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/SHA-1 | SHA-1 | SHA-1 or SHA1 is a one-way hash function;
it computes a 160-bit message digest.
SHA-1 often appears in security protocols; for example,
many HTTPS websites use RSA with SHA-1 to secure their connections.
BitTorrent uses SHA-1 to verify downloads.
Git and Mercurial use SHA-1 digests to identify commits.
A US government... | #Seed7 | Seed7 | $ include "seed7_05.s7i";
include "msgdigest.s7i";
const proc: main is func
begin
writeln(hex(sha1("Rosetta Code")));
end func; | Give a code snippet in #Seed7
SHA-1 or SHA1 is a one-way hash function;
it computes a 160-bit message digest.
SHA-1 often appears in security protocols; for example,
many HTTPS websites use RSA with SHA-1 to secure their connections.
BitTorrent uses SHA-1 to verify downloads.
Git and Mercurial use SHA-1 digests to ide... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Unicode_variable_names | Unicode variable names | Task
Describe, and give a pointer to documentation on your languages use of characters beyond those of the ASCII character set in the naming of variables.
Show how to:
Set a variable with a name including the 'Δ', (delta character), to 1
Increment it
Print its value.
Related task
Case-sensitivity of identif... | #Bracmat | Bracmat | ( (Δ=1)
& 1+!Δ:?Δ
& out$("Δ:" !Δ)
); | Give a code snippet in #Bracmat
Task
Describe, and give a pointer to documentation on your languages use of characters beyond those of the ASCII character set in the naming of variables.
Show how to:
Set a variable with a name including the 'Δ', (delta character), to 1
Increment it
Print its value.
Related ta... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Chaos_game | Chaos game | The Chaos Game is a method of generating the attractor of an iterated function system (IFS).
One of the best-known and simplest examples creates a fractal, using a polygon and an initial point selected at random.
Task
Play the Chaos Game using the corners of an equilateral triangle as the reference points. Add a ... | #REXX | REXX | /*REXX pgm draws a Sierpinski triangle by running the chaos game with a million points*/
parse value scrsize() with sd sw . /*obtain the depth and width of screen.*/
sw= sw - 2 /*adjust the screen width down by two. */
sd= sd - 4 ... | Give a code snippet in #REXX
The Chaos Game is a method of generating the attractor of an iterated function system (IFS).
One of the best-known and simplest examples creates a fractal, using a polygon and an initial point selected at random.
Task
Play the Chaos Game using the corners of an equilateral triangle as ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Short-circuit_evaluation | Short-circuit evaluation | Control Structures
These are examples of control structures. You may also be interested in:
Conditional structures
Exceptions
Flow-control structures
Loops
Assume functions a and b return boolean values, and further, the execution of function b takes considerable resources without side effects, an... | #Fortran | Fortran | program Short_Circuit_Eval
implicit none
logical :: x, y
logical, dimension(2) :: l = (/ .false., .true. /)
integer :: i, j
do i = 1, 2
do j = 1, 2
write(*, "(a,l1,a,l1,a)") "Calculating x = a(", l(i), ") and b(", l(j), ")"
! a AND b
x = a(l(i))
if(x) then
x = b(l(... | Give a code snippet in #Fortran
Control Structures
These are examples of control structures. You may also be interested in:
Conditional structures
Exceptions
Flow-control structures
Loops
Assume functions a and b return boolean values, and further, the execution of function b takes considerable r... | 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... | #C | C | #include <stdio.h>
int main(int argc, char **argv) {
printf("Executable: %s\n", argv[0]);
return 0;
} | Give a code snippet in #C
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... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sorting_algorithms/Bubble_sort | Sorting algorithms/Bubble sort |
Sorting Algorithm
This is a sorting algorithm. It may be applied to a set of data in order to sort it.
For comparing various sorts, see compare sorts.
For other sorting algorithms, see sorting algorithms, or:
O(n logn) sorts
Heap sort |
Merge sort |
Patience sort |
Quick sort
O(n log2n) sorts
Shell Sort
... | #Ol | Ol |
(define (bubble-sort x ??)
(define (sort-step l)
(if (or (null? l) (null? (cdr l)))
l
(if (?? (car l) (cadr l))
(cons (cadr l) (sort-step (cons (car l) (cddr l))))
(cons (car l) (sort-step (cdr l))))))
(let loop ((i x))
(if (equal? i (sort-step i))
... | Give a code snippet in #Ol
Sorting Algorithm
This is a sorting algorithm. It may be applied to a set of data in order to sort it.
For comparing various sorts, see compare sorts.
For other sorting algorithms, see sorting algorithms, or:
O(n logn) sorts
Heap sort |
Merge sort |
Patience sort |
Quick sort
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Comments | Comments | Task
Show all ways to include text in a language source file
that's completely ignored by the compiler or interpreter.
Related tasks
Documentation
Here_document
See also
Wikipedia
xkcd (Humor: hand gesture denoting // for "commenting out" people.)
| #Mirah | Mirah | puts 'code' # I am a comment
/* This is
* a multiple
* line comment */
| Give a code snippet in #Mirah
Task
Show all ways to include text in a language source file
that's completely ignored by the compiler or interpreter.
Related tasks
Documentation
Here_document
See also
Wikipedia
xkcd (Humor: hand gesture denoting // for "commenting out" people.)
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Send_an_unknown_method_call | Send an unknown method call | Task
Invoke an object method where the name of the method to be invoked can be generated at run time.
Related tasks
Respond to an unknown method call.
Runtime evaluation
| #MATLAB_.2F_Octave | MATLAB / Octave |
funName = 'foo'; % generate function name
feval (funNAME, ...) % evaluation function with optional parameters
funName = 'a=atan(pi)'; % generate function name
eval (funName, 'printf(''Error\n'')')
| Give a code snippet in #MATLAB_.2F_Octave
Task
Invoke an object method where the name of the method to be invoked can be generated at run time.
Related tasks
Respond to an unknown method call.
Runtime evaluation
| 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... | #Smalltalk | Smalltalk | digitalRoot :=
[:nr :arIn |
r := (nr printString asArray collect:#digitValue) sum.
r > 9 ifTrue:[
digitalRoot value:r value:arIn+1.
] ifFalse:[
{ arIn+1 . r }
].
].
#(
627615 39390 588225 393900588225 10 199
199999999999999999999999999999999999999999999999999999999999999999999... | Give a code snippet in #Smalltalk
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/Determine_if_a_string_has_all_unique_characters | Determine if a string has all unique characters | Task
Given a character string (which may be empty, or have a length of zero characters):
create a function/procedure/routine to:
determine if all the characters in the string are unique
indicate if or which character is duplicated and where
display each string and its length (as the strings are being ... | #Visual_Basic_.NET | Visual Basic .NET | Module Module1
Sub Main()
Dim input() = {"", ".", "abcABC", "XYZ ZYX", "1234567890ABCDEFGHIJKLMN0PQRSTUVWXYZ"}
For Each s In input
Console.WriteLine($"'{s}' (Length {s.Length}) " + String.Join(", ", s.Select(Function(c, i) (c, i)).GroupBy(Function(t) t.c).Where(Function(g) g.Count() > ... | Give a code snippet in #Visual_Basic_.NET
Task
Given a character string (which may be empty, or have a length of zero characters):
create a function/procedure/routine to:
determine if all the characters in the string are unique
indicate if or which character is duplicated and where
display each string ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Loops/While | Loops/While | Task
Start an integer value at 1024.
Loop while it is greater than zero.
Print the value (with a newline) and divide it by two each time through the loop.
Related tasks
Loop over multiple arrays simultaneously
Loops/Break
Loops/Continue
Loops/Do-while
Loops/Downward for
Loops/For
Loops/For... | #Nim | Nim | var n: int = 1024
while n > 0:
echo(n)
n = n div 2 | Give a code snippet in #Nim
Task
Start an integer value at 1024.
Loop while it is greater than zero.
Print the value (with a newline) and divide it by two each time through the loop.
Related tasks
Loop over multiple arrays simultaneously
Loops/Break
Loops/Continue
Loops/Do-while
Loops/Downward ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Balanced_brackets | Balanced brackets | Task:
Generate a string with N opening brackets [ and with N closing brackets ], in some arbitrary order.
Determine whether the generated string is balanced; that is, whether it consists entirely of pairs of opening/closing brackets (in that order), none of which mis-nest.
Examples
(empty) ... | #Standard_ML | Standard ML | fun isBalanced s = checkBrackets 0 (String.explode s)
and checkBrackets 0 [] = true
| checkBrackets _ [] = false
| checkBrackets ~1 _ = false
| checkBrackets counter (#"["::rest) = checkBrackets (counter + 1) rest
| checkBrackets counter (#"]"::rest) = checkBrackets (counter - 1) rest
| checkBrackets counter ... | Give a code snippet in #Standard_ML
Task:
Generate a string with N opening brackets [ and with N closing brackets ], in some arbitrary order.
Determine whether the generated string is balanced; that is, whether it consists entirely of pairs of opening/closing brackets (in that order), none of which... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Ranking_methods | Ranking methods |
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
... | #Kotlin | Kotlin | // version 1.0.6
/* all ranking functions assume the array of Pairs is non-empty and already sorted by decreasing order of scores
and then, if the scores are equal, by reverse alphabetic order of names
*/
fun standardRanking(scores: Array<Pair<Int, String>>): IntArray {
val rankings = IntArray(scores.size... | Give a code snippet in #Kotlin
Sorting Algorithm
This is a sorting algorithm. It may be applied to a set of data in order to sort it.
For comparing various sorts, see compare sorts.
For other sorting algorithms, see sorting algorithms, or:
O(n logn) sorts
Heap sort |
Merge sort |
Patience sort |
Quick s... | christopher/rosetta-code | |
http://rosettacode.org/wiki/URL_encoding | URL encoding | Task
Provide a function or mechanism to convert a provided string into URL encoding representation.
In URL encoding, special characters, control characters and extended characters
are converted into a percent symbol followed by a two digit hexadecimal code,
So a space character encodes into %20 within the string.
Fo... | #J | J | require'strings convert'
urlencode=: rplc&((#~2|_1 47 57 64 90 96 122 I.i.@#)a.;"_1'%',.hfd i.#a.) | Give a code snippet in #J
Task
Provide a function or mechanism to convert a provided string into URL encoding representation.
In URL encoding, special characters, control characters and extended characters
are converted into a percent symbol followed by a two digit hexadecimal code,
So a space character encodes into... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Non-decimal_radices/Output | Non-decimal radices/Output | Programming languages often have built-in routines to convert a non-negative integer for printing in different number bases. Such common number bases might include binary, Octal and Hexadecimal.
Task
Print a small range of integers in some different bases, as supported by standard routines of your programming langu... | #PowerShell | PowerShell | foreach ($n in 0..33) {
"Base 2: " + [Convert]::ToString($n, 2)
"Base 8: " + [Convert]::ToString($n, 8)
"Base 10: " + $n
"Base 10: " + [Convert]::ToString($n, 10)
"Base 10: " + ("{0:D}" -f $n)
"Base 16: " + [Convert]::ToString($n, 16)
"Base 16: " + ("{0:X}" -f $n)
} | Give a code snippet in #PowerShell
Programming languages often have built-in routines to convert a non-negative integer for printing in different number bases. Such common number bases might include binary, Octal and Hexadecimal.
Task
Print a small range of integers in some different bases, as supported by standar... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Higher-order_functions | Higher-order functions | Task
Pass a function as an argument to another function.
Related task
First-class functions
| #Frink | Frink |
cmpFunc = {|a,b| length[a] <=> length[b]}
a = ["tree", "apple", "bee", "monkey", "z"]
sort[a, cmpFunc]
| Give a code snippet in #Frink
Task
Pass a function as an argument to another function.
Related task
First-class functions
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Cyclotomic_polynomial | Cyclotomic polynomial | The nth Cyclotomic polynomial, for any positive integer n, is the unique irreducible polynomial of largest degree with integer coefficients that is a divisor of x^n − 1, and is not a divisor of x^k − 1 for any k < n.
Task
Find and print the first 30 cyclotomic polynomials.
Find and print the order of the first 10... | #C.23 | C# | using System;
using System.Collections;
using System.Collections.Generic;
using System.Linq;
using IntMap = System.Collections.Generic.Dictionary<int, int>;
public static class CyclotomicPolynomial
{
public static void Main2() {
Console.WriteLine("Task 1: Cyclotomic polynomials for n <= 30:");
for... | Give a code snippet in #C.23
The nth Cyclotomic polynomial, for any positive integer n, is the unique irreducible polynomial of largest degree with integer coefficients that is a divisor of x^n − 1, and is not a divisor of x^k − 1 for any k < n.
Task
Find and print the first 30 cyclotomic polynomials.
Find and p... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Magic_squares_of_singly_even_order | Magic squares of singly even order | A magic square is an NxN square matrix whose numbers consist of consecutive numbers arranged so that the sum of each row and column, and both diagonals are equal to the same sum (which is called the magic number or magic constant).
A magic square of singly even order has a size that is a multiple of 4, plus 2 (e.g. 6,... | #Phix | Phix | with javascript_semantics
function swap(sequence s, integer x1, y1, x2, y2)
{s[x1,y1],s[x2,y2]} = {s[x2,y2],s[x1,y1]}
return s
end function
function se_magicsq(integer n)
if n<6 or mod(n-2,4)!=0 then
crash("illegal size (%d)",{n})
end if
sequence sq = repeat(repeat(0,n),n)
integer ... | Give a code snippet in #Phix
A magic square is an NxN square matrix whose numbers consist of consecutive numbers arranged so that the sum of each row and column, and both diagonals are equal to the same sum (which is called the magic number or magic constant).
A magic square of singly even order has a size that is a ... | 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
| #Tcl | Tcl | $env(HOME) | Give a code snippet in #Tcl
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/Word_wheel | Word wheel | A "word wheel" is a type of word game commonly found on the "puzzle" page of
newspapers. You are presented with nine letters arranged in a circle or 3×3
grid. The objective is to find as many words as you can using only the letters
contained in the wheel or grid. Each word must contain the letter in the centre
of the w... | #8080_Assembly | 8080 Assembly | puts: equ 9 ; CP/M syscall to print string
fopen: equ 15 ; CP/M syscall to open a file
fread: equ 20 ; CP/M syscall to read from file
FCB1: equ 5Ch ; First FCB (input file)
DTA: equ 80h ; Disk transfer address
org 100h
;;; Make wheel (2nd argument) lowercase and store it
lxi d,DTA+1 ; Start of command line arg... | Give a code snippet in #8080_Assembly
A "word wheel" is a type of word game commonly found on the "puzzle" page of
newspapers. You are presented with nine letters arranged in a circle or 3×3
grid. The objective is to find as many words as you can using only the letters
contained in the wheel or grid. Each word must co... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Delete_a_file | Delete a file | Task
Delete a file called "input.txt" and delete a directory called "docs".
This should be done twice: once "here", i.e. in the current working directory and once in the filesystem root.
| #Ada | Ada | with Ada.Directories; use Ada.Directories; | Give a code snippet in #Ada
Task
Delete a file called "input.txt" and delete a directory called "docs".
This should be done twice: once "here", i.e. in the current working directory and once in the filesystem root.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/100_prisoners | 100 prisoners |
The Problem
100 prisoners are individually numbered 1 to 100
A room having a cupboard of 100 opaque drawers numbered 1 to 100, that cannot be seen from outside.
Cards numbered 1 to 100 are placed randomly, one to a drawer, and the drawers all closed; at the start.
Prisoners start outside the room
They can decid... | #Scala | Scala | import scala.util.Random
import scala.util.control.Breaks._
object Main {
def playOptimal(n: Int): Boolean = {
val secretList = Random.shuffle((0 until n).toBuffer)
for (i <- secretList.indices) {
var prev = i
breakable {
for (_ <- 0 until secretList.size / 2) {
if (secretLis... | Give a code snippet in #Scala
The Problem
100 prisoners are individually numbered 1 to 100
A room having a cupboard of 100 opaque drawers numbered 1 to 100, that cannot be seen from outside.
Cards numbered 1 to 100 are placed randomly, one to a drawer, and the drawers all closed; at the start.
Prisoners start o... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Loops/Foreach | Loops/Foreach | Loop through and print each element in a collection in order.
Use your language's "for each" loop if it has one, otherwise iterate through the collection in order with some other loop.
Related tasks
Loop over multiple arrays simultaneously
Loops/Break
Loops/Continue
Loops/Do-while
Loops/Downward for... | #Dragon | Dragon |
for value : array {
showln value
}
| Give a code snippet in #Dragon
Loop through and print each element in a collection in order.
Use your language's "for each" loop if it has one, otherwise iterate through the collection in order with some other loop.
Related tasks
Loop over multiple arrays simultaneously
Loops/Break
Loops/Continue
Loop... | 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... | #C.23 | C# | using System;
class Program
{
static void Main(string[] args)
{
for (int i = 99; i > -1; i--)
{
if (i == 0)
{
Console.WriteLine("No more bottles of beer on the wall, no more bottles of beer.");
Console.WriteLine("Go to the store and buy s... | Give a code snippet in #C.23
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 ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Nth_root | Nth root | Task
Implement the algorithm to compute the principal nth root
A
n
{\displaystyle {\sqrt[{n}]{A}}}
of a positive real number A, as explained at the Wikipedia page.
| #Raku | Raku | sub nth-root ($n, $A, $p=1e-9)
{
my $x0 = $A / $n;
loop {
my $x1 = (($n-1) * $x0 + $A / ($x0 ** ($n-1))) / $n;
return $x1 if abs($x1-$x0) < abs($x0 * $p);
$x0 = $x1;
}
}
say nth-root(3,8); | Give a code snippet in #Raku
Task
Implement the algorithm to compute the principal nth root
A
n
{\displaystyle {\sqrt[{n}]{A}}}
of a positive real number A, as explained at the Wikipedia page.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Day_of_the_week | Day of the week | A company decides that whenever Xmas falls on a Sunday they will give their workers all extra paid holidays so that, together with any public holidays, workers will not have to work the following week (between the 25th of December and the first of January).
Task
In what years between 2008 and 2121 will the 25th of ... | #Lua | Lua | require("date")
for year=2008,2121 do
if date(year, 12, 25):getweekday() == 1 then
print(year)
end
end | Give a code snippet in #Lua
A company decides that whenever Xmas falls on a Sunday they will give their workers all extra paid holidays so that, together with any public holidays, workers will not have to work the following week (between the 25th of December and the first of January).
Task
In what years between 20... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Draw_a_cuboid | Draw a cuboid | Task
Draw a cuboid with relative dimensions of 2 × 3 × 4.
The cuboid can be represented graphically, or in ASCII art, depending on the language capabilities.
To fulfill the criteria of being a cuboid, three faces must be visible.
Either static or rotational projection is acceptable for this task.
R... | #PARI.2FGP | PARI/GP |
\\ Simple "cuboid". Try different parameters of this Cuboid() function.
\\ 4/11/16 aev
Cuboid(a,b,c,u=10)={
my(dx,dy,ttl="Cuboid AxBxC: ",size=200,da=a*u,db=b*u,dc=c*u);
print(" *** ",ttl,a,"x",b,"x",c,"; u=",u);
plotinit(0);
plotscale(0, 0,size, 0,size);
plotcolor(0,7); \\grey
plotmove(0, 0,0);
plotrline(0,dc,da\2)... | Give a code snippet in #PARI.2FGP
Task
Draw a cuboid with relative dimensions of 2 × 3 × 4.
The cuboid can be represented graphically, or in ASCII art, depending on the language capabilities.
To fulfill the criteria of being a cuboid, three faces must be visible.
Either static or rotational projectio... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Colour_pinstripe/Printer | Colour pinstripe/Printer | The task is to create 1 point wide colour vertical pinstripes with a sufficient number of pinstripes to span the entire width of the colour graphics printer. The pinstripes should alternate between each individual cartridge ink and ink pair and black and white pinstripes should be included. A typical pinstripe sequence... | #FreeBASIC | FreeBASIC | Dim As String exename
#ifdef __FB_WIN32__
exename = "mspaint.exe /pt"
#endif
#ifdef __FB_LINUX__
exename = "lp -o media=A4 "
#endif
Dim As Uinteger ps, col, h, w, x, y1, y2
' (A4) # 595 x 842 dots
w = 842 : h = 595
' create display size window, 8bit color (palette), no frame
Screenres w, h, 8,, 8
h \= 7 :... | Give a code snippet in #FreeBASIC
The task is to create 1 point wide colour vertical pinstripes with a sufficient number of pinstripes to span the entire width of the colour graphics printer. The pinstripes should alternate between each individual cartridge ink and ink pair and black and white pinstripes should be inc... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sorting_algorithms/Merge_sort | Sorting algorithms/Merge sort |
Sorting Algorithm
This is a sorting algorithm. It may be applied to a set of data in order to sort it.
For comparing various sorts, see compare sorts.
For other sorting algorithms, see sorting algorithms, or:
O(n logn) sorts
Heap sort |
Merge sort |
Patience sort |
Quick sort
O(n log2n) sorts
Shell Sort
... | #Common_Lisp | Common Lisp | (defun merge-sort (result-type sequence predicate)
(let ((split (floor (length sequence) 2)))
(if (zerop split)
(copy-seq sequence)
(merge result-type (merge-sort result-type (subseq sequence 0 split) predicate)
(merge-sort result-type (subseq sequence split) predicate)... | Give a code snippet in #Common_Lisp
Sorting Algorithm
This is a sorting algorithm. It may be applied to a set of data in order to sort it.
For comparing various sorts, see compare sorts.
For other sorting algorithms, see sorting algorithms, or:
O(n logn) sorts
Heap sort |
Merge sort |
Patience sort |
Qu... | 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.
| #Maple | Maple | printf(" ");
for i to 12 do
printf("%-3d ", i);
end do;
printf("\n");
for i to 75 do
printf("-");
end do;
for i to 12 do
printf("\n%2d| ", i);
for j to 12 do
if j<i then
printf(" ");
else
printf("%-3d ", i * j);
end if
end do
end do | Give a code snippet in #Maple
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/Terminal_control/Ringing_the_terminal_bell | Terminal control/Ringing the terminal bell |
Task
Make the terminal running the program ring its "bell".
On modern terminal emulators, this may be done by playing some other sound which might or might not be configurable, or by flashing the title bar or inverting the colors of the screen, but was classically a physical bell within the terminal. It is usua... | #COBOL | COBOL | DISPLAY SPACE WITH BELL | Give a code snippet in #COBOL
Task
Make the terminal running the program ring its "bell".
On modern terminal emulators, this may be done by playing some other sound which might or might not be configurable, or by flashing the title bar or inverting the colors of the screen, but was classically a physical bell wi... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Multiple_regression | Multiple regression | Task
Given a set of data vectors in the following format:
y
=
{
y
1
,
y
2
,
.
.
.
,
... | #JavaScript | JavaScript | // modifies the matrix "in place"
Matrix.prototype.inverse = function() {
if (this.height != this.width) {
throw "can't invert a non-square matrix";
}
var I = new IdentityMatrix(this.height);
for (var i = 0; i < this.height; i++)
this.mtx[i] = this.mtx[i].concat(I.mtx[i])
this.... | Give a code snippet in #JavaScript
Task
Given a set of data vectors in the following format:
y
=
{
y
1
,
y
2
,
.
.
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Last_letter-first_letter | Last letter-first letter | A certain children's game involves starting with a word in a particular category. Each participant in turn says a word, but that word must begin with the final letter of the previous word. Once a word has been given, it cannot be repeated. If an opponent cannot give a word in the category, they fall out of the ga... | #Seed7 | Seed7 | $ include "seed7_05.s7i";
var integer: maxPathLength is 0;
var integer: maxPathLengthCount is 0;
var string: maxPathExample is "";
var array string: names is [] (
"audino", "bagon", "baltoy", "banette", "bidoof", "braviary", "bronzor",
"carracosta", "charmeleon", "cresselia", "croagunk", "darmanitan", "dein... | Give a code snippet in #Seed7
A certain children's game involves starting with a word in a particular category. Each participant in turn says a word, but that word must begin with the final letter of the previous word. Once a word has been given, it cannot be repeated. If an opponent cannot give a word in the ca... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Rock-paper-scissors | Rock-paper-scissors | Task
Implement the classic children's game Rock-paper-scissors, as well as a simple predictive AI (artificial intelligence) player.
Rock Paper Scissors is a two player game.
Each player chooses one of rock, paper or scissors, without knowing the other player's choice.
The winner is decided by a set of rules:
... | #Seed7 | Seed7 | $ include "seed7_05.s7i";
$ include "keybd.s7i";
const array string: rockPaperScissors is [] ("Rock", "Paper", "Scissors");
const proc: main is func
local
var char: command is ' ';
var integer: user is 0;
var integer: comp is 0;
begin
writeln("Hello, Welcome to rock-paper-scissors");
repeat
... | Give a code snippet in #Seed7
Task
Implement the classic children's game Rock-paper-scissors, as well as a simple predictive AI (artificial intelligence) player.
Rock Paper Scissors is a two player game.
Each player chooses one of rock, paper or scissors, without knowing the other player's choice.
The winner... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Repeat_a_string | Repeat a string | Take a string and repeat it some number of times.
Example: repeat("ha", 5) => "hahahahaha"
If there is a simpler/more efficient way to repeat a single “character” (i.e. creating a string filled with a certain character), you might want to show that as well (i.e. repeat-char("*", 5) => "*****").
Other tasks re... | #jq | jq | "a " * 3' # => "a a a " | Give a code snippet in #jq
Take a string and repeat it some number of times.
Example: repeat("ha", 5) => "hahahahaha"
If there is a simpler/more efficient way to repeat a single “character” (i.e. creating a string filled with a certain character), you might want to show that as well (i.e. repeat-char("*", 5) => ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Arithmetic_evaluation | Arithmetic evaluation | Create a program which parses and evaluates arithmetic expressions.
Requirements
An abstract-syntax tree (AST) for the expression must be created from parsing the input.
The AST must be used in evaluation, also, so the input may not be directly evaluated (e.g. by calling eval or a similar language feature.)
The ... | #JavaScript | JavaScript | function evalArithmeticExp(s) {
s = s.replace(/\s/g,'').replace(/^\+/,'');
var rePara = /\([^\(\)]*\)/;
var exp = s.match(rePara);
while (exp = s.match(rePara)) {
s = s.replace(exp[0], evalExp(exp[0]));
}
return evalExp(s);
function evalExp(s) {
s = s.replace(/[\(\)]/g,'');
var reMD = /\d+... | Give a code snippet in #JavaScript
Create a program which parses and evaluates arithmetic expressions.
Requirements
An abstract-syntax tree (AST) for the expression must be created from parsing the input.
The AST must be used in evaluation, also, so the input may not be directly evaluated (e.g. by calling eval or... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Variables | Variables | Task
Demonstrate a language's methods of:
variable declaration
initialization
assignment
datatypes
scope
referencing, and
other variable related facilities
| #Maple | Maple | a := 1:
print ("a is "||a);
"a is 1" | Give a code snippet in #Maple
Task
Demonstrate a language's methods of:
variable declaration
initialization
assignment
datatypes
scope
referencing, and
other variable related facilities
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Tree_datastructures | Tree datastructures | The following shows a tree of data with nesting denoted by visual levels of indentation:
RosettaCode
rocks
code
comparison
wiki
mocks
trolling
A common datastructure for trees is to define node structures having a name and a, (possibly empty), list of child nodes. The nesting of... | #Python | Python | from pprint import pprint as pp
def to_indent(node, depth=0, flat=None):
if flat is None:
flat = []
if node:
flat.append((depth, node[0]))
for child in node[1]:
to_indent(child, depth + 1, flat)
return flat
def to_nest(lst, depth=0, level=None):
if level is None:
... | Give a code snippet in #Python
The following shows a tree of data with nesting denoted by visual levels of indentation:
RosettaCode
rocks
code
comparison
wiki
mocks
trolling
A common datastructure for trees is to define node structures having a name and a, (possibly empty), lis... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Nautical_bell | Nautical bell |
Task
Write a small program that emulates a nautical bell producing a ringing bell pattern at certain times throughout the day.
The bell timing should be in accordance with Greenwich Mean Time, unless locale dictates otherwise.
It is permissible for the program to daemonize, or to slave off a scheduler, and it is per... | #OoRexx | OoRexx | /*REXX pgm beep's "bells" (using PC speaker) when running (perpetually).*/
Parse Arg msg
If msg='?' Then Do
Say 'Ring a nautical bell'
Exit
End
Signal on Halt /* allow a clean way to stop prog.*/
Do Forever
Parse Value time() With hh ':' mn ':' ss
ct=time('C')
hhmmc=lef... | Give a code snippet in #OoRexx
Task
Write a small program that emulates a nautical bell producing a ringing bell pattern at certain times throughout the day.
The bell timing should be in accordance with Greenwich Mean Time, unless locale dictates otherwise.
It is permissible for the program to daemonize, or to slav... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sort_a_list_of_object_identifiers | Sort a list of object identifiers |
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
... | #Ada | Ada | with Ada.Containers.Generic_Array_Sort;
with Ada.Strings.Fixed;
with Ada.Strings.Unbounded; use Ada.Strings.Unbounded;
with Ada.Text_IO;
with Ada.Unchecked_Deallocation;
procedure Sort_List_Identifiers is
type Natural_Array is array (Positive range <>) of Natural;
type Unbounded_String_Array is array(Positive r... | Give a code snippet in #Ada
Sorting Algorithm
This is a sorting algorithm. It may be applied to a set of data in order to sort it.
For comparing various sorts, see compare sorts.
For other sorting algorithms, see sorting algorithms, or:
O(n logn) sorts
Heap sort |
Merge sort |
Patience sort |
Quick sort... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Zeckendorf_arithmetic | Zeckendorf arithmetic | This task is a total immersion zeckendorf task; using decimal numbers will attract serious disapprobation.
The task is to implement addition, subtraction, multiplication, and division using Zeckendorf number representation. Optionally provide decrement, increment and comparitive operation functions.
Addition
Like bin... | #Scala | Scala |
import scala.collection.mutable.ListBuffer
object ZeckendorfArithmetic extends App {
val elapsed: (=> Unit) => Long = f => {
val s = System.currentTimeMillis
f
(System.currentTimeMillis - s) / 1000
}
val add: (Z, Z) => Z = (z1, z2) => z1 + z2
val subtract: (Z, Z) => Z = (z1, z2) => z1 - ... | Give a code snippet in #Scala
This task is a total immersion zeckendorf task; using decimal numbers will attract serious disapprobation.
The task is to implement addition, subtraction, multiplication, and division using Zeckendorf number representation. Optionally provide decrement, increment and comparitive operatio... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Execute_a_system_command | Execute a system command | Task
Run either the ls system command (dir on Windows), or the pause system command.
Related task
Get system command output
| #Clojure | Clojure | (.. Runtime getRuntime (exec "cmd /C dir")) | Give a code snippet in #Clojure
Task
Run either the ls system command (dir on Windows), or the pause system command.
Related task
Get system command output
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Hello_world/Newline_omission | Hello world/Newline omission | Some languages automatically insert a newline after outputting a string, unless measures are taken to prevent its output.
Task
Display the string Goodbye, World! without a trailing newline.
Related tasks
Hello world/Graphical
Hello world/Line Printer
Hello world/Standard error
Hello world/Text
| #Lua | Lua | io.write("Goodbye, World!") | Give a code snippet in #Lua
Some languages automatically insert a newline after outputting a string, unless measures are taken to prevent its output.
Task
Display the string Goodbye, World! without a trailing newline.
Related tasks
Hello world/Graphical
Hello world/Line Printer
Hello world/Standar... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Copy_a_string | Copy a string | This task is about copying a string.
Task
Where it is relevant, distinguish between copying the contents of a string
versus making an additional reference to an existing string.
Other tasks related to string operations:
Metrics
Array length
String length
Copy a string
Empty string (assignment)
Counting
W... | #V | V | "hello" dup | Give a code snippet in #V
This task is about copying a string.
Task
Where it is relevant, distinguish between copying the contents of a string
versus making an additional reference to an existing string.
Other tasks related to string operations:
Metrics
Array length
String length
Copy a string
Empty strin... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Dynamic_variable_names | Dynamic variable names | Task
Create a variable with a user-defined name.
The variable name should not be written in the program text, but should be taken from the user dynamically.
See also
Eval in environment is a similar task.
| #Batch_File | Batch File | @echo off
setlocal enableDelayedExpansion
set /p "name=Enter a variable name: "
set /p "value=Enter a value: "
::Create the variable and set its value
set "%name%=%value%"
::Display the value without delayed expansion
call echo %name%=%%%name%%%
::Display the value using delayed expansion
echo %name%=!%name%! | Give a code snippet in #Batch_File
Task
Create a variable with a user-defined name.
The variable name should not be written in the program text, but should be taken from the user dynamically.
See also
Eval in environment is a similar task.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/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... | #REXX | REXX | /*REXX program performs some operations on quaternion type numbers and displays results*/
q = 1 2 3 4 ; q1 = 2 3 4 5
r = 7 ; q2 = 3 4 5 6
call qShow q , 'q'
call qShow q1 ... | Give a code snippet in #REXX
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 m... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Department_numbers | Department numbers | There is a highly organized city that has decided to assign a number to each of their departments:
police department
sanitation department
fire department
Each department can have a number between 1 and 7 (inclusive).
The three department numbers are to be unique (different from each other) and mu... | #F.23 | F# |
// A function to generate department numbers. Nigel Galloway: May 2nd., 2018
type dNum = {Police:int; Fire:int; Sanitation:int}
let fN n=n.Police%2=0&&n.Police+n.Fire+n.Sanitation=12&&n.Police<>n.Fire&&n.Police<>n.Sanitation&&n.Fire<>n.Sanitation
List.init (7*7*7) (fun n->{Police=n%7+1;Fire=(n/7)%7+1;Sanitation=(n/49... | Give a code snippet in #F.23
There is a highly organized city that has decided to assign a number to each of their departments:
police department
sanitation department
fire department
Each department can have a number between 1 and 7 (inclusive).
The three department numbers are to be unique (dif... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Luhn_test_of_credit_card_numbers | Luhn test of credit card numbers | The Luhn test is used by some credit card companies to distinguish valid credit card numbers from what could be a random selection of digits.
Those companies using credit card numbers that can be validated by the Luhn test have numbers that pass the following test:
Reverse the order of the digits in the number.
Tak... | #Befunge | Befunge | v 1 >$0 v v <
>&:19+`|v < >v 5 6 7 8
^ \ <>09p19p>09g+09p:|>2*:19+%19g+19p19+/19g+19p:|
2 3 4 > v
v"invalid"<10 9
|%+91+g91g90<
... | Give a code snippet in #Befunge
The Luhn test is used by some credit card companies to distinguish valid credit card numbers from what could be a random selection of digits.
Those companies using credit card numbers that can be validated by the Luhn test have numbers that pass the following test:
Reverse the order ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Knuth_shuffle | Knuth shuffle | The Knuth shuffle (a.k.a. the Fisher-Yates shuffle) is an algorithm for randomly shuffling the elements of an array.
Task
Implement the Knuth shuffle for an integer array (or, if possible, an array of any type).
Specification
Given an array items with indices ranging from 0 to last, the algorithm can be d... | #Sidef | Sidef | func knuth_shuffle(a) {
for i (a.len ^.. 1) {
var j = i.irand
a[i, j] = a[j, i]
}
return a
}
say knuth_shuffle(@(1..10)) | Give a code snippet in #Sidef
The Knuth shuffle (a.k.a. the Fisher-Yates shuffle) is an algorithm for randomly shuffling the elements of an array.
Task
Implement the Knuth shuffle for an integer array (or, if possible, an array of any type).
Specification
Given an array items with indices ranging from 0 ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Random_number_generator_(included) | Random number generator (included) | The task is to:
State the type of random number generator algorithm used in a language's built-in random number generator. If the language or its immediate libraries don't provide a random number generator, skip this task.
If possible, give a link to a wider explanation of the algorithm used.
Note: the task is not t... | #Icon_and_Unicon | Icon and Unicon | setrand(3)
random(6)+1
\\ chosen by fair dice roll.
\\ guaranteed to the random. | Give a code snippet in #Icon_and_Unicon
The task is to:
State the type of random number generator algorithm used in a language's built-in random number generator. If the language or its immediate libraries don't provide a random number generator, skip this task.
If possible, give a link to a wider explanation of th... | christopher/rosetta-code | |
http://rosettacode.org/wiki/State_name_puzzle | State name puzzle | Background
This task is inspired by Mark Nelson's DDJ Column "Wordplay" and one of the weekly puzzle challenges from Will Shortz on NPR Weekend Edition [1] and originally attributed to David Edelheit.
The challenge was to take the names of two U.S. States, mix them all together, then rearrange the letters to form the... | #REXX | REXX | /*REXX program (state name puzzle) rearranges two state's names ──► two new states. */
!='Alabama, Alaska, Arizona, Arkansas, California, Colorado, Connecticut, Delaware, Florida, Georgia,',
'Hawaii, Idaho, Illinois, Indiana, Iowa, Kansas, Kentucky, Louisiana, Maine, Maryland, Massachusetts, ',... | Give a code snippet in #REXX
Background
This task is inspired by Mark Nelson's DDJ Column "Wordplay" and one of the weekly puzzle challenges from Will Shortz on NPR Weekend Edition [1] and originally attributed to David Edelheit.
The challenge was to take the names of two U.S. States, mix them all together, then rea... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Accumulator_factory | Accumulator factory | A problem posed by Paul Graham is that of creating a function that takes a single (numeric) argument and which returns another function that is an accumulator. The returned accumulator function in turn also takes a single numeric argument, and returns the sum of all the numeric values passed in so far to that accumulat... | #Ada | Ada | with Accumulator;
with Ada.Text_IO; use Ada.Text_IO;
procedure Example is
package A is new Accumulator;
package B is new Accumulator;
begin
Put_Line (Integer'Image (A.The_Function (5)));
Put_Line (Integer'Image (B.The_Function (3)));
Put_Line (Float'Image (A.The_Function (2.3)));
end; | Give a code snippet in #Ada
A problem posed by Paul Graham is that of creating a function that takes a single (numeric) argument and which returns another function that is an accumulator. The returned accumulator function in turn also takes a single numeric argument, and returns the sum of all the numeric values passe... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Substring | Substring |
Basic Data Operation
This is a basic data operation. It represents a fundamental action on a basic data type.
You may see other such operations in the Basic Data Operations category, or:
Integer Operations
Arithmetic |
Comparison
Boolean Operations
Bitwise |
Logical
String Operations
Concatenation |
Interpolation |... | #Ruby | Ruby | str = 'abcdefgh'
n = 2
m = 3
puts str[n, m] #=> cde
puts str[n..m] #=> cd
puts str[n..-1] #=> cdefgh
puts str[0..-2] #=> abcdefg
puts str[str.index('d'), m] #=> def
puts str[str.index('de'), m] #=> def
puts str[/a.*d/] #=> abcd | Give a code snippet in #Ruby
Basic Data Operation
This is a basic data operation. It represents a fundamental action on a basic data type.
You may see other such operations in the Basic Data Operations category, or:
Integer Operations
Arithmetic |
Comparison
Boolean Operations
Bitwise |
Logical
String Operations
C... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Quine | Quine | A quine is a self-referential program that can,
without any external access, output its own source.
A quine (named after Willard Van Orman Quine) is also known as:
self-reproducing automata (1972)
self-replicating program or self-replicating computer program
self-reproducing program ... | #Scheme | Scheme | ((lambda (s) (display (list s (list (quote quote) s)))) (quote (lambda (s) (display (list s (list (quote quote) s)))))) | Give a code snippet in #Scheme
A quine is a self-referential program that can,
without any external access, output its own source.
A quine (named after Willard Van Orman Quine) is also known as:
self-reproducing automata (1972)
self-replicating program or self-replicating computer program
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Huffman_coding | Huffman coding | Huffman encoding is a way to assign binary codes to symbols that reduces the overall number of bits used to encode a typical string of those symbols.
For example, if you use letters as symbols and have details of the frequency of occurrence of those letters in typical strings, then you could just encode each letter wi... | #Common_Lisp | Common Lisp | (defstruct huffman-node
(weight 0 :type number)
(element nil :type t)
(encoding nil :type (or null bit-vector))
(left nil :type (or null huffman-node))
(right nil :type (or null huffman-node)))
(defun initial-huffman-nodes (sequence &key (test 'eql))
(let* ((length (length sequence))
(increment (... | Give a code snippet in #Common_Lisp
Huffman encoding is a way to assign binary codes to symbols that reduces the overall number of bits used to encode a typical string of those symbols.
For example, if you use letters as symbols and have details of the frequency of occurrence of those letters in typical strings, then... | 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... | #Pyret | Pyret |
data Door:
| open
| closed
end
fun flip-door(d :: Door) -> Door:
cases(Door) d:
| open => closed
| closed => open
end
end
fun flip-doors(doors :: List<Door>) -> List<Door>:
doc:```Given a list of door positions, repeatedly switch the positions of
every nth door for every nth pass, and re... | Give a code snippet in #Pyret
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/Munchausen_numbers | Munchausen numbers | A Munchausen number is a natural number n the sum of whose digits (in base 10), each raised to the power of itself, equals n.
(Munchausen is also spelled: Münchhausen.)
For instance: 3435 = 33 + 44 + 33 + 55
Task
Find all Munchausen numbers between 1 and 5000.
Also see
The OEIS entry: A046253
The ... | #C.2B.2B | C++ |
#include <math.h>
#include <iostream>
unsigned pwr[10];
unsigned munch( unsigned i ) {
unsigned sum = 0;
while( i ) {
sum += pwr[(i % 10)];
i /= 10;
}
return sum;
}
int main( int argc, char* argv[] ) {
for( int i = 0; i < 10; i++ )
pwr[i] = (unsigned)pow( (float)i, (f... | Give a code snippet in #C.2B.2B
A Munchausen number is a natural number n the sum of whose digits (in base 10), each raised to the power of itself, equals n.
(Munchausen is also spelled: Münchhausen.)
For instance: 3435 = 33 + 44 + 33 + 55
Task
Find all Munchausen numbers between 1 and 5000.
Also see... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Check_that_file_exists | Check that file exists | Task
Verify that a file called input.txt and a directory called docs exist.
This should be done twice:
once for the current working directory, and
once for a file and a directory in the filesystem root.
Optional criteria (May 2015): verify it works with:
zero-length files
an ... | #Action.21 | Action! | BYTE lastError
PROC MyError(BYTE errCode)
lastError=errCode
RETURN
BYTE FUNC FileExists(CHAR ARRAY fname)
DEFINE PTR="CARD"
PTR old
BYTE dev=[1]
lastError=0
old=Error
Error=MyError ;replace error handling to capture I/O error
Close(dev)
Open(dev,fname,4)
Close(dev)
Error=old ;restore the... | Give a code snippet in #Action.21
Task
Verify that a file called input.txt and a directory called docs exist.
This should be done twice:
once for the current working directory, and
once for a file and a directory in the filesystem root.
Optional criteria (May 2015): verify it works... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Matrix_transposition | Matrix transposition | Transpose an arbitrarily sized rectangular Matrix.
| #RLaB | RLaB | >> m = rand(3,5)
0.41844289 0.476591435 0.75054022 0.226388925 0.963880314
0.91267171 0.941762397 0.464227895 0.693482786 0.203839405
0.261512966 0.157981873 0.26582235 0.11557427 0.0442493069
>> m'
0.41844289 0.91267171 0.261512966
0.476591435 0.941762397 0.157981873
0.750... | Give a code snippet in #RLaB
Transpose an arbitrarily sized rectangular Matrix.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Reverse_a_string | Reverse a string | Task
Take a string and reverse it.
For example, "asdf" becomes "fdsa".
Extra credit
Preserve Unicode combining characters.
For example, "as⃝df̅" becomes "f̅ds⃝a", not "̅fd⃝sa".
Other tasks related to string operations:
Metrics
Array length
String length
Copy a string
Empty string (assignment)
Counting
... | #Lingo | Lingo | on reverse (str)
res = ""
repeat with i = str.length down to 1
put str.char[i] after res
end repeat
return res
end | Give a code snippet in #Lingo
Task
Take a string and reverse it.
For example, "asdf" becomes "fdsa".
Extra credit
Preserve Unicode combining characters.
For example, "as⃝df̅" becomes "f̅ds⃝a", not "̅fd⃝sa".
Other tasks related to string operations:
Metrics
Array length
String length
Copy a string
Empty... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Determine_sentence_type | Determine sentence type | Use these sentences:
"hi there, how are you today? I'd like to present to you the washing machine 9001. You have been nominated to win one of these! Just make sure you don't break it."
Task
Search for the last used punctuation in a sentence, and determine its type according to its punctuation.
Output one of these le... | #AutoHotkey | AutoHotkey | Sentence := "hi there, how are you today? I'd like to present to you the washing machine 9001. You have been nominated to win one of these! Just make sure you don't break it"
Msgbox, % SentenceType(Sentence)
SentenceType(Sentence) {
Sentence := Trim(Sentence)
Loop, Parse, Sentence, .?!
{
N := (!E && !Q && !S)
... | Give a code snippet in #AutoHotkey
Use these sentences:
"hi there, how are you today? I'd like to present to you the washing machine 9001. You have been nominated to win one of these! Just make sure you don't break it."
Task
Search for the last used punctuation in a sentence, and determine its type according to its ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sorting_algorithms/Quicksort | Sorting algorithms/Quicksort |
Sorting Algorithm
This is a sorting algorithm. It may be applied to a set of data in order to sort it.
For comparing various sorts, see compare sorts.
For other sorting algorithms, see sorting algorithms, or:
O(n logn) sorts
Heap sort |
Merge sort |
Patience sort |
Quick sort
O(n log2n) sorts
Shell Sort
... | #NetRexx | NetRexx | /* NetRexx */
options replace format comments java crossref savelog symbols binary
import java.util.List
placesList = [String -
"UK London", "US New York", "US Boston", "US Washington" -
, "UK Washington", "US Birmingham", "UK Birmingham", "UK Boston" -
]
lists = [ -
placesList -
,... | Give a code snippet in #NetRexx
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 ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Loops/Nested | Loops/Nested | Show a nested loop which searches a two-dimensional array filled with random numbers uniformly distributed over
[
1
,
…
,
20
]
{\displaystyle [1,\ldots ,20]}
.
The loops iterate rows and columns of the array printing the elements until the value
20
{\displaystyle 20}
is met.
Specifically, this task als... | #Dyalect | Dyalect | let array = [[2, 12, 10, 4], [18, 11, 20, 2]]
for row in array {
break when {
for element in row {
print("\(element)")
if element == 20 {
break true
}
}
}
}
print("*Done") | Give a code snippet in #Dyalect
Show a nested loop which searches a two-dimensional array filled with random numbers uniformly distributed over
[
1
,
…
,
20
]
{\displaystyle [1,\ldots ,20]}
.
The loops iterate rows and columns of the array printing the elements until the value
20
{\displaystyle 20}
is ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Totient_function | Totient function | The totient function is also known as:
Euler's totient function
Euler's phi totient function
phi totient function
Φ function (uppercase Greek phi)
φ function (lowercase Greek phi)
Definitions (as per number theory)
The totient function:
counts the integers up to a given positiv... | #C.2B.2B | C++ | #include <cassert>
#include <iomanip>
#include <iostream>
#include <vector>
class totient_calculator {
public:
explicit totient_calculator(int max) : totient_(max + 1) {
for (int i = 1; i <= max; ++i)
totient_[i] = i;
for (int i = 2; i <= max; ++i) {
if (totient_[i] < i)
... | Give a code snippet in #C.2B.2B
The totient function is also known as:
Euler's totient function
Euler's phi totient function
phi totient function
Φ function (uppercase Greek phi)
φ function (lowercase Greek phi)
Definitions (as per number theory)
The totient function:
counts t... | 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... | #Clojure | Clojure | (require '[clojure.java.jdbc :as sql])
; Using h2database for this simple example.
(def db {:classname "org.h2.Driver"
:subprotocol "h2:file"
:subname "db/my-dbname"})
(sql/db-do-commands db
(sql/create-table-ddl :address
[:id "bigint primary key auto_increment"]
[:street "varchar"]
[:... | Give a code snippet in #Clojure
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 ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Non-decimal_radices/Output | Non-decimal radices/Output | Programming languages often have built-in routines to convert a non-negative integer for printing in different number bases. Such common number bases might include binary, Octal and Hexadecimal.
Task
Print a small range of integers in some different bases, as supported by standard routines of your programming langu... | #AWK | AWK | $ awk '{printf("%d 0%o 0x%x\n",$1,$1,$1)}'
10
10 012 0xa
16
16 020 0x10
255
255 0377 0xff | Give a code snippet in #AWK
Programming languages often have built-in routines to convert a non-negative integer for printing in different number bases. Such common number bases might include binary, Octal and Hexadecimal.
Task
Print a small range of integers in some different bases, as supported by standard routi... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Special_characters | Special characters | Special characters are symbols (single characters or sequences of characters) that have a "special" built-in meaning in the language and typically cannot be used in identifiers.
Escape sequences are methods that the language uses to remove the special meaning from the symbol, enabling it to be used as a normal charact... | #HTML | HTML | \b backspace
\d delete
\e escape
\f formfeed
\l linefeed
\n newline
\r return
\t horizontal tab
\v vertical tab
\' single quote
\" double quote
\\ backslash
\ddd octal code
\xdd hexadecimal code
\^c control code | Give a code snippet in #HTML
Special characters are symbols (single characters or sequences of characters) that have a "special" built-in meaning in the language and typically cannot be used in identifiers.
Escape sequences are methods that the language uses to remove the special meaning from the symbol, enabling it ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sexy_primes | Sexy primes |
This page uses content from Wikipedia. The original article was at Sexy_prime. 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 mathematics, sexy primes are prime numbers that differ from each ot... | #Prolog | Prolog | sexy_prime_group(1, N, _, [N]):-
is_prime(N),
!.
sexy_prime_group(Size, N, Limit, [N|Group]):-
is_prime(N),
N1 is N + 6,
N1 =< Limit,
S1 is Size - 1,
sexy_prime_group(S1, N1, Limit, Group).
print_sexy_prime_groups(Size, Limit):-
findall(G, (is_prime(P), P =< Limit, sexy_prime_group(Siz... | Give a code snippet in #Prolog
This page uses content from Wikipedia. The original article was at Sexy_prime. 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 mathematics, sexy primes are prime ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/CRC-32 | CRC-32 |
Task
Demonstrate a method of deriving the Cyclic Redundancy Check from within the language.
The result should be in accordance with ISO 3309, ITU-T V.42, Gzip and PNG.
Algorithms are described on Computation of CRC in Wikipedia.
This variant of CRC-32 uses LSB-first order, sets the initial CRC to FFFFFFFF16, and... | #FBSL | FBSL | #APPTYPE CONSOLE
PRINT HEX(CHECKSUM("The quick brown fox jumps over the lazy dog"))
PAUSE | Give a code snippet in #FBSL
Task
Demonstrate a method of deriving the Cyclic Redundancy Check from within the language.
The result should be in accordance with ISO 3309, ITU-T V.42, Gzip and PNG.
Algorithms are described on Computation of CRC in Wikipedia.
This variant of CRC-32 uses LSB-first order, sets the ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Factors_of_a_Mersenne_number | Factors of a Mersenne number | A Mersenne number is a number in the form of 2P-1.
If P is prime, the Mersenne number may be a Mersenne prime
(if P is not prime, the Mersenne number is also not prime).
In the search for Mersenne prime numbers it is advantageous to eliminate exponents by finding a small factor before starting a, potentially lengthy,... | #Elixir | Elixir | defmodule Mersenne do
def mersenne_factor(p) do
limit = :math.sqrt(:math.pow(2, p) - 1)
mersenne_loop(p, limit, 1)
end
defp mersenne_loop(p, limit, k) when (2*k*p - 1) > limit, do: nil
defp mersenne_loop(p, limit, k) do
q = 2*k*p + 1
if prime?(q) and rem(q,8) in [1,7] and trial_factor(2,p,q),
... | Give a code snippet in #Elixir
A Mersenne number is a number in the form of 2P-1.
If P is prime, the Mersenne number may be a Mersenne prime
(if P is not prime, the Mersenne number is also not prime).
In the search for Mersenne prime numbers it is advantageous to eliminate exponents by finding a small factor before ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Colour_pinstripe/Printer | Colour pinstripe/Printer | The task is to create 1 point wide colour vertical pinstripes with a sufficient number of pinstripes to span the entire width of the colour graphics printer. The pinstripes should alternate between each individual cartridge ink and ink pair and black and white pinstripes should be included. A typical pinstripe sequence... | #Raku | Raku | unit sub MAIN ($dpi = 300, $size = 'letter');
my $filename = './Color-pinstripe-printer-perl6.png';
my %paper = (
'letter' => { :width(8.5), :height(11.0) }
'A4' => { :width(8.2677), :height(11.6929)}
);
my ($w, $h) = %paper{$size}<width height> »*» $dpi;
# ROYGBIVK
my @color = (1,0,0),(1,.598,0)... | Give a code snippet in #Raku
The task is to create 1 point wide colour vertical pinstripes with a sufficient number of pinstripes to span the entire width of the colour graphics printer. The pinstripes should alternate between each individual cartridge ink and ink pair and black and white pinstripes should be included... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Menu | Menu | Task
Given a prompt and a list containing a number of strings of which one is to be selected, create a function that:
prints a textual menu formatted as an index value followed by its corresponding string for each item in the list;
prompts the user to enter a number;
returns the string corresponding to the selecte... | #11l | 11l | V items = [‘fee fie’, ‘huff and puff’, ‘mirror mirror’, ‘tick tock’]
L
L(item) items
print(‘#2. #.’.format(L.index + 1, item))
V reply = input(‘Which is from the three pigs: ’).trim(‘ ’)
I !reply.is_digit()
L.continue
I Int(reply) C 1..items.len
print(‘You chose: ’items[Int(reply) - ... | Give a code snippet in #11l
Task
Given a prompt and a list containing a number of strings of which one is to be selected, create a function that:
prints a textual menu formatted as an index value followed by its corresponding string for each item in the list;
prompts the user to enter a number;
returns the string... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sorting_algorithms/Merge_sort | Sorting algorithms/Merge sort |
Sorting Algorithm
This is a sorting algorithm. It may be applied to a set of data in order to sort it.
For comparing various sorts, see compare sorts.
For other sorting algorithms, see sorting algorithms, or:
O(n logn) sorts
Heap sort |
Merge sort |
Patience sort |
Quick sort
O(n log2n) sorts
Shell Sort
... | #Forth | Forth | : merge-step ( right mid left -- right mid+ left+ )
over @ over @ < if
over @ >r
2dup - over dup cell+ rot move
r> over !
>r cell+ 2dup = if rdrop dup else r> then
then cell+ ;
: merge ( right mid left -- right left )
dup >r begin 2dup > while merge-step repeat 2drop r> ;
: mid ( l r -- mid ) ov... | Give a code snippet in #Forth
Sorting Algorithm
This is a sorting algorithm. It may be applied to a set of data in order to sort it.
For comparing various sorts, see compare sorts.
For other sorting algorithms, see sorting algorithms, or:
O(n logn) sorts
Heap sort |
Merge sort |
Patience sort |
Quick so... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Calendar | Calendar | Create a routine that will generate a text calendar for any year.
Test the calendar by generating a calendar for the year 1969, on a device of the time.
Choose one of the following devices:
A line printer with a width of 132 characters.
An IBM 3278 model 4 terminal (80×43 display with accented characters). Target fo... | #Icon_and_Unicon | Icon and Unicon | procedure main(A)
printCalendar(\A[1]|1969)
end
procedure printCalendar(year) #: Print a 3 column x 80 char calendar
cols := 3 # fixed width
mons := [] # table of months
"January February March April May June " ||
... | Give a code snippet in #Icon_and_Unicon
Create a routine that will generate a text calendar for any year.
Test the calendar by generating a calendar for the year 1969, on a device of the time.
Choose one of the following devices:
A line printer with a width of 132 characters.
An IBM 3278 model 4 terminal (80×43 dis... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Random_numbers | Random numbers | Task
Generate a collection filled with 1000 normally distributed random (or pseudo-random) numbers
with a mean of 1.0 and a standard deviation of 0.5
Many libraries only generate uniformly distributed random numbers. If so, you may use one of these algorithms.
Related task
Standard deviation
| #Scheme | Scheme | ; linear congruential generator given in C99 section 7.20.2.1
(define ((c-rand seed)) (set! seed (remainder (+ (* 1103515245 seed) 12345) 2147483648)) (quotient seed 65536))
; uniform real numbers in open interval (0, 1)
(define (unif-rand seed) (let ((r (c-rand seed))) (lambda () (/ (+ (r) 1) 32769.0))))
; Box-Mul... | Give a code snippet in #Scheme
Task
Generate a collection filled with 1000 normally distributed random (or pseudo-random) numbers
with a mean of 1.0 and a standard deviation of 0.5
Many libraries only generate uniformly distributed random numbers. If so, you may use one of these algorithms.
Relate... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Runge-Kutta_method | Runge-Kutta method | Given the example Differential equation:
y
′
(
t
)
=
t
×
y
(
t
)
{\displaystyle y'(t)=t\times {\sqrt {y(t)}}}
With initial condition:
t
0
=
0
{\displaystyle t_{0}=0}
and
y
0
=
y
(
t
0
)
=
y
(
0
)
=
1
{\displaystyle y_{0}=y(t_{0})=y(0)=1}
This equation has an exact solution:
... | #Run_BASIC | Run BASIC | y = 1
while t <= 10
k1 = t * sqr(y)
k2 = (t + .05) * sqr(y + .05 * k1)
k3 = (t + .05) * sqr(y + .05 * k2)
k4 = (t + .1) * sqr(y + .1 * k3)
if right$(using("##.#",t),1) = "0" then print "y(";using("##",t);") ="; using("####.#######", y);chr$(9);"Error ="; (((t^2 + 4)^2) /16) -y
y = y + .1 *(... | Give a code snippet in #Run_BASIC
Given the example Differential equation:
y
′
(
t
)
=
t
×
y
(
t
)
{\displaystyle y'(t)=t\times {\sqrt {y(t)}}}
With initial condition:
t
0
=
0
{\displaystyle t_{0}=0}
and
y
0
=
y
(
t
0
)
=
y
(
0
)
=
1
{\displaystyle y_{0}=y(t_{0})=y(0)=1}
Thi... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sorting_algorithms/Cocktail_sort | Sorting algorithms/Cocktail 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
... | #Perl | Perl | use strict;
use warnings;
use feature 'say';
sub cocktail_sort {
my @a = @_;
while (1) {
my $swapped_forward = 0;
for my $i (0..$#a-1) {
if ($a[$i] gt $a[$i+1]) {
@a[$i, $i+1] = @a[$i+1, $i];
$swapped_forward = 1;
}
}
last... | Give a code snippet in #Perl
Sorting Algorithm
This is a sorting algorithm. It may be applied to a set of data in order to sort it.
For comparing various sorts, see compare sorts.
For other sorting algorithms, see sorting algorithms, or:
O(n logn) sorts
Heap sort |
Merge sort |
Patience sort |
Quick sor... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Partial_function_application | Partial function application | Partial function application is the ability to take a function of many
parameters and apply arguments to some of the parameters to create a new
function that needs only the application of the remaining arguments to
produce the equivalent of applying all arguments to the original function.
E.g:
Given values v1, v2
... | #Bracmat | Bracmat | ( (fs=/('(x./('(y.map'($x.$y))))))
& (f1=/('(x.$x*2)))
& (f2=/('(x.$x^2)))
& (partial=/('(x./('(y.($x)$($y))))))
& (!partial$!fs)$!f1:?fsf1
& (!partial$!fs)$!f2:?fsf2
& out$(!fsf1$(0 1 2 3))
& out$(!fsf2$(0 1 2 3))
& out$(!fsf1$(2 4 6 8))
& out$(!fsf2$(2 4 6 8))
); | Give a code snippet in #Bracmat
Partial function application is the ability to take a function of many
parameters and apply arguments to some of the parameters to create a new
function that needs only the application of the remaining arguments to
produce the equivalent of applying all arguments to the original funct... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Boolean_values | Boolean values | Task
Show how to represent the boolean states "true" and "false" in a language.
If other objects represent "true" or "false" in conditionals, note it.
Related tasks
Logical operations
| #Nemerle | Nemerle | /* NetRexx */
options replace format comments java crossref savelog symbols nobinary
bval = [1, 0, 5, 'a', 1 == 1, 1 \= 1, isTrue, isFalse]
loop b_ = 0 for bval.length
select case bval[b_]
when isTrue then say bval[b_] 'is true'
when isFalse then say bval[b_] 'is false'
otherwise say bval[b_]... | Give a code snippet in #Nemerle
Task
Show how to represent the boolean states "true" and "false" in a language.
If other objects represent "true" or "false" in conditionals, note it.
Related tasks
Logical operations
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Generic_swap | Generic swap | Task
Write a generic swap function or operator which exchanges the values of two variables (or, more generally, any two storage places that can be assigned), regardless of their types.
If your solution language is statically typed please describe the way your language provides genericity.
If variables are typed in t... | #Ada | Ada | generic
type Swap_Type is private; -- Generic parameter
procedure Generic_Swap (Left, Right : in out Swap_Type);
procedure Generic_Swap (Left, Right : in out Swap_Type) is
Temp : constant Swap_Type := Left;
begin
Left := Right;
Right := Temp;
end Generic_Swap; | Give a code snippet in #Ada
Task
Write a generic swap function or operator which exchanges the values of two variables (or, more generally, any two storage places that can be assigned), regardless of their types.
If your solution language is statically typed please describe the way your language provides genericity.... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Determine_if_a_string_is_numeric | Determine if a string is numeric | Task
Create a boolean function which takes in a string and tells whether it is a numeric string (floating point and negative numbers included) in the syntax the language uses for numeric literals or numbers converted from strings.
Other tasks related to string operations:
Metrics
Array length
String length
Cop... | #Octave | Octave | function r = isnum(a)
if ( isnumeric(a) )
r = 1;
else
r = ~isnan(str2double(a));
endif
endfunction
% tests
disp(isnum(123)) % 1
disp(isnum("123")) % 1
disp(isnum("foo123")) % 0
disp(isnum("123bar")) % 0
disp(isnum("3.1415")) % 1 | Give a code snippet in #Octave
Task
Create a boolean function which takes in a string and tells whether it is a numeric string (floating point and negative numbers included) in the syntax the language uses for numeric literals or numbers converted from strings.
Other tasks related to string operations:
Metrics
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Dinesman%27s_multiple-dwelling_problem | Dinesman's multiple-dwelling problem | Task
Solve Dinesman's multiple dwelling problem but in a way that most naturally follows the problem statement given below.
Solutions are allowed (but not required) to parse and interpret the problem text, but should remain flexible and should state what changes to the problem text are allowed. Flexibility and ease of... | #Clojure | Clojure | (ns rosettacode.dinesman
(:use [clojure.core.logic]
[clojure.tools.macro :as macro]))
; whether x is immediately above (left of) y in list s; uses pattern matching on s
(defne aboveo [x y s]
([_ _ (x y . ?rest)])
([_ _ [_ . ?rest]] (aboveo x y ?rest)))
; whether x is on a higher floor than y... | Give a code snippet in #Clojure
Task
Solve Dinesman's multiple dwelling problem but in a way that most naturally follows the problem statement given below.
Solutions are allowed (but not required) to parse and interpret the problem text, but should remain flexible and should state what changes to the problem text are... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Hostname | Hostname | Task
Find the name of the host on which the routine is running.
| #AWK | AWK | $ awk 'BEGIN{print ENVIRON["HOST"]}'
E51A08ZD | Give a code snippet in #AWK
Task
Find the name of the host on which the routine is running.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Jensen%27s_Device | Jensen's Device | Jensen's Device
You are encouraged to solve this task according to the task description, using any language you may know.
This task is an exercise in call by name.
Jensen's Device is a computer programming technique devised by Danish computer scientist Jørn Jensen after studying the ALGOL 60 Report.
The following pr... | #Ruby | Ruby | def sum(var, lo, hi, term, context)
sum = 0.0
lo.upto(hi) do |n|
sum += eval "#{var} = #{n}; #{term}", context
end
sum
end
p sum "i", 1, 100, "1.0 / i", binding # => 5.18737751763962 | Give a code snippet in #Ruby
Jensen's Device
You are encouraged to solve this task according to the task description, using any language you may know.
This task is an exercise in call by name.
Jensen's Device is a computer programming technique devised by Danish computer scientist Jørn Jensen after studying the ALGO... | 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... | #PicoLisp | PicoLisp | (de **Mod (X Y N)
(let M 1
(loop
(when (bit? 1 Y)
(setq M (% (* M X) N)) )
(T (=0 (setq Y (>> 1 Y)))
M )
(setq X (% (* X X) N)) ) ) ) | Give a code snippet in #PicoLisp
Find the last 40 decimal digits of
a
b
{\displaystyle a^{b}}
, where
a
=
2988348162058574136915891421498819466320163312926952423791023078876139
{\displaystyle a=2988348162058574136915891421498819466320163312926952423791023078876139}
b
=
23513993033... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Entropy | Entropy | Task
Calculate the Shannon entropy H of a given input string.
Given the discrete random variable
X
{\displaystyle X}
that is a string of
N
{\displaystyle N}
"symbols" (total characters) consisting of
n
{\displaystyle n}
different characters (n=2 for binary), the Shannon entropy of X in bit... | #PowerShell | PowerShell |
function entropy ($string) {
$n = $string.Length
$string.ToCharArray() | group | foreach{
$p = $_.Count/$n
$i = [Math]::Log($p,2)
-$p*$i
} | measure -Sum | foreach Sum
}
entropy "1223334444"
| Give a code snippet in #PowerShell
Task
Calculate the Shannon entropy H of a given input string.
Given the discrete random variable
X
{\displaystyle X}
that is a string of
N
{\displaystyle N}
"symbols" (total characters) consisting of
n
{\displaystyle n}
different characters (n=2 for bina... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Validate_International_Securities_Identification_Number | Validate International Securities Identification Number | An International Securities Identification Number (ISIN) is a unique international identifier for a financial security such as a stock or bond.
Task
Write a function or program that takes a string as input, and checks whether it is a valid ISIN.
It is only valid if it has the correct format, and the embedded c... | #Julia | Julia | using Printf
luhntest(x) = luhntest(parse(Int, x))
function checkISIN(inum::AbstractString)
if length(inum) != 12 || !all(isalpha, inum[1:2]) return false end
return parse.(Int, collect(inum), 36) |> join |> luhntest
end
for inum in ["US0378331005", "US0373831005", "U50378331005",
"US03378331005", "AU... | Give a code snippet in #Julia
An International Securities Identification Number (ISIN) is a unique international identifier for a financial security such as a stock or bond.
Task
Write a function or program that takes a string as input, and checks whether it is a valid ISIN.
It is only valid if it has the correct... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Zumkeller_numbers | Zumkeller numbers | Zumkeller numbers are the set of numbers whose divisors can be partitioned into two disjoint sets that sum to the same value. Each sum must contain divisor values that are not in the other sum, and all of the divisors must be in one or the other. There are no restrictions on how the divisors are partitioned, only that ... | #Mathematica_.2F_Wolfram_Language | Mathematica / Wolfram Language | ClearAll[ZumkellerQ]
ZumkellerQ[n_] := Module[{d = Divisors[n], t, ds, x},
ds = Total[d];
If[Mod[ds, 2] == 1,
False
,
t = CoefficientList[Product[1 + x^i, {i, d}], x];
t[[1 + ds/2]] > 0
]
];
i = 1;
res = {};
While[Length[res] < 220,
r = ZumkellerQ[i];
If[r, AppendTo[res, i]];
i++;
]... | Give a code snippet in #Mathematica_.2F_Wolfram_Language
Zumkeller numbers are the set of numbers whose divisors can be partitioned into two disjoint sets that sum to the same value. Each sum must contain divisor values that are not in the other sum, and all of the divisors must be in one or the other. There are no re... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Maze_generation | Maze generation |
This page uses content from Wikipedia. The original article was at Maze generation algorithm. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance)
Task
Generate and show a maze, using the simple Depth... | #TXR | TXR | @(bind (width height) (15 15))
@(do
(defvar *r* (make-random-state nil))
(defvar vi)
(defvar pa)
(defun neigh (loc)
(let ((x (from loc))
(y (to loc)))
(list (- x 1)..y (+ x 1)..y
x..(- y 1) x..(+ y 1))))
(defun make-maze-rec (cu)
(set [vi cu] t)
(each ((n... | Give a code snippet in #TXR
This page uses content from Wikipedia. The original article was at Maze generation algorithm. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance)
Task
Generate and show a... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Truncatable_primes | Truncatable primes | A truncatable prime is a prime number that when you successively remove digits from one end of the prime, you are left with a new prime number.
Examples
The number 997 is called a left-truncatable prime as the numbers 997, 97, and 7 are all prime.
The number 7393 is a right-truncatable prime as the numbers 7393, 7... | #PicoLisp | PicoLisp | (load "@lib/rsa.l") # Use the 'prime?' function from RSA package
(de truncatablePrime? (N Fun)
(for (L (chop N) L (Fun L))
(T (= "0" (car L)))
(NIL (prime? (format L)))
T ) )
(let (Left 1000000 Right 1000000)
(until (truncatablePrime? (dec 'Left) cdr))
(until (truncatablePrime? (dec 'Ri... | Give a code snippet in #PicoLisp
A truncatable prime is a prime number that when you successively remove digits from one end of the prime, you are left with a new prime number.
Examples
The number 997 is called a left-truncatable prime as the numbers 997, 97, and 7 are all prime.
The number 7393 is a right-trunca... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sum_of_a_series | Sum of a series | Compute the nth term of a series, i.e. the sum of the n first terms of the corresponding sequence.
Informally this value, or its limit when n tends to infinity, is also called the sum of the series, thus the title of this task.
For this task, use:
S
n
=
∑
k
=
1
n
1
k
2
{\displa... | #K | K | ssr: +/1%_sqr
ssr 1+!1000
1.643935 | Give a code snippet in #K
Compute the nth term of a series, i.e. the sum of the n first terms of the corresponding sequence.
Informally this value, or its limit when n tends to infinity, is also called the sum of the series, thus the title of this task.
For this task, use:
S
n
=
∑
k
=
1
n... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Bitwise_IO | Bitwise IO | The aim of this task is to write functions (or create a class if your
language is Object Oriented and you prefer) for reading and writing sequences of
bits, most significant bit first. While the output of a asciiprint "STRING" is the ASCII byte sequence
"S", "T", "R", "I", "N", "G", the output of a "print" of the bits ... | #Julia | Julia |
function compress7(inio, outio)
nextwritebyte = read(inio, UInt8) & 0x7f
filled = 7
while !eof(inio)
inbyte = read(inio, UInt8)
write(outio, UInt8(nextwritebyte | inbyte << filled))
nextwritebyte = inbyte >> (8 - filled)
filled = (filled + 7) % 8
if filled == 0
... | Give a code snippet in #Julia
The aim of this task is to write functions (or create a class if your
language is Object Oriented and you prefer) for reading and writing sequences of
bits, most significant bit first. While the output of a asciiprint "STRING" is the ASCII byte sequence
"S", "T", "R", "I", "N", "G", the o... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Generator/Exponential | Generator/Exponential | A generator is an executable entity (like a function or procedure) that contains code that yields a sequence of values, one at a time, so that each time you call the generator, the next value in the sequence is provided.
Generators are often built on top of coroutines or objects so that the internal state of the objec... | #Factor | Factor | USING: fry kernel lists lists.lazy math math.functions
prettyprint ;
IN: rosetta-code.generator-exponential
: mth-powers-generator ( m -- lazy-list )
[ 0 lfrom ] dip [ ^ ] curry lmap-lazy ;
: lmember? ( elt list -- ? )
over '[ unswons dup _ >= ] [ drop ] until nip = ;
: 2-not-3-generator ( -- lazy-list )
... | Give a code snippet in #Factor
A generator is an executable entity (like a function or procedure) that contains code that yields a sequence of values, one at a time, so that each time you call the generator, the next value in the sequence is provided.
Generators are often built on top of coroutines or objects so that... | 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 ... | #OpenEdge.2FProgress | OpenEdge/Progress | FUNCTION multiply RETURNS DEC (a AS DEC , b AS DEC ):
RETURN a * b .
END. | Give a code snippet in #OpenEdge.2FProgress
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 no... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Archimedean_spiral | Archimedean spiral |
The Archimedean spiral is a spiral named after the Greek mathematician Archimedes.
An Archimedean spiral can be described by the equation:
r
=
a
+
b
θ
{\displaystyle \,r=a+b\theta }
with real numbers a and b.
Task
Draw an Archimedean spiral.
| #Racket | Racket | #lang racket/base
(require plot
racket/math)
;; x and y bounds set to centralise the circle
(define (archemedian-spiral-renderer2d a b θ/τ-max
#:samples (samples (line-samples)))
(define (f θ) (+ a (* b θ)))
(define max-dim (+ a (* θ/τ-max 2 pi b)))
(polar f
... | Give a code snippet in #Racket
The Archimedean spiral is a spiral named after the Greek mathematician Archimedes.
An Archimedean spiral can be described by the equation:
r
=
a
+
b
θ
{\displaystyle \,r=a+b\theta }
with real numbers a and b.
Task
Draw an Archimedean spiral.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Hash_from_two_arrays | Hash from two arrays | Task
Using two Arrays of equal length, create a Hash object
where the elements from one array (the keys) are linked
to the elements of the other (the values)
Related task
Associative arrays/Creation
| #Nemerle | Nemerle | using System;
using System.Console;
using Nemerle.Collections;
using Nemerle.Collections.NCollectionsExtensions;
module AssocArray
{
Main() : void
{
def list1 = ["apples", "oranges", "bananas", "kumquats"];
def list2 = [13, 34, 12];
def inventory = Hashtable(ZipLazy(list1, list2));
... | Give a code snippet in #Nemerle
Task
Using two Arrays of equal length, create a Hash object
where the elements from one array (the keys) are linked
to the elements of the other (the values)
Related task
Associative arrays/Creation
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Perfect_numbers | Perfect numbers | Write a function which says whether a number is perfect.
A perfect number is a positive integer that is the sum of its proper positive divisors excluding the number itself.
Equivalently, a perfect number is a number that is half the sum of all of its positive divisors (including itself).
Note: The faster Luca... | #Maple | Maple | isperfect := proc(n) return evalb(NumberTheory:-SumOfDivisors(n) = 2*n); end proc:
isperfect(6);
true | Give a code snippet in #Maple
Write a function which says whether a number is perfect.
A perfect number is a positive integer that is the sum of its proper positive divisors excluding the number itself.
Equivalently, a perfect number is a number that is half the sum of all of its positive divisors (including itself... | 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... | #Scala | Scala | import scala.math.BigInt
val a = BigInt(
"2988348162058574136915891421498819466320163312926952423791023078876139")
val b = BigInt(
"2351399303373464486466122544523690094744975233415544072992656881240319")
println(a.modPow(b, BigInt(10).pow(40))) | Give a code snippet in #Scala
Find the last 40 decimal digits of
a
b
{\displaystyle a^{b}}
, where
a
=
2988348162058574136915891421498819466320163312926952423791023078876139
{\displaystyle a=2988348162058574136915891421498819466320163312926952423791023078876139}
b
=
23513993033734... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Jewels_and_stones | Jewels and stones | Jewels and stones
You are encouraged to solve this task according to the task description, using any language you may know.
Task
Create a function which takes two string parameters: 'stones' and 'jewels' and returns an integer.
Both strings can contain any number of upper or lower case letters. However, in the case ... | #Kotlin | Kotlin | // Version 1.2.40
fun countJewels(s: String, j: String) = s.count { it in j }
fun main(args: Array<String>) {
println(countJewels("aAAbbbb", "aA"))
println(countJewels("ZZ", "z"))
} | Give a code snippet in #Kotlin
Jewels and stones
You are encouraged to solve this task according to the task description, using any language you may know.
Task
Create a function which takes two string parameters: 'stones' and 'jewels' and returns an integer.
Both strings can contain any number of upper or lower cas... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sort_an_array_of_composite_structures | Sort an array of composite structures |
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
... | #Ada | Ada | with Ada.Strings.Unbounded; use Ada.Strings.Unbounded;
with Ada.Text_IO; use Ada.Text_IO;
with Ada.Containers.Generic_Array_Sort;
procedure Demo_Array_Sort is
function "+" (S : String) return Unbounded_String renames To_Unbounded_String;
type A_Composite is
record
Name : Unbounde... | Give a code snippet in #Ada
Sorting Algorithm
This is a sorting algorithm. It may be applied to a set of data in order to sort it.
For comparing various sorts, see compare sorts.
For other sorting algorithms, see sorting algorithms, or:
O(n logn) sorts
Heap sort |
Merge sort |
Patience sort |
Quick sort... | christopher/rosetta-code |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.