Serialize and Deserialize Binary Tree

Implement an algorithm to serialize and deserialize a binary tree. Serialization is the process of converting an in-memory structure into a sequence of bits so that it can be stored or sent across a network to be reconstructed later in another computer environment. 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. There is no additional restriction on how your serialization/deserialization algorithm should work. Note: The input/output format in the examples is the same as how NeetCode serializes a binary tree. You do not necessarily need to follow this format.