样例都对，但就是不知道哪错了。故求助大佬！

#include <iostream>
#include <iomanip>
#include <cstdio>
using namespace std;
int main()
{
    int i,n,k;
    int ans = 0,total = 0;
    int a,b;
    cin >> n >> k;
    for(i = 1; i <= n ; i++)
    {
        if(i % k != 0)
       {
                b += i;
                total++;
       }
        if(i % k == 0)
       {
                a += i;
                ans++;
        }
    }
    cout << fixed << setprecision(1) << a/ans << ".0" << " " <<(double)b / total; 
   return 0;
}