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/Repeat | Repeat | Task
Write a procedure which accepts as arguments another procedure and a positive integer.
The latter procedure is executed a number of times equal to the accepted integer.
| #OCaml | OCaml | let repeat ~f ~n =
for i = 1 to n do
f ()
done
let func () =
print_endline "Example"
let () =
repeat ~n:4 ~f:func
| Give a code snippet in #OCaml
Task
Write a procedure which accepts as arguments another procedure and a positive integer.
The latter procedure is executed a number of times equal to the accepted integer.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Case-sensitivity_of_identifiers | Case-sensitivity of identifiers | Three dogs (Are there three dogs or one dog?) is a code snippet used to illustrate the lettercase sensitivity of the programming language. For a case-sensitive language, the identifiers dog, Dog and DOG are all different and we should get the output:
The three dogs are named Benjamin, Samba and Bernie.
For a language... | #Tcl | Tcl | set dog "Benjamin"
set Dog "Samba"
set DOG "Bernie"
puts "The three dogs are named $dog, $Dog and $DOG" | Give a code snippet in #Tcl
Three dogs (Are there three dogs or one dog?) is a code snippet used to illustrate the lettercase sensitivity of the programming language. For a case-sensitive language, the identifiers dog, Dog and DOG are all different and we should get the output:
The three dogs are named Benjamin, Samb... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Magic_8-ball | Magic 8-ball | Task
Create Magic 8-Ball.
See details at: Magic 8-Ball.
Other tasks related to string operations:
Metrics
Array length
String length
Copy a string
Empty string (assignment)
Counting
Word frequency
Letter frequency
Jewels and stones
I before E except after C
Bioinformatics/base count
Count occurren... | #PureBasic | PureBasic | Define.s Magic8="● It is certain."+#LF$+
"● It is decidedly so."+#LF$+
"● Without a doubt."+#LF$+
"● Yes – definitely."+#LF$+
"● You may rely on it."+#LF$+
"● As I see it, yes."+#LF$+
"● Most likely."+#LF$+
"... | Give a code snippet in #PureBasic
Task
Create Magic 8-Ball.
See details at: Magic 8-Ball.
Other tasks related to string operations:
Metrics
Array length
String length
Copy a string
Empty string (assignment)
Counting
Word frequency
Letter frequency
Jewels and stones
I before E except after C
Bioinf... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Inverted_syntax | Inverted syntax | Inverted syntax with conditional expressions
In traditional syntax conditional expressions are usually shown before the action within a statement or code block:
IF raining=true THEN needumbrella=true
In inverted syntax, the action is listed before the conditional expression in the statement or code block:
needumb... | #Raku | Raku | if $guess == 6 { say "Wow! Lucky Guess!" } # Traditional
say 'Wow! Lucky Guess!' if $guess == 6; # Inverted
unless $guess == 6 { say "Huh! You Guessed Rong!" } # Traditional
say 'Huh! You Guessed Rong!' unless $guess == 6; # Inverted | Give a code snippet in #Raku
Inverted syntax with conditional expressions
In traditional syntax conditional expressions are usually shown before the action within a statement or code block:
IF raining=true THEN needumbrella=true
In inverted syntax, the action is listed before the conditional expression in the stat... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Man_or_boy_test | Man or boy test | Man or boy test
You are encouraged to solve this task according to the task description, using any language you may know.
Background: The man or boy test was proposed by computer scientist Donald Knuth as a means of evaluating implementations of the ALGOL 60 programming language. The aim of the test was to distinguis... | #Aime | Aime | integer
F(list l)
{
l[1];
}
integer
eval(list l)
{
l[0](l);
}
integer A(list);
integer
B(list l)
{
A(list(B, l[1] = l[1] - 1, l, l[-5], l[-4], l[-3], l[-2]));
}
integer
A(list l)
{
integer x;
if (l[1] < 1) {
x = eval(l[-2]) + eval(l[-1]);
} else {
x = B(l);
}
... | Give a code snippet in #Aime
Man or boy test
You are encouraged to solve this task according to the task description, using any language you may know.
Background: The man or boy test was proposed by computer scientist Donald Knuth as a means of evaluating implementations of the ALGOL 60 programming language. The aim... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Happy_numbers | Happy numbers | From Wikipedia, the free encyclopedia:
A happy number is defined by the following process:
Starting with any positive integer, replace the number by the sum of the squares of its digits, and repeat the process until the number equals 1 (where it will stay), or it loops endlessly in a cycle which does not inclu... | #VBScript | VBScript |
count = 0
firsteigth=""
For i = 1 To 100
If IsHappy(CInt(i)) Then
firsteight = firsteight & i & ","
count = count + 1
End If
If count = 8 Then
Exit For
End If
Next
WScript.Echo firsteight
Function IsHappy(n)
IsHappy = False
m = 0
Do Until m = 60
sum = 0
For j = 1 To Len(n)
sum = sum + (Mid(n,j,1... | Give a code snippet in #VBScript
From Wikipedia, the free encyclopedia:
A happy number is defined by the following process:
Starting with any positive integer, replace the number by the sum of the squares of its digits, and repeat the process until the number equals 1 (where it will stay), or it loops endless... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Happy_numbers | Happy numbers | From Wikipedia, the free encyclopedia:
A happy number is defined by the following process:
Starting with any positive integer, replace the number by the sum of the squares of its digits, and repeat the process until the number equals 1 (where it will stay), or it loops endlessly in a cycle which does not inclu... | #Nim | Nim | import intsets
proc happy(n: int): bool =
var
n = n
past = initIntSet()
while n != 1:
let s = $n
n = 0
for c in s:
let i = ord(c) - ord('0')
n += i * i
if n in past:
return false
past.incl(n)
return true
for x in 0..31:
if happy(x):
echo x | Give a code snippet in #Nim
From Wikipedia, the free encyclopedia:
A happy number is defined by the following process:
Starting with any positive integer, replace the number by the sum of the squares of its digits, and repeat the process until the number equals 1 (where it will stay), or it loops endlessly in... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sum_of_squares | Sum of squares | Task
Write a program to find the sum of squares of a numeric vector.
The program should work on a zero-length vector (with an answer of 0).
Related task
Mean
| #360_Assembly | 360 Assembly | * Sum of squares 27/08/2015
SUMOFSQR CSECT
USING SUMOFSQR,R12
LR R12,R15
LA R7,A a(1)
SR R6,R6 sum=0
LA R3,1 i=1
LOOPI CH R3,N do i=1 to hbound(a)
BH ELOOPI
... | Give a code snippet in #360_Assembly
Task
Write a program to find the sum of squares of a numeric vector.
The program should work on a zero-length vector (with an answer of 0).
Related task
Mean
| 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
| #GML | GML | show_message("Goodbye, World!") | Give a code snippet in #GML
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/Standar... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Magic_squares_of_odd_order | Magic squares of odd order | A magic square is an NxN square matrix whose numbers (usually integers) consist of consecutive numbers arranged so that the sum of each row and column, and both long (main) diagonals are equal to the same sum (which is called the magic number or magic constant).
The numbers are usually (but not always) t... | #Cowgol | Cowgol | include "cowgol.coh";
sub magic(n: uint16) is
sub f(x: uint16, y: uint16): (r: uint16) is
r := (x + y*2 + 1) % n;
end sub;
sub cell(x: uint16, y: uint16): (c: uint16) is
c := f(n-x-1, y)*n + f(x, y) + 1;
end sub;
var y: uint16 := 0;
while y < n loop
var x: uint16 :=... | Give a code snippet in #Cowgol
A magic square is an NxN square matrix whose numbers (usually integers) consist of consecutive numbers arranged so that the sum of each row and column, and both long (main) diagonals are equal to the same sum (which is called the magic number or magic constant).
The number... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Arithmetic-geometric_mean/Calculate_Pi | Arithmetic-geometric mean/Calculate Pi | Almkvist Berndt 1988 begins with an investigation of why the agm is such an efficient algorithm, and proves that it converges quadratically. This is an efficient method to calculate
π
{\displaystyle \pi }
.
With the same notations used in Arithmetic-geometric mean, we can summarize the paper by writing:
π
... | #Wren | Wren | import "/big" for BigRat
var digits = 500
var an = BigRat.one
var bn = BigRat.half.sqrt(digits)
var tn = BigRat.half.square
var pn = BigRat.one
while (pn <= digits) {
var prevAn = an
an = (bn + an) * BigRat.half
bn = (bn * prevAn).sqrt(digits)
prevAn = prevAn - an
tn = tn - (prevAn.square * pn)
... | Give a code snippet in #Wren
Almkvist Berndt 1988 begins with an investigation of why the agm is such an efficient algorithm, and proves that it converges quadratically. This is an efficient method to calculate
π
{\displaystyle \pi }
.
With the same notations used in Arithmetic-geometric mean, we can summarize... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Strassen%27s_algorithm | Strassen's algorithm | Description
In linear algebra, the Strassen algorithm (named after Volker Strassen), is an algorithm for matrix multiplication.
It is faster than the standard matrix multiplication algorithm and is useful in practice for large matrices, but would be slower than the fastest known algorithms for extremely large ma... | #Swift | Swift |
// Matrix Strassen Multiplication
func strassenMultiply(matrix1: Matrix, matrix2: Matrix) -> Matrix {
precondition(matrix1.columns == matrix2.columns,
"Two matrices can only be matrix multiplied if one has dimensions mxn & the other has dimensions nxp where m, n, p are in R")
// Transform to sq... | Give a code snippet in #Swift
Description
In linear algebra, the Strassen algorithm (named after Volker Strassen), is an algorithm for matrix multiplication.
It is faster than the standard matrix multiplication algorithm and is useful in practice for large matrices, but would be slower than the fastest known al... | 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... | #TUSCRIPT | TUSCRIPT |
$$ MODE TUSCRIPT
numbers=RANDOM_NUMBERS (1,9,9),nr=0
SECTION check
LOOP o,n=numbers
IF (n!=o) THEN
DO PRINT
EXIT
ELSEIF (n==9&&o==9) THEN
DO PRINT
PRINT " You made it ... in round ",r
STOP
ELSE
CYCLE
ENDIF
ENDLOOP
ENDSECTION
SECTION print
PRINT numbers
ENDSECTION
DO PRINT
LOOP r=1,14
IF (nr>... | Give a code snippet in #TUSCRIPT
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... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Draw_a_pixel | Draw a pixel | Task
Create a window and draw a pixel in it, subject to the following:
the window is 320 x 240
the color of the pixel must be red (255,0,0)
the position of the pixel is x = 100, y = 100 | #Delphi | Delphi |
program Draw_a_pixel;
{$APPTYPE CONSOLE}
{$R *.res}
uses
Windows,
Messages,
SysUtils;
var
Msg: TMSG;
LWndClass: TWndClass;
hMainHandle: HWND;
procedure Paint(Handle: hWnd); forward;
procedure ReleaseResources;
begin
PostQuitMessage(0);
end;
function WindowProc(hWnd, Msg: Longint; wParam: w... | Give a code snippet in #Delphi
Task
Create a window and draw a pixel in it, subject to the following:
the window is 320 x 240
the color of the pixel must be red (255,0,0)
the position of the pixel is x = 100, y = 100 | christopher/rosetta-code | |
http://rosettacode.org/wiki/Read_a_file_line_by_line | Read a file line by line | Read a file one line at a time,
as opposed to reading the entire file at once.
Related tasks
Read a file character by character
Input loop.
| #Draco | Draco | \util.g
proc nonrec main() void:
/* first we need to declare a file buffer and an input channel */
file() infile;
channel input text in_ch;
/* a buffer to store the line in is also handy */
[256] char line;
word counter; /* to count the lines */
/* open the file, and exit if it fails */... | Give a code snippet in #Draco
Read a file one line at a time,
as opposed to reading the entire file at once.
Related tasks
Read a file character by character
Input loop.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Yahoo!_search_interface | Yahoo! search interface | Create a class for searching Yahoo! results.
It must implement a Next Page method, and read URL, Title and Content from results.
| #AArch64_Assembly | AArch64 Assembly |
/* ARM assembly AARCH64 Raspberry PI 3B */
/* program yahoosearch64.s */
/* access RosettaCode.org and data extract */
/* use openssl for access to port 443 */
/* test openssl : package libssl-dev */
/*******************************************/
/* Constantes file */
/************... | Give a code snippet in #AArch64_Assembly
Create a class for searching Yahoo! results.
It must implement a Next Page method, and read URL, Title and Content from results.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Map_range | Map range | Given two ranges:
[
a
1
,
a
2
]
{\displaystyle [a_{1},a_{2}]}
and
[
b
1
,
b
2
]
{\displaystyle [b_{1},b_{2}]}
;
then a value
s
{\displaystyle s}
in range
[
a
1
,
a
2
]
{\displaystyle [a_{1},a_{2}]}
is linearly mapped to a value
t
{\di... | #Ursala | Ursala | #import flo
f((("a1","a2"),("b1","b2")),"s") = plus("b1",div(minus("s","a1"),minus("a2","a1")))
#cast %eL
test = f* ((0.,10.),(-1.,0.))-* ari11/0. 10. | Give a code snippet in #Ursala
Given two ranges:
[
a
1
,
a
2
]
{\displaystyle [a_{1},a_{2}]}
and
[
b
1
,
b
2
]
{\displaystyle [b_{1},b_{2}]}
;
then a value
s
{\displaystyle s}
in range
[
a
1
,
a
2
]
{\displaystyle [a_{1},a_{2}]}
is linearly ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/RIPEMD-160 | RIPEMD-160 | RIPEMD-160 is another hash function; it computes a 160-bit message digest.
There is a RIPEMD-160 home page, with test vectors and pseudocode for RIPEMD-160.
For padding the message, RIPEMD-160 acts like MD4 (RFC 1320).
Find the RIPEMD-160 message digest of a string of octets.
Use the ASCII encoded string “Rosetta Cod... | #PicoLisp | PicoLisp | (de *R160-R1 . (1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
8 5 14 2 11 7 16 4 13 1 10 6 3 15 12 9
4 11 15 5 10 16 9 2 3 8 1 7 14 12 6 13
2 10 12 11 1 9 13 5 14 4 8 16 15 6 7 3
5 1 6 10 8 13 3 11 15 2 4 9 12 7 16 14 .))
(de *R160-R2 . (6 15 8 1 10 3 12 5 14 7 16 9 ... | Give a code snippet in #PicoLisp
RIPEMD-160 is another hash function; it computes a 160-bit message digest.
There is a RIPEMD-160 home page, with test vectors and pseudocode for RIPEMD-160.
For padding the message, RIPEMD-160 acts like MD4 (RFC 1320).
Find the RIPEMD-160 message digest of a string of octets.
Use the... | 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
... | #PHP | PHP | function cocktailSort($arr){
if (is_string($arr)) $arr = str_split(preg_replace('/\s+/','',$arr));
do{
$swapped = false;
for($i=0;$i<count($arr);$i++){
if(isset($arr[$i+1])){
if($arr[$i] > $arr[$i+1]){
list($arr[$i], $arr[$i+1]) = array($arr[$i+1], $arr[$i]);
$swapped = true;
}
}
}
... | Give a code snippet in #PHP
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/Check_input_device_is_a_terminal | Check input device is a terminal | Task
Demonstrate how to check whether the input device is a terminal or not.
Related task
Check output device is a terminal
| #Jsish | Jsish | /* Check input device is a terminal, in Jsish */
;Interp.conf().subOpts.istty;
/*
=!EXPECTSTART!=
Interp.conf().subOpts.istty ==> false
=!EXPECTEND!=
*/ | Give a code snippet in #Jsish
Task
Demonstrate how to check whether the input device is a terminal or not.
Related task
Check output device is a terminal
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Halt_and_catch_fire | Halt and catch fire | Task
Create a program that crashes as soon as possible, with as few lines of code as possible. Be smart and don't damage your computer, ok?
The code should be syntactically valid. It should be possible to insert [a subset of] your submission into another program, presumably to help debug it, or perhaps for use when an... | #ALGOL_68 | ALGOL 68 | ( print( ( 1 OVER 0 ) ) ) | Give a code snippet in #ALGOL_68
Task
Create a program that crashes as soon as possible, with as few lines of code as possible. Be smart and don't damage your computer, ok?
The code should be syntactically valid. It should be possible to insert [a subset of] your submission into another program, presumably to help de... | 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... | #D | D | import std.stdio;
void main() {
int n=8;
foreach(row; magicSquareDoublyEven(n)) {
foreach(col; row) {
writef("%2s ", col);
}
writeln;
}
writeln("\nMagic constant: ", (n*n+1)*n/2);
}
int[][] magicSquareDoublyEven(int n) {
import std.exception;
enforce(n>=4 ... | Give a code snippet in #D
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... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Arithmetic_evaluation | Arithmetic evaluation | Create a program which parses and evaluates arithmetic expressions.
Requirements
An abstract-syntax tree (AST) for the expression must be created from parsing the input.
The AST must be used in evaluation, also, so the input may not be directly evaluated (e.g. by calling eval or a similar language feature.)
The ... | #Racket | Racket | #lang racket
(require parser-tools/yacc
parser-tools/lex
(prefix-in ~ parser-tools/lex-sre))
(define-tokens value-tokens (NUM))
(define-empty-tokens op-tokens (OPEN CLOSE + - * / EOF NEG))
(define lex
(lexer [(eof) 'EOF]
[whitespace (lex input-port)]
[(~or "+" "-" "*" "/") (... | Give a code snippet in #Racket
Create a program which parses and evaluates arithmetic expressions.
Requirements
An abstract-syntax tree (AST) for the expression must be created from parsing the input.
The AST must be used in evaluation, also, so the input may not be directly evaluated (e.g. by calling eval or a s... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Babbage_problem | Babbage problem |
Charles Babbage, looking ahead to the sorts of problems his Analytical Engine would be able to solve, gave this example:
What is the smallest positive integer whose square ends in the digits 269,696?
— Babbage, letter to Lord Bowden, 1837; see Hollingdale and Tootill, Electronic Computers, second edition, 1970, p.... | #Arturo | Arturo | n: new 0
while [269696 <> (n^2) % 1000000]
-> inc 'n
print n | Give a code snippet in #Arturo
Charles Babbage, looking ahead to the sorts of problems his Analytical Engine would be able to solve, gave this example:
What is the smallest positive integer whose square ends in the digits 269,696?
— Babbage, letter to Lord Bowden, 1837; see Hollingdale and Tootill, Electronic Com... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Stack | Stack |
Data Structure
This illustrates a data structure, a means of storing data within a program.
You may see other such structures in the Data Structures category.
A stack is a container of elements with last in, first out access policy. Sometimes it also called LIFO.
The stack is accessed through its top.
The ba... | #MiniScript | MiniScript | // Note in Miniscript, a value of zero is false,
// and any other number is true.
// therefore the .len function works as the inverse of a .empty function
stack = [2, 4, 6]
stack.push 8
print "Stack is " + stack
print "Adding '9' to stack " + stack.push(9)
print "Top of stack is " + stack.pop
print "Stack is " + stack
... | Give a code snippet in #MiniScript
Data Structure
This illustrates a data structure, a means of storing data within a program.
You may see other such structures in the Data Structures category.
A stack is a container of elements with last in, first out access policy. Sometimes it also called LIFO.
The stack ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Rot-13 | Rot-13 |
Task
Implement a rot-13 function (or procedure, class, subroutine, or other "callable" object as appropriate to your programming environment).
Optionally wrap this function in a utility program (like tr, which acts like a common UNIX utility, performing a line-by-line rot-13 encoding of every line of inpu... | #VBScript | VBScript |
option explicit
function rot13(a)
dim b,n1,n,i
b=""
for i=1 to len(a)
n=asc(mid(a,i,1))
if n>=65 and n<= 91 then
n1=(((n-65)+13)mod 26)+65
elseif n>=97 and n<= 123 then
n1=(((n-97)+13)mod 26)+97
else
n1=n
end if
b=b & chr(n1)
next
rot13=b
end function
con... | Give a code snippet in #VBScript
Task
Implement a rot-13 function (or procedure, class, subroutine, or other "callable" object as appropriate to your programming environment).
Optionally wrap this function in a utility program (like tr, which acts like a common UNIX utility, performing a line-by-line rot... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Inverted_index | Inverted index | An Inverted Index is a data structure used to create full text search.
Task
Given a set of text files, implement a program to create an inverted index.
Also create a user interface to do a search using that inverted index which returns a list of files that contain the query term / terms.
The search index can be i... | #PicoLisp | PicoLisp | $ cat file1
it is what it is
$ cat file2
what is it
$ cat file3
it is a banana | Give a code snippet in #PicoLisp
An Inverted Index is a data structure used to create full text search.
Task
Given a set of text files, implement a program to create an inverted index.
Also create a user interface to do a search using that inverted index which returns a list of files that contain the query term /... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Non-decimal_radices/Input | Non-decimal radices/Input | It is common to have a string containing a number written in some format, with the most common ones being decimal, hexadecimal, octal and binary. Such strings are found in many places (user interfaces, configuration files, XML data, network protocols, etc.)
This task requires parsing of such a string (which may be ass... | #Scala | Scala | object Main extends App {
val (s, bases) = ("100", Seq(2, 8, 10, 16, 19, 36))
bases.foreach(base => println(f"String $s in base $base%2d is $BigInt(s, base)%5d"))
} | Give a code snippet in #Scala
It is common to have a string containing a number written in some format, with the most common ones being decimal, hexadecimal, octal and binary. Such strings are found in many places (user interfaces, configuration files, XML data, network protocols, etc.)
This task requires parsing of ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Hash_from_two_arrays | Hash from two arrays | Task
Using two Arrays of equal length, create a Hash object
where the elements from one array (the keys) are linked
to the elements of the other (the values)
Related task
Associative arrays/Creation
| #Swift | Swift | let keys = ["a","b","c"]
let vals = [1,2,3]
var hash = [String: Int]()
for (key, val) in zip(keys, vals) {
hash[key] = val
} | Give a code snippet in #Swift
Task
Using two Arrays of equal length, create a Hash object
where the elements from one array (the keys) are linked
to the elements of the other (the values)
Related task
Associative arrays/Creation
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Create_a_file_on_magnetic_tape | Create a file on magnetic tape | The task is to create a new file called "TAPE.FILE" of any size on Magnetic Tape.
| #Racket | Racket |
#lang racket
(with-output-to-file "/dev/tape" #:exists 'append
(λ() (displayln "I am a cheap imitation of the Perl code for a boring problem")))
| Give a code snippet in #Racket
The task is to create a new file called "TAPE.FILE" of any size on Magnetic Tape.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Pythagorean_triples | Pythagorean triples | A Pythagorean triple is defined as three positive integers
(
a
,
b
,
c
)
{\displaystyle (a,b,c)}
where
a
<
b
<
c
{\displaystyle a<b<c}
, and
a
2
+
b
2
=
c
2
.
{\displaystyle a^{2}+b^{2}=c^{2}.}
They are called primitive triples if
a
,
b
,
c
{\displaystyle a,b,c}
are co-prime,... | #FreeBASIC | FreeBASIC | ' version 30-05-2016
' compile with: fbc -s console
' primitive pythagoras triples
' a = m^2 - n^2, b = 2mn, c = m^2 + n^2
' m, n are positive integers and m > n
' m - n = odd and GCD(m, n) = 1
' p = a + b + c
' max m for give perimeter
' p = m^2 - n^2 + 2mn + m^2 + n^2
' p = 2mn + m^2 + m^2 + n^2 - n^2 = 2mn + 2m^... | Give a code snippet in #FreeBASIC
A Pythagorean triple is defined as three positive integers
(
a
,
b
,
c
)
{\displaystyle (a,b,c)}
where
a
<
b
<
c
{\displaystyle a<b<c}
, and
a
2
+
b
2
=
c
2
.
{\displaystyle a^{2}+b^{2}=c^{2}.}
They are called primitive triples if
a
,
b
,
c
{\... | 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 ... | #newLISP | newLISP | ; file: abstract.lsp
; url: http://rosettacode.org/wiki/Abstract_type
; author: oofoe 2012-01-28
; Abstract Shape Class
(new Class 'Shape) ; Derive new class.
(define (Shape:Shape ; Shape constructor.
(pen "X")) ; Default value.
(list (context) ; Assemble data packet.
(list '... | Give a code snippet in #newLISP
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 operat... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Strip_a_set_of_characters_from_a_string | Strip a set of characters from a string | Task
Create a function that strips a set of characters from a string.
The function should take two arguments:
a string to be stripped
a string containing the set of characters to be stripped
The returned string should contain the first string, stripped of any characters in the second argument:
print str... | #Forth | Forth | : append-char ( char str -- ) dup >r count dup 1+ r> c! + c! ; \ append char to a counted string
: strippers ( -- addr len) s" aeiAEI" ; \ a string literal returns addr and length
: stripchars ( addr1 len1 addr2 len2 -- PAD len )
0 PAD c! \ clear the PAD buffer
... | Give a code snippet in #Forth
Task
Create a function that strips a set of characters from a string.
The function should take two arguments:
a string to be stripped
a string containing the set of characters to be stripped
The returned string should contain the first string, stripped of any characters in t... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Catamorphism | Catamorphism | Reduce is a function or method that is used to take the values in an array or a list and apply a function to successive members of the list to produce (or reduce them to), a single value.
Task
Show how reduce (or foldl or foldr etc), work (or would be implemented) in your language.
See also
Wikipedia article: ... | #Elixir | Elixir | iex(1)> Enum.reduce(1..10, fn i,acc -> i+acc end)
55
iex(2)> Enum.reduce(1..10, fn i,acc -> i*acc end)
3628800
iex(3)> Enum.reduce(10..-10, "", fn i,acc -> acc <> to_string(i) end)
"109876543210-1-2-3-4-5-6-7-8-9-10" | Give a code snippet in #Elixir
Reduce is a function or method that is used to take the values in an array or a list and apply a function to successive members of the list to produce (or reduce them to), a single value.
Task
Show how reduce (or foldl or foldr etc), work (or would be implemented) in your language.
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/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
| #Dylan | Dylan | notify-user("Goodbye, World!", frame: make(<frame>)); | Give a code snippet in #Dylan
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/MD5 | MD5 | Task
Encode a string using an MD5 algorithm. The algorithm can be found on Wikipedia.
Optionally, validate your implementation by running all of the test values in IETF RFC (1321) for MD5.
Additionally, RFC 1321 provides more precise information on the algorithm than the Wikipedia article.
Warning:... | #MOO | MOO | string = "The quick brown fox jumped over the lazy dog's back";
player:tell(string_hash(string)); | Give a code snippet in #MOO
Task
Encode a string using an MD5 algorithm. The algorithm can be found on Wikipedia.
Optionally, validate your implementation by running all of the test values in IETF RFC (1321) for MD5.
Additionally, RFC 1321 provides more precise information on the algorithm than the Wi... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Terminal_control/Unicode_output | Terminal control/Unicode output | The task is to check that the terminal supports Unicode output, before outputting a Unicode character. If the terminal supports Unicode, then the terminal should output a Unicode delta (U+25b3). If the terminal does not support Unicode, then an appropriate error should be raised.
Note that it is permissible to use sys... | #Common_Lisp | Common Lisp |
(defun my-getenv (name &optional default)
#+CMU
(let ((x (assoc name ext:*environment-list*
:test #'string=)))
(if x (cdr x) default))
#-CMU
(or
#+Allegro (sys:getenv name)
#+CLISP (ext:getenv name)
#+ECL (si:getenv name)
#+SBCL (sb-unix::posix-getenv name)
#+ABCL (ge... | Give a code snippet in #Common_Lisp
The task is to check that the terminal supports Unicode output, before outputting a Unicode character. If the terminal supports Unicode, then the terminal should output a Unicode delta (U+25b3). If the terminal does not support Unicode, then an appropriate error should be raised.
N... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Largest_number_divisible_by_its_digits | Largest number divisible by its digits | Task
Find the largest base 10 integer whose digits are all different, and is evenly divisible by each of its individual digits.
These numbers are also known as Lynch-Bell numbers, numbers n such that the
(base ten) digits are all different (and do not include zero) and n is divisible by each of it... | #R | R | largest_LynchBell_number <- function(from, to){
from = round(from)
to = round(to)
to_chosen = to
if(to > 9876432) to = 9876432 #cap the search space to this number
LynchBell = NULL
range <- to:from #search starting from the end of the range
range <- range[range %% 5 != 0] #reduce search space
f... | Give a code snippet in #R
Task
Find the largest base 10 integer whose digits are all different, and is evenly divisible by each of its individual digits.
These numbers are also known as Lynch-Bell numbers, numbers n such that the
(base ten) digits are all different (and do not include zero) and n ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Execute_HQ9%2B | Execute HQ9+ | Task
Implement a HQ9+ interpreter or compiler.
| #Ursa | Ursa | import "os" for Process
var hq9plus = Fn.new { |code|
var acc = 0
var sb = ""
for (c in code) {
if (c == "h" || c == "H") {
sb = sb + "Hello, world!\n"
} else if (c == "q" || c == "Q") {
sb = sb + code + "\n"
} else if (c == "9") {
for (i in 99..... | Give a code snippet in #Ursa
Task
Implement a HQ9+ interpreter or compiler.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/First-class_functions | First-class functions | A language has first-class functions if it can do each of the following without recursively invoking a compiler or interpreter or otherwise metaprogramming:
Create new functions from preexisting functions at run-time
Store functions in collections
Use functions as arguments to other functions
Use functions as retu... | #Delphi | Delphi |
program First_class_functions;
{$APPTYPE CONSOLE}
uses
System.SysUtils,
System.Math;
type
TFunctionTuple = record
forward, backward: TFunc<Double, Double>;
procedure Assign(forward, backward: TFunc<Double, Double>);
end;
TFunctionTuples = array of TFunctionTuple;
var
cube, croot, fsin, f... | Give a code snippet in #Delphi
A language has first-class functions if it can do each of the following without recursively invoking a compiler or interpreter or otherwise metaprogramming:
Create new functions from preexisting functions at run-time
Store functions in collections
Use functions as arguments to other ... | 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.
| #Rust | Rust | #[macro_use(px)]
extern crate bmp;
use bmp::{Image, Pixel};
use std::f64;
fn main() {
let width = 600u32;
let half_width = (width / 2) as i32;
let mut img = Image::new(width, width);
let draw_color = px!(255, 128, 128);
// Constants defining the spiral size.
let a = 1.0_f64;
let b = 9.... | Give a code snippet in #Rust
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/Sequence:_smallest_number_with_exactly_n_divisors | Sequence: smallest number with exactly n divisors | Calculate the sequence where each term an is the smallest natural number that has exactly n divisors.
Task
Show here, on this page, at least the first 15 terms of the sequence.
Related tasks
Sequence: smallest number greater than previous term with exactly n divisors
Sequence: nth number with exactly... | #Wren | Wren | import "/math" for Int
var limit = 22
var numbers = List.filled(limit, 0)
var i = 1
while (true) {
var nd = Int.divisors(i).count
if (nd <= limit && numbers[nd-1] == 0) {
numbers[nd-1] = i
if (numbers.all { |n| n > 0 }) break
}
i = i + 1
}
System.print("The first %(limit) terms are:")
... | Give a code snippet in #Wren
Calculate the sequence where each term an is the smallest natural number that has exactly n divisors.
Task
Show here, on this page, at least the first 15 terms of the sequence.
Related tasks
Sequence: smallest number greater than previous term with exactly n divisors
Seq... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Catalan_numbers | Catalan numbers | Catalan numbers
You are encouraged to solve this task according to the task description, using any language you may know.
Catalan numbers are a sequence of numbers which can be defined directly:
C
n
=
1
n
+
1
(
2
n
n
)
=
(
2
n
)
!
(
n
+
1
)
!
n
!
for
n
≥
0.
{\displaystyle C... | #Frink | Frink | catalan[n] := binomial[2n,n]/(n+1)
for n = 0 to 15
println[catalan[n]] | Give a code snippet in #Frink
Catalan numbers
You are encouraged to solve this task according to the task description, using any language you may know.
Catalan numbers are a sequence of numbers which can be defined directly:
C
n
=
1
n
+
1
(
2
n
n
)
=
(
2
n
)
!
(
n
+
1
)
!
n
!
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/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... | #REXX | REXX | /*REXX program demonstrates how to create and show a single-linked list.*/
@.=0 /*define a null linked list. */
call set@ 3 /*linked list: 12 Proth Primes. */
call set@ 5
call set@ 13
call set@ 17
call set@ 41
call set@ 97
call set@ 113
call set@ 193
cal... | Give a code snippet in #REXX
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 defi... | 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... | #LOLCODE | LOLCODE | HAI 1.3
I HAS A n ITZ 1024
IM IN YR LOOP UPPIN YR nop WILE n
VISIBLE n
n R QUOSHUNT OF n AN 2
IM OUTTA YR LOOP
KTHXBYE | Give a code snippet in #LOLCODE
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/Downw... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Substring | Substring |
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 |... | #Nim | Nim | import strformat, strutils, unicode
let
s1 = "abcdefgh" # ASCII string.
s2 = "àbĉdéfgĥ" # UTF-8 string.
n = 2
m = 3
c = 'd'
cs1 = "de"
cs2 = "dé"
var pos: int
# ASCII strings.
# We can take a substring using "s.substr(first, last)" or "s[first..last]".
# The latter form can also be used as lvalu... | Give a code snippet in #Nim
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
Co... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Mad_Libs | Mad Libs |
This page uses content from Wikipedia. The original article was at Mad Libs. 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)
Mad Libs is a phrasal template word game where one player prompts another... | #Arturo | Arturo | story: strip input "Enter a story: "
vars: unique map match story {/\|([^\|]+)\|/} 'v -> replace v "|" ""
i: 0
while [i < size vars].import [
let vars\[i] input ~"Enter value for <|vars\[i]|>: "
i: i + 1
]
print ~story | Give a code snippet in #Arturo
This page uses content from Wikipedia. The original article was at Mad Libs. 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)
Mad Libs is a phrasal template word game ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Dynamic_variable_names | Dynamic variable names | Task
Create a variable with a user-defined name.
The variable name should not be written in the program text, but should be taken from the user dynamically.
See also
Eval in environment is a similar task.
| #APL | APL |
is←{ t←⍵ ⋄ ⎕this⍎⍺,'←t' } ⍝⍝ the 'Slick Willie' function ;)
'test' is ⍳2 3
test
1 1 1 2 1 3
2 1 2 2 2 3
| Give a code snippet in #APL
Task
Create a variable with a user-defined name.
The variable name should not be written in the program text, but should be taken from the user dynamically.
See also
Eval in environment is a similar task.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Left_factorials | Left factorials | Left factorials, !n, may refer to either subfactorials or to factorial sums;
the same notation can be confusingly seen being used for the two different definitions.
Sometimes, subfactorials (also known as derangements) may use any of the notations:
!n`
!n
n¡
(It may not be vis... | #R | R | library(gmp)
left_factorial <- function(n) {
if (n == 0) return(0)
result <- as.bigz(0)
adder <- as.bigz(1)
for (k in 1:n) {
result <- result + adder
adder <- adder * k
}
result
}
digit_count <- function(n) {
nchar(as.character(n))
}
for (n in 0:10) {
cat("!",n," = ",sep = "")
cat(as.character(lef... | Give a code snippet in #R
Left factorials, !n, may refer to either subfactorials or to factorial sums;
the same notation can be confusingly seen being used for the two different definitions.
Sometimes, subfactorials (also known as derangements) may use any of the notations:
!n`
!n
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Knapsack_problem/0-1 | Knapsack problem/0-1 | A tourist wants to make a good trip at the weekend with his friends.
They will go to the mountains to see the wonders of nature, so he needs to pack well for the trip.
He has a good knapsack for carrying things, but knows that he can carry a maximum of only 4kg in it, and it will have to last the whole day.
He cre... | #Euler_Math_Toolbox | Euler Math Toolbox |
>items=["map","compass","water","sandwich","glucose", ...
> "tin","banana","apple","cheese","beer","suntan creame", ...
> "camera","t-shirt","trousers","umbrella","waterproof trousers", ...
> "waterproof overclothes","note-case","sunglasses", ...
> "towel","socks","book"];
>ws = [9,13,153,50,15,68,27,39,23,52,11,... | Give a code snippet in #Euler_Math_Toolbox
A tourist wants to make a good trip at the weekend with his friends.
They will go to the mountains to see the wonders of nature, so he needs to pack well for the trip.
He has a good knapsack for carrying things, but knows that he can carry a maximum of only 4kg in it, and... | christopher/rosetta-code | |
http://rosettacode.org/wiki/99_bottles_of_beer | 99 bottles of beer | Task
Display the complete lyrics for the song: 99 Bottles of Beer on the Wall.
The beer song
The lyrics follow this form:
99 bottles of beer on the wall
99 bottles of beer
Take one down, pass it around
98 bottles of beer on the wall
98 bottles of beer on the wall
98 bottles of beer
Take one dow... | #ArnoldC | ArnoldC | IT'S SHOWTIME
HEY CHRISTMAS TREE is0
YOU SET US UP @NO PROBLEMO
HEY CHRISTMAS TREE bottles
YOU SET US UP 99
STICK AROUND is0
TALK TO THE HAND bottles
TALK TO THE HAND " bottles of beer on the wall"
TALK TO THE HAND bottles
TALK TO THE HAND " bottles of beer"
TALK TO THE HAND "Take one down, pass it around"
GET TO THE C... | Give a code snippet in #ArnoldC
Task
Display the complete lyrics for the song: 99 Bottles of Beer on the Wall.
The beer song
The lyrics follow this form:
99 bottles of beer on the wall
99 bottles of beer
Take one down, pass it around
98 bottles of beer on the wall
98 bottles of beer on the wall
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Monads/List_monad | Monads/List monad | A Monad is a combination of a data-type with two helper functions written for that type.
The data-type can be of any kind which can contain values of some other type – common examples are lists, records, sum-types, even functions or IO streams. The two special functions, mathematically known as eta and mu, but usually... | #Factor | Factor | USING: kernel math monads prettyprint ;
FROM: monads => do ;
{ 3 4 5 }
>>= [ 1 + array-monad return ] swap call
>>= [ 2 * array-monad return ] swap call . | Give a code snippet in #Factor
A Monad is a combination of a data-type with two helper functions written for that type.
The data-type can be of any kind which can contain values of some other type – common examples are lists, records, sum-types, even functions or IO streams. The two special functions, mathematically ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Vogel%27s_approximation_method | Vogel's approximation method | Vogel's Approximation Method (VAM) is a technique for finding a good initial feasible solution to an allocation problem.
The powers that be have identified 5 tasks that need to be solved urgently. Being imaginative chaps, they have called them “A”, “B”, “C”, “D”, and “E”. They estimate that:
A will require 30 hours ... | #Phix | Phix | with javascript_semantics
sequence supply = {50,60,50,50},
demand = {30,20,70,30,60},
costs = {{16,16,13,22,17},
{14,14,13,19,15},
{19,19,20,23,50},
{50,12,50,15,11}}
sequence row_done = repeat(false,length(supply)),
col_done = repeat(fa... | Give a code snippet in #Phix
Vogel's Approximation Method (VAM) is a technique for finding a good initial feasible solution to an allocation problem.
The powers that be have identified 5 tasks that need to be solved urgently. Being imaginative chaps, they have called them “A”, “B”, “C”, “D”, and “E”. They estimate th... | 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 ... | #jq | jq | def median:
length as $length
| sort as $s
| if $length == 0 then null
else ($length / 2 | floor) as $l2
| if ($length % 2) == 0 then
($s[$l2 - 1] + $s[$l2]) / 2
else $s[$l2]
end
end ; | Give a code snippet in #jq
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.
T... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Maze_solving | Maze solving | Task
For a maze generated by this task, write a function
that finds (and displays) the shortest path between two cells.
Note that because these mazes are generated by the Depth-first search algorithm, they contain no circular paths,
and a simple depth-first tree search can be used.
| #Red | Red | Red ["Maze solver"]
do %mazegen.red
print [
"start:" start: random size - 1x1
"end:" end: random size - 1x1
]
isnew?: function [pos] [not find visited pos]
open?: function [pos d] [
o: pos/y * size/x + pos/x + 1
0 = pick walls/:o d
]
expand: function [pos][
either any [
all [pos/x > 0 isnew? p: pos - 1x0 ope... | Give a code snippet in #Red
Task
For a maze generated by this task, write a function
that finds (and displays) the shortest path between two cells.
Note that because these mazes are generated by the Depth-first search algorithm, they contain no circular paths,
and a simple depth-first tree search can be used.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Sorting_algorithms/Sleep_sort | Sorting algorithms/Sleep 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
... | #F.23 | F# |
let sleepSort (values: seq<int>) =
values
|> Seq.map (fun x -> async {
do! Async.Sleep x
Console.WriteLine x
})
|> Async.Parallel
|> Async.Ignore
|> Async.RunSynchronously
| Give a code snippet in #F.23
Sorting Algorithm
This is a sorting algorithm. It may be applied to a set of data in order to sort it.
For comparing various sorts, see compare sorts.
For other sorting algorithms, see sorting algorithms, or:
O(n logn) sorts
Heap sort |
Merge sort |
Patience sort |
Quick sor... | christopher/rosetta-code | |
http://rosettacode.org/wiki/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 ... | #Raku | Raku | use Image::PNG::Portable;
my ($w, $h) = (640, 640);
my $png = Image::PNG::Portable.new: :width($w), :height($h);
my @vertex = [0, 0], [$w, 0], [$w/2, $h];
my @xy = [0,0], [0,0], [0,0], [0,0];
# :degree must be equal to or less than @xy elements.
(^1e5).race(:4degree).map: {
my $p = ++$ % +@xy;
@xy[$p]... | Give a code snippet in #Raku
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 ... | 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 ... | #Lisaac | Lisaac | + haystack : ARRAY[STRING];
haystack := "Zig Zag Wally Ronald Bush Krusty Charlie Bush Bozo".split;
"Washington Bush".split.foreach { needle : STRING;
haystack.has(needle).if {
haystack.first_index_of(needle).print;
' '.print;
needle.print;
'\n'.print;
} else {
needle.print;
" is not in hays... | Give a code snippet in #Lisaac
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 t... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Stack | Stack |
Data Structure
This illustrates a data structure, a means of storing data within a program.
You may see other such structures in the Data Structures category.
A stack is a container of elements with last in, first out access policy. Sometimes it also called LIFO.
The stack is accessed through its top.
The ba... | #Oz | Oz | functor
export
New
Push
Pop
Empty
define
fun {New}
{NewCell nil}
end
proc {Push Stack Element}
NewStack
%% Use atomic swap for thread safety
OldStack = Stack := NewStack
in
NewStack = Element|OldStack
end
proc {Pop Stack ?Result}
NewStack
%%... | Give a code snippet in #Oz
Data Structure
This illustrates a data structure, a means of storing data within a program.
You may see other such structures in the Data Structures category.
A stack is a container of elements with last in, first out access policy. Sometimes it also called LIFO.
The stack is acces... | 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 ... | #PHP | PHP | <?php
$foo = 3;
if ($foo == 2)
//do something
if ($foo == 3)
//do something
else
//do something else
if ($foo != 0)
{
//do something
}
else
{
//do another thing
}
?> | Give a code snippet in #PHP
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 co... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Count_the_coins | Count the coins | There are four types of common coins in US currency:
quarters (25 cents)
dimes (10 cents)
nickels (5 cents), and
pennies (1 cent)
There are six ways to make change for 15 cents:
A dime and a nickel
A dime and 5 pennies
3 nickels
2 nickels and 5 pennies
A nickel and 10 pen... | #Phix | Phix | function coin_count(sequence coins, integer amount)
sequence s = repeat(0,amount+1)
s[1] = 1
for c=1 to length(coins) do
for n=coins[c] to amount do
s[n+1] += s[n-coins[c]+1]
end for
end for
return s[amount+1]
end function
| Give a code snippet in #Phix
There are four types of common coins in US currency:
quarters (25 cents)
dimes (10 cents)
nickels (5 cents), and
pennies (1 cent)
There are six ways to make change for 15 cents:
A dime and a nickel
A dime and 5 pennies
3 nickels
2 nickels and 5 ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Anonymous_recursion | Anonymous recursion | While implementing a recursive function, it often happens that we must resort to a separate helper function to handle the actual recursion.
This is usually the case when directly calling the current function would waste too many resources (stack space, execution time), causing unwanted side-effects, and/or the f... | #Dylan | Dylan |
define function fib (n)
when (n < 0)
error("Can't take fibonacci of negative integer: %d\n", n)
end;
local method fib1 (n, a, b)
if (n = 0)
a
else
fib1(n - 1, b, a + b)
end
end;
fib1(n, 0, 1)
end
| Give a code snippet in #Dylan
While implementing a recursive function, it often happens that we must resort to a separate helper function to handle the actual recursion.
This is usually the case when directly calling the current function would waste too many resources (stack space, execution time), causing unwant... | 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.
| #Gri | Gri | `Recurse'
{
show .depth.
.depth. = {rpn .depth. 1 +}
Recurse
}
.depth. = 1
Recurse | Give a code snippet in #Gri
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/99_bottles_of_beer | 99 bottles of beer | Task
Display the complete lyrics for the song: 99 Bottles of Beer on the Wall.
The beer song
The lyrics follow this form:
99 bottles of beer on the wall
99 bottles of beer
Take one down, pass it around
98 bottles of beer on the wall
98 bottles of beer on the wall
98 bottles of beer
Take one dow... | #MiniScript | MiniScript | bottles = function(n)
if n == 0 then return "no bottles"
if n == 1 then return "1 bottle"
return n + " bottles"
end function
verse = function(n)
print bottles(n) + " of beer on the wall"
print bottles(n) + " of beer"
print "Take one down, pass it around"
print bottles(n-1) + " of beer on t... | Give a code snippet in #MiniScript
Task
Display the complete lyrics for the song: 99 Bottles of Beer on the Wall.
The beer song
The lyrics follow this form:
99 bottles of beer on the wall
99 bottles of beer
Take one down, pass it around
98 bottles of beer on the wall
98 bottles of beer on the wall... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Terminal_control/Cursor_movement | Terminal control/Cursor movement | Task
Demonstrate how to achieve movement of the terminal cursor:
how to move the cursor one position to the left
how to move the cursor one position to the right
how to move the cursor up one line (without affecting its horizontal position)
how to move the cursor down one line (without affecting its horizontal po... | #Julia | Julia | const ESC = "\u001B" # escape code
const moves = Dict( "left" => "[1D", "right" => "[1C", "up" => "[1A", "down" => "[1B",
"linestart" => "[9D", "topleft" => "[H", "bottomright" => "[24;79H")
print("$ESC[2J") # clear terminal first
print("$ESC[10;10H") # move cursor to (10, 10) say
const count ... | Give a code snippet in #Julia
Task
Demonstrate how to achieve movement of the terminal cursor:
how to move the cursor one position to the left
how to move the cursor one position to the right
how to move the cursor up one line (without affecting its horizontal position)
how to move the cursor down one line (with... | christopher/rosetta-code | |
http://rosettacode.org/wiki/I_before_E_except_after_C | I before E except after C | The phrase "I before E, except after C" is a
widely known mnemonic which is supposed to help when spelling English words.
Task
Using the word list from http://wiki.puzzlers.org/pub/wordlists/unixdict.txt,
check if the two sub-clauses of the phrase are plausible individually:
"I before E when not pre... | #QBasic | QBasic | DEFINT A-Z
DIM W AS STRING
CLS
OPEN "I", 1, "UNIXDICT.TXT"
DO
LINE INPUT #1, W
IF INSTR(W, "ie") THEN IF INSTR(W, "cie") THEN CI = CI + 1 ELSE XI = XI + 1
IF INSTR(W, "ei") THEN IF INSTR(W, "cei") THEN CE = CE + 1 ELSE XE = XE + 1
LOOP WHILE NOT EOF(1)
CLOSE #1
PRINT "CIE:"; CI
PRINT "xIE:"; XI
PRINT "CEI... | Give a code snippet in #QBasic
The phrase "I before E, except after C" is a
widely known mnemonic which is supposed to help when spelling English words.
Task
Using the word list from http://wiki.puzzlers.org/pub/wordlists/unixdict.txt,
check if the two sub-clauses of the phrase are plausible individual... | 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 ... | #Nemerle | Nemerle | using System;
using System.Console;
using Nemerle.Collections.NCollectionsExtensions;
module DotProduct
{
DotProduct(x : array[int], y : array[int]) : int
{
$[(a * b)|(a, b) in ZipLazy(x, y)].FoldLeft(0, _+_);
}
Main() : void
{
def arr1 = array[1, 3, -5]; def arr2 = array[4, ... | Give a code snippet in #Nemerle
Task
Create a function/use an in-built function, to compute the dot product, also known as the scalar product of two vectors.
If possible, make the vectors of arbitrary length.
As an example, compute the dot product of the vectors:
[1, 3, -5] and
[4, -2, ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/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... | #Mathematica.2FWolfram_Language | Mathematica/Wolfram Language | fromrank[list_, 0] := list;
fromrank[list_, n_] :=
Prepend[fromrank[DeleteCases[list, #],
Mod[n, (Length@list - 1)!]], #] &@
RankedMin[list, Quotient[n, (Length@list - 1)!] + 1];
rank[{}] = 0;
rank[{x_, y___}] := Count[{y}, _?(# < x &)] Length@{y}! + rank[{y}];
Print /@ Table[{n, fromrank[{0, 1, 2, 3},... | Give a code snippet in #Mathematica.2FWolfram_Language
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... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Modular_exponentiation | Modular exponentiation | Find the last 40 decimal digits of
a
b
{\displaystyle a^{b}}
, where
a
=
2988348162058574136915891421498819466320163312926952423791023078876139
{\displaystyle a=2988348162058574136915891421498819466320163312926952423791023078876139}
b
=
235139930337346448646612254452369009474497523... | #Swift | Swift | import BigInt
func modPow<T: BinaryInteger>(n: T, e: T, m: T) -> T {
guard e != 0 else {
return 1
}
var res = T(1)
var base = n % m
var exp = e
while true {
if exp & 1 == 1 {
res *= base
res %= m
}
if exp == 1 {
return res
}
exp /= 2
base *= base
b... | Give a code snippet in #Swift
Find the last 40 decimal digits of
a
b
{\displaystyle a^{b}}
, where
a
=
2988348162058574136915891421498819466320163312926952423791023078876139
{\displaystyle a=2988348162058574136915891421498819466320163312926952423791023078876139}
b
=
23513993033734... | christopher/rosetta-code | |
http://rosettacode.org/wiki/String_concatenation | String concatenation | String concatenation
You are encouraged to solve this task according to the task description, using any language you may know.
Task
Create a string variable equal to any text value.
Create another string variable whose value is the original variable concatenated with another string literal.
To illustrate the operat... | #min | min | "butter" :a
(a "scotch")=> "" join :b
a puts!
b puts! | Give a code snippet in #min
String concatenation
You are encouraged to solve this task according to the task description, using any language you may know.
Task
Create a string variable equal to any text value.
Create another string variable whose value is the original variable concatenated with another string liter... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Read_entire_file | Read entire file | Task
Load the entire contents of some text file as a single string variable.
If applicable, discuss: encoding selection, the possibility of memory-mapping.
Of course, in practice one should avoid reading an entire file at once
if the file is large and the task can be accomplished incrementally instead
(in which case... | #REXX | REXX | /*REXX program reads an entire file line-by-line and stores it as a continuous string.*/
parse arg iFID . /*obtain optional argument from the CL.*/
if iFID=='' then iFID= 'a_file' /*Not specified? Then use the default.*/
$= ... | Give a code snippet in #REXX
Task
Load the entire contents of some text file as a single string variable.
If applicable, discuss: encoding selection, the possibility of memory-mapping.
Of course, in practice one should avoid reading an entire file at once
if the file is large and the task can be accomplished increm... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Truncate_a_file | Truncate a file | Task
Truncate a file to a specific length. This should be implemented as a routine that takes two parameters: the filename and the required file length (in bytes).
Truncation can be achieved using system or library calls intended for such a task, if such methods exist, or by creating a temporary file of a reduced... | #Icon_and_Unicon | Icon and Unicon | truncate(f := open(filename, "bu"), newsizeinbytes) & close(f) | Give a code snippet in #Icon_and_Unicon
Task
Truncate a file to a specific length. This should be implemented as a routine that takes two parameters: the filename and the required file length (in bytes).
Truncation can be achieved using system or library calls intended for such a task, if such methods exist, or ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Bitmap | Bitmap | Show a basic storage type to handle a simple RGB raster graphics image,
and some primitive associated functions.
If possible provide a function to allocate an uninitialised image,
given its width and height, and provide 3 additional functions:
one to fill an image with a plain RGB color,
one to set a given pixe... | #MATLAB | MATLAB |
%Bitmap class
%
%Implements a class to manage bitmap images without the need for the
%various conversion and display functions
%
%Available functions:
%
%fill(obj,color)
%setPixel(obj,pixel,color)
%getPixel(obj,pixel,[optional: color channel])
%display(obj)
%disp(obj)
%plot(obj)
%image(obj)
%save(obj)
%open(obj)
cl... | Give a code snippet in #MATLAB
Show a basic storage type to handle a simple RGB raster graphics image,
and some primitive associated functions.
If possible provide a function to allocate an uninitialised image,
given its width and height, and provide 3 additional functions:
one to fill an image with a plain RGB c... | 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
| #Batch_File | Batch File |
@echo off
::setting variables in defferent ways
set myInt1=5
set myString1=Rosetta Code
set "myInt2=5"
set "myString2=Rosetta Code"
::Arithmetic
set /a myInt1=%myInt1%+1
set /a myInt2+=1
set /a myInt3=myInt2+ 5
set myInt
set myString
pause>nul
| Give a code snippet in #Batch_File
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/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 ... | #APL | APL |
fib←{⍵≤1:⍵ ⋄ (∇ ⍵-1)+∇ ⍵-2}
| Give a code snippet in #APL
The Fibonacci sequence is a sequence Fn of natural numbers defined recursively:
F0 = 0
F1 = 1
Fn = Fn-1 + Fn-2, if n>1
Task
Write a function to generate the nth Fibonacci number.
Solutions can be iterative or recursive (though recursive solutions are g... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Hamming_numbers | Hamming numbers | Hamming numbers are numbers of the form
H = 2i × 3j × 5k
where
i, j, k ≥ 0
Hamming numbers are also known as ugly numbers and also 5-smooth numbers (numbers whose prime divisors are less or equal to 5).
Task
Generate the sequence of Hamming numbers, in increasing order. In ... | #SQL | SQL |
CREATE TEMPORARY TABLE factors(n INT);
INSERT INTO factors VALUES(2);
INSERT INTO factors VALUES(3);
INSERT INTO factors VALUES(5);
CREATE TEMPORARY TABLE hamming AS
WITH RECURSIVE ham AS (
SELECT 1 AS h
UNION
SELECT h*n x FROM ham JOIN factors ORDER BY x
LIMIT 1700
... | Give a code snippet in #SQL
Hamming numbers are numbers of the form
H = 2i × 3j × 5k
where
i, j, k ≥ 0
Hamming numbers are also known as ugly numbers and also 5-smooth numbers (numbers whose prime divisors are less or equal to 5).
Task
Generate the sequence of Hamming number... | christopher/rosetta-code | |
http://rosettacode.org/wiki/GUI_component_interaction | GUI component interaction |
Almost every application needs to communicate with the user in some way.
Therefore, a substantial part of the code deals with the interaction
of program logic with GUI components.
Typically, the following is needed:
put values into input fields under program control
read and check input from the user
pop up dial... | #Ruby | Ruby | Shoes.app(title: "GUI component interaction") do
stack do
textbox = edit_line
textbox.change do
textbox.text = textbox.text.gsub(/[^\d]/, '') and alert "Input must be a number!" if textbox.text !~ /^\d*$/
end
flow do
button "Increment" do
textbox.text = textbox.text.to_i + 1
... | Give a code snippet in #Ruby
Almost every application needs to communicate with the user in some way.
Therefore, a substantial part of the code deals with the interaction
of program logic with GUI components.
Typically, the following is needed:
put values into input fields under program control
read and check in... | 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 ... | #Phix | Phix | function fibonacci(integer n) -- iterative, works for -ve numbers
atom a=0, b=1
if n=0 then return 0 end if
if abs(n)>=79 then ?9/0 end if -- inaccuracies creep in above 78
for i=1 to abs(n)-1 do
{a,b} = {b,a+b}
end for
if n<0 and remainder(n,2)=0 then return -b end if
return b
end ... | Give a code snippet in #Phix
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 ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Last_letter-first_letter | Last letter-first letter | A certain children's game involves starting with a word in a particular category. Each participant in turn says a word, but that word must begin with the final letter of the previous word. Once a word has been given, it cannot be repeated. If an opponent cannot give a word in the category, they fall out of the ga... | #BBC_BASIC | BBC BASIC | DIM names$(69)
names$() = "audino", "bagon", "baltoy", "banette", \
\ "bidoof", "braviary", "bronzor", "carracosta", "charmeleon", \
\ "cresselia", "croagunk", "darmanitan", "deino", "emboar", \
\ "emolga", "exeggcute", "gabite", "girafarig", "gulpin", \
\ "haxorus", "heatmor", "heat... | Give a code snippet in #BBC_BASIC
A certain children's game involves starting with a word in a particular category. Each participant in turn says a word, but that word must begin with the final letter of the previous word. Once a word has been given, it cannot be repeated. If an opponent cannot give a word in th... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Reverse_a_string | Reverse a string | Task
Take a string and reverse it.
For example, "asdf" becomes "fdsa".
Extra credit
Preserve Unicode combining characters.
For example, "as⃝df̅" becomes "f̅ds⃝a", not "̅fd⃝sa".
Other tasks related to string operations:
Metrics
Array length
String length
Copy a string
Empty string (assignment)
Counting
... | #PureBasic | PureBasic | Debug ReverseString("!dekrow tI") | Give a code snippet in #PureBasic
Task
Take a string and reverse it.
For example, "asdf" becomes "fdsa".
Extra credit
Preserve Unicode combining characters.
For example, "as⃝df̅" becomes "f̅ds⃝a", not "̅fd⃝sa".
Other tasks related to string operations:
Metrics
Array length
String length
Copy a string
E... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Go_Fish | Go Fish | Write a program to let the user play Go Fish against a computer opponent. Use the following rules:
Each player is dealt nine cards to start with.
On their turn, a player asks their opponent for a given rank (such as threes or kings). A player must already have at least one card of a given rank to ask for more.
If t... | #Julia | Julia | #!/usr/bin/perl
use strict; # https://rosettacode.org/wiki/Go_Fish
use warnings;
use List::Util qw( first shuffle );
my $pat = qr/[atjqk2-9]/; # ranks
my $deck = join '', shuffle map { my $rank = $_; map "$rank$_", qw( S H C D ) }
qw( a t j q k ), 2 .. 9;
my $mebooks = my $youbooks = 0;
my $me = substr $deck,... | Give a code snippet in #Julia
Write a program to let the user play Go Fish against a computer opponent. Use the following rules:
Each player is dealt nine cards to start with.
On their turn, a player asks their opponent for a given rank (such as threes or kings). A player must already have at least one card of a gi... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Synchronous_concurrency | Synchronous concurrency | The goal of this task is to create two concurrent activities ("Threads" or "Tasks", not processes.) that share data synchronously. Your language may provide syntax or libraries to perform concurrency. Different languages provide different implementations of concurrency, often with different names. Some languages use th... | #Oforth | Oforth | import: parallel
: printing(chPrint, chCount)
0 while( chPrint receive dup notNull ) [ println 1+ ] drop
chCount send drop ;
: concurrentPrint(aFileName)
| chPrint chCount line |
Channel new ->chPrint
Channel new ->chCount
#[ printing(chPrint, chCount) ] &
aFileName File new forEach: line [ chPr... | Give a code snippet in #Oforth
The goal of this task is to create two concurrent activities ("Threads" or "Tasks", not processes.) that share data synchronously. Your language may provide syntax or libraries to perform concurrency. Different languages provide different implementations of concurrency, often with differ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/S-expressions | S-expressions | S-Expressions are one convenient way to parse and store data.
Task
Write a simple reader and writer for S-Expressions that handles quoted and unquoted strings, integers and floats.
The reader should read a single but nested S-Expression from a string and store it in a suitable datastructure (list, array, etc).
... | #Lua | Lua | lpeg = require 'lpeg' -- see http://www.inf.puc-rio.br/~roberto/lpeg/
imports = 'P R S C V match'
for w in imports:gmatch('%a+') do _G[w] = lpeg[w] end -- make e.g. 'lpeg.P' function available as 'P'
function tosymbol(s) return s end
function tolist(x, ...) return {...} end -- ignore the first capture, the whole s... | Give a code snippet in #Lua
S-Expressions are one convenient way to parse and store data.
Task
Write a simple reader and writer for S-Expressions that handles quoted and unquoted strings, integers and floats.
The reader should read a single but nested S-Expression from a string and store it in a suitable datast... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Real_constants_and_functions | Real constants and functions | Task
Show how to use the following math constants and functions in your language (if not available, note it):
e (base of the natural logarithm)
π
{\displaystyle \pi }
square root
logarithm (any base allowed)
exponential (ex )
absolute value (a.k.a. "magnitude")
floor (largest ... | #D | D | import std.math ; // need to import this module
E // Euler's number
PI // pi constant
sqrt(x) // square root
log(x) // natural logarithm
log10(x) // logarithm base 10
log2(x) // logarithm base 2
exp(x) // exponential
abs(x) // absolute value (= magnitude for complex)
floor(x) // floor
ceil(x) // c... | Give a code snippet in #D
Task
Show how to use the following math constants and functions in your language (if not available, note it):
e (base of the natural logarithm)
π
{\displaystyle \pi }
square root
logarithm (any base allowed)
exponential (ex )
absolute value (a.k.a. "magni... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Filter | Filter | Task
Select certain elements from an Array into a new Array in a generic way.
To demonstrate, select all even numbers from an Array.
As an option, give a second solution which filters destructively,
by modifying the original Array rather than creating a new Array.
| #Bracmat | Bracmat | ( :?odds
& ( 1 2 3 4 5 6 7 8 9 10 16 25 36 49 64 81 100:? (=.!sjt*1/2:/&!odds !sjt:?odds)$() ()
| !odds
)
)
| Give a code snippet in #Bracmat
Task
Select certain elements from an Array into a new Array in a generic way.
To demonstrate, select all even numbers from an Array.
As an option, give a second solution which filters destructively,
by modifying the original Array rather than creating a new Array.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Repeat_a_string | Repeat a string | Take a string and repeat it some number of times.
Example: repeat("ha", 5) => "hahahahaha"
If there is a simpler/more efficient way to repeat a single “character” (i.e. creating a string filled with a certain character), you might want to show that as well (i.e. repeat-char("*", 5) => "*****").
Other tasks re... | #Action.21 | Action! | Proc Main()
byte REPEAT
REPEAT=5
Do
Print("ha")
REPEAT==-1
Until REPEAT=0
Do
Return | Give a code snippet in #Action.21
Take a string and repeat it some number of times.
Example: repeat("ha", 5) => "hahahahaha"
If there is a simpler/more efficient way to repeat a single “character” (i.e. creating a string filled with a certain character), you might want to show that as well (i.e. repeat-char("*",... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Host_introspection | Host introspection | Print the word size and endianness of the host machine.
See also: Variable size/Get
| #Perl | Perl | use Config;
print "UV size: $Config{uvsize}, byte order: $Config{byteorder}\n"; | Give a code snippet in #Perl
Print the word size and endianness of the host machine.
See also: Variable size/Get
| 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 ... | #APL | APL | 1 3 ¯5 +.× 4 ¯2 ¯1 | Give a code snippet in #APL
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/Record_sound | Record sound | Record a monophonic 16-bit PCM sound into either memory space, a file or array.
(This task neglects to specify the sample rate, and whether to use signed samples.
The programs in this page might use signed 16-bit or unsigned 16-bit samples, at 8000 Hz, 44100 Hz, or any other sample rate.
Therefore, these programs migh... | #Wee_Basic | Wee Basic | print 1 "Recording..."
micrec
print 1 "Playing..."
micpla
end | Give a code snippet in #Wee_Basic
Record a monophonic 16-bit PCM sound into either memory space, a file or array.
(This task neglects to specify the sample rate, and whether to use signed samples.
The programs in this page might use signed 16-bit or unsigned 16-bit samples, at 8000 Hz, 44100 Hz, or any other sample r... | 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... | #AWK | AWK | # Tested using GAWK
function bits2str(bits, data, mask)
{
# Source: https://www.gnu.org/software/gawk/manual/html_node/Bitwise-Functions.html
if (bits == 0)
return "0"
mask = 1
for (; bits != 0; bits = rshift(bits, 1))
data = (and(bits, mask) ? "1" : "0") data
while ((le... | Give a code snippet in #AWK
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 po... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Mutual_recursion | Mutual recursion | Two functions are said to be mutually recursive if the first calls the second,
and in turn the second calls the first.
Write two mutually recursive functions that compute members of the Hofstadter Female and Male sequences defined as:
F
(
0
)
=
1
;
M
(
0
)
=
0
F
(
n
)
=
n
−
M
(
F
(
n
−
1
)
)
,
... | #MATLAB | MATLAB | function Fn = female(n)
if n == 0
Fn = 1;
return
end
Fn = n - male(female(n-1));
end | Give a code snippet in #MATLAB
Two functions are said to be mutually recursive if the first calls the second,
and in turn the second calls the first.
Write two mutually recursive functions that compute members of the Hofstadter Female and Male sequences defined as:
F
(
0
)
=
1
;
M
(
0
)
=
0
F
(
n... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Long_multiplication | Long multiplication | Task
Explicitly implement long multiplication.
This is one possible approach to arbitrary-precision integer algebra.
For output, display the result of 264 * 264.
Optionally, verify your result against builtin arbitrary precision support.
The decimal representation of 264 is:
18,446,744,073,709,551,61... | #zkl | zkl | var BN=Import("zklBigNum");
BN(2).pow(64) * BN(2).pow(64)
340282366920938463463374607431768211456
BN(2).pow(128) : "%,d".fmt(_)
340,282,366,920,938,463,463,374,607,431,768,211,456
//42!, also BN(42).factorial()
[2..42].reduce(fcn(p,n){p*n},BN(1)) : "%,d".fmt(_)
1,405,006,117,752,879,898,543,142,606,244,511,569,9... | Give a code snippet in #zkl
Task
Explicitly implement long multiplication.
This is one possible approach to arbitrary-precision integer algebra.
For output, display the result of 264 * 264.
Optionally, verify your result against builtin arbitrary precision support.
The decimal representation of 264 i... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Leonardo_numbers | Leonardo numbers |
Leonardo numbers are also known as the Leonardo series.
The Leonardo numbers are a sequence of numbers defined by:
L(0) = 1 [1st equation]
L(1) = 1 [2nd equation]
L(n) = L(n-1) + L(n-2) + 1 ... | #AutoHotkey | AutoHotkey | Leonardo(n, L0:=1, L1:=1, step:=1){
if n=0
return L0
if n=1
return L1
return Leonardo(n-1, L0, L1, step) + Leonardo(n-2, L0, L1, step) + step
} | Give a code snippet in #AutoHotkey
Leonardo numbers are also known as the Leonardo series.
The Leonardo numbers are a sequence of numbers defined by:
L(0) = 1 [1st equation]
L(1) = 1 [2nd equation]
L... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Problem_of_Apollonius | Problem of Apollonius |
Task
Implement a solution to the Problem of Apollonius (description on Wikipedia) which is the problem of finding the circle that is tangent to three specified circles (colored black in the diagram below to the right).
There is an algebraic solution which is pretty straightforward.
The solutions to the ... | #BBC_BASIC | BBC BASIC | DIM Circle{x, y, r}
DIM Circles{(2)} = Circle{}
Circles{(0)}.x = 0 : Circles{(0)}.y = 0 : Circles{(0)}.r = 1
Circles{(1)}.x = 4 : Circles{(1)}.y = 0 : Circles{(1)}.r = 1
Circles{(2)}.x = 2 : Circles{(2)}.y = 4 : Circles{(2)}.r = 2
@% = &2030A
REM Solution for internal circle:... | Give a code snippet in #BBC_BASIC
Task
Implement a solution to the Problem of Apollonius (description on Wikipedia) which is the problem of finding the circle that is tangent to three specified circles (colored black in the diagram below to the right).
There is an algebraic solution which is pretty straig... | 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
| #FUZE_BASIC | FUZE BASIC | PRINT "Hello world!" | Give a code snippet in #FUZE_BASIC
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 er... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Test_a_function | Test a function |
Task
Using a well-known testing-specific library/module/suite for your language, write some tests for your language's entry in Palindrome.
If your language does not have a testing specific library well known to the language's community then state this or omit the language.
| #Delphi | Delphi | Assert(IsPalindrome('salàlas'), 'salàlas is a valid palindrome');
Assert(IsPalindrome('Ingirumimusnocteetconsumimurigni'), 'Ingirumimusnocteetconsumimurigni is a valid palindrome');
Assert(not IsPalindrome('123'), '123 is not a valid palindrome'); | Give a code snippet in #Delphi
Task
Using a well-known testing-specific library/module/suite for your language, write some tests for your language's entry in Palindrome.
If your language does not have a testing specific library well known to the language's community then state this or omit the language.
| 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.
| #Ring | Ring |
a = 10*9*8*7*6*5*4*3*2*1
b = factorial(10)
see a + nl
see b + nl
func factorial nr if nr = 1 return 1 else return nr * factorial(nr-1) ok
| Give a code snippet in #Ring
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/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... | #Kotlin | Kotlin | val romanNumerals = mapOf(
1000 to "M",
900 to "CM",
500 to "D",
400 to "CD",
100 to "C",
90 to "XC",
50 to "L",
40 to "XL",
10 to "X",
9 to "IX",
5 to "V",
4 to "IV",
1 to "I"
)
fun encode(number: Int): String? {
if (number > 5000 || number < 1) {
retur... | Give a code snippet in #Kotlin
Task
Create a function taking a positive integer as its parameter and returning a string containing the Roman numeral representation of that integer. Modern Roman numerals are written by expressing each digit separately, starting with the left most digit and skipping any digit with a va... | christopher/rosetta-code | |
http://rosettacode.org/wiki/N-smooth_numbers | N-smooth numbers | n-smooth numbers are positive integers which have no prime factors > n.
The n (when using it in the expression) n-smooth is always prime,
there are no 9-smooth numbers.
1 (unity) is always included in n-smooth numbers.
2-smooth numbers are non-negative powers of two.
5-smooth numbers are... | #JavaScript | JavaScript |
function isPrime(n){
var x = Math.floor(Math.sqrt(n)), i = 2
while ((i <= x) && (n % i != 0)) i++
return (x < i)
}
function smooth(n, s, k){
var p = []
for (let i = 2; i <= n; i++){
if (isPrime(i)){
p.push([BigInt(i), [1n], 0])
}
}
var res = []
for (... | Give a code snippet in #JavaScript
n-smooth numbers are positive integers which have no prime factors > n.
The n (when using it in the expression) n-smooth is always prime,
there are no 9-smooth numbers.
1 (unity) is always included in n-smooth numbers.
2-smooth numbers are non-negative po... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Walk_a_directory/Recursively | Walk a directory/Recursively | Task
Walk a given directory tree and print files matching a given pattern.
Note: This task is for recursive methods. These tasks should read an entire directory tree, not a single directory.
Note: Please be careful when running any code examples found here.
Related task
Walk a directory/Non-recursively ... | #ooRexx | ooRexx | /* REXX ---------------------------------------------------------------
* List all file names on my disk D: that contain the string TTTT
*--------------------------------------------------------------------*/
call SysFileTree "d:\*.*", "file", "FS" -- F get all Files
-- S search ... | Give a code snippet in #ooRexx
Task
Walk a given directory tree and print files matching a given pattern.
Note: This task is for recursive methods. These tasks should read an entire directory tree, not a single directory.
Note: Please be careful when running any code examples found here.
Related task
Wal... | christopher/rosetta-code |
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