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;
}
};