public Move GetMove(Byte[] board, Player player)
{
_board = board;
var savedPlayerColor = player.Color;
var move = (mustJumpFromSquare == 0) ? DoAI(player) : GetJumpFromChoices(player);
player.SetColor(savedPlayerColor);
return move;
}
private Int32 alphabeta(List<Move> moves, Int32 plies, Player player, Int32 alpha, Int32 beta)
{
if (moves.Count == 0)
{
if (player.Color == Player.PlayerColor.WHITE)
return Int32.MaxValue;
else
return Int32.MinValue;
}
if (plies == 0)
return EvaluateBoard(null);
Int32 best = Int32.MinValue;
Int32 current;
Int32 localAlpha = alpha;
foreach (var m in moves)
{
_history.Push((Byte[])_board.Clone());
MakeMove(m);
player.SetColor((player.Color == Player.PlayerColor.RED) ? Player.PlayerColor.WHITE : Player.PlayerColor.RED);
var nextMoves = GetPlayerLegalMoves(player);
current = -(alphabeta(nextMoves, plies - 1, player, -beta, -localAlpha));
player.SetColor((player.Color == Player.PlayerColor.RED) ? Player.PlayerColor.WHITE : Player.PlayerColor.RED);
_board = _history.Pop();
if (current > best)
best = current;
if (best >= beta)
break;
if (best > localAlpha)
localAlpha = best;
}
return best;
}
private Move DoAI(Player player, List<Move> movePool)
{
List<Move> potentialMoves = (movePool == null) ? GetPlayerLegalMoves(player) : movePool;
// no moves, game's over
if (potentialMoves.Count == 0)
return null;
// one move, must take it
if (potentialMoves.Count == 1)
{
DoMustJumpLogic(potentialMoves[0]);
return potentialMoves[0];
}
Move bestMove = potentialMoves[0];
//_evaluated = 0; // Statistics only
for (var i = 0; i < potentialMoves.Count(); i++)
{
_history.Push((Byte[])_board.Clone());
MakeMove(potentialMoves[i]);
player.SetColor((player.Color == Player.PlayerColor.RED) ? Player.PlayerColor.WHITE : Player.PlayerColor.RED);
var moves = GetPlayerLegalMoves(player);
//potentialMoves[i].SetScore(negamax(moves, 6, player));
//potentialMoves[i].SetScore(minimax(moves, 6, player));
potentialMoves[i].SetScore(alphabeta(moves, 6, player, Int32.MinValue, Int32.MaxValue));
player.SetColor((player.Color == Player.PlayerColor.RED) ? Player.PlayerColor.WHITE : Player.PlayerColor.RED);
if (potentialMoves[i].Score > bestMove.Score)
bestMove = potentialMoves[i];
_board = (Byte[])_history.Pop();
}
if (bestMove != null)
DoMustJumpLogic(bestMove);
score = bestMove.Score;
return bestMove;
}
private static void ChangeSides(Player player)
{
player.SetColor((player.Color == Player.PlayerColor.RED) ? Player.PlayerColor.WHITE : Player.PlayerColor.RED);
}
