题解

#include<bits/stdc++.h>
using namespace std;
int factor_sum(int a){  //求因子之和的函数
    int sum = 0;
    for (int i = 1 ; i <= a ; i++)
        if (a % i == 0)  //如果i是a的因数，sum就加上i
            sum += i;
    return sum;
};
int main(){
    int n;
    cin >> n;
    cout << factor_sum(n);
    return 0;
}