private int Search(TicTacToe.Game.TicTacToe game, int alpha, int beta, bool maximizing)
{
if (game.IsGameOver())
{
var winner = game.GetWinner();
if (winner == _playerId)
{
return(1);
}
if (winner == 0)
{
return(0);
}
return(-1);
}
if (maximizing)
{
var value = -100;
for (var i = 0; i < 9; i++)
{
if (game.IsPossible(i))
{
game.DoMove(i, _playerId);
var score = Search(game, alpha, beta, false);
game.RevertMove(i);
value = Math.Max(score, value);
alpha = Math.Max(alpha, value);
if (alpha >= beta)
{
return(value);
}
}
}
return(value);
}
else
{
var value = 100;
for (var i = 0; i < 9; i++)
{
if (game.IsPossible(i))
{
game.DoMove(i, OtherPlayer);
var score = Search(game, alpha, beta, true);
game.RevertMove(i);
value = Math.Min(score, value);
beta = Math.Min(beta, value);
if (alpha >= beta)
{
return(value);
}
}
}
return(value);
}
}
public int GetMove(TicTacToe.Game.TicTacToe game)
{
// if (rnd.NextDouble() < 0.5)
// {
// var move = -1;
// while (!game.IsPossible(move))
// {
// move = rnd.Next(0, 9);
// }
//
// return move;
// }
var bestMoves = new List <int>();
var bestScore = -10;
var a = -100;
var b = 100;
for (var i = 0; i < 9; i++)
{
if (game.IsPossible(i))
{
game.DoMove(i, _playerId);
var score = Search(game, a, b, false);
if (score > bestScore)
{
bestMoves.Clear();
bestMoves.Add(i);
bestScore = score;
}
else if (score == bestScore)
{
bestMoves.Add(i);
}
game.RevertMove(i);
}
}
var best = bestMoves.OrderBy(i => rnd.NextDouble()).First();
var state = game.GetBoard();
if (_data.Add(GetHash(state)))
{
FileSaver.AddData(string.Join(",", state.Select(s => s == _playerId?1:(0)).Concat(state.Select(s => s == _playerId?0:(s == OtherPlayer?1:0))).Concat(state.Select(s => s == _playerId?0:(s == OtherPlayer?0:1)))) + "," + best + "\n");
}
// Console.Error.WriteLine();
// Console.Error.WriteLine("TIME: " + s.ElapsedMilliseconds);
// Console.Error.WriteLine("BestScore: " + bestScore);
return(best);
}