task_url stringlengths 30 116 | task_name stringlengths 2 86 | task_description stringlengths 0 14.4k | language_url stringlengths 2 53 | language_name stringlengths 1 52 | code stringlengths 0 61.9k | response_seed stringclasses 1
value | instruction_seed stringlengths 27 14.4k | _source stringclasses 1
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|---|---|---|---|---|---|---|---|---|
http://rosettacode.org/wiki/Topic_variable | Topic variable | Several programming languages offer syntax shortcuts to deal with the notion of "current" or "topic" variable.
A topic variable is a special variable with a very short name which can also often be omitted.
Demonstrate the utilization and behaviour of the topic variable within the language and explain or demonstrate h... | #Oforth | Oforth | 3 dup sq swap sqrt | Give a code snippet in #Oforth
Several programming languages offer syntax shortcuts to deal with the notion of "current" or "topic" variable.
A topic variable is a special variable with a very short name which can also often be omitted.
Demonstrate the utilization and behaviour of the topic variable within the langu... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Test_integerness | Test integerness | Mathematically,
the integers Z are included in the rational numbers Q,
which are included in the real numbers R,
which can be generalized to the complex numbers C.
This means that each of those larger sets, and the data types used to represent them, include some integers.
Task[edit]
Given a rational, real, or co... | #11l | 11l | F isint(f)
R Complex(f).imag == 0 & fract(Complex(f).real) == 0
print([Complex(1.0), 2, (3.0 + 0.0i), 4.1, (3 + 4i), (5.6 + 0i)].map(f -> isint(f)))
print(isint(25.000000))
print(isint(24.999999))
print(isint(25.000100))
print(isint(-5e-2))
print(isint(Float.infinity))
print(isint(5.0 + 0.0i))
print(isint(5 - 5i)) | Give a code snippet in #11l
Mathematically,
the integers Z are included in the rational numbers Q,
which are included in the real numbers R,
which can be generalized to the complex numbers C.
This means that each of those larger sets, and the data types used to represent them, include some integers.
Task[edit]
... | 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... | #BQN | BQN | o ← @‿'A'‿@‿'a'‿@ ⋄ m ← 5⥊↕2 ⋄ p ← m⊏∞‿26
Rot ← {i←⊑"A[a{"⍋𝕩 ⋄ i⊑o+p|(𝕨×m)+𝕩-o}⎉0 | Give a code snippet in #BQN
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... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Polyspiral | Polyspiral | A Polyspiral is a spiral made of multiple line segments, whereby each segment is larger (or smaller) than the previous one by a given amount. Each segment also changes direction at a given angle.
Task
Animate a series of polyspirals, by drawing a complete spiral then incrementing the angle, and (after clearing the b... | #IS-BASIC | IS-BASIC | 100 PROGRAM "PolySp.bas"
110 OPTION ANGLE DEGREES
120 LET CH=2
130 SET VIDEO X 40:SET VIDEO Y 27:SET VIDEO MODE 1:SET VIDEO COLOR 0
140 OPEN #1:"video:"
150 OPEN #2:"video:"
160 WHEN EXCEPTION USE POSERROR
170 FOR ANG=40 TO 150 STEP 2
180 IF CH=2 THEN
190 LET CH=1
200 ELSE
210 LET CH=2
220 END... | Give a code snippet in #IS-BASIC
A Polyspiral is a spiral made of multiple line segments, whereby each segment is larger (or smaller) than the previous one by a given amount. Each segment also changes direction at a given angle.
Task
Animate a series of polyspirals, by drawing a complete spiral then incrementing th... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Arithmetic/Integer | Arithmetic/Integer |
Basic Data Operation
This is a basic data operation. It represents a fundamental action on a basic data type.
You may see other such operations in the Basic Data Operations category, or:
Integer Operations
Arithmetic |
Comparison
Boolean Operations
Bitwise |
Logical
String Operations
Concatenation |
Interpolation |... | #FutureBasic | FutureBasic |
window 1, @"Integer Arithmetic", ( 0, 0, 400, 300 )
NSInteger a = 25
NSInteger b = 53
print "addition "a" + "b" = " (a + b)
print "subtraction "a" - "b" = " (a - b)
print "multiplication "a" * "b" = " (a * b)
print "division "a" / "b" = " (a / b)
printf @"float division %ld / %ld = %f", a, b, ... | Give a code snippet in #FutureBasic
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 Opera... | 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
... | #Sather | Sather | class MAIN is
main is
s ::= "asdf";
reversed ::= s.reverse;
-- current implementation does not handle multibyte encodings correctly
end;
end; | Give a code snippet in #Sather
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
Empt... | 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
| #Boo | Boo | a ← 10 | Give a code snippet in #Boo
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/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
... | #Racket | Racket |
#lang racket
(define (sort-table table
[ordering string<=?]
[column 0]
[reverse? #f])
(sort table (if reverse?
(negate ordering)
ordering)
#:key (λ (row) (list-ref row column))))
| Give a code snippet in #Racket
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; le... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sort_an_integer_array | Sort an integer array |
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
... | #TI-83_BASIC | TI-83 BASIC | :L1→L2
:SortA(L2)
| Give a code snippet in #TI-83_BASIC
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 |
Qu... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Knuth%27s_algorithm_S | Knuth's algorithm S | This is a method of randomly sampling n items from a set of M items, with equal probability; where M >= n and M, the number of items is unknown until the end.
This means that the equal probability sampling should be maintained for all successive items > n as they become available (although the content of successive sam... | #Icon_and_Unicon | Icon and Unicon | import Utils
procedure main(A)
freq := table(0)
every 1 to (\A[2] | 100000)\1 do {
s_of_n := s_of_n_creator(\A[1] | 3)
every sample := s_of_n(0 to 9)
every freq[!sample] +:= 1
}
every write(i := 0 to 9,": ",right(freq[i],6))
end
procedure s_of_n_creator(n)
items := []... | Give a code snippet in #Icon_and_Unicon
This is a method of randomly sampling n items from a set of M items, with equal probability; where M >= n and M, the number of items is unknown until the end.
This means that the equal probability sampling should be maintained for all successive items > n as they become availabl... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Shell_one-liner | Shell one-liner | Task
Show how to specify and execute a short program in the language from a command shell, where the input to the command shell is only one line in length.
Avoid depending on the particular shell or operating system used as much as is reasonable; if the language has notable implementations which have different comman... | #Rust | Rust | $ echo 'fn main(){println!("Hello!")}' | rustc -;./rust_out | Give a code snippet in #Rust
Task
Show how to specify and execute a short program in the language from a command shell, where the input to the command shell is only one line in length.
Avoid depending on the particular shell or operating system used as much as is reasonable; if the language has notable implementatio... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Reverse_words_in_a_string | Reverse words in a string | Task
Reverse the order of all tokens in each of a number of strings and display the result; the order of characters within a token should not be modified.
Example
Hey you, Bub! would be shown reversed as: Bub! you, Hey
Tokens are any non-space characters separated by spaces (formally, white-space); t... | #UNIX_Shell | UNIX Shell | while read -a words; do
for ((i=${#words[@]}-1; i>=0; i--)); do
printf "%s " "${words[i]}"
done
echo
done << END
---------- Ice and Fire ------------
fire, in end will world the say Some
ice. in say Some
desire of tasted I've what From
fire. favor who those with hold I
... ... | Give a code snippet in #UNIX_Shell
Task
Reverse the order of all tokens in each of a number of strings and display the result; the order of characters within a token should not be modified.
Example
Hey you, Bub! would be shown reversed as: Bub! you, Hey
Tokens are any non-space characters separated by... | 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... | #Free_Pascal | Free Pascal | program AssociativeArrayCreation;
{$IFDEF FPC}{$MODE DELPHI}{$ENDIF}
{$IFDEF WINDOWS}{$APPTYPE CONSOLE}{$ENDIF}
uses Generics.Collections;
var
lDictionary: TDictionary<string, Integer>;
begin
lDictionary := TDictionary<string, Integer>.Create;
try
lDictionary.Add('foo', 5);
lDictionary.Add('bar', 10);
... | Give a code snippet in #Free_Pascal
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: Defini... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Window_creation | Window creation | Display a GUI window. The window need not have any contents, but should respond to requests to be closed.
| #J | J | wdinfo 'Hamlet';'To be, or not to be: that is the question:' | Give a code snippet in #J
Display a GUI window. The window need not have any contents, but should respond to requests to be closed.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Count_occurrences_of_a_substring | Count occurrences of a substring | Task
Create a function, or show a built-in function, to count the number of non-overlapping occurrences of a substring inside a string.
The function should take two arguments:
the first argument being the string to search, and
the second a substring to be searched for.
It should return an integer cou... | #Factor | Factor | USING: math sequences splitting ;
: occurences ( seq subseq -- n ) split-subseq length 1 - ; | Give a code snippet in #Factor
Task
Create a function, or show a built-in function, to count the number of non-overlapping occurrences of a substring inside a string.
The function should take two arguments:
the first argument being the string to search, and
the second a substring to be searched for.
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Cumulative_standard_deviation | Cumulative standard deviation | Task[edit]
Write a stateful function, class, generator or co-routine that takes a series of floating point numbers, one at a time, and returns the running standard deviation of the series.
The task implementation should use the most natural programming style of those listed for the function in the implementation langu... | #COBOL | COBOL | IDENTIFICATION DIVISION.
PROGRAM-ID. run-stddev.
environment division.
input-output section.
file-control.
select input-file assign to "input.txt"
organization is line sequential.
data division.
file section.
fd input-file.
01 inp-record.
03 inp-fld pic 9(03).
working-storage section.
01 filler pic 9(01... | Give a code snippet in #COBOL
Task[edit]
Write a stateful function, class, generator or co-routine that takes a series of floating point numbers, one at a time, and returns the running standard deviation of the series.
The task implementation should use the most natural programming style of those listed for the funct... | 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 ... | #S-lang | S-lang | variable haystack = ["Zig","Zag","Wally","Ronald","Bush","Krusty","Charlie","Bush","Bozo","Ronald"];
define find(needle)
{
variable i = where(haystack == needle);
if (length(i)) {
% print(sprintf("%s: first=%d, last=%d", needle, i[0], i[-1]));
return(i[0], i[-1]);
}
else
throw App... | Give a code snippet in #S-lang
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/Monads/Writer_monad | Monads/Writer monad | The Writer monad is a programming design pattern which makes it possible to compose functions which return their result values paired with a log string. The final result of a composed function yields both a value, and a concatenation of the logs from each component function application.
Demonstrate in your programming... | #AppleScript | AppleScript | -- WRITER MONAD FOR APPLESCRIPT
-- How can we compose functions which take simple values as arguments
-- but return an output value which is paired with a log string ?
-- We can prevent functions which expect simple values from choking
-- on log-wrapped output (from nested functions)
-- by writing Unit/Return() an... | Give a code snippet in #AppleScript
The Writer monad is a programming design pattern which makes it possible to compose functions which return their result values paired with a log string. The final result of a composed function yields both a value, and a concatenation of the logs from each component function applicat... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Four_bit_adder | Four bit adder | Task
"Simulate" a four-bit adder.
This design can be realized using four 1-bit full adders.
Each of these 1-bit full adders can be built with two half adders and an or gate. ;
Finally a half adder can be made using an xor gate and an and gate.
The xor gate can be made using two nots, two ands ... | #PowerShell | PowerShell | function bxor2 ( [byte] $a, [byte] $b )
{
$out1 = $a -band ( -bnot $b )
$out2 = ( -bnot $a ) -band $b
$out1 -bor $out2
}
function hadder ( [byte] $a, [byte] $b )
{
@{
"S"=bxor2 $a $b
"C"=$a -band $b
}
}
function fadder ( [byte] $a, [byte] $b, [byte] $cd )
{
$out1 = hadder $cd... | Give a code snippet in #PowerShell
Task
"Simulate" a four-bit adder.
This design can be realized using four 1-bit full adders.
Each of these 1-bit full adders can be built with two half adders and an or gate. ;
Finally a half adder can be made using an xor gate and an and gate.
The xor gate can be ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Delegates | Delegates | A delegate is a helper object used by another object. The delegator may send the delegate certain messages, and provide a default implementation when there is no delegate or the delegate does not respond to a message. This pattern is heavily used in Cocoa framework on Mac OS X. See also wp:Delegation pattern.
Objects ... | #Racket | Racket | #lang racket
;; Delegates. Tim Brown 2014-10-16
(define delegator%
(class object%
(init-field [delegate #f])
(define/public (operation)
(cond [(and (object? delegate) (object-method-arity-includes? delegate 'thing 0))
(send delegate thing)]
[else "default implementation"]))
... | Give a code snippet in #Racket
A delegate is a helper object used by another object. The delegator may send the delegate certain messages, and provide a default implementation when there is no delegate or the delegate does not respond to a message. This pattern is heavily used in Cocoa framework on Mac OS X. See also ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sorting_algorithms/Insertion_sort | Sorting algorithms/Insertion 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
... | #Rascal | Rascal | import List;
public list[int] insertionSort(a){
for(i <- [0..size(a)-1]){
v = a[i];
j = i-1;
while(j >= 0 && a[j] > v){
a[j+1] = a[j];
j -= 1;
}
a[j+1] = v;
}
return a;
} | Give a code snippet in #Rascal
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/Sum_multiples_of_3_and_5 | Sum multiples of 3 and 5 | Task
The objective is to write a function that finds the sum of all positive multiples of 3 or 5 below n.
Show output for n = 1000.
This is is the same as Project Euler problem 1.
Extra credit: do this efficiently for n = 1e20 or higher.
| #EchoLisp | EchoLisp |
(lib 'math) ;; divides?
(lib 'sequences) ;; sum/when
(define (task n (k 3) (p 5 ))
(when (!= (gcd k p) 1) (error "expected coprimes" (list k p)))
(-
(+ (sum/mults n k) (sum/mults n p)) ;; add multiples of k , multiples of p
(sum/mults n (* k p)))) ;; remove multiples of k * p
;; using sequences
;; su... | Give a code snippet in #EchoLisp
Task
The objective is to write a function that finds the sum of all positive multiples of 3 or 5 below n.
Show output for n = 1000.
This is is the same as Project Euler problem 1.
Extra credit: do this efficiently for n = 1e20 or higher.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Program_name | Program name | The task is to programmatically obtain the name used to invoke the program. (For example determine whether the user ran "python hello.py", or "python hellocaller.py", a program importing the code from "hello.py".)
Sometimes a multiline shebang is necessary in order to provide the script name to a language's internal A... | #Octave | Octave | function main()
program = program_name();
printf("Program: %s", program);
endfunction
main(); | Give a code snippet in #Octave
The task is to programmatically obtain the name used to invoke the program. (For example determine whether the user ran "python hello.py", or "python hellocaller.py", a program importing the code from "hello.py".)
Sometimes a multiline shebang is necessary in order to provide the script... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Inheritance/Multiple | Inheritance/Multiple | Multiple inheritance allows to specify that one class is a subclass of several other classes.
Some languages allow multiple inheritance for arbitrary classes, others restrict it to interfaces, some don't allow it at all.
Task
Write two classes (or interfaces) Camera and MobilePhone, then write a class Camer... | #Pascal | Pascal | package Camera;
#functions go here...
1; | Give a code snippet in #Pascal
Multiple inheritance allows to specify that one class is a subclass of several other classes.
Some languages allow multiple inheritance for arbitrary classes, others restrict it to interfaces, some don't allow it at all.
Task
Write two classes (or interfaces) Camera and MobileP... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Square_but_not_cube | Square but not cube | Task
Show the first 30 positive integers which are squares but not cubes of such integers.
Optionally, show also the first 3 positive integers which are both squares and cubes, and mark them as such.
| #Perl | Perl | while ($cnt < 30) {
$n++;
$h{$n**2}++;
$h{$n**3}--;
$cnt++ if $h{$n**2} > 0;
}
print "First 30 positive integers that are a square but not a cube:\n";
print "$_ " for sort { $a <=> $b } grep { $h{$_} == 1 } keys %h;
print "\n\nFirst 3 positive integers that are both a square and a cube:\n";
print "$... | Give a code snippet in #Perl
Task
Show the first 30 positive integers which are squares but not cubes of such integers.
Optionally, show also the first 3 positive integers which are both squares and cubes, and mark them as such.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Program_termination | Program termination |
Task
Show the syntax for a complete stoppage of a program inside a conditional.
This includes all threads/processes which are part of your program.
Explain the cleanup (or lack thereof) caused by the termination (allocated memory, database connections, open files, object finalizers/destructors, run-on-exit hooks... | #Haskell | Haskell | import Control.Monad
import System.Exit
when problem do
exitWith ExitSuccess -- success
exitWith (ExitFailure integerErrorCode) -- some failure with code
exitSuccess -- success; in GHC 6.10+
exitFailure -- generic failure | Give a code snippet in #Haskell
Task
Show the syntax for a complete stoppage of a program inside a conditional.
This includes all threads/processes which are part of your program.
Explain the cleanup (or lack thereof) caused by the termination (allocated memory, database connections, open files, object finalize... | 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... | #ALGOL_68 | ALGOL 68 | # simple guess-the-number game #
main:(
BOOL valid input := TRUE;
# register an error handler so we can detect and recover from #
# invalid input #
on value error( stand in
, ( REF FILE f )BOOL:
BEGIN
valid input := FALSE;
... | Give a code snippet in #ALGOL_68
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:
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Even_or_odd | Even or odd | Task
Test whether an integer is even or odd.
There is more than one way to solve this task:
Use the even and odd predicates, if the language provides them.
Check the least significant digit. With binary integers, i bitwise-and 1 equals 0 iff i is even, or equals 1 iff i is odd.
Divide i by 2. The remainder equals... | #Z80_Assembly | Z80 Assembly | rrca
jp nc,isEven | Give a code snippet in #Z80_Assembly
Task
Test whether an integer is even or odd.
There is more than one way to solve this task:
Use the even and odd predicates, if the language provides them.
Check the least significant digit. With binary integers, i bitwise-and 1 equals 0 iff i is even, or equals 1 iff i is odd... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Increment_a_numerical_string | Increment a numerical string | Task
Increment a numerical string.
| #Kotlin | Kotlin | // version 1.0.5-2
/** overload ++ operator to increment a numeric string */
operator fun String.inc(): String =
try {
val num = this.toInt()
(num + 1).toString()
}
catch(e: NumberFormatException) {
this // return string unaltered
}
fun main(args: Array<String>) {
var ns... | Give a code snippet in #Kotlin
Task
Increment a numerical string.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Holidays_related_to_Easter | Holidays related to Easter | Task
Calculate the dates of:
Easter
Ascension Thursday
Pentecost
Trinity Sunday
Corpus Christi feast (for Catholic)
All Saints' Sunday (for Orthodox)
As an example, calculate for the first year of each century from;
years 400 to 2100 CE and for
years 2010 to 2020 CE.
Note
... | #PowerShell | PowerShell |
function Get-Easter
{
[CmdletBinding()]
[OutputType([PSCustomObject])]
Param
(
[Parameter(Mandatory=$true,
ValueFromPipeline=$true,
ValueFromPipelineByPropertyName=$true,
Position=0)]
[int]
$Year
)
Begin
{
... | Give a code snippet in #PowerShell
Task
Calculate the dates of:
Easter
Ascension Thursday
Pentecost
Trinity Sunday
Corpus Christi feast (for Catholic)
All Saints' Sunday (for Orthodox)
As an example, calculate for the first year of each century from;
years 400 to 2100 CE and for
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Check_output_device_is_a_terminal | Check output device is a terminal | Task
Demonstrate how to check whether the output device is a terminal or not.
Related task
Check input device is a terminal
| #Quackery | Quackery | [ $ |from sys import stdout
to_stack( 1 if stdout.isatty() else 0)|
python ] is ttyout ( --> b )
ttyout if
[ say "Looks like a teletype." ]
else
[ say "Not a teletype." ] | Give a code snippet in #Quackery
Task
Demonstrate how to check whether the output device is a terminal or not.
Related task
Check input device is a terminal
| 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 ... | #REXX | REXX | /*REXX program validates a user "word" against a "command table" with abbreviations.*/
parse arg uw /*obtain optional arguments from the CL*/
if uw='' then uw= 'riG rePEAT copies put mo rest types fup. 6 poweRin'
say 'user words: ' uw
@= 'add 1 alter 3 b... | Give a code snippet in #REXX
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 b... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Factorial | Factorial | Definitions
The factorial of 0 (zero) is defined as being 1 (unity).
The Factorial Function of a positive integer, n, is defined as the product of the sequence:
n, n-1, n-2, ... 1
Task
Write a function to return the factorial of a number.
Solutions can be iterat... | #Wart | Wart | def (fact n)
if (n = 0)
1
(n * (fact n-1)) | Give a code snippet in #Wart
Definitions
The factorial of 0 (zero) is defined as being 1 (unity).
The Factorial Function of a positive integer, n, is defined as the product of the sequence:
n, n-1, n-2, ... 1
Task
Write a function to return the factorial of a nu... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Even_or_odd | Even or odd | Task
Test whether an integer is even or odd.
There is more than one way to solve this task:
Use the even and odd predicates, if the language provides them.
Check the least significant digit. With binary integers, i bitwise-and 1 equals 0 iff i is even, or equals 1 iff i is odd.
Divide i by 2. The remainder equals... | #XBS | XBS | #>
Typed XBS
evenOrOdd function
true = even
false = odd
<#
func evenOrOdd(a:number=0){
send a%2==0;
}
set arr:array = [0,1,2,3,4,5,6,7,9,10];
foreach(v of arr){
log(v+" is even? "+evenOrOdd(v))
} | Give a code snippet in #XBS
Task
Test whether an integer is even or odd.
There is more than one way to solve this task:
Use the even and odd predicates, if the language provides them.
Check the least significant digit. With binary integers, i bitwise-and 1 equals 0 iff i is even, or equals 1 iff i is odd.
Divide... | 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 ... | #Elixir | Elixir | defmodule Prime do
def conspiracy(m) do
IO.puts "#{m} first primes. Transitions prime % 10 → next-prime % 10."
Enum.map(prime(m), &rem(&1, 10))
|> Enum.chunk(2,1)
|> Enum.reduce(Map.new, fn [a,b],acc -> Map.update(acc, {a,b}, 1, &(&1+1)) end)
|> Enum.sort
|> Enum.each(fn {{a,b},v} ->
... | Give a code snippet in #Elixir
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/Variable_size/Set | Variable size/Set | Task
Demonstrate how to specify the minimum size of a variable or a data type.
| #Raku | Raku | /*REXX program demonstrates on setting a variable (using a "minimum var size".*/
numeric digits 100 /*default: 9 (decimal digs) for numbers*/
/*── 1 2 3 4 5 6 7──*/
/*──1234567890123456789012345678901234567890123456789012345678901234567890──*... | Give a code snippet in #Raku
Task
Demonstrate how to specify the minimum size of a variable or a data type.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Ethiopian_multiplication | Ethiopian multiplication | Ethiopian multiplication is a method of multiplying integers using only addition, doubling, and halving.
Method:
Take two numbers to be multiplied and write them down at the top of two columns.
In the left-hand column repeatedly halve the last number, discarding any remainders, and write the result below the last ... | #Rascal | Rascal | import IO;
public int halve(int n) = n/2;
public int double(int n) = n*2;
public bool uneven(int n) = (n % 2) != 0);
public int ethiopianMul(int n, int m) {
result = 0;
while(n >= 1) {
if(uneven(n))
result += m;
n = halve(n);
m = double(m);
}
return result;
} | Give a code snippet in #Rascal
Ethiopian multiplication is a method of multiplying integers using only addition, doubling, and halving.
Method:
Take two numbers to be multiplied and write them down at the top of two columns.
In the left-hand column repeatedly halve the last number, discarding any remainders, and ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Bin_given_limits | Bin given limits | You are given a list of n ascending, unique numbers which are to form limits
for n+1 bins which count how many of a large set of input numbers fall in the
range of each bin.
(Assuming zero-based indexing)
bin[0] counts how many inputs are < limit[0]
bin[1] counts how many inputs are >= limit[0] and < limit[1]
... | #Phix | Phix | with javascript_semantics
function bin_it(sequence limits, data)
-- Bin data according to (ascending) limits.
sequence bins = repeat(0,length(limits)+1) -- adds under/over range bins too
for i=1 to length(data) do
integer bdx = binary_search(data[i],limits)
bdx = abs(bdx)+(bdx>0)
bi... | Give a code snippet in #Phix
You are given a list of n ascending, unique numbers which are to form limits
for n+1 bins which count how many of a large set of input numbers fall in the
range of each bin.
(Assuming zero-based indexing)
bin[0] counts how many inputs are < limit[0]
bin[1] counts how many inputs ar... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Catmull%E2%80%93Clark_subdivision_surface | Catmull–Clark subdivision surface | Implement the Catmull-Clark surface subdivision (description on Wikipedia), which is an algorithm that maps from a surface (described as a set of points and a set of polygons with vertices at those points) to another more refined surface. The resulting surface will always consist of a mesh of quadrilaterals.
The proce... | #Nim | Nim | import algorithm
import tables
const None = -1 # Index number used to indicate no data.
type
Point = array[3, float]
Face = seq[int]
Edge = object
pn1: int # Point number 1.
pn2: int # Point number 2.
fn1: int # Face number 1.
fn2: int # Face number 2.
cp: Point # Cente... | Give a code snippet in #Nim
Implement the Catmull-Clark surface subdivision (description on Wikipedia), which is an algorithm that maps from a surface (described as a set of points and a set of polygons with vertices at those points) to another more refined surface. The resulting surface will always consist of a mesh ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Idiomatically_determine_all_the_characters_that_can_be_used_for_symbols | Idiomatically determine all the characters that can be used for symbols | Idiomatically determine all the characters that can be used for symbols.
The word symbols is meant things like names of variables, procedures (i.e., named fragments of programs, functions, subroutines, routines), statement labels, events or conditions, and in general, anything a computer programmer can choose to name, ... | #Racket | Racket | #lang racket
;; Symbols that don't need to be specially quoted:
(printf "~s~%" '(a a-z 3rd ...---... .hidden-files-look-like-this))
;; Symbols that do need to be specially quoted:
(define bar-sym-list
`(|3|
|i have a space|
|i've got a quote in me|
|i'm not a "dot on my own", but my neighbour is!|
|... | Give a code snippet in #Racket
Idiomatically determine all the characters that can be used for symbols.
The word symbols is meant things like names of variables, procedures (i.e., named fragments of programs, functions, subroutines, routines), statement labels, events or conditions, and in general, anything a computer... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Arithmetic-geometric_mean | Arithmetic-geometric mean |
This page uses content from Wikipedia. The original article was at Arithmetic-geometric mean. 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
Write a function to compute the arithmetic-geomet... | #VBScript | VBScript |
Function agm(a,g)
Do Until a = tmp_a
tmp_a = a
a = (a + g)/2
g = Sqr(tmp_a * g)
Loop
agm = a
End Function
WScript.Echo agm(1,1/Sqr(2))
| Give a code snippet in #VBScript
This page uses content from Wikipedia. The original article was at Arithmetic-geometric mean. 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
Write a functio... | christopher/rosetta-code | |
http://rosettacode.org/wiki/24_game | 24 game | The 24 Game tests one's mental arithmetic.
Task
Write a program that randomly chooses and displays four digits, each from 1 ──► 9 (inclusive) with repetitions allowed.
The program should prompt for the player to enter an arithmetic expression using just those, and all of those four digits, used exactly once each. T... | #Elixir | Elixir | defmodule Game24 do
def main do
IO.puts "24 Game"
play
end
defp play do
IO.puts "Generating 4 digits..."
digts = for _ <- 1..4, do: Enum.random(1..9)
IO.puts "Your digits\t#{inspect digts, char_lists: :as_lists}"
read_eval(digts)
play
end
defp read_eval(digits) do
exp = IO.... | Give a code snippet in #Elixir
The 24 Game tests one's mental arithmetic.
Task
Write a program that randomly chooses and displays four digits, each from 1 ──► 9 (inclusive) with repetitions allowed.
The program should prompt for the player to enter an arithmetic expression using just those, and all of those four d... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Linear_congruential_generator | Linear congruential generator | The linear congruential generator is a very simple example of a random number generator.
All linear congruential generators use this formula:
r
n
+
1
=
a
×
r
n
+
c
(
mod
m
)
{\displaystyle r_{n+1}=a\times r_{n}+c{\pmod {m}}}
Where:
r
0
{\displaystyle r_{0}}
is a seed.
r
1
... | #PL.2FI | PL/I |
(nofixedoverflow, nosize):
LCG: procedure options (main);
declare i fixed binary;
put skip list ('BSD', 'MS');
do i = 1 to 20;
put skip list (BSD(), MS());
end;
bsd: procedure returns (fixed binary (31));
declare const fixed binary static initial (12345);
declare s fixed binary (31) stat... | Give a code snippet in #PL.2FI
The linear congruential generator is a very simple example of a random number generator.
All linear congruential generators use this formula:
r
n
+
1
=
a
×
r
n
+
c
(
mod
m
)
{\displaystyle r_{n+1}=a\times r_{n}+c{\pmod {m}}}
Where:
r
0
{\displaystyle ... | 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... | #PureBasic | PureBasic |
If OpenConsole()
cadena$ = "<name> went for a walk in the park. <he or she> found a <noun>. <name> decided to take it home."
k = FindString(cadena$, "<")
PrintN("La historia: ")
Print(cadena$ + Chr(10))
While k
reemplaza$ = Mid(cadena$, k, FindString(cadena$, ">") - k + 1)
Print(Chr(10) + "What ... | Give a code snippet in #PureBasic
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 ga... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Angle_difference_between_two_bearings | Angle difference between two bearings | Finding the angle between two bearings is often confusing.[1]
Task
Find the angle which is the result of the subtraction b2 - b1, where b1 and b2 are the bearings.
Input bearings are expressed in the range -180 to +180 degrees.
The result is also expressed in the range -180 to +180 degrees.
... | #AWK | AWK |
# syntax: GAWK -f ANGLE_DIFFERENCE_BETWEEN_TWO_BEARINGS.AWK
BEGIN {
fmt = "%11s %11s %11s\n"
while (++i <= 11) { u = u "-" }
printf(fmt,"B1","B2","DIFFERENCE")
printf(fmt,u,u,u)
main(20,45)
main(-45,45)
main(-85,90)
main(-95,90)
main(-45,125)
main(-45,145)
main(29.4803,-88.... | Give a code snippet in #AWK
Finding the angle between two bearings is often confusing.[1]
Task
Find the angle which is the result of the subtraction b2 - b1, where b1 and b2 are the bearings.
Input bearings are expressed in the range -180 to +180 degrees.
The result is also expressed in the range -1... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sequence_of_non-squares | Sequence of non-squares | Task
Show that the following remarkable formula gives the sequence of non-square natural numbers:
n + floor(1/2 + sqrt(n))
Print out the values for n in the range 1 to 22
Show that no squares occur for n less than one million
This is sequence A000037 in the OEIS database.
| #Red | Red | Red ["Sequence of non-squares"]
repeat i 999'999 [
n: i + round/floor 0.5 + sqrt i
if i < 23 [prin [to-integer n ""]]
if equal? round/floor n sqrt n [
print "Square found!"
break
]
] | Give a code snippet in #Red
Task
Show that the following remarkable formula gives the sequence of non-square natural numbers:
n + floor(1/2 + sqrt(n))
Print out the values for n in the range 1 to 22
Show that no squares occur for n less than one million
This is sequence A000037 ... | 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... | #Forth | Forth | include random.fs
variable flips
create nums 9 cells allot
: .array ( addr len -- ) 0 ?do dup @ . cell+ loop drop ;
: shuffle ( addr len -- )
2 swap do
dup i random cells +
over @ over @ swap
rot ! over !
cell+
-1 +loop drop ;
: sorted? ( addr len -- )
1- cells bounds ?do
i 2@ < if u... | Give a code snippet in #Forth
Task
Given a jumbled list of the numbers 1 to 9 that are definitely not in
ascending order.
Show the list, and then ask the player how many digits from the
left to reverse.
Reverse those digits, then ask again, until all the digits end up in ascending order.
The sc... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Doubly-linked_list/Traversal | Doubly-linked list/Traversal | Traverse from the beginning of a doubly-linked list to the end, and from the end to the beginning.
See also
Array
Associative array: Creation, Iteration
Collections
Compound data type
Doubly-linked list: Definition, Element definition, Element insertion, List Traversal, Element Removal
Linked list
Queue: Def... | #Clojure | Clojure | (def dl (double-list [:a :b :c :d]))
;=> #'user/dl
((juxt seq rseq) dl)
;=> [(:a :b :c :d) (:d :c :b :a)]
(take-while identity (iterate get-next (get-head dl)))
;=> (#:double_list.Node{:prev nil, :next #<Object...>, :data :a, :key #<Object...>}
;=> #:double_list.Node{:prev #<Object...>, :next #<Object...>... | Give a code snippet in #Clojure
Traverse from the beginning of a doubly-linked list to the end, and from the end to the beginning.
See also
Array
Associative array: Creation, Iteration
Collections
Compound data type
Doubly-linked list: Definition, Element definition, Element insertion, List Traversal, Element... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Department_numbers | Department numbers | There is a highly organized city that has decided to assign a number to each of their departments:
police department
sanitation department
fire department
Each department can have a number between 1 and 7 (inclusive).
The three department numbers are to be unique (different from each other) and mu... | #Tiny_BASIC | Tiny BASIC | PRINT "Police Sanitation Fire"
PRINT "------|----------|----"
10 LET P = P + 2
LET S = 0
20 LET S = S + 1
LET F = 0
IF S = P THEN GOTO 20
30 LET F = F + 1
IF S = F THEN GOTO 30
IF F = P THEN GOTO 30
IF P + S + F = 12 THEN PRINT " ",P," ", S," ", F
IF F < 7 THEN GOTO 30
IF S <... | Give a code snippet in #Tiny_BASIC
There is a highly organized city that has decided to assign a number to each of their departments:
police department
sanitation department
fire department
Each department can have a number between 1 and 7 (inclusive).
The three department numbers are to be uniqu... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Linear_congruential_generator | Linear congruential generator | The linear congruential generator is a very simple example of a random number generator.
All linear congruential generators use this formula:
r
n
+
1
=
a
×
r
n
+
c
(
mod
m
)
{\displaystyle r_{n+1}=a\times r_{n}+c{\pmod {m}}}
Where:
r
0
{\displaystyle r_{0}}
is a seed.
r
1
... | #Seed7 | Seed7 | $ include "seed7_05.s7i";
include "bigint.s7i";
var bigInteger: bsdSeed is 0_;
var bigInteger: msSeed is 0_;
const func integer: bsdRand is func
result
var integer: bsdRand is 0;
begin
bsdSeed := (1103515245_ * bsdSeed + 12345_) mod 2147483648_;
bsdRand := ord(bsdSeed);
end func;
const func in... | Give a code snippet in #Seed7
The linear congruential generator is a very simple example of a random number generator.
All linear congruential generators use this formula:
r
n
+
1
=
a
×
r
n
+
c
(
mod
m
)
{\displaystyle r_{n+1}=a\times r_{n}+c{\pmod {m}}}
Where:
r
0
{\displaystyle r... | christopher/rosetta-code | |
http://rosettacode.org/wiki/XML/DOM_serialization | XML/DOM serialization | Create a simple DOM and having it serialize to:
<?xml version="1.0" ?>
<root>
<element>
Some text here
</element>
</root>
| #Clojure | Clojure |
(require '[clojure.data.xml :as xml])
(def xml-example (xml/element :root {} (xml/element :element {} "Some text here")))
(with-open [out-file (java.io.OutputStreamWriter.
(java.io.FileOutputStream. "/tmp/output.xml") "UTF-8")]
(xml/emit xml-example out-file))
| Give a code snippet in #Clojure
Create a simple DOM and having it serialize to:
<?xml version="1.0" ?>
<root>
<element>
Some text here
</element>
</root>
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Shell_one-liner | Shell one-liner | Task
Show how to specify and execute a short program in the language from a command shell, where the input to the command shell is only one line in length.
Avoid depending on the particular shell or operating system used as much as is reasonable; if the language has notable implementations which have different comman... | #E | E | rune --src.e 'println("Hello")' | Give a code snippet in #E
Task
Show how to specify and execute a short program in the language from a command shell, where the input to the command shell is only one line in length.
Avoid depending on the particular shell or operating system used as much as is reasonable; if the language has notable implementations ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/CSV_data_manipulation | CSV data manipulation | CSV spreadsheet files are suitable for storing tabular data in a relatively portable way.
The CSV format is flexible but somewhat ill-defined.
For present purposes, authors may assume that the data fields contain no commas, backslashes, or quotation marks.
Task
Read a CSV file, change some values and save the cha... | #UNIX_Shell | UNIX Shell | cat csv | while read S; do
[ -z ${S##*C*} ] && echo $S,SUM || echo $S,`echo $S | tr ',' '+' | bc`
done | Give a code snippet in #UNIX_Shell
CSV spreadsheet files are suitable for storing tabular data in a relatively portable way.
The CSV format is flexible but somewhat ill-defined.
For present purposes, authors may assume that the data fields contain no commas, backslashes, or quotation marks.
Task
Read a CSV file,... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Box_the_compass | Box the compass | There be many a land lubber that knows naught of the pirate ways and gives direction by degree!
They know not how to box the compass!
Task description
Create a function that takes a heading in degrees and returns the correct 32-point compass heading.
Use the function to print and display a table of Index, Compass... | #Befunge | Befunge | >>::"}"9**\4+3%79*9*5-*79*9*5--+:5>>>06p:55+%68*+v
^_@#!`*84:+1<v*9"}"*+55,,,".",,,$$_^#!:-1g60/+55\<
>_06g:v>55+,^>/5+55+/48*::::,,,,%:1+.9,:06p48*\-0v
|p60-1<|<!p80:<N|Ev"northwest"0"North by west"0p8<
>:#,_>>>_08g1-^W|S>"-htroN"0"htron yb tsewhtroN"0v
#v"est-northwest"0"Northwest by west"0"Northwest"<
N>"W"0"htron y... | Give a code snippet in #Befunge
There be many a land lubber that knows naught of the pirate ways and gives direction by degree!
They know not how to box the compass!
Task description
Create a function that takes a heading in degrees and returns the correct 32-point compass heading.
Use the function to print and ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Copy_a_string | Copy a string | This task is about copying a string.
Task
Where it is relevant, distinguish between copying the contents of a string
versus making an additional reference to an existing string.
Other tasks related to string operations:
Metrics
Array length
String length
Copy a string
Empty string (assignment)
Counting
W... | #Lingo | Lingo | str = "Hello world!"
str2 = str | Give a code snippet in #Lingo
This task is about copying a string.
Task
Where it is relevant, distinguish between copying the contents of a string
versus making an additional reference to an existing string.
Other tasks related to string operations:
Metrics
Array length
String length
Copy a string
Empty s... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Start_from_a_main_routine | Start from a main routine |
Some languages (like Gambas and Visual Basic) support two startup modes. Applications written in these languages start with an open window that waits for events, and it is necessary to do some trickery to cause a main procedure to run instead. Data driven or event driven languages may also require similar tricker... | #Ada | Ada | with Ada.Text_IO;
procedure Foo is
begin
Ada.Text_IO.Put_Line("Bar");
end Foo; | Give a code snippet in #Ada
Some languages (like Gambas and Visual Basic) support two startup modes. Applications written in these languages start with an open window that waits for events, and it is necessary to do some trickery to cause a main procedure to run instead. Data driven or event driven languages may... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Best_shuffle | Best shuffle | Task
Shuffle the characters of a string in such a way that as many of the character values are in a different position as possible.
A shuffle that produces a randomized result among the best choices is to be preferred. A deterministic approach that produces the same sequence every time is acceptable as an alternative... | #Ruby | Ruby | def best_shuffle(s)
# Fill _pos_ with positions in the order
# that we want to fill them.
pos = []
# g["a"] = [2, 4] implies that s[2] == s[4] == "a"
g = s.length.times.group_by { |i| s[i] }
# k sorts letters from low to high count
k = g.sort_by { |k, v| v.length }.map { |k, v| k }
until g.empty?
... | Give a code snippet in #Ruby
Task
Shuffle the characters of a string in such a way that as many of the character values are in a different position as possible.
A shuffle that produces a randomized result among the best choices is to be preferred. A deterministic approach that produces the same sequence every time i... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Symmetric_difference | Symmetric difference | Task
Given two sets A and B, compute
(
A
∖
B
)
∪
(
B
∖
A
)
.
{\displaystyle (A\setminus B)\cup (B\setminus A).}
That is, enumerate the items that are in A or B but not both. This set is called the symmetric difference of A and B.
In other words:
(
A
∪
B
)
∖
(
A
∩
B
)
{\displaystyle (A\cup B)\setminus (A... | #Java | Java | import java.util.Arrays;
import java.util.HashSet;
import java.util.Set;
public class SymmetricDifference {
public static void main(String[] args) {
Set<String> setA = new HashSet<String>(Arrays.asList("John", "Serena", "Bob", "Mary", "Serena"));
Set<String> setB = new HashSet<String>(Arrays.asLis... | Give a code snippet in #Java
Task
Given two sets A and B, compute
(
A
∖
B
)
∪
(
B
∖
A
)
.
{\displaystyle (A\setminus B)\cup (B\setminus A).}
That is, enumerate the items that are in A or B but not both. This set is called the symmetric difference of A and B.
In other words:
(
A
∪
B
)
∖
(
A
∩
B
)
{\disp... | 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... | #Wren | Wren | var x = 1.5
var y = x / 0
System.print("x = %(x)")
System.print("y = %(y)")
System.print("'x' is infinite? %(x.isInfinity)")
System.print("'y' is infinite? %(y.isInfinity)") | Give a code snippet in #Wren
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/Loops/Break | Loops/Break | Task
Show a loop which prints random numbers (each number newly generated each loop) from 0 to 19 (inclusive).
If a number is 10, stop the loop after printing it, and do not generate any further numbers.
Otherwise, generate and print a second random number before restarting the loop.
If the number 10 is never gener... | #360_Assembly | 360 Assembly | * Loops Break 15/02/2017
LOOPBREA CSECT
USING LOOPBREA,R13 base register
B 72(R15) skip savearea
DC 17F'0' savearea
STM R14,R12,12(R13) prolog
ST R13,4(R15) " <-
ST R15,8(R13) ... | Give a code snippet in #360_Assembly
Task
Show a loop which prints random numbers (each number newly generated each loop) from 0 to 19 (inclusive).
If a number is 10, stop the loop after printing it, and do not generate any further numbers.
Otherwise, generate and print a second random number before restarting the ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Literals/Floating_point | Literals/Floating point | Programming languages have different ways of expressing floating-point literals.
Task
Show how floating-point literals can be expressed in your language: decimal or other bases, exponential notation, and any other special features.
You may want to include a regular expression or BNF/ABNF/EBNF defining allowable fo... | #Maple | Maple |
> 123.456; # decimal notation
123.456
> 1.23456e2; # scientific notation
123.456
> Float( 23, -2 ); # float constructor notation, by mantissa and exponent
0.23
> Float( .123456, 3 ); # again
... | Give a code snippet in #Maple
Programming languages have different ways of expressing floating-point literals.
Task
Show how floating-point literals can be expressed in your language: decimal or other bases, exponential notation, and any other special features.
You may want to include a regular expression or BNF/... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Power_set | Power set | A set is a collection (container) of certain values,
without any particular order, and no repeated values.
It corresponds with a finite set in mathematics.
A set can be implemented as an associative array (partial mapping)
in which the value of each key-value pair is ignored.
Given a set S, the power set (or pow... | #XPL0 | XPL0 | func PowSet(Set, Size);
int Set, Size;
int N, M, Mask, DoComma;
[ChOut(0, ^{);
for N:= 0 to 1<<Size -1 do
[if N>0 then ChOut(0, ^,);
ChOut(0, ^{);
Mask:= 1; DoComma:= false;
for M:= 0 to Size-1 do
[if Mask & N then
[if DoComma then ChOut(0, ^,);
IntOut(0, Set(M));
... | Give a code snippet in #XPL0
A set is a collection (container) of certain values,
without any particular order, and no repeated values.
It corresponds with a finite set in mathematics.
A set can be implemented as an associative array (partial mapping)
in which the value of each key-value pair is ignored.
Given ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Temperature_conversion | Temperature conversion | There are quite a number of temperature scales. For this task we will concentrate on four of the perhaps best-known ones:
Kelvin, Celsius, Fahrenheit, and Rankine.
The Celsius and Kelvin scales have the same magnitude, but different null points.
0 degrees Celsius corresponds to 273.15 kelvin.
0 kelvin is absolute z... | #UNIX_Shell | UNIX Shell | #!/bin/ksh
# Temperature conversion
typeset tt[1]=0.00 tt[2]=273.15 tt[3]=373.15
for i in {1..3}
do
((t=tt[i]))
echo $i
echo "Kelvin: $t K"
echo "Celsius: $((t-273.15)) C"
echo "Fahrenheit: $((t*18/10-459.67)) F"
echo "Rankine: $((t*18/10)) R"
done | Give a code snippet in #UNIX_Shell
There are quite a number of temperature scales. For this task we will concentrate on four of the perhaps best-known ones:
Kelvin, Celsius, Fahrenheit, and Rankine.
The Celsius and Kelvin scales have the same magnitude, but different null points.
0 degrees Celsius corresponds to 27... | 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... | #Groovy | Groovy | def fib = {
assert it > -1
{i -> i < 2 ? i : {j -> owner.call(j)}(i-1) + {k -> owner.call(k)}(i-2)}(it)
} | Give a code snippet in #Groovy
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 unwan... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Pangram_checker | Pangram checker | Pangram checker
You are encouraged to solve this task according to the task description, using any language you may know.
A pangram is a sentence that contains all the letters of the English alphabet at least once.
For example: The quick brown fox jumps over the lazy dog.
Task
Write a function or method to chec... | #Seed7 | Seed7 | $ include "seed7_05.s7i";
const func boolean: isPangram (in string: stri) is func
result
var boolean: isPangram is FALSE;
local
var char: ch is ' ';
var set of char: usedChars is (set of char).value;
begin
for ch range lower(stri) do
if ch in {'a' .. 'z'} then
incl(usedChars, ch);
... | Give a code snippet in #Seed7
Pangram checker
You are encouraged to solve this task according to the task description, using any language you may know.
A pangram is a sentence that contains all the letters of the English alphabet at least once.
For example: The quick brown fox jumps over the lazy dog.
Task
Wri... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Non-continuous_subsequences | Non-continuous subsequences | Consider some sequence of elements. (It differs from a mere set of elements by having an ordering among members.)
A subsequence contains some subset of the elements of this sequence, in the same order.
A continuous subsequence is one in which no elements are missing between the first and last elements of the subseque... | #Clojure | Clojure |
(use '[clojure.contrib.combinatorics :only (subsets)])
(defn of-min-length [min-length]
(fn [s] (>= (count s) min-length)))
(defn runs [c l]
(map (partial take l) (take-while not-empty (iterate rest c))))
(defn is-subseq? [c sub]
(some identity (map = (runs c (count sub)) (repeat sub))))
(defn non-conti... | Give a code snippet in #Clojure
Consider some sequence of elements. (It differs from a mere set of elements by having an ordering among members.)
A subsequence contains some subset of the elements of this sequence, in the same order.
A continuous subsequence is one in which no elements are missing between the first ... | 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... | #Lingo | Lingo | the floatprecision = 8
sum = 0
repeat with i = 1 to 1000
sum = sum + 1/power(i, 2)
end repeat
put sum
-- 1.64393457 | Give a code snippet in #Lingo
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... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Pick_random_element | Pick random element | Demonstrate how to pick a random element from a list.
| #PHP | PHP | $arr = array('foo', 'bar', 'baz');
$x = $arr[array_rand($arr)]; | Give a code snippet in #PHP
Demonstrate how to pick a random element from a list.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Copy_a_string | Copy a string | This task is about copying a string.
Task
Where it is relevant, distinguish between copying the contents of a string
versus making an additional reference to an existing string.
Other tasks related to string operations:
Metrics
Array length
String length
Copy a string
Empty string (assignment)
Counting
W... | #OxygenBasic | OxygenBasic |
string s, t="hello"
s=t
| Give a code snippet in #OxygenBasic
This task is about copying a string.
Task
Where it is relevant, distinguish between copying the contents of a string
versus making an additional reference to an existing string.
Other tasks related to string operations:
Metrics
Array length
String length
Copy a string
E... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Loops/For | Loops/For | “For” loops are used to make some block of code be iterated a number of times, setting a variable or parameter to a monotonically increasing integer value for each execution of the block of code.
Common extensions of this allow other counting patterns or iterating over abstract structures other than the integers.
... | #Octave | Octave | for i = 0:1:4
for j = 0:1:i
printf("*");
endfor
printf("\n");
endfor | Give a code snippet in #Octave
“For” loops are used to make some block of code be iterated a number of times, setting a variable or parameter to a monotonically increasing integer value for each execution of the block of code.
Common extensions of this allow other counting patterns or iterating over abstract struct... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Increment_a_numerical_string | Increment a numerical string | Task
Increment a numerical string.
| #Elixir | Elixir | increment1 = fn n -> to_string(String.to_integer(n) + 1) end
# Or piped
increment2 = fn n -> n |> String.to_integer |> +1 |> to_string end
increment1.("1")
increment2.("100") | Give a code snippet in #Elixir
Task
Increment a numerical string.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Remove_duplicate_elements | Remove duplicate elements |
Sorting Algorithm
This is a sorting algorithm. It may be applied to a set of data in order to sort it.
For comparing various sorts, see compare sorts.
For other sorting algorithms, see sorting algorithms, or:
O(n logn) sorts
Heap sort |
Merge sort |
Patience sort |
Quick sort
O(n log2n) sorts
Shell Sort
... | #MAXScript | MAXScript | uniques = #(1, 2, 3, "a", "b", "c", 2, 3, 4, "b", "c", "d")
for i in uniques.count to 1 by -1 do
(
id = findItem uniques uniques[i]
if (id != i) do deleteItem uniques i
) | Give a code snippet in #MAXScript
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 |
Quic... | 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... | #ALGOL_68 | ALGOL 68 | BEGIN # find the largest decimal integer with unique digits, divisible by its digits #
INT magic = 9 * 8 * 7; # see analysis in the Raku sample #
INT high = 9876432 OVER magic * magic;
BOOL found := FALSE;
FOR i FROM high BY - magic TO magic WHILE NOT found DO
IF INT d1 = i MOD 10;
... | Give a code snippet in #ALGOL_68
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) an... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Pangram_checker | Pangram checker | Pangram checker
You are encouraged to solve this task according to the task description, using any language you may know.
A pangram is a sentence that contains all the letters of the English alphabet at least once.
For example: The quick brown fox jumps over the lazy dog.
Task
Write a function or method to chec... | #Ksh | Ksh |
#!/bin/ksh
# Pangram checker
# # Variables:
#
alphabet='abcdefghijklmnopqrstuvwxyz'
typeset -a strs
strs+=( 'Mr. Jock, TV quiz PhD., bags few lynx.' )
strs+=( 'A very mad quack might jinx zippy fowls.' )
# # Functions:
#
# # Function _ispangram(str) - return 0 if str is a pangram
#
function _ispangram {
ty... | Give a code snippet in #Ksh
Pangram checker
You are encouraged to solve this task according to the task description, using any language you may know.
A pangram is a sentence that contains all the letters of the English alphabet at least once.
For example: The quick brown fox jumps over the lazy dog.
Task
Write... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Zig-zag_matrix | Zig-zag matrix | Task
Produce a zig-zag array.
A zig-zag array is a square arrangement of the first N2 natural numbers, where the
numbers increase sequentially as you zig-zag along the array's anti-diagonals.
For a graphical representation, see JPG zigzag (JPG uses such arrays to encode images).
For example, gi... | #Objeck | Objeck |
function : native : ZigZag(size : Int) ~ Int[,] {
data := Int->New[size, size];
i := 1;
j := 1;
max := size * size;
for(element := 0; element < max ; element += 1;) {
data[i - 1, j - 1] := element;
if((i + j) % 2 = 0) {
# even stripes
if(j < size){
j += 1;
}
else{... | Give a code snippet in #Objeck
Task
Produce a zig-zag array.
A zig-zag array is a square arrangement of the first N2 natural numbers, where the
numbers increase sequentially as you zig-zag along the array's anti-diagonals.
For a graphical representation, see JPG zigzag (JPG uses such arrays to en... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sum_and_product_of_an_array | Sum and product of an array | Task
Compute the sum and product of an array of integers.
| #Mathematica.2FWolfram_Language | Mathematica/Wolfram Language | a = {1, 2, 3, 4, 5}
Plus @@ a
Apply[Plus, a]
Total[a]
Total@a
a // Total
Sum[a[[i]], {i, 1, Length[a]}]
Sum[i, {i, a}] | Give a code snippet in #Mathematica.2FWolfram_Language
Task
Compute the sum and product of an array of integers.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Population_count | Population count | Population count
You are encouraged to solve this task according to the task description, using any language you may know.
The population count is the number of 1s (ones) in the binary representation of a non-negative integer.
Population count is also known as:
pop count
popcount
sideways sum
... | #Clojure | Clojure |
(defn population-count [n]
(Long/bitCount n)) ; use Java inter-op
(defn exp [n pow]
(reduce * (repeat pow n)))
(defn evil? [n]
(even? (population-count n)))
(defn odious? [n]
(odd? (population-count n)))
;;
;; Clojure's support for generating "lazily-evaluated" infinite sequences can
;; be use... | Give a code snippet in #Clojure
Population count
You are encouraged to solve this task according to the task description, using any language you may know.
The population count is the number of 1s (ones) in the binary representation of a non-negative integer.
Population count is also known as:
pop cou... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sierpinski_triangle | Sierpinski triangle | Task
Produce an ASCII representation of a Sierpinski triangle of order N.
Example
The Sierpinski triangle of order 4 should look like this:
*
* *
* *
* * * *
* *
* * * *
... | #Haskell | Haskell | sierpinski 0 = ["*"]
sierpinski n = map ((space ++) . (++ space)) down ++
map (unwords . replicate 2) down
where down = sierpinski (n - 1)
space = replicate (2 ^ (n - 1)) ' '
main = mapM_ putStrLn $ sierpinski 4 | Give a code snippet in #Haskell
Task
Produce an ASCII representation of a Sierpinski triangle of order N.
Example
The Sierpinski triangle of order 4 should look like this:
*
* *
* *
* * * *
* *
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Temperature_conversion | Temperature conversion | There are quite a number of temperature scales. For this task we will concentrate on four of the perhaps best-known ones:
Kelvin, Celsius, Fahrenheit, and Rankine.
The Celsius and Kelvin scales have the same magnitude, but different null points.
0 degrees Celsius corresponds to 273.15 kelvin.
0 kelvin is absolute z... | #Plain_English | Plain English | To run:
Start up.
Put 21 into a kelvin temperature.
Show the kelvin temperature in various temperature scales.
Wait for the escape key.
Shut down.
A temperature is a fraction.
A kelvin temperature is a temperature.
A celsius temperature is a temperature.
A rankine temperature is a temperature.
A fahrenheit temperatur... | Give a code snippet in #Plain_English
There are quite a number of temperature scales. For this task we will concentrate on four of the perhaps best-known ones:
Kelvin, Celsius, Fahrenheit, and Rankine.
The Celsius and Kelvin scales have the same magnitude, but different null points.
0 degrees Celsius corresponds to... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Special_characters | Special characters | Special characters are symbols (single characters or sequences of characters) that have a "special" built-in meaning in the language and typically cannot be used in identifiers.
Escape sequences are methods that the language uses to remove the special meaning from the symbol, enabling it to be used as a normal charact... | #HicEst | HicEst | \b backspace
\d delete
\e escape
\f formfeed
\l linefeed
\n newline
\r return
\t horizontal tab
\v vertical tab
\' single quote
\" double quote
\\ backslash
\ddd octal code
\xdd hexadecimal code
\^c control code | Give a code snippet in #HicEst
Special characters are symbols (single characters or sequences of characters) that have a "special" built-in meaning in the language and typically cannot be used in identifiers.
Escape sequences are methods that the language uses to remove the special meaning from the symbol, enabling i... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Count_occurrences_of_a_substring | Count occurrences of a substring | Task
Create a function, or show a built-in function, to count the number of non-overlapping occurrences of a substring inside a string.
The function should take two arguments:
the first argument being the string to search, and
the second a substring to be searched for.
It should return an integer cou... | #UNIX_Shell | UNIX Shell | #!/bin/bash
function countString(){
input=$1
cnt=0
until [ "${input/$2/}" == "$input" ]; do
input=${input/$2/}
let cnt+=1
done
echo $cnt
}
countString "the three truths" "th"
countString "ababababab" "abab" | Give a code snippet in #UNIX_Shell
Task
Create a function, or show a built-in function, to count the number of non-overlapping occurrences of a substring inside a string.
The function should take two arguments:
the first argument being the string to search, and
the second a substring to be searched for... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Multiplication_tables | Multiplication tables | Task
Produce a formatted 12×12 multiplication table of the kind memorized by rote when in primary (or elementary) school.
Only print the top half triangle of products.
| #Julia | Julia | using Printf
println(" X | 1 2 3 4 5 6 7 8 9 10 11 12")
println("---+------------------------------------------------")
for i=1:12, j=0:12
if j == 0
@printf("%2d | ", i)
elseif i <= j
@printf("%3d%c", i * j, j == 12 ? '\n' : ' ')
else
print(" ")
end
en... | Give a code snippet in #Julia
Task
Produce a formatted 12×12 multiplication table of the kind memorized by rote when in primary (or elementary) school.
Only print the top half triangle of products.
| 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
| #GW-BASIC | GW-BASIC | 10 PRINT "Hello world!" | Give a code snippet in #GW-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 erro... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Seven-sided_dice_from_five-sided_dice | Seven-sided dice from five-sided dice | Task
(Given an equal-probability generator of one of the integers 1 to 5
as dice5), create dice7 that generates a pseudo-random integer from
1 to 7 in equal probability using only dice5 as a source of random
numbers, and check the distribution for at least one million calls using the function created in Simple R... | #Fortran | Fortran | module rand_mod
implicit none
contains
function rand5()
integer :: rand5
real :: r
call random_number(r)
rand5 = 5*r + 1
end function
function rand7()
integer :: rand7
do
rand7 = 5*rand5() + rand5() - 6
if (rand7 < 21) then
rand7 = rand7 / 3 + 1
return
end if
end do
end... | Give a code snippet in #Fortran
Task
(Given an equal-probability generator of one of the integers 1 to 5
as dice5), create dice7 that generates a pseudo-random integer from
1 to 7 in equal probability using only dice5 as a source of random
numbers, and check the distribution for at least one million calls using t... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Undefined_values | Undefined values | #Scala | Scala | var x; # declared, but not defined
x == nil && say "nil value";
defined(x) || say "undefined";
# Give "x" some value
x = 42;
defined(x) && say "defined";
# Change "x" back to `nil`
x = nil;
defined(x) || say "undefined"; | Give a code snippet in #Scala
| christopher/rosetta-code | ||
http://rosettacode.org/wiki/Execute_a_system_command | Execute a system command | Task
Run either the ls system command (dir on Windows), or the pause system command.
Related task
Get system command output
| #Maxima | Maxima | system("dir > list.txt")$ | Give a code snippet in #Maxima
Task
Run either the ls system command (dir on Windows), or the pause system command.
Related task
Get system command output
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Fusc_sequence | Fusc sequence |
Definitions
The fusc integer sequence is defined as:
fusc(0) = 0
fusc(1) = 1
for n>1, the nth term is defined as:
if n is even; fusc(n) = fusc(n/2)
if n is odd; fusc(n) = fusc((n-1)/2) + fusc((n+1)/2)
Note that MathWorld's definition starts with unity, not zero. Th... | #Java | Java |
public class FuscSequence {
public static void main(String[] args) {
System.out.println("Show the first 61 fusc numbers (starting at zero) in a horizontal format");
for ( int n = 0 ; n < 61 ; n++ ) {
System.out.printf("%,d ", fusc[n]);
}
System.out.printf("%n%nSho... | Give a code snippet in #Java
Definitions
The fusc integer sequence is defined as:
fusc(0) = 0
fusc(1) = 1
for n>1, the nth term is defined as:
if n is even; fusc(n) = fusc(n/2)
if n is odd; fusc(n) = fusc((n-1)/2) + fusc((n+1)/2)
Note that MathWorld's definition sta... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Loop_over_multiple_arrays_simultaneously | Loop over multiple arrays simultaneously | Task
Loop over multiple arrays (or lists or tuples or whatever they're called in
your language) and display the i th element of each.
Use your language's "for each" loop if it has one, otherwise iterate
through the collection in order with some other loop.
For this example, loop over the arrays:
... | #BaCon | BaCon |
DECLARE a1$[] = {"a", "b", "c"} TYPE STRING
DECLARE a2$[] = {"A", "B", "C"} TYPE STRING
DECLARE a3[] = {1, 2, 3} TYPE int
WHILE (a3[i] <= 3)
PRINT a1$[i], a2$[i], a3[i]
INCR i
WEND
| Give a code snippet in #BaCon
Task
Loop over multiple arrays (or lists or tuples or whatever they're called in
your language) and display the i th element of each.
Use your language's "for each" loop if it has one, otherwise iterate
through the collection in order with some other loop.
For this exam... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Variable_size/Get | Variable size/Get | Demonstrate how to get the size of a variable.
See also: Host introspection
| #Lasso | Lasso | local(
mystring = 'Hello World',
myarray = array('one', 'two', 3),
myinteger = 1234
)
// size of a string will be a character count
#mystring -> size
'<br />'
// size of an array or map will be a count of elements
#myarray -> size
'<br />'
// elements within an array can report size
#myarray -> get(2) -> size... | Give a code snippet in #Lasso
Demonstrate how to get the size of a variable.
See also: Host introspection
| 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... | #Seed7 | Seed7 | $ include "seed7_05.s7i";
include "time.s7i";
const proc: main is func
begin
writeln(time(NOW));
end func; | Give a code snippet in #Seed7
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/Create_a_two-dimensional_array_at_runtime | Create a two-dimensional array at runtime |
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.
Get two integers from the user, then create a two-dimensional array where the two dimensions have the sizes given by those numbers, and which can be accessed ... | #Action.21 | Action! | SET EndProg=* | Give a code snippet in #Action.21
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.
Get two integers from the user, then create a two-dimensional array where the two dimensions have the sizes given by those ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Arrays | Arrays | This task is about arrays.
For hashes or associative arrays, please see Creating an Associative Array.
For a definition and in-depth discussion of what an array is, see Array.
Task
Show basic array syntax in your language.
Basically, create an array, assign a value to it, and retrieve an element (if available,... | #zkl | zkl | var array=List(); // array of size 0
array=(0).pump(10,List().write,5).copy(); // [writable] array of size 10 filled with 5
array[3]=4;
array[3] //-->4
array+9; //append a 9 to the end, same as array.append(9) | Give a code snippet in #zkl
This task is about arrays.
For hashes or associative arrays, please see Creating an Associative Array.
For a definition and in-depth discussion of what an array is, see Array.
Task
Show basic array syntax in your language.
Basically, create an array, assign a value to it, and retriev... | 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... | #Ada | Ada | with Ada.Text_IO;
with CryptAda.Pragmatics;
with CryptAda.Digests.Message_Digests.RIPEMD_160;
with CryptAda.Digests.Hashes;
with CryptAda.Utils.Format;
procedure RC_RIPEMD_160 is
use CryptAda.Pragmatics;
use CryptAda.Digests.Message_Digests;
use CryptAda.Digests;
function To_Byte_Array (Item : String)... | Give a code snippet in #Ada
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 ASCI... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Hello_world/Line_printer | Hello world/Line printer | Task
Cause a line printer attached to the computer to print a line containing the message: Hello World!
Note
A line printer is not the same as standard output.
A line printer was an older-style printer which prints one line at a time to a continuous ream of paper.
With some systems, a line printer can be... | #Ruby | Ruby | open("| lpr", "w") { |f| f.puts "Hello World!" } | Give a code snippet in #Ruby
Task
Cause a line printer attached to the computer to print a line containing the message: Hello World!
Note
A line printer is not the same as standard output.
A line printer was an older-style printer which prints one line at a time to a continuous ream of paper.
With some ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Bulls_and_cows | Bulls and cows | Bulls and Cows
Task
Create a four digit random number from the digits 1 to 9, without duplication.
The program should:
ask for guesses to this number
reject guesses that are malformed
print the score for the guess
The score is computed as:
The player wins if the guess is the same as the random... | #Scheme | Scheme |
;generate a random non-repeating list of 4 digits, 1-9 inclusive
(define (get-num)
(define (gen lst)
(if (= (length lst) 4) lst
(let ((digit (+ (random 9) 1)))
(if (member digit lst) ;make sure the new digit isn't in the
;list
(gen lst)
... | Give a code snippet in #Scheme
Bulls and Cows
Task
Create a four digit random number from the digits 1 to 9, without duplication.
The program should:
ask for guesses to this number
reject guesses that are malformed
print the score for the guess
The score is computed as:
The player wins if the... | 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 ... | #VBA | VBA | Function IsInArray(stringToBeFound As Variant, arr As Variant, _
Optional start As Integer = 1, Optional reverse As Boolean = False) As Long
'Adapted from https://stackoverflow.com/questions/12414168/use-of-custom-data-types-in-vba
Dim i As Long, lo As Long, hi As Long, stp As Long
' default return value if... | Give a code snippet in #VBA
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... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Greatest_common_divisor | Greatest common divisor | Greatest common divisor
You are encouraged to solve this task according to the task description, using any language you may know.
Task
Find the greatest common divisor (GCD) of two integers.
Greatest common divisor is also known as greatest common factor (gcf) and greatest common measure.
Related tas... | #Nanoquery | Nanoquery | def gcd(a, b)
factor = a.min(b)
for loop in range(factor, 2)
if (a % loop = 0) and (b % loop = 0)
return loop
end
end
return 1
end | Give a code snippet in #Nanoquery
Greatest common divisor
You are encouraged to solve this task according to the task description, using any language you may know.
Task
Find the greatest common divisor (GCD) of two integers.
Greatest common divisor is also known as greatest common factor (gcf) and grea... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Send_email | Send email | Task
Write a function to send an email.
The function should have parameters for setting From, To and Cc addresses; the Subject, and the message text, and optionally fields for the server name and login details.
If appropriate, explain what notifications of problems/success are given.
Solutions using libraries or f... | #PowerShell | PowerShell |
[hashtable]$mailMessage = @{
From = "weirdBoy@gmail.com"
To = "anudderBoy@YourDomain.com"
Cc = "daWaghBoss@YourDomain.com"
Attachment = "C:\temp\Waggghhhh!_plan.txt"
Subject = "Waggghhhh!"
Body = "Wagggghhhhhh!"
SMTPServer = "smtp.gmail.com"
SMTPPort = "587"
UseSsl = $true
Erro... | Give a code snippet in #PowerShell
Task
Write a function to send an email.
The function should have parameters for setting From, To and Cc addresses; the Subject, and the message text, and optionally fields for the server name and login details.
If appropriate, explain what notifications of problems/success are gi... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Introspection | Introspection | Task
verify the version/revision of your currently running (compiler/interpreter/byte-compiler/runtime environment/whatever your language uses) and exit if it is too old.
check whether the variable "bloop" exists and whether the math-function "abs()" is available and if yes compute abs(bloop).
Extra credit
Repor... | #Common_Lisp | Common Lisp | (let* ((ver (lisp-implementation-version))
(major (parse-integer ver :start 0 :end (position #\. ver))))
#+lispworks (assert (>= 5 major) () "Requires Lispworks version 5 or above")
#+clisp (assert (>= 2 major) () "Requires CLISP 2.n")
) | Give a code snippet in #Common_Lisp
Task
verify the version/revision of your currently running (compiler/interpreter/byte-compiler/runtime environment/whatever your language uses) and exit if it is too old.
check whether the variable "bloop" exists and whether the math-function "abs()" is available and if yes compu... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Tau_function | Tau function | Given a positive integer, count the number of its positive divisors.
Task
Show the result for the first 100 positive integers.
Related task
Tau number
| #PureBasic | PureBasic | If OpenConsole()
For i=1 To 100
If i<3 : Print(RSet(Str(i),4)) : Continue :EndIf
c=2
For j=2 To i/2+1 : c+Bool(i%j=0) : Next
Print(RSet(Str(c),4))
If i%10=0 : PrintN("") : EndIf
Next
Input()
EndIf
End | Give a code snippet in #PureBasic
Given a positive integer, count the number of its positive divisors.
Task
Show the result for the first 100 positive integers.
Related task
Tau number
| christopher/rosetta-code |
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