```cpp
#include<bits/stdc++.h>
using namespace std;
double n,a1,a2,b1,b2,c1,c2,pen1,pen2,pen3,x[3];
int main(){
cin>>n>>a1>>a2>>b1>>b2>>c1>>c2;
pen1 = ceil(n/a1)*a2;
pen2 = ceil(n/b1)*b2;
pen3 = ceil(n/c1)*c2;
if (pen1<pen2&&pen1<pen3) cout<<long(pen1);
else if (pen2<pen1&&pen2<pen3) cout<<long(pen2);
else cout<<long(pen3);
return 0;
}
```
这样就好了，因为你long/long后会下取整，先用小数强转long
by U_K_E @ 2022-11-28 15:28:54
@[Error__404](/user/691596) AC了，感谢！！
by bj12z_zhangyongqi @ 2022-11-28 16:59:26