/// <summary>
/// Determines whether the game board is valid or not. Valid is defined as having all of
/// the game tiles connected together. NOTE - this method does not check to see whether
/// all of the game tiles are on the game board and none are remaining in the tile rack.
/// </summary>
/// <returns></returns>
public bool IsGameBoardValid()
{
bool isValid = true;
int unoccupiedTileCount = 0;
int markedTileCount = 0;
//ToDo: Does this array need to be initialized to some default value?
var connections = new TileValidity[BoardSpaceDimension, BoardSpaceDimension];
//
// Start with marking all of the unoccupied spots.
//
for (int i = 0; i < BoardSpaceDimension; i++)
{
for (int j = 0; j < BoardSpaceDimension; j++)
{
if (!_boardMatrix[i, j]._isOccupied)
{
connections[i, j] = TileValidity.Unoccupied;
unoccupiedTileCount++;
}
else if (connections[i, j] != TileValidity.Valid)
{
markedTileCount = MarkConnectedTiles(ref connections, i, j);
}
}
}
//ToDo: Find some way to mark the smallest groups of unoccupied tiles as Invalid.
if ((markedTileCount + unoccupiedTileCount) != BoardSpaceDimension * BoardSpaceDimension)
{
isValid = false;
}
return(isValid);
}
/// <summary>
/// Helper method for IsGameBoardValid(). This method is recursive and finds the number
/// of connected tiles.
/// </summary>
/// <param name="connections"></param>
/// <param name="i">X index into the connections array to examine.</param>
/// <param name="j">Y index into the connections array to examine.</param>
/// <returns>The count of connected tiles.</returns>
private int MarkConnectedTiles(ref TileValidity[,] connections, int i, int j)
{
Debug.Assert(0 < i && i < BoardSpaceDimension);
Debug.Assert(0 < j && j < BoardSpaceDimension);
int tileCountMarked = 1;
//
// Mark current tile as valid.
//
connections[i,j] = TileValidity.Valid;
//
// Check the tile to the West.
//
if (i > 0)
{
if ((_boardMatrix[i - 1, j]._isOccupied) && (connections[i - 1, j] != TileValidity.Valid))
{
tileCountMarked += MarkConnectedTiles(ref connections, i - 1, j);
}
}
//
// Check the tile to the East.
//
if (i < BoardSpaceDimension - 1)
{
if ((_boardMatrix[i + 1, j]._isOccupied) && (connections[i + 1, j] != TileValidity.Valid))
{
tileCountMarked += MarkConnectedTiles(ref connections, i + 1, j);
}
}
//
// Check the tile to the North
//
if (j > 0)
{
if ((_boardMatrix[i, j - 1]._isOccupied) && (connections[i, j - 1] != TileValidity.Valid))
{
tileCountMarked += MarkConnectedTiles(ref connections, i, j - 1);
}
}
//
// Check the tile to the South
//
if (j < BoardSpaceDimension - 1)
{
if ((_boardMatrix[i, j + 1]._isOccupied) && (connections[i, j + 1] != TileValidity.Valid))
{
tileCountMarked += MarkConnectedTiles(ref connections, i, j + 1);
}
}
return tileCountMarked;
}
/// <summary>
/// Determines whether the game board is valid or not. Valid is defined as having all of
/// the game tiles connected together. NOTE - this method does not check to see whether
/// all of the game tiles are on the game board and none are remaining in the tile rack.
/// </summary>
/// <returns></returns>
public bool IsGameBoardValid()
{
bool isValid = true;
int unoccupiedTileCount = 0;
int markedTileCount = 0;
//ToDo: Does this array need to be initialized to some default value?
var connections = new TileValidity[BoardSpaceDimension,BoardSpaceDimension];
//
// Start with marking all of the unoccupied spots.
//
for (int i = 0; i < BoardSpaceDimension; i++)
{
for (int j = 0; j < BoardSpaceDimension; j++)
{
if (!_boardMatrix[i, j]._isOccupied)
{
connections[i, j] = TileValidity.Unoccupied;
unoccupiedTileCount++;
}
else if (connections[i,j] != TileValidity.Valid)
{
markedTileCount = MarkConnectedTiles(ref connections, i, j);
}
}
}
//ToDo: Find some way to mark the smallest groups of unoccupied tiles as Invalid.
if ((markedTileCount + unoccupiedTileCount) != BoardSpaceDimension*BoardSpaceDimension)
{
isValid = false;
}
return isValid;
}
