LeetCode 252. Meeting Rooms

Question

Given an array of meeting time intervals where intervals[i] = [starti, endi], determine if a person could attend all meetings.

Example 1:

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

Example 2:

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

Constraints:

• 0 <= intervals.length <= 104
• intervals[i].length == 2
• 0 <= starti < endi <= 106

Source: https://leetcode.com/problems/meeting-rooms/

Solution

Sort intervals by start.

// sort, O(nlog(n))
public boolean canAttendMeetings(int[][] intervals) {
    // sort intervals by the start in ascending order
    Arrays.sort(intervals, new Comparator<int[]>() {
        @Override
        public int compare(int[] o1, int[] o2) {
            return o1[0] - o2[0];
        }
    });
    for (int i = 1; i < intervals.length; i++) {
        if (intervals[i - 1][1] > intervals[i][0]) {
            return false;
        }
    }
    return true;
}