Navie level questions

1. Binary Tree Maximum Node

Find the maximum node in a binary tree,return the node.

 public class MaximumNode{
       public TreeNode maxNode(TreeNode root){
                  if(root == null) return root;
                  TreeNode left = maxNode(root.left);
                  TreeNode right = maxNode(root.right);
                  return max(root,max(left,right));
       }
       public TreeNode max(TreeNode node,TreeNode anotherNode){
                  if(node == null) return anotherNode;
                  if(anotherNode == null) return node;
                  if(node.val > anotherNode.val) return node;
                  return anotherNode;
       }
 }