M-253. Meeting Rooms II

https://leetcode.com/problems/meeting-rooms-ii/solution/leetcode.com

heapq in python:

heapq — Heap queue algorithm — Python 3.10.2 documentation

注意, heapq.heapify之后的heap也只是个list而已, 只不过满足heap的性质.

# 这道题贪心法解, 用pq(或者heapq实现)

# Definition for an interval.
# class Interval(object):
#     def __init__(self, s=0, e=0):
#         self.start = s
#         self.end = e

import heapq

class Solution(object):
    def minMeetingRooms(self, intervals):
        if not intervals:
            return 0
            
        intervals.sort(key= lambda x: x[0])
        meeting_room = [intervals[0][1]]
        
        for i in range(1, len(intervals)):
            if meeting_room[0] <= intervals[i][0]:
                heapq.heappop(meeting_room)
            heapq.heappush(meeting_room, intervals[i][1])
            
        return len(meeting_room)