private (Team?WinningTeam, Point Move) BestMove(Board board)
{
(bool Win, Point Move)ai = (false, new Point());
(bool Win, Point Move)player = (false, new Point());
var _possibleMoves = new Stack <Point>(board.PossibleMoves());
while (_possibleMoves.Count > 0)
{
var possibleMove = _possibleMoves.Pop();
if (board.IsWinningMove(possibleMove, Team.Ai))
{
ai = (true, possibleMove);
break;
}
if (board.IsWinningMove(possibleMove, Team.Player))
{
player = (true, possibleMove);
}
}
if (!ai.Win && !player.Win)
{
_possibleMoves = new Stack <Point>(board.PossibleMoves());
bool CheckMove(Point point, Team team)
{
board.AddStone(point, team);
var winningMove = _possibleMoves
.Concat(point.GetNeighbors().Where(p => !board.Stones.ContainsKey(p)))
.Any(p => board.IsWinningMove(p, team));
board.RemoveStone(point);
return(winningMove);
}
while (_possibleMoves.Count > 0)
{
var possibleMove = _possibleMoves.Pop();
if (CheckMove(possibleMove, Team.Ai))
{
ai = (true, possibleMove);
}
if (CheckMove(possibleMove, Team.Player))
{
player = (true, possibleMove);
}
}
}
if (!ai.Win && !player.Win)
{
return(null, new Point());
}
if (ai.Win || (ai.Win && player.Win))
{
return(Team.Ai, ai.Move);
}
return(Team.Player, player.Move);
}