task_url stringlengths 30 116 | task_name stringlengths 2 86 | task_description stringlengths 0 14.4k | language_url stringlengths 2 53 | language_name stringlengths 1 52 | code stringlengths 0 61.9k | response_seed stringclasses 1
value | instruction_seed stringlengths 27 14.4k | _source stringclasses 1
value |
|---|---|---|---|---|---|---|---|---|
http://rosettacode.org/wiki/Tic-tac-toe | Tic-tac-toe |
Task
Play a game of tic-tac-toe.
Ensure that legal moves are played and that a winning position is notified.
Tic-tac-toe is also known as:
naughts and crosses
tic tac toe
tick tack toe
three in a row
tres en rayo and
Xs and Os
See also
MathWorld™, Tic-Tac-Toe game.
Wikipedi... | #BASIC | BASIC |
# basado en código de Antonio Rodrigo dos Santos Silva (gracias):
# http://statusgear.freeforums.net/thread/17/basic-256-tic-tac-toe
global playerturn$
global endGame$
global space$
global player1Score$
global player2Score$
global invalidMove$
global tecla$
global keyQ$
global keyW$
global keyE$
global keyA$
global... | Give a code snippet in #BASIC
Task
Play a game of tic-tac-toe.
Ensure that legal moves are played and that a winning position is notified.
Tic-tac-toe is also known as:
naughts and crosses
tic tac toe
tick tack toe
three in a row
tres en rayo and
Xs and Os
See also
MathWorld™... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Knapsack_problem/Bounded | Knapsack problem/Bounded | A tourist wants to make a good trip at the weekend with his friends.
They will go to the mountains to see the wonders of nature. So he needs some items during the trip. Food, clothing, etc. He has a good knapsack for carrying the things, but he knows that he can carry only 4 kg weight in his knapsack, because th... | #Sidef | Sidef | var raw = <<'TABLE'
map 9 150 1
compass 13 35 1
water 153 200 2
sandwich 50 60 2
glucose 15 60 2
tin 68 45 3
banana 27 60 3
apple 39 40 3
cheese 23 30 1
beer 52 ... | Give a code snippet in #Sidef
A tourist wants to make a good trip at the weekend with his friends.
They will go to the mountains to see the wonders of nature. So he needs some items during the trip. Food, clothing, etc. He has a good knapsack for carrying the things, but he knows that he can carry only 4 kg wei... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Walk_a_directory/Recursively | Walk a directory/Recursively | Task
Walk a given directory tree and print files matching a given pattern.
Note: This task is for recursive methods. These tasks should read an entire directory tree, not a single directory.
Note: Please be careful when running any code examples found here.
Related task
Walk a directory/Non-recursively ... | #OCaml | OCaml | #!/usr/bin/env ocaml
#load "unix.cma"
#load "str.cma"
open Unix
let walk_directory_tree dir pattern =
let re = Str.regexp pattern in (* pre-compile the regexp *)
let select str = Str.string_match re str 0 in
let rec walk acc = function
| [] -> (acc)
| dir::tail ->
let contents = Array.to_list (Sys.rea... | Give a code snippet in #OCaml
Task
Walk a given directory tree and print files matching a given pattern.
Note: This task is for recursive methods. These tasks should read an entire directory tree, not a single directory.
Note: Please be careful when running any code examples found here.
Related task
Walk... | 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... | #MUMPS | MUMPS | SET S1="Greetings, Planet"
SET S2=S1 | Give a code snippet in #MUMPS
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/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... | #Euphoria | Euphoria |
include std/console.e
atom K
while 1 do
K = prompt_number("Enter temperature in Kelvin >=0: ",{0,4294967296})
printf(1,"K = %5.2f\nC = %5.2f\nF = %5.2f\nR = %5.2f\n\n",{K,K-273.15,K*1.8-459.67,K*1.8})
end while
| Give a code snippet in #Euphoria
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.... | christopher/rosetta-code | |
http://rosettacode.org/wiki/OpenGL | OpenGL |
Task
Display a smooth shaded triangle with OpenGL.
Triangle created using C example compiled with GCC 4.1.2 and freeglut3.
| #Ring | Ring |
# Project: OpenGL
load "freeglut.ring"
load "opengl21lib.ring"
func main
glutInit()
glutInitDisplayMode(GLUT_DEPTH | GLUT_DOUBLE | GLUT_RGBA)
glutInitWindowSize(320,320)
glutInitWindowPosition(100, 10)
glutCreateWindow("OpenGL")
glutDisplayFunc(:renderScene)
... | Give a code snippet in #Ring
Task
Display a smooth shaded triangle with OpenGL.
Triangle created using C example compiled with GCC 4.1.2 and freeglut3.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Keyboard_input/Obtain_a_Y_or_N_response | Keyboard input/Obtain a Y or N response |
Task
Obtain a valid Y or N response from the keyboard.
The keyboard should be flushed, so that any outstanding key-presses are removed, preventing any existing Y or N key-press from being evaluated.
The response should be obtained as soon as Y or N are pressed, and there should be no need t... | #Tcl | Tcl | proc yesno {{message "Press Y or N to continue"}} {
fconfigure stdin -blocking 0
exec stty raw
read stdin ; # flush
puts -nonewline "${message}: "
flush stdout
while {![eof stdin]} {
set c [string tolower [read stdin 1]]
if {$c eq "y" || $c eq "n"} break
}
puts [string to... | Give a code snippet in #Tcl
Task
Obtain a valid Y or N response from the keyboard.
The keyboard should be flushed, so that any outstanding key-presses are removed, preventing any existing Y or N key-press from being evaluated.
The response should be obtained as soon as Y or N are pressed, ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Loops/Foreach | Loops/Foreach | Loop through and print each element in a collection in order.
Use your language's "for each" loop if it has one, otherwise iterate through the collection in order with some other loop.
Related tasks
Loop over multiple arrays simultaneously
Loops/Break
Loops/Continue
Loops/Do-while
Loops/Downward for... | #AWK | AWK |
BEGIN {
split("Mary had a little lamb", strs, " ")
for(el in strs) {
print strs[el]
}
} | Give a code snippet in #AWK
Loop through and print each element in a collection in order.
Use your language's "for each" loop if it has one, otherwise iterate through the collection in order with some other loop.
Related tasks
Loop over multiple arrays simultaneously
Loops/Break
Loops/Continue
Loops/D... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Collections | Collections | This task has been clarified. Its programming examples are in need of review to ensure that they still fit the requirements of the task.
Collections are abstractions to represent sets of values.
In statically-typed languages, the values are typically of a common data type.
Task
Create a collection, and add a fe... | #Rust | Rust | let a = [1u8,2,3,4,5]; // a is of type [u8; 5];
let b = [0;256] // Equivalent to `let b = [0,0,0,0,0,0... repeat 256 times]` | Give a code snippet in #Rust
This task has been clarified. Its programming examples are in need of review to ensure that they still fit the requirements of the task.
Collections are abstractions to represent sets of values.
In statically-typed languages, the values are typically of a common data type.
Task
Cre... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Knapsack_problem/Continuous | Knapsack problem/Continuous |
A thief burgles a butcher's shop, where he can select from some items.
The thief knows the weights and prices of each items. Because he has a knapsack with 15 kg maximal capacity, he wants to select the items such that he would have his profit maximized. He may cut the items; the item has a reduced price after... | #jq | jq | # continuous_knapsack(W) expects the input to be
# an array of objects {"name": _, "weight": _, "value": _}
# where "value" is the value of the given weight of the object.
def continuous_knapsack(W):
map( .price = (if .weight > 0 then (.value/.weight) else 0 end) )
| sort_by( .price )
| reverse
| reduce .[] a... | Give a code snippet in #jq
A thief burgles a butcher's shop, where he can select from some items.
The thief knows the weights and prices of each items. Because he has a knapsack with 15 kg maximal capacity, he wants to select the items such that he would have his profit maximized. He may cut the items; the it... | 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
... | #Swift | Swift | println(Array(Set([3,2,1,2,3,4]))) | Give a code snippet in #Swift
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 so... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Loops/Infinite | Loops/Infinite | Task
Print out SPAM followed by a newline in an infinite loop.
Related tasks
Loop over multiple arrays simultaneously
Loops/Break
Loops/Continue
Loops/Do-while
Loops/Downward for
Loops/For
Loops/For with a specified step
Loops/Foreach
Loops/Increment loop index within l... | #CoffeeScript | CoffeeScript | loop
console.log 'SPAM'
| Give a code snippet in #CoffeeScript
Task
Print out SPAM followed by a newline in an infinite loop.
Related tasks
Loop over multiple arrays simultaneously
Loops/Break
Loops/Continue
Loops/Do-while
Loops/Downward for
Loops/For
Loops/For with a specified step
Loops/Foreach
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Catalan_numbers | Catalan numbers | Catalan numbers
You are encouraged to solve this task according to the task description, using any language you may know.
Catalan numbers are a sequence of numbers which can be defined directly:
C
n
=
1
n
+
1
(
2
n
n
)
=
(
2
n
)
!
(
n
+
1
)
!
n
!
for
n
≥
0.
{\displaystyle C... | #Logo | Logo | to factorial :n
output ifelse [less? :n 1] 1 [product :n factorial difference :n 1]
end
to choose :n :r
output quotient factorial :n product factorial :r factorial difference :n :r
end
to catalan :n
output product (quotient sum :n 1) choose product 2 :n :n
end
repeat 15 [print catalan repcount] | Give a code snippet in #Logo
Catalan numbers
You are encouraged to solve this task according to the task description, using any language you may know.
Catalan numbers are a sequence of numbers which can be defined directly:
C
n
=
1
n
+
1
(
2
n
n
)
=
(
2
n
)
!
(
n
+
1
)
!
n
!
f... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Jensen%27s_Device | Jensen's Device | Jensen's Device
You are encouraged to solve this task according to the task description, using any language you may know.
This task is an exercise in call by name.
Jensen's Device is a computer programming technique devised by Danish computer scientist Jørn Jensen after studying the ALGOL 60 Report.
The following pr... | #Simula | Simula | comment Jensen's Device;
begin
integer i;
real procedure sum (i, lo, hi, term);
name i, term;
value lo, hi;
integer i, lo, hi;
real term;
comment term is passed by-name, and so is i;
begin
integer j;
real temp;
temp := 0;
for j := lo step 1 until hi do
... | Give a code snippet in #Simula
Jensen's Device
You are encouraged to solve this task according to the task description, using any language you may know.
This task is an exercise in call by name.
Jensen's Device is a computer programming technique devised by Danish computer scientist Jørn Jensen after studying the AL... | 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)
... | #Perl | Perl |
use strict;
use warnings;
use feature qw(say);
for my $i (1..100) {
say $i % 15 == 0 ? "FizzBuzz"
: $i % 3 == 0 ? "Fizz"
: $i % 5 == 0 ? "Buzz"
: $i;
} | Give a code snippet in #Perl
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 ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Stem-and-leaf_plot | Stem-and-leaf plot | Create a well-formatted stem-and-leaf plot from the following data set, where the leaves are the last digits:
12 127 28 42 39 113 42 18 44 118 44 37 113 124 37 48 127 36 29 31 125 139 131 115 105 132 104 123 35 113 122 42 117 119 58 109 23 105 63 27 44 105 99 41 128 121 116 125 32 61 37 127 29 113 121 58 114 126 53 11... | #Maple | Maple | StemPlot := proc( datatable::{rtable,list,algebraic} )
local i, j, k, tf, LeafStemTable, LeafStemIndices;
k:=0;
LeafStemTable := ListTools:-Categorize( (x,y) -> iquo(x, 10) = iquo(y, 10), sort(datatable));
if LeafStemTable = NULL then
error "Empty List";
elif nops( [ LeafStemTable ] )... | Give a code snippet in #Maple
Create a well-formatted stem-and-leaf plot from the following data set, where the leaves are the last digits:
12 127 28 42 39 113 42 18 44 118 44 37 113 124 37 48 127 36 29 31 125 139 131 115 105 132 104 123 35 113 122 42 117 119 58 109 23 105 63 27 44 105 99 41 128 121 116 125 32 61 37 ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Benford%27s_law | Benford's law |
This page uses content from Wikipedia. The original article was at Benford's_law. 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)
Benford's law, also called the first-digit law, refers to the freque... | #Icon_and_Unicon | Icon and Unicon | global counts, total
procedure main()
counts := table(0)
total := 0.0
every benlaw(fib(1 to 1000))
every i := 1 to 9 do
write(i,": ",right(100*counts[string(i)]/total,9)," ",100*P(i))
end
procedure benlaw(n)
if counts[n ? (tab(upto('123456789')),move(1))] +:= 1 then total +:= 1
end
pro... | Give a code snippet in #Icon_and_Unicon
This page uses content from Wikipedia. The original article was at Benford's_law. 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)
Benford's law, also called ... | 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.
... | #Frink | Frink |
for n = 1 to 5
{
for a = 1 to n
print["*"]
println[]
}
| Give a code snippet in #Frink
“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 structu... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Kernighans_large_earthquake_problem | Kernighans large earthquake problem | Brian Kernighan, in a lecture at the University of Nottingham, described a problem on which this task is based.
Problem
You are given a a data file of thousands of lines; each of three `whitespace` separated fields: a date, a one word name and the magnitude of the event.
Example lines from the file would be lines li... | #Phixmonti | Phixmonti | argument tail nip len dup
if
get nip
else
drop drop "data.txt"
endif
dup "r" fopen
dup 0 < if drop "Could not open '" print print "' for reading" print -1 quit endif
nip
true
while
dup fgets
dup 0 < if
drop false
else
dup split 3 get tonum 6 > if drop print else drop drop endif
... | Give a code snippet in #Phixmonti
Brian Kernighan, in a lecture at the University of Nottingham, described a problem on which this task is based.
Problem
You are given a a data file of thousands of lines; each of three `whitespace` separated fields: a date, a one word name and the magnitude of the event.
Example li... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Rot-13 | Rot-13 |
Task
Implement a rot-13 function (or procedure, class, subroutine, or other "callable" object as appropriate to your programming environment).
Optionally wrap this function in a utility program (like tr, which acts like a common UNIX utility, performing a line-by-line rot-13 encoding of every line of inpu... | #11l | 11l | F rot13(string)
V r = ‘ ’ * string.len
L(c) string
r[L.index] = S c
‘a’..‘z’
Char(code' (c.code - ‘a’.code + 13) % 26 + ‘a’.code)
‘A’..‘Z’
Char(code' (c.code - ‘A’.code + 13) % 26 + ‘A’.code)
... | Give a code snippet in #11l
Task
Implement a rot-13 function (or procedure, class, subroutine, or other "callable" object as appropriate to your programming environment).
Optionally wrap this function in a utility program (like tr, which acts like a common UNIX utility, performing a line-by-line rot-13 e... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Base64_decode_data | Base64 decode data | See Base64 encode data.
Now write a program that takes the output of the Base64 encode data task as input and regenerate the original file.
When working on the VBA implementation I found several 'solutions' on the net, including one from the software maker himself, that showed output with incorrect padding. Obviously... | #C.23 | C# | using System;
using System.Text;
namespace Base64DecodeData {
class Program {
static void Main(string[] args) {
var data = "VG8gZXJyIGlzIGh1bWFuLCBidXQgdG8gcmVhbGx5IGZvdWwgdGhpbmdzIHVwIHlvdSBuZWVkIGEgY29tcHV0ZXIuCiAgICAtLSBQYXVsIFIuIEVocmxpY2g=";
Console.WriteLine(data);
... | Give a code snippet in #C.23
See Base64 encode data.
Now write a program that takes the output of the Base64 encode data task as input and regenerate the original file.
When working on the VBA implementation I found several 'solutions' on the net, including one from the software maker himself, that showed output wit... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Hash_join | Hash join | An inner join is an operation that combines two data tables into one table, based on matching column values. The simplest way of implementing this operation is the nested loop join algorithm, but a more scalable alternative is the hash join algorithm.
Task[edit]
Implement the "hash join" algorithm, and demonstrate tha... | #Scala | Scala | def join[Type](left: Seq[Seq[Type]], right: Seq[Seq[Type]]) = {
val hash = right.groupBy(_.head) withDefaultValue Seq()
left.flatMap(cols => hash(cols.last).map(cols ++ _.tail))
}
// Example:
val table1 = List(List("27", "Jonah"),
List("18", "Alan"),
List("28", "Glory"),
... | Give a code snippet in #Scala
An inner join is an operation that combines two data tables into one table, based on matching column values. The simplest way of implementing this operation is the nested loop join algorithm, but a more scalable alternative is the hash join algorithm.
Task[edit]
Implement the "hash join"... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Pascal%27s_triangle | Pascal's triangle | Pascal's triangle is an arithmetic and geometric figure often associated with the name of Blaise Pascal, but also studied centuries earlier in India, Persia, China and elsewhere.
Its first few rows look like this:
1
1 1
1 2 1
1 3 3 1
where each element of each row is either 1 or the sum of the two elemen... | #BBC_BASIC | BBC BASIC | nrows% = 10
colwidth% = 4
@% = colwidth% : REM Set column width
FOR row% = 1 TO nrows%
PRINT SPC(colwidth%*(nrows% - row%)/2);
acc% = 1
FOR element% = 1 TO row%
PRINT acc%;
acc% = acc% * (row% - element%) / element% + 0.5
NEXT
PRINT
... | Give a code snippet in #BBC_BASIC
Pascal's triangle is an arithmetic and geometric figure often associated with the name of Blaise Pascal, but also studied centuries earlier in India, Persia, China and elsewhere.
Its first few rows look like this:
1
1 1
1 2 1
1 3 3 1
where each element of each row is ei... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Empty_program | Empty program | Task
Create the simplest possible program that is still considered "correct."
| #C.2B.2B | C++ | int main(){} | Give a code snippet in #C.2B.2B
Task
Create the simplest possible program that is still considered "correct."
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Knapsack_problem/Unbounded | Knapsack problem/Unbounded | A traveler gets diverted and has to make an unscheduled stop in what turns out to be Shangri La. Opting to leave, he is allowed to take as much as he likes of the following items, so long as it will fit in his knapsack, and he can carry it.
He knows that he can carry no more than 25 'weights' in total; and tha... | #PowerShell | PowerShell | # Define the items to pack
$Item = @(
[pscustomobject]@{ Name = 'panacea'; Unit = 'vials' ; value = 3000; Weight = 0.3; Volume = 0.025 }
[pscustomobject]@{ Name = 'ichor' ; Unit = 'ampules'; value = 1800; Weight = 0.2; Volume = 0.015 }
[pscustomobject]@{ Name = 'gold' ; Unit = 'bars' ; value = 2500; ... | Give a code snippet in #PowerShell
A traveler gets diverted and has to make an unscheduled stop in what turns out to be Shangri La. Opting to leave, he is allowed to take as much as he likes of the following items, so long as it will fit in his knapsack, and he can carry it.
He knows that he can carry no more than ... | 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... | #Joy | Joy |
DEFINE write-floats ==
['g 0] [formatf] enconcat map rollup
['g 0] [formatf] enconcat map swap zip
"filename" "w" fopen swap
[[fputchars] 9 fputch] step 10 fputch] step
fclose.
| Give a code snippet in #Joy
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/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.
| #V | V | [4 3 2 7 8 9] 0 [max] fold
=9 | Give a code snippet in #V
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/Partition_function_P | Partition function P |
The Partition Function P, often notated P(n) is the number of solutions where n∈ℤ can be expressed as the sum of a set of positive integers.
Example
P(4) = 5 because 4 = Σ(4) = Σ(3,1) = Σ(2,2) = Σ(2,1,1) = Σ(1,1,1,1)
P(n) can be expressed as the recurrence relation:
P(n) = P(n-1) +P(n-2) -P(n-5) -P(n-7)... | #Nim | Nim | import sequtils, strformat, times
import bignum
func partitions(n: int): Int =
var p = newSeqWith(n + 1, newInt())
p[0] = newInt(1)
for i in 1..n:
var k = 1
while true:
var j = k * (3 * k - 1) div 2
if j > i: break
if (k and 1) != 0:
inc p[i], p[i - j]
else:
dec p... | Give a code snippet in #Nim
The Partition Function P, often notated P(n) is the number of solutions where n∈ℤ can be expressed as the sum of a set of positive integers.
Example
P(4) = 5 because 4 = Σ(4) = Σ(3,1) = Σ(2,2) = Σ(2,1,1) = Σ(1,1,1,1)
P(n) can be expressed as the recurrence relation:
P(n) = P... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Globally_replace_text_in_several_files | Globally replace text in several files | Task
Replace every occurring instance of a piece of text in a group of text files with another one.
For this task we want to replace the text "Goodbye London!" with "Hello New York!" for a list of files.
| #C | C | #include <stdio.h>
#include <stdlib.h>
#include <stddef.h>
#include <string.h>
#include <sys/types.h>
#include <fcntl.h>
#include <sys/stat.h>
#include <unistd.h>
#include <err.h>
#include <string.h>
char * find_match(const char *buf, const char * buf_end, const char *pat, size_t len)
{
ptrdiff_t i;
char *start = b... | Give a code snippet in #C
Task
Replace every occurring instance of a piece of text in a group of text files with another one.
For this task we want to replace the text "Goodbye London!" with "Hello New York!" for a list of files.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Substring | Substring |
Basic Data Operation
This is a basic data operation. It represents a fundamental action on a basic data type.
You may see other such operations in the Basic Data Operations category, or:
Integer Operations
Arithmetic |
Comparison
Boolean Operations
Bitwise |
Logical
String Operations
Concatenation |
Interpolation |... | #Smalltalk | Smalltalk | |s|
s := 'hello world shortest program'.
(s copyFrom: 13 to: (13+4)) displayNl.
"4 is the length (5) - 1, since we need the index of the
last char we want, which is included"
(s copyFrom: 7) displayNl.
(s allButLast) displayNl.
(s copyFrom: ((s indexOfRegex: 'w') first)
to: ( ((s indexOfRegex: 'w') first) +... | Give a code snippet in #Smalltalk
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 Operati... | 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... | #BBC_BASIC | BBC BASIC | SWP_NOMOVE = 2
SWP_NOZORDER = 4
SW_MAXIMIZE = 3
SW_MINIMIZE = 6
SW_RESTORE = 9
SW_HIDE = 0
SW_SHOW = 5
REM Store window handle in a variable:
myWindowHandle% = @hwnd%
PRINT "Hiding the window in two seconds..."
WAIT 200
SYS "ShowWindow", myWind... | Give a code snippet in #BBC_BASIC
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 windo... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Additive_primes | Additive primes | Definitions
In mathematics, additive primes are prime numbers for which the sum of their decimal digits are also primes.
Task
Write a program to determine (and show here) all additive primes less than 500.
Optionally, show the number of additive primes.
Also see
the OEIS entry: A046704 additive primes.
... | #Frink | Frink | vals = toArray[select[primes[2, 500], {|x| isPrime[sum[integerDigits[x]]]}]]
println[formatTable[columnize[vals, 10]]]
println["\n" + length[vals] + " values found."] | Give a code snippet in #Frink
Definitions
In mathematics, additive primes are prime numbers for which the sum of their decimal digits are also primes.
Task
Write a program to determine (and show here) all additive primes less than 500.
Optionally, show the number of additive primes.
Also see
the OEIS entry:... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Stern-Brocot_sequence | Stern-Brocot sequence | For this task, the Stern-Brocot sequence is to be generated by an algorithm similar to that employed in generating the Fibonacci sequence.
The first and second members of the sequence are both 1:
1, 1
Start by considering the second member of the sequence
Sum the considered member of the sequence and its prece... | #Scheme | Scheme | ; Recursive function to return the Nth Stern-Brocot sequence number.
(define stern-brocot
(lambda (n)
(cond
((<= n 0)
0)
((<= n 2)
1)
((even? n)
(stern-brocot (/ n 2)))
(else
(let ((earlier (/ (1+ n) 2)))
(+ (stern-brocot earlier) (stern-brocot (... | Give a code snippet in #Scheme
For this task, the Stern-Brocot sequence is to be generated by an algorithm similar to that employed in generating the Fibonacci sequence.
The first and second members of the sequence are both 1:
1, 1
Start by considering the second member of the sequence
Sum the considered memb... | 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... | #PostScript | PostScript |
(Hello World) length =
11
| Give a code snippet in #PostScript
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... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Rot-13 | Rot-13 |
Task
Implement a rot-13 function (or procedure, class, subroutine, or other "callable" object as appropriate to your programming environment).
Optionally wrap this function in a utility program (like tr, which acts like a common UNIX utility, performing a line-by-line rot-13 encoding of every line of inpu... | #Ada | Ada | with Ada.Text_IO.Text_Streams; use Ada.Text_IO.Text_Streams;
with Ada.Strings.Maps; use Ada.Strings.Maps;
with Ada.Command_Line; use Ada.Command_Line;
procedure Rot_13 is
From_Sequence : Character_Sequence := "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";
Result_Sequence : Character_Sequence := "nopq... | Give a code snippet in #Ada
Task
Implement a rot-13 function (or procedure, class, subroutine, or other "callable" object as appropriate to your programming environment).
Optionally wrap this function in a utility program (like tr, which acts like a common UNIX utility, performing a line-by-line rot-13 e... | 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.
| #Perl | Perl | sub foo {
my ($a, $b) = @_;
return $a + $b, $a * $b;
} | Give a code snippet in #Perl
Task
Show how to return more than one value from a function.
| 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... | #Gambas | Gambas | Public Sub Form_Open()
Dim sData As String = File.Load("data.csv")
Dim sLine, sTemp As String
Dim sOutput As New String[]
Dim siCount As Short
Dim bLine1 As Boolean
For Each sLine In Split(sData, gb.NewLine)
If Not bLine1 Then
sLine &= ",SUM"
sOutput.Add(sLine)
bLine1 = True
Continue
End If
For... | Give a code snippet in #Gambas
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, cha... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Increment_a_numerical_string | Increment a numerical string | Task
Increment a numerical string.
| #AppleScript | AppleScript | use AppleScript version "2.4"
use framework "Foundation"
use scripting additions
-- succString :: Bool -> String -> String
on succString(blnPruned, s)
script go
on |λ|(w)
try
if w contains "." then
set v to w as real
else
... | Give a code snippet in #AppleScript
Task
Increment a numerical string.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Pig_the_dice_game | Pig the dice game | The game of Pig is a multiplayer game played with a single six-sided die. The
object of the game is to reach 100 points or more.
Play is taken in turns. On each person's turn that person has the option of either:
Rolling the dice: where a roll of two to six is added to their score for that turn and th... | #Groovy | Groovy |
class PigDice {
final static int maxScore = 100;
final static yesses = ["yes", "y", "", "Y", "YES"]
static main(args) {
def playersCount = 2
Scanner sc = new Scanner(System.in)
Map scores = [:]
def current = 0
def player = 0
def gameOver = false
def firstThrow = true
Random rnd = new Random()
... | Give a code snippet in #Groovy
The game of Pig is a multiplayer game played with a single six-sided die. The
object of the game is to reach 100 points or more.
Play is taken in turns. On each person's turn that person has the option of either:
Rolling the dice: where a roll of two to six is added to ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Inverted_index | Inverted index | An Inverted Index is a data structure used to create full text search.
Task
Given a set of text files, implement a program to create an inverted index.
Also create a user interface to do a search using that inverted index which returns a list of files that contain the query term / terms.
The search index can be i... | #C | C | #include <stdio.h>
#include <stdlib.h>
char chr_legal[] = "abcdefghijklmnopqrstuvwxyz0123456789_-./";
int chr_idx[256] = {0};
char idx_chr[256] = {0};
#define FNAME 0
typedef struct trie_t *trie, trie_t;
struct trie_t {
trie next[sizeof(chr_legal)]; /* next letter; slot 0 is for file name */
int eow;
};
... | Give a code snippet in #C
An Inverted Index is a data structure used to create full text search.
Task
Given a set of text files, implement a program to create an inverted index.
Also create a user interface to do a search using that inverted index which returns a list of files that contain the query term / terms.... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Isqrt_(integer_square_root)_of_X | Isqrt (integer square root) of X | Sometimes a function is needed to find the integer square root of X, where X can be a
real non─negative number.
Often X is actually a non─negative integer.
For the purposes of this task, X can be an integer or a real number, but if it
simplifies things in your computer programming language, assume... | #Haskell | Haskell | import Data.Bits
isqrt :: Integer -> Integer
isqrt n = go n 0 (q `shiftR` 2)
where
q = head $ dropWhile (< n) $ iterate (`shiftL` 2) 1
go z r 0 = r
go z r q = let t = z - r - q
in if t >= 0
then go t (r `shiftR` 1 + q) (q `shiftR` 2)
else go z (r `shiftR` 1) (... | Give a code snippet in #Haskell
Sometimes a function is needed to find the integer square root of X, where X can be a
real non─negative number.
Often X is actually a non─negative integer.
For the purposes of this task, X can be an integer or a real number, but if it
simplifies things in your comput... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Input_loop | Input loop | Input loop is part of Short Circuit's Console Program Basics selection.
Task
Read from a text stream either word-by-word or line-by-line until the stream runs out of data.
The stream will have an unknown amount of data on it.
| #NetRexx | NetRexx | /* NetRexx */
options replace format comments java crossref symbols nobinary
-- Read from default input stream (console) until end of data
lines = ''
lines[0] = 0
lineNo = 0
loop label ioloop forever
inLine = ask
if inLine = null then leave ioloop -- stop on EOF (Try Ctrl-D on UNIX-like systems or Ctrl-Z on W... | Give a code snippet in #NetRexx
Input loop is part of Short Circuit's Console Program Basics selection.
Task
Read from a text stream either word-by-word or line-by-line until the stream runs out of data.
The stream will have an unknown amount of data on it.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Luhn_test_of_credit_card_numbers | Luhn test of credit card numbers | The Luhn test is used by some credit card companies to distinguish valid credit card numbers from what could be a random selection of digits.
Those companies using credit card numbers that can be validated by the Luhn test have numbers that pass the following test:
Reverse the order of the digits in the number.
Tak... | #ABAP | ABAP | METHOD luhn_check.
DATA: sum(1) TYPE n VALUE 0. " Sum of checksum.
DATA: current TYPE i. " Current digit.
DATA: odd TYPE i VALUE 1. " Multiplier.
DATA: len TYPE i. " String crowler.
" Luhn algorithm.
len = NUMOFCHAR( pi_string ) - 1.
WHILE ( len >= 0 ).
current = pi_string+len(1) * odd.
IF (... | Give a code snippet in #ABAP
The Luhn test is used by some credit card companies to distinguish valid credit card numbers from what could be a random selection of digits.
Those companies using credit card numbers that can be validated by the Luhn test have numbers that pass the following test:
Reverse the order of ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Repeat_a_string | Repeat a string | Take a string and repeat it some number of times.
Example: repeat("ha", 5) => "hahahahaha"
If there is a simpler/more efficient way to repeat a single “character” (i.e. creating a string filled with a certain character), you might want to show that as well (i.e. repeat-char("*", 5) => "*****").
Other tasks re... | #Pike | Pike | "ha"*5; | Give a code snippet in #Pike
Take a string and repeat it some number of times.
Example: repeat("ha", 5) => "hahahahaha"
If there is a simpler/more efficient way to repeat a single “character” (i.e. creating a string filled with a certain character), you might want to show that as well (i.e. repeat-char("*", 5) =... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Palindrome_detection | Palindrome detection | A palindrome is a phrase which reads the same backward and forward.
Task[edit]
Write a function or program that checks whether a given sequence of characters (or, if you prefer, bytes)
is a palindrome.
For extra credit:
Support Unicode characters.
Write a second function (possibly as a wrapper to the first) which ... | #Falcon | Falcon |
/* created by Aykayayciti Earl Lamont Montgomery
April 9th, 2018 */
function is_palindrome(a)
a = strUpper(a).replace(" ", "")
b = a[-1:0]
return b == a
end
a = "mom"
> is_palindrome(a)
| Give a code snippet in #Falcon
A palindrome is a phrase which reads the same backward and forward.
Task[edit]
Write a function or program that checks whether a given sequence of characters (or, if you prefer, bytes)
is a palindrome.
For extra credit:
Support Unicode characters.
Write a second function (possibly a... | christopher/rosetta-code | |
http://rosettacode.org/wiki/AVL_tree | AVL tree |
This page uses content from Wikipedia. The original article was at AVL tree. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance)
In computer science, an AVL tree is a self-balancing binary search tree.... | #Objeck | Objeck | class AVLNode {
@key : Int;
@balance : Int;
@height : Int;
@left : AVLNode;
@right : AVLNode;
@above : AVLNode;
New(key : Int, above : AVLNode) {
@key := key;
@above := above;
}
method : public : GetKey() ~ Int {
return @key;
}
method : public : GetLeft() ~ AVLNode {
return @... | Give a code snippet in #Objeck
This page uses content from Wikipedia. The original article was at AVL tree. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance)
In computer science, an AVL tree is a se... | 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... | #XPL0 | XPL0 | int List(810); \list of numbers in a cycle
int Inx; \index for List
include c:\cxpl\codes;
func HadNum(N); \Return 'true' if number N is in the List
int N;
int I;
[for I:= 0 to Inx-1 do
if N = List(I) then return true;
return false;
]; \HadNum
func SqDigits(N); \Ret... | Give a code snippet in #XPL0
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 i... | 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
| #Dragon | Dragon |
showln "Hello world!"
| Give a code snippet in #Dragon
Hello world/Text is part of Short Circuit's Console Program Basics selection.
Task
Display the string Hello world! on a text console.
Related tasks
Hello world/Graphical
Hello world/Line Printer
Hello world/Newbie
Hello world/Newline omission
Hello world/Standard error
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/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,... | #Modula-3 | Modula-3 | VAR staticArray: ARRAY [1..10] OF INTEGER; | Give a code snippet in #Modula-3
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 re... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Naming_conventions | Naming conventions | Many languages have naming conventions regarding the identifiers used in the language, its libraries, and programs written in the language. Such conventions, which may be classified as de facto or de jure depending on how they are enforced,
often take the form of rules regarding prefixes, suffixes, and the use of upper... | #Arturo | Arturo |
# Field names begin with $ so $1 is the first field, $2 the second and $NF the
# last. $0 references the entire input record.
#
# Function and variable names are case sensitive and begin with an alphabetic
# character or underscore followed by any number of: a-z, A-Z, 0-9, _
#
# The awk language is type less; variab... | Give a code snippet in #Arturo
Many languages have naming conventions regarding the identifiers used in the language, its libraries, and programs written in the language. Such conventions, which may be classified as de facto or de jure depending on how they are enforced,
often take the form of rules regarding prefixes... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Arithmetic/Integer | Arithmetic/Integer |
Basic Data Operation
This is a basic data operation. It represents a fundamental action on a basic data type.
You may see other such operations in the Basic Data Operations category, or:
Integer Operations
Arithmetic |
Comparison
Boolean Operations
Bitwise |
Logical
String Operations
Concatenation |
Interpolation |... | #E | E | def arithmetic(a :int, b :int) {
return `$\
Sum: ${a + b}
Difference: ${a - b}
Product: ${a * b}
Quotient: ${a // b}
Remainder: ${a % b}$\n`
} | Give a code snippet in #E
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
Conc... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Odd_word_problem | Odd word problem | Task
Write a program that solves the odd word problem with the restrictions given below.
Description
You are promised an input stream consisting of English letters and punctuations.
It is guaranteed that:
the words (sequence of consecutive letters) are delimited by one and only one punctuation,
the stream will... | #J | J | putch=: 4 :0 NB. coroutine verb
outch y
return x
)
isletter=: toupper ~: tolower
do_char=: 3 :0 NB. coroutine verb
ch=. getch''
if. isletter ch do.
if. odd do.
putch&ch yield do_char '' return.
end.
else.
odd=: -. odd
end.
return ch
)
evenodd=: 3 :0
... | Give a code snippet in #J
Task
Write a program that solves the odd word problem with the restrictions given below.
Description
You are promised an input stream consisting of English letters and punctuations.
It is guaranteed that:
the words (sequence of consecutive letters) are delimited by one and only one pu... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Palindrome_detection | Palindrome detection | A palindrome is a phrase which reads the same backward and forward.
Task[edit]
Write a function or program that checks whether a given sequence of characters (or, if you prefer, bytes)
is a palindrome.
For extra credit:
Support Unicode characters.
Write a second function (possibly as a wrapper to the first) which ... | #PowerBASIC | PowerBASIC | FUNCTION isPalindrome (what AS STRING) AS LONG
DIM whatcopy AS STRING, chk AS STRING, tmp AS STRING * 1, L0 AS LONG
FOR L0 = 1 TO LEN(what)
tmp = UCASE$(MID$(what, L0, 1))
SELECT CASE tmp
CASE "A" TO "Z"
whatcopy = whatcopy & tmp
chk = tmp & chk
... | Give a code snippet in #PowerBASIC
A palindrome is a phrase which reads the same backward and forward.
Task[edit]
Write a function or program that checks whether a given sequence of characters (or, if you prefer, bytes)
is a palindrome.
For extra credit:
Support Unicode characters.
Write a second function (possib... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Fixed_length_records | Fixed length records | Fixed length read/write
Before terminals, computers commonly used punch card readers or paper tape input.
A common format before these devices were superseded by terminal technology was based on the Hollerith code, Hollerith code.
These input devices handled 80 columns per card and had a limited character set, encod... | #Go | Go | package main
import (
"fmt"
"log"
"os"
"os/exec"
)
func reverseBytes(bytes []byte) {
for i, j := 0, len(bytes)-1; i < j; i, j = i+1, j-1 {
bytes[i], bytes[j] = bytes[j], bytes[i]
}
}
func check(err error) {
if err != nil {
log.Fatal(err)
}
}
func main() {
in, ... | Give a code snippet in #Go
Fixed length read/write
Before terminals, computers commonly used punch card readers or paper tape input.
A common format before these devices were superseded by terminal technology was based on the Hollerith code, Hollerith code.
These input devices handled 80 columns per card and had a ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Towers_of_Hanoi | Towers of Hanoi | Task
Solve the Towers of Hanoi problem with recursion.
| #AppleScript | AppleScript | --------------------- TOWERS OF HANOI --------------------
-- hanoi :: Int -> (String, String, String) -> [(String, String)]
on hanoi(n, abc)
script go
on |λ|(n, {x, y, z})
if n > 0 then
set m to n - 1
|λ|(m, {x, z, y}) & ¬
{{x, y}} & |λ|(m... | Give a code snippet in #AppleScript
Task
Solve the Towers of Hanoi problem with recursion.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Sequence:_smallest_number_greater_than_previous_term_with_exactly_n_divisors | Sequence: smallest number greater than previous term with exactly n divisors | Calculate the sequence where each term an is the smallest natural number greater than the previous term, that has exactly n divisors.
Task
Show here, on this page, at least the first 15 terms of the sequence.
See also
OEIS:A069654
Related tasks
Sequence: smallest number with exactly n divisors
Sequence: nth ... | #Dyalect | Dyalect | func countDivisors(n) {
var count = 0
var i = 1
while i * i <= n {
if n % i == 0 {
if i == n / i {
count += 1
} else {
count += 2
}
}
i += 1
}
return count
}
let max = 15
print("The first \(max) terms of th... | Give a code snippet in #Dyalect
Calculate the sequence where each term an is the smallest natural number greater than the previous term, that has exactly n divisors.
Task
Show here, on this page, at least the first 15 terms of the sequence.
See also
OEIS:A069654
Related tasks
Sequence: smallest number with e... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Identity_matrix | Identity matrix | Task
Build an identity matrix of a size known at run-time.
An identity matrix is a square matrix of size n × n,
where the diagonal elements are all 1s (ones),
and all the other elements are all 0s (zeroes).
I
n
=
[
1
0
0
⋯
0
0
1
0
⋯
0
0
0
1
⋯
0
⋮
⋮
⋮
⋱
... | #Java | Java | public class PrintIdentityMatrix {
public static void main(String[] args) {
int n = 5;
int[][] array = new int[n][n];
IntStream.range(0, n).forEach(i -> array[i][i] = 1);
Arrays.stream(array)
.map((int[] a) -> Arrays.toString(a))
.forEach(System.... | Give a code snippet in #Java
Task
Build an identity matrix of a size known at run-time.
An identity matrix is a square matrix of size n × n,
where the diagonal elements are all 1s (ones),
and all the other elements are all 0s (zeroes).
I
n
=
[
1
0
0
⋯
0
0
1
0
⋯
0
0
0
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Exceptions/Catch_an_exception_thrown_in_a_nested_call | Exceptions/Catch an exception thrown in a nested call | Show how to create a user-defined exception and show how to catch an exception raised from several nested calls away.
Create two user-defined exceptions, U0 and U1.
Have function foo call function bar twice.
Have function bar call function baz.
Arrange for function baz to rais... | #jq | jq | # n is assumed to be the number of times baz has been previously called:
def baz(n):
if n==0 then error("U0")
elif n==1 then error("U1")
else "Goodbye"
end;
def bar(n): baz(n);
def foo:
(try bar(0) catch if . == "U0" then "We caught U0" else error(.) end),
(try bar(1) catch if . == "U0" then "We caught ... | Give a code snippet in #jq
Show how to create a user-defined exception and show how to catch an exception raised from several nested calls away.
Create two user-defined exceptions, U0 and U1.
Have function foo call function bar twice.
Have function bar call function baz.
Arrange ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Perlin_noise | Perlin noise | The Perlin noise is a kind of gradient noise invented by Ken Perlin around the end of the twentieth century and still currently heavily used in computer graphics, most notably to procedurally generate textures or heightmaps.
The Perlin noise is basically a pseudo-random mapping of
R
d
... | #Common_Lisp | Common Lisp | ;;;; Translation from: Java
(declaim (optimize (speed 3) (debug 0)))
(defconstant +p+
(let ((permutation
#(151 160 137 91 90 15
131 13 201 95 96 53 194 233 7 225 140 36 103 30 69 142 8 99 37 240 21 10 23
190 6 148 247 120 234 75 0 26 197 62 94 252 219 203 117 35 11 32 57 177 33
88 237 149 56 87 ... | Give a code snippet in #Common_Lisp
The Perlin noise is a kind of gradient noise invented by Ken Perlin around the end of the twentieth century and still currently heavily used in computer graphics, most notably to procedurally generate textures or heightmaps.
The Perlin noise is basically a pseudo-... | christopher/rosetta-code | |
http://rosettacode.org/wiki/UTF-8_encode_and_decode | UTF-8 encode and decode | As described in UTF-8 and in Wikipedia, UTF-8 is a popular encoding of (multi-byte) Unicode code-points into eight-bit octets.
The goal of this task is to write a encoder that takes a unicode code-point (an integer representing a unicode character) and returns a sequence of 1-4 bytes representing that character in the... | #Wren | Wren | import "/fmt" for Fmt
var utf8_encode = Fn.new { |cp| String.fromCodePoint(cp).bytes.toList }
var utf8_decode = Fn.new { |b|
var mbMask = 0x3f // non-first bytes start 10 and carry 6 bits of data
var b0 = b[0]
if (b0 < 0x80) {
return b0
} else if (b0 < 0xe0) {
var b2Mask = 0x1f // fi... | Give a code snippet in #Wren
As described in UTF-8 and in Wikipedia, UTF-8 is a popular encoding of (multi-byte) Unicode code-points into eight-bit octets.
The goal of this task is to write a encoder that takes a unicode code-point (an integer representing a unicode character) and returns a sequence of 1-4 bytes repr... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Walk_a_directory/Non-recursively | Walk a directory/Non-recursively | Task
Walk a given directory and print the names of files matching a given pattern.
(How is "pattern" defined? substring match? DOS pattern? BASH pattern? ZSH pattern? Perl regular expression?)
Note: This task is for non-recursive methods. These tasks should read a single directory, not an entire directory tree.
... | #C | C | #include <sys/types.h>
#include <dirent.h>
#include <regex.h>
#include <stdio.h>
enum {
WALK_OK = 0,
WALK_BADPATTERN,
WALK_BADOPEN,
};
int walker(const char *dir, const char *pattern)
{
struct dirent *entry;
regex_t reg;
DIR *d;
if (regcomp(®, pattern, REG_EXTENDED | REG_NOSUB))
... | Give a code snippet in #C
Task
Walk a given directory and print the names of files matching a given pattern.
(How is "pattern" defined? substring match? DOS pattern? BASH pattern? ZSH pattern? Perl regular expression?)
Note: This task is for non-recursive methods. These tasks should read a single directory, not ... | 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.)
| #Raku | Raku | # the answer to everything
my $x = 42; | Give a code snippet in #Raku
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/Repeat_a_string | Repeat a string | Take a string and repeat it some number of times.
Example: repeat("ha", 5) => "hahahahaha"
If there is a simpler/more efficient way to repeat a single “character” (i.e. creating a string filled with a certain character), you might want to show that as well (i.e. repeat-char("*", 5) => "*****").
Other tasks re... | #REXX | REXX | /*REXX program to show various ways to repeat a string (or repeat a single char).*/
/*all examples are equivalent, but not created equal.*/
/*───────────────────────────────────────────*/
y='ha'
z=copies(y,5)
/*───────────────────────────────────────────*/
z=cop... | Give a code snippet in #REXX
Take a string and repeat it some number of times.
Example: repeat("ha", 5) => "hahahahaha"
If there is a simpler/more efficient way to repeat a single “character” (i.e. creating a string filled with a certain character), you might want to show that as well (i.e. repeat-char("*", 5) =... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Bitmap/Write_a_PPM_file | Bitmap/Write a PPM file | Using the data storage type defined on this page for raster images, write the image to a PPM file (binary P6 prefered).
(Read the definition of PPM file on Wikipedia.)
| #Forth | Forth | : write-ppm { bmp fid -- }
s" P6" fid write-line throw
bmp bdim swap
0 <# bl hold #s #> fid write-file throw
0 <# #s #> fid write-line throw
s" 255" fid write-line throw
bmp bdata bmp bdim * pixels
bounds do
i 3 fid write-file throw
pixel +loop ;
s" red... | Give a code snippet in #Forth
Using the data storage type defined on this page for raster images, write the image to a PPM file (binary P6 prefered).
(Read the definition of PPM file on Wikipedia.)
| 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... | #Elixir | Elixir |
fib = fn f -> (
fn x -> if x == 0, do: 0, else: (if x == 1, do: 1, else: f.(x - 1) + f.(x - 2)) end
)
end
y = fn x -> (
fn f -> f.(f)
end).(
fn g -> x.(fn z ->(g.(g)).(z) end)
end)
end
IO.inspect y.(&(fib.(&1))).(40)
| Give a code snippet in #Elixir
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/Queue/Usage | Queue/Usage |
Data Structure
This illustrates a data structure, a means of storing data within a program.
You may see other such structures in the Data Structures category.
Illustration of FIFO behavior
Task
Create a queue data structure and demonstrate its operations.
(For implementations of queues, see the FIFO task.)
Ope... | #PicoLisp | PicoLisp | (println (fifo 'Queue)) # Retrieve the number '1'
(println (fifo 'Queue)) # Retrieve an internal symbol 'abc'
(println (fifo 'Queue)) # Retrieve a transient symbol "abc"
(println (fifo 'Queue)) # and a list (abc)
(println (fifo 'Queue)) # Queue is empty -> NIL | Give a code snippet in #PicoLisp
Data Structure
This illustrates a data structure, a means of storing data within a program.
You may see other such structures in the Data Structures category.
Illustration of FIFO behavior
Task
Create a queue data structure and demonstrate its operations.
(For implementations of ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/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
... | #jq | jq | # 15-bit integers generated using the same formula as rand()
# from the Microsoft C Runtime.
# Input: [ count, state, rand ]
def next_rand_Microsoft:
.[0] as $count | .[1] as $state
| ( (214013 * $state) + 2531011) % 2147483648 # mod 2^31
| [$count+1 , ., (. / 65536 | floor) ];
# Generate the first n pseudo-ra... | Give a code snippet in #jq
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... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Digital_root | Digital root | The digital root,
X
{\displaystyle X}
, of a number,
n
{\displaystyle n}
, is calculated:
find
X
{\displaystyle X}
as the sum of the digits of
n
{\displaystyle n}
find a new
X
{\displaystyle X}
by summing the digits of
X
{\displaystyle X}
, repeating until
X
{\displ... | #K | K |
/ print digital root and additive persistence
prt: {`"Digital root = ", x, `"Additive persistence = ",y}
/ sum of digits of an integer
sumdig: {d::(); (0<){d::d,x!10; x%:10}/x; +/d}
/ compute digital root and additive persistence
digroot: {sm::sumdig x; ap::0; (9<){sm::sumdig x;ap::ap+1; x:sm}/x; prt[sm;ap]}
| Give a code snippet in #K
The digital root,
X
{\displaystyle X}
, of a number,
n
{\displaystyle n}
, is calculated:
find
X
{\displaystyle X}
as the sum of the digits of
n
{\displaystyle n}
find a new
X
{\displaystyle X}
by summing the digits of
X
{\displaystyle X}
, repe... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Monty_Hall_problem | Monty Hall problem |
Suppose you're on a game show and you're given the choice of three doors.
Behind one door is a car; behind the others, goats.
The car and the goats were placed randomly behind the doors before the show.
Rules of the game
After you have chosen a door, the door remains closed for the time being.
The game show hos... | #MAXScript | MAXScript | fn montyHall choice switch =
(
doors = #(false, false, false)
doors[random 1 3] = true
chosen = doors[choice]
if switch then chosen = not chosen
chosen
)
fn iterate iterations switched =
(
wins = 0
for i in 1 to iterations do
(
if (montyHall (random 1 3) switched) then
... | Give a code snippet in #MAXScript
Suppose you're on a game show and you're given the choice of three doors.
Behind one door is a car; behind the others, goats.
The car and the goats were placed randomly behind the doors before the show.
Rules of the game
After you have chosen a door, the door remains closed for... | 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 |... | #friendly_interactive_shell | friendly interactive shell |
read a
read b
echo 'a + b =' (math "$a + $b") # Sum
echo 'a - b =' (math "$a - $b") # Difference
echo 'a * b =' (math "$a * $b") # Product
echo 'a / b =' (math "$a / $b") # Integer quotient
echo 'a % b =' (math "$a % $b") # Remainder
echo 'a ^ b =' (math "$a ^ $b") # Exponentation
| Give a code snippet in #friendly_interactive_shell
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 |
Logic... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Hash_from_two_arrays | Hash from two arrays | Task
Using two Arrays of equal length, create a Hash object
where the elements from one array (the keys) are linked
to the elements of the other (the values)
Related task
Associative arrays/Creation
| #Racket | Racket |
(make-hash (map cons '("a" "b" "c" "d") '(1 2 3 4))) | Give a code snippet in #Racket
Task
Using two Arrays of equal length, create a Hash object
where the elements from one array (the keys) are linked
to the elements of the other (the values)
Related task
Associative arrays/Creation
| christopher/rosetta-code | |
http://rosettacode.org/wiki/First_perfect_square_in_base_n_with_n_unique_digits | First perfect square in base n with n unique digits | Find the first perfect square in a given base N that has at least N digits and
exactly N significant unique digits when expressed in base N.
E.G. In base 10, the first perfect square with at least 10 unique digits is 1026753849 (32043²).
You may use analytical methods to reduce the search space, but the code must do ... | #11l | 11l | L(base) 2..16
V n = Int64(Float(base) ^ ((base - 1) / 2))
L
V sq = n * n
V sqstr = String(sq, radix' base)
I sqstr.len >= base & Set(Array(sqstr)).len == base
V nstr = String(n, radix' base)
print(‘Base #2: #8^2 = #.’.format(base, nstr, sqstr))
L.break
n++ | Give a code snippet in #11l
Find the first perfect square in a given base N that has at least N digits and
exactly N significant unique digits when expressed in base N.
E.G. In base 10, the first perfect square with at least 10 unique digits is 1026753849 (32043²).
You may use analytical methods to reduce the search... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Bitmap/Flood_fill | Bitmap/Flood fill | Implement a flood fill.
A flood fill is a way of filling an area using color banks to define the contained area or a target color which "determines" the area (the valley that can be flooded; Wikipedia uses the term target color). It works almost like a water flooding from a point towards the banks (or: inside the vall... | #Tcl | Tcl | package require Tcl 8.5
package require Tk
package require struct::queue
proc floodFill {img colour point} {
set new [colour2rgb $colour]
set old [getPixel $img $point]
struct::queue Q
Q put $point
while {[Q size] > 0} {
set p [Q get]
if {[getPixel $img $p] eq $old} {
s... | Give a code snippet in #Tcl
Implement a flood fill.
A flood fill is a way of filling an area using color banks to define the contained area or a target color which "determines" the area (the valley that can be flooded; Wikipedia uses the term target color). It works almost like a water flooding from a point towards t... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Summarize_primes | Summarize primes | Task
Considering in order of length, n, all sequences of consecutive
primes, p, from 2 onwards, where p < 1000 and n>0, select those
sequences whose sum is prime, and for these display the length of the
sequence, the last item in the sequence, and the sum.
| #Nim | Nim | import math, strformat
const N = 999
func isPrime(n: Positive): bool =
if (n and 1) == 0: return n == 2
if (n mod 3) == 0: return n == 3
var d = 5
var delta = 2
while d <= sqrt(n.toFloat).int:
if n mod d == 0: return false
inc d, delta
delta = 6 - delta
result = true
echo "index prime pr... | Give a code snippet in #Nim
Task
Considering in order of length, n, all sequences of consecutive
primes, p, from 2 onwards, where p < 1000 and n>0, select those
sequences whose sum is prime, and for these display the length of the
sequence, the last item in the sequence, and the sum.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/N%27th | N'th | Write a function/method/subroutine/... that when given an integer greater than or equal to zero returns a string of the number followed by an apostrophe then the ordinal suffix.
Example
Returns would include 1'st 2'nd 3'rd 11'th 111'th 1001'st 1012'th
Task
Use your routine to show here the output for at least t... | #Stata | Stata | mata
function maps(f,a) {
nr = rows(a)
nc = cols(a)
b = J(nr,nc,"")
for (i=1;i<=nr;i++) {
for (j=1;j<=nc;j++) b[i,j] = (*f)(a[i,j])
}
return(b)
}
function nth(n) {
k = max((min((mod(n-1,10)+1,4)),4*(mod(n-10,100)<10)))
return(strofreal(n)+("st","nd","rd","th")[k])
}
maps(&nth(),((0::25),(250::275),(1000::... | Give a code snippet in #Stata
Write a function/method/subroutine/... that when given an integer greater than or equal to zero returns a string of the number followed by an apostrophe then the ordinal suffix.
Example
Returns would include 1'st 2'nd 3'rd 11'th 111'th 1001'st 1012'th
Task
Use your routine to show... | 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.... | #R | R |
is_prime <- function(num) {
if (num < 2) return(FALSE)
if (num %% 2 == 0) return(num == 2)
if (num %% 3 == 0) return(num == 3)
d <- 5
while (d*d <= num) {
if (num %% d == 0) return(FALSE)
d <- d + 2
if (num %% d == 0) return(FALSE)
d <- d + 4
}
TRUE
}
count_prime_factors <- function(... | Give a code snippet in #R
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/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... | #XPL0 | XPL0 | include c:\cxpl\codes;
int N;
loop [N:= Ran(20);
IntOut(0, N);
if N=10 then quit;
ChOut(0, 9\tab\);
IntOut(0, Ran(20));
CrLf(0);
] | Give a code snippet in #XPL0
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.
I... | 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... | #Lang5 | Lang5 | : <range> over iota swap * rot + tuck swap <= select ; : tuck swap over ;
: >>say.(*) . ;
1 10 2 <range> >>say. | Give a code snippet in #Lang5
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/Inc... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Negative_base_numbers | Negative base numbers | Negative base numbers are an alternate way to encode numbers without the need for a minus sign. Various negative bases may be used including negadecimal (base -10), negabinary (-2) and negaternary (-3).[1][2]
Task
Encode the decimal number 10 as negabinary (expect 11110)
Encode the decimal number 146 as negaternary... | #Haskell | Haskell | import Data.Char (chr, ord)
import Numeric (showIntAtBase)
-- The remainder and quotient of n/d, where the remainder is guaranteed to be
-- non-negative. The divisor, d, is assumed to be negative.
quotRemP :: Integral a => a -> a -> (a, a)
quotRemP n d = let (q, r) = quotRem n d
in if r < 0 then (q+1,... | Give a code snippet in #Haskell
Negative base numbers are an alternate way to encode numbers without the need for a minus sign. Various negative bases may be used including negadecimal (base -10), negabinary (-2) and negaternary (-3).[1][2]
Task
Encode the decimal number 10 as negabinary (expect 11110)
Encode the ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Count_in_octal | Count in octal | Task
Produce a sequential count in octal, starting at zero, and using an increment of a one for each consecutive number.
Each number should appear on a single line, and the program should count until terminated, or until the maximum value of the numeric type in use is reached.
Related task
Integer sequ... | #BASIC | BASIC | DIM n AS LONG
FOR n = 0 TO &h7FFFFFFF
PRINT OCT$(n)
NEXT | Give a code snippet in #BASIC
Task
Produce a sequential count in octal, starting at zero, and using an increment of a one for each consecutive number.
Each number should appear on a single line, and the program should count until terminated, or until the maximum value of the numeric type in use is reached.
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Compare_a_list_of_strings | Compare a list of strings | Task
Given a list of arbitrarily many strings, show how to:
test if they are all lexically equal
test if every string is lexically less than the one after it (i.e. whether the list is in strict ascending order)
Each of those two tests should result in a single true or false value, which could be used as t... | #Tcl | Tcl | tcl::mathop::eq {*}$strings; # All values string-equal
tcl::mathop::< {*}$strings; # All values in strict order | Give a code snippet in #Tcl
Task
Given a list of arbitrarily many strings, show how to:
test if they are all lexically equal
test if every string is lexically less than the one after it (i.e. whether the list is in strict ascending order)
Each of those two tests should result in a single true or false va... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Polymorphic_copy | Polymorphic copy | An object is polymorphic when its specific type may vary.
The types a specific value may take, is called class.
It is trivial to copy an object if its type is known:
int x;
int y = x;
Here x is not polymorphic, so y is declared of same type (int) as x.
But if the specific type of x were unknown, then y could not be d... | #ALGOL_68 | ALGOL 68 | BEGIN
# Algol 68 doesn't have classes and inheritence as such, however structures #
# can contain procedures and different instances of a structure can have #
# different versons of the procedure #
# this allows us to simulate inheritence by creating structure i... | Give a code snippet in #ALGOL_68
An object is polymorphic when its specific type may vary.
The types a specific value may take, is called class.
It is trivial to copy an object if its type is known:
int x;
int y = x;
Here x is not polymorphic, so y is declared of same type (int) as x.
But if the specific type of x w... | 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.
| #68000_Assembly | 68000 Assembly | foo:
MOVE.L D2,D0
MOVE.L D3,D1
ADD.L D1,D0
SUB.L D2,D3
MOVE.L D3,D1
RTS | Give a code snippet in #68000_Assembly
Task
Show how to return more than one value from a function.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Detect_division_by_zero | Detect division by zero | Task
Write a function to detect a divide by zero error without checking if the denominator is zero.
| #Nim | Nim | {.push overflowChecks: on.}
proc divCheck(x, y): bool =
try:
discard x div y
except DivByZeroDefect:
return true
return false
{.pop.} # Restore default check settings
echo divCheck(2, 0) | Give a code snippet in #Nim
Task
Write a function to detect a divide by zero error without checking if the denominator is zero.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Read_a_specific_line_from_a_file | Read a specific line from a file | Some languages have special semantics for obtaining a known line number from a file.
Task
Demonstrate how to obtain the contents of a specific line within a file.
For the purpose of this task demonstrate how the contents of the seventh line of a file can be obtained, and store it in a variable or in memory (fo... | #Nim | Nim | import strformat
proc readLine(f: File; num: Positive): string =
for n in 1..num:
try:
result = f.readLine()
except EOFError:
raise newException(IOError, &"Not enough lines in file; expected {num}, found {n - 1}.")
let f = open("test.txt", fmRead)
echo f.readLine(7)
f.close()
| Give a code snippet in #Nim
Some languages have special semantics for obtaining a known line number from a file.
Task
Demonstrate how to obtain the contents of a specific line within a file.
For the purpose of this task demonstrate how the contents of the seventh line of a file can be obtained, and store it in ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Self-describing_numbers | Self-describing numbers | Self-describing numbers
You are encouraged to solve this task according to the task description, using any language you may know.
There are several so-called "self-describing" or "self-descriptive" integers.
An integer is said to be "self-describing" if it has the property that, when digit positions are labeled 0 to ... | #PHP | PHP | <?php
function is_describing($number) {
foreach (str_split((int) $number) as $place => $value) {
if (substr_count($number, $place) != $value) {
return false;
}
}
return true;
}
for ($i = 0; $i <= 50000000; $i += 10) {
if (is_describing($i)) {
echo $i . PHP_EO... | Give a code snippet in #PHP
Self-describing numbers
You are encouraged to solve this task according to the task description, using any language you may know.
There are several so-called "self-describing" or "self-descriptive" integers.
An integer is said to be "self-describing" if it has the property that, when digi... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Word_wrap | Word wrap | Even today, with proportional fonts and complex layouts, there are still cases where you need to wrap text at a specified column.
Basic task
The basic task is to wrap a paragraph of text in a simple way in your language.
If there is a way to do this that is built-in, trivial, or provided in a standard library, sho... | #AWK | AWK | function wordwrap_paragraph(p)
{
if ( length(p) < 1 ) return
split(p, words)
spaceLeft = lineWidth
line = words[1]
delete words[1]
for (i = 1; i <= length(words); i++) {
word = words[i]
if ( (length(word) + 1) > spaceLeft ) {
print line
line = word
spaceLeft = lineWidth - leng... | Give a code snippet in #AWK
Even today, with proportional fonts and complex layouts, there are still cases where you need to wrap text at a specified column.
Basic task
The basic task is to wrap a paragraph of text in a simple way in your language.
If there is a way to do this that is built-in, trivial, or provid... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Stack | Stack |
Data Structure
This illustrates a data structure, a means of storing data within a program.
You may see other such structures in the Data Structures category.
A stack is a container of elements with last in, first out access policy. Sometimes it also called LIFO.
The stack is accessed through its top.
The ba... | #Standard_ML | Standard ML | signature STACK =
sig
type 'a stack
exception EmptyStack
val empty : 'a stack
val isEmpty : 'a stack -> bool
val push : ('a * 'a stack) -> 'a stack
val pop : 'a stack -> 'a stack
val top : 'a stack -> 'a
val popTop : 'a stack -> 'a stack * 'a
val map : ('a -> 'b) -> 'a stack ... | Give a code snippet in #Standard_ML
Data Structure
This illustrates a data structure, a means of storing data within a program.
You may see other such structures in the Data Structures category.
A stack is a container of elements with last in, first out access policy. Sometimes it also called LIFO.
The stack... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Variable_size/Set | Variable size/Set | Task
Demonstrate how to specify the minimum size of a variable or a data type.
| #TXR | TXR | (make-buf 8 0 4096) | Give a code snippet in #TXR
Task
Demonstrate how to specify the minimum size of a variable or a data type.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Generator/Exponential | Generator/Exponential | A generator is an executable entity (like a function or procedure) that contains code that yields a sequence of values, one at a time, so that each time you call the generator, the next value in the sequence is provided.
Generators are often built on top of coroutines or objects so that the internal state of the objec... | #Ruby | Ruby | # This solution cheats and uses only one generator!
def powers(m)
return enum_for(__method__, m) unless block_given?
0.step{|n| yield n**m}
end
def squares_without_cubes
return enum_for(__method__) unless block_given?
cubes = powers(3)
c = cubes.next
powers(2) do |s|
c = cubes.next while c < s
... | Give a code snippet in #Ruby
A generator is an executable entity (like a function or procedure) that contains code that yields a sequence of values, one at a time, so that each time you call the generator, the next value in the sequence is provided.
Generators are often built on top of coroutines or objects so that t... | christopher/rosetta-code | |
http://rosettacode.org/wiki/String_comparison | String comparison |
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 |... | #BBC_BASIC | BBC BASIC | REM >strcomp
shav$ = "Shaw, George Bernard"
shakes$ = "Shakespeare, William"
:
REM test equality
IF shav$ = shakes$ THEN PRINT "The two strings are equal" ELSE PRINT "The two strings are not equal"
:
REM test inequality
IF shav$ <> shakes$ THEN PRINT "The two strings are unequal" ELSE PRINT "The two strings are not une... | Give a code snippet in #BBC_BASIC
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 Operati... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Naming_conventions | Naming conventions | Many languages have naming conventions regarding the identifiers used in the language, its libraries, and programs written in the language. Such conventions, which may be classified as de facto or de jure depending on how they are enforced,
often take the form of rules regarding prefixes, suffixes, and the use of upper... | #Racket | Racket | #lang racket
render-game-state
send-message-to-client
traverse-forest | Give a code snippet in #Racket
Many languages have naming conventions regarding the identifiers used in the language, its libraries, and programs written in the language. Such conventions, which may be classified as de facto or de jure depending on how they are enforced,
often take the form of rules regarding prefixes... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sum_of_squares | Sum of squares | Task
Write a program to find the sum of squares of a numeric vector.
The program should work on a zero-length vector (with an answer of 0).
Related task
Mean
| #C.2B.2B | C++ | #include <iostream>
#include <numeric>
#include <vector>
double add_square(double prev_sum, double new_val)
{
return prev_sum + new_val*new_val;
}
double vec_add_squares(std::vector<double>& v)
{
return std::accumulate(v.begin(), v.end(), 0.0, add_square);
}
int main()
{
// first, show that for empty vector... | Give a code snippet in #C.2B.2B
Task
Write a program to find the sum of squares of a numeric vector.
The program should work on a zero-length vector (with an answer of 0).
Related task
Mean
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Day_of_the_week | Day of the week | A company decides that whenever Xmas falls on a Sunday they will give their workers all extra paid holidays so that, together with any public holidays, workers will not have to work the following week (between the 25th of December and the first of January).
Task
In what years between 2008 and 2121 will the 25th of ... | #Mathematica_.2F_Wolfram_Language | Mathematica / Wolfram Language | Reap[If[DateString[{#,12,25},"DayName"]=="Sunday",Sow[#]]&/@Range[2008,2121]][[2,1]] | Give a code snippet in #Mathematica_.2F_Wolfram_Language
A company decides that whenever Xmas falls on a Sunday they will give their workers all extra paid holidays so that, together with any public holidays, workers will not have to work the following week (between the 25th of December and the first of January).
T... | christopher/rosetta-code | |
http://rosettacode.org/wiki/ABC_problem | ABC problem | ABC problem
You are encouraged to solve this task according to the task description, using any language you may know.
You are given a collection of ABC blocks (maybe like the ones you had when you were a kid).
There are twenty blocks with two letters on each block.
A complete alphabet is guaranteed amongst all sid... | #FreeBASIC | FreeBASIC | ' version 28-01-2019
' compile with: fbc -s console
Dim As String blocks(1 To 20, 1 To 2) => {{"B", "O"}, {"X", "K"}, {"D", "Q"}, _
{"C", "P"}, {"N", "A"}, {"G", "T"}, {"R", "E"}, {"T", "G"}, {"Q", "D"}, _
{"F", "S"}, {"J", "W"}, {"H", "U"}, {"V", "I"}, {"A", "N"}, {"O", "B"}, _
{"E", "R"}, {"F", "S"}, {"L", "Y"}, {"... | Give a code snippet in #FreeBASIC
ABC problem
You are encouraged to solve this task according to the task description, using any language you may know.
You are given a collection of ABC blocks (maybe like the ones you had when you were a kid).
There are twenty blocks with two letters on each block.
A complete alp... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Combinations | Combinations | Task
Given non-negative integers m and n, generate all size m combinations of the integers from 0 (zero) to n-1 in sorted order (each combination is sorted and the entire table is sorted).
Example
3 comb 5 is:
0 1 2
0 1 3
0 1 4
0 2 3
0 2 4
0 3 4
1 2 3
1 2 4
1 3 4
2 3 4
... | #J | J | require'stats' | Give a code snippet in #J
Task
Given non-negative integers m and n, generate all size m combinations of the integers from 0 (zero) to n-1 in sorted order (each combination is sorted and the entire table is sorted).
Example
3 comb 5 is:
0 1 2
0 1 3
0 1 4
0 2 3
0 2 4
0 3... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Find_common_directory_path | Find common directory path | Create a routine that, given a set of strings representing directory paths and a single character directory separator, will return a string representing that part of the directory tree that is common to all the directories.
Test your routine using the forward slash '/' character as the directory separator and the foll... | #Racket | Racket |
#lang racket
(define (common-directory path . paths)
(string-join
(let loop ([path (string-split path "/" #:trim? #f)]
[paths (map (λ(p) (string-split p "/" #:trim? #f)) paths)])
(if (and (pair? path)
(andmap (λ(p) (and (pair? p) (equal? (car p) (car path))))
... | Give a code snippet in #Racket
Create a routine that, given a set of strings representing directory paths and a single character directory separator, will return a string representing that part of the directory tree that is common to all the directories.
Test your routine using the forward slash '/' character as the ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Stair-climbing_puzzle | Stair-climbing puzzle | From Chung-Chieh Shan (LtU):
Your stair-climbing robot has a very simple low-level API: the "step" function takes no argument and attempts to climb one step as a side effect. Unfortunately, sometimes the attempt fails and the robot clumsily falls one step instead. The "step" function detects what happens and returns a... | #XPL0 | XPL0 | proc Step_up; \Iterative version
int I;
[I:= 0;
while I<1 do
if Step then I:= I+1
else I:= I-1;
];
proc Step_up; \Recursive version
while not Step do Step_up; | Give a code snippet in #XPL0
From Chung-Chieh Shan (LtU):
Your stair-climbing robot has a very simple low-level API: the "step" function takes no argument and attempts to climb one step as a side effect. Unfortunately, sometimes the attempt fails and the robot clumsily falls one step instead. The "step" function dete... | 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... | #Arturo | Arturo | oneOfN: function [n][
result: 0
loop 0..dec n 'x [
if zero? random 0 x ->
result: x
]
return result
]
oneOfNTest: function [n,trials][
ret: array.of:n 0
if n > 0 [
loop 1..trials 'i [
oon: oneOfN n
ret\[oon]: ret\[oon] + 1
]
]
... | Give a code snippet in #Arturo
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/Gamma_function | Gamma function | Task
Implement one algorithm (or more) to compute the Gamma (
Γ
{\displaystyle \Gamma }
) function (in the real field only).
If your language has the function as built-in or you know a library which has it, compare your implementation's results with the results of the built-in/library function.
The Gamma funct... | #C.2B.2B | C++ | #include <math.h>
#include <numbers>
#include <stdio.h>
#include <vector>
// Calculate the coefficients used by Spouge's approximation (based on the C
// implemetation)
std::vector<double> CalculateCoefficients(int numCoeff)
{
std::vector<double> c(numCoeff);
double k1_factrl = 1.0;
c[0] = sqrt(2.0 * std:... | Give a code snippet in #C.2B.2B
Task
Implement one algorithm (or more) to compute the Gamma (
Γ
{\displaystyle \Gamma }
) function (in the real field only).
If your language has the function as built-in or you know a library which has it, compare your implementation's results with the results of the built-in/l... | christopher/rosetta-code |
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