【leetcode】145. Binary Tree Postorder Traversal
阿新 • • 發佈:2018-08-01
tor ron medium div lee har pos tco urn
題目如下:
解題思路:湊數題+3,搞不懂為什麽本題的難度是Hard,而【leetcode】590. N-ary Tree Postorder Traversal是Medium。
代碼如下:
# 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 postorderTraversal(self, root):""" :type root: TreeNode :rtype: List[int] """ if root == None: return [] res = [] stack = [root] while len(stack) > 0: node = stack.pop(0) res.insert(0,node.val) if node.left != None: stack.insert(0,node.left)if node.right != None: stack.insert(0,node.right) return res
【leetcode】145. Binary Tree Postorder Traversal