LeetCode – Refresh – Maximum Depth of Binary Tree

 1 /**
 2  * Definition for binary tree
 3  * struct TreeNode {
 4  *     int val;
 5  *     TreeNode *left;
 6  *     TreeNode *right;
 7  *     TreeNode(int x) : val(x), left(NULL), right(NULL) {}
 8  * };
 9  */
10 class Solution {
11 public:
12     int maxDepth(TreeNode *root) {
13         if (!root) return 0;
14         return max(maxDepth(root->left), maxDepth(root->right)) + 1;
15     }
16 };