题解 | #质数因子#

#include <cmath>
#include <iostream>
using namespace std;

int main() {
    int num,i;
    cin >> num;
    if(num == 1)
        return 0;
    for(i = 2 ; i <= sqrt(num) ; ){//从2到该数的算术平方根循环判断
        if(num%i == 0){//为质数因子输出
            cout << i << " ";
            num = num/i;
            i=2;//再次从2开始判断
        }else{
            i++;
        }
    }
    if(num != 1)//判断最后的数是否为质数。是则输出
        cout << num << " ";

    return 0;
}