public GameResults PlayGame(int games)
{
GameResults results = new GameResults(Player1.Name, Player2.Name);
Player playerToMoveFirst = Player1;
for (int index = 0; index < games; index++)
{
NaughtsAndCrossesGame game = new NaughtsAndCrossesGame();
Player currentPlayer = playerToMoveFirst;
GameMove nextMove = currentPlayer.MakeMove(game.GameState);
MoveResult moveResult = game.ApplyMove(nextMove);
while (moveResult == MoveResult.Success)
{
// Switch player
currentPlayer = currentPlayer == Player1 ? Player2 : Player1;
nextMove = currentPlayer.MakeMove(game.GameState);
moveResult = game.ApplyMove(nextMove);
}
if (moveResult == MoveResult.Win)
{
if (currentPlayer == Player1)
{
results.PlayerScore1++;
}
else
{
results.PlayerScore2++;
}
}
if (moveResult == MoveResult.Draw)
{
results.Draw++;
}
if (moveResult == MoveResult.Illegal)
{
throw new Exception($"An illegal move was made by {currentPlayer.Name}");
}
if (AlternateFirstMove)
{
playerToMoveFirst = playerToMoveFirst == Player1 ? Player2 : Player1;
}
}
return(results);
}
private UtilityGameMove MinValue(GameState gs, int alpha, int beta, GameMove lastMove = null, int depth = 0)
{
//var lastMoveValue = lastMove != null ? $"{lastMove.Location}, ${((lastMove.GameSymbol == GameSymbol.Cross) ? "Cross" : "Naught")}" : "null";
//Console.WriteLine($"Min value is called. Alpha: {alpha}, Beta: {beta}, lastMove: {lastMoveValue}");
var terminalState = PlayerUtilities.GetTerminalState(gs, PlayerSymbol);
if (terminalState != PlayerUtilities.TerminalState.Incomplete)
{
if (lastMove == null)
{
throw new Exception("Cannot find best move, in terminal state but with no last move");
}
var utilityValue = GetUtilityOfTerminalState(terminalState);
return(new UtilityGameMove(lastMove.Location, lastMove.GameSymbol, utilityValue));
}
var moves = gs.GetMoves();
var v = new UtilityGameMove(moves.First().Location, moves.First().GameSymbol, Int32.MaxValue);
foreach (var move in moves)
{
var copiedGameState = gs.Clone() as GameState;
copiedGameState.ApplyMove(move);
var u = MaxValue(copiedGameState, alpha, beta, move, ++depth);
v = GetMinUtilityMove(v, u);
beta = Math.Min(beta, v.Utility);
if (alpha >= beta)
{
if (lastMove != null)
{
return(new UtilityGameMove(lastMove.Location, lastMove.GameSymbol, v.Utility));
}
return(v);
}
}
if (lastMove != null)
{
return(new UtilityGameMove(lastMove.Location, lastMove.GameSymbol, v.Utility));
}
return(v);
}
public MoveResult ApplyMove(GameMove move)
{
if (move.Location >= GameState.GameBoard.Length || GameState.GameBoard[move.Location] != GameSymbol.Blank)
{
return(MoveResult.Illegal);
}
GameState.GameBoard[move.Location] = move.GameSymbol;
GameState.SwitchSymbol();
GameCompletion gameCompletion = GetGameCompletion();
if (gameCompletion == GameCompletion.Won)
{
return(MoveResult.Win);
}
if (gameCompletion == GameCompletion.Draw)
{
return(MoveResult.Draw);
}
return(MoveResult.Success);
}
public void ApplyMove(GameMove move)
{
GameBoard[move.Location] = move.GameSymbol;
SwitchSymbol();
}
public UtilityGameMove(int location, GameSymbol gameSymbol, int utility)
{
Utility = utility;
GameMove = new GameMove(location, gameSymbol);
}
