# Leetcode 449 Solution

https://leetcode.com/problems/serialize-and-deserialize-bst

## Solution

``````# Definition for a binary tree node.
# class TreeNode:
#     def __init__(self, x):
#         self.val = x
#         self.left = None
#         self.right = None

class Codec:

def serialize(self, root: Optional[TreeNode]) -> str:
"""Encodes a tree to a single string.
"""
tokens = []

def _serialize(node):
if not node:
tokens.append("#")
return

tokens.append(str(node.val))
_serialize(node.left)
_serialize(node.right)

_serialize(root)

return " ".join(tokens)

def deserialize(self, data: str) -> Optional[TreeNode]:
"""Decodes your encoded data to tree.
"""
tokens = data.split(" ")

i = 0
def _deserialize():
nonlocal i

if i == len(tokens) or tokens[i] == "#":
i += 1
return None

node = TreeNode(int(tokens[i]))
i += 1

node.left = _deserialize()
node.right = _deserialize()

return node

return _deserialize()

# Your Codec object will be instantiated and called as such:
# Your Codec object will be instantiated and called as such:
# ser = Codec()
# deser = Codec()
# tree = ser.serialize(root)
# ans = deser.deserialize(tree)
# return ans
``````