243. The Kth Smallest Value

Print the kth smallest of n integers, counting from 1. So k = 1 is the minimum.

Duplicates count as separate values. In 2 2 2, the 2nd smallest is 2.

The direct approach is to sort and read position k - 1. That is O(n log n) and entirely acceptable here. It is worth knowing that a selection algorithm can do it in O(n) on average without fully sorting, which matters when n is enormous and k is small.

Constraints - `1 ≤ k ≤ n ≤ 200000` - `-1000000000 ≤ a[i] ≤ 1000000000`