler.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/String_interpolation_(included) | String interpolation (included) |
Basic Data Operation
This is a basic data operation. It represents a fundamental action on a basic data type.
You may see other such operations in the Basic Data Operations category, or:
Integer Operations
Arithmetic |
Comparison
Boolean Operations
Bitwise |
Logical
String Operations
Concatenation |
Interpolation |... | #Ada | Ada | with Ada.Strings.Fixed, Ada.Text_IO;
use Ada.Strings, Ada.Text_IO;
procedure String_Replace is
Original : constant String := "Mary had a @__@ lamb.";
Tbr : constant String := "@__@";
New_Str : constant String := "little";
Index : Natural := Fixed.Index (Original, Tbr);
begin
Put_Line (Fixed.Replace_Slic... | Give a code snippet in #Ada
Basic Data Operation
This is a basic data operation. It represents a fundamental action on a basic data type.
You may see other such operations in the Basic Data Operations category, or:
Integer Operations
Arithmetic |
Comparison
Boolean Operations
Bitwise |
Logical
String Operations
Co... | christopher/rosetta-code | |
http://rosettacode.org/wiki/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... | #Groovy | Groovy | def lower = ('a'..'z') | Give a code snippet in #Groovy
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... | 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.... | #TI-89_BASIC | TI-89 BASIC | FnOff
PlotsOff
NewPlot 1, 1, x, y
ZoomData | Give a code snippet in #TI-89_BASIC
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,... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Scope_modifiers | Scope modifiers | Most programming languages offer support for subroutines.
When execution changes between subroutines, different sets of variables and functions ("scopes") are available to the program.
Frequently these sets are defined by the placement of the variable and function declarations ("static scoping" or "lexical scoping").
T... | #bc | bc | define g(a) {
auto b
b = 3
"Inside g: a = "; a
"Inside g: b = "; b
"Inside g: c = "; c
"Inside g: d = "; d
a = 3; b = 3; c = 3; d = 3
}
define f(a) {
auto b, c
b = 2; c = 2
"Inside f (before call): a = "; a
"Inside f (before call): b = "; b
"Inside f (before cal... | Give a code snippet in #bc
Most programming languages offer support for subroutines.
When execution changes between subroutines, different sets of variables and functions ("scopes") are available to the program.
Frequently these sets are defined by the placement of the variable and function declarations ("static scopi... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Strip_a_set_of_characters_from_a_string | Strip a set of characters from a string | Task
Create a function that strips a set of characters from a string.
The function should take two arguments:
a string to be stripped
a string containing the set of characters to be stripped
The returned string should contain the first string, stripped of any characters in the second argument:
print str... | #Standard_ML | Standard ML | fun stripchars (string, chars) = let
fun aux c =
if String.isSubstring (str c) chars then
""
else
str c
in
String.translate aux string
end | Give a code snippet in #Standard_ML
Task
Create a function that strips a set of characters from a string.
The function should take two arguments:
a string to be stripped
a string containing the set of characters to be stripped
The returned string should contain the first string, stripped of any character... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Anagrams/Deranged_anagrams | Anagrams/Deranged anagrams | Two or more words are said to be anagrams if they have the same characters, but in a different order.
By analogy with derangements we define a deranged anagram as two words with the same characters, but in which the same character does not appear in the same position in both words.
Task[edit]
Use the word list at uni... | #Groovy | Groovy | def map = new TreeMap<Integer,Map<String,List<String>>>()
new URL('http://www.puzzlers.org/pub/wordlists/unixdict.txt').eachLine { word ->
def size = - word.size()
map[size] = map[size] ?: new TreeMap<String,List<String>>()
def norm = word.toList().sort().sum()
map[size][norm] = map[size][norm] ?: []
... | Give a code snippet in #Groovy
Two or more words are said to be anagrams if they have the same characters, but in a different order.
By analogy with derangements we define a deranged anagram as two words with the same characters, but in which the same character does not appear in the same position in both words.
Tas... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Barnsley_fern | Barnsley fern |
A Barnsley fern is a fractal named after British mathematician Michael Barnsley and can be created using an iterated function system (IFS).
Task
Create this fractal fern, using the following transformations:
ƒ1 (chosen 1% of the time)
xn + 1 = 0
yn + 1 = 0.16 yn
ƒ2 (chosen 85% of the time)
... | #Delphi | Delphi | unit Unit1;
interface
uses
Windows, SysUtils, Graphics, Forms, Controls, Classes, ExtCtrls;
type
TForm1 = class(TForm)
PaintBox1: TPaintBox;
procedure FormPaint(Sender: TObject);
private
{ Private declarations }
public
{ Public declarations }
end;
var
Form1: TForm1;
implementation
... | Give a code snippet in #Delphi
A Barnsley fern is a fractal named after British mathematician Michael Barnsley and can be created using an iterated function system (IFS).
Task
Create this fractal fern, using the following transformations:
ƒ1 (chosen 1% of the time)
xn + 1 = 0
yn + 1 = 0.16 yn
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Pseudo-random_numbers/Combined_recursive_generator_MRG32k3a | Pseudo-random numbers/Combined recursive generator MRG32k3a | MRG32k3a Combined recursive generator (pseudo-code)
/* Constants */
/* First generator */
a1 = [0, 1403580, -810728]
m1 = 2**32 - 209
/* Second Generator */
a2 = [527612, 0, -1370589]
m2 = 2**32 - 22853
d = m1 + 1
class MRG32k3a
x1 = [0, 0, 0] /* list of three last values of... | #Python | Python | # Constants
a1 = [0, 1403580, -810728]
m1 = 2**32 - 209
#
a2 = [527612, 0, -1370589]
m2 = 2**32 - 22853
#
d = m1 + 1
class MRG32k3a():
def __init__(self, seed_state=123):
self.seed(seed_state)
def seed(self, seed_state):
assert 0 <seed_state < d, f"Out of Range 0 x < {d}"
self.x1 =... | Give a code snippet in #Python
MRG32k3a Combined recursive generator (pseudo-code)
/* Constants */
/* First generator */
a1 = [0, 1403580, -810728]
m1 = 2**32 - 209
/* Second Generator */
a2 = [527612, 0, -1370589]
m2 = 2**32 - 22853
d = m1 + 1
class MRG32k3a
x1 = [0, 0, 0] ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Total_circles_area | Total circles area | Total circles area
You are encouraged to solve this task according to the task description, using any language you may know.
Example circles
Example circles filtered
Given some partially overlapping circles on the plane, compute and show the total area covered by them, with four or six (or a little more) decimal dig... | #XPL0 | XPL0 | real Circles, MinX, MaxX, MinY, MaxY, Temp, X, Y, DX, DY, Area;
int N, Cnt1, Cnt2;
def Del = 0.0005;
def Inf = float(-1>>1);
[\ X Y R
Circles:= [
1.6417233788, 1.6121789534, 0.0848270516,
-1.4944608174, 1.2077959613, 1.1039549836,
0.6110294452, -0.6... | Give a code snippet in #XPL0
Total circles area
You are encouraged to solve this task according to the task description, using any language you may know.
Example circles
Example circles filtered
Given some partially overlapping circles on the plane, compute and show the total area covered by them, with four or six ... | 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... | #Yabasic | Yabasic | sub isPrime(v)
if v < 2 then return False : fi
if mod(v, 2) = 0 then return v = 2 : fi
if mod(v, 3) = 0 then return v = 3 : fi
d = 5
while d * d <= v
if mod(v, d) = 0 then return False else d = d + 2 : fi
wend
return True
end sub
for i = 101 to 999
if isPrime(i) print str$(i), "... | Give a code snippet in #Yabasic
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 ... | 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... | #Haskell | Haskell | import Data.Array (Array, listArray, (!))
------------------- TRADITIONAL STRINGS ------------------
ats :: Array Int (Char, String)
ats =
listArray (0, 9) $
zip
-- 天干 tiangan – 10 heavenly stems
"甲乙丙丁戊己庚辛壬癸"
(words "jiă yĭ bĭng dīng wù jĭ gēng xīn rén gŭi")
ads :: Array Int (String, String)... | Give a code snippet in #Haskell
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 resu... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Factors_of_an_integer | Factors of an 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 |... | #Swift | Swift | func factors(n: Int) -> [Int] {
return filter(1...n) { n % $0 == 0 }
} | Give a code snippet in #Swift
Basic Data Operation
This is a basic data operation. It represents a fundamental action on a basic data type.
You may see other such operations in the Basic Data Operations category, or:
Integer Operations
Arithmetic |
Comparison
Boolean Operations
Bitwise |
Logical
String Operations
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Lucas-Lehmer_test | Lucas-Lehmer test | Lucas-Lehmer Test:
for
p
{\displaystyle p}
an odd prime, the Mersenne number
2
p
−
1
{\displaystyle 2^{p}-1}
is prime if and only if
2
p
−
1
{\displaystyle 2^{p}-1}
divides
S
(
p
−
1
)
{\displaystyle S(p-1)}
where
S
(
n
+
1
)
=
(
S
(
n
)
)
2
−
2
{\displaystyle S(n+1)=(... | #Forth | Forth | : lucas-lehmer
1+ 2 do
4 i 2 <> * abs swap 1+ dup + 1- swap
i 1- 1 ?do dup * 2 - over mod loop 0= if ." M" i . then
loop cr
;
1 15 lucas-lehmer | Give a code snippet in #Forth
Lucas-Lehmer Test:
for
p
{\displaystyle p}
an odd prime, the Mersenne number
2
p
−
1
{\displaystyle 2^{p}-1}
is prime if and only if
2
p
−
1
{\displaystyle 2^{p}-1}
divides
S
(
p
−
1
)
{\displaystyle S(p-1)}
where
S
(
n
+
1
)
=
(
S
(
n
)
)
2
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Use_another_language_to_call_a_function | Use another language to call a 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.
This task is inverse to the task Call foreign language function. Consider the following C program:
#include <stdio.h>
extern int Query (char * Data, size_t * Length);
int main (i... | #Phix | Phix | without js -- (peek/poke, call_back)
constant Here_am_I = "Here am I"
function Query(atom pData, pLength)
integer len = peekNS(pLength,machine_word(),0)
if poke_string(pData,len,Here_am_I) then
return 0
end if
pokeN(pLength,length(Here_am_I)+1,machine_word())
return 1
end function
constant Q... | Give a code snippet in #Phix
This task has been clarified. Its programming examples are in need of review to ensure that they still fit the requirements of the task.
This task is inverse to the task Call foreign language function. Consider the following C program:
#include <stdio.h>
extern int Query (char * Data, s... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Chinese_remainder_theorem | Chinese remainder theorem | Suppose
n
1
{\displaystyle n_{1}}
,
n
2
{\displaystyle n_{2}}
,
…
{\displaystyle \ldots }
,
n
k
{\displaystyle n_{k}}
are positive integers that are pairwise co-prime.
Then, for any given sequence of integers
a
1
{\displaystyle a_{1}}
,
a
2
... | #Forth | Forth | : egcd ( a b -- a b )
dup 0= IF
2drop 1 0
ELSE
dup -rot /mod \ -- b r=a%b q=a/b
-rot recurse \ -- q (s,t) = egcd(b, r)
>r swap r@ * - r> swap \ -- t (s - q*t)
THEN ;
: egcd>gcd ( a b x y -- n ) \ calculate gcd from egcd
rot * -rot * +... | Give a code snippet in #Forth
Suppose
n
1
{\displaystyle n_{1}}
,
n
2
{\displaystyle n_{2}}
,
…
{\displaystyle \ldots }
,
n
k
{\displaystyle n_{k}}
are positive integers that are pairwise co-prime.
Then, for any given sequence of integers
a
1
{\displays... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Dynamic_variable_names | Dynamic variable names | Task
Create a variable with a user-defined name.
The variable name should not be written in the program text, but should be taken from the user dynamically.
See also
Eval in environment is a similar task.
| #Arturo | Arturo | name: strip input "enter a variable name: "
value: strip input "enter a variable value: "
let name value
print ["the value of variable" name "is:" var name] | Give a code snippet in #Arturo
Task
Create a variable with a user-defined name.
The variable name should not be written in the program text, but should be taken from the user dynamically.
See also
Eval in environment is a similar task.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Bitmap/Histogram | Bitmap/Histogram | Extend the basic bitmap storage defined on this page to support dealing with image histograms. The image histogram contains for each luminance the count of image pixels having this luminance. Choosing a histogram representation take care about the data type used for the counts. It must have range of at least 0..NxM, wh... | #Phix | Phix | -- demo\rosetta\Bitmap_Histogram.exw (runnable version)
include ppm.e -- black, white, read_ppm(), write_ppm() (covers above requirements)
function to_bw(sequence image)
sequence hist = repeat(0,256)
for x=1 to length(image) do
for y=1 to length(image[x]) do
integer pixel = image[x][y]... | Give a code snippet in #Phix
Extend the basic bitmap storage defined on this page to support dealing with image histograms. The image histogram contains for each luminance the count of image pixels having this luminance. Choosing a histogram representation take care about the data type used for the counts. It must hav... | 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
| #Lua | Lua |
math.randomseed( os.time() )
local puz = { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 0 }
local dir = { { 1, 0 }, { -1, 0 }, { 0, 1 }, { 0, -1 } }
local sx, sy = 4, 4
function isValid( tx, ty )
return tx > 0 and tx < 5 and ty > 0 and ty < 5
end
function display()
io.write( "\n\n" )
for j = 1,... | Give a code snippet in #Lua
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/24_game | 24 game | The 24 Game tests one's mental arithmetic.
Task
Write a program that randomly chooses and displays four digits, each from 1 ──► 9 (inclusive) with repetitions allowed.
The program should prompt for the player to enter an arithmetic expression using just those, and all of those four digits, used exactly once each. T... | #Bracmat | Bracmat | ( 24-game
= m-w m-z 4numbers answer expr numbers
, seed get-random convertBinaryMinusToUnary
, convertDivisionToMultiplication isExpresssion reciprocal
. (seed=.!arg:(~0:~/#?m-w.~0:~/#?m-z))
& seed$!arg
& ( get-random
=
. 36969*mod$(!m-z.65536)+div$(!m-z.6553... | Give a code snippet in #Bracmat
The 24 Game tests one's mental arithmetic.
Task
Write a program that randomly chooses and displays four digits, each from 1 ──► 9 (inclusive) with repetitions allowed.
The program should prompt for the player to enter an arithmetic expression using just those, and all of those four ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Fortunate_numbers | Fortunate numbers | Definition
A Fortunate number is the smallest integer m > 1 such that for a given positive integer n, primorial(n) + m is a prime number, where primorial(n) is the product of the first n prime numbers.
For example the first fortunate number is 3 because primorial(1) is 2 and 2 + 3 = 5 which is prime whereas 2 + 2 = 4 ... | #Phix | Phix | with javascript_semantics
include mpfr.e
mpz primorial = mpz_init(1),
pj = mpz_init()
sequence fortunates = {}
for p=1 to 75 do
mpz_mul_si(primorial,primorial,get_prime(p))
integer j = 3
mpz_add_si(pj,primorial,3)
while not mpz_prime(pj) do
mpz_add_si(pj,pj,2)
j = j + 2
end while... | Give a code snippet in #Phix
Definition
A Fortunate number is the smallest integer m > 1 such that for a given positive integer n, primorial(n) + m is a prime number, where primorial(n) is the product of the first n prime numbers.
For example the first fortunate number is 3 because primorial(1) is 2 and 2 + 3 = 5 whi... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Top_rank_per_group | Top rank per group | Task
Find the top N salaries in each department, where N is provided as a parameter.
Use this data as a formatted internal data structure (adapt it to your language-native idioms, rather than parse at runtime), or identify your external data source:
Employee Name,Employee ID,Salary,Department
Tyler Bennett... | #Picat | Picat | go =>
Emp = [
% Employee Name,Employee ID,Salary,Department
["Tyler Bennett","E10297","32000","D101"],
["John Rappl","E21437","47000","D050"],
["George Woltman","E00127","53500","D101"],
["Adam Smith","E63535","18000","D202"],
["Claire Buckman","E39876","278... | Give a code snippet in #Picat
Task
Find the top N salaries in each department, where N is provided as a parameter.
Use this data as a formatted internal data structure (adapt it to your language-native idioms, rather than parse at runtime), or identify your external data source:
Employee Name,Employee ID,... | 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... | #FreeBASIC | FreeBASIC |
' FB 1.05.0 Win64
Function Mean(array() As Double) As Double
Dim length As Integer = Ubound(array) - Lbound(array) + 1
If length = 0 Then
Return 0.0/0.0 'NaN
End If
Dim As Double sum = 0.0
For i As Integer = LBound(array) To UBound(array)
sum += array(i)
Next
Return sum/length
End Function
F... | Give a code snippet in #FreeBASIC
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 ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Determine_if_two_triangles_overlap | Determine if two triangles overlap | Determining if two triangles in the same plane overlap is an important topic in collision detection.
Task
Determine which of these pairs of triangles overlap in 2D:
(0,0),(5,0),(0,5) and (0,0),(5,0),(0,6)
(0,0),(0,5),(5,0) and (0,0),(0,5),(5,0)
(0,0),(5,0),(0,5) and (-10,0),(-5,0),(-1,6)... | #Go | Go | package main
import "fmt"
type point struct {
x, y float64
}
func (p point) String() string {
return fmt.Sprintf("(%.1f, %.1f)", p.x, p.y)
}
type triangle struct {
p1, p2, p3 point
}
func (t *triangle) String() string {
return fmt.Sprintf("Triangle %s, %s, %s", t.p1, t.p2, t.p3)
}
func (t *t... | Give a code snippet in #Go
Determining if two triangles in the same plane overlap is an important topic in collision detection.
Task
Determine which of these pairs of triangles overlap in 2D:
(0,0),(5,0),(0,5) and (0,0),(5,0),(0,6)
(0,0),(0,5),(5,0) and (0,0),(0,5),(5,0)
(0,0),(5,0),(0,5) ... | 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
... | #Objeck | Objeck |
function : Swap(p : Int[]) ~ Nil {
t := p[0];
p[0] := p[1];
p[1] := t;
}
function : Sort(a : Int[]) ~ Nil {
do {
sorted := true;
size -= 1;
for (i:=0; i<a->Size(); i+=1;) {
if (a[i+1] < a[i]) {
swap(a+i);
sorted := 0;
};
};
}
while (sorted = false);
}
| Give a code snippet in #Objeck
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 s... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Extend_your_language | Extend your language | Control Structures
These are examples of control structures. You may also be interested in:
Conditional structures
Exceptions
Flow-control structures
Loops
Some programming languages allow you to extend the language. While this can be done to a certain degree in most languages (e.g. by using macros), other langua... | #Ada | Ada | with Ada.Text_IO; use Ada.Text_IO;
procedure Test_If_2 is
type Two_Bool is range 0 .. 3;
function If_2(Cond_1, Cond_2: Boolean) return Two_Bool is
(Two_Bool(2*Boolean'Pos(Cond_1)) + Two_Bool(Boolean'Pos(Cond_2)));
begin
for N in 10 .. 20 loop
Put(Integer'Image(N) & " is ");
case If_2(... | Give a code snippet in #Ada
Control Structures
These are examples of control structures. You may also be interested in:
Conditional structures
Exceptions
Flow-control structures
Loops
Some programming languages allow you to extend the language. While this can be done to a certain degree in most languages (e.g. b... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Function_composition | Function composition | Task
Create a function, compose, whose two arguments f and g, are both functions with one argument.
The result of compose is to be a function of one argument, (lets call the argument x), which works like applying function f to the result of applying function g to x.
Example
compose... | #OCaml | OCaml | let compose f g x = f (g x) | Give a code snippet in #OCaml
Task
Create a function, compose, whose two arguments f and g, are both functions with one argument.
The result of compose is to be a function of one argument, (lets call the argument x), which works like applying function f to the result of applying function g ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Hash_from_two_arrays | Hash from two arrays | Task
Using two Arrays of equal length, create a Hash object
where the elements from one array (the keys) are linked
to the elements of the other (the values)
Related task
Associative arrays/Creation
| #Scala | Scala | val keys = List(1, 2, 3)
val values = Array("A", "B", "C") // Array mixed with List
val map = keys.zip(values).toMap // and other Seq are possible.
// Testing
assert(map == Map(1 ->"A", 2 -> "B", 3 -> "C"))
println("Successfully completed without errors.") | Give a code snippet in #Scala
Task
Using two Arrays of equal length, create a Hash object
where the elements from one array (the keys) are linked
to the elements of the other (the values)
Related task
Associative arrays/Creation
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Averages/Mean_angle | Averages/Mean angle | When calculating the average or mean of an angle one has to take into account how angles wrap around so that any angle in degrees plus any integer multiple of 360 degrees is a measure of the same angle.
If one wanted an average direction of the wind over two readings where the first reading was of 350 degrees and the ... | #Common_Lisp | Common Lisp | (defun average (list)
(/ (reduce #'+ list) (length list)))
(defun radians (angle)
(* pi 1/180 angle))
(defun degrees (angle)
(* (/ 180 pi) angle))
(defun mean-angle (angles)
(let* ((angles (map 'list #'radians angles))
(cosines (map 'list #'cos angles))
(sines (map 'list #'sin angles)))
(degrees (... | Give a code snippet in #Common_Lisp
When calculating the average or mean of an angle one has to take into account how angles wrap around so that any angle in degrees plus any integer multiple of 360 degrees is a measure of the same angle.
If one wanted an average direction of the wind over two readings where the firs... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Multi-base_primes | Multi-base primes | Prime numbers are prime no matter what base they are represented in.
A prime number in a base other than 10 may not look prime at first glance.
For instance: 19 base 10 is 25 in base 7.
Several different prime numbers may be expressed as the "same" string when converted to a different base.
107 base 10 converted... | #Sidef | Sidef | func max_prime_bases(ndig, maxbase=36) {
var maxprimebases = [[]]
var nwithbases = [0]
var maxprime = (10**ndig - 1)
for p in (idiv(maxprime + 1, 10) .. maxprime) {
var dig = p.digits
var bases = (2..maxbase -> grep {|b| dig.all { _ < b } && dig.digits2num(b).is_prime })
if (... | Give a code snippet in #Sidef
Prime numbers are prime no matter what base they are represented in.
A prime number in a base other than 10 may not look prime at first glance.
For instance: 19 base 10 is 25 in base 7.
Several different prime numbers may be expressed as the "same" string when converted to a differen... | christopher/rosetta-code | |
http://rosettacode.org/wiki/List_comprehensions | List comprehensions | A list comprehension is a special syntax in some programming languages to describe lists. It is similar to the way mathematicians describe sets, with a set comprehension, hence the name.
Some attributes of a list comprehension are:
They should be distinct from (nested) for loops and the use of map and filter functio... | #Haskell | Haskell | pyth :: Int -> [(Int, Int, Int)]
pyth n =
[ (x, y, z)
| x <- [1 .. n]
, y <- [x .. n]
, z <- [y .. n]
, x ^ 2 + y ^ 2 == z ^ 2 ] | Give a code snippet in #Haskell
A list comprehension is a special syntax in some programming languages to describe lists. It is similar to the way mathematicians describe sets, with a set comprehension, hence the name.
Some attributes of a list comprehension are:
They should be distinct from (nested) for loops and ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sorting_algorithms/Quicksort | Sorting algorithms/Quicksort |
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
... | #Emacs_Lisp | Emacs Lisp | (require 'seq)
(defun quicksort (xs)
(if (null xs)
()
(let* ((head (car xs))
(tail (cdr xs))
(lower-part (quicksort (seq-filter (lambda (x) (<= x head)) tail)))
(higher-part (quicksort (seq-filter (lambda (x) (> x head)) tail))))
(append lower-part (list head) higher... | Give a code snippet in #Emacs_Lisp
Sorting Algorithm
This is a sorting algorithm. It may be applied to a set of data in order to sort it.
For comparing various sorts, see compare sorts.
For other sorting algorithms, see sorting algorithms, or:
O(n logn) sorts
Heap sort |
Merge sort |
Patience sort |
Qui... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Brazilian_numbers | Brazilian numbers | Brazilian numbers are so called as they were first formally presented at the 1994 math Olympiad Olimpiada Iberoamericana de Matematica in Fortaleza, Brazil.
Brazilian numbers are defined as:
The set of positive integer numbers where each number N has at least one natural number B where 1 < B < N-1 where the represent... | #REXX | REXX | /*REXX pgm finds: 1st N Brazilian #s; odd Brazilian #s; prime Brazilian #s; ZZZth #.*/
parse arg t.1 t.2 t.3 t.4 . /*obtain optional arguments from the CL*/
if t.4=='' | t.4=="," then t.4= 0 /*special test case of Nth Brazilian #.*/
hdr.1= 'first'; hdr.2= "first odd"; hdr.3= ... | Give a code snippet in #REXX
Brazilian numbers are so called as they were first formally presented at the 1994 math Olympiad Olimpiada Iberoamericana de Matematica in Fortaleza, Brazil.
Brazilian numbers are defined as:
The set of positive integer numbers where each number N has at least one natural number B where 1... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Map_range | Map range | Given two ranges:
[
a
1
,
a
2
]
{\displaystyle [a_{1},a_{2}]}
and
[
b
1
,
b
2
]
{\displaystyle [b_{1},b_{2}]}
;
then a value
s
{\displaystyle s}
in range
[
a
1
,
a
2
]
{\displaystyle [a_{1},a_{2}]}
is linearly mapped to a value
t
{\di... | #Lambdatalk | Lambdatalk |
{def maprange
{lambda {:a0 :a1 :b0 :b1 :s}
{+ :b0 {/ {* {- :s :a0} {- :b1 :b0}} {- :a1 :a0}}}}}
-> maprange
{maprange 0 10 -1 0 5}
-> -0.5
{S.map {maprange 0 10 -1 0} {S.serie 0 10}}
->
0 maps to -1
1 maps to -0.9
2 maps to -0.8
3 maps to -0.7
4 maps to -0.6
5 maps to -0.5
6 maps to -0.4
7 maps to -0.3... | Give a code snippet in #Lambdatalk
Given two ranges:
[
a
1
,
a
2
]
{\displaystyle [a_{1},a_{2}]}
and
[
b
1
,
b
2
]
{\displaystyle [b_{1},b_{2}]}
;
then a value
s
{\displaystyle s}
in range
[
a
1
,
a
2
]
{\displaystyle [a_{1},a_{2}]}
is linea... | 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
| #Perl | Perl | sub complement
{
my $s = shift;
$s =~ tr/01/10/;
return $s;
}
my $str = '0';
for (0..6) {
say $str;
$str .= complement($str);
}
| Give a code snippet in #Perl
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/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-... | #Phix | Phix | with javascript_semantics
function entropy(sequence s)
sequence symbols = unique(s),
counts = repeat(0,length(symbols))
for i=1 to length(s) do
integer k = find(s[i],symbols)
counts[k] += 1
end for
atom H = 0
for i=1 to length(counts) do
atom ci = counts[i]/lengt... | Give a code snippet in #Phix
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/Entropy | Entropy | Task
Calculate the Shannon entropy H of a given input string.
Given the discrete random variable
X
{\displaystyle X}
that is a string of
N
{\displaystyle N}
"symbols" (total characters) consisting of
n
{\displaystyle n}
different characters (n=2 for binary), the Shannon entropy of X in bit... | #C.2B.2B | C++ | #include <string>
#include <map>
#include <iostream>
#include <algorithm>
#include <cmath>
double log2( double number ) {
return log( number ) / log( 2 ) ;
}
int main( int argc , char *argv[ ] ) {
std::string teststring( argv[ 1 ] ) ;
std::map<char , int> frequencies ;
for ( char c : teststring )
f... | Give a code snippet in #C.2B.2B
Task
Calculate the Shannon entropy H of a given input string.
Given the discrete random variable
X
{\displaystyle X}
that is a string of
N
{\displaystyle N}
"symbols" (total characters) consisting of
n
{\displaystyle n}
different characters (n=2 for binary)... | 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 ... | #Modula-2 | Modula-2 | MODULE Palindrome;
FROM FormatString IMPORT FormatString;
FROM Terminal IMPORT WriteString,ReadChar;
PROCEDURE IsPalindrome(str : ARRAY OF CHAR) : BOOLEAN;
VAR i,m : INTEGER;
VAR buf : ARRAY[0..63] OF CHAR;
BEGIN
i := 0;
m := HIGH(str) - 1;
WHILE i<m DO
IF str[i] # str[m-i] THEN
RETURN... | Give a code snippet in #Modula-2
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... | 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 ... | #Quackery | Quackery | []
$ "rosetta/unixdict.txt" sharefile drop
nest$
[ behead reverse swap
2dup find over found iff
[ dip [ nested join ] ]
else nip
dup [] = until ]
drop
say "Number of semordnilaps: "
dup size echo cr
sortwith [ size swap size > ]
5 split drop
say "Five longest: "
witheach
[ ... | Give a code snippet in #Quackery
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 t... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Van_der_Corput_sequence | Van der Corput sequence | When counting integers in binary, if you put a (binary) point to the righEasyLangt of the count then the column immediately to the left denotes a digit with a multiplier of
2
0
{\displaystyle 2^{0}}
; the digit in the next column to the left has a multiplier of
2
1
{\displaystyle 2^{1}}
; and so o... | #Elixir | Elixir | defmodule Van_der_corput do
def sequence( n, base \\ 2 ) do
"0." <> (Integer.to_string(n, base) |> String.reverse )
end
def float( n, base \\ 2 ) do
Integer.digits(n, base) |> Enum.reduce(0, fn i,acc -> (i + acc) / base end)
end
def fraction( n, base \\ 2 ) do
str = Integer.to_string(n, base) ... | Give a code snippet in #Elixir
When counting integers in binary, if you put a (binary) point to the righEasyLangt of the count then the column immediately to the left denotes a digit with a multiplier of
2
0
{\displaystyle 2^{0}}
; the digit in the next column to the left has a multiplier of
2
1
{... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Variable-length_quantity | Variable-length quantity | Implement some operations on variable-length quantities, at least including conversions from a normal number in the language to the binary representation of the variable-length quantity for that number, and vice versa. Any variants are acceptable.
Task
With above operations,
convert these two numbers 0x200000 (209... | #Visual_Basic_.NET | Visual Basic .NET | Module Module1
Function ToVlq(v As ULong) As ULong
Dim array(8) As Byte
Dim buffer = ToVlqCollection(v).SkipWhile(Function(b) b = 0).Reverse().ToArray
buffer.CopyTo(array, 0)
Return BitConverter.ToUInt64(array, 0)
End Function
Function FromVlq(v As ULong) As ULong
... | Give a code snippet in #Visual_Basic_.NET
Implement some operations on variable-length quantities, at least including conversions from a normal number in the language to the binary representation of the variable-length quantity for that number, and vice versa. Any variants are acceptable.
Task
With above operation... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Count_occurrences_of_a_substring | Count occurrences of a substring | Task
Create a function, or show a built-in function, to count the number of non-overlapping occurrences of a substring inside a string.
The function should take two arguments:
the first argument being the string to search, and
the second a substring to be searched for.
It should return an integer cou... | #PowerShell | PowerShell |
[regex]::Matches("the three truths", "th").count
| Give a code snippet in #PowerShell
Task
Create a function, or show a built-in function, to count the number of non-overlapping occurrences of a substring inside a string.
The function should take two arguments:
the first argument being the string to search, and
the second a substring to be searched for... | christopher/rosetta-code | |
http://rosettacode.org/wiki/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.
| #PowerShell | PowerShell | $date = [DateTime]::Parse("March 7 2009 7:30pm -5" )
write-host $date
write-host $date.AddHours(12)
write-host [TimeZoneInfo]::ConvertTimeBySystemTimeZoneId($date.AddHours(12),"Vladivostok Standard Time") | Give a code snippet in #PowerShell
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/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... | #Rust | Rust | fn sum(arr: &[f64]) -> f64 {
arr.iter().fold(0.0, |p,&q| p + q)
}
fn mean(arr: &[f64]) -> f64 {
sum(arr) / arr.len() as f64
}
fn main() {
let v = &[2.0, 3.0, 5.0, 7.0, 13.0, 21.0, 33.0, 54.0];
println!("mean of {:?}: {:?}", v, mean(v));
let w = &[];
println!("mean of {:?}: {:?}", w, mean(w... | Give a code snippet in #Rust
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 estab... | christopher/rosetta-code | |
http://rosettacode.org/wiki/HTTP | HTTP | Task
Access and print a URL's content (the located resource) to the console.
There is a separate task for HTTPS Requests.
| #Batch_File | Batch File |
curl.exe -s -L http://rosettacode.org/
| Give a code snippet in #Batch_File
Task
Access and print a URL's content (the located resource) to the console.
There is a separate task for HTTPS Requests.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Machine_code | Machine code | The task requires poking machine code directly into memory and executing it. The machine code is the architecture-specific opcodes which have the simple task of adding two unsigned bytes together and making the result available to the high-level language.
For example, the following assembly language program is given f... | #PicoLisp | PicoLisp | (setq P
(struct (native "@" "malloc" 'N 39) 'N
# Align
144 # nop
144 # nop
# Prepare stack
106 12 # pushq $12
184 7 0 0 0 # mov $7, %eax
72 193 224 32 # shl $32, %rax
80 # pushq %rax
... | Give a code snippet in #PicoLisp
The task requires poking machine code directly into memory and executing it. The machine code is the architecture-specific opcodes which have the simple task of adding two unsigned bytes together and making the result available to the high-level language.
For example, the following as... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Bitmap/Write_a_PPM_file | Bitmap/Write a PPM file | Using the data storage type defined on this page for raster images, write the image to a PPM file (binary P6 prefered).
(Read the definition of PPM file on Wikipedia.)
| #PHP | PHP | class Bitmap {
public $data;
public $w;
public $h;
public function __construct($w = 16, $h = 16){
$white = array_fill(0, $w, array(255,255,255));
$this->data = array_fill(0, $h, $white);
$this->w = $w;
$this->h = $h;
}
//Fills a rectangle, or the whole image with black by default
public fu... | Give a code snippet in #PHP
Using the data storage type defined on this page for raster images, write the image to a PPM file (binary P6 prefered).
(Read the definition of PPM file on Wikipedia.)
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Find_the_intersection_of_two_lines | Find the intersection of two lines | [1]
Task
Find the point of intersection of two lines in 2D.
The 1st line passes though (4,0) and (6,10) .
The 2nd line passes though (0,3) and (10,7) .
| #AutoHotkey | AutoHotkey | LineIntersectionByPoints(L1, L2){
x1 := L1[1,1], y1 := L1[1,2]
x2 := L1[2,1], y2 := L1[2,2]
x3 := L2[1,1], y3 := L2[1,2]
x4 := L2[2,1], y4 := L2[2,2]
return ((x1*y2-y1*x2)*(x3-x4) - (x1-x2)*(x3*y4-y3*x4)) / ((x1-x2)*(y3-y4) - (y1-y2)*(x3-x4)) ", "
. ((x1*y2-y1*x2)*(y3-y4) - (y1-y2)*(x3*y4-y3*x4)) / ((x1-x2)*... | Give a code snippet in #AutoHotkey
[1]
Task
Find the point of intersection of two lines in 2D.
The 1st line passes though (4,0) and (6,10) .
The 2nd line passes though (0,3) and (10,7) .
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Closest-pair_problem | Closest-pair problem |
This page uses content from Wikipedia. The original article was at Closest pair of points problem. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance)
Task
Provide a function to find the closest two p... | #C.23 | C# | class Segment
{
public Segment(PointF p1, PointF p2)
{
P1 = p1;
P2 = p2;
}
public readonly PointF P1;
public readonly PointF P2;
public float Length()
{
return (float)Math.Sqrt(LengthSquared());
}
public float LengthSquared()
{
return (P1.X -... | Give a code snippet in #C.23
This page uses content from Wikipedia. The original article was at Closest pair of points problem. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance)
Task
Provide a func... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Call_a_function | Call a function | Task
Demonstrate the different syntax and semantics provided for calling a function.
This may include:
Calling a function that requires no arguments
Calling a function with a fixed number of arguments
Calling a function with optional arguments
Calling a function with a variable number of arguments
C... | #WDTE | WDTE | let noargs => + 2 5;
noargs -- print;
let fixedargs a b => + a b;
fixedargs 3 5 -- print;
let m => import 'math';
m.cos 3 -- print;
# WDTE only has expressions, not statements, so statement vs.
# first-class context doesn't make sense.
# Arguments in WDTE are technically passed by reference, in a way, but
# bec... | Give a code snippet in #WDTE
Task
Demonstrate the different syntax and semantics provided for calling a function.
This may include:
Calling a function that requires no arguments
Calling a function with a fixed number of arguments
Calling a function with optional arguments
Calling a function with a var... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Integer_comparison | Integer comparison |
Basic Data Operation
This is a basic data operation. It represents a fundamental action on a basic data type.
You may see other such operations in the Basic Data Operations category, or:
Integer Operations
Arithmetic |
Comparison
Boolean Operations
Bitwise |
Logical
String Operations
Concatenation |
Interpolation |... | #MMIX | MMIX | // main registers
p IS $255 % pointer
pp GREG % backup for p
A GREG % first int
B GREG % second int
// arg registers
argc IS $0
argv IS $1
LOC Data_Segment
GREG @
ERR BYTE "Wrong number of arguments",#a,0
ILLH BYTE "Argument -> ",0
ILLT BYTE " <- contains an illegal character",#a,0
LT BYTE "A is less than B",#a... | Give a code snippet in #MMIX
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/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... | #Ruby | Ruby | module TicTacToe
LINES = [[1,2,3],[4,5,6],[7,8,9],[1,4,7],[2,5,8],[3,6,9],[1,5,9],[3,5,7]]
class Game
def initialize(player_1_class, player_2_class)
@board = Array.new(10) # we ignore index 0 for convenience
@current_player_id = 0
@players = [player_1_class.new(self, "X"), player_2_class.n... | Give a code snippet in #Ruby
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™,... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Singly-linked_list/Element_insertion | Singly-linked list/Element insertion | Singly-Linked List (element)
singly-linked list
Using this method, insert an element C into a list comprised of elements A->B, following element A.
See also
Array
Associative array: Creation, Iteration
Collections
Compound data type
Doubly-linked list: Definition, Element definition, Element insertion, List Trav... | #D | D | struct SLinkedNode(T) {
T data;
typeof(this)* next;
}
void insertAfter(T)(SLinkedNode!T* listNode, SLinkedNode!T* newNode) {
newNode.next = listNode.next;
listNode.next = newNode;
}
void main() {
alias N = SLinkedNode!char;
auto lh = new N('A', new N('B'));
auto c = new N('C');
/... | Give a code snippet in #D
Singly-Linked List (element)
singly-linked list
Using this method, insert an element C into a list comprised of elements A->B, following element A.
See also
Array
Associative array: Creation, Iteration
Collections
Compound data type
Doubly-linked list: Definition, Element definition, E... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Inverted_syntax | Inverted syntax | Inverted syntax with conditional expressions
In traditional syntax conditional expressions are usually shown before the action within a statement or code block:
IF raining=true THEN needumbrella=true
In inverted syntax, the action is listed before the conditional expression in the statement or code block:
needumb... | #Nim | Nim | #--
# if statements
#--
template `?`(expression, condition) =
if condition:
expression
let raining = true
var needUmbrella: bool
# Normal syntax
if raining: needUmbrella = true
# Inverted syntax
(needUmbrella = true) ? (raining == true)
#--
# Assignments
#--
template `~=`(right, left) =
left = right... | Give a code snippet in #Nim
Inverted syntax with conditional expressions
In traditional syntax conditional expressions are usually shown before the action within a statement or code block:
IF raining=true THEN needumbrella=true
In inverted syntax, the action is listed before the conditional expression in the state... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Main_step_of_GOST_28147-89 | Main step of GOST 28147-89 | GOST 28147-89 is a standard symmetric encryption based on a Feistel network.
The structure of the algorithm consists of three levels:
encryption modes - simple replacement, application range, imposing a range of feedback and authentication code generation;
cycles - 32-З, 32-Р and 16-З, is a repetition of the ... | #Rust | Rust | use std::convert::TryInto;
use std::env;
use std::num::Wrapping;
const REPLACEMENT_TABLE: [[u8; 16]; 8] = [
[4, 10, 9, 2, 13, 8, 0, 14, 6, 11, 1, 12, 7, 15, 5, 3],
[14, 11, 4, 12, 6, 13, 15, 10, 2, 3, 8, 1, 0, 7, 5, 9],
[5, 8, 1, 13, 10, 3, 4, 2, 14, 15, 12, 7, 6, 0, 9, 11],
[7, 13, 10, 1, 0, 8, 9, 15... | Give a code snippet in #Rust
GOST 28147-89 is a standard symmetric encryption based on a Feistel network.
The structure of the algorithm consists of three levels:
encryption modes - simple replacement, application range, imposing a range of feedback and authentication code generation;
cycles - 32-З, 32-Р and... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Holidays_related_to_Easter | Holidays related to Easter | Task
Calculate the dates of:
Easter
Ascension Thursday
Pentecost
Trinity Sunday
Corpus Christi feast (for Catholic)
All Saints' Sunday (for Orthodox)
As an example, calculate for the first year of each century from;
years 400 to 2100 CE and for
years 2010 to 2020 CE.
Note
... | #Scala | Scala | import java.util._
import scala.swing._
def easter(year: Int) = {
// Start at March 21.
val cal = new GregorianCalendar(year, 2, 21);
/*
* Calculate e = day of Easter, following the 1886 paper,
* Kalender-Formeln (Calendar Formulae) by Chr. Zeller.
* http://www.merlyn.demon.co.uk/zel-1886.htm
*
... | Give a code snippet in #Scala
Task
Calculate the dates of:
Easter
Ascension Thursday
Pentecost
Trinity Sunday
Corpus Christi feast (for Catholic)
All Saints' Sunday (for Orthodox)
As an example, calculate for the first year of each century from;
years 400 to 2100 CE and for
year... | christopher/rosetta-code | |
http://rosettacode.org/wiki/User_input/Text | User input/Text | User input/Text is part of Short Circuit's Console Program Basics selection.
Task
Input a string and the integer 75000 from the text console.
See also: User input/Graphical
| #PureBasic | PureBasic | If OpenConsole()
; Declare a string and a integer to be used
Define txt.s, num.i
Print("Enter a string: ")
txt=Input()
Repeat
Print("Enter the number 75000: ")
num=Val(Input()) ; Converts the Input to a Value with Val()
Until num=75000
; Check that the user really gives us 75000!
Print("Yo... | Give a code snippet in #PureBasic
User input/Text is part of Short Circuit's Console Program Basics selection.
Task
Input a string and the integer 75000 from the text console.
See also: User input/Graphical
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Inheritance/Single | Inheritance/Single | This task is about derived types; for implementation inheritance, see Polymorphism.
Inheritance is an operation of type algebra that creates a new type from one or several parent types.
The obtained type is called derived type.
It inherits some of the properties of its parent types.
Usually inherited properties... | #J | J | coclass 'Animal' | Give a code snippet in #J
This task is about derived types; for implementation inheritance, see Polymorphism.
Inheritance is an operation of type algebra that creates a new type from one or several parent types.
The obtained type is called derived type.
It inherits some of the properties of its parent types.
U... | 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 ...... | #Raku | Raku | # based on http://www.mathpropress.com/stan/bibliography/spigot.pdf
sub stream(&next, &safe, &prod, &cons, $z is copy, @x) {
gather loop {
$z = safe($z, my $y = next($z)) ??
prod($z, take $y) !!
cons($z, @x[$++])
}
}
sub extr([$q, $r, $s, $t], $x) {
($q * $x ... | Give a code snippet in #Raku
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 seque... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Super-d_numbers | Super-d numbers | A super-d number is a positive, decimal (base ten) integer n such that d × nd has at least d consecutive digits d where
2 ≤ d ≤ 9
For instance, 753 is a super-3 number because 3 × 7533 = 1280873331.
Super-d numbers are also shown on MathWorld™ as super-d or super-d.
Task
Write a... | #Sidef | Sidef | func super_d(d) {
var D = Str(d)*d
1..Inf -> lazy.grep {|n| Str(d * n**d).contains(D) }
}
for d in (2..8) {
say ("#{d}: ", super_d(d).first(10))
} | Give a code snippet in #Sidef
A super-d number is a positive, decimal (base ten) integer n such that d × nd has at least d consecutive digits d where
2 ≤ d ≤ 9
For instance, 753 is a super-3 number because 3 × 7533 = 1280873331.
Super-d numbers are also shown on MathWorld™ as super-d ... | 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
| #Standard_ML | Standard ML | foldl (fn (a, sum) => sum + a * a) 0 ints | Give a code snippet in #Standard_ML
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/Permutations | Permutations | Task
Write a program that generates all permutations of n different objects. (Practically numerals!)
Related tasks
Find the missing permutation
Permutations/Derangements
The number of samples of size k from n objects.
With combinations and permutations generation tasks.
Order Uni... | #Shen | Shen |
(define permute
[] -> []
[X] -> [[X]]
X -> (permute-helper [] X))
(define permute-helper
_ [] -> []
Done [X|Rest] -> (append (prepend-all X (permute (append Done Rest))) (permute-helper [X|Done] Rest))
)
(define prepend-all
_ [] -> []
X [Next|Rest] -> [[X|Next]|(prepend-all X Rest)]
)
(set *ma... | Give a code snippet in #Shen
Task
Write a program that generates all permutations of n different objects. (Practically numerals!)
Related tasks
Find the missing permutation
Permutations/Derangements
The number of samples of size k from n objects.
With combinations and permutations gener... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Formatted_numeric_output | Formatted numeric output | Task
Express a number in decimal as a fixed-length string with leading zeros.
For example, the number 7.125 could be expressed as 00007.125.
| #XSLT | XSLT | <xsl:value-of select="format-number(7.125, '00000000.#############')" />
| Give a code snippet in #XSLT
Task
Express a number in decimal as a fixed-length string with leading zeros.
For example, the number 7.125 could be expressed as 00007.125.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/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 ... | #Arturo | Arturo | print levenshtein "kitten" "sitting" | Give a code snippet in #Arturo
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 co... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Integer_sequence | Integer sequence | Task
Create a program that, when run, would display all integers from 1 to ∞ (or any relevant implementation limit), in sequence (i.e. 1, 2, 3, 4, etc) if given enough time.
An example may not be able to reach arbitrarily-large numbers based on implementations limits. For example, if integer... | #Prolog | Prolog | loop(I) :-
writeln(I),
I1 is I+1,
loop(I1).
| Give a code snippet in #Prolog
Task
Create a program that, when run, would display all integers from 1 to ∞ (or any relevant implementation limit), in sequence (i.e. 1, 2, 3, 4, etc) if given enough time.
An example may not be able to reach arbitrarily-large numbers based on implementations l... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Copy_a_string | Copy a string | This task is about copying a string.
Task
Where it is relevant, distinguish between copying the contents of a string
versus making an additional reference to an existing string.
Other tasks related to string operations:
Metrics
Array length
String length
Copy a string
Empty string (assignment)
Counting
W... | #GML | GML | src = "string";
dest = src; | Give a code snippet in #GML
This task is about copying a string.
Task
Where it is relevant, distinguish between copying the contents of a string
versus making an additional reference to an existing string.
Other tasks related to string operations:
Metrics
Array length
String length
Copy a string
Empty str... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Jensen%27s_Device | Jensen's Device | Jensen's Device
You are encouraged to solve this task according to the task description, using any language you may know.
This task is an exercise in call by name.
Jensen's Device is a computer programming technique devised by Danish computer scientist Jørn Jensen after studying the ALGOL 60 Report.
The following pr... | #Elixir | Elixir | defmodule JensenDevice do
def task, do: sum( 1, 100, fn i -> 1 / i end )
defp sum( i, high, _term ) when i > high, do: 0
defp sum( i, high, term ) do
temp = term.( i )
temp + sum( i + 1, high, term )
end
end
IO.puts JensenDevice.task | Give a code snippet in #Elixir
Jensen's Device
You are encouraged to solve this task according to the task description, using any language you may know.
This task is an exercise in call by name.
Jensen's Device is a computer programming technique devised by Danish computer scientist Jørn Jensen after studying the AL... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Hash_join | Hash join | An inner join is an operation that combines two data tables into one table, based on matching column values. The simplest way of implementing this operation is the nested loop join algorithm, but a more scalable alternative is the hash join algorithm.
Task[edit]
Implement the "hash join" algorithm, and demonstrate tha... | #Java | Java | import java.util.*;
public class HashJoin {
public static void main(String[] args) {
String[][] table1 = {{"27", "Jonah"}, {"18", "Alan"}, {"28", "Glory"},
{"18", "Popeye"}, {"28", "Alan"}};
String[][] table2 = {{"Jonah", "Whales"}, {"Jonah", "Spiders"},
{"Alan", "Ghosts"}, {"A... | Give a code snippet in #Java
An inner join is an operation that combines two data tables into one table, based on matching column values. The simplest way of implementing this operation is the nested loop join algorithm, but a more scalable alternative is the hash join algorithm.
Task[edit]
Implement the "hash join" ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Proper_divisors | Proper divisors | The proper divisors of a positive integer N are those numbers, other than N itself, that divide N without remainder.
For N > 1 they will always include 1, but for N == 1 there are no proper divisors.
Examples
The proper divisors of 6 are 1, 2, and 3.
The proper divisors of 100 are 1, 2, 4, 5... | #D | D | void main() /*@safe*/ {
import std.stdio, std.algorithm, std.range, std.typecons;
immutable properDivs = (in uint n) pure nothrow @safe /*@nogc*/ =>
iota(1, (n + 1) / 2 + 1).filter!(x => n % x == 0 && n != x);
iota(1, 11).map!properDivs.writeln;
iota(1, 20_001).map!(n => tuple(properDivs(n).... | Give a code snippet in #D
The proper divisors of a positive integer N are those numbers, other than N itself, that divide N without remainder.
For N > 1 they will always include 1, but for N == 1 there are no proper divisors.
Examples
The proper divisors of 6 are 1, 2, and 3.
The proper divisors ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Faulhaber%27s_triangle | Faulhaber's triangle | Named after Johann Faulhaber, the rows of Faulhaber's triangle are the coefficients of polynomials that represent sums of integer powers, which are extracted from Faulhaber's formula:
∑
k
=
1
n
k
p
=
1
p
+
1
∑
j
=
0
p
(
p
+
1
j
)
B
j
n
p
+
1
−
j
{\displaystyle \sum _{k... | #Julia | Julia | function bernoulli(n)
A = Vector{Rational{BigInt}}(undef, n + 1)
for i in 0:n
A[i + 1] = 1 // (i + 1)
for j = i:-1:1
A[j] = j * (A[j] - A[j + 1])
end
end
return n == 1 ? -A[1] : A[1]
end
function faulhabercoeffs(p)
coeffs = Vector{Rational{BigInt}}(undef, p + 1)... | Give a code snippet in #Julia
Named after Johann Faulhaber, the rows of Faulhaber's triangle are the coefficients of polynomials that represent sums of integer powers, which are extracted from Faulhaber's formula:
∑
k
=
1
n
k
p
=
1
p
+
1
∑
j
=
0
p
(
p
+
1
j
)
B
j
n
p
+
1
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Globally_replace_text_in_several_files | Globally replace text in several files | Task
Replace every occurring instance of a piece of text in a group of text files with another one.
For this task we want to replace the text "Goodbye London!" with "Hello New York!" for a list of files.
| #REXX | REXX | /*REXX program reads the files specified and globally replaces a string. */
old= "Goodbye London!" /*the old text to be replaced. */
new= "Hello New York!" /* " new " used for replacement. */
parse arg fileList ... | Give a code snippet in #REXX
Task
Replace every occurring instance of a piece of text in a group of text files with another one.
For this task we want to replace the text "Goodbye London!" with "Hello New York!" for a list of files.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Bitmap/B%C3%A9zier_curves/Cubic | Bitmap/Bézier curves/Cubic | Using the data storage type defined on this page for raster images, and the draw_line function defined in this other one, draw a cubic bezier curve
(definition on Wikipedia).
| #Go | Go | package raster
const b3Seg = 30
func (b *Bitmap) Bézier3(x1, y1, x2, y2, x3, y3, x4, y4 int, p Pixel) {
var px, py [b3Seg + 1]int
fx1, fy1 := float64(x1), float64(y1)
fx2, fy2 := float64(x2), float64(y2)
fx3, fy3 := float64(x3), float64(y3)
fx4, fy4 := float64(x4), float64(y4)
for i := range... | Give a code snippet in #Go
Using the data storage type defined on this page for raster images, and the draw_line function defined in this other one, draw a cubic bezier curve
(definition on Wikipedia).
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Universal_Turing_machine | Universal Turing machine | One of the foundational mathematical constructs behind computer science
is the universal Turing Machine.
(Alan Turing introduced the idea of such a machine in 1936–1937.)
Indeed one way to definitively prove that a language
is turing-complete
is to implement a universal Turing machine in it.
Task
Simulate such ... | #Tcl | Tcl | proc turing {states initial terminating symbols blank tape rules {doTrace 1}} {
set state $initial
set idx 0
set tape [split $tape ""]
if {[llength $tape] == 0} {
set tape [list $blank]
}
foreach rule $rules {
lassign $rule state0 sym0 sym1 move state1
set R($state0,$sym0) [list $sym1 $move $... | Give a code snippet in #Tcl
One of the foundational mathematical constructs behind computer science
is the universal Turing Machine.
(Alan Turing introduced the idea of such a machine in 1936–1937.)
Indeed one way to definitively prove that a language
is turing-complete
is to implement a universal Turing machine i... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Hello_world/Line_printer | Hello world/Line printer | Task
Cause a line printer attached to the computer to print a line containing the message: Hello World!
Note
A line printer is not the same as standard output.
A line printer was an older-style printer which prints one line at a time to a continuous ream of paper.
With some systems, a line printer can be... | #UNIX_Shell | UNIX Shell | # Use the default printer queue, with lp(1) or lpr(1).
# 1. The system must have a printer queue.
# 2. The printer queue must understand plain text.
# 3. System V has lp(1). BSD has lpr(1).
# CUPS has both lp(1) and lpr(1).
#
echo 'Hello World!' | lp
echo 'Hello World!' | lpr
# Use a character device.
# 1. Th... | Give a code snippet in #UNIX_Shell
Task
Cause a line printer attached to the computer to print a line containing the message: Hello World!
Note
A line printer is not the same as standard output.
A line printer was an older-style printer which prints one line at a time to a continuous ream of paper.
With... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Factorial | Factorial | Definitions
The factorial of 0 (zero) is defined as being 1 (unity).
The Factorial Function of a positive integer, n, is defined as the product of the sequence:
n, n-1, n-2, ... 1
Task
Write a function to return the factorial of a number.
Solutions can be iterat... | #Vim_Script | Vim Script | function! Factorial(n)
if a:n < 2
return 1
else
return a:n * Factorial(a:n-1)
endif
endfunction | Give a code snippet in #Vim_Script
Definitions
The factorial of 0 (zero) is defined as being 1 (unity).
The Factorial Function of a positive integer, n, is defined as the product of the sequence:
n, n-1, n-2, ... 1
Task
Write a function to return the factorial o... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Deconvolution/2D%2B | Deconvolution/2D+ | This task is a straightforward generalization of Deconvolution/1D to higher dimensions. For example, the one dimensional case would be applicable to audio signals, whereas two dimensions would pertain to images. Define the discrete convolution in
d
{\displaystyle {\mathit {d}}}
dimensions of two functions
... | #Wren | Wren | import "/complex" for Complex
import "/fmt" for Fmt
var fft2 // recursive
fft2 = Fn.new { |buf, out, n, step, start|
if (step < n) {
fft2.call(out, buf, n, step*2, start)
fft2.call(out, buf, n, step*2, start + step)
var j = 0
while (j < n) {
var t = (Complex.imagMinusOn... | Give a code snippet in #Wren
This task is a straightforward generalization of Deconvolution/1D to higher dimensions. For example, the one dimensional case would be applicable to audio signals, whereas two dimensions would pertain to images. Define the discrete convolution in
d
{\displaystyle {\mathit {d}}}
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Program_name | Program name | The task is to programmatically obtain the name used to invoke the program. (For example determine whether the user ran "python hello.py", or "python hellocaller.py", a program importing the code from "hello.py".)
Sometimes a multiline shebang is necessary in order to provide the script name to a language's internal A... | #Erlang | Erlang | %% Compile
%%
%% erlc scriptname.erl
%%
%% Run
%%
%% erl -noshell -s scriptname
-module(scriptname).
-export([start/0]).
start() ->
Program = ?FILE,
io:format("Program: ~s~n", [Program]),
init:stop(). | Give a code snippet in #Erlang
The task is to programmatically obtain the name used to invoke the program. (For example determine whether the user ran "python hello.py", or "python hellocaller.py", a program importing the code from "hello.py".)
Sometimes a multiline shebang is necessary in order to provide the script... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Polynomial_long_division | Polynomial long division |
This page uses content from Wikipedia. The original article was at Polynomial long division. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance)
In algebra, polynomial long division is an algorithm for d... | #Mathematica.2FWolfram_Language | Mathematica/Wolfram Language | PolynomialQuotientRemainder[x^3-12 x^2-42,x-3,x] | Give a code snippet in #Mathematica.2FWolfram_Language
This page uses content from Wikipedia. The original article was at Polynomial long division. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance)
In... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Variable-length_quantity | Variable-length quantity | Implement some operations on variable-length quantities, at least including conversions from a normal number in the language to the binary representation of the variable-length quantity for that number, and vice versa. Any variants are acceptable.
Task
With above operations,
convert these two numbers 0x200000 (209... | #Wren | Wren | import "/fmt" for Fmt, Conv
import "/str" for Str
var toOctets = Fn.new { |n|
var s = Conv.itoa(n, 2)
var le = s.count
var r = le % 7
var d = (le/7).floor
if (r > 0) {
d = d + 1
s = Fmt.zfill(7 * d, s)
}
var chunks = Str.chunks(s, 7)
var last = "0" + chunks[-1]
s = ... | Give a code snippet in #Wren
Implement some operations on variable-length quantities, at least including conversions from a normal number in the language to the binary representation of the variable-length quantity for that number, and vice versa. Any variants are acceptable.
Task
With above operations,
convert t... | christopher/rosetta-code | |
http://rosettacode.org/wiki/ABC_problem | ABC problem | ABC problem
You are encouraged to solve this task according to the task description, using any language you may know.
You are given a collection of ABC blocks (maybe like the ones you had when you were a kid).
There are twenty blocks with two letters on each block.
A complete alphabet is guaranteed amongst all sid... | #MATLAB_.2F_Octave | MATLAB / Octave | function testABC
combos = ['BO' ; 'XK' ; 'DQ' ; 'CP' ; 'NA' ; 'GT' ; 'RE' ; 'TG' ; 'QD' ; ...
'FS' ; 'JW' ; 'HU' ; 'VI' ; 'AN' ; 'OB' ; 'ER' ; 'FS' ; 'LY' ; ...
'PC' ; 'ZM'];
words = {'A' 'BARK' 'BOOK' 'TREAT' 'COMMON' 'SQUAD' 'CONFUSE'};
for k = 1:length(words)
possible = canMakeWor... | Give a code snippet in #MATLAB_.2F_Octave
ABC problem
You are encouraged to solve this task according to the task description, using any language you may know.
You are given a collection of ABC blocks (maybe like the ones you had when you were a kid).
There are twenty blocks with two letters on each block.
A comp... | christopher/rosetta-code | |
http://rosettacode.org/wiki/CUSIP | CUSIP |
This page uses content from Wikipedia. The original article was at CUSIP. 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)
A CUSIP is a nine-character alphanumeric code that identifies a North A... | #Vlang | Vlang | fn is_cusip(s string) bool {
if s.len != 9 { return false }
mut sum := 0
for i in 0..8 {
c := s[i]
mut v :=0
match true {
c >= '0'[0] && c <= '9'[0] {
v = c - 48
}
c >= 'A'[0] && c <= 'Z'[0] {
v = c - 55
}
c ==... | Give a code snippet in #Vlang
This page uses content from Wikipedia. The original article was at CUSIP. 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)
A CUSIP is a nine-character alphanumeric... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Fibonacci_sequence | Fibonacci sequence | The Fibonacci sequence is a sequence Fn of natural numbers defined recursively:
F0 = 0
F1 = 1
Fn = Fn-1 + Fn-2, if n>1
Task
Write a function to generate the nth Fibonacci number.
Solutions can be iterative or recursive (though recursive solutions are generally considered too slow ... | #ZX_Spectrum_Basic | ZX Spectrum Basic | 10 REM Only positive numbers
20 LET n=10
30 LET n1=0: LET n2=1
40 FOR k=1 TO n
50 LET sum=n1+n2
60 LET n1=n2
70 LET n2=sum
80 NEXT k
90 PRINT n1 | Give a code snippet in #ZX_Spectrum_Basic
The Fibonacci sequence is a sequence Fn of natural numbers defined recursively:
F0 = 0
F1 = 1
Fn = Fn-1 + Fn-2, if n>1
Task
Write a function to generate the nth Fibonacci number.
Solutions can be iterative or recursive (though recursive s... | 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 |... | #jq | jq | # Lines which do not have two integers are skipped:
def arithmetic:
split(" ") | select(length > 0) | map(tonumber)
| if length > 1 then
.[0] as $a | .[1] as $b
| "For a = \($a) and b = \($b):\n" +
"a + b = \($a + $b)\n" +
"a - b = \($a - $b)\n" +
"a * b = \($a * $b)\n" +
"a/b|floo... | Give a code snippet in #jq
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
Con... | christopher/rosetta-code | |
http://rosettacode.org/wiki/URL_decoding | URL decoding | This task (the reverse of URL encoding and distinct from URL parser) is to provide a function
or mechanism to convert an URL-encoded string into its original unencoded form.
Test cases
The encoded string "http%3A%2F%2Ffoo%20bar%2F" should be reverted to the unencoded form "http://foo bar/".
Th... | #Groovy | Groovy | assert URLDecoder.decode('http%3A%2F%2Ffoo%20bar%2F') == 'http://foo bar/' | Give a code snippet in #Groovy
This task (the reverse of URL encoding and distinct from URL parser) is to provide a function
or mechanism to convert an URL-encoded string into its original unencoded form.
Test cases
The encoded string "http%3A%2F%2Ffoo%20bar%2F" should be reverted to the unencoded... | christopher/rosetta-code |
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