private BoradStatus GetBoardStatus(Model model, ChessType chessType)
{
BoradStatus status = BoradStatus.Nothing;
ConnectStrategy connectStrategy = new ConnectStrategy(model);
if (connectStrategy.IsWin(chessType))
{
status = BoradStatus.Winlose;
}
else if (connectStrategy.IsTie())
{
status = BoradStatus.Tie;
}
return(status);
}
private MinMaxSearchInfo MinMaxSearch(Model pModel, ChessType chessType, bool isMaxLayer, int depth, int alpha, int beta)
{
MinMaxSearchCount++;
int bestScore = isMaxLayer ? -999 : 999;
MinMaxSearchInfo bestPosInfo = new MinMaxSearchInfo(-1, -1, bestScore);
Console.WriteLine($"depth: {depth} isMaxLayer: {isMaxLayer} MinMaxSearchCount: {MinMaxSearchCount.ToString()} alpha: {alpha.ToString()} beta: {beta}");
for (int y = 0; y < GameDef.board_cell_length; y++)
{
for (int x = 0; x < GameDef.board_cell_length; x++)
{
var board = pModel.GetBoardByCopy();
if (board[y][x] == ChessType.None)
{
Model cloneModel = pModel.Clone() as Model;
cloneModel.PutChessToBoard(x, y, chessType);
int score = 0;
BoradStatus boradStatus = GetBoardStatus(cloneModel, chessType);
if (boradStatus == BoradStatus.Nothing) //沒有勝負 繼續往下找
{
ChessType nextChessType = Utility.GetOppositeChessType(chessType);
MinMaxSearchInfo info = MinMaxSearch(cloneModel, nextChessType, !isMaxLayer, depth + 1, alpha, beta);
//--------- alpha-beta pruning ---------
if (isMaxLayer)
{
alpha = Math.Max(alpha, info.Score);
}
else
{
beta = Math.Min(beta, info.Score);
}
if (alpha >= beta)
{
return(info);
}
//--------------------------------------
score = info.Score;
}
else if (boradStatus == BoradStatus.Winlose)
{
SearchHasResultCount++;
score = MyChessType == chessType ? 1 : -1;//If chess is mychessType get 1 point else get -1 point
}
else if (boradStatus == BoradStatus.Tie)
{
SearchHasResultCount++;
score = 0;
}
if (isMaxLayer)
{
if (score > bestPosInfo.Score)
{
bestPosInfo.Score = score;
bestPosInfo.X = x;
bestPosInfo.Y = y;
}
}
else
{
if (score < bestPosInfo.Score)
{
bestPosInfo.Score = score;
bestPosInfo.X = x;
bestPosInfo.Y = y;
}
}
}
}
}
return(bestPosInfo);
}