[leetcode] 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.

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

思路：递归求解。

public class Solution {
    public int maxDepth(TreeNode root) {
        if (root == null)
            return 0;
        return Math.max(maxDepth(root.left), maxDepth(root.right)) + 1;

    }
}

第二遍记录：递归求深度时，不要忘记+1.