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) {

        if (root == null) {
            return 0;
        }

        int leftDeep = maxDepth(root.left);
        int rightDeep = maxDepth(root.right);

        return Math.max(leftDeep, rightDeep) + 1;
    }
}