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Design a meeting room reservation API

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This problem tests your ability to design an in-memory scheduling system that efficiently manages room availability and handles time-interval overlaps.

Meeting Room Reservation API

Design an in-memory API to manage reservations for a set of meeting rooms in an office building. You need to provide functionality to add rooms and book them for specific time slots.

Requirements

Implement a class MeetingScheduler with the following methods:

  • add_room(room_id: str) -> None: Adds a new room to the system.
  • reserve(room_id: str, start_time: int, end_time: int) -> bool: Attempts to reserve the given room from start_time to end_time (exclusive). Returns True if the booking is successful, False otherwise.

Constraints

  • start_time and end_time are integers representing time units (e.g., hours or timestamps).
  • The same room cannot have overlapping bookings.
  • Assume a reasonable number of rooms and bookings for an in-memory solution.

Example

scheduler = MeetingScheduler()
scheduler.add_room("Room_A")

# Returns True
scheduler.reserve("Room_A", 9, 11)

# Returns False (overlap: 10-12 overlaps with 9-11)
scheduler.reserve("Room_A", 10, 12)

# Returns True
scheduler.reserve("Room_A", 11, 13)

Edge Cases

  • Booking a room that does not exist.
  • An end time that is less than or equal to a start time.
  • Back-to-back bookings (e.g., 9-10 and 10-11 should be allowed).

Hints

Hint 1

Use a dictionary to map room IDs to a list of existing reservations.

Hint 2

Store reservations as sorted tuples or objects representing the [start, end) intervals to simplify overlap detection.

Hint 3

Consider using binary search (or a library equivalent) to find the insertion point and check for overlaps with neighbors efficiently.

Follow-up questions

  • How would you modify the API to find the first available room across all rooms for a requested time slot?
  • What data structure would you use if you needed to support cancelling a reservation efficiently?
  • How would you adapt this design to handle concurrent requests in a multi-threaded environment?