ReplaceNodeWithDepth2.java

// Replace node with depth
// Send Feedback
// In a given Generic Tree, replace each node with its depth value. You need to
// just update the data of each node, no need to return or print anything. Depth
// of a node is defined as the distance of the node from root. You may assume
// that depth of root node is 0.
// Input format :
// Line 1 : Elements in level order form separated by space (as per done in
// class) in the below given order:
// node_data, n (number of children of node), n children, and so on for every
// element `
// Output format :
// Print the depth of each node level wise.
// Sample Input 1 :
// 10 3 20 30 40 2 40 50 0 0 0 0
// Representation of Input:

// Sample Output 1 : (Level wise, each level in new line)
// 0
// 1 1 1
// 2 2
// Explanation
// Since root is 10 , so it's depth is 0
// Node 20, 30 , 40 are present at 1st level , so their depth is 1.
// Node 40,50 are present at 2nd level, so their depth is 2.

public class Solution {

    /*
     * TreeNode structure
     * 
     * class TreeNode<T> {
     * T data;
     * ArrayList<TreeNode<T>> children;
     * 
     * TreeNode(T data){
     * this.data = data;
     * children = new ArrayList<TreeNode<T>>();
     * }
     * }
     */

    public static void helper(TreeNode<Integer> root, int k) {
        if (root == null) {
            return;
        }
        root.data = k;
        k = k + 1;
        for (int i = 0; i < root.children.size(); i++) {
            helper(root.children.get(i), k);
        }
    }

    public static void replaceWithDepthValue(TreeNode<Integer> root) {

        // Write your code here
        helper(root, 0);
    }

}