不能四舍五入，所以要用点小技巧

解题思路:

注意事项:

参考代码:

#include<bits/stdc++.h>

using namespace std;

int main()

{

int n,t;

double m;

cin >> n >> t >> m;

double cnt = 0.0,sum = 0.0;

int num = 0;

for(int i = 1;i <= t;i ++)

{

sum += n;

cnt = sum*m; //利息

sum += cnt;

num ++; 

}

sum -= num * n;

sum = (int)(sum*100);

printf("%.2f",sum/100);

return 0;

}