private double Mini(int depth, List <Piece> player1, List <Piece> player2, double alpha, double beta)
{
if (depth == 0)
{
return(Evaluator.Evaluate(player1, player2));
}
for (int i = 0; i < player1.Count; i++)
{
var piece = player1[i];
foreach (var point in AvailableMovesFinder.GetPossibleMoves(player2, player1, piece))
{
var oldPieceX = piece.X;
var oldPieceY = piece.Y;
piece.X = point.X;
piece.Y = point.Y;
var takenPieceIndex = player2.FindIndex(0, player2.Count, p => p.X == point.X && p.Y == point.Y);
Piece takenPiece = default(Piece);
if (takenPieceIndex >= 0)
{
takenPiece = player2[takenPieceIndex];
player2.RemoveAt(takenPieceIndex);
}
double value = Maxi(depth - 1, player1, player2, alpha, beta);
piece.X = oldPieceX;
piece.Y = oldPieceY;
if (takenPieceIndex >= 0)
{
player2.Insert(takenPieceIndex, takenPiece);
}
if (value < beta)
{
beta = value;
}
if (beta <= alpha)
{
break;
}
}
}
return(beta);
}
private double Maxi(int depth, List <Piece> player1, List <Piece> player2, double alpha, double beta)
{
if (depth == 0)
{
return(Evaluator.Evaluate(player1, player2));
}
for (int i = 0; i < player2.Count; i++)
{
var piece = player2[i];
foreach (var point in AvailableMovesFinder.GetPossibleMoves(player1, player2, piece))
{
//store the old location of the current piece
var oldPieceX = piece.X;
var oldPieceY = piece.Y;
//move the current piece
piece.X = point.X;
piece.Y = point.Y;
//remove any pieces from the opponent that the current piece landed on
var takenPieceIndex = player1.FindIndex(0, player1.Count, p => p.X == point.X && p.Y == point.Y);
Piece takenPiece = default(Piece);
if (takenPieceIndex >= 0)
{
takenPiece = player1[takenPieceIndex];
player1.RemoveAt(takenPieceIndex);
}
double value = Mini(depth - 1, player1, player2, alpha, beta);
//reset pieces to original location
piece.X = oldPieceX;
piece.Y = oldPieceY;
if (takenPieceIndex >= 0)
{
player1.Insert(takenPieceIndex, takenPiece);
}
//set alpha to be the max value for this node's children
if (value > alpha)
{
alpha = value;
if (MaxDepth == depth)
{
_moveToMake.FromX = piece.X;
_moveToMake.FromY = piece.Y;
_moveToMake.DestX = point.X;
_moveToMake.DestY = point.Y;
}
}
if (beta <= alpha)
{
break;
}
}
}
return(alpha);
}