public int fitness(PieceSide max)
{
int fitness = 0;
int[] blackPieces = { 0, 0, 0, 0, 0, 0 };
int[] whitePieces = { 0, 0, 0, 0, 0, 0 };
int blackMoves = 0;
int whiteMoves = 0;
// sum up the number of moves and pieces
foreach (Position pos in Pieces[PieceSide.Black])
{
blackMoves += LegalMoveSet.getLegalMove(this, pos).Count;
blackPieces[(int)Grid[pos.number][pos.letter].piece]++;
}
// sum up the number of moves and pieces
foreach (Position pos in Pieces[PieceSide.White])
{
whiteMoves += LegalMoveSet.getLegalMove(this, pos).Count;
whitePieces[(int)Grid[pos.number][pos.letter].piece]++;
}
// if viewing from black side
if (max == PieceSide.Black)
{
// apply weighting to piece counts
for (int i = 0; i < 6; i++)
{
fitness += pieceWeights[i] * (blackPieces[i] - whitePieces[i]);
}
// apply move value
fitness += (int)(0.5 * (blackMoves - whiteMoves));
}
else
{
// apply weighting to piece counts
for (int i = 0; i < 6; i++)
{
fitness += pieceWeights[i] * (whitePieces[i] - blackPieces[i]);
}
// apply move value
fitness += (int)(0.5 * (whiteMoves - blackMoves));
}
return(fitness);
}
/// <summary>
/// Get all legal moves for the player on the current board.
/// </summary>
/// <param name="b">The state of the game.</param>
/// <param name="player">The player whose moves you want.</param>
/// <returns>A 1-to-many dictionary of moves from one position to many</returns>
public static Dictionary <Position, List <Position> > getPlayerMoves(BoardHelper b, PieceSide player)
{
Dictionary <Position, List <Position> > moves = new Dictionary <Position, List <Position> >();
foreach (Position pos in b.Pieces[player])
{
if (b.Grid[pos.number][pos.letter].piece != PieceType.None)
{
if (!moves.ContainsKey(pos))
{
moves[pos] = new List <Position>();
}
moves[pos].AddRange(LegalMoveSet.getLegalMove(b, pos));
}
}
return(moves);
}
private int mimaab(BoardHelper board, PieceSide turn, int depth, int alpha, int beta)
{
// base case, at maximum depth return board fitness
if (depth >= DEPTH)
{
return(board.fitness(MAX));
}
else
{
List <BoardHelper> boards = new List <BoardHelper>();
// get available moves / board states from moves for the current player
foreach (Position pos in board.Pieces[turn])
{
if (STOP)
{
return(-1); // interupts
}
List <Position> moves = LegalMoveSet.getLegalMove(board, pos);
foreach (Position move in moves)
{
if (STOP)
{
return(-1); // interupts
}
BoardHelper b2 = LegalMoveSet.move(board, new Move(pos, move));
boards.Add(b2);
}
}
int a = alpha, b = beta;
if (turn != MAX) // minimize
{
foreach (BoardHelper b2 in boards)
{
if (STOP)
{
return(-1); // interupt
}
b = Math.Min(b, mimaab(b2, (turn == PieceSide.White) ? PieceSide.Black : PieceSide.White, depth + 1, a, b));
if (a >= b)
{
return(a);
}
}
return(b);
}
else // maximize
{
foreach (BoardHelper b2 in boards)
{
if (STOP)
{
return(-1); // interupt
}
a = Math.Max(a, mimaab(b2, (turn == PieceSide.White) ? PieceSide.Black : PieceSide.White, depth + 1, a, b));
if (a >= b)
{
return(b);
}
}
return(a);
}
}
}
