[Leetcode] 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.

Analysis:

class Solution {
public:
    int maxDepth(TreeNode *root) {
        if (root == NULL)
            return 0;
        else
        {
            return max(maxDepth(root->left), maxDepth(root->right)) + 1;
        }
    }
};