[leetcode]252. Meeting Rooms会议室有冲突吗

Given an array of meeting time intervals consisting of start and end times [[s1,e1],[s2,e2],...] (si < ei), determine if a person could attend all meetings.

Example 1:

Input: [[0,30],[5,10],[15,20]]
Output: false

Example 2:

Input: [[7,10],[2,4]]
Output: true

题目

给定一些区间，判断是否有重合。

还是挺实际的场景，经常在图书馆预定study room的系统，内部也应该是这个逻辑。 当有overlapping的时候，就会报错。

思路

任何一组intervals， 若当前start < 之前end，即出现了overlapping

代码

 class Solution {
     public boolean canAttendMeetings(Interval[] intervals) {
         if(intervals == null || intervals.length==0) return true;
         int []start = new int[intervals.length];
         int []end = new int[intervals.length];
         for(int i = 0; i<intervals.length;i++){
             start[i] = intervals[i].start;
             end[i] = intervals[i].end;
         }
         Arrays.sort(start);
         Arrays.sort(end);
         /* 任何一组intervals, 若当前start < 之前end，即出现了overlapping
             | i-1 |
                 |  i  |
         */
         for(int i = 1; i< start.length; i++){
             if(start[i]<end[i-1]) return false;
         }
         return true;
     }
 }