LeetCode(42) 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.

题目要求计算一棵二叉树的高度。本题最简单的解法是递归计算左右子树的高度，并在左右子树高度的最大值的基础上加1，则得到本层到叶子节点的高度。

解题代码

/** * Definition for a binary tree node. * struct TreeNode { *     int val; *     TreeNode *left; *     TreeNode *right; *     TreeNode(int x) : val(x), left(NULL), right(NULL) {} * }; */class Solution {public:    int maxDepth(TreeNode* root) {        if (root == NULL)            return 0;        int left = 0, right = 0;        if (root != NULL)        {            if(root->left != NULL)                left = maxDepth(root->left);            if(root->right != NULL)                right = maxDepth(root->right);        }        return max(left,right)+1;    }};