UVA_10773_Back_To_Intermediate

#include <iostream>
#include <cstdio>
#include <algorithm>
#include <cstring>
#include <string>
#include <cctype>
#include <stack>
#include <queue>
#include <list>
#include <vector>
#include <map>
#include <set>
#include <sstream>
#include <stdlib.h>
#include <cmath>
#define LL unsigned long long
using namespace std;

int main()
{
    int test,i;
    double d,u,v,t1,t2,x,y;
    scanf("%d",&test);
    for(i=1; i<=test; i++)
    {
        scanf("%lf %lf %lf",&d,&v,&u);
        t1=d/u;
        x=u*u-v*v;
        y=sqrt(x);
        t2=d/y;
        if(u!=0.0 && v!=0.0 && u>v)
            printf("Case %d: %.3lf\n",i,t2-t1);
        else
            printf("Case %d: can't determine\n",i);
    }
    return 0;
}