Python 1-20 heap

1046. 最后一块石头的重量

class Solution:
    def lastStoneWeight(self, stones: List[int]) -> int:
        q = []
        for s in stones:
            heappush(q, -s)
        while q:
            if len(q) == 1: return -q[0]
            a, b = heappop(q), heappop(q)
            if a != b: heappush(q, -abs(a-b))

        return 0