题解 | #完全数计算#

#include <iostream>
using namespace std;
bool judge(int n) { //判断n是否是完全数
    int a, b;
    b = 0;
    for (int i = 1; i < n; i++)
        if (n % i == 0)
            b += i; //求真因子之和
    if (b == n) return 1;
    else return 0;
}
int main() {
    int n, a = 0;
    cin >> n;
    for (int i = 1; i <= n; i++)
        if (judge(i) == 1)
            a++;
    cout << a << endl;
}