Meeting Scheduler

class Solution {
    public List<Integer> findMeetingSlot(int[][] slotsA, int[][] slotsB, int requiredDuration) {
        PriorityQueue<int[]> availableSlots = new PriorityQueue<>((a, b) -> a[0] - b[0]);

        for (int[] slot: slotsA) {
            if (slot[1] - slot[0] >= requiredDuration) availableSlots.offer(slot);
        }
        for (int[] slot: slotsB) {
            if (slot[1] - slot[0] >= requiredDuration) availableSlots.offer(slot);
        }

        while (!availableSlots.isEmpty()) {
            int[] first = availableSlots.poll();
            if (availableSlots.isEmpty()) break;
            int[] next = availableSlots.peek();
            if (first[1] >= next[0] + requiredDuration) {
                return new ArrayList<Integer>(Arrays.asList(next[0], next[0] + requiredDuration));
            }
        }
        return new ArrayList<Integer>();
    }
}

The "Meeting Scheduler" solution in Java focuses on finding a common available meeting time slot between two individuals based on their separate available time slots and a required duration for the meeting.

Procedure:

1. Initiate a priority queue to store available time slots, ordering them by their start times.

2. Iterate through each time slot of the first person (slotsA). Add the time slot to the priority queue if it meets or exceeds the required duration.

3. Repeat the above step for the second person's time slots (slotsB).

4. Process the priority queue to find overlapping time slots between the two schedules:

   • Retrieve and remove the earliest slot from the queue.
   • Check if there's another slot available in the queue; if not, break the loop as no further checks are necessary.
   • Compare the end time of the first slot and the start time of the next slot in the queue. If they overlap for at least the required duration, create and return a list representing the start time of the meeting and the end time, which is start time plus the required duration.

5. If no overlapping slots meet the conditions, return an empty list.

Key features:

• Utilizing a priority queue simplifies the process of sorting and accessing the earliest time slots.
• By only adding slots to the queue that are equal to or longer than the required duration, the function efficiently narrows down potential meeting times.
• This approach ensures optimal time complexity by reducing unnecessary comparisons between time slots that don't meet the criteria.

class Solution:
    def findMutualAvailableSlot(self, slotsA: List[List[int]], slotsB: List[List[int]], duration: int) -> List[int]:
        # Filtering slots that have enough duration and merging lists
        availableSlots = list(filter(lambda x: x[1] - x[0] >= duration, slotsA + slotsB))
        heapq.heapify(availableSlots)

        while len(availableSlots) > 1:
            s1, e1 = heapq.heappop(availableSlots)
            s2, e2 = availableSlots[0]
            if e1 >= s2 + duration:
                return [s2, s2 + duration]
        return []

The Python program presented solves the problem of finding a mutual available time slot for two participants given their individual availability and the duration of the meeting needed. The code performs the following steps:

1. Merges the time slots of both participants into one list and filters out those slots that are shorter than the required meeting duration.

2. Converts the list of available slots into a min-heap to efficiently find the earliest possible meeting time.

3. Continuously checks pairs of slots starting from the earliest. For each pair, it checks if they overlap for at least the required duration. If such an overlap exists, it immediately returns the starting time of the meeting and the calculated end time.

4. If no overlapping pairs are found that meet the duration requirement, the function returns an empty list, indicating no available meeting time could be found.

This solution efficiently manages time complexity by using a heap and reduces unnecessary comparisons, making it suitable for situations with potentially many available time slots.