Challenge: Find kth Maximum Value in a Binary Search Tree

Problem Statement

In this problem, you have to implement the findKthMax() function to take a BST and any number “k” as an input, and return kth maximum number from that tree. An illustration is also provided for your understanding.

Function Prototype

int findKthMax(Node root, int k);

Here, root is the root node of the Binary Search Tree and k is an integer number.

Output

It returns the kth maximum value from the given tree.

Sample Input

bst = {
		6 -> 4,9
    4 -> 2,5
    9 -> 8,12
    12 -> 10,14
}
where parent -> leftChild,rightChild

k = 3

Sample Output

10

Explanation

As “k” equals 3, we need to find the 3rd maximum value from the given tree. The maximum value in the tree is 14, while 12 is the second-maximum, which leaves us with our required value 10 as the third-maximum value in the given tree. Here’s an illustration of the given challenge: