Find the meeting room that hosts the most meetings

An office books its meeting rooms with a simple rule: take the lowest-numbered free room, and if every room is busy, wait for the first one to free up.

Write most_booked_room(n, meetings) that returns the room that held the most meetings.

Input and output:

• n: the number of rooms, from 1 to 100. Rooms are numbered 0 to n - 1.
• meetings: a list of 1 to 10,000 pairs [start, end] of integers between 0 and 1,000,000,000, with start less than end. A meeting runs from start up to, but not including, end.
• Returns a room number.

Rules:

• Handle the meetings in order of start. Meetings with the same start keep their order from the list.
• Before placing a meeting, every room whose current meeting ends at or before that meeting's start is free again.
• If any room is free, the meeting takes the lowest-numbered free room.
• If no room is free, the meeting waits for the room that frees up first, or the lowest-numbered of those that free up at the same moment. It starts at that moment and keeps its original length.
• A delayed meeting does not change the order in which the remaining meetings are handled.
• Return the room that held the most meetings. If rooms tie, return the lowest-numbered one.