Leetcode 253

Coding question asked in Meta, Google, and Amazon interviews.

'''
intervals = [[0,30],[5,10],[15,20]]
heapq: heapq sorted base on the end time, so that we can remove the finished meetings before adding a new meeting.
'''
from heapq import heappop, heappush
class Solution:
    def minMeetingRooms(self, intervals: List[List[int]]) -> int:
        res = 0
        q = []
        intervals.sort(key=lambda x: x[0])

        for start, end in intervals:
            while q and start >= q[0]:
                heappop(q)
            heappush(q, end)
            res = max(res, len(q))
        return res