public double GetWins(GameState gameState, int repeats)
{
var result = PlayerUtilities.GetTerminalState(gameState, PlayerSymbol);
switch (result)
{
case PlayerUtilities.TerminalState.Win:
return(repeats);
case PlayerUtilities.TerminalState.Draw:
return(50);
case PlayerUtilities.TerminalState.Lose:
return(0);
}
double wins = 0;
int countWins = 0;
int countLoss = 0;
for (int gamesPlayed = 0; gamesPlayed < repeats; gamesPlayed++)
{
var gs = gameState.Clone() as GameState;
var player = SmarterOpponent;
gs.ApplyMove(player.MakeMove(gs));
result = PlayerUtilities.GetTerminalState(gs, PlayerSymbol);
while (result == PlayerUtilities.TerminalState.Incomplete)
{
var gameMove = player.MakeMove(gs);
gs.ApplyMove(gameMove);
result = PlayerUtilities.GetTerminalState(gs, PlayerSymbol);
player = player == SmarterOpponent ? RandomMe : SmarterOpponent;
}
if (result == PlayerUtilities.TerminalState.Win)
{
wins += 1;
countWins++;
}
else if (result == PlayerUtilities.TerminalState.Draw)
{
wins += 0.5;
countLoss++;
}
result = PlayerUtilities.TerminalState.Incomplete;
}
return(wins);
}
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);
}