using Microsoft.VisualStudio.TestTools.UnitTesting;

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Threading.Tasks;

namespace Algorithms.Problem.InterviewCake

{

[TestClass]

public class Meeting

{

public Meeting() { }

public int StartTime { get; set; }

public int EndTime { get; set; }

public Meeting(int startTime, int endTime)

{

// Number of 30 min blocks past 9:00 am

StartTime = startTime;

EndTime = endTime;

}

public override bool Equals(object obj)

{

if (obj == null || GetType() != obj.GetType())

{

return false;

}

if (ReferenceEquals(obj, this))

{

return true;

}

var meeting = (Meeting)obj;

return StartTime == meeting.StartTime && EndTime == meeting.EndTime;

}

public override int GetHashCode()

{

var result = 17;

result = result * 31 + StartTime;

result = result * 31 + EndTime;

return result;

}

public override string ToString()

{

return $"({StartTime}, {EndTime})";

}

public static List<Meeting> MergeRanges(List<Meeting> meetings)

{

// Meeting(1,3) overlaps with Meeting(2,4) Merge to Meeting(1,4)

// SO, if the end time is greater than the start time of next then merge the two meetings.

// Sort the original meeting requests by start time.

var sortedMeetingList = meetings

.Select(m => new Meeting(m.StartTime, m.EndTime))

.OrderBy(m => m.StartTime);

// Initialize the new list to the first item in the sorted list.

IList<Meeting> ouputMeetingList = new List<Meeting> { sortedMeetingList.First() };

foreach (var meeting in sortedMeetingList)

{

// get the lastly added item to the output list.

var lastAddedMeeting = ouputMeetingList.Last();

// If the start time of the incoming list is less than the end time of the existing list.

// As it is ordered by start time, we can merge to the existing list.

if (meeting.StartTime <= lastAddedMeeting.EndTime)

{

// Update the end time to the max end time of both the meeting request.

// For instance Meeting(1,3), the new meeting could be Meeting(1,2) => result should be Meeting (1,3)

// Second case: Meeting(1,3), the new meeting coule be Meeting(2, 4) => result should be Meeting (1,4)

lastAddedMeeting.EndTime = Math.Max(meeting.EndTime, lastAddedMeeting.EndTime);

}

else

{

ouputMeetingList.Add(meeting);

}

}

return ouputMeetingList.ToList();

}

[TestMethod]

public void MeetingsOverlapTest()

{

var meetings = new List<Meeting>()

{

new Meeting(1, 3), new Meeting(2, 4)

};

var actual = MergeRanges(meetings);

var expected = new List<Meeting>()

{

new Meeting(1, 4)

};

Assert.AreEqual(expected.Count, actual.Count);

}

}

}