Serialize and Deserialize Binary Tree Leetcode solution

Serialization is the process of converting a data structure or object into a sequence of bits so that it can be stored in a file or memory buffer, or transmitted across a network connection link to be reconstructed later in the same or another computer environment.

Design an algorithm to serialize and deserialize a binary tree. There is no restriction on how your serialization/deserialization algorithm should work. You just need to ensure that a binary tree can be serialized to a string and this string can be deserialized to the original tree structure.

Clarification: The input/output format is the same as how LeetCode serializes a binary tree. You do not necessarily need to follow this format, so please be creative and come up with different approaches yourself.

Explanation

Lets first implement serialize method. We will use a pre order traversal. Just to revise preorder traversal, the sequence is

Visit the root
Traverse the left subtree
Traverse the right subtree

For deserialize we will first split the string by a serpator (we are using comma as a separtor). Next we will consruct the tree from the string.

Java
Python

Complexity

Time Complexity of Preorder traversal is $$O(n)$$

Space complexity is $$O(n)$$