Sicily 1051. Biker's Trip Odomete

/*
简单的求周长乘以转数得到总长，除以时间得到均速
重点在于精度控制，小数点后两位
*/
/*
Run Time: 0secs
Run Memory: 312KB
*/

#include <iostream>
#include <iomanip>

using namespace std;

double pi = 3.1415927;
double mile = 5280 * 12;        //5280 feet = 1 mile； 12 inches = 1 foot
double hour = 60 * 60;

int main()
{
int N = 1;

double diam;   // inches
int revo;      // role
double time;   // second

double total;    //总长度
double evarage;  //平均速度

cin >> diam >> revo >> time;
while (revo != 0){
double total = (pi * diam * revo) / mile;
double evarage = (total / time) * hour;

cout << "Trip #" << N << ": "
<< fixed << setprecision(2) << total << " "    //加了fixed意味着是固定点方式显示
<< setprecision(2) << evarage << endl;         //所以这里的精度指的是小数位2位

cin >> diam >> revo >> time;
N++;
}

return 0;
}