栈和队列_leetcode347(优先队列)

class Solution1(object):
    def topKFrequent(self, nums, k):
        """
        :type nums: List[int]
        :type k: int
        :rtype: List[int]
        """
        Dict = {}
        for i in range(len(nums)):
            if nums[i] in Dict:
                Dict[nums[i]] = Dict[nums[i]] + 1
            else:
                Dict[nums[i]] = 1

        output = sorted(Dict.items(), key=lambda e: e[1], reverse=True)

        final = []
        for i in range(k):
            final.append(output[i][0])
        return final




class Solution:
    def topKFrequent(self, nums, k):
        """
        :type nums: List[int]
        :type k: int
        :rtype: List[int]
        """
        from queue import PriorityQueue

        count_list = dict()
        for i in nums:
            count_list[i] = count_list.get(i, 0) + 1

        p = PriorityQueue()
        for i in count_list.items():
            if p.qsize() == k:
        # 判断优先队列长度是否满足k
                if i[1] > p[0]: #bug
                    p.get()
                    p.put((i[1], i[0]))#  通过 (频率,元素) 形式存储
                else:
                    p.put((i[1], i[0]))

        result = list()
        while not p.empty():
            _, v = p.get()
            result.append(v)
            return result



class Solution:
    def topKFrequent(self, nums, k):
        """
        :type nums: List[int]
        :type k: int
        :rtype: List[int]
        """
        import heapq
        count_list = dict()

        for i in nums:
            count_list[i] = count_list.get(i, 0) + 1

        p = list()

        for i in count_list.items():
            if len(p) == k:
                if i[1] > p[0][0]:
                    heapq.heappop(p)
                    heapq.heappush(p, (i[1], i[0]))
                else:
                    heapq.heappush(p, (i[1], i[0]))

        return [i[1] for i in p]