Serialize and Deserialize Binary Tree

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.   **Example 1:** **Input:** root = [1,2,3,null,null,4,5] **Output:** [1,2,3,null,null,4,5] ``` **Example 2:** **Input:** root = [] **Output:** [] ```   **Constraints:** - The number of nodes in the tree is in the range `[0, 104]`. - `-1000 <= Node.val <= 1000`