Serialize and Deserialize Binary Tree
CodingPhone ScreenData EngineerReported Mar, 2026
Examples
Example 1:
Input: root = [1,2,3,null,null,4,5]
Output: [1,2,3,null,null,4,5]
Example 2:
Input: root = []
Output: []
Example 1:
Input: root = [1,2,3,null,null,4,5]
Output: [1,2,3,null,null,4,5]
Example 2:
Input: root = []
Output: []
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.
0 <= The number of nodes in the tree <= 1000-1000 <= Node.val <= 1000