Recursive Inorder Traversal

Given a binary tree, write a method to perform the inorder traversal recursively. Append the data of each node visited to an ArrayList. Return an empty Arraylist in case of an empty tree.

Example:  
     1
    / \
   2   3     ==> 4251637
  / \ / \
 4  5 6  7

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

Quick hint to get things rolling

In-order traversal
1. Traverse the left subtree by recursively calling the Inorder method.
2. Add the data part of root element(or current element) in the arraylist
3. Traverse the right subtree by recursively calling the inorder method.

A more detailed explanation

Use add method to add the node's data in the inorderedList list

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

1. Recurse through the left nodes starting from the root. Data of the elements in the left subtree will get added to the ArrayList.

2. Add the data of the root node to the ArrayList.

3. Recurse through the right nodes. Data of the elements in the right subtree will get added to the ArrayListt.

//Populate the data in the below list in inorder.
public ArrayList<Integer> inorderedList = new ArrayList<Integer>();
public void inorder(TreeNode root) {
    



}

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

Java

Python

Recursive Inorder Traversal

Quick hint to get things rolling

A more detailed explanation

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 :