Simulate room assignments for scheduled meetings

Problem

You are given n meeting rooms labeled 0..n-1 and a list of meetings meetings, where each meeting is [start, end] with start < end. Meetings are processed in increasing order of start time.

Assign each meeting to a room using these rules:

1. If one or more rooms are free at start , assign the meeting to the free room with the smallest index .
2. If no rooms are free at start , the meeting must wait until a room becomes free. It is then scheduled in the room that becomes available earliest (break ties by smallest room index). If it waits, its duration stays the same , so if the original duration is end - start and the room becomes free at time t , the meeting runs on [t, t + (end - start)] .

Each time a meeting is assigned to a room (even after waiting), that room’s meeting count increases by 1.

Task

Return the index of the room that hosted the most meetings. If there is a tie, return the smallest index.

Input/Output

• Input: n (int), meetings (list of [start,end] )
• Output: an integer room index

Constraints (reasonable interview assumptions)

• 1 <= n <= 10^5
• 1 <= len(meetings) <= 10^5
• Times fit in 32-bit signed integer; waiting can increase end times beyond original but still fits in 64-bit.