Binary Tree Maximum Node

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

Example

Given a binary tree:

     1
   /   \
 -5     2
 / \   /  \
0   3 -4  -5

return the node with value 3.

 public class Solution {
     /**
      * @param root the root of binary tree
      * @return the max ndoe
      */
     public TreeNode maxNode(TreeNode root) {
         // Write your code here
         if(root == null) return root;
         TreeNode leftMax = null;
         if(root.left!=null){
              leftMax = maxNode(root.left);
         }
         TreeNode rightMax = null;
         if(root.right!=null){
             rightMax = maxNode(root.right);
         }
         TreeNode max  = root;
         if(leftMax!=null){
             max = leftMax.val>max.val? leftMax : max;
         }
         if(rightMax!=null){
             max = rightMax.val>max.val? rightMax : max;
         }
         return max;
     }
 }