////////////////////////////////////////////////////////////////////////////////////////////////////
/// <summary> Determine how many monos we can fit in a number of rooms. </summary>
///
/// <remarks>
/// This returns a list of room assignments. Each room assignment is a list with one element for
/// each room. Each of those elements is a list of the monopoles that can be placed in that
/// room. Darrell Plank, 6/10/2020.
/// </remarks>
///
/// <param name="cRooms"> The count of rooms. </param>
///
/// <returns> A List of an array of lists. </returns>
////////////////////////////////////////////////////////////////////////////////////////////////////
private List <List <int>[]> MonosInRooms(int cRooms)
{
var ra = new RoomAssignments(cRooms);
var(assignments, _) = TryPlace(1, 0, ra, 1);
return(assignments);
}
private static (List <List <int>[]> assignments, int maxMono) TryPlace(int monopole, int room, RoomAssignments ra, int minMonos)
{
if (!ra.Place(monopole, room))
{
return(new List <List <int>[]>()
{
ra.CloneAssignments()
}, ra.NextUnassigned - 1);
}
var ret = new List <List <int>[]>();
// Good - we were able to place mono in requested room. Go on and try to place the next monopole
// in each valid room.
var nextMono = ra.NextUnassigned;
var fPlacedInEmptyRoom = false;
for (var iRoom = 0; iRoom < ra.RoomCount; iRoom++)
{
var isEmptyRoom = ra.MonosInRoom(iRoom).Count == 0;
if (fPlacedInEmptyRoom && isEmptyRoom)
{
// No sense in trying to place the monopole in two separate empty rooms
continue;
}
fPlacedInEmptyRoom = fPlacedInEmptyRoom || isEmptyRoom;
var(assignments, count) = TryPlace(nextMono, iRoom, ra, minMonos);
if (count > minMonos)
{
ret = assignments;
minMonos = count;
}
else if (count == minMonos && count >= nextMono)
{
ret.AddRange(assignments);
}
// Only remove if we successfully placed
if (count >= nextMono)
{
ra.Unplace(nextMono, iRoom);
}
}
return(ret, minMonos);
}
