public List<int[]> sortAlphaBeta(ChessBoard cb, bool isWhite, List<int[]> possibleMoves)
{
List<int[]> retVal = new List<int[]>();
List<int> valueSet = new List<int>();
for (int i = 0; i < possibleMoves.Count; i++)
{
numIterations++;
if (numIterations == 33000)
{
gui.addText("Found bug");
}
int[] currMove = possibleMoves[i];
cb.movePiece(isWhite, currMove[0], currMove[1], true);
valueSet.Add(Rating.rating(isWhite, cb, possibleMoves.Count, searchDepth));
cb.undoMove(isWhite);
if (!matchesMoveList(cb))
{
gui.addText("More errors!");
}
}
while (valueSet.Count > 0)
{
int index = indexOfMax(valueSet);
retVal.Add(possibleMoves[index]);
possibleMoves.RemoveAt(index);
valueSet.RemoveAt(index);
}
return retVal;
}
private static List<position_t> Rook(ChessBoard board, position_t pos, bool verify_check = true)
{
List<position_t> moves = new List<position_t>();
piece_t p = board.Grid[pos.number][pos.letter];
if (p.piece == Piece.NONE) return moves;
// slide along vert/hor for possible moves
moves.AddRange(Slide(board, p.player, pos, new position_t(1, 0)));
moves.AddRange(Slide(board, p.player, pos, new position_t(-1, 0)));
moves.AddRange(Slide(board, p.player, pos, new position_t(0, 1)));
moves.AddRange(Slide(board, p.player, pos, new position_t(0, -1)));
if (verify_check)// make sure each move doesn't put us in check
{
for (int i = moves.Count - 1; i >= 0; i--)
{
ChessBoard b2 = LegalMoveSet.move(board, new move_t(pos, moves[i]));
if (isCheck(b2, p.player))
{
moves.RemoveAt(i);
}
}
}
return moves;
}
private static List<position_t> Pawn(ChessBoard board, position_t pos, bool verify_check = true)
{
List<position_t> moves = new List<position_t>();
piece_t p = board.Grid[pos.number][pos.letter];
if (p.piece == Piece.NONE) return moves;
// gather relative moves
List<position_t> relative = new List<position_t>();
relative.Add(new position_t(-1, 1 * ((p.player == Player.BLACK) ? -1 : 1)));
relative.Add(new position_t(0, 1 * ((p.player == Player.BLACK) ? -1 : 1)));
relative.Add(new position_t(0, 2 * ((p.player == Player.BLACK) ? -1 : 1)));
relative.Add(new position_t(1, 1 * ((p.player == Player.BLACK) ? -1 : 1)));
// iterate moves
foreach (position_t move in relative)
{
position_t moved = new position_t(move.letter + pos.letter, move.number + pos.number);
// bounds check
if (moved.letter < 0 || moved.letter > 7 || moved.number < 0 || moved.number > 7)
continue;
// double forward move
if (moved.letter == pos.letter && board.Grid[moved.number][moved.letter].piece == Piece.NONE && Math.Abs(moved.number - pos.number) == 2)
{
// check the first step
int step = -((moved.number - pos.number) / (Math.Abs(moved.number - pos.number)));
bool hasnt_moved = pos.number == ((p.player == Player.BLACK) ? 6 : 1);
if (board.Grid[moved.number + step][moved.letter].piece == Piece.NONE && hasnt_moved)
{
moves.Add(moved);
}
}
// if it's not blocked we can move forward
else if (moved.letter == pos.letter && board.Grid[moved.number][moved.letter].piece == Piece.NONE)
{
moves.Add(moved);
}
// angled attack
else if (moved.letter != pos.letter && board.Grid[moved.number][moved.letter].piece != Piece.NONE && board.Grid[moved.number][moved.letter].player != p.player)
{
moves.Add(moved);
}
// en passant
else if(isEnPassant(board, new move_t(pos,moved)))
{
moves.Add(moved);
}
}
if (verify_check)// make sure each move doesn't put us in check
{
for (int i = moves.Count - 1; i >= 0; i--)
{
ChessBoard b2 = LegalMoveSet.move(board, new move_t(pos, moves[i]));
if (isCheck(b2, p.player))
{
moves.RemoveAt(i);
}
}
}
return moves;
}
private static List<position_t> Knight(ChessBoard board, position_t pos, bool verify_check = true)
{
List<position_t> moves = new List<position_t>();
piece_t p = board.Grid[pos.number][pos.letter];
if (p.piece == Piece.NONE) return moves;
// collect all relative moves possible
List<position_t> relative = new List<position_t>();
relative.Add(new position_t(2, 1));
relative.Add(new position_t(2, -1));
relative.Add(new position_t(-2, 1));
relative.Add(new position_t(-2, -1));
relative.Add(new position_t(1, 2));
relative.Add(new position_t(-1, 2));
relative.Add(new position_t(1, -2));
relative.Add(new position_t(-1, -2));
// iterate moves
foreach (position_t move in relative)
{
position_t moved = new position_t(move.letter + pos.letter, move.number + pos.number);
// bounds check
if (moved.letter < 0 || moved.letter > 7 || moved.number < 0 || moved.number > 7)
continue;
// if empty space or attacking
if (board.Grid[moved.number][moved.letter].piece == Piece.NONE ||
board.Grid[moved.number][moved.letter].player != p.player)
moves.Add(moved);
}
if (verify_check)// make sure each move doesn't put us in check
{
for (int i = moves.Count - 1; i >= 0; i--)
{
ChessBoard b2 = LegalMoveSet.move(board, new move_t(pos, moves[i]));
if (isCheck(b2, p.player))
{
moves.RemoveAt(i);
}
}
}
return moves;
}
