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
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|---|---|---|---|---|---|---|---|---|
http://rosettacode.org/wiki/Sum_digits_of_an_integer | Sum digits of an integer | Task
Take a Natural Number in a given base and return the sum of its digits:
110 sums to 1
123410 sums to 10
fe16 sums to 29
f0e16 sums to 29
| #R | R | change.base <- function(n, base)
{
ret <- integer(as.integer(logb(x=n, base=base))+1L)
for (i in 1:length(ret))
{
ret[i] <- n %% base
n <- n %/% base
}
return(ret)
}
sum.digits <- function(n, base=10)
{
if (base < 2)
stop("base must be at least 2")
return(sum(change.base(n=n, base=ba... | Give a code snippet in #R
Task
Take a Natural Number in a given base and return the sum of its digits:
110 sums to 1
123410 sums to 10
fe16 sums to 29
f0e16 sums to 29
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Pinstripe/Display | Pinstripe/Display | Sample image
The task is to demonstrate the creation of a series of vertical pinstripes across the entire width of the display.
in the first quarter the pinstripes should alternate one pixel white, one pixel black = 1 pixel wide vertical pinestripes
Quarter of the way down the display, we can switch to a wider 2 pi... | #Wren | Wren | import "graphics" for Canvas, Color
import "dome" for Window
class Game {
static init() {
Window.title = "Pinstripe"
__width = 900
__height = 600
Canvas.resize(__width, __height)
Window.resize(__width, __height)
var colors = [
Color.hex("FFFFFF"), // whi... | Give a code snippet in #Wren
Sample image
The task is to demonstrate the creation of a series of vertical pinstripes across the entire width of the display.
in the first quarter the pinstripes should alternate one pixel white, one pixel black = 1 pixel wide vertical pinestripes
Quarter of the way down the display,... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Time_a_function | Time a function | Task
Write a program which uses a timer (with the least granularity available
on your system) to time how long a function takes to execute.
Whenever possible, use methods which measure only the processing time used
by the current process; instead of the difference in system time
between start and finish, which could ... | #Groovy | Groovy | import java.lang.management.ManagementFactory
import java.lang.management.ThreadMXBean
def threadMX = ManagementFactory.threadMXBean
assert threadMX.currentThreadCpuTimeSupported
threadMX.threadCpuTimeEnabled = true
def clockCpuTime = { Closure c ->
def start = threadMX.currentThreadCpuTime
c.call()
(th... | Give a code snippet in #Groovy
Task
Write a program which uses a timer (with the least granularity available
on your system) to time how long a function takes to execute.
Whenever possible, use methods which measure only the processing time used
by the current process; instead of the difference in system time
betwee... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Include_a_file | Include a file | Task
Demonstrate the language's ability to include source code from other files.
See Also
Compiler/Simple file inclusion pre processor
| #Action.21 | Action! | INCLUDE "D2:REAL.ACT" ;from the Action! Tool Kit
PROC Main()
RETURN | Give a code snippet in #Action.21
Task
Demonstrate the language's ability to include source code from other files.
See Also
Compiler/Simple file inclusion pre processor
| 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 ... | #ALGOL_68 | ALGOL 68 |
BEGIN
COMMENT
Mathematical preliminaries.
First note that the homogeneous polynomial (a+b)^n is symmetrical
(to see this just swap the variables a and b). Therefore its
coefficients need be calculated only to that of (ab)^{n/2} for even
n or (ab)^{(n-1)/2} for odd n.
Second, the coefficients ar... | Give a code snippet in #ALGOL_68
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 t... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Euler%27s_identity | Euler's identity |
This page uses content from Wikipedia. The original article was at Euler's_identity. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance)
In mathematics, Euler's identity is the equality:
... | #Factor | Factor | USING: math math.constants math.functions prettyprint ;
1 e pi C{ 0 1 } * ^ + . | Give a code snippet in #Factor
This page uses content from Wikipedia. The original article was at Euler's_identity. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance)
In mathematics, Euler's identity... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Display_a_linear_combination | Display a linear combination | Task
Display a finite linear combination in an infinite vector basis
(
e
1
,
e
2
,
…
)
{\displaystyle (e_{1},e_{2},\ldots )}
.
Write a function that, when given a finite list of scalars
(
α
1
,
α
2
,
…
)
{\displaystyle (\alpha ^{1},\alpha ^{2},\ldots )}
,
creates a string representing t... | #EchoLisp | EchoLisp |
;; build an html string from list of coeffs
(define (linear->html coeffs)
(define plus #f)
(or*
(for/fold (html "") ((a coeffs) (i (in-naturals 1)))
(unless (zero? a)
(set! plus (if plus "+" "")))
(string-append html
(cond
((= a 1) (format "%a e<sub>%d</sub> " plus i))
((= a -... | Give a code snippet in #EchoLisp
Task
Display a finite linear combination in an infinite vector basis
(
e
1
,
e
2
,
…
)
{\displaystyle (e_{1},e_{2},\ldots )}
.
Write a function that, when given a finite list of scalars
(
α
1
,
α
2
,
…
)
{\displaystyle (\alpha ^{1},\alpha ^{2},\ldots )}
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/A%2BB | A+B | A+B ─── a classic problem in programming contests, it's given so contestants can gain familiarity with the online judging system being used.
Task
Given two integers, A and B.
Their sum needs to be calculated.
Input data
Two integers are written in the input stream, separated by space(s):
(
−
1000
≤... | #Fantom | Fantom | class APlusB
{
public static Void main ()
{
echo ("Enter two numbers: ")
Str input := Env.cur.in.readLine
Int sum := 0
input.split.each |n| { sum += n.toInt }
echo (sum)
}
} | Give a code snippet in #Fantom
A+B ─── a classic problem in programming contests, it's given so contestants can gain familiarity with the online judging system being used.
Task
Given two integers, A and B.
Their sum needs to be calculated.
Input data
Two integers are written in the input stream, separat... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Brace_expansion | Brace expansion | Brace expansion is a type of parameter expansion made popular by Unix shells, where it allows users to specify multiple similar string parameters without having to type them all out. E.g. the parameter enable_{audio,video} would be interpreted as if both enable_audio and enable_video had been specified.
Task[edit]
W... | #C.2B.2B | C++ | #include <iostream>
#include <iterator>
#include <string>
#include <utility>
#include <vector>
namespace detail {
template <typename ForwardIterator>
class tokenizer
{
ForwardIterator _tbegin, _tend, _end;
public:
tokenizer(ForwardIterator begin, ForwardIterator end)
: _tbegin(begin), _tend(begin), _end(e... | Give a code snippet in #C.2B.2B
Brace expansion is a type of parameter expansion made popular by Unix shells, where it allows users to specify multiple similar string parameters without having to type them all out. E.g. the parameter enable_{audio,video} would be interpreted as if both enable_audio and enable_video ha... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sum_and_product_of_an_array | Sum and product of an array | Task
Compute the sum and product of an array of integers.
| #SNOBOL4 | SNOBOL4 | t = table()
* read the integer from the std. input
init_tab t<x = x + 1> = trim(input) :s(init_tab)
product = 1
sum = 0
* counting backwards to 1
loop i = t< x = ?gt(x,1) x - 1> :f(out)
sum = sum + i
product = product * i :(loop)
out output = "S... | Give a code snippet in #SNOBOL4
Task
Compute the sum and product of an array of integers.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Infinity | Infinity | Task
Write a function which tests if infinity is supported for floating point numbers (this step should be omitted for languages where the language specification already demands the existence of infinity, e.g. by demanding IEEE numbers), and if so, returns positive infinity. Otherwise, return the largest possible po... | #PostScript | PostScript | /infinity { 9 99 exp } def | Give a code snippet in #PostScript
Task
Write a function which tests if infinity is supported for floating point numbers (this step should be omitted for languages where the language specification already demands the existence of infinity, e.g. by demanding IEEE numbers), and if so, returns positive infinity. Other... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Averages/Median | Averages/Median | Task[edit]
Write a program to find the median value of a vector of floating-point numbers.
The program need not handle the case where the vector is empty, but must handle the case where there are an even number of elements. In that case, return the average of the two middle values.
There are several approaches ... | #ReScript | ReScript | let median = (arr) =>
{
let float_compare = (a, b) => {
let diff = a -. b
if diff == 0.0 { 0 } else
if diff > 0.0 { 1 } else { -1 }
}
let _ = Js.Array2.sortInPlaceWith(arr, float_compare)
let count = Js.Array.length(arr)
// find the middle value, or the lowest middle value
let ... | Give a code snippet in #ReScript
Task[edit]
Write a program to find the median value of a vector of floating-point numbers.
The program need not handle the case where the vector is empty, but must handle the case where there are an even number of elements. In that case, return the average of the two middle valu... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Truncatable_primes | Truncatable primes | A truncatable prime is a prime number that when you successively remove digits from one end of the prime, you are left with a new prime number.
Examples
The number 997 is called a left-truncatable prime as the numbers 997, 97, and 7 are all prime.
The number 7393 is a right-truncatable prime as the numbers 7393, 7... | #Nim | Nim | import sets, strutils, algorithm
proc primes(n: int64): seq[int64] =
var multiples: HashSet[int64]
for i in 2..n:
if i notin multiples:
result.add i
for j in countup(i*i, n, i.int):
multiples.incl j
proc truncatablePrime(n: int64): tuple[left, right: int64] =
var
primelist: seq[str... | Give a code snippet in #Nim
A truncatable prime is a prime number that when you successively remove digits from one end of the prime, you are left with a new prime number.
Examples
The number 997 is called a left-truncatable prime as the numbers 997, 97, and 7 are all prime.
The number 7393 is a right-truncatable... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Assertions | Assertions | Assertions are a way of breaking out of code when there is an error or an unexpected input.
Some languages throw exceptions and some treat it as a break point.
Task
Show an assertion in your language by asserting that an integer variable is equal to 42.
| #Mathematica_.2F_Wolfram_Language | Mathematica / Wolfram Language | Assert[var===42] | Give a code snippet in #Mathematica_.2F_Wolfram_Language
Assertions are a way of breaking out of code when there is an error or an unexpected input.
Some languages throw exceptions and some treat it as a break point.
Task
Show an assertion in your language by asserting that an integer variable is equal to 42.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Bioinformatics/base_count | Bioinformatics/base count | Given this string representing ordered DNA bases:
CGTAAAAAATTACAACGTCCTTTGGCTATCTCTTAAACTCCTGCTAAATG
CTCGTGCTTTCCAATTATGTAAGCGTTCCGAGACGGGGTGGTCGATTCTG
AGGACAAAGGTCAAGATGGAGCGCATCGAACGCAATAAGGATCATTTGAT
GGGACGTTTCGTCGACAAAGTCTTGTTTCGAGAGTAACGGCTACCGTCTT
CGATTCTGCTTATAACACTATGTTCTTATGAAATGGATGTTCTGAGTTGG
TCAGTCCCAATGTG... | #PicoLisp | PicoLisp | (let
(S (chop "CGTAAAAAATTACAACGTCCTTTGGCTATCTCTTAAACTCCTGCTAAATG\
CTCGTGCTTTCCAATTATGTAAGCGTTCCGAGACGGGGTGGTCGATTCTG\
AGGACAAAGGTCAAGATGGAGCGCATCGAACGCAATAAGGATCATTTGAT\
GGGACGTTTCGTCGACAAAGTCTTGTTTCGAGAGTAACGGCTACCGTCTT\
CGATTCTGCTTATAACACTATGTTCTTATGAAATGGATGTTCTGAGTTGG\
TCAGTCCCAATG... | Give a code snippet in #PicoLisp
Given this string representing ordered DNA bases:
CGTAAAAAATTACAACGTCCTTTGGCTATCTCTTAAACTCCTGCTAAATG
CTCGTGCTTTCCAATTATGTAAGCGTTCCGAGACGGGGTGGTCGATTCTG
AGGACAAAGGTCAAGATGGAGCGCATCGAACGCAATAAGGATCATTTGAT
GGGACGTTTCGTCGACAAAGTCTTGTTTCGAGAGTAACGGCTACCGTCTT
CGATTCTGCTTATAACACTATGTTCTTATGA... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Window_management | Window management | Treat windows or at least window identities as first class objects.
Store window identities in variables, compare them for equality.
Provide examples of performing some of the following:
hide,
show,
close,
minimize,
maximize,
move, and
resize a window.
The window of interest may or may not have b... | #Racket | Racket |
#lang racket/gui
(define (say . xs) (printf ">>> ~a\n" (apply ~a xs)) (flush-output))
(define frame (new frame% [label "Demo"] [width 400] [height 400]))
(say "frame = " frame) ; plain value
(say 'Show) (send frame show #t) (sleep 1)
(say 'Hide) (send frame show #f) (sleep 1)
(say 'Show) (... | Give a code snippet in #Racket
Treat windows or at least window identities as first class objects.
Store window identities in variables, compare them for equality.
Provide examples of performing some of the following:
hide,
show,
close,
minimize,
maximize,
move, and
resize a window.
The window o... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Use_another_language_to_call_a_function | Use another language to call a 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.
This task is inverse to the task Call foreign language function. Consider the following C program:
#include <stdio.h>
extern int Query (char * Data, size_t * Length);
int main (i... | #X86-64_Assembly | X86-64 Assembly |
option casemap:none
strlen proto :qword
strncpy proto :qword, :qword, :dword
Query proto :qword, :qword
.data
szstr db "Here am I",0
.code
Query proc Data:qword, len:qword
local d:qword, l:qword, s:dword
mov d, Data
mov l, len
invoke strlen, addr szstr
.if rax <= l
mov s, eax
invo... | Give a code snippet in #X86-64_Assembly
This task has been clarified. Its programming examples are in need of review to ensure that they still fit the requirements of the task.
This task is inverse to the task Call foreign language function. Consider the following C program:
#include <stdio.h>
extern int Query (cha... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Convex_hull | Convex hull | Find the points which form a convex hull from a set of arbitrary two dimensional points.
For example, given the points (16,3), (12,17), (0,6), (-4,-6), (16,6), (16,-7), (16,-3), (17,-4), (5,19), (19,-8), (3,16), (12,13), (3,-4), (17,5), (-3,15), (-3,-9), (0,11), (-9,-3), (-4,-2) and (12,10) the convex hull would be (-... | #Standard_ML | Standard ML | (*
* Convex hulls by Andrew's monotone chain algorithm.
*
* For a description of the algorithm, see
* https://en.wikibooks.org/w/index.php?title=Algorithm_Implementation/Geometry/Convex_hull/Monotone_chain&stableid=40169
*)
(*------------------------------------------------------------------*)
(*
* Just enough ... | Give a code snippet in #Standard_ML
Find the points which form a convex hull from a set of arbitrary two dimensional points.
For example, given the points (16,3), (12,17), (0,6), (-4,-6), (16,6), (16,-7), (16,-3), (17,-4), (5,19), (19,-8), (3,16), (12,13), (3,-4), (17,5), (-3,15), (-3,-9), (0,11), (-9,-3), (-4,-2) an... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sorting_algorithms/Heapsort | Sorting algorithms/Heapsort |
Sorting Algorithm
This is a sorting algorithm. It may be applied to a set of data in order to sort it.
For comparing various sorts, see compare sorts.
For other sorting algorithms, see sorting algorithms, or:
O(n logn) sorts
Heap sort |
Merge sort |
Patience sort |
Quick sort
O(n log2n) sorts
Shell Sort
... | #E | E | def heapsort := {
def cswap(c, a, b) {
def t := c[a]
c[a] := c[b]
c[b] := t
# println(c)
}
def siftDown(array, start, finish) {
var root := start
while (var child := root * 2 + 1
child <= finish) {
if (child + 1 <= finish && array[child] < array[child + 1]) {
c... | Give a code snippet in #E
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/Associative_array/Creation | Associative array/Creation | Task
The goal is to create an associative array (also known as a dictionary, map, or hash).
Related tasks:
Associative arrays/Iteration
Hash from two arrays
See also
Array
Associative array: Creation, Iteration
Collections
Compound data type
Doubly-linked list: Definition, Element definition, Element ins... | #Jsish | Jsish | var assoc = {};
assoc['foo'] = 'bar';
assoc['another-key'] = 3;
// dot notation can be used if the property name is a valid identifier
assoc.thirdKey = 'we can also do this!';
assoc[2] = "the index here is the string '2'";
;assoc;
//using JavaScript's object literal notation
var assoc = {
foo: 'bar',
'another... | Give a code snippet in #Jsish
Task
The goal is to create an associative array (also known as a dictionary, map, or hash).
Related tasks:
Associative arrays/Iteration
Hash from two arrays
See also
Array
Associative array: Creation, Iteration
Collections
Compound data type
Doubly-linked list: Definition, ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Filter | Filter | Task
Select certain elements from an Array into a new Array in a generic way.
To demonstrate, select all even numbers from an Array.
As an option, give a second solution which filters destructively,
by modifying the original Array rather than creating a new Array.
| #C.23 | C# | ArrayList array = new ArrayList( new int[] { 1, 2, 3, 4, 5 } );
ArrayList evens = new ArrayList();
foreach( int i in array )
{
if( (i%2) == 0 )
evens.Add( i );
}
foreach( int i in evens )
System.Console.WriteLine( i.ToString() ); | Give a code snippet in #C.23
Task
Select certain elements from an Array into a new Array in a generic way.
To demonstrate, select all even numbers from an Array.
As an option, give a second solution which filters destructively,
by modifying the original Array rather than creating a new Array.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Write_entire_file | Write entire file | Task
(Over)write a file so that it contains a string.
The reverse of Read entire file—for when you want to update or create a file which you would read in its entirety all at once.
| #Free_Pascal | Free Pascal | program overwriteFile(input, output, stdErr);
{$mode objFPC} // for exception treatment
uses
sysUtils; // for applicationName, getTempDir, getTempFileName
// also: importing sysUtils converts all run-time errors to exceptions
resourcestring
hooray = 'Hello world!';
var
FD: text;
begin
// on a Debian GNU/Linux dist... | Give a code snippet in #Free_Pascal
Task
(Over)write a file so that it contains a string.
The reverse of Read entire file—for when you want to update or create a file which you would read in its entirety all at once.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Pascal%27s_triangle/Puzzle | Pascal's triangle/Puzzle | This puzzle involves a Pascals Triangle, also known as a Pyramid of Numbers.
[ 151]
[ ][ ]
[40][ ][ ]
[ ][ ][ ][ ]
[ X][11][ Y][ 4][ Z]
Each brick of the pyramid is the sum of the two bricks situated below it.
Of the three missing numbers at the base of the pyramid,
the... | #Scala | Scala | object PascalTriangle extends App {
val (x, y, z) = pascal(11, 4, 40, 151)
def pascal(a: Int, b: Int, mid: Int, top: Int): (Int, Int, Int) = {
val y = (top - 4 * (a + b)) / 7
val x = mid - 2 * a - y
(x, y, y - x)
}
println(if (x != 0) s"Solution is: x = $x, y = $y, z = $z" else "There is no so... | Give a code snippet in #Scala
This puzzle involves a Pascals Triangle, also known as a Pyramid of Numbers.
[ 151]
[ ][ ]
[40][ ][ ]
[ ][ ][ ][ ]
[ X][11][ Y][ 4][ Z]
Each brick of the pyramid is the sum of the two bricks situated below it.
Of the three missing numbers ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Binary_strings | Binary strings | Many languages have powerful and useful (binary safe) string manipulation functions, while others don't, making it harder for these languages to accomplish some tasks.
This task is about creating functions to handle binary strings (strings made of arbitrary bytes, i.e. byte strings according to Wikipedia) for those la... | #PicoLisp | PicoLisp | : (out "rawfile"
(mapc wr (range 0 255)) ) | Give a code snippet in #PicoLisp
Many languages have powerful and useful (binary safe) string manipulation functions, while others don't, making it harder for these languages to accomplish some tasks.
This task is about creating functions to handle binary strings (strings made of arbitrary bytes, i.e. byte strings ac... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Unicode_strings | Unicode strings | As the world gets smaller each day, internationalization becomes more and more important. For handling multiple languages, Unicode is your best friend.
It is a very capable tool, but also quite complex compared to older single- and double-byte character encodings.
How well prepared is your programming language for ... | #Rust | Rust | # International class; name and street
class 国際( なまえ, Straße ) {
# Say who am I!
method 言え {
say "I am #{self.なまえ} from #{self.Straße}";
}
}
# all the people of the world!
var 民族 = [
国際( "高田 Friederich", "台湾" ),
国際( "Smith Σωκράτης", "Cantù" ),
国際( "S... | Give a code snippet in #Rust
As the world gets smaller each day, internationalization becomes more and more important. For handling multiple languages, Unicode is your best friend.
It is a very capable tool, but also quite complex compared to older single- and double-byte character encodings.
How well prepared is ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sort_stability | Sort stability |
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
... | #Raku | Raku | use v6;
my @cities =
['UK', 'London'],
['US', 'New York'],
['US', 'Birmingham'],
['UK', 'Birmingham'],
;
.say for @cities.sort: { .[1] }; | Give a code snippet in #Raku
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/Jaro-Winkler_distance | Jaro-Winkler distance | The Jaro-Winkler distance is a metric for measuring the edit distance between words.
It is similar to the more basic Levenstein distance but the Jaro distance also accounts
for transpositions between letters in the words. With the Winkler modification to the Jaro
metric, the Jaro-Winkler distance also adds an increase ... | #C.2B.2B | C++ | #include <algorithm>
#include <cstdlib>
#include <fstream>
#include <iomanip>
#include <iostream>
#include <string>
#include <vector>
auto load_dictionary(const std::string& path) {
std::ifstream in(path);
if (!in)
throw std::runtime_error("Cannot open file " + path);
std::string line;
std::ve... | Give a code snippet in #C.2B.2B
The Jaro-Winkler distance is a metric for measuring the edit distance between words.
It is similar to the more basic Levenstein distance but the Jaro distance also accounts
for transpositions between letters in the words. With the Winkler modification to the Jaro
metric, the Jaro-Winkle... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Environment_variables | Environment variables | Task
Show how to get one of your process's environment variables.
The available variables vary by system; some of the common ones available on Unix include:
PATH
HOME
USER
| #Groovy | Groovy | System.getenv().each { property, value -> println "$property = $value"} | Give a code snippet in #Groovy
Task
Show how to get one of your process's environment variables.
The available variables vary by system; some of the common ones available on Unix include:
PATH
HOME
USER
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Latin_Squares_in_reduced_form/Randomizing_using_Jacobson_and_Matthews%E2%80%99_Technique | Latin Squares in reduced form/Randomizing using Jacobson and Matthews’ Technique | Section 3.3 of [Generalised 2-designs with Block Size 3(Andy L. Drizen)] describes a method of generating Latin Squares of order n attributed to Jacobson and Matthews. The purpose of this task is to produce a function which given a valid Latin Square transforms it to another using this method.
part 1
Use one of the 4 ... | #Wren | Wren | import "random" for Random
import "/fmt" for Fmt
import "/seq" for Lst
var rand = Random.new()
var toReduced = Fn.new { |m|
var n = m.count
var r = List.filled(n, null)
for (i in 0...n) r[i] = m[i].toList
for (j in 0...n-1) {
if (r[0][j] != j) {
for (k in j+1...n) {
... | Give a code snippet in #Wren
Section 3.3 of [Generalised 2-designs with Block Size 3(Andy L. Drizen)] describes a method of generating Latin Squares of order n attributed to Jacobson and Matthews. The purpose of this task is to produce a function which given a valid Latin Square transforms it to another using this met... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Partition_function_P | Partition function P |
The Partition Function P, often notated P(n) is the number of solutions where n∈ℤ can be expressed as the sum of a set of positive integers.
Example
P(4) = 5 because 4 = Σ(4) = Σ(3,1) = Σ(2,2) = Σ(2,1,1) = Σ(1,1,1,1)
P(n) can be expressed as the recurrence relation:
P(n) = P(n-1) +P(n-2) -P(n-5) -P(n-7)... | #Prolog | Prolog |
/* SWI-Prolog 8.3.21 */
/* Author: Jan Burse */
:- table p/2.
p(0, 1) :- !.
p(N, X) :-
aggregate_all(sum(Z), (between(1,inf,K), M is K*(3*K-1)//2,
(M>N, !, fail; L is N-M, p(L,Y), Z is (-1)^K*Y)), A),
aggregate_all(sum(Z), (between(1,inf,K), M is K*(3*K+1)//2,
(M>N, !, fail; L is N-M, p(... | Give a code snippet in #Prolog
The Partition Function P, often notated P(n) is the number of solutions where n∈ℤ can be expressed as the sum of a set of positive integers.
Example
P(4) = 5 because 4 = Σ(4) = Σ(3,1) = Σ(2,2) = Σ(2,1,1) = Σ(1,1,1,1)
P(n) can be expressed as the recurrence relation:
P(n) ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Calculating_the_value_of_e | Calculating the value of e | Task
Calculate the value of e.
(e is also known as Euler's number and Napier's constant.)
See details: Calculating the value of e
| #langur | langur | mode divMaxScale = 104
val .epsilon = 1.0e-104
var .e = 2
for .fact, .n = 1, 2 ; ; .n += 1 {
val .e0 = .e
.fact x= .n
.e += 1 / .fact
if abs(.e - .e0) < .epsilon: break
}
writeln ".e = ", .e
# compare to built-in constant e
writeln " e = ", e | Give a code snippet in #langur
Task
Calculate the value of e.
(e is also known as Euler's number and Napier's constant.)
See details: Calculating the value of e
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Pierpont_primes | Pierpont primes | A Pierpont prime is a prime number of the form: 2u3v + 1 for some non-negative integers u and v .
A Pierpont prime of the second kind is a prime number of the form: 2u3v - 1 for some non-negative integers u and v .
The term "Pierpont primes" is generally understood to mean the first definition, but will be c... | #Phix | Phix | -- demo/rosetta/Pierpont_primes.exw
with javascript_semantics
include mpfr.e
function pierpont(integer n)
sequence p = {{mpz_init(2)},{}},
s = {mpz_init(1)}
integer i2 = 1, i3 = 1
mpz {n2, n3, t} = mpz_inits(3)
atom t1 = time()+1
while min(length(p[1]),length(p[2])) < n do
mpz... | Give a code snippet in #Phix
A Pierpont prime is a prime number of the form: 2u3v + 1 for some non-negative integers u and v .
A Pierpont prime of the second kind is a prime number of the form: 2u3v - 1 for some non-negative integers u and v .
The term "Pierpont primes" is generally understood to mean the f... | christopher/rosetta-code | |
http://rosettacode.org/wiki/URL_decoding | URL decoding | This task (the reverse of URL encoding and distinct from URL parser) is to provide a function
or mechanism to convert an URL-encoded string into its original unencoded form.
Test cases
The encoded string "http%3A%2F%2Ffoo%20bar%2F" should be reverted to the unencoded form "http://foo bar/".
Th... | #Lasso | Lasso | bytes('http%3A%2F%2Ffoo%20bar%2F') -> decodeurl | Give a code snippet in #Lasso
This task (the reverse of URL encoding and distinct from URL parser) is to provide a function
or mechanism to convert an URL-encoded string into its original unencoded form.
Test cases
The encoded string "http%3A%2F%2Ffoo%20bar%2F" should be reverted to the unencoded ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Documentation | Documentation |
See also
Related task: Comments
Related task: Here_document
| #Delphi | Delphi | type
/// <summary>Sample class.</summary>
TMyClass = class
public
/// <summary>Converts a string into a number.</summary>
/// <param name="aValue">String parameter</param>
/// <returns>Numeric equivalent of aValue</returns>
/// <exception cref="EConvertError">aValue is not a valid integer.</except... | Give a code snippet in #Delphi
See also
Related task: Comments
Related task: Here_document
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Random_numbers | Random numbers | Task
Generate a collection filled with 1000 normally distributed random (or pseudo-random) numbers
with a mean of 1.0 and a standard deviation of 0.5
Many libraries only generate uniformly distributed random numbers. If so, you may use one of these algorithms.
Related task
Standard deviation
| #C.23 | C# |
private static double randomNormal()
{
return Math.Cos(2 * Math.PI * tRand.NextDouble()) * Math.Sqrt(-2 * Math.Log(tRand.NextDouble()));
}
| Give a code snippet in #C.23
Task
Generate a collection filled with 1000 normally distributed random (or pseudo-random) numbers
with a mean of 1.0 and a standard deviation of 0.5
Many libraries only generate uniformly distributed random numbers. If so, you may use one of these algorithms.
Related ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Aliquot_sequence_classifications | Aliquot sequence classifications | An aliquot sequence of a positive integer K is defined recursively as the first member
being K and subsequent members being the sum of the Proper divisors of the previous term.
If the terms eventually reach 0 then the series for K is said to terminate.
There are several classifications for non termination:
If the s... | #Oforth | Oforth | import: mapping
import: quicksort
import: math
Object method: sum ( coll -- m )
#+ self reduce dup ifNull: [ drop 0 ] ;
Integer method: properDivs
| i l |
Array new dup 1 over add ->l
2 self nsqrt tuck for: i [ self i mod ifFalse: [ i l add self i / l add ] ]
sq self == ifTrue: [ l pop drop ]
dup so... | Give a code snippet in #Oforth
An aliquot sequence of a positive integer K is defined recursively as the first member
being K and subsequent members being the sum of the Proper divisors of the previous term.
If the terms eventually reach 0 then the series for K is said to terminate.
There are several classification... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Topswops | Topswops | Topswops is a card game created by John Conway in the 1970's.
Assume you have a particular permutation of a set of n cards numbered 1..n on both of their faces, for example the arrangement of four cards given by [2, 4, 1, 3] where the leftmost card is on top.
A round is composed of reversing the first ... | #Haskell | Haskell | import Data.List (permutations)
topswops :: Int -> Int
topswops n = maximum $ map tops $ permutations [1 .. n]
where
tops (1:_) = 0
tops xa@(x:_) = 1 + tops reordered
where
reordered = reverse (take x xa) ++ drop x xa
main =
mapM_ (putStrLn . ((++) <$> show <*> (":\t" ++) . show . topswops... | Give a code snippet in #Haskell
Topswops is a card game created by John Conway in the 1970's.
Assume you have a particular permutation of a set of n cards numbered 1..n on both of their faces, for example the arrangement of four cards given by [2, 4, 1, 3] where the leftmost card is on top.
A round is ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Remove_duplicate_elements | Remove duplicate elements |
Sorting Algorithm
This is a sorting algorithm. It may be applied to a set of data in order to sort it.
For comparing various sorts, see compare sorts.
For other sorting algorithms, see sorting algorithms, or:
O(n logn) sorts
Heap sort |
Merge sort |
Patience sort |
Quick sort
O(n log2n) sorts
Shell Sort
... | #Neko | Neko | /**
Remove duplicate elements, in Neko
*/
var original = $array(1, 2, 1, 4, 5, 2, 15, 1, 3, 4)
/* Create a table with only unique elements from the array */
var dedup = function(a) {
var size = $asize(a)
var hash = $hnew(size)
while size > 0 {
var v = a[size - 1]
var k = $hkey(v)
... | Give a code snippet in #Neko
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/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
)
)
,
... | #Smalltalk | Smalltalk | |F M ra rb|
F := [ :n |
(n == 0)
ifTrue: [ 1 ]
ifFalse: [ n - (M value: (F value: (n-1))) ]
].
M := [ :n |
(n == 0)
ifTrue: [ 0 ]
ifFalse: [ n - (F value: (M value: (n-1))) ]
].
ra := OrderedCollection new.
rb := OrderedCollection new.
0 to: 19 do: [ :i |
ra add: (F value: i).
rb ad... | Give a code snippet in #Smalltalk
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
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Arithmetic/Rational | Arithmetic/Rational | Task
Create a reasonably complete implementation of rational arithmetic in the particular language using the idioms of the language.
Example
Define a new type called frac with binary operator "//" of two integers that returns a structure made up of the numerator and the denominator (as per a rational number).
Fur... | #Lingo | Lingo | -- parent script "Frac"
property num
property denom
----------------------------------------
-- @constructor
-- @param {integer} numerator
-- @param {integer} [denominator=1]
----------------------------------------
on new (me, numerator, denominator)
if voidP(denominator) then denominator = 1
if denominator=0 th... | Give a code snippet in #Lingo
Task
Create a reasonably complete implementation of rational arithmetic in the particular language using the idioms of the language.
Example
Define a new type called frac with binary operator "//" of two integers that returns a structure made up of the numerator and the denominator (... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Comments | Comments | Task
Show all ways to include text in a language source file
that's completely ignored by the compiler or interpreter.
Related tasks
Documentation
Here_document
See also
Wikipedia
xkcd (Humor: hand gesture denoting // for "commenting out" people.)
| #Wart | Wart | # single-line comment | Give a code snippet in #Wart
Task
Show all ways to include text in a language source file
that's completely ignored by the compiler or interpreter.
Related tasks
Documentation
Here_document
See also
Wikipedia
xkcd (Humor: hand gesture denoting // for "commenting out" people.)
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Naming_conventions | Naming conventions | Many languages have naming conventions regarding the identifiers used in the language, its libraries, and programs written in the language. Such conventions, which may be classified as de facto or de jure depending on how they are enforced,
often take the form of rules regarding prefixes, suffixes, and the use of upper... | #Julia | Julia | // version 1.0.6
const val SOLAR_DIAMETER = 864938
enum class Planet { MERCURY, VENUS, EARTH, MARS, JUPITER, SATURN, URANUS, NEPTUNE, PLUTO } // Yeah, Pluto!
class Star(val name: String) {
fun showDiameter() {
println("The diameter of the $name is ${"%,d".format(SOLAR_DIAMETER)} miles")
}
}
clas... | Give a code snippet in #Julia
Many languages have naming conventions regarding the identifiers used in the language, its libraries, and programs written in the language. Such conventions, which may be classified as de facto or de jure depending on how they are enforced,
often take the form of rules regarding prefixes,... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Pig_the_dice_game | Pig the dice game | The game of Pig is a multiplayer game played with a single six-sided die. The
object of the game is to reach 100 points or more.
Play is taken in turns. On each person's turn that person has the option of either:
Rolling the dice: where a roll of two to six is added to their score for that turn and th... | #FOCAL | FOCAL | 01.10 T "GAME OF PIG"!
01.20 S S(1)=0;S S(2)=0;S P=1
01.30 T !"PLAYER",%1,P," TURN BEGINS"!
01.40 D 3;I (99-S(P))1.7
01.50 S P=3-P
01.60 G 1.3
01.70 T !"THE WINNER IS PLAYER",%1,P,!
01.80 Q
02.10 S A=10*FRAN();S A=1+FITR(6*(A-FITR(A)))
03.10 S T=0
03.20 T "PLAYER",%1,P," SCORE",%3,S(P)," TURN",%3,T
03.25 D 2;T " ... | Give a code snippet in #FOCAL
The game of Pig is a multiplayer game played with a single six-sided die. The
object of the game is to reach 100 points or more.
Play is taken in turns. On each person's turn that person has the option of either:
Rolling the dice: where a roll of two to six is added to t... | christopher/rosetta-code | |
http://rosettacode.org/wiki/The_Twelve_Days_of_Christmas | The Twelve Days of Christmas | Task
Write a program that outputs the lyrics of the Christmas carol The Twelve Days of Christmas.
The lyrics can be found here.
(You must reproduce the words in the correct order, but case, format, and punctuation are left to your discretion.)
Other tasks related to string operations:
Metrics
Array length
Stri... | #Scala | Scala | val gifts = Array(
"A partridge in a pear tree.",
"Two turtle doves and",
"Three French hens,",
"Four calling birds,",
"Five gold rings,",
"Six geese a-laying,",
"Seven swans a-swimming,",
"Eight maids a-milking,",
"Nine ladies dancing,",
"Ten lords a-leaping,",
"Eleven piper... | Give a code snippet in #Scala
Task
Write a program that outputs the lyrics of the Christmas carol The Twelve Days of Christmas.
The lyrics can be found here.
(You must reproduce the words in the correct order, but case, format, and punctuation are left to your discretion.)
Other tasks related to string operation... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Classes | Classes | In object-oriented programming class is a set (a transitive closure) of types bound by the relation of inheritance. It is said that all types derived from some base type T and the type T itself form a class T.
The first type T from the class T sometimes is called the root type of the class.
A class of types itself, a... | #Portugol | Portugol |
programa {
inclua biblioteca Objetos --> obj
// "constructor" returns address of object
funcao inteiro my_class_new(inteiro value) {
inteiro this = obj.criar_objeto()
obj.atribuir_propriedade(this, "variable", value) // add property to object
retorne this
}
// "method" ... | Give a code snippet in #Portugol
In object-oriented programming class is a set (a transitive closure) of types bound by the relation of inheritance. It is said that all types derived from some base type T and the type T itself form a class T.
The first type T from the class T sometimes is called the root type of the ... | 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... | #Ring | Ring |
see char(7)
| Give a code snippet in #Ring
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 wit... | christopher/rosetta-code | |
http://rosettacode.org/wiki/K-means%2B%2B_clustering | K-means++ clustering | K-means++ clustering
K-means
This data was partitioned into 7 clusters using the K-means algorithm.
The task is to implement the K-means++ algorithm. Produce a function which takes two arguments: the number of clusters K, and the dataset to classify. K is a positive integer and the dataset is a list of points in the C... | #Mathematica.2FWolfram_Language | Mathematica/Wolfram Language | initM[list_List, k_Integer, distFunc_Symbol] :=
Module[{m = {RandomChoice[list]}, n, d},
While[Length[m] < k,
n = RandomChoice@Nearest[m, #] & /@ list;
d = Apply[distFunc, Transpose[{n, list}], {1}];
m = Append[m, RandomChoice[d -> list]]
];
m
];
kmeanspp[list_, k_,
opts : OptionsPatter... | Give a code snippet in #Mathematica.2FWolfram_Language
K-means++ clustering
K-means
This data was partitioned into 7 clusters using the K-means algorithm.
The task is to implement the K-means++ algorithm. Produce a function which takes two arguments: the number of clusters K, and the dataset to classify. K is a posit... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Thiele%27s_interpolation_formula | Thiele's interpolation formula |
This page uses content from Wikipedia. The original article was at Thiele's interpolation formula. 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)
Thiele's interpolation formula is an interpolation ... | #Sidef | Sidef | func thiele(x, y) {
var ρ = {|i| [y[i]]*(y.len-i) }.map(^y)
for i in ^(ρ.end) {
ρ[i][1] = ((x[i] - x[i+1]) / (ρ[i][0] - ρ[i+1][0]))
}
for i (2 .. ρ.end) {
for j (0 .. ρ.end-i) {
ρ[j][i] = (((x[j]-x[j+i]) / (ρ[j][i-1]-ρ[j+1][i-1])) + ρ[j+1][i-2])
}
}
var ρ0... | Give a code snippet in #Sidef
This page uses content from Wikipedia. The original article was at Thiele's interpolation formula. 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)
Thiele's interpolati... | 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... | #Lambdatalk | Lambdatalk |
{def foo
{lambda {:s}
{if {S.empty? {S.rest :s}}
then {br}{S.first :s}
else {br}{S.first :s} {foo {S.rest :s}}}}}
{foo hello brave new world} ->
hello
brave
new
world
{foo {S.serie 1 10}} ->
1
2
3
4
5
6
7
8
9
10
| Give a code snippet in #Lambdatalk
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.... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Strip_block_comments | Strip block comments | A block comment begins with a beginning delimiter and ends with a ending delimiter, including the delimiters. These delimiters are often multi-character sequences.
Task
Strip block comments from program text (of a programming language much like classic C).
Your demos should at least handle simple, non-ne... | #Python | Python | def _commentstripper(txt, delim):
'Strips first nest of block comments'
deliml, delimr = delim
out = ''
if deliml in txt:
indx = txt.index(deliml)
out += txt[:indx]
txt = txt[indx+len(deliml):]
txt = _commentstripper(txt, delim)
assert delimr in txt, 'Cannot fin... | Give a code snippet in #Python
A block comment begins with a beginning delimiter and ends with a ending delimiter, including the delimiters. These delimiters are often multi-character sequences.
Task
Strip block comments from program text (of a programming language much like classic C).
Your demos shoul... | christopher/rosetta-code | |
http://rosettacode.org/wiki/String_case | String case | Task
Take the string alphaBETA and demonstrate how to convert it to:
upper-case and
lower-case
Use the default encoding of a string literal or plain ASCII if there is no string literal in your language.
Note: In some languages alphabets toLower and toUpper is not reversable.
Show any additional... | #OCaml | OCaml | let () =
let str = "alphaBETA" in
print_endline (String.uppercase_ascii str); (* ALPHABETA *)
print_endline (String.lowercase_ascii str); (* alphabeta *)
print_endline (String.capitalize_ascii str); (* AlphaBETA *)
;; | Give a code snippet in #OCaml
Task
Take the string alphaBETA and demonstrate how to convert it to:
upper-case and
lower-case
Use the default encoding of a string literal or plain ASCII if there is no string literal in your language.
Note: In some languages alphabets toLower and toUpper is not r... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Thue-Morse | Thue-Morse | Task
Create a Thue-Morse sequence.
See also
YouTube entry: The Fairest Sharing Sequence Ever
YouTube entry: Math and OCD - My story with the Thue-Morse sequence
Task: Fairshare between two and more
| #Yabasic | Yabasic | tm$ = "0"
for i=1 to 8
? tm$
tm$ = tm$ + inverte$(tm$)
next
sub inverte$(tm$)
local i
for i = 1 to len(tm$)
mid$(tm$, i, 1) = str$(not val(mid$(tm$, i, 1)))
next
return tm$
end sub | Give a code snippet in #Yabasic
Task
Create a Thue-Morse sequence.
See also
YouTube entry: The Fairest Sharing Sequence Ever
YouTube entry: Math and OCD - My story with the Thue-Morse sequence
Task: Fairshare between two and more
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Literals/String | Literals/String | Task
Show literal specification of characters and strings.
If supported, show how the following work:
verbatim strings (quotes where escape sequences are quoted literally)
here-strings
Also, discuss which quotes expand variables.
Related tasks
Special characters
Here document
Other tasks r... | #Inform_7 | Inform 7 | Home is a room. The description is "This is where you live...
...with your [number of animals in Home] pet[s]." | Give a code snippet in #Inform_7
Task
Show literal specification of characters and strings.
If supported, show how the following work:
verbatim strings (quotes where escape sequences are quoted literally)
here-strings
Also, discuss which quotes expand variables.
Related tasks
Special characters... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Pascal%27s_triangle | Pascal's triangle | Pascal's triangle is an arithmetic and geometric figure often associated with the name of Blaise Pascal, but also studied centuries earlier in India, Persia, China and elsewhere.
Its first few rows look like this:
1
1 1
1 2 1
1 3 3 1
where each element of each row is either 1 or the sum of the two elemen... | #Action.21 | Action! | PROC Main()
BYTE count=[10],row,item
CHAR ARRAY s(5)
INT v
FOR row=0 TO count-1
DO
v=1
FOR item=0 TO row
DO
StrI(v,s)
Position(2*(count-row)+4*item-s(0),row+1)
Print(s)
v=v*(row-item)/(item+1)
OD
PutE()
OD
RETURN | Give a code snippet in #Action.21
Pascal's triangle is an arithmetic and geometric figure often associated with the name of Blaise Pascal, but also studied centuries earlier in India, Persia, China and elsewhere.
Its first few rows look like this:
1
1 1
1 2 1
1 3 3 1
where each element of each row is ei... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Rot-13 | Rot-13 |
Task
Implement a rot-13 function (or procedure, class, subroutine, or other "callable" object as appropriate to your programming environment).
Optionally wrap this function in a utility program (like tr, which acts like a common UNIX utility, performing a line-by-line rot-13 encoding of every line of inpu... | #Smalltalk | Smalltalk | "1. simple approach"
rot13 := [ :string |
string collect: [ :each | | index |
index := 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ'
indexOf: each ifAbsent: [ 0 ]. "Smalltalk uses 1-based indexing"
index isZero
ifTrue: [ each ]
ifFalse: [ 'nopqrstuvwxyzabcdefghijklmNOP... | Give a code snippet in #Smalltalk
Task
Implement a rot-13 function (or procedure, class, subroutine, or other "callable" object as appropriate to your programming environment).
Optionally wrap this function in a utility program (like tr, which acts like a common UNIX utility, performing a line-by-line ro... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Color_of_a_screen_pixel | Color of a screen pixel | Task
Get color information from an arbitrary pixel on the screen, such as the current location of the mouse cursor.
The mouse cursor may or may not have to be active in a GUI created by your program. These functions are OS related.
| #Standard_ML | Standard ML | open XWindows ;
val disp = XOpenDisplay "" ;
val im =
let
val pos = #4 (XQueryPointer (RootWindow disp)) ;
in
XGetImage (RootWindow disp) (MakeRect pos (AddPoint(pos,XPoint{x=1,y=1})) ) AllPlanes ZPixmap
end;
XGetPixel disp im (XPoint {x=0,y=0}) ; | Give a code snippet in #Standard_ML
Task
Get color information from an arbitrary pixel on the screen, such as the current location of the mouse cursor.
The mouse cursor may or may not have to be active in a GUI created by your program. These functions are OS related.
| 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... | #Objeck | Objeck |
class FileExtension {
function : Main(args : String[]) ~ Nil {
files := ["MyData.a##", "MyData.tar.Gz", "MyData.gzip",
"MyData.7z.backup", "MyData...", "MyData", "MyData_v1.0.tar.bz2", "MyData_v1.0.bz2"];
exts := ["zip", "rar", "7z", "gz", "archive", "A##", "tar.bz2"];
each(i : files) {
Ha... | Give a code snippet in #Objeck
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 exten... | 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
... | #UNIX_Shell | UNIX Shell | http_get_body() {
local host=$1
local uri=$2
exec 5<> /dev/tcp/$host/80
printf >&5 "%s\r\n" "GET $uri HTTP/1.1" "Host: $host" "Connection: close" ""
mapfile -t -u5
local lines=( "${MAPFILE[@]//$'\r'}" )
local i=0 found=0
for (( ; found == 0; i++ )); do
[[ -z ${lines[i]} ]] && (... | Give a code snippet in #UNIX_Shell
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... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Averages/Median | Averages/Median | Task[edit]
Write a program to find the median value of a vector of floating-point numbers.
The program need not handle the case where the vector is empty, but must handle the case where there are an even number of elements. In that case, return the average of the two middle values.
There are several approaches ... | #ooRexx | ooRexx |
call testMedian .array~of(10, 9, 8, 7, 6, 5, 4, 3, 2, 1)
call testMedian .array~of(10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0, 0, 0, 0, .11)
call testMedian .array~of(10, 20, 30, 40, 50, -100, 4.7, -11e2)
call testMedian .array~new
::routine testMedian
use arg numbers
say "numbers =" numbers~toString("l", ", ")
say "me... | Give a code snippet in #ooRexx
Task[edit]
Write a program to find the median value of a vector of floating-point numbers.
The program need not handle the case where the vector is empty, but must handle the case where there are an even number of elements. In that case, return the average of the two middle values... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Rock-paper-scissors | Rock-paper-scissors | Task
Implement the classic children's game Rock-paper-scissors, as well as a simple predictive AI (artificial intelligence) player.
Rock Paper Scissors is a two player game.
Each player chooses one of rock, paper or scissors, without knowing the other player's choice.
The winner is decided by a set of rules:
... | #Nim | Nim | import random, strutils, tables
type
Choice {.pure.} = enum Rock, Paper, Scissors
History = tuple[total: int; counts: CountTable[Choice]]
const Successor: array[Choice, Choice] = [Paper, Scissors, Rock]
func `>`(a, b: Choice): bool =
## By construction, only the successor is greater than the choice.
a == ... | Give a code snippet in #Nim
Task
Implement the classic children's game Rock-paper-scissors, as well as a simple predictive AI (artificial intelligence) player.
Rock Paper Scissors is a two player game.
Each player chooses one of rock, paper or scissors, without knowing the other player's choice.
The winner i... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Rename_a_file | Rename a file | Task
Rename:
a file called input.txt into output.txt and
a directory called docs into mydocs.
This should be done twice:
once "here", i.e. in the current working directory and once in the filesystem root.
It can be assumed that the user has the rights to do so.
(In unix-type s... | #HicEst | HicEst | WRITE(FIle='input.txt', REName='.\output.txt')
SYSTEM(DIR='E:\HicEst\Rosetta')
WRITE(FIle='.\docs', REName='.\mydocs')
WRITE(FIle='\input.txt', REName='\output.txt')
SYSTEM(DIR='\')
WRITE(FIle='\docs', REName='\mydocs') | Give a code snippet in #HicEst
Task
Rename:
a file called input.txt into output.txt and
a directory called docs into mydocs.
This should be done twice:
once "here", i.e. in the current working directory and once in the filesystem root.
It can be assumed that the user has the r... | christopher/rosetta-code | |
http://rosettacode.org/wiki/File_size | File size | Verify the size of a file called input.txt for a file in the current working directory, and another one in the file system root.
| #Retro | Retro | with files'
"input.txt" :R open &size sip close drop putn
"/input.txt" :R open &size sip close drop putn | Give a code snippet in #Retro
Verify the size of a file called input.txt for a file in the current working directory, and another one in the file system root.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Make_directory_path | Make directory path | Task
Create a directory and any missing parents.
This task is named after the posix mkdir -p command, and several libraries which implement the same behavior.
Please implement a function of a single path string (for example ./path/to/dir) which has the above side-effect.
If the directory already exists, return succe... | #Objeck | Objeck | class Program {
function : Main(args : String[]) ~ Nil {
System.IO.File.Directory->CreatePath("your/path/name")->PrintLine();
}
} | Give a code snippet in #Objeck
Task
Create a directory and any missing parents.
This task is named after the posix mkdir -p command, and several libraries which implement the same behavior.
Please implement a function of a single path string (for example ./path/to/dir) which has the above side-effect.
If the direct... | 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... | #Common_Lisp | Common Lisp | (defun split (string)
(loop :for prev := nil :then c
:for c :across string
:do (format t "~:[~;, ~]~c" (and prev (char/= c prev)) c)))
(split "gHHH5YY++///\\")
| Give a code snippet in #Common_Lisp
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)... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Loops/Downward_for | Loops/Downward for | Task
Write a for loop which writes a countdown from 10 to 0.
Related tasks
Loop over multiple arrays simultaneously
Loops/Break
Loops/Continue
Loops/Do-while
Loops/Downward for
Loops/For
Loops/For with a specified step
Loops/Foreach
Loops/Increment loop index within loop body... | #COBOL | COBOL | identification division.
program-id. countdown.
environment division.
data division.
working-storage section.
01 counter pic 99.
88 counter-done value 0.
01 counter-disp pic Z9.
procedure division.
perform with test after varying counter from 10 by -1 until counter-done
move counter to counter-disp
display coun... | Give a code snippet in #COBOL
Task
Write a for loop which writes a countdown from 10 to 0.
Related tasks
Loop over multiple arrays simultaneously
Loops/Break
Loops/Continue
Loops/Do-while
Loops/Downward for
Loops/For
Loops/For with a specified step
Loops/Foreach
Loops/Increm... | christopher/rosetta-code | |
http://rosettacode.org/wiki/IBAN | IBAN |
This page uses content from Wikipedia. The original article was at IBAN. 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)
The International Bank Account Number (IBAN) is an internationally agree... | #Seed7 | Seed7 | $ include "seed7_05.s7i";
include "bigint.s7i";
const type: countryHash is hash [string] integer;
const func countryHash: initCountryCode is func
result
var countryHash: cc is countryHash.value;
begin
cc @:= ["AL"] 28; cc @:= ["AD"] 24; cc @:= ["AT"] 20; cc @:= ["AZ"] 28; cc @:= ["BE"] 16; cc @:= ["BH... | Give a code snippet in #Seed7
This page uses content from Wikipedia. The original article was at IBAN. 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)
The International Bank Account Number (IBAN... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Assertions | Assertions | Assertions are a way of breaking out of code when there is an error or an unexpected input.
Some languages throw exceptions and some treat it as a break point.
Task
Show an assertion in your language by asserting that an integer variable is equal to 42.
| #Yabasic | Yabasic | sub assert(a)
if not a then
error "Assertion failed"
end if
end sub
assert(myVar = 42) | Give a code snippet in #Yabasic
Assertions are a way of breaking out of code when there is an error or an unexpected input.
Some languages throw exceptions and some treat it as a break point.
Task
Show an assertion in your language by asserting that an integer variable is equal to 42.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Gauss-Jordan_matrix_inversion | Gauss-Jordan matrix inversion | Task
Invert matrix A using Gauss-Jordan method.
A being an n × n matrix.
| #Python | Python |
import numpy as np
from numpy.linalg import inv
a = np.array([[1., 2., 3.], [4., 1., 6.],[ 7., 8., 9.]])
ainv = inv(a)
print(a)
print(ainv)
| Give a code snippet in #Python
Task
Invert matrix A using Gauss-Jordan method.
A being an n × n matrix.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Sorting_algorithms/Merge_sort | Sorting algorithms/Merge sort |
Sorting Algorithm
This is a sorting algorithm. It may be applied to a set of data in order to sort it.
For comparing various sorts, see compare sorts.
For other sorting algorithms, see sorting algorithms, or:
O(n logn) sorts
Heap sort |
Merge sort |
Patience sort |
Quick sort
O(n log2n) sorts
Shell Sort
... | #AArch64_Assembly | AArch64 Assembly |
/* ARM assembly AARCH64 Raspberry PI 3B */
/* program mergeSort64.s */
/*******************************************/
/* Constantes file */
/*******************************************/
/* for this file see task include a file in language AArch64 assembly */
.include "../includeConstantesAR... | Give a code snippet in #AArch64_Assembly
Sorting Algorithm
This is a sorting algorithm. It may be applied to a set of data in order to sort it.
For comparing various sorts, see compare sorts.
For other sorting algorithms, see sorting algorithms, or:
O(n logn) sorts
Heap sort |
Merge sort |
Patience sort... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Permutations/Rank_of_a_permutation | Permutations/Rank of a permutation | A particular ranking of a permutation associates an integer with a particular ordering of all the permutations of a set of distinct items.
For our purposes the ranking will assign integers
0..
(
n
!
−
1
)
{\displaystyle 0..(n!-1)}
to an ordering of all the permutations of the integers
0..
(
n
−
1
)
{\disp... | #jq | jq | # Assuming sufficiently-precise integer arithmetic,
# if the input and $j are integers, then the result will be a pair of integers,
# except that if $j is 0, then an error condition is raised.
def divmod($j):
. as $i
| ($i % $j) as $mod
| [($i - $mod) / $j, $mod] ;
# Input may be an object or an array
def swap(... | Give a code snippet in #jq
A particular ranking of a permutation associates an integer with a particular ordering of all the permutations of a set of distinct items.
For our purposes the ranking will assign integers
0..
(
n
!
−
1
)
{\displaystyle 0..(n!-1)}
to an ordering of all the permutations of the integer... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Horizontal_sundial_calculations | Horizontal sundial calculations | Task
Create a program that calculates the hour, sun hour angle, dial hour line angle from 6am to 6pm for an operator entered location.
For example, the user is prompted for a location and inputs the latitude and longitude 4°57′S 150°30′W (4.95°S 150.5°W of Jules Verne's Lincoln Island, aka Ernest Legouve Reef), wit... | #AWK | AWK |
# syntax: GAWK -f HORIZONTAL_SUNDIAL_CALCULATIONS.AWK
BEGIN {
printf("enter latitude (degrees): ") ; getline latitude
printf("enter longitude (degrees): ") ; getline longitude
printf("enter legal meridian (degrees): ") ; getline meridian
printf("\nhour sun hour angle dial hour line angle\n")
sla... | Give a code snippet in #AWK
Task
Create a program that calculates the hour, sun hour angle, dial hour line angle from 6am to 6pm for an operator entered location.
For example, the user is prompted for a location and inputs the latitude and longitude 4°57′S 150°30′W (4.95°S 150.5°W of Jules Verne's Lincoln Island, ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/CRC-32 | CRC-32 |
Task
Demonstrate a method of deriving the Cyclic Redundancy Check from within the language.
The result should be in accordance with ISO 3309, ITU-T V.42, Gzip and PNG.
Algorithms are described on Computation of CRC in Wikipedia.
This variant of CRC-32 uses LSB-first order, sets the initial CRC to FFFFFFFF16, and... | #ALGOL_68 | ALGOL 68 |
[0:255]BITS crc_table;
BOOL crc_table_computed := FALSE;
PROC make_crc_table = VOID:
BEGIN
INT n, k;
FOR n FROM 0 TO 255 DO
BITS c := BIN n;
FOR k TO 8 DO
c := IF 32 ELEM c THEN
16redb88320 XOR (c SHR 1)
ELSE
c... | Give a code snippet in #ALGOL_68
Task
Demonstrate a method of deriving the Cyclic Redundancy Check from within the language.
The result should be in accordance with ISO 3309, ITU-T V.42, Gzip and PNG.
Algorithms are described on Computation of CRC in Wikipedia.
This variant of CRC-32 uses LSB-first order, sets ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sort_using_a_custom_comparator | Sort using a custom comparator |
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
... | #Visual_Basic_.NET | Visual Basic .NET | Imports System
Module Sorting_Using_a_Custom_Comparator
Function CustomComparator(ByVal x As String, ByVal y As String) As Integer
Dim result As Integer
result = y.Length - x.Length
If result = 0 Then
result = String.Compare(x, y, True)
End If
Return result
... | Give a code snippet in #Visual_Basic_.NET
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 sor... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Multifactorial | Multifactorial | The factorial of a number, written as
n
!
{\displaystyle n!}
, is defined as
n
!
=
n
(
n
−
1
)
(
n
−
2
)
.
.
.
(
2
)
(
1
)
{\displaystyle n!=n(n-1)(n-2)...(2)(1)}
.
Multifactorials generalize factorials as follows:
n
!
=
n
(
n
−
1
)
(
n
−
2
)
.
.
.
(
2
)
(
1
)
{\displaystyle n!=n(n-1)(n-2)...(2)(... | #Elixir | Elixir | defmodule RC do
def multifactorial(n,d) do
Enum.take_every(n..1, d) |> Enum.reduce(1, fn x,p -> x*p end)
end
end
Enum.each(1..5, fn d ->
multifac = for n <- 1..10, do: RC.multifactorial(n,d)
IO.puts "Degree #{d}: #{inspect multifac}"
end) | Give a code snippet in #Elixir
The factorial of a number, written as
n
!
{\displaystyle n!}
, is defined as
n
!
=
n
(
n
−
1
)
(
n
−
2
)
.
.
.
(
2
)
(
1
)
{\displaystyle n!=n(n-1)(n-2)...(2)(1)}
.
Multifactorials generalize factorials as follows:
n
!
=
n
(
n
−
1
)
(
n
−
2
)
.
.
.
(
2
)
(
1
)
{\di... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Unicode_strings | Unicode strings | As the world gets smaller each day, internationalization becomes more and more important. For handling multiple languages, Unicode is your best friend.
It is a very capable tool, but also quite complex compared to older single- and double-byte character encodings.
How well prepared is your programming language for ... | #UNIX_Shell | UNIX Shell | stdout.printf ("UTF-8 encoded string. Let's go to a café!"); | Give a code snippet in #UNIX_Shell
As the world gets smaller each day, internationalization becomes more and more important. For handling multiple languages, Unicode is your best friend.
It is a very capable tool, but also quite complex compared to older single- and double-byte character encodings.
How well prepar... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sequence:_smallest_number_greater_than_previous_term_with_exactly_n_divisors | Sequence: smallest number greater than previous term with exactly n divisors | Calculate the sequence where each term an is the smallest natural number greater than the previous term, that has exactly n divisors.
Task
Show here, on this page, at least the first 15 terms of the sequence.
See also
OEIS:A069654
Related tasks
Sequence: smallest number with exactly n divisors
Sequence: nth ... | #Ring | Ring |
# Project : ANti-primes
see "working..." + nl
see "wait for done..." + nl + nl
see "the first 15 Anti-primes Plus are:" + nl + nl
num = 1
n = 0
result = list(15)
while num < 16
n = n + 1
div = factors(n)
if div = num
result[num] = n
num = num + 1
ok
end
see "["
for n = 1 to... | Give a code snippet in #Ring
Calculate the sequence where each term an is the smallest natural number greater than the previous term, that has exactly n divisors.
Task
Show here, on this page, at least the first 15 terms of the sequence.
See also
OEIS:A069654
Related tasks
Sequence: smallest number with exac... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Longest_increasing_subsequence | Longest increasing subsequence | Calculate and show here a longest increasing subsequence of the list:
{
3
,
2
,
6
,
4
,
5
,
1
}
{\displaystyle \{3,2,6,4,5,1\}}
And of the list:
{
0
,
8
,
4
,
12
,
2
,
10
,
6
,
14
,
1
,
9
,
5
,
13
,
3
,
11
,
7
,
15
}
{\displaystyle \{0,8,4,12,2,10,6,14,1,9,5,13,3,11,7,15\}}
Note that a list may have m... | #PowerShell | PowerShell | function Get-LongestSubsequence ( [int[]]$A )
{
If ( $A.Count -lt 2 ) { return $A }
# Start with an "empty" pile
# (We will only store the top value in each "pile".)
$Pile = @( [int]::MaxValue )
$Last = 0
# Hashtable to hold the back pointers
$BP = @{}
# For each number in ... | Give a code snippet in #PowerShell
Calculate and show here a longest increasing subsequence of the list:
{
3
,
2
,
6
,
4
,
5
,
1
}
{\displaystyle \{3,2,6,4,5,1\}}
And of the list:
{
0
,
8
,
4
,
12
,
2
,
10
,
6
,
14
,
1
,
9
,
5
,
13
,
3
,
11
,
7
,
15
}
{\displaystyle \{0,8,4,12,2,10,6,14,1,9,5,13,3,11,7... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Hello_world/Text | Hello world/Text | Hello world/Text is part of Short Circuit's Console Program Basics selection.
Task
Display the string Hello world! on a text console.
Related tasks
Hello world/Graphical
Hello world/Line Printer
Hello world/Newbie
Hello world/Newline omission
Hello world/Standard error
Hello world/Web server
| #Efene | Efene | io.format("Hello world!~n") | Give a code snippet in #Efene
Hello world/Text is part of Short Circuit's Console Program Basics selection.
Task
Display the string Hello world! on a text console.
Related tasks
Hello world/Graphical
Hello world/Line Printer
Hello world/Newbie
Hello world/Newline omission
Hello world/Standard error
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Self_numbers | Self numbers | A number n is a self number if there is no number g such that g + the sum of g's digits = n. So 18 is not a self number because 9+9=18, 43 is not a self number because 35+5+3=43.
The task is:
Display the first 50 self numbers;
I believe that the 100000000th self number is 1022727208. You should either confirm or d... | #Julia | Julia | gsum(i) = sum(digits(i)) + i
isnonself(i) = any(x -> gsum(x) == i, i-1:-1:i-max(1, ndigits(i)*9))
const last81 = filter(isnonself, 1:5000)[1:81]
function checkselfnumbers()
i, selfcount = 1, 0
while selfcount <= 100_000_000 && i <= 1022727208
if !(i in last81)
selfcount += 1
if... | Give a code snippet in #Julia
A number n is a self number if there is no number g such that g + the sum of g's digits = n. So 18 is not a self number because 9+9=18, 43 is not a self number because 35+5+3=43.
The task is:
Display the first 50 self numbers;
I believe that the 100000000th self number is 1022727208.... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Entropy | Entropy | Task
Calculate the Shannon entropy H of a given input string.
Given the discrete random variable
X
{\displaystyle X}
that is a string of
N
{\displaystyle N}
"symbols" (total characters) consisting of
n
{\displaystyle n}
different characters (n=2 for binary), the Shannon entropy of X in bit... | #Python | Python | from __future__ import division
import math
def hist(source):
hist = {}; l = 0;
for e in source:
l += 1
if e not in hist:
hist[e] = 0
hist[e] += 1
return (l,hist)
def entropy(hist,l):
elist = []
for v in hist.values():
c = v / l
elist.append(-c... | Give a code snippet in #Python
Task
Calculate the Shannon entropy H of a given input string.
Given the discrete random variable
X
{\displaystyle X}
that is a string of
N
{\displaystyle N}
"symbols" (total characters) consisting of
n
{\displaystyle n}
different characters (n=2 for binary),... | 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
)
)
,
... | #Elena | Elena | import extensions;
import system'collections;
F = (n => (n == 0) ? 1 : (n - M(F(n-1))) );
M = (n => (n == 0) ? 0 : (n - F(M(n-1))) );
public program()
{
var ra := new ArrayList();
var rb := new ArrayList();
for(int i := 0, i <= 19, i += 1)
{
ra.append(F(i));
rb.append(M(i))
};
... | Give a code snippet in #Elena
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/Inverted_syntax | Inverted syntax | Inverted syntax with conditional expressions
In traditional syntax conditional expressions are usually shown before the action within a statement or code block:
IF raining=true THEN needumbrella=true
In inverted syntax, the action is listed before the conditional expression in the statement or code block:
needumb... | #Wren | Wren | class IBool {
construct new(b) {
if (!(b is Bool)) Fiber.abort("B must be a boolean")
_b = b
}
iff(cond) { cond ? _b : !_b }
}
var itrue = IBool.new(true)
var needUmbrella
var raining = true
// normal syntax
if (raining) needUmbrella = true
System.print("Is it raining? %(raining). Do... | Give a code snippet in #Wren
Inverted syntax with conditional expressions
In traditional syntax conditional expressions are usually shown before the action within a statement or code block:
IF raining=true THEN needumbrella=true
In inverted syntax, the action is listed before the conditional expression in the stat... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Program_termination | Program termination |
Task
Show the syntax for a complete stoppage of a program inside a conditional.
This includes all threads/processes which are part of your program.
Explain the cleanup (or lack thereof) caused by the termination (allocated memory, database connections, open files, object finalizers/destructors, run-on-exit hooks... | #R | R | if(problem) q(status=10) | Give a code snippet in #R
Task
Show the syntax for a complete stoppage of a program inside a conditional.
This includes all threads/processes which are part of your program.
Explain the cleanup (or lack thereof) caused by the termination (allocated memory, database connections, open files, object finalizers/des... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Find_common_directory_path | Find common directory path | Create a routine that, given a set of strings representing directory paths and a single character directory separator, will return a string representing that part of the directory tree that is common to all the directories.
Test your routine using the forward slash '/' character as the directory separator and the foll... | #Groovy | Groovy | def commonPath = { delim, Object[] paths ->
def pathParts = paths.collect { it.split(delim) }
pathParts.transpose().inject([match:true, commonParts:[]]) { aggregator, part ->
aggregator.match = aggregator.match && part.every { it == part [0] }
if (aggregator.match) { aggregator.commonParts << pa... | Give a code snippet in #Groovy
Create a routine that, given a set of strings representing directory paths and a single character directory separator, will return a string representing that part of the directory tree that is common to all the directories.
Test your routine using the forward slash '/' character as the ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Copy_a_string | Copy a string | This task is about copying a string.
Task
Where it is relevant, distinguish between copying the contents of a string
versus making an additional reference to an existing string.
Other tasks related to string operations:
Metrics
Array length
String length
Copy a string
Empty string (assignment)
Counting
W... | #REXX | REXX | src = "this is a string"
dst = src | Give a code snippet in #REXX
This task is about copying a string.
Task
Where it is relevant, distinguish between copying the contents of a string
versus making an additional reference to an existing string.
Other tasks related to string operations:
Metrics
Array length
String length
Copy a string
Empty st... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Array_concatenation | Array concatenation | Task
Show how to concatenate two arrays in your language.
If this is as simple as array1 + array2, so be it.
| #ECL | ECL |
A := [1, 2, 3, 4];
B := [5, 6, 7, 8];
C := A + B; | Give a code snippet in #ECL
Task
Show how to concatenate two arrays in your language.
If this is as simple as array1 + array2, so be it.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Draw_a_cuboid | Draw a cuboid | Task
Draw a cuboid with relative dimensions of 2 × 3 × 4.
The cuboid can be represented graphically, or in ASCII art, depending on the language capabilities.
To fulfill the criteria of being a cuboid, three faces must be visible.
Either static or rotational projection is acceptable for this task.
R... | #REXX | REXX | /*REXX program displays a cuboid (dimensions, if specified, must be positive integers).*/
parse arg x y z indent . /*x, y, z: dimensions and indentation.*/
x=p(x 2); y=p(y 3); z=p(z 4); in=p(indent 0) /*use the defaults if not specified. */
pad=left('', in) ... | Give a code snippet in #REXX
Task
Draw a cuboid with relative dimensions of 2 × 3 × 4.
The cuboid can be represented graphically, or in ASCII art, depending on the language capabilities.
To fulfill the criteria of being a cuboid, three faces must be visible.
Either static or rotational projection is ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Play_recorded_sounds | Play recorded sounds | Load at least two prerecorded sounds, and demonstrate as many of these features as you can:
playing them individually and simultaneously
stopping before the end of the sound
looping (preferably glitch-free)
setting the volume of each sound
stereo or 3D positional mixing
performing other actions when marked times... | #Nim | Nim | import osproc
let args = ["-m", "-v", "0.75", "a.wav", "-v", "0.25", "b.wav",
"-d",
"trim", "4", "6",
"repeat", "5"]
echo execProcess("sox", args = args, options = {poStdErrToStdOut, poUsePath}) | Give a code snippet in #Nim
Load at least two prerecorded sounds, and demonstrate as many of these features as you can:
playing them individually and simultaneously
stopping before the end of the sound
looping (preferably glitch-free)
setting the volume of each sound
stereo or 3D positional mixing
performing ot... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Linear_congruential_generator | Linear congruential generator | The linear congruential generator is a very simple example of a random number generator.
All linear congruential generators use this formula:
r
n
+
1
=
a
×
r
n
+
c
(
mod
m
)
{\displaystyle r_{n+1}=a\times r_{n}+c{\pmod {m}}}
Where:
r
0
{\displaystyle r_{0}}
is a seed.
r
1
... | #Rust | Rust | extern crate rand;
pub use rand::{Rng, SeedableRng};
pub struct BsdLcg {
state: u32,
}
impl Rng for BsdLcg {
// Because the output is in the range [0, 2147483647], this should technically be `next_u16`
// (the largest integer size which is fully covered, as `rand::Rng` assumes). The `rand`
// cra... | Give a code snippet in #Rust
The linear congruential generator is a very simple example of a random number generator.
All linear congruential generators use this formula:
r
n
+
1
=
a
×
r
n
+
c
(
mod
m
)
{\displaystyle r_{n+1}=a\times r_{n}+c{\pmod {m}}}
Where:
r
0
{\displaystyle r_... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Quine | Quine | A quine is a self-referential program that can,
without any external access, output its own source.
A quine (named after Willard Van Orman Quine) is also known as:
self-reproducing automata (1972)
self-replicating program or self-replicating computer program
self-reproducing program ... | #ooRexx | ooRexx | say sourceline(1) | Give a code snippet in #ooRexx
A quine is a self-referential program that can,
without any external access, output its own source.
A quine (named after Willard Van Orman Quine) is also known as:
self-reproducing automata (1972)
self-replicating program or self-replicating computer program
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Parsing/RPN_calculator_algorithm | Parsing/RPN calculator algorithm | Task
Create a stack-based evaluator for an expression in reverse Polish notation (RPN) that also shows the changes in the stack as each individual token is processed as a table.
Assume an input of a correct, space separated, string of tokens of an RPN expression
Test with the RPN expression generated from the... | #Scala | Scala | object RPN {
val PRINT_STACK_CONTENTS: Boolean = true
def main(args: Array[String]): Unit = {
val result = evaluate("3 4 2 * 1 5 - 2 3 ^ ^ / +".split(" ").toList)
println("Answer: " + result)
}
def evaluate(tokens: List[String]): Double = {
import scala.collection.mutable.Stack
val stack: St... | Give a code snippet in #Scala
Task
Create a stack-based evaluator for an expression in reverse Polish notation (RPN) that also shows the changes in the stack as each individual token is processed as a table.
Assume an input of a correct, space separated, string of tokens of an RPN expression
Test with the RP... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Synchronous_concurrency | Synchronous concurrency | The goal of this task is to create two concurrent activities ("Threads" or "Tasks", not processes.) that share data synchronously. Your language may provide syntax or libraries to perform concurrency. Different languages provide different implementations of concurrency, often with different names. Some languages use th... | #Phix | Phix | -- demo\rosetta\Synchronous_concurrency.exw
without js -- threads, file i/o, command_line()
string filename = substitute(command_line()[2],".exe",".exw")
atom frThread, -- file reader thread
lcThread -- line counter thread
sequence queue = {}
integer qlock = init_cs(),
linecount = 1
procedure readfile()
... | Give a code snippet in #Phix
The goal of this task is to create two concurrent activities ("Threads" or "Tasks", not processes.) that share data synchronously. Your language may provide syntax or libraries to perform concurrency. Different languages provide different implementations of concurrency, often with differen... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Loop_over_multiple_arrays_simultaneously | Loop over multiple arrays simultaneously | Task
Loop over multiple arrays (or lists or tuples or whatever they're called in
your language) and display the i th element of each.
Use your language's "for each" loop if it has one, otherwise iterate
through the collection in order with some other loop.
For this example, loop over the arrays:
... | #NS-HUBASIC | NS-HUBASIC | 10 DIM A$(3)
20 DIM B$(3)
30 DIM C$(3)
40 A$(1)="THIS"
50 A$(2)=" LOOPS"
60 A$(3)=" ARRAYS"
70 B$(1)=" NS-HUBASIC"
80 B$(2)=" OVER"
90 B$(3)=" AT"
100 C$(1)=" PROGRAM"
110 C$(2)=" MULTIPLE"
120 C$(3)=" ONCE."
130 FOR I=1 TO 3
140 PRINT A$(I)B$(I)C$(I)
150 NEXT | Give a code snippet in #NS-HUBASIC
Task
Loop over multiple arrays (or lists or tuples or whatever they're called in
your language) and display the i th element of each.
Use your language's "for each" loop if it has one, otherwise iterate
through the collection in order with some other loop.
For this... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Strip_a_set_of_characters_from_a_string | Strip a set of characters from a string | Task
Create a function that strips a set of characters from a string.
The function should take two arguments:
a string to be stripped
a string containing the set of characters to be stripped
The returned string should contain the first string, stripped of any characters in the second argument:
print str... | #Nim | Nim | import strutils
echo "She was a soul stripper. She took my heart!".split({'a','e','i'}).join()
echo "She was a soul stripper. She took my heart!".multiReplace(
("a", ""),
("e", ""),
("i", "")
)
# And another way using module "sequtils".
import sequtils
echo "She was a soul stripper. She took my heart!".filt... | Give a code snippet in #Nim
Task
Create a function that strips a set of characters from a string.
The function should take two arguments:
a string to be stripped
a string containing the set of characters to be stripped
The returned string should contain the first string, stripped of any characters in the... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Deming%27s_Funnel | Deming's Funnel | W Edwards Deming was an American statistician and management guru who used physical demonstrations to illuminate his teachings. In one demonstration Deming repeatedly dropped marbles through a funnel at a target, marking where they landed, and observing the resulting pattern. He applied a sequence of "rules" to try to ... | #Elixir | Elixir | defmodule Deming do
def funnel(dxs, rule) do
{_, rxs} = Enum.reduce(dxs, {0, []}, fn dx,{x,rxs} ->
{rule.(x, dx), [x + dx | rxs]}
end)
rxs
end
def mean(xs), do: Enum.sum(xs) / length(xs)
def stddev(xs) do
m = mean(xs)
Enum.reduce(xs, 0.0, fn x,sum -> sum + (x-m)*(x-m) / length(xs) ... | Give a code snippet in #Elixir
W Edwards Deming was an American statistician and management guru who used physical demonstrations to illuminate his teachings. In one demonstration Deming repeatedly dropped marbles through a funnel at a target, marking where they landed, and observing the resulting pattern. He applied ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Jump_anywhere | Jump anywhere | Imperative programs
conditional structures
loops
local jumps
This task is to demonstrate a local jump and a global jump and the various other types of jumps that the language supports.
For the purpose of this task, the jumps need not be used for a single purpose and you have the freedom to use these jumps for different... | #Z80_Assembly | Z80 Assembly | and &01 ;returns 0 if the accumulator is even and 1 if odd. Also sets the zero flag accordingly.
jr z,SkipOddCode
;whatever you want to do when the accumulator is odd goes here, but it must be 127 bytes or fewer.
SkipOddCode:
;rest of program | Give a code snippet in #Z80_Assembly
Imperative programs
conditional structures
loops
local jumps
This task is to demonstrate a local jump and a global jump and the various other types of jumps that the language supports.
For the purpose of this task, the jumps need not be used for a single purpose and you have the fr... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Guess_the_number/With_feedback | Guess the number/With feedback | Task
Write a game (computer program) that follows the following rules:
The computer chooses a number between given set limits.
The player is asked for repeated guesses until the the target number is guessed correctly
At each guess, the computer responds with whether the guess is:
higher than the target,
equal to... | #VTL-2 | VTL-2 | 10 ?="Minimum? ";
20 L=?
30 ?="Maximum? ";
40 H=?
50 #=L<H*80
60 ?="Minimum must be lower than maximum."
70 #=10
80 S='/(H-L+1)*0+L+%
90 T=0
100 ?="Guess? ";
110 G=?
120 #=G>L*(H>G)*150
130 ?="Guess must be in between minimum and maximum."
140 #=100
150 T=T+1
160 #=G=S*220
170 #=G<S*200
180 ?="Too high."
190 #=100
200 ... | Give a code snippet in #VTL-2
Task
Write a game (computer program) that follows the following rules:
The computer chooses a number between given set limits.
The player is asked for repeated guesses until the the target number is guessed correctly
At each guess, the computer responds with whether the guess is:
hi... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Factorial | Factorial | Definitions
The factorial of 0 (zero) is defined as being 1 (unity).
The Factorial Function of a positive integer, n, is defined as the product of the sequence:
n, n-1, n-2, ... 1
Task
Write a function to return the factorial of a number.
Solutions can be iterat... | #Nickle | Nickle | int fact(int n) { return n!; } | Give a code snippet in #Nickle
Definitions
The factorial of 0 (zero) is defined as being 1 (unity).
The Factorial Function of a positive integer, n, is defined as the product of the sequence:
n, n-1, n-2, ... 1
Task
Write a function to return the factorial of a ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Pernicious_numbers | Pernicious numbers | A pernicious number is a positive integer whose population count is a prime.
The population count is the number of ones in the binary representation of a non-negative integer.
Example
22 (which is 10110 in binary) has a population count of 3, which is prime, and therefore
22 is a pe... | #COBOL | COBOL | IDENTIFICATION DIVISION.
PROGRAM-ID. PERNICIOUS-NUMBERS.
DATA DIVISION.
WORKING-STORAGE SECTION.
01 VARIABLES.
03 AMOUNT PIC 99.
03 CAND PIC 9(9).
03 POPCOUNT PIC 99.
03 POP-N PIC 9(9).
... | Give a code snippet in #COBOL
A pernicious number is a positive integer whose population count is a prime.
The population count is the number of ones in the binary representation of a non-negative integer.
Example
22 (which is 10110 in binary) has a population count of 3, which is prime... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Return_multiple_values | Return multiple values | Task
Show how to return more than one value from a function.
| #Wren | Wren | var splitName = Fn.new { |fullName| fullName.split(" ") }
var names = splitName.call("George Bernard Shaw")
System.print("First name: %(names[0]), middle name: %(names[1]) and surname: %(names[2]).") | Give a code snippet in #Wren
Task
Show how to return more than one value from a function.
| christopher/rosetta-code |
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