剑指Offer 32

 1 # -*- coding:utf-8 -*-
 2 # class TreeNode:
 3 #     def __init__(self, x):
 4 #         self.val = x
 5 #         self.left = None
 6 #         self.right = None
 7 class Solution:
 8     # 返回从上到下每个节点值列表，例：[1,2,3]
 9     def __init__(self):
10         self.list = []
11         
12     def levelOrder(self,level):
13         count = len(level)
14         while count > 0:
15             root = level.pop(0)
16             self.list.append(root.val)
17             if root.left != None:
18                 level.append(root.left)
19             if root.right != None:
20                 level.append(root.right)
21             count -= 1
22         if len(level) > 0:
23             self.levelOrder(level)
24         
25         
26     def PrintFromTopToBottom(self, root):
27         if root == None:
28             return self.list
29         else:
30             level = []
31             level.append(root)
32             self.levelOrder(level)
33             return self.list
34         # write code here