题解 | #二叉树的后序遍历#
二叉树的后序遍历
http://www.nowcoder.com/practice/1291064f4d5d4bdeaefbf0dd47d78541
解题思路:
- 先序:根左右
- 中序:左根右
- 后续:左右根
- 根往列表里面加值,左右调用递归函数就行了
# def __init__(self, x):
# self.val = x
# self.left = None
# self.right = None
#
# 代码中的类名、方法名、参数名已经指定,请勿修改,直接返回方法规定的值即可
#
#
# @param root TreeNode类
# @return int整型一维数组
#
lst = []
class Solution:
def postorderTraversal(self , root: TreeNode) -> List[int]:
# write code here
self.lastOrder(root)
return lst
def lastOrder(self, root):
if not root:
return
self.lastOrder(root.left)
self.lastOrder(root.right)
lst.append(root.val)