python实现基于最小堆的topk

class MyTopK:
    def topK(self,k: int, nums: list):
        heap = self.buidHeap(nums[0:k])
        for i in range(k,len(nums)):
            if nums[i] > heap[0]:
                heap[0] = nums[i]
                heap[0],heap[-1] = heap[-1], heap[0]
                heap = self.buidHeap(heap)
        return heap

    def buidHeap(self,heap:list):
        # 数组中的数据是按照二叉树 层次遍历的，自下而上,遍历所有根节点， 将最小值放入根节点
        heap_len = len(heap)
        for i in range(heap_len // 2,-1,-1):
            left, right = 2*i + 1,2*i + 2
            if left < heap_len and heap[left] < heap[i]:
                heap[left], heap[i] = heap[i], heap[left]
            if right < heap_len and heap[right] < heap[i]:
                heap[right], heap[i] = heap[i], heap[right]
        return heap

        pass
if __name__ == '__main__':
    s = MyTopK().topK(5,[2,3,6,1,8,23,56,78,12])
    print(s)