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 target = in.nextInt();
        int tmp = 2;
        StringBuilder result = new StringBuilder();
        while(tmp*tmp<=target){
            if(target%tmp == 0){
                result.append(tmp).append(" ");
                target = target/tmp;
            }else{
                tmp++;
                while(isPrime(tmp) != true){
                    tmp++;
                    if(tmp*tmp>target){
                        break;
                    }
                }
            }
        }
        result.append(target);
        System.out.println(result.toString());
    }
    public static Boolean isPrime(int k){
        for(int i = 2;i*i<=k;i++){
            if(k%i == 0){
                return false;
            }
        }
        return true;
    }
}