浙江大学PAT_甲级_1006. Sign In and Sign Out (25)

题目链接

http://www.patest.cn/contests/pat-a-practise/1006

At the beginning of every day, the first person who signs in the computer room will unlock the door, and the last one who signs out will lock the door. Given the records of signing in's and out's, you are supposed to find the ones who have unlocked and locked the door on that day.

Input Specification:

Each input file contains one test case. Each case contains the records for one day. The case starts with a positive integer M, which is the total number of records, followed by M lines, each in the format:

ID_number Sign_in_time Sign_out_time

where times are given in the format HH:MM:SS, and ID number is a string with no more than 15 characters.

Output Specification:

For each test case, output in one line the ID numbers of the persons who have unlocked and locked the door on that day. The two ID numbers must be separated by one space.

Note: It is guaranteed that the records are consistent. That is, the sign in time must be earlier than the sign out time for each person, and there are no two persons sign in or out at the same moment.

Sample Input:

3
CS301111 15:30:28 17:00:10
SC3021234 08:00:00 11:25:25
CS301133 21:45:00 21:58:40

Sample Output:

SC3021234 CS301133

我的c++代码：

#include <iostream>
#include <string>
using namespace std;
int main()
{
	int i,n;//n总人数
	string first_id, last_id;//irst_id第一个到的人， last_id最后走的人
	string first_time="23:59:59", last_time="00:00:01";//first_time最早签到时间，last_time最晚离开时间
	string id; //普通id
	string in_time, out_time;//in_time普通签到时间，out_time普通离开时间
	cin >> n;
	for (i = 0; i < n; i++)
	{
		cin >> id >> in_time >> out_time;
		if (in_time < first_time)
		{
			first_id = id;//记录最早签到的人
			first_time = in_time;//记录最早签到时间
		}
		if (out_time > last_time)
		{
			last_id = id;
			last_time = out_time;
		}
	}
	cout << first_id << ' ' << last_id;
	//system("pause");
	return 0;
}