PAT甲级——A1006 Sign In and Sign Out

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

很简单。。。。

#include <iostream>
#include <string>

using namespace std;


//很简单，就是找到来的最早的人和回去最晚的人即可
int getTime(string Time)
{
    //由于时间时标准输入，所以很好计算
    return ((Time[0] - '0') * 10 + (Time[1] - '0')) * 60 * 60 +
        ((Time[3] - '0') * 10 + (Time[4] - '0')) * 60 + 
        (Time[6] - '0') * 10 + (Time[7] - '0');
     
}

int main()
{
    int M;
    cin >> M;
    string firstMan, lastMan;
    int firstTime, lastTime;
    firstTime = 24 * 60*60 + 1;//24小时多一秒，属于第二天了
    lastTime = -1;//属于前一天
    string No, InTime, OutTime;
    for (int i = 0; i < M; ++i)
    {
        cin >> No >> InTime >> OutTime;
        if (firstTime > getTime(InTime))
        {
            firstTime = getTime(InTime);
            firstMan = No;
        }
        if (lastTime < getTime(OutTime))
        {
            lastTime = getTime(OutTime);
            lastMan = No;
        }
    }
    cout << firstMan << " " << lastMan << endl;
    return 0;
}