Hduoj1036【水题】

/*Average is not Fast Enough!
Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others)
Total Submission(s): 4785    Accepted Submission(s): 1937


Problem Description
A relay is a race for two or more teams of runners. Each member of a team runs one section of the race. Your task is to help to 
evaluate the results of a relay race. 

You have to process several teams. For each team you are given a list with the running times for every section of the race. You 
are to compute the average time per kilometer over the whole distance. That's easy, isn't it? 
So if you like the fun and challenge competing at this contest, perhaps you like a relay race, too. Students from Ulm 
participated e.g. at the "SOLA" relay in Zurich, Switzerland. For more information visit http://www.sola.asvz.ethz.ch/ after 
the contest is over.

 

Input
The first line of the input specifies the number of sections n followed by the total distance of the relay d in kilometers. 
You may safely assume that 1 <= n <= 20 and 0.0 < d < 200.0. Every following line gives information about one team: the team 
number t (an integer, right-justified in a field of width 3) is followed by the n results for each section, separated by a 
single space. These running times are given in the format "h:mm:ss" with integer numbers for the hours, minutes and seconds, 
respectively. In the special case of a runner being disqualified, the running time will be denoted by "-:--:--". Finally, the 
data on every line is terminated by a newline character. Input is terminated by EOF.

 

Output
For each team output exactly one line giving the team's number t right aligned in a field of width 3, and the average time for 
this team rounded to whole seconds in the format "m:ss". If at least one of the team's runners has been disqualified, output "-"
 instead. Adhere to the sample output for the exact format of presentation.

 

Sample Input
2 12.5
  5 0:23:21 0:25:01
 42 0:23:32 -:--:--
  7 0:33:20 0:41:35
 

Sample Output
  5: 3:52 min/km
 42: -
  7: 6:00 min/km
 

Source
University of Ulm Local Contest 2001 
 

Recommend
We have carefully selected several similar problems for you:  1039 1037 1038 1048 1062 
*/
#include<stdio.h>
#include<string.h>
int main()
{
	int i, j, k, n;
	double dis;
	scanf("%d%lf", &n, &dis);
	int num;
	while(scanf("%d", &num) != EOF)
	{
		int sum = 0, ok = 0;
		for(i = 0; i < n; ++i)
		{
			char s[15];
			scanf("%s", s);
			if(s[0] == '-')
			ok = 1;
			else
			{
				sum += (s[0] - '0') * 3600;
				sum += ( (s[2] - '0') * 10 + (s[3] - '0') ) * 60;
				sum += (s[5] - '0') * 10 + s[6] - '0';
			}
		}
		if(ok)
		{
			printf("%3d: -\n", num);
			continue;
		}
		double ans = (double)sum / dis;
		ans += 0.5;
		printf("%3d:%2d:%02d min/km\n", num, (int)ans / 60, (int)ans % 60); 
	}
	return 0;
}

题意：给出接力赛的段数和总长度，并且给出每个参赛队伍的编号和每一段的完成时间，求每个小组的完成比赛的平均时间。

思路：题意就是模拟，将小时和分钟转换为秒，计算每秒的速度，接着再转换为分钟：秒的形式，这里有很多细节问题，首先要注意的是题目给的输入格式是定死的-:--:--，所以对于输入处理来说算是一个福利，按照它的格式只要取字符串的固定位置即可计算总时间，最后就是输出格式，也是定死的，m:ss，这里要注意的是分钟位占2列，其次就是秒位也是2列，如果不足2位要在左边补0，而分钟位不需要补0，只要空格就好。最后处理好，被取消参赛资格的情况就ok了。