Python通过堆寻找数据流中的中位数

题解中第三种做法的python实现，大顶堆通过取反实现，然后需要注意的是编译器是python2所以要除以2.0，要不然会丢失精度

# -*- coding:utf-8 -*-
import heapq
class Solution:
    def __init__(self):
        self.left = []
        self.right = []

    def Insert(self, num):
        # write code here
        if not self.right:
            heapq.heappush(self.right, num)
        elif len(self.left) == len(self.right):
            left = -self.left[0]
            if num < left:
                le = heapq.heappop(self.left)
                heapq.heappush(self.left, -num)
                heapq.heappush(self.right, -le)
            else:
                heapq.heappush(self.right, num)
        else:
            r = self.right[0]
            if num <= r:
                heapq.heappush(self.left, -num)
            else:
                ri = heapq.heappop(self.right)
                heapq.heappush(self.left, -ri)
                heapq.heappush(self.right, num)

    def GetMedian(self, s):
        # write code here
        # print(self.left, self.right)
        if len(self.left) == len(self.right):
            return (-self.left[0] + self.right[0]) / 2.0
        else:
            return self.right[0]