Leo.py

class Solution:
    def canAttendMeetings(self, intervals: List[List[int]]) -> bool:
        intervals.sort() ## nlogn

        for i in range(len(intervals) - 1):
            if intervals[i][1] > intervals[i+1][0]:
                return False

        return True

        ## TC: O(nlogn), SC: O(1)