maxMeeting.java

// I have an array that represents starting time for meetings - [1,3,3,5,7]. Another array that represents the time taken for the above meeting - [2,2,1,2,1]

// As per the above data, the first meeting starts at 1 and continues for 2hrs. so it covers from 1hr to 3hrs as meeting duration is 2hrs. The second and third meeting starts at 3 and they continue for 2hrs or 1hrs. so they cover 3 to 5 for 2nd meeting, 3 to 4 for the third meeting. The fourth meething starts at 5 and continues for 2hrs. So it covers 5 to 7 as duration is 2hrs The last meeting starts at 7 and continues for 1hr.

// The second and third are occurring at same time, so we just need to pick only one such that we can arrange maximum number of meetings.

// For the given above sample data we can arrange 4 meetings.

// Another example:

// starting time for meetings - [1,3,5]. Time taken for meetings - [2,2,2].

// Here none of the meetings can conflict so maximum we can arrange 3 meetings.
class Interval {
    int start;
    int end;    
    Interval(int start, int end) {
        this.start = start;
        this.end = end;
    }
}
static int getMaximumMeetings(List<Integer> start, List<Integer> timeTaken) {
    List<Interval> list = new ArrayList<>(); // create a List of Interval
    for (int i = 0; i < start.size(); i++) {
        list.add(new Interval(start.get(i), start.get(i) + timeTaken.get(i)));
    }
    list.sort(Comparator.comparingInt(i -> i.end)); // sort by finish times ascending

    int res = 0;
    int prevEnd = Integer.MIN_VALUE; // finish time of the previous meeting

    for (Interval i : list) {
        if (i.start >= prevEnd) { // is there a conflict with the previous meeting?
            res++;
            prevEnd = i.end; // update the previous finish time
        }
    }
    return res;
}