private int GetScore(GameVariant variant, AlphaBetaNode node, int alpha, int beta, int depth, int numberOfLastKingMovesWithoutBeat)
{
List <Move> moves = node.Board.GetAllPossibleMoves(node.Color);
List <AlphaBetaNode> childrens = new List <AlphaBetaNode>();
foreach (var move in moves)
{
var board = node.Board.GetBoardAfterMove(move);
var color = node.Color == PieceColor.Black ? PieceColor.White : PieceColor.Black;
var child = new AlphaBetaNode(board, move, color, depth + 1);
child.Parent = node;
childrens.Add(child);
}
node.Children = childrens;
if (node.Children == null || node.Children.Count == 0 || depth + 1 == Depth || numberOfLastKingMovesWithoutBeat == 50)
{
node.CurrentScore = node.GetHeuristicScore(variant, numberOfLastKingMovesWithoutBeat == 50);
return(node.CurrentScore);
}
if (node.Color == PieceColor.Black)
{
foreach (var n in node.Children)
{
var tempNumberOfLastKingMovesWithoutBeat = numberOfLastKingMovesWithoutBeat;
if (n.Move.OldPiece.IsKing && (n.Move.BeatedPieces == null || n.Move.BeatedPieces.Count == 0))
{
tempNumberOfLastKingMovesWithoutBeat++;
}
else
{
tempNumberOfLastKingMovesWithoutBeat = 0;
}
beta = new List <int>()
{
beta, GetScore(variant, n, alpha, beta, depth + 1, tempNumberOfLastKingMovesWithoutBeat)
}.Min();
if (alpha >= beta)
{
break;
}
}
node.CurrentScore = beta;
return(beta);
}
else
{
foreach (var n in node.Children)
{
var tempNumberOfLastKingMovesWithoutBeat = numberOfLastKingMovesWithoutBeat;
if (n.Move.OldPiece.IsKing && (n.Move.BeatedPieces == null || n.Move.BeatedPieces.Count == 0))
{
tempNumberOfLastKingMovesWithoutBeat++;
}
else
{
tempNumberOfLastKingMovesWithoutBeat = 0;
}
alpha = new List <int>()
{
alpha, GetScore(variant, n, alpha, beta, depth + 1, numberOfLastKingMovesWithoutBeat)
}.Max();
if (alpha >= beta)
{
break;
}
}
node.CurrentScore = alpha;
return(alpha);
}
}
public AlphaBetaTree(int depth, PieceColor color, CheckersBoard board)
{
Depth = depth;
Root = new AlphaBetaNode(board, null, color, 0);
}
