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/JSON | JSON | Load a JSON string into a data structure.
Also, create a new data structure and serialize it into JSON.
Use objects and arrays (as appropriate for your language)
and make sure your JSON is valid (https://jsonformatter.org).
| #Mathematica.2FWolfram_Language | Mathematica/Wolfram Language | data = ImportString["{ \"foo\": 1, \"bar\": [10, \"apples\"] }","JSON"]
ExportString[data, "JSON"] | Give a code snippet in #Mathematica.2FWolfram_Language
Load a JSON string into a data structure.
Also, create a new data structure and serialize it into JSON.
Use objects and arrays (as appropriate for your language)
and make sure your JSON is valid (https://jsonformatter.org).
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Closures/Value_capture | Closures/Value capture | Task
Create a list of ten functions, in the simplest manner possible (anonymous functions are encouraged), such that the function at index i (you may choose to start i from either 0 or 1), when run, should return the square of the index, that is, i 2.
Display the result of runnin... | #Lambdatalk | Lambdatalk |
{def A
{A.new
{S.map {lambda {:x} {* :x :x}}
{S.serie 0 10}
}}}
{A.get 3 {A}} // equivalent to A[3]
-> 9
{A.get 4 {A}}
-> 16
| Give a code snippet in #Lambdatalk
Task
Create a list of ten functions, in the simplest manner possible (anonymous functions are encouraged), such that the function at index i (you may choose to start i from either 0 or 1), when run, should return the square of the index, that is, ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Loops/Wrong_ranges | Loops/Wrong ranges | Loops/Wrong ranges
You are encouraged to solve this task according to the task description, using any language you may know.
Some languages have syntax or function(s) to generate a range of numeric values from a start value, a stop value, and an increment.
The purpose of this task is to select the range syntax/functi... | #Julia | Julia |
collect(-2:1:2) # → [-2, -1, 0, 1, 2]
collect(-2:0:2) # fails
collect(-2:-1:2) # → []
collect(-2:10:2) # → [-2]
collect(2:1:-2) # → []
collect(2:1:2) # → [2]
collect(2:-1:2) # → [2]
collect(2:0:2) # fails
collect(0:0:0) # fails
| Give a code snippet in #Julia
Loops/Wrong ranges
You are encouraged to solve this task according to the task description, using any language you may know.
Some languages have syntax or function(s) to generate a range of numeric values from a start value, a stop value, and an increment.
The purpose of this task is to... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Hello_world/Standard_error | Hello world/Standard error | Hello world/Standard error is part of Short Circuit's Console Program Basics selection.
A common practice in computing is to send error messages
to a different output stream than normal text console messages.
The normal messages print to what is called "standard output" or "standard out".
The error messages print to ... | #Erlang | Erlang | io:put_chars(standard_error, "Goodbye, World!\n"). | Give a code snippet in #Erlang
Hello world/Standard error is part of Short Circuit's Console Program Basics selection.
A common practice in computing is to send error messages
to a different output stream than normal text console messages.
The normal messages print to what is called "standard output" or "standard out... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Pythagorean_triples | Pythagorean triples | A Pythagorean triple is defined as three positive integers
(
a
,
b
,
c
)
{\displaystyle (a,b,c)}
where
a
<
b
<
c
{\displaystyle a<b<c}
, and
a
2
+
b
2
=
c
2
.
{\displaystyle a^{2}+b^{2}=c^{2}.}
They are called primitive triples if
a
,
b
,
c
{\displaystyle a,b,c}
are co-prime,... | #Pascal | Pascal | Program PythagoreanTriples (output);
var
total, prim, maxPeri: int64;
procedure newTri(s0, s1, s2: int64);
var
p: int64;
begin
p := s0 + s1 + s2;
if p <= maxPeri then
begin
inc(prim);
total := total + maxPeri div p;
newTri( s0 + 2*(-s1+s2), 2*( s0+s2) - s1, 2*( s0-s1+s2) + ... | Give a code snippet in #Pascal
A Pythagorean triple is defined as three positive integers
(
a
,
b
,
c
)
{\displaystyle (a,b,c)}
where
a
<
b
<
c
{\displaystyle a<b<c}
, and
a
2
+
b
2
=
c
2
.
{\displaystyle a^{2}+b^{2}=c^{2}.}
They are called primitive triples if
a
,
b
,
c
{\dis... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Show_ASCII_table | Show ASCII table | Task
Show the ASCII character set from values 32 to 127 (decimal) in a table format.
Other tasks related to string operations:
Metrics
Array length
String length
Copy a string
Empty string (assignment)
Counting
Word frequency
Letter frequency
Jewels and stones
I before E except after C
Bioin... | #AutoHotkey | AutoHotkey | AutoTrim,Off ;Allows for whitespace at end of variable to separate converted characters
MessageText := ;The text to display in the final message box.
CurrentASCII := 32 ;Current ASCII number to convert and add to MessageText
ConvertedCharacter := ;Stores the currently converted ASCII code
RowLength := 0 ;Keeps track... | Give a code snippet in #AutoHotkey
Task
Show the ASCII character set from values 32 to 127 (decimal) in a table format.
Other tasks related to string operations:
Metrics
Array length
String length
Copy a string
Empty string (assignment)
Counting
Word frequency
Letter frequency
Jewels and ston... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sorting_algorithms/Stooge_sort | Sorting algorithms/Stooge 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
... | #Raku | Raku | sub stoogesort( @L, $i = 0, $j = @L.end ) {
@L[$j,$i] = @L[$i,$j] if @L[$i] > @L[$j];
my $interval = $j - $i;
if $interval > 1 {
my $t = ( $interval + 1 ) div 3;
stoogesort( @L, $i , $j-$t );
stoogesort( @L, $i+$t, $j );
stoogesort( @L, $i , $j-$t );
}
... | Give a code snippet in #Raku
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/Rep-string | Rep-string | Given a series of ones and zeroes in a string, define a repeated string or rep-string as a string which is created by repeating a substring of the first N characters of the string truncated on the right to the length of the input string, and in which the substring appears repeated at least twice in the original.
For e... | #PARI.2FGP | PARI/GP | rep(v)=for(i=1,#v\2,for(j=i+1,#v,if(v[j]!=v[j-i],next(2)));return(i));0;
v=["1001110011","1110111011","0010010010","1010101010","1111111111","0100101101","0100100","101","11","00","1"];
for(i=1,#v,print(v[i]" "rep(Vec(v[i])))) | Give a code snippet in #PARI.2FGP
Given a series of ones and zeroes in a string, define a repeated string or rep-string as a string which is created by repeating a substring of the first N characters of the string truncated on the right to the length of the input string, and in which the substring appears repeated at ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Ternary_logic | Ternary logic |
This page uses content from Wikipedia. The original article was at Ternary logic. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance)
In logic, a three-valued logic (also trivalent, ternary, or trinary... | #Nim | Nim | type Trit* = enum ttrue, tmaybe, tfalse
proc `$`*(a: Trit): string =
case a
of ttrue: "T"
of tmaybe: "?"
of tfalse: "F"
proc `not`*(a: Trit): Trit =
case a
of ttrue: tfalse
of tmaybe: tmaybe
of tfalse: ttrue
proc `and`*(a, b: Trit): Trit =
const t: array[Trit, array[Trit, Trit]] =
[ [ttrue, ... | Give a code snippet in #Nim
This page uses content from Wikipedia. The original article was at Ternary logic. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance)
In logic, a three-valued logic (also t... | christopher/rosetta-code | |
http://rosettacode.org/wiki/99_bottles_of_beer | 99 bottles of beer | Task
Display the complete lyrics for the song: 99 Bottles of Beer on the Wall.
The beer song
The lyrics follow this form:
99 bottles of beer on the wall
99 bottles of beer
Take one down, pass it around
98 bottles of beer on the wall
98 bottles of beer on the wall
98 bottles of beer
Take one dow... | #CLU | CLU | bottles = proc (n: int) returns (string)
if n<0 then return("99 bottles")
elseif n=0 then return("No more bottles")
elseif n=1 then return("1 bottle")
else return(int$unparse(n) || " bottles")
end
end bottles
thirdline = proc (n: int) returns (string)
if n=0 then
return("Go to the stor... | Give a code snippet in #CLU
Task
Display the complete lyrics for the song: 99 Bottles of Beer on the Wall.
The beer song
The lyrics follow this form:
99 bottles of beer on the wall
99 bottles of beer
Take one down, pass it around
98 bottles of beer on the wall
98 bottles of beer on the wall
98 b... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Literals/String | Literals/String | Task
Show literal specification of characters and strings.
If supported, show how the following work:
verbatim strings (quotes where escape sequences are quoted literally)
here-strings
Also, discuss which quotes expand variables.
Related tasks
Special characters
Here document
Other tasks r... | #Axe | Axe | 'A' | Give a code snippet in #Axe
Task
Show literal specification of characters and strings.
If supported, show how the following work:
verbatim strings (quotes where escape sequences are quoted literally)
here-strings
Also, discuss which quotes expand variables.
Related tasks
Special characters
H... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Hunt_the_Wumpus | Hunt the Wumpus | This task has been flagged for clarification. Code on this page in its current state may be flagged incorrect once this task has been clarified. See this page's Talk page for discussion.
Create a simple implementation of the classic textual game Hunt The Wumpus.
The rules are:
The game is set in a cave that consists ... | #Ada | Ada | package Wumpus is
procedure Start_Game;
end Wumpus;
| Give a code snippet in #Ada
This task has been flagged for clarification. Code on this page in its current state may be flagged incorrect once this task has been clarified. See this page's Talk page for discussion.
Create a simple implementation of the classic textual game Hunt The Wumpus.
The rules are:
The game is... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Longest_common_substring | Longest common substring | Task
Write a function that returns the longest common substring of two strings.
Use it within a program that demonstrates sample output from the function, which will consist of the longest common substring between "thisisatest" and "testing123testing".
Note that substrings are consecutive characters within a string.... | #Prolog | Prolog | common_sublist(A, B, M) :-
append(_, Ma, A),
append(M, _, Ma),
append(_, Mb, B),
append(M, _, Mb).
longest_list([], L, _, L).
longest_list([L|Ls], LongestList, LongestLength, Result) :-
length(L, Len),
Len >= LongestLength -> longest_list(Ls, L, Len, Result)
; longest_list(Ls, LongestList, LongestLength, Re... | Give a code snippet in #Prolog
Task
Write a function that returns the longest common substring of two strings.
Use it within a program that demonstrates sample output from the function, which will consist of the longest common substring between "thisisatest" and "testing123testing".
Note that substrings are consecu... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Box_the_compass | Box the compass | There be many a land lubber that knows naught of the pirate ways and gives direction by degree!
They know not how to box the compass!
Task description
Create a function that takes a heading in degrees and returns the correct 32-point compass heading.
Use the function to print and display a table of Index, Compass... | #BBC_BASIC | BBC BASIC | DIM bearing(32)
bearing() = 0.0, 16.87, 16.88, 33.75, 50.62, 50.63, 67.5, 84.37, \
\ 84.38, 101.25, 118.12, 118.13, 135.0, 151.87, 151.88, 168.75, \
\ 185.62, 185.63, 202.5, 219.37, 219.38, 236.25, 253.12, 253.13, \
\ 270.0, 286.87, 286.88, 303.75, 320.62, 320.63, 337.5, 354.37, 354.38
... | Give a code snippet in #BBC_BASIC
There be many a land lubber that knows naught of the pirate ways and gives direction by degree!
They know not how to box the compass!
Task description
Create a function that takes a heading in degrees and returns the correct 32-point compass heading.
Use the function to print an... | christopher/rosetta-code | |
http://rosettacode.org/wiki/100_doors | 100 doors | There are 100 doors in a row that are all initially closed.
You make 100 passes by the doors.
The first time through, visit every door and toggle the door (if the door is closed, open it; if it is open, close it).
The second time, only visit every 2nd door (door #2, #4, #6, ...), and toggle it.
The third... | #jq | jq | # Solution for n doors:
def doors(n):
def print:
. as $doors
| range(1; length+1)
| if $doors[.] then "Door \(.) is open" else empty end;
[range(n+1)|null] as $doors
| reduce range(1; n+1) as $run
( $doors; reduce range($run; n+1; $run ) as $door
( .; .[$door] = (.[$door]... | Give a code snippet in #jq
There are 100 doors in a row that are all initially closed.
You make 100 passes by the doors.
The first time through, visit every door and toggle the door (if the door is closed, open it; if it is open, close it).
The second time, only visit every 2nd door (door #2, #4, #6, ...),... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Consecutive_primes_with_ascending_or_descending_differences | Consecutive primes with ascending or descending differences | Task
Find and display here on this page, the longest sequence of consecutive prime numbers where the differences between the primes are strictly ascending.
Do the same for sequences of primes where the differences are strictly descending.
In both cases, show the sequence for primes < 1,000,000.
If there... | #jq | jq | # For streams of strings or of arrays or of numbers:
def add(s): reduce s as $x (null; .+$x);
# Primes less than . // infinite
def primes:
(. // infinite) as $n
| if $n < 3 then empty
else 2, (range(3; $n) | select(is_prime))
end;
| Give a code snippet in #jq
Task
Find and display here on this page, the longest sequence of consecutive prime numbers where the differences between the primes are strictly ascending.
Do the same for sequences of primes where the differences are strictly descending.
In both cases, show the sequence for primes ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Abundant,_deficient_and_perfect_number_classifications | Abundant, deficient and perfect number classifications | These define three classifications of positive integers based on their proper divisors.
Let P(n) be the sum of the proper divisors of n where the proper divisors are all positive divisors of n other than n itself.
if P(n) < n then n is classed as deficient (OEIS A005100).
if P(n)... | #Vlang | Vlang | fn p_fac_sum(i int) int {
mut sum := 0
for p := 1; p <= i/2; p++ {
if i%p == 0 {
sum += p
}
}
return sum
}
fn main() {
mut d := 0
mut a := 0
mut p := 0
for i := 1; i <= 20000; i++ {
j := p_fac_sum(i)
if j < i {
d++
} else ... | Give a code snippet in #Vlang
These define three classifications of positive integers based on their proper divisors.
Let P(n) be the sum of the proper divisors of n where the proper divisors are all positive divisors of n other than n itself.
if P(n) < n then n is classed as deficient... | 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... | #Wren | Wren | /* curzon_numbers.wren */
import "./gmp" for Mpz
import "./seq" for Lst
import "./fmt" for Fmt
for (k in [2, 4, 6, 8, 10]) {
System.print("The first 50 Curzon numbers using a base of %(k):")
var count = 0
var n = 1
var pow = Mpz.from(k)
var curzon50 = []
while (true) {
var z = pow + ... | Give a code snippet in #Wren
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... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Integer_sequence | Integer sequence | Task
Create a program that, when run, would display all integers from 1 to ∞ (or any relevant implementation limit), in sequence (i.e. 1, 2, 3, 4, etc) if given enough time.
An example may not be able to reach arbitrarily-large numbers based on implementations limits. For example, if integer... | #PostScript | PostScript |
1 {succ dup =} loop
| Give a code snippet in #PostScript
Task
Create a program that, when run, would display all integers from 1 to ∞ (or any relevant implementation limit), in sequence (i.e. 1, 2, 3, 4, etc) if given enough time.
An example may not be able to reach arbitrarily-large numbers based on implementatio... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Hough_transform | Hough transform | Task
Implement the Hough transform, which is used as part of feature extraction with digital images.
It is a tool that makes it far easier to identify straight lines in the source image, whatever their orientation.
The transform maps each point in the target image,
(
ρ
,
θ
)
{\displaystyle (\rho ,\theta )}
, ... | #Scala | Scala | import java.awt.image._
import java.io.File
import javax.imageio._
object HoughTransform extends App {
override def main(args: Array[String]) {
val inputData = readDataFromImage(args(0))
val minContrast = if (args.length >= 4) 64 else args(4).toInt
inputData(args(2).toInt, args(3).toInt, m... | Give a code snippet in #Scala
Task
Implement the Hough transform, which is used as part of feature extraction with digital images.
It is a tool that makes it far easier to identify straight lines in the source image, whatever their orientation.
The transform maps each point in the target image,
(
ρ
,
θ
)
{\di... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Zero_to_the_zero_power | Zero to the zero power | Some computer programming languages are not exactly consistent (with other computer programming languages)
when raising zero to the zeroth power: 00
Task
Show the results of raising zero to the zeroth power.
If your computer language objects to 0**0 or 0^0 at compile time, ... | #Nanoquery | Nanoquery | println 0^0 | Give a code snippet in #Nanoquery
Some computer programming languages are not exactly consistent (with other computer programming languages)
when raising zero to the zeroth power: 00
Task
Show the results of raising zero to the zeroth power.
If your computer language objects to 0**0 ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Jewels_and_stones | Jewels and stones | Jewels and stones
You are encouraged to solve this task according to the task description, using any language you may know.
Task
Create a function which takes two string parameters: 'stones' and 'jewels' and returns an integer.
Both strings can contain any number of upper or lower case letters. However, in the case ... | #Maple | Maple | count_jewel := proc(stones, jewels)
local count, j, letter:
j := convert(jewels,set):
count := 0:
for letter in stones do
if (member(letter, j)) then
count++:
end if:
end do:
return count:
end proc:
count_jewel("aAAbbbb", "aA") | Give a code snippet in #Maple
Jewels and stones
You are encouraged to solve this task according to the task description, using any language you may know.
Task
Create a function which takes two string parameters: 'stones' and 'jewels' and returns an integer.
Both strings can contain any number of upper or lower case... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Best_shuffle | Best shuffle | Task
Shuffle the characters of a string in such a way that as many of the character values are in a different position as possible.
A shuffle that produces a randomized result among the best choices is to be preferred. A deterministic approach that produces the same sequence every time is acceptable as an alternative... | #Scheme | Scheme |
(define count
(lambda (str1 str2)
(let ((len (string-length str1)))
(let loop ((index 0)
(result 0))
(if (= index len)
result
(loop (+ index 1)
(if (eq? (string-ref str1 index)
(string-ref str2 index))
... | Give a code snippet in #Scheme
Task
Shuffle the characters of a string in such a way that as many of the character values are in a different position as possible.
A shuffle that produces a randomized result among the best choices is to be preferred. A deterministic approach that produces the same sequence every time... | 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... | #Rascal | Rascal | public num Jenssen(int lo, int hi, num (int i) term){
temp = 0;
while (lo <= hi){
temp += term(lo);
lo += 1;}
return temp;
} | Give a code snippet in #Rascal
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/Interactive_programming_(repl) | Interactive programming (repl) | Many language implementations come with an interactive mode.
This is a command-line interpreter that reads lines from the user and evaluates these lines as statements or expressions.
An interactive mode may also be known as a command mode, a read-eval-print loop (REPL), or a shell.
Task
Show how to start this... | #Picat | Picat | Picat> cl
f(X,Y,Sep) = X ++ [Sep,Sep] ++ Y.
<Ctrl-D>
Picat> print(f("Rosetta","Code",':'))
Rosetta::Code
yes | Give a code snippet in #Picat
Many language implementations come with an interactive mode.
This is a command-line interpreter that reads lines from the user and evaluates these lines as statements or expressions.
An interactive mode may also be known as a command mode, a read-eval-print loop (REPL), or a shell.
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Command-line_arguments | Command-line arguments | Command-line arguments is part of Short Circuit's Console Program Basics selection.
Scripted main
See also Program name.
For parsing command line arguments intelligently, see Parsing command-line arguments.
Example command line:
myprogram -c "alpha beta" -h "gamma"
| #AutoHotkey | AutoHotkey | Loop %0% ; number of parameters
params .= %A_Index% . A_Space
If params !=
MsgBox, %0% parameters were passed:`n`n %params%
Else
Run, %A_AhkPath% "%A_ScriptFullPath%" -c "\"alpha beta\"" -h "\"gamma\"" | Give a code snippet in #AutoHotkey
Command-line arguments is part of Short Circuit's Console Program Basics selection.
Scripted main
See also Program name.
For parsing command line arguments intelligently, see Parsing command-line arguments.
Example command line:
myprogram -c "alpha beta" -h "gamma"
| christopher/rosetta-code | |
http://rosettacode.org/wiki/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... | #Retro | Retro | 1024 [ cr &putn sip 2 / dup ] while | Give a code snippet in #Retro
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/Downwar... | christopher/rosetta-code | |
http://rosettacode.org/wiki/99_bottles_of_beer | 99 bottles of beer | Task
Display the complete lyrics for the song: 99 Bottles of Beer on the Wall.
The beer song
The lyrics follow this form:
99 bottles of beer on the wall
99 bottles of beer
Take one down, pass it around
98 bottles of beer on the wall
98 bottles of beer on the wall
98 bottles of beer
Take one dow... | #Babel | Babel | -- beer.sp
{b " bottles of beer" <
bi { itoa << } <
bb { bi ! b << w << "\n" << } <
w " on the wall" <
beer
{<-
{ iter 1 + dup
<- bb ! ->
bi ! b << "\n" <<
"Take one down, pass it around\n" <<
iter bb ! "\n" << }
->
... | Give a code snippet in #Babel
Task
Display the complete lyrics for the song: 99 Bottles of Beer on the Wall.
The beer song
The lyrics follow this form:
99 bottles of beer on the wall
99 bottles of beer
Take one down, pass it around
98 bottles of beer on the wall
98 bottles of beer on the wall
98... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Loops/Do-while | Loops/Do-while | Start with a value at 0. Loop while value mod 6 is not equal to 0.
Each time through the loop, add 1 to the value then print it.
The loop must execute at least once.
Related tasks
Loop over multiple arrays simultaneously
Loops/Break
Loops/Continue
Loops/Do-while
Loops/Downward for
Loops/For
Loo... | #Lua | Lua |
i=0
repeat
i=i+1
print(i)
until i%6 == 0
| Give a code snippet in #Lua
Start with a value at 0. Loop while value mod 6 is not equal to 0.
Each time through the loop, add 1 to the value then print it.
The loop must execute at least once.
Related tasks
Loop over multiple arrays simultaneously
Loops/Break
Loops/Continue
Loops/Do-while
Loops/Dow... | 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... | #Applesoft_BASIC | Applesoft BASIC | ? LEN("HELLO, WORLD!") | Give a code snippet in #Applesoft_BASIC
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 gra... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Accumulator_factory | Accumulator factory | A problem posed by Paul Graham is that of creating a function that takes a single (numeric) argument and which returns another function that is an accumulator. The returned accumulator function in turn also takes a single numeric argument, and returns the sum of all the numeric values passed in so far to that accumulat... | #EchoLisp | EchoLisp |
(define-syntax-rule (inc x v) (set! x (+ x v)))
(define (accumulator (sum 0)) (lambda(x) (inc sum x) sum))
(define x (accumulator 1)) → x
(x 5) → 6
;; another closure
(accumulator 3) → (🔒 λ (_x) (📝 #set! sum (#+ sum _x)) sum)
(x 2.3) → 8.3
| Give a code snippet in #EchoLisp
A problem posed by Paul Graham is that of creating a function that takes a single (numeric) argument and which returns another function that is an accumulator. The returned accumulator function in turn also takes a single numeric argument, and returns the sum of all the numeric values ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sorting_algorithms/Bubble_sort | Sorting algorithms/Bubble 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
... | #EchoLisp | EchoLisp |
;; sorts a vector of objects in place
;; proc is an user defined comparison procedure
(define (bubble-sort V proc)
(define length (vector-length V))
(for* ((i (in-range 0 (1- length))) (j (in-range (1+ i) length)))
(unless (proc (vector-ref V i) (vector-ref V j)) (vector-swap! V i j)))
V)
(define V ... | Give a code snippet in #EchoLisp
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/Circular_primes | Circular primes | Definitions
A circular prime is a prime number with the property that the number generated at each intermediate step when cyclically permuting its (base 10) digits will also be prime.
For example:
1193 is a circular prime, since 1931, 9311 and 3119 are all also prime.
Note that a number which is a cyclic permutation ... | #Prolog | Prolog |
?- use_module(library(primality)).
circular(N) :- member(N, [2, 3, 5, 7]).
circular(N) :-
limit(15, (
candidate(N),
N > 9,
circular_prime(N))).
circular(r(K)) :-
between(6, inf, K),
N is (10**K - 1) div 9,
prime(N).
candidate(0).
candidate(N) :-
candidate(M),
member... | Give a code snippet in #Prolog
Definitions
A circular prime is a prime number with the property that the number generated at each intermediate step when cyclically permuting its (base 10) digits will also be prime.
For example:
1193 is a circular prime, since 1931, 9311 and 3119 are all also prime.
Note that a numbe... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Strip_whitespace_from_a_string/Top_and_tail | Strip whitespace from a string/Top and tail | Task
Demonstrate how to strip leading and trailing whitespace from a string.
The solution should demonstrate how to achieve the following three results:
String with leading whitespace removed
String with trailing whitespace removed
String with both leading and trailing whitespace removed
For the purposes of thi... | #Ada | Ada | with Ada.Text_IO; use Ada.Text_IO;
with Ada.Strings; use Ada.Strings;
with Ada.Strings.Fixed; use Ada.Strings.Fixed;
procedure StripDemo is
str : String := " Jabberwocky ";
begin
Put_Line ("'" & Trim (str, Left) & "'");
Put_Line ("'" & Trim (str, Right) & "'");
Put_Line ("'" & Trim (str, Both) & "'"... | Give a code snippet in #Ada
Task
Demonstrate how to strip leading and trailing whitespace from a string.
The solution should demonstrate how to achieve the following three results:
String with leading whitespace removed
String with trailing whitespace removed
String with both leading and trailing whitespace remo... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Mayan_numerals | Mayan numerals | Task
Present numbers using the Mayan numbering system (displaying the Mayan numerals in a cartouche).
Mayan numbers
Normally, Mayan numbers are written vertically (top─to─bottom) with the most significant
numeral at the top (in the sense that decimal numbers are written left─to─right with the most signific... | #Cowgol | Cowgol | include "cowgol.coh";
include "argv.coh";
# convert number to base 20
sub base20(n: uint32, out: [uint8]): (n_digits: uint8) is
n_digits := 0;
loop
[out] := (n % 20) as uint8;
n := n / 20;
out := @next out;
n_digits := n_digits + 1;
if n == 0 then break; end if;
end... | Give a code snippet in #Cowgol
Task
Present numbers using the Mayan numbering system (displaying the Mayan numerals in a cartouche).
Mayan numbers
Normally, Mayan numbers are written vertically (top─to─bottom) with the most significant
numeral at the top (in the sense that decimal numbers are written left... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Combinations_with_repetitions | Combinations with repetitions | The set of combinations with repetitions is computed from a set,
S
{\displaystyle S}
(of cardinality
n
{\displaystyle n}
), and a size of resulting selection,
k
{\displaystyle k}
, by reporting the sets of cardinality
k
{\displaystyle k}
where each member of those sets is chosen from
S... | #Ada | Ada | with Ada.Text_IO;
procedure Combinations is
generic
type Set is (<>);
function Combinations
(Count : Positive;
Output : Boolean := False)
return Natural;
function Combinations
(Count : Positive;
Output : Boolean := False)
return Natural
is
package Set_... | Give a code snippet in #Ada
The set of combinations with repetitions is computed from a set,
S
{\displaystyle S}
(of cardinality
n
{\displaystyle n}
), and a size of resulting selection,
k
{\displaystyle k}
, by reporting the sets of cardinality
k
{\displaystyle k}
where each member of th... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Read_entire_file | Read entire file | Task
Load the entire contents of some text file as a single string variable.
If applicable, discuss: encoding selection, the possibility of memory-mapping.
Of course, in practice one should avoid reading an entire file at once
if the file is large and the task can be accomplished incrementally instead
(in which case... | #C | C | #include <stdio.h>
#include <stdlib.h>
int main()
{
char *buffer;
FILE *fh = fopen("readentirefile.c", "rb");
if ( fh != NULL )
{
fseek(fh, 0L, SEEK_END);
long s = ftell(fh);
rewind(fh);
buffer = malloc(s);
if ( buffer != NULL )
{
fread(buffer, s, 1, fh);
// we can now clos... | Give a code snippet in #C
Task
Load the entire contents of some text file as a single string variable.
If applicable, discuss: encoding selection, the possibility of memory-mapping.
Of course, in practice one should avoid reading an entire file at once
if the file is large and the task can be accomplished increment... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Start_from_a_main_routine | Start from a main routine |
Some languages (like Gambas and Visual Basic) support two startup modes. Applications written in these languages start with an open window that waits for events, and it is necessary to do some trickery to cause a main procedure to run instead. Data driven or event driven languages may also require similar tricker... | #Logtalk | Logtalk |
:- initialization(main).
| Give a code snippet in #Logtalk
Some languages (like Gambas and Visual Basic) support two startup modes. Applications written in these languages start with an open window that waits for events, and it is necessary to do some trickery to cause a main procedure to run instead. Data driven or event driven languages... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Even_or_odd | Even or odd | Task
Test whether an integer is even or odd.
There is more than one way to solve this task:
Use the even and odd predicates, if the language provides them.
Check the least significant digit. With binary integers, i bitwise-and 1 equals 0 iff i is even, or equals 1 iff i is odd.
Divide i by 2. The remainder equals... | #0815 | 0815 |
}:s:|=<:2:x~#:e:=/~%~<:20:~$=<:73:x<:69:~$~$~<:20:~$=^:o:<:65:
x<:76:=$=$~$<:6E:~$<:a:~$^:s:}:o:<:6F:x<:64:x~$~$$<:a:~$^:s:
| Give a code snippet in #0815
Task
Test whether an integer is even or odd.
There is more than one way to solve this task:
Use the even and odd predicates, if the language provides them.
Check the least significant digit. With binary integers, i bitwise-and 1 equals 0 iff i is even, or equals 1 iff i is odd.
Divid... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Pangram_checker | Pangram checker | Pangram checker
You are encouraged to solve this task according to the task description, using any language you may know.
A pangram is a sentence that contains all the letters of the English alphabet at least once.
For example: The quick brown fox jumps over the lazy dog.
Task
Write a function or method to chec... | #Go | Go | package main
import "fmt"
func main() {
for _, s := range []string{
"The quick brown fox jumps over the lazy dog.",
`Watch "Jeopardy!", Alex Trebek's fun TV quiz game.`,
"Not a pangram.",
} {
if pangram(s) {
fmt.Println("Yes:", s)
} else {
fmt.... | Give a code snippet in #Go
Pangram checker
You are encouraged to solve this task according to the task description, using any language you may know.
A pangram is a sentence that contains all the letters of the English alphabet at least once.
For example: The quick brown fox jumps over the lazy dog.
Task
Write ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/I_before_E_except_after_C | I before E except after C | The phrase "I before E, except after C" is a
widely known mnemonic which is supposed to help when spelling English words.
Task
Using the word list from http://wiki.puzzlers.org/pub/wordlists/unixdict.txt,
check if the two sub-clauses of the phrase are plausible individually:
"I before E when not pre... | #VBScript | VBScript |
Set objFSO = CreateObject("Scripting.FileSystemObject")
Set srcFile = objFSO.OpenTextFile(objFSO.GetParentFolderName(WScript.ScriptFullName) &_
"\unixdict.txt",1,False,0)
cei = 0 : cie = 0 : ei = 0 : ie = 0
Do Until srcFile.AtEndOfStream
word = srcFile.ReadLine
If InStr(word,"cei") Then
cei = cei + 1
ElseIf... | Give a code snippet in #VBScript
The phrase "I before E, except after C" is a
widely known mnemonic which is supposed to help when spelling English words.
Task
Using the word list from http://wiki.puzzlers.org/pub/wordlists/unixdict.txt,
check if the two sub-clauses of the phrase are plausible individu... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Hostname | Hostname | Task
Find the name of the host on which the routine is running.
| #COBOL | COBOL | identification division.
program-id. hostname.
data division.
working-storage section.
01 hostname pic x(256).
01 nullpos pic 999 value 1.
procedure division.
call "gethostname" using hostname by value length of hostname
string hostname delimited by lo... | Give a code snippet in #COBOL
Task
Find the name of the host on which the routine is running.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Greatest_common_divisor | Greatest common divisor | Greatest common divisor
You are encouraged to solve this task according to the task description, using any language you may know.
Task
Find the greatest common divisor (GCD) of two integers.
Greatest common divisor is also known as greatest common factor (gcf) and greatest common measure.
Related tas... | #F.23 | F# |
let rec gcd a b =
if b = 0
then abs a
else gcd b (a % b)
>gcd 400 600
val it : int = 200 | Give a code snippet in #F.23
Greatest common divisor
You are encouraged to solve this task according to the task description, using any language you may know.
Task
Find the greatest common divisor (GCD) of two integers.
Greatest common divisor is also known as greatest common factor (gcf) and greatest ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/S-expressions | S-expressions | S-Expressions are one convenient way to parse and store data.
Task
Write a simple reader and writer for S-Expressions that handles quoted and unquoted strings, integers and floats.
The reader should read a single but nested S-Expression from a string and store it in a suitable datastructure (list, array, etc).
... | #Raku | Raku | grammar S-Exp {
rule TOP {^ <s-list> $};
token s-list { '(' ~ ')' [ <in_list>+ % [\s+] | '' ] }
token in_list { <s-token> | <s-list> }
proto token s-token {*}
token s-token:sym<Num> {\d*\.?\d+}
token s-token:sym<String> {'"' ['\"' |<-[\\"]>]*? '"'} #'
token s-token:sym<Atom> {<-[()\s]>+}
}
... | Give a code snippet in #Raku
S-Expressions are one convenient way to parse and store data.
Task
Write a simple reader and writer for S-Expressions that handles quoted and unquoted strings, integers and floats.
The reader should read a single but nested S-Expression from a string and store it in a suitable datas... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Yin_and_yang | Yin and yang | One well-known symbol of the philosophy of duality known as yin and yang is the taijitu.
Task
Create a function that, given a parameter representing size, generates such a symbol scaled to the requested size.
Generate and display the symbol for two different (small) sizes.
| #CLU | CLU | taijitu = cluster is make
rep = null
circle = proc (x,y,c,r: int) returns (bool)
return (r**2 >= (x/2)**2 + (y-c)**2)
end circle
pixel = proc (x,y,r: int) returns (char)
if circle(x,y,-r/2,r/6) then return('#')
elseif circle(x,y, r/2,r/6) then return('.')
elseif c... | Give a code snippet in #CLU
One well-known symbol of the philosophy of duality known as yin and yang is the taijitu.
Task
Create a function that, given a parameter representing size, generates such a symbol scaled to the requested size.
Generate and display the symbol for two different (small) sizes.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Letter_frequency | Letter frequency | Task
Open a text file and count the occurrences of each letter.
Some of these programs count all characters (including punctuation),
but some only count letters A to Z.
Other tasks related to string operations:
Metrics
Array length
String length
Copy a string
Empty string (assignment)
Counting
Word frequen... | #D | D | void main() {
import std.stdio, std.ascii, std.algorithm, std.range;
uint[26] frequency;
foreach (const buffer; "unixdict.txt".File.byChunk(2 ^^ 15))
foreach (immutable c; buffer.filter!isAlpha)
frequency[c.toLower - 'a']++;
writefln("%(%(%s, %),\n%)", frequency[].chunks(10));
... | Give a code snippet in #D
Task
Open a text file and count the occurrences of each letter.
Some of these programs count all characters (including punctuation),
but some only count letters A to Z.
Other tasks related to string operations:
Metrics
Array length
String length
Copy a string
Empty string (assignm... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Vector | Vector | Task
Implement a Vector class (or a set of functions) that models a Physical Vector. The four basic operations and a pretty print function should be implemented.
The Vector may be initialized in any reasonable way.
Start and end points, and direction
Angular coefficient and value (length)
The four operations to... | #Julia | Julia | module SpatialVectors
export SpatialVector
struct SpatialVector{N, T}
coord::NTuple{N, T}
end
SpatialVector(s::NTuple{N,T}, e::NTuple{N,T}) where {N,T} =
SpatialVector{N, T}(e .- s)
function SpatialVector(∠::T, val::T) where T
θ = atan(∠)
x = val * cos(θ)
y = val * sin(θ)
return SpatialVec... | Give a code snippet in #Julia
Task
Implement a Vector class (or a set of functions) that models a Physical Vector. The four basic operations and a pretty print function should be implemented.
The Vector may be initialized in any reasonable way.
Start and end points, and direction
Angular coefficient and value (l... | 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 |... | #SAS | SAS | data _null_;
a="abracadabra";
b=substr(a,2,3); /* first number is position, starting at 1,
second number is length */
put _all_;
run; | Give a code snippet in #SAS
Basic Data Operation
This is a basic data operation. It represents a fundamental action on a basic data type.
You may see other such operations in the Basic Data Operations category, or:
Integer Operations
Arithmetic |
Comparison
Boolean Operations
Bitwise |
Logical
String Operations
Co... | christopher/rosetta-code | |
http://rosettacode.org/wiki/The_ISAAC_Cipher | The ISAAC Cipher | ISAAC is a cryptographically secure pseudo-random number generator (CSPRNG) and stream cipher. It was developed by Bob Jenkins from 1993 (http://burtleburtle.net/bob/rand/isaac.html) and placed in the Public Domain. ISAAC is fast - especially when optimised - and portable to most architectures in nearly all programming... | #C.23 | C# |
using System;
namespace cipher {
static class Cipher {
// external results
static uint[] randrsl = new uint[256];
static uint randcnt;
// internal state
static uint[] mm = new uint[256];
static uint aa=0, bb=0, cc=0;
static void isaac() {
uint i,x,y;
cc++; // cc just gets incremented once per 256... | Give a code snippet in #C.23
ISAAC is a cryptographically secure pseudo-random number generator (CSPRNG) and stream cipher. It was developed by Bob Jenkins from 1993 (http://burtleburtle.net/bob/rand/isaac.html) and placed in the Public Domain. ISAAC is fast - especially when optimised - and portable to most architect... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Fractran | Fractran | FRACTRAN is a Turing-complete esoteric programming language invented by the mathematician John Horton Conway.
A FRACTRAN program is an ordered list of positive fractions
P
=
(
f
1
,
f
2
,
…
,
f
m
)
{\displaystyle P=(f_{1},f_{2},\ldots ,f_{m})}
, together with an initial positive integer input
n
... | #C | C | #include <stdio.h>
#include <stdlib.h>
#include <gmp.h>
typedef struct frac_s *frac;
struct frac_s {
int n, d;
frac next;
};
frac parse(char *s)
{
int offset = 0;
struct frac_s h = {0}, *p = &h;
while (2 == sscanf(s, "%d/%d%n", &h.n, &h.d, &offset)) {
s += offset;
p = p->next = malloc(sizeof *p);
*p = ... | Give a code snippet in #C
FRACTRAN is a Turing-complete esoteric programming language invented by the mathematician John Horton Conway.
A FRACTRAN program is an ordered list of positive fractions
P
=
(
f
1
,
f
2
,
…
,
f
m
)
{\displaystyle P=(f_{1},f_{2},\ldots ,f_{m})}
, together with an initial po... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Parallel_brute_force | Parallel brute force | Task
Find, through brute force, the five-letter passwords corresponding with the following SHA-256 hashes:
1. 1115dd800feaacefdf481f1f9070374a2a81e27880f187396db67958b207cbad
2. 3a7bd3e2360a3d29eea436fcfb7e44c735d117c42d1c1835420b6b9942dd4f1b
3. 74e1bb62f8dabb8125a58852b63bdf6eaef667cb56ac7f7cdba6d7305c50a22f
Your p... | #Java | Java | import javax.xml.bind.DatatypeConverter;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.util.Arrays;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
/**
* "Main Program" that does the parallel processing
*/
public class ParallelBrut... | Give a code snippet in #Java
Task
Find, through brute force, the five-letter passwords corresponding with the following SHA-256 hashes:
1. 1115dd800feaacefdf481f1f9070374a2a81e27880f187396db67958b207cbad
2. 3a7bd3e2360a3d29eea436fcfb7e44c735d117c42d1c1835420b6b9942dd4f1b
3. 74e1bb62f8dabb8125a58852b63bdf6eaef667cb56... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Check_that_file_exists | Check that file exists | Task
Verify that a file called input.txt and a directory called docs exist.
This should be done twice:
once for the current working directory, and
once for a file and a directory in the filesystem root.
Optional criteria (May 2015): verify it works with:
zero-length files
an ... | #Neko | Neko | /**
Check that file/dir exists, in Neko
*/
var sys_exists = $loader.loadprim("std@sys_exists", 1)
var sys_file_type = $loader.loadprim("std@sys_file_type", 1)
var sys_command = $loader.loadprim("std@sys_command", 1)
var name = "input.txt"
$print(name, " exists as file: ", sys_exists(name), "\n")
$print(name = "d... | Give a code snippet in #Neko
Task
Verify that a file called input.txt and a directory called docs exist.
This should be done twice:
once for the current working directory, and
once for a file and a directory in the filesystem root.
Optional criteria (May 2015): verify it works with... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sort_three_variables | Sort three variables |
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
... | #Nim | Nim | proc sortThree[T](a, b, c: var T) =
# Bubble sort, why not?
while not (a <= b and b <= c):
if a > b: swap a, b
if b > c: swap b, c
proc testWith[T](a, b, c: T) =
var (x, y, z) = (a, b, c)
echo "Before: ", x, ", ", y, ", ", z
sortThree(x, y, z)
echo "After: ", x, ", ", y, ", ", z
testWith(6, 4, 2... | Give a code snippet in #Nim
Sorting Algorithm
This is a sorting algorithm. It may be applied to a set of data in order to sort it.
For comparing various sorts, see compare sorts.
For other sorting algorithms, see sorting algorithms, or:
O(n logn) sorts
Heap sort |
Merge sort |
Patience sort |
Quick sort... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Inheritance/Multiple | Inheritance/Multiple | Multiple inheritance allows to specify that one class is a subclass of several other classes.
Some languages allow multiple inheritance for arbitrary classes, others restrict it to interfaces, some don't allow it at all.
Task
Write two classes (or interfaces) Camera and MobilePhone, then write a class Camer... | #Java | Java | public interface Camera{
//functions here with no definition...
//ex:
//public void takePicture();
} | Give a code snippet in #Java
Multiple inheritance allows to specify that one class is a subclass of several other classes.
Some languages allow multiple inheritance for arbitrary classes, others restrict it to interfaces, some don't allow it at all.
Task
Write two classes (or interfaces) Camera and MobilePho... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Heronian_triangles | Heronian triangles | Hero's formula for the area of a triangle given the length of its three sides a, b, and c is given by:
A
=
s
(
s
−
a
)
(
s
−
b
)
(
s
−
c
)
,
{\displaystyle A={\sqrt {s(s-a)(s-b)(s-c)}},}
where s is half the perimeter of the triangle; that is,
s
=
a
+
b
+
c
2
.
{\displaystyle s... | #Smalltalk | Smalltalk | perimeter := [:triangle | triangle reduce: #+].
squaredArea := [:triangle |
| s |
s := (perimeter value: triangle) / 2.
triangle inject: s into: [:a2 :edge | s - edge * a2]].
isPrimitive := [:triangle | (triangle reduce: #gcd:) = 1].
isHeronian := [:triangle | (squaredArea value: triangle) sqrt isInteger].
... | Give a code snippet in #Smalltalk
Hero's formula for the area of a triangle given the length of its three sides a, b, and c is given by:
A
=
s
(
s
−
a
)
(
s
−
b
)
(
s
−
c
)
,
{\displaystyle A={\sqrt {s(s-a)(s-b)(s-c)}},}
where s is half the perimeter of the triangle; that is,
s
=
... | 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... | #Vlang | Vlang | struct Item {
item string
weight f64
price f64
}
fn main(){
mut left := 15.0
mut items := [
Item{'beef', 3.8, 36},
Item{'pork', 5.4, 43},
Item{'ham', 3.6, 90},
Item{'greaves', 2.4, 45},
Item{'flitch', 4.0, 30},
Item{'brawn', 2.5, 56},
Item{'w... | Give a code snippet in #Vlang
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... | 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... | #Bracmat | Bracmat | ( 1:?number
& 0:?lines
& whl
' ( 1+!lines:~>10:?lines
& :?say { This will accumulate all that has to be said after one iteration. }
& 0:?begin
& ( @( !number { Pattern matching. The '@' indicates we're looking in a string rather than a tree structure. }
... | Give a code snippet in #Bracmat
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 sequen... | 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 ... | #Groovy | Groovy | new File('.').eachFileRecurse {
if (it.name =~ /.*\.txt/) println it;
} | Give a code snippet in #Groovy
Task
Walk a given directory tree and print files matching a given pattern.
Note: This task is for recursive methods. These tasks should read an entire directory tree, not a single directory.
Note: Please be careful when running any code examples found here.
Related task
Wal... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Munchausen_numbers | Munchausen numbers | A Munchausen number is a natural number n the sum of whose digits (in base 10), each raised to the power of itself, equals n.
(Munchausen is also spelled: Münchhausen.)
For instance: 3435 = 33 + 44 + 33 + 55
Task
Find all Munchausen numbers between 1 and 5000.
Also see
The OEIS entry: A046253
The ... | #Wren | Wren | var powers = List.filled(10, 0)
for (i in 1..9) powers[i] = i.pow(i).round // cache powers
var munchausen = Fn.new {|n|
if (n <= 0) Fiber.abort("Argument must be a positive integer.")
var nn = n
var sum = 0
while (n > 0) {
var digit = n % 10
sum = sum + powers[digit]
n = (n/10)... | Give a code snippet in #Wren
A Munchausen number is a natural number n the sum of whose digits (in base 10), each raised to the power of itself, equals n.
(Munchausen is also spelled: Münchhausen.)
For instance: 3435 = 33 + 44 + 33 + 55
Task
Find all Munchausen numbers between 1 and 5000.
Also see
... | 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.
| #Vlang | Vlang | fn repeat(n int, f fn()) {
for _ in 0.. n {
f()
}
}
fn func() {
println("Example")
}
fn main() {
repeat(4, func)
} | Give a code snippet in #Vlang
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/Convert_decimal_number_to_rational | Convert decimal number to rational | This task has been flagged for clarification. Code on this page in its current state may be flagged incorrect once this task has been clarified. See this page's Talk page for discussion.
The task is to write a program to transform a decimal number into a fraction in lowest terms.
It is not always possible to do this... | #Seed7 | Seed7 | $ include "seed7_05.s7i";
include "bigrat.s7i";
const proc: main is func
begin
writeln(bigRational parse "0.9(054)");
writeln(bigRational parse "0.(518)");
writeln(bigRational parse "0.75");
writeln(bigRational parse "3.(142857)");
writeln(bigRational parse "0.(8867924528301)");
writeln(bi... | Give a code snippet in #Seed7
This task has been flagged for clarification. Code on this page in its current state may be flagged incorrect once this task has been clarified. See this page's Talk page for discussion.
The task is to write a program to transform a decimal number into a fraction in lowest terms.
It is... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Filter | Filter | Task
Select certain elements from an Array into a new Array in a generic way.
To demonstrate, select all even numbers from an Array.
As an option, give a second solution which filters destructively,
by modifying the original Array rather than creating a new Array.
| #PL.2FI | PL/I | (subscriptrange):
filter_values: procedure options (main); /* 15 November 2013 */
declare a(20) fixed, b(*) fixed controlled;
declare (i, j, n) fixed binary;
a = random()*99999; /* fill the array with random elements from 0-99998 */
put list ('Unfiltered values:');
put skip edit (a) (f(6));
/* Loop ... | Give a code snippet in #PL.2FI
Task
Select certain elements from an Array into a new Array in a generic way.
To demonstrate, select all even numbers from an Array.
As an option, give a second solution which filters destructively,
by modifying the original Array rather than creating a new Array.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Number_names | Number names | Task
Show how to spell out a number in English.
You can use a preexisting implementation or roll your own, but you should support inputs up to at least one million (or the maximum value of your language's default bounded integer type, if that's less).
Support for inputs other than positive integers (like zero, negat... | #Delphi | Delphi |
program Number_names;
{$APPTYPE CONSOLE}
const
smallies: array[1..19] of string = ('one', 'two', 'three', 'four', 'five',
'six', 'seven', 'eight', 'nine', 'ten', 'eleven', 'twelve', 'thirteen',
'fourteen', 'fifteen', 'sixteen', 'seventeen', 'eighteen', 'nineteen');
tens: array[2..9] of string = ('twen... | Give a code snippet in #Delphi
Task
Show how to spell out a number in English.
You can use a preexisting implementation or roll your own, but you should support inputs up to at least one million (or the maximum value of your language's default bounded integer type, if that's less).
Support for inputs other than pos... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Next_highest_int_from_digits | Next highest int from digits | Given a zero or positive integer, the task is to generate the next largest
integer using only the given digits*1.
Numbers will not be padded to the left with zeroes.
Use all given digits, with their given multiplicity. (If a digit appears twice in the input number, it should appear twice in the result).
If th... | #Raku | Raku | use Lingua::EN::Numbers;
sub next-greatest-index ($str, &op = &infix:«<» ) {
my @i = $str.comb;
(1..^@i).first: { &op(@i[$_ - 1], @i[$_]) }, :end, :k;
}
multi next-greatest-integer (Int $num where * >= 0) {
return 0 if $num.chars < 2;
return $num.flip > $num ?? $num.flip !! 0 if $num.chars == 2;
... | Give a code snippet in #Raku
Given a zero or positive integer, the task is to generate the next largest
integer using only the given digits*1.
Numbers will not be padded to the left with zeroes.
Use all given digits, with their given multiplicity. (If a digit appears twice in the input number, it should appear ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Empty_directory | Empty directory | Starting with a path to some directory, determine whether the directory is empty.
An empty directory contains no files nor subdirectories.
With Unix or Windows systems, every directory contains an entry for “.” and almost every directory contains “..” (except for a root directory); an empty directory contains no other... | #D | D | import std.stdio, std.file;
void main() {
auto dir = "somedir";
writeln(dir ~ " is empty: ", dirEmpty(dir));
}
bool dirEmpty(string dirname) {
if (!exists(dirname) || !isDir(dirname))
throw new Exception("dir not found: " ~ dirname);
return dirEntries(dirname, SpanMode.shallow).empty;
} | Give a code snippet in #D
Starting with a path to some directory, determine whether the directory is empty.
An empty directory contains no files nor subdirectories.
With Unix or Windows systems, every directory contains an entry for “.” and almost every directory contains “..” (except for a root directory); an empty ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Read_a_file_character_by_character/UTF8 | Read a file character by character/UTF8 | Task
Read a file one character at a time, as opposed to reading the entire file at once.
The solution may be implemented as a procedure, which returns the next character in the file on each consecutive call (returning EOF when the end of the file is reached).
The procedure should support the reading of files contain... | #Delphi | Delphi |
program Read_a_file_character_by_character_UTF8;
{$APPTYPE CONSOLE}
uses
System.SysUtils,
System.Classes;
function GetNextCharacter(StreamReader: TStreamReader): char;
begin
Result := chr(StreamReader.Read);
end;
const
FileName: TFileName = 'input.txt';
begin
if not FileExists(FileName) then
r... | Give a code snippet in #Delphi
Task
Read a file one character at a time, as opposed to reading the entire file at once.
The solution may be implemented as a procedure, which returns the next character in the file on each consecutive call (returning EOF when the end of the file is reached).
The procedure should supp... | 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.)
| #M4 | M4 | eval(2*3) # eval(2*3) "#" and text after it aren't processed but passed along
dnl this text completely disappears, including the new line
divert(-1)
Everything diverted to -1 is processed but the output is discarded.
A comment could take this form as long as no macro names are used.
divert | Give a code snippet in #M4
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/Lucas-Lehmer_test | Lucas-Lehmer test | Lucas-Lehmer Test:
for
p
{\displaystyle p}
an odd prime, the Mersenne number
2
p
−
1
{\displaystyle 2^{p}-1}
is prime if and only if
2
p
−
1
{\displaystyle 2^{p}-1}
divides
S
(
p
−
1
)
{\displaystyle S(p-1)}
where
S
(
n
+
1
)
=
(
S
(
n
)
)
2
−
2
{\displaystyle S(n+1)=(... | #Pascal | Pascal | Program LucasLehmer(output);
var
s, n: int64;
i, exponent: integer;
begin
n := 1;
for exponent := 2 to 31 do
begin
if exponent = 2 then
s := 0
else
s := 4;
n := (n + 1)*2 - 1; // This saves from needing the math unit for exponentiation
for i := 1 to exponent-2 do
s := (s*s -... | Give a code snippet in #Pascal
Lucas-Lehmer Test:
for
p
{\displaystyle p}
an odd prime, the Mersenne number
2
p
−
1
{\displaystyle 2^{p}-1}
is prime if and only if
2
p
−
1
{\displaystyle 2^{p}-1}
divides
S
(
p
−
1
)
{\displaystyle S(p-1)}
where
S
(
n
+
1
)
=
(
S
(
n
)
)
2... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Pseudo-random_numbers/Xorshift_star | Pseudo-random numbers/Xorshift star | Some definitions to help in the explanation
Floor operation
https://en.wikipedia.org/wiki/Floor_and_ceiling_functions
Greatest integer less than or equal to a real number.
Bitwise Logical shift operators (c-inspired)
https://en.wikipedia.org/wiki/Bitwise_operation#Bit_shifts
Binary bits of value shifted left or ri... | #Nim | Nim | import algorithm, sequtils, strutils, tables
const C = 0x2545F4914F6CDD1Du64
type XorShift = object
state: uint64
func seed(gen: var XorShift; num: uint64) =
gen.state = num
func nextInt(gen: var XorShift): uint32 =
var x = gen.state
x = x xor x shr 12
x = x xor x shl 25
x = x xor x shr 27
gen.sta... | Give a code snippet in #Nim
Some definitions to help in the explanation
Floor operation
https://en.wikipedia.org/wiki/Floor_and_ceiling_functions
Greatest integer less than or equal to a real number.
Bitwise Logical shift operators (c-inspired)
https://en.wikipedia.org/wiki/Bitwise_operation#Bit_shifts
Binary bit... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Fractran | Fractran | FRACTRAN is a Turing-complete esoteric programming language invented by the mathematician John Horton Conway.
A FRACTRAN program is an ordered list of positive fractions
P
=
(
f
1
,
f
2
,
…
,
f
m
)
{\displaystyle P=(f_{1},f_{2},\ldots ,f_{m})}
, together with an initial positive integer input
n
... | #Python | Python | from fractions import Fraction
def fractran(n, fstring='17 / 91, 78 / 85, 19 / 51, 23 / 38, 29 / 33,'
'77 / 29, 95 / 23, 77 / 19, 1 / 17, 11 / 13,'
'13 / 11, 15 / 14, 15 / 2, 55 / 1'):
flist = [Fraction(f) for f in fstring.replace(' ', '').split(',')]
n = Frac... | Give a code snippet in #Python
FRACTRAN is a Turing-complete esoteric programming language invented by the mathematician John Horton Conway.
A FRACTRAN program is an ordered list of positive fractions
P
=
(
f
1
,
f
2
,
…
,
f
m
)
{\displaystyle P=(f_{1},f_{2},\ldots ,f_{m})}
, together with an initi... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Mutual_recursion | Mutual recursion | Two functions are said to be mutually recursive if the first calls the second,
and in turn the second calls the first.
Write two mutually recursive functions that compute members of the Hofstadter Female and Male sequences defined as:
F
(
0
)
=
1
;
M
(
0
)
=
0
F
(
n
)
=
n
−
M
(
F
(
n
−
1
)
)
,
... | #x86_Assembly | x86 Assembly | global main
extern printf
section .text
func_f
mov eax, [esp+4]
cmp eax, 0
jz f_ret
dec eax
push eax
call func_f
mov [esp+0], eax
call func_m
add esp, 4
mov ebx, [esp+4]
sub ebx, eax
mov eax, ebx
ret
f_ret
mov eax, 1
ret
func_m
mov eax, [esp+4]
cmp eax, 0
jz m_ret
dec eax
push eax
call fun... | Give a code snippet in #x86_Assembly
Two functions are said to be mutually recursive if the first calls the second,
and in turn the second calls the first.
Write two mutually recursive functions that compute members of the Hofstadter Female and Male sequences defined as:
F
(
0
)
=
1
;
M
(
0
)
=
0
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Quine | Quine | A quine is a self-referential program that can,
without any external access, output its own source.
A quine (named after Willard Van Orman Quine) is also known as:
self-reproducing automata (1972)
self-replicating program or self-replicating computer program
self-reproducing program ... | #Clojure | Clojure | ((fn [x] (list x (list (quote quote) x))) (quote (fn [x] (list x (list (quote quote) x))))) | Give a code snippet in #Clojure
A quine is a self-referential program that can,
without any external access, output its own source.
A quine (named after Willard Van Orman Quine) is also known as:
self-reproducing automata (1972)
self-replicating program or self-replicating computer program
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Special_variables | Special variables | Special variables have a predefined meaning within a computer programming language.
Task
List the special variables used within the language.
| #NetRexx | NetRexx | /* NetRexx */
options replace format comments java crossref savelog symbols binary
class RCSpecialVariables
method RCSpecialVariables()
x = super.toString
y = this.toString
say '<super>'x'</super>'
say '<this>'y'</this>'
say '<class>'RCSpecialVariables.class'</class>'
say '<digits>'digits'</digits>'
s... | Give a code snippet in #NetRexx
Special variables have a predefined meaning within a computer programming language.
Task
List the special variables used within the language.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Anagrams/Deranged_anagrams | Anagrams/Deranged anagrams | Two or more words are said to be anagrams if they have the same characters, but in a different order.
By analogy with derangements we define a deranged anagram as two words with the same characters, but in which the same character does not appear in the same position in both words.
Task[edit]
Use the word list at uni... | #ooRexx | ooRexx | -- This assumes you've already downloaded the following file and placed it
-- in the current directory: http://www.puzzlers.org/pub/wordlists/unixdict.txt
-- There are several different ways of reading the file. I chose the
-- supplier method just because I haven't used it yet in any other examples.
source = .stream... | Give a code snippet in #ooRexx
Two or more words are said to be anagrams if they have the same characters, but in a different order.
By analogy with derangements we define a deranged anagram as two words with the same characters, but in which the same character does not appear in the same position in both words.
Tas... | 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... | #OCaml | OCaml | for i = 10 downto 0 do
Printf.printf "%d\n" i
done | Give a code snippet in #OCaml
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/Increm... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Stirling_numbers_of_the_second_kind | Stirling numbers of the second kind | Stirling numbers of the second kind, or Stirling partition numbers, are the
number of ways to partition a set of n objects into k non-empty subsets. They are
closely related to Bell numbers, and may be derived from them.
Stirling numbers of the second kind obey the recurrence relation:
S2(n, 0) and S2(0, k) = 0 ... | #Java | Java |
import java.math.BigInteger;
import java.util.HashMap;
import java.util.Map;
public class SterlingNumbersSecondKind {
public static void main(String[] args) {
System.out.println("Stirling numbers of the second kind:");
int max = 12;
System.out.printf("n/k");
for ( int n = 0 ; n... | Give a code snippet in #Java
Stirling numbers of the second kind, or Stirling partition numbers, are the
number of ways to partition a set of n objects into k non-empty subsets. They are
closely related to Bell numbers, and may be derived from them.
Stirling numbers of the second kind obey the recurrence relation:
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Deepcopy | Deepcopy | Task
Demonstrate how to copy data structures containing complex heterogeneous and cyclic semantics.
This is often referred to as deep copying, and is normally required where structures are mutable and to ensure that independent copies can be manipulated without side-effects.
If this facility is not built into the la... | #D.C3.A9j.C3.A0_Vu | Déjà Vu | local :(copy-action) {}
(copy-action)!list obj cache:
local :new []
set-to cache obj new
for i range 0 -- len obj:
push-to new (deepcopy) @obj! i cache
return new
(copy-action)!dict obj cache:
local :new {}
set-to cache obj new
for key in keys obj:
set-to new (deepcopy) @key cache (deepcopy) @obj! @key c... | Give a code snippet in #D.C3.A9j.C3.A0_Vu
Task
Demonstrate how to copy data structures containing complex heterogeneous and cyclic semantics.
This is often referred to as deep copying, and is normally required where structures are mutable and to ensure that independent copies can be manipulated without side-effects.... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Colour_bars/Display | Colour bars/Display | Task
Display a series of vertical color bars across the width of the display.
The color bars should either use:
the system palette, or
the sequence of colors:
black
red
green
blue
magenta
cyan
yellow
white
| #Action.21 | Action! | PROC Main()
BYTE
i,
CH=$02FC, ;Internal hardware value for last key pressed
PALNTSC=$D014, ;To check if PAL or NTSC system is used
PCOLR0=$02C0,PCOLR1=$02C1,
PCOLR2=$02C2,PCOLR3=$02C3,
COLOR0=$02C4,COLOR1=$02C5,
COLOR2=$02C6,COLOR3=$02C7,
COLOR4=$02C8
Graphics(10)
PCOLR0=$04 ;gra... | Give a code snippet in #Action.21
Task
Display a series of vertical color bars across the width of the display.
The color bars should either use:
the system palette, or
the sequence of colors:
black
red
green
blue
magenta
cyan
yellow
white
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Elliptic_curve_arithmetic | Elliptic curve arithmetic | Elliptic curves are sometimes used in cryptography as a way to perform digital signatures.
The purpose of this task is to implement a simplified (without modular arithmetic) version of the elliptic curve arithmetic which is required by the elliptic curve DSA protocol.
In a nutshell, an elliptic curve is a... | #zkl | zkl | const C=7, INFINITY=(0.0).inf;
fcn zero{ T(INFINITY, INFINITY) }
// should be INFINITY, but numeric precision is very much in the way
fcn is_zero(p){ x,_:=p; (x < -1e20 or x > 1e20) }
fcn neg(p){ return(p[0], -p[1]) }
fcn dbl(p){
if(is_zero(p)) return(p);
px,py := p;
L:=(3.0 * px * px) / (2.0 * py);
... | Give a code snippet in #zkl
Elliptic curves are sometimes used in cryptography as a way to perform digital signatures.
The purpose of this task is to implement a simplified (without modular arithmetic) version of the elliptic curve arithmetic which is required by the elliptic curve DSA protocol.
In a nut... | 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.23 | C# | using System;
using System.IO;
namespace DirectoryWalk
{
class Program
{
static void Main(string[] args)
{
string[] filePaths = Directory.GetFiles(@"c:\MyDir", "a*");
foreach (string filename in filePaths)
Console.WriteLine(filename);
... | Give a code snippet in #C.23
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, n... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sum_digits_of_an_integer | Sum digits of an integer | Task
Take a Natural Number in a given base and return the sum of its digits:
110 sums to 1
123410 sums to 10
fe16 sums to 29
f0e16 sums to 29
| #ALGOL_68 | ALGOL 68 |
# operator to return the sum of the digits of an integer value in the #
# specified base #
PRIO SUMDIGITS = 1;
OP SUMDIGITS = ( INT value, INT base )INT:
IF base < 2
THEN
# invalid base #
print( ( "Base for digit sum must be at least 2... | Give a code snippet in #ALGOL_68
Task
Take a Natural Number in a given base and return the sum of its digits:
110 sums to 1
123410 sums to 10
fe16 sums to 29
f0e16 sums to 29
| christopher/rosetta-code | |
http://rosettacode.org/wiki/String_concatenation | String concatenation | String concatenation
You are encouraged to solve this task according to the task description, using any language you may know.
Task
Create a string variable equal to any text value.
Create another string variable whose value is the original variable concatenated with another string literal.
To illustrate the operat... | #Dyalect | Dyalect | var s = "hello"
print(s + " literal")
var s1 = s + " literal"
print(s1) | Give a code snippet in #Dyalect
String concatenation
You are encouraged to solve this task according to the task description, using any language you may know.
Task
Create a string variable equal to any text value.
Create another string variable whose value is the original variable concatenated with another string l... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Matrix_digital_rain | Matrix digital rain | Implement the Matrix Digital Rain visual effect from the movie "The Matrix" as described in Wikipedia.
Provided is a reference implementation in Common Lisp to be run in a terminal.
| #Locomotive_Basic | Locomotive Basic | 10 mode 0:defint a-z:randomize time:ink 0,0:ink 1,26:ink 2,19:border 0
20 dim p(20):mm=5:dim act(mm):for i=1 to mm:act(i)=rnd*19+1:next
30 md=mm-2:dim del(md):for i=1 to md:del(i)=rnd*19+1:next
40 for i=1 to mm:x=act(i):locate x,p(x)+1:pen 1:print chr$(rnd*55+145);
50 if p(x)>0 then locate x,p(x):pen 2:print chr$(rnd*5... | Give a code snippet in #Locomotive_Basic
Implement the Matrix Digital Rain visual effect from the movie "The Matrix" as described in Wikipedia.
Provided is a reference implementation in Common Lisp to be run in a terminal.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Tokenize_a_string | Tokenize a string | Separate the string "Hello,How,Are,You,Today" by commas into an array (or list) so that each element of it stores a different word.
Display the words to the 'user', in the simplest manner possible, separated by a period.
To simplify, you may display a trailing period.
Other tasks related to string operations:
Me... | #AWK | AWK | BEGIN {
s = "Hello,How,Are,You,Today"
split(s, arr, ",")
for(i=1; i < length(arr); i++) {
printf arr[i] "."
}
print
} | Give a code snippet in #AWK
Separate the string "Hello,How,Are,You,Today" by commas into an array (or list) so that each element of it stores a different word.
Display the words to the 'user', in the simplest manner possible, separated by a period.
To simplify, you may display a trailing period.
Other tasks rela... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Amb | Amb | Define and give an example of the Amb operator.
The Amb operator (short for "ambiguous") expresses nondeterminism. This doesn't refer to randomness (as in "nondeterministic universe") but is closely related to the term as it is used in automata theory ("non-deterministic finite automaton").
The Amb operator takes a v... | #Yabasic | Yabasic | sub wordsOK(string1$, string2$)
return right$(string1$, 1) == left$(string2$, 1)
End sub
sub Amb$(A$(), B$(), C$(), D$())
local a2, b2, c2, d2
For a2 = 1 To arraysize(A$(), 1)
For b2 = 1 To arraysize(B$(), 1)
For c2 = 1 To arraysize(C$(), 1)
For d2 = 1 To arraysize(D$... | Give a code snippet in #Yabasic
Define and give an example of the Amb operator.
The Amb operator (short for "ambiguous") expresses nondeterminism. This doesn't refer to randomness (as in "nondeterministic universe") but is closely related to the term as it is used in automata theory ("non-deterministic finite automat... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Price_fraction | Price fraction | A friend of mine runs a pharmacy. He has a specialized function in his Dispensary application which receives a decimal value of currency and replaces it to a standard value. This value is regulated by a government department.
Task
Given a floating point value between 0.00 and 1.00, rescale according to ... | #Ruby | Ruby | def rescale_price_fraction(value)
raise ArgumentError, "value=#{value}, must have: 0 <= value < 1.01" if value < 0 || value >= 1.01
if value < 0.06 then 0.10
elsif value < 0.11 then 0.18
elsif value < 0.16 then 0.26
elsif value < 0.21 then 0.32
elsif value < 0.26 then 0.38
elsif value <... | Give a code snippet in #Ruby
A friend of mine runs a pharmacy. He has a specialized function in his Dispensary application which receives a decimal value of currency and replaces it to a standard value. This value is regulated by a government department.
Task
Given a floating point value between 0.00 and ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sexy_primes | Sexy primes |
This page uses content from Wikipedia. The original article was at Sexy_prime. 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 mathematics, sexy primes are prime numbers that differ from each ot... | #Python | Python | LIMIT = 1_000_035
def primes2(limit=LIMIT):
if limit < 2: return []
if limit < 3: return [2]
lmtbf = (limit - 3) // 2
buf = [True] * (lmtbf + 1)
for i in range((int(limit ** 0.5) - 3) // 2 + 1):
if buf[i]:
p = i + i + 3
s = p * (i + 1) + i
buf[s::p] = [Fal... | Give a code snippet in #Python
This page uses content from Wikipedia. The original article was at Sexy_prime. 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 mathematics, sexy primes are prime ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Averages/Pythagorean_means | Averages/Pythagorean means | Task[edit]
Compute all three of the Pythagorean means of the set of integers 1 through 10 (inclusive).
Show that
A
(
x
1
,
…
,
x
n
)
≥
G
(
x
1
,
…
,
x
n
)
≥
H
(
x
1
,
…
,
x
n
)
{\displaystyle A(x_{1},\ldots ,x_{n})\geq G(x_{1},\ldots ,x_{n})\geq H(x_{1},\ldots ,x_{n})}
for this set of p... | #Oz | Oz | declare
%% helpers
fun {Sum Xs} {FoldL Xs Number.'+' 0.0} end
fun {Product Xs} {FoldL Xs Number.'*' 1.0} end
fun {Len Xs} {Int.toFloat {Length Xs}} end
fun {AMean Xs}
{Sum Xs}
/
{Len Xs}
end
fun {GMean Xs}
{Pow
{Product Xs}
1.0/{Len Xs}}
end
fun {HMean Xs}
{L... | Give a code snippet in #Oz
Task[edit]
Compute all three of the Pythagorean means of the set of integers 1 through 10 (inclusive).
Show that
A
(
x
1
,
…
,
x
n
)
≥
G
(
x
1
,
…
,
x
n
)
≥
H
(
x
1
,
…
,
x
n
)
{\displaystyle A(x_{1},\ldots ,x_{n})\geq G(x_{1},\ldots ,x_{n})\geq H(x_{1},\ldots ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Hamming_numbers | Hamming numbers | Hamming numbers are numbers of the form
H = 2i × 3j × 5k
where
i, j, k ≥ 0
Hamming numbers are also known as ugly numbers and also 5-smooth numbers (numbers whose prime divisors are less or equal to 5).
Task
Generate the sequence of Hamming numbers, in increasing order. In ... | #JavaScript | JavaScript | function hamming() {
var queues = {2: [], 3: [], 5: []};
var base;
var next_ham = 1;
while (true) {
yield next_ham;
for (base in queues) {queues[base].push(next_ham * base)}
next_ham = [ queue[0] for each (queue in queues) ].reduce(function(min, val) {
return Math... | Give a code snippet in #JavaScript
Hamming numbers are numbers of the form
H = 2i × 3j × 5k
where
i, j, k ≥ 0
Hamming numbers are also known as ugly numbers and also 5-smooth numbers (numbers whose prime divisors are less or equal to 5).
Task
Generate the sequence of Hamming... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Determinant_and_permanent | Determinant and permanent | For a given matrix, return the determinant and the permanent of the matrix.
The determinant is given by
det
(
A
)
=
∑
σ
sgn
(
σ
)
∏
i
=
1
n
M
i
,
σ
i
{\displaystyle \det(A)=\sum _{\sigma }\operatorname {sgn}(\sigma )\prod _{i=1}^{n}M_{i,\sigma _{i}}}
while the permanent is given by
... | #JavaScript | JavaScript | const determinant = arr =>
arr.length === 1 ? (
arr[0][0]
) : arr[0].reduce(
(sum, v, i) => sum + v * (-1) ** i * determinant(
arr.slice(1)
.map(x => x.filter((_, j) => i !== j))
), 0
);
const permanent = arr =>
arr.length === 1 ? (
arr[0][0]
... | Give a code snippet in #JavaScript
For a given matrix, return the determinant and the permanent of the matrix.
The determinant is given by
det
(
A
)
=
∑
σ
sgn
(
σ
)
∏
i
=
1
n
M
i
,
σ
i
{\displaystyle \det(A)=\sum _{\sigma }\operatorname {sgn}(\sigma )\prod _{i=1}^{n}M_{i,\sigma _{i}}}
wh... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Fusc_sequence | Fusc sequence |
Definitions
The fusc integer sequence is defined as:
fusc(0) = 0
fusc(1) = 1
for n>1, the nth term is defined as:
if n is even; fusc(n) = fusc(n/2)
if n is odd; fusc(n) = fusc((n-1)/2) + fusc((n+1)/2)
Note that MathWorld's definition starts with unity, not zero. Th... | #Racket | Racket | #lang racket
(require racket/generator)
(define (memoize f)
(define table (make-hash))
(λ args (hash-ref! table args (thunk (apply f args)))))
(define fusc
(memoize
(λ (n)
(cond
[(<= n 1) n]
[(even? n) (fusc (/ n 2))]
[else (+ (fusc (/ (sub1 n) 2)) (fusc (/ (add1 n) 2)))]))))
... | Give a code snippet in #Racket
Definitions
The fusc integer sequence is defined as:
fusc(0) = 0
fusc(1) = 1
for n>1, the nth term is defined as:
if n is even; fusc(n) = fusc(n/2)
if n is odd; fusc(n) = fusc((n-1)/2) + fusc((n+1)/2)
Note that MathWorld's definition s... | christopher/rosetta-code | |
http://rosettacode.org/wiki/CRC-32 | CRC-32 |
Task
Demonstrate a method of deriving the Cyclic Redundancy Check from within the language.
The result should be in accordance with ISO 3309, ITU-T V.42, Gzip and PNG.
Algorithms are described on Computation of CRC in Wikipedia.
This variant of CRC-32 uses LSB-first order, sets the initial CRC to FFFFFFFF16, and... | #Objeck | Objeck | class CRC32 {
function : Main(args : String[]) ~ Nil {
"The quick brown fox jumps over the lazy dog"->ToByteArray()->CRC32()->PrintLine();
}
}
| Give a code snippet in #Objeck
Task
Demonstrate a method of deriving the Cyclic Redundancy Check from within the language.
The result should be in accordance with ISO 3309, ITU-T V.42, Gzip and PNG.
Algorithms are described on Computation of CRC in Wikipedia.
This variant of CRC-32 uses LSB-first order, sets th... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Terminal_control/Ringing_the_terminal_bell | Terminal control/Ringing the terminal bell |
Task
Make the terminal running the program ring its "bell".
On modern terminal emulators, this may be done by playing some other sound which might or might not be configurable, or by flashing the title bar or inverting the colors of the screen, but was classically a physical bell within the terminal. It is usua... | #C.2B.2B | C++ | #include <iostream>
int main() {
std::cout << "\a";
return 0;
} | Give a code snippet in #C.2B.2B
Task
Make the terminal running the program ring its "bell".
On modern terminal emulators, this may be done by playing some other sound which might or might not be configurable, or by flashing the title bar or inverting the colors of the screen, but was classically a physical bell ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Brazilian_numbers | Brazilian numbers | Brazilian numbers are so called as they were first formally presented at the 1994 math Olympiad Olimpiada Iberoamericana de Matematica in Fortaleza, Brazil.
Brazilian numbers are defined as:
The set of positive integer numbers where each number N has at least one natural number B where 1 < B < N-1 where the represent... | #Isabelle | Isabelle | theory Brazilian
imports Main
begin
function (sequential) base :: "nat ⇒ nat ⇒ nat list" where
"base n 0 = undefined"
| "base n (Suc 0) = replicate n 1"
| "base n b = (if n < b then [n]
else (base (n div b) b) @ [n mod b]
)"
by pat_completeness auto
termination base
apply(relation "... | Give a code snippet in #Isabelle
Brazilian numbers are so called as they were first formally presented at the 1994 math Olympiad Olimpiada Iberoamericana de Matematica in Fortaleza, Brazil.
Brazilian numbers are defined as:
The set of positive integer numbers where each number N has at least one natural number B whe... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Heronian_triangles | Heronian triangles | Hero's formula for the area of a triangle given the length of its three sides a, b, and c is given by:
A
=
s
(
s
−
a
)
(
s
−
b
)
(
s
−
c
)
,
{\displaystyle A={\sqrt {s(s-a)(s-b)(s-c)}},}
where s is half the perimeter of the triangle; that is,
s
=
a
+
b
+
c
2
.
{\displaystyle s... | #Elixir | Elixir | defmodule Heronian do
def triangle?(a,b,c) when a+b <= c, do: false
def triangle?(a,b,c) do
area = area(a,b,c)
area == round(area) and primitive?(a,b,c)
end
def area(a,b,c) do
s = (a + b + c) / 2
:math.sqrt(s * (s-a) * (s-b) * (s-c))
end
defp primitive?(a,b,c), do: gcd(gcd(a,b),c) == 1
... | Give a code snippet in #Elixir
Hero's formula for the area of a triangle given the length of its three sides a, b, and c is given by:
A
=
s
(
s
−
a
)
(
s
−
b
)
(
s
−
c
)
,
{\displaystyle A={\sqrt {s(s-a)(s-b)(s-c)}},}
where s is half the perimeter of the triangle; that is,
s
=
a
+... | 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
| #AutoHotkey | AutoHotkey | DllCall("AllocConsole")
FileAppend, please type something`n, CONOUT$
FileReadLine, line, CONIN$, 1
msgbox % line
FileAppend, please type '75000'`n, CONOUT$
FileReadLine, line, CONIN$, 1
msgbox % line | Give a code snippet in #AutoHotkey
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/Five_weekends | Five weekends | The month of October in 2010 has five Fridays, five Saturdays, and five Sundays.
Task
Write a program to show all months that have this same characteristic of five full weekends from the year 1900 through 2100 (Gregorian calendar).
Show the number of months with this property (there should be 201).
Show at leas... | #Maple | Maple | five_weekends:= proc()
local i, month, count;
#Only months with 31 days can possibly satisfy the condition
local long_months := [1,3,5,7,8,10,12];
local months := ["January","February","March","April","May","June","July","August","September","October","November","December"];
count := 0;
for i from 1900 to 2100 by... | Give a code snippet in #Maple
The month of October in 2010 has five Fridays, five Saturdays, and five Sundays.
Task
Write a program to show all months that have this same characteristic of five full weekends from the year 1900 through 2100 (Gregorian calendar).
Show the number of months with this property (ther... | 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 ... | #Lingo | Lingo | put "December 25 is a Sunday in:"
refDateObj = date(1905,1,2)
repeat with year = 2008 to 2121
dateObj = date(year, 12, 25)
dayOfWeek = ((dateObj - refDateObj) mod 7)+1 -- 1=Monday..7=Sunday
if dayOfWeek=7 then put year
end repeat | Give a code snippet in #Lingo
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 ... | 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
| #Robotic | Robotic | require 'gtk2'
window = Gtk::Window.new
window.title = 'Goodbye, World'
window.signal_connect(:delete-event) { Gtk.main_quit }
window.show_all
Gtk.main | Give a code snippet in #Robotic
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/Active_Directory/Search_for_a_user | Active Directory/Search for a user | Make sure you Connect to Active Directory
| #Java | Java | import java.io.IOException;
import org.apache.directory.api.ldap.model.cursor.CursorException;
import org.apache.directory.api.ldap.model.cursor.EntryCursor;
import org.apache.directory.api.ldap.model.entry.Entry;
import org.apache.directory.api.ldap.model.exception.LdapException;
import org.apache.directory.api.ldap.m... | Give a code snippet in #Java
Make sure you Connect to Active Directory
| christopher/rosetta-code |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.