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/EKG_sequence_convergence | EKG sequence convergence | The sequence is from the natural numbers and is defined by:
a(1) = 1;
a(2) = Start = 2;
for n > 2, a(n) shares at least one prime factor with a(n-1) and is the smallest such natural number not already used.
The sequence is called the EKG sequence (after its visual similarity to an electrocardiogram when graphed).... | #Raku | Raku | sub infix:<shares-divisors-with> { ($^a gcd $^b) > 1 }
sub next-EKG ( *@s ) {
return first {
@s ∌ $_ and @s.tail shares-divisors-with $_
}, 2..*;
}
sub EKG ( Int $start ) { 1, $start, &next-EKG … * }
sub converge-at ( @ints ) {
my @ekgs = @ints.map: &EKG;
return (2 .. *).first: -> $i... | Give a code snippet in #Raku
The sequence is from the natural numbers and is defined by:
a(1) = 1;
a(2) = Start = 2;
for n > 2, a(n) shares at least one prime factor with a(n-1) and is the smallest such natural number not already used.
The sequence is called the EKG sequence (after its visual similarity to an el... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sorting_algorithms/Shell_sort | Sorting algorithms/Shell 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
... | #Common_Lisp | Common Lisp | (defun gap-insertion-sort (array predicate gap)
(let ((length (length array)))
(if (< length 2) array
(do ((i 1 (1+ i))) ((eql i length) array)
(do ((x (aref array i))
(j i (- j gap)))
((or (< (- j gap) 0)
(not (funcall predicate x (aref array (1- j)))))
... | Give a code snippet in #Common_Lisp
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/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... | #Ada | Ada |
with Ada.Text_Io; use Ada.Text_Io;
with Ada.Integer_Text_Io; use Ada.Integer_Text_Io;
with Ada.Numerics.Discrete_Random;
procedure NumberReverse is
subtype RandRange is Integer range 1..9;
type NumArrayType is array (Integer range 1..9) of Integer;
package RandNumbers is new Ada.Numerics.Discrete_Rando... | Give a code snippet in #Ada
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 scor... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Curzon_numbers | Curzon numbers | A Curzon number is defined to be a positive integer n for which 2n + 1 is evenly divisible by 2 × n + 1.
Generalized Curzon numbers are those where the positive integer n, using a base integer k, satisfy the condition that kn + 1 is evenly divisible by k × n + 1.
Base here does not imply the radix of the counting sys... | #Sidef | Sidef | func is_curzon(n, k) {
powmod(k, n, k*n + 1).is_congruent(-1, k*n + 1) && (n > 0)
}
for k in (2 .. 10 `by` 2) {
say "\nFirst 50 Curzon numbers using a base of #{k}:"
say 50.by {|n| is_curzon(n, k) }.join(' ')
say ("1000th term: ", 1000.th {|n| is_curzon(n,k) })
} | Give a code snippet in #Sidef
A Curzon number is defined to be a positive integer n for which 2n + 1 is evenly divisible by 2 × n + 1.
Generalized Curzon numbers are those where the positive integer n, using a base integer k, satisfy the condition that kn + 1 is evenly divisible by k × n + 1.
Base here does not impl... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Attractive_numbers | Attractive numbers | A number is an attractive number if the number of its prime factors (whether distinct or not) is also prime.
Example
The number 20, whose prime decomposition is 2 × 2 × 5, is an attractive number because the number of its prime factors (3) is also prime.
Task
Show sequence items up to 120.... | #jq | jq |
def count(s): reduce s as $x (null; .+1);
def is_attractive:
count(prime_factors) | is_prime;
def printattractive($m; $n):
"The attractive numbers from \($m) to \($n) are:\n",
[range($m; $n+1) | select(is_attractive)];
printattractive(1; 120) | Give a code snippet in #jq
A number is an attractive number if the number of its prime factors (whether distinct or not) is also prime.
Example
The number 20, whose prime decomposition is 2 × 2 × 5, is an attractive number because the number of its prime factors (3) is also prime.
Task
Show... | 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... | #PureBasic | PureBasic | CompilerIf #PB_Compiler_Version<441
CompilerError "You failed the version check!"
CompilerEndIf
CompilerIf Defined(bloop,#PB_Variable)
CompilerIf Defined(Abs(),#PB_Function)
Abs(bloop)
CompilerEndIf
CompilerEndIf | Give a code snippet in #PureBasic
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... | 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... | #zkl | zkl | d:=Dictionary(); do{ d[(1).random(10)]=True }while(d.len()<4);
abcd:=d.keys.shuffle();
while(1){
guess:=ask("4 digits: ")-" ,";
if(guess.len()!=4 or guess.unique().len()!=4) continue;
bulls:=abcd.zipWith('==,guess).sum(0);
cows:=guess.split("").enumerate()
.reduce('wrap(s,[(n,c)]){ s + (d.find(c,False... | Give a code snippet in #zkl
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 gu... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Search_a_list_of_records | Search a list of records | Many programming languages provide convenient ways to look for a known value in a simple list of strings or numbers.
But what if the elements of the list are themselves compound records/objects/data-structures, and the search condition is more complex than a simple equality test?
Task[edit]
Write a function/method/et... | #Haskell | Haskell | import Data.List (findIndex, find)
data City = City
{ name :: String
, population :: Float
} deriving (Read, Show)
-- CITY PROPERTIES ------------------------------------------------------------
cityName :: City -> String
cityName (City x _) = x
cityPop :: City -> Float
cityPop (City _ x) = x
mbCityName :... | Give a code snippet in #Haskell
Many programming languages provide convenient ways to look for a known value in a simple list of strings or numbers.
But what if the elements of the list are themselves compound records/objects/data-structures, and the search condition is more complex than a simple equality test?
Task... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Binary_strings | Binary strings | Many languages have powerful and useful (binary safe) string manipulation functions, while others don't, making it harder for these languages to accomplish some tasks.
This task is about creating functions to handle binary strings (strings made of arbitrary bytes, i.e. byte strings according to Wikipedia) for those la... | #OCaml | OCaml | # String.create 10 ;;
- : string = "\000\023\000\000\001\000\000\000\000\000" | Give a code snippet in #OCaml
Many languages have powerful and useful (binary safe) string manipulation functions, while others don't, making it harder for these languages to accomplish some tasks.
This task is about creating functions to handle binary strings (strings made of arbitrary bytes, i.e. byte strings accor... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Fork | Fork | Task
Spawn a new process which can run simultaneously with, and independently of, the original parent process.
| #HicEst | HicEst | SYSTEM( RUN )
WRITE(Messagebox='?Y', IOStat=ios) "Another Fork?"
IF(ios == 2) ALARM(999) ! quit immediately
! assume this script is stored as 'Fork.hic'
SYSTEM(SHell='Fork.hic')
BEEP("c e g 'c")
WRITE(Messagebox="!") "Waiting ..."
ALARM(999) ! quit immediately | Give a code snippet in #HicEst
Task
Spawn a new process which can run simultaneously with, and independently of, the original parent process.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Display_an_outline_as_a_nested_table | Display an outline as a nested table |
Display an outline as a nested table.
Parse the outline to a tree,
count the leaves descending from each node,
and write out a table with 'colspan' values
measuring the indent of each line,
translating the indentation to a nested structure,
and padding the tree to even depth.
defining the width of a ... | #Haskell | Haskell | {-# LANGUAGE TupleSections #-}
module OutlineTree where
import Data.Bifunctor (first)
import Data.Bool (bool)
import Data.Char (isSpace)
import Data.List (find, intercalate)
import Data.Tree (Tree (..), foldTree, levels)
---------------- NESTED TABLES FROM OUTLINE --------------
wikiTablesFromOutline :: [String... | Give a code snippet in #Haskell
Display an outline as a nested table.
Parse the outline to a tree,
count the leaves descending from each node,
and write out a table with 'colspan' values
measuring the indent of each line,
translating the indentation to a nested structure,
and padding the tree to even ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Fibonacci_word/fractal | Fibonacci word/fractal |
The Fibonacci word may be represented as a fractal as described here:
(Clicking on the above website (hal.archives-ouvertes.fr) will leave a cookie.)
For F_wordm start with F_wordCharn=1
Draw a segment forward
If current F_wordChar is 0
Turn left if n is even
Turn right if n is odd
next n and iterate until e... | #Wren | Wren | import "graphics" for Canvas, Color
import "dome" for Window
class FibonacciWordFractal {
construct new(width, height, n) {
Window.title = "Fibonacci Word Fractal"
Window.resize(width, height)
Canvas.resize(width, height)
_fore = Color.green
_wordFractal = wordFractal(n)
... | Give a code snippet in #Wren
The Fibonacci word may be represented as a fractal as described here:
(Clicking on the above website (hal.archives-ouvertes.fr) will leave a cookie.)
For F_wordm start with F_wordCharn=1
Draw a segment forward
If current F_wordChar is 0
Turn left if n is even
Turn right if n is ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Nth_root | Nth root | Task
Implement the algorithm to compute the principal nth root
A
n
{\displaystyle {\sqrt[{n}]{A}}}
of a positive real number A, as explained at the Wikipedia page.
| #Java | Java | public static double nthroot(int n, double A) {
return nthroot(n, A, .001);
}
public static double nthroot(int n, double A, double p) {
if(A < 0) {
System.err.println("A < 0");// we handle only real positive numbers
return -1;
} else if(A == 0) {
return 0;
}
double x_prev = A;
double x = A / n; // starting... | Give a code snippet in #Java
Task
Implement the algorithm to compute the principal nth root
A
n
{\displaystyle {\sqrt[{n}]{A}}}
of a positive real number A, as explained at the Wikipedia page.
| 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... | #Pascal | Pascal | if true then
begin
halt
end | Give a code snippet in #Pascal
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 finalizer... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sorting_algorithms/Gnome_sort | Sorting algorithms/Gnome 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
... | #Rust | Rust | fn gnome_sort<T: PartialOrd>(a: &mut [T]) {
let len = a.len();
let mut i: usize = 1;
let mut j: usize = 2;
while i < len {
if a[i - 1] <= a[i] {
// for descending sort, use >= for comparison
i = j;
j += 1;
} else {
a.swap(i - 1, i);
... | Give a code snippet in #Rust
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/String_matching | String matching |
Basic Data Operation
This is a basic data operation. It represents a fundamental action on a basic data type.
You may see other such operations in the Basic Data Operations category, or:
Integer Operations
Arithmetic |
Comparison
Boolean Operations
Bitwise |
Logical
String Operations
Concatenation |
Interpolation |... | #Delphi | Delphi | program CharacterMatching;
{$APPTYPE CONSOLE}
uses StrUtils;
begin
WriteLn(AnsiStartsText('ab', 'abcd')); // True
WriteLn(AnsiEndsText('zn', 'abcd')); // False
WriteLn(AnsiContainsText('abcd', 'bb')); // False
Writeln(AnsiContainsText('abcd', 'ab')); // True
WriteLn(Pos('ab', 'abcd')); // 1
end. | Give a code snippet in #Delphi
Basic Data Operation
This is a basic data operation. It represents a fundamental action on a basic data type.
You may see other such operations in the Basic Data Operations category, or:
Integer Operations
Arithmetic |
Comparison
Boolean Operations
Bitwise |
Logical
String Operations... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Emirp_primes | Emirp primes | An emirp (prime spelled backwards) are primes that when reversed (in their decimal representation) are a different prime.
(This rules out palindromic primes.)
Task
show the first twenty emirps
show all emirps between 7,700 and 8,000
show the 10,000th emirp
In each list, the numbe... | #Rust | Rust | #![feature(iterator_step_by)]
extern crate primal;
fn is_prime(n: u64) -> bool {
if n == 2 || n == 3 || n == 5 || n == 7 || n == 11 || n == 13 { return true; }
if n % 2 == 0 || n % 3 == 0 || n % 5 == 0 || n % 7 == 0 || n % 11 == 0 || n % 13 == 0 { return false; }
let root = (n as f64).sqrt() as u64 + 1;... | Give a code snippet in #Rust
An emirp (prime spelled backwards) are primes that when reversed (in their decimal representation) are a different prime.
(This rules out palindromic primes.)
Task
show the first twenty emirps
show all emirps between 7,700 and 8,000
show the 10,000th e... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Pascal%27s_triangle/Puzzle | Pascal's triangle/Puzzle | This puzzle involves a Pascals Triangle, also known as a Pyramid of Numbers.
[ 151]
[ ][ ]
[40][ ][ ]
[ ][ ][ ][ ]
[ X][11][ Y][ 4][ Z]
Each brick of the pyramid is the sum of the two bricks situated below it.
Of the three missing numbers at the base of the pyramid,
the... | #PicoLisp | PicoLisp | (be number (@N @Max)
(^ @C (box 0))
(repeat)
(or
((^ @ (>= (val (-> @C)) (-> @Max))) T (fail))
((^ @N (inc (-> @C)))) ) )
(be + (@A @B @Sum)
(^ @ (-> @A))
(^ @ (-> @B))
(^ @Sum (+ (-> @A) (-> @B))) )
(be + (@A @B @Sum)
(^ @ (-> @A))
(^ @ (-> @Sum))
(^ @B (- (-> @Sum) (-> @A)))... | Give a code snippet in #PicoLisp
This puzzle involves a Pascals Triangle, also known as a Pyramid of Numbers.
[ 151]
[ ][ ]
[40][ ][ ]
[ ][ ][ ][ ]
[ X][11][ Y][ 4][ Z]
Each brick of the pyramid is the sum of the two bricks situated below it.
Of the three missing numbe... | 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... | #DCL | DCL | $ i = 1024
$Loop:
$ IF ( i .LE. 0 ) THEN GOTO LoopEnd
$ WRITE sys$output F$FAO( " i = !4UL", i ) ! formatted ASCII output, fixed-width field
$ ! Output alternatives:
$ ! WRITE sys$output F$STRING( i ) ! explicit integer-to-string conversion
$ ! WRITE sys$output i ! implicit conversion ... | Give a code snippet in #DCL
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 ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Array_length | Array length | Task
Determine the amount of elements in an array.
As an example use an array holding the strings 'apple' and 'orange'.
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 befo... | #DataWeave | DataWeave | var arr = ["apple", "orange"]
sizeOf(arr)
| Give a code snippet in #DataWeave
Task
Determine the amount of elements in an array.
As an example use an array holding the strings 'apple' and 'orange'.
Other tasks related to string operations:
Metrics
Array length
String length
Copy a string
Empty string (assignment)
Counting
Word frequency
Letter f... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Currying | Currying |
This page uses content from Wikipedia. The original article was at Currying. 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
Create a simple demonstrative example of Currying in a specific la... | #AppleScript | AppleScript | -- curry :: (Script|Handler) -> Script
on curry(f)
script
on |λ|(a)
script
on |λ|(b)
|λ|(a, b) of mReturn(f)
end |λ|
end script
end |λ|
end script
end curry
-- TESTS --------------------------------------------------... | Give a code snippet in #AppleScript
This page uses content from Wikipedia. The original article was at Currying. 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
Create a simple demonstrative... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Cistercian_numerals | Cistercian numerals | Cistercian numerals were used across Europe by Cistercian monks during the Late Medieval Period as an alternative to Roman numerals. They were used to represent base 10 integers from 0 to 9999.
How they work
All Cistercian numerals begin with a vertical line segment, which by itself represents the number 0. Then, glyp... | #Ruby | Ruby | def initN
n = Array.new(15){Array.new(11, ' ')}
for i in 1..15
n[i - 1][5] = 'x'
end
return n
end
def horiz(n, c1, c2, r)
for c in c1..c2
n[r][c] = 'x'
end
end
def verti(n, r1, r2, c)
for r in r1..r2
n[r][c] = 'x'
end
end
def diagd(n, c1, c2, r)
for c in... | Give a code snippet in #Ruby
Cistercian numerals were used across Europe by Cistercian monks during the Late Medieval Period as an alternative to Roman numerals. They were used to represent base 10 integers from 0 to 9999.
How they work
All Cistercian numerals begin with a vertical line segment, which by itself repre... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Trabb_Pardo%E2%80%93Knuth_algorithm | Trabb Pardo–Knuth algorithm | The TPK algorithm is an early example of a programming chrestomathy.
It was used in Donald Knuth and Luis Trabb Pardo's Stanford tech report The Early Development of Programming Languages.
The report traces the early history of work in developing computer languages in the 1940s and 1950s, giving several translations of... | #Picat | Picat | import util.
go =>
L = [I.parse_term() : I in split(read_line())],
S = [[I,cond(F<=400,F,'TOO LARGE')] : I in L.len..-1..1, F=f(L[I])],
println(S),
nl.
f(T) = sqrt(abs(T)) + 5*T**3. | Give a code snippet in #Picat
The TPK algorithm is an early example of a programming chrestomathy.
It was used in Donald Knuth and Luis Trabb Pardo's Stanford tech report The Early Development of Programming Languages.
The report traces the early history of work in developing computer languages in the 1940s and 1950s,... | 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... | #Scratch | Scratch | $ include "seed7_05.s7i";
const type: cacheType is hash [integer] boolean;
var cacheType: cache is cacheType.value;
const func boolean: happy (in var integer: number) is func
result
var boolean: isHappy is FALSE;
local
var bitset: cycle is bitset.value;
var integer: newnumber is 0;
var integer: ... | Give a code snippet in #Scratch
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 endlessl... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sorting_algorithms/Bogosort | Sorting algorithms/Bogosort |
Sorting Algorithm
This is a sorting algorithm. It may be applied to a set of data in order to sort it.
For comparing various sorts, see compare sorts.
For other sorting algorithms, see sorting algorithms, or:
O(n logn) sorts
Heap sort |
Merge sort |
Patience sort |
Quick sort
O(n log2n) sorts
Shell Sort
... | #Euphoria | Euphoria | function shuffle(sequence s)
object temp
integer j
for i = length(s) to 1 by -1 do
j = rand(i)
if i != j then
temp = s[i]
s[i] = s[j]
s[j] = temp
end if
end for
return s
end function
function inOrder(sequence s)
for i = 1 to length(s)... | Give a code snippet in #Euphoria
Sorting Algorithm
This is a sorting algorithm. It may be applied to a set of data in order to sort it.
For comparing various sorts, see compare sorts.
For other sorting algorithms, see sorting algorithms, or:
O(n logn) sorts
Heap sort |
Merge sort |
Patience sort |
Quick... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Factorions | Factorions |
Definition
A factorion is a natural number that equals the sum of the factorials of its digits.
Example
145 is a factorion in base 10 because:
1! + 4! + 5! = 1 + 24 + 120 = 145
It can be shown (see talk page) that no factorion in base 10 can exceed 1,499,999.
Task
Write a progr... | #Mathematica_.2F_Wolfram_Language | Mathematica / Wolfram Language | ClearAll[FactorionQ]
FactorionQ[n_,b_:10]:=Total[IntegerDigits[n,b]!]==n
Select[Range[1500000],FactorionQ[#,9]&]
Select[Range[1500000],FactorionQ[#,10]&]
Select[Range[1500000],FactorionQ[#,11]&]
Select[Range[1500000],FactorionQ[#,12]&] | Give a code snippet in #Mathematica_.2F_Wolfram_Language
Definition
A factorion is a natural number that equals the sum of the factorials of its digits.
Example
145 is a factorion in base 10 because:
1! + 4! + 5! = 1 + 24 + 120 = 145
It can be shown (see talk page) that no factorion... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Loops/For_with_a_specified_step | Loops/For with a specified step |
Task
Demonstrate a for-loop where the step-value is greater than one.
Related tasks
Loop over multiple arrays simultaneously
Loops/Break
Loops/Continue
Loops/Do-while
Loops/Downward for
Loops/For
Loops/For with a specified step
Loops/Foreach
Loops/Increment loop index within loop b... | #MAXScript | MAXScript | for i = 0 to 10 by 2 do format "%\n" i | Give a code snippet in #MAXScript
Task
Demonstrate a for-loop where the step-value is greater than one.
Related tasks
Loop over multiple arrays simultaneously
Loops/Break
Loops/Continue
Loops/Do-while
Loops/Downward for
Loops/For
Loops/For with a specified step
Loops/Foreach
Loops... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Greatest_element_of_a_list | Greatest element of a list | Task
Create a function that returns the maximum value in a provided set of values,
where the number of values may not be known until run-time.
| #Batch_File | Batch File | ::max.cmd
@echo off
setlocal enabledelayedexpansion
set a=.%~1
if "%a%" equ "." set /p a="Input stream: "
call :max res %a%
echo %res%
endlocal
goto :eof
:max
set %1=%2
:loop
shift /2
if "%2" equ "" goto :eof
if %2 gtr !%1! set res=%2
goto loop | Give a code snippet in #Batch_File
Task
Create a function that returns the maximum value in a provided set of values,
where the number of values may not be known until run-time.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Mandelbrot_set | Mandelbrot set | Mandelbrot set
You are encouraged to solve this task according to the task description, using any language you may know.
Task
Generate and draw the Mandelbrot set.
Note that there are many algorithms to draw Mandelbrot set and there are many functions which generate it .
| #Inform_7 | Inform 7 | "Mandelbrot"
The story headline is "A Non-Interactive Set".
Include Glimmr Drawing Commands by Erik Temple.
[Q20 fixed-point or floating-point: see definitions below]
Use floating-point math.
Finished is a room.
The graphics-window is a graphics g-window spawned by the main-window.
The position is g-placeabov... | Give a code snippet in #Inform_7
Mandelbrot set
You are encouraged to solve this task according to the task description, using any language you may know.
Task
Generate and draw the Mandelbrot set.
Note that there are many algorithms to draw Mandelbrot set and there are many functions which generate it .
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Doubly-linked_list/Definition | Doubly-linked list/Definition | Define the data structure for a complete Doubly Linked List.
The structure should support adding elements to the head, tail and middle of the list.
The structure should not allow circular loops
See also
Array
Associative array: Creation, Iteration
Collections
Compound data type
Doubly-linked list: Definitio... | #Racket | Racket |
#lang racket
(define-struct dlist (head tail) #:mutable #:transparent)
(define-struct dlink (content prev next) #:mutable #:transparent)
(define (insert-between dlist before after data)
; Insert a fresh link containing DATA after existing link
; BEFORE if not nil and before existing link AFTER if not nil
(de... | Give a code snippet in #Racket
Define the data structure for a complete Doubly Linked List.
The structure should support adding elements to the head, tail and middle of the list.
The structure should not allow circular loops
See also
Array
Associative array: Creation, Iteration
Collections
Compound data typ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/User_input/Text | User input/Text | User input/Text is part of Short Circuit's Console Program Basics selection.
Task
Input a string and the integer 75000 from the text console.
See also: User input/Graphical
| #Julia | Julia |
print("String? ")
y = readline()
println("Your input was \"", y, "\".\n")
print("Integer? ")
y = readline()
try
y = parse(Int, y)
println("Your input was \"", y, "\".\n")
catch
println("Sorry, but \"", y, "\" does not compute as an integer.")
end
| Give a code snippet in #Julia
User input/Text is part of Short Circuit's Console Program Basics selection.
Task
Input a string and the integer 75000 from the text console.
See also: User input/Graphical
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Sequence_of_primorial_primes | Sequence of primorial primes | The sequence of primorial primes is given as the increasing values of n where primorial(n) ± 1 is prime.
Noting that the n'th primorial is defined as the multiplication of the smallest n primes, the sequence is of the number of primes, in order that when multiplied together is one-off being a prime number itself.
T... | #Ring | Ring |
# Project : Sequence of primorial primes
max = 9999
primes = []
for n = 1 to max
if isprime(n) = 1
add(primes, n)
ok
next
for n = 1 to len(primes)
sum = 1
for m = 1 to n
sum = sum * primes[m]
next
if (isprime(sum+1) or isprime(sum-1)) = 1
see "" + n + " "
... | Give a code snippet in #Ring
The sequence of primorial primes is given as the increasing values of n where primorial(n) ± 1 is prime.
Noting that the n'th primorial is defined as the multiplication of the smallest n primes, the sequence is of the number of primes, in order that when multiplied together is one-off bei... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Window_management | Window management | Treat windows or at least window identities as first class objects.
Store window identities in variables, compare them for equality.
Provide examples of performing some of the following:
hide,
show,
close,
minimize,
maximize,
move, and
resize a window.
The window of interest may or may not have b... | #Mathematica.2FWolfram_Language | Mathematica/Wolfram Language | nb=NotebookCreate[]; (*Create a window and store in a variable*)
nb===nb2 (*test for equality with another window object*)
SetOptions[nb,Visible->False](*Hide*)
SetOptions[nb,Visible->True](*Show*)
NotebookClose[nb] (*Close*)
SetOptions[nb,WindowMargins->{{x,Automatic},{y,Automatic}}](*Move to x,y screen position*)
Set... | Give a code snippet in #Mathematica.2FWolfram_Language
Treat windows or at least window identities as first class objects.
Store window identities in variables, compare them for equality.
Provide examples of performing some of the following:
hide,
show,
close,
minimize,
maximize,
move, and
resize a... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Statistics/Basic | Statistics/Basic | Statistics is all about large groups of numbers.
When talking about a set of sampled data, most frequently used is their mean value and standard deviation (stddev).
If you have set of data
x
i
{\displaystyle x_{i}}
where
i
=
1
,
2
,
…
,
n
{\displaystyle i=1,2,\ldots ,n\,\!}
, the mean is
x
¯... | #PL.2FI | PL/I | stat: procedure options (main); /* 21 May 2014 */
stats: procedure (values, mean, standard_deviation);
declare (values(*), mean, standard_deviation) float;
declare n fixed binary (31) initial ( (hbound(values,1)) );
mean = sum(values)/n;
standard_deviation = sqrt( sum(values - mean)**2 / n);
end st... | Give a code snippet in #PL.2FI
Statistics is all about large groups of numbers.
When talking about a set of sampled data, most frequently used is their mean value and standard deviation (stddev).
If you have set of data
x
i
{\displaystyle x_{i}}
where
i
=
1
,
2
,
…
,
n
{\displaystyle i=1,2,\ldots ,... | 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
... | #SequenceL | SequenceL | import <Utilities/Sequence.sl>;
main(args(2)) := Sequence::reverse(args[1]); | Give a code snippet in #SequenceL
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/Matrix_multiplication | Matrix multiplication | Task
Multiply two matrices together.
They can be of any dimensions, so long as the number of columns of the first matrix is equal to the number of rows of the second matrix.
| #Generic | Generic |
generic coordinaat
{
ecs
uuii
coordinaat() { ecs=+a uuii=+a}
coordinaat(ecs_set uuii_set) { ecs = ecs_set uuii=uuii_set }
operaator<(c)
{
iph ecs < c.ecs return troo
iph c.ecs < ecs return phals
iph uuii < c.uuii return troo
return phals
}
operaator==(connpair) // eecuuols and not eecuuols... | Give a code snippet in #Generic
Task
Multiply two matrices together.
They can be of any dimensions, so long as the number of columns of the first matrix is equal to the number of rows of the second matrix.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Euler%27s_sum_of_powers_conjecture | Euler's sum of powers conjecture | There is a conjecture in mathematics that held for over two hundred years before it was disproved by the finding of a counterexample in 1966 by Lander and Parkin.
Euler's (disproved) sum of powers conjecture
At least k positive kth powers are required to sum to a kth power,
except for the trivial case... | #Microsoft_Small_Basic | Microsoft Small Basic | ' Euler sum of powers conjecture - 03/07/2015
'find: x1^5+x2^5+x3^5+x4^5=x5^5
'-> x1=27 x2=84 x3=110 x4=133 x5=144
maxn=250
For i=1 to maxn
p5[i]=Math.Power(i,5)
EndFor
For x1=1 to maxn-4
For x2=x1+1 to maxn-3
'TextWindow.WriteLine("x1="+x1+", x2="+x2)
For x3=x2+1 to maxn-2
'TextWin... | Give a code snippet in #Microsoft_Small_Basic
There is a conjecture in mathematics that held for over two hundred years before it was disproved by the finding of a counterexample in 1966 by Lander and Parkin.
Euler's (disproved) sum of powers conjecture
At least k positive kth powers are required to sum to... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Singleton | Singleton | A Global Singleton is a class of which only one instance exists within a program.
Any attempt to use non-static members of the class involves performing operations on this one instance.
| #OxygenBasic | OxygenBasic |
Class Singleton
static sys inst 'private
int instantiated() { return inst }
void constructor(){ if not inst then inst=@this }
'all other methods start with @this=inst
end class
'if not singleton.instantiated
new Singleton MySingleton
'endif
| Give a code snippet in #OxygenBasic
A Global Singleton is a class of which only one instance exists within a program.
Any attempt to use non-static members of the class involves performing operations on this one instance.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Use_another_language_to_call_a_function | Use another language to call a function | This task has been clarified. Its programming examples are in need of review to ensure that they still fit the requirements of the task.
This task is inverse to the task Call foreign language function. Consider the following C program:
#include <stdio.h>
extern int Query (char * Data, size_t * Length);
int main (i... | #COBOL | COBOL | identification division.
program-id. Query.
environment division.
configuration section.
special-names.
call-convention 0 is extern.
repository.
function all intrinsic.
data division.
working-storage section.
01 query-result.
... | Give a code snippet in #COBOL
This task has been clarified. Its programming examples are in need of review to ensure that they still fit the requirements of the task.
This task is inverse to the task Call foreign language function. Consider the following C program:
#include <stdio.h>
extern int Query (char * Data, ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Josephus_problem | Josephus problem | Josephus problem is a math puzzle with a grim description:
n
{\displaystyle n}
prisoners are standing on a circle, sequentially numbered from
0
{\displaystyle 0}
to
n
−
1
{\displaystyle n-1}
.
An executioner walks along the circle, starting from prisoner
0
{\displaystyle 0}
,
removing eve... | #Icon_and_Unicon | Icon and Unicon | procedure main(A)
m := integer(A[1]) | 41
c := integer(A[2]) | 3
write("With ",m," men, counting to ",c," last position is: ", j(m,c))
end
procedure j(m,c)
return if m==1 then 0 else (j(m-1,c)+c)%m
end | Give a code snippet in #Icon_and_Unicon
Josephus problem is a math puzzle with a grim description:
n
{\displaystyle n}
prisoners are standing on a circle, sequentially numbered from
0
{\displaystyle 0}
to
n
−
1
{\displaystyle n-1}
.
An executioner walks along the circle, starting from prisoner ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Truth_table | Truth table | A truth table is a display of the inputs to, and the output of a Boolean function organized as a table where each row gives one combination of input values and the corresponding value of the function.
Task
Input a Boolean function from the user as a string then calculate and print a formatted truth table for the g... | #8080_Assembly | 8080 Assembly | ;;; CP/M truth table generator
;;; Supported operators:
;;; ~ (not), & (and), | (or), ^ (xor) and => (implies)
;;; Variables are A-Z, constants are 0 and 1.
putch: equ 2
puts: equ 9
TVAR: equ 32
TCONST: equ 64
TOP: equ 96
TPAR: equ 128
TMASK: equ 31
TTYPE: equ 224
org 100h
lxi h,80h ; Have we got a command line ... | Give a code snippet in #8080_Assembly
A truth table is a display of the inputs to, and the output of a Boolean function organized as a table where each row gives one combination of input values and the corresponding value of the function.
Task
Input a Boolean function from the user as a string then calculate and ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sierpinski_carpet | Sierpinski carpet | Task
Produce a graphical or ASCII-art representation of a Sierpinski carpet of order N.
For example, the Sierpinski carpet of order 3 should look like this:
###########################
# ## ## ## ## ## ## ## ## #
###########################
### ###### ###### ###
# # # ## # # ## # # #
### ###### ... | #PL.2FI | PL/I |
/* Sierpinski carpet */
Sierpinski_carpet: procedure options (main); /* 28 January 2013 */
call carpet(3);
In_carpet: procedure (a, b) returns (bit(1));
declare (a, b) fixed binary nonassignable;
declare (x, y) fixed binary;
declare (true value ('1'b), false value ('0'b)) bit (1);
x = a ; y = b;
... | Give a code snippet in #PL.2FI
Task
Produce a graphical or ASCII-art representation of a Sierpinski carpet of order N.
For example, the Sierpinski carpet of order 3 should look like this:
###########################
# ## ## ## ## ## ## ## ## #
###########################
### ###### ###### ###
# # # #... | 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... | #BBC_BASIC | BBC BASIC | DIM node{pNext%, iData%}
| Give a code snippet in #BBC_BASIC
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... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Loops/Downward_for | Loops/Downward for | Task
Write a for loop which writes a countdown from 10 to 0.
Related tasks
Loop over multiple arrays simultaneously
Loops/Break
Loops/Continue
Loops/Do-while
Loops/Downward for
Loops/For
Loops/For with a specified step
Loops/Foreach
Loops/Increment loop index within loop body... | #Wren | Wren | for (i in 10..0) System.write("%(i) ")
System.print() | Give a code snippet in #Wren
Task
Write a for loop which writes a countdown from 10 to 0.
Related tasks
Loop over multiple arrays simultaneously
Loops/Break
Loops/Continue
Loops/Do-while
Loops/Downward for
Loops/For
Loops/For with a specified step
Loops/Foreach
Loops/Increme... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Empty_program | Empty program | Task
Create the simplest possible program that is still considered "correct."
| #Argile | Argile | Give a code snippet in #Argile
Task
Create the simplest possible program that is still considered "correct."
| christopher/rosetta-code | ||
http://rosettacode.org/wiki/Julia_set | Julia set |
Task
Generate and draw a Julia set.
Related tasks
Mandelbrot Set
| #REXX | REXX | /*REXX program displays an ASCII plot (character plot) of a Julia set. */
parse arg real imag fine . /*obtain optional arguments from the CL*/
if real=='' | real=="," then real= -0.8 /*Not specified? Then use the default.*/
if imag=='' | imag=="," then imag= 0.156 ... | Give a code snippet in #REXX
Task
Generate and draw a Julia set.
Related tasks
Mandelbrot Set
| christopher/rosetta-code | |
http://rosettacode.org/wiki/FizzBuzz | FizzBuzz | Task
Write a program that prints the integers from 1 to 100 (inclusive).
But:
for multiples of three, print Fizz (instead of the number)
for multiples of five, print Buzz (instead of the number)
for multiples of both three and five, print FizzBuzz (instead of the number)
... | #PL.2FI | PL/I | do i = 1 to 100;
select;
when (mod(i,15) = 0) put skip list ('FizzBuzz');
when (mod(i,3) = 0) put skip list ('Fizz');
when (mod(i,5) = 0) put skip list ('Buzz');
otherwise put skip list (i);
end;
end; | Give a code snippet in #PL.2FI
Task
Write a program that prints the integers from 1 to 100 (inclusive).
But:
for multiples of three, print Fizz (instead of the number)
for multiples of five, print Buzz (instead of the number)
for multiples of both three and five, print FizzBuz... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Comments | Comments | Task
Show all ways to include text in a language source file
that's completely ignored by the compiler or interpreter.
Related tasks
Documentation
Here_document
See also
Wikipedia
xkcd (Humor: hand gesture denoting // for "commenting out" people.)
| #Liberty_BASIC | Liberty BASIC | 'This is a comment
REM This is a comment
print "This has a comment on the end of the line." 'This is a comment
print "This also has a comment on the end of the line." : REM This is a comment | Give a code snippet in #Liberty_BASIC
Task
Show all ways to include text in a language source file
that's completely ignored by the compiler or interpreter.
Related tasks
Documentation
Here_document
See also
Wikipedia
xkcd (Humor: hand gesture denoting // for "commenting out" people.)
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Fork | Fork | Task
Spawn a new process which can run simultaneously with, and independently of, the original parent process.
| #Perl | Perl | FORK:
if ($pid = fork()) {
# parent code
} elsif (defined($pid)) {
setsid; # tells apache to let go of this process and let it run solo
# disconnect ourselves from input, output, and errors
close(STDOUT);
close(STDIN);
close(STDERR);
# re-open to /dev/null to prevent irrelevant warn mess... | Give a code snippet in #Perl
Task
Spawn a new process which can run simultaneously with, and independently of, the original parent process.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Return_multiple_values | Return multiple values | Task
Show how to return more than one value from a function.
| #Oforth | Oforth | import: date
: returnFourValues 12 13 14 15 ;
: returnOneObject [ 12, 13, 14, 15, [16, 17 ], Date now, 1.2, "abcd" ] ;
"Showing four values returned on the parameter stack:" println
returnFourValues .s clr
"\nShowing one object containing four values returned on the parameter stack:" println
returnOneObject .s c... | Give a code snippet in #Oforth
Task
Show how to return more than one value from a function.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/URL_encoding | URL encoding | Task
Provide a function or mechanism to convert a provided string into URL encoding representation.
In URL encoding, special characters, control characters and extended characters
are converted into a percent symbol followed by a two digit hexadecimal code,
So a space character encodes into %20 within the string.
Fo... | #Ada | Ada | with AWS.URL;
with Ada.Text_IO; use Ada.Text_IO;
procedure Encode is
Normal : constant String := "http://foo bar/";
begin
Put_Line (AWS.URL.Encode (Normal));
end Encode; | Give a code snippet in #Ada
Task
Provide a function or mechanism to convert a provided string into URL encoding representation.
In URL encoding, special characters, control characters and extended characters
are converted into a percent symbol followed by a two digit hexadecimal code,
So a space character encodes in... | 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
... | #Scala | Scala | import java.lang.Long.bitCount
object PopCount extends App {
val nNumber = 30
def powersThree(start: Long): LazyList[Long] = start #:: powersThree(start * 3L)
println("Population count of 3ⁿ :")
println(powersThree(1L).map(bitCount).take(nNumber).mkString(", "))
def series(start: Long): LazyList[Long]... | Give a code snippet in #Scala
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... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Binary_strings | Binary strings | Many languages have powerful and useful (binary safe) string manipulation functions, while others don't, making it harder for these languages to accomplish some tasks.
This task is about creating functions to handle binary strings (strings made of arbitrary bytes, i.e. byte strings according to Wikipedia) for those la... | #Mathematica_.2F_Wolfram_Language | Mathematica / Wolfram Language | (* String creation and destruction *) BinaryString = {}; BinaryString = . ;
(* String assignment *) BinaryString1 = {12,56,82,65} , BinaryString2 = {83,12,56,65}
-> {12,56,82,65}
-> {83,12,56,65}
(* String comparison *) BinaryString1 === BinaryString2
-> False
(* String cloning and copying *) BinaryString3 = Bi... | Give a code snippet in #Mathematica_.2F_Wolfram_Language
Many languages have powerful and useful (binary safe) string manipulation functions, while others don't, making it harder for these languages to accomplish some tasks.
This task is about creating functions to handle binary strings (strings made of arbitrary byt... | christopher/rosetta-code | |
http://rosettacode.org/wiki/String_length | String length | Task
Find the character and byte length of a string.
This means encodings like UTF-8 need to be handled properly, as there is not necessarily a one-to-one relationship between bytes and characters.
By character, we mean an individual Unicode code point, not a user-visible grapheme containing combining characters.
F... | #Nemerle | Nemerle | def message = "How long am I anyways?";
def charlength = message.Length; | Give a code snippet in #Nemerle
Task
Find the character and byte length of a string.
This means encodings like UTF-8 need to be handled properly, as there is not necessarily a one-to-one relationship between bytes and characters.
By character, we mean an individual Unicode code point, not a user-visible grapheme co... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Ackermann_function | Ackermann function | The Ackermann function is a classic example of a recursive function, notable especially because it is not a primitive recursive function. It grows very quickly in value, as does the size of its call tree.
The Ackermann function is usually defined as follows:
A
(
m
,
n
)
=
{
n
+
1
if
m
=
0
A
(
m
... | #BQN | BQN | A ← {
A 0‿n: n+1;
A m‿0: A (m-1)‿1;
A m‿n: A (m-1)‿(A m‿(n-1))
} | Give a code snippet in #BQN
The Ackermann function is a classic example of a recursive function, notable especially because it is not a primitive recursive function. It grows very quickly in value, as does the size of its call tree.
The Ackermann function is usually defined as follows:
A
(
m
,
n
)
=
{
n... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Loops/Nested | Loops/Nested | Show a nested loop which searches a two-dimensional array filled with random numbers uniformly distributed over
[
1
,
…
,
20
]
{\displaystyle [1,\ldots ,20]}
.
The loops iterate rows and columns of the array printing the elements until the value
20
{\displaystyle 20}
is met.
Specifically, this task als... | #Logo | Logo | make "a mdarray [10 10]
for [j 1 10] [for [i 1 10] [mdsetitem list :i :j :a (1 + random 20)]]
to until.20
for [j 1 10] [
for [i 1 10] [
type mditem list :i :j :a
type "| |
if equal? 20 mditem list :i :j :a [stop]
]
print "||
]
end
until.20 | Give a code snippet in #Logo
Show a nested loop which searches a two-dimensional array filled with random numbers uniformly distributed over
[
1
,
…
,
20
]
{\displaystyle [1,\ldots ,20]}
.
The loops iterate rows and columns of the array printing the elements until the value
20
{\displaystyle 20}
is met... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Abelian_sandpile_model/Identity | Abelian sandpile model/Identity | Our sandpiles are based on a 3 by 3 rectangular grid giving nine areas that
contain a number from 0 to 3 inclusive. (The numbers are said to represent
grains of sand in each area of the sandpile).
E.g. s1 =
1 2 0
2 1 1
0 1 3
and s2 =
2 1 3
1 0 1
0 1 0
Addition on sandpiles is done by a... | #Raku | Raku | class ASP {
has $.h = 3;
has $.w = 3;
has @.pile = 0 xx $!w * $!h;
method topple {
my $buf = $!w * $!h;
my $done;
repeat {
$done = True;
loop (my int $row; $row < $!h; $row = $row + 1) {
my int $rs = $row * $!w; # row start
... | Give a code snippet in #Raku
Our sandpiles are based on a 3 by 3 rectangular grid giving nine areas that
contain a number from 0 to 3 inclusive. (The numbers are said to represent
grains of sand in each area of the sandpile).
E.g. s1 =
1 2 0
2 1 1
0 1 3
and s2 =
2 1 3
1 0 1
0 1 0
Addi... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Append_a_record_to_the_end_of_a_text_file | Append a record to the end of a text file | Many systems offer the ability to open a file for writing, such that any data written will be appended to the end of the file. Further, the file operations will always adjust the position pointer to guarantee the end of the file, even in a multitasking environment.
This feature is most useful in the case of log files,... | #Common_Lisp | Common Lisp | (defvar *initial_data*
(list
(list "jsmith" "x" 1001 1000
(list "Joe Smith" "Room 1007" "(234)555-8917" "(234)555-0077" "jsmith@rosettacode.org")
"/home/jsmith" "/bin/bash")
(list "jdoe" "x" 1002 1000
(list "Jane Doe" "Room 1004" "(234)555-8914" "(234)555-0044" "jdoe@rosettacode.org")
... | Give a code snippet in #Common_Lisp
Many systems offer the ability to open a file for writing, such that any data written will be appended to the end of the file. Further, the file operations will always adjust the position pointer to guarantee the end of the file, even in a multitasking environment.
This feature is ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Narcissist | Narcissist | Quoting from the Esolangs wiki page:
A narcissist (or Narcissus program) is the decision-problem version of a quine.
A quine, when run, takes no input, but produces a copy of its own source code at its output. In contrast, a narcissist reads a string of symbols from its input, and produces no output except a "1" o... | #Sidef | Sidef | say (File.new(__FILE__).open_r.slurp == ARGF.slurp); | Give a code snippet in #Sidef
Quoting from the Esolangs wiki page:
A narcissist (or Narcissus program) is the decision-problem version of a quine.
A quine, when run, takes no input, but produces a copy of its own source code at its output. In contrast, a narcissist reads a string of symbols from its input, and pr... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Largest_int_from_concatenated_ints | Largest int from concatenated ints | Task
Given a set of positive integers, write a function to order the integers in such a way that the concatenation of the numbers forms the largest possible integer and return this integer.
Use the following two sets of integers as tests and show your program output here.
{1, 34, 3, 98, 9, 76, 45, 4}
{54,... | #Ceylon | Ceylon | shared void run() {
function comparator(Integer x, Integer y) {
assert (is Integer xy = Integer.parse(x.string + y.string),
is Integer yx = Integer.parse(y.string + x.string));
return yx <=> xy;
}
function biggestConcatenation({Integer*} ints) => "".join(ints.sort(comparator));
value test1 = {1, 34, 3,... | Give a code snippet in #Ceylon
Task
Given a set of positive integers, write a function to order the integers in such a way that the concatenation of the numbers forms the largest possible integer and return this integer.
Use the following two sets of integers as tests and show your program output here.
{1, ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Formatted_numeric_output | Formatted numeric output | Task
Express a number in decimal as a fixed-length string with leading zeros.
For example, the number 7.125 could be expressed as 00007.125.
| #R | R | > sprintf("%f", pi)
[1] "3.141593"
> sprintf("%.3f", pi)
[1] "3.142"
> sprintf("%1.0f", pi)
[1] "3"
> sprintf("%5.1f", pi)
[1] " 3.1"
> sprintf("%05.1f", pi)
[1] "003.1"
> sprintf("%+f", pi)
[1] "+3.141593"
> sprintf("% f", pi)
[1] " 3.141593"
> sprintf("%-10f", pi)# left justified
[1] "3.141593 "
> sprintf("%e", pi)... | Give a code snippet in #R
Task
Express a number in decimal as a fixed-length string with leading zeros.
For example, the number 7.125 could be expressed as 00007.125.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Environment_variables | Environment variables | Task
Show how to get one of your process's environment variables.
The available variables vary by system; some of the common ones available on Unix include:
PATH
HOME
USER
| #zkl | zkl | System.getenv("HOME")
/home/craigd
System.getenv() //--> Dictionary of all env vars | Give a code snippet in #zkl
Task
Show how to get one of your process's environment variables.
The available variables vary by system; some of the common ones available on Unix include:
PATH
HOME
USER
| christopher/rosetta-code | |
http://rosettacode.org/wiki/State_name_puzzle | State name puzzle | Background
This task is inspired by Mark Nelson's DDJ Column "Wordplay" and one of the weekly puzzle challenges from Will Shortz on NPR Weekend Edition [1] and originally attributed to David Edelheit.
The challenge was to take the names of two U.S. States, mix them all together, then rearrange the letters to form the... | #zkl | zkl | #<<< // here doc
states:=("Alabama, Alaska, Arizona, Arkansas,
California, Colorado, Connecticut, Delaware, Florida,
Georgia, Hawaii, Idaho, Illinois, Indiana, Iowa, Kansas,
Kentucky, Louisiana, Maine, Maryland, Massachusetts,
Michigan, Minnesota, Mississippi, Missouri, Montana,
Nebraska, Nevada, New Ha... | Give a code snippet in #zkl
Background
This task is inspired by Mark Nelson's DDJ Column "Wordplay" and one of the weekly puzzle challenges from Will Shortz on NPR Weekend Edition [1] and originally attributed to David Edelheit.
The challenge was to take the names of two U.S. States, mix them all together, then rear... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sorting_algorithms/Quicksort | Sorting algorithms/Quicksort |
Sorting Algorithm
This is a sorting algorithm. It may be applied to a set of data in order to sort it.
For comparing various sorts, see compare sorts.
For other sorting algorithms, see sorting algorithms, or:
O(n logn) sorts
Heap sort |
Merge sort |
Patience sort |
Quick sort
O(n log2n) sorts
Shell Sort
... | #Clojure | Clojure | (defn qsort [L]
(if (empty? L)
'()
(let [[pivot & L2] L]
(lazy-cat (qsort (for [y L2 :when (< y pivot)] y))
(list pivot)
(qsort (for [y L2 :when (>= y pivot)] y)))))) | Give a code snippet in #Clojure
Sorting Algorithm
This is a sorting algorithm. It may be applied to a set of data in order to sort it.
For comparing various sorts, see compare sorts.
For other sorting algorithms, see sorting algorithms, or:
O(n logn) sorts
Heap sort |
Merge sort |
Patience sort |
Quick ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Get_system_command_output | Get system command output | Task
Execute a system command and get its output into the program. The output may be stored in any kind of collection (array, list, etc.).
Related task
Execute a system command
| #Aime | Aime | o_("-- ", sshell().plan("expr", "8", "*", "9").link.b_dump('\n'), " --\n"); | Give a code snippet in #Aime
Task
Execute a system command and get its output into the program. The output may be stored in any kind of collection (array, list, etc.).
Related task
Execute a system command
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Abundant_odd_numbers | Abundant odd numbers | An Abundant number is a number n for which the sum of divisors σ(n) > 2n,
or, equivalently, the sum of proper divisors (or aliquot sum) s(n) > n.
E.G.
12 is abundant, it has the proper divisors 1,2,3,4 & 6 which sum to 16 ( > 12 or n);
or alternately, has the sigma sum of ... | #zkl | zkl | fcn oddAbundants(startAt=3){ //--> iterator
Walker.zero().tweak(fcn(rn){
n:=rn.value;
while(True){
sum:=0;
foreach d in ([3.. n.toFloat().sqrt().toInt(), 2]){
if( (y:=n/d) *d != n) continue;
sum += ((y==d) and y or y+d)
}
if(sum>n){ rn.set(n+2); return(n) }
n+=2;
}
}.fp(Ref(... | Give a code snippet in #zkl
An Abundant number is a number n for which the sum of divisors σ(n) > 2n,
or, equivalently, the sum of proper divisors (or aliquot sum) s(n) > n.
E.G.
12 is abundant, it has the proper divisors 1,2,3,4 & 6 which sum to 16 ( > 12 or n);
or alterna... | christopher/rosetta-code | |
http://rosettacode.org/wiki/File_size | File size | Verify the size of a file called input.txt for a file in the current working directory, and another one in the file system root.
| #Slate | Slate | (File newNamed: 'input.txt') fileInfo fileSize.
(File newNamed: '/input.txt') fileInfo fileSize. | Give a code snippet in #Slate
Verify the size of a file called input.txt for a file in the current working directory, and another one in the file system root.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Egyptian_fractions | Egyptian fractions | An Egyptian fraction is the sum of distinct unit fractions such as:
1
2
+
1
3
+
1
16
(
=
43
48
)
{\displaystyle {\tfrac {1}{2}}+{\tfrac {1}{3}}+{\tfrac {1}{16}}\,(={\tfrac {43}{48}})}
Each fraction in the expression has a numerator equal to 1 (unity) and a denominator that... | #Python | Python | from fractions import Fraction
from math import ceil
class Fr(Fraction):
def __repr__(self):
return '%s/%s' % (self.numerator, self.denominator)
def ef(fr):
ans = []
if fr >= 1:
if fr.denominator == 1:
return [[int(fr)], Fr(0, 1)]
intfr = int(fr)
ans, fr = [[i... | Give a code snippet in #Python
An Egyptian fraction is the sum of distinct unit fractions such as:
1
2
+
1
3
+
1
16
(
=
43
48
)
{\displaystyle {\tfrac {1}{2}}+{\tfrac {1}{3}}+{\tfrac {1}{16}}\,(={\tfrac {43}{48}})}
Each fraction in the expression has a numerator equal to 1 ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Guess_the_number | Guess the number | Task
Write a program where the program chooses a number between 1 and 10.
A player is then prompted to enter a guess. If the player guesses wrong, then the prompt appears again until the guess is correct.
When the player has made a successful guess the computer will issue a "Well guessed!" message, a... | #AWK | AWK |
# syntax: GAWK -f GUESS_THE_NUMBER.AWK
BEGIN {
srand()
n = int(rand() * 10) + 1
print("I am thinking of a number between 1 and 10. Try to guess it.")
while (1) {
getline ans
if (ans !~ /^[0-9]+$/) {
print("Your input was not a number. Try again.")
continue
}
if ... | Give a code snippet in #AWK
Task
Write a program where the program chooses a number between 1 and 10.
A player is then prompted to enter a guess. If the player guesses wrong, then the prompt appears again until the guess is correct.
When the player has made a successful guess the computer will issue a "... | christopher/rosetta-code | |
http://rosettacode.org/wiki/MD4 | MD4 | Find the MD4 message digest of a string of octets.
Use the ASCII encoded string “Rosetta Code” (without quotes).
You may either call an MD4 library, or implement MD4 in your language.
MD4 is an obsolete hash function that computes a 128-bit message digest that sometimes appears in obsolete protocols.
RFC 1320 specifi... | #D | D | import std.stdio, std.string, std.range;
ubyte[16] md4(const(ubyte)[] inData) pure nothrow {
enum f = (uint x, uint y, uint z) => (x & y) | (~x & z);
enum g = (uint x, uint y, uint z) => (x & y) | (x & z) | (y & z);
enum h = (uint x, uint y, uint z) => x ^ y ^ z;
enum r = (uint v, uint s) => (v << s) ... | Give a code snippet in #D
Find the MD4 message digest of a string of octets.
Use the ASCII encoded string “Rosetta Code” (without quotes).
You may either call an MD4 library, or implement MD4 in your language.
MD4 is an obsolete hash function that computes a 128-bit message digest that sometimes appears in obsolete p... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Maximum_triangle_path_sum | Maximum triangle path sum | Starting from the top of a pyramid of numbers like this, you can walk down going one step on the right or on the left, until you reach the bottom row:
55
94 48
95 30 96
77 71 26 67
One of such walks is 55 - 94 - 30 - 26.
You... | #Tcl | Tcl | package require Tcl 8.6
proc maxTrianglePathSum {definition} {
# Parse the definition, stripping whitespace and leading zeroes.
set lines [lmap line [split [string trim $definition] "\n"] {
lmap val $line {scan $val %d}
}]
# Paths are bit strings (0 = go left, 1 = go right).
# Enumerate the possi... | Give a code snippet in #Tcl
Starting from the top of a pyramid of numbers like this, you can walk down going one step on the right or on the left, until you reach the bottom row:
55
94 48
95 30 96
77 71 26 67
One of such wa... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Concurrent_computing | Concurrent computing | Task
Using either native language concurrency syntax or freely available libraries, write a program to display the strings "Enjoy" "Rosetta" "Code", one string per line, in random order.
Concurrency syntax must use threads, tasks, co-routines, or whatever concurrency is called in your language.
| #Forth | Forth | require tasker.fs
require random.fs
: task ( str len -- )
64 NewTask 2 swap pass
( str len -- )
10 0 do
100 random ms
pause 2dup cr type
loop 2drop ;
: main
s" Enjoy" task
s" Rosetta" task
s" Code" task
begin pause single-tasking? until ;
main | Give a code snippet in #Forth
Task
Using either native language concurrency syntax or freely available libraries, write a program to display the strings "Enjoy" "Rosetta" "Code", one string per line, in random order.
Concurrency syntax must use threads, tasks, co-routines, or whatever concurrency is called in your l... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Convert_seconds_to_compound_duration | Convert seconds to compound duration | Task
Write a function or program which:
takes a positive integer representing a duration in seconds as input (e.g., 100), and
returns a string which shows the same duration decomposed into:
weeks,
days,
hours,
minutes, and
seconds.
This is detailed below (e.g., "2 hr, 59 sec").
Demonstrat... | #REXX | REXX | /* REXX ---------------------------------------------------------------
* Format seconds into a time string
*--------------------------------------------------------------------*/
Call test 7259 ,'2 hr, 59 sec'
Call test 86400 ,'1 d'
Call test 6000000 ,'9 wk, 6 d, 10 hr, 40 min'
Call test 123.50 ,'2 min, 3.5 sec'... | Give a code snippet in #REXX
Task
Write a function or program which:
takes a positive integer representing a duration in seconds as input (e.g., 100), and
returns a string which shows the same duration decomposed into:
weeks,
days,
hours,
minutes, and
seconds.
This is detailed below (e.g., ... | christopher/rosetta-code | |
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.
| #jq | jq | def unoptimized_repeat(f; n):
if n <= 0 then empty
else f, repeat(f; n-1)
end; | Give a code snippet in #jq
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/Character_codes | Character codes |
Task
Given a character value in your language, print its code (could be ASCII code, Unicode code, or whatever your language uses).
Example
The character 'a' (lowercase letter A) has a code of 97 in ASCII (as well as Unicode, as ASCII forms the beginning of Unicode).
Conversely, given a code, print out... | #Ruby | Ruby | > "a".ord
=> 97
> 97.chr
=> "a" | Give a code snippet in #Ruby
Task
Given a character value in your language, print its code (could be ASCII code, Unicode code, or whatever your language uses).
Example
The character 'a' (lowercase letter A) has a code of 97 in ASCII (as well as Unicode, as ASCII forms the beginning of Unicode).
Conve... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Closest-pair_problem | Closest-pair problem |
This page uses content from Wikipedia. The original article was at Closest pair of points problem. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance)
Task
Provide a function to find the closest two p... | #Pascal | Pascal | program closestPoints;
{$IFDEF FPC}
{$MODE Delphi}
{$ENDIF}
const
PointCnt = 10000;//31623;
type
TdblPoint = Record
ptX,
ptY : double;
end;
tPtLst = array of TdblPoint;
tMinDIstIdx = record
md1,
md2 : NativeInt;
... | Give a code snippet in #Pascal
This page uses content from Wikipedia. The original article was at Closest pair of points problem. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance)
Task
Provide a fu... | christopher/rosetta-code | |
http://rosettacode.org/wiki/SHA-256 | SHA-256 | SHA-256 is the recommended stronger alternative to SHA-1. See FIPS PUB 180-4 for implementation details.
Either by using a dedicated library or implementing the algorithm in your language, show that the SHA-256 digest of the string "Rosetta code" is: 764faf5c61ac315f1497f9dfa542713965b785e5cc2f707d6468d7d1124cdfcf
| #C | C | #include <stdio.h>
#include <string.h>
#include <openssl/sha.h>
int main (void) {
const char *s = "Rosetta code";
unsigned char *d = SHA256(s, strlen(s), 0);
int i;
for (i = 0; i < SHA256_DIGEST_LENGTH; i++)
printf("%02x", d[i]);
putchar('\n');
return 0;
} | Give a code snippet in #C
SHA-256 is the recommended stronger alternative to SHA-1. See FIPS PUB 180-4 for implementation details.
Either by using a dedicated library or implementing the algorithm in your language, show that the SHA-256 digest of the string "Rosetta code" is: 764faf5c61ac315f1497f9dfa542713965b785e5c... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Write_float_arrays_to_a_text_file | Write float arrays to a text file | Task
Write two equal-sized numerical arrays 'x' and 'y' to
a two-column text file named 'filename'.
The first column of the file contains values from an 'x'-array with a
given 'xprecision', the second -- values from 'y'-array with 'yprecision'.
For example, considering:
x = {1, 2, 3, 1e11};
y = {1, 1.41421356... | #Java | Java | import java.io.*;
public class FloatArray {
public static void writeDat(String filename, double[] x, double[] y,
int xprecision, int yprecision)
throws IOException {
assert x.length == y.length;
PrintWriter out = new PrintWriter(filename);
for (int i... | Give a code snippet in #Java
Task
Write two equal-sized numerical arrays 'x' and 'y' to
a two-column text file named 'filename'.
The first column of the file contains values from an 'x'-array with a
given 'xprecision', the second -- values from 'y'-array with 'yprecision'.
For example, considering:
x = {1, 2, 3... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Index_finite_lists_of_positive_integers | Index finite lists of positive integers | It is known that the set of finite lists of positive integers is countable.
This means that there exists a subset of natural integers which can be mapped to the set of finite lists of positive integers.
Task
Implement such a mapping:
write a function rank which assigns an integer to any finite, arbi... | #REXX | REXX | /*REXX program assigns an integer for a finite list of arbitrary non-negative integers. */
parse arg $ /*obtain optional argument (int list).*/
if $='' | $="," then $=3 14 159 265358979323846 /*Not specified? Then use the default.*/
... | Give a code snippet in #REXX
It is known that the set of finite lists of positive integers is countable.
This means that there exists a subset of natural integers which can be mapped to the set of finite lists of positive integers.
Task
Implement such a mapping:
write a function rank which assigns ... | 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... | #Ada | Ada | package Synchronous_Concurrent is
task Printer is
entry Put(Item : in String);
entry Get_Count(Count : out Natural);
end Printer;
end Synchronous_Concurrent; | Give a code snippet in #Ada
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... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Multiple_regression | Multiple regression | Task
Given a set of data vectors in the following format:
y
=
{
y
1
,
y
2
,
.
.
.
,
... | #Mathematica.2FWolfram_Language | Mathematica/Wolfram Language | x = {1.47, 1.50 , 1.52, 1.55, 1.57, 1.60, 1.63, 1.65, 1.68, 1.70, 1.73, 1.75, 1.78, 1.80, 1.83};
y = {52.21, 53.12, 54.48, 55.84, 57.20, 58.57, 59.93, 61.29, 63.11, 64.47, 66.28, 68.10, 69.92, 72.19, 74.46};
X = {x^0, x^1, x^2};
LeastSquares[Transpose@X, y] | Give a code snippet in #Mathematica.2FWolfram_Language
Task
Given a set of data vectors in the following format:
y
=
{
y
1
,
y
2
,
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/One_of_n_lines_in_a_file | One of n lines in a file | A method of choosing a line randomly from a file:
Without reading the file more than once
When substantial parts of the file cannot be held in memory
Without knowing how many lines are in the file
Is to:
keep the first line of the file as a possible choice, then
Read the second line of the file if possible and m... | #Kotlin | Kotlin | // version 1.1.51
import java.util.Random
val r = Random()
fun oneOfN(n: Int): Int {
var choice = 1
for (i in 2..n) {
if (r.nextDouble() < 1.0 / i) choice = i
}
return choice
}
fun main(args: Array<String>) {
val n = 10
val freqs = IntArray(n)
val reps = 1_000_000
repeat(... | Give a code snippet in #Kotlin
A method of choosing a line randomly from a file:
Without reading the file more than once
When substantial parts of the file cannot be held in memory
Without knowing how many lines are in the file
Is to:
keep the first line of the file as a possible choice, then
Read the second li... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Yellowstone_sequence | Yellowstone sequence | The Yellowstone sequence, also called the Yellowstone permutation, is defined as:
For n <= 3,
a(n) = n
For n >= 4,
a(n) = the smallest number not already in sequence such that a(n) is relatively prime to a(n-1) and
is not relatively prime to a(n-2).
The sequence is a permutation of the natural n... | #D | D | import std.numeric;
import std.range;
import std.stdio;
class Yellowstone {
private bool[int] sequence_;
private int min_ = 1;
private int n_ = 0;
private int n1_ = 0;
private int n2_ = 0;
public this() {
popFront();
}
public bool empty() {
return false;
}
... | Give a code snippet in #D
The Yellowstone sequence, also called the Yellowstone permutation, is defined as:
For n <= 3,
a(n) = n
For n >= 4,
a(n) = the smallest number not already in sequence such that a(n) is relatively prime to a(n-1) and
is not relatively prime to a(n-2).
The sequence is a p... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Stream_merge | Stream merge | 2-stream merge
Read two sorted streams of items from external source (e.g. disk, or network), and write one stream of sorted items to external sink.
Common algorithm: keep 1 buffered item from each source, select minimal of them, write it, fetch another item from that stream from which the written item was.
N-strea... | #C.2B.2B | C++ | //#include <functional>
#include <iostream>
#include <vector>
template <typename C, typename A>
void merge2(const C& c1, const C& c2, const A& action) {
auto i1 = std::cbegin(c1);
auto i2 = std::cbegin(c2);
while (i1 != std::cend(c1) && i2 != std::cend(c2)) {
if (*i1 <= *i2) {
action... | Give a code snippet in #C.2B.2B
2-stream merge
Read two sorted streams of items from external source (e.g. disk, or network), and write one stream of sorted items to external sink.
Common algorithm: keep 1 buffered item from each source, select minimal of them, write it, fetch another item from that stream from whi... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Empty_program | Empty program | Task
Create the simplest possible program that is still considered "correct."
| #Intercal | Intercal | PLEASE GIVE UP | Give a code snippet in #Intercal
Task
Create the simplest possible program that is still considered "correct."
| 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
... | #Lasso | Lasso | define sortarray( // params are set by position
items::array, // required param
ordering::string = 'lexicographic', // optional param
column::integer = 1,
reverse::boolean = false
) => {
// sorting process
local(sorteditems = array)
// Lasso has no build in method to sort an array of arrays by position in the c... | Give a code snippet in #Lasso
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; lex... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Matrix_transposition | Matrix transposition | Transpose an arbitrarily sized rectangular Matrix.
| #EchoLisp | EchoLisp |
(lib 'matrix)
(define M (list->array (iota 6) 3 2))
(array-print M)
0 1
2 3
4 5
(array-print (matrix-transpose M))
0 2 4
1 3 5
| Give a code snippet in #EchoLisp
Transpose an arbitrarily sized rectangular Matrix.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Cholesky_decomposition | Cholesky decomposition | Every symmetric, positive definite matrix A can be decomposed into a product of a unique lower triangular matrix L and its transpose:
A
=
L
L
T
{\displaystyle A=LL^{T}}
L
{\displaystyle L}
is called the Cholesky factor of
A
{\displaystyle A}
, and can be interpreted as a generalized square r... | #Julia | Julia |
a = [25 15 5; 15 18 0; -5 0 11]
b = [18 22 54 22; 22 70 86 62; 54 86 174 134; 42 62 134 106]
println(a, "\n => \n", chol(a, :L))
println(b, "\n => \n", chol(b, :L))
| Give a code snippet in #Julia
Every symmetric, positive definite matrix A can be decomposed into a product of a unique lower triangular matrix L and its transpose:
A
=
L
L
T
{\displaystyle A=LL^{T}}
L
{\displaystyle L}
is called the Cholesky factor of
A
{\displaystyle A}
, and can be interp... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Vector_products | Vector products | A vector is defined as having three dimensions as being represented by an ordered collection of three numbers: (X, Y, Z).
If you imagine a graph with the x and y axis being at right angles to each other and having a third, z axis coming out of the page, then a triplet of numbers, (X, Y, Z) would repr... | #PHP | PHP | <?php
class Vector
{
private $values;
public function setValues(array $values)
{
if (count($values) != 3)
throw new Exception('Values must contain exactly 3 values');
foreach ($values as $value)
if (!is_int($value) && !is_float($value))
throw new Exception('Value "' . $value . '" has an invalid typ... | Give a code snippet in #PHP
A vector is defined as having three dimensions as being represented by an ordered collection of three numbers: (X, Y, Z).
If you imagine a graph with the x and y axis being at right angles to each other and having a third, z axis coming out of the page, then a triplet of numb... | 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... | #Gambas | Gambas | Public Sub Main()
Dim sString As New String[10] 'Array for the input text
Dim sLine As New String[] 'Array of each word in a line
Dim siCount0, siCount1 As Short 'Counters
Dim sOutput, sReverse, sTemp As String... | Give a code snippet in #Gambas
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 spa... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Minkowski_question-mark_function | Minkowski question-mark function | The Minkowski question-mark function converts the continued fraction representation [a0; a1, a2, a3, ...] of a number into a binary decimal representation in which the integer part a0 is unchanged and the a1, a2, ... become alternating runs of binary zeroes and ones of those lengths. The decimal point takes the place o... | #Perl | Perl | use strict;
use warnings;
use feature 'say';
use POSIX qw(floor);
my $MAXITER = 50;
sub minkowski {
my($x) = @_;
return floor($x) + minkowski( $x - floor($x) ) if $x > 1 || $x < 0 ;
my $y = my $p = floor($x);
my ($q,$s,$d) = (1,1,1);
my $r = $p + 1;
while () {
last if ( $y + ($... | Give a code snippet in #Perl
The Minkowski question-mark function converts the continued fraction representation [a0; a1, a2, a3, ...] of a number into a binary decimal representation in which the integer part a0 is unchanged and the a1, a2, ... become alternating runs of binary zeroes and ones of those lengths. The d... | 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
| #C.23 | C# | using System;
using System.Windows.Forms;
class Program {
static void Main(string[] args) {
Application.EnableVisualStyles(); //Optional.
MessageBox.Show("Goodbye, World!");
}
} | Give a code snippet in #C.23
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/Extensible_prime_generator | Extensible prime generator | Task
Write a generator of prime numbers, in order, that will automatically adjust to accommodate the generation of any reasonably high prime.
The routine should demonstrably rely on either:
Being based on an open-ended counter set to count without upper limit other than system or programming language limits. In thi... | #Nim | Nim | import tables
type PrimeType = int
proc primesHashTable(): iterator(): PrimeType {.closure.} =
iterator output(): PrimeType {.closure.} =
# some initial values to avoid race and reduce initializations...
yield 2.PrimeType; yield 3.PrimeType; yield 5.PrimeType; yield 7.PrimeType
var h = initTable[Prime... | Give a code snippet in #Nim
Task
Write a generator of prime numbers, in order, that will automatically adjust to accommodate the generation of any reasonably high prime.
The routine should demonstrably rely on either:
Being based on an open-ended counter set to count without upper limit other than system or progra... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Look-and-say_sequence | Look-and-say sequence | The Look and say sequence is a recursively defined sequence of numbers studied most notably by John Conway.
The look-and-say sequence is also known as the Morris Number Sequence, after cryptographer Robert Morris, and the puzzle What is the next number in the sequence 1, 11, 21, 1211, 11122... | #jq | jq | def look_and_say:
def head(c; n): if .[n:n+1] == c then head(c; n+1) else n end;
tostring
| if length == 0 then ""
else head(.[0:1]; 1) as $len
| .[0:$len] as $head
| ($len | tostring) + $head[0:1] + (.[$len:] | look_and_say)
end ;
# look and say n times
def look_and_say(n):
if n == 0 then... | Give a code snippet in #jq
The Look and say sequence is a recursively defined sequence of numbers studied most notably by John Conway.
The look-and-say sequence is also known as the Morris Number Sequence, after cryptographer Robert Morris, and the puzzle What is the next number in the sequence 1,... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Greatest_element_of_a_list | Greatest element of a list | Task
Create a function that returns the maximum value in a provided set of values,
where the number of values may not be known until run-time.
| #Crystal | Crystal | values.max | Give a code snippet in #Crystal
Task
Create a function that returns the maximum value in a provided set of values,
where the number of values may not be known until run-time.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Classes | Classes | In object-oriented programming class is a set (a transitive closure) of types bound by the relation of inheritance. It is said that all types derived from some base type T and the type T itself form a class T.
The first type T from the class T sometimes is called the root type of the class.
A class of types itself, a... | #PowerShell | PowerShell |
Add-Type -Language CSharp -TypeDefinition @'
public class MyClass
{
public MyClass()
{
}
public void SomeMethod()
{
}
private int _variable;
public int Variable
{
get { return _variable; }
set { _variable = value; }
}
public static void Main()
{
... | Give a code snippet in #PowerShell
In object-oriented programming class is a set (a transitive closure) of types bound by the relation of inheritance. It is said that all types derived from some base type T and the type T itself form a class T.
The first type T from the class T sometimes is called the root type of th... | 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... | #Rust | Rust | /// # Panics
///
/// If string is empty.
fn first_char(string: &str) -> char {
string.chars().next().unwrap()
}
/// # Panics
///
/// If string is empty.
fn first_and_last_char(string: &str) -> (char, char) {
(
first_char(string),
first_char(string.rmatches(|_: char| true).next().unwrap()),
... | Give a code snippet in #Rust
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 cat... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Least_common_multiple | Least common multiple | Least common multiple
You are encouraged to solve this task according to the task description, using any language you may know.
Task
Compute the least common multiple (LCM) of two integers.
Given m and n, the least common multiple is the smallest positive integer that has both m and n as factor... | #Draco | Draco | proc gcd(word m, n) word:
word t;
while n /= 0 do
t := m;
m := n;
n := t % n
od;
m
corp
proc lcm(word m, n) word:
if m=0 or n=0
then 0
else m*n / gcd(m,n)
fi
corp
proc main() void:
writeln(lcm(12, 18))
corp | Give a code snippet in #Draco
Least common multiple
You are encouraged to solve this task according to the task description, using any language you may know.
Task
Compute the least common multiple (LCM) of two integers.
Given m and n, the least common multiple is the smallest positive integer that has... | 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
... | #Ela | Ela | reverse_string str = rev len str
where len = length str
rev 0 str = ""
rev n str = toString (str : nn) +> rev nn str
where nn = n - 1
reverse_string "Hello" | Give a code snippet in #Ela
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 s... | christopher/rosetta-code | |
http://rosettacode.org/wiki/First_class_environments | First class environments | According to Wikipedia, "In computing, a first-class object ... is an entity that can be constructed at run-time, passed as a parameter, returned from a subroutine, or assigned into a variable".
Often this term is used in the context of "first class functions". In an analogous way, a programming language may support "... | #Icon_and_Unicon | Icon and Unicon | link printf
procedure main()
every put(environment := [], hailenv(1 to 12,0)) # setup environments
printf("Sequences:\n")
while (e := !environment).sequence > 1 do {
every hailstep(!environment)
printf("\n")
}
printf("\nCounts:\n")
every printf("%4d ",(!environment).count)
prin... | Give a code snippet in #Icon_and_Unicon
According to Wikipedia, "In computing, a first-class object ... is an entity that can be constructed at run-time, passed as a parameter, returned from a subroutine, or assigned into a variable".
Often this term is used in the context of "first class functions". In an analogous ... | christopher/rosetta-code |
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