Challenge: Find Nodes at "k" Distance from the Root

Problem Statement

In this problem, you have to implement the findKNodes() function to find nodes at k distance from the root in the given Binary Tree. An illustration is also provided for your understanding.

Function Prototype

String findKNodes(Node root, int k);

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

Output

It returns all the nodes at k distance from the root node in a string format.

Sample Input

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

Sample Output

2,5,8,12

Explanation

The depth of a node is equal to the number of edges between that node and the root of tree. The depth of Nodes 2,5,8 and 12 is 2. Here’s an illustration of the given challenge: