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/Append_a_record_to_the_end_of_a_text_file | Append a record to the end of a text file | Many systems offer the ability to open a file for writing, such that any data written will be appended to the end of the file. Further, the file operations will always adjust the position pointer to guarantee the end of the file, even in a multitasking environment.
This feature is most useful in the case of log files,... | #Sidef | Sidef | define (
RECORD_FIELDS = %w(account password UID GID GECOS directory shell),
GECOS_FIELDS = %w(fullname office extension homephone email),
RECORD_SEP = ':',
GECOS_SEP = ',',
PASSWD_FILE = 'passwd.txt',
)
# here's our three records
var records_to_write = [
Hash(
account => 'j... | Give a code snippet in #Sidef
Many systems offer the ability to open a file for writing, such that any data written will be appended to the end of the file. Further, the file operations will always adjust the position pointer to guarantee the end of the file, even in a multitasking environment.
This feature is most u... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Binary_search | Binary search | A binary search divides a range of values into halves, and continues to narrow down the field of search until the unknown value is found. It is the classic example of a "divide and conquer" algorithm.
As an analogy, consider the children's game "guess a number." The scorer has a secret number, and will only tell the p... | #CoffeeScript | CoffeeScript | binarySearch = (xs, x) ->
do recurse = (low = 0, high = xs.length - 1) ->
mid = Math.floor (low + high) / 2
switch
when high < low then NaN
when xs[mid] > x then recurse low, mid - 1
when xs[mid] < x then recurse mid + 1, high
else mid | Give a code snippet in #CoffeeScript
A binary search divides a range of values into halves, and continues to narrow down the field of search until the unknown value is found. It is the classic example of a "divide and conquer" algorithm.
As an analogy, consider the children's game "guess a number." The scorer has a s... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Associative_array/Iteration | Associative array/Iteration | Show how to iterate over the key-value pairs of an associative array, and print each pair out.
Also show how to iterate just over the keys, or the values, if there is a separate way to do that in your language.
See also
Array
Associative array: Creation, Iteration
Collections
Compound data type
Doubly-linked ... | #Raku | Raku | my %pairs = hello => 13, world => 31, '!' => 71;
for %pairs.kv -> $k, $v {
say "(k,v) = ($k, $v)";
}
# Stable order
for %pairs.sort(*.value)>>.kv -> ($k, $v) {
say "(k,v) = ($k, $v)";
}
{ say "$^a => $^b" } for %pairs.kv;
say "key = $_" for %pairs.keys;
say "value = $_" for %pairs.values; | Give a code snippet in #Raku
Show how to iterate over the key-value pairs of an associative array, and print each pair out.
Also show how to iterate just over the keys, or the values, if there is a separate way to do that in your language.
See also
Array
Associative array: Creation, Iteration
Collections
Comp... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Maze_solving | Maze solving | Task
For a maze generated by this task, write a function
that finds (and displays) the shortest path between two cells.
Note that because these mazes are generated by the Depth-first search algorithm, they contain no circular paths,
and a simple depth-first tree search can be used.
| #Action.21 | Action! | DEFINE TOP="0"
DEFINE RIGHT="1"
DEFINE BOTTOM="2"
DEFINE LEFT="3"
DEFINE WIDTH="160"
DEFINE HEIGHT="96"
DEFINE STACK_SIZE="5000"
BYTE ARRAY stack(STACK_SIZE)
INT stackSize
PROC InitStack()
stackSize=0
RETURN
BYTE FUNC IsEmpty()
IF stackSize=0 THEN
RETURN (1)
FI
RETURN (0)
BYTE FUNC IsFull()
IF stack... | Give a code snippet in #Action.21
Task
For a maze generated by this task, write a function
that finds (and displays) the shortest path between two cells.
Note that because these mazes are generated by the Depth-first search algorithm, they contain no circular paths,
and a simple depth-first tree search can be used... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Pangram_checker | Pangram checker | Pangram checker
You are encouraged to solve this task according to the task description, using any language you may know.
A pangram is a sentence that contains all the letters of the English alphabet at least once.
For example: The quick brown fox jumps over the lazy dog.
Task
Write a function or method to chec... | #jq | jq | def is_pangram:
explode
| map( if 65 <= . and . <= 90 then . + 32 # uppercase
elif 97 <= . and . <= 122 then . # lowercase
else empty
end )
| unique
| length == 26;
# Example:
"The quick brown fox jumps over the lazy dog" | is_pangram | Give a code snippet in #jq
Pangram checker
You are encouraged to solve this task according to the task description, using any language you may know.
A pangram is a sentence that contains all the letters of the English alphabet at least once.
For example: The quick brown fox jumps over the lazy dog.
Task
Write ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Strip_block_comments | Strip block comments | A block comment begins with a beginning delimiter and ends with a ending delimiter, including the delimiters. These delimiters are often multi-character sequences.
Task
Strip block comments from program text (of a programming language much like classic C).
Your demos should at least handle simple, non-ne... | #C | C | #include <stdio.h>
#include <string.h>
#include <stdlib.h>
const char *ca = "/*", *cb = "*/";
int al = 2, bl = 2;
char *loadfile(const char *fn) {
FILE *f = fopen(fn, "rb");
int l;
char *s;
if (f != NULL) {
fseek(f, 0, SEEK_END);
l = ftell(f);
s = malloc(l+1);
rewind(f);
if (s)
fread(s, ... | Give a code snippet in #C
A block comment begins with a beginning delimiter and ends with a ending delimiter, including the delimiters. These delimiters are often multi-character sequences.
Task
Strip block comments from program text (of a programming language much like classic C).
Your demos should at ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Palindromic_gapful_numbers | Palindromic gapful numbers | Palindromic gapful numbers
You are encouraged to solve this task according to the task description, using any language you may know.
Numbers (positive integers expressed in base ten) that are (evenly) divisible by the number formed by the
first and last digit are known as gapful numbers.
Evenly divisible mea... | #Wren | Wren | import "/fmt" for Conv, Fmt
var reverse = Fn.new { |s|
var e = 0
while (s > 0) {
e = e * 10 + (s % 10)
s = (s/10).floor
}
return e
}
var MAX = 100000
var data = [ [1, 20, 7], [86, 100, 8], [991, 1000, 10], [9995, 10000, 12], [99996, 100000, 14] ]
var results = {}
for (d in data) {
... | Give a code snippet in #Wren
Palindromic gapful numbers
You are encouraged to solve this task according to the task description, using any language you may know.
Numbers (positive integers expressed in base ten) that are (evenly) divisible by the number formed by the
first and last digit are known as gapful num... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Terminal_control/Preserve_screen | Terminal control/Preserve screen |
Task
Clear the screen, output something on the display, and then restore the screen to the preserved state that it was in before the task was carried out.
There is no requirement to change the font or kerning in this task, however character decorations and attributes are expected to be preserved. If the implement... | #Go | Go | package main
import (
"fmt"
"time"
)
func main() {
fmt.Print("\033[?1049h\033[H")
fmt.Println("Alternate screen buffer\n")
s := "s"
for i := 5; i > 0; i-- {
if i == 1 {
s = ""
}
fmt.Printf("\rgoing back in %d second%s...", i, s)
time.Sleep(time.Sec... | Give a code snippet in #Go
Task
Clear the screen, output something on the display, and then restore the screen to the preserved state that it was in before the task was carried out.
There is no requirement to change the font or kerning in this task, however character decorations and attributes are expected to be p... | 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... | #Scala | Scala | import java.awt.print.PrinterException
import scala.swing.TextArea
object LinePrinter extends App {
val (show, context) = (false, "Hello, World!")
try // Default Helvetica, 12p
new TextArea(context) {
append(" in printing.")
peer.print(null, null, show, null, null, show)
}
catch {
case e... | Give a code snippet in #Scala
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... | 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
| #C | C | /* RosettaCode: Fifteen puzle game, C89, plain vanillia TTY, MVC, § 22 */
#define _CRT_SECURE_NO_WARNINGS
#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#define N 4
#define M 4
enum Move{UP,DOWN,LEFT,RIGHT};int hR;int hC;int cc[N][M];const int nS=100;int
update(enum Move m){const int dx[]={0,0,-1,1};const int... | Give a code snippet in #C
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/Cut_a_rectangle | Cut a rectangle | A given rectangle is made from m × n squares. If m and n are not both odd, then it is possible to cut a path through the rectangle along the square edges such that the rectangle splits into two connected pieces with the same shape (after rotating one of the pieces by 180°). All such paths for 2 × 2 and 4 × 3 rectangles... | #Eiffel | Eiffel |
class
APPLICATION
create
make
feature {NONE} -- Initialization
make
-- Finds solution for cut a rectangle up to 10 x 10.
local
i, j, n: Integer
r: GRID
do
n := 10
from
i := 1
until
i > n
loop
from
j := 1
until
j > i
loop
if i.bit_and (1) /= 1 or j.b... | Give a code snippet in #Eiffel
A given rectangle is made from m × n squares. If m and n are not both odd, then it is possible to cut a path through the rectangle along the square edges such that the rectangle splits into two connected pieces with the same shape (after rotating one of the pieces by 180°). All such path... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Pell%27s_equation | Pell's equation | Pell's equation (also called the Pell–Fermat equation) is a Diophantine equation of the form:
x2 - ny2 = 1
with integer solutions for x and y, where n is a given non-square positive integer.
Task requirements
find the smallest solution in positive integers to Pell's equation for... | #C | C | #include <math.h>
#include <stdbool.h>
#include <stdint.h>
#include <stdio.h>
struct Pair {
uint64_t v1, v2;
};
struct Pair makePair(uint64_t a, uint64_t b) {
struct Pair r;
r.v1 = a;
r.v2 = b;
return r;
}
struct Pair solvePell(int n) {
int x = (int) sqrt(n);
if (x * x == n) {
... | Give a code snippet in #C
Pell's equation (also called the Pell–Fermat equation) is a Diophantine equation of the form:
x2 - ny2 = 1
with integer solutions for x and y, where n is a given non-square positive integer.
Task requirements
find the smallest solution in positive inte... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Pascal%27s_triangle | Pascal's triangle | Pascal's triangle is an arithmetic and geometric figure often associated with the name of Blaise Pascal, but also studied centuries earlier in India, Persia, China and elsewhere.
Its first few rows look like this:
1
1 1
1 2 1
1 3 3 1
where each element of each row is either 1 or the sum of the two elemen... | #Burlesque | Burlesque |
blsq ) {1}{1 1}{^^2CO{p^?+}m[1+]1[+}15E!#s<-spbx#S
1
1 1
1 2 1
1 3 3 1
1 4 6 4 1
1 5 10 10 5 1
1 6 15 20 15 6 1
1 7 21 35 35 21 7 1
1 8 28 56 70 56 28 8 1
1 9 36 84 126 126 84 36 9 1
1 10 45 120 210 252 210 120 45 10 1
1 11 55 165 330 462 462 330 165 55 11 1
1 12 66 220 495 792 924 792 495 220 66 12 1
1 13 78 286 715... | Give a code snippet in #Burlesque
Pascal's triangle is an arithmetic and geometric figure often associated with the name of Blaise Pascal, but also studied centuries earlier in India, Persia, China and elsewhere.
Its first few rows look like this:
1
1 1
1 2 1
1 3 3 1
where each element of each row is ei... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Factorions | Factorions |
Definition
A factorion is a natural number that equals the sum of the factorials of its digits.
Example
145 is a factorion in base 10 because:
1! + 4! + 5! = 1 + 24 + 120 = 145
It can be shown (see talk page) that no factorion in base 10 can exceed 1,499,999.
Task
Write a progr... | #ALGOL_68 | ALGOL 68 | BEGIN
# cache factorials from 0 to 11 #
[ 0 : 11 ]INT fact;
fact[0] := 1;
FOR n TO 11 DO
fact[n] := fact[n-1] * n
OD;
FOR b FROM 9 TO 12 DO
print( ( "The factorions for base ", whole( b, 0 ), " are:", newline ) );
FOR i TO 1500000 - 1 DO
INT sum := 0;
... | Give a code snippet in #ALGOL_68
Definition
A factorion is a natural number that equals the sum of the factorials of its digits.
Example
145 is a factorion in base 10 because:
1! + 4! + 5! = 1 + 24 + 120 = 145
It can be shown (see talk page) that no factorion in base 10 can exceed ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Humble_numbers | Humble numbers | Humble numbers are positive integers which have no prime factors > 7.
Humble numbers are also called 7-smooth numbers, and sometimes called highly composite,
although this conflicts with another meaning of highly composite numbers.
Another way to express the above is:
humble = 2i × 3j × 5k... | #Java | Java |
import java.math.BigInteger;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
public class HumbleNumbers {
public static void main(String[] args) {
System.out.println("First 50 humble numbers:");
... | Give a code snippet in #Java
Humble numbers are positive integers which have no prime factors > 7.
Humble numbers are also called 7-smooth numbers, and sometimes called highly composite,
although this conflicts with another meaning of highly composite numbers.
Another way to express the above ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Digital_root | Digital root | The digital root,
X
{\displaystyle X}
, of a number,
n
{\displaystyle n}
, is calculated:
find
X
{\displaystyle X}
as the sum of the digits of
n
{\displaystyle n}
find a new
X
{\displaystyle X}
by summing the digits of
X
{\displaystyle X}
, repeating until
X
{\displ... | #TI-83_BASIC | TI-83 BASIC | :ClrHome
:1→X
:Input ">",Str1
:Str1→Str2
:Repeat L≤1
:Disp Str1
:length(Str1→L
:L→dim(L₁
:seq(expr(sub(Str1,A,1)),A,1,L)→L₁
:sum(L₁→N
:{0,.5,1→L₂
:NL₂→L₃
:Med-Med L₂,L₃,Y₁
:Equ►String(Y₁,Str1
:sub(Str1,1,length(Str1)-3→Str1
:X+1→X
:End
:Pause
:ClrHome
:Disp Str2,"DIGITAL ROOT",expr(Str1),"ADDITIVE","PERSISTENCE",X... | Give a code snippet in #TI-83_BASIC
The digital root,
X
{\displaystyle X}
, of a number,
n
{\displaystyle n}
, is calculated:
find
X
{\displaystyle X}
as the sum of the digits of
n
{\displaystyle n}
find a new
X
{\displaystyle X}
by summing the digits of
X
{\displaystyle ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Guess_the_number/With_feedback | Guess the number/With feedback | Task
Write a game (computer program) that follows the following rules:
The computer chooses a number between given set limits.
The player is asked for repeated guesses until the the target number is guessed correctly
At each guess, the computer responds with whether the guess is:
higher than the target,
equal to... | #PureBasic | PureBasic | OpenConsole()
Repeat
; Ask for limits, with sanity check
Print("Enter low limit : "): low =Val(Input())
Print("Enter high limit: "): High =Val(Input())
Until High>low
TheNumber=Random(High-low)+low
Debug TheNumber
Repeat
Print("Guess what number I have: "): Guess=Val(Input())
If Guess=TheNumber
Pri... | Give a code snippet in #PureBasic
Task
Write a game (computer program) that follows the following rules:
The computer chooses a number between given set limits.
The player is asked for repeated guesses until the the target number is guessed correctly
At each guess, the computer responds with whether the guess is:... | 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.
| #RLaB | RLaB | >> s = "myusername"
myusername
>> $$.[s] = 10;
>> myusername
10 | Give a code snippet in #RLaB
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/Look-and-say_sequence | Look-and-say sequence | The Look and say sequence is a recursively defined sequence of numbers studied most notably by John Conway.
The look-and-say sequence is also known as the Morris Number Sequence, after cryptographer Robert Morris, and the puzzle What is the next number in the sequence 1, 11, 21, 1211, 11122... | #Smalltalk | Smalltalk | String extend [
lookAndSay [ |anElement nextElement counter coll newColl|
coll := (self asOrderedCollection).
newColl := OrderedCollection new.
counter := 0.
anElement := (coll first).
[ coll size > 0 ]
whileTrue: [
nextElement := coll removeFirst.
( anElement == nextElement ) i... | Give a code snippet in #Smalltalk
The Look and say sequence is a recursively defined sequence of numbers studied most notably by John Conway.
The look-and-say sequence is also known as the Morris Number Sequence, after cryptographer Robert Morris, and the puzzle What is the next number in the sequ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Combinations_with_repetitions | Combinations with repetitions | The set of combinations with repetitions is computed from a set,
S
{\displaystyle S}
(of cardinality
n
{\displaystyle n}
), and a size of resulting selection,
k
{\displaystyle k}
, by reporting the sets of cardinality
k
{\displaystyle k}
where each member of those sets is chosen from
S... | #Elixir | Elixir | defmodule RC do
def comb_rep(0, _), do: [[]]
def comb_rep(_, []), do: []
def comb_rep(n, [h|t]=s) do
(for l <- comb_rep(n-1, s), do: [h|l]) ++ comb_rep(n, t)
end
end
s = [:iced, :jam, :plain]
Enum.each(RC.comb_rep(2, s), fn x -> IO.inspect x end)
IO.puts "\nExtra credit: #{length(RC.comb_rep(3, Enum.to... | Give a code snippet in #Elixir
The set of combinations with repetitions is computed from a set,
S
{\displaystyle S}
(of cardinality
n
{\displaystyle n}
), and a size of resulting selection,
k
{\displaystyle k}
, by reporting the sets of cardinality
k
{\displaystyle k}
where each member of... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Hello_world/Newline_omission | Hello world/Newline omission | Some languages automatically insert a newline after outputting a string, unless measures are taken to prevent its output.
Task
Display the string Goodbye, World! without a trailing newline.
Related tasks
Hello world/Graphical
Hello world/Line Printer
Hello world/Standard error
Hello world/Text
| #Jack | Jack | class Main {
function void main () {
do Output.printString("Goodbye, World!");und
return;
}
} | Give a code snippet in #Jack
Some languages automatically insert a newline after outputting a string, unless measures are taken to prevent its output.
Task
Display the string Goodbye, World! without a trailing newline.
Related tasks
Hello world/Graphical
Hello world/Line Printer
Hello world/Standa... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Hickerson_series_of_almost_integers | Hickerson series of almost integers | The following function, due to D. Hickerson, is said to generate "Almost integers" by the
"Almost Integer" page of Wolfram MathWorld, (December 31 2013). (See formula numbered 51.)
The function is:
h
(
n
)
=
n
!
2
(
ln
2
)
n
+
1
{\displaystyle h(n)={\operatorname {n} ! \ove... | #Ada | Ada | with Ada.Text_IO;
with Ada.Numerics.Generic_Elementary_Functions;
procedure Almost_Integers is
type Real is new Long_Long_Float;
package Real_IO is
new Ada.Text_IO.Float_IO (Real);
package Integer_IO is
new Ada.Text_IO.Integer_IO (Integer);
function Faculty (N : in Long_Long_Integer) ret... | Give a code snippet in #Ada
The following function, due to D. Hickerson, is said to generate "Almost integers" by the
"Almost Integer" page of Wolfram MathWorld, (December 31 2013). (See formula numbered 51.)
The function is:
h
(
n
)
=
n
!
2
(
ln
2
)
n
+
1
{\displaystyle h... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Stair-climbing_puzzle | Stair-climbing puzzle | From Chung-Chieh Shan (LtU):
Your stair-climbing robot has a very simple low-level API: the "step" function takes no argument and attempts to climb one step as a side effect. Unfortunately, sometimes the attempt fails and the robot clumsily falls one step instead. The "step" function detects what happens and returns a... | #AWK | AWK |
function step_up() {
while (!step()) { step_up() }
}
| Give a code snippet in #AWK
From Chung-Chieh Shan (LtU):
Your stair-climbing robot has a very simple low-level API: the "step" function takes no argument and attempts to climb one step as a side effect. Unfortunately, sometimes the attempt fails and the robot clumsily falls one step instead. The "step" function detec... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Secure_temporary_file | Secure temporary file | Task
Create a temporary file, securely and exclusively (opening it such that there are no possible race conditions).
It's fine assuming local filesystem semantics (NFS or other networking filesystems can have signficantly more complicated semantics for satisfying the "no race conditions" criteria).
The function shou... | #Ada | Ada | with Ada.Text_Io; use Ada.Text_Io;
procedure Temp_File is
Temp : File_Type;
Contents : String(1..80);
Length : Natural;
begin
-- Create a temporary file
Create(File => Temp);
Put_Line(File => Temp, Item => "Hello World");
Reset(File => Temp, Mode => In_File);
Get_Line(File => Temp, Item => Con... | Give a code snippet in #Ada
Task
Create a temporary file, securely and exclusively (opening it such that there are no possible race conditions).
It's fine assuming local filesystem semantics (NFS or other networking filesystems can have signficantly more complicated semantics for satisfying the "no race conditions" ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Enforced_immutability | Enforced immutability | Task
Demonstrate any means your language has to prevent the modification of values, or to create objects that cannot be modified after they have been created.
| #Python | Python | >>> s = "Hello"
>>> s[0] = "h"
Traceback (most recent call last):
File "<pyshell#1>", line 1, in <module>
s[0] = "h"
TypeError: 'str' object does not support item assignment | Give a code snippet in #Python
Task
Demonstrate any means your language has to prevent the modification of values, or to create objects that cannot be modified after they have been created.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Combinations_with_repetitions | Combinations with repetitions | The set of combinations with repetitions is computed from a set,
S
{\displaystyle S}
(of cardinality
n
{\displaystyle n}
), and a size of resulting selection,
k
{\displaystyle k}
, by reporting the sets of cardinality
k
{\displaystyle k}
where each member of those sets is chosen from
S... | #Sidef | Sidef | func cwr (n, l, a = []) {
n>0 ? (^l -> map {|k| __FUNC__(n-1, l.slice(k), [a..., l[k]]) }) : a
}
cwr(2, %w(iced jam plain)).each {|a|
say a.map{ .join(' ') }.join("\n")
} | Give a code snippet in #Sidef
The set of combinations with repetitions is computed from a set,
S
{\displaystyle S}
(of cardinality
n
{\displaystyle n}
), and a size of resulting selection,
k
{\displaystyle k}
, by reporting the sets of cardinality
k
{\displaystyle k}
where each member of ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Deepcopy | Deepcopy | Task
Demonstrate how to copy data structures containing complex heterogeneous and cyclic semantics.
This is often referred to as deep copying, and is normally required where structures are mutable and to ensure that independent copies can be manipulated without side-effects.
If this facility is not built into the la... | #Perl | Perl |
#!/usr/bin/perl
use strict;
use warnings;
use Storable;
use Data::Dumper;
my $src = { foo => 0, bar => [0, 1] };
$src->{baz} = $src;
my $dst = Storable::dclone($src);
print Dumper($src);
print Dumper($dst);
| Give a code snippet in #Perl
Task
Demonstrate how to copy data structures containing complex heterogeneous and cyclic semantics.
This is often referred to as deep copying, and is normally required where structures are mutable and to ensure that independent copies can be manipulated without side-effects.
If this fac... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Shoelace_formula_for_polygonal_area | Shoelace formula for polygonal area | Given the n + 1 vertices x[0], y[0] .. x[N], y[N] of a simple polygon described in a clockwise direction, then the polygon's area can be calculated by:
abs( (sum(x[0]*y[1] + ... x[n-1]*y[n]) + x[N]*y[0]) -
(sum(x[1]*y[0] + ... x[n]*y[n-1]) + x[0]*y[N])
) / 2
(Where abs returns the absolute value)
Task
Write ... | #REXX | REXX | /*REXX program uses a Shoelace formula to calculate the area of an N─sided polygon.*/
parse arg $; if $='' then $= "(3,4),(5,11),(12,8),(9,5),(5,6)" /*Use the default?*/
A= 0; @= space($, 0) /*init A; elide blanks from pts.*/
do #=1 until @==''; parse var @... | Give a code snippet in #REXX
Given the n + 1 vertices x[0], y[0] .. x[N], y[N] of a simple polygon described in a clockwise direction, then the polygon's area can be calculated by:
abs( (sum(x[0]*y[1] + ... x[n-1]*y[n]) + x[N]*y[0]) -
(sum(x[1]*y[0] + ... x[n]*y[n-1]) + x[0]*y[N])
) / 2
(Where abs returns the... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Knapsack_problem/Bounded | Knapsack problem/Bounded | A tourist wants to make a good trip at the weekend with his friends.
They will go to the mountains to see the wonders of nature. So he needs some items during the trip. Food, clothing, etc. He has a good knapsack for carrying the things, but he knows that he can carry only 4 kg weight in his knapsack, because th... | #AutoHotkey | AutoHotkey | Item = map,compass,water,sandwich,glucose,tin,banana,apple,cheese,beer,suntan cream
,camera,tshirt,trousers,umbrella,waterproof trousers,waterproof overclothes,notecase
,sunglasses,towel,socks,book
Weight= 9,13,153,50,15,68,27,39,23,52,11,32,24,48,73,42,43,22,7,18,4,30
Value = 150,35,200,60,60,45,60,40,30,1... | Give a code snippet in #AutoHotkey
A tourist wants to make a good trip at the weekend with his friends.
They will go to the mountains to see the wonders of nature. So he needs some items during the trip. Food, clothing, etc. He has a good knapsack for carrying the things, but he knows that he can carry only 4 k... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Parsing/RPN_calculator_algorithm | Parsing/RPN calculator algorithm | Task
Create a stack-based evaluator for an expression in reverse Polish notation (RPN) that also shows the changes in the stack as each individual token is processed as a table.
Assume an input of a correct, space separated, string of tokens of an RPN expression
Test with the RPN expression generated from the... | #Java_2 | Java |
import java.util.LinkedList;
public class RPN{
public static void main(String[] args) {
evalRPN("3 4 2 * 1 5 - 2 3 ^ ^ / +");
}
private static void evalRPN(String expr){
LinkedList<Double> stack = new LinkedList<Double>();
System.out.println("Input\tOperation\tStack after");
for (String token : expr.sp... | Give a code snippet in #Java_2
Task
Create a stack-based evaluator for an expression in reverse Polish notation (RPN) that also shows the changes in the stack as each individual token is processed as a table.
Assume an input of a correct, space separated, string of tokens of an RPN expression
Test with the R... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Monads/List_monad | Monads/List monad | A Monad is a combination of a data-type with two helper functions written for that type.
The data-type can be of any kind which can contain values of some other type – common examples are lists, records, sum-types, even functions or IO streams. The two special functions, mathematically known as eta and mu, but usually... | #Raku | Raku | multi bind (@list, &code) { @list.map: &code };
multi bind ($item, &code) { $item.&code };
sub divisors (Int $int) { gather for 1 .. $int { .take if $int %% $_ } }
put (^10).&bind(* + 3).&bind(&divisors)».&bind(*.base: 2).join: "\n"; | Give a code snippet in #Raku
A Monad is a combination of a data-type with two helper functions written for that type.
The data-type can be of any kind which can contain values of some other type – common examples are lists, records, sum-types, even functions or IO streams. The two special functions, mathematically kn... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Arithmetic/Complex | Arithmetic/Complex | A complex number is a number which can be written as:
a
+
b
×
i
{\displaystyle a+b\times i}
(sometimes shown as:
b
+
a
×
i
{\displaystyle b+a\times i}
where
a
{\displaystyle a}
and
b
{\displaystyle b}
are real numbers, and
i
{\displaystyle i}
is √ -1
Typica... | #Raku | Raku | my $a = 1 + i;
my $b = pi + 1.25i;
.say for $a + $b, $a * $b, -$a, 1 / $a, $a.conj;
.say for $a.abs, $a.sqrt, $a.re, $a.im; | Give a code snippet in #Raku
A complex number is a number which can be written as:
a
+
b
×
i
{\displaystyle a+b\times i}
(sometimes shown as:
b
+
a
×
i
{\displaystyle b+a\times i}
where
a
{\displaystyle a}
and
b
{\displaystyle b}
are real numbers, and
i
{\displaysty... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Command-line_arguments | Command-line arguments | Command-line arguments is part of Short Circuit's Console Program Basics selection.
Scripted main
See also Program name.
For parsing command line arguments intelligently, see Parsing command-line arguments.
Example command line:
myprogram -c "alpha beta" -h "gamma"
| #Go | Go |
package main
import (
"fmt"
"os"
)
func main() {
for i, x := range os.Args[1:] {
fmt.Printf("the argument #%d is %s\n", i, x)
}
}
| Give a code snippet in #Go
Command-line arguments is part of Short Circuit's Console Program Basics selection.
Scripted main
See also Program name.
For parsing command line arguments intelligently, see Parsing command-line arguments.
Example command line:
myprogram -c "alpha beta" -h "gamma"
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Evolutionary_algorithm | Evolutionary algorithm | Starting with:
The target string: "METHINKS IT IS LIKE A WEASEL".
An array of random characters chosen from the set of upper-case letters together with the space, and of the same length as the target string. (Call it the parent).
A fitness function that computes the ‘closeness’ of its argument to the target string.... | #Euphoria | Euphoria | constant table = "ABCDEFGHIJKLMNOPQRSTUVWXYZ "
function random_generation(integer len)
sequence s
s = rand(repeat(length(table),len))
for i = 1 to len do
s[i] = table[s[i]]
end for
return s
end function
function mutate(sequence s, integer n)
for i = 1 to length(s) do
if rand(n)... | Give a code snippet in #Euphoria
Starting with:
The target string: "METHINKS IT IS LIKE A WEASEL".
An array of random characters chosen from the set of upper-case letters together with the space, and of the same length as the target string. (Call it the parent).
A fitness function that computes the ‘closeness’ of ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Levenshtein_distance/Alignment | Levenshtein distance/Alignment | The Levenshtein distance algorithm returns the number of atomic operations (insertion, deletion or edition) that must be performed on a string in order to obtain an other one, but it does not say anything about the actual operations used or their order.
An alignment is a notation used to describe the operations used t... | #Julia | Julia | function levenshteinalign(a::AbstractString, b::AbstractString)
a = lowercase(a)
b = lowercase(b)
len_a = length(a)
len_b = length(b)
costs = Matrix{Int}(len_a + 1, len_b + 1)
costs[1, :] .= 0:len_b
@inbounds for i in 2:(len_a + 1)
costs[i, 1] = i
for j in 2:(len_b + 1)
... | Give a code snippet in #Julia
The Levenshtein distance algorithm returns the number of atomic operations (insertion, deletion or edition) that must be performed on a string in order to obtain an other one, but it does not say anything about the actual operations used or their order.
An alignment is a notation used to... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Non-decimal_radices/Output | Non-decimal radices/Output | Programming languages often have built-in routines to convert a non-negative integer for printing in different number bases. Such common number bases might include binary, Octal and Hexadecimal.
Task
Print a small range of integers in some different bases, as supported by standard routines of your programming langu... | #Raku | Raku | say 30.base(2); # "11110"
say 30.base(8); # "36"
say 30.base(10); # "30"
say 30.base(16); # "1E"
say 30.base(30); # "10" | Give a code snippet in #Raku
Programming languages often have built-in routines to convert a non-negative integer for printing in different number bases. Such common number bases might include binary, Octal and Hexadecimal.
Task
Print a small range of integers in some different bases, as supported by standard rout... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Abbreviations,_easy | Abbreviations, easy | This task is an easier (to code) variant of the Rosetta Code task: Abbreviations, simple.
For this task, the following command table will be used:
Add ALTer BAckup Bottom CAppend Change SCHANGE CInsert CLAst COMPress COpy
COUnt COVerlay CURsor DELete CDelete Down DUPlicate Xedit EXPand EXTract Find
... | #Raku | Raku | <
Add ALTer BAckup Bottom CAppend Change SCHANGE CInsert CLAst COMPress COpy
COUnt COVerlay CURsor DELete CDelete Down DUPlicate Xedit EXPand EXTract Find
NFind NFINDUp NFUp CFind FINdup FUp FOrward GET Help HEXType Input POWerinput
Join SPlit SPLTJOIN LOAD Locate CLocate LOWercase UPPercase LPrefix MACRO
MErge ... | Give a code snippet in #Raku
This task is an easier (to code) variant of the Rosetta Code task: Abbreviations, simple.
For this task, the following command table will be used:
Add ALTer BAckup Bottom CAppend Change SCHANGE CInsert CLAst COMPress COpy
COUnt COVerlay CURsor DELete CDelete Down DUPlic... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sorting_algorithms/Merge_sort | Sorting algorithms/Merge 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
... | #Standard_ML | Standard ML | fun merge cmp ([], ys) = ys
| merge cmp (xs, []) = xs
| merge cmp (xs as x::xs', ys as y::ys') =
case cmp (x, y) of GREATER => y :: merge cmp (xs, ys')
| _ => x :: merge cmp (xs', ys)
;
fun merge_sort cmp [] = []
| merge_sort cmp [x] = [x]
| merge_sort cmp xs = let
val y... | Give a code snippet in #Standard_ML
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 |
Qu... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Find_the_last_Sunday_of_each_month | Find the last Sunday of each month | Write a program or a script that returns the last Sundays of each month of a given year. The year may be given through any simple input method in your language (command line, std in, etc).
Example of an expected output:
./last_sundays 2013
2013-01-27
2013-02-24
2013-03-31
2013-04-28
2013-05-26
2013-06-30
2013-07-28
2... | #AppleScript | AppleScript | -- LAST SUNDAYS OF YEAR ------------------------------------------------------
-- lastSundaysOfYear :: Int -> [Date]
on lastSundaysOfYear(y)
-- lastWeekDaysOfYear :: Int -> Int -> [Date]
script lastWeekDaysOfYear
on |λ|(intYear, iWeekday)
-- lastWeekDay :: Int -> Int -> Date
... | Give a code snippet in #AppleScript
Write a program or a script that returns the last Sundays of each month of a given year. The year may be given through any simple input method in your language (command line, std in, etc).
Example of an expected output:
./last_sundays 2013
2013-01-27
2013-02-24
2013-03-31
2013-04-... | christopher/rosetta-code | |
http://rosettacode.org/wiki/First-class_functions/Use_numbers_analogously | First-class functions/Use numbers analogously | In First-class functions, a language is showing how its manipulation of functions is similar to its manipulation of other types.
This tasks aim is to compare and contrast a language's implementation of first class functions, with its normal handling of numbers.
Write a program to create an ordered collection of a m... | #Scala | Scala | scala> val x = 2.0
x: Double = 2.0
scala> val xi = 0.5
xi: Double = 0.5
scala> val y = 4.0
y: Double = 4.0
scala> val yi = 0.25
yi: Double = 0.25
scala> val z = x + y
z: Double = 6.0
scala> val zi = 1.0 / ( x + y )
zi: Double = 0.16666666666666666
scala> val numbers = List(x, y, z)
numbers: List[Double] = L... | Give a code snippet in #Scala
In First-class functions, a language is showing how its manipulation of functions is similar to its manipulation of other types.
This tasks aim is to compare and contrast a language's implementation of first class functions, with its normal handling of numbers.
Write a program to crea... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Zero_to_the_zero_power | Zero to the zero power | Some computer programming languages are not exactly consistent (with other computer programming languages)
when raising zero to the zeroth power: 00
Task
Show the results of raising zero to the zeroth power.
If your computer language objects to 0**0 or 0^0 at compile time, ... | #OCaml | OCaml | # 0.0 ** 0.0;;
- : float = 1.
# Complex.pow Complex.zero Complex.zero;;
- : Complex.t = {Complex.re = nan; Complex.im = nan}
# #load "nums.cma";;
# open Num;;
# Int 0 **/ Int 0;;
- : Num.num = Int 1
| Give a code snippet in #OCaml
Some computer programming languages are not exactly consistent (with other computer programming languages)
when raising zero to the zeroth power: 00
Task
Show the results of raising zero to the zeroth power.
If your computer language objects to 0**0 or ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Catalan_numbers/Pascal%27s_triangle | Catalan numbers/Pascal's triangle | Task
Print out the first 15 Catalan numbers by extracting them from Pascal's triangle.
See
Catalan Numbers and the Pascal Triangle. This method enables calculation of Catalan Numbers using only addition and subtraction.
Catalan's Triangle for a Number Triangle that generates Catalan Numbers using onl... | #Wren | Wren | var n = 15
var t = List.filled(n+2, 0)
t[1] = 1
for (i in 1..n) {
if (i > 1) for (j in i..2) t[j] = t[j] + t[j-1]
t[i+1] = t[i]
if (i > 0) for (j in i+1..2) t[j] = t[j] + t[j-1]
System.write("%(t[i+1]-t[i]) ")
}
System.print() | Give a code snippet in #Wren
Task
Print out the first 15 Catalan numbers by extracting them from Pascal's triangle.
See
Catalan Numbers and the Pascal Triangle. This method enables calculation of Catalan Numbers using only addition and subtraction.
Catalan's Triangle for a Number Triangle that gener... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Averages/Root_mean_square | Averages/Root mean square | Task[edit]
Compute the Root mean square of the numbers 1..10.
The root mean square is also known by its initials RMS (or rms), and as the quadratic mean.
The RMS is calculated as the mean of the squares of the numbers, square-rooted:
x
r
m
s
=
x
1
2
+
x
2
2
+
⋯
+
x
... | #MATLAB | MATLAB | function rms = quadraticMean(list)
rms = sqrt(mean(list.^2));
end | Give a code snippet in #MATLAB
Task[edit]
Compute the Root mean square of the numbers 1..10.
The root mean square is also known by its initials RMS (or rms), and as the quadratic mean.
The RMS is calculated as the mean of the squares of the numbers, square-rooted:
x
r
m
s
=
x
1
2
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Classes | Classes | In object-oriented programming class is a set (a transitive closure) of types bound by the relation of inheritance. It is said that all types derived from some base type T and the type T itself form a class T.
The first type T from the class T sometimes is called the root type of the class.
A class of types itself, a... | #Ada | Ada | package My_Package is
type My_Type is tagged private;
procedure Some_Procedure(Item : out My_Type);
function Set(Value : in Integer) return My_Type;
private
type My_Type is tagged record
Variable : Integer := -12;
end record;
end My_Package; | Give a code snippet in #Ada
In object-oriented programming class is a set (a transitive closure) of types bound by the relation of inheritance. It is said that all types derived from some base type T and the type T itself form a class T.
The first type T from the class T sometimes is called the root type of the class... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Remove_duplicate_elements | Remove duplicate elements |
Sorting Algorithm
This is a sorting algorithm. It may be applied to a set of data in order to sort it.
For comparing various sorts, see compare sorts.
For other sorting algorithms, see sorting algorithms, or:
O(n logn) sorts
Heap sort |
Merge sort |
Patience sort |
Quick sort
O(n log2n) sorts
Shell Sort
... | #Liberty_BASIC | Liberty BASIC |
a$ =" 1 $23.19 2 elbow 3 2 Bork 4 3 elbow 2 $23.19 "
print "Original set of elements = ["; a$; "]"
b$ =removeDuplicates$( a$)
print "With duplicates removed = ["; b$; "]"
end
function removeDuplicates$( in$)
o$ =" "
i =1
do
term$ =word$( in$, i, " ")
if instr( o$, " "; term$; " ... | Give a code snippet in #Liberty_BASIC
Sorting Algorithm
This is a sorting algorithm. It may be applied to a set of data in order to sort it.
For comparing various sorts, see compare sorts.
For other sorting algorithms, see sorting algorithms, or:
O(n logn) sorts
Heap sort |
Merge sort |
Patience sort |
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Loops/Foreach | Loops/Foreach | Loop through and print each element in a collection in order.
Use your language's "for each" loop if it has one, otherwise iterate through the collection in order with some other loop.
Related tasks
Loop over multiple arrays simultaneously
Loops/Break
Loops/Continue
Loops/Do-while
Loops/Downward for... | #Common_Lisp | Common Lisp | (loop for i in list do (print i)) | Give a code snippet in #Common_Lisp
Loop through and print each element in a collection in order.
Use your language's "for each" loop if it has one, otherwise iterate through the collection in order with some other loop.
Related tasks
Loop over multiple arrays simultaneously
Loops/Break
Loops/Continue
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sorting_algorithms/Insertion_sort | Sorting algorithms/Insertion 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 |
bundle Default {
class Insert {
function : Main(args : String[]) ~ Nil {
values := [9, 7, 10, 2, 9, 7, 4, 3, 10, 2, 7, 10];
InsertionSort(values);
each(i : values) {
values[i]->PrintLine();
};
}
function : InsertionSort (a : Int[]) ~ Nil {
each(i : a) {
va... | 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/Probabilistic_choice | Probabilistic choice | Given a mapping between items and their required probability of occurrence, generate a million items randomly subject to the given probabilities and compare the target probability of occurrence versus the generated values.
The total of all the probabilities should equal one. (Because floating point arithmetic is invol... | #AWK | AWK | #!/usr/bin/awk -f
BEGIN {
ITERATIONS = 1000000
delete symbMap
delete probMap
delete counts
initData();
for (i = 0; i < ITERATIONS; i++) {
distribute(rand())
}
showDistributions()
exit
}
function distribute(rnd, cnt, symNum, sym, symPrb) {
cnt = length(symbMap)
... | Give a code snippet in #AWK
Given a mapping between items and their required probability of occurrence, generate a million items randomly subject to the given probabilities and compare the target probability of occurrence versus the generated values.
The total of all the probabilities should equal one. (Because float... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Filter | Filter | Task
Select certain elements from an Array into a new Array in a generic way.
To demonstrate, select all even numbers from an Array.
As an option, give a second solution which filters destructively,
by modifying the original Array rather than creating a new Array.
| #OCaml | OCaml | let lst = [1;2;3;4;5;6]
let even_lst = List.filter (fun x -> x mod 2 = 0) lst | Give a code snippet in #OCaml
Task
Select certain elements from an Array into a new Array in a generic way.
To demonstrate, select all even numbers from an Array.
As an option, give a second solution which filters destructively,
by modifying the original Array rather than creating a new Array.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/24_game/Solve | 24 game/Solve | task
Write a program that takes four digits, either from user input or by random generation, and computes arithmetic expressions following the rules of the 24 game.
Show examples of solutions generated by the program.
Related task
Arithmetic Evaluator
| #AArch64_Assembly | AArch64 Assembly |
/* ARM assembly AARCH64 Raspberry PI 3B */
/* program game24Solvex64.s */
/*******************************************/
/* Constantes file */
/*******************************************/
/* for this file see task include a file in language AArch64 assembly*/
.include "../includeConstant... | Give a code snippet in #AArch64_Assembly
task
Write a program that takes four digits, either from user input or by random generation, and computes arithmetic expressions following the rules of the 24 game.
Show examples of solutions generated by the program.
Related task
Arithmetic Evaluator
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Dutch_national_flag_problem | Dutch national flag problem |
The Dutch national flag is composed of three coloured bands in the order:
red (top)
then white, and
lastly blue (at the bottom).
The problem posed by Edsger Dijkstra is:
Given a number of red, blue and white balls in random order, arrange them in the order of the colours in the Dutch national fla... | #Icon_and_Unicon | Icon and Unicon | procedure main(a)
n := integer(!a) | 20
every (nr|nw|nb) := ?n-1
sIn := repl("r",nw)||repl("w",nb)||repl("b",nr)
write(sRand := bestShuffle(sIn))
write(sOut := map(csort(map(sRand,"rwb","123")),"123","rwb"))
if sIn ~== sOut then write("Eh? Not in correct order!")
end
procedure bestShuffle(s) ... | Give a code snippet in #Icon_and_Unicon
The Dutch national flag is composed of three coloured bands in the order:
red (top)
then white, and
lastly blue (at the bottom).
The problem posed by Edsger Dijkstra is:
Given a number of red, blue and white balls in random order, arrange them in the order... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Carmichael_3_strong_pseudoprimes | Carmichael 3 strong pseudoprimes | A lot of composite numbers can be separated from primes by Fermat's Little Theorem, but there are some that completely confound it.
The Miller Rabin Test uses a combination of Fermat's Little Theorem and Chinese Division Theorem to overcome this.
The purpose of this task is to investigate such numbers using a met... | #Fortran | Fortran | LOGICAL FUNCTION ISPRIME(N) !Ad-hoc, since N is not going to be big...
INTEGER N !Despite this intimidating allowance of 32 bits...
INTEGER F !A possible factor.
ISPRIME = .FALSE. !Most numbers aren't prime.
DO F = 2,SQRT(DFLOAT(N)) !Wince...
IF (MOD(N,F).EQ.0) RETURN ... | Give a code snippet in #Fortran
A lot of composite numbers can be separated from primes by Fermat's Little Theorem, but there are some that completely confound it.
The Miller Rabin Test uses a combination of Fermat's Little Theorem and Chinese Division Theorem to overcome this.
The purpose of this task is to inv... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Comments | Comments | Task
Show all ways to include text in a language source file
that's completely ignored by the compiler or interpreter.
Related tasks
Documentation
Here_document
See also
Wikipedia
xkcd (Humor: hand gesture denoting // for "commenting out" people.)
| #SenseTalk | SenseTalk |
# Hashtag is a comment
-- Dash dash is another comment
// Slash slash is yet another comment
— Alt/Option + Underscore creates an m-dash comment
(* Parentheses and star is used for commenting
blocks of code (* and can be nested *) *)
set foo to true // all comments can append to statements
| Give a code snippet in #SenseTalk
Task
Show all ways to include text in a language source file
that's completely ignored by the compiler or interpreter.
Related tasks
Documentation
Here_document
See also
Wikipedia
xkcd (Humor: hand gesture denoting // for "commenting out" people.)
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Modular_exponentiation | Modular exponentiation | Find the last 40 decimal digits of
a
b
{\displaystyle a^{b}}
, where
a
=
2988348162058574136915891421498819466320163312926952423791023078876139
{\displaystyle a=2988348162058574136915891421498819466320163312926952423791023078876139}
b
=
235139930337346448646612254452369009474497523... | #TXR | TXR | $ txr -p '(exptmod 2988348162058574136915891421498819466320163312926952423791023078876139
2351399303373464486466122544523690094744975233415544072992656881240319
(expt 10 40)))'
1527229998585248450016808958343740453059 | Give a code snippet in #TXR
Find the last 40 decimal digits of
a
b
{\displaystyle a^{b}}
, where
a
=
2988348162058574136915891421498819466320163312926952423791023078876139
{\displaystyle a=2988348162058574136915891421498819466320163312926952423791023078876139}
b
=
2351399303373464... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Ackermann_function | Ackermann function | The Ackermann function is a classic example of a recursive function, notable especially because it is not a primitive recursive function. It grows very quickly in value, as does the size of its call tree.
The Ackermann function is usually defined as follows:
A
(
m
,
n
)
=
{
n
+
1
if
m
=
0
A
(
m
... | #XSLT | XSLT |
<xsl:template name="ackermann">
<xsl:param name="m"/>
<xsl:param name="n"/>
<xsl:choose>
<xsl:when test="$m = 0">
<xsl:value-of select="$n+1"/>
</xsl:when>
<xsl:when test="$n = 0">
<xsl:call-template name="ackermann">
<xsl:with-param name="m" select="$m - 1"... | Give a code snippet in #XSLT
The Ackermann function is a classic example of a recursive function, notable especially because it is not a primitive recursive function. It grows very quickly in value, as does the size of its call tree.
The Ackermann function is usually defined as follows:
A
(
m
,
n
)
=
{
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Four_bit_adder | Four bit adder | Task
"Simulate" a four-bit adder.
This design can be realized using four 1-bit full adders.
Each of these 1-bit full adders can be built with two half adders and an or gate. ;
Finally a half adder can be made using an xor gate and an and gate.
The xor gate can be made using two nots, two ands ... | #Erlang | Erlang |
-module( four_bit_adder ).
-export( [add_bits/3, create/1, task/0] ).
add_bits( Adder, A_bits, B_bits ) ->
Adder ! {erlang:self(), lists:reverse(A_bits), lists:reverse(B_bits)},
receive
{Adder, Sum, Carry} -> {Sum, Carry}
end.
create( How_many_bits ) ->
Full_adders = connect_full_adders( [full_adder_create... | Give a code snippet in #Erlang
Task
"Simulate" a four-bit adder.
This design can be realized using four 1-bit full adders.
Each of these 1-bit full adders can be built with two half adders and an or gate. ;
Finally a half adder can be made using an xor gate and an and gate.
The xor gate can be made... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Parse_an_IP_Address | Parse an IP Address | The purpose of this task is to demonstrate parsing of text-format IP addresses, using IPv4 and IPv6.
Taking the following as inputs:
127.0.0.1
The "localhost" IPv4 address
127.0.0.1:80
The "localhost" IPv4 address, with a specified port (80)
::1
The "localhost" IPv6 address
[::1]:80
The "localhost" IPv6... | #C | C |
#include <string.h>
#include <memory.h>
static unsigned int _parseDecimal ( const char** pchCursor )
{
unsigned int nVal = 0;
char chNow;
while ( chNow = **pchCursor, chNow >= '0' && chNow <= '9' )
{
//shift digit in
nVal *= 10;
nVal += chNow - '0';
++*pchCursor;
... | Give a code snippet in #C
The purpose of this task is to demonstrate parsing of text-format IP addresses, using IPv4 and IPv6.
Taking the following as inputs:
127.0.0.1
The "localhost" IPv4 address
127.0.0.1:80
The "localhost" IPv4 address, with a specified port (80)
::1
The "localhost" IPv6 address
[::... | christopher/rosetta-code | |
http://rosettacode.org/wiki/4-rings_or_4-squares_puzzle | 4-rings or 4-squares puzzle | 4-rings or 4-squares puzzle
You are encouraged to solve this task according to the task description, using any language you may know.
Task
Replace a, b, c, d, e, f, and
g with the decimal
digits LOW ───► HIGH
such that the sum of the letters inside of each of the four large squares add up to
t... | #Prolog | Prolog |
:- use_module(library(clpfd)).
% main predicate
my_sum(Min, Max, Top, LL):-
L = [A,B,C,D,E,F,G],
L ins Min..Max,
( Top == 0
-> all_distinct(L)
; true),
R #= A+B,
R #= B+C+D,
R #= D+E+F,
R #= F+G,
setof(L, labeling([ff], L), LL).
my_sum_1(Min, Max) :-
my_sum(Min,... | Give a code snippet in #Prolog
4-rings or 4-squares puzzle
You are encouraged to solve this task according to the task description, using any language you may know.
Task
Replace a, b, c, d, e, f, and
g with the decimal
digits LOW ───► HIGH
such that the sum of the letters inside of each of th... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sequence:_smallest_number_with_exactly_n_divisors | Sequence: smallest number with exactly n divisors | Calculate the sequence where each term an is the smallest natural number that has exactly n divisors.
Task
Show here, on this page, at least the first 15 terms of the sequence.
Related tasks
Sequence: smallest number greater than previous term with exactly n divisors
Sequence: nth number with exactly... | #REXX | REXX | /*REXX program finds and displays the smallest number with exactly N divisors.*/
parse arg N . /*obtain optional argument from the CL.*/
if N=='' | N=="," then N= 15 /*Not specified? Then use the default.*/
say '──divisors── ──smallest number with N div... | Give a code snippet in #REXX
Calculate the sequence where each term an is the smallest natural number that has exactly n divisors.
Task
Show here, on this page, at least the first 15 terms of the sequence.
Related tasks
Sequence: smallest number greater than previous term with exactly n divisors
Seq... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Higher-order_functions | Higher-order functions | Task
Pass a function as an argument to another function.
Related task
First-class functions
| #Lua | Lua | a = function() return 1 end
b = function(r) print( r() ) end
b(a) | Give a code snippet in #Lua
Task
Pass a function as an argument to another function.
Related task
First-class functions
| christopher/rosetta-code | |
http://rosettacode.org/wiki/General_FizzBuzz | General FizzBuzz | Task
Write a generalized version of FizzBuzz that works for any list of factors, along with their words.
This is basically a "fizzbuzz" implementation where the user supplies the parameters.
The user will enter the max number, then they will enter the factors to be calculated along with the corresponding word to be ... | #BQN | BQN | GenFizzBuzz ← {factors‿words ← <˘⍉>𝕨 ⋄ (∾´∾⟜words/˜·(¬∨´)⊸∾0=factors|⊢)¨1+↕𝕩} | Give a code snippet in #BQN
Task
Write a generalized version of FizzBuzz that works for any list of factors, along with their words.
This is basically a "fizzbuzz" implementation where the user supplies the parameters.
The user will enter the max number, then they will enter the factors to be calculated along with ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Short-circuit_evaluation | Short-circuit evaluation | Control Structures
These are examples of control structures. You may also be interested in:
Conditional structures
Exceptions
Flow-control structures
Loops
Assume functions a and b return boolean values, and further, the execution of function b takes considerable resources without side effects, an... | #Seed7 | Seed7 | $ include "seed7_05.s7i";
const func boolean: a (in boolean: aBool) is func
result
var boolean: result is FALSE;
begin
writeln("a");
result := aBool;
end func;
const func boolean: b (in boolean: aBool) is func
result
var boolean: result is FALSE;
begin
writeln("b");
result := aBool... | Give a code snippet in #Seed7
Control Structures
These are examples of control structures. You may also be interested in:
Conditional structures
Exceptions
Flow-control structures
Loops
Assume functions a and b return boolean values, and further, the execution of function b takes considerable res... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Hilbert_curve | Hilbert curve |
Task
Produce a graphical or ASCII-art representation of a Hilbert curve of at least order 3.
| #Raku | Raku | use SVG;
role Lindenmayer {
has %.rules;
method succ {
self.comb.map( { %!rules{$^c} // $c } ).join but Lindenmayer(%!rules)
}
}
my $hilbert = 'A' but Lindenmayer( { A => '-BF+AFA+FB-', B => '+AF-BFB-FA+' } );
$hilbert++ xx 7;
my @points = (647, 13);
for $hilbert.comb {
state ($x, $y) = ... | Give a code snippet in #Raku
Task
Produce a graphical or ASCII-art representation of a Hilbert curve of at least order 3.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Combinations_with_repetitions | Combinations with repetitions | The set of combinations with repetitions is computed from a set,
S
{\displaystyle S}
(of cardinality
n
{\displaystyle n}
), and a size of resulting selection,
k
{\displaystyle k}
, by reporting the sets of cardinality
k
{\displaystyle k}
where each member of those sets is chosen from
S... | #ZX_Spectrum_Basic | ZX Spectrum Basic | 10 READ n
20 DIM d$(n,5)
30 FOR i=1 TO n
40 READ d$(i)
50 NEXT i
60 DATA 3,"iced","jam","plain"
70 FOR i=1 TO n
80 FOR j=i TO n
90 PRINT d$(i);" ";d$(j)
100 NEXT j
110 NEXT i | Give a code snippet in #ZX_Spectrum_Basic
The set of combinations with repetitions is computed from a set,
S
{\displaystyle S}
(of cardinality
n
{\displaystyle n}
), and a size of resulting selection,
k
{\displaystyle k}
, by reporting the sets of cardinality
k
{\displaystyle k}
where eac... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Digital_root/Multiplicative_digital_root | Digital root/Multiplicative digital root | The multiplicative digital root (MDR) and multiplicative persistence (MP) of a number,
n
{\displaystyle n}
, is calculated rather like the Digital root except digits are multiplied instead of being added:
Set
m
{\displaystyle m}
to
n
{\displaystyle n}
and
i
{\displaystyle i}
to
0
... | #Pascal | Pascal | program MultRoot;
{$IFDEF FPC}
{$MODE DELPHI}{$OPTIMIZATION ON,ALL}{$CODEALIGN proc=16}
{$ENDIF}
{$IFDEF WINDOWS}
{$APPTYPE CONSOLE}
{$ENDIF}
uses
sysutils;
type
tMul3Dgt = array[0..999] of Uint32;
tMulRoot = record
mrNum,
mrMul,
mrPers : Uint64;
end;
... | Give a code snippet in #Pascal
The multiplicative digital root (MDR) and multiplicative persistence (MP) of a number,
n
{\displaystyle n}
, is calculated rather like the Digital root except digits are multiplied instead of being added:
Set
m
{\displaystyle m}
to
n
{\displaystyle n}
and
i
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Greatest_common_divisor | Greatest common divisor | Greatest common divisor
You are encouraged to solve this task according to the task description, using any language you may know.
Task
Find the greatest common divisor (GCD) of two integers.
Greatest common divisor is also known as greatest common factor (gcf) and greatest common measure.
Related tas... | #Cobra | Cobra |
class Rosetta
def gcd(u as number, v as number) as number
u, v = u.abs, v.abs
while v > 0
u, v = v, u % v
return u
def main
print "gcd of [12] and [8] is [.gcd(12, 8)]"
print "gcd of [12] and [-8] is [.gcd(12, -8)]"
print "gcd of [96] and [27] is [.gcd(27, 96)]"
print "gcd of [51] and [34] is [.g... | Give a code snippet in #Cobra
Greatest common divisor
You are encouraged to solve this task according to the task description, using any language you may know.
Task
Find the greatest common divisor (GCD) of two integers.
Greatest common divisor is also known as greatest common factor (gcf) and greatest... | christopher/rosetta-code | |
http://rosettacode.org/wiki/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... | #Java | Java |
import java.math.BigInteger;
public class SuperDNumbers {
public static void main(String[] args) {
for ( int i = 2 ; i <= 9 ; i++ ) {
superD(i, 10);
}
}
private static final void superD(int d, int max) {
long start = System.currentTimeMillis();
String test... | Give a code snippet in #Java
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 o... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Ulam_spiral_(for_primes) | Ulam spiral (for primes) | An Ulam spiral (of primes) is a method of visualizing primes when expressed in a (normally counter-clockwise) outward spiral (usually starting at 1), constructed on a square grid, starting at the "center".
An Ulam spiral is also known as a prime spiral.
The first grid (green) is shown with sequential integers, ... | #Python | Python | # coding=UTF-8
from __future__ import print_function, division
from math import sqrt
def cell(n, x, y, start=1):
d, y, x = 0, y - n//2, x - (n - 1)//2
l = 2*max(abs(x), abs(y))
d = (l*3 + x + y) if y >= x else (l - x - y)
return (l - 1)**2 + d + start - 1
def show_spiral(n, symbol='# ', start=1, spa... | Give a code snippet in #Python
An Ulam spiral (of primes) is a method of visualizing primes when expressed in a (normally counter-clockwise) outward spiral (usually starting at 1), constructed on a square grid, starting at the "center".
An Ulam spiral is also known as a prime spiral.
The first grid (green) is sh... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sorting_algorithms/Strand_sort | Sorting algorithms/Strand 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
... | #jq | jq | # merge input array with array x by comparing the heads of the arrays
# in turn; # if both arrays are sorted, the result will be sorted:
def merge(x):
length as $length
| (x|length) as $xl
| if $length == 0 then x
elif $xl == 0 then .
else
. as $in
| reduce range(0; $xl + $length) as $z
... | Give a code snippet in #jq
Sorting Algorithm
This is a sorting algorithm. It may be applied to a set of data in order to sort it.
For comparing various sorts, see compare sorts.
For other sorting algorithms, see sorting algorithms, or:
O(n logn) sorts
Heap sort |
Merge sort |
Patience sort |
Quick sort
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Write_float_arrays_to_a_text_file | Write float arrays to a text file | Task
Write two equal-sized numerical arrays 'x' and 'y' to
a two-column text file named 'filename'.
The first column of the file contains values from an 'x'-array with a
given 'xprecision', the second -- values from 'y'-array with 'yprecision'.
For example, considering:
x = {1, 2, 3, 1e11};
y = {1, 1.41421356... | #Erlang | Erlang |
-module( write_float_arrays ).
-export( [task/0, to_a_text_file/3, to_a_text_file/4] ).
task() ->
File = "afile",
Xs = [1.0, 2.0, 3.0, 1.0e11],
Ys = [1.0, 1.4142135623730951, 1.7320508075688772, 316227.76601683791],
Options = [{xprecision, 3}, {yprecision, 5}],
to_a_text_file( File, Xs, Ys, Options ),
{ok, ... | Give a code snippet in #Erlang
Task
Write two equal-sized numerical arrays 'x' and 'y' to
a two-column text file named 'filename'.
The first column of the file contains values from an 'x'-array with a
given 'xprecision', the second -- values from 'y'-array with 'yprecision'.
For example, considering:
x = {1, 2,... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Parameterized_SQL_statement | Parameterized SQL statement | SQL injection
Using a SQL update statement like this one (spacing is optional):
UPDATE players
SET name = 'Smith, Steve', score = 42, active = TRUE
WHERE jerseyNum = 99
Non-parameterized SQL is the GoTo statement of database programming. Don't do it, and make sure your coworkers don't either. | #PicoLisp | PicoLisp | (for P (collect 'jerseyNum '+Players 99)
(put!> P 'name "Smith, Steve")
(put!> P 'score 42)
(put!> P 'active T) ) | Give a code snippet in #PicoLisp
SQL injection
Using a SQL update statement like this one (spacing is optional):
UPDATE players
SET name = 'Smith, Steve', score = 42, active = TRUE
WHERE jerseyNum = 99
Non-parameterized SQL is the GoTo statement of database programming. Don't do it, and make sure your coworkers... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Guess_the_number | Guess the number | Task
Write a program where the program chooses a number between 1 and 10.
A player is then prompted to enter a guess. If the player guesses wrong, then the prompt appears again until the guess is correct.
When the player has made a successful guess the computer will issue a "Well guessed!" message, a... | #FreeBASIC | FreeBASIC | ' FB 1.05.0 Win64
Randomize
Dim n As Integer = Int(Rnd * 10) + 1
Dim guess As Integer
Print "Guess which number I've chosen in the range 1 to 10"
Print
Do
Input " Your guess : "; guess
If n = guess Then
Print "Well guessed!"
End
End If
Loop | Give a code snippet in #FreeBASIC
Task
Write a program where the program chooses a number between 1 and 10.
A player is then prompted to enter a guess. If the player guesses wrong, then the prompt appears again until the guess is correct.
When the player has made a successful guess the computer will issue... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Damm_algorithm | Damm algorithm | The Damm algorithm is a checksum algorithm which detects all single digit errors and adjacent transposition errors.
The algorithm is named after H. Michael Damm.
Task
Verify the checksum, stored as last digit of an input.
| #Nim | Nim |
from algorithm import reverse
const Table = [[0, 3, 1, 7, 5, 9, 8, 6, 4, 2],
[7, 0, 9, 2, 1, 5, 4, 8, 6, 3],
[4, 2, 0, 6, 8, 7, 1, 3, 5, 9],
[1, 7, 5, 0, 9, 8, 3, 4, 2, 6],
[6, 1, 2, 3, 0, 4, 5, 9, 7, 8],
[3, 6, 7, 4, 2, 0, 9, 5, 8, 1],
... | Give a code snippet in #Nim
The Damm algorithm is a checksum algorithm which detects all single digit errors and adjacent transposition errors.
The algorithm is named after H. Michael Damm.
Task
Verify the checksum, stored as last digit of an input.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Roman_numerals/Encode | Roman numerals/Encode | Task
Create a function taking a positive integer as its parameter and returning a string containing the Roman numeral representation of that integer. Modern Roman numerals are written by expressing each digit separately, starting with the left most digit and skipping any digit with a value of zero.
In Roman numeral... | #Clojure | Clojure | (def arabic->roman
(partial clojure.pprint/cl-format nil "~@R"))
(arabic->roman 147)
;"CXXIII"
(arabic->roman 99)
;"XCIX" | Give a code snippet in #Clojure
Task
Create a function taking a positive integer as its parameter and returning a string containing the Roman numeral representation of that integer. Modern Roman numerals are written by expressing each digit separately, starting with the left most digit and skipping any digit with a v... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Happy_numbers | Happy numbers | From Wikipedia, the free encyclopedia:
A happy number is defined by the following process:
Starting with any positive integer, replace the number by the sum of the squares of its digits, and repeat the process until the number equals 1 (where it will stay), or it loops endlessly in a cycle which does not inclu... | #BQN | BQN | SumSqDgt ← +´2⋆˜ •Fmt-'0'˙
Happy ← ⟨⟩{𝕨((⊑∊˜ )◶⟨∾𝕊(SumSqDgt⊢),1=⊢⟩)𝕩}⊢
8↑Happy¨⊸/↕50 | Give a code snippet in #BQN
From Wikipedia, the free encyclopedia:
A happy number is defined by the following process:
Starting with any positive integer, replace the number by the sum of the squares of its digits, and repeat the process until the number equals 1 (where it will stay), or it loops endlessly in... | christopher/rosetta-code | |
http://rosettacode.org/wiki/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
... | #Action.21 | Action! | DEFINE MAX_COUNT="100"
INT ARRAY stack(MAX_COUNT)
INT stackSize
PROC PrintArray(INT ARRAY a INT size)
INT i
Put('[)
FOR i=0 TO size-1
DO
IF i>0 THEN Put(' ) FI
PrintI(a(i))
OD
Put(']) PutE()
RETURN
PROC InitStack()
stackSize=0
RETURN
BYTE FUNC IsEmpty()
IF stackSize=0 THEN
RETURN (1)... | Give a code snippet in #Action.21
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 |
Quic... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sieve_of_Eratosthenes | Sieve of Eratosthenes | This task has been clarified. Its programming examples are in need of review to ensure that they still fit the requirements of the task.
The Sieve of Eratosthenes is a simple algorithm that finds the prime numbers up to a given integer.
Task
Implement the Sieve of Eratosthenes algorithm, with the only allowed... | #R | R | sieve <- function(n) {
if (n < 2) integer(0)
else {
primes <- rep(T, n)
primes[[1]] <- F
for(i in seq(sqrt(n))) {
if(primes[[i]]) {
primes[seq(i * i, n, i)] <- F
}
}
which(primes)
}
}
sieve(1000) | Give a code snippet in #R
This task has been clarified. Its programming examples are in need of review to ensure that they still fit the requirements of the task.
The Sieve of Eratosthenes is a simple algorithm that finds the prime numbers up to a given integer.
Task
Implement the Sieve of Eratosthenes algor... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Multisplit | Multisplit | It is often necessary to split a string into pieces
based on several different (potentially multi-character) separator strings,
while still retaining the information about which separators were present in the input.
This is particularly useful when doing small parsing tasks.
The task is to write code to demonstrate ... | #Nim | Nim | import strutils
iterator tokenize(text: string; sep: openArray[string]): tuple[token: string, isSep: bool] =
var i, lastMatch = 0
while i < text.len:
for j, s in sep:
if text[i..text.high].startsWith s:
if i > lastMatch: yield (text[lastMatch ..< i], false)
yield (s, true)
lastMa... | Give a code snippet in #Nim
It is often necessary to split a string into pieces
based on several different (potentially multi-character) separator strings,
while still retaining the information about which separators were present in the input.
This is particularly useful when doing small parsing tasks.
The task is ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Letter_frequency | Letter frequency | Task
Open a text file and count the occurrences of each letter.
Some of these programs count all characters (including punctuation),
but some only count letters A to Z.
Other tasks related to string operations:
Metrics
Array length
String length
Copy a string
Empty string (assignment)
Counting
Word frequen... | #Ada | Ada | with Ada.Text_IO;
procedure Letter_Frequency is
Counters: array (Character) of Natural := (others => 0); -- initialize all Counters to 0
C: Character;
File: Ada.Text_IO.File_Type;
begin
Ada.Text_IO.Open(File, Mode => Ada.Text_IO.In_File, Name => "letter_frequency.adb");
while not Ada.Text_... | Give a code snippet in #Ada
Task
Open a text file and count the occurrences of each letter.
Some of these programs count all characters (including punctuation),
but some only count letters A to Z.
Other tasks related to string operations:
Metrics
Array length
String length
Copy a string
Empty string (assig... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Roman_numerals/Decode | Roman numerals/Decode | Task
Create a function that takes a Roman numeral as its argument and returns its value as a numeric decimal integer.
You don't need to validate the form of the Roman numeral.
Modern Roman numerals are written by expressing each decimal digit of the number to be encoded separately,
starting with the leftmost decima... | #Sidef | Sidef | func roman2arabic(roman) {
var arabic = 0
var last_digit = 1000
static m = Hash(
I => 1,
V => 5,
X => 10,
L => 50,
C => 100,
D => 500,
M => 1000,
)
roman.uc.chars.map{m{_} \\ 0}.each { |digit|
if (last_digit < digit) {... | Give a code snippet in #Sidef
Task
Create a function that takes a Roman numeral as its argument and returns its value as a numeric decimal integer.
You don't need to validate the form of the Roman numeral.
Modern Roman numerals are written by expressing each decimal digit of the number to be encoded separately,
st... | christopher/rosetta-code | |
http://rosettacode.org/wiki/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
| #SkookumScript | SkookumScript | print("Hello world!") | Give a code snippet in #SkookumScript
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... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Numbers_which_are_not_the_sum_of_distinct_squares | Numbers which are not the sum of distinct squares |
Integer squares are the set of integers multiplied by themselves: 1 x 1 = 1, 2 × 2 = 4, 3 × 3 = 9, etc. ( 1, 4, 9, 16 ... )
Most positive integers can be generated as the sum of 1 or more distinct integer squares.
1 == 1
5 == 4 + 1
25 == 16 + 9
77 == 36 + 25 + 16
103 == 49 + 25 + 16 + 9 + 4
Ma... | #C.23 | C# | using System;
using System.Collections.Generic;
using System.Linq;
class Program {
// recursively permutates the list of squares to seek a matching sum
static bool soms(int n, IEnumerable<int> f) {
if (n <= 0) return false;
if (f.Contains(n)) return true;
switch(n.CompareTo(f.Sum())) {
case 1:... | Give a code snippet in #C.23
Integer squares are the set of integers multiplied by themselves: 1 x 1 = 1, 2 × 2 = 4, 3 × 3 = 9, etc. ( 1, 4, 9, 16 ... )
Most positive integers can be generated as the sum of 1 or more distinct integer squares.
1 == 1
5 == 4 + 1
25 == 16 + 9
77 == 36 + 25 + 16
1... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Literals/String | Literals/String | Task
Show literal specification of characters and strings.
If supported, show how the following work:
verbatim strings (quotes where escape sequences are quoted literally)
here-strings
Also, discuss which quotes expand variables.
Related tasks
Special characters
Here document
Other tasks r... | #TOML | TOML | str = "I'm a string. \"You can quote me\". Name\tJos\u00E9\nLocation\tSF." | Give a code snippet in #TOML
Task
Show literal specification of characters and strings.
If supported, show how the following work:
verbatim strings (quotes where escape sequences are quoted literally)
here-strings
Also, discuss which quotes expand variables.
Related tasks
Special characters
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Casting_out_nines | Casting out nines | Task (in three parts)
Part 1
Write a procedure (say
c
o
9
(
x
)
{\displaystyle {\mathit {co9}}(x)}
) which implements Casting Out Nines as described by returning the checksum for
x
{\displaystyle x}
. Demonstrate the procedure using the examples given there, or others you may consider lucky.
Par... | #C.23 | C# | using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
namespace CastingOutNines {
public static class Helper {
public static string AsString<T>(this IEnumerable<T> e) {
var it = e.GetEnumerator();
StringBuilder builder = new StringBuilder();
... | Give a code snippet in #C.23
Task (in three parts)
Part 1
Write a procedure (say
c
o
9
(
x
)
{\displaystyle {\mathit {co9}}(x)}
) which implements Casting Out Nines as described by returning the checksum for
x
{\displaystyle x}
. Demonstrate the procedure using the examples given there, or other... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Non-continuous_subsequences | Non-continuous subsequences | Consider some sequence of elements. (It differs from a mere set of elements by having an ordering among members.)
A subsequence contains some subset of the elements of this sequence, in the same order.
A continuous subsequence is one in which no elements are missing between the first and last elements of the subseque... | #M2000_Interpreter | M2000 Interpreter |
Module Non_continuous_subsequences (item$(), display){
Function positions(n) {
function onebit {
=lambda b=false (&c)-> {
=b :if c then b~:c=not b
}
}
dim k(n)=onebit(), p(n)
m=true
flush
for i=1 to 2^n {
for j=0 to n-1 :p(j)= k(j)(&m) :next
m1=p(0)
m2=0
for j=1 to n-1
if m2 t... | Give a code snippet in #M2000_Interpreter
Consider some sequence of elements. (It differs from a mere set of elements by having an ordering among members.)
A subsequence contains some subset of the elements of this sequence, in the same order.
A continuous subsequence is one in which no elements are missing between ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Word_frequency | Word frequency | Task
Given a text file and an integer n, print/display the n most
common words in the file (and the number of their occurrences) in decreasing frequency.
For the purposes of this task:
A word is a sequence of one or more contiguous letters.
You are free to define what a letter is.
Undersc... | #Tcl | Tcl | lassign $argv head
while { [gets stdin line] >= 0 } {
foreach word [regexp -all -inline {[A-Za-z]+} $line] {
dict incr wordcount [string tolower $word]
}
}
set sorted [lsort -stride 2 -index 1 -int -decr $wordcount]
foreach {word count} [lrange $sorted 0 [expr {$head * 2 - 1}]] {
puts "$count\t$wo... | Give a code snippet in #Tcl
Task
Given a text file and an integer n, print/display the n most
common words in the file (and the number of their occurrences) in decreasing frequency.
For the purposes of this task:
A word is a sequence of one or more contiguous letters.
You are free to define what... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Flow-control_structures | Flow-control structures | Control Structures
These are examples of control structures. You may also be interested in:
Conditional structures
Exceptions
Flow-control structures
Loops
Task
Document common flow-control structures.
One common example of a flow-control structure is the goto construct.
Note that Conditional Struc... | #Maxima | Maxima | /* goto */
block(..., label, ..., go(label), ...);
/* throw, which is like trapping errors, and can do non-local jumps to return a value */
catch(..., throw(value), ...);
/* error trapping */
errcatch(..., error("Bad luck!"), ...); | Give a code snippet in #Maxima
Control Structures
These are examples of control structures. You may also be interested in:
Conditional structures
Exceptions
Flow-control structures
Loops
Task
Document common flow-control structures.
One common example of a flow-control structure is the goto construct... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Longest_increasing_subsequence | Longest increasing subsequence | Calculate and show here a longest increasing subsequence of the list:
{
3
,
2
,
6
,
4
,
5
,
1
}
{\displaystyle \{3,2,6,4,5,1\}}
And of the list:
{
0
,
8
,
4
,
12
,
2
,
10
,
6
,
14
,
1
,
9
,
5
,
13
,
3
,
11
,
7
,
15
}
{\displaystyle \{0,8,4,12,2,10,6,14,1,9,5,13,3,11,7,15\}}
Note that a list may have m... | #D.C3.A9j.C3.A0_Vu | Déjà Vu | in-pair:
if = :nil dup:
false drop
else:
@in-pair &> swap &< dup
get-last lst:
get-from lst -- len lst
lis-sub pile i di:
for j range 0 -- len pile:
local :pj get-from pile j
if > &< get-last pj di:
push-to pj & di if j get-last get-from pile -- j :nil
return
push-to pile [ & di get-last get-last... | Give a code snippet in #D.C3.A9j.C3.A0_Vu
Calculate and show here a longest increasing subsequence of the list:
{
3
,
2
,
6
,
4
,
5
,
1
}
{\displaystyle \{3,2,6,4,5,1\}}
And of the list:
{
0
,
8
,
4
,
12
,
2
,
10
,
6
,
14
,
1
,
9
,
5
,
13
,
3
,
11
,
7
,
15
}
{\displaystyle \{0,8,4,12,2,10,6,14,1,9,5,13... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Write_language_name_in_3D_ASCII | Write language name in 3D ASCII | Task
Write/display a language's name in 3D ASCII.
(We can leave the definition of "3D ASCII" fuzzy,
so long as the result is interesting or amusing,
not a cheap hack to satisfy the task.)
Related tasks
draw a sphere
draw a cuboid
draw a rotating cube
draw a Deathstar
| #SQL | SQL | SELECT ' SSS\ ' AS s, ' QQQ\ ' AS q, 'L\ ' AS l FROM dual
UNION ALL SELECT 'S \|', 'Q Q\ ', 'L | ' FROM dual
UNION ALL SELECT '\SSS ', 'Q Q |', 'L | ' FROM dual
UNION ALL SELECT ' \ S\', 'Q Q Q |', 'L | ' from dual
union all select ' SSS |', ... | Give a code snippet in #SQL
Task
Write/display a language's name in 3D ASCII.
(We can leave the definition of "3D ASCII" fuzzy,
so long as the result is interesting or amusing,
not a cheap hack to satisfy the task.)
Related tasks
draw a sphere
draw a cuboid
draw a rotating cube
draw a Deathstar
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Simple_windowed_application | Simple windowed application | Task
Create a window that has:
a label that says "There have been no clicks yet"
a button that says "click me"
Upon clicking the button with the mouse, the label should change and show the number of times the button has been clicked.
| #AArch64_Assembly | AArch64 Assembly |
/* ARM assembly AARCH64 Raspberry PI 3B */
/* program simpleWin64.s link with X11 library */
/*******************************************/
/* Constantes file */
/*******************************************/
/* for this file see task include a file in language AArch64 assembly*/
.include "... | Give a code snippet in #AArch64_Assembly
Task
Create a window that has:
a label that says "There have been no clicks yet"
a button that says "click me"
Upon clicking the button with the mouse, the label should change and show the number of times the button has been clicked.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Queue/Definition | Queue/Definition |
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.
Illustration of FIFO behavior
Task
Implement a FIFO queue.
Elements are added at one side and popped from the other in the order of insertion.
Operation... | #M2000_Interpreter | M2000 Interpreter |
Module Checkit {
a=Stack
Stack a {
Data 100,200, 300
}
Stack a {
While not empty {
Read N
Print N
}
}
}
Checkit
| Give a code snippet in #M2000_Interpreter
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.
Illustration of FIFO behavior
Task
Implement a FIFO queue.
Elements are added at one side and popped from the ot... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Array_length | Array length | Task
Determine the amount of elements in an array.
As an example use an array holding the strings 'apple' and 'orange'.
Other tasks related to string operations:
Metrics
Array length
String length
Copy a string
Empty string (assignment)
Counting
Word frequency
Letter frequency
Jewels and stones
I befo... | #Ruby | Ruby | puts ['apple', 'orange'].length # or .size | Give a code snippet in #Ruby
Task
Determine the amount of elements in an array.
As an example use an array holding the strings 'apple' and 'orange'.
Other tasks related to string operations:
Metrics
Array length
String length
Copy a string
Empty string (assignment)
Counting
Word frequency
Letter freque... | christopher/rosetta-code | |
http://rosettacode.org/wiki/HTTPS | HTTPS | Task
Send a GET request to obtain the resource located at the URL "https://www.w3.org/", then print it to the console.
Checking the host certificate for validity is recommended.
Do not authenticate. That is the subject of other tasks.
Readers may wish to contrast with the HTTP Request task, and also the task on HTT... | #Scala | Scala | import scala.io.Source
object HttpsTest extends App {
System.setProperty("http.agent", "*")
Source.fromURL("https://sourceforge.net").getLines.foreach(println)
} | Give a code snippet in #Scala
Task
Send a GET request to obtain the resource located at the URL "https://www.w3.org/", then print it to the console.
Checking the host certificate for validity is recommended.
Do not authenticate. That is the subject of other tasks.
Readers may wish to contrast with the HTTP Request... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Menu | Menu | Task
Given a prompt and a list containing a number of strings of which one is to be selected, create a function that:
prints a textual menu formatted as an index value followed by its corresponding string for each item in the list;
prompts the user to enter a number;
returns the string corresponding to the selecte... | #Arturo | Arturo | menu: function [items][
selection: neg 1
while [not? in? selection 1..size items][
loop.with:'i items 'item -> print ~"|i+1|. |item|"
inp: input "Enter a number: "
if numeric? inp ->
selection: to :integer inp
]
print items\[selection-1]
]
menu ["fee fie" "huff and puf... | Give a code snippet in #Arturo
Task
Given a prompt and a list containing a number of strings of which one is to be selected, create a function that:
prints a textual menu formatted as an index value followed by its corresponding string for each item in the list;
prompts the user to enter a number;
returns the str... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Case-sensitivity_of_identifiers | Case-sensitivity of identifiers | Three dogs (Are there three dogs or one dog?) is a code snippet used to illustrate the lettercase sensitivity of the programming language. For a case-sensitive language, the identifiers dog, Dog and DOG are all different and we should get the output:
The three dogs are named Benjamin, Samba and Bernie.
For a language... | #Swift | Swift | let dog = "Benjamin"
let Dog = "Samba"
let DOG = "Bernie"
println("The three dogs are named \(dog), \(Dog), and \(DOG).") | Give a code snippet in #Swift
Three dogs (Are there three dogs or one dog?) is a code snippet used to illustrate the lettercase sensitivity of the programming language. For a case-sensitive language, the identifiers dog, Dog and DOG are all different and we should get the output:
The three dogs are named Benjamin, Sa... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Undefined_values | Undefined values | #D.C3.A9j.C3.A0_Vu | Déjà Vu | try:
bogus
catch name-error:
!print "There is *no* :bogus in the current context"
return
!print "You won't see this." | Give a code snippet in #D.C3.A9j.C3.A0_Vu
| christopher/rosetta-code | ||
http://rosettacode.org/wiki/RIPEMD-160 | RIPEMD-160 | RIPEMD-160 is another hash function; it computes a 160-bit message digest.
There is a RIPEMD-160 home page, with test vectors and pseudocode for RIPEMD-160.
For padding the message, RIPEMD-160 acts like MD4 (RFC 1320).
Find the RIPEMD-160 message digest of a string of octets.
Use the ASCII encoded string “Rosetta Cod... | #Tcl | Tcl | package require ripemd160
puts [ripemd::ripemd160 -hex "Rosetta Code"] | Give a code snippet in #Tcl
RIPEMD-160 is another hash function; it computes a 160-bit message digest.
There is a RIPEMD-160 home page, with test vectors and pseudocode for RIPEMD-160.
For padding the message, RIPEMD-160 acts like MD4 (RFC 1320).
Find the RIPEMD-160 message digest of a string of octets.
Use the ASCI... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Apply_a_callback_to_an_array | Apply a callback to an array | Task
Take a combined set of elements and apply a function to each element.
| #V | V | [1 2 3 4] [dup *] map | Give a code snippet in #V
Task
Take a combined set of elements and apply a function to each element.
| christopher/rosetta-code |
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