task_url stringlengths 30 116 | task_name stringlengths 2 86 | task_description stringlengths 0 14.4k | language_url stringlengths 2 53 | language_name stringlengths 1 52 | code stringlengths 0 61.9k | response_seed stringclasses 1
value | instruction_seed stringlengths 27 14.4k | _source stringclasses 1
value |
|---|---|---|---|---|---|---|---|---|
http://rosettacode.org/wiki/Multiple_regression | Multiple regression | Task
Given a set of data vectors in the following format:
y
=
{
y
1
,
y
2
,
.
.
.
,
... | #BBC_BASIC | BBC BASIC | *FLOAT 64
INSTALL @lib$+"ARRAYLIB"
DIM y(14), x(2,14), c(2)
y() = 52.21, 53.12, 54.48, 55.84, 57.20, 58.57, 59.93, 61.29, \
\ 63.11, 64.47, 66.28, 68.10, 69.92, 72.19, 74.46
x() = 1.47, 1.50, 1.52, 1.55, 1.57, 1.60, 1.63, 1.65, \
\ 1.68, 1.70, 1.73, 1.75, ... | Give a code snippet in #BBC_BASIC
Task
Given a set of data vectors in the following format:
y
=
{
y
1
,
y
2
,
.
.
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Abstract_type | Abstract type | Abstract type is a type without instances or without definition.
For example in object-oriented programming using some languages, abstract types can be partial implementations of other types, which are to be derived there-from. An abstract type may provide implementation of some operations and/or components. Abstract ... | #Seed7 | Seed7 |
const type: myInterf is sub object interface;
const func integer: method1 (in myInterf: interf, in float: aFloat) is DYNAMIC;
const func integer: method2 (in myInterf: interf, in string: name) is DYNAMIC;
const func integer: add (in myInterf: interf, in integer: a, in integer: b) is DYNAMIC;
| Give a code snippet in #Seed7
Abstract type is a type without instances or without definition.
For example in object-oriented programming using some languages, abstract types can be partial implementations of other types, which are to be derived there-from. An abstract type may provide implementation of some operatio... | 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... | #Picat | Picat | go =>
% Create an empty map
Map = new_map(),
println(Map),
% add some data
Map.put(a,1),
Map.put("picat",2),
Map.put("picat",3), % overwrite values
% Add a new value (a long list of different stuff)
Map.put([a,list,of,different,"things",[including, lists],3.14159],2),
println(Map),
... | Give a code snippet in #Picat
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/100_prisoners | 100 prisoners |
The Problem
100 prisoners are individually numbered 1 to 100
A room having a cupboard of 100 opaque drawers numbered 1 to 100, that cannot be seen from outside.
Cards numbered 1 to 100 are placed randomly, one to a drawer, and the drawers all closed; at the start.
Prisoners start outside the room
They can decid... | #Phixmonti | Phixmonti | /# Rosetta Code problem: http://rosettacode.org/wiki/100_prisoners
by Galileo, 05/2022 #/
include ..\Utilitys.pmt
def random rand * 1 + int enddef
def shuffle
len var l
l for var a
l random var b
b get var p
a get b set
p a set
endfor
enddef
def play var optimal var i... | Give a code snippet in #Phixmonti
The Problem
100 prisoners are individually numbered 1 to 100
A room having a cupboard of 100 opaque drawers numbered 1 to 100, that cannot be seen from outside.
Cards numbered 1 to 100 are placed randomly, one to a drawer, and the drawers all closed; at the start.
Prisoners sta... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Operator_precedence | Operator precedence |
This page uses content from Wikipedia. The original article was at Operators in C and C++. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance)
Task
Provide a list of precedence and associativity... | #Bracmat | Bracmat | SAMPLES>write 18 / 2 * 3 + 7
34
SAMPLES>write 18 / (2 * 3) + 7
10
| Give a code snippet in #Bracmat
This page uses content from Wikipedia. The original article was at Operators in C and C++. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance)
Task
Provide a list of ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Loops/While | Loops/While | Task
Start an integer value at 1024.
Loop while it is greater than zero.
Print the value (with a newline) and divide it by two each time through the loop.
Related tasks
Loop over multiple arrays simultaneously
Loops/Break
Loops/Continue
Loops/Do-while
Loops/Downward for
Loops/For
Loops/For... | #Maxima | Maxima | block([n], n: 1024, while n > 0 do (print(n), n: quotient(n, 2)));
/* using a C-like loop: divide control variable by two instead of incrementing it */
for n: 1024 next quotient(n, 2) while n > 0 do print(n); | Give a code snippet in #Maxima
Task
Start an integer value at 1024.
Loop while it is greater than zero.
Print the value (with a newline) and divide it by two each time through the loop.
Related tasks
Loop over multiple arrays simultaneously
Loops/Break
Loops/Continue
Loops/Do-while
Loops/Downwa... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Self-describing_numbers | Self-describing numbers | Self-describing numbers
You are encouraged to solve this task according to the task description, using any language you may know.
There are several so-called "self-describing" or "self-descriptive" integers.
An integer is said to be "self-describing" if it has the property that, when digit positions are labeled 0 to ... | #zkl | zkl | fcn isSelfDescribing(n){
if (n.bitAnd(1)) return(False); // Wikipedia: last digit must be zero
nu:= n.toString();
ns:=["0".."9"].pump(String,nu.inCommon,"len"); //"12233".inCommon("2")-->"22"
(nu+"0000000000")[0,10] == ns; //"2020","2020000000"
} | Give a code snippet in #zkl
Self-describing numbers
You are encouraged to solve this task according to the task description, using any language you may know.
There are several so-called "self-describing" or "self-descriptive" integers.
An integer is said to be "self-describing" if it has the property that, when digi... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Order_disjoint_list_items | Order disjoint list items |
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
... | #Python | Python | from __future__ import print_function
def order_disjoint_list_items(data, items):
#Modifies data list in-place
itemindices = []
for item in set(items):
itemcount = items.count(item)
#assert data.count(item) >= itemcount, 'More of %r than in data' % item
lastindex = [-1]
for... | Give a code snippet in #Python
Sorting Algorithm
This is a sorting algorithm. It may be applied to a set of data in order to sort it.
For comparing various sorts, see compare sorts.
For other sorting algorithms, see sorting algorithms, or:
O(n logn) sorts
Heap sort |
Merge sort |
Patience sort |
Quick s... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Ternary_logic | Ternary logic |
This page uses content from Wikipedia. The original article was at Ternary logic. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance)
In logic, a three-valued logic (also trivalent, ternary, or trinary... | #Tcl | Tcl | package require Tcl 8.5
namespace eval ternary {
# Code generator
proc maketable {name count values} {
set sep ""
for {set i 0; set c 97} {$i<$count} {incr i;incr c} {
set v [format "%c" $c]
lappend args $v; append key $sep "$" $v
set sep ","
}
foreach row [split $values \n] {
if {[lleng... | Give a code snippet in #Tcl
This page uses content from Wikipedia. The original article was at Ternary logic. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance)
In logic, a three-valued logic (also t... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Apply_a_callback_to_an_array | Apply a callback to an array | Task
Take a combined set of elements and apply a function to each element.
| #ZX_Spectrum_Basic | ZX Spectrum Basic | 10 LET a$="x+x"
20 LET b$="x*x"
30 LET c$="x+x^2"
40 LET f$=c$: REM Assign a$, b$ or c$
150 FOR i=1 TO 5
160 READ x
170 PRINT x;" = ";VAL f$
180 NEXT i
190 STOP
200 DATA 2,5,6,10,100
| Give a code snippet in #ZX_Spectrum_Basic
Task
Take a combined set of elements and apply a function to each element.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Draw_a_sphere | Draw a sphere | Task
Draw a sphere.
The sphere can be represented graphically, or in ASCII art, depending on the language capabilities.
Either static or rotational projection is acceptable for this task.
Related tasks
draw a cuboid
draw a rotating cube
write language name in 3D ASCII
draw a Deathstar
| #Forth | Forth | : 3dup 2 pick 2 pick 2 pick ;
: sqrt ( u -- sqrt ) ( Babylonian method )
dup 2/ ( first square root guess is half )
dup 0= if drop exit then ( sqrt[0]=0, sqrt[1]=1 )
begin dup >r 2dup / r> + 2/ ( stack: square old-guess new-guess )
2dup >... | Give a code snippet in #Forth
Task
Draw a sphere.
The sphere can be represented graphically, or in ASCII art, depending on the language capabilities.
Either static or rotational projection is acceptable for this task.
Related tasks
draw a cuboid
draw a rotating cube
write language name in 3D ASCII
draw a De... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Leap_year | Leap year | Task
Determine whether a given year is a leap year in the Gregorian calendar.
See also
Leap year (wiki)
| #Fortran | Fortran | program leap
implicit none
write(*,*) leap_year([1900, 1996, 1997, 2000])
contains
pure elemental function leap_year(y) result(is_leap)
implicit none
logical :: is_leap
integer,intent(in) :: y
is_leap = (mod(y,4)==0 .and. .not. mod(y,100)==0) .or. (mod(y,400)==0)
end function leap_year
end progra... | Give a code snippet in #Fortran
Task
Determine whether a given year is a leap year in the Gregorian calendar.
See also
Leap year (wiki)
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Average_loop_length | Average loop length | Let f be a uniformly-randomly chosen mapping from the numbers 1..N to the numbers 1..N (note: not necessarily a permutation of 1..N; the mapping could produce a number in more than one way or not at all). At some point, the sequence 1, f(1), f(f(1))... will contain a repetition, a number that occurring for the second t... | #Lua | Lua | function average(n, reps)
local count = 0
for r = 1, reps do
local f = {}
for i = 1, n do f[i] = math.random(n) end
local seen, x = {}, 1
while not seen[x] do
seen[x], x, count = true, f[x], count+1
end
end
return count / reps
end
function analytical(n)
local s, t = 1, 1
for i = ... | Give a code snippet in #Lua
Let f be a uniformly-randomly chosen mapping from the numbers 1..N to the numbers 1..N (note: not necessarily a permutation of 1..N; the mapping could produce a number in more than one way or not at all). At some point, the sequence 1, f(1), f(f(1))... will contain a repetition, a number th... | 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... | #REXX | REXX | /*REXX program supports the Caesar cypher for the Latin alphabet only, no punctuation */
/*──────────── or blanks allowed, all lowercase Latin letters are treated as uppercase.*/
parse arg key .; arg . p /*get key & uppercased text to be used.*/
p= space(p, 0) ... | Give a code snippet in #REXX
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 ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Loops/Infinite | Loops/Infinite | Task
Print out SPAM followed by a newline in an infinite loop.
Related tasks
Loop over multiple arrays simultaneously
Loops/Break
Loops/Continue
Loops/Do-while
Loops/Downward for
Loops/For
Loops/For with a specified step
Loops/Foreach
Loops/Increment loop index within l... | #UNIX_Shell | UNIX Shell | while :; do echo SPAM; done | Give a code snippet in #UNIX_Shell
Task
Print out SPAM followed by a newline in an infinite loop.
Related tasks
Loop over multiple arrays simultaneously
Loops/Break
Loops/Continue
Loops/Do-while
Loops/Downward for
Loops/For
Loops/For with a specified step
Loops/Foreach
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Abbreviations,_simple | Abbreviations, simple | The use of abbreviations (also sometimes called synonyms, nicknames, AKAs, or aliases) can be an
easy way to add flexibility when specifying or using commands, sub─commands, options, etc.
For this task, the following command table will be used:
add 1 alter 3 backup 2 bottom 1 Cappend 2 change 1 ... | #Clojure | Clojure |
(defn words
"Split string into words"
[^String str]
(.split (.stripLeading str) "\\s+"))
(defn join-words
"Join words into a single string"
^String [strings]
(String/join " " strings))
;; SOURCE: https://www.stackoverflow.com/a/38947571/12947681
(defn starts-with-ignore-case
"Does string start with ... | Give a code snippet in #Clojure
The use of abbreviations (also sometimes called synonyms, nicknames, AKAs, or aliases) can be an
easy way to add flexibility when specifying or using commands, sub─commands, options, etc.
For this task, the following command table will be used:
add 1 alter 3 backup 2... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Table_creation/Postal_addresses | Table creation/Postal addresses | Task
Create a table to store addresses.
You may assume that all the addresses to be stored will be located in the USA. As such, you will need (in addition to a field holding a unique identifier) a field holding the street address, a field holding the city, a field holding the state code, and a field holding the zip... | #Kotlin | Kotlin | // Version 1.2.41
import java.io.File
import java.io.RandomAccessFile
fun String.toFixedLength(len: Int) = this.padEnd(len).substring(0, len)
class Address(
var name: String,
var street: String = "",
var city: String = "",
var state: String = "",
var zipCode: String = "",
val autoId: Boole... | Give a code snippet in #Kotlin
Task
Create a table to store addresses.
You may assume that all the addresses to be stored will be located in the USA. As such, you will need (in addition to a field holding a unique identifier) a field holding the street address, a field holding the city, a field holding the state c... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Least_common_multiple | Least common multiple | Least common multiple
You are encouraged to solve this task according to the task description, using any language you may know.
Task
Compute the least common multiple (LCM) of two integers.
Given m and n, the least common multiple is the smallest positive integer that has both m and n as factor... | #Wortel | Wortel | @lcm a b | Give a code snippet in #Wortel
Least common multiple
You are encouraged to solve this task according to the task description, using any language you may know.
Task
Compute the least common multiple (LCM) of two integers.
Given m and n, the least common multiple is the smallest positive integer that ha... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Playing_cards | Playing cards | Task
Create a data structure and the associated methods to define and manipulate a deck of playing cards.
The deck should contain 52 unique cards.
The methods must include the ability to:
make a new deck
shuffle (randomize) the deck
deal from the deck
print the current contents of a deck
Each card mu... | #REXX | REXX | /* REXX ***************************************************************
* 1) Build ordered Card deck
* 2) Create shuffled stack
* 3) Deal 5 cards to 4 players each
* 4) show what cards have been dealt and what's left on the stack
* 05.07.2012 Walter Pachl
****************************************************************... | Give a code snippet in #REXX
Task
Create a data structure and the associated methods to define and manipulate a deck of playing cards.
The deck should contain 52 unique cards.
The methods must include the ability to:
make a new deck
shuffle (randomize) the deck
deal from the deck
print the current co... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Classes | Classes | In object-oriented programming class is a set (a transitive closure) of types bound by the relation of inheritance. It is said that all types derived from some base type T and the type T itself form a class T.
The first type T from the class T sometimes is called the root type of the class.
A class of types itself, a... | #Aikido | Aikido | class Circle (radius, x, y) extends Shape (x, y) implements Drawable {
var myvec = new Vector (x, y)
public function draw() {
// draw the circle
}
} | Give a code snippet in #Aikido
In object-oriented programming class is a set (a transitive closure) of types bound by the relation of inheritance. It is said that all types derived from some base type T and the type T itself form a class T.
The first type T from the class T sometimes is called the root type of the cl... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Forest_fire | Forest fire |
This page uses content from Wikipedia. The original article was at Forest-fire model. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance)
Task
Implement the Drossel and Schwabl definition of the fores... | #Scala | Scala | import scala.util.Random
class Forest(matrix:Array[Array[Char]]){
import Forest._
val f=0.01; // auto combustion probability
val p=0.1; // tree creation probability
val rows=matrix.size
val cols=matrix(0).size
def evolve():Forest=new Forest(Array.tabulate(rows, cols){(y,x)=>
matrix(y)(x) match {
... | Give a code snippet in #Scala
This page uses content from Wikipedia. The original article was at Forest-fire model. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance)
Task
Implement the Drossel and ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Zumkeller_numbers | Zumkeller numbers | Zumkeller numbers are the set of numbers whose divisors can be partitioned into two disjoint sets that sum to the same value. Each sum must contain divisor values that are not in the other sum, and all of the divisors must be in one or the other. There are no restrictions on how the divisors are partitioned, only that ... | #C.23 | C# | using System;
using System.Collections.Generic;
using System.Linq;
namespace ZumkellerNumbers {
class Program {
static List<int> GetDivisors(int n) {
List<int> divs = new List<int> {
1, n
};
for (int i = 2; i * i <= n; i++) {
if (n % i ==... | Give a code snippet in #C.23
Zumkeller numbers are the set of numbers whose divisors can be partitioned into two disjoint sets that sum to the same value. Each sum must contain divisor values that are not in the other sum, and all of the divisors must be in one or the other. There are no restrictions on how the diviso... | christopher/rosetta-code | |
http://rosettacode.org/wiki/LZW_compression | LZW compression | The Lempel-Ziv-Welch (LZW) algorithm provides loss-less data compression.
You can read a complete description of it in the Wikipedia article on the subject. It was patented, but it entered the public domain in 2004.
| #Eiffel | Eiffel |
class
APPLICATION
create
make
feature {NONE}
make
local
test: LINKED_LIST [INTEGER]
do
create test.make
test := compress ("TOBEORNOTTOBEORTOBEORNOT")
across
test as t
loop
io.put_string (t.item.out + " ")
end
io.new_line
io.put_string... | Give a code snippet in #Eiffel
The Lempel-Ziv-Welch (LZW) algorithm provides loss-less data compression.
You can read a complete description of it in the Wikipedia article on the subject. It was patented, but it entered the public domain in 2004.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Morse_code | Morse code | Morse code
It has been in use for more than 175 years — longer than any other electronic encoding system.
Task
Send a string as audible Morse code to an audio device (e.g., the PC speaker).
As the standard Morse code does not contain all possible characters,
you may either ignore unknown characters in the file... | #Lua | Lua | local M = {}
-- module-local variables
local BUZZER = pio.PB_10
local dit_length, dah_length, word_length
-- module-local functions
local buzz, dah, dit, init, inter_element_gap, medium_gap, pause, sequence, short_gap
buzz = function(duration)
pio.pin.output(BUZZER)
pio.pin.setlow(BUZZER)
tmr.delay(tmr.SYS_... | Give a code snippet in #Lua
Morse code
It has been in use for more than 175 years — longer than any other electronic encoding system.
Task
Send a string as audible Morse code to an audio device (e.g., the PC speaker).
As the standard Morse code does not contain all possible characters,
you may either ignore u... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Cantor_set | Cantor set | Task
Draw a Cantor set.
See details at this Wikipedia webpage: Cantor set
| #Ruby | Ruby | lines = 5
(0..lines).each do |exp|
seg_size = 3**(lines-exp-1)
chars = (3**exp).times.map{ |n| n.digits(3).any?(1) ? " " : "█"}
puts chars.map{ |c| c * seg_size }.join
end
| Give a code snippet in #Ruby
Task
Draw a Cantor set.
See details at this Wikipedia webpage: Cantor set
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Call_a_foreign-language_function | Call a foreign-language function | Task
Show how a foreign language function can be called from the language.
As an example, consider calling functions defined in the C language. Create a string containing "Hello World!" of the string type typical to the language. Pass the string content to C's strdup. The content can be copied if necessary. Get the... | #Maxima | Maxima | /* Maxima is written in Lisp and can call Lisp functions.
Use load("funcs.lisp"), or inside Maxima: */
to_lisp();
> (defun $f (a b) (+ a b))
> (to-maxima)
f(5, 6);
11 | Give a code snippet in #Maxima
Task
Show how a foreign language function can be called from the language.
As an example, consider calling functions defined in the C language. Create a string containing "Hello World!" of the string type typical to the language. Pass the string content to C's strdup. The content can... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Tokenize_a_string | Tokenize a string | Separate the string "Hello,How,Are,You,Today" by commas into an array (or list) so that each element of it stores a different word.
Display the words to the 'user', in the simplest manner possible, separated by a period.
To simplify, you may display a trailing period.
Other tasks related to string operations:
Me... | #Objective-C | Objective-C | NSString *text = @"Hello,How,Are,You,Today";
NSArray *tokens = [text componentsSeparatedByString:@","];
NSString *result = [tokens componentsJoinedByString:@"."];
NSLog(result); | Give a code snippet in #Objective-C
Separate the string "Hello,How,Are,You,Today" by commas into an array (or list) so that each element of it stores a different word.
Display the words to the 'user', in the simplest manner possible, separated by a period.
To simplify, you may display a trailing period.
Other ta... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Formatted_numeric_output | Formatted numeric output | Task
Express a number in decimal as a fixed-length string with leading zeros.
For example, the number 7.125 could be expressed as 00007.125.
| #IS-BASIC | IS-BASIC | 100 LET F=7.125
110 PRINT USING "-%%%%%.###":F | Give a code snippet in #IS-BASIC
Task
Express a number in decimal as a fixed-length string with leading zeros.
For example, the number 7.125 could be expressed as 00007.125.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Sierpinski_pentagon | Sierpinski pentagon | Produce a graphical or ASCII-art representation of a Sierpinski pentagon (aka a Pentaflake) of order 5. Your code should also be able to correctly generate representations of lower orders: 1 to 4.
See also
Sierpinski pentagon
| #Raku | Raku | constant $sides = 5;
constant order = 5;
constant $dim = 250;
constant scaling-factor = ( 3 - 5**.5 ) / 2;
my @orders = ((1 - scaling-factor) * $dim) «*» scaling-factor «**» (^order);
my $fh = open('sierpinski_pentagon.svg', :w);
$fh.say: qq|<svg height="{$dim*2}" width="{$dim*2}" style="fill:blue" version="1.1"... | Give a code snippet in #Raku
Produce a graphical or ASCII-art representation of a Sierpinski pentagon (aka a Pentaflake) of order 5. Your code should also be able to correctly generate representations of lower orders: 1 to 4.
See also
Sierpinski pentagon
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Optional_parameters | Optional parameters | Task
Define a function/method/subroutine which sorts a sequence ("table") of sequences ("rows") of strings ("cells"), by one of the strings. Besides the input to be sorted, it shall have the following optional parameters:
ordering
A function specifying the ordering of strings; lexicographic by default.
column
... | #zkl | zkl | const lex="L";
fcn mystrySort(table,ordering=lex,column=0,reverse=False,other){
vm.arglist.println();
}
mystrySort.prototype.println();
mystrySort("table");
mystrySort("table",lex,1);
mystrySort("table",lex,1,True,D("row",35,"type","foobar"));
| Give a code snippet in #zkl
Task
Define a function/method/subroutine which sorts a sequence ("table") of sequences ("rows") of strings ("cells"), by one of the strings. Besides the input to be sorted, it shall have the following optional parameters:
ordering
A function specifying the ordering of strings; lexic... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Hello_world/Graphical | Hello world/Graphical |
Task
Display the string Goodbye, World! on a GUI object (alert box, plain window, text area, etc.).
Related task
Hello world/Text
| #R | R | library(RGtk2) # bindings to Gtk
w <- gtkWindowNew()
l <- gtkLabelNew("Goodbye, World!")
w$add(l) | Give a code snippet in #R
Task
Display the string Goodbye, World! on a GUI object (alert box, plain window, text area, etc.).
Related task
Hello world/Text
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Intersecting_number_wheels | Intersecting number wheels | A number wheel has:
A name which is an uppercase letter.
A set of ordered values which are either numbers or names.
A number is generated/yielded from a named wheel by:
1. Starting at the first value of the named wheel and advancing through subsequent values and wrapping around to the first value to form a "wheel"... | #AutoHotkey | AutoHotkey | obj1 := {"A":[1, 2, 3]}
obj2 := {"A":[1, "B", 2] , "B":[3, 4]}
obj3 := {"A":[1, "D", "D"] , "D":[6, 7, 8]}
obj4 := {"A":[1, "B", "C"] , "B":[3, 4] , "C":[5, "B"]}
loop 4
{
str := ""
for k, v in obj%A_Index% {
str .= "{" k " : "
for i, t in v
str .= t ","
str := Trim(str, ",") "}, "
}
str := Trim(str, ",... | Give a code snippet in #AutoHotkey
A number wheel has:
A name which is an uppercase letter.
A set of ordered values which are either numbers or names.
A number is generated/yielded from a named wheel by:
1. Starting at the first value of the named wheel and advancing through subsequent values and wrapping around ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Interactive_programming_(repl) | Interactive programming (repl) | Many language implementations come with an interactive mode.
This is a command-line interpreter that reads lines from the user and evaluates these lines as statements or expressions.
An interactive mode may also be known as a command mode, a read-eval-print loop (REPL), or a shell.
Task
Show how to start this... | #Lua | Lua | $ lua
Lua 5.1.2 Copyright (C) 1994-2007 Lua.org, PUC-Rio
> function conc(a, b, c)
>> return a..c..c..b
>> end
> print(conc("Rosetta", "Code", ":"))
Rosetta::Code
> | Give a code snippet in #Lua
Many language implementations come with an interactive mode.
This is a command-line interpreter that reads lines from the user and evaluates these lines as statements or expressions.
An interactive mode may also be known as a command mode, a read-eval-print loop (REPL), or a shell.
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Send_an_unknown_method_call | Send an unknown method call | Task
Invoke an object method where the name of the method to be invoked can be generated at run time.
Related tasks
Respond to an unknown method call.
Runtime evaluation
| #Racket | Racket |
#lang racket
(define greeter
(new (class object% (super-new)
(define/public (hello name)
(displayln (~a "Hello " name "."))))))
; normal method call
(send greeter hello "World")
; sending an unknown method
(define unknown 'hello)
(dynamic-send greeter unknown "World")
| Give a code snippet in #Racket
Task
Invoke an object method where the name of the method to be invoked can be generated at run time.
Related tasks
Respond to an unknown method call.
Runtime evaluation
| 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... | #AWK | AWK | # Usage: GAWK -f MAGIC_SQUARES_OF_DOUBLY_EVEN_ORDER.AWK
BEGIN {
n = 8
msquare[0, 0] = 0
if (magicsquaredoublyeven(msquare, n)) {
for (i = 0; i < n; i++) {
for (j = 0; j < n; j++) {
printf("%2d ", msquare[i, j])
}
printf("\n")
}
prin... | Give a code snippet in #AWK
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/Run-length_encoding | Run-length encoding | Run-length encoding
You are encouraged to solve this task according to the task description, using any language you may know.
Task
Given a string containing uppercase characters (A-Z), compress repeated 'runs' of the same character by storing the length of that run, and provide a function to reverse the compression... | #Elena | Elena | import system'text;
import system'routines;
import extensions;
import extensions'text;
singleton compressor
{
string compress(string s)
{
auto tb := new TextBuilder();
int count := 0;
char current := s[0];
s.forEach:(ch)
{
if (ch == current)
{
... | Give a code snippet in #Elena
Run-length encoding
You are encouraged to solve this task according to the task description, using any language you may know.
Task
Given a string containing uppercase characters (A-Z), compress repeated 'runs' of the same character by storing the length of that run, and provide a func... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Character_codes | Character codes |
Task
Given a character value in your language, print its code (could be ASCII code, Unicode code, or whatever your language uses).
Example
The character 'a' (lowercase letter A) has a code of 97 in ASCII (as well as Unicode, as ASCII forms the beginning of Unicode).
Conversely, given a code, print out... | #Wren | Wren | var cps = []
for (c in ["a", "π", "字", "🐘"]) {
var cp = c.codePoints[0]
cps.add(cp)
System.print("%(c) = %(cp)")
}
System.print()
for (i in cps) {
var c = String.fromCodePoint(i)
System.print("%(i) = %(c)")
} | Give a code snippet in #Wren
Task
Given a character value in your language, print its code (could be ASCII code, Unicode code, or whatever your language uses).
Example
The character 'a' (lowercase letter A) has a code of 97 in ASCII (as well as Unicode, as ASCII forms the beginning of Unicode).
Conve... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Discordian_date | Discordian date |
Task
Convert a given date from the Gregorian calendar to the Discordian calendar.
| #Icon_and_Unicon | Icon and Unicon | link printf
procedure main()
Demo(2010,1,1)
Demo(2010,7,22)
Demo(2012,2,28)
Demo(2012,2,29)
Demo(2012,3,1)
Demo(2010,1,5)
Demo(2011,5,3)
Demo(2012,2,28)
Demo(2012,2,29)
Demo(2012,3,1)
Demo(2010,7,22)
Demo(2012,12,22)
end
procedure Demo(y,m,d) #: demo display
printf("%i-%... | Give a code snippet in #Icon_and_Unicon
Task
Convert a given date from the Gregorian calendar to the Discordian calendar.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Undefined_values | Undefined values | #PureBasic | PureBasic | If OpenConsole()
CompilerIf Defined(var, #PB_Variable)
PrintN("var is defined at first check")
CompilerElse
PrintN("var is undefined at first check")
Define var
CompilerEndIf
CompilerIf Defined(var, #PB_Variable)
PrintN("var is defined at second check")
CompilerElse
PrintN("var is unde... | Give a code snippet in #PureBasic
| christopher/rosetta-code | ||
http://rosettacode.org/wiki/Break_OO_privacy | Break OO privacy | Show how to access private or protected members of a class in an object-oriented language from outside an instance of the class, without calling non-private or non-protected members of the class as a proxy.
The intent is to show how a debugger, serializer, or other meta-programming tool might access information that is... | #Julia | Julia | import kotlin.reflect.full.declaredMemberProperties
import kotlin.reflect.jvm.isAccessible
class ToBeBroken {
@Suppress("unused")
private val secret: Int = 42
}
fun main(args: Array<String>) {
val tbb = ToBeBroken()
val props = ToBeBroken::class.declaredMemberProperties
for (prop in props) {
... | Give a code snippet in #Julia
Show how to access private or protected members of a class in an object-oriented language from outside an instance of the class, without calling non-private or non-protected members of the class as a proxy.
The intent is to show how a debugger, serializer, or other meta-programming tool m... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Soundex | Soundex | Soundex is an algorithm for creating indices for words based on their pronunciation.
Task
The goal is for homophones to be encoded to the same representation so that they can be matched despite minor differences in spelling (from the soundex Wikipedia article).
Caution
There is a major issue in many of the ... | #REXX | REXX | /*REXX program demonstrates Soundex codes from some words or from the command line.*/
_=; @.= /*set a couple of vars to "null".*/
parse arg @.0 . /*allow input from command line. */
@.1 = "12346" ; ... | Give a code snippet in #REXX
Soundex is an algorithm for creating indices for words based on their pronunciation.
Task
The goal is for homophones to be encoded to the same representation so that they can be matched despite minor differences in spelling (from the soundex Wikipedia article).
Caution
There is... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Kernighans_large_earthquake_problem | Kernighans large earthquake problem | Brian Kernighan, in a lecture at the University of Nottingham, described a problem on which this task is based.
Problem
You are given a a data file of thousands of lines; each of three `whitespace` separated fields: a date, a one word name and the magnitude of the event.
Example lines from the file would be lines li... | #Factor | Factor | USING: io math math.parser prettyprint sequences splitting ;
IN: rosetta-code.kernighan
lines [ "\s" split last string>number 6 > ] filter . | Give a code snippet in #Factor
Brian Kernighan, in a lecture at the University of Nottingham, described a problem on which this task is based.
Problem
You are given a a data file of thousands of lines; each of three `whitespace` separated fields: a date, a one word name and the magnitude of the event.
Example lines... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Infinity | Infinity | Task
Write a function which tests if infinity is supported for floating point numbers (this step should be omitted for languages where the language specification already demands the existence of infinity, e.g. by demanding IEEE numbers), and if so, returns positive infinity. Otherwise, return the largest possible po... | #Trith | Trith |
: inf 1.0 0.0 / ;
: -inf inf neg ;
: inf? abs inf = ;
| Give a code snippet in #Trith
Task
Write a function which tests if infinity is supported for floating point numbers (this step should be omitted for languages where the language specification already demands the existence of infinity, e.g. by demanding IEEE numbers), and if so, returns positive infinity. Otherwise,... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Singly-linked_list/Element_definition | Singly-linked list/Element definition | singly-linked list
See also
Array
Associative array: Creation, Iteration
Collections
Compound data type
Doubly-linked list: Definition, Element definition, Element insertion, List Traversal, Element Removal
Linked list
Queue: Definition, Usage
Set
Singly-linked list: Element definition, Element insertion, Lis... | #Tcl | Tcl | oo::class create List {
variable content next
constructor {value {list ""}} {
set content $value
set next $list
}
method value args {
set content {*}$args
}
method attach {list} {
set next $list
}
method detach {} {
set next ""
}
method nex... | Give a code snippet in #Tcl
singly-linked list
See also
Array
Associative array: Creation, Iteration
Collections
Compound data type
Doubly-linked list: Definition, Element definition, Element insertion, List Traversal, Element Removal
Linked list
Queue: Definition, Usage
Set
Singly-linked list: Element defin... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Tokenize_a_string_with_escaping | Tokenize a string with escaping | Task[edit]
Write a function or program that can split a string at each non-escaped occurrence of a separator character.
It should accept three input parameters:
The string
The separator character
The escape character
It should output a list of strings.
Details
Rules for splitting:
The fields that were s... | #F.23 | F# | open System
open System.Text.RegularExpressions
(*
.NET regexes have unlimited look-behind, so we can look for separators
which are preceeded by an even number of (or no) escape characters
*)
let split esc sep s =
Regex.Split (
s,
String.Format("(?<=(?:\b|[^{0}])(?:{0}{0})*){1}", Regex.Esc... | Give a code snippet in #F.23
Task[edit]
Write a function or program that can split a string at each non-escaped occurrence of a separator character.
It should accept three input parameters:
The string
The separator character
The escape character
It should output a list of strings.
Details
Rules for split... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Variables | Variables | Task
Demonstrate a language's methods of:
variable declaration
initialization
assignment
datatypes
scope
referencing, and
other variable related facilities
| #MATLAB_.2F_Octave | MATLAB / Octave | a = 4; % declare variable and initialize double value,
s = 'abc'; % string
i8 = int8(5); % signed byte
u8 = uint8(5); % unsigned byte
i16 = int16(5); % signed 2 byte
u16 = uint16(5); % unsigned 2 byte integer
i32 = int32(5); % signed 4 byte integer
u32 = uin... | Give a code snippet in #MATLAB_.2F_Octave
Task
Demonstrate a language's methods of:
variable declaration
initialization
assignment
datatypes
scope
referencing, and
other variable related facilities
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Isqrt_(integer_square_root)_of_X | Isqrt (integer square root) of X | Sometimes a function is needed to find the integer square root of X, where X can be a
real non─negative number.
Often X is actually a non─negative integer.
For the purposes of this task, X can be an integer or a real number, but if it
simplifies things in your computer programming language, assume... | #Maxima | Maxima | /* -*- Maxima -*- */
/*
The Rosetta Code integer square root task, in Maxima.
I have not tried to make the output conform quite to the task
description, because Maxima is not a general purpose programming
language. Perhaps someone else will care to do it.
I *do* check that the Rosetta Code routine gives the sam... | Give a code snippet in #Maxima
Sometimes a function is needed to find the integer square root of X, where X can be a
real non─negative number.
Often X is actually a non─negative integer.
For the purposes of this task, X can be an integer or a real number, but if it
simplifies things in your compute... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Roman_numerals/Encode | Roman numerals/Encode | Task
Create a function taking a positive integer as its parameter and returning a string containing the Roman numeral representation of that integer. Modern Roman numerals are written by expressing each digit separately, starting with the left most digit and skipping any digit with a value of zero.
In Roman numeral... | #VBA | VBA | Private Function roman(n As Integer) As String
roman = WorksheetFunction.roman(n)
End Function
Public Sub main()
s = [{10, 2016, 800, 2769, 1666, 476, 1453}]
For Each x In s
Debug.Print roman(CInt(x)); " ";
Next x
End Sub | Give a code snippet in #VBA
Task
Create a function taking a positive integer as its parameter and returning a string containing the Roman numeral representation of that integer. Modern Roman numerals are written by expressing each digit separately, starting with the left most digit and skipping any digit with a value... | 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... | #CLU | CLU | valid_cusip = proc (s: string) returns (bool)
own chars: string := "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ*@#"
if string$size(s) ~= 9 then return(false) end
sum: int := 0
for i: int in int$from_to(1,8) do
v: int := string$indexc(s[i], chars)-1
if v<0 then return(false) end
if i//2=... | Give a code snippet in #CLU
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 c... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Higher-order_functions | Higher-order functions | Task
Pass a function as an argument to another function.
Related task
First-class functions
| #Trith | Trith | : twice 2 times ;
: hello "Hello, world!" print ;
[hello] twice | Give a code snippet in #Trith
Task
Pass a function as an argument to another function.
Related task
First-class functions
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Ulam_spiral_(for_primes) | Ulam spiral (for primes) | An Ulam spiral (of primes) is a method of visualizing primes when expressed in a (normally counter-clockwise) outward spiral (usually starting at 1), constructed on a square grid, starting at the "center".
An Ulam spiral is also known as a prime spiral.
The first grid (green) is shown with sequential integers, ... | #Yabasic | Yabasic | sub is_prime(n)
local p
for p=2 to n
if p*p>n break
if mod(n,p)=0 return false
next
return n>=2
end sub
sub spiral(w, h, x, y)
if y then
return w+spiral(h-1,w,y-1,w-x-1)
else
return x
end if
end sub
w = 9 : h = 9
for i=h-1 to 0 step -1
for j=w-1 to 0... | Give a code snippet in #Yabasic
An Ulam spiral (of primes) is a method of visualizing primes when expressed in a (normally counter-clockwise) outward spiral (usually starting at 1), constructed on a square grid, starting at the "center".
An Ulam spiral is also known as a prime spiral.
The first grid (green) is s... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sum_of_a_series | Sum of a series | Compute the nth term of a series, i.e. the sum of the n first terms of the corresponding sequence.
Informally this value, or its limit when n tends to infinity, is also called the sum of the series, thus the title of this task.
For this task, use:
S
n
=
∑
k
=
1
n
1
k
2
{\displa... | #.D0.9C.D0.9A-61.2F52 | МК-61/52 | 0 П0 П1 ИП1 1 + П1 x^2 1/x ИП0
+ П0 ИП1 1 0 0 0 - x>=0 03
ИП0 С/П | Give a code snippet in #.D0.9C.D0.9A-61.2F52
Compute the nth term of a series, i.e. the sum of the n first terms of the corresponding sequence.
Informally this value, or its limit when n tends to infinity, is also called the sum of the series, thus the title of this task.
For this task, use:
S
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Enforced_immutability | Enforced immutability | Task
Demonstrate any means your language has to prevent the modification of values, or to create objects that cannot be modified after they have been created.
| #Nemerle | Nemerle | def foo = 42; // immutable by default
mutable bar = "O'Malleys"; // mutable because you asked it to be | Give a code snippet in #Nemerle
Task
Demonstrate any means your language has to prevent the modification of values, or to create objects that cannot be modified after they have been created.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Permutations/Rank_of_a_permutation | Permutations/Rank of a permutation | A particular ranking of a permutation associates an integer with a particular ordering of all the permutations of a set of distinct items.
For our purposes the ranking will assign integers
0..
(
n
!
−
1
)
{\displaystyle 0..(n!-1)}
to an ordering of all the permutations of the integers
0..
(
n
−
1
)
{\disp... | #11l | 11l | UInt32 seed = 0
F nonrandom()
:seed = 1664525 * :seed + 1013904223
R (:seed >> 16) / Float(FF'FF)
F mrUnrank1(&vec, rank, n)
I n < 1 {R}
V (q, r) = divmod(rank, n)
swap(&vec[r], &vec[n - 1])
mrUnrank1(&vec, q, n - 1)
F mrRank1(&vec, &inv, n)
I n < 2 {R 0}
V s = vec[n - 1]
swap(&vec[n - 1]... | Give a code snippet in #11l
A particular ranking of a permutation associates an integer with a particular ordering of all the permutations of a set of distinct items.
For our purposes the ranking will assign integers
0..
(
n
!
−
1
)
{\displaystyle 0..(n!-1)}
to an ordering of all the permutations of the intege... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Include_a_file | Include a file | Task
Demonstrate the language's ability to include source code from other files.
See Also
Compiler/Simple file inclusion pre processor
| #Dragon | Dragon | func my(){
showln "hello"
//this is program.dgn
} | Give a code snippet in #Dragon
Task
Demonstrate the language's ability to include source code from other files.
See Also
Compiler/Simple file inclusion pre processor
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Iterated_digits_squaring | Iterated digits squaring | If you add the square of the digits of a Natural number (an integer bigger than zero), you always end with either 1 or 89:
15 -> 26 -> 40 -> 16 -> 37 -> 58 -> 89
7 -> 49 -> 97 -> 130 -> 10 -> 1
An example in Python:
>>> step = lambda x: sum(int(d) ** 2 for d in str(x))
>>> iterate = lambda x: x if x in [1, 89] else i... | #BQN | BQN | +´1↓1≠ ⊏˜⍟(⌈2⋆⁼≠) ⥊+⌜´6⥊<ט↕10
856929 | Give a code snippet in #BQN
If you add the square of the digits of a Natural number (an integer bigger than zero), you always end with either 1 or 89:
15 -> 26 -> 40 -> 16 -> 37 -> 58 -> 89
7 -> 49 -> 97 -> 130 -> 10 -> 1
An example in Python:
>>> step = lambda x: sum(int(d) ** 2 for d in str(x))
>>> iterate = lambd... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Show_the_epoch | Show the epoch | Task
Choose popular date libraries used by your language and show the epoch those libraries use.
A demonstration is preferable (e.g. setting the internal representation of the date to 0 ms/ns/etc., or another way that will still show the epoch even if it is changed behind the scenes by the implementers), b... | #PowerShell | PowerShell | [datetime] 0 | Give a code snippet in #PowerShell
Task
Choose popular date libraries used by your language and show the epoch those libraries use.
A demonstration is preferable (e.g. setting the internal representation of the date to 0 ms/ns/etc., or another way that will still show the epoch even if it is changed behind ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Permutations/Rank_of_a_permutation | Permutations/Rank of a permutation | A particular ranking of a permutation associates an integer with a particular ordering of all the permutations of a set of distinct items.
For our purposes the ranking will assign integers
0..
(
n
!
−
1
)
{\displaystyle 0..(n!-1)}
to an ordering of all the permutations of the integers
0..
(
n
−
1
)
{\disp... | #Scala | Scala | import scala.math._
def factorial(n: Int): BigInt = {
(1 to n).map(BigInt.apply).fold(BigInt(1))(_ * _)
}
def indexToPermutation(n: Int, x: BigInt): List[Int] = {
indexToPermutation((0 until n).toList, x)
}
def indexToPermutation(ns: List[Int], x: BigInt): List[Int] = ns match {
case Nil => Nil
case _ => ... | Give a code snippet in #Scala
A particular ranking of a permutation associates an integer with a particular ordering of all the permutations of a set of distinct items.
For our purposes the ranking will assign integers
0..
(
n
!
−
1
)
{\displaystyle 0..(n!-1)}
to an ordering of all the permutations of the inte... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Balanced_brackets | Balanced brackets | Task:
Generate a string with N opening brackets [ and with N closing brackets ], in some arbitrary order.
Determine whether the generated string is balanced; that is, whether it consists entirely of pairs of opening/closing brackets (in that order), none of which mis-nest.
Examples
(empty) ... | #Prolog | Prolog | rosetta_brackets :-
test_brackets([]),
test_brackets(['[',']']),
test_brackets(['[',']','[',']']),
test_brackets(['[','[',']','[',']',']']),
test_brackets([']','[']),
test_brackets([']','[',']','[']),
test_brackets(['[',']',']','[','[',']']).
balanced_brackets :-
gen_bracket(2, B1, []), test_brackets(B1),
g... | Give a code snippet in #Prolog
Task:
Generate a string with N opening brackets [ and with N closing brackets ], in some arbitrary order.
Determine whether the generated string is balanced; that is, whether it consists entirely of pairs of opening/closing brackets (in that order), none of which mis-... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Pinstripe/Display | Pinstripe/Display | Sample image
The task is to demonstrate the creation of a series of vertical pinstripes across the entire width of the display.
in the first quarter the pinstripes should alternate one pixel white, one pixel black = 1 pixel wide vertical pinestripes
Quarter of the way down the display, we can switch to a wider 2 pi... | #PicoLisp | PicoLisp | (let Pbm # Create PBM of 384 x 288 pixels
(make
(for N 4
(let
(C 0
L (make
(do (/ 384 N)
(do N (link C))
(setq C (x| 1 C)) ) ) )
(do 72 (link L)) ) ) )
(out '(display) # Pipe to ImageMagick
(p... | Give a code snippet in #PicoLisp
Sample image
The task is to demonstrate the creation of a series of vertical pinstripes across the entire width of the display.
in the first quarter the pinstripes should alternate one pixel white, one pixel black = 1 pixel wide vertical pinestripes
Quarter of the way down the disp... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Prime_conspiracy | Prime conspiracy | A recent discovery, quoted from Quantamagazine (March 13, 2016):
Two mathematicians have uncovered a simple, previously unnoticed property of
prime numbers — those numbers that are divisible only by 1 and themselves.
Prime numbers, it seems, have decided preferences about the final digits of ... | #Kotlin | Kotlin | // version 1.1.2
// compiled with flag -Xcoroutines=enable to suppress 'experimental' warning
import kotlin.coroutines.experimental.*
typealias Transition = Pair<Int, Int>
fun isPrime(n: Int) : Boolean {
if (n < 2) return false
if (n % 2 == 0) return n == 2
if (n % 3 == 0) return n == 3
var d : In... | Give a code snippet in #Kotlin
A recent discovery, quoted from Quantamagazine (March 13, 2016):
Two mathematicians have uncovered a simple, previously unnoticed property of
prime numbers — those numbers that are divisible only by 1 and themselves.
Prime numbers, it seems, have decided prefere... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Josephus_problem | Josephus problem | Josephus problem is a math puzzle with a grim description:
n
{\displaystyle n}
prisoners are standing on a circle, sequentially numbered from
0
{\displaystyle 0}
to
n
−
1
{\displaystyle n-1}
.
An executioner walks along the circle, starting from prisoner
0
{\displaystyle 0}
,
removing eve... | #Objeck | Objeck | class Josephus {
function : Execute(n : Int, k : Int) ~ Int {
killIdx := 0;
prisoners := Collection.IntVector->New();
for(i := 0;i < n;i+=1;){
prisoners->AddBack(i);
};
"Prisoners executed in order:"->PrintLine();
while(prisoners->Size() > 1){
killIdx := (killIdx + k - 1) % priso... | Give a code snippet in #Objeck
Josephus problem is a math puzzle with a grim description:
n
{\displaystyle n}
prisoners are standing on a circle, sequentially numbered from
0
{\displaystyle 0}
to
n
−
1
{\displaystyle n-1}
.
An executioner walks along the circle, starting from prisoner
0
{... | christopher/rosetta-code | |
http://rosettacode.org/wiki/String_length | String length | Task
Find the character and byte length of a string.
This means encodings like UTF-8 need to be handled properly, as there is not necessarily a one-to-one relationship between bytes and characters.
By character, we mean an individual Unicode code point, not a user-visible grapheme containing combining characters.
F... | #J | J | # 'møøse'
7 | Give a code snippet in #J
Task
Find the character and byte length of a string.
This means encodings like UTF-8 need to be handled properly, as there is not necessarily a one-to-one relationship between bytes and characters.
By character, we mean an individual Unicode code point, not a user-visible grapheme containi... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Singly-linked_list/Element_insertion | Singly-linked list/Element insertion | Singly-Linked List (element)
singly-linked list
Using this method, insert an element C into a list comprised of elements A->B, following element A.
See also
Array
Associative array: Creation, Iteration
Collections
Compound data type
Doubly-linked list: Definition, Element definition, Element insertion, List Trav... | #ACL2 | ACL2 | (defun insert-after (x e xs)
(cond ((endp xs)
nil)
((equal x (first xs))
(cons (first xs)
(cons e (rest xs))))
(t (cons (first xs)
(insert-after x e (rest xs)))))) | Give a code snippet in #ACL2
Singly-Linked List (element)
singly-linked list
Using this method, insert an element C into a list comprised of elements A->B, following element A.
See also
Array
Associative array: Creation, Iteration
Collections
Compound data type
Doubly-linked list: Definition, Element definition... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Pseudo-random_numbers/Xorshift_star | Pseudo-random numbers/Xorshift star | Some definitions to help in the explanation
Floor operation
https://en.wikipedia.org/wiki/Floor_and_ceiling_functions
Greatest integer less than or equal to a real number.
Bitwise Logical shift operators (c-inspired)
https://en.wikipedia.org/wiki/Bitwise_operation#Bit_shifts
Binary bits of value shifted left or ri... | #Perl | Perl | use strict;
use warnings;
no warnings 'portable';
use feature 'say';
use Math::AnyNum qw(:overload);
package Xorshift_star {
sub new {
my ($class, %opt) = @_;
bless {state => $opt{seed}}, $class;
}
sub next_int {
my ($self) = @_;
my $state = $self->{state};
$sta... | Give a code snippet in #Perl
Some definitions to help in the explanation
Floor operation
https://en.wikipedia.org/wiki/Floor_and_ceiling_functions
Greatest integer less than or equal to a real number.
Bitwise Logical shift operators (c-inspired)
https://en.wikipedia.org/wiki/Bitwise_operation#Bit_shifts
Binary bi... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Terminal_control/Ringing_the_terminal_bell | Terminal control/Ringing the terminal bell |
Task
Make the terminal running the program ring its "bell".
On modern terminal emulators, this may be done by playing some other sound which might or might not be configurable, or by flashing the title bar or inverting the colors of the screen, but was classically a physical bell within the terminal. It is usua... | #AWK | AWK | BEGIN {
print "\a" # Ring the bell
} | Give a code snippet in #AWK
Task
Make the terminal running the program ring its "bell".
On modern terminal emulators, this may be done by playing some other sound which might or might not be configurable, or by flashing the title bar or inverting the colors of the screen, but was classically a physical bell with... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Church_numerals | Church numerals | Task
In the Church encoding of natural numbers, the number N is encoded by a function that applies its first argument N times to its second argument.
Church zero always returns the identity function, regardless of its first argument. In other words, the first argument is not applied to the second argument at all.
C... | #Lua | Lua |
function churchZero()
return function(x) return x end
end
function churchSucc(c)
return function(f)
return function(x)
return f(c(f)(x))
end
end
end
function churchAdd(c, d)
return function(f)
return function(x)
return c(f)(d(f)(x))
end
end
end
function churchMul... | Give a code snippet in #Lua
Task
In the Church encoding of natural numbers, the number N is encoded by a function that applies its first argument N times to its second argument.
Church zero always returns the identity function, regardless of its first argument. In other words, the first argument is not applied to t... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Naming_conventions | Naming conventions | Many languages have naming conventions regarding the identifiers used in the language, its libraries, and programs written in the language. Such conventions, which may be classified as de facto or de jure depending on how they are enforced,
often take the form of rules regarding prefixes, suffixes, and the use of upper... | #Quackery | Quackery | #lang racket
render-game-state
send-message-to-client
traverse-forest | Give a code snippet in #Quackery
Many languages have naming conventions regarding the identifiers used in the language, its libraries, and programs written in the language. Such conventions, which may be classified as de facto or de jure depending on how they are enforced,
often take the form of rules regarding prefix... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Terminal_control/Ringing_the_terminal_bell | Terminal control/Ringing the terminal bell |
Task
Make the terminal running the program ring its "bell".
On modern terminal emulators, this may be done by playing some other sound which might or might not be configurable, or by flashing the title bar or inverting the colors of the screen, but was classically a physical bell within the terminal. It is usua... | #Asymptote | Asymptote | beep() | Give a code snippet in #Asymptote
Task
Make the terminal running the program ring its "bell".
On modern terminal emulators, this may be done by playing some other sound which might or might not be configurable, or by flashing the title bar or inverting the colors of the screen, but was classically a physical bel... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Isqrt_(integer_square_root)_of_X | Isqrt (integer square root) of X | Sometimes a function is needed to find the integer square root of X, where X can be a
real non─negative number.
Often X is actually a non─negative integer.
For the purposes of this task, X can be an integer or a real number, but if it
simplifies things in your computer programming language, assume... | #jq | jq | # For gojq
def idivide($j):
. as $i
| ($i % $j) as $mod
| ($i - $mod) / $j ;
# input should be non-negative
def isqrt:
. as $x
| 1 | until(. > $x; . * 4) as $q
| {$q, $x, r: 0}
| until( .q <= 1;
.q |= idivide(4)
| .t = .x - .r - .q
| .r |= idivide(2)
| if .t >... | Give a code snippet in #jq
Sometimes a function is needed to find the integer square root of X, where X can be a
real non─negative number.
Often X is actually a non─negative integer.
For the purposes of this task, X can be an integer or a real number, but if it
simplifies things in your computer pr... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Exponentiation_operator | Exponentiation operator | Most programming languages have a built-in implementation of exponentiation.
Task
Re-implement integer exponentiation for both intint and floatint as both a procedure, and an operator (if your language supports operator definition).
If the language supports operator (or procedure) overloading, then an ov... | #Java | Java | public class Exp{
public static void main(String[] args){
System.out.println(pow(2,30));
System.out.println(pow(2.0,30)); //tests
System.out.println(pow(2.0,-2));
}
public static double pow(double base, int exp){
if(exp < 0) return 1 / pow(base, -exp);
double ans = 1.0;
fo... | Give a code snippet in #Java
Most programming languages have a built-in implementation of exponentiation.
Task
Re-implement integer exponentiation for both intint and floatint as both a procedure, and an operator (if your language supports operator definition).
If the language supports operator (or proc... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Command-line_arguments | Command-line arguments | Command-line arguments is part of Short Circuit's Console Program Basics selection.
Scripted main
See also Program name.
For parsing command line arguments intelligently, see Parsing command-line arguments.
Example command line:
myprogram -c "alpha beta" -h "gamma"
| #Nim | Nim | import os
echo "program name: ", getAppFilename()
echo "Arguments:"
for arg in commandLineParams():
echo arg | Give a code snippet in #Nim
Command-line arguments is part of Short Circuit's Console Program Basics selection.
Scripted main
See also Program name.
For parsing command line arguments intelligently, see Parsing command-line arguments.
Example command line:
myprogram -c "alpha beta" -h "gamma"
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Doubly-linked_list/Definition | Doubly-linked list/Definition | Define the data structure for a complete Doubly Linked List.
The structure should support adding elements to the head, tail and middle of the list.
The structure should not allow circular loops
See also
Array
Associative array: Creation, Iteration
Collections
Compound data type
Doubly-linked list: Definitio... | #Go | Go | type dlNode struct {
int
next, prev *dlNode
}
// Field 'members' allows loops to be prevented. All nodes
// inserted should be added to members. Code that operates
// on the list can check any pointer against members to
// find out if the pointer is already in the list.
type dlList struct {
members map[... | Give a code snippet in #Go
Define the data structure for a complete Doubly Linked List.
The structure should support adding elements to the head, tail and middle of the list.
The structure should not allow circular loops
See also
Array
Associative array: Creation, Iteration
Collections
Compound data type
D... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Anti-primes | Anti-primes | The anti-primes
(or highly composite numbers, sequence A002182 in the OEIS)
are the natural numbers with more factors than any smaller than itself.
Task
Generate and show here, the first twenty anti-primes.
Related tasks
Factors of an integer
Sieve of Eratosthenes
| #XPL0 | XPL0 | int Counter, Num, Cnt, Div, Max;
[Counter:= 0;
Max:= 0;
Num:= 1;
loop [Cnt:= 0;
Div:= 1;
repeat if rem(Num/Div) = 0 then Cnt:= Cnt+1;
Div:= Div+1;
until Div > Num;
if Cnt > Max then
[IntOut(0, Num); ChOut(0, ^ );
Max:= Cnt;
... | Give a code snippet in #XPL0
The anti-primes
(or highly composite numbers, sequence A002182 in the OEIS)
are the natural numbers with more factors than any smaller than itself.
Task
Generate and show here, the first twenty anti-primes.
Related tasks
Factors of an integer
Sieve of Eratosthenes
| 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
≤... | #SSEM | SSEM | 10100000000000100000000000000000 0. -5 to c acc = -A
01100000000001010000000000000000 1. Sub. 6 acc -= B
11100000000001100000000000000000 2. c to 7 X = acc
11100000000000100000000000000000 3. -7 to c acc = -X
00000000000001110000000000000000 4. Stop
10100100000000000000000000000000 5. 37 ... | Give a code snippet in #SSEM
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/Fractran | Fractran | FRACTRAN is a Turing-complete esoteric programming language invented by the mathematician John Horton Conway.
A FRACTRAN program is an ordered list of positive fractions
P
=
(
f
1
,
f
2
,
…
,
f
m
)
{\displaystyle P=(f_{1},f_{2},\ldots ,f_{m})}
, together with an initial positive integer input
n
... | #zkl | zkl | var fracs="17/91, 78/85, 19/51, 23/38, 29/33, 77/29, 95/23, 77/19, 1/17,"
"11/13, 13/11, 15/14, 15/2, 55/1";
fcn fractranW(n,fracsAsOneBigString){ //-->Walker (iterator)
fracs:=(fracsAsOneBigString-" ").split(",").apply(
fcn(frac){ frac.split("/").apply("toInt") }); //( (n,d), (n,d), ...)
Walker(fcn(rn,fracs... | Give a code snippet in #zkl
FRACTRAN is a Turing-complete esoteric programming language invented by the mathematician John Horton Conway.
A FRACTRAN program is an ordered list of positive fractions
P
=
(
f
1
,
f
2
,
…
,
f
m
)
{\displaystyle P=(f_{1},f_{2},\ldots ,f_{m})}
, together with an initial ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Archimedean_spiral | Archimedean spiral |
The Archimedean spiral is a spiral named after the Greek mathematician Archimedes.
An Archimedean spiral can be described by the equation:
r
=
a
+
b
θ
{\displaystyle \,r=a+b\theta }
with real numbers a and b.
Task
Draw an Archimedean spiral.
| #Haskell | Haskell | #!/usr/bin/env stack
-- stack --resolver lts-7.0 --install-ghc runghc --package Rasterific --package JuicyPixels
import Codec.Picture( PixelRGBA8( .. ), writePng )
import Graphics.Rasterific
import Graphics.Rasterific.Texture
import Graphics.Rasterific.Transformations
archimedeanPoint a b t = V2 x y
where r = a +... | Give a code snippet in #Haskell
The Archimedean spiral is a spiral named after the Greek mathematician Archimedes.
An Archimedean spiral can be described by the equation:
r
=
a
+
b
θ
{\displaystyle \,r=a+b\theta }
with real numbers a and b.
Task
Draw an Archimedean spiral.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Write_language_name_in_3D_ASCII | Write language name in 3D ASCII | Task
Write/display a language's name in 3D ASCII.
(We can leave the definition of "3D ASCII" fuzzy,
so long as the result is interesting or amusing,
not a cheap hack to satisfy the task.)
Related tasks
draw a sphere
draw a cuboid
draw a rotating cube
draw a Deathstar
| #Raven | Raven | [
" ##### #### # # #### # #"
" # # # # # # # ## #"
" # # # # # # ### # # #"
" ##### ###### # # ### # # #"
" # # # # # # # # ##"
" # # # # # #### # #"
] as $str
"/" as $r1
">" as $r2
#$str each "%s\n" print
$str each... | Give a code snippet in #Raven
Task
Write/display a language's name in 3D ASCII.
(We can leave the definition of "3D ASCII" fuzzy,
so long as the result is interesting or amusing,
not a cheap hack to satisfy the task.)
Related tasks
draw a sphere
draw a cuboid
draw a rotating cube
draw a Deathstar
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Bitcoin/public_point_to_address | Bitcoin/public point to address | Bitcoin uses a specific encoding format to encode the digest of an elliptic curve public point into a short ASCII string. The purpose of this task is to perform such a conversion.
The encoding steps are:
take the X and Y coordinates of the given public point, and concatenate them in order to have a 64 byte-longed st... | #Raku | Raku | sub dgst(blob8 $b, Str :$dgst) returns blob8 {
given run «openssl dgst "-$dgst" -binary», :in, :out, :bin {
.in.write: $b;
.in.close;
return .out.slurp;
}
}
sub sha256($b) { dgst $b, :dgst<sha256> }
sub rmd160($b) { dgst $b, :dgst<rmd160> }
sub public_point_to_address( UInt $x, UInt $y ) {
my @byt... | Give a code snippet in #Raku
Bitcoin uses a specific encoding format to encode the digest of an elliptic curve public point into a short ASCII string. The purpose of this task is to perform such a conversion.
The encoding steps are:
take the X and Y coordinates of the given public point, and concatenate them in ord... | christopher/rosetta-code | |
http://rosettacode.org/wiki/File_size | File size | Verify the size of a file called input.txt for a file in the current working directory, and another one in the file system root.
| #BBC_BASIC | BBC BASIC | file% = OPENIN(@dir$+"input.txt")
IF file% THEN
PRINT "File size = " ; EXT#file%
CLOSE #file%
ENDIF
file% = OPENIN("\input.txt")
IF file% THEN
PRINT "File size = " ; EXT#file%
CLOSE #file%
ENDIF | Give a code snippet in #BBC_BASIC
Verify the size of a file called input.txt for a file in the current working directory, and another one in the file system root.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Arithmetic/Complex | Arithmetic/Complex | A complex number is a number which can be written as:
a
+
b
×
i
{\displaystyle a+b\times i}
(sometimes shown as:
b
+
a
×
i
{\displaystyle b+a\times i}
where
a
{\displaystyle a}
and
b
{\displaystyle b}
are real numbers, and
i
{\displaystyle i}
is √ -1
Typica... | #Pop11 | Pop11 | lvars a = 1.0 +: 1.0, b = 2.0 +: 5.0 ;
a+b =>
a*b =>
1/a =>
a-b =>
a-a =>
a/b =>
a/a =>
;;; The same, but using exact values
1 +: 1 -> a;
2 +: 5 -> b;
a+b =>
a*b =>
1/a =>
a-b =>
a-a =>
a/b =>
a/a => | Give a code snippet in #Pop11
A complex number is a number which can be written as:
a
+
b
×
i
{\displaystyle a+b\times i}
(sometimes shown as:
b
+
a
×
i
{\displaystyle b+a\times i}
where
a
{\displaystyle a}
and
b
{\displaystyle b}
are real numbers, and
i
{\displayst... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Identity_matrix | Identity matrix | Task
Build an identity matrix of a size known at run-time.
An identity matrix is a square matrix of size n × n,
where the diagonal elements are all 1s (ones),
and all the other elements are all 0s (zeroes).
I
n
=
[
1
0
0
⋯
0
0
1
0
⋯
0
0
0
1
⋯
0
⋮
⋮
⋮
⋱
... | #Smalltalk | Smalltalk | (Array2D identity: (UIManager default request: 'Enter size of the matrix:') asInteger) asString | Give a code snippet in #Smalltalk
Task
Build an identity matrix of a size known at run-time.
An identity matrix is a square matrix of size n × n,
where the diagonal elements are all 1s (ones),
and all the other elements are all 0s (zeroes).
I
n
=
[
1
0
0
⋯
0
0
1
0
⋯
0
0... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Dijkstra%27s_algorithm | Dijkstra's algorithm | This task has been clarified. Its programming examples are in need of review to ensure that they still fit the requirements of the task.
Dijkstra's algorithm, conceived by Dutch computer scientist Edsger Dijkstra in 1956 and published in 1959, is a graph search algorithm that solves the single-source shortest path pro... | #Pascal | Pascal | program dijkstra(output);
type
{ We dynamically build the list of vertices from the edge list,
just to avoid repeating ourselves in the graph input. Vertices are linked
together via their `next` pointers to form a list of all vertices (sorted by
name), while the `previous` pointer indicates the previous... | Give a code snippet in #Pascal
This task has been clarified. Its programming examples are in need of review to ensure that they still fit the requirements of the task.
Dijkstra's algorithm, conceived by Dutch computer scientist Edsger Dijkstra in 1956 and published in 1959, is a graph search algorithm that solves the... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Find_duplicate_files | Find duplicate files | In a large directory structure it is easy to inadvertently leave unnecessary copies of files around, which can use considerable disk space and create confusion.
Task
Create a program which, given a minimum size and a folder/directory, will find all files of at least size bytes with duplicate contents under the dire... | #Mathematica.2FWolfram_Language | Mathematica/Wolfram Language | hash="SHA256";
minSize=Quantity[1,"Megabytes"];
allfiles=Once@Select[FileNames["*","",∞],!Once@DirectoryQ[#]&&Once@FileSize[#]>minSize&];
data={#,Once[FileHash[#,hash,All,"HexString"]]}&/@allfiles[[;;5]];
Grid[Select[GatherBy[data,Last],Length[#]>1&][[All,All,1]]] | Give a code snippet in #Mathematica.2FWolfram_Language
In a large directory structure it is easy to inadvertently leave unnecessary copies of files around, which can use considerable disk space and create confusion.
Task
Create a program which, given a minimum size and a folder/directory, will find all files of at... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Gaussian_elimination | Gaussian elimination | Task
Solve Ax=b using Gaussian elimination then backwards substitution.
A being an n by n matrix.
Also, x and b are n by 1 vectors.
To improve accuracy, please use partial pivoting and scaling.
See also
the Wikipedia entry: Gaussian elimination
| #Tcl | Tcl | package require math::linearalgebra
set A {
{1.00 0.00 0.00 0.00 0.00 0.00}
{1.00 0.63 0.39 0.25 0.16 0.10}
{1.00 1.26 1.58 1.98 2.49 3.13}
{1.00 1.88 3.55 6.70 12.62 23.80}
{1.00 2.51 6.32 15.88 39.90 100.28}
{1.00 3.14 9.87 31.01 97.41 306.02}
}
set b {-0.01 0.61 0.... | Give a code snippet in #Tcl
Task
Solve Ax=b using Gaussian elimination then backwards substitution.
A being an n by n matrix.
Also, x and b are n by 1 vectors.
To improve accuracy, please use partial pivoting and scaling.
See also
the Wikipedia entry: Gaussian elimination
| christopher/rosetta-code | |
http://rosettacode.org/wiki/System_time | System time | Task
Output the system time (any units will do as long as they are noted) either by a system command or one built into the language.
The system time can be used for debugging, network information, random number seeds, or something as simple as program performance.
Related task
Date format
See also
Retr... | #Forth | Forth | [UNDEFINED] MS@ [IF] \ Win32Forth (rolls over daily)
[DEFINED] ?MS [IF] ( -- ms )
: ms@ ?MS ; \ iForth
[ELSE] [DEFINED] cputime [IF] ( -- Dusec )
: ms@ cputime d+ 1000 um/mod nip ; \ gforth: Anton Ertl
[ELSE] [DEFINED] t... | Give a code snippet in #Forth
Task
Output the system time (any units will do as long as they are noted) either by a system command or one built into the language.
The system time can be used for debugging, network information, random number seeds, or something as simple as program performance.
Related task
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/String_append | String append |
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 |... | #Vlang | Vlang | mut s:= 'foo'
s += 'bar'
println(s)
foo := 'foo'
bar := 'bar'
foobar := '$foo$bar'
println(foobar) | Give a code snippet in #Vlang
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
... | 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... | #Lua | Lua | local socket = require("socket")
local function has_value(tab, value)
for i, v in ipairs(tab) do
if v == value then return i end
end
return false
end
local function checkOn(client)
local line, err = client:receive()
if line then
client:send(line .. "\n")
end
if err and err ~= "timeout" t... | Give a code snippet in #Lua
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 s... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Perfect_totient_numbers | Perfect totient numbers | Generate and show here, the first twenty Perfect totient numbers.
Related task
Totient function
Also see
the OEIS entry for perfect totient numbers.
mrob list of the first 54
| #Nim | Nim | import strformat
func totient(n: int): int =
var tot = n
var nn = n
var i = 2
while i * i <= nn:
if nn mod i == 0:
while nn mod i == 0:
nn = nn div i
dec tot, tot div i
if i == 2:
i = 1
inc i, 2
if nn > 1:
dec tot, tot div nn
tot
var n = 1
var num = 0
echo "The ... | Give a code snippet in #Nim
Generate and show here, the first twenty Perfect totient numbers.
Related task
Totient function
Also see
the OEIS entry for perfect totient numbers.
mrob list of the first 54
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Search_a_list | Search a list | Task[edit]
Find the index of a string (needle) in an indexable, ordered collection of strings (haystack).
Raise an exception if the needle is missing.
If there is more than one occurrence then return the smallest index to the needle.
Extra credit
Return the largest index to a needle that has multiple occurrences in ... | #Euphoria | Euphoria |
include std/search.e
include std/console.e
--the string "needle" and example haystacks to test the procedure
sequence searchStr1 = "needle"
sequence haystack1 = { "needle", "needle", "noodle", "node", "need", "needle ", "needle" }
sequence haystack2 = {"spoon", "fork", "hay", "knife", "needle", "barn", "etcetera",... | Give a code snippet in #Euphoria
Task[edit]
Find the index of a string (needle) in an indexable, ordered collection of strings (haystack).
Raise an exception if the needle is missing.
If there is more than one occurrence then return the smallest index to the needle.
Extra credit
Return the largest index to a needle... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Chaos_game | Chaos game | The Chaos Game is a method of generating the attractor of an iterated function system (IFS).
One of the best-known and simplest examples creates a fractal, using a polygon and an initial point selected at random.
Task
Play the Chaos Game using the corners of an equilateral triangle as the reference points. Add a ... | #Kotlin | Kotlin | //Version 1.1.51
import java.awt.*
import java.util.Stack
import java.util.Random
import javax.swing.JPanel
import javax.swing.JFrame
import javax.swing.Timer
import javax.swing.SwingUtilities
class ChaosGame : JPanel() {
class ColoredPoint(x: Int, y: Int, val colorIndex: Int) : Point(x, y)
val stack = ... | Give a code snippet in #Kotlin
The Chaos Game is a method of generating the attractor of an iterated function system (IFS).
One of the best-known and simplest examples creates a fractal, using a polygon and an initial point selected at random.
Task
Play the Chaos Game using the corners of an equilateral triangle a... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Command-line_arguments | Command-line arguments | Command-line arguments is part of Short Circuit's Console Program Basics selection.
Scripted main
See also Program name.
For parsing command line arguments intelligently, see Parsing command-line arguments.
Example command line:
myprogram -c "alpha beta" -h "gamma"
| #Scala | Scala | object CommandLineArguments extends App {
println(s"Received the following arguments: + ${args.mkString("", ", ", ".")}")
} | Give a code snippet in #Scala
Command-line arguments is part of Short Circuit's Console Program Basics selection.
Scripted main
See also Program name.
For parsing command line arguments intelligently, see Parsing command-line arguments.
Example command line:
myprogram -c "alpha beta" -h "gamma"
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Draw_a_cuboid | Draw a cuboid | Task
Draw a cuboid with relative dimensions of 2 × 3 × 4.
The cuboid can be represented graphically, or in ASCII art, depending on the language capabilities.
To fulfill the criteria of being a cuboid, three faces must be visible.
Either static or rotational projection is acceptable for this task.
R... | #ZX_Spectrum_Basic | ZX Spectrum Basic | 10 LET width=50: LET height=width*1.5: LET depth=width*2
20 LET x=80: LET y=10
30 PLOT x,y
40 DRAW 0,height: DRAW width,0: DRAW 0,-height: DRAW -width,0: REM Front
50 PLOT x,y+height: DRAW depth/2,height: DRAW width,0: DRAW 0,-height: DRAW -width,-height
60 PLOT x+width,y+height: DRAW depth/2,height | Give a code snippet in #ZX_Spectrum_Basic
Task
Draw a cuboid with relative dimensions of 2 × 3 × 4.
The cuboid can be represented graphically, or in ASCII art, depending on the language capabilities.
To fulfill the criteria of being a cuboid, three faces must be visible.
Either static or rotational p... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Guess_the_number/With_feedback | Guess the number/With feedback | Task
Write a game (computer program) that follows the following rules:
The computer chooses a number between given set limits.
The player is asked for repeated guesses until the the target number is guessed correctly
At each guess, the computer responds with whether the guess is:
higher than the target,
equal to... | #Maple | Maple | GuessANumber := proc(low, high)
local number, input;
randomize():
printf( "Guess a number between %d and %d:\n:> ", low, high );
number := rand(low..high)();
do
input := parse(readline());
if input > number then
printf("Too high, try again!\n:> ");
elif input < nu... | Give a code snippet in #Maple
Task
Write a game (computer program) that follows the following rules:
The computer chooses a number between given set limits.
The player is asked for repeated guesses until the the target number is guessed correctly
At each guess, the computer responds with whether the guess is:
hi... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Averages/Pythagorean_means | Averages/Pythagorean means | Task[edit]
Compute all three of the Pythagorean means of the set of integers 1 through 10 (inclusive).
Show that
A
(
x
1
,
…
,
x
n
)
≥
G
(
x
1
,
…
,
x
n
)
≥
H
(
x
1
,
…
,
x
n
)
{\displaystyle A(x_{1},\ldots ,x_{n})\geq G(x_{1},\ldots ,x_{n})\geq H(x_{1},\ldots ,x_{n})}
for this set of p... | #Vlang | Vlang | import math
fn main() {
mut sum := 0.0
mut prod :=1.0
mut recip_sum := 0.0
n := 10
for val in 1..(n + 1) {
sum += val
prod *= val
recip_sum = recip_sum + ( 1.0 / val )
}
a := sum / n
g := math.pow( prod, ( 1.0 / f32(n) ) )
h := n / recip_sum
result... | Give a code snippet in #Vlang
Task[edit]
Compute all three of the Pythagorean means of the set of integers 1 through 10 (inclusive).
Show that
A
(
x
1
,
…
,
x
n
)
≥
G
(
x
1
,
…
,
x
n
)
≥
H
(
x
1
,
…
,
x
n
)
{\displaystyle A(x_{1},\ldots ,x_{n})\geq G(x_{1},\ldots ,x_{n})\geq H(x_{1},\ldo... | 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... | #UNIX_Shell | UNIX Shell | # assign an empty string to a variable
s=""
# the "test" command can determine truth by examining the string itself
if [ "$s" ]; then echo "not empty"; else echo "empty"; fi
# compare the string to the empty string
if [ "$s" = "" ]; then echo "s is the empty string"; fi
if [ "$s" != "" ]; then echo "s is not empty"... | Give a code snippet in #UNIX_Shell
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.
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Emirp_primes | Emirp primes | An emirp (prime spelled backwards) are primes that when reversed (in their decimal representation) are a different prime.
(This rules out palindromic primes.)
Task
show the first twenty emirps
show all emirps between 7,700 and 8,000
show the 10,000th emirp
In each list, the numbe... | #Fortran | Fortran | MODULE BAG !A mixed assortment.
INTEGER MSG !I/O unit number to share about.
INTEGER PF16LIMIT,PF32LIMIT,NP !Know that P(3512) = 32749, the last within two's complement 16-bit integers.
PARAMETER (PF16LIMIT = 3512, PF32LIMIT = 4793) !32749² = 1,072,497,001; the integer limit is 2,147,483,64... | Give a code snippet in #Fortran
An emirp (prime spelled backwards) are primes that when reversed (in their decimal representation) are a different prime.
(This rules out palindromic primes.)
Task
show the first twenty emirps
show all emirps between 7,700 and 8,000
show the 10,000th ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Element-wise_operations | Element-wise operations | This task is similar to:
Matrix multiplication
Matrix transposition
Task
Implement basic element-wise matrix-matrix and scalar-matrix operations, which can be referred to in other, higher-order tasks.
Implement:
addition
subtraction
multiplication
division
exponentiation
Extend the task if ... | #Nim | Nim | import math, strutils
type Matrix[height, width: static Positive; T: SomeNumber] = array[height, array[width, T]]
####################################################################################################
proc `$`(m: Matrix): string =
for i, row in m:
var line = "["
for j, val in row:
li... | Give a code snippet in #Nim
This task is similar to:
Matrix multiplication
Matrix transposition
Task
Implement basic element-wise matrix-matrix and scalar-matrix operations, which can be referred to in other, higher-order tasks.
Implement:
addition
subtraction
multiplication
division
exponen... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Modular_inverse | Modular inverse | From Wikipedia:
In modular arithmetic, the modular multiplicative inverse of an integer a modulo m is an integer x such that
a
x
≡
1
(
mod
m
)
.
{\displaystyle a\,x\equiv 1{\pmod {m}}.}
Or in other words, such that:
∃
k
∈
Z
,
a
x
=
1
+
k
m
{\displaystyle \exists k\in \math... | #AutoHotkey | AutoHotkey | MsgBox, % ModInv(42, 2017)
ModInv(a, b) {
if (b = 1)
return 1
b0 := b, x0 := 0, x1 :=1
while (a > 1) {
q := a // b
, t := b
, b := Mod(a, b)
, a := t
, t := x0
, x0 := x1 - q * x0
, x1 := t
}
if (x1 < 0)
x1 += b0
return x1
} | Give a code snippet in #AutoHotkey
From Wikipedia:
In modular arithmetic, the modular multiplicative inverse of an integer a modulo m is an integer x such that
a
x
≡
1
(
mod
m
)
.
{\displaystyle a\,x\equiv 1{\pmod {m}}.}
Or in other words, such that:
∃
k
∈
Z
,
a
x
=
1
+
k
m... | christopher/rosetta-code | |
http://rosettacode.org/wiki/User_input/Graphical | User input/Graphical |
In this task, the goal is to input a string and the integer 75000, from graphical user interface.
See also: User input/Text
| #Kotlin | Kotlin | // version 1.1
import javax.swing.JOptionPane
fun main(args: Array<String>) {
do {
val number = JOptionPane.showInputDialog("Enter 75000").toInt()
} while (number != 75000)
} | Give a code snippet in #Kotlin
In this task, the goal is to input a string and the integer 75000, from graphical user interface.
See also: User input/Text
| christopher/rosetta-code |
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