gmp_prob_prime

gmp_prob_prime

Check if number is "probably prime"

int **gmp_prob_prime**  $num int $repetitions

The function uses Miller-Rabin's probabilistic test to check if a number is a prime.

numThe number being checked as a prime.

repetitions Reasonable values of vary from 5 to 10 (default being 10); a higher value lowers the probability for a non-prime to pass as a "probable" prime. repetitions

If this function returns 0, is definitely not prime. If it returns 1, then is "probably" prime. If it returns 2, then is surely prime. num``num``num

Voorbeeld: example

<?php
// definitely not a prime
echo gmp_prob_prime("6") . "\n";

// probably a prime
echo gmp_prob_prime("1111111111111111111") . "\n";

// definitely a prime
echo gmp_prob_prime("11") . "\n";
?>

0
1
2