Sign In and Sign Out

1006. Sign In and Sign Out (25)

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:

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

Sample Output:

SC3021234 CS301133

本题的考点就是寻找最小时间和最大时间。虽然时间是字符串形式的，但是也可以按位比对来判断大小。

#include <iostream>#include <vector>#include <string>using namespace std;bool earlyTime(int index);bool lastTime(int index);vector<string> id, signIn, signOut;int unlockIndex, lockIndex;int main() {int m;cin >> m;id.resize(m);signIn.resize(m);signOut.resize(m);for (int i = 0; i < m; i++){cin >> id[i] >> signIn[i] >> signOut[i];}for (int i = 0; i < m; i++){if (earlyTime(i))unlockIndex = i;if (lastTime(i))lockIndex = i;}cout << id[unlockIndex] << " " << id[lockIndex];//system("pause");return 0;}bool earlyTime(int index) {for (int i = 0; i < 6; i++){if (signIn[index][i] < signIn[unlockIndex][i])return true;else if (signIn[index][i] > signIn[unlockIndex][i])return false;}return false;}bool lastTime(int index) {for (int i = 0; i < 6; i++){if (signOut[index][i] > signOut[lockIndex][i])return true;else if (signOut[index][i] < signOut[lockIndex][i])return false;}return false;}