题解 | #二叉树的最大深度#

import java.util.*;

/*
 * public class TreeNode {
 *   int val = 0;
 *   TreeNode left = null;
 *   TreeNode right = null;
 * }
 */

public class Solution {
    /**
     *
     * @param root TreeNode类
     * @return int整型
     */
    public int maxDepth (TreeNode root) {
        // write code here
        return root == null ? 0 : Math.max(maxDepth(root.left),
                                           maxDepth(root.right)) + 1;
    }
}