104. Maximum Depth of Binary Tree leetcode in c++

 /**

 * Definition for a binary tree node.

 * struct TreeNode {

 *     int val;

 *     TreeNode *left;

 *     TreeNode *right;

 *     TreeNode() : val(0), left(nullptr), right(nullptr) {}

 *     TreeNode(int x) : val(x), left(nullptr), right(nullptr) {}

 *     TreeNode(int x, TreeNode *left, TreeNode *right) : val(x), left(left), right(right) {}

 * };

 */

class Solution {

public:

    int maxDepth(TreeNode* root) {

        

        if(!root)return 0;

        

        int left=maxDepth(root->left)+1;

        int right=maxDepth(root->right)+1;

        

        return max(left,right);

    }

};