Design a waitlist manager

Q: Design a waitlist manager

This question evaluates object-oriented design and data-structure competency—modeling a FIFO waitlist API, managing unique party identifiers and edge cases, and reasoning about time and space complexity; it falls under the Software Engineering Fundamentals domain with emphasis on OOP and algorithms.

Q: How do I approach Software Engineering Fundamentals interview questions?

Software Engineering Fundamentals questions require understanding of core concepts and practice. PracHub provides solutions with explanations to help you master software engineering fundamentals interviews.

Question

Loading...

Object-Oriented Design: Waitlist Manager

Design a waitlist management component (e.g., for a restaurant or event) that maintains FIFO order for parties as they join a waitlist.

Requirements

Implement a class (or set of classes) with APIs similar to:

add(partyId, partySize, metadata) -> void : Add a party to the end of the waitlist.
cancel(partyId) -> bool : Remove a party if they are currently waiting.
nextParty() -> Party | null : Return (and remove) the next eligible party to be seated.
peekNext() -> Party | null : Return the next party without removing.
position(partyId) -> int | null : Return the party’s current position (optional follow-up).

Constraints / Expectations

Aim for efficient operations (discuss time/space complexity).
Assume partyId is unique.
Handle edge cases (duplicate adds, canceling a non-existent party, empty waitlist).

Follow-ups

How would you support skipping parties temporarily (e.g., they don’t respond) and re-adding them later?
How would your complexity change if you must support position(partyId) efficiently?

Design a waitlist manager

Quick Overview

Object-Oriented Design: Waitlist Manager

Requirements

Constraints / Expectations

Follow-ups

Solution

Comments (0)