题解 | #完全数计算#

#include <iostream>
using namespace std;

int main() {
    int num, cnt = 0;
    cin >> num;
    for (int i = 2; i <= num; ++i)
    {
        int sum = 0;
        for (int j = 1; j < i; ++j)
        {
            if (i % j == 0)
            {
                sum += j;
            }
        }
        if (sum == i)
        {
            cnt++;
        }
    }
    cout << cnt << endl;
    return 0;
}