Hduoj1038【水題】

/*Biker's Trip Odometer
Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others)
Total Submission(s): 4913    Accepted Submission(s): 3272


Problem Description
Most bicycle speedometers work by using a Hall Effect sensor fastened to the front fork of the bicycle. A magnet is attached to 
one of the spokes on the front wheel so that it will line up with the Hall Effect switch once per revolution of the wheel. The 
speedometer monitors the sensor to count wheel revolutions. If the diameter of the wheel is known, the distance traveled can be 
easily be calculated if you know how many revolutions the wheel has made. In addition, if the time it takes to complete the 
revolutions is known, the average speed can also be calculated. 
For this problem, you will write a program to determine the total distance traveled (in miles) and the average speed (in Miles 
Per Hour) given the wheel diameter, the number of revolutions and the total time of the trip. You can assume that the front 
wheel never leaves the ground, and there is no slipping or skidding.


Input
Input consists of multiple datasets, one per line, of the form:

diameter revolutions time

The diameter is expressed in inches as a floating point value. The revolutions is an integer value. The time is expressed in 
seconds as a floating point value. Input ends when the value of revolutions is 0 (zero).

Output
For each data set, print:

Trip #N: distance MPH

Of course N should be replaced by the data set number, distance by the total distance in miles (accurate to 2 decimal places) 
and MPH by the speed in miles per hour (accurate to 2 decimal places). Your program should not generate any output for the 
ending case when revolutions is 0.

Constants

For p use the value: 3.1415927.
There are 5280 feet in a mile.
There are 12 inches in a foot.
There are 60 minutes in an hour.
There are 60 seconds in a minute.
There are 201.168 meters in a furlong.

Sample Input
26 1000 5
27.25 873234 3000
26 0 1000
 

Sample Output
Trip #1: 1.29 928.20
Trip #2: 1179.86 1415.84
 

Source
Greater New York 2003 
 

Recommend
We have carefully selected several similar problems for you:  1046 1060 1041 1124 1039 
*/
#include<stdio.h>
#define pi 3.1415927
double dia, time;
int rev;
int main()
{
	int i, j, k, cas = 1;
	while(scanf("%lf%d%lf", &dia, &rev, &time) != EOF)
	{
		if(rev == 0)
		break;
		double c, mile, speed;
		c = pi*dia;
		c *= (double)rev;
		mile = c / 12.0 / 5280.0;
		speed = mile * 3600.0 / time;
		printf("Trip #%d: %.2lf %.2lf\n", cas++, mile, speed);
	}
	return 0;
} 

題意：給出自行車車輪的直徑以及所轉過的圈數和花費的時間，求所經過的距離和速度。

思路：就是按照正常的思路去計算就可以了，這裏要注意的就是數據類型，要和題目的相符然後注意保留的小數位即可。