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 |
|---|---|---|---|---|---|
http://rosettacode.org/wiki/Empty_program | Empty program | Task
Create the simplest possible program that is still considered "correct."
| #AWK | AWK | 1 |
http://rosettacode.org/wiki/Empty_program | Empty program | Task
Create the simplest possible program that is still considered "correct."
| #Axe | Axe | :.PRGMNAME
: |
http://rosettacode.org/wiki/Enforced_immutability | Enforced immutability | Task
Demonstrate any means your language has to prevent the modification of values, or to create objects that cannot be modified after they have been created.
| #Wren | Wren | class A {
construct new(f) {
_f = f // sets field _f to the argument f
}
// getter property to allow access to _f
f { _f }
// setter property to allow _f to be mutated
f=(other) { _f = other }
}
var a = A.new(6)
System.print(a.f)
a.f = 8
System.print(a.f) |
http://rosettacode.org/wiki/Enforced_immutability | Enforced immutability | Task
Demonstrate any means your language has to prevent the modification of values, or to create objects that cannot be modified after they have been created.
| #Z80_Assembly | Z80 Assembly | List:
byte 2,3,4,5,6 ;this could be either mutable or immutable, it depends on the hardware. |
http://rosettacode.org/wiki/Enforced_immutability | Enforced immutability | Task
Demonstrate any means your language has to prevent the modification of values, or to create objects that cannot be modified after they have been created.
| #zkl | zkl | List(1,2,3).del(0) //--> L(2,3)
ROList(1,2,3).del(0) //-->SyntaxError : Can't find del, which means you can't call it
d:=Dictionary(); d.add("one",1)
D(one:1)
d.makeReadOnly(); d.add("2",2) //-->AccessError(This Dictionary is read only) |
http://rosettacode.org/wiki/Entropy | Entropy | Task
Calculate the Shannon entropy H of a given input string.
Given the discrete random variable
X
{\displaystyle X}
that is a string of
N
{\displaystyle N}
"symbols" (total characters) consisting of
n
{\displaystyle n}
different characters (n=2 for binary), the Shannon entropy of X in bit... | #EchoLisp | EchoLisp |
(lib 'hash)
;; counter: hash-table[key]++
(define (count++ ht k )
(hash-set ht k (1+ (hash-ref! ht k 0))))
(define (hi count n )
(define pi (// count n))
(- (* pi (log2 pi))))
;; (H [string|list]) → entropy (bits)
(define (H info)
(define S (if(string? info) (string->list info) info))
(define ht (make-hash))... |
http://rosettacode.org/wiki/Ethiopian_multiplication | Ethiopian multiplication | Ethiopian multiplication is a method of multiplying integers using only addition, doubling, and halving.
Method:
Take two numbers to be multiplied and write them down at the top of two columns.
In the left-hand column repeatedly halve the last number, discarding any remainders, and write the result below the last ... | #D | D | int ethiopian(int n1, int n2) pure nothrow @nogc
in {
assert(n1 >= 0, "Multiplier can't be negative");
} body {
static enum doubleNum = (in int n) pure nothrow @nogc => n * 2;
static enum halveNum = (in int n) pure nothrow @nogc => n / 2;
static enum isEven = (in int n) pure nothrow @nogc => !(n & 1);
... |
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}
... | #Logo | Logo | to equilibrium.iter :i :before :after :tail :ret
if equal? :before :after [make "ret lput :i :ret]
if empty? butfirst :tail [output :ret]
output equilibrium.iter :i+1 (:before+first :tail) (:after-first butfirst :tail) (butfirst :tail) :ret
end
to equilibrium.index :list
output equilibrium.iter 1 0 (apply "sum ... |
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}
... | #Lua | Lua |
function array_sum(t)
assert(type(t) == "table", "t must be a table!")
local sum = 0
for i=1, #t do sum = sum + t[i] end
return sum
end
function equilibrium_index(t)
assert(type(t) == "table", "t must be a table!")
local left, right, ret = 0, array_sum(t), -1
for i,j in pairs(t) do
right ... |
http://rosettacode.org/wiki/Environment_variables | Environment variables | Task
Show how to get one of your process's environment variables.
The available variables vary by system; some of the common ones available on Unix include:
PATH
HOME
USER
| #Python | Python | import os
os.environ['HOME'] |
http://rosettacode.org/wiki/Environment_variables | Environment variables | Task
Show how to get one of your process's environment variables.
The available variables vary by system; some of the common ones available on Unix include:
PATH
HOME
USER
| #R | R | Sys.getenv("PATH") |
http://rosettacode.org/wiki/Environment_variables | Environment variables | Task
Show how to get one of your process's environment variables.
The available variables vary by system; some of the common ones available on Unix include:
PATH
HOME
USER
| #Racket | Racket |
#lang racket
(getenv "HOME")
|
http://rosettacode.org/wiki/Environment_variables | Environment variables | Task
Show how to get one of your process's environment variables.
The available variables vary by system; some of the common ones available on Unix include:
PATH
HOME
USER
| #Raku | Raku | say %*ENV<HOME>; |
http://rosettacode.org/wiki/Euler%27s_sum_of_powers_conjecture | Euler's sum of powers conjecture | There is a conjecture in mathematics that held for over two hundred years before it was disproved by the finding of a counterexample in 1966 by Lander and Parkin.
Euler's (disproved) sum of powers conjecture
At least k positive kth powers are required to sum to a kth power,
except for the trivial case... | #JavaScript | JavaScript | var eulers_sum_of_powers = function (iMaxN) {
var aPow5 = [];
var oPow5ToN = {};
for (var iP = 0; iP <= iMaxN; iP++) {
var iPow5 = Math.pow(iP, 5);
aPow5.push(iPow5);
oPow5ToN[iPow5] = iP;
}
for (var i0 = 1; i0 <= iMaxN; i0++) {
for (var i1 = 1; i1 <= i0; i1++) ... |
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... | #Octave | Octave | % built in factorial
printf("%d\n", factorial(50));
% let's define our recursive...
function fact = my_fact(n)
if ( n <= 1 )
fact = 1;
else
fact = n * my_fact(n-1);
endif
endfunction
printf("%d\n", my_fact(50));
% let's define our iterative
function fact = iter_fact(n)
fact = 1;
for i = 2:n
... |
http://rosettacode.org/wiki/Even_or_odd | Even or odd | Task
Test whether an integer is even or odd.
There is more than one way to solve this task:
Use the even and odd predicates, if the language provides them.
Check the least significant digit. With binary integers, i bitwise-and 1 equals 0 iff i is even, or equals 1 iff i is odd.
Divide i by 2. The remainder equals... | #Delphi | Delphi |
program EvenOdd;
{$APPTYPE CONSOLE}
{$R *.res}
uses
System.SysUtils;
procedure IsOdd(aValue: Integer);
var
Odd: Boolean;
begin
Odd := aValue and 1 <> 0;
Write(Format('%d is ', [aValue]));
if Odd then
Writeln('odd')
else
Writeln('even');
end;
var
i: Integer;
begin
for i := -5 to 10 d... |
http://rosettacode.org/wiki/Euler_method | Euler method | Euler's method numerically approximates solutions of first-order ordinary differential equations (ODEs) with a given initial value. It is an explicit method for solving initial value problems (IVPs), as described in the wikipedia page.
The ODE has to be provided in the following form:
d
y
(
t
)
d
t
=
f... | #Vlang | Vlang | import math
// Fdy is a type for fntion f used in Euler's method.
type Fdy = fn(f64, f64) f64
// euler_step computes a single new value using Euler's method.
// Note that step size h is a parameter, so a variable step size
// could be used.
fn euler_step(f Fdy, x f64, y f64, h f64) f64 {
return y + h*f(x, y)
}
... |
http://rosettacode.org/wiki/Evaluate_binomial_coefficients | Evaluate binomial coefficients | This programming task, is to calculate ANY binomial coefficient.
However, it has to be able to output
(
5
3
)
{\displaystyle {\binom {5}{3}}}
, which is 10.
This formula is recommended:
(
n
k
)
=
n
!
(
n
−
k
)
!
k
!
=
n
(
n
−
1
)
(
n
−
2
)
…
(
n
−
k
+
1
)
k
(
k
−
1... | #MATLAB_.2F_Octave | MATLAB / Octave | >> nchoosek(5,3)
ans =
10 |
http://rosettacode.org/wiki/Evaluate_binomial_coefficients | Evaluate binomial coefficients | This programming task, is to calculate ANY binomial coefficient.
However, it has to be able to output
(
5
3
)
{\displaystyle {\binom {5}{3}}}
, which is 10.
This formula is recommended:
(
n
k
)
=
n
!
(
n
−
k
)
!
k
!
=
n
(
n
−
1
)
(
n
−
2
)
…
(
n
−
k
+
1
)
k
(
k
−
1... | #Maxima | Maxima | binomial( 5, 3); /* 10 */
binomial(-5, 3); /* -35 */
binomial( 5, -3); /* 0 */
binomial(-5, -3); /* 0 */
binomial( 3, 5); /* 0 */
binomial(x, 3); /* ((x - 2)*(x - 1)*x)/6 */
binomial(3, 1/2); /* binomial(3, 1/2) */
makegamma(%); /* 32/(5*%pi) */
binomial(a, b); ... |
http://rosettacode.org/wiki/Emirp_primes | Emirp primes | An emirp (prime spelled backwards) are primes that when reversed (in their decimal representation) are a different prime.
(This rules out palindromic primes.)
Task
show the first twenty emirps
show all emirps between 7,700 and 8,000
show the 10,000th emirp
In each list, the numbe... | #D | D | bool isEmirp(uint n) pure nothrow @nogc {
bool isPrime(in uint n) pure nothrow @nogc {
if (n == 2 || n == 3)
return true;
else if (n < 2 || n % 2 == 0 || n % 3 == 0)
return false;
for (uint div = 5, inc = 2; div ^^ 2 <= n;
div += inc, inc = 6 - inc)
... |
http://rosettacode.org/wiki/Elliptic_curve_arithmetic | Elliptic curve arithmetic | Elliptic curves are sometimes used in cryptography as a way to perform digital signatures.
The purpose of this task is to implement a simplified (without modular arithmetic) version of the elliptic curve arithmetic which is required by the elliptic curve DSA protocol.
In a nutshell, an elliptic curve is a... | #Racket | Racket |
#lang racket
(define a 0) (define b 7)
(define (ε? x) (<= (abs x) 1e-14))
(define (== p q) (for/and ([pi p] [qi q]) (ε? (- pi qi))))
(define zero #(0 0))
(define (zero? p) (== p zero))
(define (neg p) (match-define (vector x y) p) (vector x (- y)))
(define (⊕ p q)
(cond [(== q (neg p)) zero]
[else
... |
http://rosettacode.org/wiki/Elliptic_curve_arithmetic | Elliptic curve arithmetic | Elliptic curves are sometimes used in cryptography as a way to perform digital signatures.
The purpose of this task is to implement a simplified (without modular arithmetic) version of the elliptic curve arithmetic which is required by the elliptic curve DSA protocol.
In a nutshell, an elliptic curve is a... | #Raku | Raku | unit module EC;
our ($A, $B) = (0, 7);
role Horizon { method gist { 'EC Point at horizon' } }
class Point {
has ($.x, $.y);
multi method new(
$x, $y where $y**2 ~~ $x**3 + $A*$x + $B
) { self.bless(:$x, :$y) }
multi method new(Horizon $) { self.bless but Horizon }
method gist { "EC Point a... |
http://rosettacode.org/wiki/Enumerations | Enumerations | Task
Create an enumeration of constants with and without explicit values.
| #OxygenBasic | OxygenBasic |
enum fruits
apple
pear
orange = 14
banana
mango
end enum
print banana '15
'fruits values:
' apple 0
' pear 1
' orange 14
' banana 15
' mango 16
|
http://rosettacode.org/wiki/Enumerations | Enumerations | Task
Create an enumeration of constants with and without explicit values.
| #Oz | Oz | declare
fun {IsFruit A}
{Member A [apple banana cherry]}
end
in
{Show {IsFruit banana}} |
http://rosettacode.org/wiki/Empty_string | Empty string | Languages may have features for dealing specifically with empty strings
(those containing no characters).
Task
Demonstrate how to assign an empty string to a variable.
Demonstrate how to check that a string is empty.
Demonstrate how to check that a string is not empty.
Other tasks related to string oper... | #C | C | #include <string.h>
/* ... */
/* assign an empty string */
const char *str = "";
/* to test a null string */
if (str) { ... }
/* to test if string is empty */
if (str[0] == '\0') { ... }
/* or equivalently use strlen function
strlen will seg fault on NULL pointer, so check first */
if ( (str == NULL) || (... |
http://rosettacode.org/wiki/Empty_directory | Empty directory | Starting with a path to some directory, determine whether the directory is empty.
An empty directory contains no files nor subdirectories.
With Unix or Windows systems, every directory contains an entry for “.” and almost every directory contains “..” (except for a root directory); an empty directory contains no other... | #Liberty_BASIC | Liberty BASIC |
dim info$(10, 10)
files "c:\", info$()
qtyFiles=val(info$(0,0))
n = qtyFiles+1 'begin directory info
folder$ = info$(n,0) 'path to first directory in c:
files folder$, info$() 're-fill array with data from sub folder
if val(info$(0,0)) + val(info$(0, 1)) <> 0 then
print "Folder ";folder$;" is not empty.... |
http://rosettacode.org/wiki/Empty_directory | Empty directory | Starting with a path to some directory, determine whether the directory is empty.
An empty directory contains no files nor subdirectories.
With Unix or Windows systems, every directory contains an entry for “.” and almost every directory contains “..” (except for a root directory); an empty directory contains no other... | #Lingo | Lingo | on isDirEmpty (dir)
return getNthFileNameInFolder(dir, 1) = EMPTY
end |
http://rosettacode.org/wiki/Empty_program | Empty program | Task
Create the simplest possible program that is still considered "correct."
| #BASIC | BASIC | |
http://rosettacode.org/wiki/Empty_program | Empty program | Task
Create the simplest possible program that is still considered "correct."
| #Batch_File | Batch File | |
http://rosettacode.org/wiki/Empty_program | Empty program | Task
Create the simplest possible program that is still considered "correct."
| #BaCon | BaCon | |
http://rosettacode.org/wiki/Entropy | Entropy | Task
Calculate the Shannon entropy H of a given input string.
Given the discrete random variable
X
{\displaystyle X}
that is a string of
N
{\displaystyle N}
"symbols" (total characters) consisting of
n
{\displaystyle n}
different characters (n=2 for binary), the Shannon entropy of X in bit... | #Elena | Elena | import system'math;
import system'collections;
import system'routines;
import extensions;
extension op
{
logTwo()
= self.ln() / 2.ln();
}
public program()
{
var input := console.readLine();
var infoC := 0.0r;
var table := Dictionary.new();
input.forEach:(ch)
{
var n := tabl... |
http://rosettacode.org/wiki/Entropy | Entropy | Task
Calculate the Shannon entropy H of a given input string.
Given the discrete random variable
X
{\displaystyle X}
that is a string of
N
{\displaystyle N}
"symbols" (total characters) consisting of
n
{\displaystyle n}
different characters (n=2 for binary), the Shannon entropy of X in bit... | #Elixir | Elixir | defmodule RC do
def entropy(str) do
leng = String.length(str)
String.graphemes(str)
|> Enum.group_by(&(&1))
|> Enum.map(fn{_,value} -> length(value) end)
|> Enum.reduce(0, fn count, entropy ->
freq = count / leng
entropy - freq * :math.log2(freq)
end)
end
end
IO.inspec... |
http://rosettacode.org/wiki/Ethiopian_multiplication | Ethiopian multiplication | Ethiopian multiplication is a method of multiplying integers using only addition, doubling, and halving.
Method:
Take two numbers to be multiplied and write them down at the top of two columns.
In the left-hand column repeatedly halve the last number, discarding any remainders, and write the result below the last ... | #dc | dc | 0k [ Make sure we're doing integer division ]sx
[ 2 / ] sH [ Define "halve" function in register H ]sx
[ 2 * ] sD [ Define "double" function in register D ]sx
[ 2 % 1 r - ] sE [ Define "even?" function in register E ]sx
[ Entry into the main Ethiopian multiplication... |
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}
... | #Mathematica_.2F_Wolfram_Language | Mathematica / Wolfram Language | equilibriumIndex[data_]:=Reap[
Do[If[Total[data[[;; n - 1]]] == Total[data[[n + 1 ;;]]],Sow[n]],
{n, Length[data]}]][[2, 1]] |
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}
... | #MATLAB | MATLAB | function indicies = equilibriumIndex(list)
indicies = [];
for i = (1:numel(list))
if ( sum(-list(1:i)) == sum(-list(i:end)) )
indicies = [indicies i];
end
end
end |
http://rosettacode.org/wiki/Environment_variables | Environment variables | Task
Show how to get one of your process's environment variables.
The available variables vary by system; some of the common ones available on Unix include:
PATH
HOME
USER
| #REBOL | REBOL | print get-env "HOME" |
http://rosettacode.org/wiki/Environment_variables | Environment variables | Task
Show how to get one of your process's environment variables.
The available variables vary by system; some of the common ones available on Unix include:
PATH
HOME
USER
| #Retro | Retro | here "HOME" getEnv
here puts |
http://rosettacode.org/wiki/Environment_variables | Environment variables | Task
Show how to get one of your process's environment variables.
The available variables vary by system; some of the common ones available on Unix include:
PATH
HOME
USER
| #REXX | REXX | /*REXX program shows how to get an environmental variable under Windows*/
x=value('TEMP',,'SYSTEM') |
http://rosettacode.org/wiki/Environment_variables | Environment variables | Task
Show how to get one of your process's environment variables.
The available variables vary by system; some of the common ones available on Unix include:
PATH
HOME
USER
| #Ring | Ring |
see get("path")
|
http://rosettacode.org/wiki/Euler%27s_sum_of_powers_conjecture | Euler's sum of powers conjecture | There is a conjecture in mathematics that held for over two hundred years before it was disproved by the finding of a counterexample in 1966 by Lander and Parkin.
Euler's (disproved) sum of powers conjecture
At least k positive kth powers are required to sum to a kth power,
except for the trivial case... | #jq | jq | # Search for y in 1 .. maxn (inclusive) for a solution to SIGMA (xi ^ 5) = y^5
# and for each solution with x0<=x1<=...<x3, print [x0, x1, x3, x3, y]
#
def sum_of_powers_conjecture(maxn):
def p5: . as $in | (.*.) | ((.*.) * $in);
def fifth: log / 5 | exp;
# return the fifth root if . is a power of 5
def integ... |
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... | #Oforth | Oforth | : fact(n) n ifZero: [ 1 ] else: [ n n 1- fact * ] ; |
http://rosettacode.org/wiki/Even_or_odd | Even or odd | Task
Test whether an integer is even or odd.
There is more than one way to solve this task:
Use the even and odd predicates, if the language provides them.
Check the least significant digit. With binary integers, i bitwise-and 1 equals 0 iff i is even, or equals 1 iff i is odd.
Divide i by 2. The remainder equals... | #DWScript | DWScript | var isOdd := Odd(i); |
http://rosettacode.org/wiki/Even_or_odd | Even or odd | Task
Test whether an integer is even or odd.
There is more than one way to solve this task:
Use the even and odd predicates, if the language provides them.
Check the least significant digit. With binary integers, i bitwise-and 1 equals 0 iff i is even, or equals 1 iff i is odd.
Divide i by 2. The remainder equals... | #D.C3.A9j.C3.A0_Vu | Déjà Vu | even n:
= 0 % n 2
odd:
not even
!. odd 0
!. even 0
!. odd 7
!. even 7
|
http://rosettacode.org/wiki/Euler_method | Euler method | Euler's method numerically approximates solutions of first-order ordinary differential equations (ODEs) with a given initial value. It is an explicit method for solving initial value problems (IVPs), as described in the wikipedia page.
The ODE has to be provided in the following form:
d
y
(
t
)
d
t
=
f... | #XPL0 | XPL0 | include c:\cxpl\codes; \intrinsic 'code' declarations
proc Euler(Step); \Display cooling temperatures using Euler's method
int Step;
int Time; real Temp;
[Text(0, "Step "); IntOut(0, Step); Text(0, " ");
Time:= 0; Temp:= 100.0;
repeat if rem(Time/10) = 0 then RlOut(0, Temp);
Temp:= Temp + float(... |
http://rosettacode.org/wiki/Euler_method | Euler method | Euler's method numerically approximates solutions of first-order ordinary differential equations (ODEs) with a given initial value. It is an explicit method for solving initial value problems (IVPs), as described in the wikipedia page.
The ODE has to be provided in the following form:
d
y
(
t
)
d
t
=
f... | #Wren | Wren | import "/fmt" for Fmt
import "/trait" for Stepped
var euler = Fn.new { |f, y, step, end|
Fmt.write(" Step $2d: ", step)
for (t in Stepped.new(0..end, step)) {
if (t%10 == 0) Fmt.write(" $7.3f", y)
y = y + step * f.call(y)
}
System.print()
}
var analytic = Fn.new {
System.write(" ... |
http://rosettacode.org/wiki/Evaluate_binomial_coefficients | Evaluate binomial coefficients | This programming task, is to calculate ANY binomial coefficient.
However, it has to be able to output
(
5
3
)
{\displaystyle {\binom {5}{3}}}
, which is 10.
This formula is recommended:
(
n
k
)
=
n
!
(
n
−
k
)
!
k
!
=
n
(
n
−
1
)
(
n
−
2
)
…
(
n
−
k
+
1
)
k
(
k
−
1... | #min | min | ((dup 0 ==) 'succ (dup pred) '* linrec) :fact
('dup dip dup ((fact) () (- fact) (fact * div)) spread) :binomial
5 3 binomial puts! |
http://rosettacode.org/wiki/Evaluate_binomial_coefficients | Evaluate binomial coefficients | This programming task, is to calculate ANY binomial coefficient.
However, it has to be able to output
(
5
3
)
{\displaystyle {\binom {5}{3}}}
, which is 10.
This formula is recommended:
(
n
k
)
=
n
!
(
n
−
k
)
!
k
!
=
n
(
n
−
1
)
(
n
−
2
)
…
(
n
−
k
+
1
)
k
(
k
−
1... | #MINIL | MINIL | // Number of combinations nCr
00 0E Go: ENT R0 // n
01 1E ENT R1 // r
02 2C CLR R2
03 2A Loop: ADD1 R2
04 0D DEC R0
05 1D DEC R1
06 C3 JNZ Loop
07 3C CLR R3 // for result
08 3A ADD1 R3
09 0A Next: ADD1 R0
0A 1A ADD1 R1
0B 50 R5... |
http://rosettacode.org/wiki/Emirp_primes | Emirp primes | An emirp (prime spelled backwards) are primes that when reversed (in their decimal representation) are a different prime.
(This rules out palindromic primes.)
Task
show the first twenty emirps
show all emirps between 7,700 and 8,000
show the 10,000th emirp
In each list, the numbe... | #Delphi | Delphi | defmodule Emirp do
defp prime?(2), do: true
defp prime?(n) when n<2 or rem(n,2)==0, do: false
defp prime?(n), do: prime?(n,3)
defp prime?(n,k) when n<k*k, do: true
defp prime?(n,k) when rem(n,k)==0, do: false
defp prime?(n,k), do: prime?(n,k+2)
def emirp?(n) do
if prime?(n) do
reverse = to_s... |
http://rosettacode.org/wiki/Emirp_primes | Emirp primes | An emirp (prime spelled backwards) are primes that when reversed (in their decimal representation) are a different prime.
(This rules out palindromic primes.)
Task
show the first twenty emirps
show all emirps between 7,700 and 8,000
show the 10,000th emirp
In each list, the numbe... | #Elixir | Elixir | defmodule Emirp do
defp prime?(2), do: true
defp prime?(n) when n<2 or rem(n,2)==0, do: false
defp prime?(n), do: prime?(n,3)
defp prime?(n,k) when n<k*k, do: true
defp prime?(n,k) when rem(n,k)==0, do: false
defp prime?(n,k), do: prime?(n,k+2)
def emirp?(n) do
if prime?(n) do
reverse = to_s... |
http://rosettacode.org/wiki/Elliptic_curve_arithmetic | Elliptic curve arithmetic | Elliptic curves are sometimes used in cryptography as a way to perform digital signatures.
The purpose of this task is to implement a simplified (without modular arithmetic) version of the elliptic curve arithmetic which is required by the elliptic curve DSA protocol.
In a nutshell, an elliptic curve is a... | #REXX | REXX | /*REXX program defines (for any 2 points on the curve), returns the sum of the 2 points.*/
numeric digits 100 /*try to ensure a min. of accuracy loss*/
a= func(1) ; say ' a = ' show(a)
b= func(2) ; say ' b = ... |
http://rosettacode.org/wiki/Enumerations | Enumerations | Task
Create an enumeration of constants with and without explicit values.
| #Pascal | Pascal | type
phase = (red, green, blue); |
http://rosettacode.org/wiki/Enumerations | Enumerations | Task
Create an enumeration of constants with and without explicit values.
| #Perl | Perl | # Using an array
my @fruits = qw(apple banana cherry);
# Using a hash
my %fruits = ( apple => 0, banana => 1, cherry => 2 ); |
http://rosettacode.org/wiki/Enumerations | Enumerations | Task
Create an enumeration of constants with and without explicit values.
| #Phix | Phix | enum apple, banana, orange
enum apple=5, banana=10, orange=
|
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... | #C.23 | C# | using System;
class Program {
static void Main (string[] args) {
string example = string.Empty;
if (string.IsNullOrEmpty(example)) { }
if (!string.IsNullOrEmpty(example)) { }
}
} |
http://rosettacode.org/wiki/Empty_directory | Empty directory | Starting with a path to some directory, determine whether the directory is empty.
An empty directory contains no files nor subdirectories.
With Unix or Windows systems, every directory contains an entry for “.” and almost every directory contains “..” (except for a root directory); an empty directory contains no other... | #Lua | Lua |
function scandir(directory)
local i, t, popen = 0, {}, io.popen
local pfile = popen('ls -a "'..directory..'"')
for filename in pfile:lines() do
if filename ~= '.' and filename ~= '..' then
i = i + 1
t[i] = filename
end
end
pfile:close()
return t
end
function isemptydir(directory)
return #scandir(di... |
http://rosettacode.org/wiki/Empty_directory | Empty directory | Starting with a path to some directory, determine whether the directory is empty.
An empty directory contains no files nor subdirectories.
With Unix or Windows systems, every directory contains an entry for “.” and almost every directory contains “..” (except for a root directory); an empty directory contains no other... | #Maple | Maple |
emptydirectory := proc (dir)
is(listdir(dir) = [".", ".."]);
end proc;
|
http://rosettacode.org/wiki/Empty_program | Empty program | Task
Create the simplest possible program that is still considered "correct."
| #BASIC256 | BASIC256 | |
http://rosettacode.org/wiki/Empty_program | Empty program | Task
Create the simplest possible program that is still considered "correct."
| #BBC_BASIC | BBC BASIC | |
http://rosettacode.org/wiki/Entropy | Entropy | Task
Calculate the Shannon entropy H of a given input string.
Given the discrete random variable
X
{\displaystyle X}
that is a string of
N
{\displaystyle N}
"symbols" (total characters) consisting of
n
{\displaystyle n}
different characters (n=2 for binary), the Shannon entropy of X in bit... | #Emacs_Lisp | Emacs Lisp | (defun shannon-entropy (input)
(let ((freq-table (make-hash-table))
(entropy 0)
(length (+ (length input) 0.0)))
(mapcar (lambda (x)
(puthash x
(+ 1 (gethash x freq-table 0))
freq-table))
input)
(maphash (lambda (k v)
(set 'entropy (+ entropy
(* (/ v length)
... |
http://rosettacode.org/wiki/Ethiopian_multiplication | Ethiopian multiplication | Ethiopian multiplication is a method of multiplying integers using only addition, doubling, and halving.
Method:
Take two numbers to be multiplied and write them down at the top of two columns.
In the left-hand column repeatedly halve the last number, discarding any remainders, and write the result below the last ... | #Delphi | Delphi | proc nonrec halve(word n) word: n >> 1 corp
proc nonrec double(word n) word: n << 1 corp
proc nonrec even(word n) bool: n & 1 = 0 corp
proc nonrec emul(word a, b) word:
word total;
total := 0;
while a > 0 do
if not even(a) then total := total + b fi;
a := halve(a);
b :=... |
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}
... | #NetRexx | NetRexx | /* NetRexx */
options replace format comments java crossref symbols nobinary
numeric digits 20
runSample(arg)
return
-- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-- @see http://www.geeksforgeeks.org/equilibrium-index-of-an-array/
method equilibriumIndex(sequence) private static
... |
http://rosettacode.org/wiki/Environment_variables | Environment variables | Task
Show how to get one of your process's environment variables.
The available variables vary by system; some of the common ones available on Unix include:
PATH
HOME
USER
| #Ruby | Ruby | ENV['HOME'] |
http://rosettacode.org/wiki/Environment_variables | Environment variables | Task
Show how to get one of your process's environment variables.
The available variables vary by system; some of the common ones available on Unix include:
PATH
HOME
USER
| #Run_BASIC | Run BASIC | ' ------- Major environment variables -------------------------------------------
'DefaultDir$ - The folder path where program files are read/written by default
'Platform$ - The operating system on which Run BASIC is being hosted
'UserInfo$ - This is information about the user's web browser
'UrlKeys$ ... |
http://rosettacode.org/wiki/Environment_variables | Environment variables | Task
Show how to get one of your process's environment variables.
The available variables vary by system; some of the common ones available on Unix include:
PATH
HOME
USER
| #Rust | Rust | use std::env;
fn main() {
println!("{:?}", env::var("HOME"));
println!();
for (k, v) in env::vars().filter(|(k, _)| k.starts_with('P')) {
println!("{}: {}", k, v);
}
}
|
http://rosettacode.org/wiki/Environment_variables | Environment variables | Task
Show how to get one of your process's environment variables.
The available variables vary by system; some of the common ones available on Unix include:
PATH
HOME
USER
| #Scala | Scala | sys.env.get("HOME") |
http://rosettacode.org/wiki/Euler%27s_sum_of_powers_conjecture | Euler's sum of powers conjecture | There is a conjecture in mathematics that held for over two hundred years before it was disproved by the finding of a counterexample in 1966 by Lander and Parkin.
Euler's (disproved) sum of powers conjecture
At least k positive kth powers are required to sum to a kth power,
except for the trivial case... | #Julia | Julia |
const lim = 250
const pwr = 5
const p = [i^pwr for i in 1:lim]
x = zeros(Int, pwr-1)
y = 0
for a in combinations(1:lim, pwr-1)
b = searchsorted(p, sum(p[a]))
0 < length(b) || continue
x = a
y = b[1]
break
end
if y == 0
println("No solution found for power = ", pwr, " and limit = ", lim, ... |
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... | #Order | Order | #include <order/interpreter.h>
#define ORDER_PP_DEF_8fac \
ORDER_PP_FN(8fn(8N, \
8if(8less_eq(8N, 0), \
1, \
8mul(8N, 8fac(8dec(8N))))))
ORDER_PP(8to_lit(8fac(8))) // 40320 |
http://rosettacode.org/wiki/Even_or_odd | Even or odd | Task
Test whether an integer is even or odd.
There is more than one way to solve this task:
Use the even and odd predicates, if the language provides them.
Check the least significant digit. With binary integers, i bitwise-and 1 equals 0 iff i is even, or equals 1 iff i is odd.
Divide i by 2. The remainder equals... | #EDSAC_order_code | EDSAC order code | [ Even or odd
===========
A program for the EDSAC
Determines whether the number stored at
address 15@ is even or odd, and prints
'E' or 'O' accordingly
Works with Initial Orders 2 ]
T56K [ load point ]
GK [ base address ]
O11@ [ print letter shift ]
T10@ [ cle... |
http://rosettacode.org/wiki/Even_or_odd | Even or odd | Task
Test whether an integer is even or odd.
There is more than one way to solve this task:
Use the even and odd predicates, if the language provides them.
Check the least significant digit. With binary integers, i bitwise-and 1 equals 0 iff i is even, or equals 1 iff i is odd.
Divide i by 2. The remainder equals... | #Eiffel | Eiffel | --bit testing
if i.bit_and (1) = 0 then
-- i is even
end
--built-in bit testing (uses bit_and)
if i.bit_test (0) then
-- i is odd
end
--integer remainder (modulo)
if i \\ 2 = 0 then
-- i is even
end |
http://rosettacode.org/wiki/Euler_method | Euler method | Euler's method numerically approximates solutions of first-order ordinary differential equations (ODEs) with a given initial value. It is an explicit method for solving initial value problems (IVPs), as described in the wikipedia page.
The ODE has to be provided in the following form:
d
y
(
t
)
d
t
=
f... | #zkl | zkl | const FMT=" %7.3f";
fcn ivp_euler(f,y,step,end_t){
print(" Step %2d: ".fmt(step));
foreach t in ([0..end_t,step]){
if (t % 10 == 0) print(FMT.fmt(y));
y += f(t,y) * step;
}
println();
}
fcn analytic{
print(" Time: ");
foreach t in ([0..100,10]){ print(" %7g".fmt(t)) }
print("\nA... |
http://rosettacode.org/wiki/Euler_method | Euler method | Euler's method numerically approximates solutions of first-order ordinary differential equations (ODEs) with a given initial value. It is an explicit method for solving initial value problems (IVPs), as described in the wikipedia page.
The ODE has to be provided in the following form:
d
y
(
t
)
d
t
=
f... | #ZX_Spectrum_Basic | ZX Spectrum Basic | 10 LET d$="-0.07*(y-20)": LET y=100: LET a=0: LET b=100: LET s=10
20 LET t=a
30 IF t<=b THEN PRINT t;TAB 10;y: LET y=y+s*VAL d$: LET t=t+s: GO TO 30 |
http://rosettacode.org/wiki/Evaluate_binomial_coefficients | Evaluate binomial coefficients | This programming task, is to calculate ANY binomial coefficient.
However, it has to be able to output
(
5
3
)
{\displaystyle {\binom {5}{3}}}
, which is 10.
This formula is recommended:
(
n
k
)
=
n
!
(
n
−
k
)
!
k
!
=
n
(
n
−
1
)
(
n
−
2
)
…
(
n
−
k
+
1
)
k
(
k
−
1... | #.D0.9C.D0.9A-61.2F52 | МК-61/52 | П1 <-> П0 ПП 22 П2 ИП1 ПП 22 П3
ИП0 ИП1 - ПП 22 ИП3 * П3 ИП2 ИП3
/ С/П ВП П0 1 ИП0 * L0 25 В/О |
http://rosettacode.org/wiki/Evaluate_binomial_coefficients | Evaluate binomial coefficients | This programming task, is to calculate ANY binomial coefficient.
However, it has to be able to output
(
5
3
)
{\displaystyle {\binom {5}{3}}}
, which is 10.
This formula is recommended:
(
n
k
)
=
n
!
(
n
−
k
)
!
k
!
=
n
(
n
−
1
)
(
n
−
2
)
…
(
n
−
k
+
1
)
k
(
k
−
1... | #Nanoquery | Nanoquery | def binomialCoeff(n, k)
result = 1
for i in range(1, k)
result = result * (n-i+1) / i
end
return result
end
if main
println binomialCoeff(5,3)
end |
http://rosettacode.org/wiki/Emirp_primes | Emirp primes | An emirp (prime spelled backwards) are primes that when reversed (in their decimal representation) are a different prime.
(This rules out palindromic primes.)
Task
show the first twenty emirps
show all emirps between 7,700 and 8,000
show the 10,000th emirp
In each list, the numbe... | #F.23 | F# |
// Generate emirps. Nigel Galloway: November 19th., 2017
let emirp =
let rec fN n g = match n with |0->g |_->fN (n/10) (g*10+n%10)
let fG n g = n<>g && isPrime g
primes32() |> Seq.filter (fun n -> fG n (fN n 0))
|
http://rosettacode.org/wiki/Elliptic_curve_arithmetic | Elliptic curve arithmetic | Elliptic curves are sometimes used in cryptography as a way to perform digital signatures.
The purpose of this task is to implement a simplified (without modular arithmetic) version of the elliptic curve arithmetic which is required by the elliptic curve DSA protocol.
In a nutshell, an elliptic curve is a... | #Sage | Sage | Ellie = EllipticCurve(RR,[0,7]) # RR = field of real numbers
# a point (x,y) on Ellie, given y
def point ( y) :
x = var('x')
x = (y^2 - 7 - x^3).roots(x,ring=RR,multiplicities = False)[0]
P = Ellie([x,y])
return P
print(Ellie)
P = point(1)
print('P',P)
Q = point(2)
print('Q',Q)
S = P+Q
print('S = P ... |
http://rosettacode.org/wiki/Elliptic_curve_arithmetic | Elliptic curve arithmetic | Elliptic curves are sometimes used in cryptography as a way to perform digital signatures.
The purpose of this task is to implement a simplified (without modular arithmetic) version of the elliptic curve arithmetic which is required by the elliptic curve DSA protocol.
In a nutshell, an elliptic curve is a... | #Sidef | Sidef | module EC {
var A = 0
var B = 7
class Horizon {
method to_s {
"EC Point at horizon"
}
method *(_) {
self
}
method -(_) {
self
}
}
class Point(Number x, Number y) {
method to_s {
"EC Poin... |
http://rosettacode.org/wiki/Enumerations | Enumerations | Task
Create an enumeration of constants with and without explicit values.
| #PHP | PHP | // Using an array/hash
$fruits = array( "apple", "banana", "cherry" );
$fruits = array( "apple" => 0, "banana" => 1, "cherry" => 2 );
// If you are inside a class scope
class Fruit {
const APPLE = 0;
const BANANA = 1;
const CHERRY = 2;
}
// Then you can access them as such
$value = Fruit::APPLE;
// Or, you ... |
http://rosettacode.org/wiki/Enumerations | Enumerations | Task
Create an enumeration of constants with and without explicit values.
| #Picat | Picat | fruit(apple,1).
fruit(banana,2).
fruit(cherry,4).
print_fruit_name(N) :-
fruit(Name,N),
printf("It is %w\nn", Name). |
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... | #C.2B.2B | C++ | #include <string>
// ...
// empty string declaration
std::string str; // (default constructed)
std::string str(); // (default constructor, no parameters)
std::string str{}; // (default initialized)
std::string str(""); // (const char[] conversion)
std::string str{""}; // (const char[]... |
http://rosettacode.org/wiki/Empty_directory | Empty directory | Starting with a path to some directory, determine whether the directory is empty.
An empty directory contains no files nor subdirectories.
With Unix or Windows systems, every directory contains an entry for “.” and almost every directory contains “..” (except for a root directory); an empty directory contains no other... | #Mathematica_.2F_Wolfram_Language | Mathematica / Wolfram Language | EmptyDirectoryQ[x_] := (SetDirectory[x]; If[FileNames[] == {}, True, False])
Example use:
EmptyDirectoryQ["C:\\Program Files\\Wolfram Research\\Mathematica\\9"]
->True |
http://rosettacode.org/wiki/Empty_directory | Empty directory | Starting with a path to some directory, determine whether the directory is empty.
An empty directory contains no files nor subdirectories.
With Unix or Windows systems, every directory contains an entry for “.” and almost every directory contains “..” (except for a root directory); an empty directory contains no other... | #MATLAB_.2F_Octave | MATLAB / Octave |
function x = isEmptyDirectory(p)
if isdir(p)
f = dir(p)
x = length(f)>2;
else
error('Error: %s is not a directory');
end;
end;
|
http://rosettacode.org/wiki/Empty_directory | Empty directory | Starting with a path to some directory, determine whether the directory is empty.
An empty directory contains no files nor subdirectories.
With Unix or Windows systems, every directory contains an entry for “.” and almost every directory contains “..” (except for a root directory); an empty directory contains no other... | #min | min | (ls bool not) :empty-dir? |
http://rosettacode.org/wiki/Empty_directory | Empty directory | Starting with a path to some directory, determine whether the directory is empty.
An empty directory contains no files nor subdirectories.
With Unix or Windows systems, every directory contains an entry for “.” and almost every directory contains “..” (except for a root directory); an empty directory contains no other... | #MS-DOS | MS-DOS | C:\>rd GAMES
Unable to remove: GAMES.
C:\> |
http://rosettacode.org/wiki/Empty_program | Empty program | Task
Create the simplest possible program that is still considered "correct."
| #bc | bc | * |
http://rosettacode.org/wiki/Empty_program | Empty program | Task
Create the simplest possible program that is still considered "correct."
| #Beeswax | Beeswax | * |
http://rosettacode.org/wiki/Empty_program | Empty program | Task
Create the simplest possible program that is still considered "correct."
| #Befunge | Befunge | @
|
http://rosettacode.org/wiki/Entropy | Entropy | Task
Calculate the Shannon entropy H of a given input string.
Given the discrete random variable
X
{\displaystyle X}
that is a string of
N
{\displaystyle N}
"symbols" (total characters) consisting of
n
{\displaystyle n}
different characters (n=2 for binary), the Shannon entropy of X in bit... | #Erlang | Erlang |
-module( entropy ).
-export( [shannon/1, task/0] ).
shannon( String ) -> shannon_information_content( lists:foldl(fun count/2, dict:new(), String), erlang:length(String) ).
task() -> shannon( "1223334444" ).
count( Character, Dict ) -> dict:update_counter( Character, 1, Dict ).
shannon_information_conte... |
http://rosettacode.org/wiki/Ethiopian_multiplication | Ethiopian multiplication | Ethiopian multiplication is a method of multiplying integers using only addition, doubling, and halving.
Method:
Take two numbers to be multiplied and write them down at the top of two columns.
In the left-hand column repeatedly halve the last number, discarding any remainders, and write the result below the last ... | #Draco | Draco | proc nonrec halve(word n) word: n >> 1 corp
proc nonrec double(word n) word: n << 1 corp
proc nonrec even(word n) bool: n & 1 = 0 corp
proc nonrec emul(word a, b) word:
word total;
total := 0;
while a > 0 do
if not even(a) then total := total + b fi;
a := halve(a);
b :=... |
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}
... | #Nim | Nim | import math, sequtils, strutils
iterator eqindex(data: openArray[int]): int =
var suml, ddelayed = 0
var sumr = sum(data)
for i,d in data:
suml += ddelayed
sumr -= d
ddelayed = d
if suml == sumr:
yield i
const d = @[@[-7, 1, 5, 2, -4, 3, 0],
@[2, 4, 6],
@[2, 9, 2]... |
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}
... | #Objeck | Objeck | class Rosetta {
function : Main(args : String[]) ~ Nil {
sequence := [-7, 1, 5, 2, -4, 3, 0];
EqulibriumIndices(sequence);
}
function : EqulibriumIndices(sequence : Int[]) ~ Nil {
# find total sum
totalSum := 0;
each(i : sequence) {
totalSum += sequence[i];
};
# compare runni... |
http://rosettacode.org/wiki/Environment_variables | Environment variables | Task
Show how to get one of your process's environment variables.
The available variables vary by system; some of the common ones available on Unix include:
PATH
HOME
USER
| #Seed7 | Seed7 | $ include "seed7_05.s7i";
const proc: main is func
begin
writeln(getenv("HOME"));
end func; |
http://rosettacode.org/wiki/Environment_variables | Environment variables | Task
Show how to get one of your process's environment variables.
The available variables vary by system; some of the common ones available on Unix include:
PATH
HOME
USER
| #Sidef | Sidef | say ENV{'HOME'}; |
http://rosettacode.org/wiki/Environment_variables | Environment variables | Task
Show how to get one of your process's environment variables.
The available variables vary by system; some of the common ones available on Unix include:
PATH
HOME
USER
| #Slate | Slate | Environment variables at: 'PATH'.
"==> '/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games'" |
http://rosettacode.org/wiki/Environment_variables | Environment variables | Task
Show how to get one of your process's environment variables.
The available variables vary by system; some of the common ones available on Unix include:
PATH
HOME
USER
| #Smalltalk | Smalltalk |
OSProcess thisOSProcess environment at: #HOME.
OSProcess thisOSProcess environment at: #PATH.
OSProcess thisOSProcess environment at: #USER.
|
http://rosettacode.org/wiki/Environment_variables | Environment variables | Task
Show how to get one of your process's environment variables.
The available variables vary by system; some of the common ones available on Unix include:
PATH
HOME
USER
| #SNOBOL4 | SNOBOL4 | output = host(4,'PATH')
end |
http://rosettacode.org/wiki/Euler%27s_sum_of_powers_conjecture | Euler's sum of powers conjecture | There is a conjecture in mathematics that held for over two hundred years before it was disproved by the finding of a counterexample in 1966 by Lander and Parkin.
Euler's (disproved) sum of powers conjecture
At least k positive kth powers are required to sum to a kth power,
except for the trivial case... | #Kotlin | Kotlin | fun main(args: Array<String>) {
val p5 = LongArray(250){ it.toLong() * it * it * it * it }
var sum: Long
var y: Int
var found = false
loop@ for (x0 in 0 .. 249)
for (x1 in 0 .. x0 - 1)
for (x2 in 0 .. x1 - 1)
for (x3 in 0 .. x2 - 1) {
sum = p5[... |
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... | #Oz | Oz | fun {Fac1 N}
{FoldL {List.number 1 N 1} Number.'*' 1}
end |
http://rosettacode.org/wiki/Even_or_odd | Even or odd | Task
Test whether an integer is even or odd.
There is more than one way to solve this task:
Use the even and odd predicates, if the language provides them.
Check the least significant digit. With binary integers, i bitwise-and 1 equals 0 iff i is even, or equals 1 iff i is odd.
Divide i by 2. The remainder equals... | #Elixir | Elixir | defmodule RC do
import Integer
def even_or_odd(n) when is_even(n), do: "#{n} is even"
def even_or_odd(n) , do: "#{n} is odd"
# In second "def", the guard clauses of "is_odd(n)" is unnecessary.
# Another definition way
def even_or_odd2(n) do
if is_even(n), do: "#{n} is even", else:... |
http://rosettacode.org/wiki/Even_or_odd | Even or odd | Task
Test whether an integer is even or odd.
There is more than one way to solve this task:
Use the even and odd predicates, if the language provides them.
Check the least significant digit. With binary integers, i bitwise-and 1 equals 0 iff i is even, or equals 1 iff i is odd.
Divide i by 2. The remainder equals... | #Emacs_Lisp | Emacs Lisp | (require 'cl-lib)
(defun even-or-odd-p (n)
(if (cl-evenp n) 'even 'odd))
(defun even-or-odd-p (n)
(if (zerop (% n 2)) 'even 'odd))
(message "%d is %s" 3 (even-or-oddp 3))
(message "%d is %s" 2 (even-or-oddp 2)) |
http://rosettacode.org/wiki/Evaluate_binomial_coefficients | Evaluate binomial coefficients | This programming task, is to calculate ANY binomial coefficient.
However, it has to be able to output
(
5
3
)
{\displaystyle {\binom {5}{3}}}
, which is 10.
This formula is recommended:
(
n
k
)
=
n
!
(
n
−
k
)
!
k
!
=
n
(
n
−
1
)
(
n
−
2
)
…
(
n
−
k
+
1
)
k
(
k
−
1... | #Nim | Nim | proc binomialCoeff(n, k: int): int =
result = 1
for i in 1..k:
result = result * (n-i+1) div i
echo binomialCoeff(5, 3) |
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