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/Nested_function | Nested function | In many languages, functions can be nested, resulting in outer functions and inner functions. The inner function can access variables from the outer function. In most languages, the inner function can also modify variables in the outer function.
Task
Write a program consisting of two nested functions that prints t... | #Cowgol | Cowgol | include "cowgol.coh";
include "strings.coh";
sub MakeList(sep: [uint8], buf: [uint8]): (out: [uint8]) is
out := buf; # return begin of buffer for ease of use
var counter: uint32 := 0;
# Add item to string
sub AddStr(str: [uint8]) is
var length := StrLen(str);
MemCopy(str, length, buf... | Give a code snippet in #Cowgol
In many languages, functions can be nested, resulting in outer functions and inner functions. The inner function can access variables from the outer function. In most languages, the inner function can also modify variables in the outer function.
Task
Write a program consisting of tw... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Averages/Mode | Averages/Mode | Task[edit]
Write a program to find the mode value of a collection.
The case where the collection is empty may be ignored. Care must be taken to handle the case where the mode is non-unique.
If it is not appropriate or possible to support a general collection, use a vector (array), if possible. If it is not appropriat... | #F.23 | F# | let mode (l:'a seq) =
l
|> Seq.countBy (fun item -> item) // Count individual items
|> Seq.fold // Find max counts
(fun (cp, lst) (item, c) -> // State is (count, list of items with that count)
if c > cp then (c, [item]) ... | Give a code snippet in #F.23
Task[edit]
Write a program to find the mode value of a collection.
The case where the collection is empty may be ignored. Care must be taken to handle the case where the mode is non-unique.
If it is not appropriate or possible to support a general collection, use a vector (array), if pos... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Matrix_transposition | Matrix transposition | Transpose an arbitrarily sized rectangular Matrix.
| #IDL | IDL | m=[[1,1,1,1],[2, 4, 8, 16],[3, 9,27, 81],[5, 25,125, 625]]
print,transpose(m) | Give a code snippet in #IDL
Transpose an arbitrarily sized rectangular Matrix.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Substring/Top_and_tail | Substring/Top and tail | The task is to demonstrate how to remove the first and last characters from a string.
The solution should demonstrate how to obtain the following results:
String with first character removed
String with last character removed
String with both the first and last characters removed
If the program uses UTF-8 or UTF... | #Oforth | Oforth | : topAndTail(s)
s right(s size 1-) println
s left(s size 1-) println
s extract(2, s size 1- ) println ; | Give a code snippet in #Oforth
The task is to demonstrate how to remove the first and last characters from a string.
The solution should demonstrate how to obtain the following results:
String with first character removed
String with last character removed
String with both the first and last characters removed
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sum_of_a_series | Sum of a series | Compute the nth term of a series, i.e. the sum of the n first terms of the corresponding sequence.
Informally this value, or its limit when n tends to infinity, is also called the sum of the series, thus the title of this task.
For this task, use:
S
n
=
∑
k
=
1
n
1
k
2
{\displa... | #Octave | Octave | sum(1 ./ [1:1000] .^ 2) | Give a code snippet in #Octave
Compute the nth term of a series, i.e. the sum of the n first terms of the corresponding sequence.
Informally this value, or its limit when n tends to infinity, is also called the sum of the series, thus the title of this task.
For this task, use:
S
n
=
∑
k
=
... | 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... | #VBScript | VBScript | dim s
s = createobject("scripting.filesystemobject").opentextfile("slurp.vbs",1).readall
wscript.echo s | Give a code snippet in #VBScript
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 in... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Rosetta_Code/Find_bare_lang_tags | Rosetta Code/Find bare lang tags | Task
Find all <lang> tags without a language specified in the text of a page.
Display counts by language section:
Description
<lang>Pseudocode</lang>
=={{header|C}}==
<lang C>printf("Hello world!\n");</lang>
=={{header|Perl}}==
<lang>print "Hello world!\n"</lang>
should display something like
2 bare langu... | #Nim | Nim | import algorithm, htmlparser, httpclient, json
import sequtils, strformat, strscans, tables, times, xmltree
import strutils except escape
const
Rosorg = "http://rosettacode.org"
QUri = "/mw/api.php?action=query&list=categorymembers&cmtitle=Category:Programming_Tasks&cmlimit=500&format=json"
QdUri = "/mw/api.p... | Give a code snippet in #Nim
Task
Find all <lang> tags without a language specified in the text of a page.
Display counts by language section:
Description
<lang>Pseudocode</lang>
=={{header|C}}==
<lang C>printf("Hello world!\n");</lang>
=={{header|Perl}}==
<lang>print "Hello world!\n"</lang>
should display... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Assertions | Assertions | Assertions are a way of breaking out of code when there is an error or an unexpected input.
Some languages throw exceptions and some treat it as a break point.
Task
Show an assertion in your language by asserting that an integer variable is equal to 42.
| #Common_Lisp | Common Lisp | (let ((x 42))
(assert (and (integerp x) (= 42 x)) (x))) | Give a code snippet in #Common_Lisp
Assertions are a way of breaking out of code when there is an error or an unexpected input.
Some languages throw exceptions and some treat it as a break point.
Task
Show an assertion in your language by asserting that an integer variable is equal to 42.
| 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... | #C.2B.2B | C++ | #include <algorithm>
#include <cctype>
#include <string>
#include <iostream>
const std::string alphabet("abcdefghijklmnopqrstuvwxyz");
bool is_pangram(std::string s)
{
std::transform(s.begin(), s.end(), s.begin(), ::tolower);
std::sort(s.begin(), s.end());
return std::includes(s.begin(), s.end(), alphab... | Give a code snippet in #C.2B.2B
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
W... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Stream_merge | Stream merge | 2-stream merge
Read two sorted streams of items from external source (e.g. disk, or network), and write one stream of sorted items to external sink.
Common algorithm: keep 1 buffered item from each source, select minimal of them, write it, fetch another item from that stream from which the written item was.
N-strea... | #ATS | ATS |
(* ****** ****** *)
//
// This is a memory-clean implementation:
// Every byte of allocated memory is freed
// before the program exits.
//
(* ****** ****** *)
//
#include
"share/atspre_define.hats"
#include
"share/atspre_staload.hats"
//
(*
#include
"share/HATS/atspre_staload_libats_ML.hats"
*)
//
(* ****** ****** *... | Give a code snippet in #ATS
2-stream merge
Read two sorted streams of items from external source (e.g. disk, or network), and write one stream of sorted items to external sink.
Common algorithm: keep 1 buffered item from each source, select minimal of them, write it, fetch another item from that stream from which t... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Keyboard_input/Obtain_a_Y_or_N_response | Keyboard input/Obtain a Y or N response |
Task
Obtain a valid Y or N response from the keyboard.
The keyboard should be flushed, so that any outstanding key-presses are removed, preventing any existing Y or N key-press from being evaluated.
The response should be obtained as soon as Y or N are pressed, and there should be no need t... | #Scala | Scala | println(if (scala.io.StdIn.readBoolean) "Yes typed." else "Something else.") | Give a code snippet in #Scala
Task
Obtain a valid Y or N response from the keyboard.
The keyboard should be flushed, so that any outstanding key-presses are removed, preventing any existing Y or N key-press from being evaluated.
The response should be obtained as soon as Y or N are pressed... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sequence:_smallest_number_with_exactly_n_divisors | Sequence: smallest number with exactly n divisors | Calculate the sequence where each term an is the smallest natural number that has exactly n divisors.
Task
Show here, on this page, at least the first 15 terms of the sequence.
Related tasks
Sequence: smallest number greater than previous term with exactly n divisors
Sequence: nth number with exactly... | #Tcl | Tcl | proc divCount {n} {
set cnt 0
for {set d 1} {($d * $d) <= $n} {incr d} {
if {0 == ($n % $d)} {
incr cnt
if {$d < ($n / $d)} {
incr cnt
}
}
}
return $cnt
}
proc A005179 {n} {
if {$n >= 1} {
for {set k 1} {1} {incr k} {
... | Give a code snippet in #Tcl
Calculate the sequence where each term an is the smallest natural number that has exactly n divisors.
Task
Show here, on this page, at least the first 15 terms of the sequence.
Related tasks
Sequence: smallest number greater than previous term with exactly n divisors
Sequ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Anagrams | Anagrams | When two or more words are composed of the same characters, but in a different order, they are called anagrams.
Task[edit]
Using the word list at http://wiki.puzzlers.org/pub/wordlists/unixdict.txt,
find the sets of words that share the same characters that contain the most words in them.
Related tasks
Word plays
... | #EchoLisp | EchoLisp |
(require 'struct)
(require 'hash)
(require 'sql)
(require 'words)
(require 'dico.fr.no-accent)
(define mots-français (words-select #:any null 999999))
(string-delimiter "")
(define (string-sort str)
(list->string (list-sort string<? (string->list str))))
(define (ana-sort H words) ;; bump counter for each w... | Give a code snippet in #EchoLisp
When two or more words are composed of the same characters, but in a different order, they are called anagrams.
Task[edit]
Using the word list at http://wiki.puzzlers.org/pub/wordlists/unixdict.txt,
find the sets of words that share the same characters that contain the most words i... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Loops/Nested | Loops/Nested | Show a nested loop which searches a two-dimensional array filled with random numbers uniformly distributed over
[
1
,
…
,
20
]
{\displaystyle [1,\ldots ,20]}
.
The loops iterate rows and columns of the array printing the elements until the value
20
{\displaystyle 20}
is met.
Specifically, this task als... | #Phix | Phix | constant s = sq_rand(repeat(repeat(20,20),20))
integer found = 0
for i=1 to 20 do
for j=1 to 20 do
printf(1,"%d",s[i][j])
if s[i][j]=20 then
found = 1
exit
end if
printf(1,", ")
end for
printf(1,"\n")
if found then exit end if
end for
| Give a code snippet in #Phix
Show a nested loop which searches a two-dimensional array filled with random numbers uniformly distributed over
[
1
,
…
,
20
]
{\displaystyle [1,\ldots ,20]}
.
The loops iterate rows and columns of the array printing the elements until the value
20
{\displaystyle 20}
is met... | christopher/rosetta-code | |
http://rosettacode.org/wiki/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... | #PARI.2FGP | PARI/GP | str = concat(apply(s->concat(s,"\n"), readstr("file.txt"))) | Give a code snippet in #PARI.2FGP
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 i... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Assertions | Assertions | Assertions are a way of breaking out of code when there is an error or an unexpected input.
Some languages throw exceptions and some treat it as a break point.
Task
Show an assertion in your language by asserting that an integer variable is equal to 42.
| #PureBasic | PureBasic | Macro Assert(TEST,MSG="Assert: ")
CompilerIf #PB_Compiler_Debugger
If Not (TEST)
Debug MSG+" Line="+Str(#PB_Compiler_Line)+" in "+#PB_Compiler_File
CallDebugger
EndIf
CompilerEndIf
EndMacro | Give a code snippet in #PureBasic
Assertions are a way of breaking out of code when there is an error or an unexpected input.
Some languages throw exceptions and some treat it as a break point.
Task
Show an assertion in your language by asserting that an integer variable is equal to 42.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Compound_data_type | Compound data type |
Data Structure
This illustrates a data structure, a means of storing data within a program.
You may see other such structures in the Data Structures category.
Task
Create a compound data type:
Point(x,y)
A compound data type is one that holds multiple independent values.
Related task
Enumeration
S... | #VBA | VBA | Type point
x As Integer
y As Integer
End Type | Give a code snippet in #VBA
Data Structure
This illustrates a data structure, a means of storing data within a program.
You may see other such structures in the Data Structures category.
Task
Create a compound data type:
Point(x,y)
A compound data type is one that holds multiple independent values.
Rel... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Levenshtein_distance | Levenshtein distance |
This page uses content from Wikipedia. The original article was at Levenshtein distance. 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 information theory and computer science, the Levenshtein ... | #SequenceL | SequenceL |
import <Utilities/Sequence.sl>;
import <Utilities/Math.sl>;
main(args(2)) := LenenshteinDistance(args[1], args[2]);
LenenshteinDistance(s(1), t(1)) :=
0 when equalList(s,t) else
size(t) when size(s) = 0 else
size(s) when size(t) = 0 else
LenenshteinDistanceIterative(s, t, 0 ... size(t), duplicate(0, size(t) +... | Give a code snippet in #SequenceL
This page uses content from Wikipedia. The original article was at Levenshtein distance. 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 information theory and... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Catalan_numbers/Pascal%27s_triangle | Catalan numbers/Pascal's triangle | Task
Print out the first 15 Catalan numbers by extracting them from Pascal's triangle.
See
Catalan Numbers and the Pascal Triangle. This method enables calculation of Catalan Numbers using only addition and subtraction.
Catalan's Triangle for a Number Triangle that generates Catalan Numbers using onl... | #REXX | REXX | /*REXX program obtains and displays Catalan numbers from a Pascal's triangle. */
parse arg N . /*Obtain the optional argument from CL.*/
if N=='' | N=="," then N=15 /*Not specified? Then use the default.*/
numeric digits max(9, N%2 + N%8) ... | Give a code snippet in #REXX
Task
Print out the first 15 Catalan numbers by extracting them from Pascal's triangle.
See
Catalan Numbers and the Pascal Triangle. This method enables calculation of Catalan Numbers using only addition and subtraction.
Catalan's Triangle for a Number Triangle that gener... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Loops/For_with_a_specified_step | Loops/For with a specified step |
Task
Demonstrate a for-loop where the step-value is greater than one.
Related tasks
Loop over multiple arrays simultaneously
Loops/Break
Loops/Continue
Loops/Do-while
Loops/Downward for
Loops/For
Loops/For with a specified step
Loops/Foreach
Loops/Increment loop index within loop b... | #ColdFusion | ColdFusion |
<cfloop from="0" to="99" step="3" index="i">
<Cfoutput>#i#</Cfoutput>
</cfloop>
| Give a code snippet in #ColdFusion
Task
Demonstrate a for-loop where the step-value is greater than one.
Related tasks
Loop over multiple arrays simultaneously
Loops/Break
Loops/Continue
Loops/Do-while
Loops/Downward for
Loops/For
Loops/For with a specified step
Loops/Foreach
Loop... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Stirling_numbers_of_the_first_kind | Stirling numbers of the first kind | Stirling numbers of the first kind, or Stirling cycle numbers, count permutations according to their number
of cycles (counting fixed points as cycles of length one).
They may be defined directly to be the number of permutations of n
elements with k disjoint cycles.
Stirling numbers of the first kind express coeffici... | #Kotlin | Kotlin | import java.math.BigInteger
fun main() {
println("Unsigned Stirling numbers of the first kind:")
val max = 12
print("n/k")
for (n in 0..max) {
print("%10d".format(n))
}
println()
for (n in 0..max) {
print("%-3d".format(n))
for (k in 0..n) {
print("%10s".... | Give a code snippet in #Kotlin
Stirling numbers of the first kind, or Stirling cycle numbers, count permutations according to their number
of cycles (counting fixed points as cycles of length one).
They may be defined directly to be the number of permutations of n
elements with k disjoint cycles.
Stirling numbers of... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Generator/Exponential | Generator/Exponential | A generator is an executable entity (like a function or procedure) that contains code that yields a sequence of values, one at a time, so that each time you call the generator, the next value in the sequence is provided.
Generators are often built on top of coroutines or objects so that the internal state of the objec... | #PL.2FI | PL/I |
Generate: procedure options (main); /* 27 October 2013 */
declare j fixed binary;
declare r fixed binary;
/* Ignore the first 20 values */
do j = 1 to 20;
/* put edit (filter() ) (f(6)); */
r = filter ();
end;
put skip;
do j = 1 to 10;
... | Give a code snippet in #PL.2FI
A generator is an executable entity (like a function or procedure) that contains code that yields a sequence of values, one at a time, so that each time you call the generator, the next value in the sequence is provided.
Generators are often built on top of coroutines or objects so that... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Averages/Mean_time_of_day | Averages/Mean time of day | Task[edit]
A particular activity of bats occurs at these times of the day:
23:00:17, 23:40:20, 00:12:45, 00:17:19
Using the idea that there are twenty-four hours in a day,
which is analogous to there being 360 degrees in a circle,
map times of day to and from angles;
and using the ideas of Averages/Mean angle
compute ... | #Tcl | Tcl | proc meanTime {times} {
set secsPerRad [expr {60 * 60 * 12 / atan2(0,-1)}]
set sumSin [set sumCos 0.0]
foreach t $times {
# Convert time to count of seconds from midnight
scan $t "%02d:%02d:%02d" h m s
incr s [expr {[incr m [expr {$h * 60}]] * 60}]
# Feed into averaging
set sumSin [expr {$sumSin + sin(... | Give a code snippet in #Tcl
Task[edit]
A particular activity of bats occurs at these times of the day:
23:00:17, 23:40:20, 00:12:45, 00:17:19
Using the idea that there are twenty-four hours in a day,
which is analogous to there being 360 degrees in a circle,
map times of day to and from angles;
and using the ideas of... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Send_an_unknown_method_call | Send an unknown method call | Task
Invoke an object method where the name of the method to be invoked can be generated at run time.
Related tasks
Respond to an unknown method call.
Runtime evaluation
| #Clojure | Clojure |
(import '[java.util Date])
(import '[clojure.lang Reflector])
(def date1 (Date.))
(def date2 (Date.))
(def method "equals")
;; Two ways of invoking method "equals" on object date1
;; using date2 as argument
;; Way 1 - Using Reflector class
;; NOTE: The argument date2 is passed inside an array
(Reflector/invokeM... | Give a code snippet in #Clojure
Task
Invoke an object method where the name of the method to be invoked can be generated at run time.
Related tasks
Respond to an unknown method call.
Runtime evaluation
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Variable_size/Get | Variable size/Get | Demonstrate how to get the size of a variable.
See also: Host introspection
| #Mathematica.2FWolfram_Language | Mathematica/Wolfram Language | ByteCount["somerandomstring"] | Give a code snippet in #Mathematica.2FWolfram_Language
Demonstrate how to get the size of a variable.
See also: Host introspection
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Draw_a_sphere | Draw a sphere | Task
Draw a sphere.
The sphere can be represented graphically, or in ASCII art, depending on the language capabilities.
Either static or rotational projection is acceptable for this task.
Related tasks
draw a cuboid
draw a rotating cube
write language name in 3D ASCII
draw a Deathstar
| #Nim | Nim | import math
type Point = tuple[x,y,z: float]
const shades = ".:!*oe&#%@"
proc normalize(x, y, z: float): Point =
let len = sqrt(x*x + y*y + z*z)
(x / len, y / len, z / len)
proc dot(a, b: Point): float =
result = max(0, - a.x*b.x - a.y*b.y - a.z*b.z)
let light = normalize(30.0, 30.0, -50.0)
proc drawS... | Give a code snippet in #Nim
Task
Draw a sphere.
The sphere can be represented graphically, or in ASCII art, depending on the language capabilities.
Either static or rotational projection is acceptable for this task.
Related tasks
draw a cuboid
draw a rotating cube
write language name in 3D ASCII
draw a Deat... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Find_largest_left_truncatable_prime_in_a_given_base | Find largest left truncatable prime in a given base | A truncatable prime is one where all non-empty substrings that finish at the end of the number (right-substrings) are also primes when understood as numbers in a particular base. The largest such prime in a given (integer) base is therefore computable, provided the base is larger than 2.
Let's consider what happens in... | #Sidef | Sidef | func lltp(n) {
var b = 1
var best = nil
var v = (n-1 -> primes)
while (v) {
best = v.max
b *= n
v.map! { |vi|
{|i| i*b + vi }.map(1..^n).grep{.is_prime}...
}
}
return best
}
for i in (3..17) {
printf("%2d %s\n", i, lltp(i))
} | Give a code snippet in #Sidef
A truncatable prime is one where all non-empty substrings that finish at the end of the number (right-substrings) are also primes when understood as numbers in a particular base. The largest such prime in a given (integer) base is therefore computable, provided the base is larger than 2.
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Balanced_ternary | Balanced ternary | Balanced ternary is a way of representing numbers. Unlike the prevailing binary representation, a balanced ternary integer is in base 3, and each digit can have the values 1, 0, or −1.
Examples
Decimal 11 = 32 + 31 − 30, thus it can be written as "++−"
Decimal 6 = 32 − 31 + 0 × 30, thus it can be written as "+−0"
... | #Liberty_BASIC | Liberty BASIC |
global tt$
tt$="-0+" '-1 0 1; +2 -> 1 2 3, instr
'Test case:
'With balanced ternaries a from string "+-0++0+", b from native integer -436, c "+-++-":
'* write out a, b and c in decimal notation;
'* calculate a * (b - c), write out the result in both ternary and decimal notations.
a$="+-0++0+"
a=deci(a$)
print "... | Give a code snippet in #Liberty_BASIC
Balanced ternary is a way of representing numbers. Unlike the prevailing binary representation, a balanced ternary integer is in base 3, and each digit can have the values 1, 0, or −1.
Examples
Decimal 11 = 32 + 31 − 30, thus it can be written as "++−"
Decimal 6 = 32 − 31 + 0... | christopher/rosetta-code | |
http://rosettacode.org/wiki/String_matching | String matching |
Basic Data Operation
This is a basic data operation. It represents a fundamental action on a basic data type.
You may see other such operations in the Basic Data Operations category, or:
Integer Operations
Arithmetic |
Comparison
Boolean Operations
Bitwise |
Logical
String Operations
Concatenation |
Interpolation |... | #QB64 | QB64 |
DefStr S
DefInt P
string2 = "dogs"
string1 = "dogs and cats are often enemies,because dogs are stronger than cats, but cats sometimes can be friend to dogs"
position = 0
pcount = 0
Print "Searching "; string2; " into "; string1
While (InStr(position, string1, string2) > 0)
position = InStr(position + 1, string1, ... | Give a code snippet in #QB64
Basic Data Operation
This is a basic data operation. It represents a fundamental action on a basic data type.
You may see other such operations in the Basic Data Operations category, or:
Integer Operations
Arithmetic |
Comparison
Boolean Operations
Bitwise |
Logical
String Operations
C... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Bitcoin/public_point_to_address | Bitcoin/public point to address | Bitcoin uses a specific encoding format to encode the digest of an elliptic curve public point into a short ASCII string. The purpose of this task is to perform such a conversion.
The encoding steps are:
take the X and Y coordinates of the given public point, and concatenate them in order to have a 64 byte-longed st... | #Delphi | Delphi |
program Public_point_to_address;
{$APPTYPE CONSOLE}
uses
System.SysUtils,
Winapi.Windows,
DCPsha256,
DCPripemd160;
const
bitcoinVersion = 0;
type
TByteArray = array of Byte;
TA25 = TByteArray;
TPPoint = record
x, y: TByteArray;
constructor SetHex(xi, yi: ansistring);
end;
TA2... | Give a code snippet in #Delphi
Bitcoin uses a specific encoding format to encode the digest of an elliptic curve public point into a short ASCII string. The purpose of this task is to perform such a conversion.
The encoding steps are:
take the X and Y coordinates of the given public point, and concatenate them in o... | christopher/rosetta-code | |
http://rosettacode.org/wiki/CSV_data_manipulation | CSV data manipulation | CSV spreadsheet files are suitable for storing tabular data in a relatively portable way.
The CSV format is flexible but somewhat ill-defined.
For present purposes, authors may assume that the data fields contain no commas, backslashes, or quotation marks.
Task
Read a CSV file, change some values and save the cha... | #Rust | Rust | use std::error::Error;
use std::num::ParseIntError;
use csv::{Reader, Writer};
fn main() -> Result<(), Box<dyn Error>> {
let mut reader = Reader::from_path("data.csv")?;
let mut writer = Writer::from_path("output.csv")?;
// headers() returns an immutable reference, so clone() before appending
let mu... | Give a code snippet in #Rust
CSV spreadsheet files are suitable for storing tabular data in a relatively portable way.
The CSV format is flexible but somewhat ill-defined.
For present purposes, authors may assume that the data fields contain no commas, backslashes, or quotation marks.
Task
Read a CSV file, chang... | christopher/rosetta-code | |
http://rosettacode.org/wiki/N-smooth_numbers | N-smooth numbers | n-smooth numbers are positive integers which have no prime factors > n.
The n (when using it in the expression) n-smooth is always prime,
there are no 9-smooth numbers.
1 (unity) is always included in n-smooth numbers.
2-smooth numbers are non-negative powers of two.
5-smooth numbers are... | #Julia | Julia | using Primes
function nsmooth(N, needed)
nexts, smooths = [BigInt(i) for i in 2:N if isprime(i)], [BigInt(1)]
prim, count = deepcopy(nexts), 1
indices = ones(Int, length(nexts))
while count < needed
x = minimum(nexts)
push!(smooths, x)
count += 1
for j in 1:length(nexts... | Give a code snippet in #Julia
n-smooth numbers are positive integers which have no prime factors > n.
The n (when using it in the expression) n-smooth is always prime,
there are no 9-smooth numbers.
1 (unity) is always included in n-smooth numbers.
2-smooth numbers are non-negative powers ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Cheryl%27s_birthday | Cheryl's birthday | Albert and Bernard just became friends with Cheryl, and they want to know when her birthday is.
Cheryl gave them a list of ten possible dates:
May 15, May 16, May 19
June 17, June 18
July 14, July 16
August 14, August 15, August 17
Cheryl then tells Albert the month of birth, ... | #Arturo | Arturo | dates: [
[May 15] [May 16] [May 19]
[June 17] [June 18]
[July 14] [July 16]
[August 14] [August 15] [August 17]
]
print ["possible dates:" dates]
print "\n(1) Albert: I don't know when Cheryl's birthday is, but I know that Bernard does not know too."
print "\t-> meaning: the month cannot have a uniq... | Give a code snippet in #Arturo
Albert and Bernard just became friends with Cheryl, and they want to know when her birthday is.
Cheryl gave them a list of ten possible dates:
May 15, May 16, May 19
June 17, June 18
July 14, July 16
August 14, August 15, August 17
Cheryl then tells... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Musical_scale | Musical scale | Task
Output the 8 notes of the C major diatonic scale to the default musical sound device on the system. Specifically, pitch must be tuned to 12-tone equal temperament (12TET) with the modern standard A=440Hz.
These are the notes "C, D, E, F, G, A, B, C(1 octave higher)", or "Do, Re, Mi, Fa, Sol, La, Si/Ti, Do(1 octa... | #R | R |
install.packages("audio")
library(audio)
hz=c(1635,1835,2060,2183,2450,2750,3087,3270)
for (i in 1:8){
play(audioSample(sin(1:1000), hz[i]))
Sys.sleep(.7)
}
| Give a code snippet in #R
Task
Output the 8 notes of the C major diatonic scale to the default musical sound device on the system. Specifically, pitch must be tuned to 12-tone equal temperament (12TET) with the modern standard A=440Hz.
These are the notes "C, D, E, F, G, A, B, C(1 octave higher)", or "Do, Re, Mi, Fa... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Literals/Integer | Literals/Integer | Some programming languages have ways of expressing integer literals in bases other than the normal base ten.
Task
Show how integer literals can be expressed in as many bases as your language allows.
Note: this should not involve the calling of any functions/methods, but should be interpreted by the compiler or... | #AmigaE | AmigaE | PROC main()
IF ($2d7 = 727) AND (%001011010111 = 727) THEN WriteF('true\n')
ENDPROC | Give a code snippet in #AmigaE
Some programming languages have ways of expressing integer literals in bases other than the normal base ten.
Task
Show how integer literals can be expressed in as many bases as your language allows.
Note: this should not involve the calling of any functions/methods, but should b... | christopher/rosetta-code | |
http://rosettacode.org/wiki/One_of_n_lines_in_a_file | One of n lines in a file | A method of choosing a line randomly from a file:
Without reading the file more than once
When substantial parts of the file cannot be held in memory
Without knowing how many lines are in the file
Is to:
keep the first line of the file as a possible choice, then
Read the second line of the file if possible and m... | #11l | 11l | F one_of_n(lines)
V choice = 0
L(line) lines
I random:(0..L.index) == 0
choice = line
R choice
F one_of_n_test(n = 10, trials = 1000000)
V bins = [0] * n
I n != 0
L 1..trials
bins[one_of_n(0 .< n)]++
R bins
print(one_of_n_test()) | Give a code snippet in #11l
A method of choosing a line randomly from a file:
Without reading the file more than once
When substantial parts of the file cannot be held in memory
Without knowing how many lines are in the file
Is to:
keep the first line of the file as a possible choice, then
Read the second line ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Table_creation/Postal_addresses | Table creation/Postal addresses | Task
Create a table to store addresses.
You may assume that all the addresses to be stored will be located in the USA. As such, you will need (in addition to a field holding a unique identifier) a field holding the street address, a field holding the city, a field holding the state code, and a field holding the zip... | #Perl | Perl | use DBI;
my $db = DBI->connect('DBI:mysql:database:server','login','password');
my $statment = <<EOF;
CREATE TABLE `Address` (
`addrID` int(11) NOT NULL auto_increment,
`addrStreet` varchar(50) NOT NULL default '',
`addrCity` varchar(25) NOT NULL default '',
`addrState` char... | Give a code snippet in #Perl
Task
Create a table to store addresses.
You may assume that all the addresses to be stored will be located in the USA. As such, you will need (in addition to a field holding a unique identifier) a field holding the street address, a field holding the city, a field holding the state cod... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Dragon_curve | Dragon curve |
Create and display a dragon curve fractal.
(You may either display the curve directly or write it to an image file.)
Algorithms
Here are some brief notes the algorithms used and how they might suit various languages.
Recursively a right curling dragon is a right dragon followed by a left dragon, at 90-degree an... | #X86_Assembly | X86 Assembly | .model tiny
.code
.486
org 100h ;assume ax=0, bx=0, sp=-2
start: mov al, 13h ;(ah=0) set 320x200 video graphics mode
int 10h
push 0A000h
pop es
mov si, 8000h ;color
mov cx, 75*256+100 ;coordi... | Give a code snippet in #X86_Assembly
Create and display a dragon curve fractal.
(You may either display the curve directly or write it to an image file.)
Algorithms
Here are some brief notes the algorithms used and how they might suit various languages.
Recursively a right curling dragon is a right dragon foll... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Roman_numerals/Decode | Roman numerals/Decode | Task
Create a function that takes a Roman numeral as its argument and returns its value as a numeric decimal integer.
You don't need to validate the form of the Roman numeral.
Modern Roman numerals are written by expressing each decimal digit of the number to be encoded separately,
starting with the leftmost decima... | #Swift | Swift | extension Int {
init(romanNumerals: String) {
let values = [
( "M", 1000),
("CM", 900),
( "D", 500),
("CD", 400),
( "C", 100),
("XC", 90),
( "L", 50),
("XL", 40),
( "X", 10),
(... | Give a code snippet in #Swift
Task
Create a function that takes a Roman numeral as its argument and returns its value as a numeric decimal integer.
You don't need to validate the form of the Roman numeral.
Modern Roman numerals are written by expressing each decimal digit of the number to be encoded separately,
st... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Hostname | Hostname | Task
Find the name of the host on which the routine is running.
| #Slate | Slate | Platform current nodeName | Give a code snippet in #Slate
Task
Find the name of the host on which the routine is running.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Conway%27s_Game_of_Life | Conway's Game of Life | The Game of Life is a cellular automaton devised by the British mathematician John Horton Conway in 1970. It is the best-known example of a cellular automaton.
Conway's game of life is described here:
A cell C is represented by a 1 when alive, or 0 when dead, in an m-by-m (or m×m) sq... | #FunL | FunL | import lists.zipWithIndex
import util.Regex
data Rule( birth, survival )
val Mirek = Regex( '([0-8]+)/([0-8]+)' )
val Golly = Regex( 'B([0-8]+)/S([0-8]+)' )
def decode( rule ) =
def makerule( b, s ) = Rule( [int(d) | d <- b], [int(d) | d <- s] )
case rule
Mirek( s, b ) -> makerule( b, s )
Golly( b, ... | Give a code snippet in #FunL
The Game of Life is a cellular automaton devised by the British mathematician John Horton Conway in 1970. It is the best-known example of a cellular automaton.
Conway's game of life is described here:
A cell C is represented by a 1 when alive, or 0 when dead, ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Averages/Mean_time_of_day | Averages/Mean time of day | Task[edit]
A particular activity of bats occurs at these times of the day:
23:00:17, 23:40:20, 00:12:45, 00:17:19
Using the idea that there are twenty-four hours in a day,
which is analogous to there being 360 degrees in a circle,
map times of day to and from angles;
and using the ideas of Averages/Mean angle
compute ... | #AutoHotkey | AutoHotkey | MsgBox, % "The mean time is: " MeanTime(["23:00:17", "23:40:20", "00:12:45", "00:17:19"])
MeanTime(t, x=0, y=0) {
static c := ATan(1) / 45
for k, v in t {
n := StrSplit(v, ":")
r := c * (n[1] * 3600 + n[2] * 60 + n[3]) / 240
x += Cos(r)
y += Sin(r)
}
r := atan2(x, y) / c
r := (r < 0 ? r + 360 : r) / 15
... | Give a code snippet in #AutoHotkey
Task[edit]
A particular activity of bats occurs at these times of the day:
23:00:17, 23:40:20, 00:12:45, 00:17:19
Using the idea that there are twenty-four hours in a day,
which is analogous to there being 360 degrees in a circle,
map times of day to and from angles;
and using the i... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Equilibrium_index | Equilibrium index | An equilibrium index of a sequence is an index into the sequence such that the sum of elements at lower indices is equal to the sum of elements at higher indices.
For example, in a sequence
A
{\displaystyle A}
:
A
0
=
−
7
{\displaystyle A_{0}=-7}
A
1
=
1
{\displaystyle A_{1}=1}
... | #Go | Go | package main
import (
"fmt"
"math/rand"
"time"
)
func main() {
fmt.Println(ex([]int32{-7, 1, 5, 2, -4, 3, 0}))
// sequence of 1,000,000 random numbers, with values
// chosen so that it will be likely to have a couple
// of equalibrium indexes.
rand.Seed(time.Now().UnixNano())
v... | Give a code snippet in #Go
An equilibrium index of a sequence is an index into the sequence such that the sum of elements at lower indices is equal to the sum of elements at higher indices.
For example, in a sequence
A
{\displaystyle A}
:
A
0
=
−
7
{\displaystyle A_{0}=-7}
A
1
=
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/4-rings_or_4-squares_puzzle | 4-rings or 4-squares puzzle | 4-rings or 4-squares puzzle
You are encouraged to solve this task according to the task description, using any language you may know.
Task
Replace a, b, c, d, e, f, and
g with the decimal
digits LOW ───► HIGH
such that the sum of the letters inside of each of the four large squares add up to
t... | #Mathematica.2FWolfram_Language | Mathematica/Wolfram Language | {low, high} = {1, 7};
SolveValues[{a + b == b + c + d == d + e + f == f + g, low <= a <= high,
low <= b <= high, low <= c <= high, low <= d <= high,
low <= e <= high, low <= f <= high, low <= g <= high,
a != b != c != d != e != f != g}, {a, b, c, d, e, f, g}, Integers]
{low, high} = {3, 9};
SolveValues[{a + ... | Give a code snippet in #Mathematica.2FWolfram_Language
4-rings or 4-squares puzzle
You are encouraged to solve this task according to the task description, using any language you may know.
Task
Replace a, b, c, d, e, f, and
g with the decimal
digits LOW ───► HIGH
such that the sum of the lett... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sum_of_a_series | Sum of a series | Compute the nth term of a series, i.e. the sum of the n first terms of the corresponding sequence.
Informally this value, or its limit when n tends to infinity, is also called the sum of the series, thus the title of this task.
For this task, use:
S
n
=
∑
k
=
1
n
1
k
2
{\displa... | #Factor | Factor | 1000 [1,b] [ >float sq recip ] map-sum | Give a code snippet in #Factor
Compute the nth term of a series, i.e. the sum of the n first terms of the corresponding sequence.
Informally this value, or its limit when n tends to infinity, is also called the sum of the series, thus the title of this task.
For this task, use:
S
n
=
∑
k
=
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Active_Directory/Connect | Active Directory/Connect | The task is to establish a connection to an Active Directory or Lightweight Directory Access Protocol server.
| #Wren | Wren | /* active_directory_connect.wren */
foreign class LDAP {
construct init(host, port) {}
foreign simpleBindS(name, password)
foreign unbind()
}
class C {
foreign static getInput(maxSize)
}
var name = ""
while (name == "") {
System.write("Enter name : ")
name = C.getInput(40)
}
var pass... | Give a code snippet in #Wren
The task is to establish a connection to an Active Directory or Lightweight Directory Access Protocol server.
| 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
... | #Python | Python | def bubble_sort(seq):
"""Inefficiently sort the mutable sequence (list) in place.
seq MUST BE A MUTABLE SEQUENCE.
As with list.sort() and random.shuffle this does NOT return
"""
changed = True
while changed:
changed = False
for i in range(len(seq) - 1):
if se... | Give a code snippet in #Python
Sorting Algorithm
This is a sorting algorithm. It may be applied to a set of data in order to sort it.
For comparing various sorts, see compare sorts.
For other sorting algorithms, see sorting algorithms, or:
O(n logn) sorts
Heap sort |
Merge sort |
Patience sort |
Quick s... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Dijkstra%27s_algorithm | Dijkstra's algorithm | This task has been clarified. Its programming examples are in need of review to ensure that they still fit the requirements of the task.
Dijkstra's algorithm, conceived by Dutch computer scientist Edsger Dijkstra in 1956 and published in 1959, is a graph search algorithm that solves the single-source shortest path pro... | #AutoHotkey | AutoHotkey | Dijkstra(data, start){
nodes := [], dist := [], Distance := [], dist := [], prev := [], Q := [], min := "x"
for each, line in StrSplit(data, "`n" , "`r")
field := StrSplit(line,"`t"), nodes[field.1] := 1, nodes[field.2] := 1
, Distance[field.1,field.2] := field.3, Distance[field.2,field.1] := field.3
dist[start]... | Give a code snippet in #AutoHotkey
This task has been clarified. Its programming examples are in need of review to ensure that they still fit the requirements of the task.
Dijkstra's algorithm, conceived by Dutch computer scientist Edsger Dijkstra in 1956 and published in 1959, is a graph search algorithm that solves... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Padovan_n-step_number_sequences | Padovan n-step number sequences | As the Fibonacci sequence expands to the Fibonacci n-step number sequences; We similarly expand the Padovan sequence to form these Padovan n-step number sequences.
The Fibonacci-like sequences can be defined like this:
For n == 2:
start: 1, 1
Recurrence: R(n, x) = R(n, x-1) + R(n, x-2); for n ==... | #AppleScript | AppleScript | use AppleScript version "2.4"
use framework "Foundation"
use scripting additions
------------------ PADOVAN N-STEP NUMBERS ----------------
-- padovans :: [Int]
on padovans(n)
script recurrence
on |λ|(xs)
{item 1 of xs, ¬
rest of xs & {sum(take(n, xs)) as integer}}
en... | Give a code snippet in #AppleScript
As the Fibonacci sequence expands to the Fibonacci n-step number sequences; We similarly expand the Padovan sequence to form these Padovan n-step number sequences.
The Fibonacci-like sequences can be defined like this:
For n == 2:
start: 1, 1
Recurrence: R(n,... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Factorial | Factorial | Definitions
The factorial of 0 (zero) is defined as being 1 (unity).
The Factorial Function of a positive integer, n, is defined as the product of the sequence:
n, n-1, n-2, ... 1
Task
Write a function to return the factorial of a number.
Solutions can be iterat... | #Kotlin | Kotlin | fun facti(n: Int) = when {
n < 0 -> throw IllegalArgumentException("negative numbers not allowed")
else -> {
var ans = 1L
for (i in 2..n) ans *= i
ans
}
}
fun factr(n: Int): Long = when {
n < 0 -> throw IllegalArgumentException("negative numbers not allowed")
n < 2 -> 1L
... | Give a code snippet in #Kotlin
Definitions
The factorial of 0 (zero) is defined as being 1 (unity).
The Factorial Function of a positive integer, n, is defined as the product of the sequence:
n, n-1, n-2, ... 1
Task
Write a function to return the factorial of a ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Read_a_file_line_by_line | Read a file line by line | Read a file one line at a time,
as opposed to reading the entire file at once.
Related tasks
Read a file character by character
Input loop.
| #Frink | Frink |
for line = lines["file:yourfile.txt"]
println[line]
| Give a code snippet in #Frink
Read a file one line at a time,
as opposed to reading the entire file at once.
Related tasks
Read a file character by character
Input loop.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Integer_comparison | Integer comparison |
Basic Data Operation
This is a basic data operation. It represents a fundamental action on a basic data type.
You may see other such operations in the Basic Data Operations category, or:
Integer Operations
Arithmetic |
Comparison
Boolean Operations
Bitwise |
Logical
String Operations
Concatenation |
Interpolation |... | #J | J | compare=: < , = , >
cti=: dyad define
select =. ;@#
English =. ' is less than ';' is equal to ';' is greater than '
x (":@[, (compare select English"_), ":@]) y
) | Give a code snippet in #J
Basic Data Operation
This is a basic data operation. It represents a fundamental action on a basic data type.
You may see other such operations in the Basic Data Operations category, or:
Integer Operations
Arithmetic |
Comparison
Boolean Operations
Bitwise |
Logical
String Operations
Conc... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Superpermutation_minimisation | Superpermutation minimisation | A superpermutation of N different characters is a string consisting of an arrangement of multiple copies of those N different characters in which every permutation of those characters can be found as a substring.
For example, representing the characters as A..Z, using N=2 we choose to use the first two characters 'AB'... | #Groovy | Groovy | import static java.util.stream.IntStream.rangeClosed
class Superpermutation {
final static int nMax = 12
static char[] superperm
static int pos
static int[] count = new int[nMax]
static int factSum(int n) {
return rangeClosed(1, n)
.map({ m -> rangeClosed(1, m).reduce(1, { ... | Give a code snippet in #Groovy
A superpermutation of N different characters is a string consisting of an arrangement of multiple copies of those N different characters in which every permutation of those characters can be found as a substring.
For example, representing the characters as A..Z, using N=2 we choose to u... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Jump_anywhere | Jump anywhere | Imperative programs
conditional structures
loops
local jumps
This task is to demonstrate a local jump and a global jump and the various other types of jumps that the language supports.
For the purpose of this task, the jumps need not be used for a single purpose and you have the freedom to use these jumps for different... | #Forth | Forth | \ this prints five lines containing elements from the two
\ words 'proc1' and 'proc2'. gotos are used here to jump
\ into and out of the two words at various points, as well
\ as to create a loop. this functions with ficl, pfe,
\ gforth, bigforth, swiftforth, iforth, and vfxforth; it
\ may work with other forths as wel... | Give a code snippet in #Forth
Imperative programs
conditional structures
loops
local jumps
This task is to demonstrate a local jump and a global jump and the various other types of jumps that the language supports.
For the purpose of this task, the jumps need not be used for a single purpose and you have the freedom t... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Record_sound | Record sound | Record a monophonic 16-bit PCM sound into either memory space, a file or array.
(This task neglects to specify the sample rate, and whether to use signed samples.
The programs in this page might use signed 16-bit or unsigned 16-bit samples, at 8000 Hz, 44100 Hz, or any other sample rate.
Therefore, these programs migh... | #ChucK | ChucK | // chuck this with other shreds to record to file
// example> chuck foo.ck bar.ck rec
// arguments: rec:<filename>
// get name
me.arg(0) => string filename;
if( filename.length() == 0 ) "foo.wav" => filename;
// pull samples from the dac
dac => Gain g => WvOut w => blackhole;
// this is the output file name
file... | Give a code snippet in #ChucK
Record a monophonic 16-bit PCM sound into either memory space, a file or array.
(This task neglects to specify the sample rate, and whether to use signed samples.
The programs in this page might use signed 16-bit or unsigned 16-bit samples, at 8000 Hz, 44100 Hz, or any other sample rate.... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Associative_array/Creation | Associative array/Creation | Task
The goal is to create an associative array (also known as a dictionary, map, or hash).
Related tasks:
Associative arrays/Iteration
Hash from two arrays
See also
Array
Associative array: Creation, Iteration
Collections
Compound data type
Doubly-linked list: Definition, Element definition, Element ins... | #Mathematica_.2F_Wolfram_Language | Mathematica / Wolfram Language | a[2] = "string"; a["sometext"] = 23; | Give a code snippet in #Mathematica_.2F_Wolfram_Language
Task
The goal is to create an associative array (also known as a dictionary, map, or hash).
Related tasks:
Associative arrays/Iteration
Hash from two arrays
See also
Array
Associative array: Creation, Iteration
Collections
Compound data type
Doubl... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sorting_algorithms/Gnome_sort | Sorting algorithms/Gnome sort |
Sorting Algorithm
This is a sorting algorithm. It may be applied to a set of data in order to sort it.
For comparing various sorts, see compare sorts.
For other sorting algorithms, see sorting algorithms, or:
O(n logn) sorts
Heap sort |
Merge sort |
Patience sort |
Quick sort
O(n log2n) sorts
Shell Sort
... | #Julia | Julia | function gnomesort!(arr::Vector)
i, j = 1, 2
while i < length(arr)
if arr[i] ≤ arr[i+1]
i = j
j += 1
else
arr[i], arr[i+1] = arr[i+1], arr[i]
i -= 1
if i == 0
i = j
j += 1
end
end
... | Give a code snippet in #Julia
Sorting Algorithm
This is a sorting algorithm. It may be applied to a set of data in order to sort it.
For comparing various sorts, see compare sorts.
For other sorting algorithms, see sorting algorithms, or:
O(n logn) sorts
Heap sort |
Merge sort |
Patience sort |
Quick so... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Check_input_device_is_a_terminal | Check input device is a terminal | Task
Demonstrate how to check whether the input device is a terminal or not.
Related task
Check output device is a terminal
| #Perl | Perl | use strict;
use warnings;
use 5.010;
if (-t) {
say "Input comes from tty.";
}
else {
say "Input doesn't come from tty.";
} | Give a code snippet in #Perl
Task
Demonstrate how to check whether the input device is a terminal or not.
Related task
Check output device is a terminal
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Guess_the_number | Guess the number | Task
Write a program where the program chooses a number between 1 and 10.
A player is then prompted to enter a guess. If the player guesses wrong, then the prompt appears again until the guess is correct.
When the player has made a successful guess the computer will issue a "Well guessed!" message, a... | #Picat | Picat | go =>
N = random(1,10),
do print("Guess a number: ")
while (read_int() != N),
println("Well guessed!"). | Give a code snippet in #Picat
Task
Write a program where the program chooses a number between 1 and 10.
A player is then prompted to enter a guess. If the player guesses wrong, then the prompt appears again until the guess is correct.
When the player has made a successful guess the computer will issue a ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Strip_a_set_of_characters_from_a_string | Strip a set of characters from a string | Task
Create a function that strips a set of characters from a string.
The function should take two arguments:
a string to be stripped
a string containing the set of characters to be stripped
The returned string should contain the first string, stripped of any characters in the second argument:
print str... | #Frink | Frink | stripchars[str, remove] :=
{
set = toSet[chars[remove]]
return char[remove[char[str], {|c, set| set.contains[c]}, set]]
}
println[stripchars["She was a soul stripper. She took my heart!","aei"]]
| Give a code snippet in #Frink
Task
Create a function that strips a set of characters from a string.
The function should take two arguments:
a string to be stripped
a string containing the set of characters to be stripped
The returned string should contain the first string, stripped of any characters in t... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Polymorphic_copy | Polymorphic copy | An object is polymorphic when its specific type may vary.
The types a specific value may take, is called class.
It is trivial to copy an object if its type is known:
int x;
int y = x;
Here x is not polymorphic, so y is declared of same type (int) as x.
But if the specific type of x were unknown, then y could not be d... | #OCaml | OCaml | let obj1 =
object
method name = "T"
end
let obj2 =
object
method name = "S"
end
let () =
print_endline (Oo.copy obj1)#name; (* prints "T" *)
print_endline (Oo.copy obj2)#name; (* prints "S" *) | Give a code snippet in #OCaml
An object is polymorphic when its specific type may vary.
The types a specific value may take, is called class.
It is trivial to copy an object if its type is known:
int x;
int y = x;
Here x is not polymorphic, so y is declared of same type (int) as x.
But if the specific type of x were... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Priority_queue | Priority queue | A priority queue is somewhat similar to a queue, with an important distinction: each item is added to a priority queue with a priority level, and will be later removed from the queue with the highest priority element first. That is, the items are (conceptually) stored in the queue in priority order instead of in insert... | #VBA | VBA | Type Tuple
Priority As Integer
Data As String
End Type
Dim a() As Tuple
Dim n As Integer 'number of elements in array, last element is n-1
Private Function Left(i As Integer) As Integer
Left = 2 * i + 1
End Function
Private Function Right(i As Integer) As Integer
Right = 2 * i + 2
End Function
Private F... | Give a code snippet in #VBA
A priority queue is somewhat similar to a queue, with an important distinction: each item is added to a priority queue with a priority level, and will be later removed from the queue with the highest priority element first. That is, the items are (conceptually) stored in the queue in priori... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Retrieve_and_search_chat_history | Retrieve and search chat history | Task
Summary: Find and print the mentions of a given string in the recent chat logs from a chatroom. Only use your programming language's standard library.
Details:
The Tcl Chatroom is an online chatroom. Its conversations are logged. It's useful to know if someone has mentioned you or your project in the chatroom r... | #Elixir | Elixir | #! /usr/bin/env elixir
defmodule Mentions do
def get(url) do
{:ok, {{_, 200, _}, _, body}} =
url
|> String.to_charlist()
|> :httpc.request()
data = List.to_string(body)
if Regex.match?(~r|<!Doctype HTML.*<Title>URL Not Found</Title>|s, data) do
{:error, "log file not found"}
el... | Give a code snippet in #Elixir
Task
Summary: Find and print the mentions of a given string in the recent chat logs from a chatroom. Only use your programming language's standard library.
Details:
The Tcl Chatroom is an online chatroom. Its conversations are logged. It's useful to know if someone has mentioned you o... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Variables | Variables | Task
Demonstrate a language's methods of:
variable declaration
initialization
assignment
datatypes
scope
referencing, and
other variable related facilities
| #ALGOL_W | ALGOL W | % declare some variables %
integer a1, a2; real b; long real c; complex d; long complex f;
logical g; bits h; string(32) j;
% assign "initial values" %
f := d := c := b := a2 := a1 := 0; % multiple assignment %
g := false; h := #a0; j := "Hello, World!";
| Give a code snippet in #ALGOL_W
Task
Demonstrate a language's methods of:
variable declaration
initialization
assignment
datatypes
scope
referencing, and
other variable related facilities
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Flipping_bits_game | Flipping bits game | The game
Given an N×N square array of zeroes or ones in an initial configuration, and a target configuration of zeroes and ones.
The game is to transform one to the other in as few moves as possible by inverting whole numbered rows or whole lettered
columns at once (as one move).
In an inversion. any 1 ... | #Maple | Maple | FlippingBits := module()
export ModuleApply;
local gameSetup, flip, printGrid, checkInput;
local board;
gameSetup := proc(n)
local r, c, i, toFlip, target;
randomize():
target := Array( 1..n, 1..n, rand(0..1) );
board := copy(target);
for i to rand(3..9)() do
toFlip := [0, 0];
toFlip[1] := StringT... | Give a code snippet in #Maple
The game
Given an N×N square array of zeroes or ones in an initial configuration, and a target configuration of zeroes and ones.
The game is to transform one to the other in as few moves as possible by inverting whole numbered rows or whole lettered
columns at once (as one mov... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Generate_random_chess_position | Generate random chess position | Task
Generate a random chess position in FEN format.
The position does not have to be realistic or even balanced, but it must comply to the following rules:
there is one and only one king of each color (one black king and one white king);
the kings must not be placed on adjacent squares;
there can not be any p... | #PicoLisp | PicoLisp | (load "@lib/simul.l")
(seed (in "/dev/urandom" (rd 8)))
(de pieceN (P)
(case P
("p" 8)
("q" 1)
(T 2) ) )
(de pieceset ()
(let C 0
(make
(for P (conc (cons "p") (shuffle '("r" "n" "b" "q")))
(let (X (pieceN P) N (rand 0 (+ X C)))
(do N
... | Give a code snippet in #PicoLisp
Task
Generate a random chess position in FEN format.
The position does not have to be realistic or even balanced, but it must comply to the following rules:
there is one and only one king of each color (one black king and one white king);
the kings must not be placed on adjacen... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Empty_string | Empty string | Languages may have features for dealing specifically with empty strings
(those containing no characters).
Task
Demonstrate how to assign an empty string to a variable.
Demonstrate how to check that a string is empty.
Demonstrate how to check that a string is not empty.
Other tasks related to string oper... | #XLISP | XLISP | [1] (define my-empty-string "") ;; assign an empty string to a variable
MY-EMPTY-STRING
[2] (string-null? my-empty-string)
#T
[3] (string-null? "A non-empty string")
() | Give a code snippet in #XLISP
Languages may have features for dealing specifically with empty strings
(those containing no characters).
Task
Demonstrate how to assign an empty string to a variable.
Demonstrate how to check that a string is empty.
Demonstrate how to check that a string is not empty.
Oth... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Boolean_values | Boolean values | Task
Show how to represent the boolean states "true" and "false" in a language.
If other objects represent "true" or "false" in conditionals, note it.
Related tasks
Logical operations
| #M2000_Interpreter | M2000 Interpreter |
Module CheckBoolean {
A=True
Print Type$(A)="Double"
B=1=1
Print Type$(B)="Boolean"
Print A=B ' true
Print A, B ' -1 True
Def boolean C=True, D=False
Print C, D , 1>-3 ' True False True
K$=Str$(C)
Print K$="True" ' True
Function ShowBoolean$(&x) ... | Give a code snippet in #M2000_Interpreter
Task
Show how to represent the boolean states "true" and "false" in a language.
If other objects represent "true" or "false" in conditionals, note it.
Related tasks
Logical operations
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Forward_difference | Forward difference | Task
Provide code that produces a list of numbers which is the nth order forward difference, given a non-negative integer (specifying the order) and a list of numbers.
The first-order forward difference of a list of numbers A is a new list B, where Bn = An+1 - An.
List B should have one fewer elem... | #Factor | Factor | USING: kernel math math.vectors sequences ;
IN: rosetacode
: 1-order ( seq -- seq' )
[ rest-slice ] keep v- ;
: n-order ( seq n -- seq' )
dup 0 <=
[ drop ] [ [ 1-order ] times ] if ;
| Give a code snippet in #Factor
Task
Provide code that produces a list of numbers which is the nth order forward difference, given a non-negative integer (specifying the order) and a list of numbers.
The first-order forward difference of a list of numbers A is a new list B, where Bn = An+1 - An.
List ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Arithmetic/Rational | Arithmetic/Rational | Task
Create a reasonably complete implementation of rational arithmetic in the particular language using the idioms of the language.
Example
Define a new type called frac with binary operator "//" of two integers that returns a structure made up of the numerator and the denominator (as per a rational number).
Fur... | #Prolog | Prolog |
divisor(N, Div) :-
Max is floor(sqrt(N)),
between(1, Max, D),
divmod(N, D, _, 0),
(Div = D; Div is N div D, Div =\= D).
divisors(N, Divs) :-
setof(M, divisor(N, M), Divs).
recip(A, B) :- B is 1 rdiv A.
sumrecip(N, A) :-
divisors(N, [1 | Ds]),
maplist(recip, Ds, As),
sum_list(As, ... | Give a code snippet in #Prolog
Task
Create a reasonably complete implementation of rational arithmetic in the particular language using the idioms of the language.
Example
Define a new type called frac with binary operator "//" of two integers that returns a structure made up of the numerator and the denominator ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Read_a_file_line_by_line | Read a file line by line | Read a file one line at a time,
as opposed to reading the entire file at once.
Related tasks
Read a file character by character
Input loop.
| #Maple | Maple | path := "file.txt":
while (true) do
input := readline(path):
if input = 0 then break; end if:
#The line is stored in input
end do: | Give a code snippet in #Maple
Read a file one line at a time,
as opposed to reading the entire file at once.
Related tasks
Read a file character by character
Input loop.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Conditional_structures | Conditional structures | Control Structures
These are examples of control structures. You may also be interested in:
Conditional structures
Exceptions
Flow-control structures
Loops
Task
List the conditional structures offered by a programming language. See Wikipedia: conditionals for descriptions.
Common conditional structures include ... | #Sparkling | Sparkling | var odd = 13;
if odd % 2 != 0 {
print("odd");
} | Give a code snippet in #Sparkling
Control Structures
These are examples of control structures. You may also be interested in:
Conditional structures
Exceptions
Flow-control structures
Loops
Task
List the conditional structures offered by a programming language. See Wikipedia: conditionals for descriptions.
Com... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Random_number_generator_(included) | Random number generator (included) | The task is to:
State the type of random number generator algorithm used in a language's built-in random number generator. If the language or its immediate libraries don't provide a random number generator, skip this task.
If possible, give a link to a wider explanation of the algorithm used.
Note: the task is not t... | #PureBasic | PureBasic | typedef unsigned long long u8;
typedef struct ranctx { u8 a; u8 b; u8 c; u8 d; } ranctx;
#define rot(x,k) (((x)<<(k))|((x)>>(64-(k))))
u8 ranval( ranctx *x ) {
u8 e = x->a - rot(x->b, 7);
x->a = x->b ^ rot(x->c, 13);
x->b = x->c + rot(x->d, 37);
x->c = x->d + e;
x->d = e + x->a;
return x->d;
}... | Give a code snippet in #PureBasic
The task is to:
State the type of random number generator algorithm used in a language's built-in random number generator. If the language or its immediate libraries don't provide a random number generator, skip this task.
If possible, give a link to a wider explanation of the algo... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Logical_operations | Logical operations |
Basic Data Operation
This is a basic data operation. It represents a fundamental action on a basic data type.
You may see other such operations in the Basic Data Operations category, or:
Integer Operations
Arithmetic |
Comparison
Boolean Operations
Bitwise |
Logical
String Operations
Concatenation |
Interpolation |... | #E | E | def logicalOperations(a :boolean, b :boolean) {
return ["and" => a & b,
"or" => a | b,
"not" => !a,
"xor" => a ^ b]
} | Give a code snippet in #E
Basic Data Operation
This is a basic data operation. It represents a fundamental action on a basic data type.
You may see other such operations in the Basic Data Operations category, or:
Integer Operations
Arithmetic |
Comparison
Boolean Operations
Bitwise |
Logical
String Operations
Conc... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Runtime_evaluation/In_an_environment | Runtime evaluation/In an environment | x
x
x
Do so in a way which:
does not involve string manipulation of the input source code
is plausibly extensible to a runtime-chosen set of bindings rather than just x
does not make x a global variable
or note that these are impossible.
See also
For more general examples and language-specific details, see... | #Jsish | Jsish | /* Runtime evaluation in an environment, in Jsish */
function evalWithX(expr, a, b) {
var x = a;
var atA = eval(expr);
x = b;
var atB = eval(expr);
return atB - atA;
}
;evalWithX('Math.exp(x)', 0, 1);
;evalWithX('Math.exp(x)', 1, 0);
/*
=!EXPECTSTART!=
evalWithX('Math.exp(x)', 0, 1) ==> 1.718281... | Give a code snippet in #Jsish
x
x
x
Do so in a way which:
does not involve string manipulation of the input source code
is plausibly extensible to a runtime-chosen set of bindings rather than just x
does not make x a global variable
or note that these are impossible.
See also
For more general examples and... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Leap_year | Leap year | Task
Determine whether a given year is a leap year in the Gregorian calendar.
See also
Leap year (wiki)
| #Stata | Stata | gen leap = mod(year,400)==0 | mod(year,4)==0 & mod(year,100)!=0 | Give a code snippet in #Stata
Task
Determine whether a given year is a leap year in the Gregorian calendar.
See also
Leap year (wiki)
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Permutations_by_swapping | Permutations by swapping | Task
Generate permutations of n items in which successive permutations differ from each other by the swapping of any two items.
Also generate the sign of the permutation which is +1 when the permutation is generated from an even number of swaps from the initial state, and -1 for odd.
Show the permutations and signs ... | #Elixir | Elixir | defmodule Permutation do
def by_swap(n) do
p = Enum.to_list(0..-n) |> List.to_tuple
by_swap(n, p, 1)
end
defp by_swap(n, p, s) do
IO.puts "Perm: #{inspect for i <- 1..n, do: abs(elem(p,i))} Sign: #{s}"
k = 0 |> step_up(n, p) |> step_down(n, p)
if k > 0 do
pk = elem(p,k)
i = if p... | Give a code snippet in #Elixir
Task
Generate permutations of n items in which successive permutations differ from each other by the swapping of any two items.
Also generate the sign of the permutation which is +1 when the permutation is generated from an even number of swaps from the initial state, and -1 for odd.
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sort_an_integer_array | Sort an integer array |
Sorting Algorithm
This is a sorting algorithm. It may be applied to a set of data in order to sort it.
For comparing various sorts, see compare sorts.
For other sorting algorithms, see sorting algorithms, or:
O(n logn) sorts
Heap sort |
Merge sort |
Patience sort |
Quick sort
O(n log2n) sorts
Shell Sort
... | #Slate | Slate | #(7 5 2 9 0 -1) sort | Give a code snippet in #Slate
Sorting Algorithm
This is a sorting algorithm. It may be applied to a set of data in order to sort it.
For comparing various sorts, see compare sorts.
For other sorting algorithms, see sorting algorithms, or:
O(n logn) sorts
Heap sort |
Merge sort |
Patience sort |
Quick so... | christopher/rosetta-code | |
http://rosettacode.org/wiki/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... | #VBScript | VBScript | class accumulator
dim A
public default function acc(x)
A = A + x
acc = A
end function
public property get accum
accum = A
end property
end class | Give a code snippet in #VBScript
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/Modular_inverse | Modular inverse | From Wikipedia:
In modular arithmetic, the modular multiplicative inverse of an integer a modulo m is an integer x such that
a
x
≡
1
(
mod
m
)
.
{\displaystyle a\,x\equiv 1{\pmod {m}}.}
Or in other words, such that:
∃
k
∈
Z
,
a
x
=
1
+
k
m
{\displaystyle \exists k\in \math... | #Run_BASIC | Run BASIC | print multInv(42, 2017)
end
function multInv(a,b)
b0 = b
multInv = 1
if b = 1 then goto [endFun]
while a > 1
q = a / b
t = b
b = a mod b
a = t
t = x0
x0 = multInv - q * x0
multInv = int(t)
wend
if multInv < 0 then multInv = multInv + b0
[endFun]
end function | Give a code snippet in #Run_BASIC
From Wikipedia:
In modular arithmetic, the modular multiplicative inverse of an integer a modulo m is an integer x such that
a
x
≡
1
(
mod
m
)
.
{\displaystyle a\,x\equiv 1{\pmod {m}}.}
Or in other words, such that:
∃
k
∈
Z
,
a
x
=
1
+
k
m
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Zumkeller_numbers | Zumkeller numbers | Zumkeller numbers are the set of numbers whose divisors can be partitioned into two disjoint sets that sum to the same value. Each sum must contain divisor values that are not in the other sum, and all of the divisors must be in one or the other. There are no restrictions on how the divisors are partitioned, only that ... | #Standard_ML | Standard ML |
exception Found of string ;
val divisors = fn n =>
let
val rec divr = fn ( c, divlist ,i) =>
if c <2*i then c::divlist
else divr (if c mod i = 0 then (c,i::divlist,i+1) else (c,divlist,i+1) )
in
divr (n,[],1)
end;
val subsetSums = fn M => fn input =>
let
val getnrs = fn (v,x) => ... | Give a code snippet in #Standard_ML
Zumkeller numbers are the set of numbers whose divisors can be partitioned into two disjoint sets that sum to the same value. Each sum must contain divisor values that are not in the other sum, and all of the divisors must be in one or the other. There are no restrictions on how the... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Polymorphic_copy | Polymorphic copy | An object is polymorphic when its specific type may vary.
The types a specific value may take, is called class.
It is trivial to copy an object if its type is known:
int x;
int y = x;
Here x is not polymorphic, so y is declared of same type (int) as x.
But if the specific type of x were unknown, then y could not be d... | #Racket | Racket | #lang racket/base
(define (copy-prefab-struct str)
(apply make-prefab-struct (vector->list (struct->vector str))))
(struct point (x y) #:prefab)
(struct point/color point (color) #:prefab)
(let* ([original (point 0 0)]
[copied (copy-prefab-struct original)])
(displayln copied)
(displayln (eq? origi... | Give a code snippet in #Racket
An object is polymorphic when its specific type may vary.
The types a specific value may take, is called class.
It is trivial to copy an object if its type is known:
int x;
int y = x;
Here x is not polymorphic, so y is declared of same type (int) as x.
But if the specific type of x wer... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Two_bullet_roulette | Two bullet roulette | The following is supposedly a question given to mathematics graduates seeking jobs on Wall Street:
A revolver handgun has a revolving cylinder with six chambers for bullets.
It is loaded with the following procedure:
1. Check the first chamber to the right of the trigger for a bullet. If a bullet
is seen, the cyli... | #Go | Go | package main
import (
"fmt"
"math/rand"
"strings"
"time"
)
var cylinder = [6]bool{}
func rshift() {
t := cylinder[5]
for i := 4; i >= 0; i-- {
cylinder[i+1] = cylinder[i]
}
cylinder[0] = t
}
func unload() {
for i := 0; i < 6; i++ {
cylinder[i] = false
}
}
... | Give a code snippet in #Go
The following is supposedly a question given to mathematics graduates seeking jobs on Wall Street:
A revolver handgun has a revolving cylinder with six chambers for bullets.
It is loaded with the following procedure:
1. Check the first chamber to the right of the trigger for a bullet. I... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Lah_numbers | Lah numbers | Lah numbers, sometimes referred to as Stirling numbers of the third kind, are coefficients of polynomial expansions expressing rising factorials in terms of falling factorials.
Unsigned Lah numbers count the number of ways a set of n elements can be partitioned into k non-empty linearly ordered subsets.
Lah numbers a... | #Mathematica_.2F_Wolfram_Language | Mathematica / Wolfram Language | ClearAll[Lah]
Lah[n_?Positive, 0] := 0
Lah[0, k_?Positive] := 0
Lah[n_, n_] := 1
Lah[n_, 1] := n!
Lah[n_, k_] := (-1)^n (n! ((n - 1)!))/((k! ((k - 1)!)) ((n - k)!))
Table[Lah[i, j], {i, 0, 12}, {j, 0, 12}] // Grid
Max[Lah[100, Range[0, 100]]] | Give a code snippet in #Mathematica_.2F_Wolfram_Language
Lah numbers, sometimes referred to as Stirling numbers of the third kind, are coefficients of polynomial expansions expressing rising factorials in terms of falling factorials.
Unsigned Lah numbers count the number of ways a set of n elements can be partitioned... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Entropy/Narcissist | Entropy/Narcissist |
Task
Write a computer program that computes and shows its own entropy.
Related Tasks
Fibonacci_word
Entropy
| #Wren | Wren | import "os" for Process
import "io" for File
var args = Process.allArguments
var s = File.read(args[1]).trim()
var m = {}
for (c in s) {
var d = m[c]
m[c] = (d) ? d + 1 : 1
}
var hm = 0
for (k in m.keys) {
var c = m[k]
hm = hm + c * c.log2
}
var l = s.count
System.print(l.log2 - hm/l) | Give a code snippet in #Wren
Task
Write a computer program that computes and shows its own entropy.
Related Tasks
Fibonacci_word
Entropy
| christopher/rosetta-code | |
http://rosettacode.org/wiki/FASTA_format | FASTA format | In bioinformatics, long character strings are often encoded in a format called FASTA.
A FASTA file can contain several strings, each identified by a name marked by a > (greater than) character at the beginning of the line.
Task
Write a program that reads a FASTA file such as:
>Rosetta_Example_1
THERECANBENOSPACE
... | #Delphi | Delphi | USING: formatting io kernel sequences ;
IN: rosetta-code.fasta
: process-fasta-line ( str -- )
dup ">" head? [ rest "\n%s: " printf ] [ write ] if ;
: main ( -- )
readln rest "%s: " printf [ process-fasta-line ] each-line ;
MAIN: main | Give a code snippet in #Delphi
In bioinformatics, long character strings are often encoded in a format called FASTA.
A FASTA file can contain several strings, each identified by a name marked by a > (greater than) character at the beginning of the line.
Task
Write a program that reads a FASTA file such as:
>Rose... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Balanced_ternary | Balanced ternary | Balanced ternary is a way of representing numbers. Unlike the prevailing binary representation, a balanced ternary integer is in base 3, and each digit can have the values 1, 0, or −1.
Examples
Decimal 11 = 32 + 31 − 30, thus it can be written as "++−"
Decimal 6 = 32 − 31 + 0 × 30, thus it can be written as "+−0"
... | #Ada | Ada | with Ada.Finalization;
package BT is
type Balanced_Ternary is private;
-- conversions
function To_Balanced_Ternary (Num : Integer) return Balanced_Ternary;
function To_Balanced_Ternary (Str : String) return Balanced_Ternary;
function To_Integer (Num : Balanced_Ternary) return Integer;
function... | Give a code snippet in #Ada
Balanced ternary is a way of representing numbers. Unlike the prevailing binary representation, a balanced ternary integer is in base 3, and each digit can have the values 1, 0, or −1.
Examples
Decimal 11 = 32 + 31 − 30, thus it can be written as "++−"
Decimal 6 = 32 − 31 + 0 × 30, thu... | christopher/rosetta-code | |
http://rosettacode.org/wiki/String_matching | String matching |
Basic Data Operation
This is a basic data operation. It represents a fundamental action on a basic data type.
You may see other such operations in the Basic Data Operations category, or:
Integer Operations
Arithmetic |
Comparison
Boolean Operations
Bitwise |
Logical
String Operations
Concatenation |
Interpolation |... | #Python | Python | "abcd".startswith("ab") #returns True
"abcd".endswith("zn") #returns False
"bb" in "abab" #returns False
"ab" in "abab" #returns True
loc = "abab".find("bb") #returns -1
loc = "abab".find("ab") #returns 0
loc = "abab".find("ab",loc+1) #returns 2 | Give a code snippet in #Python
Basic Data Operation
This is a basic data operation. It represents a fundamental action on a basic data type.
You may see other such operations in the Basic Data Operations category, or:
Integer Operations
Arithmetic |
Comparison
Boolean Operations
Bitwise |
Logical
String Operations... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Simple_database | Simple database | Task
Write a simple tool to track a small set of data.
The tool should have a command-line interface to enter at least two different values.
The entered data should be stored in a structured format and saved to disk.
It does not matter what kind of data is being tracked. It could be a collection (CDs, coins, base... | #PowerShell | PowerShell |
function db
{
[CmdletBinding(DefaultParameterSetName="None")]
[OutputType([PSCustomObject])]
Param
(
[Parameter(Mandatory=$false,
Position=0,
ParameterSetName="Add a new entry")]
[string]
$Path = ".\SimpleDatabase.csv",
[Parameter... | Give a code snippet in #PowerShell
Task
Write a simple tool to track a small set of data.
The tool should have a command-line interface to enter at least two different values.
The entered data should be stored in a structured format and saved to disk.
It does not matter what kind of data is being tracked. It cou... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Faulhaber%27s_triangle | Faulhaber's triangle | Named after Johann Faulhaber, the rows of Faulhaber's triangle are the coefficients of polynomials that represent sums of integer powers, which are extracted from Faulhaber's formula:
∑
k
=
1
n
k
p
=
1
p
+
1
∑
j
=
0
p
(
p
+
1
j
)
B
j
n
p
+
1
−
j
{\displaystyle \sum _{k... | #Kotlin | Kotlin | // version 1.1.2
import java.math.BigDecimal
import java.math.MathContext
val mc = MathContext(256)
fun gcd(a: Long, b: Long): Long = if (b == 0L) a else gcd(b, a % b)
class Frac : Comparable<Frac> {
val num: Long
val denom: Long
companion object {
val ZERO = Frac(0, 1)
val ONE = ... | Give a code snippet in #Kotlin
Named after Johann Faulhaber, the rows of Faulhaber's triangle are the coefficients of polynomials that represent sums of integer powers, which are extracted from Faulhaber's formula:
∑
k
=
1
n
k
p
=
1
p
+
1
∑
j
=
0
p
(
p
+
1
j
)
B
j
n
p
+
1... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sierpinski_triangle | Sierpinski triangle | Task
Produce an ASCII representation of a Sierpinski triangle of order N.
Example
The Sierpinski triangle of order 4 should look like this:
*
* *
* *
* * * *
* *
* * * *
... | #Kotlin | Kotlin | // version 1.1.2
const val ORDER = 4
const val SIZE = 1 shl ORDER
fun main(args: Array<String>) {
for (y in SIZE - 1 downTo 0) {
for (i in 0 until y) print(" ")
for (x in 0 until SIZE - y) print(if ((x and y) != 0) " " else "* ")
println()
}
} | Give a code snippet in #Kotlin
Task
Produce an ASCII representation of a Sierpinski triangle of order N.
Example
The Sierpinski triangle of order 4 should look like this:
*
* *
* *
* * * *
* *
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Topological_sort | Topological 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
... | #Bracmat | Bracmat | ( ("des_system_lib".std synopsys "std_cell_lib" "des_system_lib" dw02 dw01 ramlib ieee)
(dw01.ieee dw01 dware gtech)
(dw02.ieee dw02 dware)
(dw03.std synopsys dware dw03 dw02 dw01 ieee gtech)
(dw04.dw04 ieee dw01 dware gtech)
(dw05.dw05 ieee dware)
(dw06.dw06 ieee dware)
(d... | Give a code snippet in #Bracmat
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/Fibonacci_sequence | Fibonacci sequence | The Fibonacci sequence is a sequence Fn of natural numbers defined recursively:
F0 = 0
F1 = 1
Fn = Fn-1 + Fn-2, if n>1
Task
Write a function to generate the nth Fibonacci number.
Solutions can be iterative or recursive (though recursive solutions are generally considered too slow ... | #True_BASIC | True BASIC | FUNCTION fibonacci (n)
LET n1 = 0
LET n2 = 1
FOR k = 1 TO ABS(n)
LET sum = n1 + n2
LET n1 = n2
LET n2 = sum
NEXT k
IF n < 0 THEN
LET fibonacci = n1 * ((-1) ^ ((-n) + 1))
ELSE
LET fibonacci = n1
END IF
END FUNCTION
PRINT fibonacci(0) ! 0
PRINT fibo... | Give a code snippet in #True_BASIC
The Fibonacci sequence is a sequence Fn of natural numbers defined recursively:
F0 = 0
F1 = 1
Fn = Fn-1 + Fn-2, if n>1
Task
Write a function to generate the nth Fibonacci number.
Solutions can be iterative or recursive (though recursive solution... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Pi | Pi |
Create a program to continually calculate and output the next decimal digit of
π
{\displaystyle \pi }
(pi).
The program should continue forever (until it is aborted by the user) calculating and outputting each decimal digit in succession.
The output should be a decimal sequence beginning 3.14159265 ...... | #Picat | Picat | go =>
pi2(1,0,1,1,3,3,0),
nl.
pi2(Q,R,T,K,N,L,C) =>
if C == 50 then
nl,
pi2(Q,R,T,K,N,L,0)
else
if (4*Q + R-T) < (N*T) then
print(N),
P := 10*(R-N*T),
pi2(Q*10, P, T, K, ((10*(3*Q+R)) div T)-10*N, L,C+1)
else
P := (2*Q+R)*L,
M := (Q*(7*K)+2+(R*L)) di... | Give a code snippet in #Picat
Create a program to continually calculate and output the next decimal digit of
π
{\displaystyle \pi }
(pi).
The program should continue forever (until it is aborted by the user) calculating and outputting each decimal digit in succession.
The output should be a decimal sequ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Arithmetic/Rational | Arithmetic/Rational | Task
Create a reasonably complete implementation of rational arithmetic in the particular language using the idioms of the language.
Example
Define a new type called frac with binary operator "//" of two integers that returns a structure made up of the numerator and the denominator (as per a rational number).
Fur... | #C.23 | C# | using System;
struct Fraction : IEquatable<Fraction>, IComparable<Fraction>
{
public readonly long Num;
public readonly long Denom;
public Fraction(long num, long denom)
{
if (num == 0)
{
denom = 1;
}
else if (denom == 0)
{
throw new Ar... | Give a code snippet in #C.23
Task
Create a reasonably complete implementation of rational arithmetic in the particular language using the idioms of the language.
Example
Define a new type called frac with binary operator "//" of two integers that returns a structure made up of the numerator and the denominator (a... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Use_another_language_to_call_a_function | Use another language to call a function | This task has been clarified. Its programming examples are in need of review to ensure that they still fit the requirements of the task.
This task is inverse to the task Call foreign language function. Consider the following C program:
#include <stdio.h>
extern int Query (char * Data, size_t * Length);
int main (i... | #Ruby | Ruby | # query.rb
require 'fiddle'
# Look for a C variable named QueryPointer.
# Raise an error if it is missing.
c_var = Fiddle.dlopen(nil)['QueryPointer']
int = Fiddle::TYPE_INT
voidp = Fiddle::TYPE_VOIDP
sz_voidp = Fiddle::SIZEOF_VOIDP
# Implement the C function
# int Query(void *data, size_t *length)
# in Ruby cod... | Give a code snippet in #Ruby
This task has been clarified. Its programming examples are in need of review to ensure that they still fit the requirements of the task.
This task is inverse to the task Call foreign language function. Consider the following C program:
#include <stdio.h>
extern int Query (char * Data, s... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Factors_of_an_integer | Factors of an integer |
Basic Data Operation
This is a basic data operation. It represents a fundamental action on a basic data type.
You may see other such operations in the Basic Data Operations category, or:
Integer Operations
Arithmetic |
Comparison
Boolean Operations
Bitwise |
Logical
String Operations
Concatenation |
Interpolation |... | #Ruby | Ruby | class Integer
def factors() (1..self).select { |n| (self % n).zero? } end
end
p 45.factors | Give a code snippet in #Ruby
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
C... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Conditional_structures | Conditional structures | Control Structures
These are examples of control structures. You may also be interested in:
Conditional structures
Exceptions
Flow-control structures
Loops
Task
List the conditional structures offered by a programming language. See Wikipedia: conditionals for descriptions.
Common conditional structures include ... | #AutoHotkey | AutoHotkey | x = 1
If x
MsgBox, x is %x%
Else If x > 1
MsgBox, x is %x%
Else
MsgBox, x is %x% | Give a code snippet in #AutoHotkey
Control Structures
These are examples of control structures. You may also be interested in:
Conditional structures
Exceptions
Flow-control structures
Loops
Task
List the conditional structures offered by a programming language. See Wikipedia: conditionals for descriptions.
Co... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sum_of_a_series | Sum of a series | Compute the nth term of a series, i.e. the sum of the n first terms of the corresponding sequence.
Informally this value, or its limit when n tends to infinity, is also called the sum of the series, thus the title of this task.
For this task, use:
S
n
=
∑
k
=
1
n
1
k
2
{\displa... | #SQL | SQL | CREATE TABLE t1 (n REAL);
-- this is postgresql specific, fill the table
INSERT INTO t1 (SELECT generate_series(1,1000)::REAL);
WITH tt AS (
SELECT 1/(n*n) AS recip FROM t1
) SELECT SUM(recip) FROM tt;
| Give a code snippet in #SQL
Compute the nth term of a series, i.e. the sum of the n first terms of the corresponding sequence.
Informally this value, or its limit when n tends to infinity, is also called the sum of the series, thus the title of this task.
For this task, use:
S
n
=
∑
k
=
1
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Substring/Top_and_tail | Substring/Top and tail | The task is to demonstrate how to remove the first and last characters from a string.
The solution should demonstrate how to obtain the following results:
String with first character removed
String with last character removed
String with both the first and last characters removed
If the program uses UTF-8 or UTF... | #Perl | Perl | print substr("knight",1), "\n"; # strip first character
print substr("socks", 0, -1), "\n"; # strip last character
print substr("brooms", 1, -1), "\n"; # strip both first and last characters | Give a code snippet in #Perl
The task is to demonstrate how to remove the first and last characters from a string.
The solution should demonstrate how to obtain the following results:
String with first character removed
String with last character removed
String with both the first and last characters removed
If... | christopher/rosetta-code |
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