Kth Largest Element in an Array

Kth Largest Element in an Array

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.

Can you solve it without sorting?

Examples

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

Example 3:

Input: nums = [1], k = 1
Output: 1

Constraints

• 1 <= k <= nums.length <= 10^5
• -10^4 <= nums[i] <= 10^4

Expected Complexity

• Time: O(n) average with Quickselect, or O(n log k) with Heap
• Space: O(k) with Heap, O(1) with Quickselect (in-place)