task_url stringlengths 30 116 | task_name stringlengths 2 86 | task_description stringlengths 0 14.4k | language_url stringlengths 2 53 | language_name stringlengths 1 52 | code stringlengths 0 61.9k | response_seed stringclasses 1
value | instruction_seed stringlengths 27 14.4k | _source stringclasses 1
value |
|---|---|---|---|---|---|---|---|---|
http://rosettacode.org/wiki/Loops/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... | #Erlang | Erlang | -module(while).
-export([loop/0]).
loop() ->
loop(1024).
loop(N) when N div 2 =:= 0 ->
io:format("~w~n", [N]);
loop(N) when N >0 ->
io:format("~w~n", [N]),
loop(N div 2). | Give a code snippet in #Erlang
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/Downwa... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Ulam_spiral_(for_primes) | Ulam spiral (for primes) | An Ulam spiral (of primes) is a method of visualizing primes when expressed in a (normally counter-clockwise) outward spiral (usually starting at 1), constructed on a square grid, starting at the "center".
An Ulam spiral is also known as a prime spiral.
The first grid (green) is shown with sequential integers, ... | #Ring | Ring |
# Project : Ulam spiral (for primes)
load "guilib.ring"
load "stdlib.ring"
paint = null
new qapp
{
win1 = new qwidget() {
setwindowtitle("Ulam spiral")
setgeometry(100,100,560,600)
label1 = new qlabel(win1) {
se... | Give a code snippet in #Ring
An Ulam spiral (of primes) is a method of visualizing primes when expressed in a (normally counter-clockwise) outward spiral (usually starting at 1), constructed on a square grid, starting at the "center".
An Ulam spiral is also known as a prime spiral.
The first grid (green) is show... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Fibonacci_sequence | Fibonacci sequence | The Fibonacci sequence is a sequence Fn of natural numbers defined recursively:
F0 = 0
F1 = 1
Fn = Fn-1 + Fn-2, if n>1
Task
Write a function to generate the nth Fibonacci number.
Solutions can be iterative or recursive (though recursive solutions are generally considered too slow ... | #Groovy | Groovy | def rFib
rFib = {
it == 0 ? 0
: it == 1 ? 1
: it > 1 ? rFib(it-1) + rFib(it-2)
/*it < 0*/: rFib(it+2) - rFib(it+1)
} | Give a code snippet in #Groovy
The Fibonacci sequence is a sequence Fn of natural numbers defined recursively:
F0 = 0
F1 = 1
Fn = Fn-1 + Fn-2, if n>1
Task
Write a function to generate the nth Fibonacci number.
Solutions can be iterative or recursive (though recursive solutions ar... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Loop_over_multiple_arrays_simultaneously | Loop over multiple arrays simultaneously | Task
Loop over multiple arrays (or lists or tuples or whatever they're called in
your language) and display the i th element of each.
Use your language's "for each" loop if it has one, otherwise iterate
through the collection in order with some other loop.
For this example, loop over the arrays:
... | #Pascal | Pascal | sub zip (&@)
{
my $code = shift;
my $min;
$min = $min && $#$_ > $min ? $min : $#$_ for @_;
for my $i(0..$min){ $code->(map $_->[$i] ,@_) }
}
my @a1 = qw( a b c );
my @a2 = qw( A B C );
my @a3 = qw( 1 2 3 );
zip { print @_,"\n" }\(@a1, @a2, @a3); | Give a code snippet in #Pascal
Task
Loop over multiple arrays (or lists or tuples or whatever they're called in
your language) and display the i th element of each.
Use your language's "for each" loop if it has one, otherwise iterate
through the collection in order with some other loop.
For this exa... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Rare_numbers | Rare numbers | Definitions and restrictions
Rare numbers are positive integers n where:
n is expressed in base ten
r is the reverse of n (decimal digits)
n must be non-palindromic (n ≠ r)
(n+r) is the sum
(n-r) is the difference and must be positive
the sum and the ... | #Quackery | Quackery | [ dup 1
[ 2dup > while
+ 1 >>
2dup / again ]
drop nip ] is sqrt ( n --> n )
[ dup sqrt 2 ** = not ] is !square ( n --> b )
[ number$ reverse
$->n drop ] is revnumber ( n --> n )
[ 0 swap
[ base share /mod
rot + swap
... | Give a code snippet in #Quackery
Definitions and restrictions
Rare numbers are positive integers n where:
n is expressed in base ten
r is the reverse of n (decimal digits)
n must be non-palindromic (n ≠ r)
(n+r) is the sum
(n-r) is the difference and must be... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Matrix_transposition | Matrix transposition | Transpose an arbitrarily sized rectangular Matrix.
| #Groovy | Groovy | def matrix = [ [ 1, 2, 3, 4 ],
[ 5, 6, 7, 8 ] ]
matrix.each { println it }
println()
def transpose = matrix.transpose()
transpose.each { println it } | Give a code snippet in #Groovy
Transpose an arbitrarily sized rectangular Matrix.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Prime_decomposition | Prime decomposition | The prime decomposition of a number is defined as a list of prime numbers
which when all multiplied together, are equal to that number.
Example
12 = 2 × 2 × 3, so its prime decomposition is {2, 2, 3}
Task
Write a function which returns an array or collection which contains the prime decomposition of a given ... | #SPAD | SPAD |
(1) -> factor 102400
12 2
(1) 2 5
Type: Factored(Integer)
(2) -> factor 23193931893819371
(2) 83 3469 71341 1129153
Type: Factored(Integer)
| Give a code snippet in #SPAD
The prime decomposition of a number is defined as a list of prime numbers
which when all multiplied together, are equal to that number.
Example
12 = 2 × 2 × 3, so its prime decomposition is {2, 2, 3}
Task
Write a function which returns an array or collection which contains the p... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Matrix_transposition | Matrix transposition | Transpose an arbitrarily sized rectangular Matrix.
| #REXX | REXX | /*REXX program transposes any sized rectangular matrix, displays before & after matrices*/
@.=; @.1 = 1.02 2.03 3.04 4.05 5.06 6.07 7.08
@.2 = 111 2222 33333 444444 5555555 66666666 777777777
w=0
do row=1 whil... | Give a code snippet in #REXX
Transpose an arbitrarily sized rectangular Matrix.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Exponentiation_operator | Exponentiation operator | Most programming languages have a built-in implementation of exponentiation.
Task
Re-implement integer exponentiation for both intint and floatint as both a procedure, and an operator (if your language supports operator definition).
If the language supports operator (or procedure) overloading, then an ov... | #Slate | Slate | x@(Number traits) raisedTo: y@(Integer traits)
[
y isZero ifTrue: [^ x unit].
x isZero \/ [y = 1] ifTrue: [^ x].
y isPositive
ifTrue:
"(x * x raisedTo: y // 2) * (x raisedTo: y \\ 2)"
[| count result |
count: 1.
[(count: (count bitShift: 1)) < y] whileTrue.
result: x unit.
... | Give a code snippet in #Slate
Most programming languages have a built-in implementation of exponentiation.
Task
Re-implement integer exponentiation for both intint and floatint as both a procedure, and an operator (if your language supports operator definition).
If the language supports operator (or pro... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Align_columns | Align columns | Given a text file of many lines, where fields within a line
are delineated by a single 'dollar' character, write a program
that aligns each column of fields by ensuring that words in each
column are separated by at least one space.
Further, allow for each word in a column to be either left
justified, right justified, o... | #TSE_SAL | TSE SAL |
INTEGER PROC FNBlockChangeColumnAlignLeftB( INTEGER columnTotalI, INTEGER spaceTotalI, INTEGER buffer1I )
INTEGER B = FALSE
INTEGER downB = TRUE
INTEGER minI = 1
INTEGER I = 0
INTEGER J = 0
INTEGER K = 0
INTEGER L = 0
INTEGER buffer2I = 0
STRING s[255] = ""
INTEGER wordRightB = FALSE
STRING s1[255] = Query... | Give a code snippet in #TSE_SAL
Given a text file of many lines, where fields within a line
are delineated by a single 'dollar' character, write a program
that aligns each column of fields by ensuring that words in each
column are separated by at least one space.
Further, allow for each word in a column to be either l... | christopher/rosetta-code | |
http://rosettacode.org/wiki/String_comparison | String comparison |
Basic Data Operation
This is a basic data operation. It represents a fundamental action on a basic data type.
You may see other such operations in the Basic Data Operations category, or:
Integer Operations
Arithmetic |
Comparison
Boolean Operations
Bitwise |
Logical
String Operations
Concatenation |
Interpolation |... | #Harbour | Harbour | IF s1 == s2
? "The strings are equal"
ENDIF
IF !( s1 == s2 )
? "The strings are not equal"
ENDIF
IF s1 > s2
? "s2 is lexically ordered before than s1"
ENDIF
IF s1 < s2
? "s2 is lexically ordered after than s1"
ENDIF | Give a code snippet in #Harbour
Basic Data Operation
This is a basic data operation. It represents a fundamental action on a basic data type.
You may see other such operations in the Basic Data Operations category, or:
Integer Operations
Arithmetic |
Comparison
Boolean Operations
Bitwise |
Logical
String Operation... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Terminal_control/Display_an_extended_character | Terminal control/Display an extended character | Task
Display an extended (non ASCII) character onto the terminal.
Specifically, display a £ (GBP currency sign).
| #Python | Python | print u'\u00a3' | Give a code snippet in #Python
Task
Display an extended (non ASCII) character onto the terminal.
Specifically, display a £ (GBP currency sign).
| 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... | #Go | Go | package main
import (
"fmt"
"log"
"strconv"
)
func Sum(i uint64, base int) (sum int) {
b64 := uint64(base)
for ; i > 0; i /= b64 {
sum += int(i % b64)
}
return
}
func DigitalRoot(n uint64, base int) (persistence, root int) {
root = int(n)
for x := n; x >= uint64(base); x = uint64(root) {
root = Sum(x... | Give a code snippet in #Go
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}
, rep... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Modular_inverse | Modular inverse | From Wikipedia:
In modular arithmetic, the modular multiplicative inverse of an integer a modulo m is an integer x such that
a
x
≡
1
(
mod
m
)
.
{\displaystyle a\,x\equiv 1{\pmod {m}}.}
Or in other words, such that:
∃
k
∈
Z
,
a
x
=
1
+
k
m
{\displaystyle \exists k\in \math... | #Java | Java | System.out.println(BigInteger.valueOf(42).modInverse(BigInteger.valueOf(2017))); | Give a code snippet in #Java
From Wikipedia:
In modular arithmetic, the modular multiplicative inverse of an integer a modulo m is an integer x such that
a
x
≡
1
(
mod
m
)
.
{\displaystyle a\,x\equiv 1{\pmod {m}}.}
Or in other words, such that:
∃
k
∈
Z
,
a
x
=
1
+
k
m
{\d... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Keyboard_macros | Keyboard macros | Show how to link user defined methods to user defined keys.
An example of this is the facility provided by emacs for key bindings.
These key bindings may be application-specific or system-wide; state which you have done.
| #Perl | Perl | use strict;
use warnings;
use Term::ReadKey;
ReadMode 4; # change to raw input mode
sub logger { my($message) = @_; print "$message\n" }
while (1) {
if (my $c = ReadKey 0) { # read a single character
if ($c eq 'q') { logger "QUIT"; last }
elsif ($c =~ /\n|\r/) { logger "CR" }
elsif ($c... | Give a code snippet in #Perl
Show how to link user defined methods to user defined keys.
An example of this is the facility provided by emacs for key bindings.
These key bindings may be application-specific or system-wide; state which you have done.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Integer_sequence | Integer sequence | Task
Create a program that, when run, would display all integers from 1 to ∞ (or any relevant implementation limit), in sequence (i.e. 1, 2, 3, 4, etc) if given enough time.
An example may not be able to reach arbitrarily-large numbers based on implementations limits. For example, if integer... | #C.23 | C# | using System;
using System.Numerics;
class Program
{
static void Main()
{
BigInteger i = 1;
while (true)
{
Console.WriteLine(i++);
}
}
} | Give a code snippet in #C.23
Task
Create a program that, when run, would display all integers from 1 to ∞ (or any relevant implementation limit), in sequence (i.e. 1, 2, 3, 4, etc) if given enough time.
An example may not be able to reach arbitrarily-large numbers based on implementations lim... | 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
... | #ERRE | ERRE |
PROGRAM REVERSE_STRING
PROCEDURE REVERSE(A$->R$)
LOCAL I%
R$=""
FOR I=1 TO LEN(A$) DO
R$=MID$(A$,I,1)+R$
END FOR
END PROCEDURE
BEGIN
A$="THE FIVE BOXING WIZARDS JUMP QUICKLY"
REVERSE(A$->R$)
PRINT(R$)
END PROGRAM
| Give a code snippet in #ERRE
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/Sequence_of_non-squares | Sequence of non-squares | Task
Show that the following remarkable formula gives the sequence of non-square natural numbers:
n + floor(1/2 + sqrt(n))
Print out the values for n in the range 1 to 22
Show that no squares occur for n less than one million
This is sequence A000037 in the OEIS database.
| #Mathematica.2FWolfram_Language | Mathematica/Wolfram Language | nonsq = (# + Floor[0.5 + Sqrt[#]]) &;
nonsq@Range[22]
If[! Or @@ (IntegerQ /@ Sqrt /@ nonsq@Range[10^6]),
Print["No squares for n <= ", 10^6]
] | Give a code snippet in #Mathematica.2FWolfram_Language
Task
Show that the following remarkable formula gives the sequence of non-square natural numbers:
n + floor(1/2 + sqrt(n))
Print out the values for n in the range 1 to 22
Show that no squares occur for n less than one million
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Caesar_cipher | Caesar cipher |
Task
Implement a Caesar cipher, both encoding and decoding.
The key is an integer from 1 to 25.
This cipher rotates (either towards left or right) the letters of the alphabet (A to Z).
The encoding replaces each letter with the 1st to 25th next letter in the alphabet (wrapping Z to A).
So key 2 encrypts "HI" to... | #Icon_and_Unicon | Icon and Unicon | procedure main()
ctext := caesar(ptext := map("The quick brown fox jumped over the lazy dog"))
dtext := caesar(ctext,,"decrypt")
write("Plain text = ",image(ptext))
write("Encphered text = ",image(ctext))
write("Decphered text = ",image(dtext))
end
procedure caesar(text,k,mode) #: mono-alphabetic shift cipher
/k :... | Give a code snippet in #Icon_and_Unicon
Task
Implement a Caesar cipher, both encoding and decoding.
The key is an integer from 1 to 25.
This cipher rotates (either towards left or right) the letters of the alphabet (A to Z).
The encoding replaces each letter with the 1st to 25th next letter in the alphabet (wra... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Rosetta_Code/Rank_languages_by_popularity | Rosetta Code/Rank languages by popularity | Rosetta Code/Rank languages by popularity
You are encouraged to solve this task according to the task description, using any language you may know.
Task
Sort the most popular computer programming languages based in number of members in Rosetta Code categories.
Sample output on 01 juin 2022 at 14:13 +02
Rank: 1 (1,... | #TUSCRIPT | TUSCRIPT | $$ MODE TUSCRIPT
remotedata = REQUEST ("http://www.rosettacode.org/mw/index.php?title=Special:Categories&limit=5000")
allmembers=allnames=""
COMPILE
LOOP d=remotedata
IF (d.sw."<li>") THEN
name=EXTRACT (d,":<<a<><%>>:"|,":<</a>>:")
IF (name.eq."Language users") CYCLE
IF (name.sw."Unimplemented tasks") CYCLE
IF (nam... | Give a code snippet in #TUSCRIPT
Rosetta Code/Rank languages by popularity
You are encouraged to solve this task according to the task description, using any language you may know.
Task
Sort the most popular computer programming languages based in number of members in Rosetta Code categories.
Sample output on 01 ju... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Loops/Infinite | Loops/Infinite | Task
Print out SPAM followed by a newline in an infinite loop.
Related tasks
Loop over multiple arrays simultaneously
Loops/Break
Loops/Continue
Loops/Do-while
Loops/Downward for
Loops/For
Loops/For with a specified step
Loops/Foreach
Loops/Increment loop index within l... | #Perl | Perl | while(1){
print "SPAM\n";
} | Give a code snippet in #Perl
Task
Print out SPAM followed by a newline in an infinite loop.
Related tasks
Loop over multiple arrays simultaneously
Loops/Break
Loops/Continue
Loops/Do-while
Loops/Downward for
Loops/For
Loops/For with a specified step
Loops/Foreach
Loops... | christopher/rosetta-code | |
http://rosettacode.org/wiki/User_input/Text | User input/Text | User input/Text is part of Short Circuit's Console Program Basics selection.
Task
Input a string and the integer 75000 from the text console.
See also: User input/Graphical
| #Smalltalk | Smalltalk | 'Enter a number: ' display.
a := stdin nextLine asInteger.
'Enter a string: ' display.
b := stdin nextLine. | Give a code snippet in #Smalltalk
User input/Text is part of Short Circuit's Console Program Basics selection.
Task
Input a string and the integer 75000 from the text console.
See also: User input/Graphical
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Keyboard_input/Obtain_a_Y_or_N_response | Keyboard input/Obtain a Y or N response |
Task
Obtain a valid Y or N response from the keyboard.
The keyboard should be flushed, so that any outstanding key-presses are removed, preventing any existing Y or N key-press from being evaluated.
The response should be obtained as soon as Y or N are pressed, and there should be no need t... | #FutureBasic | FutureBasic | void local fn DoDialog( ev as long )
CFStringRef key
select ( ev )
case _windowKeyDown
cls
key = fn EventCharacters
select ( lcase(key) )
case @"y",@"n"
printf @"You pressed the \"%@\" key",key
DialogEventSetBool(YES)// we handled the event
end select
end ... | Give a code snippet in #FutureBasic
Task
Obtain a valid Y or N response from the keyboard.
The keyboard should be flushed, so that any outstanding key-presses are removed, preventing any existing Y or N key-press from being evaluated.
The response should be obtained as soon as Y or N are p... | christopher/rosetta-code | |
http://rosettacode.org/wiki/LZW_compression | LZW compression | The Lempel-Ziv-Welch (LZW) algorithm provides loss-less data compression.
You can read a complete description of it in the Wikipedia article on the subject. It was patented, but it entered the public domain in 2004.
| #Clojure | Clojure | (defn make-dict []
(let [vals (range 0 256)]
(zipmap (map (comp #'list #'char) vals) vals)))
(defn compress [#^String text]
(loop [t (seq text)
r '()
w '()
dict (make-dict)
s 256]
(let [c (first t)]
(if c
(let [wc (cons c w)]
(if (get dict wc)
... | Give a code snippet in #Clojure
The Lempel-Ziv-Welch (LZW) algorithm provides loss-less data compression.
You can read a complete description of it in the Wikipedia article on the subject. It was patented, but it entered the public domain in 2004.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Vector_products | Vector products | A vector is defined as having three dimensions as being represented by an ordered collection of three numbers: (X, Y, Z).
If you imagine a graph with the x and y axis being at right angles to each other and having a third, z axis coming out of the page, then a triplet of numbers, (X, Y, Z) would repr... | #D | D | import std.stdio, std.conv, std.numeric;
struct V3 {
union {
immutable struct { double x, y, z; }
immutable double[3] v;
}
double dot(in V3 rhs) const pure nothrow /*@safe*/ @nogc {
return dotProduct(v, rhs.v);
}
V3 cross(in V3 rhs) const pure nothrow @safe @nogc {
... | Give a code snippet in #D
A vector is defined as having three dimensions as being represented by an ordered collection of three numbers: (X, Y, Z).
If you imagine a graph with the x and y axis being at right angles to each other and having a third, z axis coming out of the page, then a triplet of number... | 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.
| #Fortran | Fortran | program multtable
implicit none
integer :: i, j, k
write(*, "(a)") " x| 1 2 3 4 5 6 7 8 9 10 11 12"
write(*, "(a)") "--+------------------------------------------------"
do i = 1, 12
write(*, "(i2, a)", advance="no") i, "|"
do k = 2, i
write(*, "(a4)", advance="no") ... | Give a code snippet in #Fortran
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/Bernoulli_numbers | Bernoulli numbers | Bernoulli numbers are used in some series expansions of several functions (trigonometric, hyperbolic, gamma, etc.), and are extremely important in number theory and analysis.
Note that there are two definitions of Bernoulli numbers; this task will be using the modern usage (as per The National Institute of S... | #FunL | FunL | import integers.choose
def B( n ) = sum( 1/(k + 1)*sum((if 2|r then 1 else -1)*choose(k, r)*(r^n) | r <- 0..k) | k <- 0..n )
for i <- 0..60 if i == 1 or 2|i
printf( "B(%2d) = %s\n", i, B(i) ) | Give a code snippet in #FunL
Bernoulli numbers are used in some series expansions of several functions (trigonometric, hyperbolic, gamma, etc.), and are extremely important in number theory and analysis.
Note that there are two definitions of Bernoulli numbers; this task will be using the modern usage (as per... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Mutual_recursion | Mutual recursion | Two functions are said to be mutually recursive if the first calls the second,
and in turn the second calls the first.
Write two mutually recursive functions that compute members of the Hofstadter Female and Male sequences defined as:
F
(
0
)
=
1
;
M
(
0
)
=
0
F
(
n
)
=
n
−
M
(
F
(
n
−
1
)
)
,
... | #Io | Io | f := method(n, if( n == 0, 1, n - m(f(n-1))))
m := method(n, if( n == 0, 0, n - f(m(n-1))))
Range
0 to(19) map(n,f(n)) println
0 to(19) map(n,m(n)) println | Give a code snippet in #Io
Two functions are said to be mutually recursive if the first calls the second,
and in turn the second calls the first.
Write two mutually recursive functions that compute members of the Hofstadter Female and Male sequences defined as:
F
(
0
)
=
1
;
M
(
0
)
=
0
F
(
n
)
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sorting_algorithms/Shell_sort | Sorting algorithms/Shell 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
... | #360_Assembly | 360 Assembly | * Shell sort 24/06/2016
SHELLSRT CSECT
USING SHELLSRT,R13 base register
B 72(R15) skip savearea
DC 17F'0' savearea
STM R14,R12,12(R13) prolog
ST R13,4(R15) "
ST R15,8(R13) " ... | Give a code snippet in #360_Assembly
Sorting Algorithm
This is a sorting algorithm. It may be applied to a set of data in order to sort it.
For comparing various sorts, see compare sorts.
For other sorting algorithms, see sorting algorithms, or:
O(n logn) sorts
Heap sort |
Merge sort |
Patience sort |
Q... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Doubly-linked_list/Element_insertion | Doubly-linked list/Element insertion | Doubly-Linked List (element)
This is much like inserting into a Singly-Linked List, but with added assignments so that the backwards-pointing links remain correct.
See also
Array
Associative array: Creation, Iteration
Collections
Compound data type
Doubly-linked list: Definition, Element definition, Element inse... | #Julia | Julia | mutable struct DLNode{T}
value::T
pred::Union{DLNode{T}, Nothing}
succ::Union{DLNode{T}, Nothing}
DLNode(v) = new{typeof(v)}(v, nothing, nothing)
end
function insertpost(prevnode, node)
succ = prevnode.succ
prevnode.succ = node
node.pred = prevnode
node.succ = succ
if succ != nothi... | Give a code snippet in #Julia
Doubly-Linked List (element)
This is much like inserting into a Singly-Linked List, but with added assignments so that the backwards-pointing links remain correct.
See also
Array
Associative array: Creation, Iteration
Collections
Compound data type
Doubly-linked list: Definition, E... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Stern-Brocot_sequence | Stern-Brocot sequence | For this task, the Stern-Brocot sequence is to be generated by an algorithm similar to that employed in generating the Fibonacci sequence.
The first and second members of the sequence are both 1:
1, 1
Start by considering the second member of the sequence
Sum the considered member of the sequence and its prece... | #PL.2FM | PL/M | 100H:
/* FIND LOCATION OF FIRST ELEMENT IN ARRAY */
FIND$FIRST: PROCEDURE (ARR, EL) ADDRESS;
DECLARE (ARR, N) ADDRESS, (EL, A BASED ARR) BYTE;
N = 0;
LOOP:
IF A(N) = EL THEN RETURN N;
ELSE N = N + 1;
GO TO LOOP;
END FIND$FIRST;
/* CP/M CALL */
BDOS: PROCEDURE (FN, ARG);
DECLARE FN BYTE, ARG AD... | Give a code snippet in #PL.2FM
For this task, the Stern-Brocot sequence is to be generated by an algorithm similar to that employed in generating the Fibonacci sequence.
The first and second members of the sequence are both 1:
1, 1
Start by considering the second member of the sequence
Sum the considered memb... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Respond_to_an_unknown_method_call | Respond to an unknown method call | Task
Demonstrate how to make the object respond (sensibly/usefully) to an invocation of a method on it that it does not support through its class definitions.
Note that this is not the same as just invoking a defined method whose name is given dynamically; the method named at the point of invocation must not be defin... | #Io | Io | Example := Object clone do(
foo := method(writeln("this is foo"))
bar := method(writeln("this is bar"))
forward := method(
writeln("tried to handle unknown method ",call message name)
if( call hasArgs,
writeln("it had arguments: ",call evalArgs)
)
)
)
example := Exa... | Give a code snippet in #Io
Task
Demonstrate how to make the object respond (sensibly/usefully) to an invocation of a method on it that it does not support through its class definitions.
Note that this is not the same as just invoking a defined method whose name is given dynamically; the method named at the point of ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Compile-time_calculation | Compile-time calculation | Some programming languages allow calculation of values at compile time.
Task
Calculate 10! (ten factorial) at compile time.
Print the result when the program is run.
Discuss what limitations apply to compile-time calculations in your language.
| #6502_Assembly | 6502 Assembly | ; Display the value of 10!, which is precomputed at assembly time
; on any Commodore 8-bit.
.ifndef __CBM__
.error "Target must be a Commodore system."
.endif
; zero-page work pointer
temp = $fb
; ROM routines used
chrout = $ffd2
.code
lda #<tenfactorial
sta temp
lda #>tenfactori... | Give a code snippet in #6502_Assembly
Some programming languages allow calculation of values at compile time.
Task
Calculate 10! (ten factorial) at compile time.
Print the result when the program is run.
Discuss what limitations apply to compile-time calculations in your language.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Find_duplicate_files | Find duplicate files | In a large directory structure it is easy to inadvertently leave unnecessary copies of files around, which can use considerable disk space and create confusion.
Task
Create a program which, given a minimum size and a folder/directory, will find all files of at least size bytes with duplicate contents under the dire... | #Racket | Racket |
#lang racket
(struct F (name id size [links #:mutable]))
(require openssl/sha1)
(define (find-duplicate-files path size)
(define Fs
(sort
(fold-files
(λ(path type acc)
(define s (and (eq? 'file type) (file-size path)))
(define i (and s (<= size s) (file-or-directory-identity path)... | Give a code snippet in #Racket
In a large directory structure it is easy to inadvertently leave unnecessary copies of files around, which can use considerable disk space and create confusion.
Task
Create a program which, given a minimum size and a folder/directory, will find all files of at least size bytes with d... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Arrays | Arrays | This task is about arrays.
For hashes or associative arrays, please see Creating an Associative Array.
For a definition and in-depth discussion of what an array is, see Array.
Task
Show basic array syntax in your language.
Basically, create an array, assign a value to it, and retrieve an element (if available,... | #D | D | // All D arrays are capable of bounds checks.
import std.stdio, core.stdc.stdlib;
import std.container: Array;
void main() {
// GC-managed heap allocated dynamic array:
auto array1 = new int[1];
array1[0] = 1;
array1 ~= 3; // append a second item
// array1[10] = 4; // run-time error
writeln(... | Give a code snippet in #D
This task is about arrays.
For hashes or associative arrays, please see Creating an Associative Array.
For a definition and in-depth discussion of what an array is, see Array.
Task
Show basic array syntax in your language.
Basically, create an array, assign a value to it, and retrieve ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Greatest_common_divisor | Greatest common divisor | Greatest common divisor
You are encouraged to solve this task according to the task description, using any language you may know.
Task
Find the greatest common divisor (GCD) of two integers.
Greatest common divisor is also known as greatest common factor (gcf) and greatest common measure.
Related tas... | #J | J | x+.y | Give a code snippet in #J
Greatest common divisor
You are encouraged to solve this task according to the task description, using any language you may know.
Task
Find the greatest common divisor (GCD) of two integers.
Greatest common divisor is also known as greatest common factor (gcf) and greatest com... | christopher/rosetta-code | |
http://rosettacode.org/wiki/FASTA_format | FASTA format | In bioinformatics, long character strings are often encoded in a format called FASTA.
A FASTA file can contain several strings, each identified by a name marked by a > (greater than) character at the beginning of the line.
Task
Write a program that reads a FASTA file such as:
>Rosetta_Example_1
THERECANBENOSPACE
... | #Seed7 | Seed7 | $ include "seed7_05.s7i";
const proc: main is func
local
var file: fastaFile is STD_NULL;
var string: line is "";
var boolean: first is TRUE;
begin
fastaFile := open("fasta_format.in", "r");
if fastaFile <> STD_NULL then
while hasNext(fastaFile) do
line := getln(fastaFile);
... | Give a code snippet in #Seed7
In bioinformatics, long character strings are often encoded in a format called FASTA.
A FASTA file can contain several strings, each identified by a name marked by a > (greater than) character at the beginning of the line.
Task
Write a program that reads a FASTA file such as:
>Roset... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Knapsack_problem/Bounded | Knapsack problem/Bounded | A tourist wants to make a good trip at the weekend with his friends.
They will go to the mountains to see the wonders of nature. So he needs some items during the trip. Food, clothing, etc. He has a good knapsack for carrying the things, but he knows that he can carry only 4 kg weight in his knapsack, because th... | #Mathprog | Mathprog | /*Knapsack
This model finds the integer optimal packing of a knapsack
Nigel_Galloway
January 9th., 2012
*/
set Items;
param weight{t in Items};
param value{t in Items};
param quantity{t in Items};
var take{t in Items}, integer, >=0, <=quantity[t];
knap_weight : sum{t in Items} take[t] * weight[t] <= 400;
... | Give a code snippet in #Mathprog
A tourist wants to make a good trip at the weekend with his friends.
They will go to the mountains to see the wonders of nature. So he needs some items during the trip. Food, clothing, etc. He has a good knapsack for carrying the things, but he knows that he can carry only 4 kg ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Ackermann_function | Ackermann function | The Ackermann function is a classic example of a recursive function, notable especially because it is not a primitive recursive function. It grows very quickly in value, as does the size of its call tree.
The Ackermann function is usually defined as follows:
A
(
m
,
n
)
=
{
n
+
1
if
m
=
0
A
(
m
... | #Swift | Swift | func ackerman(m:Int, n:Int) -> Int {
if m == 0 {
return n+1
} else if n == 0 {
return ackerman(m-1, 1)
} else {
return ackerman(m-1, ackerman(m, n-1))
}
} | Give a code snippet in #Swift
The Ackermann function is a classic example of a recursive function, notable especially because it is not a primitive recursive function. It grows very quickly in value, as does the size of its call tree.
The Ackermann function is usually defined as follows:
A
(
m
,
n
)
=
{
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Multiplicative_order | Multiplicative order | The multiplicative order of a relative to m is the least positive integer n such that a^n is 1 (modulo m).
Example
The multiplicative order of 37 relative to 1000 is 100 because 37^100 is 1 (modulo 1000), and no number smaller than 100 would do.
One possible algorithm that is efficient also for large numbers is ... | #zkl | zkl | var BN =Import("zklBigNum");
var Sieve=Import("sieve");
// factor n into powers of primes
// eg 9090 == 2^1 * 3^2 * 5^1 * 101^1
fcn factor2PP(n){ // lazy factors using lazy primes --> (prime,power) ...
Utils.Generator(fcn(a){
primes:=Utils.Generator(Sieve.postponed_sieve);
foreach p in (prime... | Give a code snippet in #zkl
The multiplicative order of a relative to m is the least positive integer n such that a^n is 1 (modulo m).
Example
The multiplicative order of 37 relative to 1000 is 100 because 37^100 is 1 (modulo 1000), and no number smaller than 100 would do.
One possible algorithm that is efficie... | christopher/rosetta-code | |
http://rosettacode.org/wiki/GUI_component_interaction | GUI component interaction |
Almost every application needs to communicate with the user in some way.
Therefore, a substantial part of the code deals with the interaction
of program logic with GUI components.
Typically, the following is needed:
put values into input fields under program control
read and check input from the user
pop up dial... | #Scala | Scala | import scala.swing._
import scala.swing.Swing._
import scala.swing.event._
object Interact extends SimpleSwingApplication {
def top = new MainFrame {
title = "Rosetta Code >>> Task: component interaction | Language: Scala"
val numberField = new TextField {
text = "0" // start at 0
horizontalAl... | Give a code snippet in #Scala
Almost every application needs to communicate with the user in some way.
Therefore, a substantial part of the code deals with the interaction
of program logic with GUI components.
Typically, the following is needed:
put values into input fields under program control
read and check i... | christopher/rosetta-code | |
http://rosettacode.org/wiki/XML/XPath | XML/XPath | Perform the following three XPath queries on the XML Document below:
//item[1]: Retrieve the first "item" element
//price/text(): Perform an action on each "price" element (print it out)
//name: Get an array of all the "name" elements
XML Document:
<inventory title="OmniCorp Store #45x10^3">
<section name="heal... | #ARM_Assembly | ARM Assembly |
/* ARM assembly Raspberry PI */
/* program xpathXml.s */
/* Constantes */
.equ STDOUT, 1 @ Linux output console
.equ EXIT, 1 @ Linux syscall
.equ WRITE, 4 @ Linux syscall
.equ NBMAXELEMENTS, 100
/*******************************************/
/* Structures */... | Give a code snippet in #ARM_Assembly
Perform the following three XPath queries on the XML Document below:
//item[1]: Retrieve the first "item" element
//price/text(): Perform an action on each "price" element (print it out)
//name: Get an array of all the "name" elements
XML Document:
<inventory title="OmniCorp ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Parameterized_SQL_statement | Parameterized SQL statement | SQL injection
Using a SQL update statement like this one (spacing is optional):
UPDATE players
SET name = 'Smith, Steve', score = 42, active = TRUE
WHERE jerseyNum = 99
Non-parameterized SQL is the GoTo statement of database programming. Don't do it, and make sure your coworkers don't either. | #Python | Python | import sqlite3
db = sqlite3.connect(':memory:')
# setup
db.execute('create temp table players (name, score, active, jerseyNum)')
db.execute('insert into players values ("name",0,"false",99)')
db.execute('insert into players values ("name",0,"false",100)')
# demonstrate parameterized SQL
# example 1 -- simple pl... | Give a code snippet in #Python
SQL injection
Using a SQL update statement like this one (spacing is optional):
UPDATE players
SET name = 'Smith, Steve', score = 42, active = TRUE
WHERE jerseyNum = 99
Non-parameterized SQL is the GoTo statement of database programming. Don't do it, and make sure your coworkers d... | 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 |... | #Aime | Aime | text s;
data b, d;
s = "The quick brown fox jumps over the lazy dog.";
o_text(cut(s, 4, 15));
o_newline();
o_text(cut(s, 4, length(s)));
o_newline();
o_text(delete(s, -1));
o_newline();
o_text(cut(s, index(s, 'q'), 5));
o_newline();
b_cast(b, s);
b_cast(d, "brown");
o_text(cut(s, b_find(b, d), 15));
o_newline(); | Give a code snippet in #Aime
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/Perfect_shuffle | Perfect shuffle | A perfect shuffle (or faro/weave shuffle) means splitting a deck of cards into equal halves, and perfectly interleaving them - so that you end up with the first card from the left half, followed by the first card from the right half, and so on:
7♠ 8♠ 9♠ J♠ Q♠ K♠→7♠ 8♠ 9♠
J♠ Q♠ K♠→7♠ J♠ 8♠ Q♠ 9♠ K♠
When you ... | #jq | jq | def perfect_shuffle:
. as $a
| if (length % 2) == 1 then "cannot perform perfect shuffle on odd-length array" | error
else (length / 2) as $mid
| reduce range(0; $mid) as $i (null;
.[2*$i] = $a[$i]
| .[2*$i + 1] = $a[$mid+$i] )
end;
# How many iterations of f are required to get back to... | Give a code snippet in #jq
A perfect shuffle (or faro/weave shuffle) means splitting a deck of cards into equal halves, and perfectly interleaving them - so that you end up with the first card from the left half, followed by the first card from the right half, and so on:
7♠ 8♠ 9♠ J♠ Q♠ K♠→7♠ 8♠ 9♠
J♠ Q♠ K♠→7... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Grayscale_image | Grayscale image | Many image processing algorithms are defined for grayscale (or else monochromatic) images.
Task
Extend the data storage type defined on this page to support grayscale images.
Define two operations, one to convert a color image to a grayscale image and one for the backward conversion.
To get luminance of a color u... | #REXX | REXX | /*REXX program converts a RGB (red─green─blue) image into a grayscale/greyscale image.*/
blue= '00 00 ff'x /*define the blue color (hexadecimal).*/
@.= blue /*set the entire image to blue color.*/
width= 60 ... | Give a code snippet in #REXX
Many image processing algorithms are defined for grayscale (or else monochromatic) images.
Task
Extend the data storage type defined on this page to support grayscale images.
Define two operations, one to convert a color image to a grayscale image and one for the backward conversion.
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/XML/Output | XML/Output | Create a function that takes a list of character names and a list of corresponding remarks and returns an XML document of <Character> elements each with a name attributes and each enclosing its remarks.
All <Character> elements are to be enclosed in turn, in an outer <CharacterRemarks> element.
As an example, calling ... | #Action.21 | Action! | DEFINE PTR="CARD"
DEFINE CHARACTER_SIZE="4"
TYPE Character=[PTR name,remark]
PTR FUNC GetCharacterPointer(BYTE ARRAY d INT index)
RETURN (d+index*CHARACTER_SIZE)
PROC SetCharacter(BYTE ARRAY d INT index CHAR ARRAY n,r)
Character POINTER ch
ch=GetCharacterPointer(d,index)
ch.name=n
ch.remark=r
RETURN
PRO... | Give a code snippet in #Action.21
Create a function that takes a list of character names and a list of corresponding remarks and returns an XML document of <Character> elements each with a name attributes and each enclosing its remarks.
All <Character> elements are to be enclosed in turn, in an outer <CharacterRemarks... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Self_numbers | Self numbers | A number n is a self number if there is no number g such that g + the sum of g's digits = n. So 18 is not a self number because 9+9=18, 43 is not a self number because 35+5+3=43.
The task is:
Display the first 50 self numbers;
I believe that the 100000000th self number is 1022727208. You should either confirm or d... | #Elixir | Elixir |
defmodule SelfNums do
def digAndSum(number) when is_number(number) do
Integer.digits(number) |>
Enum.reduce( 0, fn(num, acc) -> num + acc end ) |>
(fn(x) -> x + number end).()
end
def selfFilter(list, firstNth) do
numRange = Enum.to_list 1..firstNth
numRange -- list
end
end
defmod... | Give a code snippet in #Elixir
A number n is a self number if there is no number g such that g + the sum of g's digits = n. So 18 is not a self number because 9+9=18, 43 is not a self number because 35+5+3=43.
The task is:
Display the first 50 self numbers;
I believe that the 100000000th self number is 1022727208... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Shoelace_formula_for_polygonal_area | Shoelace formula for polygonal area | Given the n + 1 vertices x[0], y[0] .. x[N], y[N] of a simple polygon described in a clockwise direction, then the polygon's area can be calculated by:
abs( (sum(x[0]*y[1] + ... x[n-1]*y[n]) + x[N]*y[0]) -
(sum(x[1]*y[0] + ... x[n]*y[n-1]) + x[0]*y[N])
) / 2
(Where abs returns the absolute value)
Task
Write ... | #ALGOL_60 | ALGOL 60 | begin
comment Shoelace formula for polygonal area - Algol 60;
real array x[1:33],y[1:33];
integer i,n;
real a;
ininteger(0,n);
for i:=1 step 1 until n do
begin
inreal(0,x[i]);
inreal(0,y[i])
end;
x[i]:=x[1];
y[i]:=y[1];
a:=0;
for i:=1 step 1 until n do
... | Give a code snippet in #ALGOL_60
Given the n + 1 vertices x[0], y[0] .. x[N], y[N] of a simple polygon described in a clockwise direction, then the polygon's area can be calculated by:
abs( (sum(x[0]*y[1] + ... x[n-1]*y[n]) + x[N]*y[0]) -
(sum(x[1]*y[0] + ... x[n]*y[n-1]) + x[0]*y[N])
) / 2
(Where abs returns... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Fibonacci_sequence | Fibonacci sequence | The Fibonacci sequence is a sequence Fn of natural numbers defined recursively:
F0 = 0
F1 = 1
Fn = Fn-1 + Fn-2, if n>1
Task
Write a function to generate the nth Fibonacci number.
Solutions can be iterative or recursive (though recursive solutions are generally considered too slow ... | #PL.2FSQL | PL/SQL |
CREATE OR REPLACE FUNCTION fnu_fibonacci(p_num INTEGER) RETURN INTEGER IS
f INTEGER;
p INTEGER;
q INTEGER;
BEGIN
CASE WHEN p_num < 0 OR p_num != TRUNC(p_num)
THEN raise_application_error(-20001, 'Invalid input: ' || p_num, TRUE);
WHEN p_num IN (0, 1) THEN f := p_num;
... | Give a code snippet in #PL.2FSQL
The Fibonacci sequence is a sequence Fn of natural numbers defined recursively:
F0 = 0
F1 = 1
Fn = Fn-1 + Fn-2, if n>1
Task
Write a function to generate the nth Fibonacci number.
Solutions can be iterative or recursive (though recursive solutions ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Case-sensitivity_of_identifiers | Case-sensitivity of identifiers | Three dogs (Are there three dogs or one dog?) is a code snippet used to illustrate the lettercase sensitivity of the programming language. For a case-sensitive language, the identifiers dog, Dog and DOG are all different and we should get the output:
The three dogs are named Benjamin, Samba and Bernie.
For a language... | #Gambas | Gambas | Public Sub Main()
Dim dog As String
Dog = "Benjamin"
DOG = "Samba"
dog = "Bernie"
Print "There is just one dog, named "; dog
End | Give a code snippet in #Gambas
Three dogs (Are there three dogs or one dog?) is a code snippet used to illustrate the lettercase sensitivity of the programming language. For a case-sensitive language, the identifiers dog, Dog and DOG are all different and we should get the output:
The three dogs are named Benjamin, S... | 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
| #M2000_Interpreter | M2000 Interpreter |
Module CheckIt {
Function StdDev (A()) {
\\ A() has a copy of values
N=Len(A())
if N<1 then Error "Empty Array"
M=Each(A())
k=0
\\ make sum, dev same type as A(k)
sum=A(k)-A(k)
dev=sum
\\ find mean
... | Give a code snippet in #M2000_Interpreter
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... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Number_names | Number names | Task
Show how to spell out a number in English.
You can use a preexisting implementation or roll your own, but you should support inputs up to at least one million (or the maximum value of your language's default bounded integer type, if that's less).
Support for inputs other than positive integers (like zero, negat... | #Haskell | Haskell | import Data.List (intercalate, unfoldr)
spellInteger :: Integer -> String
spellInteger n
| n < 0 = "negative " ++ spellInteger (-n)
| n < 20 = small n
| n < 100 = let (a, b) = n `divMod` 10
in tens a ++ nonzero '-' b
| n < 1000 = let (a, b) = n `divMod` 100
in small a ++ ... | Give a code snippet in #Haskell
Task
Show how to spell out a number in English.
You can use a preexisting implementation or roll your own, but you should support inputs up to at least one million (or the maximum value of your language's default bounded integer type, if that's less).
Support for inputs other than po... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Enumerations | Enumerations | Task
Create an enumeration of constants with and without explicit values.
| #Kotlin | Kotlin | // version 1.0.5-2
enum class Animals {
CAT, DOG, ZEBRA
}
enum class Dogs(val id: Int) {
BULLDOG(1), TERRIER(2), WOLFHOUND(4)
}
fun main(args: Array<String>) {
for (value in Animals.values()) println("${value.name.padEnd(5)} : ${value.ordinal}")
println()
for (value in Dogs.values()) println("... | Give a code snippet in #Kotlin
Task
Create an enumeration of constants with and without explicit values.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Determinant_and_permanent | Determinant and permanent | For a given matrix, return the determinant and the permanent of the matrix.
The determinant is given by
det
(
A
)
=
∑
σ
sgn
(
σ
)
∏
i
=
1
n
M
i
,
σ
i
{\displaystyle \det(A)=\sum _{\sigma }\operatorname {sgn}(\sigma )\prod _{i=1}^{n}M_{i,\sigma _{i}}}
while the permanent is given by
... | #PARI.2FGP | PARI/GP | matdet(M) | Give a code snippet in #PARI.2FGP
For a given matrix, return the determinant and the permanent of the matrix.
The determinant is given by
det
(
A
)
=
∑
σ
sgn
(
σ
)
∏
i
=
1
n
M
i
,
σ
i
{\displaystyle \det(A)=\sum _{\sigma }\operatorname {sgn}(\sigma )\prod _{i=1}^{n}M_{i,\sigma _{i}}}
whi... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Empty_string | Empty string | Languages may have features for dealing specifically with empty strings
(those containing no characters).
Task
Demonstrate how to assign an empty string to a variable.
Demonstrate how to check that a string is empty.
Demonstrate how to check that a string is not empty.
Other tasks related to string oper... | #Nyquist | Nyquist |
(setf emptystring "") ;binds variable'emptystring' to the empty string ""
(let ((emptystring "")) ;; Binds local variable 'emptystring' to the empty string ""
(when (string-equal emptystring "") ;;case insensitive string comparison
(print "Is an empty string")) ;;bad argument error if not a string
(when (... | Give a code snippet in #Nyquist
Languages may have features for dealing specifically with empty strings
(those containing no characters).
Task
Demonstrate how to assign an empty string to a variable.
Demonstrate how to check that a string is empty.
Demonstrate how to check that a string is not empty.
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... | #PARI.2FGP | PARI/GP | g = List(1); \\ generator stack
genpow(p) = my(a=g[1]++);listput(g,[0,p]);()->g[a][1]++^g[a][2];
genpowf(p,f) = my(a=g[1]++);listput(g,[0,p]);(s=0)->my(q);while(ispower(p=g[a][1]++^g[a][2],f)||(s&&q++<=s),);p; | Give a code snippet in #PARI.2FGP
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 t... | christopher/rosetta-code | |
http://rosettacode.org/wiki/MD5 | MD5 | Task
Encode a string using an MD5 algorithm. The algorithm can be found on Wikipedia.
Optionally, validate your implementation by running all of the test values in IETF RFC (1321) for MD5.
Additionally, RFC 1321 provides more precise information on the algorithm than the Wikipedia article.
Warning:... | #PowerShell | PowerShell | $string = "The quick brown fox jumped over the lazy dog's back"
$data = [Text.Encoding]::UTF8.GetBytes($string)
$hash = [Security.Cryptography.MD5]::Create().ComputeHash($data)
([BitConverter]::ToString($hash) -replace '-').ToLower() | Give a code snippet in #PowerShell
Task
Encode a string using an MD5 algorithm. The algorithm can be found on Wikipedia.
Optionally, validate your implementation by running all of the test values in IETF RFC (1321) for MD5.
Additionally, RFC 1321 provides more precise information on the algorithm than... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Digital_root/Multiplicative_digital_root | Digital root/Multiplicative digital root | The multiplicative digital root (MDR) and multiplicative persistence (MP) of a number,
n
{\displaystyle n}
, is calculated rather like the Digital root except digits are multiplied instead of being added:
Set
m
{\displaystyle m}
to
n
{\displaystyle n}
and
i
{\displaystyle i}
to
0
... | #FreeBASIC | FreeBASIC | ' FB 1.05.0 Win64
Function multDigitalRoot(n As UInteger, ByRef mp As Integer, base_ As Integer = 10) As Integer
Dim mdr As Integer
mp = 0
Do
mdr = IIf(n > 0, 1, 0)
While n > 0
mdr *= n Mod base_
n = n \ base_
Wend
mp += 1
n = mdr
Loop until mdr < base_
Return mdr
End Funct... | Give a code snippet in #FreeBASIC
The multiplicative digital root (MDR) and multiplicative persistence (MP) of a number,
n
{\displaystyle n}
, is calculated rather like the Digital root except digits are multiplied instead of being added:
Set
m
{\displaystyle m}
to
n
{\displaystyle n}
and
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Active_Directory/Search_for_a_user | Active Directory/Search for a user | Make sure you Connect to Active Directory
| #Scala | Scala | import org.apache.directory.api.ldap.model.message.SearchScope
import org.apache.directory.ldap.client.api.{LdapConnection, LdapNetworkConnection}
object LdapSearchDemo extends App {
class LdapSearch {
def demonstrateSearch(): Unit = {
val conn = new LdapNetworkConnection("localhost", 11389)
t... | Give a code snippet in #Scala
Make sure you Connect to Active Directory
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Ulam_spiral_(for_primes) | Ulam spiral (for primes) | An Ulam spiral (of primes) is a method of visualizing primes when expressed in a (normally counter-clockwise) outward spiral (usually starting at 1), constructed on a square grid, starting at the "center".
An Ulam spiral is also known as a prime spiral.
The first grid (green) is shown with sequential integers, ... | #ERRE | ERRE | PROGRAM SPIRAL
!$INTEGER
CONST RIGHT=1,UP=2,LEFT=3,DOWN=4
!$DYNAMIC
DIM SPIRAL$[0,0]
PROCEDURE PRT_ULAM(N)
FOR ROW=0 TO N DO
FOR COL=0 TO N DO
PRINT(SPIRAL$[ROW,COL];)
END FOR
PRINT
END FOR
PRINT
GET(K$)
FOR ROW=0 TO N DO
FOR COL=0 TO N DO
IF VAL(SPIRAL$[ROW,COL])<>0 TH... | Give a code snippet in #ERRE
An Ulam spiral (of primes) is a method of visualizing primes when expressed in a (normally counter-clockwise) outward spiral (usually starting at 1), constructed on a square grid, starting at the "center".
An Ulam spiral is also known as a prime spiral.
The first grid (green) is show... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Loops/Infinite | Loops/Infinite | Task
Print out SPAM followed by a newline in an infinite loop.
Related tasks
Loop over multiple arrays simultaneously
Loops/Break
Loops/Continue
Loops/Do-while
Loops/Downward for
Loops/For
Loops/For with a specified step
Loops/Foreach
Loops/Increment loop index within l... | #Slate | Slate | [inform: 'SPAM'] loop | Give a code snippet in #Slate
Task
Print out SPAM followed by a newline in an infinite loop.
Related tasks
Loop over multiple arrays simultaneously
Loops/Break
Loops/Continue
Loops/Do-while
Loops/Downward for
Loops/For
Loops/For with a specified step
Loops/Foreach
Loop... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Bitmap/Bresenham%27s_line_algorithm | Bitmap/Bresenham's line algorithm | Task
Using the data storage type defined on the Bitmap page for raster graphics images,
draw a line given two points with Bresenham's line algorithm.
| #Korn_Shell | Korn Shell | function line {
x0=$1; y0=$2 x1=$3; y1=$4
if (( x0 > x1 ))
then
((dx = x0 - x1)); ((sx = -1))
else
((dx = x1 - x0)); ((sx = 1))
fi
if (( y0 > y1 ))
then
((dy = y0 - y1)); ((sy = -1))
else
... | Give a code snippet in #Korn_Shell
Task
Using the data storage type defined on the Bitmap page for raster graphics images,
draw a line given two points with Bresenham's line algorithm.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Strong_and_weak_primes | Strong and weak primes |
Definitions (as per number theory)
The prime(p) is the pth prime.
prime(1) is 2
prime(4) is 7
A strong prime is when prime(p) is > [prime(p-1) + prime(p+1)] ÷ 2
A weak prime is when prime(p) is < [prime(p-1) + prime(p+1)] ÷ 2
Note that the defin... | #Go | Go | package main
import "fmt"
func sieve(limit int) []bool {
limit++
// True denotes composite, false denotes prime.
// Don't bother marking even numbers >= 4 as composite.
c := make([]bool, limit)
c[0] = true
c[1] = true
p := 3 // start from 3
for {
p2 := p * p
if p2 >... | Give a code snippet in #Go
Definitions (as per number theory)
The prime(p) is the pth prime.
prime(1) is 2
prime(4) is 7
A strong prime is when prime(p) is > [prime(p-1) + prime(p+1)] ÷ 2
A weak prime is when prime(p) is < [prime(p-1) + prime(p+1... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Van_der_Corput_sequence | Van der Corput sequence | When counting integers in binary, if you put a (binary) point to the righEasyLangt of the count then the column immediately to the left denotes a digit with a multiplier of
2
0
{\displaystyle 2^{0}}
; the digit in the next column to the left has a multiplier of
2
1
{\displaystyle 2^{1}}
; and so o... | #C.23 | C# |
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
namespace VanDerCorput
{
/// <summary>
/// Computes the Van der Corput sequence for any number base.
/// The numbers in the sequence vary from zero to one, including zero but excluding one.
/// The sequence possess... | Give a code snippet in #C.23
When counting integers in binary, if you put a (binary) point to the righEasyLangt of the count then the column immediately to the left denotes a digit with a multiplier of
2
0
{\displaystyle 2^{0}}
; the digit in the next column to the left has a multiplier of
2
1
{\d... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Substring/Top_and_tail | Substring/Top and tail | The task is to demonstrate how to remove the first and last characters from a string.
The solution should demonstrate how to obtain the following results:
String with first character removed
String with last character removed
String with both the first and last characters removed
If the program uses UTF-8 or UTF... | #COBOL | COBOL | identification division.
program-id. toptail.
data division.
working-storage section.
01 data-field.
05 value "[this is a test]".
procedure division.
sample-main.
display data-field
*> Using reference modification, which is (start-position:leng... | Give a code snippet in #COBOL
The task is to demonstrate how to remove the first and last characters from a string.
The solution should demonstrate how to obtain the following results:
String with first character removed
String with last character removed
String with both the first and last characters removed
I... | 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... | #Seed7 | Seed7 | const proc: generate_swap (in type: aType) is func
begin
const proc: swap (inout aType: left, inout aType: right) is func
local
var aType: temp is aType.value;
begin
temp := left;
left := right;
right := temp;
end func;
end func; | Give a code snippet in #Seed7
Task
Write a generic swap function or operator which exchanges the values of two variables (or, more generally, any two storage places that can be assigned), regardless of their types.
If your solution language is statically typed please describe the way your language provides genericit... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Compile-time_calculation | Compile-time calculation | Some programming languages allow calculation of values at compile time.
Task
Calculate 10! (ten factorial) at compile time.
Print the result when the program is run.
Discuss what limitations apply to compile-time calculations in your language.
| #PicoLisp | PicoLisp | (de fact (N)
(apply * (range 1 N)) )
(de foo ()
(prinl "The value of fact(10) is " `(fact 10)) ) | Give a code snippet in #PicoLisp
Some programming languages allow calculation of values at compile time.
Task
Calculate 10! (ten factorial) at compile time.
Print the result when the program is run.
Discuss what limitations apply to compile-time calculations in your language.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Greatest_common_divisor | Greatest common divisor | Greatest common divisor
You are encouraged to solve this task according to the task description, using any language you may know.
Task
Find the greatest common divisor (GCD) of two integers.
Greatest common divisor is also known as greatest common factor (gcf) and greatest common measure.
Related tas... | #Bc | Bc | define even(a)
{
if ( a % 2 == 0 ) {
return(1);
} else {
return(0);
}
}
define abs(a)
{
if (a<0) {
return(-a);
} else {
return(a);
}
} | Give a code snippet in #Bc
Greatest common divisor
You are encouraged to solve this task according to the task description, using any language you may know.
Task
Find the greatest common divisor (GCD) of two integers.
Greatest common divisor is also known as greatest common factor (gcf) and greatest co... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Respond_to_an_unknown_method_call | Respond to an unknown method call | Task
Demonstrate how to make the object respond (sensibly/usefully) to an invocation of a method on it that it does not support through its class definitions.
Note that this is not the same as just invoking a defined method whose name is given dynamically; the method named at the point of invocation must not be defin... | #Lasso | Lasso | define exampletype => type {
public foo() => {
return 'this is foo\r'
}
public bar() => {
return 'this is bar\r'
}
public _unknownTag(...) => {
local(n = method_name->asString)
return 'tried to handle unknown method called "'+#n+'"'+
(#rest->size ? ' with args: "'+#rest->join(',')+'"')+'\r'
}
}
local... | Give a code snippet in #Lasso
Task
Demonstrate how to make the object respond (sensibly/usefully) to an invocation of a method on it that it does not support through its class definitions.
Note that this is not the same as just invoking a defined method whose name is given dynamically; the method named at the point ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Subtractive_generator | Subtractive generator | A subtractive generator calculates a sequence of random numbers, where each number is congruent to the subtraction of two previous numbers from the sequence.
The formula is
r
n
=
r
(
n
−
i
)
−
r
(
n
−
j
)
(
mod
m
)
{\displaystyle r_{n}=r_{(n-i)}-r_{(n-j)}{\pmod {m}}}
for some fixed values of... | #jq | jq | # If $p is null, then call `subrand`,
# which sets .x as the PRN and which expects the the input to
# be the PRNG state, which is updated.
def subrandSeed($p):
def subrand:
if (.si == .sj) then subrandSeed(0) else . end
| .si |= (if . == 0 then 54 else . - 1 end)
| .sj |= (if . == 0 then 54 else . - 1... | Give a code snippet in #jq
A subtractive generator calculates a sequence of random numbers, where each number is congruent to the subtraction of two previous numbers from the sequence.
The formula is
r
n
=
r
(
n
−
i
)
−
r
(
n
−
j
)
(
mod
m
)
{\displaystyle r_{n}=r_{(n-i)}-r_{(n-j)}{\pmod {m}}... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Time_a_function | Time a function | Task
Write a program which uses a timer (with the least granularity available
on your system) to time how long a function takes to execute.
Whenever possible, use methods which measure only the processing time used
by the current process; instead of the difference in system time
between start and finish, which could ... | #PARI.2FGP | PARI/GP | time(foo)={
foo();
gettime();
} | Give a code snippet in #PARI.2FGP
Task
Write a program which uses a timer (with the least granularity available
on your system) to time how long a function takes to execute.
Whenever possible, use methods which measure only the processing time used
by the current process; instead of the difference in system time
bet... | christopher/rosetta-code | |
http://rosettacode.org/wiki/First-class_functions | First-class functions | A language has first-class functions if it can do each of the following without recursively invoking a compiler or interpreter or otherwise metaprogramming:
Create new functions from preexisting functions at run-time
Store functions in collections
Use functions as arguments to other functions
Use functions as retu... | #Slate | Slate | m@(Method traits) ** n@(Method traits)
"Answers a new Method whose effect is that of calling the first method
on the results of the second method applied to whatever arguments are passed.
This composition is associative, i.e. (a ** b) ** c = a ** (b ** c).
When the second method, n, does not take a *rest option or the ... | Give a code snippet in #Slate
A language has first-class functions if it can do each of the following without recursively invoking a compiler or interpreter or otherwise metaprogramming:
Create new functions from preexisting functions at run-time
Store functions in collections
Use functions as arguments to other f... | christopher/rosetta-code | |
http://rosettacode.org/wiki/System_time | System time | Task
Output the system time (any units will do as long as they are noted) either by a system command or one built into the language.
The system time can be used for debugging, network information, random number seeds, or something as simple as program performance.
Related task
Date format
See also
Retr... | #Prolog | Prolog | date_time(H). | Give a code snippet in #Prolog
Task
Output the system time (any units will do as long as they are noted) either by a system command or one built into the language.
The system time can be used for debugging, network information, random number seeds, or something as simple as program performance.
Related task
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Set_puzzle | Set puzzle | Set Puzzles are created with a deck of cards from the Set Game™. The object of the puzzle is to find sets of 3 cards in a rectangle of cards that have been dealt face up.
There are 81 cards in a deck.
Each card contains a unique variation of the following four features: color, symbol, number and shading.
there are... | #C.23 | C# | using System;
using System.Collections.Generic;
using static System.Linq.Enumerable;
public static class SetPuzzle
{
static readonly Feature[] numbers = { (1, "One"), (2, "Two"), (3, "Three") };
static readonly Feature[] colors = { (1, "Red"), (2, "Green"), (3, "Purple") };
static readonly Feature[] sh... | Give a code snippet in #C.23
Set Puzzles are created with a deck of cards from the Set Game™. The object of the puzzle is to find sets of 3 cards in a rectangle of cards that have been dealt face up.
There are 81 cards in a deck.
Each card contains a unique variation of the following four features: color, symbol, n... | christopher/rosetta-code | |
http://rosettacode.org/wiki/String_case | String case | Task
Take the string alphaBETA and demonstrate how to convert it to:
upper-case and
lower-case
Use the default encoding of a string literal or plain ASCII if there is no string literal in your language.
Note: In some languages alphabets toLower and toUpper is not reversable.
Show any additional... | #Lua | Lua | str = "alphaBETA"
print( string.upper(str) )
print( string.lower(str) ) | Give a code snippet in #Lua
Task
Take the string alphaBETA and demonstrate how to convert it to:
upper-case and
lower-case
Use the default encoding of a string literal or plain ASCII if there is no string literal in your language.
Note: In some languages alphabets toLower and toUpper is not rev... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Terminal_control/Dimensions | Terminal control/Dimensions | Determine the height and width of the terminal, and store this information into variables for subsequent use.
| #Scala | Scala | /*
First execute the terminal command: 'export COLUMNS LINES'
before running this program for it to work (returned 'null' sizes otherwise).
*/
val (lines, columns) = (System.getenv("LINES"), System.getenv("COLUMNS"))
println(s"Lines = $lines, Columns = $columns") | Give a code snippet in #Scala
Determine the height and width of the terminal, and store this information into variables for subsequent use.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/JortSort | JortSort |
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
fun <T> jortSort(a: Array<T>): Boolean {
val b = a.copyOf()
b.sort()
for (i in 0 until a.size)
if (a[i] != b[i]) return false
return true
}
fun <T> printResults(a: Array<T>) {
println(a.joinToString(" ") + " => " + if (jortSort(a)) "sorted" else "not sorted")
}
fun mai... | 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/Colour_bars/Display | Colour bars/Display | Task
Display a series of vertical color bars across the width of the display.
The color bars should either use:
the system palette, or
the sequence of colors:
black
red
green
blue
magenta
cyan
yellow
white
| #Maple | Maple |
with(plottools):
plots:-display([rectangle([0, 0], [.3, 2.1], color = black), rectangle([.3, 0], [.6, 2.1], color = red), rectangle([.6, 0], [.9, 2.1], color = green), rectangle([.9, 0], [1.2, 2.1], color = magenta), rectangle([1.2, 0], [1.5, 2.1], color = cyan), rectangle([1.5, 0], [1.8, 2.1], color = white), rectan... | Give a code snippet in #Maple
Task
Display a series of vertical color bars across the width of the display.
The color bars should either use:
the system palette, or
the sequence of colors:
black
red
green
blue
magenta
cyan
yellow
white
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Chaocipher | Chaocipher | Description
The Chaocipher was invented by J.F.Byrne in 1918 and, although simple by modern cryptographic standards, does not appear to have been broken until the algorithm was finally disclosed by his family in 2010.
The algorithm is described in this paper by M.Rubin in 2010 and there is a C# implementation here.
... | #Wren | Wren | class Chao {
static encrypt { 0 }
static decrypt { 1 }
static exec(text, mode, showSteps) {
var len = text.count
if (len != text.bytes.count) Fiber.abort("Text contains non-ASCII characters.")
var left = "HXUCZVAMDSLKPEFJRIGTWOBNYQ"
var right = "PTLNBQDEOYSFAVZKGJRIHWXUMC"... | Give a code snippet in #Wren
Description
The Chaocipher was invented by J.F.Byrne in 1918 and, although simple by modern cryptographic standards, does not appear to have been broken until the algorithm was finally disclosed by his family in 2010.
The algorithm is described in this paper by M.Rubin in 2010 and there ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sudoku | Sudoku | Task
Solve a partially filled-in normal 9x9 Sudoku grid and display the result in a human-readable format.
references
Algorithmics of Sudoku may help implement this.
Python Sudoku Solver Computerphile video.
| #Stata | Stata | mata
function sudoku(a) {
s = J(81,20,.)
t = J(81,3,.)
v = J(81,9,1)
w = J(81,1,0)
for (i=1; i<=9; i++) {
for (j=1; j<=9; j++) {
n = (i-1)*9+j
k = floor((i-1)/3)*3+floor((j-1)/3)+1
t[n,.] = i,j,k
}
}
for (i=1; i<=81; i++) {
for (j=i+1; j<=81; j++) {
if (any(t[i,.]:==t[j,.])) {
w[i]=w[i]+1
... | Give a code snippet in #Stata
Task
Solve a partially filled-in normal 9x9 Sudoku grid and display the result in a human-readable format.
references
Algorithmics of Sudoku may help implement this.
Python Sudoku Solver Computerphile video.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Calculating_the_value_of_e | Calculating the value of e | Task
Calculate the value of e.
(e is also known as Euler's number and Napier's constant.)
See details: Calculating the value of e
| #min | min | (:n (n 0 ==) ((0)) (-1 () ((succ dup) dip append) n times) if) :iota
(iota 'succ '* map-reduce) :factorial
20 iota (factorial 1 swap /) '+ map-reduce print | Give a code snippet in #min
Task
Calculate the value of e.
(e is also known as Euler's number and Napier's constant.)
See details: Calculating the value of e
| 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... | #LiveCode | LiveCode | repeat with i = 1 to 1000
add 1/(i^2) to summ
end repeat
put summ //1.643935 | Give a code snippet in #LiveCode
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
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Roots_of_a_function | Roots of a function | Task
Create a program that finds and outputs the roots of a given function, range and (if applicable) step width.
The program should identify whether the root is exact or approximate.
For this task, use: ƒ(x) = x3 - 3x2 + 2x
| #Maple | Maple | f := x^3-3*x^2+2*x;
roots(f,x); | Give a code snippet in #Maple
Task
Create a program that finds and outputs the roots of a given function, range and (if applicable) step width.
The program should identify whether the root is exact or approximate.
For this task, use: ƒ(x) = x3 - 3x2 + 2x
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Return_multiple_values | Return multiple values | Task
Show how to return more than one value from a function.
| #Go | Go | func addsub(x, y int) (int, int) {
return x + y, x - y
} | Give a code snippet in #Go
Task
Show how to return more than one value from a function.
| 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... | #MiniScript | MiniScript | entropy = function(s)
count = {}
for c in s
if count.hasIndex(c) then count[c] = count[c]+1 else count[c] = 1
end for
sum = 0
for x in count.values
countOverN = x / s.len
sum = sum + countOverN * log(countOverN, 2)
end for
return -sum
end function
print entropy("122... | Give a code snippet in #MiniScript
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/Function_composition | Function composition | Task
Create a function, compose, whose two arguments f and g, are both functions with one argument.
The result of compose is to be a function of one argument, (lets call the argument x), which works like applying function f to the result of applying function g to x.
Example
compose... | #Order | Order | #include <order/interpreter.h>
#define ORDER_PP_DEF_8comp ORDER_PP_FN( \
8fn(8F, 8G, 8fn(8X, 8ap(8F, 8ap(8G, 8X)))) ) | Give a code snippet in #Order
Task
Create a function, compose, whose two arguments f and g, are both functions with one argument.
The result of compose is to be a function of one argument, (lets call the argument x), which works like applying function f to the result of applying function g ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/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... | #Raku | Raku | my $months-per-row = 3;
my @weekday-names = <Mo Tu We Th Fr Sa Su>;
my @month-names = <Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec>;
my Int() $year = @*ARGS.shift || 1969;
say fmt-year($year);
sub fmt-year ($year) {
my @month-strs;
@month-strs[$_] = [fmt-month($year, $_).lines] for 1 .. 12;
my @... | Give a code snippet in #Raku
Create a routine that will generate a text calendar for any year.
Test the calendar by generating a calendar for the year 1969, on a device of the time.
Choose one of the following devices:
A line printer with a width of 132 characters.
An IBM 3278 model 4 terminal (80×43 display with a... | christopher/rosetta-code | |
http://rosettacode.org/wiki/MD5 | MD5 | Task
Encode a string using an MD5 algorithm. The algorithm can be found on Wikipedia.
Optionally, validate your implementation by running all of the test values in IETF RFC (1321) for MD5.
Additionally, RFC 1321 provides more precise information on the algorithm than the Wikipedia article.
Warning:... | #PARI.2FGP | PARI/GP | #include <pari/pari.h>
#include <openssl/md5.h>
#define HEX(x) (((x) < 10)? (x)+'0': (x)-10+'a')
/*
* PARI/GP func: MD5 hash
*
* gp code: install("plug_md5", "s", "MD5", "<library path>");
*/
GEN plug_md5(char *text)
{
char md[MD5_DIGEST_LENGTH];
char hash[sizeof(md) * 2 + 1];
int i;
MD5((unsigned ch... | Give a code snippet in #PARI.2FGP
Task
Encode a string using an MD5 algorithm. The algorithm can be found on Wikipedia.
Optionally, validate your implementation by running all of the test values in IETF RFC (1321) for MD5.
Additionally, RFC 1321 provides more precise information on the algorithm than ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Singly-linked_list/Element_insertion | Singly-linked list/Element insertion | Singly-Linked List (element)
singly-linked list
Using this method, insert an element C into a list comprised of elements A->B, following element A.
See also
Array
Associative array: Creation, Iteration
Collections
Compound data type
Doubly-linked list: Definition, Element definition, Element insertion, List Trav... | #Raku | Raku | method insert ($value) {
$.next = Cell.new(:$value, :$.next)
} | Give a code snippet in #Raku
Singly-Linked List (element)
singly-linked list
Using this method, insert an element C into a list comprised of elements A->B, following element A.
See also
Array
Associative array: Creation, Iteration
Collections
Compound data type
Doubly-linked list: Definition, Element definition... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Knapsack_problem/Continuous | Knapsack problem/Continuous |
A thief burgles a butcher's shop, where he can select from some items.
The thief knows the weights and prices of each items. Because he has a knapsack with 15 kg maximal capacity, he wants to select the items such that he would have his profit maximized. He may cut the items; the item has a reduced price after... | #Erlang | Erlang |
-module( knapsack_problem_continuous ).
-export( [price_per_weight/1, select/2, task/0] ).
price_per_weight( Items ) -> [{Name, Weight, Price / Weight} || {Name, Weight, Price} <-Items].
select( Max_weight, Items ) ->
{_Remains, Selected_items} = lists:foldr( fun select_until/2, {Max_weight, []}, lists:keysort... | Give a code snippet in #Erlang
A thief burgles a butcher's shop, where he can select from some items.
The thief knows the weights and prices of each items. Because he has a knapsack with 15 kg maximal capacity, he wants to select the items such that he would have his profit maximized. He may cut the items; th... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sorting_algorithms/Strand_sort | Sorting algorithms/Strand sort |
Sorting Algorithm
This is a sorting algorithm. It may be applied to a set of data in order to sort it.
For comparing various sorts, see compare sorts.
For other sorting algorithms, see sorting algorithms, or:
O(n logn) sorts
Heap sort |
Merge sort |
Patience sort |
Quick sort
O(n log2n) sorts
Shell Sort
... | #zkl | zkl | fcn strandSort(A){ //--> new list, A is cleared, should add A=A.copy()
sublist:=List.createLong(A.len()); results:=List.createLong(A.len());
while(A){
sublist.clear(A.pop(0));
foreach i in (A.len() - 1){
if(A[i]>sublist[-1]) sublist.append(A.pop(i));
}
results.merge(sublist);
}
res... | Give a code snippet in #zkl
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/Harshad_or_Niven_series | Harshad or Niven series | The Harshad or Niven numbers are positive integers ≥ 1 that are divisible by the sum of their digits.
For example, 42 is a Harshad number as 42 is divisible by (4 + 2) without remainder.
Assume that the series is defined as the numbers in increasing order.
Task
The task is to create a function/method/... | #Common_Lisp | Common Lisp | (defun harshadp (n)
(zerop (rem n (digit-sum n))))
(defun digit-sum (n &optional (a 0))
(cond ((zerop n) a)
(t (digit-sum (floor n 10) (+ a (rem n 10))))))
(defun list-harshad (n &optional (i 1) (lst nil))
"list the first n Harshad numbers starting from i (default 1)"
(cond ((= (length lst) n) (reverse lst... | Give a code snippet in #Common_Lisp
The Harshad or Niven numbers are positive integers ≥ 1 that are divisible by the sum of their digits.
For example, 42 is a Harshad number as 42 is divisible by (4 + 2) without remainder.
Assume that the series is defined as the numbers in increasing order.
Task
The... | christopher/rosetta-code | |
http://rosettacode.org/wiki/HTTP | HTTP | Task
Access and print a URL's content (the located resource) to the console.
There is a separate task for HTTPS Requests.
| #OCaml | OCaml |
let () =
let url = "http://www.rosettacode.org" in
let _,_, page_content = make_request ~url ~kind:GET () in
print_endline page_content;
;;
| Give a code snippet in #OCaml
Task
Access and print a URL's content (the located resource) to the console.
There is a separate task for HTTPS Requests.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Filter | Filter | Task
Select certain elements from an Array into a new Array in a generic way.
To demonstrate, select all even numbers from an Array.
As an option, give a second solution which filters destructively,
by modifying the original Array rather than creating a new Array.
| #Fortran | Fortran | module funcs
implicit none
contains
pure function iseven(x)
logical :: iseven
integer, intent(in) :: x
iseven = mod(x, 2) == 0
end function iseven
end module funcs | Give a code snippet in #Fortran
Task
Select certain elements from an Array into a new Array in a generic way.
To demonstrate, select all even numbers from an Array.
As an option, give a second solution which filters destructively,
by modifying the original Array rather than creating a new Array.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Apply_a_callback_to_an_array | Apply a callback to an array | Task
Take a combined set of elements and apply a function to each element.
| #Lambdatalk | Lambdatalk |
{A.map {lambda {:x} {* :x :x}} {A.new 1 2 3 4 5 6 7 8 9 10}}
-> [1,4,9,16,25,36,49,64,81,100]
| Give a code snippet in #Lambdatalk
Task
Take a combined set of elements and apply a function to each element.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Averages/Arithmetic_mean | Averages/Arithmetic mean | Task[edit]
Write a program to find the mean (arithmetic average) of a numeric vector.
In case of a zero-length input, since the mean of an empty set of numbers is ill-defined, the program may choose to behave in any way it deems appropriate, though if the programming language has an established convention for conveyin... | #TI-89_BASIC | TI-89 BASIC | Define rcmean(nums) = when(dim(nums) = 0, 0, mean(nums)) | Give a code snippet in #TI-89_BASIC
Task[edit]
Write a program to find the mean (arithmetic average) of a numeric vector.
In case of a zero-length input, since the mean of an empty set of numbers is ill-defined, the program may choose to behave in any way it deems appropriate, though if the programming language has a... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Object_serialization | Object serialization | Create a set of data types based upon inheritance. Each data type or class should have a print command that displays the contents of an instance of that class to standard output. Create instances of each class in your inheritance hierarchy and display them to standard output. Write each of the objects to a file named o... | #Oz | Oz | {
package Greeting;
sub new {
my $v = "Hello world!\n";
bless \$v, shift;
};
sub stringify {
${shift()};
};
};
{
package Son::of::Greeting;
use base qw(Greeting); # inherit methods
sub new { # overwrite method of super class
my $v = "Hello world from Juni... | Give a code snippet in #Oz
Create a set of data types based upon inheritance. Each data type or class should have a print command that displays the contents of an instance of that class to standard output. Create instances of each class in your inheritance hierarchy and display them to standard output. Write each of t... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Narcissist | Narcissist | Quoting from the Esolangs wiki page:
A narcissist (or Narcissus program) is the decision-problem version of a quine.
A quine, when run, takes no input, but produces a copy of its own source code at its output. In contrast, a narcissist reads a string of symbols from its input, and produces no output except a "1" o... | #Perl | Perl | # this is file narc.pl
local $/;
print do { open 0; <0> } eq <> ? "accept" : "reject"; | Give a code snippet in #Perl
Quoting from the Esolangs wiki page:
A narcissist (or Narcissus program) is the decision-problem version of a quine.
A quine, when run, takes no input, but produces a copy of its own source code at its output. In contrast, a narcissist reads a string of symbols from its input, and pro... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Factors_of_an_integer | Factors of an integer |
Basic Data Operation
This is a basic data operation. It represents a fundamental action on a basic data type.
You may see other such operations in the Basic Data Operations category, or:
Integer Operations
Arithmetic |
Comparison
Boolean Operations
Bitwise |
Logical
String Operations
Concatenation |
Interpolation |... | #Liberty_BASIC | Liberty BASIC | num = 10677106534462215678539721403561279
maxnFactors = 1000
dim primeFactors(maxnFactors), nPrimeFactors(maxnFactors)
global nDifferentPrimeNumbersFound, nFactors, iFactor
print "Start finding all factors of ";num; ":"
nDifferentPrimeNumbersFound=0
dummy = factorize(num,2)
nFactors = showPrimeFactors(num)
dim f... | Give a code snippet in #Liberty_BASIC
Basic Data Operation
This is a basic data operation. It represents a fundamental action on a basic data type.
You may see other such operations in the Basic Data Operations category, or:
Integer Operations
Arithmetic |
Comparison
Boolean Operations
Bitwise |
Logical
String Ope... | christopher/rosetta-code |
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