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。
Solutions
每次在打印一个结点时,将其子结点加入到待打印队列中!
# -*- 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 root is None:
return []
res = []
queue = []
queue.append(root)
while len(queue):
res.append(queue[0].val)
if queue[0].left:
queue.append(queue[0].left)
if queue[0].right:
queue.append(queue[0].right)
# pop the first node
queue.pop(0)
return res