leetcode maximum-depth-of-binary-tree

题目描述

 

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.

 

在下的代码 时间257ms 空间13340k

/**
 * Definition for binary tree
 * 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 0;
        if (root.left == null && root.right == null)
            return 1;
        
        if (root.left == null)
            return maxDepth(root.right) + 1;
        if (root.right == null)
            return maxDepth(root.left) + 1;
        
        return Math.max(maxDepth(root.left), maxDepth(root.right)) + 1;
    }
}