**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.

Solution

**Approach 1:**

/** * Definition for a binary tree node. * public class TreeNode { * int val; * TreeNode left; * TreeNode right; * TreeNode(int x) { val = x; } * } */ public class Solution { public int maxDepth(TreeNode root) { if(root!=null){ return 1+ Math.max(maxDepth(root.left),maxDepth(root.right)); } else return 0; } }

**Optimized :**

/** * Definition for a binary tree node. * public class TreeNode { * int val; * TreeNode left; * TreeNode right; * TreeNode(int x) { val = x; } * } */ public class Solution { public int maxDepth(TreeNode root) { int lheight; int rheight; if(root == null){ return 0; } else{ lheight = maxDepth(root.left); rheight = maxDepth(root.right); if(lheight > rheight){ return lheight+1; } else{ return rheight+1; } } } }