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);
        long longNum = in.nextLong();
        int i = 2;
        // 注意 hasNext 和 hasNextLine 的区别
        while (i <= longNum) { // 注意 while 处理多个 case
            if (longNum % i == 0) {
                System.out.print(i + " ");
                if (longNum == i) {
                    return;
                }
                longNum = longNum / i;
                // 判断新longNum是否是素数
                boolean flag = true;
                for (int j = 2; j <= Math.sqrt(longNum); ++j) {
                    if (longNum % j == 0) {
                        flag = false;
                        break;
                    }
                }
                if (flag) {
                    System.out.print(longNum);
                    return;
                }
                i = 2;
            } else {
                i++;
            }
        }
    }
}