Esempio n. 1
0
        public int Minimax(int depth, int turn, int alpha, int beta, int player) // turn - 1 for max, 2 for min
        {
            if (beta <= alpha)
            {
                return(turn == 1 ? int.MaxValue : int.MinValue);
            }
            var gameResult = GameResult(_b);

            switch (gameResult)
            {
            case 1:
                return(int.MaxValue / 2);

            case 2:
                return(int.MinValue / 2);

            case 0:
                return(0);
            }

            if (depth == _maxDepth)
            {
                return(EvaluateBoard(_b, player));
            }

            int maxScore = int.MinValue, minScore = int.MaxValue;

            for (var j = 0; j <= 6; ++j)
            {
                var currentScore = 0;

                if (!_b.IsLegalMove(j))
                {
                    continue;
                }

                if (turn == 1)
                {
                    _b.PlaceMove(j, 1);
                    currentScore = Minimax(depth + 1, 2, alpha, beta, player);

                    if (depth == 0)
                    {
                        if (currentScore > maxScore)
                        {
                            _nextMoveLocation = j;
                        }
                        if (currentScore == int.MaxValue / 2)
                        {
                            _b.UndoMove(j);
                            break;
                        }
                    }

                    maxScore = Math.Max(currentScore, maxScore);

                    alpha = Math.Max(currentScore, alpha);
                }
                else if (turn == 2)
                {
                    _b.PlaceMove(j, 2);
                    currentScore = Minimax(depth + 1, 1, alpha, beta, player);
                    minScore     = Math.Min(currentScore, minScore);

                    beta = Math.Min(currentScore, beta);
                }
                _b.UndoMove(j);
                if (currentScore == int.MaxValue || currentScore == int.MinValue)
                {
                    break;
                }
            }
            return(turn == 1 ? maxScore : minScore);
        }