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/Hamming_numbers | Hamming numbers | Hamming numbers are numbers of the form
H = 2i × 3j × 5k
where
i, j, k ≥ 0
Hamming numbers are also known as ugly numbers and also 5-smooth numbers (numbers whose prime divisors are less or equal to 5).
Task
Generate the sequence of Hamming numbers, in increasing order. In ... | #Quackery | Quackery | ' [ 2 3 5 ] smoothwith [ size 1000000 = ]
dup 20 split drop echo cr
dup 1690 peek echo cr
-1 peek echo
| Give a code snippet in #Quackery
Hamming numbers are numbers of the form
H = 2i × 3j × 5k
where
i, j, k ≥ 0
Hamming numbers are also known as ugly numbers and also 5-smooth numbers (numbers whose prime divisors are less or equal to 5).
Task
Generate the sequence of Hamming n... | 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... | #J | J |
query=:3 :'0&#^:(y < #)''Here am I'''
| Give a code snippet in #J
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... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Trigonometric_functions | Trigonometric functions | Task
If your language has a library or built-in functions for trigonometry, show examples of:
sine
cosine
tangent
inverses (of the above)
using the same angle in radians and degrees.
For the non-inverse functions, each radian/degree pair should use arguments that evaluate to the same angle (that i... | #Arturo | Arturo | pi: 4*atan 1.0
radians: pi/4
degrees: 45.0
print "sine"
print [sin radians, sin degrees*pi/180]
print "cosine"
print [cos radians, cos degrees*pi/180]
print "tangent"
print [tan radians, tan degrees*pi/180]
print "arcsine"
print [asin sin radians, (asin sin radians)*180/pi]
print "arccosine"
print [acos cos... | Give a code snippet in #Arturo
Task
If your language has a library or built-in functions for trigonometry, show examples of:
sine
cosine
tangent
inverses (of the above)
using the same angle in radians and degrees.
For the non-inverse functions, each radian/degree pair should use arguments that eval... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Primality_by_Wilson%27s_theorem | Primality by Wilson's theorem | Task
Write a boolean function that tells whether a given integer is prime using Wilson's theorem.
By Wilson's theorem, a number p is prime if and only if p divides (p - 1)! + 1.
Remember that 1 and all non-positive integers are not prime.
See also
Cut-the-knot: Wilson's theorem.
Wikipedia: Wilson's theorem
| #CLU | CLU | % Wilson primality test
wilson = proc (n: int) returns (bool)
if n<2 then return (false) end
fac_mod: int := 1
for i: int in int$from_to(2, n-1) do
fac_mod := fac_mod * i // n
end
return (fac_mod + 1 = n)
end wilson
% Print primes up to 100 using Wilson's theorem
start_up = proc ()
... | Give a code snippet in #CLU
Task
Write a boolean function that tells whether a given integer is prime using Wilson's theorem.
By Wilson's theorem, a number p is prime if and only if p divides (p - 1)! + 1.
Remember that 1 and all non-positive integers are not prime.
See also
Cut-the-knot: Wilson's theorem.
Wi... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Eertree | Eertree | An eertree is a data structure designed for efficient processing of certain palindrome tasks, for instance counting the number of sub-palindromes in an input string.
The data structure has commonalities to both tries and suffix trees.
See links below.
Task
Construct an eertree for the string "eertree", then outp... | #zkl | zkl | class Node{
fcn init(length){
var edges=Dictionary(), # edges (or forward links). (char:Node)
link=Void, # suffix link (backward links)
sz =length; # node length.
}
}
class Eertree{
fcn init(string=Void){
var nodes=List(),
# two initial root nodes
rto=Node(-1), # odd length r... | Give a code snippet in #zkl
An eertree is a data structure designed for efficient processing of certain palindrome tasks, for instance counting the number of sub-palindromes in an input string.
The data structure has commonalities to both tries and suffix trees.
See links below.
Task
Construct an eertree for th... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Repeat_a_string | Repeat a string | Take a string and repeat it some number of times.
Example: repeat("ha", 5) => "hahahahaha"
If there is a simpler/more efficient way to repeat a single “character” (i.e. creating a string filled with a certain character), you might want to show that as well (i.e. repeat-char("*", 5) => "*****").
Other tasks re... | #Java | Java | public static String repeat(String str, int times) {
StringBuilder sb = new StringBuilder(str.length() * times);
for (int i = 0; i < times; i++)
sb.append(str);
return sb.toString();
}
public static void main(String[] args) {
System.out.println(repeat("ha", 5));
} | Give a code snippet in #Java
Take a string and repeat it some number of times.
Example: repeat("ha", 5) => "hahahahaha"
If there is a simpler/more efficient way to repeat a single “character” (i.e. creating a string filled with a certain character), you might want to show that as well (i.e. repeat-char("*", 5) =... | christopher/rosetta-code | |
http://rosettacode.org/wiki/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... | #APL | APL |
{⍕0~¨⍨(-⌽A)⌽↑,/0,¨⍉A∘.!A←0,⍳⍵}
| Give a code snippet in #APL
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... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sieve_of_Eratosthenes | Sieve of Eratosthenes | This task has been clarified. Its programming examples are in need of review to ensure that they still fit the requirements of the task.
The Sieve of Eratosthenes is a simple algorithm that finds the prime numbers up to a given integer.
Task
Implement the Sieve of Eratosthenes algorithm, with the only allowed... | #Nim | Nim | from math import sqrt
iterator primesUpto(limit: int): int =
let sqrtLimit = int(sqrt(float64(limit)))
var composites = newSeq[bool](limit + 1)
for n in 2 .. sqrtLimit: # cull to square root of limit
if not composites[n]: # if prime -> cull its composites
for c in countup(n * n, limit, n): # start at ... | Give a code snippet in #Nim
This task has been clarified. Its programming examples are in need of review to ensure that they still fit the requirements of the task.
The Sieve of Eratosthenes is a simple algorithm that finds the prime numbers up to a given integer.
Task
Implement the Sieve of Eratosthenes alg... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Kaprekar_numbers | Kaprekar numbers | A positive integer is a Kaprekar number if:
It is 1 (unity)
The decimal representation of its square may be split once into two parts consisting of positive integers which sum to the original number.
Note that a split resulting in a part consisting purely of 0s is not valid,
as 0 is not considered positive.
... | #Scala | Scala | object Kaprekar extends App {
def isKaprekar(n: Int, base: Int = 10):Option[Triple[String,String,String]] = {
val check: Long => Option[Triple[String,String,String]] = n => {
val split: Pair[String, Int] => Pair[String, String] = p => (p._1.slice(0,p._2),p._1.slice(p._2,p._1.size).padTo[Char,String](1,'0'... | Give a code snippet in #Scala
A positive integer is a Kaprekar number if:
It is 1 (unity)
The decimal representation of its square may be split once into two parts consisting of positive integers which sum to the original number.
Note that a split resulting in a part consisting purely of 0s is not valid,
as... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Fractal_tree | Fractal tree | Generate and draw a fractal tree.
Draw the trunk
At the end of the trunk, split by some angle and draw two branches
Repeat at the end of each branch until a sufficient level of branching is reached
Related tasks
Pythagoras Tree
| #D | D | import std.stdio, std.math;
enum width = 1000, height = 1000; // Image dimension.
enum length = 400; // Trunk size.
enum scale = 6.0 / 10; // Branch scale relative to trunk.
void tree(in double x, in double y, in double length, in double angle) {
if (length < 1)
return;
imm... | Give a code snippet in #D
Generate and draw a fractal tree.
Draw the trunk
At the end of the trunk, split by some angle and draw two branches
Repeat at the end of each branch until a sufficient level of branching is reached
Related tasks
Pythagoras Tree
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Repeat_a_string | Repeat a string | Take a string and repeat it some number of times.
Example: repeat("ha", 5) => "hahahahaha"
If there is a simpler/more efficient way to repeat a single “character” (i.e. creating a string filled with a certain character), you might want to show that as well (i.e. repeat-char("*", 5) => "*****").
Other tasks re... | #Nim | Nim | import strutils
# Repeat a char.
echo repeat('a', 5) # -> "aaaaa".
# Repeat a string.
echo repeat("ha", 5) # -> "hahahahaha". | Give a code snippet in #Nim
Take a string and repeat it some number of times.
Example: repeat("ha", 5) => "hahahahaha"
If there is a simpler/more efficient way to repeat a single “character” (i.e. creating a string filled with a certain character), you might want to show that as well (i.e. repeat-char("*", 5) =>... | christopher/rosetta-code | |
http://rosettacode.org/wiki/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... | #Icon_and_Unicon | Icon and Unicon | procedure main(a)
s := !a | "1223334444"
write(H(s))
end
procedure H(s)
P := table(0.0)
every P[!s] +:= 1.0/*s
every (h := 0.0) -:= P[c := key(P)] * log(P[c],2)
return h
end | Give a code snippet in #Icon_and_Unicon
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... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Primality_by_trial_division | Primality by trial division | Task
Write a boolean function that tells whether a given integer is prime.
Remember that 1 and all non-positive numbers are not prime.
Use trial division.
Even numbers greater than 2 may be eliminated right away.
A loop from 3 to √ n will suffice, but other loops are allowed.
Related tasks
... | #PL.2FM | PL/M | 100H: /* TEST FOR PRIMALITY BY TRIAL DIVISION */
DECLARE FALSE LITERALLY '0', TRUE LITERALLY '0FFH';
/* CP/M BDOS SYSTEM CALL */
BDOS: PROCEDURE( FN, ARG ); DECLARE FN BYTE, ARG ADDRESS; GOTO 5; END;
PR$CHAR: PROCEDURE( C );... | Give a code snippet in #PL.2FM
Task
Write a boolean function that tells whether a given integer is prime.
Remember that 1 and all non-positive numbers are not prime.
Use trial division.
Even numbers greater than 2 may be eliminated right away.
A loop from 3 to √ n will suffice, but other loop... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Prime_decomposition | Prime decomposition | The prime decomposition of a number is defined as a list of prime numbers
which when all multiplied together, are equal to that number.
Example
12 = 2 × 2 × 3, so its prime decomposition is {2, 2, 3}
Task
Write a function which returns an array or collection which contains the prime decomposition of a given ... | #Wren | Wren | import "/big" for BigInt
import "/fmt" for Fmt
var vals = [1 << 31, 1234567, 333333, 987653, 2 * 3 * 5 * 7 * 11 * 13 * 17]
for (val in vals) {
Fmt.print("$10d -> $n", val, BigInt.primeFactors(val))
} | Give a code snippet in #Wren
The prime decomposition of a number is defined as a list of prime numbers
which when all multiplied together, are equal to that number.
Example
12 = 2 × 2 × 3, so its prime decomposition is {2, 2, 3}
Task
Write a function which returns an array or collection which contains the p... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Abundant,_deficient_and_perfect_number_classifications | Abundant, deficient and perfect number classifications | These define three classifications of positive integers based on their proper divisors.
Let P(n) be the sum of the proper divisors of n where the proper divisors are all positive divisors of n other than n itself.
if P(n) < n then n is classed as deficient (OEIS A005100).
if P(n)... | #Processing | Processing | void setup() {
int deficient = 0, perfect = 0, abundant = 0;
for (int i = 1; i <= 20000; i++) {
int sum_divisors = propDivSum(i);
if (sum_divisors < i) {
deficient++;
} else if (sum_divisors == i) {
perfect++;
} else {
abundant++;
}
}
println("Deficient numbers less than 20... | Give a code snippet in #Processing
These define three classifications of positive integers based on their proper divisors.
Let P(n) be the sum of the proper divisors of n where the proper divisors are all positive divisors of n other than n itself.
if P(n) < n then n is classed as defi... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Horner%27s_rule_for_polynomial_evaluation | Horner's rule for polynomial evaluation | A fast scheme for evaluating a polynomial such as:
−
19
+
7
x
−
4
x
2
+
6
x
3
{\displaystyle -19+7x-4x^{2}+6x^{3}\,}
when
x
=
3
{\displaystyle x=3\;}
.
is to arrange the computation as follows:
(
(
(
(
0
)
x
+
6
)
x
+
(
−
4
)
)
x
+
7
)
x
+
(
−
19
)
{\displaystyle ((((0)x+6)x+(-4))x... | #Octave | Octave | function r = horner(a, x)
r = 0.0;
for i = length(a):-1:1
r = r*x + a(i);
endfor
endfunction
horner([-19, 7, -4, 6], 3) | Give a code snippet in #Octave
A fast scheme for evaluating a polynomial such as:
−
19
+
7
x
−
4
x
2
+
6
x
3
{\displaystyle -19+7x-4x^{2}+6x^{3}\,}
when
x
=
3
{\displaystyle x=3\;}
.
is to arrange the computation as follows:
(
(
(
(
0
)
x
+
6
)
x
+
(
−
4
)
)
x
+
7
)
x
+
(
−
19
)
{... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Colour_bars/Display | Colour bars/Display | Task
Display a series of vertical color bars across the width of the display.
The color bars should either use:
the system palette, or
the sequence of colors:
black
red
green
blue
magenta
cyan
yellow
white
| #Raku | Raku | my ($x,$y) = 1280, 720;
my @colors = map -> $r, $g, $b { Buf.new: |(($r, $g, $b) xx $x div 8) },
0, 0, 0,
255, 0, 0,
0, 255, 0,
0, 0, 255,
255, 0, 255,
0, 255, 255,
255, 255, 0,
255, 255, 255;
my $img = open "colorbars.ppm", :w orelse die "Can't create colorba... | Give a code snippet in #Raku
Task
Display a series of vertical color bars across the width of the display.
The color bars should either use:
the system palette, or
the sequence of colors:
black
red
green
blue
magenta
cyan
yellow
white
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Day_of_the_week | Day of the week | A company decides that whenever Xmas falls on a Sunday they will give their workers all extra paid holidays so that, together with any public holidays, workers will not have to work the following week (between the 25th of December and the first of January).
Task
In what years between 2008 and 2121 will the 25th of ... | #Bracmat | Bracmat | { Calculate day of week in proleptic Gregorian calendar. Sunday == 0. }
( wday
= year month day adjustment mm yy
. !arg:(?year,?month,?day)
& div$(14+-1*!month,12):?adjustment
& !month+12*!adjustment+-2:?mm
& !year+-1*!adjustment:?yy
& mod
$ ( !day
... | Give a code snippet in #Bracmat
A company decides that whenever Xmas falls on a Sunday they will give their workers all extra paid holidays so that, together with any public holidays, workers will not have to work the following week (between the 25th of December and the first of January).
Task
In what years betwee... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Evolutionary_algorithm | Evolutionary algorithm | Starting with:
The target string: "METHINKS IT IS LIKE A WEASEL".
An array of random characters chosen from the set of upper-case letters together with the space, and of the same length as the target string. (Call it the parent).
A fitness function that computes the ‘closeness’ of its argument to the target string.... | #m4 | m4 | divert(-1)
# Get a random number from 0 to one less than $1.
# (Note that this is not a very good RNG. Also it writes a file.)
#
# Usage: randnum(N) (Produces a random integer in 0..N-1)
#
define(`randnum',
`syscmd(`echo $RANDOM > __random_number__')eval(include(__random_number__) % ( $1 ))')
# The *target* spe... | Give a code snippet in #m4
Starting with:
The target string: "METHINKS IT IS LIKE A WEASEL".
An array of random characters chosen from the set of upper-case letters together with the space, and of the same length as the target string. (Call it the parent).
A fitness function that computes the ‘closeness’ of its ar... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Balanced_brackets | Balanced brackets | Task:
Generate a string with N opening brackets [ and with N closing brackets ], in some arbitrary order.
Determine whether the generated string is balanced; that is, whether it consists entirely of pairs of opening/closing brackets (in that order), none of which mis-nest.
Examples
(empty) ... | #Simula | Simula | BEGIN
INTEGER U;
U := ININT;
BEGIN
TEXT PROCEDURE GENERATE(N); INTEGER N;
BEGIN
INTEGER R;
TEXT T;
T :- NOTEXT;
WHILE N > 0 DO BEGIN
R := RANDINT(1,2,U);
T :- T & (IF R = 1 THEN "[" ELSE "]");
N... | Give a code snippet in #Simula
Task:
Generate a string with N opening brackets [ and with N closing brackets ], in some arbitrary order.
Determine whether the generated string is balanced; that is, whether it consists entirely of pairs of opening/closing brackets (in that order), none of which mis-... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Truncate_a_file | Truncate a file | Task
Truncate a file to a specific length. This should be implemented as a routine that takes two parameters: the filename and the required file length (in bytes).
Truncation can be achieved using system or library calls intended for such a task, if such methods exist, or by creating a temporary file of a reduced... | #Clojure | Clojure | (defn truncate [file size]
(with-open [chan (.getChannel (java.io.FileOutputStream. file true))]
(.truncate chan size)))
(truncate "truncate_test.txt" 2) | Give a code snippet in #Clojure
Task
Truncate a file to a specific length. This should be implemented as a routine that takes two parameters: the filename and the required file length (in bytes).
Truncation can be achieved using system or library calls intended for such a task, if such methods exist, or by creat... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Musical_scale | Musical scale | Task
Output the 8 notes of the C major diatonic scale to the default musical sound device on the system. Specifically, pitch must be tuned to 12-tone equal temperament (12TET) with the modern standard A=440Hz.
These are the notes "C, D, E, F, G, A, B, C(1 octave higher)", or "Do, Re, Mi, Fa, Sol, La, Si/Ti, Do(1 octa... | #Mathematica.2FWolfram_Language | Mathematica/Wolfram Language | EmitSound@Sound[SoundNote /@ {0, 2, 4, 5, 7, 9, 11, 12}] | Give a code snippet in #Mathematica.2FWolfram_Language
Task
Output the 8 notes of the C major diatonic scale to the default musical sound device on the system. Specifically, pitch must be tuned to 12-tone equal temperament (12TET) with the modern standard A=440Hz.
These are the notes "C, D, E, F, G, A, B, C(1 octave... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Binary_search | Binary search | A binary search divides a range of values into halves, and continues to narrow down the field of search until the unknown value is found. It is the classic example of a "divide and conquer" algorithm.
As an analogy, consider the children's game "guess a number." The scorer has a secret number, and will only tell the p... | #JavaScript | JavaScript | function binary_search_recursive(a, value, lo, hi) {
if (hi < lo) { return null; }
var mid = Math.floor((lo + hi) / 2);
if (a[mid] > value) {
return binary_search_recursive(a, value, lo, mid - 1);
}
if (a[mid] < value) {
return binary_search_recursive(a, value, mid + 1, hi);
}
return mid;
} | Give a code snippet in #JavaScript
A binary search divides a range of values into halves, and continues to narrow down the field of search until the unknown value is found. It is the classic example of a "divide and conquer" algorithm.
As an analogy, consider the children's game "guess a number." The scorer has a sec... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Levenshtein_distance | Levenshtein distance |
This page uses content from Wikipedia. The original article was at Levenshtein distance. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance)
In information theory and computer science, the Levenshtein ... | #JavaScript | JavaScript | function levenshtein(a, b) {
var t = [], u, i, j, m = a.length, n = b.length;
if (!m) { return n; }
if (!n) { return m; }
for (j = 0; j <= n; j++) { t[j] = j; }
for (i = 1; i <= m; i++) {
for (u = [i], j = 1; j <= n; j++) {
u[j] = a[i - 1] === b[j - 1] ? t[j - 1] : Math.min(t[j - 1], t[j], u[j - 1])... | Give a code snippet in #JavaScript
This page uses content from Wikipedia. The original article was at Levenshtein distance. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance)
In information theory an... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Chinese_remainder_theorem | Chinese remainder theorem | Suppose
n
1
{\displaystyle n_{1}}
,
n
2
{\displaystyle n_{2}}
,
…
{\displaystyle \ldots }
,
n
k
{\displaystyle n_{k}}
are positive integers that are pairwise co-prime.
Then, for any given sequence of integers
a
1
{\displaystyle a_{1}}
,
a
2
... | #PARI.2FGP | PARI/GP | chivec(residues, moduli)={
my(m=Mod(0,1));
for(i=1,#residues,
m=chinese(Mod(residues[i],moduli[i]),m)
);
lift(m)
};
chivec([2,3,2], [3,5,7]) | Give a code snippet in #PARI.2FGP
Suppose
n
1
{\displaystyle n_{1}}
,
n
2
{\displaystyle n_{2}}
,
…
{\displaystyle \ldots }
,
n
k
{\displaystyle n_{k}}
are positive integers that are pairwise co-prime.
Then, for any given sequence of integers
a
1
{\disp... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Doubly-linked_list/Definition | Doubly-linked list/Definition | Define the data structure for a complete Doubly Linked List.
The structure should support adding elements to the head, tail and middle of the list.
The structure should not allow circular loops
See also
Array
Associative array: Creation, Iteration
Collections
Compound data type
Doubly-linked list: Definitio... | #PureBasic | PureBasic | DataSection
;the list of words that will be added to the list
words:
Data.s "One", "Two", "Three", "Four", "Five", "Six", "EndOfData"
EndDataSection
Procedure displayList(List x.s(), title$)
;display all elements from list of strings
Print(title$)
ForEach x()
Print(x() + " ")
Next
PrintN("")
E... | Give a code snippet in #PureBasic
Define the data structure for a complete Doubly Linked List.
The structure should support adding elements to the head, tail and middle of the list.
The structure should not allow circular loops
See also
Array
Associative array: Creation, Iteration
Collections
Compound data ... | 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... | #Scala | Scala | /** This class implicitly includes a constructor which accepts an Int and
* creates "val variable1: Int" with that value.
*/
class MyClass(val myMethod: Int) { // Acts like a getter, getter automatically generated.
var variable2 = "asdf" // Another instance variable; a public var this time
def this() = this(0) /... | Give a code snippet in #Scala
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 cla... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Conditional_structures | Conditional structures | Control Structures
These are examples of control structures. You may also be interested in:
Conditional structures
Exceptions
Flow-control structures
Loops
Task
List the conditional structures offered by a programming language. See Wikipedia: conditionals for descriptions.
Common conditional structures include ... | #DM | DM | if (condition)
// Do thing, DM uses indentation for control flow.
if (condition)
// Do thing
else if (condition)
// Do thing
else
// Do thing
| Give a code snippet in #DM
Control Structures
These are examples of control structures. You may also be interested in:
Conditional structures
Exceptions
Flow-control structures
Loops
Task
List the conditional structures offered by a programming language. See Wikipedia: conditionals for descriptions.
Common con... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Catalan_numbers | Catalan numbers | Catalan numbers
You are encouraged to solve this task according to the task description, using any language you may know.
Catalan numbers are a sequence of numbers which can be defined directly:
C
n
=
1
n
+
1
(
2
n
n
)
=
(
2
n
)
!
(
n
+
1
)
!
n
!
for
n
≥
0.
{\displaystyle C... | #Pascal | Pascal | Program CatalanNumbers(output);
function catalanNumber1(n: integer): double;
begin
if n = 0 then
catalanNumber1 := 1.0
else
catalanNumber1 := double(4 * n - 2) / double(n + 1) * catalanNumber1(n-1);
end;
var
number: integer;
begin
writeln('Catalan Numbers');
writeln('Recursion with ... | Give a code snippet in #Pascal
Catalan numbers
You are encouraged to solve this task according to the task description, using any language you may know.
Catalan numbers are a sequence of numbers which can be defined directly:
C
n
=
1
n
+
1
(
2
n
n
)
=
(
2
n
)
!
(
n
+
1
)
!
n
!
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Loops/While | Loops/While | Task
Start an integer value at 1024.
Loop while it is greater than zero.
Print the value (with a newline) and divide it by two each time through the loop.
Related tasks
Loop over multiple arrays simultaneously
Loops/Break
Loops/Continue
Loops/Do-while
Loops/Downward for
Loops/For
Loops/For... | #Fermat | Fermat | n:=1024;
while n>2/3 do !!n;n:=n/2; od; | Give a code snippet in #Fermat
Task
Start an integer value at 1024.
Loop while it is greater than zero.
Print the value (with a newline) and divide it by two each time through the loop.
Related tasks
Loop over multiple arrays simultaneously
Loops/Break
Loops/Continue
Loops/Do-while
Loops/Downwa... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Handle_a_signal | Handle a signal | Most operating systems provide interrupt facilities, sometimes called signals either generated by the user or as a result of program failure or reaching a limit like file space.
Unhandled signals generally terminate a program in a disorderly manner.
Signal handlers are created so that the program behaves in a well-defi... | #Perl | Perl |
my $start = time; # seconds since epohc
my $arlm=5; # every 5 seconds show how we're doing
my $i;
$SIG{QUIT} = sub
{print " Ran for ", time - $start, " seconds.\n"; die; };
$SIG{INT} = sub
{print " Running for ", time - $start, " seconds.\n"; };
$SIG{ALRM} = sub
{print " After $arlm seconds i= $i. Execu... | Give a code snippet in #Perl
Most operating systems provide interrupt facilities, sometimes called signals either generated by the user or as a result of program failure or reaching a limit like file space.
Unhandled signals generally terminate a program in a disorderly manner.
Signal handlers are created so that the ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Isqrt_(integer_square_root)_of_X | Isqrt (integer square root) of X | Sometimes a function is needed to find the integer square root of X, where X can be a
real non─negative number.
Often X is actually a non─negative integer.
For the purposes of this task, X can be an integer or a real number, but if it
simplifies things in your computer programming language, assume... | #Go | Go | package main
import (
"fmt"
"log"
"math/big"
)
var zero = big.NewInt(0)
var one = big.NewInt(1)
func isqrt(x *big.Int) *big.Int {
if x.Cmp(zero) < 0 {
log.Fatal("Argument cannot be negative.")
}
q := big.NewInt(1)
for q.Cmp(x) <= 0 {
q.Lsh(q, 2)
}
z := new(big.I... | Give a code snippet in #Go
Sometimes a function is needed to find the integer square root of X, where X can be a
real non─negative number.
Often X is actually a non─negative integer.
For the purposes of this task, X can be an integer or a real number, but if it
simplifies things in your computer pr... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Pseudo-random_numbers/Middle-square_method | Pseudo-random numbers/Middle-square method | Middle-square_method Generator
The Method
To generate a sequence of n-digit pseudorandom numbers, an n-digit starting value is created and squared, producing a 2n-digit number. If the result has fewer than 2n digits, leading zeroes are added to compensate. The middle n digits of the result would be the next number i... | #Haskell | Haskell | findPseudoRandom :: Int -> Int
findPseudoRandom seed =
let square = seed * seed
squarestr = show square
enlarged = replicate ( 12 - length squarestr ) '0' ++ squarestr
in read $ take 6 $ drop 3 enlarged
solution :: [Int]
solution = tail $ take 6 $ iterate findPseudoRandom 675248 | Give a code snippet in #Haskell
Middle-square_method Generator
The Method
To generate a sequence of n-digit pseudorandom numbers, an n-digit starting value is created and squared, producing a 2n-digit number. If the result has fewer than 2n digits, leading zeroes are added to compensate. The middle n digits of the ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Read_entire_file | Read entire file | Task
Load the entire contents of some text file as a single string variable.
If applicable, discuss: encoding selection, the possibility of memory-mapping.
Of course, in practice one should avoid reading an entire file at once
if the file is large and the task can be accomplished incrementally instead
(in which case... | #Seed7 | Seed7 | $ include "seed7_05.s7i";
include "getf.s7i";
const proc: main is func
local
var string: fileContent is "";
begin
fileContent := getf("text.txt");
end func; | Give a code snippet in #Seed7
Task
Load the entire contents of some text file as a single string variable.
If applicable, discuss: encoding selection, the possibility of memory-mapping.
Of course, in practice one should avoid reading an entire file at once
if the file is large and the task can be accomplished incre... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Dinesman%27s_multiple-dwelling_problem | Dinesman's multiple-dwelling problem | Task
Solve Dinesman's multiple dwelling problem but in a way that most naturally follows the problem statement given below.
Solutions are allowed (but not required) to parse and interpret the problem text, but should remain flexible and should state what changes to the problem text are allowed. Flexibility and ease of... | #EchoLisp | EchoLisp |
(require 'hash)
(require' amb)
;;
;; Solver
;;
(define (dwelling-puzzle context names floors H)
;; each amb calls gives a floor to a name
(for ((name names))
(hash-set H name (amb context floors)))
;; They live on different floors.
(amb-require (distinct? (amb-choices context)))
(constraints floors ... | Give a code snippet in #EchoLisp
Task
Solve Dinesman's multiple dwelling problem but in a way that most naturally follows the problem statement given below.
Solutions are allowed (but not required) to parse and interpret the problem text, but should remain flexible and should state what changes to the problem text ar... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Mind_boggling_card_trick | Mind boggling card trick | Mind boggling card trick
You are encouraged to solve this task according to the task description, using any language you may know.
Matt Parker of the "Stand Up Maths channel" has a YouTube video of a card trick that creates a semblance of order from chaos.
The task is to simulate the trick in a way that mimics th... | #J | J |
NB. A failed assertion looks like this
assert 0
|assertion failure: assert
| assert 0
| Give a code snippet in #J
Mind boggling card trick
You are encouraged to solve this task according to the task description, using any language you may know.
Matt Parker of the "Stand Up Maths channel" has a YouTube video of a card trick that creates a semblance of order from chaos.
The task is to simulate the tr... | 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... | #PicoLisp | PicoLisp | (call 'sox
"-m" "-v" "0.75" "a.wav" "-v" "0.25" "b.wav"
"-d"
"trim" 4 6
"repeat" 5 ) | Give a code snippet in #PicoLisp
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
performi... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Menu | Menu | Task
Given a prompt and a list containing a number of strings of which one is to be selected, create a function that:
prints a textual menu formatted as an index value followed by its corresponding string for each item in the list;
prompts the user to enter a number;
returns the string corresponding to the selecte... | #Yabasic | Yabasic | // Rosetta Code problem: https://www.rosettacode.org/wiki/Menu
// by Jjuanhdez, 06/2022
dim choose$(5)
restore menudata
for a = 0 to 5 : read choose$(a) : next a
print menu$(choose$())
end
sub menu$(m$())
clear screen
repeat
print color("green","black") at(0,0) "Menu selection"
vc = 0
... | Give a code snippet in #Yabasic
Task
Given a prompt and a list containing a number of strings of which one is to be selected, create a function that:
prints a textual menu formatted as an index value followed by its corresponding string for each item in the list;
prompts the user to enter a number;
returns the st... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Ackermann_function | Ackermann function | The Ackermann function is a classic example of a recursive function, notable especially because it is not a primitive recursive function. It grows very quickly in value, as does the size of its call tree.
The Ackermann function is usually defined as follows:
A
(
m
,
n
)
=
{
n
+
1
if
m
=
0
A
(
m
... | #Haskell | Haskell | ack :: Int -> Int -> Int
ack 0 n = succ n
ack m 0 = ack (pred m) 1
ack m n = ack (pred m) (ack m (pred n))
main :: IO ()
main = mapM_ print $ uncurry ack <$> [(0, 0), (3, 4)] | Give a code snippet in #Haskell
The Ackermann function is a classic example of a recursive function, notable especially because it is not a primitive recursive function. It grows very quickly in value, as does the size of its call tree.
The Ackermann function is usually defined as follows:
A
(
m
,
n
)
=
{
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Roman_numerals/Encode | Roman numerals/Encode | Task
Create a function taking a positive integer as its parameter and returning a string containing the Roman numeral representation of that integer. Modern Roman numerals are written by expressing each digit separately, starting with the left most digit and skipping any digit with a value of zero.
In Roman numeral... | #Ursala | Ursala | #import nat
roman =
-+
'IIII'%='IV'+ 'VIIII'%='IX'+ 'XXXX'%='XL'+ 'LXXXX'%='XC'+ 'CCCC'%='CD'+ 'DCCCC'%='CM',
~&plrDlSPSL/'MDCLXVI'+ iota*+ +^|(^|C/~&,\/division)@rlX=>~&iNC <1000,500,100,50,10,5>+- | Give a code snippet in #Ursala
Task
Create a function taking a positive integer as its parameter and returning a string containing the Roman numeral representation of that integer. Modern Roman numerals are written by expressing each digit separately, starting with the left most digit and skipping any digit with a va... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Strong_and_weak_primes | Strong and weak primes |
Definitions (as per number theory)
The prime(p) is the pth prime.
prime(1) is 2
prime(4) is 7
A strong prime is when prime(p) is > [prime(p-1) + prime(p+1)] ÷ 2
A weak prime is when prime(p) is < [prime(p-1) + prime(p+1)] ÷ 2
Note that the defin... | #FreeBASIC | FreeBASIC |
#include "isprime.bas"
function nextprime( n as uinteger ) as uinteger
'finds the next prime after n, excluding n if it happens to be prime itself
if n = 0 then return 2
if n < 3 then return n + 1
dim as integer q = n + 2
while not isprime(q)
q+=2
wend
return q
end function
fun... | Give a code snippet in #FreeBASIC
Definitions (as per number theory)
The prime(p) is the pth prime.
prime(1) is 2
prime(4) is 7
A strong prime is when prime(p) is > [prime(p-1) + prime(p+1)] ÷ 2
A weak prime is when prime(p) is < [prime(p-1) + pr... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Show_ASCII_table | Show ASCII table | Task
Show the ASCII character set from values 32 to 127 (decimal) in a table format.
Other tasks related to string operations:
Metrics
Array length
String length
Copy a string
Empty string (assignment)
Counting
Word frequency
Letter frequency
Jewels and stones
I before E except after C
Bioin... | #Jsish | Jsish | #!/usr/bin/env jsish
/* Show ASCII table, -showAll true to include control codes */
function showASCIITable(args:array|string=void, conf:object=void) {
var options = { // Rosetta Code, Show ASCII table
rootdir :'', // Root directory.
showAll : false // include control cod... | Give a code snippet in #Jsish
Task
Show the ASCII character set from values 32 to 127 (decimal) in a table format.
Other tasks related to string operations:
Metrics
Array length
String length
Copy a string
Empty string (assignment)
Counting
Word frequency
Letter frequency
Jewels and stones
I... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Stack_traces | Stack traces | Many programming languages allow for introspection of the current call stack environment. This can be for a variety of purposes such as enforcing security checks, debugging, or for getting access to the stack frame of callers.
Task
Print out (in a manner considered suitable for the platform) the current call stack.... | #Ada | Ada | with Ada.Text_IO; use Ada.Text_IO;
with GNAT.Traceback;
with GNAT.Traceback.Symbolic;
procedure Test_Stack_Trace is
procedure Call_Stack is
Trace : GNAT.Traceback.Tracebacks_Array (1..1_000);
Length : Natural;
begin
GNAT.Traceback.Call_Chain (Trace, Length);
Put_Line (GNAT.Traceback.Sy... | Give a code snippet in #Ada
Many programming languages allow for introspection of the current call stack environment. This can be for a variety of purposes such as enforcing security checks, debugging, or for getting access to the stack frame of callers.
Task
Print out (in a manner considered suitable for the plat... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Doubly-linked_list/Traversal | Doubly-linked list/Traversal | Traverse from the beginning of a doubly-linked list to the end, and from the end to the beginning.
See also
Array
Associative array: Creation, Iteration
Collections
Compound data type
Doubly-linked list: Definition, Element definition, Element insertion, List Traversal, Element Removal
Linked list
Queue: Def... | #Nim | Nim | type
List[T] = object
head, tail: Node[T]
Node[T] = ref TNode[T]
TNode[T] = object
next, prev: Node[T]
data: T
proc initList[T](): List[T] = discard
proc newNode[T](data: T): Node[T] =
new(result)
result.data = data
proc prepend[T](l: var List[T], n: Node[T]) =
n.next = l.head
if l.h... | Give a code snippet in #Nim
Traverse from the beginning of a doubly-linked list to the end, and from the end to the beginning.
See also
Array
Associative array: Creation, Iteration
Collections
Compound data type
Doubly-linked list: Definition, Element definition, Element insertion, List Traversal, Element Rem... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Boolean_values | Boolean values | Task
Show how to represent the boolean states "true" and "false" in a language.
If other objects represent "true" or "false" in conditionals, note it.
Related tasks
Logical operations
| #Quackery | Quackery | (cond ([(< 4 3) 'apple]
['bloggle 'pear]
[else 'nectarine]) | Give a code snippet in #Quackery
Task
Show how to represent the boolean states "true" and "false" in a language.
If other objects represent "true" or "false" in conditionals, note it.
Related tasks
Logical operations
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Loops/Increment_loop_index_within_loop_body | Loops/Increment loop index within loop body | Sometimes, one may need (or want) a loop which
its iterator (the index
variable) is modified within the
loop body in addition to the normal incrementation by the (do) loop structure index.
Goal
Demonstrate the best way to accomplish this.
Task
Write a loop which:
starts the index (variable... | #360_Assembly | 360 Assembly | * Loops/Increment loop index within loop body - 16/07/2018
LOOPILWB PROLOG
SR R6,R6 i=0
ZAP N,=P'42' n=42
DO WHILE=(C,R6,LT,IMAX) do while(i<imax)
BAL R14,ISPRIME call isprime(n)
IF C,R0,EQ,=F'1' THEN if n is prime the... | Give a code snippet in #360_Assembly
Sometimes, one may need (or want) a loop which
its iterator (the index
variable) is modified within the
loop body in addition to the normal incrementation by the (do) loop structure index.
Goal
Demonstrate the best way to accomplish this.
Task
Write a loop... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Elliptic_curve_arithmetic | Elliptic curve arithmetic | Elliptic curves are sometimes used in cryptography as a way to perform digital signatures.
The purpose of this task is to implement a simplified (without modular arithmetic) version of the elliptic curve arithmetic which is required by the elliptic curve DSA protocol.
In a nutshell, an elliptic curve is a... | #Tcl | Tcl | set C 7
set zero {x inf y inf}
proc tcl::mathfunc::cuberoot n {
# General power operator doesn't like negative, but its defined for root3
expr {$n>=0 ? $n**(1./3) : -((-$n)**(1./3))}
}
proc iszero p {
dict with p {}
return [expr {$x > 1e20 || $x<-1e20}]
}
proc negate p {
dict set p y [expr {-[dict g... | Give a code snippet in #Tcl
Elliptic curves are sometimes used in cryptography as a way to perform digital signatures.
The purpose of this task is to implement a simplified (without modular arithmetic) version of the elliptic curve arithmetic which is required by the elliptic curve DSA protocol.
In a nut... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Variable_declaration_reset | Variable declaration reset | A decidely non-challenging task to highlight a potential difference between programming languages.
Using a straightforward longhand loop as in the JavaScript and Phix examples below, show the locations of elements which are identical to the immediately preceding element in {1,2,2,3,4,4,5}. The (non-blank) results may ... | #Perl | Perl | @s = <1 2 2 3 4 4 5>;
for ($i = 0; $i < 7; $i++) {
$curr = $s[$i];
if ($i > 1 and $curr == $prev) { print "$i\n" }
$prev = $curr;
} | Give a code snippet in #Perl
A decidely non-challenging task to highlight a potential difference between programming languages.
Using a straightforward longhand loop as in the JavaScript and Phix examples below, show the locations of elements which are identical to the immediately preceding element in {1,2,2,3,4,4,5}... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Abbreviations,_simple | Abbreviations, simple | The use of abbreviations (also sometimes called synonyms, nicknames, AKAs, or aliases) can be an
easy way to add flexibility when specifying or using commands, sub─commands, options, etc.
For this task, the following command table will be used:
add 1 alter 3 backup 2 bottom 1 Cappend 2 change 1 ... | #Haskell | Haskell | import Data.List (find, isPrefixOf)
import Data.Char (isDigit, toUpper)
import Data.Maybe (maybe)
withExpansions :: [(String, Int)] -> String -> String
withExpansions tbl s = unwords $ expanded tbl <$> words s
expanded :: [(String, Int)] -> String -> String
expanded tbl k = maybe "*error" fst (expand k)
where
... | Give a code snippet in #Haskell
The use of abbreviations (also sometimes called synonyms, nicknames, AKAs, or aliases) can be an
easy way to add flexibility when specifying or using commands, sub─commands, options, etc.
For this task, the following command table will be used:
add 1 alter 3 backup 2... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Permutations | Permutations | Task
Write a program that generates all permutations of n different objects. (Practically numerals!)
Related tasks
Find the missing permutation
Permutations/Derangements
The number of samples of size k from n objects.
With combinations and permutations generation tasks.
Order Uni... | #Logtalk | Logtalk | :- object(list).
:- public(permutation/2).
permutation(List, Permutation) :-
same_length(List, Permutation),
permutation2(List, Permutation).
permutation2([], []).
permutation2(List, [Head| Tail]) :-
select(Head, List, Remaining),
permutation2(Remaining, Tail).
... | Give a code snippet in #Logtalk
Task
Write a program that generates all permutations of n different objects. (Practically numerals!)
Related tasks
Find the missing permutation
Permutations/Derangements
The number of samples of size k from n objects.
With combinations and permutations ge... | christopher/rosetta-code | |
http://rosettacode.org/wiki/String_comparison | String comparison |
Basic Data Operation
This is a basic data operation. It represents a fundamental action on a basic data type.
You may see other such operations in the Basic Data Operations category, or:
Integer Operations
Arithmetic |
Comparison
Boolean Operations
Bitwise |
Logical
String Operations
Concatenation |
Interpolation |... | #Rust | Rust | use std::ascii::AsciiExt; // for case insensitives only
fn main() {
// only same types can be compared
// String and String or &str and &str
// exception: strict equality and inequality also work on &str and String
let a: &str = "abc";
let b: String = "Bac".to_owned();
// Strings are coerced... | Give a code snippet in #Rust
Basic Data Operation
This is a basic data operation. It represents a fundamental action on a basic data type.
You may see other such operations in the Basic Data Operations category, or:
Integer Operations
Arithmetic |
Comparison
Boolean Operations
Bitwise |
Logical
String Operations
C... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Function_definition | Function definition | A function is a body of code that returns a value.
The value returned may depend on arguments provided to the function.
Task
Write a definition of a function called "multiply" that takes two arguments and returns their product.
(Argument types should be chosen so as not to distract from showing how functions are ... | #ActionScript | ActionScript | function multiply(a:Number, b:Number):Number {
return a * b;
} | Give a code snippet in #ActionScript
A function is a body of code that returns a value.
The value returned may depend on arguments provided to the function.
Task
Write a definition of a function called "multiply" that takes two arguments and returns their product.
(Argument types should be chosen so as not to di... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Partial_function_application | Partial function application | Partial function application is the ability to take a function of many
parameters and apply arguments to some of the parameters to create a new
function that needs only the application of the remaining arguments to
produce the equivalent of applying all arguments to the original function.
E.g:
Given values v1, v2
... | #Lua | Lua | function map(f, ...)
local t = {}
for k, v in ipairs(...) do
t[#t+1] = f(v)
end
return t
end
function timestwo(n)
return n * 2
end
function squared(n)
return n ^ 2
end
function partial(f, arg)
return function(...)
return f(arg, ...)
end
end
timestwo_s = partial(ma... | Give a code snippet in #Lua
Partial function application is the ability to take a function of many
parameters and apply arguments to some of the parameters to create a new
function that needs only the application of the remaining arguments to
produce the equivalent of applying all arguments to the original function.... | 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:
... | #FunL | FunL | import lists.zip3
for x <- zip3( ['a', 'b', 'c'], ['A', 'B', 'C'], [1, 2, 3] )
println( x.mkString() ) | Give a code snippet in #FunL
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 examp... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Smith_numbers | Smith numbers | Smith numbers are numbers such that the sum of the decimal digits of the integers that make up that number is the same as the sum of the decimal digits of its prime factors excluding 1.
By definition, all primes are excluded as they (naturally) satisfy this condition!
Smith numbers are also known as joke numbers.... | #Pascal | Pascal | program SmithNum;
{$IFDEF FPC}
{$MODE objFPC} //result and useful for x64
{$CODEALIGN PROC=64}
{$ENDIF}
uses
sysutils;
type
tdigit = byte;
tSum = LongInt;
const
base = 10;
//maxDigitCnt *(base-1) <= High(tSum)
//maxDigitCnt <= High(tSum) DIV (base-1);
maxDigitCnt = 16;
StartPrimNo = 6;
cseg... | Give a code snippet in #Pascal
Smith numbers are numbers such that the sum of the decimal digits of the integers that make up that number is the same as the sum of the decimal digits of its prime factors excluding 1.
By definition, all primes are excluded as they (naturally) satisfy this condition!
Smith numbers are... | 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... | #Racket | Racket |
(define (reader)
(for ([line (in-lines (open-input-file "input.txt"))])
(thread-send printer-thread line))
(thread-send printer-thread eof)
(printf "Number of lines: ~a\n" (thread-receive)))
(define (printer)
(thread-send reader-thread
(for/sum ([line (in-producer thread-receive eof)])
... | Give a code snippet in #Racket
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 differ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sorting_algorithms/Bubble_sort | Sorting algorithms/Bubble sort |
Sorting Algorithm
This is a sorting algorithm. It may be applied to a set of data in order to sort it.
For comparing various sorts, see compare sorts.
For other sorting algorithms, see sorting algorithms, or:
O(n logn) sorts
Heap sort |
Merge sort |
Patience sort |
Quick sort
O(n log2n) sorts
Shell Sort
... | #Forth | Forth | defer bubble-test
' > is bubble-test
: bubble { addr cnt -- }
cnt 1 do
addr cnt i - cells bounds do
i 2@ bubble-test if i 2@ swap i 2! then
cell +loop
loop ; | Give a code snippet in #Forth
Sorting Algorithm
This is a sorting algorithm. It may be applied to a set of data in order to sort it.
For comparing various sorts, see compare sorts.
For other sorting algorithms, see sorting algorithms, or:
O(n logn) sorts
Heap sort |
Merge sort |
Patience sort |
Quick so... | christopher/rosetta-code | |
http://rosettacode.org/wiki/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.
| #Go | Go | package main
import (
"fmt"
"github.com/go-vgo/robotgo"
)
func main() {
// get position of mouse cursor
x, y := robotgo.GetMousePos()
// get color of pixel at that position
color := robotgo.GetPixelColor(x, y)
fmt.Printf("Color of pixel at (%d, %d) is 0x%s\n", x, y, color)
} | Give a code snippet in #Go
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/Dutch_national_flag_problem | Dutch national flag problem |
The Dutch national flag is composed of three coloured bands in the order:
red (top)
then white, and
lastly blue (at the bottom).
The problem posed by Edsger Dijkstra is:
Given a number of red, blue and white balls in random order, arrange them in the order of the colours in the Dutch national fla... | #Go | Go | package main
import (
"fmt"
"math/rand"
"time"
)
// constants define order of colors in Dutch national flag
const (
red = iota
white
blue
nColors
)
// zero object of type is valid red ball.
type ball struct {
color int
}
// order of balls based on DNF
func (b1 ball) lt(b2 ball) b... | Give a code snippet in #Go
The Dutch national flag is composed of three coloured bands in the order:
red (top)
then white, and
lastly blue (at the bottom).
The problem posed by Edsger Dijkstra is:
Given a number of red, blue and white balls in random order, arrange them in the order of the colou... | christopher/rosetta-code | |
http://rosettacode.org/wiki/4-rings_or_4-squares_puzzle | 4-rings or 4-squares puzzle | 4-rings or 4-squares puzzle
You are encouraged to solve this task according to the task description, using any language you may know.
Task
Replace a, b, c, d, e, f, and
g with the decimal
digits LOW ───► HIGH
such that the sum of the letters inside of each of the four large squares add up to
t... | #C.2B.2B | C++ |
//C++14/17
#include <algorithm>//std::for_each
#include <iostream> //std::cout
#include <numeric> //std::iota
#include <vector> //std::vector, save solutions
#include <list> //std::list, for fast erase
using std::begin, std::end, std::for_each;
//Generates all the valid solutions for the problem in the spe... | Give a code snippet in #C.2B.2B
4-rings or 4-squares puzzle
You are encouraged to solve this task according to the task description, using any language you may know.
Task
Replace a, b, c, d, e, f, and
g with the decimal
digits LOW ───► HIGH
such that the sum of the letters inside of each of t... | christopher/rosetta-code | |
http://rosettacode.org/wiki/List_comprehensions | List comprehensions | A list comprehension is a special syntax in some programming languages to describe lists. It is similar to the way mathematicians describe sets, with a set comprehension, hence the name.
Some attributes of a list comprehension are:
They should be distinct from (nested) for loops and the use of map and filter functio... | #Python | Python | [(x,y,z) for x in xrange(1,n+1) for y in xrange(x,n+1) for z in xrange(y,n+1) if x**2 + y**2 == z**2] | Give a code snippet in #Python
A list comprehension is a special syntax in some programming languages to describe lists. It is similar to the way mathematicians describe sets, with a set comprehension, hence the name.
Some attributes of a list comprehension are:
They should be distinct from (nested) for loops and t... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Summarize_and_say_sequence | Summarize and say sequence | There are several ways to generate a self-referential sequence. One very common one (the Look-and-say sequence) is to start with a positive integer, then generate the next term by concatenating enumerated groups of adjacent alike digits:
0, 10, 1110, 3110, 132110, 1113122110, 311311222110 ...
The terms generat... | #C | C | #include <stdio.h>
#include <stdlib.h>
#include <string.h>
typedef struct rec_t rec_t;
struct rec_t {
int depth;
rec_t * p[10];
};
rec_t root = {0, {0}};
#define USE_POOL_ALLOC
#ifdef USE_POOL_ALLOC /* not all that big a deal */
rec_t *tail = 0, *head = 0;
#define POOL_SIZE (1 << 20)
inline rec_t *new_rec()
{
... | Give a code snippet in #C
There are several ways to generate a self-referential sequence. One very common one (the Look-and-say sequence) is to start with a positive integer, then generate the next term by concatenating enumerated groups of adjacent alike digits:
0, 10, 1110, 3110, 132110, 1113122110, 31131122... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Variable-length_quantity | Variable-length quantity | Implement some operations on variable-length quantities, at least including conversions from a normal number in the language to the binary representation of the variable-length quantity for that number, and vice versa. Any variants are acceptable.
Task
With above operations,
convert these two numbers 0x200000 (209... | #Tcl | Tcl | package require Tcl 8.5
proc vlqEncode number {
if {$number < 0} {error "negative not supported"}
while 1 {
lappend digits [expr {$number & 0x7f}]
if {[set number [expr {$number >> 7}]] == 0} break
}
set out [format %c [lindex $digits 0]]
foreach digit [lrange $digits 1 end] {
set out [format %... | Give a code snippet in #Tcl
Implement some operations on variable-length quantities, at least including conversions from a normal number in the language to the binary representation of the variable-length quantity for that number, and vice versa. Any variants are acceptable.
Task
With above operations,
convert th... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Hello_world/Newbie | Hello world/Newbie | Task
Guide a new user of a language through the steps necessary
to install the programming language and selection of a text editor if needed,
to run the languages' example in the Hello world/Text task.
Assume the language-newbie is a programmer in another language.
Assume the language-newbie is competent in install... | #Corescript | Corescript | import std.stdio;
void main()
{
writeln("Hello world!");
} | Give a code snippet in #Corescript
Task
Guide a new user of a language through the steps necessary
to install the programming language and selection of a text editor if needed,
to run the languages' example in the Hello world/Text task.
Assume the language-newbie is a programmer in another language.
Assume the lan... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Even_or_odd | Even or odd | Task
Test whether an integer is even or odd.
There is more than one way to solve this task:
Use the even and odd predicates, if the language provides them.
Check the least significant digit. With binary integers, i bitwise-and 1 equals 0 iff i is even, or equals 1 iff i is odd.
Divide i by 2. The remainder equals... | #Oforth | Oforth | 12 isEven
12 isOdd | Give a code snippet in #Oforth
Task
Test whether an integer is even or odd.
There is more than one way to solve this task:
Use the even and odd predicates, if the language provides them.
Check the least significant digit. With binary integers, i bitwise-and 1 equals 0 iff i is even, or equals 1 iff i is odd.
Div... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sequence:_nth_number_with_exactly_n_divisors | Sequence: nth number with exactly n divisors | Calculate the sequence where each term an is the nth that has n divisors.
Task
Show here, on this page, at least the first 15 terms of the sequence.
See also
OEIS:A073916
Related tasks
Sequence: smallest number greater than previous term with exactly n divisors
Sequence: smallest number with exactly n divisors | #Julia | Julia | using Primes
function countdivisors(n)
f = [one(n)]
for (p, e) in factor(n)
f = reduce(vcat, [f * p ^ j for j in 1:e], init = f)
end
length(f)
end
function nthwithndivisors(N)
parray = findall(primesmask(100 * N))
for i = 1:N
if isprime(i)
println("$i : ", BigInt(... | Give a code snippet in #Julia
Calculate the sequence where each term an is the nth that has n divisors.
Task
Show here, on this page, at least the first 15 terms of the sequence.
See also
OEIS:A073916
Related tasks
Sequence: smallest number greater than previous term with exactly n divisors
Sequence: smallest number... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Optional_parameters | Optional parameters | Task
Define a function/method/subroutine which sorts a sequence ("table") of sequences ("rows") of strings ("cells"), by one of the strings. Besides the input to be sorted, it shall have the following optional parameters:
ordering
A function specifying the ordering of strings; lexicographic by default.
column
... | #Ruby | Ruby | def table_sort(table, ordering=:<=>, column=0, reverse=false)
# ... | Give a code snippet in #Ruby
Task
Define a function/method/subroutine which sorts a sequence ("table") of sequences ("rows") of strings ("cells"), by one of the strings. Besides the input to be sorted, it shall have the following optional parameters:
ordering
A function specifying the ordering of strings; lexi... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Conditional_structures | Conditional structures | Control Structures
These are examples of control structures. You may also be interested in:
Conditional structures
Exceptions
Flow-control structures
Loops
Task
List the conditional structures offered by a programming language. See Wikipedia: conditionals for descriptions.
Common conditional structures include ... | #BBC_BASIC | BBC BASIC | REM Single-line IF ... THEN ... ELSE (ELSE clause is optional):
IF condition% THEN statements ELSE statements
REM Multi-line IF ... ENDIF (ELSE clause is optional):
IF condition% THEN
statements
ELSE
statements
ENDIF
REM CASE ... ENDCASE (OTHERWISE clause is... | Give a code snippet in #BBC_BASIC
Control Structures
These are examples of control structures. You may also be interested in:
Conditional structures
Exceptions
Flow-control structures
Loops
Task
List the conditional structures offered by a programming language. See Wikipedia: conditionals for descriptions.
Com... | 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
... | #Arturo | Arturo | arr: [1 2 3 2 1 2 3 4 5 3 2 1]
print unique arr | Give a code snippet in #Arturo
Sorting Algorithm
This is a sorting algorithm. It may be applied to a set of data in order to sort it.
For comparing various sorts, see compare sorts.
For other sorting algorithms, see sorting algorithms, or:
O(n logn) sorts
Heap sort |
Merge sort |
Patience sort |
Quick s... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Walk_a_directory/Recursively | Walk a directory/Recursively | Task
Walk a given directory tree and print files matching a given pattern.
Note: This task is for recursive methods. These tasks should read an entire directory tree, not a single directory.
Note: Please be careful when running any code examples found here.
Related task
Walk a directory/Non-recursively ... | #C.23 | C# | using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
namespace RosettaRecursiveDirectory
{
class Program
{
static IEnumerable<FileInfo> TraverseDirectory(string rootPath, Func<FileInfo, bool> Pattern)
{
var directoryStack = new Stack<DirectoryInfo>();... | Give a code snippet in #C.23
Task
Walk a given directory tree and print files matching a given pattern.
Note: This task is for recursive methods. These tasks should read an entire directory tree, not a single directory.
Note: Please be careful when running any code examples found here.
Related task
Walk ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Flipping_bits_game | Flipping bits game | The game
Given an N×N square array of zeroes or ones in an initial configuration, and a target configuration of zeroes and ones.
The game is to transform one to the other in as few moves as possible by inverting whole numbered rows or whole lettered
columns at once (as one move).
In an inversion. any 1 ... | #Ruby | Ruby | class FlipBoard
def initialize(size)
raise ArgumentError.new("Invalid board size: #{size}") if size < 2
@size = size
@board = Array.new(size**2, 0)
randomize_board
loop do
@target = generate_target
break unless solved?
end
# these are used for validating user input
@... | Give a code snippet in #Ruby
The game
Given an N×N square array of zeroes or ones in an initial configuration, and a target configuration of zeroes and ones.
The game is to transform one to the other in as few moves as possible by inverting whole numbered rows or whole lettered
columns at once (as one move... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Roots_of_a_function | Roots of a function | Task
Create a program that finds and outputs the roots of a given function, range and (if applicable) step width.
The program should identify whether the root is exact or approximate.
For this task, use: ƒ(x) = x3 - 3x2 + 2x
| #Lambdatalk | Lambdatalk |
1) defining the function:
{def func {lambda {:x} {+ {* 1 :x :x :x} {* -3 :x :x} {* 2 :x}}}}
-> func
2) printing roots:
{S.map {lambda {:x}
{if {< {abs {func :x}} 0.0001}
then {br}- a root found at :x else}}
{S.serie -1 3 0.01}}
->
- a root found at 7.528699885739343e-16 ... | Give a code snippet in #Lambdatalk
Task
Create a program that finds and outputs the roots of a given function, range and (if applicable) step width.
The program should identify whether the root is exact or approximate.
For this task, use: ƒ(x) = x3 - 3x2 + 2x
| christopher/rosetta-code | |
http://rosettacode.org/wiki/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
| #Astro | Astro | print "Hello world!" | Give a code snippet in #Astro
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/Flow-control_structures | Flow-control structures | Control Structures
These are examples of control structures. You may also be interested in:
Conditional structures
Exceptions
Flow-control structures
Loops
Task
Document common flow-control structures.
One common example of a flow-control structure is the goto construct.
Note that Conditional Struc... | #GW-BASIC | GW-BASIC | 10 LET a=1
20 IF a=2 THEN PRINT "This is a conditional statement"
30 IF a=1 THEN GOTO 50: REM a conditional jump
40 PRINT "This statement will be skipped"
50 PRINT ("Hello" AND (1=2)): REM This does NOT PRINT
100 PRINT "Endless loop"
110 GOTO 100:REM an unconditional jump | Give a code snippet in #GW-BASIC
Control Structures
These are examples of control structures. You may also be interested in:
Conditional structures
Exceptions
Flow-control structures
Loops
Task
Document common flow-control structures.
One common example of a flow-control structure is the goto constru... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Catamorphism | Catamorphism | Reduce is a function or method that is used to take the values in an array or a list and apply a function to successive members of the list to produce (or reduce them to), a single value.
Task
Show how reduce (or foldl or foldr etc), work (or would be implemented) in your language.
See also
Wikipedia article: ... | #OCaml | OCaml | # let nums = [1;2;3;4;5;6;7;8;9;10];;
val nums : int list = [1; 2; 3; 4; 5; 6; 7; 8; 9; 10]
# let sum = List.fold_left (+) 0 nums;;
val sum : int = 55
# let product = List.fold_left ( * ) 1 nums;;
val product : int = 3628800 | Give a code snippet in #OCaml
Reduce is a function or method that is used to take the values in an array or a list and apply a function to successive members of the list to produce (or reduce them to), a single value.
Task
Show how reduce (or foldl or foldr etc), work (or would be implemented) in your language.
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Function_definition | Function definition | A function is a body of code that returns a value.
The value returned may depend on arguments provided to the function.
Task
Write a definition of a function called "multiply" that takes two arguments and returns their product.
(Argument types should be chosen so as not to distract from showing how functions are ... | #Ursala | Ursala | multiply = math..mul | Give a code snippet in #Ursala
A function is a body of code that returns a value.
The value returned may depend on arguments provided to the function.
Task
Write a definition of a function called "multiply" that takes two arguments and returns their product.
(Argument types should be chosen so as not to distract... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Fibonacci_sequence | Fibonacci sequence | The Fibonacci sequence is a sequence Fn of natural numbers defined recursively:
F0 = 0
F1 = 1
Fn = Fn-1 + Fn-2, if n>1
Task
Write a function to generate the nth Fibonacci number.
Solutions can be iterative or recursive (though recursive solutions are generally considered too slow ... | #11l | 11l | F fib_iter(n)
I n < 2
R n
V fib_prev = 1
V fib = 1
L 2 .< n
(fib_prev, fib) = (fib, fib + fib_prev)
R fib
L(i) 1..20
print(fib_iter(i), end' ‘ ’)
print() | Give a code snippet in #11l
The Fibonacci sequence is a sequence Fn of natural numbers defined recursively:
F0 = 0
F1 = 1
Fn = Fn-1 + Fn-2, if n>1
Task
Write a function to generate the nth Fibonacci number.
Solutions can be iterative or recursive (though recursive solutions are g... | 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.)
| #Brlcad | Brlcad |
# Comments in mget scripts are prefixed with a hash symbol
ls # comments may appear at the end of a line
| Give a code snippet in #Brlcad
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/Matrix_multiplication | Matrix multiplication | Task
Multiply two matrices together.
They can be of any dimensions, so long as the number of columns of the first matrix is equal to the number of rows of the second matrix.
| #Scheme | Scheme | (define (matrix-multiply matrix1 matrix2)
(map
(lambda (row)
(apply map
(lambda column
(apply + (map * row column)))
matrix2))
matrix1)) | Give a code snippet in #Scheme
Task
Multiply two matrices together.
They can be of any dimensions, so long as the number of columns of the first matrix is equal to the number of rows of the second matrix.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Sort_three_variables | Sort three variables |
Sorting Algorithm
This is a sorting algorithm. It may be applied to a set of data in order to sort it.
For comparing various sorts, see compare sorts.
For other sorting algorithms, see sorting algorithms, or:
O(n logn) sorts
Heap sort |
Merge sort |
Patience sort |
Quick sort
O(n log2n) sorts
Shell Sort
... | #APL | APL | x y z←{⍵[⍋⍵]}x y z | Give a code snippet in #APL
Sorting Algorithm
This is a sorting algorithm. It may be applied to a set of data in order to sort it.
For comparing various sorts, see compare sorts.
For other sorting algorithms, see sorting algorithms, or:
O(n logn) sorts
Heap sort |
Merge sort |
Patience sort |
Quick sort... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Minesweeper_game | Minesweeper game | There is an n by m grid that has a random number (between 10% to 20% of the total number of tiles, though older implementations may use 20%..60% instead) of randomly placed mines that need to be found.
Positions in the grid are modified by entering their coordinates where the first coordinate is horizontal in the grid... | #Wren | Wren | import "/dynamic" for Struct
import "/fmt" for Fmt
import "random" for Random
import "/ioutil" for Input
import "/str" for Str
var Cell = Struct.create("Cell", ["isMine", "display"])
var lMargin = 4
var grid = []
var mineCount = 0
var minesMarked = 0
var isGameOver = false
var rand = Random.new()
var makeGrid = ... | Give a code snippet in #Wren
There is an n by m grid that has a random number (between 10% to 20% of the total number of tiles, though older implementations may use 20%..60% instead) of randomly placed mines that need to be found.
Positions in the grid are modified by entering their coordinates where the first coordi... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sorting_algorithms/Bogosort | Sorting algorithms/Bogosort |
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
... | #PowerShell | PowerShell | function shuffle ($a) {
$c = $a.Clone() # make copy to avoid clobbering $a
1..($c.Length - 1) | ForEach-Object {
$i = Get-Random -Minimum $_ -Maximum $c.Length
$c[$_-1],$c[$i] = $c[$i],$c[$_-1]
$c[$_-1] # return newly-shuffled value
}
$c[-1] # last value
}
function isSorted... | Give a code snippet in #PowerShell
Sorting Algorithm
This is a sorting algorithm. It may be applied to a set of data in order to sort it.
For comparing various sorts, see compare sorts.
For other sorting algorithms, see sorting algorithms, or:
O(n logn) sorts
Heap sort |
Merge sort |
Patience sort |
Qui... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Luhn_test_of_credit_card_numbers | Luhn test of credit card numbers | The Luhn test is used by some credit card companies to distinguish valid credit card numbers from what could be a random selection of digits.
Those companies using credit card numbers that can be validated by the Luhn test have numbers that pass the following test:
Reverse the order of the digits in the number.
Tak... | #ARM_Assembly | ARM Assembly | .text
.global _start
_start:
ldr r0, =example_numbers
bl test_number
add r1, r0, #1
bl length
add r0, r1, r0
bl test_number
add r1, r0, #1
bl length
add r0, r1, r0
bl test_number
add r1, r0, #1
bl length
add r0, r1, r0
bl test_number
mov r0, #0
mov... | Give a code snippet in #ARM_Assembly
The Luhn test is used by some credit card companies to distinguish valid credit card numbers from what could be a random selection of digits.
Those companies using credit card numbers that can be validated by the Luhn test have numbers that pass the following test:
Reverse the o... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Pancake_numbers | Pancake numbers | Adrian Monk has problems and an assistant, Sharona Fleming. Sharona can deal with most of Adrian's problems except his lack of punctuality paying her remuneration. 2 pay checks down and she prepares him pancakes for breakfast. Knowing that he will be unable to eat them unless they are stacked in ascending order of size... | #Python | Python | """Pancake numbers. Requires Python>=3.7."""
import time
from collections import deque
from operator import itemgetter
from typing import Tuple
Pancakes = Tuple[int, ...]
def flip(pancakes: Pancakes, position: int) -> Pancakes:
"""Flip the stack of pancakes at the given position."""
return tuple([*rever... | Give a code snippet in #Python
Adrian Monk has problems and an assistant, Sharona Fleming. Sharona can deal with most of Adrian's problems except his lack of punctuality paying her remuneration. 2 pay checks down and she prepares him pancakes for breakfast. Knowing that he will be unable to eat them unless they are st... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Simple_windowed_application | Simple windowed application | Task
Create a window that has:
a label that says "There have been no clicks yet"
a button that says "click me"
Upon clicking the button with the mouse, the label should change and show the number of times the button has been clicked.
| #Liberty_BASIC | Liberty BASIC | nomainwin
button #demo.btn, "Click Me", [btnClick], UL, 20, 50
statictext #demo.num, "There have been no clicks yet.", 20, 100, 240, 30
open "Rosetta Task: Simple windowed application" for window as #demo
#demo "trapclose [quit]"
nClicks = 0
wait
[quit]
close #demo
end
[btnClick]
nClicks... | Give a code snippet in #Liberty_BASIC
Task
Create a window that has:
a label that says "There have been no clicks yet"
a button that says "click me"
Upon clicking the button with the mouse, the label should change and show the number of times the button has been clicked.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Identity_matrix | Identity matrix | Task
Build an identity matrix of a size known at run-time.
An identity matrix is a square matrix of size n × n,
where the diagonal elements are all 1s (ones),
and all the other elements are all 0s (zeroes).
I
n
=
[
1
0
0
⋯
0
0
1
0
⋯
0
0
0
1
⋯
0
⋮
⋮
⋮
⋱
... | #REXX | REXX | /*REXX program creates and displays any sized identity matrix (centered, with title).*/
do k=3 to 6 /* [↓] build and display a sq. matrix.*/
call ident_mat k /*build & display a KxK square matrix. */
end /*k*/ ... | Give a code snippet in #REXX
Task
Build an identity matrix of a size known at run-time.
An identity matrix is a square matrix of size n × n,
where the diagonal elements are all 1s (ones),
and all the other elements are all 0s (zeroes).
I
n
=
[
1
0
0
⋯
0
0
1
0
⋯
0
0
0
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Long_multiplication | Long multiplication | Task
Explicitly implement long multiplication.
This is one possible approach to arbitrary-precision integer algebra.
For output, display the result of 264 * 264.
Optionally, verify your result against builtin arbitrary precision support.
The decimal representation of 264 is:
18,446,744,073,709,551,61... | #Arturo | Arturo | print 2^64 * 2 | Give a code snippet in #Arturo
Task
Explicitly implement long multiplication.
This is one possible approach to arbitrary-precision integer algebra.
For output, display the result of 264 * 264.
Optionally, verify your result against builtin arbitrary precision support.
The decimal representation of 264 ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sequence:_smallest_number_with_exactly_n_divisors | Sequence: smallest number with exactly n divisors | Calculate the sequence where each term an is the smallest natural number that has exactly n divisors.
Task
Show here, on this page, at least the first 15 terms of the sequence.
Related tasks
Sequence: smallest number greater than previous term with exactly n divisors
Sequence: nth number with exactly... | #ALGOL_68 | ALGOL 68 | BEGIN
PROC count divisors = ( INT n )INT:
BEGIN
INT count := 0;
FOR i WHILE i*i <= n DO
IF n MOD i = 0 THEN
count +:= IF i = n OVER i THEN 1 ELSE 2 FI
FI
OD;
count
END # count divisors # ;
I... | Give a code snippet in #ALGOL_68
Calculate the sequence where each term an is the smallest natural number that has exactly n divisors.
Task
Show here, on this page, at least the first 15 terms of the sequence.
Related tasks
Sequence: smallest number greater than previous term with exactly n divisors
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Show_ASCII_table | Show ASCII table | Task
Show the ASCII character set from values 32 to 127 (decimal) in a table format.
Other tasks related to string operations:
Metrics
Array length
String length
Copy a string
Empty string (assignment)
Counting
Word frequency
Letter frequency
Jewels and stones
I before E except after C
Bioin... | #Ring | Ring |
# Project : Show Ascii table
load "guilib.ring"
load "stdlib.ring"
decarr = newlist(16,6)
ascarr = newlist(16,6)
new qapp
{
win1 = new qwidget() {
setwindowtitle("Show Ascii table")
setgeometry(100,100,800,600)
for n = 1 to 16
... | Give a code snippet in #Ring
Task
Show the ASCII character set from values 32 to 127 (decimal) in a table format.
Other tasks related to string operations:
Metrics
Array length
String length
Copy a string
Empty string (assignment)
Counting
Word frequency
Letter frequency
Jewels and stones
I ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Walk_a_directory/Non-recursively | Walk a directory/Non-recursively | Task
Walk a given directory and print the names of files matching a given pattern.
(How is "pattern" defined? substring match? DOS pattern? BASH pattern? ZSH pattern? Perl regular expression?)
Note: This task is for non-recursive methods. These tasks should read a single directory, not an entire directory tree.
... | #Frink | Frink | for f = select[files["."], {|f1| f1.getName[] =~ %r/\.frink$/}]
println[f.getName[]] | Give a code snippet in #Frink
Task
Walk a given directory and print the names of files matching a given pattern.
(How is "pattern" defined? substring match? DOS pattern? BASH pattern? ZSH pattern? Perl regular expression?)
Note: This task is for non-recursive methods. These tasks should read a single directory, ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Munching_squares | Munching squares | Render a graphical pattern where each pixel is colored by the value of 'x xor y' from an arbitrary color table.
| #BBC_BASIC | BBC BASIC | size% = 256
VDU 23,22,size%;size%;8,8,16,0
OFF
DIM coltab%(size%-1)
FOR I% = 0 TO size%-1
coltab%(I%) = ((I% AND &FF) * &010101) EOR &FF0000
NEXT
GCOL 1
FOR I% = 0 TO size%-1
FOR J% = 0 TO size%-1
C% = coltab%(I% EOR J%)
COLOUR 1,... | Give a code snippet in #BBC_BASIC
Render a graphical pattern where each pixel is colored by the value of 'x xor y' from an arbitrary color table.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Generic_swap | Generic swap | Task
Write a generic swap function or operator which exchanges the values of two variables (or, more generally, any two storage places that can be assigned), regardless of their types.
If your solution language is statically typed please describe the way your language provides genericity.
If variables are typed in t... | #Quackery | Quackery | [ over take over take
2swap dip put put ] is exchange ( s s --> ) | Give a code snippet in #Quackery
Task
Write a generic swap function or operator which exchanges the values of two variables (or, more generally, any two storage places that can be assigned), regardless of their types.
If your solution language is statically typed please describe the way your language provides generi... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Date_manipulation | Date manipulation | Task
Given the date string "March 7 2009 7:30pm EST",
output the time 12 hours later in any human-readable format.
As extra credit, display the resulting time in a time zone different from your own.
| #jq | jq | "March 7 2009 7:30pm EST"
| strptime("%B %d %Y %I:%M%p %Z")
| .[3] += 12
| mktime | strftime("%B %d %Y %I:%M%p %Z") | Give a code snippet in #jq
Task
Given the date string "March 7 2009 7:30pm EST",
output the time 12 hours later in any human-readable format.
As extra credit, display the resulting time in a time zone different from your own.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Factors_of_an_integer | Factors of an integer |
Basic Data Operation
This is a basic data operation. It represents a fundamental action on a basic data type.
You may see other such operations in the Basic Data Operations category, or:
Integer Operations
Arithmetic |
Comparison
Boolean Operations
Bitwise |
Logical
String Operations
Concatenation |
Interpolation |... | #Ursa | Ursa | decl int n
set n (int args<1>)
decl int i
for (set i 1) (< i (+ (/ n 2) 1)) (inc i)
if (= (mod n i) 0)
out i " " console
end if
end for
out n endl console | Give a code snippet in #Ursa
Basic Data Operation
This is a basic data operation. It represents a fundamental action on a basic data type.
You may see other such operations in the Basic Data Operations category, or:
Integer Operations
Arithmetic |
Comparison
Boolean Operations
Bitwise |
Logical
String Operations
C... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sequence_of_primorial_primes | Sequence of primorial primes | The sequence of primorial primes is given as the increasing values of n where primorial(n) ± 1 is prime.
Noting that the n'th primorial is defined as the multiplication of the smallest n primes, the sequence is of the number of primes, in order that when multiplied together is one-off being a prime number itself.
T... | #C | C |
#include <gmp.h>
int main(void)
{
mpz_t p, s;
mpz_init_set_ui(p, 1);
mpz_init_set_ui(s, 1);
for (int n = 1, i = 0; i < 20; n++) {
mpz_nextprime(s, s);
mpz_mul(p, p, s);
mpz_add_ui(p, p, 1);
if (mpz_probab_prime_p(p, 25)) {
mpz_sub_ui(p, p, 1);
... | Give a code snippet in #C
The sequence of primorial primes is given as the increasing values of n where primorial(n) ± 1 is prime.
Noting that the n'th primorial is defined as the multiplication of the smallest n primes, the sequence is of the number of primes, in order that when multiplied together is one-off being ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Convert_decimal_number_to_rational | Convert decimal number to rational | This task has been flagged for clarification. Code on this page in its current state may be flagged incorrect once this task has been clarified. See this page's Talk page for discussion.
The task is to write a program to transform a decimal number into a fraction in lowest terms.
It is not always possible to do this... | #PL.2FI | PL/I | (size, fofl):
Convert_Decimal_To_Rational: procedure options (main); /* 14 January 2014, from Ada */
Real_To_Rational: procedure (R, Bound, Numerator, Denominator) recursive
options (reorder);
declare R float (18), Bound float,
(Numerator, Denominator) fixed binary (31);
declare Error float;
... | Give a code snippet in #PL.2FI
This task has been flagged for clarification. Code on this page in its current state may be flagged incorrect once this task has been clarified. See this page's Talk page for discussion.
The task is to write a program to transform a decimal number into a fraction in lowest terms.
It i... | 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
| #Icon_and_Unicon | Icon and Unicon | procedure main(arglist)
if *envars = 0 then envars := ["HOME", "TRACE", "BLKSIZE","STRSIZE","COEXPSIZE","MSTKSIZE", "IPATH","LPATH","NOERRBUF"]
every v := !sort(envars) do
write(v," = ",image(getenv(v))|"* not set *")
end | Give a code snippet in #Icon_and_Unicon
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/Greatest_element_of_a_list | Greatest element of a list | Task
Create a function that returns the maximum value in a provided set of values,
where the number of values may not be known until run-time.
| #OCaml | OCaml | let my_max = function
[] -> invalid_arg "empty list"
| x::xs -> List.fold_left max x xs | Give a code snippet in #OCaml
Task
Create a function that returns the maximum value in a provided set of values,
where the number of values may not be known until run-time.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Euler_method | Euler method | Euler's method numerically approximates solutions of first-order ordinary differential equations (ODEs) with a given initial value. It is an explicit method for solving initial value problems (IVPs), as described in the wikipedia page.
The ODE has to be provided in the following form:
d
y
(
t
)
d
t
=
f... | #Common_Lisp | Common Lisp | ;; 't' usually means "true" in CL, but we need 't' here for time/temperature.
(defconstant true 'cl:t)
(shadow 't)
;; Approximates y(t) in y'(t)=f(t,y) with y(a)=y0 and t=a..b and the step size h.
(defun euler (f y0 a b h)
;; Set the initial values and increments of the iteration variables.
(do ((t a (+ t h)... | Give a code snippet in #Common_Lisp
Euler's method numerically approximates solutions of first-order ordinary differential equations (ODEs) with a given initial value. It is an explicit method for solving initial value problems (IVPs), as described in the wikipedia page.
The ODE has to be provided in the following ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Execute_a_system_command | Execute a system command | Task
Run either the ls system command (dir on Windows), or the pause system command.
Related task
Get system command output
| #MUMPS | MUMPS | Set X=$ZF(-1,"DIR") | Give a code snippet in #MUMPS
Task
Run either the ls system command (dir on Windows), or the pause system command.
Related task
Get system command output
| christopher/rosetta-code |
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