Implement Memory-Efficient Document Undo/Redo

Company: Figma

Role: Software Engineer

Category: Coding & Algorithms

Difficulty: easy

Interview Round: Technical Screen

Overview: This question evaluates data structure design and algorithmic reasoning for implementing memory-efficient undo/redo semantics on a key-value document, emphasizing space-efficient per-batch state tracking (storage proportional to distinct keys changed) and correct handling of key creation and deletion.

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