剑指Offer-32 从上往下打印二叉树

题目：

从上往下打印出二叉树的每个节点，同层节点从左至右打印。

解答：

# -*- coding:utf-8 -*-
# class TreeNode:
#     def __init__(self, x):
#         self.val = x
#         self.left = None
#         self.right = None
import Queue
class Solution:
    # 返回从上到下每个节点值列表，例：[1,2,3]
    def PrintFromTopToBottom(self, root):
        # write code here
        rlist = []
        q = Queue.Queue()
        if root != None:
            q.put(root)
        while(not q.empty()):
            node = q.get()
            rlist.append(node.val)
            if node.left:
                q.put(node.left)
            if node.right:
                q.put(node.right)
        return rlist