// Return true if there is some valid path from the specified source
// position to the specified target position; otherwise return false.
public bool IsValidPath(TzaarBoard board, int fromCol, int fromRow, int toCol, int toRow)
{
if (!board.IsValidPosition(fromCol, fromRow) || !board.IsValidPosition(toCol, toRow))
// Parameters are out of range.
return false;
Node fromNode = paths[fromCol][fromRow];
Node toNode = paths[toCol][toRow];
if (fromCol == toCol)
{
if (fromRow == toRow)
// We can't move to ourselves!
return false;
// The target is in the same column as the source. So, we are
// either going north or south.
if (fromRow < toRow)
// Go north!
return ExplorePath(board, fromNode, toNode, "n");
else
// Go south!
return ExplorePath(board, fromNode, toNode, "s");
}
else if (toCol > fromCol)
{
// Go east!
// Try northeast first.
if (ExplorePath(board, fromNode, toNode, "ne"))
return true;
else
// Try southeast.
return ExplorePath(board, fromNode, toNode, "se");
}
else
{
// Go west!
// Try northwest first.
if (ExplorePath(board, fromNode, toNode, "nw"))
return true;
else
// Try southwest.
return ExplorePath(board, fromNode, toNode, "sw");
}
}
// Scan the board and update the counts for each piece still remaining.
private static void UpdatePieceCount(TzaarBoard board)
{
// The entire board is scanned for the update, so destroy the old
// count values.
board.blackTzaarCount = 0;
board.blackTzarraCount = 0;
board.blackTottCount = 0;
board.whiteTzaarCount = 0;
board.whiteTzarraCount = 0;
board.whiteTottCount = 0;
// Scan each space of the board to update.
for (int i = 0; i < 9; i++)
for (int j = 0; j < 9; j++)
{
// If the position is not valid, we have passed the end of
// the column. Move to the next column.
if (!board.IsValidPosition(i, j))
break;
// Otherwise, find the color and number of pieces at the
// current position and update accordingly.
Stack<TzaarPiece> S = board.board[i][j].Query();
if (S.Count == 0)
continue;
TzaarPiece topPiece = S.Peek();
if (topPiece.Color == TzaarColor.WHITE)
{
if (topPiece.GetType() == typeof(TzaarPiece.Tzaar))
board.whiteTzaarCount++;
else if (topPiece.GetType() == typeof(TzaarPiece.Tzarra))
board.whiteTzarraCount++;
else
board.whiteTottCount++;
}
else
{
if (topPiece.GetType() == typeof(TzaarPiece.Tzaar))
board.blackTzaarCount++;
else if (topPiece.GetType() == typeof(TzaarPiece.Tzarra))
board.blackTzarraCount++;
else
board.blackTottCount++;
}
}
}
