描述
思路：
自行序列化和反序列化。元素用逗号分隔。
序列化： 使用队列+层序遍历。遍历每一层节点，并访问其左右孩子，如果是空则序列化成#，如果是数字，则序列化成str。
反序列化： 使用队列+两两遍历字符串，按层次构造二叉树。具体做法是：先将根节点入队。然后遍历队列，每取出一个节点，就取两个字符，作为其左右孩子。如果字符为#，说明孩子为空，如果字符为数字，说明孩子不为空，并将其压进队列。（讲的有点难懂。。）
import queue
# -*- coding:utf-8 -*-
# class TreeNode:
# def __init__(self, x):
# self.val = x
# self.left = None
# self.right = None
class Solution:
def Serialize(self, root):
# write code here
result = ""
if root is None:
return result
q = queue.Queue()
q.put(root)
result += str(root.val) + ","
while not q.empty():
node = q.get()
if node.left:
q.put(node.left)
result += str(node.left.val) + ","
else:
result += "#,"
if node.right:
q.put(node.right)
result += str(node.right.val) + ","
else:
result += "#,"
return result
def Deserialize(self, s):
if s == "":
return None
s = s.split(",")
# 数字压进队列，get一个数字就赋值左右孩子
q = queue.Queue()
root = TreeNode(int(s[0]))
q.put(root)
cur = 1
while not q.empty() and cur < len(s):
node = q.get()
# 处理左节点
val = s[cur]
print(val, cur)
if val == "#":
node.left = None
else:
new_node = TreeNode(int(val))
node.left = new_node
q.put(new_node)
cur += 1
# 处理右节点
val = s[cur]
if val == "#":
node.right = None
else:
new_node = TreeNode(int(val))
node.right = new_node
q.put(new_node)
cur += 1
return root
来还债了