[Python3] priority queue
Please pull this commit for solutions of weekly 301. \n\n\nclass Solution:\n    def fillCups(self, amount: List[int]) -> int:\n        pq = [-x for x in amount]
Please pull this [commit](https://github.com/gaosanyong/leetcode/commit/f00c06cefbc1b2305f127a8cde7ff9b010197930) for solutions of weekly 301. \n\n```\nclass Solution:\n    def fillCups(self, amount: List[int]) -> int:\n        pq = [-x for x in amount]\n        heapify(pq)\n        ans = 0 \n        while pq[0]: \n            x = heappop(pq)\n            if pq[0]: heapreplace(pq, pq[0]+1)\n            heappush(pq, x+1)\n            ans += 1\n        return ans \n```\n\nPer @lee215, a easier solution is \n```\nclass Solution: \n    def fillCups(self, amount: List[int]) -> int:\n        return max(max(amount), (sum(amount)+1)//2)\n```
['Python3']