252. Meeting Rooms

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

Solution:

class Solution {
    public boolean canAttendMeetings(int[][] intervals) {
        // sort
        Arrays.sort(intervals, (a,b) -> Integer.compare(a[0], b[0]));

        for (int i = 1; i < intervals.length; i++){
            if (intervals[i-1][1] > intervals[i][0]){
                return false;
            }
        }

        return true;
    }
}

// TC: O(nlogn)
// SC: O(1)