414 Third Maximum Number

使用类似于215的解法，使用heapq包来进行解

import heapq
class Solution(object):
    def thirdMax(self, nums):
        """
        :type nums: List[int]
        :rtype: int
        """
        nums = [-i for i in nums]
        heapq.heapify(nums)
        maxmum = nums[0]

        if len(nums) < 3:
            return -heapq.heappop(nums)
        for i in range(3):
            ans = heapq.heappop(nums)

            while len(nums) and nums[0] == ans:
                heapq.heappop(nums)
            if len(nums) == 0 and i != 2:
                return -maxmum
        return -ans