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Neighbour primes (view source)

Revision as of 23:43, 27 August 2022

845 bytes added ,  1 year ago
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syntax highlighting fixup automation
(Neighbour primes in various BASIC dialents)
m (syntax highlighting fixup automation)
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=={{header|ALGOL W}}==
<langsyntaxhighlight lang="algolw">begin % find some primes where ( p*q ) + 2 is also a prime ( where p and q are adjacent primes ) %
% sets p( 1 :: n ) to a sieve of primes up to n %
procedure sieve ( logical array p( * ) ; integer value n ) ;
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write( i_w := 1, s_w := 0, "Found ", pCount, " neighbour primes up to 500" )
end
end.</langsyntaxhighlight>
{{out}}
<pre>
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=={{header|AppleScript}}==
<langsyntaxhighlight lang="applescript">on isPrime(n)
if (n < 6) then return ((n > 1) and (n is not 4))
if ((n mod 2 = 0) or (n mod 3 = 0) or (n mod 5 = 0)) then return false
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end neighbourPrimes
 
neighbourPrimes(499)</langsyntaxhighlight>
 
{{output}}
<langsyntaxhighlight lang="applescript">{3, 5, 7, 13, 19, 67, 149, 179, 229, 239, 241, 269, 277, 307, 313, 397, 401, 419, 439, 487}</langsyntaxhighlight>
 
=={{header|Arturo}}==
 
<langsyntaxhighlight lang="rebol">primesUpTo500: select 1..500 => prime?
 
print [pad "p" 5 pad "q" 4 pad "p*q+2" 7]
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]
i: i + 1
]</langsyntaxhighlight>
 
{{out}}
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=={{header|AWK}}==
<syntaxhighlight lang="awk">
<lang AWK>
# syntax: GAWK -f NEIGHBOUR_PRIMES.AWK
BEGIN {
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return(1)
}
</syntaxhighlight>
</lang>
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<pre>
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=={{header|BASIC}}==
==={{header|BASIC256}}===
<langsyntaxhighlight BASIC256lang="basic256">function isPrime(v)
if v < 2 then return False
if v mod 2 = 0 then return v = 2
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print p; chr(9); q; chr(9); 2+p*q
next p
end</langsyntaxhighlight>
 
==={{header|PureBasic}}===
<langsyntaxhighlight PureBasiclang="purebasic">Procedure isPrime(v.i)
If v <= 1 : ProcedureReturn #False
ElseIf v < 4 : ProcedureReturn #True
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Next p
PrintN(#CRLF$ + "--- terminado, pulsa RETURN---"): Input()
CloseConsole()</langsyntaxhighlight>
 
==={{header|Yabasic}}===
<langsyntaxhighlight lang="yabasic">sub isPrime(v)
if v < 2 then return False : fi
if mod(v, 2) = 0 then return v = 2 : fi
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print p, chr$(9), q, chr$(9), 2+p*q
next p
end</langsyntaxhighlight>
 
 
=={{header|C#|CSharp}}==
How about some other offsets besides <code>+ 2</code> ?
<langsyntaxhighlight lang="fsharp">using System; using System.Collections.Generic;
using System.Linq; using static System.Console; using System.Collections;
 
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if (!flags[j]) { yield return j;
for (int k = sq, i=j<<1; k<=lim; k += i) flags[k] = true; }
for (; j <= lim; j += 2) if (!flags[j]) yield return j; } }</langsyntaxhighlight>
{{out}}
<pre>Multiply two consecutive prime numbers, add an even number, see if the result is a prime number (up to a limit).
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=={{header|F_Sharp|F#}}==
This task uses [http://www.rosettacode.org/wiki/Extensible_prime_generator#The_functions Extensible Prime Generator (F#)]
<langsyntaxhighlight lang="fsharp">
// Nigel Galloway. April 13th., 2021
primes32()|>Seq.pairwise|>Seq.takeWhile(fun(n,_)->n<500)|>Seq.filter(fun(n,g)->isPrime(n*g+2))|>Seq.iter(fun(n,g)->printfn "%d*%d=%d" n g (n*g+2))
</syntaxhighlight>
</lang>
{{out}}
<pre>
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=={{header|Factor}}==
{{works with|Factor|0.99 2021-02-05}}
<langsyntaxhighlight lang="factor">USING: formatting io kernel math math.primes ;
 
"p q p*q+2" print
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[ 3dup "%-4d %-4d %-6d\n" printf ] when
drop nip dup next-prime
] while 2drop</langsyntaxhighlight>
{{out}}
<pre>
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=={{header|Fermat}}==
{{trans|PARI/GP}}
<langsyntaxhighlight lang="fermat">for i = 1 to 95 do if Isprime(2+Prime(i)*Prime(i+1)) then !!Prime(i) fi od</langsyntaxhighlight>
 
=={{header|FreeBASIC}}==
<langsyntaxhighlight lang="freebasic">#include "isprime.bas"
 
dim as uinteger q
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if not isprime( 2 + p*q ) then continue for
print p,q,2+p*q
next p</langsyntaxhighlight>
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<pre>
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{{trans|Wren}}
{{libheader|Go-rcu}}
<langsyntaxhighlight lang="go">package main
 
import (
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rcu.PrintTable(nprimes, 10, 3, false)
fmt.Println("\nFound", len(nprimes), "such primes.")
}</langsyntaxhighlight>
 
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This entry uses `is_prime` as defined at [[Erd%C5%91s-primes#jq]].
<langsyntaxhighlight lang="jq">def next_prime:
if . == 2 then 3
else first(range(.+2; infinite; 2) | select(is_prime))
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| .p = $np )
| select(.emit).emit
</syntaxhighlight>
</lang>
{{out}}
<pre>
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=={{header|Julia}}==
<langsyntaxhighlight lang="julia">using Primes
 
isneiprime(known) = isprime(known) && isprime(known * nextprime(known + 1) + 2)
println(filter(isneiprime, primes(500)))
</langsyntaxhighlight>{{out}}<pre>[3, 5, 7, 13, 19, 67, 149, 179, 229, 239, 241, 269, 277, 307, 313, 397, 401, 419, 439, 487]</pre>
 
=={{header|Ksh}}==
<langsyntaxhighlight lang="ksh">
#!/bin/ksh
 
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np=$(_neighbourprime ${i} parr)
(( np > 0 )) && printf "%3d %3d %6d\n" ${parr[i]} ${parr[i+1]} ${np}
done</langsyntaxhighlight>
{{out}}<pre>
p q p*q+2
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=={{header|Mathematica}}/{{header|Wolfram Language}}==
<langsyntaxhighlight Mathematicalang="mathematica">p = Prime@Range@PrimePi[499];
Select[p, PrimeQ[# NextPrime[#] + 2] &]</langsyntaxhighlight>
{{out}}
<pre>{3, 5, 7, 13, 19, 67, 149, 179, 229, 239, 241, 269, 277, 307, 313, 397, 401, 419, 439, 487}</pre>
 
=={{header|Nim}}==
<langsyntaxhighlight Nimlang="nim">import strformat, sugar
 
const
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if (p * q + 2).isPrime:
echo &"{p:3} {q:3} {p*q+2:6}"
p = q</langsyntaxhighlight>
 
{{out}}
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=={{header|PARI/GP}}==
Cheats a little in the sense that it requires knowing the 95th prime is 499 beforehand.
<langsyntaxhighlight lang="parigp">for(i=1, 95, if(isprime(2+prime(i)*prime(i+1)),print(prime(i))))</langsyntaxhighlight>
 
=={{header|Perl}}==
{{libheader|ntheory}}
<langsyntaxhighlight lang="perl">use strict;
use warnings;
use ntheory <next_prime is_prime>;
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printf "%3d%5d%8d\n", $p, $q, $p*$q+2 if is_prime $p*$q+2;
$p = $q;
} until $p >= 500;</langsyntaxhighlight>
{{out}}
<pre> 3 5 17
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=={{header|Phix}}==
<!--<langsyntaxhighlight Phixlang="phix">(phixonline)-->
<span style="color: #008080;">function</span> <span style="color: #000000;">np</span><span style="color: #0000FF;">(</span><span style="color: #004080;">integer</span> <span style="color: #000000;">p</span><span style="color: #0000FF;">)</span> <span style="color: #008080;">return</span> <span style="color: #7060A8;">is_prime</span><span style="color: #0000FF;">(</span><span style="color: #7060A8;">get_prime</span><span style="color: #0000FF;">(</span><span style="color: #000000;">p</span><span style="color: #0000FF;">)*</span><span style="color: #7060A8;">get_prime</span><span style="color: #0000FF;">(</span><span style="color: #000000;">p</span><span style="color: #0000FF;">+</span><span style="color: #000000;">1</span><span style="color: #0000FF;">)+</span><span style="color: #000000;">2</span><span style="color: #0000FF;">)</span> <span style="color: #008080;">end</span> <span style="color: #008080;">function</span>
<span style="color: #008080;">constant</span> <span style="color: #000000;">N</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">length</span><span style="color: #0000FF;">(</span><span style="color: #7060A8;">get_primes_le</span><span style="color: #0000FF;">(</span><span style="color: #000000;">500</span><span style="color: #0000FF;">))</span>
<span style="color: #004080;">sequence</span> <span style="color: #000000;">res</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">apply</span><span style="color: #0000FF;">(</span><span style="color: #7060A8;">apply</span><span style="color: #0000FF;">(</span><span style="color: #7060A8;">filter</span><span style="color: #0000FF;">(</span><span style="color: #7060A8;">tagset</span><span style="color: #0000FF;">(</span><span style="color: #000000;">N</span><span style="color: #0000FF;">),</span><span style="color: #000000;">np</span><span style="color: #0000FF;">),</span><span style="color: #7060A8;">get_prime</span><span style="color: #0000FF;">),</span><span style="color: #7060A8;">sprint</span><span style="color: #0000FF;">)</span>
<span style="color: #7060A8;">printf</span><span style="color: #0000FF;">(</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"Found %d such primes: %s\n"</span><span style="color: #0000FF;">,{</span><span style="color: #7060A8;">length</span><span style="color: #0000FF;">(</span><span style="color: #000000;">res</span><span style="color: #0000FF;">),</span><span style="color: #7060A8;">join</span><span style="color: #0000FF;">(</span><span style="color: #7060A8;">shorten</span><span style="color: #0000FF;">(</span><span style="color: #000000;">res</span><span style="color: #0000FF;">,</span><span style="color: #008000;">""</span><span style="color: #0000FF;">,</span><span style="color: #000000;">5</span><span style="color: #0000FF;">),</span><span style="color: #008000;">", "</span><span style="color: #0000FF;">)})</span>
<!--</langsyntaxhighlight>-->
{{out}}
<pre>
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=={{header|Python}}==
<langsyntaxhighlight lang="python">#!/usr/bin/python
 
def isPrime(n):
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if not isPrime(2 + p*q):
continue
print(p, "\t", q, "\t", 2+p*q)</langsyntaxhighlight>
{{out}}
<pre>p q pq+2
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=={{header|Raku}}==
<syntaxhighlight lang="raku" perl6line>my @primes = grep &is-prime, ^Inf;
my $last_p = @primes.first: :k, * >= 500;
my $last_q = $last_p + 1;
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.grep( *.[2].is-prime );
 
say .fmt('%6d') for @cousins;</langsyntaxhighlight>
{{out}}
<pre>
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=={{header|REXX}}==
'''Neighbor''' primes can also be spelled '''neighbour''' primes.
<langsyntaxhighlight lang="rexx">/*REXX program finds neighbor primes: P, Q, P*Q+2 are primes, and P < some specified N.*/
parse arg hi cols . /*obtain optional argument from the CL.*/
if hi=='' | hi=="," then hi= 500 /*Not specified? Then use the default.*/
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end /*k*/ /* [↑] only process numbers ≤ √ J */
#= #+1; @.#= j; s.#= j*j; !.j= 1 /*bump # of Ps; assign next P; P²; P# */
end /*j*/; return</langsyntaxhighlight>
{{out|output|text=&nbsp; when using the default inputs:}}
<pre>
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=={{header|Ring}}==
<langsyntaxhighlight lang="ring">
load "stdlib.ring"
see "working..." + nl
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see "Found " + row + " neighbour primes" + nl
see "done..." + nl
</syntaxhighlight>
</lang>
{{out}}
<pre>
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=={{header|Sidef}}==
<langsyntaxhighlight lang="ruby">500.primes.grep {|p| p * p.next_prime + 2 -> is_prime }.say</langsyntaxhighlight>
{{out}}
<pre>
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{{libheader|Wren-seq}}
{{libheader|Wren-fmt}}
<langsyntaxhighlight lang="ecmascript">import "/math" for Int
import "/seq" for Lst
import "/fmt" for Fmt
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}
for (chunk in Lst.chunks(nprimes, 10)) Fmt.print("$3d", chunk)
System.print("\nFound %(nprimes.count) such primes.")</langsyntaxhighlight>
 
{{out}}
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=={{header|XPL0}}==
<langsyntaxhighlight XPL0lang="xpl0">func IsPrime(N); \Return 'true' if N is a prime number
int N, I;
[if N <= 1 then return false;
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Text(0, " neighbour primes found below 500.
");
]</langsyntaxhighlight>
 
{{out}}
Thundergnat
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