[Introduction to programming in Java 笔记] 1.3.9 Factoring integers 素因子分解

素数 A prime is an integer greater than one whose only positive divisors are one and itself.
整数的素因子分解是乘积等于此素数的集合。
例如：3757208 = 2*2*2*7*13*13*397

public class Factors
{
    public static void main(String[] args)
    { // Print the prime factors of N.
        long N = Long.parseLong(args[0]);
        long n = N;
        for (long i = 2; i <= n/i; i++)
        { // Cast out and print i factors
            while(n % i == 0)
            {
            n /= i;
            System.out.print(i + " ");
            // Any factors of n are greater than i.
            }
        }
    if (n > 1) System.out.print(n);
    System.out.println();
    }
}

没看懂...