[LeetCode][Python3] 297. Serialize and Deserialize Binary Tree

Problem :

https://leetcode.com/problems/serialize-and-deserialize-binary-tree/

My Solution :

# Definition for a binary tree node.

# class TreeNode(object):

# def __init__(self, x):

# self.val = x

# self.left = None

# self.right = None

class Codec:

def serialize(self, root):

"""Encodes a tree to a single string.

:type root: TreeNode

:rtype: str

"""

def preorder(root, tree):

if root:

tree.append(root.val)

preorder(root.left, tree)

preorder(root.right, tree)

else:

tree.append('N')

tree = []

preorder(root, tree)

return ','.join(map(str, tree))

def deserialize(self, data):

"""Decodes your encoded data to tree.

:type data: str

:rtype: TreeNode

"""

def build(data):

val = data.pop()

if val == 'N':

return

node = TreeNode(int(val))

node.left = build(data)

node.right = build(data)

return node

data = data.split(',')

data = data[::-1]

return build(data)