Strange unique prime triplets: Difference between revisions

{{Draft task|Prime numbersNumbers}}

Primes &nbsp; '''n, &nbsp; m,''' &nbsp; and &nbsp; '''p''' &nbsp; are &nbsp; ''strange unique primes'' &nbsp; if &nbsp; '''n, &nbsp; m,''' &nbsp; and &nbsp; '''p''' &nbsp; are unique and their sum &nbsp; &nbsp; '''n&nbsp;+&nbsp;m&nbsp;+&nbsp;p''' &nbsp; &nbsp; is also prime. Assume '''n''' < '''m''' < '''p'''.

<langsyntaxhighlight lang="algolw">begin % find some strange unique primes - triplets of primes n, m, p %

% count the nicestrange prime triplets whose members are less than< 1000 and %

% andwhose sum is prime the first 30 %

for l := m + 2 STEPstep 2 until MAX_PRIME do begin

end.</langsyntaxhighlight>

<langsyntaxhighlight lang="csharp">using System; using System.Collections.Generic; using static System.Console; using System.Linq; using DT = System.DateTime;

for (; j <= lim; j++) if (!flags[j]) yield return j; } }</langsyntaxhighlight>

<langsyntaxhighlight lang="cpp">#include <iomanip>

}</langsyntaxhighlight>

end.</langsyntaxhighlight>

<langsyntaxhighlight lang="fsharp">

<langsyntaxhighlight lang="factor">USING: formatting io kernel math math.combinatorics math.primes

"Found %s strange prime triplets with n, m, p < 1,000.\n" printf</langsyntaxhighlight>

<langsyntaxhighlight lang="forth">: prime? ( n -- ? ) here + c@ 0= ;

bye</langsyntaxhighlight>

<langsyntaxhighlight lang="go">package main

}</langsyntaxhighlight>

<langsyntaxhighlight lang="go">package main

}</langsyntaxhighlight>

<langsyntaxhighlight lang="java">import java.util.*;

System.out.printf("Strange unique prime triplets < %d:\n", limit);

System.out.printf("%2d + %2d + %2d = %2d\n", primes[i], primes[j], primes[k], sum);

System.out.printf("\nCount of strange unique prime triplets < %d is %d.\n", limit, count);

<langsyntaxhighlight lang="julia">using Primes

</langsyntaxhighlight>{{out}}

<langsyntaxhighlight lang="pascal">program PrimeTriplets;

END.</langsyntaxhighlight>

-- alsoIt weis maynot asworth wellinvolving leave2, spaceie for {j,k}primes[1],

-- {k}since in(2 the+ any other two outerprimes) is loops.even,

-- Usingalso awe sievemay onas thewell innerleave testspace isfor over{j,k},

-- ten{k} timesin fasterthe thantwo is_prime(),outer whereasloops.

-- usingUsing a separatesieve tableon ofthe primesinner fortest theis over

-- interestingly,two usingouter nm = n+mloops is about twice as fast as

-- fastscanning asthe nmpsieve =skipping n+m+pfalsies. Also

<span style="color: #000000;">count</span> res<span style= append(res,sprintf("%2dcolor: %2d#0000FF;">+%2d+%2d=</span> <span style="color: %d#000000;",>1</span>

<span style="color: #008080;">end</span> <span progress(style="Working...color: (%,d)\r#008080;",{count})>if</span>

<langsyntaxhighlight lang="python">from sympy import primerange

print(f"\nIf n, m, p < {mx:_} finds {sum(1 for _ in strange_triplets(mx)):_}")</langsyntaxhighlight>

<syntaxhighlight lang="raku" perl6line># 20210312 Raku programming solution

}</langsyntaxhighlight>

<langsyntaxhighlight lang="rexx">/*REXX program finds/lists triplet strange primes (<HI) where the triplets' sum is prime*/

end /*j*/; return</langsyntaxhighlight>

<langsyntaxhighlight lang="ring">

<langsyntaxhighlight lang="rust">fn prime_sieve(limit: usize) -> Vec<bool> {

}</langsyntaxhighlight>

<langsyntaxhighlight lang="swift">import Foundation

strangeUniquePrimeTriplets(limit: 1000, verbose: false)</langsyntaxhighlight>

{{libheader|Wren-traititerate}}

<langsyntaxhighlight ecmascriptlang="wren">import "./math" for Int

import "./traititerate" for Stepped

import "./fmt" for Fmt

Fmt.print("\nThere are $,d unique prime triples under 1,000 which sum to a prime.", c)</langsyntaxhighlight>

<langsyntaxhighlight ecmascriptlang="wren">import "./math" for Int

import "./fmt" for Fmt

Fmt.print("\nThere are $,d unique prime triples under 1,000 which sum to a prime.", c)</langsyntaxhighlight>