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215. Kth Largest Element In An Array

215. Kth Largest Element in an Array

Medium


Given an integer array nums and an integer k, return the kth largest element in the array.

Note that it is the kth largest element in the sorted order, not the kth distinct element.

You must solve it in O(n) time complexity.

 

Example 1:

Input: nums = [3,2,1,5,6,4], k = 2
Output: 5

Example 2:

Input: nums = [3,2,3,1,2,4,5,5,6], k = 4
Output: 4

 

Constraints:

  • 1 <= k <= nums.length <= 105
  • -104 <= nums[i] <= 104

 class Solution:
    def findKthLargest(self, nums: List[int], k: int) -> int:

        #nums = [x*-1 for x in nums]
#         heapq.heapify(nums)

#         for i in range(len(nums)):
#             num = nums[0]
#             heapq.heappop(nums)

#             if i == k-1:
#                 return -num

        heap = nums[:k]
        heapq.heapify(heap)
        for num in nums[k:]:
            if num > heap[0]:
                heapq.heappushpop(heap, num)

        return heap[0]

Floyd's Tortoise and Hare is used to detect linked list cycle.

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