Пример #1
0
        private MNResult EvaluateNode(Move move, bool player, bool debug)
        {
            int score;

            if (!debug)
            {
                score = evaluation.EvaluateBoard(this.examinedBoard);
                //Negate the value
                if (player == BLACK)
                {
                    score = -score;
                }
            }
            else
            {
                Console.Write("What is the score:");
                score = Convert.ToInt32(Console.ReadLine());
            }
            MNResult result = new MNResult(move, score);

            return(result);
        }
Пример #2
0
        private MNResult AlphaBeta(int depth, int beta, int alpha, Move move, bool player, bool debug = false)
        {
            //BLACK is max player
            bool isMaxPlayer = (player == BLACK) ? true : false;

            if (depth == 0)
            {
                return(EvaluateNode(move, player, debug));
            }
            List <Move> possibleMoves = null;

            if (!debug)
            {
                possibleMoves = examinedBoard.PossibleMoves(player);
            }
            else
            {
                Console.Write("How many moves are there:");
                int count = Convert.ToInt32(Console.ReadLine());
                possibleMoves = new List <Move>();


                for (int i = 0; i < count; i++)
                {
                    Move debugMove = new Move(1, 4, 3, 4, this.examinedBoard);
                    possibleMoves.Add(debugMove);
                }
            }


            if (possibleMoves.Count == 0)
            {
                return(EvaluateNode(move, player, debug));
            }
            //sort later
            foreach (Move eleMove in possibleMoves)
            {
                examinedBoard.MakeMove(eleMove);
                bool     nextPlayer = !player;
                MNResult result     = AlphaBeta(depth - 1, beta, alpha, eleMove, nextPlayer, debug);
                int      value      = result.Value;

                examinedBoard.UndoMove(eleMove);
                //BLACK is Max Player
                if (isMaxPlayer)
                {
                    if (value > alpha) //Max Nodes can only make restriction on the lower bound
                    {
                        alpha = value;
                        if (depth == MaxDepth)
                        {
                            move = result.Move;
                        }
                    }
                }
                else
                {
                    if (value < beta)
                    {
                        beta = value;
                        if (depth == MaxDepth)
                        {
                            move = result.Move;
                        }
                    }
                }
                if (alpha >= beta) //pruning
                {
                    if (isMaxPlayer)
                    {
                        return(new MNResult(move, alpha));
                    }
                    else
                    {
                        return(new MNResult(move, beta));
                    }
                }
            }

            // Travel all child node, no prunning
            if (isMaxPlayer)
            {
                //value of node is alpha value
                return(new MNResult(move, alpha));
            }
            else
            {
                //value of min node is beta value
                return(new MNResult(move, beta));
            }
        }