Meeting Rooms II

edit  Updated by Benjo

Given an array of meeting time intervals consisting of start and end times [[s1,e1],[s2,e2],...] (si < ei), find the minimum number of conference rooms required.

For example,
Given [[0, 30],[5, 10],[15, 20]],
return 2.

Meeting Rooms Ii Solution

/**
 * Definition for an interval.
 * public class Interval {
 *     int start;
 *     int end;
 *     Interval() { start = 0; end = 0; }
 *     Interval(int s, int e) { start = s; end = e; }
 * }
 */
public class MeetingRoomsII {
    public int minMeetingRooms(Interval[] intervals) {
        int[] starts = new int[intervals.length];
        int[] ends = new int[intervals.length];

        for(int i=0; i<intervals.length; i++) {
            starts[i] = intervals[i].start;
            ends[i] = intervals[i].end;
        }

        Arrays.sort(starts);
        Arrays.sort(ends);

        int rooms = 0;
        int endsItr = 0;

        for(int i=0; i<starts.length; i++) {
            if(starts[i]<ends[endsItr]) {
                rooms++;
            } else {
                endsItr++;
            }
        }

        return rooms;
    }
}

See Also