题目描述
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。
# -*- coding:utf-8 -*-
# class TreeNode:
# def __init__(self, x):
# self.val = x
# self.left = None
# self.right = None
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
if not root:
return []
result = []
tmp = [root]
while len(tmp):
cur = tmp.pop(0)
result.append(cur.val)
if cur.left:
tmp.append(cur.left)
if cur.right:
tmp.append(cur.right)
return result
