0104_Maximum_Depth_of_Binary_Tree.cs

// Problem statement: https://leetcode.com/problems/maximum-depth-of-binary-tree/
/**
 * Definition for a binary tree node.
 * public class TreeNode {
 *     public int val;
 *     public TreeNode left;
 *     public TreeNode right;
 *     public TreeNode(int val=0, TreeNode left=null, TreeNode right=null) {
 *         this.val = val;
 *         this.left = left;
 *         this.right = right;
 *     }
 * }
 */
public class Solution {
    public int MaxDepth(TreeNode root) {
        if (root == null) return 0;
        int ret = Math.Max(MaxDepth(root.left), MaxDepth(root.right)) + 1;
        return ret;
    }
}