Serialize and Deserialize Binary Tree — Hard Coding Interview Question

Design an algorithm to serialize a binary tree into a string, and deserialize that string back into the original tree structure.

Example

Input: root = [1,2,3,null,null,4,5]

Output: [1,2,3,null,null,4,5]

Explanation: Serializing then deserializing reproduces the original tree.

Constraints

• The number of nodes is in the range [0, 10⁴]
• -1000 ≤ Node.val ≤ 1000

Topics & Companies

Topics: trees

Asked by: Amazon, Meta, Microsoft, Google

Optimal Solution Complexity

Time complexity: O(n). Space complexity: O(n).

Practice more

• All DSA Problems
• DSA Patterns