lightoj - 1216 - Juice in the Glass

#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
int main()
{
    int test;
    cin>>test;
    for(int t=1;t<=test;t++)
    {
        double r1,r2,h,p,v;
        cin>>r1>>r2>>h>>p;
        r1=r2+((r1-r2)/h)*p;
        v=(2*acos(0.0)*p*(r1*r1+r1*r2+r2*r2))/3;
        cout<<"Case "<<t<<": "<<setprecision(9)<<fixed<<v<<endl;
    }
}