Meeting Rooms III

You are given an integer `n`. There are `n` rooms numbered from `0` to `n - 1`. You are given a 2D integer array `meetings` where `meetings[i] = [starti, endi]` means that a meeting will be held during the **half-closed** time interval `[starti, endi)`. All the values of `starti` are **unique**. Meetings are allocated to rooms in the following manner: - Each meeting will take place in the unused room with the **lowest** number. - If there are no available rooms, the meeting will be delayed until a room becomes free. The delayed meeting should have the **same** duration as the original meeting. - When a room becomes unused, meetings that have an earlier original **start** time should be given the room. Return_ the **number** of the room that held the most meetings. _If there are multiple rooms, return_ the room with the **lowest** number._ A **half-closed interval** `[a, b)` is the interval between `a` and `b` **including** `a` and **not including** `b`.   **Example 1:** **Input:** n = 2, meetings = [[0,10],[1,5],[2,7],[3,4]] **Output:** 0 **Explanation:** - At time 0, both rooms are not being used. The first meeting starts in room 0. - At time 1, only room 1 is not being used. The second meeting starts in room 1. - At time 2, both rooms are being used. The third meeting is delayed. - At time 3, both rooms are being used. The fourth meeting is delayed. - At time 5, the meeting in room 1 finishes. The third meeting starts in room 1 for the time period [5,10). - At time 10, the meetings in both rooms finish. The fourth meeting starts in room 0 for the time period [10,11). Both rooms 0 and 1 held 2 meetings, so we return 0. ``` **Example 2:** **Input:** n = 3, meetings = [[1,20],[2,10],[3,5],[4,9],[6,8]] **Output:** 1 **Explanation:** - At time 1, all three rooms are not being used. The first meeting starts in room 0. - At time 2, rooms 1 and 2 are not being used. The second meeting starts in room 1. - At time 3, only room 2 is not being used. The third meeting starts in room 2. - At time 4, all three rooms are being used. The fourth meeting is delayed. - At time 5, the meeting in room 2 finishes. The fourth meeting starts in room 2 for the time period [5,10). - At time 6, all three rooms are being used. The fifth meeting is delayed. - At time 10, the meetings in rooms 1 and 2 finish. The fifth meeting starts in room 1 for the time period [10,12). Room 0 held 1 meeting while rooms 1 and 2 each held 2 meetings, so we return 1. ```   **Constraints:** - `1 <= n <= 100` - `1 <= meetings.length <= 105` - `meetings[i].length == 2` - `0 <= starti < endi <= 5 * 105` - All the values of `starti` are **unique**.