题解 | #质数因子#

import java.util.Scanner;
import java.util.ArrayList;
import java.util.List;
// 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
        while (in.hasNextInt()) { // 注意 while 处理多个 case
            int n = in.nextInt();
            List<Integer> factors = primeFactors(n);
            for (int factor : factors) {
                System.out.print(factor + " ");
            }
        }


    }
    public static List<Integer> primeFactors(int n) {
        List<Integer> factors = new ArrayList<>();
        for (int i = 2; i <= n / i; i++) {
            while (n % i == 0) {
                factors.add(i);
                n /= i;
            }
        }
        if (n > 1) {
            factors.add(n);
        }
        return factors;
    }
}