09 - Maximum Depth of Binary Tree.cpp

/*
Given the root of a binary tree, return its maximum depth.

A binary tree's maximum depth is the number of nodes along the longest path from the root node down to the farthest leaf node.

 

Example 1:


Input: root = [3,9,20,null,null,15,7]
Output: 3
Example 2:

Input: root = [1,null,2]
Output: 2

*/


//-------------------------------------SOLUTION---------------------------------------


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