Maximum Depth of Binary Tree (LeetCode Tree)

Question: Given a binary tree, find its maximum depth.
The maximum depth is the number of nodes along the longest path from the root node down to the farthest leaf node.

Idea: Recursion. Very simple.

Time: O(n) Space: O(lgn)

Code:

 public class Solution {  
   public int maxDepth(TreeNode root) {  
     if(root==null)  
       return 0;  
     return Math.max(maxDepth(root.left),maxDepth(root.right))+1;  
   }  
 }