Find the Kth Smallest/Largest Element in an Array

Objective: Given an array of integers. find the Kth Smallest/largest element in the array.

Example:

int[] A = { 1, 2, 10, 20, 40, 32, 44, 51, 6 };

K=4. 4th smallest element in given array: 10

Approach: (Kth Smallest Element)

  • Use min-Heap. (Click here to read about Priority Queue).
  • Insert all the elements in the Priority Queue.
  • Extract K elements from the priority queue. The last element (kth) extracted with be the kth smallest element in the array.

Complete Code:

Output:
4th smallest element:10

Note: For kth largest element, implement priority queue for max-Heap.