Find Minimum Rooms Needed

You are given a list of meeting intervals, where each interval is represented as `[start, end)` and `start < end`. Two meetings conflict if their time ranges overlap. Determine the minimum number of rooms required so that all meetings can be scheduled without conflicts. Example: - Input: `[[0, 30], [5, 10], [15, 20]]` - Output: `2` A simple follow-up is to explain how you would also produce one valid room assignment for each meeting.