题解 | #质数因子#

import java.util.Scanner;

// 注意类名必须为 Main, 不要有任何 package xxx 信息
public class Main {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        // 注意 hasNext 和 hasNextLine 的区别
        int n = in.nextInt();
        for (int i = 2; i <= n/2; ++i) {//学转:n/2换成Math.sqrt(n)更省时
            while (n % i == 0) {
                System.out.print(i+" ");
                n = n / i;
            }
        }
        System.out.print(n == 1 ? "" : n);
    }
}