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/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
| #Python | Python | import sys
sys.stdout.write("Goodbye, World!") | Give a code snippet in #Python
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/Stan... | 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
)
)
,
... | #Perl | Perl | sub F { my $n = shift; $n ? $n - M(F($n-1)) : 1 }
sub M { my $n = shift; $n ? $n - F(M($n-1)) : 0 }
# Usage:
foreach my $sequence (\&F, \&M) {
print join(' ', map $sequence->($_), 0 .. 19), "\n";
} | Give a code snippet in #Perl
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/Combinations_and_permutations | Combinations and permutations |
This page uses content from Wikipedia. The original article was at Combination. 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)
This page uses content from Wikipedia. The original article was at P... | #Bracmat | Bracmat | ( ( C
= n k coef
. !arg:(?n,?k)
& (!n+-1*!k:<!k:?k|)
& 1:?coef
& whl
' ( !k:>0
& !coef*!n*!k^-1:?coef
& !k+-1:?k
& !n+-1:?n
)
& !coef
)
& ( P
= n k result
. !arg:(?n,?k)
& !n+-1*!k:?k
& 1:?result
& whl
... | Give a code snippet in #Bracmat
This page uses content from Wikipedia. The original article was at Combination. 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)
This page uses content from Wikiped... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Anagrams | Anagrams | When two or more words are composed of the same characters, but in a different order, they are called anagrams.
Task[edit]
Using the word list at http://wiki.puzzlers.org/pub/wordlists/unixdict.txt,
find the sets of words that share the same characters that contain the most words in them.
Related tasks
Word plays
... | #NetRexx | NetRexx | /* NetRexx */
options replace format comments java crossref symbols nobinary
class RAnagramsV01 public
-- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
method runSample(arg) public signals MalformedURLException, IOException
parse arg localFile .
isr = Reader
if localFil... | Give a code snippet in #NetRexx
When two or more words are composed of the same characters, but in a different order, they are called anagrams.
Task[edit]
Using the word list at http://wiki.puzzlers.org/pub/wordlists/unixdict.txt,
find the sets of words that share the same characters that contain the most words in... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Conditional_structures | Conditional structures | Control Structures
These are examples of control structures. You may also be interested in:
Conditional structures
Exceptions
Flow-control structures
Loops
Task
List the conditional structures offered by a programming language. See Wikipedia: conditionals for descriptions.
Common conditional structures include ... | #Simula | Simula | statement::= if conditional_expression then statement else statement
if X=Y then K:=I else K:=J
statement::= if conditional_expression then statement
if X=Y then K:=I
| Give a code snippet in #Simula
Control Structures
These are examples of control structures. You may also be interested in:
Conditional structures
Exceptions
Flow-control structures
Loops
Task
List the conditional structures offered by a programming language. See Wikipedia: conditionals for descriptions.
Common... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Enforced_immutability | Enforced immutability | Task
Demonstrate any means your language has to prevent the modification of values, or to create objects that cannot be modified after they have been created.
| #PARI.2FGP | PARI/GP | use constant PI => 3.14159;
use constant MSG => "Hello World"; | Give a code snippet in #PARI.2FGP
Task
Demonstrate any means your language has to prevent the modification of values, or to create objects that cannot be modified after they have been created.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/QR_decomposition | QR decomposition | Any rectangular
m
×
n
{\displaystyle m\times n}
matrix
A
{\displaystyle {\mathit {A}}}
can be decomposed to a product of an orthogonal matrix
Q
{\displaystyle {\mathit {Q}}}
and an upper (right) triangular matrix
R
{\displaystyle {\mathit {R}}}
, as described in QR decompositi... | #D | D | import std.stdio, std.math, std.algorithm, std.traits,
std.typecons, std.numeric, std.range, std.conv;
template elementwiseMat(string op) {
T[][] elementwiseMat(T)(in T[][] A, in T B) pure nothrow {
if (A.empty)
return null;
auto R = new typeof(return)(A.length, A[0].length);
... | Give a code snippet in #D
Any rectangular
m
×
n
{\displaystyle m\times n}
matrix
A
{\displaystyle {\mathit {A}}}
can be decomposed to a product of an orthogonal matrix
Q
{\displaystyle {\mathit {Q}}}
and an upper (right) triangular matrix
R
{\displaystyle {\mathit {R}}}
, as ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Split_a_character_string_based_on_change_of_character | Split a character string based on change of character |
Task
Split a (character) string into comma (plus a blank) delimited
strings based on a change of character (left to right).
Show the output here (use the 1st example below).
Blanks should be treated as any other character (except
they are problematic to display clearly). The same applies
to commas.
Fo... | #Tcl | Tcl | set string "gHHH5YY++///\\"
regsub -all {(.)\1*} $string {\0, } string
regsub {, $} $string {} string
puts $string | Give a code snippet in #Tcl
Task
Split a (character) string into comma (plus a blank) delimited
strings based on a change of character (left to right).
Show the output here (use the 1st example below).
Blanks should be treated as any other character (except
they are problematic to display clearly). The ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sort_three_variables | Sort three variables |
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
... | #Swift | Swift | func varSort<T: Comparable>(_ x: inout T, _ y: inout T, _ z: inout T) {
let res = [x, y, z].sorted()
x = res[0]
y = res[1]
z = res[2]
}
var x = "lions, tigers, and"
var y = "bears, oh my!"
var z = "(from the \"Wizard of OZ\")"
print("Before:")
print("x = \(x)")
print("y = \(y)")
print("z = \(z)")
print()
... | Give a code snippet in #Swift
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/Semordnilap | Semordnilap | A semordnilap is a word (or phrase) that spells a different word (or phrase) backward. "Semordnilap" is a word that itself is a semordnilap.
Example: lager and regal
Task
This task does not consider semordnilap phrases, only single words.
Using only words from this list, report the total number of unique semordnilap ... | #zkl | zkl | var [const] words= // create hashed unixdict of striped words (word:True, ...)
File("dict.txt").howza(11).pump(Dictionary().howza(8).add.fp1(True));
ss:=words.pump(List, // push stripped unixdict words through some functions
fcn(w){ words.holds(w.reverse()) }, Void.Filter, // filter palindromes
// create ("... | Give a code snippet in #zkl
A semordnilap is a word (or phrase) that spells a different word (or phrase) backward. "Semordnilap" is a word that itself is a semordnilap.
Example: lager and regal
Task
This task does not consider semordnilap phrases, only single words.
Using only words from this list, report the total ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/AKS_test_for_primes | AKS test for primes | The AKS algorithm for testing whether a number is prime is a polynomial-time algorithm based on an elementary theorem about Pascal triangles.
The theorem on which the test is based can be stated as follows:
a number
p
{\displaystyle p}
is prime if and only if all the coefficients of the polynomial ... | #Lambdatalk | Lambdatalk |
{require lib_BN} // for big numbers
1) pascalian binomial coefficient C(n,p) = n!/(p!(n-p)!) = (n*(n-1)...(n-p+1))/(p*(p-1)...2*1)
{def coeff
{lambda {:n :p}
{BN.intPart
{BN./ {S.reduce BN.* {S.serie :n {- :n :p -1} -1}}
{S.reduce BN.* {S.serie :p 1 -1}}}}}}
-> coeff
2) polynomial expansions of... | Give a code snippet in #Lambdatalk
The AKS algorithm for testing whether a number is prime is a polynomial-time algorithm based on an elementary theorem about Pascal triangles.
The theorem on which the test is based can be stated as follows:
a number
p
{\displaystyle p}
is prime if and only if all... | 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/... | #Sidef | Sidef | func harshad() {
var n = 0;
{
++n while !(n %% n.digits.sum);
n;
}
}
var iter = harshad();
say 20.of { iter.run };
var n;
do {
n = iter.run
} while (n <= 1000);
say n; | Give a code snippet in #Sidef
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 ... | 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... | #SQL | SQL | ' ' String literal
" " Identifier
[ ] Identifier
` ` Identifier
? Numbered host parameter
: Named host parameter
$ Named host parameter
@ Named host parameter
( ) Parentheses
+ Add
- Subtract/negative
* Multiply
/ Divide
% Modulo
& Bitwise AND
| Bitwise OR
~ Bitwise NOT
<< Lef... | Give a code snippet in #SQL
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 t... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Roots_of_a_quadratic_function | Roots of a quadratic function | This task has been clarified. Its programming examples are in need of review to ensure that they still fit the requirements of the task.
Write a program to find the roots of a quadratic equation, i.e., solve the equation
a
x
2
+
b
x
+
c
=
0
{\displaystyle ax^{2}+bx+c=0}
.
Your program must correctly handle n... | #Fortran | Fortran | PROGRAM QUADRATIC
IMPLICIT NONE
INTEGER, PARAMETER :: dp = SELECTED_REAL_KIND(15)
REAL(dp) :: a, b, c, e, discriminant, rroot1, rroot2
COMPLEX(dp) :: croot1, croot2
WRITE(*,*) "Enter the coefficients of the equation ax^2 + bx + c"
WRITE(*, "(A)", ADVANCE="NO") "a = "
READ *, a
WRITE(*,"(A)", ADVANCE="NO") "... | Give a code snippet in #Fortran
This task has been clarified. Its programming examples are in need of review to ensure that they still fit the requirements of the task.
Write a program to find the roots of a quadratic equation, i.e., solve the equation
a
x
2
+
b
x
+
c
=
0
{\displaystyle ax^{2}+bx+c=0}
.
You... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Test_a_function | Test a function |
Task
Using a well-known testing-specific library/module/suite for your language, write some tests for your language's entry in Palindrome.
If your language does not have a testing specific library well known to the language's community then state this or omit the language.
| #Mathematica.2FWolfram_Language | Mathematica/Wolfram Language | myFun[x_] := Block[{y},y = x^2; Assert[y > 5]; Sin[y]]
On[Assert];myFun[1.0] | Give a code snippet in #Mathematica.2FWolfram_Language
Task
Using a well-known testing-specific library/module/suite for your language, write some tests for your language's entry in Palindrome.
If your language does not have a testing specific library well known to the language's community then state this or omit ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Mertens_function | Mertens function | The Mertens function M(x) is the count of square-free integers up to x that have an even number of prime factors, minus the count of those that have an odd number.
It is an extension of the Möbius function. Given the Möbius function μ(n), the Mertens function M(x) is the sum of the Möbius numbers from n == 1 through n... | #Java | Java |
public class MertensFunction {
public static void main(String[] args) {
System.out.printf("First 199 terms of the merten function are as follows:%n ");
for ( int n = 1 ; n < 200 ; n++ ) {
System.out.printf("%2d ", mertenFunction(n));
if ( (n+1) % 20 == 0 ) {
... | Give a code snippet in #Java
The Mertens function M(x) is the count of square-free integers up to x that have an even number of prime factors, minus the count of those that have an odd number.
It is an extension of the Möbius function. Given the Möbius function μ(n), the Mertens function M(x) is the sum of the Möbius... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sleep | Sleep | Task
Write a program that does the following in this order:
Input an amount of time to sleep in whatever units are most natural for your language (milliseconds, seconds, ticks, etc.). This unit should be noted in comments or in a description.
Print "Sleeping..."
Sleep the main thread for the given amount of time.
... | #Clojure | Clojure | (defn sleep [ms] ; time in milliseconds
(println "Sleeping...")
(Thread/sleep ms)
(println "Awake!"))
; call it
(sleep 1000) | Give a code snippet in #Clojure
Task
Write a program that does the following in this order:
Input an amount of time to sleep in whatever units are most natural for your language (milliseconds, seconds, ticks, etc.). This unit should be noted in comments or in a description.
Print "Sleeping..."
Sleep the main thre... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Cumulative_standard_deviation | Cumulative standard deviation | Task[edit]
Write a stateful function, class, generator or co-routine that takes a series of floating point numbers, one at a time, and returns the running standard deviation of the series.
The task implementation should use the most natural programming style of those listed for the function in the implementation langu... | #JavaScript | JavaScript | function running_stddev() {
var n = 0;
var sum = 0.0;
var sum_sq = 0.0;
return function(num) {
n++;
sum += num;
sum_sq += num*num;
return Math.sqrt( (sum_sq / n) - Math.pow(sum / n, 2) );
}
}
var sd = running_stddev();
var nums = [2,4,4,4,5,5,7,9];
var stddev = [];
... | Give a code snippet in #JavaScript
Task[edit]
Write a stateful function, class, generator or co-routine that takes a series of floating point numbers, one at a time, and returns the running standard deviation of the series.
The task implementation should use the most natural programming style of those listed for the ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Loops/For | Loops/For | “For” loops are used to make some block of code be iterated a number of times, setting a variable or parameter to a monotonically increasing integer value for each execution of the block of code.
Common extensions of this allow other counting patterns or iterating over abstract structures other than the integers.
... | #Fortran | Fortran | C WARNING: This program is not valid ANSI FORTRAN 77 code. It uses
C one nonstandard character on the line labelled 5001. Many F77
C compilers should be okay with it, but it is *not* standard.
PROGRAM FORLOOP
INTEGER I, J
DO 20 I = 1, 5
DO 10 J = 1, I
C Print the ... | Give a code snippet in #Fortran
“For” loops are used to make some block of code be iterated a number of times, setting a variable or parameter to a monotonically increasing integer value for each execution of the block of code.
Common extensions of this allow other counting patterns or iterating over abstract struc... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Address_of_a_variable | Address of a variable |
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 |... | #Rust | Rust | let v1 = vec![vec![1,2,3]; 10];
println!("Original address: {:p}", &v1);
let mut v2;
// Override rust protections on reading from uninitialized memory
unsafe {v2 = mem::uninitialized();}
let addr = &mut v2 as *mut _;
// ptr::write() though it takes v1 by value, v1s destructor is not run when it goes out of
// scope,... | Give a code snippet in #Rust
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/Compiler/virtual_machine_interpreter | Compiler/virtual machine interpreter | A virtual machine implements a computer in software.
Task[edit]
Write a virtual machine interpreter. This interpreter should be able to run virtual
assembly language programs created via the task. This is a
byte-coded, 32-bit word stack based virtual machine.
The program should read input from a file and/or stdin, an... | #Perl | Perl | #!/usr/bin/perl
# http://www.rosettacode.org/wiki/Compiler/virtual_machine_interpreter
use strict; # vm.pl - run rosetta code
use warnings;
use integer;
my ($binary, $pc, @stack, @data) = ('', 0);
<> =~ /Strings: (\d+)/ or die "bad header";
my @strings = map <> =~ tr/\n""//dr =~ s/\\(.)/$1 eq 'n' ? "\n" : $1/ger,... | Give a code snippet in #Perl
A virtual machine implements a computer in software.
Task[edit]
Write a virtual machine interpreter. This interpreter should be able to run virtual
assembly language programs created via the task. This is a
byte-coded, 32-bit word stack based virtual machine.
The program should read inpu... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Reverse_words_in_a_string | Reverse words in a string | Task
Reverse the order of all tokens in each of a number of strings and display the result; the order of characters within a token should not be modified.
Example
Hey you, Bub! would be shown reversed as: Bub! you, Hey
Tokens are any non-space characters separated by spaces (formally, white-space); t... | #Perl | Perl | print join(" ", reverse split), "\n" for <DATA>;
__DATA__
---------- Ice and Fire ------------
fire, in end will world the say Some
ice. in say Some
desire of tasted I've what From
fire. favor who those with hold I
... elided paragraph last ...
Frost Robert ---------------------... | Give a code snippet in #Perl
Task
Reverse the order of all tokens in each of a number of strings and display the result; the order of characters within a token should not be modified.
Example
Hey you, Bub! would be shown reversed as: Bub! you, Hey
Tokens are any non-space characters separated by space... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Additive_primes | Additive primes | Definitions
In mathematics, additive primes are prime numbers for which the sum of their decimal digits are also primes.
Task
Write a program to determine (and show here) all additive primes less than 500.
Optionally, show the number of additive primes.
Also see
the OEIS entry: A046704 additive primes.
... | #AppleScript | AppleScript | on sieveOfEratosthenes(limit)
script o
property numberList : {missing value}
end script
repeat with n from 2 to limit
set end of o's numberList to n
end repeat
repeat with n from 2 to (limit ^ 0.5) div 1
if (item n of o's numberList is n) then
repeat with mult... | Give a code snippet in #AppleScript
Definitions
In mathematics, additive primes are prime numbers for which the sum of their decimal digits are also primes.
Task
Write a program to determine (and show here) all additive primes less than 500.
Optionally, show the number of additive primes.
Also see
the OEIS ... | 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
| #Fortran | Fortran | program bye
write (*,'(a)',advance='no') 'Goodbye, World!'
end program bye | Give a code snippet in #Fortran
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/Sta... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Walk_a_directory/Non-recursively | Walk a directory/Non-recursively | Task
Walk a given directory and print the names of files matching a given pattern.
(How is "pattern" defined? substring match? DOS pattern? BASH pattern? ZSH pattern? Perl regular expression?)
Note: This task is for non-recursive methods. These tasks should read a single directory, not an entire directory tree.
... | #Toka | Toka | needs shell
" ." " .\\.txt$" dir.listByPattern | Give a code snippet in #Toka
Task
Walk a given directory and print the names of files matching a given pattern.
(How is "pattern" defined? substring match? DOS pattern? BASH pattern? ZSH pattern? Perl regular expression?)
Note: This task is for non-recursive methods. These tasks should read a single directory, n... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Write_to_Windows_event_log | Write to Windows event log | Task
Write script status to the Windows Event Log
| #C.2B.2B | C++ | #include <iostream>
#include <sstream>
int main(int argc, char *argv[]) {
using namespace std;
#if _WIN32
if (argc != 5) {
cout << "Usage : " << argv[0] << " (type) (id) (source string) (description>)\n";
cout << " Valid types: SUCCESS, ERROR, WARNING, INFORMATION\n";
} else {
... | Give a code snippet in #C.2B.2B
Task
Write script status to the Windows Event Log
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Sorting_algorithms/Insertion_sort | Sorting algorithms/Insertion sort |
Sorting Algorithm
This is a sorting algorithm. It may be applied to a set of data in order to sort it.
For comparing various sorts, see compare sorts.
For other sorting algorithms, see sorting algorithms, or:
O(n logn) sorts
Heap sort |
Merge sort |
Patience sort |
Quick sort
O(n log2n) sorts
Shell Sort
... | #Wren | Wren | var insertionSort = Fn.new { |a|
for (i in 1..a.count-1) {
var v = a[i]
var j = i - 1
while (j >= 0 && a[j] > v) {
a[j+1] = a[j]
j = j - 1
}
a[j+1] = v
}
}
var as = [ [4, 65, 2, -31, 0, 99, 2, 83, 782, 1], [7, 5, 2, 6, 1, 4, 2, 6, 3] ]
for (a in ... | Give a code snippet in #Wren
Sorting Algorithm
This is a sorting algorithm. It may be applied to a set of data in order to sort it.
For comparing various sorts, see compare sorts.
For other sorting algorithms, see sorting algorithms, or:
O(n logn) sorts
Heap sort |
Merge sort |
Patience sort |
Quick sor... | christopher/rosetta-code | |
http://rosettacode.org/wiki/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... | #Aime | Aime | integer
is_numeric(text s)
{
return !trap_q(alpha, s, 0);
}
integer
main(void)
{
if (!is_numeric("8192&*")) {
o_text("Not numeric.\n");
}
if (is_numeric("8192")) {
o_text("Numeric.\n");
}
return 0;
} | Give a code snippet in #Aime
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
Ar... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Find_the_last_Sunday_of_each_month | Find the last Sunday of each month | Write a program or a script that returns the last Sundays of each month of a given year. The year may be given through any simple input method in your language (command line, std in, etc).
Example of an expected output:
./last_sundays 2013
2013-01-27
2013-02-24
2013-03-31
2013-04-28
2013-05-26
2013-06-30
2013-07-28
2... | #PHP | PHP | <?php
// Created with PHP 7.0
function printLastSundayOfAllMonth($year)
{
$months = array(
'January', 'February', 'March', 'April', 'June', 'July',
'August', 'September', 'October', 'November', 'December');
foreach ($months as $month) {
echo $month . ': ' . date('Y-m-d', strtotime('l... | Give a code snippet in #PHP
Write a program or a script that returns the last Sundays of each month of a given year. The year may be given through any simple input method in your language (command line, std in, etc).
Example of an expected output:
./last_sundays 2013
2013-01-27
2013-02-24
2013-03-31
2013-04-28
2013-... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Dot_product | Dot product | Task
Create a function/use an in-built function, to compute the dot product, also known as the scalar product of two vectors.
If possible, make the vectors of arbitrary length.
As an example, compute the dot product of the vectors:
[1, 3, -5] and
[4, -2, -1]
If implementing the dot ... | #Factor | Factor | USING: kernel math.vectors sequences ;
: dot-product ( u v -- w )
2dup [ length ] bi@ =
[ v. ] [ "Vector lengths must be equal" throw ] if ; | Give a code snippet in #Factor
Task
Create a function/use an in-built function, to compute the dot product, also known as the scalar product of two vectors.
If possible, make the vectors of arbitrary length.
As an example, compute the dot product of the vectors:
[1, 3, -5] and
[4, -2, -... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Variadic_function | Variadic function | Task
Create a function which takes in a variable number of arguments and prints each one on its own line.
Also show, if possible in your language, how to call the function on a list of arguments constructed at runtime.
Functions of this type are also known as Variadic Functions.
Related task
Call a function... | #Oz | Oz | declare
class Demo from BaseObject
meth test(...)=Msg
{Record.forAll Msg Show}
end
end
D = {New Demo noop}
Constructed = {List.toTuple test {List.number 1 10 1}}
in
{D test(1 2 3 4)}
{D Constructed} | Give a code snippet in #Oz
Task
Create a function which takes in a variable number of arguments and prints each one on its own line.
Also show, if possible in your language, how to call the function on a list of arguments constructed at runtime.
Functions of this type are also known as Variadic Functions.
Rela... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Real_constants_and_functions | Real constants and functions | Task
Show how to use the following math constants and functions in your language (if not available, note it):
e (base of the natural logarithm)
π
{\displaystyle \pi }
square root
logarithm (any base allowed)
exponential (ex )
absolute value (a.k.a. "magnitude")
floor (largest ... | #Smalltalk | Smalltalk | Float e.
Float pi.
aNumber sqrt.
aNumber log. "base 10 logarithm"
aNumber ln. "natural logarithm"
aNumber exp. "exponential"
aNumber abs. "absolute value"
aNumber floor.
aNumber ceiling.
aNumber raisedTo: anotherNumber | Give a code snippet in #Smalltalk
Task
Show how to use the following math constants and functions in your language (if not available, note it):
e (base of the natural logarithm)
π
{\displaystyle \pi }
square root
logarithm (any base allowed)
exponential (ex )
absolute value (a.k.a... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Universal_Turing_machine | Universal Turing machine | One of the foundational mathematical constructs behind computer science
is the universal Turing Machine.
(Alan Turing introduced the idea of such a machine in 1936–1937.)
Indeed one way to definitively prove that a language
is turing-complete
is to implement a universal Turing machine in it.
Task
Simulate such ... | #Sidef | Sidef | func run_utm(state="", blank="", rules=[], tape=[blank], halt="", pos=0) {
if (pos < 0) {
pos += tape.len;
}
if (pos !~ tape.range) {
die "Bad initial position";
}
loop {
print "#{state}\t";
tape.range.each { |i|
var v = tape[i];
print (i... | Give a code snippet in #Sidef
One of the foundational mathematical constructs behind computer science
is the universal Turing Machine.
(Alan Turing introduced the idea of such a machine in 1936–1937.)
Indeed one way to definitively prove that a language
is turing-complete
is to implement a universal Turing machine... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Numerical_integration/Gauss-Legendre_Quadrature | Numerical integration/Gauss-Legendre Quadrature |
In a general Gaussian quadrature rule, an definite integral of
f
(
x
)
{\displaystyle f(x)}
is first approximated over the interval
[
−
1
,
1
]
{\displaystyle [-1,1]}
by a polynomial approximable function
g
(
x
)
{\displaystyle g(x)}
and a known weighting function
W
(
x
)
{\displaystyle ... | #ooRexx | ooRexx | /*---------------------------------------------------------------------
* 31.10.2013 Walter Pachl Translation from REXX (from PL/I)
* using ooRexx' rxmath package
* which limits the precision to 16 digits
*---------------------------------------------------------------... | Give a code snippet in #ooRexx
In a general Gaussian quadrature rule, an definite integral of
f
(
x
)
{\displaystyle f(x)}
is first approximated over the interval
[
−
1
,
1
]
{\displaystyle [-1,1]}
by a polynomial approximable function
g
(
x
)
{\displaystyle g(x)}
and a known weighting functi... | 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... | #Nemerle | Nemerle | def empty = "";
mutable fill_later = ""; | Give a code snippet in #Nemerle
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/Count_the_coins | Count the coins | There are four types of common coins in US currency:
quarters (25 cents)
dimes (10 cents)
nickels (5 cents), and
pennies (1 cent)
There are six ways to make change for 15 cents:
A dime and a nickel
A dime and 5 pennies
3 nickels
2 nickels and 5 pennies
A nickel and 10 pen... | #FutureBasic | FutureBasic | include "NSLog.incl"
void local fn Doit
long penny, nickel, dime, quarter, count = 0
NSLogSetTabInterval(30)
for penny = 0 to 100
for nickel = 0 to 20
for dime = 0 to 10
for quarter = 0 to 4
if penny + nickel * 5 + dime * 10 + quarter * 25 == 100
NSLog(@"%ld pennies\t... | Give a code snippet in #FutureBasic
There are four types of common coins in US currency:
quarters (25 cents)
dimes (10 cents)
nickels (5 cents), and
pennies (1 cent)
There are six ways to make change for 15 cents:
A dime and a nickel
A dime and 5 pennies
3 nickels
2 nickels... | 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... | #Rebol | Rebol |
do [if "" = y: ask "Year (ENTER for current):^/^/" [prin y: now/year]
foreach m system/locale/months [
prin rejoin ["^/^/ " m "^/^/ "]
foreach day system/locale/days [prin join copy/part day 2 " "]
print "" f: to-date rejoin ["1-"m"-"y] loop f/weekday - 1 [prin " "]
repeat i 31 [
if attempt [c: to... | Give a code snippet in #Rebol
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 ... | 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... | #Go | Go | package main
import (
"fmt"
"strings"
"time"
)
func main() {
watches := []string{
"First", "Middle", "Morning", "Forenoon",
"Afternoon", "Dog", "First",
}
for {
t := time.Now()
h := t.Hour()
m := t.Minute()
s := t.Second()
if (m == 0 ||... | Give a code snippet in #Go
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 of... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Best_shuffle | Best shuffle | Task
Shuffle the characters of a string in such a way that as many of the character values are in a different position as possible.
A shuffle that produces a randomized result among the best choices is to be preferred. A deterministic approach that produces the same sequence every time is acceptable as an alternative... | #Sidef | Sidef | func best_shuffle(String orig) -> (String, Number) {
var s = orig.chars
var t = s.shuffle
for i (^s) {
for j (^s) {
if (i!=j && t[i]!=s[j] && t[j]!=s[i]) {
t[i, j] = t[j, i]
break
}
}
}
(t.join, s ~Z== t -> count(true))
}
... | Give a code snippet in #Sidef
Task
Shuffle the characters of a string in such a way that as many of the character values are in a different position as possible.
A shuffle that produces a randomized result among the best choices is to be preferred. A deterministic approach that produces the same sequence every time ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/File_extension_is_in_extensions_list | File extension is in extensions list | File extension is in extensions list
You are encouraged to solve this task according to the task description, using any language you may know.
Filename extensions are a rudimentary but commonly used way of identifying files types.
Task
Given an arbitrary filename and a list of extensions, tell whether the filename... | #D | D |
import std.stdio;
import std.string;
import std.range;
import std.algorithm;
void main()
{
auto exts = ["zip", "rar", "7z", "gz", "archive", "A##"];
auto filenames = ["MyData.a##",
"MyData.tar.Gz",
"MyData.gzip",
"MyData.7z.backup",
... | Give a code snippet in #D
File extension is in extensions list
You are encouraged to solve this task according to the task description, using any language you may know.
Filename extensions are a rudimentary but commonly used way of identifying files types.
Task
Given an arbitrary filename and a list of extensions... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Exceptions | Exceptions | Control Structures
These are examples of control structures. You may also be interested in:
Conditional structures
Exceptions
Flow-control structures
Loops
This task is to give an example of an exception handling routine
and to "throw" a new exception.
Related task
Exceptions Through Nested Calls
| #D | D | import std.stdio;
/// Throw Exceptions
/// Stack traces are generated compiling with the -g switch.
void test1() {
throw new Exception("Sample Exception");
}
/// Catch Exceptions
void test2() {
try {
test1();
} catch (Exception ex) {
writeln(ex);
throw ex; // rethrow
}
}
/// ... | Give a code snippet in #D
Control Structures
These are examples of control structures. You may also be interested in:
Conditional structures
Exceptions
Flow-control structures
Loops
This task is to give an example of an exception handling routine
and to "throw" a new exception.
Related task
Exceptions Thr... | christopher/rosetta-code | |
http://rosettacode.org/wiki/List_comprehensions | List comprehensions | A list comprehension is a special syntax in some programming languages to describe lists. It is similar to the way mathematicians describe sets, with a set comprehension, hence the name.
Some attributes of a list comprehension are:
They should be distinct from (nested) for loops and the use of map and filter functio... | #Bracmat | Bracmat |
:?py { Initialize the accumulating result list. }
& ( 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 { This is the subject }
: ? { Here starts the pattern }
%@?x
?
%@?y
?
%@?z
( ?
& -1*!z^2+!x^2+!y^2... | Give a code snippet in #Bracmat
A list comprehension is a special syntax in some programming languages to describe lists. It is similar to the way mathematicians describe sets, with a set comprehension, hence the name.
Some attributes of a list comprehension are:
They should be distinct from (nested) for loops and ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Spiral_matrix | Spiral matrix | Task
Produce a spiral array.
A spiral array is a square arrangement of the first N2 natural numbers, where the
numbers increase sequentially as you go around the edges of the array spiraling inwards.
For example, given 5, produce this array:
0 1 2 3 4
15 16 17 18 5
14 23 24 19 6
13 22 21 ... | #Groovy | Groovy | enum Direction {
East([0,1]), South([1,0]), West([0,-1]), North([-1,0]);
private static _n
private final stepDelta
private bound
private Direction(delta) {
stepDelta = delta
}
public static setN(int n) {
Direction._n = n
North.bound = 0
South.bound = n-1
... | Give a code snippet in #Groovy
Task
Produce a spiral array.
A spiral array is a square arrangement of the first N2 natural numbers, where the
numbers increase sequentially as you go around the edges of the array spiraling inwards.
For example, given 5, produce this array:
0 1 2 3 4
15 16 1... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Abundant,_deficient_and_perfect_number_classifications | Abundant, deficient and perfect number classifications | These define three classifications of positive integers based on their proper divisors.
Let P(n) be the sum of the proper divisors of n where the proper divisors are all positive divisors of n other than n itself.
if P(n) < n then n is classed as deficient (OEIS A005100).
if P(n)... | #REXX | REXX | /*REXX program counts the number of abundant/deficient/perfect numbers within a range.*/
parse arg low high . /*obtain optional arguments from the CL*/
high=word(high low 20000,1); low= word(low 1,1) /*obtain the LOW and HIGH values.*/
say center('integers from ' low " to " hi... | Give a code snippet in #REXX
These define three classifications of positive integers based on their proper divisors.
Let P(n) be the sum of the proper divisors of n where the proper divisors are all positive divisors of n other than n itself.
if P(n) < n then n is classed as deficient ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Soundex | Soundex | Soundex is an algorithm for creating indices for words based on their pronunciation.
Task
The goal is for homophones to be encoded to the same representation so that they can be matched despite minor differences in spelling (from the soundex Wikipedia article).
Caution
There is a major issue in many of the ... | #Scheme | Scheme | ;; The American Soundex System
;;
;; The soundex code consist of the first letter of the name followed
;; by three digits. These three digits are determined by dropping the
;; letters a, e, i, o, u, h, w and y and adding three digits from the
;; remaining letters of the name according to the table below. There
;; are o... | Give a code snippet in #Scheme
Soundex is an algorithm for creating indices for words based on their pronunciation.
Task
The goal is for homophones to be encoded to the same representation so that they can be matched despite minor differences in spelling (from the soundex Wikipedia article).
Caution
There ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Create_a_two-dimensional_array_at_runtime | Create a two-dimensional array at runtime |
Data Structure
This illustrates a data structure, a means of storing data within a program.
You may see other such structures in the Data Structures category.
Get two integers from the user, then create a two-dimensional array where the two dimensions have the sizes given by those numbers, and which can be accessed ... | #F.23 | F# | open System
let width = int( Console.ReadLine() )
let height = int( Console.ReadLine() )
let arr = Array2D.create width height 0
arr.[0,0] <- 42
printfn "%d" arr.[0,0] | Give a code snippet in #F.23
Data Structure
This illustrates a data structure, a means of storing data within a program.
You may see other such structures in the Data Structures category.
Get two integers from the user, then create a two-dimensional array where the two dimensions have the sizes given by those numbe... | 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... | #Vlang | Vlang | const (
input = '49927398716
49927398717
1234567812345678
1234567812345670'
t = [0, 2, 4, 6, 8, 1, 3, 5, 7, 9]
)
fn luhn(s string) bool {
odd := s.len & 1
mut sum := 0
for i, c in s.split('') {
if c < '0' || c > '9' {
return false
}
if i&1 == odd {
... | Give a code snippet in #Vlang
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... | 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
... | #JavaScript | JavaScript |
// Node 5.4.1 tested implementation (ES6)
"use strict";
let arr = [4, 9, 0, 3, 1, 5];
let isSorted = true;
while (isSorted){
for (let i = 0; i< arr.length - 1;i++){
if (arr[i] > arr[i + 1])
{
let temp = arr[i];
arr[i] = arr[i + 1];
arr[i... | Give a code snippet in #JavaScript
Sorting Algorithm
This is a sorting algorithm. It may be applied to a set of data in order to sort it.
For comparing various sorts, see compare sorts.
For other sorting algorithms, see sorting algorithms, or:
O(n logn) sorts
Heap sort |
Merge sort |
Patience sort |
Qui... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Compare_a_list_of_strings | Compare a list of strings | Task
Given a list of arbitrarily many strings, show how to:
test if they are all lexically equal
test if every string is lexically less than the one after it (i.e. whether the list is in strict ascending order)
Each of those two tests should result in a single true or false value, which could be used as t... | #AppleScript | AppleScript | -- allEqual :: [String] -> Bool
on allEqual(xs)
_and(zipWith(my _equal, xs, rest of xs))
end allEqual
-- azSorted :: [String] -> Bool
on azSorted(xs)
_and(zipWith(my azBeforeOrSame, xs, rest of xs))
end azSorted
-- _equal :: a -> a -> Bool
on _equal(a, b)
a = b
end _equal
-- azBefore :: String -> Stri... | Give a code snippet in #AppleScript
Task
Given a list of arbitrarily many strings, show how to:
test if they are all lexically equal
test if every string is lexically less than the one after it (i.e. whether the list is in strict ascending order)
Each of those two tests should result in a single true or ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Hello_world/Line_printer | Hello world/Line printer | Task
Cause a line printer attached to the computer to print a line containing the message: Hello World!
Note
A line printer is not the same as standard output.
A line printer was an older-style printer which prints one line at a time to a continuous ream of paper.
With some systems, a line printer can be... | #BASIC | BASIC | LPRINT "Hello World!" | Give a code snippet in #BASIC
Task
Cause a line printer attached to the computer to print a line containing the message: Hello World!
Note
A line printer is not the same as standard output.
A line printer was an older-style printer which prints one line at a time to a continuous ream of paper.
With some... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Smith_numbers | Smith numbers | Smith numbers are numbers such that the sum of the decimal digits of the integers that make up that number is the same as the sum of the decimal digits of its prime factors excluding 1.
By definition, all primes are excluded as they (naturally) satisfy this condition!
Smith numbers are also known as joke numbers.... | #11l | 11l | F factors(=n)
[Int] rt
V f = 2
I n == 1
rt.append(1)
E
L
I 0 == (n % f)
rt.append(f)
n I/= f
I n == 1
R rt
E
f++
R rt
F sum_digits(=n)
V sum = 0
L n > 0
V m = n % 10
sum += m
n -= m
... | Give a code snippet in #11l
Smith numbers are numbers such that the sum of the decimal digits of the integers that make up that number is the same as the sum of the decimal digits of its prime factors excluding 1.
By definition, all primes are excluded as they (naturally) satisfy this condition!
Smith numbers are al... | 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 ... | #PowerBASIC | PowerBASIC | #COMPILE EXE
#DIM ALL
#COMPILER PBCC 6
FUNCTION ShoelaceArea(x() AS DOUBLE, y() AS DOUBLE) AS DOUBLE
LOCAL i, j AS LONG
LOCAL Area AS DOUBLE
j = UBOUND(x())
FOR i = LBOUND(x()) TO UBOUND(x())
Area += (y(j) + y(i)) * (x(j) - x(i))
j = i
NEXT i
FUNCTION = ABS(Area) / 2
END FUNCTION
FUNCTION PBMAIN (... | Give a code snippet in #PowerBASIC
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 retur... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Pythagoras_tree | Pythagoras tree |
The Pythagoras tree is a fractal tree constructed from squares. It is named after Pythagoras because each triple of touching squares encloses a right triangle, in a configuration traditionally used to represent the Pythagorean theorem.
Task
Construct a Pythagoras tree of order 7 using only vectors (no rotation or ... | #Ada | Ada | with SDL.Video.Windows.Makers;
with SDL.Video.Renderers.Makers;
with SDL.Video.Rectangles;
with SDL.Events.Events;
procedure Pythagoras_Tree is
Width : constant := 600;
Height : constant := 600;
Level : constant := 7;
type Point is record X, Y : Float; end record;
B1 : constant Point := (X => ... | Give a code snippet in #Ada
The Pythagoras tree is a fractal tree constructed from squares. It is named after Pythagoras because each triple of touching squares encloses a right triangle, in a configuration traditionally used to represent the Pythagorean theorem.
Task
Construct a Pythagoras tree of order 7 using ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/General_FizzBuzz | General FizzBuzz | Task
Write a generalized version of FizzBuzz that works for any list of factors, along with their words.
This is basically a "fizzbuzz" implementation where the user supplies the parameters.
The user will enter the max number, then they will enter the factors to be calculated along with the corresponding word to be ... | #AWK | AWK | 105
3 Fizz
5 Buzz
7 Baxx | Give a code snippet in #AWK
Task
Write a generalized version of FizzBuzz that works for any list of factors, along with their words.
This is basically a "fizzbuzz" implementation where the user supplies the parameters.
The user will enter the max number, then they will enter the factors to be calculated along with ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Pseudo-random_numbers/Combined_recursive_generator_MRG32k3a | Pseudo-random numbers/Combined recursive generator MRG32k3a | MRG32k3a Combined recursive generator (pseudo-code)
/* Constants */
/* First generator */
a1 = [0, 1403580, -810728]
m1 = 2**32 - 209
/* Second Generator */
a2 = [527612, 0, -1370589]
m2 = 2**32 - 22853
d = m1 + 1
class MRG32k3a
x1 = [0, 0, 0] /* list of three last values of... | #Pari.2FGP | Pari/GP | a1 = [0, 1403580, -810728];
m1 = 2^32-209;
a2 = [527612, 0, -1370589];
m2 = 2^32-22853;
d = m1+1;
seed(s)=x1=x2=[s,0,0];
next_int()=
{
my(x1i=a1*x1~%m1, x2i=a2*x2~%m2);
x1 = [x1i, x1[1], x1[2]];
x2 = [x2i, x2[1], x2[2]];
(x1i-x2i)%m1 + 1;
}
next_float()=next_int()/d;
seed(1234567);
vector(5,i,next_int())
seed... | Give a code snippet in #Pari.2FGP
MRG32k3a Combined recursive generator (pseudo-code)
/* Constants */
/* First generator */
a1 = [0, 1403580, -810728]
m1 = 2**32 - 209
/* Second Generator */
a2 = [527612, 0, -1370589]
m2 = 2**32 - 22853
d = m1 + 1
class MRG32k3a
x1 = [0, 0, ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sorting_Algorithms/Circle_Sort | Sorting Algorithms/Circle 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
... | #Elixir | Elixir | defmodule Sort do
def circle_sort(data) do
List.to_tuple(data)
|> circle_sort(0, length(data)-1)
|> Tuple.to_list
end
defp circle_sort(data, lo, hi) do
case circle_sort(data, lo, hi, 0) do
{result, 0} -> result
{result, _} -> circle_sort(result, lo, hi)
end
end
defp circle_... | Give a code snippet in #Elixir
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/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
... | #UnixPipes | UnixPipes | split() {
(while read n ; do
test $1 -gt $n && echo $n > $2 || echo $n > $3
done)
}
qsort() {
(read p; test -n "$p" && (
lc="1.$1" ; gc="2.$1"
split $p >(qsort $lc >$lc) >(qsort $gc >$gc);
cat $lc <(echo $p) $gc
rm -f $lc $gc;
))
}
cat to.sort | qsort | Give a code snippet in #UnixPipes
Sorting Algorithm
This is a sorting algorithm. It may be applied to a set of data in order to sort it.
For comparing various sorts, see compare sorts.
For other sorting algorithms, see sorting algorithms, or:
O(n logn) sorts
Heap sort |
Merge sort |
Patience sort |
Quic... | christopher/rosetta-code | |
http://rosettacode.org/wiki/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... | #C.23 | C# | using System;
class Program {
static void Main(string[] args) {
int[,] a = new int[10, 10];
Random r = new Random();
for (int i = 0; i < 10; i++) {
for (int j = 0; j < 10; j++) {
a[i, j] = r.Next(0, 21) + 1;
}
}
for (int i = 0; i ... | Give a code snippet in #C.23
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... | 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... | #Bc | Bc | print "\a" | Give a code snippet in #Bc
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 withi... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Regular_expressions | Regular expressions |
Task
match a string against a regular expression
substitute part of a string using a regular expression
| #Ol | Ol |
; matching:
(define regex (string->regex "m/aa(bb|cc)dd/"))
(print (regex "aabbddx")) ; => true
(print (regex "aaccddx")) ; => true
(print (regex "aabcddx")) ; => false
; substitute part of a string:
(define regex (string->regex "s/aa(bb|cc)dd/HAHAHA/"))
(print (regex "aabbddx")) ; => HAHAHAx
(print (regex "aaccddx... | Give a code snippet in #Ol
Task
match a string against a regular expression
substitute part of a string using a regular expression
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Sorting_algorithms/Bead_sort | Sorting algorithms/Bead sort |
Sorting Algorithm
This is a sorting algorithm. It may be applied to a set of data in order to sort it.
For comparing various sorts, see compare sorts.
For other sorting algorithms, see sorting algorithms, or:
O(n logn) sorts
Heap sort |
Merge sort |
Patience sort |
Quick sort
O(n log2n) sorts
Shell Sort
... | #C | C | #include <stdio.h>
#include <stdlib.h>
void bead_sort(int *a, int len)
{
int i, j, max, sum;
unsigned char *beads;
# define BEAD(i, j) beads[i * max + j]
for (i = 1, max = a[0]; i < len; i++)
if (a[i] > max) max = a[i];
beads = calloc(1, max * len);
/* mark the beads */
for (i = 0; i < len; i++)
for (... | Give a code snippet in #C
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... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Introspection | Introspection | Task
verify the version/revision of your currently running (compiler/interpreter/byte-compiler/runtime environment/whatever your language uses) and exit if it is too old.
check whether the variable "bloop" exists and whether the math-function "abs()" is available and if yes compute abs(bloop).
Extra credit
Repor... | #E | E | def version := interp.getProps()["e.version"] | Give a code snippet in #E
Task
verify the version/revision of your currently running (compiler/interpreter/byte-compiler/runtime environment/whatever your language uses) and exit if it is too old.
check whether the variable "bloop" exists and whether the math-function "abs()" is available and if yes compute abs(blo... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Character_codes | Character codes |
Task
Given a character value in your language, print its code (could be ASCII code, Unicode code, or whatever your language uses).
Example
The character 'a' (lowercase letter A) has a code of 97 in ASCII (as well as Unicode, as ASCII forms the beginning of Unicode).
Conversely, given a code, print out... | #C.23 | C# | using System;
namespace RosettaCode.CharacterCode
{
class Program
{
static void Main(string[] args)
{
Console.WriteLine((int) 'a'); //Prints "97"
Console.WriteLine((char) 97); //Prints "a"
}
}
} | Give a code snippet in #C.23
Task
Given a character value in your language, print its code (could be ASCII code, Unicode code, or whatever your language uses).
Example
The character 'a' (lowercase letter A) has a code of 97 in ASCII (as well as Unicode, as ASCII forms the beginning of Unicode).
Conve... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Arithmetic/Integer | Arithmetic/Integer |
Basic Data Operation
This is a basic data operation. It represents a fundamental action on a basic data type.
You may see other such operations in the Basic Data Operations category, or:
Integer Operations
Arithmetic |
Comparison
Boolean Operations
Bitwise |
Logical
String Operations
Concatenation |
Interpolation |... | #ALGOL_68 | ALGOL 68 | main:(
LONG INT a=355, b=113;
printf(($"a+b = "gl$, a + b));
printf(($"a-b = "gl$, a - b));
printf(($"a*b = a×b = "gl$, a * b));
printf(($"a/b = "gl$, a / b));
printf(($"a OVER b = a%b = a÷b = "gl$, a % b));
printf(($"a MOD b = a%*b = a%×b = a÷×b = a÷*b = "gl$, a %* b));
printf(($"a UP b = a**b = a↑b = ... | Give a code snippet in #ALGOL_68
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 Operatio... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Stack | Stack |
Data Structure
This illustrates a data structure, a means of storing data within a program.
You may see other such structures in the Data Structures category.
A stack is a container of elements with last in, first out access policy. Sometimes it also called LIFO.
The stack is accessed through its top.
The ba... | #C.2B.2B | C++ | #include <stack> | Give a code snippet in #C.2B.2B
Data Structure
This illustrates a data structure, a means of storing data within a program.
You may see other such structures in the Data Structures category.
A stack is a container of elements with last in, first out access policy. Sometimes it also called LIFO.
The stack is ... | 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... | #Racket | Racket | #lang racket
(define (swap! vec i j)
(let ([tmp (vector-ref vec i)])
(vector-set! vec i (vector-ref vec j))
(vector-set! vec j tmp)))
(define (knuth-shuffle x)
(if (list? x)
(vector->list (knuth-shuffle (list->vector x)))
(begin (for ([i (in-range (sub1 (vector-length x)) 0 -1)])
(d... | Give a code snippet in #Racket
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/Combinations | Combinations | Task
Given non-negative integers m and n, generate all size m combinations of the integers from 0 (zero) to n-1 in sorted order (each combination is sorted and the entire table is sorted).
Example
3 comb 5 is:
0 1 2
0 1 3
0 1 4
0 2 3
0 2 4
0 3 4
1 2 3
1 2 4
1 3 4
2 3 4
... | #OpenEdge.2FProgress | OpenEdge/Progress |
define variable r as integer no-undo extent 3.
define variable m as integer no-undo initial 5.
define variable n as integer no-undo initial 3.
define variable max_n as integer no-undo.
max_n = m - n.
function combinations returns logical (input pos as integer, input val as integer):
define variable i as integer... | Give a code snippet in #OpenEdge.2FProgress
Task
Given non-negative integers m and n, generate all size m combinations of the integers from 0 (zero) to n-1 in sorted order (each combination is sorted and the entire table is sorted).
Example
3 comb 5 is:
0 1 2
0 1 3
0 1... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Greatest_element_of_a_list | Greatest element of a list | Task
Create a function that returns the maximum value in a provided set of values,
where the number of values may not be known until run-time.
| #MUMPS | MUMPS |
MV(A,U)
;A is a list of values separated by the string U
NEW MAX,T,I
FOR I=1:1 SET T=$PIECE(A,U,I) QUIT:T="" S MAX=$SELECT(($DATA(MAX)=0):T,(MAX<T):T,(MAX>=T):MAX)
QUIT MAX
| Give a code snippet in #MUMPS
Task
Create a function that returns the maximum value in a provided set of values,
where the number of values may not be known until run-time.
| 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
| #gnuplot | gnuplot | !ls | Give a code snippet in #gnuplot
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/Strip_whitespace_from_a_string/Top_and_tail | Strip whitespace from a string/Top and tail | Task
Demonstrate how to strip leading and trailing whitespace from a string.
The solution should demonstrate how to achieve the following three results:
String with leading whitespace removed
String with trailing whitespace removed
String with both leading and trailing whitespace removed
For the purposes of thi... | #Retro | Retro | '__this_is_a_test___ s:trim-left
'__this_is_a_test___ s:trim-right
'__this_is_a_test___ s:trim | Give a code snippet in #Retro
Task
Demonstrate how to strip leading and trailing whitespace from a string.
The solution should demonstrate how to achieve the following three results:
String with leading whitespace removed
String with trailing whitespace removed
String with both leading and trailing whitespace re... | 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
... | #Eiffel | Eiffel | class
APPLICATION
create
make
feature
make
-- Demonstrate string reversal.
do
my_string := "Hello World!"
my_string.mirror
print (my_string)
end
my_string: STRING
-- Used for reversal
end | Give a code snippet in #Eiffel
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
Empt... | christopher/rosetta-code | |
http://rosettacode.org/wiki/One-dimensional_cellular_automata | One-dimensional cellular automata | Assume an array of cells with an initial distribution of live and dead cells,
and imaginary cells off the end of the array having fixed values.
Cells in the next generation of the array are calculated based on the value of the cell and its left and right nearest neighbours in the current generation.
If, in the follow... | #Ada | Ada | with Ada.Text_IO; use Ada.Text_IO;
procedure Cellular_Automata is
type Petri_Dish is array (Positive range <>) of Boolean;
procedure Step (Culture : in out Petri_Dish) is
Left : Boolean := False;
This : Boolean;
Right : Boolean;
begin
for Index in Culture'First..Culture'Last - 1 ... | Give a code snippet in #Ada
Assume an array of cells with an initial distribution of live and dead cells,
and imaginary cells off the end of the array having fixed values.
Cells in the next generation of the array are calculated based on the value of the cell and its left and right nearest neighbours in the current g... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Variable_declaration_reset | Variable declaration reset | A decidely non-challenging task to highlight a potential difference between programming languages.
Using a straightforward longhand loop as in the JavaScript and Phix examples below, show the locations of elements which are identical to the immediately preceding element in {1,2,2,3,4,4,5}. The (non-blank) results may ... | #PL.2FM | PL/M | 100H:
/* CP/M BDOS SYSTEM CALL */
BDOS: PROCEDURE( FN, ARG ); DECLARE FN BYTE, ARG ADDRESS; GOTO 5;END;
/* CONSOLE OUTPUT ROUTINES */
PR$CHAR: PROCEDURE( C ); DECLARE C BYTE; CALL BDOS( 2, C ); END;
PR$STRING: PROCEDURE( S ); DECLARE S ADDRESS; CALL BDOS( 9, S ); END;
PR$NL: PROCEDURE; CALL... | Give a code snippet in #PL.2FM
A decidely non-challenging task to highlight a potential difference between programming languages.
Using a straightforward longhand loop as in the JavaScript and Phix examples below, show the locations of elements which are identical to the immediately preceding element in {1,2,2,3,4,4,... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Mayan_numerals | Mayan numerals | Task
Present numbers using the Mayan numbering system (displaying the Mayan numerals in a cartouche).
Mayan numbers
Normally, Mayan numbers are written vertically (top─to─bottom) with the most significant
numeral at the top (in the sense that decimal numbers are written left─to─right with the most signific... | #Raku | Raku | ### Formatting ###
my $t-style = '"border-collapse: separate; text-align: center; border-spacing: 3px 0px;"';
my $c-style = '"border: solid black 2px;background-color: #fffff0;border-bottom: double 6px;'~
'border-radius: 1em;-moz-border-radius: 1em;-webkit-border-radius: 1em;'~
'vertical-align: bottom;width: 3.25em... | Give a code snippet in #Raku
Task
Present numbers using the Mayan numbering system (displaying the Mayan numerals in a cartouche).
Mayan numbers
Normally, Mayan numbers are written vertically (top─to─bottom) with the most significant
numeral at the top (in the sense that decimal numbers are written left─t... | christopher/rosetta-code | |
http://rosettacode.org/wiki/FizzBuzz | FizzBuzz | Task
Write a program that prints the integers from 1 to 100 (inclusive).
But:
for multiples of three, print Fizz (instead of the number)
for multiples of five, print Buzz (instead of the number)
for multiples of both three and five, print FizzBuzz (instead of the number)
... | #Visual_Basic_.NET | Visual Basic .NET |
implement main
open core, console
class predicates
fizzbuzz : (integer) -> string procedure (i).
clauses
fizzbuzz(X) = S :- X mod 15 = 0, S = "FizzBuzz", !.
fizzbuzz(X) = S :- X mod 5 = 0, S = "Buzz", !.
fizzbuzz(X) = S :- X mod 3 = 0, S = "Fizz", !.
fizzbuzz(X) = S :- S = toString(X).
... | Give a code snippet in #Visual_Basic_.NET
Task
Write a program that prints the integers from 1 to 100 (inclusive).
But:
for multiples of three, print Fizz (instead of the number)
for multiples of five, print Buzz (instead of the number)
for multiples of both three and five, prin... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Compiler/lexical_analyzer | Compiler/lexical analyzer | Definition from Wikipedia:
Lexical analysis is the process of converting a sequence of characters (such as in a computer program or web page) into a sequence of tokens (strings with an identified "meaning"). A program that performs lexical analysis may be called a lexer, tokenizer, or scanner (though "scanner" is als... | #Icon | Icon | #
# The Rosetta Code lexical analyzer in Icon with co-expressions. Based
# upon the ATS implementation.
#
# Usage: lex [INPUTFILE [OUTPUTFILE]]
# If INPUTFILE or OUTPUTFILE is "-" or missing, then standard input
# or standard output is used, respectively. *)
#
$define EOF -1
$define TOKEN_ELSE 0
$defin... | Give a code snippet in #Icon
Definition from Wikipedia:
Lexical analysis is the process of converting a sequence of characters (such as in a computer program or web page) into a sequence of tokens (strings with an identified "meaning"). A program that performs lexical analysis may be called a lexer, tokenizer, or sc... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Look-and-say_sequence | Look-and-say sequence | The Look and say sequence is a recursively defined sequence of numbers studied most notably by John Conway.
The look-and-say sequence is also known as the Morris Number Sequence, after cryptographer Robert Morris, and the puzzle What is the next number in the sequence 1, 11, 21, 1211, 11122... | #BBC_BASIC | BBC BASIC | number$ = "1"
FOR i% = 1 TO 10
number$ = FNlooksay(number$)
PRINT number$
NEXT
END
DEF FNlooksay(n$)
LOCAL i%, j%, c$, o$
i% = 1
REPEAT
c$ = MID$(n$,i%,1)
j% = i% + 1
WHILE MID$(n$,j%,1) = c$
j% += 1
ENDWHILE
... | Give a code snippet in #BBC_BASIC
The Look and say sequence is a recursively defined sequence of numbers studied most notably by John Conway.
The look-and-say sequence is also known as the Morris Number Sequence, after cryptographer Robert Morris, and the puzzle What is the next number in the sequ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Inheritance/Multiple | Inheritance/Multiple | Multiple inheritance allows to specify that one class is a subclass of several other classes.
Some languages allow multiple inheritance for arbitrary classes, others restrict it to interfaces, some don't allow it at all.
Task
Write two classes (or interfaces) Camera and MobilePhone, then write a class Camer... | #PowerShell | PowerShell |
class Camera {}
class MobilePhone {}
class CameraPhone : Camera, MobilePhone {}
| Give a code snippet in #PowerShell
Multiple inheritance allows to specify that one class is a subclass of several other classes.
Some languages allow multiple inheritance for arbitrary classes, others restrict it to interfaces, some don't allow it at all.
Task
Write two classes (or interfaces) Camera and Mob... | 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.
| #OCaml | OCaml | (* Ocamlgraph demo program: solving the Sudoku puzzle using graph coloring
Copyright 2004-2007 Sylvain Conchon, Jean-Christophe Filliatre, Julien Signoles
This software is free software; you can redistribute it and/or modify
it under the terms of the GNU Library General Public License version 2,
with the... | Give a code snippet in #OCaml
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/Percentage_difference_between_images | Percentage difference between images | basic bitmap storage
Useful for comparing two JPEG images saved with a different compression ratios.
You can use these pictures for testing (use the full-size version of each):
50% quality JPEG
100% quality JPEG
link to full size 50% image
link to full size 100% image
The expected difference for these two... | #Go | Go | package main
import (
"fmt"
"image/jpeg"
"os"
"log"
"image"
)
func loadJpeg(filename string) (image.Image, error) {
f, err := os.Open(filename)
if err != nil {
return nil, err
}
defer f.Close()
img, err := jpeg.Decode(f)
if err != nil {
return nil, err
... | Give a code snippet in #Go
basic bitmap storage
Useful for comparing two JPEG images saved with a different compression ratios.
You can use these pictures for testing (use the full-size version of each):
50% quality JPEG
100% quality JPEG
link to full size 50% image
link to full size 100% image
The expec... | christopher/rosetta-code | |
http://rosettacode.org/wiki/SHA-256 | SHA-256 | SHA-256 is the recommended stronger alternative to SHA-1. See FIPS PUB 180-4 for implementation details.
Either by using a dedicated library or implementing the algorithm in your language, show that the SHA-256 digest of the string "Rosetta code" is: 764faf5c61ac315f1497f9dfa542713965b785e5cc2f707d6468d7d1124cdfcf
| #Sidef | Sidef | var sha = frequire('Digest::SHA');
say sha.sha256_hex('Rosetta code'); | Give a code snippet in #Sidef
SHA-256 is the recommended stronger alternative to SHA-1. See FIPS PUB 180-4 for implementation details.
Either by using a dedicated library or implementing the algorithm in your language, show that the SHA-256 digest of the string "Rosetta code" is: 764faf5c61ac315f1497f9dfa542713965b78... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sieve_of_Eratosthenes | Sieve of Eratosthenes | This task has been clarified. Its programming examples are in need of review to ensure that they still fit the requirements of the task.
The Sieve of Eratosthenes is a simple algorithm that finds the prime numbers up to a given integer.
Task
Implement the Sieve of Eratosthenes algorithm, with the only allowed... | #PicoLisp | PicoLisp | (de sieve (N)
(let Sieve (range 1 N)
(set Sieve)
(for I (cdr Sieve)
(when I
(for (S (nth Sieve (* I I)) S (nth (cdr S) I))
(set S) ) ) )
(filter bool Sieve) ) ) | Give a code snippet in #PicoLisp
This task has been clarified. Its programming examples are in need of review to ensure that they still fit the requirements of the task.
The Sieve of Eratosthenes is a simple algorithm that finds the prime numbers up to a given integer.
Task
Implement the Sieve of Eratosthenes ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Fraction_reduction | Fraction reduction | There is a fine line between numerator and denominator. ─── anonymous
A method to "reduce" some reducible fractions is to cross out a digit from the
numerator and the denominator. An example is:
16 16
──── and then (simp... | #Ada | Ada | with Ada.Integer_Text_IO; use Ada.Integer_Text_IO;
with Ada.Text_IO; use Ada.Text_IO;
procedure Fraction_Reduction is
type Int_Array is array (Natural range <>) of Integer;
function indexOf(haystack : Int_Array; needle : Integer) return Integer is
idx : Integer := 0;
begin
for straw of haystack loop
... | Give a code snippet in #Ada
There is a fine line between numerator and denominator. ─── anonymous
A method to "reduce" some reducible fractions is to cross out a digit from the
numerator and the denominator. An example is:
16 16
... | 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... | #OCaml | OCaml | let pow one mul a n =
let rec g p x = function
| 0 -> x
| i ->
g (mul p p) (if i mod 2 = 1 then mul p x else x) (i/2)
in
g a one n
;;
pow 1 ( * ) 2 16;; (* 65536 *)
pow 1.0 ( *. ) 2.0 16;; (* 65536. *)
(* pow is not limited to exponentiation *)
pow 0 ( + ) 2 16;; (* 32 *)
pow "" ( ^ ) "abc " 10;; ... | Give a code snippet in #OCaml
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/Inverted_index | Inverted index | An Inverted Index is a data structure used to create full text search.
Task
Given a set of text files, implement a program to create an inverted index.
Also create a user interface to do a search using that inverted index which returns a list of files that contain the query term / terms.
The search index can be i... | #Common_Lisp | Common Lisp | (defpackage rosettacode.inverted-index
(:use cl))
(in-package rosettacode.inverted-index)
;; Return a list of tokens in the string LINE. This is rather
;; complicated as CL has no good standard function to do it.
(defun tokenize (line)
(let ((start 0) (len (length line)))
(loop for s = (position-if #'alphanu... | Give a code snippet in #Common_Lisp
An Inverted Index is a data structure used to create full text search.
Task
Given a set of text files, implement a program to create an inverted index.
Also create a user interface to do a search using that inverted index which returns a list of files that contain the query ter... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Walk_a_directory/Recursively | Walk a directory/Recursively | Task
Walk a given directory tree and print files matching a given pattern.
Note: This task is for recursive methods. These tasks should read an entire directory tree, not a single directory.
Note: Please be careful when running any code examples found here.
Related task
Walk a directory/Non-recursively ... | #Racket | Racket |
-> (for ([f (in-directory "/tmp")] #:when (regexp-match? "\\.rkt$" f))
(displayln f))
... *.rkt files including in nested directories ...
| Give a code snippet in #Racket
Task
Walk a given directory tree and print files matching a given pattern.
Note: This task is for recursive methods. These tasks should read an entire directory tree, not a single directory.
Note: Please be careful when running any code examples found here.
Related task
Wal... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Abstract_type | Abstract type | Abstract type is a type without instances or without definition.
For example in object-oriented programming using some languages, abstract types can be partial implementations of other types, which are to be derived there-from. An abstract type may provide implementation of some operations and/or components. Abstract ... | #Fantom | Fantom |
abstract class X
{
Void method1 ()
{
echo ("Method 1 in X")
}
abstract Void method2 ()
}
class Y : X
{
// Y must override the abstract method in X
override Void method2 ()
{
echo ("Method 2 in Y")
}
}
class Main
{
public static Void main ()
{
y := Y()
y.method1
y.method2... | Give a code snippet in #Fantom
Abstract type is a type without instances or without definition.
For example in object-oriented programming using some languages, abstract types can be partial implementations of other types, which are to be derived there-from. An abstract type may provide implementation of some operati... | christopher/rosetta-code | |
http://rosettacode.org/wiki/String_comparison | String comparison |
Basic Data Operation
This is a basic data operation. It represents a fundamental action on a basic data type.
You may see other such operations in the Basic Data Operations category, or:
Integer Operations
Arithmetic |
Comparison
Boolean Operations
Bitwise |
Logical
String Operations
Concatenation |
Interpolation |... | #PureBasic | PureBasic | Macro StrTest(Check,tof)
Print("Test "+Check+#TAB$)
If tof=1 : PrintN("true") : Else : PrintN("false") : EndIf
EndMacro
Procedure.b StrBool_eq(a$,b$) : ProcedureReturn Bool(a$=b$) : EndProcedure
Procedure.b StrBool_n_eq(a$,b$) : ProcedureReturn Bool(a$<>b$) : EndProcedure
Proced... | Give a code snippet in #PureBasic
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 Operati... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Textonyms | Textonyms | When entering text on a phone's digital pad it is possible that a particular combination of digits corresponds to more than one word. Such are called textonyms.
Assuming the digit keys are mapped to letters as follows:
2 -> ABC
3 -> DEF
4 -> GHI
5 -> JKL
6 -> MNO
7 -> PQRS
8 -> TUV
9 -... | #Racket | Racket | #lang racket
(module+ test (require tests/eli-tester))
(module+ test
(test
(map char->sms-digit (string->list "ABCDEFGHIJKLMNOPQRSTUVWXYZ."))
=> (list 2 2 2 3 3 3 4 4 4 5 5 5 6 6 6 7 7 7 7 8 8 8 9 9 9 9 #f)))
(define char->sms-digit
(match-lambda
[(? char-lower-case? (app char-upcase C)) (char->sms-digi... | Give a code snippet in #Racket
When entering text on a phone's digital pad it is possible that a particular combination of digits corresponds to more than one word. Such are called textonyms.
Assuming the digit keys are mapped to letters as follows:
2 -> ABC
3 -> DEF
4 -> GHI
5 -> JKL
6 -> MNO
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Draw_a_rotating_cube | Draw a rotating cube | Task
Draw a rotating cube.
It should be oriented with one vertex pointing straight up, and its opposite vertex on the main diagonal (the one farthest away) straight down. It can be solid or wire-frame, and you can use ASCII art if your language doesn't have graphical capabilities. Perspective is optional.
Related ... | #Delphi | Delphi |
unit main;
interface
uses
Winapi.Windows, Vcl.Graphics, Vcl.Controls, Vcl.Forms, Vcl.ExtCtrls,
System.Math, System.Classes;
type
TForm1 = class(TForm)
tmr1: TTimer;
procedure FormCreate(Sender: TObject);
procedure tmr1Timer(Sender: TObject);
private
{ Private declarations }
public
... | Give a code snippet in #Delphi
Task
Draw a rotating cube.
It should be oriented with one vertex pointing straight up, and its opposite vertex on the main diagonal (the one farthest away) straight down. It can be solid or wire-frame, and you can use ASCII art if your language doesn't have graphical capabilities. Persp... | 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... | #Processing | Processing | int g_size = 10;
color background_color = color (80, 80, 220);
color runner = color (255, 50, 50);
color visited_color = color(220, 240, 240);
color done_color = color (100, 160, 250);
int c_size;
Cell[][] cell;
ArrayList<Cell> done = new ArrayList<Cell>();
ArrayList<Cell> visit = new ArrayList<Cell>();
Cell run_cell... | Give a code snippet in #Processing
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... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Check_input_device_is_a_terminal | Check input device is a terminal | Task
Demonstrate how to check whether the input device is a terminal or not.
Related task
Check output device is a terminal
| #Scala | Scala | import org.fusesource.jansi.internal.CLibrary._
object IsATty extends App {
var enabled = true
def apply(enabled: Boolean): Boolean = {
// We must be on some unix variant..
try {
enabled && isatty(STDIN_FILENO) == 1
}
catch {
case ignore: Throwable =>
ignore.printStackTrac... | Give a code snippet in #Scala
Task
Demonstrate how to check whether the input device is a terminal or not.
Related task
Check output device is a terminal
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Largest_proper_divisor_of_n | Largest proper divisor of n | Task
a(1) = 1; for n > 1, a(n) = largest proper divisor of n, where n < 101 .
| #Swift | Swift | import Foundation
func largestProperDivisor(_ n : Int) -> Int? {
guard n > 0 else {
return nil
}
if (n & 1) == 0 {
return n >> 1
}
var p = 3
while p * p <= n {
if n % p == 0 {
return n / p
}
p += 2
}
return 1
}
for n in (1..<101) {
... | Give a code snippet in #Swift
Task
a(1) = 1; for n > 1, a(n) = largest proper divisor of n, where n < 101 .
| 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... | #Wren | Wren | import "/fmt" for Fmt
import "/big" for BigRat
var bernoulli = Fn.new { |n|
if (n < 0) Fiber.abort("Argument must be non-negative")
var a = List.filled(n+1, null)
for (m in 0..n) {
a[m] = BigRat.new(1, m+1)
var j = m
while (j >= 1) {
a[j-1] = (a[j-1] - a[j]) * BigRat.ne... | Give a code snippet in #Wren
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/File_modification_time | File modification time | Task
Get and set the modification time of a file.
| #Smalltalk | Smalltalk | |a|
a := File name: 'input.txt'.
(a lastModifyTime) printNl. | Give a code snippet in #Smalltalk
Task
Get and set the modification time of a file.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Word_wrap | Word wrap | Even today, with proportional fonts and complex layouts, there are still cases where you need to wrap text at a specified column.
Basic task
The basic task is to wrap a paragraph of text in a simple way in your language.
If there is a way to do this that is built-in, trivial, or provided in a standard library, sho... | #Wren | Wren | var greedyWordWrap = Fn.new { |text, lineWidth|
var words = text.split(" ")
var sb = words[0]
var spaceLeft = lineWidth - words[0].count
for (word in words.skip(1)) {
var len = word.count
if (len + 1 > spaceLeft) {
sb = sb + "\n" + word
spaceLeft = lineWidth - len... | Give a code snippet in #Wren
Even today, with proportional fonts and complex layouts, there are still cases where you need to wrap text at a specified column.
Basic task
The basic task is to wrap a paragraph of text in a simple way in your language.
If there is a way to do this that is built-in, trivial, or provi... | 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... | #ERRE | ERRE | PROGRAM KNUTH_SHUFFLE
CONST CARDS%=52
DIM PACK%[CARDS%]
BEGIN
RANDOMIZE(TIMER)
FOR I%=1 TO CARDS% DO
PACK%[I%]=I%
END FOR
FOR N%=CARDS% TO 2 STEP -1 DO
SWAP(PACK%[N%],PACK%[1+INT(N%*RND(1))])
END FOR
FOR I%=1 TO CARDS% DO
PRINT(PACK%[I%];)
END FOR
PRINT
END PROGRAM
| Give a code snippet in #ERRE
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 t... | 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 ... | #COBOL | COBOL | IDENTIFICATION DIVISION.
PROGRAM-ID. myTest.
DATA DIVISION.
WORKING-STORAGE SECTION.
01 x PIC 9(3) VALUE 3.
01 y PIC 9(3) VALUE 2.
01 z PIC 9(9).
PROCEDURE DIVISION.
CALL "myMultiply" USING
BY CONTENT x, BY CONTENT y,
... | Give a code snippet in #COBOL
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 ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Hilbert_curve | Hilbert curve |
Task
Produce a graphical or ASCII-art representation of a Hilbert curve of at least order 3.
| #J | J | iter=: (, 1 , +@|.) @: (,~ 0j_1 ,~ 0j_1*|.)
hilbert=: {{0j1+(%{:) +/\0,iter ^: y ''}}
| Give a code snippet in #J
Task
Produce a graphical or ASCII-art representation of a Hilbert curve of at least order 3.
| 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.
| #IDL | IDL | b = a^3 | Give a code snippet in #IDL
Task
Take a combined set of elements and apply a function to each element.
| christopher/rosetta-code |
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