public Tuple <decimal, MoveType> AlphaBeta(Field.Field field, int depth, decimal alpha, decimal beta, string player, MoveType bestMovetype = MoveType.None)
{
var moves = field.Moves(player).Select(i => i.Key).ToList();
//Console.Error.WriteLine($"update Curent-depth-{depth}");
if (depth == 0 || moves.Count == 0)
{
alpha = Evaluate(field, field.GetByPlayerId(player));
return(Tuple.Create(alpha, MoveType.None));
}
moves = OrderByClosness(field, new Point(field.Height / 2, field.Width / 2), moves);
moves = OrderByClosness(field, field.EnemyPosition, moves);
if (bestMovetype != MoveType.None)
{
moves.Remove(bestMovetype);
moves.Insert(0, bestMovetype);
}
var bestMove = moves.Count > 0 ? moves[0] : MoveType.None;
foreach (var move in moves)
{
CheckTime();
field.MoveForth(move, player);
var val = -AlphaBeta(field, depth - 1, -beta, -alpha, field.EnId).Item1;
field.MoveBack(move, player);
if (val > alpha)
{
bestMove = move;
alpha = val;
if (alpha >= beta)
{
return(Tuple.Create(alpha, bestMove));
}
}
}
decimal suicideVal = -11 * (ComputePlayerValue(field, player) + 1);
if (suicideVal > alpha)
{
foreach (var direction in field.Directions)
{
if (player == field.MyId || player == field.EnId)
{
return(Tuple.Create(suicideVal, direction));
}
}
}
return(Tuple.Create(alpha, bestMove));
}
private int ComputePlayerValue(Field.Field field, string playerId)
{
var player = field.GetByPlayerId(playerId);
return(ComputePlayerValue(field, player));
}