HDOJ 1038 Biker's Trip Odometer

#include <iostream>
#include <stdio.h>
#define pi 3.1415927
using namespace std;

int 
main()
{
    double dia, rev, time;
    int t=0;;
    while(cin>>dia>>rev>>time){
      if(rev!=0){
        t++;
        cout<<"Trip #"<<t<<": ";
        printf("%.2lf ", pi*dia*rev/5280/12);
        printf("%.2lf\n", (pi*dia*rev/5280/12)/(time/3600));
        }
    }
    return 0;      
}