104. Maximum Depth of Binary Tree.cc

//Using recursion method
//TC: O(n)
//SC: O(logn)
/**
 * 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 depthL = maxDepth(root->left);
        int depthR = maxDepth(root->right);
        return 1 + max(depthL, depthR);
    }
};