LeetCode-Java-104. Maximum Depth of Binary Tree

题目

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.Note: A leaf is a node with no children.Example:Given binary tree [3,9,20,null,null,15,7],3/ \9  20/  \15   7
return its depth = 3.

代码

只需要用

/*** 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;}return Math.max(maxDepth(root.left),maxDepth(root.right))+1;} }