Design an editable sequence with marker
Company: Google
Role: Software Engineer
Category: Software Engineering Fundamentals
Difficulty: medium
Interview Round: Onsite
Design a mutable ordered sequence of elements together with a marker that points to one element in the sequence.
Support the following operations:
- Insert or remove a contiguous block of elements at a given position.
- Move a contiguous block of elements from one position to another.
- Set the marker to a new position.
Explain the API, data model, and how the marker should behave when edits happen before it, after it, or when the marked element is inside a moved or deleted block. Discuss reasonable implementation choices and their time-complexity tradeoffs.
Quick Answer: This question evaluates understanding of mutable ordered sequence data structures, marker semantics and invariants, API and data model design, and algorithmic time-complexity trade-offs for insert, delete, and move operations.