A meeting room can be reserved within the time period of 8:00 am and 23:00. This time period can receive n appointments. The appointment format is start_i, end_i. As a secretary, you must ensure that the meeting room can be used for the longest time
Input: The first line is T, indicating that there are T groups of test cases, the second line indicates that there are n appointments, and the rest indicate the appointment start and end
1
6
15 17
8 11 10
16 11
12 13
15
9 12
Output: 8
My AC solution:
import java.util.*;
public class Main {
static class Meeting implements Comparable{
public int start;
public int end;
public Meeting(int start, int end) {
this.start = start;
this.end = end;
}
@Override
public int compareTo(Object o) {
Meeting o1 = (Meeting) o;
return start-o1.start;
}
}
public static void findMaxDuration(List<Meeting> meetingList){
// 按开始时间排序
Collections.sort(meetingList);
// 动态规划
int[] dp = new int[meetingList.size()];
dp[0] = meetingList.get(0).end-meetingList.get(0).start;
for (int i = 1; i < dp.length; i++) {
int curDuration = meetingList.get(i).end-meetingList.get(i).start;
// 和在前面所有不冲突的会议比较，找出最长时间（相当于找一个最长时间的路径）
for (int j = i-1; j >= 0;j--) {
if (doAdd(meetingList.get(j),meetingList.get(i))){
dp[i] = Math.max(dp[i],dp[j]+curDuration);
}
}
// 存在一种情况：如果前面的都冲突，那么只能加上自己的duration
dp[i] = Math.max(curDuration,dp[i]);
}
int max = 0;
for (int i = 0; i < dp.length; i++) {
max = Math.max(max,dp[i]);
}
System.out.println(max);
}
// 判断会议是否冲突
public static boolean doAdd(Meeting lastMeeting,Meeting curMeeting){
// 注意大于等于
if(curMeeting.start>=lastMeeting.end){
return true;
}
return false;
}
public static void main(String[] args) throws InterruptedException {
Scanner in = new Scanner(System.in);
int T = in.nextInt();
for (int i = 0; i < T; i++) {
int meetingTimes = in.nextInt();
List<Meeting> meetingList = new ArrayList<>();
for (int j = 0; j < meetingTimes; j++) {
int start = in.nextInt();
int end = in.nextInt();
meetingList.add(new Meeting(start,end));
}
if(meetingList.size()==1){
System.out.println(meetingList.get(0).end-meetingList.get(0).start);
continue;
}
findMaxDuration(meetingList);
}
}
}