Design document layer with undo/redo

Q: Design document layer with undo/redo

This question evaluates a candidate's understanding of reversible state mutation and undo/redo semantics, covering batching, inverse operation representation, operation compression, failure handling, and choice of data structures for edit history.

Q: How do I approach Coding & Algorithms interview questions?

Coding & Algorithms questions require understanding of core concepts and practice. PracHub provides solutions with explanations to help you master coding & algorithms interviews.

Question

Design a document layer that supports applying edits and undo/redo. Implement apply(op) to mutate the document, undo() to revert the most recent committed unit of work, and redo() to reapply undone work. Add batching: beginBatch(), multiple apply(op) calls, then commitBatch() so the batch undoes in one step. Propose how to optimize batch undo (time and space), including how to store inverse operations, compress consecutive operations, and handle partial failures. Explain redo semantics after an undo and after new edits are applied. Discuss data structures, edge cases (empty stacks, nested/overlapping batches), and time/space complexity.

Design document layer with undo/redo

Overview

Comments (0)