104-Maximum-Depth-of-Binary-Tree.cpp

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

/* 104. 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.

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

Input: root = []
Output: 0

https://leetcode.com/problems/maximum-depth-of-binary-tree/
//////////////////////////////////////////////////
*/