[Leetcode]@python 94. Binary Tree Inorder Traversal

题目链接

https://leetcode.com/problems/binary-tree-inorder-traversal/

题目原文

Given a binary tree, return the inorder traversal of its nodes' values.

For example:

Given binary tree

{1,#,2,3}

,



return

[1,3,2]

.

题目大意

中序遍历一棵二叉树

解题思路

递归求解，先遍历左子树，再遍历根节点，最后遍历右子树

代码

# Definition for a binary tree node.
# class TreeNode(object):
#     def __init__(self, x):
#         self.val = x
#         self.left = None
#         self.right = None

class Solution(object):
def inorderTraversal_re(self, root, inorder):
if not root:
return inorder
inorder = self.inorderTraversal_re(root.left, inorder)
inorder.append(root.val)
inorder = self.inorderTraversal_re(root.right, inorder)
return inorder

def inorderTraversal(self, root):
"""
:type root: TreeNode
:rtype: List[int]
"""
return self.inorderTraversal_re(root, [])