d010: 盈數、虧數和完全數 FYI: https://yunlinsong.blogspot.com/2016/01/blog-post_44.html

d010.cpp

#include <iostream>
#include <cmath>

using namespace std;

void prtMsg(const int &s, const int &n)
{
    if( s == n )
        cout << "完全數";
    else if( s > n )
        cout << "盈數";
    else
        cout << "虧數";

    cout << endl;
}

int main()
{
    int n;

    while( cin >> n )
    {
        int s = 0;
        for( int i = 1; i <= n/2; i++ )
        {
            if( n % i == 0 )
                s += i;
        }

        prtMsg(s, n);
    }

    return 0;
}