二叉树的最大深度

 

/**
 * Definition for a binary tree node.
 * public class TreeNode {
 *     int val;
 *     TreeNode left;
 *     TreeNode right;
 *     TreeNode(int x) { val = x; }
 * }
 */
class Solution {

    public int maxDepth(TreeNode root) {
        
        if(root == null){
            return 0;
        }

        int left = maxDepth(root.left);
        int right =  maxDepth(root.right);
        
        if(left > right){
            return left + 1;
        }else{
            return right + 1;
        }
    }
}