private void ComputerMove()
{
AlphaBetaBoard alphaBetaBoard = new AlphaBetaBoard();
alphaBetaBoard.board = _board;
alphaBetaBoard.eval = _board.EvaluationFunction();
Board nextBoard = Minimax.AlphaBetaPruning(alphaBetaBoard, Double.NegativeInfinity, Double.PositiveInfinity, 5, PlayerType.Computer).board;
AnimateTransition(_board, nextBoard);
_board = nextBoard;
pictureBoxBoard.Refresh();
_currentPlayer = PlayerType.Human;
CheckFinish();
}
public static AlphaBetaBoard AlphaBetaPruning(AlphaBetaBoard currentNode, double alfa, double beta, int depth, PlayerType player)
{
bool finished;
PlayerType winner;
currentNode.board.CheckFinish(out finished, out winner);
if (finished || depth == 0)
{
return(currentNode);
}
AlphaBetaBoard returnBoard = new AlphaBetaBoard();
Piece p;
if (player == PlayerType.Computer)
{
//daca sunt miscari obligatorii pentru a ataca o piesa
List <Board> childBoards = new List <Board>(0);
returnBoard.eval = Double.MinValue;
List <Move> mandatoryMoves = currentNode.board.BeatingMoves(PlayerType.Computer);
//daca nu sunt piese ce trebuie atacate
if (mandatoryMoves.Count == 0)
{
for (int i = 0; i < currentNode.board.Pieces.Count; i++)
{
p = currentNode.board.Pieces[i];
if (p.Player == PlayerType.Computer && p.X != -1 && p.Y != -1)
{
mandatoryMoves = p.ValidMoves(currentNode.board);
foreach (Move m in mandatoryMoves)
{
childBoards.Add(currentNode.board.MakeMove(m));
}
}
}
}
else
{
for (int i = 0; i < mandatoryMoves.Count; i++)
{
childBoards.Add(currentNode.board.MakeMove(mandatoryMoves[i]));
}
}
for (int i = 0; i < childBoards.Count; i++)
{
AlphaBetaBoard childAlpha = new AlphaBetaBoard();
childAlpha.board = childBoards[i];
childAlpha.eval = childBoards[i].EvaluationFunction();
AlphaBetaBoard newBoad = AlphaBetaPruning(childAlpha, alfa, beta, depth - 1, PlayerType.Human);
if (newBoad.eval > returnBoard.eval) // consideram valoarea maxima a functiei de evaluare
{
returnBoard = newBoad;
returnBoard.board = childBoards[i]; // aici se pastreaza copilul care duce catre cea mai buna frunza
}
if (returnBoard.eval > alfa) // alfa = max(alfa, v)
{
alfa = returnBoard.eval;
}
if (beta <= alfa)
{
break; // retezarea beta
}
}
return(returnBoard);
}
else
{
returnBoard.eval = Double.MaxValue;
//daca sunt miscari obligatorii pentru a ataca o piesa
List <Move> mandatoryMoves = currentNode.board.BeatingMoves(player);
List <Board> childBoards = new List <Board>(0);
//daca nu sunt piese ce trebuie atacate
if (mandatoryMoves.Count == 0)
{
for (int i = 0; i < currentNode.board.Pieces.Count; i++)
{
p = currentNode.board.Pieces[i];
if (p.Player == PlayerType.Human && p.X != -1 && p.Y != -1)
{
mandatoryMoves = p.ValidMoves(currentNode.board);
foreach (Move m in mandatoryMoves)
{
childBoards.Add(currentNode.board.MakeMove(m));
}
}
}
}
else
{
for (int i = 0; i < mandatoryMoves.Count; i++)
{
childBoards.Add(currentNode.board.MakeMove(mandatoryMoves[i]));
}
}
for (int i = 0; i < childBoards.Count; i++)
{
AlphaBetaBoard childAlpha = new AlphaBetaBoard();
childAlpha.board = childBoards[i];
childAlpha.eval = childBoards[i].EvaluationFunction();
AlphaBetaBoard newBoad = AlphaBetaPruning(childAlpha, alfa, beta, depth - 1, PlayerType.Human);
if (newBoad.eval < returnBoard.eval) // consideram valoarea maxima a functiei de evaluare
{
returnBoard = newBoad;
returnBoard.board = childBoards[i]; // aici se pastreaza copilul care duce catre cea mai buna frunza
}
if (returnBoard.eval < alfa) // alfa = max(alfa, v)
{
alfa = returnBoard.eval;
}
if (beta <= alfa)
{
break; // retezarea beta
}
}
return(returnBoard);
}
}
