in order traversal

this was the geeks for geeks problem of the day today

/* A Binary Tree node

class Node {
    int data;
    Node left, right;
   Node(int item)    {
        data = item;
        left = right = null;
    }
}
*/
class Solution {
    ArrayList<Integer> result = new ArrayList<>();
    // Function to return a list containing the inorder traversal of the tree.
    ArrayList<Integer> inOrder(Node root) {
        // Code
        
        inOrderHelper(root);
        return result;
    }
    
    private void inOrderHelper( Node root ){
        if( root == null ) return;
        
        inOrderHelper( root.left );
        result.add(root.data);
        inOrderHelper( root.right );

    }
    
}