Meeting Scheduler: Minimum Number of Rooms

Implement a meeting-room scheduler. Given the start and end times of meetings, return the minimum number of rooms required to host every meeting. A meeting is represented by a half-open interval [start, end): a room occupied until time end can be reused by another meeting beginning exactly at end. Therefore, [1, 5) and [5, 8) may use the same room. Input Format n start1 end1 start2 end2 ... startn endn Output Format Print one integer: the minimum number of meeting rooms needed. Constraints 0 <= n <= 100,000 0 <= start < end <= 10^9 Example Input 3 0 30 5 10 15 20 Output 2 [0, 30) overlaps with both other meetings, so at least two rooms are required. Example Input 3 0 30 5 10 15 20 Output 2