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Leetcode 297. Serialize and Deserialize Binary Tree

Implement two complementary algorithms to convert a binary tree to a string and back, preserving exact node values and tree structure (including null children) so the process is reversible; common approaches use preorder DFS with null markers or level-order with placeholders. Ensure correctness and efficiency for trees up to ~10^4 nodes.

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Company

Level

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Early October, 2025

Amazon

Mid-level

Early August, 2025

Microsoft

Senior

Early August, 2025

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