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/Rot-13 | Rot-13 |
Task
Implement a rot-13 function (or procedure, class, subroutine, or other "callable" object as appropriate to your programming environment).
Optionally wrap this function in a utility program (like tr, which acts like a common UNIX utility, performing a line-by-line rot-13 encoding of every line of inpu... | #360_Assembly | 360 Assembly | ROT13 CSECT
USING ROT13,R15 use calling register
XPRNT CC,L'CC
TR CC,TABLE translate
XPRNT CC,L'CC
TR CC,TABLE translate
XPRNT CC,L'CC
BR R14 return to caller
CC DC CL10'{NOWHERE!}'
TA... | Give a code snippet in #360_Assembly
Task
Implement a rot-13 function (or procedure, class, subroutine, or other "callable" object as appropriate to your programming environment).
Optionally wrap this function in a utility program (like tr, which acts like a common UNIX utility, performing a line-by-line... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Reduced_row_echelon_form | Reduced row echelon form | Reduced row echelon form
You are encouraged to solve this task according to the task description, using any language you may know.
Task
Show how to compute the reduced row echelon form
(a.k.a. row canonical form) of a matrix.
The matrix can be stored in any datatype that is convenient
(for most languages, this wil... | #Groovy | Groovy | enum Pivoting {
NONE({ i, it -> 1 }),
PARTIAL({ i, it -> - (it[i].abs()) }),
SCALED({ i, it -> - it[i].abs()/(it.inject(0) { sum, elt -> sum + elt.abs() } ) });
public final Closure comparer
private Pivoting(Closure c) {
comparer = c
}
}
def isReducibleMatrix = { matrix ->
def ... | Give a code snippet in #Groovy
Reduced row echelon form
You are encouraged to solve this task according to the task description, using any language you may know.
Task
Show how to compute the reduced row echelon form
(a.k.a. row canonical form) of a matrix.
The matrix can be stored in any datatype that is convenie... | christopher/rosetta-code | |
http://rosettacode.org/wiki/One-time_pad | One-time pad | Implement a One-time pad, for encrypting and decrypting messages.
To keep it simple, we will be using letters only.
Sub-Tasks
Generate the data for a One-time pad (user needs to specify a filename and length)
The important part is to get "true random" numbers, e.g. from /dev/random
encryption / decryption ( basic... | #Perl | Perl | # 20200814 added Perl programming solution
use strict;
use warnings;
use Crypt::OTP;
use Bytes::Random::Secure qw( random_bytes );
print "Message : ", my $message = "show me the monKey", "\n";
my $otp = random_bytes(length $message);
print "Ord(OTP) : ", ( map { ord($_).' ' } (split //, $otp) ) , "\n";... | Give a code snippet in #Perl
Implement a One-time pad, for encrypting and decrypting messages.
To keep it simple, we will be using letters only.
Sub-Tasks
Generate the data for a One-time pad (user needs to specify a filename and length)
The important part is to get "true random" numbers, e.g. from /dev/random
e... | 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... | #Common_Lisp | Common Lisp | (setf (symbol-function '^) #'expt) ; Make ^ an alias for EXPT
(defun print-stack (token stack)
(format T "~a: ~{~a ~}~%" token (reverse stack)))
(defun rpn (tokens &key stack verbose )
(cond
((and (not tokens) (not stack)) 0)
((not tokens) (car stack))
(T
(let* ((current (car tokens))
... | Give a code snippet in #Common_Lisp
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 ... | 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
... | #Run_BASIC | Run BASIC | print ackermann(1, 2)
function ackermann(m, n)
if (m = 0) then ackermann = (n + 1)
if (m > 0) and (n = 0) then ackermann = ackermann((m - 1), 1)
if (m > 0) and (n > 0) then ackermann = ackermann((m - 1), ackermann(m, (n - 1)))
end function | Give a code snippet in #Run_BASIC
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/Take_notes_on_the_command_line | Take notes on the command line | Take notes on the command line is part of Short Circuit's Console Program Basics selection.
Invoking NOTES without commandline arguments displays the current contents of the local NOTES.TXT if it exists.
If NOTES has arguments, the current date and time are appended to the local NOTES.TXT followed by a newline.
Then al... | #E | E | #!/usr/bin/env rune
def f := <file:notes.txt>
def date := makeCommand("date")
switch (interp.getArgs()) {
match [] {
if (f.exists()) {
for line in f { print(line) }
}
}
match noteArgs {
def w := f.textWriter(true)
w.print(date()[0], "\t", " ".rjoin(noteArgs), ... | Give a code snippet in #E
Take notes on the command line is part of Short Circuit's Console Program Basics selection.
Invoking NOTES without commandline arguments displays the current contents of the local NOTES.TXT if it exists.
If NOTES has arguments, the current date and time are appended to the local NOTES.TXT fol... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Caesar_cipher | Caesar cipher |
Task
Implement a Caesar cipher, both encoding and decoding.
The key is an integer from 1 to 25.
This cipher rotates (either towards left or right) the letters of the alphabet (A to Z).
The encoding replaces each letter with the 1st to 25th next letter in the alphabet (wrapping Z to A).
So key 2 encrypts "HI" to... | #Crystal | Crystal | class String
ALPHABET = ("A".."Z").to_a
def caesar_cipher(num)
self.tr(ALPHABET.join, ALPHABET.rotate(num).join)
end
end
# demo
encrypted = "THEQUICKBROWNFOXJUMPSOVERTHELAZYDOG".caesar_cipher(5)
decrypted = encrypted.caesar_cipher(-5)
| Give a code snippet in #Crystal
Task
Implement a Caesar cipher, both encoding and decoding.
The key is an integer from 1 to 25.
This cipher rotates (either towards left or right) the letters of the alphabet (A to Z).
The encoding replaces each letter with the 1st to 25th next letter in the alphabet (wrapping Z ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/History_variables | History variables | Storing the history of objects in a program is a common task.
Maintaining the history of an object in a program has traditionally required programmers either to write specific code for handling the historical data, or to use a library which supports history logging.
History variables are variables in a programming la... | #Delphi | Delphi |
program History_variables;
{$APPTYPE CONSOLE}
uses
System.SysUtils;
type
THistoryVarType = record
value: variant;
timestamp: TDateTime;
function ToString: string;
end;
THistoryVar = record
Fvalue: variant;
FHistory: TArray<THistoryVarType>;
private
procedure SetValue(const Va... | Give a code snippet in #Delphi
Storing the history of objects in a program is a common task.
Maintaining the history of an object in a program has traditionally required programmers either to write specific code for handling the historical data, or to use a library which supports history logging.
History variables a... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Loops/Do-while | Loops/Do-while | Start with a value at 0. Loop while value mod 6 is not equal to 0.
Each time through the loop, add 1 to the value then print it.
The loop must execute at least once.
Related tasks
Loop over multiple arrays simultaneously
Loops/Break
Loops/Continue
Loops/Do-while
Loops/Downward for
Loops/For
Loo... | #PL.2FI | PL/I |
dcl value fixed bin (31) init (0);
do forever;
value = value + 1;
if mod(value, 6) = 0 then
leave;
put list (value);
end;
| Give a code snippet in #PL.2FI
Start with a value at 0. Loop while value mod 6 is not equal to 0.
Each time through the loop, add 1 to the value then print it.
The loop must execute at least once.
Related tasks
Loop over multiple arrays simultaneously
Loops/Break
Loops/Continue
Loops/Do-while
Loops/... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Convert_seconds_to_compound_duration | Convert seconds to compound duration | Task
Write a function or program which:
takes a positive integer representing a duration in seconds as input (e.g., 100), and
returns a string which shows the same duration decomposed into:
weeks,
days,
hours,
minutes, and
seconds.
This is detailed below (e.g., "2 hr, 59 sec").
Demonstrat... | #Go | Go | package main
import "fmt"
func main(){
fmt.Println(TimeStr(7259))
fmt.Println(TimeStr(86400))
fmt.Println(TimeStr(6000000))
}
func TimeStr(sec int)(res string){
wks, sec := sec / 604800,sec % 604800
ds, sec := sec / 86400, sec % 86400
hrs, sec := sec / 3600, sec % 3600
mins, sec := sec / 60, sec % 60
Comm... | Give a code snippet in #Go
Task
Write a function or program which:
takes a positive integer representing a duration in seconds as input (e.g., 100), and
returns a string which shows the same duration decomposed into:
weeks,
days,
hours,
minutes, and
seconds.
This is detailed below (e.g., "2... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Percolation/Bond_percolation | Percolation/Bond percolation |
Percolation Simulation
This is a simulation of aspects of mathematical percolation theory.
For other percolation simulations, see Category:Percolation Simulations, or:
1D finite grid simulation
Mean run density
2D finite grid simulations
Site percolation | Bond percolation | Mean cluster density
Given an
M
×
N... | #Racket | Racket | #lang racket
(define has-left-wall? (lambda (x) (bitwise-bit-set? x 0)))
(define has-right-wall? (lambda (x) (bitwise-bit-set? x 1)))
(define has-top-wall? (lambda (x) (bitwise-bit-set? x 2)))
(define has-bottom-wall? (lambda (x) (bitwise-bit-set? x 3)))
(define has-fluid? (lambda (x) (bitwise-bit-set? x ... | Give a code snippet in #Racket
Percolation Simulation
This is a simulation of aspects of mathematical percolation theory.
For other percolation simulations, see Category:Percolation Simulations, or:
1D finite grid simulation
Mean run density
2D finite grid simulations
Site percolation | Bond percolation | Mean clu... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Arbitrary-precision_integers_(included) | Arbitrary-precision integers (included) | Using the in-built capabilities of your language, calculate the integer value of:
5
4
3
2
... | #Oforth | Oforth | import: mapping
5 4 3 2 pow pow pow >string dup left( 20 ) . dup right( 20 ) . size . | Give a code snippet in #Oforth
Using the in-built capabilities of your language, calculate the integer value of:
5
4
3
2
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Find_the_intersection_of_two_lines | Find the intersection of two lines | [1]
Task
Find the point of intersection of two lines in 2D.
The 1st line passes though (4,0) and (6,10) .
The 2nd line passes though (0,3) and (10,7) .
| #Factor | Factor | USING: arrays combinators.extras kernel math
math.matrices.laplace math.vectors prettyprint sequences ;
: det ( pt pt -- x ) 2array determinant ;
: numerator ( x y pt pt quot -- z )
bi@ swapd [ 2array ] 2bi@ det ; inline
: intersection ( pt pt pt pt -- pt )
[ [ det ] 2bi@ ]
[ [ v- ] 2bi@ ] 4bi
[ [... | Give a code snippet in #Factor
[1]
Task
Find the point of intersection of two lines in 2D.
The 1st line passes though (4,0) and (6,10) .
The 2nd line passes though (0,3) and (10,7) .
| christopher/rosetta-code | |
http://rosettacode.org/wiki/HTTPS/Client-authenticated | HTTPS/Client-authenticated | Demonstrate how to connect to a web server over HTTPS where that server requires that the client present a certificate to prove who (s)he is. Unlike with the HTTPS request with authentication task, it is not acceptable to perform the authentication by a username/password or a set cookie.
This task is in general useful... | #Raku | Raku |
# cert creation commands
# openssl req -newkey rsa:4096 -keyout my_key.pem -out my_csr.pem -nodes -subj "/CN=ME"
# openssl x509 -req -in my_csr.pem -signkey my_key.pem -out my_cert.pem
use v6;
use OpenSSL;
my $host = "github.com";
my $ssl = OpenSSL.new(:client);
$ssl.use-certificate-file("./my_cert.pem");... | Give a code snippet in #Raku
Demonstrate how to connect to a web server over HTTPS where that server requires that the client present a certificate to prove who (s)he is. Unlike with the HTTPS request with authentication task, it is not acceptable to perform the authentication by a username/password or a set cookie.
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Increment_a_numerical_string | Increment a numerical string | Task
Increment a numerical string.
| #Fortran | Fortran | CHARACTER(10) :: intstr = "12345", realstr = "1234.5"
INTEGER :: i
REAL :: r
READ(intstr, "(I10)") i ! Read numeric string into integer i
i = i + 1 ! increment i
WRITE(intstr, "(I10)") i ! Write i back to string
READ(realstr, "(F10.1)") r
r = r + 1.0
WRITE(realstr, "(F10.1)")... | Give a code snippet in #Fortran
Task
Increment a numerical string.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Word_wrap | Word wrap | Even today, with proportional fonts and complex layouts, there are still cases where you need to wrap text at a specified column.
Basic task
The basic task is to wrap a paragraph of text in a simple way in your language.
If there is a way to do this that is built-in, trivial, or provided in a standard library, sho... | #Elena | Elena | import extensions;
import system'routines;
import extensions'text;
string text =
"In olden times when wishing still helped one, there lived a king
whose daughters were all beautiful, but the youngest was so beautiful
that the sun itself, which has seen so much, was astonished whenever
it shone in her face. Cl... | Give a code snippet in #Elena
Even today, with proportional fonts and complex layouts, there are still cases where you need to wrap text at a specified column.
Basic task
The basic task is to wrap a paragraph of text in a simple way in your language.
If there is a way to do this that is built-in, trivial, or prov... | christopher/rosetta-code | |
http://rosettacode.org/wiki/URL_decoding | URL decoding | This task (the reverse of URL encoding and distinct from URL parser) is to provide a function
or mechanism to convert an URL-encoded string into its original unencoded form.
Test cases
The encoded string "http%3A%2F%2Ffoo%20bar%2F" should be reverted to the unencoded form "http://foo bar/".
Th... | #Racket | Racket |
#lang racket
(require net/uri-codec)
(uri-decode "http%3A%2F%2Ffoo%20bar%2F")
| Give a code snippet in #Racket
This task (the reverse of URL encoding and distinct from URL parser) is to provide a function
or mechanism to convert an URL-encoded string into its original unencoded form.
Test cases
The encoded string "http%3A%2F%2Ffoo%20bar%2F" should be reverted to the unencoded... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Lah_numbers | Lah numbers | Lah numbers, sometimes referred to as Stirling numbers of the third kind, are coefficients of polynomial expansions expressing rising factorials in terms of falling factorials.
Unsigned Lah numbers count the number of ways a set of n elements can be partitioned into k non-empty linearly ordered subsets.
Lah numbers a... | #Perl | Perl | use strict;
use warnings;
use feature 'say';
use ntheory qw(factorial);
use List::Util qw(max);
sub Lah {
my($n, $k) = @_;
return factorial($n) if $k == 1;
return 1 if $k == $n;
return 0 if $k > $n;
return 0 if $k < 1 or $n < 1;
(factorial($n) * factorial($n - 1)) / (factorial($k) * factorial(... | Give a code snippet in #Perl
Lah numbers, sometimes referred to as Stirling numbers of the third kind, are coefficients of polynomial expansions expressing rising factorials in terms of falling factorials.
Unsigned Lah numbers count the number of ways a set of n elements can be partitioned into k non-empty linearly o... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Multiplication_tables | Multiplication tables | Task
Produce a formatted 12×12 multiplication table of the kind memorized by rote when in primary (or elementary) school.
Only print the top half triangle of products.
| #Delphi | Delphi | program MultiplicationTables;
{$APPTYPE CONSOLE}
uses SysUtils;
const
MAX_COUNT = 12;
var
lRow, lCol: Integer;
begin
Write(' | ');
for lRow := 1 to MAX_COUNT do
Write(Format('%4d', [lRow]));
Writeln('');
Writeln('--+-' + StringOfChar('-', MAX_COUNT * 4));
for lRow := 1 to MAX_COUNT do
begin
... | Give a code snippet in #Delphi
Task
Produce a formatted 12×12 multiplication table of the kind memorized by rote when in primary (or elementary) school.
Only print the top half triangle of products.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Matrix_multiplication | Matrix multiplication | Task
Multiply two matrices together.
They can be of any dimensions, so long as the number of columns of the first matrix is equal to the number of rows of the second matrix.
| #Yabasic | Yabasic | dim a(4, 2)
a(0, 0) = 1 : a(0, 1) = 2
a(1, 0) = 3 : a(1, 1) = 4
a(2, 0) = 5 : a(2, 1) = 6
a(3, 0) = 7 : a(3, 1) = 8
dim b(2, 3)
b(0, 0) = 1 : b(0, 1) = 2 : b(0, 2) = 3
b(1, 0) = 4 : b(1, 1) = 5 : b(1, 2) = 6
dim prod(arraysize(a(),1), arraysize(b(),2))
if (arraysize(a(),2) = arraysize(b(),1)) then
for i = 0 to array... | Give a code snippet in #Yabasic
Task
Multiply two matrices together.
They can be of any dimensions, so long as the number of columns of the first matrix is equal to the number of rows of the second matrix.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Matrix_chain_multiplication | Matrix chain multiplication | Problem
Using the most straightfoward algorithm (which we assume here), computing the product of two matrices of dimensions (n1,n2) and (n2,n3) requires n1*n2*n3 FMA operations. The number of operations required to compute the product of matrices A1, A2... An depends on the order of matrix multiplications, hence on whe... | #Racket | Racket | #lang racket
(define (memoize f)
(define table (make-hash))
(λ args (hash-ref! table args (thunk (apply f args)))))
(struct $ (cost expl))
(define @ vector-ref)
(define (+: #:combine [combine (thunk* #f)] . xs)
($ (apply + (map $-cost xs)) (apply combine (map $-expl xs))))
(define (min: . xs) (argmin $-co... | Give a code snippet in #Racket
Problem
Using the most straightfoward algorithm (which we assume here), computing the product of two matrices of dimensions (n1,n2) and (n2,n3) requires n1*n2*n3 FMA operations. The number of operations required to compute the product of matrices A1, A2... An depends on the order of matr... | christopher/rosetta-code | |
http://rosettacode.org/wiki/99_bottles_of_beer | 99 bottles of beer | Task
Display the complete lyrics for the song: 99 Bottles of Beer on the Wall.
The beer song
The lyrics follow this form:
99 bottles of beer on the wall
99 bottles of beer
Take one down, pass it around
98 bottles of beer on the wall
98 bottles of beer on the wall
98 bottles of beer
Take one dow... | #Maxima | Maxima | bottles(n) := for i from n thru 1 step -1 do (
printf(true, "~d bottle~p of beer on the wall~%", i, i),
printf(true, "~d bottle~p of beer~%", i, i),
printf(true, "Take one down, pass it around~%"),
printf(true, "~d bottle~p of beer on the wall~%", i - 1, i - 1),
disp(""))$
bottles(3);
/*
3 bottles of beer... | Give a code snippet in #Maxima
Task
Display the complete lyrics for the song: 99 Bottles of Beer on the Wall.
The beer song
The lyrics follow this form:
99 bottles of beer on the wall
99 bottles of beer
Take one down, pass it around
98 bottles of beer on the wall
98 bottles of beer on the wall
9... | christopher/rosetta-code | |
http://rosettacode.org/wiki/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... | #NetRexx | NetRexx | /* NetRexx ************************************************************
* Test digroot
**********************************************************************/
Say 'number -> digital_root persistence'
test_digroot(7 ,7, 0)
test_digroot(627615 ,9, 2)
test_digroot(39390 ,6, 2)
test_digroot(588225 ... | Give a code snippet in #NetRexx
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}
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Prime_conspiracy | Prime conspiracy | A recent discovery, quoted from Quantamagazine (March 13, 2016):
Two mathematicians have uncovered a simple, previously unnoticed property of
prime numbers — those numbers that are divisible only by 1 and themselves.
Prime numbers, it seems, have decided preferences about the final digits of ... | #Nim | Nim |
# Prime conspiracy.
from algorithm import sorted
from math import sqrt
from sequtils import toSeq
from strformat import fmt
import tables
const N = 1_020_000_000.int # Size of sieve of Eratosthenes.
proc newSieve(): seq[bool] =
## Create a sieve with only odd values.
## Index "i" in sieve represents val... | Give a code snippet in #Nim
A recent discovery, quoted from Quantamagazine (March 13, 2016):
Two mathematicians have uncovered a simple, previously unnoticed property of
prime numbers — those numbers that are divisible only by 1 and themselves.
Prime numbers, it seems, have decided preference... | 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... | #C.23 | C# | namespace Search {
using System;
public static partial class Extensions {
/// <summary>Use Binary Search to find index of GLB for value</summary>
/// <typeparam name="T">type of entries and value</typeparam>
/// <param name="entries">array of entries</param>
/// <param name="value">search value</p... | Give a code snippet in #C.23
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 nu... | christopher/rosetta-code | |
http://rosettacode.org/wiki/100_doors | 100 doors | There are 100 doors in a row that are all initially closed.
You make 100 passes by the doors.
The first time through, visit every door and toggle the door (if the door is closed, open it; if it is open, close it).
The second time, only visit every 2nd door (door #2, #4, #6, ...), and toggle it.
The third... | #Klingphix | Klingphix | include ..\Utilitys.tlhy
%n 100 !n
0 $n repeat
$n [dup sqrt int dup * over
== ( [1 swap set] [drop] ) if] for
$n [ ( "The door " over " is " ) lprint get ( ["OPEN"] ["closed"] ) if print nl] for
( "Time elapsed: " msec " seconds" ) lprint nl
pstack
" " input | Give a code snippet in #Klingphix
There are 100 doors in a row that are all initially closed.
You make 100 passes by the doors.
The first time through, visit every door and toggle the door (if the door is closed, open it; if it is open, close it).
The second time, only visit every 2nd door (door #2, #4, #6... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Towers_of_Hanoi | Towers of Hanoi | Task
Solve the Towers of Hanoi problem with recursion.
| #Elena | Elena | move = (n,from,to,via)
{
if (n == 1)
{
console.printLine("Move disk from pole ",from," to pole ",to)
}
else
{
move(n-1,from,via,to);
move(1,from,to,via);
move(n-1,via,to,from)
}
}; | Give a code snippet in #Elena
Task
Solve the Towers of Hanoi problem with recursion.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Quaternion_type | Quaternion type | Quaternions are an extension of the idea of complex numbers.
A complex number has a real and complex part, sometimes written as a + bi,
where a and b stand for real numbers, and i stands for the square root of minus 1.
An example of a complex number might be -3 + 2i,
wher... | #Fortran | Fortran | module Q_mod
implicit none
type quaternion
real :: a, b, c, d
end type
public :: norm, neg, conj
public :: operator (+)
public :: operator (*)
private :: q_plus_q, q_plus_r, r_plus_q, &
q_mult_q, q_mult_r, r_mult_q, &
norm_q, neg_q, conj_q
interface norm
modu... | Give a code snippet in #Fortran
Quaternions are an extension of the idea of complex numbers.
A complex number has a real and complex part, sometimes written as a + bi,
where a and b stand for real numbers, and i stands for the square root of minus 1.
An example of a complex numbe... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Singleton | Singleton | A Global Singleton is a class of which only one instance exists within a program.
Any attempt to use non-static members of the class involves performing operations on this one instance.
| #Latitude | Latitude | Singleton ::= Object clone tap {
self id := 0.
self newID := {
self id := self id + 1.
}.
self clone := {
err ArgError clone tap { self message := "Singleton object!". } throw.
}.
}.
println: Singleton newID. ; 1
println: Singleton newID. ; 2
println: Singleton newID. ; 3 | Give a code snippet in #Latitude
A Global Singleton is a class of which only one instance exists within a program.
Any attempt to use non-static members of the class involves performing operations on this one instance.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Delegates | Delegates | A delegate is a helper object used by another object. The delegator may send the delegate certain messages, and provide a default implementation when there is no delegate or the delegate does not respond to a message. This pattern is heavily used in Cocoa framework on Mac OS X. See also wp:Delegation pattern.
Objects ... | #Dart | Dart | class Delegator {
var delegate;
String operation() {
if (delegate == null)
return "default implementation";
else
return delegate.thing();
}
}
class Delegate {
String thing() => "delegate implementation";
}
main() {
// Without a delegate:
Delegator a = new Delegator();
Expect.equa... | Give a code snippet in #Dart
A delegate is a helper object used by another object. The delegator may send the delegate certain messages, and provide a default implementation when there is no delegate or the delegate does not respond to a message. This pattern is heavily used in Cocoa framework on Mac OS X. See also wp... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Playing_cards | Playing cards | Task
Create a data structure and the associated methods to define and manipulate a deck of playing cards.
The deck should contain 52 unique cards.
The methods must include the ability to:
make a new deck
shuffle (randomize) the deck
deal from the deck
print the current contents of a deck
Each card mu... | #Haskell | Haskell | import System.Random
data Pip = Two | Three | Four | Five | Six | Seven | Eight | Nine | Ten |
Jack | Queen | King | Ace
deriving (Ord, Enum, Bounded, Eq, Show)
data Suit = Diamonds | Spades | Hearts | Clubs
deriving (Ord, Enum, Bounded, Eq, Show)
type Card = (Pip, Suit)
fullRange :: (Bounded a... | Give a code snippet in #Haskell
Task
Create a data structure and the associated methods to define and manipulate a deck of playing cards.
The deck should contain 52 unique cards.
The methods must include the ability to:
make a new deck
shuffle (randomize) the deck
deal from the deck
print the current... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sorting_algorithms/Heapsort | Sorting algorithms/Heapsort |
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
... | #True_BASIC | True BASIC |
!creamos la matriz y la inicializamos
LET lim = 20
DIM array(20)
FOR i = 1 TO lim
LET array(i) = INT(RND * 100) + 1
NEXT i
SUB printArray (lim)
FOR i = 1 TO lim
!PRINT USING("###", array(i));
PRINT array(i); " ";
NEXT i
PRINT
END SUB
SUB heapify (count)
LET start = INT(count / ... | Give a code snippet in #True_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 |
Qui... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Terminal_control/Cursor_positioning | Terminal control/Cursor positioning |
Task
Move the cursor to column 3, row 6, and display the word "Hello" (without the quotes), so that the letter H is in column 3 on row 6.
| #Blast | Blast | # This will display a message at a specific position on the terminal screen
.begin
cursor 6,3
display "Hello!"
return
# This is the end of the script | Give a code snippet in #Blast
Task
Move the cursor to column 3, row 6, and display the word "Hello" (without the quotes), so that the letter H is in column 3 on row 6.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Table_creation/Postal_addresses | Table creation/Postal addresses | Task
Create a table to store addresses.
You may assume that all the addresses to be stored will be located in the USA. As such, you will need (in addition to a field holding a unique identifier) a field holding the street address, a field holding the city, a field holding the state code, and a field holding the zip... | #Mathematica.2FWolfram_Language | Mathematica/Wolfram Language | TableCreation="CREATE TABLE address (
addrID INTEGER PRIMARY KEY AUTOINCREMENT,
addrStreet TEXT NOT NULL, addrCity TEXT NOT NULL,
addrState TEXT NOT NULL, addrZIP TEXT NOT NULL )";
Needs["DatabaseLink`"]
conn=OpenSQLConnection[ JDBC[ "mysql","databases:1234/conn_test"], "Username" -> "test"]
SQLExecute[ conn, Tab... | Give a code snippet in #Mathematica.2FWolfram_Language
Task
Create a table to store addresses.
You may assume that all the addresses to be stored will be located in the USA. As such, you will need (in addition to a field holding a unique identifier) a field holding the street address, a field holding the city, a f... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Check_Machin-like_formulas | Check Machin-like formulas | Machin-like formulas are useful for efficiently computing numerical approximations for
π
{\displaystyle \pi }
Task
Verify the following Machin-like formulas are correct by calculating the value of tan (right hand side) for each equation using exact arithmetic and showing they equal 1:
π
4
=
ar... | #Clojure | Clojure | (ns tanevaulator
(:gen-class))
;; Notation: [a b c] -> a x arctan(a/b)
(def test-cases [
[[1, 1, 2], [1, 1, 3]],
[[2, 1, 3], [1, 1, 7]],
[[4, 1, 5], [-1, 1, 239]],
[[5, 1, 7], [2, 3, 79]],
... | Give a code snippet in #Clojure
Machin-like formulas are useful for efficiently computing numerical approximations for
π
{\displaystyle \pi }
Task
Verify the following Machin-like formulas are correct by calculating the value of tan (right hand side) for each equation using exact arithmetic and showing... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Input_loop | Input loop | Input loop is part of Short Circuit's Console Program Basics selection.
Task
Read from a text stream either word-by-word or line-by-line until the stream runs out of data.
The stream will have an unknown amount of data on it.
| #Racket | Racket |
#lang racket
(copy-port (current-input-port) (current-output-port))
| Give a code snippet in #Racket
Input loop is part of Short Circuit's Console Program Basics selection.
Task
Read from a text stream either word-by-word or line-by-line until the stream runs out of data.
The stream will have an unknown amount of data on it.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Knapsack_problem/Unbounded | Knapsack problem/Unbounded | A traveler gets diverted and has to make an unscheduled stop in what turns out to be Shangri La. Opting to leave, he is allowed to take as much as he likes of the following items, so long as it will fit in his knapsack, and he can carry it.
He knows that he can carry no more than 25 'weights' in total; and tha... | #Kotlin | Kotlin | // version 1.1.2
data class Item(val name: String, val value: Double, val weight: Double, val volume: Double)
val items = listOf(
Item("panacea", 3000.0, 0.3, 0.025),
Item("ichor", 1800.0, 0.2, 0.015),
Item("gold", 2500.0, 2.0, 0.002)
)
val n = items.size
val count = IntArray(n)
val best = IntArray(n... | Give a code snippet in #Kotlin
A traveler gets diverted and has to make an unscheduled stop in what turns out to be Shangri La. Opting to leave, he is allowed to take as much as he likes of the following items, so long as it will fit in his knapsack, and he can carry it.
He knows that he can carry no more than 25... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Window_creation | Window creation | Display a GUI window. The window need not have any contents, but should respond to requests to be closed.
| #Icon_and_Unicon | Icon and Unicon | link graphics
procedure main(arglist)
WOpen("size=300, 300", "fg=blue", "bg=light gray")
WDone()
end | Give a code snippet in #Icon_and_Unicon
Display a GUI window. The window need not have any contents, but should respond to requests to be closed.
| 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... | #J | J | rom2d=: [: (+/ .* _1^ 0,~ 2</\ ]) 1 5 10 50 100 500 1000 {~ 'IVXLCDM'&i. | Give a code snippet in #J
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,
starti... | christopher/rosetta-code | |
http://rosettacode.org/wiki/SEDOLs | SEDOLs | Task
For each number list of 6-digit SEDOLs, calculate and append the checksum digit.
That is, given this input:
710889
B0YBKJ
406566
B0YBLH
228276
B0YBKL
557910
B0YBKR
585284
B0YBKT
B00030
Produce this output:
7108899
B0YBKJ7
4065663
B0YBLH2
2282765
B0YBKL9
5579107
B0YBKR5
5852842
B0YBKT7
B000300
Extra credit
... | #Scala | Scala | class SEDOL(s: String) {
require(s.size == 6 || s.size == 7, "SEDOL length must be 6 or 7 characters")
require(s.size == 6 || s(6).asDigit == chksum, "Incorrect SEDOL checksum")
require(s forall (c => !("aeiou" contains c.toLower)), "Vowels not allowed in SEDOL")
def chksum = 10 - ((s zip List(1, 3, 1, 7, 3, 9)... | Give a code snippet in #Scala
Task
For each number list of 6-digit SEDOLs, calculate and append the checksum digit.
That is, given this input:
710889
B0YBKJ
406566
B0YBLH
228276
B0YBKL
557910
B0YBKR
585284
B0YBKT
B00030
Produce this output:
7108899
B0YBKJ7
4065663
B0YBLH2
2282765
B0YBKL9
5579107
B0YBKR5
5852842... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Tokenize_a_string | Tokenize a string | Separate the string "Hello,How,Are,You,Today" by commas into an array (or list) so that each element of it stores a different word.
Display the words to the 'user', in the simplest manner possible, separated by a period.
To simplify, you may display a trailing period.
Other tasks related to string operations:
Me... | #Erlang | Erlang | -module(tok).
-export([start/0]).
start() ->
Lst = string:tokens("Hello,How,Are,You,Today",","),
io:fwrite("~s~n", [string:join(Lst,".")]),
ok. | Give a code snippet in #Erlang
Separate the string "Hello,How,Are,You,Today" by commas into an array (or list) so that each element of it stores a different word.
Display the words to the 'user', in the simplest manner possible, separated by a period.
To simplify, you may display a trailing period.
Other tasks r... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Voronoi_diagram | Voronoi diagram | A Voronoi diagram is a diagram consisting of a number of sites.
Each Voronoi site s also has a Voronoi cell consisting of all points closest to s.
Task
Demonstrate how to generate and display a Voroni diagram.
See algo K-means++ clustering.
| #C.2B.2B | C++ |
#include <windows.h>
#include <vector>
#include <string>
using namespace std;
//////////////////////////////////////////////////////
struct Point {
int x, y;
};
//////////////////////////////////////////////////////
class MyBitmap {
public:
MyBitmap() : pen_(nullptr) {}
~MyBitmap() {
DeleteObject(pen... | Give a code snippet in #C.2B.2B
A Voronoi diagram is a diagram consisting of a number of sites.
Each Voronoi site s also has a Voronoi cell consisting of all points closest to s.
Task
Demonstrate how to generate and display a Voroni diagram.
See algo K-means++ clustering.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Exceptions | Exceptions | Control Structures
These are examples of control structures. You may also be interested in:
Conditional structures
Exceptions
Flow-control structures
Loops
This task is to give an example of an exception handling routine
and to "throw" a new exception.
Related task
Exceptions Through Nested Calls
| #Sidef | Sidef | try {
die "I'm dead!"; # throws an exception of type 'error'
}
catch { |type, msg|
say "type: #{type}"; # type: error
say "msg: #{msg}"; # msg: I'm dead! at test.sf line 2.
};
say "I'm alive...";
die "Now I'm dead!"; # this line terminates the program
say "Or am I?"; # Y... | Give a code snippet in #Sidef
Control Structures
These are examples of control structures. You may also be interested in:
Conditional structures
Exceptions
Flow-control structures
Loops
This task is to give an example of an exception handling routine
and to "throw" a new exception.
Related task
Exceptions... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Bell_numbers | Bell numbers | Bell or exponential numbers are enumerations of the number of different ways to partition a set that has exactly n elements. Each element of the sequence Bn is the number of partitions of a set of size n where order of the elements and order of the partitions are non-significant. E.G.: {a b} is the same as {b a} and {a... | #Pascal | Pascal | program BellNumbers;
{$Ifdef FPC}
{$optimization on,all}
{$ElseIf}
{Apptype console}
{$EndIf}
uses
sysutils,gmp;
var
T0 :TDateTime;
procedure BellNumbersUint64(OnlyBellNumbers:Boolean);
var
BList : array[0..24] of Uint64;
BellNum : Uint64;
BListLenght,i :nativeUInt;
begin
IF OnlyBellNUmbers then
Begin... | Give a code snippet in #Pascal
Bell or exponential numbers are enumerations of the number of different ways to partition a set that has exactly n elements. Each element of the sequence Bn is the number of partitions of a set of size n where order of the elements and order of the partitions are non-significant. E.G.: {... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Loops/For | Loops/For | “For” loops are used to make some block of code be iterated a number of times, setting a variable or parameter to a monotonically increasing integer value for each execution of the block of code.
Common extensions of this allow other counting patterns or iterating over abstract structures other than the integers.
... | #Futhark | Futhark |
fun main(n: int): [n]int =
loop (a = replicate n 0) = for i < n do
(loop (s = 0) = for j < i+1 do
s + j
let a[i] = s
in a)
in a
| Give a code snippet in #Futhark
“For” loops are used to make some block of code be iterated a number of times, setting a variable or parameter to a monotonically increasing integer value for each execution of the block of code.
Common extensions of this allow other counting patterns or iterating over abstract struc... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Loops/Do-while | Loops/Do-while | Start with a value at 0. Loop while value mod 6 is not equal to 0.
Each time through the loop, add 1 to the value then print it.
The loop must execute at least once.
Related tasks
Loop over multiple arrays simultaneously
Loops/Break
Loops/Continue
Loops/Do-while
Loops/Downward for
Loops/For
Loo... | #Suneido | Suneido | val = 0
do
{
Print(++val)
} while (val % 6 isnt 0) | Give a code snippet in #Suneido
Start with a value at 0. Loop while value mod 6 is not equal to 0.
Each time through the loop, add 1 to the value then print it.
The loop must execute at least once.
Related tasks
Loop over multiple arrays simultaneously
Loops/Break
Loops/Continue
Loops/Do-while
Loops... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Horizontal_sundial_calculations | Horizontal sundial calculations | Task
Create a program that calculates the hour, sun hour angle, dial hour line angle from 6am to 6pm for an operator entered location.
For example, the user is prompted for a location and inputs the latitude and longitude 4°57′S 150°30′W (4.95°S 150.5°W of Jules Verne's Lincoln Island, aka Ernest Legouve Reef), wit... | #OoRexx | OoRexx | /*REXX pgm shows: hour, sun hour angle, dial hour line angle, 6am ---> 6pm*/
/* Use trigonometric functions provided by rxCalc */
parse arg lat lng mer . /*get the optional arguments from the CL*/
/*None specified? Then use the default of Jules ... | Give a code snippet in #OoRexx
Task
Create a program that calculates the hour, sun hour angle, dial hour line angle from 6am to 6pm for an operator entered location.
For example, the user is prompted for a location and inputs the latitude and longitude 4°57′S 150°30′W (4.95°S 150.5°W of Jules Verne's Lincoln Islan... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Tokenize_a_string | Tokenize a string | Separate the string "Hello,How,Are,You,Today" by commas into an array (or list) so that each element of it stores a different word.
Display the words to the 'user', in the simplest manner possible, separated by a period.
To simplify, you may display a trailing period.
Other tasks related to string operations:
Me... | #Falcon | Falcon |
/* created by Aykayayciti Earl Lamont Montgomery
April 9th, 2018 */
a = []
a = strSplit("Hello,How,Are,You,Today", ",")
index = 0
start = 0
b = ""
for index in [ start : len(a)-1 : 1 ]
b = b + a[i] + "."
end
> b
| Give a code snippet in #Falcon
Separate the string "Hello,How,Are,You,Today" by commas into an array (or list) so that each element of it stores a different word.
Display the words to the 'user', in the simplest manner possible, separated by a period.
To simplify, you may display a trailing period.
Other tasks r... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Trigonometric_functions | Trigonometric functions | Task
If your language has a library or built-in functions for trigonometry, show examples of:
sine
cosine
tangent
inverses (of the above)
using the same angle in radians and degrees.
For the non-inverse functions, each radian/degree pair should use arguments that evaluate to the same angle (that i... | #Icon_and_Unicon | Icon and Unicon | invocable all
procedure main()
d := 30 # degrees
r := dtor(d) # convert to radians
every write(f := !["sin","cos","tan"],"(",r,")=",y := f(r)," ",fi := "a" || f,"(",y,")=",x := fi(y)," rad = ",rtod(x)," deg")
end | Give a code snippet in #Icon_and_Unicon
Task
If your language has a library or built-in functions for trigonometry, show examples of:
sine
cosine
tangent
inverses (of the above)
using the same angle in radians and degrees.
For the non-inverse functions, each radian/degree pair should use arguments ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Runtime_evaluation/In_an_environment | Runtime evaluation/In an environment | x
x
x
Do so in a way which:
does not involve string manipulation of the input source code
is plausibly extensible to a runtime-chosen set of bindings rather than just x
does not make x a global variable
or note that these are impossible.
See also
For more general examples and language-specific details, see... | #AutoHotkey | AutoHotkey | msgbox % first := evalWithX("x + 4", 5)
msgbox % second := evalWithX("x + 4", 6)
msgbox % second - first
return
evalWithX(expression, xvalue)
{
global script
script =
(
expression(){
x = %xvalue% ; := would need quotes
return %expression%
}
)
renameFunction("expression", "") ; remove any previous exp... | Give a code snippet in #AutoHotkey
x
x
x
Do so in a way which:
does not involve string manipulation of the input source code
is plausibly extensible to a runtime-chosen set of bindings rather than just x
does not make x a global variable
or note that these are impossible.
See also
For more general example... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sum_digits_of_an_integer | Sum digits of an integer | Task
Take a Natural Number in a given base and return the sum of its digits:
110 sums to 1
123410 sums to 10
fe16 sums to 29
f0e16 sums to 29
| #Lasso | Lasso | define br => '<br />\n'
define sumdigits(int, base = 10) => {
fail_if(#base < 2, -1, 'Base need to be at least 2')
local(
out = integer,
divmod
)
while(#int) => {
#divmod = #int -> div(#base)
#int = #divmod -> first
#out += #divmod -> second
}
return #out
}
sumdigits(1)
br
sumdigits(12345)
br
su... | Give a code snippet in #Lasso
Task
Take a Natural Number in a given base and return the sum of its digits:
110 sums to 1
123410 sums to 10
fe16 sums to 29
f0e16 sums to 29
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Kernighans_large_earthquake_problem | Kernighans large earthquake problem | Brian Kernighan, in a lecture at the University of Nottingham, described a problem on which this task is based.
Problem
You are given a a data file of thousands of lines; each of three `whitespace` separated fields: a date, a one word name and the magnitude of the event.
Example lines from the file would be lines li... | #Perl | Perl | perl -n -e '/(\S+)\s*$/ and $1 > 6 and print' data.txt | Give a code snippet in #Perl
Brian Kernighan, in a lecture at the University of Nottingham, described a problem on which this task is based.
Problem
You are given a a data file of thousands of lines; each of three `whitespace` separated fields: a date, a one word name and the magnitude of the event.
Example lines f... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Secure_temporary_file | Secure temporary file | Task
Create a temporary file, securely and exclusively (opening it such that there are no possible race conditions).
It's fine assuming local filesystem semantics (NFS or other networking filesystems can have signficantly more complicated semantics for satisfying the "no race conditions" criteria).
The function shou... | #Delphi | Delphi |
program Secure_temporary_file;
{$APPTYPE CONSOLE}
uses
System.SysUtils,
System.IOUtils;
var
FileName, buf: string;
begin
FileName := TPath.GetTempFileName;
with TFile.Open(FileName, TFileMode.fmCreate, TFileAccess.faReadWrite,
Tfileshare.fsNone) do
begin
buf := 'This is a exclusive temp fi... | Give a code snippet in #Delphi
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 condition... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Perlin_noise | Perlin noise | The Perlin noise is a kind of gradient noise invented by Ken Perlin around the end of the twentieth century and still currently heavily used in computer graphics, most notably to procedurally generate textures or heightmaps.
The Perlin noise is basically a pseudo-random mapping of
R
d
... | #XPL0 | XPL0 | func real Noise; real X, Y, Z;
real U, V, W;
int IX, IY, IZ, P(512), A, AA, AB, B, BA, BB;
func real Fade; real T;
return T*T*T * (T*(T*6.-15.) + 10.);
func real Lerp; real T, A, B;
return A + T*(B-A);
func real Grad; int Hash; real X, Y, Z;
int H; real U, V;
[H:= Hash & $0F; ... | Give a code snippet in #XPL0
The Perlin noise is a kind of gradient noise invented by Ken Perlin around the end of the twentieth century and still currently heavily used in computer graphics, most notably to procedurally generate textures or heightmaps.
The Perlin noise is basically a pseudo-random ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/String_case | String case | Task
Take the string alphaBETA and demonstrate how to convert it to:
upper-case and
lower-case
Use the default encoding of a string literal or plain ASCII if there is no string literal in your language.
Note: In some languages alphabets toLower and toUpper is not reversable.
Show any additional... | #REBOL | REBOL | print ["Original: " original: "alphaBETA"]
print ["Uppercase:" uppercase original]
print ["Lowercase:" lowercase original] | Give a code snippet in #REBOL
Task
Take the string alphaBETA and demonstrate how to convert it to:
upper-case and
lower-case
Use the default encoding of a string literal or plain ASCII if there is no string literal in your language.
Note: In some languages alphabets toLower and toUpper is not r... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Null_object | Null object |
Null (or nil) is the computer science concept of an undefined or unbound object.
Some languages have an explicit way to access the null object, and some don't.
Some languages distinguish the null object from undefined values, and some don't.
Task
Show how to access null in your language by checking to see if an ob... | #NetRexx | NetRexx | /* NetRexx */
options replace format comments java crossref symbols binary
robject = Rexx -- create an object for which the value is undefined
say String.valueOf(robject) -- will report the text "null"
if robject = null then say 'Really, it''s "null"!'
| Give a code snippet in #NetRexx
Null (or nil) is the computer science concept of an undefined or unbound object.
Some languages have an explicit way to access the null object, and some don't.
Some languages distinguish the null object from undefined values, and some don't.
Task
Show how to access null in your lan... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Best_shuffle | Best shuffle | Task
Shuffle the characters of a string in such a way that as many of the character values are in a different position as possible.
A shuffle that produces a randomized result among the best choices is to be preferred. A deterministic approach that produces the same sequence every time is acceptable as an alternative... | #Seed7 | Seed7 | $ include "seed7_05.s7i";
const func string: bestShuffle (in string: stri) is func
result
var string: shuffled is "";
local
var char: tmp is ' ';
var integer: i is 0;
var integer: j is 0;
begin
shuffled := stri;
for key i range shuffled do
for key j range shuffled do
if i <... | Give a code snippet in #Seed7
Task
Shuffle the characters of a string in such a way that as many of the character values are in a different position as possible.
A shuffle that produces a randomized result among the best choices is to be preferred. A deterministic approach that produces the same sequence every time ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Y_combinator | Y combinator | In strict functional programming and the lambda calculus, functions (lambda expressions) don't have state and are only allowed to refer to arguments of enclosing functions.
This rules out the usual definition of a recursive function wherein a function is associated with the state of a variable and this variable's stat... | #Elm | Elm | module Main exposing ( main )
import Html exposing ( Html, text )
-- As with most of the strict (non-deferred or non-lazy) languages,
-- this is the Z-combinator with the additional value parameter...
-- wrap type conversion to avoid recursive type definition...
type Mu a b = Roll (Mu a b -> a -> b)
unroll : Mu... | Give a code snippet in #Elm
In strict functional programming and the lambda calculus, functions (lambda expressions) don't have state and are only allowed to refer to arguments of enclosing functions.
This rules out the usual definition of a recursive function wherein a function is associated with the state of a vari... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Environment_variables | Environment variables | Task
Show how to get one of your process's environment variables.
The available variables vary by system; some of the common ones available on Unix include:
PATH
HOME
USER
| #Lua | Lua | print( os.getenv( "PATH" ) ) | Give a code snippet in #Lua
Task
Show how to get one of your process's environment variables.
The available variables vary by system; some of the common ones available on Unix include:
PATH
HOME
USER
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Vector | Vector | Task
Implement a Vector class (or a set of functions) that models a Physical Vector. The four basic operations and a pretty print function should be implemented.
The Vector may be initialized in any reasonable way.
Start and end points, and direction
Angular coefficient and value (length)
The four operations to... | #Perl | Perl | package Vector;
use Moose;
use feature 'say';
use overload '+' => \&add,
'-' => \&sub,
'*' => \&mul,
'/' => \&div,
'""' => \&stringify;
has 'x' => (is =>'rw', isa => 'Num', required => 1);
has 'y' => (is =>'rw', isa => 'Num', required => 1);
sub add {
my($a, $... | Give a code snippet in #Perl
Task
Implement a Vector class (or a set of functions) that models a Physical Vector. The four basic operations and a pretty print function should be implemented.
The Vector may be initialized in any reasonable way.
Start and end points, and direction
Angular coefficient and value (le... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Date_format | Date format | This task has been clarified. Its programming examples are in need of review to ensure that they still fit the requirements of the task.
Task
Display the current date in the formats of:
2007-11-23 and
Friday, November 23, 2007
| #Run_BASIC | Run BASIC | 'Display the current date in the formats of "2007-11-10" and "Sunday, November 10, 2007".
print date$("yyyy-mm-dd")
print date$("dddd");", "; 'return full day of the week (eg. Wednesday
print date$("mmmm");" "; 'return full month name (eg. March)
print date$("dd, yyyy") ... | Give a code snippet in #Run_BASIC
This task has been clarified. Its programming examples are in need of review to ensure that they still fit the requirements of the task.
Task
Display the current date in the formats of:
2007-11-23 and
Friday, November 23, 2007
| christopher/rosetta-code | |
http://rosettacode.org/wiki/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
... | #Io | Io | rms := method (figs, (figs map(** 2) reduce(+) / figs size) sqrt)
rms( Range 1 to(10) asList ) println | Give a code snippet in #Io
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/Bitmap/Read_a_PPM_file | Bitmap/Read a PPM file | Using the data storage type defined on this page for raster images, read an image from a PPM file (binary P6 prefered).
(Read the definition of PPM file on Wikipedia.)
Task: Use write ppm file solution and grayscale image solution with this one in order to convert a color image to grayscale one.
| #Racket | Racket |
#lang racket
(require racket/draw)
(define (read-ppm port)
(parameterize ([current-input-port port])
(define magic (read))
(define width (read))
(define height (read))
(define maxcol (read))
(define bm (make-object bitmap% width height))
(define dc (new bitmap-dc% [bitmap bm]))
(send d... | Give a code snippet in #Racket
Using the data storage type defined on this page for raster images, read an image from a PPM file (binary P6 prefered).
(Read the definition of PPM file on Wikipedia.)
Task: Use write ppm file solution and grayscale image solution with this one in order to convert a color image to grays... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Symmetric_difference | Symmetric difference | Task
Given two sets A and B, compute
(
A
∖
B
)
∪
(
B
∖
A
)
.
{\displaystyle (A\setminus B)\cup (B\setminus A).}
That is, enumerate the items that are in A or B but not both. This set is called the symmetric difference of A and B.
In other words:
(
A
∪
B
)
∖
(
A
∩
B
)
{\displaystyle (A\cup B)\setminus (A... | #Ada | Ada | with Ada.Text_IO; use Ada.Text_IO;
procedure Test_XOR is
type Person is (John, Bob, Mary, Serena, Jim);
type Group is array (Person) of Boolean;
procedure Put (Set : Group) is
First : Boolean := True;
begin
for I in Set'Range loop
if Set (I) then
if First then
... | Give a code snippet in #Ada
Task
Given two sets A and B, compute
(
A
∖
B
)
∪
(
B
∖
A
)
.
{\displaystyle (A\setminus B)\cup (B\setminus A).}
That is, enumerate the items that are in A or B but not both. This set is called the symmetric difference of A and B.
In other words:
(
A
∪
B
)
∖
(
A
∩
B
)
{\displ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Combinations | Combinations | Task
Given non-negative integers m and n, generate all size m combinations of the integers from 0 (zero) to n-1 in sorted order (each combination is sorted and the entire table is sorted).
Example
3 comb 5 is:
0 1 2
0 1 3
0 1 4
0 2 3
0 2 4
0 3 4
1 2 3
1 2 4
1 3 4
2 3 4
... | #Standard_ML | Standard ML | fun comb (0, _ ) = [[]]
| comb (_, [] ) = []
| comb (m, x::xs) = map (fn y => x :: y) (comb (m-1, xs)) @
comb (m, xs)
;
comb (3, [0,1,2,3,4]); | Give a code snippet in #Standard_ML
Task
Given non-negative integers m and n, generate all size m combinations of the integers from 0 (zero) to n-1 in sorted order (each combination is sorted and the entire table is sorted).
Example
3 comb 5 is:
0 1 2
0 1 3
0 1 4
0 2 3... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Euler%27s_sum_of_powers_conjecture | Euler's sum of powers conjecture | There is a conjecture in mathematics that held for over two hundred years before it was disproved by the finding of a counterexample in 1966 by Lander and Parkin.
Euler's (disproved) sum of powers conjecture
At least k positive kth powers are required to sum to a kth power,
except for the trivial case... | #EchoLisp | EchoLisp |
(define dim 250)
;; speed up n^5
(define (p5 n) (* n n n n n))
(remember 'p5) ;; memoize
;; build vector of all y^5 - x^5 diffs - length 30877
(define all-y^5-x^5
(for*/vector
[(x (in-range 1 dim)) (y (in-range (1+ x) dim))]
(- (p5 y) (p5 x))))
;; sort to use vector-search
(begin (vector-sort! < all... | Give a code snippet in #EchoLisp
There is a conjecture in mathematics that held for over two hundred years before it was disproved by the finding of a counterexample in 1966 by Lander and Parkin.
Euler's (disproved) sum of powers conjecture
At least k positive kth powers are required to sum to a kth powe... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sorting_algorithms/Bead_sort | Sorting algorithms/Bead 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
... | #Wren | Wren | var beadSort = Fn.new { |a|
var res = []
var max = a.reduce { |acc, i| (i > acc) ? i : acc }
var trans = [0] * max
for (i in a) {
for (n in 0...i) trans[n] = trans[n] + 1
}
for (i in a) {
res.add(trans.count { |n| n > 0 })
for (n in 0...trans.count) trans[n] = trans[n] - ... | Give a code snippet in #Wren
Sorting Algorithm
This is a sorting algorithm. It may be applied to a set of data in order to sort it.
For comparing various sorts, see compare sorts.
For other sorting algorithms, see sorting algorithms, or:
O(n logn) sorts
Heap sort |
Merge sort |
Patience sort |
Quick sor... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Create_an_HTML_table | Create an HTML table | Create an HTML table.
The table body should have at least three rows of three columns.
Each of these three columns should be labelled "X", "Y", and "Z".
An extra column should be added at either the extreme left or the extreme right of the table that has no heading, but is filled with sequential row numbers.
The... | #Standard_ML | Standard ML | (*
* val mkHtmlTable : ('a list * 'b list) -> ('a -> string * 'b -> string)
* -> (('a * 'b) -> string) -> string
* The int list is list of colums, the function returns the values
* at a given colum and row.
* returns the HTML code of the generated table.
*)
fun mkHtmlTable (columns, rows) (rowToStr, colToStr)... | Give a code snippet in #Standard_ML
Create an HTML table.
The table body should have at least three rows of three columns.
Each of these three columns should be labelled "X", "Y", and "Z".
An extra column should be added at either the extreme left or the extreme right of the table that has no heading, but is fill... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Solve_a_Hidato_puzzle | Solve a Hidato puzzle | The task is to write a program which solves Hidato (aka Hidoku) puzzles.
The rules are:
You are given a grid with some numbers placed in it. The other squares in the grid will be blank.
The grid is not necessarily rectangular.
The grid may have holes in it.
The grid is always connected.
The number “1” is always ... | #REXX | REXX | /*REXX program solves a Numbrix (R) puzzle, it also displays the puzzle and solution. */
maxR=0; maxC=0; maxX=0; minR=9e9; minC=9e9; minX=9e9; cells=0; @.=
parse arg xxx; PZ='Hidato puzzle' /*get the cell definitions from the CL.*/
xxx=translate(xxx, , "/\;:_", ',') ... | Give a code snippet in #REXX
The task is to write a program which solves Hidato (aka Hidoku) puzzles.
The rules are:
You are given a grid with some numbers placed in it. The other squares in the grid will be blank.
The grid is not necessarily rectangular.
The grid may have holes in it.
The grid is always connect... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Recaman%27s_sequence | Recaman's sequence | The Recamán's sequence generates Natural numbers.
Starting from a(0)=0, the n'th term a(n), where n>0, is the previous term minus n i.e a(n) = a(n-1) - n but only if this is both positive and has not been previousely generated.
If the conditions don't hold then a(n) = a(n-1) + n.
Task
Generate and show here the... | #PHP | PHP | <?php
$a = array();
array_push($a, 0);
$used = array();
array_push($used, 0);
$used1000 = array();
array_push($used1000, 0);
$foundDup = false;
$n = 1;
while($n <= 15 || !$foundDup || count($used1000) < 1001) {
$next = $a[$n - 1] - $n;
if ($next < 1 || in_array($next, $used)) {
$next += 2 * $n;
}
$already... | Give a code snippet in #PHP
The Recamán's sequence generates Natural numbers.
Starting from a(0)=0, the n'th term a(n), where n>0, is the previous term minus n i.e a(n) = a(n-1) - n but only if this is both positive and has not been previousely generated.
If the conditions don't hold then a(n) = a(n-1) + n.
Task... | 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... | #PHP | PHP | <?php
$a = '2988348162058574136915891421498819466320163312926952423791023078876139';
$b = '2351399303373464486466122544523690094744975233415544072992656881240319';
$m = '1' . str_repeat('0', 40);
echo bcpowmod($a, $b, $m), "\n"; | Give a code snippet in #PHP
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/Inverted_index | Inverted index | An Inverted Index is a data structure used to create full text search.
Task
Given a set of text files, implement a program to create an inverted index.
Also create a user interface to do a search using that inverted index which returns a list of files that contain the query term / terms.
The search index can be i... | #REXX | REXX | /*REXX program illustrates building a simple inverted index and a method of word find.*/
@.= /*a dictionary of words (so far). */
!= /*a list of found words (so far). */
call invertI 0, 'BURMA0.TXT' ... | Give a code snippet in #REXX
An Inverted Index is a data structure used to create full text search.
Task
Given a set of text files, implement a program to create an inverted index.
Also create a user interface to do a search using that inverted index which returns a list of files that contain the query term / ter... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Circles_of_given_radius_through_two_points | Circles of given radius through two points |
Given two points on a plane and a radius, usually two circles of given radius can be drawn through the points.
Exceptions
r==0.0 should be treated as never describing circles (except in the case where the points are coincident).
If the points are coincident then an infinite number of circles with the point on thei... | #Scheme | Scheme |
(import (scheme base)
(scheme inexact)
(scheme write))
;; c1 and c2 are pairs (x y), r a positive radius
(define (find-circles c1 c2 r)
(define x-coord car) ; for easier to read coordinate extraction from list
(define y-coord cadr)
(define (approx= a b) (< (- a b) 0.000001)) ; equal within tol... | Give a code snippet in #Scheme
Given two points on a plane and a radius, usually two circles of given radius can be drawn through the points.
Exceptions
r==0.0 should be treated as never describing circles (except in the case where the points are coincident).
If the points are coincident then an infinite number o... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Harshad_or_Niven_series | Harshad or Niven series | The Harshad or Niven numbers are positive integers ≥ 1 that are divisible by the sum of their digits.
For example, 42 is a Harshad number as 42 is divisible by (4 + 2) without remainder.
Assume that the series is defined as the numbers in increasing order.
Task
The task is to create a function/method/... | #Modula-2 | Modula-2 | MODULE Harshad;
FROM InOut IMPORT WriteString, WriteCard, WriteLn;
VAR n, i: CARDINAL;
PROCEDURE DigitSum(n: CARDINAL): CARDINAL;
VAR sum: CARDINAL;
BEGIN
sum := 0;
WHILE n > 0 DO;
sum := sum + n MOD 10;
n := n DIV 10;
END;
RETURN sum;
END DigitSum;
PROCEDURE NextHarshad(n: CARDINA... | Give a code snippet in #Modula-2
The Harshad or Niven numbers are positive integers ≥ 1 that are divisible by the sum of their digits.
For example, 42 is a Harshad number as 42 is divisible by (4 + 2) without remainder.
Assume that the series is defined as the numbers in increasing order.
Task
The ta... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Queue/Usage | Queue/Usage |
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
Create a queue data structure and demonstrate its operations.
(For implementations of queues, see the FIFO task.)
Ope... | #D | D | class LinkedQueue(T) {
private static struct Node {
T data;
Node* next;
}
private Node* head, tail;
bool empty() { return head is null; }
void push(T item) {
if (empty())
head = tail = new Node(item);
else {
tail.next = new Node(item);
... | Give a code snippet in #D
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
Create a queue data structure and demonstrate its operations.
(For implementations of queues,... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Knapsack_problem/Continuous | Knapsack problem/Continuous |
A thief burgles a butcher's shop, where he can select from some items.
The thief knows the weights and prices of each items. Because he has a knapsack with 15 kg maximal capacity, he wants to select the items such that he would have his profit maximized. He may cut the items; the item has a reduced price after... | #C.23 | C# | using System; //4790@3.6
class Program
{
static void Main()
{
Console.WriteLine(knapSack(15) + "\n");
var sw = System.Diagnostics.Stopwatch.StartNew();
for (int i = 1000; i > 0; i--) knapSack(15);
Console.Write(sw.Elapsed); Console.Read(); // 0.60 µs
}
static string... | Give a code snippet in #C.23
A thief burgles a butcher's shop, where he can select from some items.
The thief knows the weights and prices of each items. Because he has a knapsack with 15 kg maximal capacity, he wants to select the items such that he would have his profit maximized. He may cut the items; the ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Grayscale_image | Grayscale image | Many image processing algorithms are defined for grayscale (or else monochromatic) images.
Task
Extend the data storage type defined on this page to support grayscale images.
Define two operations, one to convert a color image to a grayscale image and one for the backward conversion.
To get luminance of a color u... | #Phix | Phix | -- demo\rosetta\Bitmap_Greyscale.exw (runnable version)
function to_grey(sequence image)
integer dimx = length(image),
dimy = length(image[1])
for x=1 to dimx do
for y=1 to dimy do
integer pixel = image[x][y] -- red,green,blue
sequence r_g_b = sq_and_bit... | Give a code snippet in #Phix
Many image processing algorithms are defined for grayscale (or else monochromatic) images.
Task
Extend the data storage type defined on this page to support grayscale images.
Define two operations, one to convert a color image to a grayscale image and one for the backward conversion.
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Pointers_and_references | Pointers and references |
Basic Data Operation
This is a basic data operation. It represents a fundamental action on a basic data type.
You may see other such operations in the Basic Data Operations category, or:
Integer Operations
Arithmetic |
Comparison
Boolean Operations
Bitwise |
Logical
String Operations
Concatenation |
Interpolation |... | #8086_Assembly | 8086 Assembly | .model small
.stack 1024
.data ; data segment begins here
UserRam byte 256 dup (0) ; the next 256 bytes have a value of zero. The address of the 0th of these bytes can be referenced as "UserRam"
tempByte equ UserRam ;this variable's address is the same as that of the 0th byte of UserRam
tempWor... | Give a code snippet in #8086_Assembly
Basic Data Operation
This is a basic data operation. It represents a fundamental action on a basic data type.
You may see other such operations in the Basic Data Operations category, or:
Integer Operations
Arithmetic |
Comparison
Boolean Operations
Bitwise |
Logical
String Ope... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Integer_sequence | Integer sequence | Task
Create a program that, when run, would display all integers from 1 to ∞ (or any relevant implementation limit), in sequence (i.e. 1, 2, 3, 4, etc) if given enough time.
An example may not be able to reach arbitrarily-large numbers based on implementations limits. For example, if integer... | #Emacs_Lisp | Emacs Lisp | (dotimes (i most-positive-fixnum)
(message "%d" (1+ i))) | Give a code snippet in #Emacs_Lisp
Task
Create a program that, when run, would display all integers from 1 to ∞ (or any relevant implementation limit), in sequence (i.e. 1, 2, 3, 4, etc) if given enough time.
An example may not be able to reach arbitrarily-large numbers based on implementatio... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Loops/For_with_a_specified_step | Loops/For with a specified step |
Task
Demonstrate a for-loop where the step-value is greater than one.
Related tasks
Loop over multiple arrays simultaneously
Loops/Break
Loops/Continue
Loops/Do-while
Loops/Downward for
Loops/For
Loops/For with a specified step
Loops/Foreach
Loops/Increment loop index within loop b... | #Ring | Ring |
for i = 0 to 10 step 2 see i + nl next
| Give a code snippet in #Ring
Task
Demonstrate a for-loop where the step-value is greater than one.
Related tasks
Loop over multiple arrays simultaneously
Loops/Break
Loops/Continue
Loops/Do-while
Loops/Downward for
Loops/For
Loops/For with a specified step
Loops/Foreach
Loops/Incr... | 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... | #Yabasic | Yabasic | roman$ = "M, CM, D, CD, C, XC, L, XL, X, IX, V, IV, I"
decml$ = "1000, 900, 500, 400, 100, 90, 50, 40, 10, 9, 5, 4, 1"
sub toRoman$(value)
local res$, i, roman$(1), decml$(1), long
long = token(roman$, roman$(), ", ")
long = token(decml$, decml$(), ", ")
for i=1 to long
while(value ... | Give a code snippet in #Yabasic
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/Function_definition | Function definition | A function is a body of code that returns a value.
The value returned may depend on arguments provided to the function.
Task
Write a definition of a function called "multiply" that takes two arguments and returns their product.
(Argument types should be chosen so as not to distract from showing how functions are ... | #ARM_Assembly | ARM Assembly |
/* ARM assembly Raspberry PI */
/* program functMul.s */
/* Constantes */
.equ STDOUT, 1
.equ WRITE, 4
.equ EXIT, 1
/***********************/
/* Initialized data */
/***********************/
.data
szRetourLigne: .asciz "\n"
szMessResult: .ascii "Resultat : " @ message result
sMessValeur: .fill 12,... | Give a code snippet in #ARM_Assembly
A function is a body of code that returns a value.
The value returned may depend on arguments provided to the function.
Task
Write a definition of a function called "multiply" that takes two arguments and returns their product.
(Argument types should be chosen so as not to di... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Old_Russian_measure_of_length | Old Russian measure of length | Task
Write a program to perform a conversion of the old Russian measures of length to the metric system (and vice versa).
It is an example of a linear transformation of several variables.
The program should accept a single value in a selected unit of measurement, and convert and return it to the other units:
... | #C | C |
#include<string.h>
#include<stdlib.h>
#include<ctype.h>
#include<stdio.h>
#define UNITS_LENGTH 13
int main(int argC,char* argV[])
{
int i,reference;
char *units[UNITS_LENGTH] = {"kilometer","meter","centimeter","tochka","liniya","diuym","vershok","piad","fut","arshin","sazhen","versta","milia"};
double fact... | Give a code snippet in #C
Task
Write a program to perform a conversion of the old Russian measures of length to the metric system (and vice versa).
It is an example of a linear transformation of several variables.
The program should accept a single value in a selected unit of measurement, and convert and retu... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Generate_random_chess_position | Generate random chess position | Task
Generate a random chess position in FEN format.
The position does not have to be realistic or even balanced, but it must comply to the following rules:
there is one and only one king of each color (one black king and one white king);
the kings must not be placed on adjacent squares;
there can not be any p... | #REXX | REXX | /*REXX program generates a chess position (random pieces & positions) in a FEN format.*/
parse arg seed CBs . /*obtain optional arguments from the CL*/
if datatype(seed,'W') then call random ,,seed /*SEED given for RANDOM repeatability? */
if CBs=='' | CBs=="," then CBs=1 ... | Give a code snippet in #REXX
Task
Generate a random chess position in FEN format.
The position does not have to be realistic or even balanced, but it must comply to the following rules:
there is one and only one king of each color (one black king and one white king);
the kings must not be placed on adjacent sq... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Define_a_primitive_data_type | Define a primitive data type | Demonstrate how to define a type that behaves like an integer but has a lowest valid value of 1 and a highest valid value of 10. Include all bounds checking you need to write, or explain how the compiler or interpreter creates those bounds checks for you.
| #C.2B.2B | C++ | #include <stdexcept>
class tiny_int
{
public:
tiny_int(int i):
value(i)
{
if (value < 1)
throw std::out_of_range("tiny_int: value smaller than 1");
if (value > 10)
throw std::out_of_range("tiny_int: value larger than 10");
}
operator int() const
{
return value;
}
tiny_int& op... | Give a code snippet in #C.2B.2B
Demonstrate how to define a type that behaves like an integer but has a lowest valid value of 1 and a highest valid value of 10. Include all bounds checking you need to write, or explain how the compiler or interpreter creates those bounds checks for you.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Walk_a_directory/Non-recursively | Walk a directory/Non-recursively | Task
Walk a given directory and print the names of files matching a given pattern.
(How is "pattern" defined? substring match? DOS pattern? BASH pattern? ZSH pattern? Perl regular expression?)
Note: This task is for non-recursive methods. These tasks should read a single directory, not an entire directory tree.
... | #BASIC | BASIC | DECLARE SUB show (pattern AS STRING)
show "*.*"
SUB show (pattern AS STRING)
DIM f AS STRING
f = DIR$(pattern)
DO WHILE LEN(f)
PRINT f
f = DIR$
LOOP
END SUB | Give a code snippet in #BASIC
Task
Walk a given directory and print the names of files matching a given pattern.
(How is "pattern" defined? substring match? DOS pattern? BASH pattern? ZSH pattern? Perl regular expression?)
Note: This task is for non-recursive methods. These tasks should read a single directory, ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/String_concatenation | String concatenation | String concatenation
You are encouraged to solve this task according to the task description, using any language you may know.
Task
Create a string variable equal to any text value.
Create another string variable whose value is the original variable concatenated with another string literal.
To illustrate the operat... | #PicoLisp | PicoLisp | (let Str1 "First text"
(prinl Str1 " literal")
(let Str2 (pack Str1 " literal")
(prinl Str2) ) ) | Give a code snippet in #PicoLisp
String concatenation
You are encouraged to solve this task according to the task description, using any language you may know.
Task
Create a string variable equal to any text value.
Create another string variable whose value is the original variable concatenated with another string ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Call_a_function | Call a function | Task
Demonstrate the different syntax and semantics provided for calling a function.
This may include:
Calling a function that requires no arguments
Calling a function with a fixed number of arguments
Calling a function with optional arguments
Calling a function with a variable number of arguments
C... | #Sidef | Sidef | foo(); # without arguments
foo(1, 2); # with two arguments
foo(args...); # with a variable number of arguments
foo(name: 'Bar', age: 42); # with named arguments
var f = foo; # store the function foo inside 'f'
var result = f(); # obta... | Give a code snippet in #Sidef
Task
Demonstrate the different syntax and semantics provided for calling a function.
This may include:
Calling a function that requires no arguments
Calling a function with a fixed number of arguments
Calling a function with optional arguments
Calling a function with a va... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Conditional_structures | Conditional structures | Control Structures
These are examples of control structures. You may also be interested in:
Conditional structures
Exceptions
Flow-control structures
Loops
Task
List the conditional structures offered by a programming language. See Wikipedia: conditionals for descriptions.
Common conditional structures include ... | #ARM_Assembly | ARM Assembly |
/* ARM assembly Raspberry PI */
/* program condstr.s */
/* Constantes */
.equ STDOUT, 1 @ Linux output console
.equ EXIT, 1 @ Linux syscall
.equ WRITE, 4 @ Linux syscall
/* Initialized data */
.data
szMessTest1: .asciz "The test 1 is equal.\n"
szMessTest1N: .asciz "The test 1 is not equal.\n... | Give a code snippet in #ARM_Assembly
Control Structures
These are examples of control structures. You may also be interested in:
Conditional structures
Exceptions
Flow-control structures
Loops
Task
List the conditional structures offered by a programming language. See Wikipedia: conditionals for descriptions.
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Compiler/lexical_analyzer | Compiler/lexical analyzer | Definition from Wikipedia:
Lexical analysis is the process of converting a sequence of characters (such as in a computer program or web page) into a sequence of tokens (strings with an identified "meaning"). A program that performs lexical analysis may be called a lexer, tokenizer, or scanner (though "scanner" is als... | #Standard_ML | Standard ML | (*------------------------------------------------------------------*)
(* The Rosetta Code lexical analyzer, in Standard ML. Based on the ATS
and the OCaml. The intended compiler is Mlton or Poly/ML; there is
a tiny difference near the end of the file, depending on which
compiler is used. *)
(*--------------... | Give a code snippet in #Standard_ML
Definition from Wikipedia:
Lexical analysis is the process of converting a sequence of characters (such as in a computer program or web page) into a sequence of tokens (strings with an identified "meaning"). A program that performs lexical analysis may be called a lexer, tokenizer... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Levenshtein_distance | Levenshtein distance |
This page uses content from Wikipedia. The original article was at Levenshtein distance. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance)
In information theory and computer science, the Levenshtein ... | #VBA | VBA | Option Base 1
Function levenshtein(s1 As String, s2 As String) As Integer
Dim n As Integer: n = Len(s1) + 1
Dim m As Integer: m = Len(s2) + 1
Dim d() As Integer, i As Integer, j As Integer
ReDim d(n, m)
If n = 1 Then
levenshtein = m - 1
Exit Function
Else
If m = 1 Then
... | Give a code snippet in #VBA
This page uses content from Wikipedia. The original article was at Levenshtein distance. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance)
In information theory and compu... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Formatted_numeric_output | Formatted numeric output | Task
Express a number in decimal as a fixed-length string with leading zeros.
For example, the number 7.125 could be expressed as 00007.125.
| #Scheme | Scheme | (load "srfi-54.scm")
(load "srfi-54.scm") ;; Don't ask.
(define x 295643087.65432)
(dotimes (i 4)
(print (cat x 25 3.0 #\0 (list #\, (- 4 i)))))
| Give a code snippet in #Scheme
Task
Express a number in decimal as a fixed-length string with leading zeros.
For example, the number 7.125 could be expressed as 00007.125.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/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
| #UNIX_Shell | UNIX Shell | #!/usr/bin/env bash
mapfile -t name <<EOF
Aimhacks
EOF
main() {
banner3d_1 "${name[@]}"
echo
banner3d_2 "${name[@]}"
echo
banner3d_3 "${name[@]}"
}
space() {
local -i n i
(( n=$1 )) || n=1
if (( n < 1 )); then n=1; fi
for ((i=0; i<n; ++i)); do
printf ' '
done
printf '\n'
}
banner3d_1() {... | Give a code snippet in #UNIX_Shell
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/Dice_game_probabilities | Dice game probabilities | Two players have a set of dice each. The first player has nine dice with four faces each, with numbers one to four. The second player has six normal dice with six faces each, each face has the usual numbers from one to six.
They roll their dice and sum the totals of the faces. The player with the highest total wins (i... | #Tcl | Tcl | foreach d0 {1 2 3 4 5 6} {
foreach d1 {1 2 3 4 5 6} {
...
foreach dN {1 2 3 4 5 6} {
dict incr sum [::tcl::mathop::+ $n $d0 $d1 ... $DN]
}
...
}
} | Give a code snippet in #Tcl
Two players have a set of dice each. The first player has nine dice with four faces each, with numbers one to four. The second player has six normal dice with six faces each, each face has the usual numbers from one to six.
They roll their dice and sum the totals of the faces. The player w... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sorting_algorithms/Gnome_sort | Sorting algorithms/Gnome 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
... | #PowerBASIC | PowerBASIC | SUB gnomeSort (a() AS LONG)
DIM i AS LONG, j AS LONG
i = 1
j = 2
WHILE (i < UBOUND(a) + 1)
IF (a(i - 1) <= a(i)) THEN
i = j
INCR j
ELSE
SWAP a(i - 1), a(i)
DECR i
IF 0 = i THEN
i = j
INCR j
... | Give a code snippet in #PowerBASIC
Sorting Algorithm
This is a sorting algorithm. It may be applied to a set of data in order to sort it.
For comparing various sorts, see compare sorts.
For other sorting algorithms, see sorting algorithms, or:
O(n logn) sorts
Heap sort |
Merge sort |
Patience sort |
Qui... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Count_in_factors | Count in factors | Task
Write a program which counts up from 1, displaying each number as the multiplication of its prime factors.
For the purpose of this task, 1 (unity) may be shown as itself.
Example
2 is prime, so it would be shown as itself.
6 is not prime; it would be shown as
2
×
3
{\di... | #AutoHotkey | AutoHotkey | factorize(n){
if n = 1
return 1
if n < 1
return false
result := 0, m := n, k := 2
While n >= k{
while !Mod(m, k){
result .= " * " . k, m /= k
}
k++
}
return SubStr(result, 5)
}
Loop 22
out .= A_Index ": " factorize(A_index) "`n"
MsgBox % out | Give a code snippet in #AutoHotkey
Task
Write a program which counts up from 1, displaying each number as the multiplication of its prime factors.
For the purpose of this task, 1 (unity) may be shown as itself.
Example
2 is prime, so it would be shown as itself.
6 is not prime; it ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Program_name | Program name | The task is to programmatically obtain the name used to invoke the program. (For example determine whether the user ran "python hello.py", or "python hellocaller.py", a program importing the code from "hello.py".)
Sometimes a multiline shebang is necessary in order to provide the script name to a language's internal A... | #ALGOL_68 | ALGOL 68 |
BEGIN
print ((program idf, newline))
END
| Give a code snippet in #ALGOL_68
The task is to programmatically obtain the name used to invoke the program. (For example determine whether the user ran "python hello.py", or "python hellocaller.py", a program importing the code from "hello.py".)
Sometimes a multiline shebang is necessary in order to provide the scri... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Feigenbaum_constant_calculation | Feigenbaum constant calculation | Task
Calculate the Feigenbaum constant.
See
Details in the Wikipedia article: Feigenbaum constant.
| #Phix | Phix | constant maxIt = 13,
maxItJ = 10
atom a1 = 1.0,
a2 = 0.0,
d1 = 3.2
puts(1," i d\n")
for i=2 to maxIt do
atom a = a1 + (a1 - a2) / d1
for j=1 to maxItJ do
atom x = 0, y = 0
for k=1 to power(2,i) do
y = 1 - 2*y*x
x = a - x*x
end for
... | Give a code snippet in #Phix
Task
Calculate the Feigenbaum constant.
See
Details in the Wikipedia article: Feigenbaum constant.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Power_set | Power set | A set is a collection (container) of certain values,
without any particular order, and no repeated values.
It corresponds with a finite set in mathematics.
A set can be implemented as an associative array (partial mapping)
in which the value of each key-value pair is ignored.
Given a set S, the power set (or pow... | #Frink | Frink |
a = new set[1,2,3,4]
a.subsets[]
| Give a code snippet in #Frink
A set is a collection (container) of certain values,
without any particular order, and no repeated values.
It corresponds with a finite set in mathematics.
A set can be implemented as an associative array (partial mapping)
in which the value of each key-value pair is ignored.
Given... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Floyd-Warshall_algorithm | Floyd-Warshall algorithm | The Floyd–Warshall algorithm is an algorithm for finding shortest paths in a weighted graph with positive or negative edge weights.
Task
Find the lengths of the shortest paths between all pairs of vertices of the given directed graph. Your code may assume that the input has already been checked for loops, parallel ... | #Common_Lisp | Common Lisp | #!/bin/sh
#|-*- mode:lisp -*-|#
#|
exec ros -Q -- $0 "$@"
|#
(progn ;;init forms
(ros:ensure-asdf)
#+quicklisp(ql:quickload '() :silent t)
)
(defpackage :ros.script.floyd-warshall.3861181636
(:use :cl))
(in-package :ros.script.floyd-warshall.3861181636)
;;;
;;; Floyd-Warshall algorithm.
;;;
;;; See https://... | Give a code snippet in #Common_Lisp
The Floyd–Warshall algorithm is an algorithm for finding shortest paths in a weighted graph with positive or negative edge weights.
Task
Find the lengths of the shortest paths between all pairs of vertices of the given directed graph. Your code may assume that the input has alre... | christopher/rosetta-code |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.