97. Maximum Depth of Binary Tree

97. Maximum Depth of Binary Tree

Description

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.

Example

Given a binary tree as follow:
  1
 / \ 
2   3
   / \
  4   5

Solution

/**
 * Definition of TreeNode:
 * public class TreeNode {
 *     public int val;
 *     public TreeNode left, right;
 *     public TreeNode(int val) {
 *         this.val = val;
 *         this.left = this.right = null;
 *     }
 * }
 */

public class Solution {
    /**
     * @param root: The root of binary tree.
     * @return: An integer
     */
    public int maxDepth(TreeNode root) {
        if(root!=null){
            int dl = maxDepth(root.left);
            int dr = maxDepth(root.right);
            int maxD = dl>dr?dl:dr;
            return maxD+1;
        }else{
            return 0;
        }
    }
}