Fill in the Ancestors of the Node in a Binary Tree

Given a binary tree's root node, an empty ArrayList and an integer nodeData, write a method that finds a target node - N with data = nodeData and populates the ArrayList with the data of the ancestor nodes of N - added from the bottom - up.

Example:  

       1             
      / \          
     2   3       
    / \ / \        
   4  5 6  7      

Node: 5 ==> [2, 1]

Need a hand? Try out these hints, one at a time.

Quick hint to get things rolling

The key here is to traverse over the nodes of the tree and to add the nodes which are in the hierarchy of the input node from the bottom to the top.

Final hint! You should be able to code the problem on viewing this.

1. If root is null, return false.

2. If root.data is equal to the node for which the ancestor needs to be found or if printAncestors(root.left, node) == true or printAncestors(root.right, node)) == true then add the data in the list and return true. Else return false.

//Populate the list of ancestors from bottom to top in the below list.
public ArrayList<Integer> ancestorsList = new ArrayList<Integer>();
public boolean printAncestors(TreeNode root, int nodeData) {
                       




    
}

This Coding Interview Question is available with an answer in the following programming languages :

Java

Python

Fill in the Ancestors of the Node in a Binary Tree

Quick hint to get things rolling

Final hint! You should be able to code the problem on viewing this.

The interview prep tool you'll fall in love with!

This Coding Interview Question is available with an answer in the following programming languages :