这是一款跳棋游戏。请参阅旧版代码的修订历史记录。我是否正确实施了这个极小极大功能?
private static Move GetBestMove(Color color, Board board, int depth)
{
var bestMoves = new List<Move>();
var validMoves = board.GetValidMoves(color);
int highestScore = int.MinValue;
Board boardAfterMove;
int tmpScore;
var rand = new Random();
Debug.WriteLine("{0}'s Moves:", color);
foreach (var move in validMoves)
{
boardAfterMove = board.Clone().ApplyMove(move);
if(move.IsJump && !move.IsCrowned && boardAfterMove.GetJumps(color).Any())
tmpScore = NegaMax(color, boardAfterMove, depth);
else
tmpScore = -NegaMax(Board.Opposite(color), boardAfterMove, depth);
Debug.WriteLine("{0}: {1}", move, tmpScore);
if (tmpScore > highestScore)
{
bestMoves.Clear();
bestMoves.Add(move);
highestScore = tmpScore;
}
else if (tmpScore == highestScore)
{
bestMoves.Add(move);
}
}
return bestMoves[rand.Next(bestMoves.Count)];
}
private static int NegaMax(Color color, Board board, int depth)
{
var validMoves = board.GetValidMoves(color);
int highestScore = int.MinValue;
Board boardAfterMove;
if (depth <= 0 || !validMoves.Any())
return BoardScore(color, board);
foreach (var move in validMoves)
{
boardAfterMove = board.Clone().ApplyMove(move);
if(move.IsJump && !move.IsCrowned && boardAfterMove.GetJumps(color).Any())
highestScore = Math.Max(highestScore, NegaMax(color, boardAfterMove, depth));
else
highestScore = Math.Max(highestScore, -NegaMax(Board.Opposite(color), boardAfterMove, depth - 1));
}
return highestScore;
}
private static int BoardScore(Color color, Board board)
{
if (!board.GetValidMoves(color).Any()) return -1000;
return board.OfType<Checker>().Sum(c => (c.Color == color ? 1 : -1) * (c.Class == Class.Man ? 2 : 3));
}
我正在尝试深度为0,分数对于大概一半的游戏是正确的,然后突然它开始搞砸了。其中一名球员将开始宣称他的得分高于实际得分。为什么它只能用于半场比赛?!
现在这是一个maximax。对于你的对手,你需要瞄准最低分。你也可以不使用浮点数,你可以使用整数乘以2的值(浮点数较慢而且不精确) – 2010-09-04 06:27:14
@lmre:没想到使用浮点数的影响会产生很大的影响,但我猜如果这样运行几十亿次,可以加起来。 – mpen 2010-09-04 23:29:02