97. Maximum Depth of Binary Tree/104. Maximum Depth of Binary Tree

• 本題難度: Easy
• Topic: Binary Tree

Description

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.

Example
Example 1:
Input: tree = {}
Output: 0

Explanation:
The height of empty tree is 0.

Example 2:
Input: tree = {1,2,3,#,#,4,5}
Output: 3

Explanation:
Like this:
      1  
     / \                
    2  3                
      /  \                
     4   5 

我的代碼

"""
Definition of TreeNode:
class TreeNode:
    def __init__(self, val):
        self.val = val
        self.left, self.right = None, None
"""

class Solution:
    """
    @param root: The root of binary tree.
    @return: An integer
    """
    def maxDepth(self, root):
        # write your code here
        return 1+max(self.maxDepth(root.left),self.maxDepth(root.right)) if root else 0
 

別人的代碼

def maxDepth(self, root):
    return 1 + max(map(self.maxDepth, (root.left, root.right))) if root else 0

思路
遞歸

• 出錯
  記得加self

[Lintcode]97. Maximum Depth of Binary Tree/[Leetcode]104. Maximum Depth of Binary Tree