104. 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.
***/

//Java solution:

/**
 * Definition for a binary tree node.
 * public class TreeNode {
 *     int val;
 *     TreeNode left;
 *     TreeNode right;
 *     TreeNode(int x) { val = x; }
 * }
 */
public class Solution {
    public int maxDepth(TreeNode root) {
        if(root == null){
            return 0;
        }
        
        int left = maxDepth(root.left);
        int right = maxDepth(root.right);
        int result = Math.max(left, right) + 1; // plus root
        
        return result;
    }
}