37 lines
839 B
PHP
37 lines
839 B
PHP
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#!/usr/bin/php
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<?php
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define("MAX", 5*(10**7));
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$nextPrime = 2;
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$primes = array($nextPrime);
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while ($nextPrime < sqrt(MAX)) {
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$nextPrime = gmp_intval(gmp_nextprime($nextPrime));
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$primes[] = $nextPrime;
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}
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$sums = array();
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$primeCount = count($primes);
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for($outer = 0; $outer < $primeCount; $outer++) {
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$fourth = $primes[$outer] ** 4;
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if ($fourth >= MAX) {
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break;
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}
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for($middle = 0; $middle < $primeCount; $middle++) {
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$cube = $fourth + $primes[$middle] ** 3;
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if ($cube >= MAX) {
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break;
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}
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for($inner = 0; $inner < $primeCount; $inner++) {
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$sum = $cube + $primes[$inner] ** 2;
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if ($sum >= MAX) {
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break;
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}
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$sums[] = $sum;
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}
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}
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}
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echo "Found ".count(array_unique($sums))." numbers\n";
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