0104._Maximum_Depth_of_Binary_Tree.md

104. Maximum Depth of Binary Tree

难度: Easy

刷题内容

原题连接

• https://leetcode.com/problems/maximum-depth-of-binary-tree

内容描述

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.

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.

解题方案

思路 1 - 时间复杂度: O(log2 N)- 空间复杂度: O(N)******

• 这道题使用递归进行解决，因为对于树的每一个儿子的处理方法是一致的。
• 将左儿子和右儿子中最大的数进行返回再加上当前的深度1即可解决。

代码：

var maxDepth = function(root) {
    if(root===null||root === undefined)
        return 0;
    return Math.max(maxDepth(root.left),maxDepth(root.right))+1;
};