Class Primes


  • public class Primes
    extends Object
    Methods related to prime numbers in the range of int:
    • primality test
    • prime number generation
    • factorization
    Since:
    3.2
    • Method Detail

      • isPrime

        public static boolean isPrime​(int n)
        Primality test: tells if the argument is a (provable) prime or not.

        It uses the Miller-Rabin probabilistic test in such a way that a result is guaranteed: it uses the firsts prime numbers as successive base (see Handbook of applied cryptography by Menezes, table 4.1).

        Parameters:
        n - number to test.
        Returns:
        true if n is prime. (All numbers < 2 return false).
      • nextPrime

        public static int nextPrime​(int n)
        Return the smallest prime greater than or equal to n.
        Parameters:
        n - a positive number.
        Returns:
        the smallest prime greater than or equal to n.
        Throws:
        MathIllegalArgumentException - if n < 0.
      • primeFactors

        public static List<Integer> primeFactors​(int n)
        Prime factors decomposition
        Parameters:
        n - number to factorize: must be ≥ 2
        Returns:
        list of prime factors of n
        Throws:
        MathIllegalArgumentException - if n < 2.