Maximum Depth of Binary Tree

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.

#include<iostream>#include<vector>#include<algorithm>using namespace std;struct TreeNode {int val;TreeNode *left;TreeNode *right;TreeNode(int x) : val(x), left(NULL), right(NULL) {}};int maxDepth(TreeNode *root) {if (root == NULL)return 0;int leftdepth  = maxDepth(root->left);int rightdepth = maxDepth(root->right);return max(leftdepth, rightdepth) + 1;}