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<?php function problem_3() { $task = 600851475143; $sqrt = ceil(sqrt($task)); if (0 === $sqrt % 2) { $sqrt++; } for ($i = $sqrt; $i >= 1; $i = $i - 2) { if (0 !== $task % $i) { continue; } if ($i === (int)gmp_nextprime($i - 1)) { return $i; } } return -1; } // echo problem_3(); // echo (int)gmp_nextprime(5000 -1);
Output for 4.3.0 - 4.3.11, 4.4.0 - 4.4.9, 5.0.0 - 5.0.5, 5.1.1 - 5.1.6, 5.2.0 - 5.2.17, 5.3.0 - 5.3.29, 5.4.0 - 5.4.45, 5.5.0 - 5.5.38, 5.6.0 - 5.6.40, 7.0.0 - 7.0.33, 7.1.0 - 7.1.33, 7.2.0 - 7.2.33, 7.3.0 - 7.3.33, 7.4.0 - 7.4.33, 8.0.0 - 8.0.30, 8.1.0 - 8.1.33, 8.2.0 - 8.2.29, 8.3.0 - 8.3.26, 8.4.1 - 8.4.13
Output for 5.1.0
Fatal error: fatal flex scanner internal error--end of buffer missed in /in/L28j0 on line 27
Process exited with code 255.
preferences:
178.61 ms | 406 KiB | 5 Q