internal static Session GetUnassignedSessionWithFewestAvailableOptions(this IEnumerable<Assignment> assignments, IEnumerable<Session> sessions, SessionAvailabilityCollection sessionMatrix)
{
Session result = null;
var assignedSessionIds = assignments.Where(a => a.SessionId != null).Select(a => a.SessionId);
var sessionDictionary = new Dictionary<int, int>();
foreach (var session in sessions.Where(s => !assignedSessionIds.Contains(s.Id)))
{
sessionDictionary.Add(session.Id, sessionMatrix.GetAvailableAssignmentCount(session.Id));
}
if (sessionDictionary.Count() > 0)
{
var min = sessionDictionary.Min(s => s.Value);
var keys = sessionDictionary.Where(sd => sd.Value == min).Select(a => a.Key);
result = sessions.Where(a => keys.Contains(a.Id))
.OrderByDescending(b => b.GetDependentDepth(sessions))
.ThenByDescending(c => c.GetDependentCount(sessions))
.FirstOrDefault();
}
return result;
}
private void Load(Solution solution)
{
_sessions = solution._sessions.ToList();
_rooms = solution._rooms.ToList();
_timeslots = solution._timeslots.ToList();
_presenters = solution._presenters.ToList();
_sessionMatrix = solution._sessionMatrix.Clone();
this.Assignments = solution.Assignments.Clone();
}
private void Load(SessionsCollection sessions, IEnumerable<Room> rooms, IEnumerable<Timeslot> timeslots)
{
_sessions = sessions;
_rooms = rooms;
_timeslots = timeslots;
_presenters = sessions.GetPresenters();
// Create the session availability matrix
_sessionMatrix = new SessionAvailabilityCollection(sessions, rooms, timeslots);
if (!_sessionMatrix.IsFeasible)
throw new Exceptions.NoFeasibleSolutionsException();
// Setup the empty assignment matrix
foreach (var room in rooms)
foreach (var timeslot in timeslots)
if (room.AvailableInTimeslot(timeslot.Id))
this.Assignments.Add(new Assignment(room.Id, timeslot.Id));
// Make sure there are enough slots/rooms for all of the sessions
if (sessions.Count() > this.Assignments.Count())
throw new Exceptions.NoFeasibleSolutionsException("There are not enough rooms and timeslots to accommodate all of the sessions.");
}
