Quickselect K-th Smallest

Given an integer array nums and an integer k (1-indexed), return the k-th smallest element.

Function signature

func QuickselectKth(nums []int, k int) int

Example

nums = [7,2,1,8,6,3,5,4]
k = 3
output = 3

Constraints

• 1 <= len(nums) <= 200000
• 1 <= k <= len(nums)
• -1_000_000_000 <= nums[i] <= 1_000_000_000

Notes

• The array may be modified in-place.