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/Circular_primes | Circular primes | Definitions
A circular prime is a prime number with the property that the number generated at each intermediate step when cyclically permuting its (base 10) digits will also be prime.
For example:
1193 is a circular prime, since 1931, 9311 and 3119 are all also prime.
Note that a number which is a cyclic permutation ... | #Sidef | Sidef | func is_circular_prime(n) {
n.is_prime || return false
var circular = n.digits
circular.min < circular.tail && return false
for k in (1 ..^ circular.len) {
with (circular.rotate(k).digits2num) {|p|
(p.is_prime && (p >= n)) || return false
}
}
return true
}
say... | Give a code snippet in #Sidef
Definitions
A circular prime is a prime number with the property that the number generated at each intermediate step when cyclically permuting its (base 10) digits will also be prime.
For example:
1193 is a circular prime, since 1931, 9311 and 3119 are all also prime.
Note that a number... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Square_but_not_cube | Square but not cube | Task
Show the first 30 positive integers which are squares but not cubes of such integers.
Optionally, show also the first 3 positive integers which are both squares and cubes, and mark them as such.
| #AppleScript | AppleScript | on run
script listing
on |λ|(x)
set sqr to x * x
set strSquare to sqr as text
if isCube(sqr) then
strSquare & " (also cube)"
else
strSquare
end if
end |λ|
end script
unlines(map(listing, ¬
... | Give a code snippet in #AppleScript
Task
Show the first 30 positive integers which are squares but not cubes of such integers.
Optionally, show also the first 3 positive integers which are both squares and cubes, and mark them as such.
| 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... | #Component_Pascal | Component Pascal |
MODULE EvenOdd;
IMPORT StdLog,Args,Strings;
PROCEDURE BitwiseOdd(i: INTEGER): BOOLEAN;
BEGIN
RETURN 0 IN BITS(i)
END BitwiseOdd;
PROCEDURE Odd(i: INTEGER): BOOLEAN;
BEGIN
RETURN (i MOD 2) # 0
END Odd;
PROCEDURE CongruenceOdd(i: INTEGER): BOOLEAN;
BEGIN
RETURN ((i -1) MOD 2) = 0
END CongruenceOdd;
PROCEDURE... | Give a code snippet in #Component_Pascal
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... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Write_float_arrays_to_a_text_file | Write float arrays to a text file | Task
Write two equal-sized numerical arrays 'x' and 'y' to
a two-column text file named 'filename'.
The first column of the file contains values from an 'x'-array with a
given 'xprecision', the second -- values from 'y'-array with 'yprecision'.
For example, considering:
x = {1, 2, 3, 1e11};
y = {1, 1.41421356... | #Euphoria | Euphoria | constant x = {1, 2, 3, 1e11},
y = {1, 1.4142135623730951, 1.7320508075688772, 316227.76601683791}
integer fn
fn = open("filename","w")
for n = 1 to length(x) do
printf(fn,"%.3g\t%.5g\n",{x[n],y[n]})
end for
close(fn) | Give a code snippet in #Euphoria
Task
Write two equal-sized numerical arrays 'x' and 'y' to
a two-column text file named 'filename'.
The first column of the file contains values from an 'x'-array with a
given 'xprecision', the second -- values from 'y'-array with 'yprecision'.
For example, considering:
x = {1, ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Regular_expressions | Regular expressions |
Task
match a string against a regular expression
substitute part of a string using a regular expression
| #Sather | Sather | class MAIN is
-- we need to implement the substitution
regex_subst(re:REGEXP, s, sb:STR):STR is
from, to:INT;
re.match(s, out from, out to);
if from = -1 then return s; end;
return s.head(from) + sb + s.tail(s.size - to);
end;
main is
s ::= "I am a string";
re ::= REGEXP::regexp("strin... | Give a code snippet in #Sather
Task
match a string against a regular expression
substitute part of a string using a regular expression
| christopher/rosetta-code | |
http://rosettacode.org/wiki/JSON | JSON | Load a JSON string into a data structure.
Also, create a new data structure and serialize it into JSON.
Use objects and arrays (as appropriate for your language)
and make sure your JSON is valid (https://jsonformatter.org).
| #Bracmat | Bracmat | put$(jsn$(get$("input.json",JSN)),"output.JSN,NEW) | Give a code snippet in #Bracmat
Load a JSON string into a data structure.
Also, create a new data structure and serialize it into JSON.
Use objects and arrays (as appropriate for your language)
and make sure your JSON is valid (https://jsonformatter.org).
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Determine_if_only_one_instance_is_running | Determine if only one instance is running | This task is to determine if there is only one instance of an application running. If the program discovers that an instance of it is already running, then it should display a message indicating that it is already running and exit.
| #Ada | Ada | with Ada.Text_IO;
procedure Single_Instance is
package IO renames Ada.Text_IO;
Lock_File: IO.File_Type;
Lock_File_Name: String := "single_instance.magic_lock";
begin
begin
IO.Open(File => Lock_File, Mode=> IO.In_File, Name => Lock_File_Name);
IO.Close(Lock_File);
IO.Put_Line("I can't... | Give a code snippet in #Ada
This task is to determine if there is only one instance of an application running. If the program discovers that an instance of it is already running, then it should display a message indicating that it is already running and exit.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Trabb_Pardo%E2%80%93Knuth_algorithm | Trabb Pardo–Knuth algorithm | The TPK algorithm is an early example of a programming chrestomathy.
It was used in Donald Knuth and Luis Trabb Pardo's Stanford tech report The Early Development of Programming Languages.
The report traces the early history of work in developing computer languages in the 1940s and 1950s, giving several translations of... | #Objective-C | Objective-C | //
// TPKA.m
// RosettaCode
//
// Created by Alexander Alvonellos on 5/26/12.
// Trabb Pardo-Knuth algorithm
//
#import <Foundation/Foundation.h>
double f(double x);
double f(double x) {
return pow(abs(x), 0.5) + 5*(pow(x, 3));
}
int main (int argc, const char * argv[])
{
@autoreleasepool {
N... | Give a code snippet in #Objective-C
The TPK algorithm is an early example of a programming chrestomathy.
It was used in Donald Knuth and Luis Trabb Pardo's Stanford tech report The Early Development of Programming Languages.
The report traces the early history of work in developing computer languages in the 1940s and ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Dragon_curve | Dragon curve |
Create and display a dragon curve fractal.
(You may either display the curve directly or write it to an image file.)
Algorithms
Here are some brief notes the algorithms used and how they might suit various languages.
Recursively a right curling dragon is a right dragon followed by a left dragon, at 90-degree an... | #C.23 | C# | using System;
using System.Collections.Generic;
using System.Drawing;
using System.Drawing.Drawing2D;
using System.Windows.Forms;
public class DragonCurve : Form
{
private List<int> turns;
private double startingAngle, side;
public DragonCurve(int iter)
{
Size = new Size(800, 600);
S... | Give a code snippet in #C.23
Create and display a dragon curve fractal.
(You may either display the curve directly or write it to an image file.)
Algorithms
Here are some brief notes the algorithms used and how they might suit various languages.
Recursively a right curling dragon is a right dragon followed by ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Magic_squares_of_doubly_even_order | Magic squares of doubly even order | A magic square is an N×N square matrix whose numbers consist of consecutive numbers arranged so that the sum of each row and column, and both diagonals are equal to the same sum (which is called the magic number or magic constant).
A magic square of doubly even order has a size that is a multiple of four (e... | #zkl | zkl | class MagicSquareDoublyEven{
fcn init(n){ var result=magicSquareDoublyEven(n) }
fcn toString{
sink,n:=Sink(String),result.len(); // num collumns
fmt:="%2s ";
foreach row in (result)
{ sink.write(row.apply('wrap(n){ fmt.fmt(n) }).concat(),"\n") }
sink.write("\nMagic constant: %d".... | Give a code snippet in #zkl
A magic square is an N×N square matrix whose numbers consist of consecutive numbers arranged so that the sum of each row and column, and both diagonals are equal to the same sum (which is called the magic number or magic constant).
A magic square of doubly even order has a size th... | christopher/rosetta-code | |
http://rosettacode.org/wiki/CRC-32 | CRC-32 |
Task
Demonstrate a method of deriving the Cyclic Redundancy Check from within the language.
The result should be in accordance with ISO 3309, ITU-T V.42, Gzip and PNG.
Algorithms are described on Computation of CRC in Wikipedia.
This variant of CRC-32 uses LSB-first order, sets the initial CRC to FFFFFFFF16, and... | #Lingo | Lingo | crcObj = script("CRC").new()
crc32 = crcObj.crc32("The quick brown fox jumps over the lazy dog")
put crc32
-- <ByteArrayObject length = 4 ByteArray = 0x41, 0x4f, 0xa3, 0x39 >
put crc32.toHexString(1, crc32.length)
-- "41 4f a3 39" | Give a code snippet in #Lingo
Task
Demonstrate a method of deriving the Cyclic Redundancy Check from within the language.
The result should be in accordance with ISO 3309, ITU-T V.42, Gzip and PNG.
Algorithms are described on Computation of CRC in Wikipedia.
This variant of CRC-32 uses LSB-first order, sets the... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Bitmap/Midpoint_circle_algorithm | Bitmap/Midpoint circle algorithm | Task
Using the data storage type defined on this page for raster images,
write an implementation of the midpoint circle algorithm (also known as Bresenham's circle algorithm).
(definition on Wikipedia).
| #Modula-3 | Modula-3 | INTERFACE Circle;
IMPORT Bitmap;
PROCEDURE Draw(
img: Bitmap.T;
center: Bitmap.Point;
radius: CARDINAL;
color: Bitmap.Pixel);
END Circle. | Give a code snippet in #Modula-3
Task
Using the data storage type defined on this page for raster images,
write an implementation of the midpoint circle algorithm (also known as Bresenham's circle algorithm).
(definition on Wikipedia).
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Memory_allocation | Memory allocation | Task
Show how to explicitly allocate and deallocate blocks of memory in your language.
Show access to different types of memory (i.e., heap, stack, shared, foreign) if applicable.
| #Action.21 | Action! | SET EndProg=* | Give a code snippet in #Action.21
Task
Show how to explicitly allocate and deallocate blocks of memory in your language.
Show access to different types of memory (i.e., heap, stack, shared, foreign) if applicable.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Non-decimal_radices/Output | Non-decimal radices/Output | Programming languages often have built-in routines to convert a non-negative integer for printing in different number bases. Such common number bases might include binary, Octal and Hexadecimal.
Task
Print a small range of integers in some different bases, as supported by standard routines of your programming langu... | #Standard_ML | Standard ML | let
fun loop i =
if i < 34 then (
print (Int.fmt StringCvt.BIN i ^ "\t"
^ Int.fmt StringCvt.OCT i ^ "\t"
^ Int.fmt StringCvt.DEC i ^ "\t"
^ Int.fmt StringCvt.HEX i ^ "\n");
loop (i+1)
) else ()
in
loop 0
end | Give a code snippet in #Standard_ML
Programming languages often have built-in routines to convert a non-negative integer for printing in different number bases. Such common number bases might include binary, Octal and Hexadecimal.
Task
Print a small range of integers in some different bases, as supported by standa... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Align_columns | Align columns | Given a text file of many lines, where fields within a line
are delineated by a single 'dollar' character, write a program
that aligns each column of fields by ensuring that words in each
column are separated by at least one space.
Further, allow for each word in a column to be either left
justified, right justified, o... | #R | R | # Read in text
lines <- readLines(tc <- textConnection("Given$a$text$file$of$many$lines,$where$fields$within$a$line$
are$delineated$by$a$single$'dollar'$character,$write$a$program
that$aligns$each$column$of$fields$by$ensuring$that$words$in$each$
column$are$separated$by$at$least$one$space.
Further,$allow$for$each$word$i... | Give a code snippet in #R
Given a text file of many lines, where fields within a line
are delineated by a single 'dollar' character, write a program
that aligns each column of fields by ensuring that words in each
column are separated by at least one space.
Further, allow for each word in a column to be either left
ju... | 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:
... | #VBA | VBA | ' Loop over multiple arrays simultaneously - VBA - 08/02/2021
Sub Main()
a = Array("a","b","c")
b = Array("A","B","C")
c = Array(1,2,3)
For i = LBound(a) To UBound(a)
buf = buf & vbCrLf & a(i) & b(i) & c(i)
Next
Debug.Print Mid(buf,3)
End Sub | Give a code snippet in #VBA
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 exampl... | christopher/rosetta-code | |
http://rosettacode.org/wiki/CUSIP | CUSIP |
This page uses content from Wikipedia. The original article was at CUSIP. 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)
A CUSIP is a nine-character alphanumeric code that identifies a North A... | #C.2B.2B | C++ | #include <iostream>
#include <vector>
bool isCusip(const std::string& s) {
if (s.size() != 9) return false;
int sum = 0;
for (int i = 0; i <= 7; ++i) {
char c = s[i];
int v;
if ('0' <= c && c <= '9') {
v = c - '0';
} else if ('A' <= c && c <= 'Z') {
... | Give a code snippet in #C.2B.2B
This page uses content from Wikipedia. The original article was at CUSIP. 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)
A CUSIP is a nine-character alphanumer... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Associative_array/Creation | Associative array/Creation | Task
The goal is to create an associative array (also known as a dictionary, map, or hash).
Related tasks:
Associative arrays/Iteration
Hash from two arrays
See also
Array
Associative array: Creation, Iteration
Collections
Compound data type
Doubly-linked list: Definition, Element definition, Element ins... | #Elena | Elena | import system'collections;
public program()
{
// 1. Create
var map := Dictionary.new();
map["key"] := "foox";
map["key"] := "foo";
map["key2"]:= "foo2";
map["key3"]:= "foo3";
map["key4"]:= "foo4";
} | Give a code snippet in #Elena
Task
The goal is to create an associative array (also known as a dictionary, map, or hash).
Related tasks:
Associative arrays/Iteration
Hash from two arrays
See also
Array
Associative array: Creation, Iteration
Collections
Compound data type
Doubly-linked list: Definition, ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Amb | Amb | Define and give an example of the Amb operator.
The Amb operator (short for "ambiguous") expresses nondeterminism. This doesn't refer to randomness (as in "nondeterministic universe") but is closely related to the term as it is used in automata theory ("non-deterministic finite automaton").
The Amb operator takes a v... | #F.23 | F# | // define the List "workflow" (monad)
type ListBuilder() =
member o.Bind( lst, f ) = List.concat( List.map (fun x -> f x) lst )
member o.Return( x ) = [x]
member o.Zero() = []
let list = ListBuilder()
let amb = id
// last element of a sequence
let last s = Seq.nth ((Seq.length s) - 1) s
// is the last ... | Give a code snippet in #F.23
Define and give an example of the Amb operator.
The Amb operator (short for "ambiguous") expresses nondeterminism. This doesn't refer to randomness (as in "nondeterministic universe") but is closely related to the term as it is used in automata theory ("non-deterministic finite automaton"... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Find_the_intersection_of_a_line_with_a_plane | Find the intersection of a line with a plane | Finding the intersection of an infinite ray with a plane in 3D is an important topic in collision detection.
Task
Find the point of intersection for the infinite ray with direction (0, -1, -1) passing through position (0, 0, 10) with the infinite plane with a normal vector of (0, 0, 1) and which passes ... | #APL | APL | ⍝ Find the intersection of a line with a plane
⍝ The intersection I belongs to a line defined by point L and vector V, translates to:
⍝ A real parameter t exists, that satisfies I = L + tV
⍝ I belongs to the plan defined by point P and normal vector N. This means that any two points of the plane make a vector
⍝ norm... | Give a code snippet in #APL
Finding the intersection of an infinite ray with a plane in 3D is an important topic in collision detection.
Task
Find the point of intersection for the infinite ray with direction (0, -1, -1) passing through position (0, 0, 10) with the infinite plane with a normal vector of ... | 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
| #RLaB | RLaB |
f = function(x)
{
rval = x .^ 3 - 3 * x .^ 2 + 2 * x;
return rval;
};
>> findroot(f, , [-5,5])
0
| Give a code snippet in #RLaB
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/Truth_table | Truth table | A truth table is a display of the inputs to, and the output of a Boolean function organized as a table where each row gives one combination of input values and the corresponding value of the function.
Task
Input a Boolean function from the user as a string then calculate and print a formatted truth table for the g... | #Smalltalk | Smalltalk | [:repeat |
expr := Stdin
request:'Enter boolean expression (name variables a,b,c...):'
defaultAnswer:'a|b'.
ast := Parser parseExpression:expr inNameSpace:nil onError:repeat.
"
ensure that only boolean logic operations are inside (sandbox)
"
(ast messageSelectors a... | Give a code snippet in #Smalltalk
A truth table is a display of the inputs to, and the output of a Boolean function organized as a table where each row gives one combination of input values and the corresponding value of the function.
Task
Input a Boolean function from the user as a string then calculate and prin... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Longest_string_challenge | Longest string challenge | Background
This "longest string challenge" is inspired by a problem that used to be given to students learning Icon. Students were expected to try to solve the problem in Icon and another language with which the student was already familiar. The basic problem is quite simple; the challenge and fun part came through th... | #BASIC | BASIC |
DO
READ test$
IF test$ = "~" THEN EXIT DO
IF LEN(test$) > LEN(test1$) THEN
test1$ = test$
test2$ = test1$ + CHR$(10)
ELSEIF LEN(test$) = LEN(test1$) THEN
LET test2$ = test2$ + test$ + CHR$(10)
END IF
LOOP
PRINT (test2$)
DATA "a", "bb", "ccc", "ddd", "ee", "f", "ggg", "~" : ' la ti... | Give a code snippet in #BASIC
Background
This "longest string challenge" is inspired by a problem that used to be given to students learning Icon. Students were expected to try to solve the problem in Icon and another language with which the student was already familiar. The basic problem is quite simple; the challen... | 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
... | #D | D | import std.stdio;
void main() {
driver(77444, -12, 0);
driver("lions, tigers, and", "bears, oh my!", "(from the \"Wizard of OZ\")");
}
void driver(T)(T x, T y, T z) {
writeln("BEFORE: x=[", x, "]; y=[", y, "]; z=[", z, "]");
sort3Var(x,y,z);
writeln("AFTER: x=[", x, "]; y=[", y, "]; z=[", z, "]"... | Give a code snippet in #D
Sorting Algorithm
This is a sorting algorithm. It may be applied to a set of data in order to sort it.
For comparing various sorts, see compare sorts.
For other sorting algorithms, see sorting algorithms, or:
O(n logn) sorts
Heap sort |
Merge sort |
Patience sort |
Quick sort
O... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Queue/Usage | Queue/Usage |
Data Structure
This illustrates a data structure, a means of storing data within a program.
You may see other such structures in the Data Structures category.
Illustration of FIFO behavior
Task
Create a queue data structure and demonstrate its operations.
(For implementations of queues, see the FIFO task.)
Ope... | #Quackery | Quackery | [ [] ] is queue ( --> q )
[ nested join ] is push ( q x --> q )
[ behead ] is pop ( q --> q x )
[ [] = ] is empty? ( q --> b ) | Give a code snippet in #Quackery
Data Structure
This illustrates a data structure, a means of storing data within a program.
You may see other such structures in the Data Structures category.
Illustration of FIFO behavior
Task
Create a queue data structure and demonstrate its operations.
(For implementations of ... | 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... | #Lambdatalk | Lambdatalk |
{def is_odd {lambda {:i} {= {% :i 2} 1}}}
-> is_odd
{def is_even {lambda {:i} {= {% :i 2} 0}}}
-> is_even
{is_odd 2}
-> false
{is_even 2}
-> true
| Give a code snippet in #Lambdatalk
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.
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Reverse_words_in_a_string | Reverse words in a string | Task
Reverse the order of all tokens in each of a number of strings and display the result; the order of characters within a token should not be modified.
Example
Hey you, Bub! would be shown reversed as: Bub! you, Hey
Tokens are any non-space characters separated by spaces (formally, white-space); t... | #Yabasic | Yabasic | data " ---------- Ice and Fire ------------ "
data " "
data " fire, in end will world the say Some "
data " ice. in say Some "
data " desire of tasted I've what From "
data " fire. favor who those with hold I "
data " ... | Give a code snippet in #Yabasic
Task
Reverse the order of all tokens in each of a number of strings and display the result; the order of characters within a token should not be modified.
Example
Hey you, Bub! would be shown reversed as: Bub! you, Hey
Tokens are any non-space characters separated by sp... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Associative_array/Creation | Associative array/Creation | Task
The goal is to create an associative array (also known as a dictionary, map, or hash).
Related tasks:
Associative arrays/Iteration
Hash from two arrays
See also
Array
Associative array: Creation, Iteration
Collections
Compound data type
Doubly-linked list: Definition, Element definition, Element ins... | #PL.2FSQL | PL/SQL | DECLARE
type ThisIsNotAnAssocArrayType is record (
myShape VARCHAR2(20),
mySize number,
isActive BOOLEAN
);
assocArray ThisIsNotAnAssocArrayType ;
BEGIN
assocArray.myShape := 'circle';
dbms_output.put_line ('assocArray.myShape: ' || assocArray.myShape);
dbms_output.put_... | Give a code snippet in #PL.2FSQL
Task
The goal is to create an associative array (also known as a dictionary, map, or hash).
Related tasks:
Associative arrays/Iteration
Hash from two arrays
See also
Array
Associative array: Creation, Iteration
Collections
Compound data type
Doubly-linked list: Definitio... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Dragon_curve | Dragon curve |
Create and display a dragon curve fractal.
(You may either display the curve directly or write it to an image file.)
Algorithms
Here are some brief notes the algorithms used and how they might suit various languages.
Recursively a right curling dragon is a right dragon followed by a left dragon, at 90-degree an... | #Yabasic | Yabasic | w = 390 : h = int(w * 11 / 16)
open window w, h
level = 18 : insize = 247
x = 92 : y = 94
iters = 2^level
qiter = 510/iters
SQ = sqrt(2) : QPI = pi/4
rotation = 0 : iter = 0 : rq = 1.0
dim rqs(level)
color 0,0,0
clear window
dragon()
sub dragon()
if level<=0 then
yn = sin(rotation)*insize + y
xn = cos(ro... | Give a code snippet in #Yabasic
Create and display a dragon curve fractal.
(You may either display the curve directly or write it to an image file.)
Algorithms
Here are some brief notes the algorithms used and how they might suit various languages.
Recursively a right curling dragon is a right dragon followed ... | 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.... | #C.2B.2B | C++ |
#include <iostream>
#include <vector>
#include <iomanip>
void primeFactors( unsigned n, std::vector<unsigned>& r ) {
int f = 2; if( n == 1 ) r.push_back( 1 );
else {
while( true ) {
if( !( n % f ) ) {
r.push_back( f );
n /= f; if( n == 1 ) return;
... | Give a code snippet in #C.2B.2B
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 ar... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Test_integerness | Test integerness | Mathematically,
the integers Z are included in the rational numbers Q,
which are included in the real numbers R,
which can be generalized to the complex numbers C.
This means that each of those larger sets, and the data types used to represent them, include some integers.
Task[edit]
Given a rational, real, or co... | #Elixir | Elixir | defmodule Test do
def integer?(n) when n == trunc(n), do: true
def integer?(_), do: false
end
Enum.each([2, 2.0, 2.5, 2.000000000000001, 1.23e300, 1.0e-300, "123", '123', :"123"], fn n ->
IO.puts "#{inspect n} is integer?: #{Test.integer?(n)}"
end) | Give a code snippet in #Elixir
Mathematically,
the integers Z are included in the rational numbers Q,
which are included in the real numbers R,
which can be generalized to the complex numbers C.
This means that each of those larger sets, and the data types used to represent them, include some integers.
Task[edi... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Averages/Simple_moving_average | Averages/Simple moving average | Computing the simple moving average of a series of numbers.
Task[edit]
Create a stateful function/class/instance that takes a period and returns a routine that takes a number as argument and returns a simple moving average of its arguments so far.
Description
A simple moving average is a method for computing an avera... | #F.23 | F# | let sma period f (list:float list) =
let sma_aux queue v =
let q = Seq.truncate period (v :: queue)
Seq.average q, Seq.toList q
List.fold (fun s v ->
let avg,state = sma_aux s v
f avg
state) [] list
printf "sma3: "
[ 1.;2.;3.;4.;5.;5.;4.;3.;2.;1.] |> sma 3 (printf "%.2f... | Give a code snippet in #F.23
Computing the simple moving average of a series of numbers.
Task[edit]
Create a stateful function/class/instance that takes a period and returns a routine that takes a number as argument and returns a simple moving average of its arguments so far.
Description
A simple moving average is a... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Monty_Hall_problem | Monty Hall problem |
Suppose you're on a game show and you're given the choice of three doors.
Behind one door is a car; behind the others, goats.
The car and the goats were placed randomly behind the doors before the show.
Rules of the game
After you have chosen a door, the door remains closed for the time being.
The game show hos... | #Scala | Scala | import scala.util.Random
object MontyHallSimulation {
def main(args: Array[String]) {
val samples = if (args.size == 1 && (args(0) matches "\\d+")) args(0).toInt else 1000
val doors = Set(0, 1, 2)
var stayStrategyWins = 0
var switchStrategyWins = 0
1 to samples foreach { _ =>
val prizeDo... | Give a code snippet in #Scala
Suppose you're on a game show and you're given the choice of three doors.
Behind one door is a car; behind the others, goats.
The car and the goats were placed randomly behind the doors before the show.
Rules of the game
After you have chosen a door, the door remains closed for the... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Nested_templated_data | Nested templated data | A template for data is an arbitrarily nested tree of integer indices.
Data payloads are given as a separate mapping, array or other simpler, flat,
association of indices to individual items of data, and are strings.
The idea is to create a data structure with the templates' nesting, and the
payload corresponding to e... | #Bracmat | Bracmat | ( get$("[
[[1, 2],
[3, 4, 1],
5]]",MEM,JSN)
: ?template
& (0.payload#0)
(1.payload#1)
(2.payload#2)
(3.payload#3)
(4.payload#4)
(5.payload#5)
(6.payload#6)
: ?payloads
& ( instantiate
= tmplt plds pld a b
. !arg:(?tmplt.?plds)
& ( !tmplt:#
... | Give a code snippet in #Bracmat
A template for data is an arbitrarily nested tree of integer indices.
Data payloads are given as a separate mapping, array or other simpler, flat,
association of indices to individual items of data, and are strings.
The idea is to create a data structure with the templates' nesting, a... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Parallel_calculations | Parallel calculations | Many programming languages allow you to specify computations to be run in parallel.
While Concurrent computing is focused on concurrency,
the purpose of this task is to distribute time-consuming calculations
on as many CPUs as possible.
Assume we have a collection of numbers, and want to find the one
with the largest ... | #Java | Java | import static java.lang.System.out;
import static java.util.Arrays.stream;
import static java.util.Comparator.comparing;
public interface ParallelCalculations {
public static final long[] NUMBERS = {
12757923,
12878611,
12878893,
12757923,
15808973,
15780709,
197622519
... | Give a code snippet in #Java
Many programming languages allow you to specify computations to be run in parallel.
While Concurrent computing is focused on concurrency,
the purpose of this task is to distribute time-consuming calculations
on as many CPUs as possible.
Assume we have a collection of numbers, and want to ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Rock-paper-scissors | Rock-paper-scissors | Task
Implement the classic children's game Rock-paper-scissors, as well as a simple predictive AI (artificial intelligence) player.
Rock Paper Scissors is a two player game.
Each player chooses one of rock, paper or scissors, without knowing the other player's choice.
The winner is decided by a set of rules:
... | #Mercury | Mercury | :- module rps.
:- interface.
:- import_module io.
:- pred main(io::di, io::uo) is det.
:- implementation.
:- use_module random, exception.
:- import_module list, string.
:- type play
---> rock
; paper
; scissors.
:- pred beats(play, play).
:- mode beats(in, in) is semidet.
beats(rock, sci... | Give a code snippet in #Mercury
Task
Implement the classic children's game Rock-paper-scissors, as well as a simple predictive AI (artificial intelligence) player.
Rock Paper Scissors is a two player game.
Each player chooses one of rock, paper or scissors, without knowing the other player's choice.
The winn... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Knuth_shuffle | Knuth shuffle | The Knuth shuffle (a.k.a. the Fisher-Yates shuffle) is an algorithm for randomly shuffling the elements of an array.
Task
Implement the Knuth shuffle for an integer array (or, if possible, an array of any type).
Specification
Given an array items with indices ranging from 0 to last, the algorithm can be d... | #Erlang | Erlang |
-module( knuth_shuffle ).
-export( [list/1] ).
list( Inputs ) ->
N = erlang:length( Inputs ),
{[], Acc} = lists:foldl( fun random_move/2, {Inputs, []}, lists:reverse(lists:seq(1, N)) ),
Acc.
random_move( N, {Inputs, Acc} ) ->
Item = lists:nth( random:uniform(N), Inputs ),
{lists:delete(Item, Inputs), [... | Give a code snippet in #Erlang
The Knuth shuffle (a.k.a. the Fisher-Yates shuffle) is an algorithm for randomly shuffling the elements of an array.
Task
Implement the Knuth shuffle for an integer array (or, if possible, an array of any type).
Specification
Given an array items with indices ranging from 0... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Return_multiple_values | Return multiple values | Task
Show how to return more than one value from a function.
| #VBA | VBA |
Type Contact
Name As String
firstname As String
Age As Byte
End Type
Function SetContact(N As String, Fn As String, A As Byte) As Contact
SetContact.Name = N
SetContact.firstname = Fn
SetContact.Age = A
End Function
'For use :
Sub Test_SetContact()
Dim Cont As Contact
Cont = SetConta... | Give a code snippet in #VBA
Task
Show how to return more than one value from a function.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/String_matching | String matching |
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 |... | #Icon_and_Unicon | Icon and Unicon | procedure main()
write("Matching s2 :=",image(s2 := "ab")," within s1:= ",image(s1 := "abcdabab"))
write("Test #1 beginning ",if match(s2,s1) then "matches " else "failed")
writes("Test #2 all matches at positions [")
every writes(" ",find(s2,s1)|"]\n")
write("Test #3 ending ", if s1[0-:*s2] == s... | Give a code snippet in #Icon_and_Unicon
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 O... | christopher/rosetta-code | |
http://rosettacode.org/wiki/File_input/output | File input/output | File input/output is part of Short Circuit's Console Program Basics selection.
Task
Create a file called "output.txt", and place in it the contents of the file "input.txt", via an intermediate variable.
In other words, your program will demonstrate:
how to read from a file into a variable
how to write ... | #E | E | <file:output.txt>.setText(<file:input.txt>.getText()) | Give a code snippet in #E
File input/output is part of Short Circuit's Console Program Basics selection.
Task
Create a file called "output.txt", and place in it the contents of the file "input.txt", via an intermediate variable.
In other words, your program will demonstrate:
how to read from a file into ... | 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
| #Icon_and_Unicon | Icon and Unicon | Idris> :doc Bool
Data type Prelude.Bool.Bool : Type
Boolean Data Type
Constructors:
False : Bool
True : Bool
| Give a code snippet in #Icon_and_Unicon
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/Hello_world/Newline_omission | Hello world/Newline omission | Some languages automatically insert a newline after outputting a string, unless measures are taken to prevent its output.
Task
Display the string Goodbye, World! without a trailing newline.
Related tasks
Hello world/Graphical
Hello world/Line Printer
Hello world/Standard error
Hello world/Text
| #Visual_Basic_.NET | Visual Basic .NET | Module Module1
Sub Main()
Console.Write("Goodbye, World!")
End Sub
End Module | Give a code snippet in #Visual_Basic_.NET
Some languages automatically insert a newline after outputting a string, unless measures are taken to prevent its output.
Task
Display the string Goodbye, World! without a trailing newline.
Related tasks
Hello world/Graphical
Hello world/Line Printer
Hello... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Caesar_cipher | Caesar cipher |
Task
Implement a Caesar cipher, both encoding and decoding.
The key is an integer from 1 to 25.
This cipher rotates (either towards left or right) the letters of the alphabet (A to Z).
The encoding replaces each letter with the 1st to 25th next letter in the alphabet (wrapping Z to A).
So key 2 encrypts "HI" to... | #Vedit_macro_language | Vedit macro language | #10 = Get_Num("Enter the key: positive to cipher, negative to de-cipher: ", STATLINE)
Goto_Pos(Block_Begin)
while(Cur_Pos < Block_End) {
#11 = Cur_Char & 0x60 + 1
if (Cur_Char >= 'A') {
Ins_Char((Cur_Char - #11 + 26 + #10) % 26 + #11, OVERWRITE)
} else {
Char(1)
}
} | Give a code snippet in #Vedit_macro_language
Task
Implement a Caesar cipher, both encoding and decoding.
The key is an integer from 1 to 25.
This cipher rotates (either towards left or right) the letters of the alphabet (A to Z).
The encoding replaces each letter with the 1st to 25th next letter in the alphabet... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Strip_comments_from_a_string | Strip comments from a string | Strip comments from a string
You are encouraged to solve this task according to the task description, using any language you may know.
The task is to remove text that follow any of a set of comment markers, (in these examples either a hash or a semicolon) from a string or input line.
Whitespace debacle: There is s... | #Kotlin | Kotlin | // version 1.0.6
val r = Regex("""(/\*.*\*/|//.*$)""")
fun stripComments(s: String) = s.replace(r, "").trim()
fun main(args: Array<String>) {
val strings = arrayOf(
"apples, pears // and bananas",
" apples, pears /* and bananas */",
"/* oranges */ apples // pears and bananas ",
... | Give a code snippet in #Kotlin
Strip comments from a string
You are encouraged to solve this task according to the task description, using any language you may know.
The task is to remove text that follow any of a set of comment markers, (in these examples either a hash or a semicolon) from a string or input line.
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Number_reversal_game | Number reversal game | Task
Given a jumbled list of the numbers 1 to 9 that are definitely not in
ascending order.
Show the list, and then ask the player how many digits from the
left to reverse.
Reverse those digits, then ask again, until all the digits end up in ascending order.
The score is the count of the reversa... | #Seed7 | Seed7 | $ include "seed7_05.s7i";
const proc: main is func
local
const array integer: sortedList is [] ( 1, 2, 3, 4, 5, 6, 7, 8, 9);
var array integer: list is 0 times 0;
var array integer: reversedList is 0 times 0;
var integer: score is 0;
var integer: index is 0;
var integer: number is 0;
var... | Give a code snippet in #Seed7
Task
Given a jumbled list of the numbers 1 to 9 that are definitely not in
ascending order.
Show the list, and then ask the player how many digits from the
left to reverse.
Reverse those digits, then ask again, until all the digits end up in ascending order.
The sc... | 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 ... | #JavaScript | JavaScript | if( s == "Hello World" ) {
foo();
} else if( s == "Bye World" ) {
bar();
} else {
deusEx();
} | Give a code snippet in #JavaScript
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.
Co... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Range_consolidation | Range consolidation | Define a range of numbers R, with bounds b0 and b1 covering all numbers between and including both bounds.
That range can be shown as:
[b0, b1]
or equally as:
[b1, b0]
Given two ranges, the act of consolidation between them compares the two ranges:
If one range covers all of the other then t... | #Racket | Racket | #lang racket
;; Racket's max and min allow inexact numbers to contaminate exact numbers
;; Use argmax and argmin instead, as they don't have this problem
(define (max . xs) (argmax identity xs))
(define (min . xs) (argmin identity xs))
;; a bag is a list of disjoint intervals
(define ((irrelevant? x y) item) (o... | Give a code snippet in #Racket
Define a range of numbers R, with bounds b0 and b1 covering all numbers between and including both bounds.
That range can be shown as:
[b0, b1]
or equally as:
[b1, b0]
Given two ranges, the act of consolidation between them compares the two ranges:
If one rang... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Echo_server | Echo server | Create a network service that sits on TCP port 12321, which accepts connections on that port, and which echoes complete lines (using a carriage-return/line-feed sequence as line separator) back to clients. No error handling is required. For the purposes of testing, it is only necessary to support connections from local... | #Forth | Forth | include unix/socket.fs
128 constant size
: (echo) ( sock buf -- sock buf )
begin
cr ." waiting..."
2dup 2dup size read-socket nip
dup 0>
while
." got: " 2dup type
rot write-socket
repeat
drop drop drop ;
create buf size allot
: echo-server ( port -- )
cr ." Listening on " dup .
... | Give a code snippet in #Forth
Create a network service that sits on TCP port 12321, which accepts connections on that port, and which echoes complete lines (using a carriage-return/line-feed sequence as line separator) back to clients. No error handling is required. For the purposes of testing, it is only necessary to... | 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... | #REBOL | REBOL | rebol [
Title: "Generic Swap"
URL: http://rosettacode.org/wiki/Generic_swap
Reference: [http://reboltutorial.com/blog/rebol-words/]
]
swap: func [
"Swap contents of variables."
a [word!] b [word!] /local x
][
x: get a
set a get b
set b x
]
answer: 42 ship: "Heart of Gold"
swap 'answer 'ship ; Note quot... | Give a code snippet in #REBOL
Task
Write a generic swap function or operator which exchanges the values of two variables (or, more generally, any two storage places that can be assigned), regardless of their types.
If your solution language is statically typed please describe the way your language provides genericit... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Bitmap/B%C3%A9zier_curves/Cubic | Bitmap/Bézier curves/Cubic | Using the data storage type defined on this page for raster images, and the draw_line function defined in this other one, draw a cubic bezier curve
(definition on Wikipedia).
| #OCaml | OCaml | let cubic_bezier ~img ~color
~p1:(_x1, _y1)
~p2:(_x2, _y2)
~p3:(_x3, _y3)
~p4:(_x4, _y4) =
let x1, y1, x2, y2, x3, y3, x4, y4 =
(float _x1, float _y1,
float _x2, float _y2,
float _x3, float _y3,
float _x4, float _y4)
in
let bz t =
let a = (1.0 -. t) ** 3.0
... | Give a code snippet in #OCaml
Using the data storage type defined on this page for raster images, and the draw_line function defined in this other one, draw a cubic bezier curve
(definition on Wikipedia).
| 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
| #Salmon | Salmon | "Hello world!"! | Give a code snippet in #Salmon
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/Function_composition | Function composition | Task
Create a function, compose, whose two arguments f and g, are both functions with one argument.
The result of compose is to be a function of one argument, (lets call the argument x), which works like applying function f to the result of applying function g to x.
Example
compose... | #WDTE | WDTE | let compose f g => (@ c x => g x -> f); | Give a code snippet in #WDTE
Task
Create a function, compose, whose two arguments f and g, are both functions with one argument.
The result of compose is to be a function of one argument, (lets call the argument x), which works like applying function f to the result of applying function g ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Brilliant_numbers | Brilliant numbers | Brilliant numbers are a subset of semiprime numbers. Specifically, they are numbers that are the product of exactly two prime numbers that both have the same number of digits when expressed in base 10.
Brilliant numbers are useful in cryptography and when testing prime factoring algorithms.
E.G.
3 × 3 (9) is a bri... | #Sidef | Sidef | func is_briliant_number(n) {
n.is_semiprime && (n.factor.map{.len}.uniq.len == 1)
}
func brilliant_numbers_count(n) {
var count = 0
var len = n.isqrt.len
for k in (1 .. len-1) {
var pi = prime_count(10**(k-1), 10**k - 1)
count += binomial(pi, 2)+pi
}
var min = (10**(len -... | Give a code snippet in #Sidef
Brilliant numbers are a subset of semiprime numbers. Specifically, they are numbers that are the product of exactly two prime numbers that both have the same number of digits when expressed in base 10.
Brilliant numbers are useful in cryptography and when testing prime factoring algorith... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Angle_difference_between_two_bearings | Angle difference between two bearings | Finding the angle between two bearings is often confusing.[1]
Task
Find the angle which is the result of the subtraction b2 - b1, where b1 and b2 are the bearings.
Input bearings are expressed in the range -180 to +180 degrees.
The result is also expressed in the range -180 to +180 degrees.
... | #Klingphix | Klingphix | include ..\Utilitys.tlhy
:bearing sub 360 mod 540 add 360 mod 180 sub ;
20 45 bearing
-45 45 bearing
-85 90 bearing
-95 90 bearing
-45 125 bearing
-45 145 bearing
29.4803 -88.6381 bearing
-78.3251 -159.036 bearing
-70099.74233810938 29840.67437876723 bearing
-165313.6666297357 33693.9894517456 bearing
1174.83805105... | Give a code snippet in #Klingphix
Finding the angle between two bearings is often confusing.[1]
Task
Find the angle which is the result of the subtraction b2 - b1, where b1 and b2 are the bearings.
Input bearings are expressed in the range -180 to +180 degrees.
The result is also expressed in the rang... | 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... | #PowerShell | PowerShell |
$Start_Time = (Get-date).second
Write-Host "Type CTRL-C to Terminate..."
$n = 1
Try
{
While($true)
{
Write-Host $n
$n ++
Start-Sleep -m 500
}
}
Finally
{
$End_Time = (Get-date).second
$Time_Diff = $End_Time - $Start_Time
Write-Host "Total time in seconds"$Time_Diff
}
| Give a code snippet in #PowerShell
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 tha... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Gray_code | Gray code | Gray code
Karnaugh maps
Create functions to encode a number to and decode a number from Gray code.
Display the normal binary representations, Gray code representations, and decoded Gray code values for all 5-bit binary numbers (0-31 inclusive, leading 0's not necessary).
There are many possible Gray codes. The follow... | #Go | Go | package main
import "fmt"
func enc(b int) int {
return b ^ b>>1
}
func dec(g int) (b int) {
for ; g != 0; g >>= 1 {
b ^= g
}
return
}
func main() {
fmt.Println("decimal binary gray decoded")
for b := 0; b < 32; b++ {
g := enc(b)
d := dec(g)
fmt.Print... | Give a code snippet in #Go
Gray code
Karnaugh maps
Create functions to encode a number to and decode a number from Gray code.
Display the normal binary representations, Gray code representations, and decoded Gray code values for all 5-bit binary numbers (0-31 inclusive, leading 0's not necessary).
There are many pos... | christopher/rosetta-code | |
http://rosettacode.org/wiki/ABC_problem | ABC problem | ABC problem
You are encouraged to solve this task according to the task description, using any language you may know.
You are given a collection of ABC blocks (maybe like the ones you had when you were a kid).
There are twenty blocks with two letters on each block.
A complete alphabet is guaranteed amongst all sid... | #Yabasic | Yabasic | letters$ = "BO,XK,DQ,CP,NA,GT,RE,TG,QD,FS,JW,HU,VI,AN,OB,ER,FS,LY,PC,ZM"
sub canMake(letters$, word$)
local i, j, p, n, pairs$(1)
n = token(letters$, pairs$(), ",")
word$ = upper$(word$)
for i = 1 to len(word$)
for j = 1 to n
p = instr(pairs$(j), mid$(word$, i, 1))
if p then
pairs$(j) = ""
bre... | Give a code snippet in #Yabasic
ABC problem
You are encouraged to solve this task according to the task description, using any language you may know.
You are given a collection of ABC blocks (maybe like the ones you had when you were a kid).
There are twenty blocks with two letters on each block.
A complete alpha... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Probabilistic_choice | Probabilistic choice | Given a mapping between items and their required probability of occurrence, generate a million items randomly subject to the given probabilities and compare the target probability of occurrence versus the generated values.
The total of all the probabilities should equal one. (Because floating point arithmetic is invol... | #Arturo | Arturo | nofTrials: 10000
probabilities: #[
aleph: to :rational [1 5]
beth: to :rational [1 6]
gimel: to :rational [1 7]
daleth: to :rational [1 8]
he: to :rational [1 9]
waw: to :rational [1 10]
zayin: to :rational [1 11]
heth: to :rational [1759 27720]
]
samples: #[]
loop 1..nofTrials 'x [
... | Give a code snippet in #Arturo
Given a mapping between items and their required probability of occurrence, generate a million items randomly subject to the given probabilities and compare the target probability of occurrence versus the generated values.
The total of all the probabilities should equal one. (Because fl... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Circles_of_given_radius_through_two_points | Circles of given radius through two points |
Given two points on a plane and a radius, usually two circles of given radius can be drawn through the points.
Exceptions
r==0.0 should be treated as never describing circles (except in the case where the points are coincident).
If the points are coincident then an infinite number of circles with the point on thei... | #Delphi | Delphi |
program Circles_of_given_radius_through_two_points;
{$APPTYPE CONSOLE}
uses
System.SysUtils,
System.Types,
System.Math;
const
Cases: array[0..9] of TPointF = ((
x: 0.1234;
y: 0.9876
), (
x: 0.8765;
y: 0.2345
), (
x: 0.0000;
y: 2.0000
), (
x: 0.0000;
y: 0.0000
), (... | Give a code snippet in #Delphi
Given two points on a plane and a radius, usually two circles of given radius can be drawn through the points.
Exceptions
r==0.0 should be treated as never describing circles (except in the case where the points are coincident).
If the points are coincident then an infinite number o... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Append_a_record_to_the_end_of_a_text_file | Append a record to the end of a text file | Many systems offer the ability to open a file for writing, such that any data written will be appended to the end of the file. Further, the file operations will always adjust the position pointer to guarantee the end of the file, even in a multitasking environment.
This feature is most useful in the case of log files,... | #Haskell | Haskell |
{-# LANGUAGE RecordWildCards #-}
import System.IO
import Data.List (intercalate)
data Gecos = Gecos { fullname :: String
, office :: String
, extension :: String
, homephone :: String
, email :: String
}
dat... | Give a code snippet in #Haskell
Many systems offer the ability to open a file for writing, such that any data written will be appended to the end of the file. Further, the file operations will always adjust the position pointer to guarantee the end of the file, even in a multitasking environment.
This feature is most... | christopher/rosetta-code | |
http://rosettacode.org/wiki/15_puzzle_solver | 15 puzzle solver | Your task is to write a program that finds a solution in the fewest moves possible single moves to a random Fifteen Puzzle Game.
For this task you will be using the following puzzle:
15 14 1 6
9 11 4 12
0 10 7 3
13 8 5 2
1 2 3 4
5 6 7 8
9 10 11 12
13 14 15 0
The output must show the moves' dir... | #F.23 | F# |
// A Naive 15 puzzle solver using no memory. Nigel Galloway: October 6th., 2017
let Nr,Nc = [|3;0;0;0;0;1;1;1;1;2;2;2;2;3;3;3|],[|3;0;1;2;3;0;1;2;3;0;1;2;3;0;1;2|]
type G= |N |I |G |E |L
type N={i:uint64;g:G list;e:int;l:int}
let fN n=let g=(11-n.e)*4 in let a=n.i&&&(15UL<<<g)
{i=n.i-a+(a<<<16);g=N:... | Give a code snippet in #F.23
Your task is to write a program that finds a solution in the fewest moves possible single moves to a random Fifteen Puzzle Game.
For this task you will be using the following puzzle:
15 14 1 6
9 11 4 12
0 10 7 3
13 8 5 2
1 2 3 4
5 6 7 8
9 10 11 12
13 14 15 0
The o... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Secure_temporary_file | Secure temporary file | Task
Create a temporary file, securely and exclusively (opening it such that there are no possible race conditions).
It's fine assuming local filesystem semantics (NFS or other networking filesystems can have signficantly more complicated semantics for satisfying the "no race conditions" criteria).
The function shou... | #OCaml | OCaml | # Filename.temp_file "prefix." ".suffix" ;;
- : string = "/home/blue_prawn/tmp/prefix.301f82.suffix" | Give a code snippet in #OCaml
Task
Create a temporary file, securely and exclusively (opening it such that there are no possible race conditions).
It's fine assuming local filesystem semantics (NFS or other networking filesystems can have signficantly more complicated semantics for satisfying the "no race conditions... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Search_a_list_of_records | Search a list of records | Many programming languages provide convenient ways to look for a known value in a simple list of strings or numbers.
But what if the elements of the list are themselves compound records/objects/data-structures, and the search condition is more complex than a simple equality test?
Task[edit]
Write a function/method/et... | #Arturo | Arturo | define :city [name population][]
records: map [
["Lagos" 21.0]
["Cairo" 15.2]
["Kinshasa-Brazzaville" 11.3]
["Greater Johannesburg" 7.55]
["Mogadishu" 5.85]
["Khartoum-Omdurman" 4.98]
["Dar Es Salaam" 4.7]
["Alexandria" 4.58]
["Abidjan" 4.4]
["Casablanca" 3.98]
] => [to :city]
... | Give a code snippet in #Arturo
Many programming languages provide convenient ways to look for a known value in a simple list of strings or numbers.
But what if the elements of the list are themselves compound records/objects/data-structures, and the search condition is more complex than a simple equality test?
Task[... | 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... | #Nim | Nim | proc luhn(cc: string): bool =
const m = [0, 2, 4, 6, 8, 1, 3, 5, 7, 9]
var sum = 0
var odd = true
for i in countdown(cc.high, 0):
let digit = ord(cc[i]) - ord('0')
sum += (if odd: digit else: m[digit])
odd = not odd
result = sum mod 10 == 0
for cc in ["49927398716", "49927398717", "1234567812345... | Give a code snippet in #Nim
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 t... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Detect_division_by_zero | Detect division by zero | Task
Write a function to detect a divide by zero error without checking if the denominator is zero.
| #Python | Python | def div_check(x, y):
try:
x / y
except ZeroDivisionError:
return True
else:
return False | Give a code snippet in #Python
Task
Write a function to detect a divide by zero error without checking if the denominator is zero.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Bioinformatics/Sequence_mutation | Bioinformatics/Sequence mutation | Task
Given a string of characters A, C, G, and T representing a DNA sequence write a routine to mutate the sequence, (string) by:
Choosing a random base position in the sequence.
Mutate the sequence by doing one of either:
Swap the base at that position by changing it to one of A, C, G, or T. (which has a chance o... | #Swift | Swift | let bases: [Character] = ["A", "C", "G", "T"]
enum Action: CaseIterable {
case swap, delete, insert
}
@discardableResult
func mutate(dna: inout String) -> Action {
guard let i = dna.indices.shuffled().first(where: { $0 != dna.endIndex }) else {
fatalError()
}
let action = Action.allCases.randomElement... | Give a code snippet in #Swift
Task
Given a string of characters A, C, G, and T representing a DNA sequence write a routine to mutate the sequence, (string) by:
Choosing a random base position in the sequence.
Mutate the sequence by doing one of either:
Swap the base at that position by changing it to one of A, C,... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sorting_algorithms/Quicksort | Sorting algorithms/Quicksort |
Sorting Algorithm
This is a sorting algorithm. It may be applied to a set of data in order to sort it.
For comparing various sorts, see compare sorts.
For other sorting algorithms, see sorting algorithms, or:
O(n logn) sorts
Heap sort |
Merge sort |
Patience sort |
Quick sort
O(n log2n) sorts
Shell Sort
... | #CoffeeScript | CoffeeScript |
quicksort = ([x, xs...]) ->
return [] unless x?
smallerOrEqual = (a for a in xs when a <= x)
larger = (a for a in xs when a > x)
(quicksort smallerOrEqual).concat(x).concat(quicksort larger)
| Give a code snippet in #CoffeeScript
Sorting Algorithm
This is a sorting algorithm. It may be applied to a set of data in order to sort it.
For comparing various sorts, see compare sorts.
For other sorting algorithms, see sorting algorithms, or:
O(n logn) sorts
Heap sort |
Merge sort |
Patience sort |
Q... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Harshad_or_Niven_series | Harshad or Niven series | The Harshad or Niven numbers are positive integers ≥ 1 that are divisible by the sum of their digits.
For example, 42 is a Harshad number as 42 is divisible by (4 + 2) without remainder.
Assume that the series is defined as the numbers in increasing order.
Task
The task is to create a function/method/... | #Comal | Comal | 0010 FUNC digit'sum(n)
0020 sum:=0
0030 WHILE n>0 DO sum:+n MOD 10;n:=n DIV 10
0040 RETURN sum
0050 ENDFUNC digit'sum
0060 //
0070 FUNC next'harshad(n)
0080 REPEAT
0090 n:+1
0100 UNTIL n MOD digit'sum(n)=0
0110 RETURN n
0120 ENDFUNC next'harshad
0130 //
0140 PRINT "First 20 Harshad numbers: "
0150 n:=0
... | Give a code snippet in #Comal
The Harshad or Niven numbers are positive integers ≥ 1 that are divisible by the sum of their digits.
For example, 42 is a Harshad number as 42 is divisible by (4 + 2) without remainder.
Assume that the series is defined as the numbers in increasing order.
Task
The task ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Hello_world/Standard_error | Hello world/Standard error | Hello world/Standard error is part of Short Circuit's Console Program Basics selection.
A common practice in computing is to send error messages
to a different output stream than normal text console messages.
The normal messages print to what is called "standard output" or "standard out".
The error messages print to ... | #Fantom | Fantom |
class Main
{
public static Void main ()
{
Env.cur.err.printLine ("Goodbye, World!")
}
}
| Give a code snippet in #Fantom
Hello world/Standard error is part of Short Circuit's Console Program Basics selection.
A common practice in computing is to send error messages
to a different output stream than normal text console messages.
The normal messages print to what is called "standard output" or "standard out... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Permutations/Derangements | Permutations/Derangements | A derangement is a permutation of the order of distinct items in which no item appears in its original place.
For example, the only two derangements of the three items (0, 1, 2) are (1, 2, 0), and (2, 0, 1).
The number of derangements of n distinct items is known as the subfactorial of n, sometimes written as !n.
The... | #SuperCollider | SuperCollider | (
d = { |array, n|
Routine {
n = n ?? { array.size.factorial };
n.do { |i|
var permuted = array.permute(i);
if(array.every { |each, i| permuted[i] != each }) {
permuted.yield
};
}
};
};
f = { |n| d.((0..n-1)) };
x = f.(4);
x.all.do(_.postln); "";
) | Give a code snippet in #SuperCollider
A derangement is a permutation of the order of distinct items in which no item appears in its original place.
For example, the only two derangements of the three items (0, 1, 2) are (1, 2, 0), and (2, 0, 1).
The number of derangements of n distinct items is known as the subfacto... | christopher/rosetta-code | |
http://rosettacode.org/wiki/A%2BB | A+B | A+B ─── a classic problem in programming contests, it's given so contestants can gain familiarity with the online judging system being used.
Task
Given two integers, A and B.
Their sum needs to be calculated.
Input data
Two integers are written in the input stream, separated by space(s):
(
−
1000
≤... | #Apex | Apex |
static Integer sumOfTwoNums(Integer A, Integer B) {
return A + B;
}
System.debug('A = 50 and B = 25: ' + sumOfTwoNums(50, 25));
System.debug('A = -50 and B = 25: ' +sumOfTwoNums(-50, 25));
System.debug('A = -50 and B = -25: ' +sumOfTwoNums(-50, -25));
System.debug('A = 50 and B = -25: ' +sumOfTwoNums(50, -25)... | Give a code snippet in #Apex
A+B ─── a classic problem in programming contests, it's given so contestants can gain familiarity with the online judging system being used.
Task
Given two integers, A and B.
Their sum needs to be calculated.
Input data
Two integers are written in the input stream, separated... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Bitmap/B%C3%A9zier_curves/Quadratic | Bitmap/Bézier curves/Quadratic | Using the data storage type defined on this page for raster images, and the draw_line function defined in this one, draw a quadratic bezier curve
(definition on Wikipedia).
| #Nim | Nim | import bitmap
import bresenham
import lenientops
proc drawQuadraticBezier*(
image: Image; pt1, pt2, pt3: Point; color: Color; nseg: Positive = 20) =
var points = newSeq[Point](nseg + 1)
for i in 0..nseg:
let t = i / nseg
let a = (1 - t) * (1 - t)
let b = 2 * t * (1 - t)
let c = t * t
... | Give a code snippet in #Nim
Using the data storage type defined on this page for raster images, and the draw_line function defined in this one, draw a quadratic bezier curve
(definition on Wikipedia).
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Find_the_intersection_of_a_line_with_a_plane | Find the intersection of a line with a plane | Finding the intersection of an infinite ray with a plane in 3D is an important topic in collision detection.
Task
Find the point of intersection for the infinite ray with direction (0, -1, -1) passing through position (0, 0, 10) with the infinite plane with a normal vector of (0, 0, 1) and which passes ... | #Python | Python | #!/bin/python
from __future__ import print_function
import numpy as np
def LinePlaneCollision(planeNormal, planePoint, rayDirection, rayPoint, epsilon=1e-6):
ndotu = planeNormal.dot(rayDirection)
if abs(ndotu) < epsilon:
raise RuntimeError("no intersection or line is within plane")
w = rayPoint - planePoint
... | Give a code snippet in #Python
Finding the intersection of an infinite ray with a plane in 3D is an important topic in collision detection.
Task
Find the point of intersection for the infinite ray with direction (0, -1, -1) passing through position (0, 0, 10) with the infinite plane with a normal vector of... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Van_Eck_sequence | Van Eck sequence | The sequence is generated by following this pseudo-code:
A: The first term is zero.
Repeatedly apply:
If the last term is *new* to the sequence so far then:
B: The next term is zero.
Otherwise:
C: The next term is how far back this last term occured previously.
Example
Using ... | #Fortran | Fortran | program VanEck
implicit none
integer eck(1000), i, j
eck(1) = 0
do 20 i=1, 999
do 10 j=i-1, 1, -1
if (eck(i) .eq. eck(j)) then
eck(i+1) = i-j
go to 20
end if
10 continue
eck(i+1) = 0
20 continue... | Give a code snippet in #Fortran
The sequence is generated by following this pseudo-code:
A: The first term is zero.
Repeatedly apply:
If the last term is *new* to the sequence so far then:
B: The next term is zero.
Otherwise:
C: The next term is how far back this last term occur... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Arrays | Arrays | This task is about arrays.
For hashes or associative arrays, please see Creating an Associative Array.
For a definition and in-depth discussion of what an array is, see Array.
Task
Show basic array syntax in your language.
Basically, create an array, assign a value to it, and retrieve an element (if available,... | #i | i | main
//Fixed-length arrays.
f $= array.integer[1]()
f[0] $= 2
print(f[0])
//Dynamic arrays.
d $= list.integer()
d[+] $= 2
print(d[1])
} | Give a code snippet in #i
This task is about arrays.
For hashes or associative arrays, please see Creating an Associative Array.
For a definition and in-depth discussion of what an array is, see Array.
Task
Show basic array syntax in your language.
Basically, create an array, assign a value to it, and retrieve ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/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.)
| #ActionScript | ActionScript | -- All Ada comments begin with "--" and extend to the end of the line | Give a code snippet in #ActionScript
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_transposition | Matrix transposition | Transpose an arbitrarily sized rectangular Matrix.
| #68000_Assembly | 68000 Assembly | Transpose2DArray_B:
;INPUT:
;A0 = POINTER TO SOURCE ARRAY
;A1 = POINTER TO BACKUP AREA
; (YOU NEED THE SAME AMOUNT OF FREE SPACE AS THE SOURCE ARRAY.)
; (IT'S YOUR RESPONSIBILITY TO KNOW WHERE THAT IS.)
;D0.W = ARRAY ROW LENGTH-1
;D1.W = ARRAY COLUMN HEIGHT-1
MOVEM.L D2-D7,-(SP)
MOVE.W D0,D4 ;width ... | Give a code snippet in #68000_Assembly
Transpose an arbitrarily sized rectangular Matrix.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Integer_sequence | Integer sequence | Task
Create a program that, when run, would display all integers from 1 to ∞ (or any relevant implementation limit), in sequence (i.e. 1, 2, 3, 4, etc) if given enough time.
An example may not be able to reach arbitrarily-large numbers based on implementations limits. For example, if integer... | #Swift | Swift | var i = 0
while true {
println(i++)
} | Give a code snippet in #Swift
Task
Create a program that, when run, would display all integers from 1 to ∞ (or any relevant implementation limit), in sequence (i.e. 1, 2, 3, 4, etc) if given enough time.
An example may not be able to reach arbitrarily-large numbers based on implementations li... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Magic_squares_of_doubly_even_order | Magic squares of doubly even order | A magic square is an N×N square matrix whose numbers consist of consecutive numbers arranged so that the sum of each row and column, and both diagonals are equal to the same sum (which is called the magic number or magic constant).
A magic square of doubly even order has a size that is a multiple of four (e... | #Julia | Julia | using Printf
function magicsquaredoubleeven(order::Int)
if order % 4 != 0; error("the order must be divisible by 4") end
sqr = Matrix{Int}(order, order)
mul = div(order, 4)
ext = vcat(1:mul, order-mul+1:order)
isext(i::Int, j::Int) = (i in ext) == (j in ext)
boolsqr = collect(isext(i, j) for... | Give a code snippet in #Julia
A magic square is an N×N square matrix whose numbers consist of consecutive numbers arranged so that the sum of each row and column, and both diagonals are equal to the same sum (which is called the magic number or magic constant).
A magic square of doubly even order has a size ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Unix/ls | Unix/ls | Task
Write a program that will list everything in the current folder, similar to:
the Unix utility “ls” [1] or
the Windows terminal command “DIR”
The output must be sorted, but printing extended details and producing multi-column output is not required.
Example output
For the list of paths:... | #Perl | Perl | opendir my $handle, '.' or die "Couldnt open current directory: $!";
while (readdir $handle) {
print "$_\n";
}
closedir $handle; | Give a code snippet in #Perl
Task
Write a program that will list everything in the current folder, similar to:
the Unix utility “ls” [1] or
the Windows terminal command “DIR”
The output must be sorted, but printing extended details and producing multi-column output is not required.
Example... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Find_limit_of_recursion | Find limit of recursion | Find limit of recursion is part of Short Circuit's Console Program Basics selection.
Task
Find the limit of recursion.
| #PowerShell | PowerShell |
function TestDepth ( $N )
{
$N
TestDepth ( $N + 1 )
}
try
{
TestDepth 1 | ForEach { $Depth = $_ }
}
catch
{
"Exception message: " + $_.Exception.Message
}
"Last level before error: " + $Depth
| Give a code snippet in #PowerShell
Find limit of recursion is part of Short Circuit's Console Program Basics selection.
Task
Find the limit of recursion.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Return_multiple_values | Return multiple values | Task
Show how to return more than one value from a function.
| #TXR | TXR | @(define func (x y z))
@ (bind w "discarded")
@ (bind (x y z) ("a" "b" "c"))
@(end) | Give a code snippet in #TXR
Task
Show how to return more than one value from a function.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Zeckendorf_arithmetic | Zeckendorf arithmetic | This task is a total immersion zeckendorf task; using decimal numbers will attract serious disapprobation.
The task is to implement addition, subtraction, multiplication, and division using Zeckendorf number representation. Optionally provide decrement, increment and comparitive operation functions.
Addition
Like bin... | #Perl | Perl | #!/usr/bin/perl
use strict; # https://rosettacode.org/wiki/Zeckendorf_arithmetic
use warnings;
for ( split /\n/, <<END ) # test cases
1 + 1
10 + 10
10100 + 1010
10100 - 1010
10100 * 1010
100010 * 100101
10100 / 1010
101000 / 1000
100001000001 / 100010
100001000001 / 100101
END
{
my ($left, $... | Give a code snippet in #Perl
This task is a total immersion zeckendorf task; using decimal numbers will attract serious disapprobation.
The task is to implement addition, subtraction, multiplication, and division using Zeckendorf number representation. Optionally provide decrement, increment and comparitive operation... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Miller%E2%80%93Rabin_primality_test | Miller–Rabin primality test |
This page uses content from Wikipedia. The original article was at Miller–Rabin primality test. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance)
The Miller–Rabin primality test or Rabin–Miller prima... | #zkl | zkl | zkl: var BN=Import("zklBigNum");
zkl: BN("4547337172376300111955330758342147474062293202868155909489").probablyPrime()
True
zkl: BN("4547337172376300111955330758342147474062293202868155909393").probablyPrime()
False | Give a code snippet in #zkl
This page uses content from Wikipedia. The original article was at Miller–Rabin primality test. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance)
The Miller–Rabin primali... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Detect_division_by_zero | Detect division by zero | Task
Write a function to detect a divide by zero error without checking if the denominator is zero.
| #Phix | Phix | try
integer i = 1/0
catch e
?e[E_USER]
end try
puts(1,"still running...\n")
| Give a code snippet in #Phix
Task
Write a function to detect a divide by zero error without checking if the denominator is zero.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Literals/Integer | Literals/Integer | Some programming languages have ways of expressing integer literals in bases other than the normal base ten.
Task
Show how integer literals can be expressed in as many bases as your language allows.
Note: this should not involve the calling of any functions/methods, but should be interpreted by the compiler or... | #DWScript | DWScript | var a : Integer := 42;
var b : Integer := $2a; | Give a code snippet in #DWScript
Some programming languages have ways of expressing integer literals in bases other than the normal base ten.
Task
Show how integer literals can be expressed in as many bases as your language allows.
Note: this should not involve the calling of any functions/methods, but should... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Topological_sort | Topological sort |
Sorting Algorithm
This is a sorting algorithm. It may be applied to a set of data in order to sort it.
For comparing various sorts, see compare sorts.
For other sorting algorithms, see sorting algorithms, or:
O(n logn) sorts
Heap sort |
Merge sort |
Patience sort |
Quick sort
O(n log2n) sorts
Shell Sort
... | #zkl | zkl | fcn topoSort(data){ // data is L( L(root,L(leaves)),...)
allDs:=data.pump(List,fcn(rds){ T(Void.Write,Void.Write,rds[1]) }).copy();
roots:=Dictionary(data); // dictionary of root:leaves
L:=List();
S:=data.pump(List,'wrap([(r,_)]){ if(allDs.holds(r)) Void.Skip else r }).copy();
while(S){ //while S ... | Give a code snippet in #zkl
Sorting Algorithm
This is a sorting algorithm. It may be applied to a set of data in order to sort it.
For comparing various sorts, see compare sorts.
For other sorting algorithms, see sorting algorithms, or:
O(n logn) sorts
Heap sort |
Merge sort |
Patience sort |
Quick sort... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Empty_string | Empty string | Languages may have features for dealing specifically with empty strings
(those containing no characters).
Task
Demonstrate how to assign an empty string to a variable.
Demonstrate how to check that a string is empty.
Demonstrate how to check that a string is not empty.
Other tasks related to string oper... | #Clojure | Clojure |
(def x "") ;x is "globally" declared to be the empty string
(let [x ""]
;x is bound to the empty string within the let
)
(= x "") ;true if x is the empty string
(not= x "") ;true if x is not the empty string
| Give a code snippet in #Clojure
Languages may have features for dealing specifically with empty strings
(those containing no characters).
Task
Demonstrate how to assign an empty string to a variable.
Demonstrate how to check that a string is empty.
Demonstrate how to check that a string is not empty.
O... | christopher/rosetta-code | |
http://rosettacode.org/wiki/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 ... | #Halon | Halon | function multiply( $a, $b )
{
return $a * $b;
} | Give a code snippet in #Halon
A function is a body of code that returns a value.
The value returned may depend on arguments provided to the function.
Task
Write a definition of a function called "multiply" that takes two arguments and returns their product.
(Argument types should be chosen so as not to distract ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Heronian_triangles | Heronian triangles | Hero's formula for the area of a triangle given the length of its three sides a, b, and c is given by:
A
=
s
(
s
−
a
)
(
s
−
b
)
(
s
−
c
)
,
{\displaystyle A={\sqrt {s(s-a)(s-b)(s-c)}},}
where s is half the perimeter of the triangle; that is,
s
=
a
+
b
+
c
2
.
{\displaystyle s... | #Nim | Nim | import math, algorithm, lenientops, strformat, sequtils
type HeronianTriangle = tuple[a, b, c: int; p: int; area: int]
func `$` (t: HeronianTriangle): string =
fmt"{t.a:3d}, {t.b:3d}, {t.c:3d} {t.p:7d} {t.area:8d}"
func hero(a, b, c: int): float =
let s = (a + b + c) / 2
result = sqrt(s * (s - a) * (s - b) ... | Give a code snippet in #Nim
Hero's formula for the area of a triangle given the length of its three sides a, b, and c is given by:
A
=
s
(
s
−
a
)
(
s
−
b
)
(
s
−
c
)
,
{\displaystyle A={\sqrt {s(s-a)(s-b)(s-c)}},}
where s is half the perimeter of the triangle; that is,
s
=
a
+
b
... | 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... | #K | K |
pascal:{(x-1){+':x,0}\1}
pascal 6
(1
1 1
1 2 1
1 3 3 1
1 4 6 4 1
1 5 10 10 5 1) | Give a code snippet in #K
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 o... | 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 ... | #FRISC_Assembly | FRISC Assembly | FIBONACCI PUSH R1
PUSH R2
PUSH R3
MOVE 0, R1
MOVE 1, R2
FIB_LOOP SUB R0, 1, R0
JP_Z FIB_DONE
MOVE R2, R3
ADD R1, R2, R2
MOVE R3, R1
JP FIB_LOOP
FIB_DONE MOVE R2, R... | Give a code snippet in #FRISC_Assembly
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 solu... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Compile-time_calculation | Compile-time calculation | Some programming languages allow calculation of values at compile time.
Task
Calculate 10! (ten factorial) at compile time.
Print the result when the program is run.
Discuss what limitations apply to compile-time calculations in your language.
| #Fortran | Fortran | program test
implicit none
integer,parameter :: t = 10*9*8*7*6*5*4*3*2 !computed at compile time
write(*,*) t !write the value the console.
end program test
| Give a code snippet in #Fortran
Some programming languages allow calculation of values at compile time.
Task
Calculate 10! (ten factorial) at compile time.
Print the result when the program is run.
Discuss what limitations apply to compile-time calculations in your language.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Sorting_algorithms/Cocktail_sort | Sorting algorithms/Cocktail sort |
Sorting Algorithm
This is a sorting algorithm. It may be applied to a set of data in order to sort it.
For comparing various sorts, see compare sorts.
For other sorting algorithms, see sorting algorithms, or:
O(n logn) sorts
Heap sort |
Merge sort |
Patience sort |
Quick sort
O(n log2n) sorts
Shell Sort
... | #C.2B.2B | C++ |
#include <iostream>
#include <windows.h>
const int EL_COUNT = 77, LLEN = 11;
class cocktailSort
{
public:
void sort( int* arr, int len )
{
bool notSorted = true;
while( notSorted )
{
notSorted = false;
for( int a = 0; a < len - 1; a++ )
{
if( arr[a] > arr[a + 1] )
{
sSwap( arr[... | Give a code snippet in #C.2B.2B
Sorting Algorithm
This is a sorting algorithm. It may be applied to a set of data in order to sort it.
For comparing various sorts, see compare sorts.
For other sorting algorithms, see sorting algorithms, or:
O(n logn) sorts
Heap sort |
Merge sort |
Patience sort |
Quick ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Averages/Median | Averages/Median | Task[edit]
Write a program to find the median value of a vector of floating-point numbers.
The program need not handle the case where the vector is empty, but must handle the case where there are an even number of elements. In that case, return the average of the two middle values.
There are several approaches ... | #Forth | Forth | -1 cells constant -cell
: cell- -cell + ;
defer lessthan ( a@ b@ -- ? ) ' < is lessthan
: mid ( l r -- mid ) over - 2/ -cell and + ;
: exch ( addr1 addr2 -- ) dup @ >r over @ swap ! r> swap ! ;
: part ( l r -- l r r2 l2 )
2dup mid @ >r ( r: pivot )
2dup begin
swap begin dup @ r@ lessthan while cell... | Give a code snippet in #Forth
Task[edit]
Write a program to find the median value of a vector of floating-point numbers.
The program need not handle the case where the vector is empty, but must handle the case where there are an even number of elements. In that case, return the average of the two middle values.... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Multifactorial | Multifactorial | The factorial of a number, written as
n
!
{\displaystyle n!}
, is defined as
n
!
=
n
(
n
−
1
)
(
n
−
2
)
.
.
.
(
2
)
(
1
)
{\displaystyle n!=n(n-1)(n-2)...(2)(1)}
.
Multifactorials generalize factorials as follows:
n
!
=
n
(
n
−
1
)
(
n
−
2
)
.
.
.
(
2
)
(
1
)
{\displaystyle n!=n(n-1)(n-2)...(2)(... | #zkl | zkl | fcn mfact(n,m){ [n..1,-m].reduce('*,1) }
foreach m in ([1..5]){ println("%d: %s".fmt(m,[1..10].apply(mfact.fp1(m)))) } | Give a code snippet in #zkl
The factorial of a number, written as
n
!
{\displaystyle n!}
, is defined as
n
!
=
n
(
n
−
1
)
(
n
−
2
)
.
.
.
(
2
)
(
1
)
{\displaystyle n!=n(n-1)(n-2)...(2)(1)}
.
Multifactorials generalize factorials as follows:
n
!
=
n
(
n
−
1
)
(
n
−
2
)
.
.
.
(
2
)
(
1
)
{\displ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Dot_product | Dot product | Task
Create a function/use an in-built function, to compute the dot product, also known as the scalar product of two vectors.
If possible, make the vectors of arbitrary length.
As an example, compute the dot product of the vectors:
[1, 3, -5] and
[4, -2, -1]
If implementing the dot ... | #Zig | Zig | const std = @import("std");
const Vector = std.meta.Vector;
pub fn main() !void {
const a: Vector(3, i32) = [_]i32{1, 3, -5};
const b: Vector(3, i32) = [_]i32{4, -2, -1};
var dot: i32 = @reduce(.Add, a*b);
try std.io.getStdOut().writer().print("{d}\n", .{dot});
} | Give a code snippet in #Zig
Task
Create a function/use an in-built function, to compute the dot product, also known as the scalar product of two vectors.
If possible, make the vectors of arbitrary length.
As an example, compute the dot product of the vectors:
[1, 3, -5] and
[4, -2, -1] ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/URL_decoding | URL decoding | This task (the reverse of URL encoding and distinct from URL parser) is to provide a function
or mechanism to convert an URL-encoded string into its original unencoded form.
Test cases
The encoded string "http%3A%2F%2Ffoo%20bar%2F" should be reverted to the unencoded form "http://foo bar/".
Th... | #Lua | Lua | function decodeChar(hex)
return string.char(tonumber(hex,16))
end
function decodeString(str)
local output, t = string.gsub(str,"%%(%x%x)",decodeChar)
return output
end
-- will print "http://foo bar/"
print(decodeString("http%3A%2F%2Ffoo%20bar%2F")) | Give a code snippet in #Lua
This task (the reverse of URL encoding and distinct from URL parser) is to provide a function
or mechanism to convert an URL-encoded string into its original unencoded form.
Test cases
The encoded string "http%3A%2F%2Ffoo%20bar%2F" should be reverted to the unencoded fo... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Van_der_Corput_sequence | Van der Corput sequence | When counting integers in binary, if you put a (binary) point to the righEasyLangt of the count then the column immediately to the left denotes a digit with a multiplier of
2
0
{\displaystyle 2^{0}}
; the digit in the next column to the left has a multiplier of
2
1
{\displaystyle 2^{1}}
; and so o... | #Java | Java | public class VanDerCorput{
public static double vdc(int n){
double vdc = 0;
int denom = 1;
while(n != 0){
vdc += n % 2.0 / (denom *= 2);
n /= 2;
}
return vdc;
}
public static void main(String[] args){
for(int i = 0; i <= 10; i++){
System.out.println(vdc(i));
}
}
} | Give a code snippet in #Java
When counting integers in binary, if you put a (binary) point to the righEasyLangt of the count then the column immediately to the left denotes a digit with a multiplier of
2
0
{\displaystyle 2^{0}}
; the digit in the next column to the left has a multiplier of
2
1
{\d... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Metaprogramming | Metaprogramming | Name and briefly demonstrate any support your language has for metaprogramming. Your demonstration may take the form of cross-references to other tasks on Rosetta Code. When possible, provide links to relevant documentation.
For the purposes of this task, "support for metaprogramming" means any way the user can effect... | #Run_BASIC | Run BASIC | ' ---------------------------------------------------
' create a file to be run
' RB can run the entire program
' or execute a function withing the RUNNED program
' ---------------------------------------------------
open "runned.bas" for output as #f ' open runned.bas as output
print #f, "text$... | Give a code snippet in #Run_BASIC
Name and briefly demonstrate any support your language has for metaprogramming. Your demonstration may take the form of cross-references to other tasks on Rosetta Code. When possible, provide links to relevant documentation.
For the purposes of this task, "support for metaprogramming... | christopher/rosetta-code |
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