Serialize and Deserialize Binary Tree

HardTreesTree

Solve this the way you would in the interview: out loud, on a timer, with an AI interviewer asking follow-ups while you code. You get a scored report at the end.

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Problem

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.

Examples

Input: root = [1,2,3,null,null,4,5]
Output: [1,2,3,null,null,4,5]
The tree is serialized to a string, then deserialized back to the original tree.
Input: root = []
Output: []

Constraints

  • The number of nodes in the tree is in the range [0, 10^4].
  • -1000 <= Node.val <= 1000

What the interviewer grades

A correct solution is one of five scores. The report also grades problem understanding (did you clarify inputs and edge cases before coding), problem solving, communication while you work, code quality, and testing. See a sample report, or read up on the pattern in the lessons.

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