直接创建堆来解决问题

class Solution:
    def findKth(self , a: List[int], n: int, K: int) -> int:
        # write code here
        if not a:
            return None
        import heapq
        heapq.heapify(a)
        res = heapq.nlargest(K, a)
        return res[K - 1]