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/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
| #MATLAB_.2F_Octave | MATLAB / Octave |
funName = 'foo'; % generate function name
feval (funNAME, ...) % evaluation function with optional parameters
funName = 'a=atan(pi)'; % generate function name
eval (funName, 'printf(''Error\n'')')
|
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
| #Objective-C | Objective-C | #import <Foundation/Foundation.h>
@interface Example : NSObject
- (NSNumber *)foo;
@end
@implementation Example
- (NSNumber *)foo {
return @42;
}
@end
int main (int argc, const char *argv[]) {
@autoreleasepool {
id example = [[Example alloc] init];
SEL selector = @selector(foo); // or = NSSelectorFromString(@"foo");
NSLog(@"%@", [example performSelector:selector]);
}
return 0;
} |
http://rosettacode.org/wiki/Sieve_of_Eratosthenes | Sieve of Eratosthenes | This task has been clarified. Its programming examples are in need of review to ensure that they still fit the requirements of the task.
The Sieve of Eratosthenes is a simple algorithm that finds the prime numbers up to a given integer.
Task
Implement the Sieve of Eratosthenes algorithm, with the only allowed optimization that the outer loop can stop at the square root of the limit, and the inner loop may start at the square of the prime just found.
That means especially that you shouldn't optimize by using pre-computed wheels, i.e. don't assume you need only to cross out odd numbers (wheel based on 2), numbers equal to 1 or 5 modulo 6 (wheel based on 2 and 3), or similar wheels based on low primes.
If there's an easy way to add such a wheel based optimization, implement it as an alternative version.
Note
It is important that the sieve algorithm be the actual algorithm used to find prime numbers for the task.
Related tasks
Emirp primes
count in factors
prime decomposition
factors of an integer
extensible prime generator
primality by trial division
factors of a Mersenne number
trial factoring of a Mersenne number
partition an integer X into N primes
sequence of primes by Trial Division
| #Agda | Agda |
-- imports
open import Data.Nat as ℕ using (ℕ; suc; zero; _+_; _∸_)
open import Data.Vec as Vec using (Vec; _∷_; []; tabulate; foldr)
open import Data.Fin as Fin using (Fin; suc; zero)
open import Function using (_∘_; const; id)
open import Data.List as List using (List; _∷_; [])
open import Data.Maybe using (Maybe; just; nothing)
-- Without square cutoff optimization
module Simple where
primes : ∀ n → List (Fin n)
primes zero = []
primes (suc zero) = []
primes (suc (suc zero)) = []
primes (suc (suc (suc m))) = sieve (tabulate (just ∘ suc))
where
sieve : ∀ {n} → Vec (Maybe (Fin (2 + m))) n → List (Fin (3 + m))
sieve [] = []
sieve (nothing ∷ xs) = sieve xs
sieve (just x ∷ xs) = suc x ∷ sieve (foldr B remove (const []) xs x)
where
B = λ n → ∀ {i} → Fin i → Vec (Maybe (Fin (2 + m))) n
remove : ∀ {n} → Maybe (Fin (2 + m)) → B n → B (suc n)
remove _ ys zero = nothing ∷ ys x
remove y ys (suc z) = y ∷ ys z
-- With square cutoff optimization
module SquareOpt where
primes : ∀ n → List (Fin n)
primes zero = []
primes (suc zero) = []
primes (suc (suc zero)) = []
primes (suc (suc (suc m))) = sieve 1 m (Vec.tabulate (just ∘ Fin.suc ∘ Fin.suc))
where
sieve : ∀ {n} → ℕ → ℕ → Vec (Maybe (Fin (3 + m))) n → List (Fin (3 + m))
sieve _ zero = List.mapMaybe id ∘ Vec.toList
sieve _ (suc _) [] = []
sieve i (suc l) (nothing ∷ xs) = sieve (suc i) (l ∸ i ∸ i) xs
sieve i (suc l) (just x ∷ xs) = x ∷ sieve (suc i) (l ∸ i ∸ i) (Vec.foldr B remove (const []) xs i)
where
B = λ n → ℕ → Vec (Maybe (Fin (3 + m))) n
remove : ∀ {i} → Maybe (Fin (3 + m)) → B i → B (suc i)
remove _ ys zero = nothing ∷ ys i
remove y ys (suc j) = y ∷ ys j
|
http://rosettacode.org/wiki/Sequence_of_primorial_primes | Sequence of primorial primes | The sequence of primorial primes is given as the increasing values of n where primorial(n) ± 1 is prime.
Noting that the n'th primorial is defined as the multiplication of the smallest n primes, the sequence is of the number of primes, in order that when multiplied together is one-off being a prime number itself.
Task
Generate and show here the first ten values of the sequence.
Optional extended task
Show the first twenty members of the series.
Notes
This task asks for the primorial indices that create the final primorial prime numbers, so there should be no ten-or-more digit numbers in the program output (although extended precision integers will be needed for intermediate results).
There is some confusion in the references, but for the purposes of this task the sequence begins with n = 1.
Probabilistic primality tests are allowed, as long as they are good enough such that the output shown is correct.
Related tasks
Primorial numbers
Factorial
See also
Primorial prime Wikipedia.
Primorial prime from The Prime Glossary.
Sequence A088411 from The On-Line Encyclopedia of Integer Sequences
| #PARI.2FGP | PARI/GP | n=0; P=1; forprime(p=2,, P*=p; n++; if(ispseudoprime(P+1) || ispseudoprime(P-1), print1(n", "))) |
http://rosettacode.org/wiki/Sequence_of_primorial_primes | Sequence of primorial primes | The sequence of primorial primes is given as the increasing values of n where primorial(n) ± 1 is prime.
Noting that the n'th primorial is defined as the multiplication of the smallest n primes, the sequence is of the number of primes, in order that when multiplied together is one-off being a prime number itself.
Task
Generate and show here the first ten values of the sequence.
Optional extended task
Show the first twenty members of the series.
Notes
This task asks for the primorial indices that create the final primorial prime numbers, so there should be no ten-or-more digit numbers in the program output (although extended precision integers will be needed for intermediate results).
There is some confusion in the references, but for the purposes of this task the sequence begins with n = 1.
Probabilistic primality tests are allowed, as long as they are good enough such that the output shown is correct.
Related tasks
Primorial numbers
Factorial
See also
Primorial prime Wikipedia.
Primorial prime from The Prime Glossary.
Sequence A088411 from The On-Line Encyclopedia of Integer Sequences
| #Perl | Perl | use ntheory ":all";
my $i = 0;
for (1..1e6) {
my $n = pn_primorial($_);
if (is_prime($n-1) || is_prime($n+1)) {
print "$_\n";
last if ++$i >= 20;
}
} |
http://rosettacode.org/wiki/Sequence:_nth_number_with_exactly_n_divisors | Sequence: nth number with exactly n divisors | Calculate the sequence where each term an is the nth that has n divisors.
Task
Show here, on this page, at least the first 15 terms of the sequence.
See also
OEIS:A073916
Related tasks
Sequence: smallest number greater than previous term with exactly n divisors
Sequence: smallest number with exactly n divisors | #Sidef | Sidef | func f(n {.is_prime}) {
n.prime**(n-1)
}
func f(n) {
n.th { .sigma0 == n }
}
say 20.of { f(_+1) } |
http://rosettacode.org/wiki/Sequence:_nth_number_with_exactly_n_divisors | Sequence: nth number with exactly n divisors | Calculate the sequence where each term an is the nth that has n divisors.
Task
Show here, on this page, at least the first 15 terms of the sequence.
See also
OEIS:A073916
Related tasks
Sequence: smallest number greater than previous term with exactly n divisors
Sequence: smallest number with exactly n divisors | #Wren | Wren | import "/math" for Int
import "/big" for BigInt
import "/fmt" for Fmt
var MAX = 33
var primes = Int.primeSieve(MAX * 5)
System.print("The first %(MAX) terms in the sequence are:")
for (i in 1..MAX) {
if (Int.isPrime(i)) {
var z = BigInt.new(primes[i-1]).pow(i-1)
Fmt.print("$2d : $i", i, z)
} else {
var count = 0
var j = 1
while (true) {
var cont = false
if (i % 2 == 1) {
var sq = j.sqrt.floor
if (sq * sq != j) {
j = j + 1
cont = true
}
}
if (!cont) {
if (Int.divisors(j).count == i) {
count = count + 1
if (count == i) {
Fmt.print("$2d : $d", i, j)
break
}
}
j = j + 1
}
}
}
} |
http://rosettacode.org/wiki/Set_consolidation | Set consolidation | Given two sets of items then if any item is common to any set then the result of applying consolidation to those sets is a set of sets whose contents is:
The two input sets if no common item exists between the two input sets of items.
The single set that is the union of the two input sets if they share a common item.
Given N sets of items where N>2 then the result is the same as repeatedly replacing all combinations of two sets by their consolidation until no further consolidation between set pairs is possible.
If N<2 then consolidation has no strict meaning and the input can be returned.
Example 1:
Given the two sets {A,B} and {C,D} then there is no common element between the sets and the result is the same as the input.
Example 2:
Given the two sets {A,B} and {B,D} then there is a common element B between the sets and the result is the single set {B,D,A}. (Note that order of items in a set is immaterial: {A,B,D} is the same as {B,D,A} and {D,A,B}, etc).
Example 3:
Given the three sets {A,B} and {C,D} and {D,B} then there is no common element between the sets {A,B} and {C,D} but the sets {A,B} and {D,B} do share a common element that consolidates to produce the result {B,D,A}. On examining this result with the remaining set, {C,D}, they share a common element and so consolidate to the final output of the single set {A,B,C,D}
Example 4:
The consolidation of the five sets:
{H,I,K}, {A,B}, {C,D}, {D,B}, and {F,G,H}
Is the two sets:
{A, C, B, D}, and {G, F, I, H, K}
See also
Connected component (graph theory)
Range consolidation
| #Kotlin | Kotlin | // version 1.0.6
fun<T : Comparable<T>> consolidateSets(sets: Array<Set<T>>): Set<Set<T>> {
val size = sets.size
val consolidated = BooleanArray(size) // all false by default
var i = 0
while (i < size - 1) {
if (!consolidated[i]) {
while (true) {
var intersects = 0
for (j in (i + 1) until size) {
if (consolidated[j]) continue
if (sets[i].intersect(sets[j]).isNotEmpty()) {
sets[i] = sets[i].union(sets[j])
consolidated[j] = true
intersects++
}
}
if (intersects == 0) break
}
}
i++
}
return (0 until size).filter { !consolidated[it] }.map { sets[it].toSortedSet() }.toSet()
}
fun main(args: Array<String>) {
val unconsolidatedSets = arrayOf(
arrayOf(setOf('A', 'B'), setOf('C', 'D')),
arrayOf(setOf('A', 'B'), setOf('B', 'D')),
arrayOf(setOf('A', 'B'), setOf('C', 'D'), setOf('D', 'B')),
arrayOf(setOf('H', 'I', 'K'), setOf('A', 'B'), setOf('C', 'D'), setOf('D', 'B'), setOf('F', 'G', 'H'))
)
for (sets in unconsolidatedSets) println(consolidateSets(sets))
} |
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 n divisors
See also
OEIS:A005179
| #Perl | Perl | use strict;
use warnings;
use ntheory 'divisors';
print "First 15 terms of OEIS: A005179\n";
for my $n (1..15) {
my $l = 0;
while (++$l) {
print "$l " and last if $n == divisors($l);
}
} |
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 n divisors
See also
OEIS:A005179
| #Phix | Phix | with javascript_semantics
constant limit = 15
sequence res = repeat(0,limit)
integer found = 0, n = 1
while found<limit do
integer k = length(factors(n,1))
if k<=limit and res[k]=0 then
res[k] = n
found += 1
end if
n += 1
end while
printf(1,"The first %d terms are: %V\n",{limit,res})
|
http://rosettacode.org/wiki/SHA-256 | SHA-256 | SHA-256 is the recommended stronger alternative to SHA-1. See FIPS PUB 180-4 for implementation details.
Either by using a dedicated library or implementing the algorithm in your language, show that the SHA-256 digest of the string "Rosetta code" is: 764faf5c61ac315f1497f9dfa542713965b785e5cc2f707d6468d7d1124cdfcf
| #PureBasic | PureBasic | a$="Rosetta code"
bit.i= 256
UseSHA2Fingerprint() : b$=StringFingerprint(a$, #PB_Cipher_SHA2, bit)
OpenConsole()
Print("[SHA2 "+Str(bit)+" bit] Text: "+a$+" ==> "+b$)
Input() |
http://rosettacode.org/wiki/Sequence:_smallest_number_greater_than_previous_term_with_exactly_n_divisors | Sequence: smallest number greater than previous term with exactly n divisors | Calculate the sequence where each term an is the smallest natural number greater than the previous term, that has exactly n divisors.
Task
Show here, on this page, at least the first 15 terms of the sequence.
See also
OEIS:A069654
Related tasks
Sequence: smallest number with exactly n divisors
Sequence: nth number with exactly n divisors
| #REXX | REXX | /*REXX program finds and displays N numbers of the "anti─primes plus" sequence. */
parse arg N . /*obtain optional argument from the CL.*/
if N=='' | N=="," then N= 15 /*Not specified? Then use the default.*/
idx= 1 /*the maximum number of divisors so far*/
say '──index── ──anti─prime plus──' /*display a title for the numbers shown*/
#= 0 /*the count of anti─primes found " " */
do i=1 until #==N /*step through possible numbers by twos*/
d= #divs(i); if d\==idx then iterate /*get # divisors; Is too small? Skip.*/
#= # + 1; idx= idx + 1 /*found an anti─prime #; set new minD.*/
say center(#, 8) right(i, 15) /*display the index and the anti─prime.*/
end /*i*/
exit 0 /*stick a fork in it, we're all done. */
/*──────────────────────────────────────────────────────────────────────────────────────*/
#divs: procedure; parse arg x 1 y /*X and Y: both set from 1st argument.*/
if x<7 then do /*handle special cases for numbers < 7.*/
if x<3 then return x /* " " " " one and two.*/
if x<5 then return x - 1 /* " " " " three & four*/
if x==5 then return 2 /* " " " " five. */
if x==6 then return 4 /* " " " " six. */
end
odd= x // 2 /*check if X is odd or not. */
if odd then #= 1; /*Odd? Assume Pdivisors count of 1.*/
else do; #= 3; y= x % 2 /*Even? " " " " 3.*/
end /* [↑] Even, so add 2 known divisors.*/
/* [↓] start with known number of Pdivs*/
do k=3 for x%2-3 by 1+odd while k<y /*for odd numbers, skip over the evens.*/
if x//k==0 then do /*if no remainder, then found a divisor*/
#= # + 2; y= x % k /*bump the # Pdivs; calculate limit Y.*/
if k>=y then do; #= # - 1; leave
end /* [↑] has the limit been reached? */
end /* ___ */
else if k*k>x then leave /*only divide up to the √ x */
end /*k*/ /* [↑] this form of DO loop is faster.*/
return # + 1 /*bump "proper divisors" to "divisors".*/ |
http://rosettacode.org/wiki/SHA-1 | SHA-1 | SHA-1 or SHA1 is a one-way hash function;
it computes a 160-bit message digest.
SHA-1 often appears in security protocols; for example,
many HTTPS websites use RSA with SHA-1 to secure their connections.
BitTorrent uses SHA-1 to verify downloads.
Git and Mercurial use SHA-1 digests to identify commits.
A US government standard, FIPS 180-1, defines SHA-1.
Find the SHA-1 message digest for a string of octets. You may either call a SHA-1 library, or implement SHA-1 in your language. Both approaches interest Rosetta Code.
Warning: SHA-1 has known weaknesses. Theoretical attacks may find a collision after 252 operations, or perhaps fewer.
This is much faster than a brute force attack of 280 operations. USgovernment deprecated SHA-1.
For production-grade cryptography, users may consider a stronger alternative, such as SHA-256 (from the SHA-2 family) or the upcoming SHA-3.
| #PureBasic | PureBasic | a$="Rosetta Code"
UseSHA1Fingerprint() : b$=StringFingerprint(a$, #PB_Cipher_SHA1)
OpenConsole()
Print("[SHA1] Text: "+a$+" ==> "+b$)
Input() |
http://rosettacode.org/wiki/SHA-1 | SHA-1 | SHA-1 or SHA1 is a one-way hash function;
it computes a 160-bit message digest.
SHA-1 often appears in security protocols; for example,
many HTTPS websites use RSA with SHA-1 to secure their connections.
BitTorrent uses SHA-1 to verify downloads.
Git and Mercurial use SHA-1 digests to identify commits.
A US government standard, FIPS 180-1, defines SHA-1.
Find the SHA-1 message digest for a string of octets. You may either call a SHA-1 library, or implement SHA-1 in your language. Both approaches interest Rosetta Code.
Warning: SHA-1 has known weaknesses. Theoretical attacks may find a collision after 252 operations, or perhaps fewer.
This is much faster than a brute force attack of 280 operations. USgovernment deprecated SHA-1.
For production-grade cryptography, users may consider a stronger alternative, such as SHA-256 (from the SHA-2 family) or the upcoming SHA-3.
| #Python | Python | import hashlib
h = hashlib.sha1()
h.update(bytes("Ars longa, vita brevis", encoding="ASCII"))
h.hexdigest()
# "e640d285242886eb96ab80cbf858389b3df52f43" |
http://rosettacode.org/wiki/Show_ASCII_table | Show ASCII table | Task
Show the ASCII character set from values 32 to 127 (decimal) in a table format.
Other tasks related to string operations:
Metrics
Array length
String length
Copy a string
Empty string (assignment)
Counting
Word frequency
Letter frequency
Jewels and stones
I before E except after C
Bioinformatics/base count
Count occurrences of a substring
Count how many vowels and consonants occur in a string
Remove/replace
XXXX redacted
Conjugate a Latin verb
Remove vowels from a string
String interpolation (included)
Strip block comments
Strip comments from a string
Strip a set of characters from a string
Strip whitespace from a string -- top and tail
Strip control codes and extended characters from a string
Anagrams/Derangements/shuffling
Word wheel
ABC problem
Sattolo cycle
Knuth shuffle
Ordered words
Superpermutation minimisation
Textonyms (using a phone text pad)
Anagrams
Anagrams/Deranged anagrams
Permutations/Derangements
Find/Search/Determine
ABC words
Odd words
Word ladder
Semordnilap
Word search
Wordiff (game)
String matching
Tea cup rim text
Alternade words
Changeable words
State name puzzle
String comparison
Unique characters
Unique characters in each string
Extract file extension
Levenshtein distance
Palindrome detection
Common list elements
Longest common suffix
Longest common prefix
Compare a list of strings
Longest common substring
Find common directory path
Words from neighbour ones
Change e letters to i in words
Non-continuous subsequences
Longest common subsequence
Longest palindromic substrings
Longest increasing subsequence
Words containing "the" substring
Sum of the digits of n is substring of n
Determine if a string is numeric
Determine if a string is collapsible
Determine if a string is squeezable
Determine if a string has all unique characters
Determine if a string has all the same characters
Longest substrings without repeating characters
Find words which contains all the vowels
Find words which contains most consonants
Find words which contains more than 3 vowels
Find words which first and last three letters are equals
Find words which odd letters are consonants and even letters are vowels or vice_versa
Formatting
Substring
Rep-string
Word wrap
String case
Align columns
Literals/String
Repeat a string
Brace expansion
Brace expansion using ranges
Reverse a string
Phrase reversals
Comma quibbling
Special characters
String concatenation
Substring/Top and tail
Commatizing numbers
Reverse words in a string
Suffixation of decimal numbers
Long literals, with continuations
Numerical and alphabetical suffixes
Abbreviations, easy
Abbreviations, simple
Abbreviations, automatic
Song lyrics/poems/Mad Libs/phrases
Mad Libs
Magic 8-ball
99 Bottles of Beer
The Name Game (a song)
The Old lady swallowed a fly
The Twelve Days of Christmas
Tokenize
Text between
Tokenize a string
Word break problem
Tokenize a string with escaping
Split a character string based on change of character
Sequences
Show ASCII table
De Bruijn sequences
Self-referential sequences
Generate lower case ASCII alphabet
| #Lua | Lua |
-- map of character values to desired representation
local chars = setmetatable({[32] = "Spc", [127] = "Del"}, {__index = function(_, k) return string.char(k) end})
-- row iterator
local function iter(s,a)
a = (a or s) + 16
if a <= 127 then return a, chars[a] end
end
-- print loop
for i = 0, 15 do
for j, repr in iter, i+16 do
io.write(("%3d : %3s "):format(j, repr))
end
io.write"\n"
end |
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:
*
* *
* *
* * * *
* *
* * * *
* * * *
* * * * * * * *
* *
* * * *
* * * *
* * * * * * * *
* * * *
* * * * * * * *
* * * * * * * *
* * * * * * * * * * * * * * * *
Related tasks
Sierpinski triangle/Graphical for graphics images of this pattern.
Sierpinski carpet
| #Python | Python | def sierpinski(n):
d = ["*"]
for i in xrange(n):
sp = " " * (2 ** i)
d = [sp+x+sp for x in d] + [x+" "+x for x in d]
return d
print "\n".join(sierpinski(4)) |
http://rosettacode.org/wiki/Sierpinski_carpet | Sierpinski carpet | Task
Produce a graphical or ASCII-art representation of a Sierpinski carpet of order N.
For example, the Sierpinski carpet of order 3 should look like this:
###########################
# ## ## ## ## ## ## ## ## #
###########################
### ###### ###### ###
# # # ## # # ## # # #
### ###### ###### ###
###########################
# ## ## ## ## ## ## ## ## #
###########################
######### #########
# ## ## # # ## ## #
######### #########
### ### ### ###
# # # # # # # #
### ### ### ###
######### #########
# ## ## # # ## ## #
######### #########
###########################
# ## ## ## ## ## ## ## ## #
###########################
### ###### ###### ###
# # # ## # # ## # # #
### ###### ###### ###
###########################
# ## ## ## ## ## ## ## ## #
###########################
The use of the # character is not rigidly required for ASCII art.
The important requirement is the placement of whitespace and non-whitespace characters.
Related task
Sierpinski triangle
| #Order | Order | #include <order/interpreter.h>
#define ORDER_PP_DEF_8in_carpet ORDER_PP_FN( \
8fn(8X, 8Y, \
8if(8or(8is_0(8X), 8is_0(8Y)), \
8true, \
8let((8Q, 8quotient(8X, 3)) \
(8R, 8remainder(8X, 3)) \
(8S, 8quotient(8Y, 3)) \
(8T, 8remainder(8Y, 3)), \
8and(8not(8and(8equal(8R, 1), 8equal(8T, 1))), \
8in_carpet(8Q, 8S))))) )
#define ORDER_PP_DEF_8carpet ORDER_PP_FN( \
8fn(8N, \
8lets((8R, 8seq_iota(0, 8pow(3, 8N))) \
(8G, 8seq_map(8fn(8Y, 8seq_map(8fn(8X, 8pair(8X, 8Y)), \
8R)), \
8R)), \
8seq_map(8fn(8S, 8seq_map(8fn(8P, 8apply(8in_carpet, 8P)), \
8S)), \
8G))) )
#define ORDER_PP_DEF_8carpet_to_string ORDER_PP_FN( \
8fn(8C, \
8seq_fold( \
8fn(8R, 8S, \
8adjoin(8R, \
8seq_fold(8fn(8P, 8B, 8adjoin(8P, 8if(8B, 8("#"), 8(" ")))), \
8nil, 8S), \
8("\n"))), \
8nil, 8C)) )
#include <stdio.h>
int main(void) {
printf(ORDER_PP( 8carpet_to_string(8carpet(3)) ));
return 0;
} |
http://rosettacode.org/wiki/Semordnilap | Semordnilap | A semordnilap is a word (or phrase) that spells a different word (or phrase) backward. "Semordnilap" is a word that itself is a semordnilap.
Example: lager and regal
Task
This task does not consider semordnilap phrases, only single words.
Using only words from this list, report the total number of unique semordnilap pairs, and print 5 examples.
Two matching semordnilaps, such as lager and regal, should be counted as one unique pair.
(Note that the word "semordnilap" is not in the above dictionary.)
Other tasks related to string operations:
Metrics
Array length
String length
Copy a string
Empty string (assignment)
Counting
Word frequency
Letter frequency
Jewels and stones
I before E except after C
Bioinformatics/base count
Count occurrences of a substring
Count how many vowels and consonants occur in a string
Remove/replace
XXXX redacted
Conjugate a Latin verb
Remove vowels from a string
String interpolation (included)
Strip block comments
Strip comments from a string
Strip a set of characters from a string
Strip whitespace from a string -- top and tail
Strip control codes and extended characters from a string
Anagrams/Derangements/shuffling
Word wheel
ABC problem
Sattolo cycle
Knuth shuffle
Ordered words
Superpermutation minimisation
Textonyms (using a phone text pad)
Anagrams
Anagrams/Deranged anagrams
Permutations/Derangements
Find/Search/Determine
ABC words
Odd words
Word ladder
Semordnilap
Word search
Wordiff (game)
String matching
Tea cup rim text
Alternade words
Changeable words
State name puzzle
String comparison
Unique characters
Unique characters in each string
Extract file extension
Levenshtein distance
Palindrome detection
Common list elements
Longest common suffix
Longest common prefix
Compare a list of strings
Longest common substring
Find common directory path
Words from neighbour ones
Change e letters to i in words
Non-continuous subsequences
Longest common subsequence
Longest palindromic substrings
Longest increasing subsequence
Words containing "the" substring
Sum of the digits of n is substring of n
Determine if a string is numeric
Determine if a string is collapsible
Determine if a string is squeezable
Determine if a string has all unique characters
Determine if a string has all the same characters
Longest substrings without repeating characters
Find words which contains all the vowels
Find words which contains most consonants
Find words which contains more than 3 vowels
Find words which first and last three letters are equals
Find words which odd letters are consonants and even letters are vowels or vice_versa
Formatting
Substring
Rep-string
Word wrap
String case
Align columns
Literals/String
Repeat a string
Brace expansion
Brace expansion using ranges
Reverse a string
Phrase reversals
Comma quibbling
Special characters
String concatenation
Substring/Top and tail
Commatizing numbers
Reverse words in a string
Suffixation of decimal numbers
Long literals, with continuations
Numerical and alphabetical suffixes
Abbreviations, easy
Abbreviations, simple
Abbreviations, automatic
Song lyrics/poems/Mad Libs/phrases
Mad Libs
Magic 8-ball
99 Bottles of Beer
The Name Game (a song)
The Old lady swallowed a fly
The Twelve Days of Christmas
Tokenize
Text between
Tokenize a string
Word break problem
Tokenize a string with escaping
Split a character string based on change of character
Sequences
Show ASCII table
De Bruijn sequences
Self-referential sequences
Generate lower case ASCII alphabet
| #Arturo | Arturo | words: read.lines "http://wiki.puzzlers.org/pub/wordlists/unixdict.txt"
pairs: []
loop words 'wrd [
if and? contains? words reverse wrd
wrd <> reverse wrd [
'pairs ++ @[@[wrd reverse wrd]]
print [wrd "-" reverse wrd]
]
]
unique 'pairs
print map 1..5 => [sample pairs] |
http://rosettacode.org/wiki/Semordnilap | Semordnilap | A semordnilap is a word (or phrase) that spells a different word (or phrase) backward. "Semordnilap" is a word that itself is a semordnilap.
Example: lager and regal
Task
This task does not consider semordnilap phrases, only single words.
Using only words from this list, report the total number of unique semordnilap pairs, and print 5 examples.
Two matching semordnilaps, such as lager and regal, should be counted as one unique pair.
(Note that the word "semordnilap" is not in the above dictionary.)
Other tasks related to string operations:
Metrics
Array length
String length
Copy a string
Empty string (assignment)
Counting
Word frequency
Letter frequency
Jewels and stones
I before E except after C
Bioinformatics/base count
Count occurrences of a substring
Count how many vowels and consonants occur in a string
Remove/replace
XXXX redacted
Conjugate a Latin verb
Remove vowels from a string
String interpolation (included)
Strip block comments
Strip comments from a string
Strip a set of characters from a string
Strip whitespace from a string -- top and tail
Strip control codes and extended characters from a string
Anagrams/Derangements/shuffling
Word wheel
ABC problem
Sattolo cycle
Knuth shuffle
Ordered words
Superpermutation minimisation
Textonyms (using a phone text pad)
Anagrams
Anagrams/Deranged anagrams
Permutations/Derangements
Find/Search/Determine
ABC words
Odd words
Word ladder
Semordnilap
Word search
Wordiff (game)
String matching
Tea cup rim text
Alternade words
Changeable words
State name puzzle
String comparison
Unique characters
Unique characters in each string
Extract file extension
Levenshtein distance
Palindrome detection
Common list elements
Longest common suffix
Longest common prefix
Compare a list of strings
Longest common substring
Find common directory path
Words from neighbour ones
Change e letters to i in words
Non-continuous subsequences
Longest common subsequence
Longest palindromic substrings
Longest increasing subsequence
Words containing "the" substring
Sum of the digits of n is substring of n
Determine if a string is numeric
Determine if a string is collapsible
Determine if a string is squeezable
Determine if a string has all unique characters
Determine if a string has all the same characters
Longest substrings without repeating characters
Find words which contains all the vowels
Find words which contains most consonants
Find words which contains more than 3 vowels
Find words which first and last three letters are equals
Find words which odd letters are consonants and even letters are vowels or vice_versa
Formatting
Substring
Rep-string
Word wrap
String case
Align columns
Literals/String
Repeat a string
Brace expansion
Brace expansion using ranges
Reverse a string
Phrase reversals
Comma quibbling
Special characters
String concatenation
Substring/Top and tail
Commatizing numbers
Reverse words in a string
Suffixation of decimal numbers
Long literals, with continuations
Numerical and alphabetical suffixes
Abbreviations, easy
Abbreviations, simple
Abbreviations, automatic
Song lyrics/poems/Mad Libs/phrases
Mad Libs
Magic 8-ball
99 Bottles of Beer
The Name Game (a song)
The Old lady swallowed a fly
The Twelve Days of Christmas
Tokenize
Text between
Tokenize a string
Word break problem
Tokenize a string with escaping
Split a character string based on change of character
Sequences
Show ASCII table
De Bruijn sequences
Self-referential sequences
Generate lower case ASCII alphabet
| #AutoHotkey | AutoHotkey | S := [], M := []
FileRead, dict, unixdict.txt
Loop, Parse, dict, `n, `r`n
{
r := Reverse(A_LoopField)
if (S[r])
M.Insert(r " / " A_LoopField)
else
S[A_LoopField] := 1
}
Loop, 5
Out .= "`t" M[A_Index] "`n"
MsgBox, % "5 Examples:`n" Out "`nTotal Pairs:`n`t" M.MaxIndex()
Reverse(s) {
Loop, Parse, s
r := A_LoopField . r
return r
} |
http://rosettacode.org/wiki/Short-circuit_evaluation | Short-circuit evaluation | Control Structures
These are examples of control structures. You may also be interested in:
Conditional structures
Exceptions
Flow-control structures
Loops
Assume functions a and b return boolean values, and further, the execution of function b takes considerable resources without side effects, and is to be minimized.
If we needed to compute the conjunction (and):
x = a() and b()
Then it would be best to not compute the value of b() if the value of a() is computed as false, as the value of x can then only ever be false.
Similarly, if we needed to compute the disjunction (or):
y = a() or b()
Then it would be best to not compute the value of b() if the value of a() is computed as true, as the value of y can then only ever be true.
Some languages will stop further computation of boolean equations as soon as the result is known, so-called short-circuit evaluation of boolean expressions
Task
Create two functions named a and b, that take and return the same boolean value.
The functions should also print their name whenever they are called.
Calculate and assign the values of the following equations to a variable in such a way that function b is only called when necessary:
x = a(i) and b(j)
y = a(i) or b(j)
If the language does not have short-circuit evaluation, this might be achieved with nested if statements.
| #PowerShell | PowerShell | # Simulated fast function
function a ( [boolean]$J ) { return $J }
# Simulated slow function
function b ( [boolean]$J ) { Sleep -Seconds 2; return $J }
# These all short-circuit and do not evaluate the right hand function
( a $True ) -or ( b $False )
( a $True ) -or ( b $True )
( a $False ) -and ( b $False )
( a $False ) -and ( b $True )
# Measure of execution time
Measure-Command {
( a $True ) -or ( b $False )
( a $True ) -or ( b $True )
( a $False ) -and ( b $False )
( a $False ) -and ( b $True )
} | Select TotalMilliseconds
# These all appropriately do evaluate the right hand function
( a $False ) -or ( b $False )
( a $False ) -or ( b $True )
( a $True ) -and ( b $False )
( a $True ) -and ( b $True )
# Measure of execution time
Measure-Command {
( a $False ) -or ( b $False )
( a $False ) -or ( b $True )
( a $True ) -and ( b $False )
( a $True ) -and ( b $True )
} | Select TotalMilliseconds |
http://rosettacode.org/wiki/Selectively_replace_multiple_instances_of_a_character_within_a_string | Selectively replace multiple instances of a character within a string | Task
This is admittedly a trivial task but I thought it would be interesting to see how succinctly (or otherwise) different languages can handle it.
Given the string: "abracadabra", replace programatically:
the first 'a' with 'A'
the second 'a' with 'B'
the fourth 'a' with 'C'
the fifth 'a' with 'D'
the first 'b' with 'E'
the second 'r' with 'F'
Note that there is no replacement for the third 'a', second 'b' or first 'r'.
The answer should, of course, be : "AErBcadCbFD".
Other tasks related to string operations:
Metrics
Array length
String length
Copy a string
Empty string (assignment)
Counting
Word frequency
Letter frequency
Jewels and stones
I before E except after C
Bioinformatics/base count
Count occurrences of a substring
Count how many vowels and consonants occur in a string
Remove/replace
XXXX redacted
Conjugate a Latin verb
Remove vowels from a string
String interpolation (included)
Strip block comments
Strip comments from a string
Strip a set of characters from a string
Strip whitespace from a string -- top and tail
Strip control codes and extended characters from a string
Anagrams/Derangements/shuffling
Word wheel
ABC problem
Sattolo cycle
Knuth shuffle
Ordered words
Superpermutation minimisation
Textonyms (using a phone text pad)
Anagrams
Anagrams/Deranged anagrams
Permutations/Derangements
Find/Search/Determine
ABC words
Odd words
Word ladder
Semordnilap
Word search
Wordiff (game)
String matching
Tea cup rim text
Alternade words
Changeable words
State name puzzle
String comparison
Unique characters
Unique characters in each string
Extract file extension
Levenshtein distance
Palindrome detection
Common list elements
Longest common suffix
Longest common prefix
Compare a list of strings
Longest common substring
Find common directory path
Words from neighbour ones
Change e letters to i in words
Non-continuous subsequences
Longest common subsequence
Longest palindromic substrings
Longest increasing subsequence
Words containing "the" substring
Sum of the digits of n is substring of n
Determine if a string is numeric
Determine if a string is collapsible
Determine if a string is squeezable
Determine if a string has all unique characters
Determine if a string has all the same characters
Longest substrings without repeating characters
Find words which contains all the vowels
Find words which contains most consonants
Find words which contains more than 3 vowels
Find words which first and last three letters are equals
Find words which odd letters are consonants and even letters are vowels or vice_versa
Formatting
Substring
Rep-string
Word wrap
String case
Align columns
Literals/String
Repeat a string
Brace expansion
Brace expansion using ranges
Reverse a string
Phrase reversals
Comma quibbling
Special characters
String concatenation
Substring/Top and tail
Commatizing numbers
Reverse words in a string
Suffixation of decimal numbers
Long literals, with continuations
Numerical and alphabetical suffixes
Abbreviations, easy
Abbreviations, simple
Abbreviations, automatic
Song lyrics/poems/Mad Libs/phrases
Mad Libs
Magic 8-ball
99 Bottles of Beer
The Name Game (a song)
The Old lady swallowed a fly
The Twelve Days of Christmas
Tokenize
Text between
Tokenize a string
Word break problem
Tokenize a string with escaping
Split a character string based on change of character
Sequences
Show ASCII table
De Bruijn sequences
Self-referential sequences
Generate lower case ASCII alphabet
| #Phix | Phix | with javascript_semantics
function replace_nth(string s, r)
string res = s
for i=1 to length(r) by 3 do
res[find_all(r[i],s)[r[i+1]-'0']] = r[i+2]
end for
return res
end function
?replace_nth("abracadabra","a1Aa2Ba4Ca5Db1Er2F")
-- Alternative version
function replace_nths(string s, sequence r)
for icr in r do
{sequence idx, integer ch, string reps} = icr
s = reinstate(s,extract(find_all(ch,s),idx),reps)
end for
return s
end function
constant r = {{{1,2,4,5},'a',"ABCD"},
{{1},'b',"E"},
{{2},'r',"F"}}
?replace_nths("abracadabra",r)
|
http://rosettacode.org/wiki/Selectively_replace_multiple_instances_of_a_character_within_a_string | Selectively replace multiple instances of a character within a string | Task
This is admittedly a trivial task but I thought it would be interesting to see how succinctly (or otherwise) different languages can handle it.
Given the string: "abracadabra", replace programatically:
the first 'a' with 'A'
the second 'a' with 'B'
the fourth 'a' with 'C'
the fifth 'a' with 'D'
the first 'b' with 'E'
the second 'r' with 'F'
Note that there is no replacement for the third 'a', second 'b' or first 'r'.
The answer should, of course, be : "AErBcadCbFD".
Other tasks related to string operations:
Metrics
Array length
String length
Copy a string
Empty string (assignment)
Counting
Word frequency
Letter frequency
Jewels and stones
I before E except after C
Bioinformatics/base count
Count occurrences of a substring
Count how many vowels and consonants occur in a string
Remove/replace
XXXX redacted
Conjugate a Latin verb
Remove vowels from a string
String interpolation (included)
Strip block comments
Strip comments from a string
Strip a set of characters from a string
Strip whitespace from a string -- top and tail
Strip control codes and extended characters from a string
Anagrams/Derangements/shuffling
Word wheel
ABC problem
Sattolo cycle
Knuth shuffle
Ordered words
Superpermutation minimisation
Textonyms (using a phone text pad)
Anagrams
Anagrams/Deranged anagrams
Permutations/Derangements
Find/Search/Determine
ABC words
Odd words
Word ladder
Semordnilap
Word search
Wordiff (game)
String matching
Tea cup rim text
Alternade words
Changeable words
State name puzzle
String comparison
Unique characters
Unique characters in each string
Extract file extension
Levenshtein distance
Palindrome detection
Common list elements
Longest common suffix
Longest common prefix
Compare a list of strings
Longest common substring
Find common directory path
Words from neighbour ones
Change e letters to i in words
Non-continuous subsequences
Longest common subsequence
Longest palindromic substrings
Longest increasing subsequence
Words containing "the" substring
Sum of the digits of n is substring of n
Determine if a string is numeric
Determine if a string is collapsible
Determine if a string is squeezable
Determine if a string has all unique characters
Determine if a string has all the same characters
Longest substrings without repeating characters
Find words which contains all the vowels
Find words which contains most consonants
Find words which contains more than 3 vowels
Find words which first and last three letters are equals
Find words which odd letters are consonants and even letters are vowels or vice_versa
Formatting
Substring
Rep-string
Word wrap
String case
Align columns
Literals/String
Repeat a string
Brace expansion
Brace expansion using ranges
Reverse a string
Phrase reversals
Comma quibbling
Special characters
String concatenation
Substring/Top and tail
Commatizing numbers
Reverse words in a string
Suffixation of decimal numbers
Long literals, with continuations
Numerical and alphabetical suffixes
Abbreviations, easy
Abbreviations, simple
Abbreviations, automatic
Song lyrics/poems/Mad Libs/phrases
Mad Libs
Magic 8-ball
99 Bottles of Beer
The Name Game (a song)
The Old lady swallowed a fly
The Twelve Days of Christmas
Tokenize
Text between
Tokenize a string
Word break problem
Tokenize a string with escaping
Split a character string based on change of character
Sequences
Show ASCII table
De Bruijn sequences
Self-referential sequences
Generate lower case ASCII alphabet
| #Python | Python | from collections import defaultdict
rep = {'a' : {1 : 'A', 2 : 'B', 4 : 'C', 5 : 'D'}, 'b' : {1 : 'E'}, 'r' : {2 : 'F'}}
def trstring(oldstring, repdict):
seen, newchars = defaultdict(lambda:1, {}), []
for c in oldstring:
i = seen[c]
newchars.append(repdict[c][i] if c in repdict and i in repdict[c] else c)
seen[c] += 1
return ''.join(newchars)
print('abracadabra ->', trstring('abracadabra', rep))
|
http://rosettacode.org/wiki/Send_email | Send email | Task
Write a function to send an email.
The function should have parameters for setting From, To and Cc addresses; the Subject, and the message text, and optionally fields for the server name and login details.
If appropriate, explain what notifications of problems/success are given.
Solutions using libraries or functions from the language are preferred, but failing that, external programs can be used with an explanation.
Note how portable the solution given is between operating systems when multi-OS languages are used.
(Remember to obfuscate any sensitive data used in examples)
| #Factor | Factor |
USING: accessors io.sockets locals namespaces smtp ;
IN: scratchpad
:: send-mail ( f t c s b -- )
default-smtp-config "smtp.gmail.com" 587 <inet> >>server
t >>tls?
"my.gmail.address@gmail.com" "qwertyuiasdfghjk" <plain-auth>
>>auth \ smtp-config set-global <email> f >>from t >>to
c >>cc s >>subject b >>body send-email ; |
http://rosettacode.org/wiki/Send_email | Send email | Task
Write a function to send an email.
The function should have parameters for setting From, To and Cc addresses; the Subject, and the message text, and optionally fields for the server name and login details.
If appropriate, explain what notifications of problems/success are given.
Solutions using libraries or functions from the language are preferred, but failing that, external programs can be used with an explanation.
Note how portable the solution given is between operating systems when multi-OS languages are used.
(Remember to obfuscate any sensitive data used in examples)
| #Fantom | Fantom |
using email
class Mail
{
// create a client for sending email - add your own host/username/password
static SmtpClient makeClient ()
{
client := SmtpClient
{
host = "yourhost"
username = "yourusername"
password = "yourpassword"
}
return client
}
public static Void main()
{
// create email
email := Email
{
to = ["to@addr"]
from = "from@addr"
cc = ["cc@addr"]
subject = test"
body = TextPart { text = "test email" }
}
// create client and send email
makeClient.send (email)
}
}
|
http://rosettacode.org/wiki/Semiprime | Semiprime | Semiprime numbers are natural numbers that are products of exactly two (possibly equal) prime numbers.
Semiprimes are also known as:
semi-primes
biprimes
bi-primes
2-almost primes
or simply: P2
Example
1679 = 23 × 73
(This particular number was chosen as the length of the Arecibo message).
Task
Write a function determining whether a given number is semiprime.
See also
The Wikipedia article: semiprime.
The Wikipedia article: almost prime.
The OEIS sequence: A001358: semiprimes which has a shorter definition: the product of two primes.
| #AWK | AWK |
# syntax: GAWK -f SEMIPRIME.AWK
BEGIN {
main(0,100)
main(1675,1680)
exit(0)
}
function main(lo,hi, i) {
printf("%d-%d:",lo,hi)
for (i=lo; i<=hi; i++) {
if (is_semiprime(i)) {
printf(" %d",i)
}
}
printf("\n")
}
function is_semiprime(n, i,nf) {
nf = 0
for (i=2; i<=n; i++) {
while (n % i == 0) {
if (nf == 2) {
return(0)
}
nf++
n /= i
}
}
return(nf == 2)
}
|
http://rosettacode.org/wiki/Self-describing_numbers | Self-describing numbers | Self-describing numbers
You are encouraged to solve this task according to the task description, using any language you may know.
There are several so-called "self-describing" or "self-descriptive" integers.
An integer is said to be "self-describing" if it has the property that, when digit positions are labeled 0 to N-1, the digit in each position is equal to the number of times that that digit appears in the number.
For example, 2020 is a four-digit self describing number:
position 0 has value 2 and there are two 0s in the number;
position 1 has value 0 and there are no 1s in the number;
position 2 has value 2 and there are two 2s;
position 3 has value 0 and there are zero 3s.
Self-describing numbers < 100.000.000 are: 1210, 2020, 21200, 3211000, 42101000.
Task Description
Write a function/routine/method/... that will check whether a given positive integer is self-describing.
As an optional stretch goal - generate and display the set of self-describing numbers.
Related tasks
Fours is the number of letters in the ...
Look-and-say sequence
Number names
Self-referential sequence
Spelling of ordinal numbers
| #ALGOL_68 | ALGOL 68 | BEGIN
# return TRUE if number is self describing, FALSE otherwise #
OP SELFDESCRIBING = ( INT number )BOOL:
BEGIN
[10]INT counts := ( 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 );
INT n := number;
INT digits := 0;
# count the occurances of each digit #
WHILE
n /= 0
DO
digits +:= 1;
counts[ ( n MOD 10 ) + 1 ] +:= 1;
n OVERAB 10
OD;
# construct the number that the counts would describe, #
# if the number was self describing #
INT described number := 0;
FOR i TO digits
DO
described number *:= 10;
described number +:= counts[ i ]
OD;
# if the described number is the input number, #
# it is self describing #
( number = described number )
END; # SELFDESCRIBING #
main: (
FOR i TO 100 000 000
DO
IF SELFDESCRIBING i
THEN
print( ( i, " is self describing", newline ) )
FI
OD
)
END |
http://rosettacode.org/wiki/Self_numbers | Self numbers | A number n is a self number if there is no number g such that g + the sum of g's digits = n. So 18 is not a self number because 9+9=18, 43 is not a self number because 35+5+3=43.
The task is:
Display the first 50 self numbers;
I believe that the 100000000th self number is 1022727208. You should either confirm or dispute my conjecture.
224036583-1 is a Mersenne prime, claimed to also be a self number. Extra credit to anyone proving it.
See also
OEIS: A003052 - Self numbers or Colombian numbers
Wikipedia: Self numbers | #AWK | AWK |
# syntax: GAWK -f SELF_NUMBERS.AWK
# converted from Go (low memory example)
BEGIN {
print("HH:MM:SS INDEX SELF")
print("-------- ---------- ----------")
count = 0
digits = 1
i = 1
last_self = 0
offset = 9
pow = 10
while (count < 1E8) {
is_self = 1
start = max(i-offset,0)
sum = sum_digits(start)
for (j=start; j<i; j++) {
if (j + sum == i) {
is_self = 0
break
}
sum = ((j+1) % 10 != 0) ? ++sum : sum_digits(j+1)
}
if (is_self) {
last_self = i
if (++count <= 50) {
selfs = selfs i " "
}
}
if (++i % pow == 0) {
pow *= 10
digits++
offset = digits * 9
}
if (count ~ /^10*$/ && arr[count]++ == 0) {
printf("%8s %10s %10s\n",strftime("%H:%M:%S"),count,last_self)
}
}
printf("\nfirst 50 self numbers:\n%s\n",selfs)
exit(0)
}
function sum_digits(x, sum,y) {
while (x) {
y = x % 10
sum += y
x = int(x/10)
}
return(sum)
}
function max(x,y) { return((x > y) ? x : y) }
|
http://rosettacode.org/wiki/Set_of_real_numbers | Set of real numbers | All real numbers form the uncountable set ℝ. Among its subsets, relatively simple are the convex sets, each expressed as a range between two real numbers a and b where a ≤ b. There are actually four cases for the meaning of "between", depending on open or closed boundary:
[a, b]: {x | a ≤ x and x ≤ b }
(a, b): {x | a < x and x < b }
[a, b): {x | a ≤ x and x < b }
(a, b]: {x | a < x and x ≤ b }
Note that if a = b, of the four only [a, a] would be non-empty.
Task
Devise a way to represent any set of real numbers, for the definition of 'any' in the implementation notes below.
Provide methods for these common set operations (x is a real number; A and B are sets):
x ∈ A: determine if x is an element of A
example: 1 is in [1, 2), while 2, 3, ... are not.
A ∪ B: union of A and B, i.e. {x | x ∈ A or x ∈ B}
example: [0, 2) ∪ (1, 3) = [0, 3); [0, 1) ∪ (2, 3] = well, [0, 1) ∪ (2, 3]
A ∩ B: intersection of A and B, i.e. {x | x ∈ A and x ∈ B}
example: [0, 2) ∩ (1, 3) = (1, 2); [0, 1) ∩ (2, 3] = empty set
A - B: difference between A and B, also written as A \ B, i.e. {x | x ∈ A and x ∉ B}
example: [0, 2) − (1, 3) = [0, 1]
Test your implementation by checking if numbers 0, 1, and 2 are in any of the following sets:
(0, 1] ∪ [0, 2)
[0, 2) ∩ (1, 2]
[0, 3) − (0, 1)
[0, 3) − [0, 1]
Implementation notes
'Any' real set means 'sets that can be expressed as the union of a finite number of convex real sets'. Cantor's set needs not apply.
Infinities should be handled gracefully; indeterminate numbers (NaN) can be ignored.
You can use your machine's native real number representation, which is probably IEEE floating point, and assume it's good enough (it usually is).
Optional work
Create a function to determine if a given set is empty (contains no element).
Define A = {x | 0 < x < 10 and |sin(π x²)| > 1/2 }, B = {x | 0 < x < 10 and |sin(π x)| > 1/2}, calculate the length of the real axis covered by the set A − B. Note that
|sin(π x)| > 1/2 is the same as n + 1/6 < x < n + 5/6 for all integers n; your program does not need to derive this by itself.
| #Icon_and_Unicon | Icon and Unicon | procedure main(A)
s1 := RealSet("(0,1]").union(RealSet("[0,2)"))
s2 := RealSet("[0,2)").intersect(RealSet("(1,2)"))
s3 := RealSet("[0,3)").difference(RealSet("(0,1)"))
s4 := RealSet("[0,3)").difference(RealSet("[0,1]"))
every s := s1|s2|s3|s4 do {
every n := 0 to 2 do
write(s.toString(),if s.contains(n) then " contains "
else " doesn't contain ",n)
write()
}
end
class Range(a,b,lbnd,rbnd,ltest,rtest)
method contains(x); return ((ltest(a,x),rtest(x,b)),self); end
method toString(); return lbnd||a||","||b||rbnd; end
method notEmpty(); return (ltest(a,b),rtest(a,b),self); end
method makeLTest(); return proc(if lbnd == "(" then "<" else "<=",2); end
method makeRTest(); return proc(if rbnd == "(" then "<" else "<=",2); end
method intersect(r)
if a < r.a then (na := r.a, nlb := r.lbnd)
else if a > r.a then (na := a, nlb := lbnd)
else (na := a, nlb := if "(" == (lbnd|r.lbnd) then "(" else "[")
if b < r.b then ( nb := b, nrb := rbnd)
else if b > r.b then (nb := r.b, nrb := r.rbnd)
else (nb := b, nrb := if ")" == (rbnd|r.rbnd) then ")" else "]")
range := Range(nlb||na||","||nb||nrb)
return range
end
method difference(r)
if /r then return RealSet(toString())
r1 := lbnd||a||","||min(b,r.a)||map(r.lbnd,"([","])")
r2 := map(r.rbnd,")]","[(")||max(a,r.b)||","||b||rbnd
return RealSet(r1).union(RealSet(r2))
end
initially(s)
static lbnds, rbnds
initial (lbnds := '([', rbnds := '])')
if \s then {
s ? {
lbnd := (tab(upto(lbnds)),move(1))
a := 1(tab(upto(',')),move(1))
b := tab(upto(rbnds))
rbnd := move(1)
}
ltest := proc(if lbnd == "(" then "<" else "<=",2)
rtest := proc(if rbnd == ")" then "<" else "<=",2)
}
end
class RealSet(ranges)
method contains(x); return ((!ranges).contains(x), self); end
method notEmpty(); return ((!ranges).notEmpty(), self); end
method toString()
sep := s := ""
every r := (!ranges).toString() do s ||:= .sep || 1(r, sep := " + ")
return s
end
method clone()
newR := RealSet()
newR.ranges := (copy(\ranges) | [])
return newR
end
method union(B)
newR := clone()
every put(newR.ranges, (!B.ranges).notEmpty())
return newR
end
method intersect(B)
newR := clone()
newR.ranges := []
every (r1 := !ranges, r2 := !B.ranges) do {
range := r1.intersect(r2)
put(newR.ranges, range.notEmpty())
}
return newR
end
method difference(B)
newR := clone()
newR.ranges := []
every (r1 := !ranges, r2 := !B.ranges) do {
rs := r1.difference(r2)
if rs.notEmpty() then every put(newR.ranges, !rs.ranges)
}
return newR
end
initially(s)
put(ranges := [],Range(\s).notEmpty())
end |
http://rosettacode.org/wiki/Sequence_of_primes_by_trial_division | Sequence of primes by trial division | Sequence of primes by trial division
You are encouraged to solve this task according to the task description, using any language you may know.
Task
Generate a sequence of primes by means of trial division.
Trial division is an algorithm where a candidate number is tested for being a prime by trying to divide it by other numbers.
You may use primes, or any numbers of your choosing, as long as the result is indeed a sequence of primes.
The sequence may be bounded (i.e. up to some limit), unbounded, starting from the start (i.e. 2) or above some given value.
Organize your function as you wish, in particular, it might resemble a filtering operation, or a sieving operation.
If you want to use a ready-made is_prime function, use one from the Primality by trial division page (i.e., add yours there if it isn't there already).
Related tasks
count in factors
prime decomposition
factors of an integer
Sieve of Eratosthenes
primality by trial division
factors of a Mersenne number
trial factoring of a Mersenne number
partition an integer X into N primes
| #BASIC256 | BASIC256 | function isPrime(v)
if v < 2 then return False
if v mod 2 = 0 then return v = 2
if v mod 3 = 0 then return v = 3
d = 5
while d * d <= v
if v mod d = 0 then return False else d += 2
end while
return True
end function
for i = 101 to 999
if isPrime(i) then print string(i); " ";
next i
end |
http://rosettacode.org/wiki/Sequence_of_primes_by_trial_division | Sequence of primes by trial division | Sequence of primes by trial division
You are encouraged to solve this task according to the task description, using any language you may know.
Task
Generate a sequence of primes by means of trial division.
Trial division is an algorithm where a candidate number is tested for being a prime by trying to divide it by other numbers.
You may use primes, or any numbers of your choosing, as long as the result is indeed a sequence of primes.
The sequence may be bounded (i.e. up to some limit), unbounded, starting from the start (i.e. 2) or above some given value.
Organize your function as you wish, in particular, it might resemble a filtering operation, or a sieving operation.
If you want to use a ready-made is_prime function, use one from the Primality by trial division page (i.e., add yours there if it isn't there already).
Related tasks
count in factors
prime decomposition
factors of an integer
Sieve of Eratosthenes
primality by trial division
factors of a Mersenne number
trial factoring of a Mersenne number
partition an integer X into N primes
| #Batch_File | Batch File |
@echo off
::Prime list using trial division
:: Unbounded (well, up to 2^31-1, but you'll kill it before :)
:: skips factors of 2 and 3 in candidates and in divisors
:: uses integer square root to find max divisor to test
:: outputs numbers in rows of 10 right aligned primes
setlocal enabledelayedexpansion
cls
echo prime list
set lin= 0:
set /a num=1, inc1=4, cnt=0
call :line 2
call :line 3
:nxtcand
set /a num+=inc1, inc1=6-inc1,div=1, inc2=4
call :sqrt2 %num% & set maxdiv=!errorlevel!
:nxtdiv
set /a div+=inc2, inc2=6-inc2, res=(num%%div)
if %div% gtr !maxdiv! call :line %num% & goto nxtcand
if %res% equ 0 (goto :nxtcand ) else ( goto nxtdiv)
:sqrt2 [num] calculates integer square root
if %1 leq 0 exit /b 0
set /A "x=%1/(11*1024)+40, x=(%1/x+x)>>1, x=(%1/x+x)>>1, x=(%1/x+x)>>1, x=(%1/x+x)>>1, x=(%1/x+x)>>1, x+=(%1-x*x)>>31,sq=x*x
if sq gtr %1 set x-=1
exit /b !x!
goto:eof
:line formats output in 10 right aligned columns
set num1= %1
set lin=!lin!%num1:~-7%
set /a cnt+=1,res1=(cnt%%10)
if %res1% neq 0 goto:eof
echo %lin%
set cnt1= !cnt!
set lin=!cnt1:~-5!:
goto:eof
|
http://rosettacode.org/wiki/Sequence_of_non-squares | Sequence of non-squares | Task
Show that the following remarkable formula gives the sequence of non-square natural numbers:
n + floor(1/2 + sqrt(n))
Print out the values for n in the range 1 to 22
Show that no squares occur for n less than one million
This is sequence A000037 in the OEIS database.
| #BASIC | BASIC | DIM i AS Integer
DIM j AS Double
DIM found AS Integer
FUNCTION nonsqr (n AS Integer) AS Integer
nonsqr = n + INT(0.5 + SQR(n))
END FUNCTION
' Display first 22 values
FOR i = 1 TO 22
PRINT nonsqr(i); " ";
NEXT i
PRINT
' Check for squares up to one million
found = 0
FOR i = 1 TO 1000000
j = SQR(nonsqr(i))
IF j = INT(j) THEN
found = 1
PRINT "Found square: "; i
EXIT FOR
END IF
NEXT i
IF found=0 THEN PRINT "No squares found" |
http://rosettacode.org/wiki/Set | Set |
Data Structure
This illustrates a data structure, a means of storing data within a program.
You may see other such structures in the Data Structures category.
A set is a collection of elements, without duplicates and without order.
Task
Show each of these set operations:
Set creation
Test m ∈ S -- "m is an element in set S"
A ∪ B -- union; a set of all elements either in set A or in set B.
A ∩ B -- intersection; a set of all elements in both set A and set B.
A ∖ B -- difference; a set of all elements in set A, except those in set B.
A ⊆ B -- subset; true if every element in set A is also in set B.
A = B -- equality; true if every element of set A is in set B and vice versa.
As an option, show some other set operations.
(If A ⊆ B, but A ≠ B, then A is called a true or proper subset of B, written A ⊂ B or A ⊊ B.)
As another option, show how to modify a mutable set.
One might implement a set using an associative array (with set elements as array keys and some dummy value as the values).
One might also implement a set with a binary search tree, or with a hash table, or with an ordered array of binary bits (operated on with bit-wise binary operators).
The basic test, m ∈ S, is O(n) with a sequential list of elements, O(log n) with a balanced binary search tree, or (O(1) average-case, O(n) worst case) with a hash table.
See also
Array
Associative array: Creation, Iteration
Collections
Compound data type
Doubly-linked list: Definition, Element definition, Element insertion, List Traversal, Element Removal
Linked list
Queue: Definition, Usage
Set
Singly-linked list: Element definition, Element insertion, List Traversal, Element Removal
Stack
| #ATS | ATS | (*------------------------------------------------------------------*)
#define ATS_DYNLOADFLAG 0
#include "share/atspre_staload.hats"
(*------------------------------------------------------------------*)
(* String hashing using XXH3_64bits from the xxHash suite. *)
#define ATS_EXTERN_PREFIX "hashsets_postiats_"
%{^ /* Embedded C code. */
#include <xxhash.h>
ATSinline() atstype_uint64
hashsets_postiats_mem_hash (atstype_ptr data, atstype_size len)
{
return (atstype_uint64) XXH3_64bits (data, len);
}
%}
extern fn mem_hash : (ptr, size_t) -<> uint64 = "mac#%"
fn
string_hash (s : string) :<> uint64 =
let
val len = string_length s
in
mem_hash ($UNSAFE.cast{ptr} s, len)
end
(*------------------------------------------------------------------*)
(* A trimmed down version of the AVL trees from the AVL Tree task. *)
datatype bal_t =
| bal_minus1
| bal_zero
| bal_plus1
datatype avl_t (key_t : t@ype+,
data_t : t@ype+,
size : int) =
| avl_t_nil (key_t, data_t, 0)
| {size_L, size_R : nat}
avl_t_cons (key_t, data_t, size_L + size_R + 1) of
(key_t, data_t, bal_t,
avl_t (key_t, data_t, size_L),
avl_t (key_t, data_t, size_R))
typedef avl_t (key_t : t@ype+,
data_t : t@ype+) =
[size : int] avl_t (key_t, data_t, size)
extern fun {key_t : t@ype}
avl_t$compare (u : key_t, v : key_t) :<> int
#define NIL avl_t_nil ()
#define CONS avl_t_cons
#define LNIL list_nil ()
#define :: list_cons
#define F false
#define T true
typedef fixbal_t = bool
prfn
lemma_avl_t_param {key_t : t@ype} {data_t : t@ype} {size : int}
(avl : avl_t (key_t, data_t, size)) :<prf>
[0 <= size] void =
case+ avl of NIL => () | CONS _ => ()
fn {}
minus_neg_bal (bal : bal_t) :<> bal_t =
case+ bal of
| bal_minus1 () => bal_plus1
| _ => bal_zero ()
fn {}
minus_pos_bal (bal : bal_t) :<> bal_t =
case+ bal of
| bal_plus1 () => bal_minus1
| _ => bal_zero ()
fn
avl_t_is_empty {key_t : t@ype} {data_t : t@ype} {size : int}
(avl : avl_t (key_t, data_t, size)) :<>
[b : bool | b == (size == 0)] bool b =
case+ avl of
| NIL => T
| CONS _ => F
fn
avl_t_isnot_empty {key_t : t@ype} {data_t : t@ype} {size : int}
(avl : avl_t (key_t, data_t, size)) :<>
[b : bool | b == (size <> 0)] bool b =
~avl_t_is_empty avl
fn {key_t : t@ype} {data_t : t@ype}
avl_t_search_ref {size : int}
(avl : avl_t (key_t, data_t, size),
key : key_t,
data : &data_t? >> opt (data_t, found),
found : &bool? >> bool found) :<!wrt>
#[found : bool] void =
let
fun
search (p : avl_t (key_t, data_t),
data : &data_t? >> opt (data_t, found),
found : &bool? >> bool found) :<!wrt,!ntm>
#[found : bool] void =
case+ p of
| NIL =>
{
prval _ = opt_none {data_t} data
val _ = found := F
}
| CONS (k, d, _, left, right) =>
begin
case+ avl_t$compare<key_t> (key, k) of
| cmp when cmp < 0 => search (left, data, found)
| cmp when cmp > 0 => search (right, data, found)
| _ =>
{
val _ = data := d
prval _ = opt_some {data_t} data
val _ = found := T
}
end
in
$effmask_ntm search (avl, data, found)
end
fn {key_t : t@ype} {data_t : t@ype}
avl_t_search_opt {size : int}
(avl : avl_t (key_t, data_t, size),
key : key_t) :<>
Option (data_t) =
let
var data : data_t?
var found : bool?
val _ = $effmask_wrt avl_t_search_ref (avl, key, data, found)
in
if found then
let
prval _ = opt_unsome data
in
Some {data_t} data
end
else
let
prval _ = opt_unnone data
in
None {data_t} ()
end
end
fn {key_t : t@ype} {data_t : t@ype}
avl_t_insert_or_replace {size : int}
(avl : avl_t (key_t, data_t, size),
key : key_t,
data : data_t) :<>
[sz : pos] (avl_t (key_t, data_t, sz), bool) =
let
fun
search {size : nat}
(p : avl_t (key_t, data_t, size),
fixbal : fixbal_t,
found : bool) :<!ntm>
[sz : pos]
(avl_t (key_t, data_t, sz), fixbal_t, bool) =
case+ p of
| NIL => (CONS (key, data, bal_zero, NIL, NIL), T, F)
| CONS (k, d, bal, left, right) =>
case+ avl_t$compare<key_t> (key, k) of
| cmp when cmp < 0 =>
let
val (p1, fixbal, found) = search (left, fixbal, found)
in
case+ (fixbal, bal) of
| (F, _) => (CONS (k, d, bal, p1, right), F, found)
| (T, bal_plus1 ()) =>
(CONS (k, d, bal_zero (), p1, right), F, found)
| (T, bal_zero ()) =>
(CONS (k, d, bal_minus1 (), p1, right), fixbal, found)
| (T, bal_minus1 ()) =>
let
val+ CONS (k1, d1, bal1, left1, right1) = p1
in
case+ bal1 of
| bal_minus1 () =>
let
val q = CONS (k, d, bal_zero (), right1, right)
val q1 = CONS (k1, d1, bal_zero (), left1, q)
in
(q1, F, found)
end
| _ =>
let
val p2 = right1
val- CONS (k2, d2, bal2, left2, right2) = p2
val q = CONS (k, d, minus_neg_bal bal2,
right2, right)
val q1 = CONS (k1, d1, minus_pos_bal bal2,
left1, left2)
val q2 = CONS (k2, d2, bal_zero (), q1, q)
in
(q2, F, found)
end
end
end
| cmp when cmp > 0 =>
let
val (p1, fixbal, found) = search (right, fixbal, found)
in
case+ (fixbal, bal) of
| (F, _) => (CONS (k, d, bal, left, p1), F, found)
| (T, bal_minus1 ()) =>
(CONS (k, d, bal_zero (), left, p1), F, found)
| (T, bal_zero ()) =>
(CONS (k, d, bal_plus1 (), left, p1), fixbal, found)
| (T, bal_plus1 ()) =>
let
val+ CONS (k1, d1, bal1, left1, right1) = p1
in
case+ bal1 of
| bal_plus1 () =>
let
val q = CONS (k, d, bal_zero (), left, left1)
val q1 = CONS (k1, d1, bal_zero (), q, right1)
in
(q1, F, found)
end
| _ =>
let
val p2 = left1
val- CONS (k2, d2, bal2, left2, right2) = p2
val q = CONS (k, d, minus_pos_bal bal2,
left, left2)
val q1 = CONS (k1, d1, minus_neg_bal bal2,
right2, right1)
val q2 = CONS (k2, d2, bal_zero (), q, q1)
in
(q2, F, found)
end
end
end
| _ => (CONS (key, data, bal, left, right), F, T)
in
if avl_t_is_empty avl then
(CONS (key, data, bal_zero, NIL, NIL), F)
else
let
prval _ = lemma_avl_t_param avl
val (avl, _, found) = $effmask_ntm search (avl, F, F)
in
(avl, found)
end
end
fn {key_t : t@ype} {data_t : t@ype}
avl_t_insert {size : int}
(avl : avl_t (key_t, data_t, size),
key : key_t,
data : data_t) :<>
[sz : pos] avl_t (key_t, data_t, sz) =
(avl_t_insert_or_replace<key_t><data_t> (avl, key, data)).0
fun {key_t : t@ype} {data_t : t@ype}
push_all_the_way_left (stack : List (avl_t (key_t, data_t)),
p : avl_t (key_t, data_t)) :
List0 (avl_t (key_t, data_t)) =
let
prval _ = lemma_list_param stack
in
case+ p of
| NIL => stack
| CONS (_, _, _, left, _) =>
push_all_the_way_left (p :: stack, left)
end
fun {key_t : t@ype} {data_t : t@ype}
update_generator_stack (stack : List (avl_t (key_t, data_t)),
right : avl_t (key_t, data_t)) :
List0 (avl_t (key_t, data_t)) =
let
prval _ = lemma_list_param stack
in
if avl_t_is_empty right then
stack
else
push_all_the_way_left<key_t><data_t> (stack, right)
end
fn {key_t : t@ype} {data_t : t@ype}
avl_t_make_data_generator {size : int}
(avl : avl_t (key_t, data_t, size)) :
() -<cloref1> Option data_t =
let
typedef avl_t = avl_t (key_t, data_t)
val stack = push_all_the_way_left<key_t><data_t> (LNIL, avl)
val stack_ref = ref stack
(* Cast stack_ref to its (otherwise untyped) pointer, so it can be
enclosed within ‘generate’. *)
val p_stack_ref = $UNSAFE.castvwtp0{ptr} stack_ref
fun
generate () :<cloref1> Option data_t =
let
(* Restore the type information for stack_ref. *)
val stack_ref =
$UNSAFE.castvwtp0{ref (List avl_t)} p_stack_ref
var stack : List0 avl_t = !stack_ref
var retval : Option data_t
in
begin
case+ stack of
| LNIL => retval := None ()
| p :: tail =>
let
val- CONS (_, d, _, left, right) = p
in
retval := Some d;
stack :=
update_generator_stack<key_t><data_t> (tail, right)
end
end;
!stack_ref := stack;
retval
end
in
generate
end
(*------------------------------------------------------------------*)
(* Sets implemented with a hash function, AVL trees and association *)
(* lists. *)
(* The interface - - - - - - - - - - - - - - - - - - - - - - - - - *)
(* For simplicity, let us support only 64-bit hashes. *)
typedef hashset_t (key_t : t@ype+) =
avl_t (uint64, List1 key_t)
extern fun {key_t : t@ype} (* Implement a hash function with this. *)
hashset_t$hashfunc : key_t -<> uint64
extern fun {key_t : t@ype} (* Implement key equality with this. *)
hashset_t$key_eq : (key_t, key_t) -<> bool
extern fun
hashset_t_nil :
{key_t : t@ype}
() -<> hashset_t key_t
extern fun {key_t : t@ype}
hashset_t_add_member :
(hashset_t key_t, key_t) -<> hashset_t key_t
(*
"remove_member" is not implemented here, because the trimmed down AVL
tree implementation above does not include deletion. We shall
implement everything else without using a member deletion routine.
extern fun {key_t : t@ype}
hashset_t_remove_member :
(hashset_t key_t, key_t) -<> hashset_t key_t
Of course you can remove a member by using hashset_t_difference.
*)
extern fun {key_t : t@ype}
hashset_t_has_member :
(hashset_t key_t, key_t) -<> bool
typedef hashset_t_binary_operation (key_t : t@ype) =
(hashset_t key_t, hashset_t key_t) -> hashset_t key_t
extern fun {key_t : t@ype}
hashset_t_union : hashset_t_binary_operation key_t
extern fun {key_t : t@ype}
hashset_t_intersection : hashset_t_binary_operation key_t
extern fun {key_t : t@ype}
hashset_t_difference : hashset_t_binary_operation key_t
extern fun {key_t : t@ype}
hashset_t_subset :
(hashset_t key_t, hashset_t key_t) -> bool
extern fun {key_t : t@ype}
hashset_t_equal :
(hashset_t key_t, hashset_t key_t) -> bool
(* Note: generators for hashset_t produce their output in unspecified
order. *)
extern fun {key_t : t@ype}
hashset_t_make_generator :
hashset_t key_t -> () -<cloref1> Option key_t
(* The implementation - - - - - - - - - - - - - - - - - - - - - - - *)
(* I make no promises that these are the most efficient
implementations I could devise. They certainly are not! But they
were easy to write and will work. *)
implement
hashset_t_nil () =
avl_t_nil ()
fun {key_t : t@ype}
find_key {n : nat} .<n>.
(lst : list (key_t, n),
key : key_t) :<>
List0 key_t =
(* This implementation is tail recursive. It will not build up the
stack. *)
case+ lst of
| list_nil () => lst
| list_cons (head, tail) =>
if hashset_t$key_eq<key_t> (key, head) then
lst
else
find_key (tail, key)
implement {key_t}
hashset_t_add_member (set, key) =
(* The following implementation assumes equal keys are
interchangeable. *)
let
implement
avl_t$compare<uint64> (u, v) =
if u < v then ~1 else if v < u then 1 else 0
typedef lst_t = List1 key_t
val hash = hashset_t$hashfunc<key_t> key
val lst_opt = avl_t_search_opt<uint64><lst_t> (set, hash)
in
case+ lst_opt of
| Some lst =>
begin
case+ find_key<key_t> (lst, key) of
| list_cons _ => set
| list_nil () =>
avl_t_insert<uint64><lst_t>
(set, hash, list_cons (key, lst))
end
| None () =>
avl_t_insert<uint64><lst_t>
(set, hash, list_cons (key, list_nil ()))
end
implement {key_t}
hashset_t_has_member (set, key) =
let
implement
avl_t$compare<uint64> (u, v) =
if u < v then ~1 else if v < u then 1 else 0
typedef lst_t = List1 key_t
val hash = hashset_t$hashfunc<key_t> key
val lst_opt = avl_t_search_opt<uint64><lst_t> (set, hash)
in
case+ lst_opt of
| None () => false
| Some lst =>
begin
case+ find_key<key_t> (lst, key) of
| list_nil () => false
| list_cons _ => true
end
end
implement {key_t}
hashset_t_union (u, v) =
let
val gen_u = hashset_t_make_generator<key_t> u
val gen_v = hashset_t_make_generator<key_t> v
var w : hashset_t key_t = hashset_t_nil ()
var k_opt : Option key_t
in
for (k_opt := gen_u (); option_is_some k_opt; k_opt := gen_u ())
w := hashset_t_add_member (w, option_unsome k_opt);
for (k_opt := gen_v (); option_is_some k_opt; k_opt := gen_v ())
w := hashset_t_add_member (w, option_unsome k_opt);
w
end
implement {key_t}
hashset_t_intersection (u, v) =
let
val gen_u = hashset_t_make_generator<key_t> u
var w : hashset_t key_t = hashset_t_nil ()
var k_opt : Option key_t
in
for (k_opt := gen_u (); option_is_some k_opt; k_opt := gen_u ())
let
val+ Some k = k_opt
in
if hashset_t_has_member<key_t> (v, k) then
w := hashset_t_add_member (w, k)
end;
w
end
implement {key_t}
hashset_t_difference (u, v) =
let
val gen_u = hashset_t_make_generator<key_t> u
var w : hashset_t key_t = hashset_t_nil ()
var k_opt : Option key_t
in
for (k_opt := gen_u (); option_is_some k_opt; k_opt := gen_u ())
let
val+ Some k = k_opt
in
if ~hashset_t_has_member<key_t> (v, k) then
w := hashset_t_add_member (w, k)
end;
w
end
implement {key_t}
hashset_t_subset (u, v) =
let
val gen_u = hashset_t_make_generator<key_t> u
var subset : bool = true
var done : bool = false
in
while (~done)
case+ gen_u () of
| None () => done := true
| Some k =>
if ~hashset_t_has_member<key_t> (v, k) then
begin
subset := false;
done := true
end;
subset
end
implement {key_t}
hashset_t_equal (u, v) =
hashset_t_subset<key_t> (u, v)
&& hashset_t_subset<key_t> (v, u)
implement {key_t}
hashset_t_make_generator (set) =
let
typedef lst_t = List1 key_t
typedef lst_t_0 = List0 key_t
val avl_gen = avl_t_make_data_generator<uint64><lst_t> (set)
val current_list_ref : ref lst_t_0 = ref (list_nil ())
val current_list_ptr =
$UNSAFE.castvwtp0{ptr} current_list_ref
in
lam () =>
let
val current_list_ref =
$UNSAFE.castvwtp0{ref lst_t_0} current_list_ptr
in
case+ !current_list_ref of
| list_nil () =>
begin
case+ avl_gen () of
| None () => None ()
| Some lst =>
begin
case+ lst of
| list_cons (head, tail) =>
begin
!current_list_ref := tail;
Some head
end
end
end
| list_cons (head, tail) =>
begin
!current_list_ref := tail;
Some head
end
end
end
(*------------------------------------------------------------------*)
implement
hashset_t$hashfunc<string> (s) =
string_hash s
implement
hashset_t$key_eq<string> (s, t) =
s = t
typedef strset_t = hashset_t string
fn {}
strset_t_nil () :<> strset_t =
hashset_t_nil ()
fn
strset_t_add_member (set : strset_t,
member : string) :<> strset_t =
hashset_t_add_member<string> (set, member)
fn {}
strset_t_member_add (member : string,
set : strset_t) :<> strset_t =
strset_t_add_member (set, member)
#define SNIL strset_t_nil ()
infixr ( :: ) ++ (* Right associative, same precedence as :: *)
overload ++ with strset_t_member_add
fn
strset_t_has_member (set : strset_t,
member : string) :<> bool =
hashset_t_has_member<string> (set, member)
overload [] with strset_t_has_member
fn
strset_t_union (u : strset_t, v : strset_t) : strset_t =
hashset_t_union<string> (u, v)
overload + with strset_t_union
fn
strset_t_intersection (u : strset_t, v : strset_t) : strset_t =
hashset_t_intersection<string> (u, v)
infixl ( + ) ^
overload ^ with strset_t_intersection
fn
strset_t_difference (u : strset_t, v : strset_t) : strset_t =
hashset_t_difference<string> (u, v)
overload - with strset_t_difference
fn
strset_t_subset (u : strset_t, v : strset_t) : bool =
hashset_t_subset<string> (u, v)
overload <= with strset_t_subset
fn
strset_t_equal (u : strset_t, v : strset_t) : bool =
hashset_t_equal<string> (u, v)
overload = with strset_t_equal
fn
strset_t_make_generator (set : strset_t) :
() -<cloref1> Option string =
hashset_t_make_generator<string> set
fn
strset_t_print (set : strset_t) : void =
let
val gen = strset_t_make_generator set
var s_opt : Option string
var separator : string = ""
in
print! ("#<strset_t ");
for (s_opt := gen (); option_is_some s_opt; s_opt := gen ())
case+ s_opt of
| Some s =>
begin
(* The following quick and dirty implemenetation does not
insert escape sequences. *)
print! (separator, "\"", s, "\"");
separator := " "
end;
print! (">")
end
implement
main0 () =
let
val set1 =
"one" ++ "two" ++ "three" ++ "guide" ++ "design" ++ SNIL
val set2 =
"ett" ++ "två" ++ "tre" ++ "guide" ++ "design" ++ SNIL
in
print! ("set1 = ");
strset_t_print set1;
println! ();
println! ();
println! ("set1[\"one\"] = ", set1["one"]);
println! ("set1[\"two\"] = ", set1["two"]);
println! ("set1[\"three\"] = ", set1["three"]);
println! ("set1[\"four\"] = ", set1["four"]);
println! ();
print! ("set2 = ");
strset_t_print set2;
println! ();
println! ();
println! ("set2[\"ett\"] = ", set2["ett"]);
println! ("set2[\"två\"] = ", set2["två"]);
println! ("set2[\"tre\"] = ", set2["tre"]);
println! ("set2[\"fyra\"] = ", set2["fyra"]);
println! ();
print! ("Union\nset1 + set2 = ");
strset_t_print (set1 + set2);
println! ();
println! ();
print! ("Intersection\nset1 ^ set2 = ");
strset_t_print (set1 ^ set2);
println! ();
println! ();
print! ("Difference\nset1 - set2 = ");
strset_t_print (set1 - set2);
println! ();
println! ();
println! ("Subset");
println! ("set1 <= set1: ", set1 <= set1);
println! ("set2 <= set2: ", set2 <= set2);
println! ("set1 <= set2: ", set1 <= set2);
println! ("set2 <= set1: ", set2 <= set1);
println! ("(set1 ^ set2) <= set1: ", (set1 ^ set2) <= set1);
println! ("(set1 ^ set2) <= set2: ", (set1 ^ set2) <= set2);
println! ();
println! ("Equal");
println! ("set1 = set1: ", set1 = set1);
println! ("set2 = set2: ", set2 = set2);
println! ("set1 = set2: ", set1 = set2);
println! ("set2 = set1: ", set2 = set1);
println! ("(set1 ^ set2) = (set2 ^ set1): ",
(set1 ^ set2) = (set2 ^ set1));
println! ("(set1 ^ set2) = set1: ", (set1 ^ set2) = set1);
println! ("(set1 ^ set2) = set2: ", (set1 ^ set2) = set2)
end
(*------------------------------------------------------------------*) |
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
| #Oforth | Oforth | 16 "sqrt" asMethod perform |
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
| #PARI.2FGP | PARI/GP | foo()=5;
eval(Str("foo","()")) |
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
| #Perl | Perl | package Example;
sub new {
bless {}
}
sub foo {
my ($self, $x) = @_;
return 42 + $x;
}
package main;
my $name = "foo";
print Example->new->$name(5), "\n"; # prints "47" |
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
| #Phix | Phix | with javascript_semantics
procedure Hello()
?"Hello"
end procedure
string erm = "Hemmm"
for i=3 to 5 do
erm[i]+=-1+(i=5)*3
end for
call_proc(routine_id(erm),{})
|
http://rosettacode.org/wiki/Sieve_of_Eratosthenes | Sieve of Eratosthenes | This task has been clarified. Its programming examples are in need of review to ensure that they still fit the requirements of the task.
The Sieve of Eratosthenes is a simple algorithm that finds the prime numbers up to a given integer.
Task
Implement the Sieve of Eratosthenes algorithm, with the only allowed optimization that the outer loop can stop at the square root of the limit, and the inner loop may start at the square of the prime just found.
That means especially that you shouldn't optimize by using pre-computed wheels, i.e. don't assume you need only to cross out odd numbers (wheel based on 2), numbers equal to 1 or 5 modulo 6 (wheel based on 2 and 3), or similar wheels based on low primes.
If there's an easy way to add such a wheel based optimization, implement it as an alternative version.
Note
It is important that the sieve algorithm be the actual algorithm used to find prime numbers for the task.
Related tasks
Emirp primes
count in factors
prime decomposition
factors of an integer
extensible prime generator
primality by trial division
factors of a Mersenne number
trial factoring of a Mersenne number
partition an integer X into N primes
sequence of primes by Trial Division
| #Agena | Agena | # Sieve of Eratosthenes
# generate and return a sequence containing the primes up to sieveSize
sieve := proc( sieveSize :: number ) :: sequence is
local sieve, result;
result := seq(); # sequence of primes - initially empty
create register sieve( sieveSize ); # "vector" to be sieved
sieve[ 1 ] := false;
for sPos from 2 to sieveSize do sieve[ sPos ] := true od;
# sieve the primes
for sPos from 2 to entier( sqrt( sieveSize ) ) do
if sieve[ sPos ] then
for p from sPos * sPos to sieveSize by sPos do
sieve[ p ] := false
od
fi
od;
# construct the sequence of primes
for sPos from 1 to sieveSize do
if sieve[ sPos ] then insert sPos into result fi
od
return result
end; # sieve
# test the sieve proc
for i in sieve( 100 ) do write( " ", i ) od; print(); |
http://rosettacode.org/wiki/Sequence_of_primorial_primes | Sequence of primorial primes | The sequence of primorial primes is given as the increasing values of n where primorial(n) ± 1 is prime.
Noting that the n'th primorial is defined as the multiplication of the smallest n primes, the sequence is of the number of primes, in order that when multiplied together is one-off being a prime number itself.
Task
Generate and show here the first ten values of the sequence.
Optional extended task
Show the first twenty members of the series.
Notes
This task asks for the primorial indices that create the final primorial prime numbers, so there should be no ten-or-more digit numbers in the program output (although extended precision integers will be needed for intermediate results).
There is some confusion in the references, but for the purposes of this task the sequence begins with n = 1.
Probabilistic primality tests are allowed, as long as they are good enough such that the output shown is correct.
Related tasks
Primorial numbers
Factorial
See also
Primorial prime Wikipedia.
Primorial prime from The Prime Glossary.
Sequence A088411 from The On-Line Encyclopedia of Integer Sequences
| #Phix | Phix | with javascript_semantics
include mpfr.e
constant limit = 9999,
flimit = iff(platform()=JS?15:20)
mpz {p,p1} = mpz_inits(2,1)
atom t0 = time()
integer found = 0, i
for n=1 to limit do
mpz_mul_si(p, p, get_prime(n))
for i=-1 to +1 do
mpz_add_si(p1, p, i)
if mpz_prime(p1) then
integer l = mpz_sizeinbase(p,10)
string ps = iff(l>20?sprintf("%d digits",l)
:mpz_get_str(p))
printf(1,"%d (%s) is a primorial prime\n",{n,ps})
found += 1
exit
end if
end for
if found>=flimit then exit end if
end for
{p,p1} = mpz_free({p,p1})
?elapsed(time()-t0)
|
http://rosettacode.org/wiki/Sequence:_nth_number_with_exactly_n_divisors | Sequence: nth number with exactly n divisors | Calculate the sequence where each term an is the nth that has n divisors.
Task
Show here, on this page, at least the first 15 terms of the sequence.
See also
OEIS:A073916
Related tasks
Sequence: smallest number greater than previous term with exactly n divisors
Sequence: smallest number with exactly n divisors | #zkl | zkl | var [const] BI=Import("zklBigNum"), pmax=25; // libGMP
p:=BI(1);
primes:=pmax.pump(List(0), p.nextPrime, "copy"); //-->(0,3,5,7,11,13,17,19,...)
fcn countDivisors(n){
count:=1;
while(n%2==0){ n/=2; count+=1; }
foreach d in ([3..*,2]){
q,r := n/d, n%d;
if(r==0){
dc:=0;
while(r==0){
dc+=count;
n,q,r = q, n/d, n%d;
}
count+=dc;
}
if(d*d > n) break;
}
if(n!=1) count*=2;
count
}
println("The first ", pmax, " terms in the sequence are:");
foreach i in ([1..pmax]){
if(BI(i).probablyPrime()) println("%2d : %,d".fmt(i,primes[i].pow(i-1)));
else{
count:=0;
foreach j in ([1..*]){
if(i%2==1 and j != j.toFloat().sqrt().toInt().pow(2)) continue;
if(countDivisors(j) == i){
count+=1;
if(count==i){
println("%2d : %,d".fmt(i,j));
break;
}
}
}
}
} |
http://rosettacode.org/wiki/Set_consolidation | Set consolidation | Given two sets of items then if any item is common to any set then the result of applying consolidation to those sets is a set of sets whose contents is:
The two input sets if no common item exists between the two input sets of items.
The single set that is the union of the two input sets if they share a common item.
Given N sets of items where N>2 then the result is the same as repeatedly replacing all combinations of two sets by their consolidation until no further consolidation between set pairs is possible.
If N<2 then consolidation has no strict meaning and the input can be returned.
Example 1:
Given the two sets {A,B} and {C,D} then there is no common element between the sets and the result is the same as the input.
Example 2:
Given the two sets {A,B} and {B,D} then there is a common element B between the sets and the result is the single set {B,D,A}. (Note that order of items in a set is immaterial: {A,B,D} is the same as {B,D,A} and {D,A,B}, etc).
Example 3:
Given the three sets {A,B} and {C,D} and {D,B} then there is no common element between the sets {A,B} and {C,D} but the sets {A,B} and {D,B} do share a common element that consolidates to produce the result {B,D,A}. On examining this result with the remaining set, {C,D}, they share a common element and so consolidate to the final output of the single set {A,B,C,D}
Example 4:
The consolidation of the five sets:
{H,I,K}, {A,B}, {C,D}, {D,B}, and {F,G,H}
Is the two sets:
{A, C, B, D}, and {G, F, I, H, K}
See also
Connected component (graph theory)
Range consolidation
| #Lua | Lua | -- SUPPORT:
function T(t) return setmetatable(t, {__index=table}) end
function S(t) local s=T{} for k,v in ipairs(t) do s[v]=v end return s end
table.each = function(t,f,...) for _,v in pairs(t) do f(v,...) end end
table.copy = function(t) local s=T{} for k,v in pairs(t) do s[k]=v end return s end
table.keys = function(t) local s=T{} for k,_ in pairs(t) do s[#s+1]=k end return s end
table.intersects = function(t1,t2) for k,_ in pairs(t1) do if t2[k] then return true end end return false end
table.union = function(t1,t2) local s=t1:copy() for k,_ in pairs(t2) do s[k]=k end return s end
table.dump = function(t) print('{ '..table.concat(t, ', ')..' }') end
-- TASK:
table.consolidate = function(t)
for a = #t, 1, -1 do
local seta = t[a]
for b = #t, a+1, -1 do
local setb = t[b]
if setb and seta:intersects(setb) then
t[a], t[b] = seta:union(setb), nil
end
end
end
return t
end
-- TESTING:
examples = {
T{ S{"A","B"}, S{"C","D"} },
T{ S{"A","B"}, S{"B","D"} },
T{ S{"A","B"}, S{"C","D"}, S{"D","B"} },
T{ S{"H","I","K"}, S{"A","B"}, S{"C","D"}, S{"D","B"}, S{"F","G","H"} },
}
for i,example in ipairs(examples) do
print("Given input sets:")
example:each(function(set) set:keys():dump() end)
print("Consolidated output sets:")
example:consolidate():each(function(set) set:keys():dump() end)
print("")
end |
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 n divisors
See also
OEIS:A005179
| #Python | Python | def divisors(n):
divs = [1]
for ii in range(2, int(n ** 0.5) + 3):
if n % ii == 0:
divs.append(ii)
divs.append(int(n / ii))
divs.append(n)
return list(set(divs))
def sequence(max_n=None):
n = 0
while True:
n += 1
ii = 0
if max_n is not None:
if n > max_n:
break
while True:
ii += 1
if len(divisors(ii)) == n:
yield ii
break
if __name__ == '__main__':
for item in sequence(15):
print(item) |
http://rosettacode.org/wiki/SHA-256 | SHA-256 | SHA-256 is the recommended stronger alternative to SHA-1. See FIPS PUB 180-4 for implementation details.
Either by using a dedicated library or implementing the algorithm in your language, show that the SHA-256 digest of the string "Rosetta code" is: 764faf5c61ac315f1497f9dfa542713965b785e5cc2f707d6468d7d1124cdfcf
| #Python | Python | >>> import hashlib
>>> hashlib.sha256( "Rosetta code".encode() ).hexdigest()
'764faf5c61ac315f1497f9dfa542713965b785e5cc2f707d6468d7d1124cdfcf'
>>> |
http://rosettacode.org/wiki/SHA-256 | SHA-256 | SHA-256 is the recommended stronger alternative to SHA-1. See FIPS PUB 180-4 for implementation details.
Either by using a dedicated library or implementing the algorithm in your language, show that the SHA-256 digest of the string "Rosetta code" is: 764faf5c61ac315f1497f9dfa542713965b785e5cc2f707d6468d7d1124cdfcf
| #R | R |
library(digest)
input <- "Rosetta code"
cat(digest(input, algo = "sha256", serialize = FALSE), "\n")
|
http://rosettacode.org/wiki/Sequence:_smallest_number_greater_than_previous_term_with_exactly_n_divisors | Sequence: smallest number greater than previous term with exactly n divisors | Calculate the sequence where each term an is the smallest natural number greater than the previous term, that has exactly n divisors.
Task
Show here, on this page, at least the first 15 terms of the sequence.
See also
OEIS:A069654
Related tasks
Sequence: smallest number with exactly n divisors
Sequence: nth number with exactly n divisors
| #Ring | Ring |
# Project : ANti-primes
see "working..." + nl
see "wait for done..." + nl + nl
see "the first 15 Anti-primes Plus are:" + nl + nl
num = 1
n = 0
result = list(15)
while num < 16
n = n + 1
div = factors(n)
if div = num
result[num] = n
num = num + 1
ok
end
see "["
for n = 1 to len(result)
if n < len(result)
see string(result[n]) + ","
else
see string(result[n]) + "]" + nl + nl
ok
next
see "done..." + nl
func factors(an)
ansum = 2
if an < 2
return(1)
ok
for nr = 2 to an/2
if an%nr = 0
ansum = ansum+1
ok
next
return ansum
|
http://rosettacode.org/wiki/Sequence:_smallest_number_greater_than_previous_term_with_exactly_n_divisors | Sequence: smallest number greater than previous term with exactly n divisors | Calculate the sequence where each term an is the smallest natural number greater than the previous term, that has exactly n divisors.
Task
Show here, on this page, at least the first 15 terms of the sequence.
See also
OEIS:A069654
Related tasks
Sequence: smallest number with exactly n divisors
Sequence: nth number with exactly n divisors
| #Ruby | Ruby | require 'prime'
def num_divisors(n)
n.prime_division.inject(1){|prod, (_p,n)| prod *= (n + 1) }
end
seq = Enumerator.new do |y|
cur = 0
(1..).each do |i|
if num_divisors(i) == cur + 1 then
y << i
cur += 1
end
end
end
p seq.take(15)
|
http://rosettacode.org/wiki/Sequence:_smallest_number_greater_than_previous_term_with_exactly_n_divisors | Sequence: smallest number greater than previous term with exactly n divisors | Calculate the sequence where each term an is the smallest natural number greater than the previous term, that has exactly n divisors.
Task
Show here, on this page, at least the first 15 terms of the sequence.
See also
OEIS:A069654
Related tasks
Sequence: smallest number with exactly n divisors
Sequence: nth number with exactly n divisors
| #Sidef | Sidef | func n_divisors(n, from=1) {
from..Inf -> first_by { .sigma0 == n }
}
with (1) { |from|
say 15.of { from = n_divisors(_+1, from) }
} |
http://rosettacode.org/wiki/SHA-1 | SHA-1 | SHA-1 or SHA1 is a one-way hash function;
it computes a 160-bit message digest.
SHA-1 often appears in security protocols; for example,
many HTTPS websites use RSA with SHA-1 to secure their connections.
BitTorrent uses SHA-1 to verify downloads.
Git and Mercurial use SHA-1 digests to identify commits.
A US government standard, FIPS 180-1, defines SHA-1.
Find the SHA-1 message digest for a string of octets. You may either call a SHA-1 library, or implement SHA-1 in your language. Both approaches interest Rosetta Code.
Warning: SHA-1 has known weaknesses. Theoretical attacks may find a collision after 252 operations, or perhaps fewer.
This is much faster than a brute force attack of 280 operations. USgovernment deprecated SHA-1.
For production-grade cryptography, users may consider a stronger alternative, such as SHA-256 (from the SHA-2 family) or the upcoming SHA-3.
| #R | R |
library(digest)
input <- "Rosetta Code"
cat(digest(input, algo = "sha1", serialize = FALSE), "\n")
|
http://rosettacode.org/wiki/SHA-1 | SHA-1 | SHA-1 or SHA1 is a one-way hash function;
it computes a 160-bit message digest.
SHA-1 often appears in security protocols; for example,
many HTTPS websites use RSA with SHA-1 to secure their connections.
BitTorrent uses SHA-1 to verify downloads.
Git and Mercurial use SHA-1 digests to identify commits.
A US government standard, FIPS 180-1, defines SHA-1.
Find the SHA-1 message digest for a string of octets. You may either call a SHA-1 library, or implement SHA-1 in your language. Both approaches interest Rosetta Code.
Warning: SHA-1 has known weaknesses. Theoretical attacks may find a collision after 252 operations, or perhaps fewer.
This is much faster than a brute force attack of 280 operations. USgovernment deprecated SHA-1.
For production-grade cryptography, users may consider a stronger alternative, such as SHA-256 (from the SHA-2 family) or the upcoming SHA-3.
| #Racket | Racket |
#lang racket
(require file/sha1)
(sha1 (open-input-string "Rosetta Code"))
|
http://rosettacode.org/wiki/Show_ASCII_table | Show ASCII table | Task
Show the ASCII character set from values 32 to 127 (decimal) in a table format.
Other tasks related to string operations:
Metrics
Array length
String length
Copy a string
Empty string (assignment)
Counting
Word frequency
Letter frequency
Jewels and stones
I before E except after C
Bioinformatics/base count
Count occurrences of a substring
Count how many vowels and consonants occur in a string
Remove/replace
XXXX redacted
Conjugate a Latin verb
Remove vowels from a string
String interpolation (included)
Strip block comments
Strip comments from a string
Strip a set of characters from a string
Strip whitespace from a string -- top and tail
Strip control codes and extended characters from a string
Anagrams/Derangements/shuffling
Word wheel
ABC problem
Sattolo cycle
Knuth shuffle
Ordered words
Superpermutation minimisation
Textonyms (using a phone text pad)
Anagrams
Anagrams/Deranged anagrams
Permutations/Derangements
Find/Search/Determine
ABC words
Odd words
Word ladder
Semordnilap
Word search
Wordiff (game)
String matching
Tea cup rim text
Alternade words
Changeable words
State name puzzle
String comparison
Unique characters
Unique characters in each string
Extract file extension
Levenshtein distance
Palindrome detection
Common list elements
Longest common suffix
Longest common prefix
Compare a list of strings
Longest common substring
Find common directory path
Words from neighbour ones
Change e letters to i in words
Non-continuous subsequences
Longest common subsequence
Longest palindromic substrings
Longest increasing subsequence
Words containing "the" substring
Sum of the digits of n is substring of n
Determine if a string is numeric
Determine if a string is collapsible
Determine if a string is squeezable
Determine if a string has all unique characters
Determine if a string has all the same characters
Longest substrings without repeating characters
Find words which contains all the vowels
Find words which contains most consonants
Find words which contains more than 3 vowels
Find words which first and last three letters are equals
Find words which odd letters are consonants and even letters are vowels or vice_versa
Formatting
Substring
Rep-string
Word wrap
String case
Align columns
Literals/String
Repeat a string
Brace expansion
Brace expansion using ranges
Reverse a string
Phrase reversals
Comma quibbling
Special characters
String concatenation
Substring/Top and tail
Commatizing numbers
Reverse words in a string
Suffixation of decimal numbers
Long literals, with continuations
Numerical and alphabetical suffixes
Abbreviations, easy
Abbreviations, simple
Abbreviations, automatic
Song lyrics/poems/Mad Libs/phrases
Mad Libs
Magic 8-ball
99 Bottles of Beer
The Name Game (a song)
The Old lady swallowed a fly
The Twelve Days of Christmas
Tokenize
Text between
Tokenize a string
Word break problem
Tokenize a string with escaping
Split a character string based on change of character
Sequences
Show ASCII table
De Bruijn sequences
Self-referential sequences
Generate lower case ASCII alphabet
| #M2000_Interpreter | M2000 Interpreter |
Function ProduceAscii$ {
Document Ascii$="\"
DelUnicode$=ChrCode$(0x2421)
j=2
Print Ascii$;
For i=0 to 15
Print Hex$(i, .5);
Ascii$=Hex$(i, .5)
Next
For i=32 to 126
If pos>16 then
Ascii$={
}+Hex$(j, .5)
Print : Print Hex$(j, .5);: j++
End if
Print Chr$(i);
Ascii$=Chr$(i)
Next
Print DelUnicode$
=Ascii$+DelUnicode$+{
}
}
Clipboard ProduceAscii$()
|
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:
*
* *
* *
* * * *
* *
* * * *
* * * *
* * * * * * * *
* *
* * * *
* * * *
* * * * * * * *
* * * *
* * * * * * * *
* * * * * * * *
* * * * * * * * * * * * * * * *
Related tasks
Sierpinski triangle/Graphical for graphics images of this pattern.
Sierpinski carpet
| #Quackery | Quackery | [ [ dup 1 &
iff char * else space
emit
1 >> dup while
sp again ]
drop ] is stars ( mask --> )
[ bit
1 over times
[ cr over i^ - times sp
dup stars
dup 1 << ^ ]
2drop ] is triangle ( order --> )
4 triangle |
http://rosettacode.org/wiki/Sierpinski_carpet | Sierpinski carpet | Task
Produce a graphical or ASCII-art representation of a Sierpinski carpet of order N.
For example, the Sierpinski carpet of order 3 should look like this:
###########################
# ## ## ## ## ## ## ## ## #
###########################
### ###### ###### ###
# # # ## # # ## # # #
### ###### ###### ###
###########################
# ## ## ## ## ## ## ## ## #
###########################
######### #########
# ## ## # # ## ## #
######### #########
### ### ### ###
# # # # # # # #
### ### ### ###
######### #########
# ## ## # # ## ## #
######### #########
###########################
# ## ## ## ## ## ## ## ## #
###########################
### ###### ###### ###
# # # ## # # ## # # #
### ###### ###### ###
###########################
# ## ## ## ## ## ## ## ## #
###########################
The use of the # character is not rigidly required for ASCII art.
The important requirement is the placement of whitespace and non-whitespace characters.
Related task
Sierpinski triangle
| #Oz | Oz | declare
%% A carpet is a list of lines.
fun {NextCarpet Carpet}
{Flatten
[{Map Carpet XXX}
{Map Carpet X_X}
{Map Carpet XXX}
]}
end
fun {XXX X} X#X#X end
fun {X_X X} X#{Spaces {VirtualString.length X}}#X end
fun {Spaces N} if N == 0 then nil else & |{Spaces N-1} end end
fun lazy {Iterate F X}
X|{Iterate F {F X}}
end
SierpinskiCarpets = {Iterate NextCarpet ["#"]}
in
%% print all lines of the Sierpinski carpet of order 3
{ForAll {Nth SierpinskiCarpets 4} System.showInfo} |
http://rosettacode.org/wiki/Semordnilap | Semordnilap | A semordnilap is a word (or phrase) that spells a different word (or phrase) backward. "Semordnilap" is a word that itself is a semordnilap.
Example: lager and regal
Task
This task does not consider semordnilap phrases, only single words.
Using only words from this list, report the total number of unique semordnilap pairs, and print 5 examples.
Two matching semordnilaps, such as lager and regal, should be counted as one unique pair.
(Note that the word "semordnilap" is not in the above dictionary.)
Other tasks related to string operations:
Metrics
Array length
String length
Copy a string
Empty string (assignment)
Counting
Word frequency
Letter frequency
Jewels and stones
I before E except after C
Bioinformatics/base count
Count occurrences of a substring
Count how many vowels and consonants occur in a string
Remove/replace
XXXX redacted
Conjugate a Latin verb
Remove vowels from a string
String interpolation (included)
Strip block comments
Strip comments from a string
Strip a set of characters from a string
Strip whitespace from a string -- top and tail
Strip control codes and extended characters from a string
Anagrams/Derangements/shuffling
Word wheel
ABC problem
Sattolo cycle
Knuth shuffle
Ordered words
Superpermutation minimisation
Textonyms (using a phone text pad)
Anagrams
Anagrams/Deranged anagrams
Permutations/Derangements
Find/Search/Determine
ABC words
Odd words
Word ladder
Semordnilap
Word search
Wordiff (game)
String matching
Tea cup rim text
Alternade words
Changeable words
State name puzzle
String comparison
Unique characters
Unique characters in each string
Extract file extension
Levenshtein distance
Palindrome detection
Common list elements
Longest common suffix
Longest common prefix
Compare a list of strings
Longest common substring
Find common directory path
Words from neighbour ones
Change e letters to i in words
Non-continuous subsequences
Longest common subsequence
Longest palindromic substrings
Longest increasing subsequence
Words containing "the" substring
Sum of the digits of n is substring of n
Determine if a string is numeric
Determine if a string is collapsible
Determine if a string is squeezable
Determine if a string has all unique characters
Determine if a string has all the same characters
Longest substrings without repeating characters
Find words which contains all the vowels
Find words which contains most consonants
Find words which contains more than 3 vowels
Find words which first and last three letters are equals
Find words which odd letters are consonants and even letters are vowels or vice_versa
Formatting
Substring
Rep-string
Word wrap
String case
Align columns
Literals/String
Repeat a string
Brace expansion
Brace expansion using ranges
Reverse a string
Phrase reversals
Comma quibbling
Special characters
String concatenation
Substring/Top and tail
Commatizing numbers
Reverse words in a string
Suffixation of decimal numbers
Long literals, with continuations
Numerical and alphabetical suffixes
Abbreviations, easy
Abbreviations, simple
Abbreviations, automatic
Song lyrics/poems/Mad Libs/phrases
Mad Libs
Magic 8-ball
99 Bottles of Beer
The Name Game (a song)
The Old lady swallowed a fly
The Twelve Days of Christmas
Tokenize
Text between
Tokenize a string
Word break problem
Tokenize a string with escaping
Split a character string based on change of character
Sequences
Show ASCII table
De Bruijn sequences
Self-referential sequences
Generate lower case ASCII alphabet
| #AWK | AWK |
# syntax: GAWK -f SEMORDNILAP.AWK unixdict.txt
{ arr[$0]++ }
END {
PROCINFO["sorted_in"] = "@ind_str_asc"
for (word in arr) {
rword = ""
for (j=length(word); j>0; j--) {
rword = rword substr(word,j,1)
}
if (word == rword) { continue } # palindrome
if (rword in arr) {
if (word in shown || rword in shown) { continue }
shown[word]++
shown[rword]++
if (n++ < 5) { printf("%s %s\n",word,rword) }
}
}
printf("%d words\n",n)
exit(0)
}
|
http://rosettacode.org/wiki/Short-circuit_evaluation | Short-circuit evaluation | Control Structures
These are examples of control structures. You may also be interested in:
Conditional structures
Exceptions
Flow-control structures
Loops
Assume functions a and b return boolean values, and further, the execution of function b takes considerable resources without side effects, and is to be minimized.
If we needed to compute the conjunction (and):
x = a() and b()
Then it would be best to not compute the value of b() if the value of a() is computed as false, as the value of x can then only ever be false.
Similarly, if we needed to compute the disjunction (or):
y = a() or b()
Then it would be best to not compute the value of b() if the value of a() is computed as true, as the value of y can then only ever be true.
Some languages will stop further computation of boolean equations as soon as the result is known, so-called short-circuit evaluation of boolean expressions
Task
Create two functions named a and b, that take and return the same boolean value.
The functions should also print their name whenever they are called.
Calculate and assign the values of the following equations to a variable in such a way that function b is only called when necessary:
x = a(i) and b(j)
y = a(i) or b(j)
If the language does not have short-circuit evaluation, this might be achieved with nested if statements.
| #Prolog | Prolog | short_circuit :-
( a_or_b(true, true) -> writeln('==> true'); writeln('==> false')) , nl,
( a_or_b(true, false)-> writeln('==> true'); writeln('==> false')) , nl,
( a_or_b(false, true)-> writeln('==> true'); writeln('==> false')) , nl,
( a_or_b(false, false)-> writeln('==> true'); writeln('==> false')) , nl,
( a_and_b(true, true)-> writeln('==> true'); writeln('==> false')) , nl,
( a_and_b(true, false)-> writeln('==> true'); writeln('==> false')) , nl,
( a_and_b(false, true)-> writeln('==> true'); writeln('==> false')) , nl,
( a_and_b(false, false)-> writeln('==> true'); writeln('==> false')) .
a_and_b(X, Y) :-
format('a(~w) and b(~w)~n', [X, Y]),
( a(X), b(Y)).
a_or_b(X, Y) :-
format('a(~w) or b(~w)~n', [X, Y]),
( a(X); b(Y)).
a(X) :-
format('a(~w)~n', [X]),
X.
b(X) :-
format('b(~w)~n', [X]),
X. |
http://rosettacode.org/wiki/Selectively_replace_multiple_instances_of_a_character_within_a_string | Selectively replace multiple instances of a character within a string | Task
This is admittedly a trivial task but I thought it would be interesting to see how succinctly (or otherwise) different languages can handle it.
Given the string: "abracadabra", replace programatically:
the first 'a' with 'A'
the second 'a' with 'B'
the fourth 'a' with 'C'
the fifth 'a' with 'D'
the first 'b' with 'E'
the second 'r' with 'F'
Note that there is no replacement for the third 'a', second 'b' or first 'r'.
The answer should, of course, be : "AErBcadCbFD".
Other tasks related to string operations:
Metrics
Array length
String length
Copy a string
Empty string (assignment)
Counting
Word frequency
Letter frequency
Jewels and stones
I before E except after C
Bioinformatics/base count
Count occurrences of a substring
Count how many vowels and consonants occur in a string
Remove/replace
XXXX redacted
Conjugate a Latin verb
Remove vowels from a string
String interpolation (included)
Strip block comments
Strip comments from a string
Strip a set of characters from a string
Strip whitespace from a string -- top and tail
Strip control codes and extended characters from a string
Anagrams/Derangements/shuffling
Word wheel
ABC problem
Sattolo cycle
Knuth shuffle
Ordered words
Superpermutation minimisation
Textonyms (using a phone text pad)
Anagrams
Anagrams/Deranged anagrams
Permutations/Derangements
Find/Search/Determine
ABC words
Odd words
Word ladder
Semordnilap
Word search
Wordiff (game)
String matching
Tea cup rim text
Alternade words
Changeable words
State name puzzle
String comparison
Unique characters
Unique characters in each string
Extract file extension
Levenshtein distance
Palindrome detection
Common list elements
Longest common suffix
Longest common prefix
Compare a list of strings
Longest common substring
Find common directory path
Words from neighbour ones
Change e letters to i in words
Non-continuous subsequences
Longest common subsequence
Longest palindromic substrings
Longest increasing subsequence
Words containing "the" substring
Sum of the digits of n is substring of n
Determine if a string is numeric
Determine if a string is collapsible
Determine if a string is squeezable
Determine if a string has all unique characters
Determine if a string has all the same characters
Longest substrings without repeating characters
Find words which contains all the vowels
Find words which contains most consonants
Find words which contains more than 3 vowels
Find words which first and last three letters are equals
Find words which odd letters are consonants and even letters are vowels or vice_versa
Formatting
Substring
Rep-string
Word wrap
String case
Align columns
Literals/String
Repeat a string
Brace expansion
Brace expansion using ranges
Reverse a string
Phrase reversals
Comma quibbling
Special characters
String concatenation
Substring/Top and tail
Commatizing numbers
Reverse words in a string
Suffixation of decimal numbers
Long literals, with continuations
Numerical and alphabetical suffixes
Abbreviations, easy
Abbreviations, simple
Abbreviations, automatic
Song lyrics/poems/Mad Libs/phrases
Mad Libs
Magic 8-ball
99 Bottles of Beer
The Name Game (a song)
The Old lady swallowed a fly
The Twelve Days of Christmas
Tokenize
Text between
Tokenize a string
Word break problem
Tokenize a string with escaping
Split a character string based on change of character
Sequences
Show ASCII table
De Bruijn sequences
Self-referential sequences
Generate lower case ASCII alphabet
| #Raku | Raku | sub mangle ($str is copy) {
$str.match(:ex, 'a')».from.map: { $str.substr-rw($_, 1) = 'ABaCD'.comb[$++] };
$str.=subst('b', 'E');
$str.substr-rw($_, 1) = 'F' given $str.match(:ex, 'r')».from[1];
$str
}
say $_, ' -> ', .&mangle given 'abracadabra';
say $_, ' -> ', .&mangle given 'abracadabra'.comb.pick(*).join; |
http://rosettacode.org/wiki/Selectively_replace_multiple_instances_of_a_character_within_a_string | Selectively replace multiple instances of a character within a string | Task
This is admittedly a trivial task but I thought it would be interesting to see how succinctly (or otherwise) different languages can handle it.
Given the string: "abracadabra", replace programatically:
the first 'a' with 'A'
the second 'a' with 'B'
the fourth 'a' with 'C'
the fifth 'a' with 'D'
the first 'b' with 'E'
the second 'r' with 'F'
Note that there is no replacement for the third 'a', second 'b' or first 'r'.
The answer should, of course, be : "AErBcadCbFD".
Other tasks related to string operations:
Metrics
Array length
String length
Copy a string
Empty string (assignment)
Counting
Word frequency
Letter frequency
Jewels and stones
I before E except after C
Bioinformatics/base count
Count occurrences of a substring
Count how many vowels and consonants occur in a string
Remove/replace
XXXX redacted
Conjugate a Latin verb
Remove vowels from a string
String interpolation (included)
Strip block comments
Strip comments from a string
Strip a set of characters from a string
Strip whitespace from a string -- top and tail
Strip control codes and extended characters from a string
Anagrams/Derangements/shuffling
Word wheel
ABC problem
Sattolo cycle
Knuth shuffle
Ordered words
Superpermutation minimisation
Textonyms (using a phone text pad)
Anagrams
Anagrams/Deranged anagrams
Permutations/Derangements
Find/Search/Determine
ABC words
Odd words
Word ladder
Semordnilap
Word search
Wordiff (game)
String matching
Tea cup rim text
Alternade words
Changeable words
State name puzzle
String comparison
Unique characters
Unique characters in each string
Extract file extension
Levenshtein distance
Palindrome detection
Common list elements
Longest common suffix
Longest common prefix
Compare a list of strings
Longest common substring
Find common directory path
Words from neighbour ones
Change e letters to i in words
Non-continuous subsequences
Longest common subsequence
Longest palindromic substrings
Longest increasing subsequence
Words containing "the" substring
Sum of the digits of n is substring of n
Determine if a string is numeric
Determine if a string is collapsible
Determine if a string is squeezable
Determine if a string has all unique characters
Determine if a string has all the same characters
Longest substrings without repeating characters
Find words which contains all the vowels
Find words which contains most consonants
Find words which contains more than 3 vowels
Find words which first and last three letters are equals
Find words which odd letters are consonants and even letters are vowels or vice_versa
Formatting
Substring
Rep-string
Word wrap
String case
Align columns
Literals/String
Repeat a string
Brace expansion
Brace expansion using ranges
Reverse a string
Phrase reversals
Comma quibbling
Special characters
String concatenation
Substring/Top and tail
Commatizing numbers
Reverse words in a string
Suffixation of decimal numbers
Long literals, with continuations
Numerical and alphabetical suffixes
Abbreviations, easy
Abbreviations, simple
Abbreviations, automatic
Song lyrics/poems/Mad Libs/phrases
Mad Libs
Magic 8-ball
99 Bottles of Beer
The Name Game (a song)
The Old lady swallowed a fly
The Twelve Days of Christmas
Tokenize
Text between
Tokenize a string
Word break problem
Tokenize a string with escaping
Split a character string based on change of character
Sequences
Show ASCII table
De Bruijn sequences
Self-referential sequences
Generate lower case ASCII alphabet
| #Vlang | Vlang | fn selectively_replace_chars(s string, char_map map[string]string) string {
mut bytes := s.bytes()
mut counts := {
'a': 0
'b': 0
'r': 0
}
for i := s.len - 1; i >= 0; i-- {
c := s[i].ascii_str()
if c in ['a', 'b', 'r'] {
bytes[i] = char_map[c][counts[c]]
counts[c]++
}
}
return bytes.bytestr()
}
fn main() {
char_map := {
'a': 'DCaBA'
'b': 'bE'
'r': 'Fr'
}
for old in ['abracadabra', 'caaarrbabad'] {
new := selectively_replace_chars(old, char_map)
println('$old -> $new')
}
} |
http://rosettacode.org/wiki/Send_email | Send email | Task
Write a function to send an email.
The function should have parameters for setting From, To and Cc addresses; the Subject, and the message text, and optionally fields for the server name and login details.
If appropriate, explain what notifications of problems/success are given.
Solutions using libraries or functions from the language are preferred, but failing that, external programs can be used with an explanation.
Note how portable the solution given is between operating systems when multi-OS languages are used.
(Remember to obfuscate any sensitive data used in examples)
| #Fortran | Fortran | program sendmail
use ifcom
use msoutl
implicit none
integer(4) :: app, status, msg
call cominitialize(status)
call comcreateobject("Outlook.Application", app, status)
msg = $Application_CreateItem(app, olMailItem, status)
call $MailItem_SetTo(msg, "somebody@somewhere", status)
call $MailItem_SetSubject(msg, "Title", status)
call $MailItem_SetBody(msg, "Hello", status)
call $MailItem_Send(msg, status)
call $Application_Quit(app, status)
call comuninitialize()
end program |
http://rosettacode.org/wiki/Send_email | Send email | Task
Write a function to send an email.
The function should have parameters for setting From, To and Cc addresses; the Subject, and the message text, and optionally fields for the server name and login details.
If appropriate, explain what notifications of problems/success are given.
Solutions using libraries or functions from the language are preferred, but failing that, external programs can be used with an explanation.
Note how portable the solution given is between operating systems when multi-OS languages are used.
(Remember to obfuscate any sensitive data used in examples)
| #Go | Go | package main
import (
"bufio"
"bytes"
"errors"
"flag"
"fmt"
"io/ioutil"
"net/smtp"
"os"
"strings"
)
type Message struct {
From string
To []string
Cc []string
Subject string
Content string
}
func (m Message) Bytes() (r []byte) {
to := strings.Join(m.To, ",")
cc := strings.Join(m.Cc, ",")
r = append(r, []byte("From: "+m.From+"\n")...)
r = append(r, []byte("To: "+to+"\n")...)
r = append(r, []byte("Cc: "+cc+"\n")...)
r = append(r, []byte("Subject: "+m.Subject+"\n\n")...)
r = append(r, []byte(m.Content)...)
return
}
func (m Message) Send(host string, port int, user, pass string) (err error) {
err = check(host, user, pass)
if err != nil {
return
}
err = smtp.SendMail(fmt.Sprintf("%v:%v", host, port),
smtp.PlainAuth("", user, pass, host),
m.From,
m.To,
m.Bytes(),
)
return
}
func check(host, user, pass string) error {
if host == "" {
return errors.New("Bad host")
}
if user == "" {
return errors.New("Bad username")
}
if pass == "" {
return errors.New("Bad password")
}
return nil
}
func main() {
var flags struct {
host string
port int
user string
pass string
}
flag.StringVar(&flags.host, "host", "", "SMTP server to connect to")
flag.IntVar(&flags.port, "port", 587, "Port to connect to SMTP server on")
flag.StringVar(&flags.user, "user", "", "Username to authenticate with")
flag.StringVar(&flags.pass, "pass", "", "Password to authenticate with")
flag.Parse()
err := check(flags.host, flags.user, flags.pass)
if err != nil {
flag.Usage()
os.Exit(1)
}
bufin := bufio.NewReader(os.Stdin)
fmt.Printf("From: ")
from, err := bufin.ReadString('\n')
if err != nil {
fmt.Printf("Error: %v\n", err)
os.Exit(1)
}
from = strings.Trim(from, " \t\n\r")
var to []string
for {
fmt.Printf("To (Blank to finish): ")
tmp, err := bufin.ReadString('\n')
if err != nil {
fmt.Printf("Error: %v\n", err)
os.Exit(1)
}
tmp = strings.Trim(tmp, " \t\n\r")
if tmp == "" {
break
}
to = append(to, tmp)
}
var cc []string
for {
fmt.Printf("Cc (Blank to finish): ")
tmp, err := bufin.ReadString('\n')
if err != nil {
fmt.Printf("Error: %v\n", err)
os.Exit(1)
}
tmp = strings.Trim(tmp, " \t\n\r")
if tmp == "" {
break
}
cc = append(cc, tmp)
}
fmt.Printf("Subject: ")
subject, err := bufin.ReadString('\n')
if err != nil {
fmt.Printf("Error: %v\n", err)
os.Exit(1)
}
subject = strings.Trim(subject, " \t\n\r")
fmt.Printf("Content (Until EOF):\n")
content, err := ioutil.ReadAll(os.Stdin)
if err != nil {
fmt.Printf("Error: %v\n", err)
os.Exit(1)
}
content = bytes.Trim(content, " \t\n\r")
m := Message{
From: from,
To: to,
Cc: cc,
Subject: subject,
Content: string(content),
}
fmt.Printf("\nSending message...\n")
err = m.Send(flags.host, flags.port, flags.user, flags.pass)
if err != nil {
fmt.Printf("Error: %v\n", err)
os.Exit(1)
}
fmt.Printf("Message sent.\n")
} |
http://rosettacode.org/wiki/Semiprime | Semiprime | Semiprime numbers are natural numbers that are products of exactly two (possibly equal) prime numbers.
Semiprimes are also known as:
semi-primes
biprimes
bi-primes
2-almost primes
or simply: P2
Example
1679 = 23 × 73
(This particular number was chosen as the length of the Arecibo message).
Task
Write a function determining whether a given number is semiprime.
See also
The Wikipedia article: semiprime.
The Wikipedia article: almost prime.
The OEIS sequence: A001358: semiprimes which has a shorter definition: the product of two primes.
| #BASIC | BASIC |
REM Semiprime
PRINT "Enter an integer ";
INPUT N
N = ABS(N)
Count = 0
IF N >= 2 THEN
FOR Factor = 2 TO N
NModFactor = N MOD Factor
WHILE NModFactor = 0
Count = Count + 1
N = N / Factor
NModFactor = N MOD Factor
WEND
NEXT Factor
ENDIF
IF Count = 2 THEN
PRINT "It is a semiprime."
ELSE
PRINT "It is not a semiprime."
ENDIF
END
|
http://rosettacode.org/wiki/Semiprime | Semiprime | Semiprime numbers are natural numbers that are products of exactly two (possibly equal) prime numbers.
Semiprimes are also known as:
semi-primes
biprimes
bi-primes
2-almost primes
or simply: P2
Example
1679 = 23 × 73
(This particular number was chosen as the length of the Arecibo message).
Task
Write a function determining whether a given number is semiprime.
See also
The Wikipedia article: semiprime.
The Wikipedia article: almost prime.
The OEIS sequence: A001358: semiprimes which has a shorter definition: the product of two primes.
| #Bracmat | Bracmat | semiprime=
m n a b
. 2^-64:?m
& 2*!m:?n
& !arg^!m
: (#%?a^!m*#%?b^!m|#%?a^!n&!a:?b)
& (!a.!b); |
http://rosettacode.org/wiki/Self-describing_numbers | Self-describing numbers | Self-describing numbers
You are encouraged to solve this task according to the task description, using any language you may know.
There are several so-called "self-describing" or "self-descriptive" integers.
An integer is said to be "self-describing" if it has the property that, when digit positions are labeled 0 to N-1, the digit in each position is equal to the number of times that that digit appears in the number.
For example, 2020 is a four-digit self describing number:
position 0 has value 2 and there are two 0s in the number;
position 1 has value 0 and there are no 1s in the number;
position 2 has value 2 and there are two 2s;
position 3 has value 0 and there are zero 3s.
Self-describing numbers < 100.000.000 are: 1210, 2020, 21200, 3211000, 42101000.
Task Description
Write a function/routine/method/... that will check whether a given positive integer is self-describing.
As an optional stretch goal - generate and display the set of self-describing numbers.
Related tasks
Fours is the number of letters in the ...
Look-and-say sequence
Number names
Self-referential sequence
Spelling of ordinal numbers
| #AppleScript | AppleScript | use AppleScript version "2.4"
use framework "Foundation"
use scripting additions
-- selfDescribes :: Int -> Bool
on selfDescribes(x)
set s to str(x)
set descripn to my str(|λ|(my groupBy(my eq, my sort(characters of s))) of my ¬
described(characters of "0123456789"))
1 = (offset of descripn in s) and ¬
0 = ((items ((length of descripn) + 1) thru -1 of s) as string as integer)
end selfDescribes
-- described :: [Char] -> [[Char]] -> [Char]
on described(digits)
script
on |λ|(groups)
if 0 < length of digits and 0 < length of groups then
set grp to item 1 of groups
set go to described(rest of digits)
if item 1 of digits = item 1 of (item 1 of grp) then
{item 1 of my str(length of grp)} & |λ|(rest of groups) of go
else
{"0"} & |λ|(groups) of go
end if
else
{}
end if
end |λ|
end script
end described
-------------------------- TEST ---------------------------
on run
script test
on |λ|(n)
str(n) & " -> " & str(selfDescribes(n))
end |λ|
end script
unlines(map(test, ¬
{1210, 1211, 2020, 2022, 21200, 21203, 3211000, 3211004}))
end run
-------------------- GENERIC FUNCTIONS --------------------
-- True if every value in the list is true.
-- and :: [Bool] -> Bool
on |and|(xs)
repeat with x in xs
if not (contents of x) then return false
end repeat
return true
end |and|
-- enumFromTo :: Int -> Int -> [Int]
on enumFromTo(m, n)
if m ≤ n then
set lst to {}
repeat with i from m to n
set end of lst to i
end repeat
lst
else
{}
end if
end enumFromTo
-- eq (==) :: Eq a => a -> a -> Bool
on eq(a, b)
a = b
end eq
-- filter :: (a -> Bool) -> [a] -> [a]
on filter(p, xs)
tell mReturn(p)
set lst to {}
set lng to length of xs
repeat with i from 1 to lng
set v to item i of xs
if |λ|(v, i, xs) then set end of lst to v
end repeat
return lst
end tell
end filter
-- foldl :: (a -> b -> a) -> a -> [b] -> a
on foldl(f, startValue, xs)
tell mReturn(f)
set v to startValue
set lng to length of xs
repeat with i from 1 to lng
set v to |λ|(v, item i of xs, i, xs)
end repeat
return v
end tell
end foldl
-- Typical usage: groupBy(on(eq, f), xs)
-- groupBy :: (a -> a -> Bool) -> [a] -> [[a]]
on groupBy(f, xs)
set mf to mReturn(f)
script enGroup
on |λ|(a, x)
if length of (active of a) > 0 then
set h to item 1 of active of a
else
set h to missing value
end if
if h is not missing value and mf's |λ|(h, x) then
{active:(active of a) & {x}, sofar:sofar of a}
else
{active:{x}, sofar:(sofar of a) & {active of a}}
end if
end |λ|
end script
if length of xs > 0 then
set dct to foldl(enGroup, {active:{item 1 of xs}, sofar:{}}, rest of xs)
if length of (active of dct) > 0 then
sofar of dct & {active of dct}
else
sofar of dct
end if
else
{}
end if
end groupBy
-- map :: (a -> b) -> [a] -> [b]
on map(f, xs)
-- The list obtained by applying f
-- to each element of xs.
tell mReturn(f)
set lng to length of xs
set lst to {}
repeat with i from 1 to lng
set end of lst to |λ|(item i of xs, i, xs)
end repeat
return lst
end tell
end map
-- mReturn :: First-class m => (a -> b) -> m (a -> b)
on mReturn(f)
-- 2nd class handler function lifted into 1st class script wrapper.
if script is class of f then
f
else
script
property |λ| : f
end script
end if
end mReturn
-- sort :: Ord a => [a] -> [a]
on sort(xs)
((current application's NSArray's arrayWithArray:xs)'s ¬
sortedArrayUsingSelector:"compare:") as list
end sort
-- str :: a -> String
on str(x)
x as string
end str
-- unlines :: [String] -> String
on unlines(xs)
-- A single string formed by the intercalation
-- of a list of strings with the newline character.
set {dlm, my text item delimiters} to ¬
{my text item delimiters, linefeed}
set s to xs as text
set my text item delimiters to dlm
s
end unlines |
http://rosettacode.org/wiki/Self_numbers | Self numbers | A number n is a self number if there is no number g such that g + the sum of g's digits = n. So 18 is not a self number because 9+9=18, 43 is not a self number because 35+5+3=43.
The task is:
Display the first 50 self numbers;
I believe that the 100000000th self number is 1022727208. You should either confirm or dispute my conjecture.
224036583-1 is a Mersenne prime, claimed to also be a self number. Extra credit to anyone proving it.
See also
OEIS: A003052 - Self numbers or Colombian numbers
Wikipedia: Self numbers | #C | C | #include <stdio.h>
#include <stdlib.h>
#include <time.h>
typedef unsigned char bool;
#define TRUE 1
#define FALSE 0
#define MILLION 1000000
#define BILLION 1000 * MILLION
#define MAX_COUNT 2*BILLION + 9*9 + 1
void sieve(bool *sv) {
int n = 0, s[8], a, b, c, d, e, f, g, h, i, j;
for (a = 0; a < 2; ++a) {
for (b = 0; b < 10; ++b) {
s[0] = a + b;
for (c = 0; c < 10; ++c) {
s[1] = s[0] + c;
for (d = 0; d < 10; ++d) {
s[2] = s[1] + d;
for (e = 0; e < 10; ++e) {
s[3] = s[2] + e;
for (f = 0; f < 10; ++f) {
s[4] = s[3] + f;
for (g = 0; g < 10; ++g) {
s[5] = s[4] + g;
for (h = 0; h < 10; ++h) {
s[6] = s[5] + h;
for (i = 0; i < 10; ++i) {
s[7] = s[6] + i;
for (j = 0; j < 10; ++j) {
sv[s[7] + j+ n++] = TRUE;
}
}
}
}
}
}
}
}
}
}
}
int main() {
int count = 0;
clock_t begin = clock();
bool *p, *sv = (bool*) calloc(MAX_COUNT, sizeof(bool));
sieve(sv);
printf("The first 50 self numbers are:\n");
for (p = sv; p < sv + MAX_COUNT; ++p) {
if (!*p) {
if (++count <= 50) printf("%ld ", p-sv);
if (count == 100 * MILLION) {
printf("\n\nThe 100 millionth self number is %ld\n", p-sv);
break;
}
}
}
free(sv);
printf("Took %lf seconds.\n", (double)(clock() - begin) / CLOCKS_PER_SEC);
return 0;
} |
http://rosettacode.org/wiki/Set_of_real_numbers | Set of real numbers | All real numbers form the uncountable set ℝ. Among its subsets, relatively simple are the convex sets, each expressed as a range between two real numbers a and b where a ≤ b. There are actually four cases for the meaning of "between", depending on open or closed boundary:
[a, b]: {x | a ≤ x and x ≤ b }
(a, b): {x | a < x and x < b }
[a, b): {x | a ≤ x and x < b }
(a, b]: {x | a < x and x ≤ b }
Note that if a = b, of the four only [a, a] would be non-empty.
Task
Devise a way to represent any set of real numbers, for the definition of 'any' in the implementation notes below.
Provide methods for these common set operations (x is a real number; A and B are sets):
x ∈ A: determine if x is an element of A
example: 1 is in [1, 2), while 2, 3, ... are not.
A ∪ B: union of A and B, i.e. {x | x ∈ A or x ∈ B}
example: [0, 2) ∪ (1, 3) = [0, 3); [0, 1) ∪ (2, 3] = well, [0, 1) ∪ (2, 3]
A ∩ B: intersection of A and B, i.e. {x | x ∈ A and x ∈ B}
example: [0, 2) ∩ (1, 3) = (1, 2); [0, 1) ∩ (2, 3] = empty set
A - B: difference between A and B, also written as A \ B, i.e. {x | x ∈ A and x ∉ B}
example: [0, 2) − (1, 3) = [0, 1]
Test your implementation by checking if numbers 0, 1, and 2 are in any of the following sets:
(0, 1] ∪ [0, 2)
[0, 2) ∩ (1, 2]
[0, 3) − (0, 1)
[0, 3) − [0, 1]
Implementation notes
'Any' real set means 'sets that can be expressed as the union of a finite number of convex real sets'. Cantor's set needs not apply.
Infinities should be handled gracefully; indeterminate numbers (NaN) can be ignored.
You can use your machine's native real number representation, which is probably IEEE floating point, and assume it's good enough (it usually is).
Optional work
Create a function to determine if a given set is empty (contains no element).
Define A = {x | 0 < x < 10 and |sin(π x²)| > 1/2 }, B = {x | 0 < x < 10 and |sin(π x)| > 1/2}, calculate the length of the real axis covered by the set A − B. Note that
|sin(π x)| > 1/2 is the same as n + 1/6 < x < n + 5/6 for all integers n; your program does not need to derive this by itself.
| #J | J | has=: 1 :'(interval m)`:6'
ing=: `''
interval=: 3 :0
if.0<L.y do.y return.end.
assert. 5=#words=. ;:y
assert. (0 { words) e. ;:'[('
assert. (2 { words) e. ;:','
assert. (4 { words) e. ;:'])'
'lo hi'=.(1 3{0".L:0 words)
'cL cH'=.0 4{words e.;:'[]'
(lo&(<`<:@.cL) *. hi&(>`>:@.cH))ing
)
union=: 4 :'(x has +. y has)ing'
intersect=: 4 :'(x has *. y has)ing'
without=: 4 :'(x has *. [: -. y has)ing' |
http://rosettacode.org/wiki/Sequence_of_primes_by_trial_division | Sequence of primes by trial division | Sequence of primes by trial division
You are encouraged to solve this task according to the task description, using any language you may know.
Task
Generate a sequence of primes by means of trial division.
Trial division is an algorithm where a candidate number is tested for being a prime by trying to divide it by other numbers.
You may use primes, or any numbers of your choosing, as long as the result is indeed a sequence of primes.
The sequence may be bounded (i.e. up to some limit), unbounded, starting from the start (i.e. 2) or above some given value.
Organize your function as you wish, in particular, it might resemble a filtering operation, or a sieving operation.
If you want to use a ready-made is_prime function, use one from the Primality by trial division page (i.e., add yours there if it isn't there already).
Related tasks
count in factors
prime decomposition
factors of an integer
Sieve of Eratosthenes
primality by trial division
factors of a Mersenne number
trial factoring of a Mersenne number
partition an integer X into N primes
| #Befunge | Befunge | 2>:::"}"8*:*>`#@_48*:**2v
v_v#`\*:%*:*84\/*:*84::+<
v#>::48*:*/\48*:*%%!#v_1^
<^+1$_.#<5#<5#<+#<,#<<0:\ |
http://rosettacode.org/wiki/Sequence_of_primes_by_trial_division | Sequence of primes by trial division | Sequence of primes by trial division
You are encouraged to solve this task according to the task description, using any language you may know.
Task
Generate a sequence of primes by means of trial division.
Trial division is an algorithm where a candidate number is tested for being a prime by trying to divide it by other numbers.
You may use primes, or any numbers of your choosing, as long as the result is indeed a sequence of primes.
The sequence may be bounded (i.e. up to some limit), unbounded, starting from the start (i.e. 2) or above some given value.
Organize your function as you wish, in particular, it might resemble a filtering operation, or a sieving operation.
If you want to use a ready-made is_prime function, use one from the Primality by trial division page (i.e., add yours there if it isn't there already).
Related tasks
count in factors
prime decomposition
factors of an integer
Sieve of Eratosthenes
primality by trial division
factors of a Mersenne number
trial factoring of a Mersenne number
partition an integer X into N primes
| #C | C |
#include<stdio.h>
int isPrime(unsigned int n)
{
unsigned int num;
if ( n < 2||!(n & 1))
return n == 2;
for (num = 3; num <= n/num; num += 2)
if (!(n % num))
return 0;
return 1;
}
int main()
{
unsigned int l,u,i,sum=0;
printf("Enter lower and upper bounds: ");
scanf("%ld%ld",&l,&u);
for(i=l;i<=u;i++){
if(isPrime(i)==1)
{
printf("\n%ld",i);
sum++;
}
}
printf("\n\nPrime numbers found in [%ld,%ld] : %ld",l,u,sum);
return 0;
}
|
http://rosettacode.org/wiki/Sequence_of_non-squares | Sequence of non-squares | Task
Show that the following remarkable formula gives the sequence of non-square natural numbers:
n + floor(1/2 + sqrt(n))
Print out the values for n in the range 1 to 22
Show that no squares occur for n less than one million
This is sequence A000037 in the OEIS database.
| #BASIC256 | BASIC256 | # Display first 22 values
print "The first 22 numbers generated by the sequence are : "
for i = 1 to 22
print nonSquare(i); " ";
next i
print
# Check for squares up to one million
found = false
for i = 1 to 1e6
j = sqrt(nonSquare(i))
if j = int(j) then
found = true
print i, " square numbers found"
exit for
end if
next i
if not found then print "No squares found"
end
function nonSquare (n)
return n + int(0.5 + sqrt(n))
end function |
http://rosettacode.org/wiki/Sequence_of_non-squares | Sequence of non-squares | Task
Show that the following remarkable formula gives the sequence of non-square natural numbers:
n + floor(1/2 + sqrt(n))
Print out the values for n in the range 1 to 22
Show that no squares occur for n less than one million
This is sequence A000037 in the OEIS database.
| #BBC_BASIC | BBC BASIC | FOR N% = 1 TO 22
S% = N% + SQR(N%) + 0.5
PRINT S%
NEXT
PRINT '"Checking...."
FOR N% = 1 TO 999999
S% = N% + SQR(N%) + 0.5
R% = SQR(S%)
IF S%/R% = R% STOP
NEXT
PRINT "No squares occur for n < 1000000" |
http://rosettacode.org/wiki/Set | Set |
Data Structure
This illustrates a data structure, a means of storing data within a program.
You may see other such structures in the Data Structures category.
A set is a collection of elements, without duplicates and without order.
Task
Show each of these set operations:
Set creation
Test m ∈ S -- "m is an element in set S"
A ∪ B -- union; a set of all elements either in set A or in set B.
A ∩ B -- intersection; a set of all elements in both set A and set B.
A ∖ B -- difference; a set of all elements in set A, except those in set B.
A ⊆ B -- subset; true if every element in set A is also in set B.
A = B -- equality; true if every element of set A is in set B and vice versa.
As an option, show some other set operations.
(If A ⊆ B, but A ≠ B, then A is called a true or proper subset of B, written A ⊂ B or A ⊊ B.)
As another option, show how to modify a mutable set.
One might implement a set using an associative array (with set elements as array keys and some dummy value as the values).
One might also implement a set with a binary search tree, or with a hash table, or with an ordered array of binary bits (operated on with bit-wise binary operators).
The basic test, m ∈ S, is O(n) with a sequential list of elements, O(log n) with a balanced binary search tree, or (O(1) average-case, O(n) worst case) with a hash table.
See also
Array
Associative array: Creation, Iteration
Collections
Compound data type
Doubly-linked list: Definition, Element definition, Element insertion, List Traversal, Element Removal
Linked list
Queue: Definition, Usage
Set
Singly-linked list: Element definition, Element insertion, List Traversal, Element Removal
Stack
| #AutoHotkey | AutoHotkey | test(Set,element){
for i, val in Set
if (val=element)
return true
return false
}
Union(SetA,SetB){
SetC:=[], Temp:=[]
for i, val in SetA
SetC.Insert(val), Temp[val] := true
for i, val in SetB
if !Temp[val]
SetC.Insert(val)
return SetC
}
intersection(SetA,SetB){
SetC:=[], Temp:=[]
for i, val in SetA
Temp[val] := true
for i, val in SetB
if Temp[val]
SetC.Insert(val)
return SetC
}
difference(SetA,SetB){
SetC:=[], Temp:=[]
for i, val in SetB
Temp[val] := true
for i, val in SetA
if !Temp[val]
SetC.Insert(val)
return SetC
}
subset(SetA,SetB){
Temp:=[], A:=B:=0
for i, val in SetA
Temp[val] := true , A++
for i, val in SetB
if Temp[val]{
B++
IfEqual, A, %B%, return 1
} return 0
}
equal(SetA,SetB){
return (SetA.MaxIndex() = SetB.MaxIndex() && subset(SetA,SetB)) ? 1: 0
} |
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
| #PHP | PHP | <?php
class Example {
function foo($x) {
return 42 + $x;
}
}
$example = new Example();
$name = 'foo';
echo $example->$name(5), "\n"; // prints "47"
// alternately:
echo call_user_func(array($example, $name), 5), "\n";
?> |
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
| #Picat | Picat | go =>
println("Function: Use apply/n"),
Fun = "fib",
A = 10,
% Convert F to an atom
println(apply(to_atom(Fun),A)),
nl,
println("Predicate: use call/n"),
Pred = "pyth",
call(Pred.to_atom,3,4,Z),
println(z=Z),
% Pred2 is an atom so it can be used directly with call/n.
Pred2 = pyth,
call(Pred.to_atom,13,14,Z2),
println(z2=Z2),
nl.
% A function
fib(1) = 1.
fib(2) = 1.
fib(N) = fib(N-1) + fib(N-2).
% A predicate
pyth(X,Y,Z) =>
Z = X**2 + Y**2. |
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
| #PicoLisp | PicoLisp | (send (expression) Obj arg1 arg2) |
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
| #Pike | Pike | string unknown = "format_nice";
object now = Calendar.now();
now[unknown](); |
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
| #PowerShell | PowerShell |
$method = ([Math] | Get-Member -MemberType Method -Static | Where-Object {$_.Definition.Split(',').Count -eq 1} | Get-Random).Name
$number = (1..9 | Get-Random) / 10
$result = [Math]::$method($number)
$output = [PSCustomObject]@{
Method = $method
Number = $number
Result = $result
}
$output | Format-List
|
http://rosettacode.org/wiki/Sieve_of_Eratosthenes | Sieve of Eratosthenes | This task has been clarified. Its programming examples are in need of review to ensure that they still fit the requirements of the task.
The Sieve of Eratosthenes is a simple algorithm that finds the prime numbers up to a given integer.
Task
Implement the Sieve of Eratosthenes algorithm, with the only allowed optimization that the outer loop can stop at the square root of the limit, and the inner loop may start at the square of the prime just found.
That means especially that you shouldn't optimize by using pre-computed wheels, i.e. don't assume you need only to cross out odd numbers (wheel based on 2), numbers equal to 1 or 5 modulo 6 (wheel based on 2 and 3), or similar wheels based on low primes.
If there's an easy way to add such a wheel based optimization, implement it as an alternative version.
Note
It is important that the sieve algorithm be the actual algorithm used to find prime numbers for the task.
Related tasks
Emirp primes
count in factors
prime decomposition
factors of an integer
extensible prime generator
primality by trial division
factors of a Mersenne number
trial factoring of a Mersenne number
partition an integer X into N primes
sequence of primes by Trial Division
| #ALGOL_60 | ALGOL 60 | comment Sieve of Eratosthenes;
begin
integer array t[0:1000];
integer i,j,k;
for i:=0 step 1 until 1000 do t[i]:=1;
t[0]:=0; t[1]:=0; i:=0;
for i:=i while i<1000 do
begin
for i:=i while i<1000 and t[i]=0 do i:=i+1;
if i<1000 then
begin
j:=2;
k:=j*i;
for k:=k while k<1000 do
begin
t[k]:=0;
j:=j+1;
k:=j*i
end;
i:=i+1
end
end;
for i:=0 step 1 until 999 do
if t[i]≠0 then print(i,ꞌ is primeꞌ)
end
|
http://rosettacode.org/wiki/Sequence_of_primorial_primes | Sequence of primorial primes | The sequence of primorial primes is given as the increasing values of n where primorial(n) ± 1 is prime.
Noting that the n'th primorial is defined as the multiplication of the smallest n primes, the sequence is of the number of primes, in order that when multiplied together is one-off being a prime number itself.
Task
Generate and show here the first ten values of the sequence.
Optional extended task
Show the first twenty members of the series.
Notes
This task asks for the primorial indices that create the final primorial prime numbers, so there should be no ten-or-more digit numbers in the program output (although extended precision integers will be needed for intermediate results).
There is some confusion in the references, but for the purposes of this task the sequence begins with n = 1.
Probabilistic primality tests are allowed, as long as they are good enough such that the output shown is correct.
Related tasks
Primorial numbers
Factorial
See also
Primorial prime Wikipedia.
Primorial prime from The Prime Glossary.
Sequence A088411 from The On-Line Encyclopedia of Integer Sequences
| #Python | Python | import pyprimes
def primorial_prime(_pmax=500):
isprime = pyprimes.isprime
n, primo = 0, 1
for prime in pyprimes.nprimes(_pmax):
n, primo = n+1, primo * prime
if isprime(primo-1) or isprime(primo+1):
yield n
if __name__ == '__main__':
# Turn off warning on use of probabilistic formula for prime test
pyprimes.warn_probably = False
for i, n in zip(range(20), primorial_prime()):
print('Primorial prime %2i at primorial index: %3i' % (i+1, n)) |
http://rosettacode.org/wiki/Sequence_of_primorial_primes | Sequence of primorial primes | The sequence of primorial primes is given as the increasing values of n where primorial(n) ± 1 is prime.
Noting that the n'th primorial is defined as the multiplication of the smallest n primes, the sequence is of the number of primes, in order that when multiplied together is one-off being a prime number itself.
Task
Generate and show here the first ten values of the sequence.
Optional extended task
Show the first twenty members of the series.
Notes
This task asks for the primorial indices that create the final primorial prime numbers, so there should be no ten-or-more digit numbers in the program output (although extended precision integers will be needed for intermediate results).
There is some confusion in the references, but for the purposes of this task the sequence begins with n = 1.
Probabilistic primality tests are allowed, as long as they are good enough such that the output shown is correct.
Related tasks
Primorial numbers
Factorial
See also
Primorial prime Wikipedia.
Primorial prime from The Prime Glossary.
Sequence A088411 from The On-Line Encyclopedia of Integer Sequences
| #Racket | Racket | #lang racket
(require math/number-theory
racket/generator)
(define-syntax-rule (define/cache (name arg) body ...)
(begin
(define cache (make-hash))
(define (name arg)
(hash-ref! cache arg (lambda () body ...)))))
(define/cache (primorial n)
(if (zero? n)
1
(* (nth-prime (sub1 n))
(primorial (sub1 n)))))
(for ([i (in-range 20)]
[n (in-generator (for ([i (in-naturals 1)])
(define pr (primorial i))
(when (or (prime? (add1 pr)) (prime? (sub1 pr)))
(yield i))))])
(displayln n)) |
http://rosettacode.org/wiki/Set_consolidation | Set consolidation | Given two sets of items then if any item is common to any set then the result of applying consolidation to those sets is a set of sets whose contents is:
The two input sets if no common item exists between the two input sets of items.
The single set that is the union of the two input sets if they share a common item.
Given N sets of items where N>2 then the result is the same as repeatedly replacing all combinations of two sets by their consolidation until no further consolidation between set pairs is possible.
If N<2 then consolidation has no strict meaning and the input can be returned.
Example 1:
Given the two sets {A,B} and {C,D} then there is no common element between the sets and the result is the same as the input.
Example 2:
Given the two sets {A,B} and {B,D} then there is a common element B between the sets and the result is the single set {B,D,A}. (Note that order of items in a set is immaterial: {A,B,D} is the same as {B,D,A} and {D,A,B}, etc).
Example 3:
Given the three sets {A,B} and {C,D} and {D,B} then there is no common element between the sets {A,B} and {C,D} but the sets {A,B} and {D,B} do share a common element that consolidates to produce the result {B,D,A}. On examining this result with the remaining set, {C,D}, they share a common element and so consolidate to the final output of the single set {A,B,C,D}
Example 4:
The consolidation of the five sets:
{H,I,K}, {A,B}, {C,D}, {D,B}, and {F,G,H}
Is the two sets:
{A, C, B, D}, and {G, F, I, H, K}
See also
Connected component (graph theory)
Range consolidation
| #Mathematica.2FWolfram_Language | Mathematica/Wolfram Language | reduce[x_] :=
Block[{pairs, unique},
pairs =
DeleteCases[
Subsets[Range@
Length@x, {2}], _?(Intersection @@ x[[#]] == {} &)];
unique = Complement[Range@Length@x, Flatten@pairs];
Join[Union[Flatten[x[[#]]]] & /@ pairs, x[[unique]]]]
consolidate[x__] := FixedPoint[reduce, {x}] |
http://rosettacode.org/wiki/Set_consolidation | Set consolidation | Given two sets of items then if any item is common to any set then the result of applying consolidation to those sets is a set of sets whose contents is:
The two input sets if no common item exists between the two input sets of items.
The single set that is the union of the two input sets if they share a common item.
Given N sets of items where N>2 then the result is the same as repeatedly replacing all combinations of two sets by their consolidation until no further consolidation between set pairs is possible.
If N<2 then consolidation has no strict meaning and the input can be returned.
Example 1:
Given the two sets {A,B} and {C,D} then there is no common element between the sets and the result is the same as the input.
Example 2:
Given the two sets {A,B} and {B,D} then there is a common element B between the sets and the result is the single set {B,D,A}. (Note that order of items in a set is immaterial: {A,B,D} is the same as {B,D,A} and {D,A,B}, etc).
Example 3:
Given the three sets {A,B} and {C,D} and {D,B} then there is no common element between the sets {A,B} and {C,D} but the sets {A,B} and {D,B} do share a common element that consolidates to produce the result {B,D,A}. On examining this result with the remaining set, {C,D}, they share a common element and so consolidate to the final output of the single set {A,B,C,D}
Example 4:
The consolidation of the five sets:
{H,I,K}, {A,B}, {C,D}, {D,B}, and {F,G,H}
Is the two sets:
{A, C, B, D}, and {G, F, I, H, K}
See also
Connected component (graph theory)
Range consolidation
| #Nim | Nim | proc consolidate(sets: varargs[set[char]]): seq[set[char]] =
if len(sets) < 2:
return @sets
var (r, b) = (@[sets[0]], consolidate(sets[1..^1]))
for x in b:
if len(r[0] * x) != 0:
r[0] = r[0] + x
else:
r.add(x)
r
echo consolidate({'A', 'B'}, {'C', 'D'})
echo consolidate({'A', 'B'}, {'B', 'D'})
echo consolidate({'A', 'B'}, {'C', 'D'}, {'D', 'B'})
echo consolidate({'H', 'I', 'K'}, {'A', 'B'}, {'C', 'D'}, {'D', 'B'}, {'F', 'G', 'H'}) |
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 n divisors
See also
OEIS:A005179
| #Quackery | Quackery | [ 0
[ 1+ 2dup
factors size =
until ]
nip ] is nfactors ( n --> n )
15 times [ i^ 1+ nfactors echo sp ] |
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 n divisors
See also
OEIS:A005179
| #R | R | #Need to add 1 to account for skipping n. Not the most efficient way to count divisors, but quite clear.
divisorCount <- function(n) length(Filter(function(x) n %% x == 0, seq_len(n %/% 2))) + 1
smallestWithNDivisors <- function(n)
{
i <- 1
while(divisorCount(i) != n) i <- i + 1
i
}
print(sapply(1:15, smallestWithNDivisors)) |
http://rosettacode.org/wiki/SHA-256 | SHA-256 | SHA-256 is the recommended stronger alternative to SHA-1. See FIPS PUB 180-4 for implementation details.
Either by using a dedicated library or implementing the algorithm in your language, show that the SHA-256 digest of the string "Rosetta code" is: 764faf5c61ac315f1497f9dfa542713965b785e5cc2f707d6468d7d1124cdfcf
| #Racket | Racket |
#lang racket/base
;; define a quick SH256 FFI interface, similar to the Racket's default
;; SHA1 interface
(require ffi/unsafe ffi/unsafe/define openssl/libcrypto
(only-in openssl/sha1 bytes->hex-string))
(define-ffi-definer defcrypto libcrypto)
(defcrypto SHA256_Init (_fun _pointer -> _int))
(defcrypto SHA256_Update (_fun _pointer _pointer _long -> _int))
(defcrypto SHA256_Final (_fun _pointer _pointer -> _int))
(define (sha256 bytes)
(define ctx (malloc 128))
(define result (make-bytes 32))
(SHA256_Init ctx)
(SHA256_Update ctx bytes (bytes-length bytes))
(SHA256_Final result ctx)
(bytes->hex-string result))
;; use the defined wrapper to solve the task
(displayln (sha256 #"Rosetta code"))
|
http://rosettacode.org/wiki/SHA-256 | SHA-256 | SHA-256 is the recommended stronger alternative to SHA-1. See FIPS PUB 180-4 for implementation details.
Either by using a dedicated library or implementing the algorithm in your language, show that the SHA-256 digest of the string "Rosetta code" is: 764faf5c61ac315f1497f9dfa542713965b785e5cc2f707d6468d7d1124cdfcf
| #Raku | Raku | say sha256 "Rosetta code";
sub init(&f) {
map { my $f = $^p.&f; (($f - $f.Int)*2**32).Int },
state @ = grep *.is-prime, 2 .. *;
}
sub infix:<m+> { ($^a + $^b) % 2**32 }
sub rotr($n, $b) { $n +> $b +| $n +< (32 - $b) }
proto sha256($) returns Blob {*}
multi sha256(Str $str where all($str.ords) < 128) {
sha256 $str.encode: 'ascii'
}
multi sha256(Blob $data) {
constant K = init(* **(1/3))[^64];
my @b = flat $data.list, 0x80;
push @b, 0 until (8 * @b - 448) %% 512;
push @b, slip reverse (8 * $data).polymod(256 xx 7);
my @word = :256[@b.shift xx 4] xx @b/4;
my @H = init(&sqrt)[^8];
my @w;
loop (my $i = 0; $i < @word; $i += 16) {
my @h = @H;
for ^64 -> $j {
@w[$j] = $j < 16 ?? @word[$j + $i] // 0 !!
[m+]
rotr(@w[$j-15], 7) +^ rotr(@w[$j-15], 18) +^ @w[$j-15] +> 3,
@w[$j-7],
rotr(@w[$j-2], 17) +^ rotr(@w[$j-2], 19) +^ @w[$j-2] +> 10,
@w[$j-16];
my $ch = @h[4] +& @h[5] +^ +^@h[4] % 2**32 +& @h[6];
my $maj = @h[0] +& @h[2] +^ @h[0] +& @h[1] +^ @h[1] +& @h[2];
my $σ0 = [+^] map { rotr @h[0], $_ }, 2, 13, 22;
my $σ1 = [+^] map { rotr @h[4], $_ }, 6, 11, 25;
my $t1 = [m+] @h[7], $σ1, $ch, K[$j], @w[$j];
my $t2 = $σ0 m+ $maj;
@h = flat $t1 m+ $t2, @h[^3], @h[3] m+ $t1, @h[4..6];
}
@H [Z[m+]]= @h;
}
return Blob.new: map { |reverse .polymod(256 xx 3) }, @H;
} |
http://rosettacode.org/wiki/Sequence:_smallest_number_greater_than_previous_term_with_exactly_n_divisors | Sequence: smallest number greater than previous term with exactly n divisors | Calculate the sequence where each term an is the smallest natural number greater than the previous term, that has exactly n divisors.
Task
Show here, on this page, at least the first 15 terms of the sequence.
See also
OEIS:A069654
Related tasks
Sequence: smallest number with exactly n divisors
Sequence: nth number with exactly n divisors
| #Swift | Swift | // See https://en.wikipedia.org/wiki/Divisor_function
func divisorCount(number: Int) -> Int {
var n = number
var total = 1
// Deal with powers of 2 first
while n % 2 == 0 {
total += 1
n /= 2
}
// Odd prime factors up to the square root
var p = 3
while p * p <= n {
var count = 1
while n % p == 0 {
count += 1
n /= p
}
total *= count
p += 2
}
// If n > 1 then it's prime
if n > 1 {
total *= 2
}
return total
}
let limit = 32
var n = 1
var next = 1
while next <= limit {
if next == divisorCount(number: n) {
print(n, terminator: " ")
next += 1
if next > 4 && divisorCount(number: next) == 2 {
n = 1 << (next - 1) - 1;
}
}
n += 1
}
print() |
http://rosettacode.org/wiki/Sequence:_smallest_number_greater_than_previous_term_with_exactly_n_divisors | Sequence: smallest number greater than previous term with exactly n divisors | Calculate the sequence where each term an is the smallest natural number greater than the previous term, that has exactly n divisors.
Task
Show here, on this page, at least the first 15 terms of the sequence.
See also
OEIS:A069654
Related tasks
Sequence: smallest number with exactly n divisors
Sequence: nth number with exactly n divisors
| #Wren | Wren | import "/math" for Int
var limit = 24
var res = List.filled(limit, 0)
var next = 1
var n = 1
while (next <= limit) {
var k = Int.divisors(n).count
if (k == next) {
res[k-1] = n
next = next + 1
if (next > 4 && Int.isPrime(next)) n = 2.pow(next-1) - 1
}
n = n + 1
}
System.print("The first %(limit) terms are:")
System.print(res) |
http://rosettacode.org/wiki/SHA-1 | SHA-1 | SHA-1 or SHA1 is a one-way hash function;
it computes a 160-bit message digest.
SHA-1 often appears in security protocols; for example,
many HTTPS websites use RSA with SHA-1 to secure their connections.
BitTorrent uses SHA-1 to verify downloads.
Git and Mercurial use SHA-1 digests to identify commits.
A US government standard, FIPS 180-1, defines SHA-1.
Find the SHA-1 message digest for a string of octets. You may either call a SHA-1 library, or implement SHA-1 in your language. Both approaches interest Rosetta Code.
Warning: SHA-1 has known weaknesses. Theoretical attacks may find a collision after 252 operations, or perhaps fewer.
This is much faster than a brute force attack of 280 operations. USgovernment deprecated SHA-1.
For production-grade cryptography, users may consider a stronger alternative, such as SHA-256 (from the SHA-2 family) or the upcoming SHA-3.
| #Raku | Raku | sub postfix:<mod2³²> { $^x % 2**32 }
sub infix:<⊕> { ($^x + $^y)mod2³² }
sub S { ($^x +< $^n)mod2³² +| ($x +> (32-$n)) }
my \f = -> \B,\C,\D { (B +& C) +| ((+^B)mod2³² +& D) },
-> \B,\C,\D { B +^ C +^ D },
-> \B,\C,\D { (B +& C) +| (B +& D) +| (C +& D) },
-> \B,\C,\D { B +^ C +^ D };
my \K = 0x5A827999, 0x6ED9EBA1, 0x8F1BBCDC, 0xCA62C1D6;
sub sha1-pad(Blob $msg)
{
my \bits = 8 * $msg.elems;
my @padded = flat $msg.list, 0x80, 0x00 xx (-($msg.elems + 1 + 8) % 64);
flat @padded.map({ :256[$^a,$^b,$^c,$^d] }), (bits +> 32)mod2³², (bits)mod2³²;
}
sub sha1-block(@H, @M is copy)
{
@M.push: S(1, [+^] @M[$_ «-« <3 8 14 16>] ) for 16 .. 79;
my ($A,$B,$C,$D,$E) = @H;
for 0..79 -> \t {
($A, $B, $C, $D, $E) =
S(5,$A) ⊕ f[t div 20]($B,$C,$D) ⊕ $E ⊕ @M[t] ⊕ K[t div 20],
$A, S(30,$B), $C, $D;
}
@H »⊕=« ($A,$B,$C,$D,$E);
}
sub sha1(Blob $msg) returns Blob
{
my @M = sha1-pad($msg);
my @H = 0x67452301, 0xEFCDAB89, 0x98BADCFE, 0x10325476, 0xC3D2E1F0;
sha1-block(@H,@M[$_..$_+15]) for 0, 16...^ +@M;
Blob.new: flat map { reverse .polymod(256 xx 3) }, @H;
}
say sha1(.encode('ascii')), " $_"
for 'abc',
'abcdbcdecdefdefgefghfghighijhijkijkljklmklmnlmnomnopnopq',
'Rosetta Code',
'Ars longa, vita brevis'; |
http://rosettacode.org/wiki/Show_ASCII_table | Show ASCII table | Task
Show the ASCII character set from values 32 to 127 (decimal) in a table format.
Other tasks related to string operations:
Metrics
Array length
String length
Copy a string
Empty string (assignment)
Counting
Word frequency
Letter frequency
Jewels and stones
I before E except after C
Bioinformatics/base count
Count occurrences of a substring
Count how many vowels and consonants occur in a string
Remove/replace
XXXX redacted
Conjugate a Latin verb
Remove vowels from a string
String interpolation (included)
Strip block comments
Strip comments from a string
Strip a set of characters from a string
Strip whitespace from a string -- top and tail
Strip control codes and extended characters from a string
Anagrams/Derangements/shuffling
Word wheel
ABC problem
Sattolo cycle
Knuth shuffle
Ordered words
Superpermutation minimisation
Textonyms (using a phone text pad)
Anagrams
Anagrams/Deranged anagrams
Permutations/Derangements
Find/Search/Determine
ABC words
Odd words
Word ladder
Semordnilap
Word search
Wordiff (game)
String matching
Tea cup rim text
Alternade words
Changeable words
State name puzzle
String comparison
Unique characters
Unique characters in each string
Extract file extension
Levenshtein distance
Palindrome detection
Common list elements
Longest common suffix
Longest common prefix
Compare a list of strings
Longest common substring
Find common directory path
Words from neighbour ones
Change e letters to i in words
Non-continuous subsequences
Longest common subsequence
Longest palindromic substrings
Longest increasing subsequence
Words containing "the" substring
Sum of the digits of n is substring of n
Determine if a string is numeric
Determine if a string is collapsible
Determine if a string is squeezable
Determine if a string has all unique characters
Determine if a string has all the same characters
Longest substrings without repeating characters
Find words which contains all the vowels
Find words which contains most consonants
Find words which contains more than 3 vowels
Find words which first and last three letters are equals
Find words which odd letters are consonants and even letters are vowels or vice_versa
Formatting
Substring
Rep-string
Word wrap
String case
Align columns
Literals/String
Repeat a string
Brace expansion
Brace expansion using ranges
Reverse a string
Phrase reversals
Comma quibbling
Special characters
String concatenation
Substring/Top and tail
Commatizing numbers
Reverse words in a string
Suffixation of decimal numbers
Long literals, with continuations
Numerical and alphabetical suffixes
Abbreviations, easy
Abbreviations, simple
Abbreviations, automatic
Song lyrics/poems/Mad Libs/phrases
Mad Libs
Magic 8-ball
99 Bottles of Beer
The Name Game (a song)
The Old lady swallowed a fly
The Twelve Days of Christmas
Tokenize
Text between
Tokenize a string
Word break problem
Tokenize a string with escaping
Split a character string based on change of character
Sequences
Show ASCII table
De Bruijn sequences
Self-referential sequences
Generate lower case ASCII alphabet
| #Mathematica_.2F_Wolfram_Language | Mathematica / Wolfram Language | StringRiffle[StringJoin@@@Transpose[Partition[ToString[#]<>": "<>Switch[#,32,"Spc ",127,"Del ",_,FromCharacterCode[#]<>" "]&/@Range[32,127],16]],"\n"] |
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:
*
* *
* *
* * * *
* *
* * * *
* * * *
* * * * * * * *
* *
* * * *
* * * *
* * * * * * * *
* * * *
* * * * * * * *
* * * * * * * *
* * * * * * * * * * * * * * * *
Related tasks
Sierpinski triangle/Graphical for graphics images of this pattern.
Sierpinski carpet
| #R | R | sierpinski.triangle = function(n) {
len <- 2^(n+1)
b <- c(rep(FALSE,len/2),TRUE,rep(FALSE,len/2))
for (i in 1:(len/2))
{
cat(paste(ifelse(b,"*"," "),collapse=""),"\n")
n <- rep(FALSE,len+1)
n[which(b)-1]<-TRUE
n[which(b)+1]<-xor(n[which(b)+1],TRUE)
b <- n
}
}
sierpinski.triangle(5) |
http://rosettacode.org/wiki/Sierpinski_carpet | Sierpinski carpet | Task
Produce a graphical or ASCII-art representation of a Sierpinski carpet of order N.
For example, the Sierpinski carpet of order 3 should look like this:
###########################
# ## ## ## ## ## ## ## ## #
###########################
### ###### ###### ###
# # # ## # # ## # # #
### ###### ###### ###
###########################
# ## ## ## ## ## ## ## ## #
###########################
######### #########
# ## ## # # ## ## #
######### #########
### ### ### ###
# # # # # # # #
### ### ### ###
######### #########
# ## ## # # ## ## #
######### #########
###########################
# ## ## ## ## ## ## ## ## #
###########################
### ###### ###### ###
# # # ## # # ## # # #
### ###### ###### ###
###########################
# ## ## ## ## ## ## ## ## #
###########################
The use of the # character is not rigidly required for ASCII art.
The important requirement is the placement of whitespace and non-whitespace characters.
Related task
Sierpinski triangle
| #PARI.2FGP | PARI/GP |
\\ Improved simple plotting using matrix mat (color and scaling added).
\\ Matrix should be filled with 0/1. 7/6/16 aev
iPlotmat(mat,clr)={
my(xz=#mat[1,],yz=#mat[,1],vx=List(),vy=vx,xmin,xmax,ymin,ymax,c=0.625);
for(i=1,yz, for(j=1,xz, if(mat[i,j]==0, next, listput(vx,i); listput(vy,j))));
xmin=listmin(vx); xmax=listmax(vx); ymin=listmin(vy); ymax=listmax(vy);
plotinit(0); plotcolor(0,clr);
plotscale(0, xmin,xmax,ymin,ymax);
plotpoints(0, Vec(vx)*c,Vec(vy));
plotdraw([0,xmin,ymin]);
print(" *** matrix: ",xz,"x",yz,", ",#vy," DOTS");
}
\\ iPlotV2(): Improved plotting from a file written by the wrtmat(). (color added)
\\ Saving possibly huge generation time if re-plotting needed.
iPlotV2(fn, clr)={
my(F,nf,vx=List(),vy=vx,Vr,xmin,xmax,ymin,ymax,c=0.625);
F=readstr(fn); nf=#F;
print(" *** Plotting from: ", fn, " - ", nf, " DOTS");
for(i=1,nf, Vr=stok(F[i]," "); listput(vx,eval(Vr[1])); listput(vy,eval(Vr[2])));
xmin=listmin(vx); xmax=listmax(vx); ymin=listmin(vy); ymax=listmax(vy);
plotinit(0); plotcolor(0,clr);
plotscale(0, xmin,xmax,ymin,ymax);
plotpoints(0, Vec(vx)*c,Vec(vy));
plotdraw([0,xmin,ymin]);
}
\\ Are x,y inside Sierpinski carpet? (1-yes, 0-no) 6/10/16 aev
inSC(x,y)={
while(1, if(!x||!y,return(1));
if(x%3==1&&y%3==1, return(0));
x\=3; y\=3;);\\wend
}
|
http://rosettacode.org/wiki/Semordnilap | Semordnilap | A semordnilap is a word (or phrase) that spells a different word (or phrase) backward. "Semordnilap" is a word that itself is a semordnilap.
Example: lager and regal
Task
This task does not consider semordnilap phrases, only single words.
Using only words from this list, report the total number of unique semordnilap pairs, and print 5 examples.
Two matching semordnilaps, such as lager and regal, should be counted as one unique pair.
(Note that the word "semordnilap" is not in the above dictionary.)
Other tasks related to string operations:
Metrics
Array length
String length
Copy a string
Empty string (assignment)
Counting
Word frequency
Letter frequency
Jewels and stones
I before E except after C
Bioinformatics/base count
Count occurrences of a substring
Count how many vowels and consonants occur in a string
Remove/replace
XXXX redacted
Conjugate a Latin verb
Remove vowels from a string
String interpolation (included)
Strip block comments
Strip comments from a string
Strip a set of characters from a string
Strip whitespace from a string -- top and tail
Strip control codes and extended characters from a string
Anagrams/Derangements/shuffling
Word wheel
ABC problem
Sattolo cycle
Knuth shuffle
Ordered words
Superpermutation minimisation
Textonyms (using a phone text pad)
Anagrams
Anagrams/Deranged anagrams
Permutations/Derangements
Find/Search/Determine
ABC words
Odd words
Word ladder
Semordnilap
Word search
Wordiff (game)
String matching
Tea cup rim text
Alternade words
Changeable words
State name puzzle
String comparison
Unique characters
Unique characters in each string
Extract file extension
Levenshtein distance
Palindrome detection
Common list elements
Longest common suffix
Longest common prefix
Compare a list of strings
Longest common substring
Find common directory path
Words from neighbour ones
Change e letters to i in words
Non-continuous subsequences
Longest common subsequence
Longest palindromic substrings
Longest increasing subsequence
Words containing "the" substring
Sum of the digits of n is substring of n
Determine if a string is numeric
Determine if a string is collapsible
Determine if a string is squeezable
Determine if a string has all unique characters
Determine if a string has all the same characters
Longest substrings without repeating characters
Find words which contains all the vowels
Find words which contains most consonants
Find words which contains more than 3 vowels
Find words which first and last three letters are equals
Find words which odd letters are consonants and even letters are vowels or vice_versa
Formatting
Substring
Rep-string
Word wrap
String case
Align columns
Literals/String
Repeat a string
Brace expansion
Brace expansion using ranges
Reverse a string
Phrase reversals
Comma quibbling
Special characters
String concatenation
Substring/Top and tail
Commatizing numbers
Reverse words in a string
Suffixation of decimal numbers
Long literals, with continuations
Numerical and alphabetical suffixes
Abbreviations, easy
Abbreviations, simple
Abbreviations, automatic
Song lyrics/poems/Mad Libs/phrases
Mad Libs
Magic 8-ball
99 Bottles of Beer
The Name Game (a song)
The Old lady swallowed a fly
The Twelve Days of Christmas
Tokenize
Text between
Tokenize a string
Word break problem
Tokenize a string with escaping
Split a character string based on change of character
Sequences
Show ASCII table
De Bruijn sequences
Self-referential sequences
Generate lower case ASCII alphabet
| #BBC_BASIC | BBC BASIC | INSTALL @lib$+"SORTLIB"
Sort% = FN_sortinit(0,0)
DIM dict$(26000*2)
REM Load the dictionary, eliminating palindromes:
dict% = OPENIN("C:\unixdict.txt")
IF dict%=0 ERROR 100, "No dictionary file"
index% = 0
REPEAT
A$ = GET$#dict%
B$ = FNreverse(A$)
IF A$<>B$ THEN
dict$(index%) = A$
dict$(index%+1) = B$
index% += 2
ENDIF
UNTIL EOF#dict%
CLOSE #dict%
Total% = index%
REM Sort the dictionary:
C% = Total%
CALL Sort%, dict$(0)
REM Find semordnilaps:
pairs% = 0
examples% = 0
FOR index% = 0 TO Total%-2
IF dict$(index%)=dict$(index%+1) THEN
IF examples%<5 IF LEN(dict$(index%))>4 THEN
PRINT dict$(index%) " " FNreverse(dict$(index%))
examples% += 1
ENDIF
pairs% += 1
ENDIF
NEXT
PRINT "Total number of unique pairs = "; pairs%/2
END
DEF FNreverse(A$)
LOCAL I%, L%, P%
IF A$="" THEN =""
L% = LENA$ - 1
P% = !^A$
FOR I% = 0 TO L% DIV 2
SWAP P%?I%, L%?(P%-I%)
NEXT
= A$ |
http://rosettacode.org/wiki/Short-circuit_evaluation | Short-circuit evaluation | Control Structures
These are examples of control structures. You may also be interested in:
Conditional structures
Exceptions
Flow-control structures
Loops
Assume functions a and b return boolean values, and further, the execution of function b takes considerable resources without side effects, and is to be minimized.
If we needed to compute the conjunction (and):
x = a() and b()
Then it would be best to not compute the value of b() if the value of a() is computed as false, as the value of x can then only ever be false.
Similarly, if we needed to compute the disjunction (or):
y = a() or b()
Then it would be best to not compute the value of b() if the value of a() is computed as true, as the value of y can then only ever be true.
Some languages will stop further computation of boolean equations as soon as the result is known, so-called short-circuit evaluation of boolean expressions
Task
Create two functions named a and b, that take and return the same boolean value.
The functions should also print their name whenever they are called.
Calculate and assign the values of the following equations to a variable in such a way that function b is only called when necessary:
x = a(i) and b(j)
y = a(i) or b(j)
If the language does not have short-circuit evaluation, this might be achieved with nested if statements.
| #PureBasic | PureBasic | Procedure a(arg)
PrintN(" # Called function a("+Str(arg)+")")
ProcedureReturn arg
EndProcedure
Procedure b(arg)
PrintN(" # Called function b("+Str(arg)+")")
ProcedureReturn arg
EndProcedure
OpenConsole()
For a=#False To #True
For b=#False To #True
PrintN(#CRLF$+"Calculating: x = a("+Str(a)+") And b("+Str(b)+")")
x= a(a) And b(b)
PrintN("Calculating: x = a("+Str(a)+") Or b("+Str(b)+")")
y= a(a) Or b(b)
Next
Next
Input() |
http://rosettacode.org/wiki/Selectively_replace_multiple_instances_of_a_character_within_a_string | Selectively replace multiple instances of a character within a string | Task
This is admittedly a trivial task but I thought it would be interesting to see how succinctly (or otherwise) different languages can handle it.
Given the string: "abracadabra", replace programatically:
the first 'a' with 'A'
the second 'a' with 'B'
the fourth 'a' with 'C'
the fifth 'a' with 'D'
the first 'b' with 'E'
the second 'r' with 'F'
Note that there is no replacement for the third 'a', second 'b' or first 'r'.
The answer should, of course, be : "AErBcadCbFD".
Other tasks related to string operations:
Metrics
Array length
String length
Copy a string
Empty string (assignment)
Counting
Word frequency
Letter frequency
Jewels and stones
I before E except after C
Bioinformatics/base count
Count occurrences of a substring
Count how many vowels and consonants occur in a string
Remove/replace
XXXX redacted
Conjugate a Latin verb
Remove vowels from a string
String interpolation (included)
Strip block comments
Strip comments from a string
Strip a set of characters from a string
Strip whitespace from a string -- top and tail
Strip control codes and extended characters from a string
Anagrams/Derangements/shuffling
Word wheel
ABC problem
Sattolo cycle
Knuth shuffle
Ordered words
Superpermutation minimisation
Textonyms (using a phone text pad)
Anagrams
Anagrams/Deranged anagrams
Permutations/Derangements
Find/Search/Determine
ABC words
Odd words
Word ladder
Semordnilap
Word search
Wordiff (game)
String matching
Tea cup rim text
Alternade words
Changeable words
State name puzzle
String comparison
Unique characters
Unique characters in each string
Extract file extension
Levenshtein distance
Palindrome detection
Common list elements
Longest common suffix
Longest common prefix
Compare a list of strings
Longest common substring
Find common directory path
Words from neighbour ones
Change e letters to i in words
Non-continuous subsequences
Longest common subsequence
Longest palindromic substrings
Longest increasing subsequence
Words containing "the" substring
Sum of the digits of n is substring of n
Determine if a string is numeric
Determine if a string is collapsible
Determine if a string is squeezable
Determine if a string has all unique characters
Determine if a string has all the same characters
Longest substrings without repeating characters
Find words which contains all the vowels
Find words which contains most consonants
Find words which contains more than 3 vowels
Find words which first and last three letters are equals
Find words which odd letters are consonants and even letters are vowels or vice_versa
Formatting
Substring
Rep-string
Word wrap
String case
Align columns
Literals/String
Repeat a string
Brace expansion
Brace expansion using ranges
Reverse a string
Phrase reversals
Comma quibbling
Special characters
String concatenation
Substring/Top and tail
Commatizing numbers
Reverse words in a string
Suffixation of decimal numbers
Long literals, with continuations
Numerical and alphabetical suffixes
Abbreviations, easy
Abbreviations, simple
Abbreviations, automatic
Song lyrics/poems/Mad Libs/phrases
Mad Libs
Magic 8-ball
99 Bottles of Beer
The Name Game (a song)
The Old lady swallowed a fly
The Twelve Days of Christmas
Tokenize
Text between
Tokenize a string
Word break problem
Tokenize a string with escaping
Split a character string based on change of character
Sequences
Show ASCII table
De Bruijn sequences
Self-referential sequences
Generate lower case ASCII alphabet
| #Wren | Wren | import "./seq" for Lst
import "./str" for Str
var s = "abracadabra"
var sl = s.toList
var ixs = Lst.indicesOf(sl, "a")[2]
var repl = "ABaCD"
for (i in 0..4) sl[ixs[i]] = repl[i]
s = sl.join()
s = Str.replace(s, "b", "E", 1)
s = Str.replace(s, "r", "F", 2, 1)
System.print(s) |
http://rosettacode.org/wiki/Selectively_replace_multiple_instances_of_a_character_within_a_string | Selectively replace multiple instances of a character within a string | Task
This is admittedly a trivial task but I thought it would be interesting to see how succinctly (or otherwise) different languages can handle it.
Given the string: "abracadabra", replace programatically:
the first 'a' with 'A'
the second 'a' with 'B'
the fourth 'a' with 'C'
the fifth 'a' with 'D'
the first 'b' with 'E'
the second 'r' with 'F'
Note that there is no replacement for the third 'a', second 'b' or first 'r'.
The answer should, of course, be : "AErBcadCbFD".
Other tasks related to string operations:
Metrics
Array length
String length
Copy a string
Empty string (assignment)
Counting
Word frequency
Letter frequency
Jewels and stones
I before E except after C
Bioinformatics/base count
Count occurrences of a substring
Count how many vowels and consonants occur in a string
Remove/replace
XXXX redacted
Conjugate a Latin verb
Remove vowels from a string
String interpolation (included)
Strip block comments
Strip comments from a string
Strip a set of characters from a string
Strip whitespace from a string -- top and tail
Strip control codes and extended characters from a string
Anagrams/Derangements/shuffling
Word wheel
ABC problem
Sattolo cycle
Knuth shuffle
Ordered words
Superpermutation minimisation
Textonyms (using a phone text pad)
Anagrams
Anagrams/Deranged anagrams
Permutations/Derangements
Find/Search/Determine
ABC words
Odd words
Word ladder
Semordnilap
Word search
Wordiff (game)
String matching
Tea cup rim text
Alternade words
Changeable words
State name puzzle
String comparison
Unique characters
Unique characters in each string
Extract file extension
Levenshtein distance
Palindrome detection
Common list elements
Longest common suffix
Longest common prefix
Compare a list of strings
Longest common substring
Find common directory path
Words from neighbour ones
Change e letters to i in words
Non-continuous subsequences
Longest common subsequence
Longest palindromic substrings
Longest increasing subsequence
Words containing "the" substring
Sum of the digits of n is substring of n
Determine if a string is numeric
Determine if a string is collapsible
Determine if a string is squeezable
Determine if a string has all unique characters
Determine if a string has all the same characters
Longest substrings without repeating characters
Find words which contains all the vowels
Find words which contains most consonants
Find words which contains more than 3 vowels
Find words which first and last three letters are equals
Find words which odd letters are consonants and even letters are vowels or vice_versa
Formatting
Substring
Rep-string
Word wrap
String case
Align columns
Literals/String
Repeat a string
Brace expansion
Brace expansion using ranges
Reverse a string
Phrase reversals
Comma quibbling
Special characters
String concatenation
Substring/Top and tail
Commatizing numbers
Reverse words in a string
Suffixation of decimal numbers
Long literals, with continuations
Numerical and alphabetical suffixes
Abbreviations, easy
Abbreviations, simple
Abbreviations, automatic
Song lyrics/poems/Mad Libs/phrases
Mad Libs
Magic 8-ball
99 Bottles of Beer
The Name Game (a song)
The Old lady swallowed a fly
The Twelve Days of Christmas
Tokenize
Text between
Tokenize a string
Word break problem
Tokenize a string with escaping
Split a character string based on change of character
Sequences
Show ASCII table
De Bruijn sequences
Self-referential sequences
Generate lower case ASCII alphabet
| #XPL0 | XPL0 | string 0;
proc Mangle(S);
char S, A, B, R;
[A:= "ABaCD"; B:= "Eb"; R:= "rF";
while S(0) do
[case S(0) of
^a: [S(0):= A(0); A:= A+1];
^b: [S(0):= B(0); B:= B+1];
^r: [S(0):= R(0); R:= R+1]
other [];
S:= S+1;
];
];
char S;
[S:= "abracadabra";
Text(0, S); Text(0, " -> "); Mangle(S); Text(0, S); CrLf(0);
S:= "caarabadrab";
Text(0, S); Text(0, " -> "); Mangle(S); Text(0, S); CrLf(0);
] |
http://rosettacode.org/wiki/Send_email | Send email | Task
Write a function to send an email.
The function should have parameters for setting From, To and Cc addresses; the Subject, and the message text, and optionally fields for the server name and login details.
If appropriate, explain what notifications of problems/success are given.
Solutions using libraries or functions from the language are preferred, but failing that, external programs can be used with an explanation.
Note how portable the solution given is between operating systems when multi-OS languages are used.
(Remember to obfuscate any sensitive data used in examples)
| #Groovy | Groovy |
import javax.mail.*
import javax.mail.internet.*
public static void simpleMail(String from, String password, String to,
String subject, String body) throws Exception {
String host = "smtp.gmail.com";
Properties props = System.getProperties();
props.put("mail.smtp.starttls.enable",true);
/* mail.smtp.ssl.trust is needed in script to avoid error "Could not convert socket to TLS" */
props.setProperty("mail.smtp.ssl.trust", host);
props.put("mail.smtp.auth", true);
props.put("mail.smtp.host", host);
props.put("mail.smtp.user", from);
props.put("mail.smtp.password", password);
props.put("mail.smtp.port", "587");
Session session = Session.getDefaultInstance(props, null);
MimeMessage message = new MimeMessage(session);
message.setFrom(new InternetAddress(from));
InternetAddress toAddress = new InternetAddress(to);
message.addRecipient(Message.RecipientType.TO, toAddress);
message.setSubject(subject);
message.setText(body);
Transport transport = session.getTransport("smtp");
transport.connect(host, from, password);
transport.sendMessage(message, message.getAllRecipients());
transport.close();
}
/* Set email address sender */
String s1 = "example@gmail.com";
/* Set password sender */
String s2 = "";
/* Set email address sender */
String s3 = "example@gmail.com"
/*Call function */
simpleMail(s1, s2 , s3, "TITLE", "TEXT");
|
http://rosettacode.org/wiki/Semiprime | Semiprime | Semiprime numbers are natural numbers that are products of exactly two (possibly equal) prime numbers.
Semiprimes are also known as:
semi-primes
biprimes
bi-primes
2-almost primes
or simply: P2
Example
1679 = 23 × 73
(This particular number was chosen as the length of the Arecibo message).
Task
Write a function determining whether a given number is semiprime.
See also
The Wikipedia article: semiprime.
The Wikipedia article: almost prime.
The OEIS sequence: A001358: semiprimes which has a shorter definition: the product of two primes.
| #C | C | #include <stdio.h>
int semiprime(int n)
{
int p, f = 0;
for (p = 2; f < 2 && p*p <= n; p++)
while (0 == n % p)
n /= p, f++;
return f + (n > 1) == 2;
}
int main(void)
{
int i;
for (i = 2; i < 100; i++)
if (semiprime(i)) printf(" %d", i);
putchar('\n');
return 0;
} |
http://rosettacode.org/wiki/SEDOLs | SEDOLs | Task
For each number list of 6-digit SEDOLs, calculate and append the checksum digit.
That is, given this input:
710889
B0YBKJ
406566
B0YBLH
228276
B0YBKL
557910
B0YBKR
585284
B0YBKT
B00030
Produce this output:
7108899
B0YBKJ7
4065663
B0YBLH2
2282765
B0YBKL9
5579107
B0YBKR5
5852842
B0YBKT7
B000300
Extra credit
Check each input is correctly formed, especially with respect to valid characters allowed in a SEDOL string.
Related tasks
Luhn test
ISIN
| #11l | 11l | F char2value(c)
assert(c !C ‘AEIOU’, ‘No vowels’)
R Int(c, radix' 36)
V sedolweight = [1, 3, 1, 7, 3, 9]
F checksum(sedol)
V tmp = sum(zip(sedol, :sedolweight).map((ch, weight) -> char2value(ch) * weight))
R String((10 - (tmp % 10)) % 10)
V sedols =
|‘710889
B0YBKJ
406566
B0YBLH
228276
B0YBKL
557910
B0YBKR
585284
B0YBKT’
L(sedol) sedols.split("\n")
print(sedol‘’checksum(sedol)) |
http://rosettacode.org/wiki/Self-describing_numbers | Self-describing numbers | Self-describing numbers
You are encouraged to solve this task according to the task description, using any language you may know.
There are several so-called "self-describing" or "self-descriptive" integers.
An integer is said to be "self-describing" if it has the property that, when digit positions are labeled 0 to N-1, the digit in each position is equal to the number of times that that digit appears in the number.
For example, 2020 is a four-digit self describing number:
position 0 has value 2 and there are two 0s in the number;
position 1 has value 0 and there are no 1s in the number;
position 2 has value 2 and there are two 2s;
position 3 has value 0 and there are zero 3s.
Self-describing numbers < 100.000.000 are: 1210, 2020, 21200, 3211000, 42101000.
Task Description
Write a function/routine/method/... that will check whether a given positive integer is self-describing.
As an optional stretch goal - generate and display the set of self-describing numbers.
Related tasks
Fours is the number of letters in the ...
Look-and-say sequence
Number names
Self-referential sequence
Spelling of ordinal numbers
| #Arturo | Arturo | selfDescribing?: function [x][
digs: digits x
loop.with:'i digs 'd [
if d <> size select digs 'z [z=i]
-> return false
]
return true
]
print select 1..22000 => selfDescribing? |
http://rosettacode.org/wiki/Self-describing_numbers | Self-describing numbers | Self-describing numbers
You are encouraged to solve this task according to the task description, using any language you may know.
There are several so-called "self-describing" or "self-descriptive" integers.
An integer is said to be "self-describing" if it has the property that, when digit positions are labeled 0 to N-1, the digit in each position is equal to the number of times that that digit appears in the number.
For example, 2020 is a four-digit self describing number:
position 0 has value 2 and there are two 0s in the number;
position 1 has value 0 and there are no 1s in the number;
position 2 has value 2 and there are two 2s;
position 3 has value 0 and there are zero 3s.
Self-describing numbers < 100.000.000 are: 1210, 2020, 21200, 3211000, 42101000.
Task Description
Write a function/routine/method/... that will check whether a given positive integer is self-describing.
As an optional stretch goal - generate and display the set of self-describing numbers.
Related tasks
Fours is the number of letters in the ...
Look-and-say sequence
Number names
Self-referential sequence
Spelling of ordinal numbers
| #AutoHotkey | AutoHotkey | ; The following directives and commands speed up execution:
#NoEnv
SetBatchlines -1
ListLines Off
Process, Priority,, high
MsgBox % 2020 ": " IsSelfDescribing(2020) "`n" 1337 ": " IsSelfDescribing(1337) "`n" 1210 ": " IsSelfDescribing(1210)
Loop 100000000
If IsSelfDescribing(A_Index)
list .= A_Index "`n"
MsgBox % "Self-describing numbers < 100000000 :`n" . list
CountSubstring(fullstring, substring){
StringReplace, junk, fullstring, %substring%, , UseErrorLevel
return errorlevel
}
IsSelfDescribing(number){
Loop Parse, number
If Not CountSubString(number, A_Index-1) = A_LoopField
return false
return true
} |
http://rosettacode.org/wiki/Self_numbers | Self numbers | A number n is a self number if there is no number g such that g + the sum of g's digits = n. So 18 is not a self number because 9+9=18, 43 is not a self number because 35+5+3=43.
The task is:
Display the first 50 self numbers;
I believe that the 100000000th self number is 1022727208. You should either confirm or dispute my conjecture.
224036583-1 is a Mersenne prime, claimed to also be a self number. Extra credit to anyone proving it.
See also
OEIS: A003052 - Self numbers or Colombian numbers
Wikipedia: Self numbers | #C.2B.2B | C++ | #include <array>
#include <iomanip>
#include <iostream>
const int MC = 103 * 1000 * 10000 + 11 * 9 + 1;
std::array<bool, MC + 1> SV;
void sieve() {
std::array<int, 10000> dS;
for (int a = 9, i = 9999; a >= 0; a--) {
for (int b = 9; b >= 0; b--) {
for (int c = 9, s = a + b; c >= 0; c--) {
for (int d = 9, t = s + c; d >= 0; d--) {
dS[i--] = t + d;
}
}
}
}
for (int a = 0, n = 0; a < 103; a++) {
for (int b = 0, d = dS[a]; b < 1000; b++, n += 10000) {
for (int c = 0, s = d + dS[b] + n; c < 10000; c++) {
SV[dS[c] + s++] = true;
}
}
}
}
int main() {
sieve();
std::cout << "The first 50 self numbers are:\n";
for (int i = 0, count = 0; count <= 50; i++) {
if (!SV[i]) {
count++;
if (count <= 50) {
std::cout << i << ' ';
} else {
std::cout << "\n\n Index Self number\n";
}
}
}
for (int i = 0, limit = 1, count = 0; i < MC; i++) {
if (!SV[i]) {
if (++count == limit) {
//System.out.printf("%,12d %,13d%n", count, i);
std::cout << std::setw(12) << count << " " << std::setw(13) << i << '\n';
limit *= 10;
}
}
}
return 0;
} |
http://rosettacode.org/wiki/Set_of_real_numbers | Set of real numbers | All real numbers form the uncountable set ℝ. Among its subsets, relatively simple are the convex sets, each expressed as a range between two real numbers a and b where a ≤ b. There are actually four cases for the meaning of "between", depending on open or closed boundary:
[a, b]: {x | a ≤ x and x ≤ b }
(a, b): {x | a < x and x < b }
[a, b): {x | a ≤ x and x < b }
(a, b]: {x | a < x and x ≤ b }
Note that if a = b, of the four only [a, a] would be non-empty.
Task
Devise a way to represent any set of real numbers, for the definition of 'any' in the implementation notes below.
Provide methods for these common set operations (x is a real number; A and B are sets):
x ∈ A: determine if x is an element of A
example: 1 is in [1, 2), while 2, 3, ... are not.
A ∪ B: union of A and B, i.e. {x | x ∈ A or x ∈ B}
example: [0, 2) ∪ (1, 3) = [0, 3); [0, 1) ∪ (2, 3] = well, [0, 1) ∪ (2, 3]
A ∩ B: intersection of A and B, i.e. {x | x ∈ A and x ∈ B}
example: [0, 2) ∩ (1, 3) = (1, 2); [0, 1) ∩ (2, 3] = empty set
A - B: difference between A and B, also written as A \ B, i.e. {x | x ∈ A and x ∉ B}
example: [0, 2) − (1, 3) = [0, 1]
Test your implementation by checking if numbers 0, 1, and 2 are in any of the following sets:
(0, 1] ∪ [0, 2)
[0, 2) ∩ (1, 2]
[0, 3) − (0, 1)
[0, 3) − [0, 1]
Implementation notes
'Any' real set means 'sets that can be expressed as the union of a finite number of convex real sets'. Cantor's set needs not apply.
Infinities should be handled gracefully; indeterminate numbers (NaN) can be ignored.
You can use your machine's native real number representation, which is probably IEEE floating point, and assume it's good enough (it usually is).
Optional work
Create a function to determine if a given set is empty (contains no element).
Define A = {x | 0 < x < 10 and |sin(π x²)| > 1/2 }, B = {x | 0 < x < 10 and |sin(π x)| > 1/2}, calculate the length of the real axis covered by the set A − B. Note that
|sin(π x)| > 1/2 is the same as n + 1/6 < x < n + 5/6 for all integers n; your program does not need to derive this by itself.
| #Java | Java | import java.util.Objects;
import java.util.function.Predicate;
public class RealNumberSet {
public enum RangeType {
CLOSED,
BOTH_OPEN,
LEFT_OPEN,
RIGHT_OPEN,
}
public static class RealSet {
private Double low;
private Double high;
private Predicate<Double> predicate;
private double interval = 0.00001;
public RealSet(Double low, Double high, Predicate<Double> predicate) {
this.low = low;
this.high = high;
this.predicate = predicate;
}
public RealSet(Double start, Double end, RangeType rangeType) {
this(start, end, d -> {
switch (rangeType) {
case CLOSED:
return start <= d && d <= end;
case BOTH_OPEN:
return start < d && d < end;
case LEFT_OPEN:
return start < d && d <= end;
case RIGHT_OPEN:
return start <= d && d < end;
default:
throw new IllegalStateException("Unhandled range type encountered.");
}
});
}
public boolean contains(Double d) {
return predicate.test(d);
}
public RealSet union(RealSet other) {
double low2 = Math.min(low, other.low);
double high2 = Math.max(high, other.high);
return new RealSet(low2, high2, d -> predicate.or(other.predicate).test(d));
}
public RealSet intersect(RealSet other) {
double low2 = Math.min(low, other.low);
double high2 = Math.max(high, other.high);
return new RealSet(low2, high2, d -> predicate.and(other.predicate).test(d));
}
public RealSet subtract(RealSet other) {
return new RealSet(low, high, d -> predicate.and(other.predicate.negate()).test(d));
}
public double length() {
if (low.isInfinite() || high.isInfinite()) return -1.0; // error value
if (high <= low) return 0.0;
Double p = low;
int count = 0;
do {
if (predicate.test(p)) count++;
p += interval;
} while (p < high);
return count * interval;
}
public boolean isEmpty() {
if (Objects.equals(high, low)) {
return predicate.negate().test(low);
}
return length() == 0.0;
}
}
public static void main(String[] args) {
RealSet a = new RealSet(0.0, 1.0, RangeType.LEFT_OPEN);
RealSet b = new RealSet(0.0, 2.0, RangeType.RIGHT_OPEN);
RealSet c = new RealSet(1.0, 2.0, RangeType.LEFT_OPEN);
RealSet d = new RealSet(0.0, 3.0, RangeType.RIGHT_OPEN);
RealSet e = new RealSet(0.0, 1.0, RangeType.BOTH_OPEN);
RealSet f = new RealSet(0.0, 1.0, RangeType.CLOSED);
RealSet g = new RealSet(0.0, 0.0, RangeType.CLOSED);
for (int i = 0; i <= 2; i++) {
Double dd = (double) i;
System.out.printf("(0, 1] ∪ [0, 2) contains %d is %s\n", i, a.union(b).contains(dd));
System.out.printf("[0, 2) ∩ (1, 2] contains %d is %s\n", i, b.intersect(c).contains(dd));
System.out.printf("[0, 3) − (0, 1) contains %d is %s\n", i, d.subtract(e).contains(dd));
System.out.printf("[0, 3) − [0, 1] contains %d is %s\n", i, d.subtract(f).contains(dd));
System.out.println();
}
System.out.printf("[0, 0] is empty is %s\n", g.isEmpty());
System.out.println();
RealSet aa = new RealSet(
0.0, 10.0,
x -> (0.0 < x && x < 10.0) && Math.abs(Math.sin(Math.PI * x * x)) > 0.5
);
RealSet bb = new RealSet(
0.0, 10.0,
x -> (0.0 < x && x < 10.0) && Math.abs(Math.sin(Math.PI * x)) > 0.5
);
RealSet cc = aa.subtract(bb);
System.out.printf("Approx length of A - B is %f\n", cc.length());
}
} |
http://rosettacode.org/wiki/Sequence_of_primes_by_trial_division | Sequence of primes by trial division | Sequence of primes by trial division
You are encouraged to solve this task according to the task description, using any language you may know.
Task
Generate a sequence of primes by means of trial division.
Trial division is an algorithm where a candidate number is tested for being a prime by trying to divide it by other numbers.
You may use primes, or any numbers of your choosing, as long as the result is indeed a sequence of primes.
The sequence may be bounded (i.e. up to some limit), unbounded, starting from the start (i.e. 2) or above some given value.
Organize your function as you wish, in particular, it might resemble a filtering operation, or a sieving operation.
If you want to use a ready-made is_prime function, use one from the Primality by trial division page (i.e., add yours there if it isn't there already).
Related tasks
count in factors
prime decomposition
factors of an integer
Sieve of Eratosthenes
primality by trial division
factors of a Mersenne number
trial factoring of a Mersenne number
partition an integer X into N primes
| #C.23 | C# | using System;
using System.Collections.Generic;
using System.Linq;
public class Program
{
static void Main() {
Console.WriteLine(string.Join(" ", Primes(100)));
}
static IEnumerable<int> Primes(int limit) => Enumerable.Range(2, limit-1).Where(IsPrime);
static bool IsPrime(int n) => Enumerable.Range(2, (int)Math.Sqrt(n)-1).All(i => n % i != 0);
} |
http://rosettacode.org/wiki/Sequence_of_primes_by_trial_division | Sequence of primes by trial division | Sequence of primes by trial division
You are encouraged to solve this task according to the task description, using any language you may know.
Task
Generate a sequence of primes by means of trial division.
Trial division is an algorithm where a candidate number is tested for being a prime by trying to divide it by other numbers.
You may use primes, or any numbers of your choosing, as long as the result is indeed a sequence of primes.
The sequence may be bounded (i.e. up to some limit), unbounded, starting from the start (i.e. 2) or above some given value.
Organize your function as you wish, in particular, it might resemble a filtering operation, or a sieving operation.
If you want to use a ready-made is_prime function, use one from the Primality by trial division page (i.e., add yours there if it isn't there already).
Related tasks
count in factors
prime decomposition
factors of an integer
Sieve of Eratosthenes
primality by trial division
factors of a Mersenne number
trial factoring of a Mersenne number
partition an integer X into N primes
| #C.2B.2B | C++ |
#include <math.h>
#include <iostream>
#include <iomanip>
bool isPrime( unsigned u ) {
if( u < 4 ) return u > 1;
if( /*!( u % 2 ) ||*/ !( u % 3 ) ) return false;
unsigned q = static_cast<unsigned>( sqrt( static_cast<long double>( u ) ) ),
c = 5;
while( c <= q ) {
if( !( u % c ) || !( u % ( c + 2 ) ) ) return false;
c += 6;
}
return true;
}
int main( int argc, char* argv[] )
{
unsigned mx = 100000000,
wid = static_cast<unsigned>( log10( static_cast<long double>( mx ) ) ) + 1;
std::cout << "[" << std::setw( wid ) << 2 << " ";
unsigned u = 3, p = 1; // <- start computing from 3
while( u < mx ) {
if( isPrime( u ) ) { std::cout << std::setw( wid ) << u << " "; p++; }
u += 2;
}
std::cout << "]\n\n Found " << p << " primes.\n\n";
return 0;
}
|
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