public void OutcomeTest()
{
TicTacToePosition board = TicTacToePosition.Build(
"a1", "a2", "a3", "b2", "b1", "c1", "b3", "c3", "c2");
Assert.IsTrue(board.Outcome == GameOutcome.Draw);
}
public void MoveExpectancyIllegal()
{
TicTacToePosition board = TicTacToePosition.Set(
crosses: new TicTacToeLocation[] { "a3", "c1" },
naughts: new TicTacToeLocation[] { "b2", "c3" });
Assert.IsTrue(board.MoveDegree("a3") == TicTacToe.MoveExpectancy.Illegal, "Must be illegal move");
}
public void MoveExpectancy()
{
TicTacToePosition board = TicTacToePosition.Set(
crosses: new TicTacToeLocation[] { "a3", "c1" },
naughts: new TicTacToeLocation[] { "b2", "c3" });
Assert.IsTrue(board.MoveDegree("a1") == TicTacToe.MoveExpectancy.Win, "Must be winning move");
Assert.IsTrue(board.MoveDegree("a2") == TicTacToe.MoveExpectancy.Lose, "Must be losing move");
}
/// <summary>
/// Expected Winner
/// </summary>
public static GameOutcome ExpectedWinner(this TicTacToePosition position)
{
if (position is null)
{
return(GameOutcome.Illegal);
}
return(s_Outcomes.TryGetValue(position, out var result)
? result
: GameOutcome.Illegal);
}
/// <summary>
/// Move quality
/// -1 worst move
/// 0 illegal move
/// +1 best move
/// </summary>
public static int MoveQuality(this TicTacToePosition position, string cell)
{
var match = Regex.Match(cell, @"^\s*(?<rank>[A-Ca-c])\s*(?<file>[1-3])\s*$");
if (!match.Success)
{
return(0);
}
return(MoveQuality(position,
'3' - match.Groups["file"].Value[0],
match.Groups["rank"].Value.ToUpper()[0] - 'A'));
}
public void BestMovesTest()
{
TicTacToePosition board = TicTacToePosition.Empty.MakeMoves(
"a1", "a2", "a3", "b3"
);
var bestMoves = board.BestMoves(); // .OrderBy(move => move);
TicTacToeLocation[] expected = new TicTacToeLocation[] {
"b2", "c1"
};
Assert.IsTrue(bestMoves.SequenceEqual(expected), string.Join(" ", bestMoves.AsEnumerable()));
}
/// <summary>
/// Move Expectation
/// </summary>
public static GameOutcome MoveExpectation(this TicTacToePosition position, int index)
{
if (position is null)
{
return(GameOutcome.Illegal);
}
if (position[index] != Mark.None)
{
return(GameOutcome.Illegal);
}
else if (index < 1 || index > 9)
{
return(GameOutcome.Illegal);
}
return(ExpectedWinner(position.MakeMove(index)));
}
/// <summary>
/// Move Expectation
/// </summary>
public static GameOutcome MoveExpectation(this TicTacToePosition position, string cell)
{
if (cell is null)
{
return(GameOutcome.Illegal);
}
var match = Regex.Match(cell, @"^\s*(?<rank>[A-Ca-c])\s*(?<file>[1-3])\s*$");
if (!match.Success)
{
return(GameOutcome.Illegal);
}
return(MoveExpectation(position,
'3' - match.Groups["file"].Value[0],
match.Groups["rank"].Value.ToUpper()[0] - 'A'));
}
/// <summary>
/// Move Expectation
/// </summary>
public static GameOutcome MoveExpectation(this TicTacToePosition position, int line, int column)
{
if (position is null)
{
return(GameOutcome.Illegal);
}
if (position[line, column] != Mark.None)
{
return(GameOutcome.Illegal);
}
else if (line < 0 || line > 2 || column < 0 || column > 2)
{
return(GameOutcome.Illegal);
}
return(ExpectedWinner(position.MakeMove(line, column)));
}
/// <summary>
/// Move quality
/// -1 worst move
/// 0 illegal move
/// +1 best move
/// </summary>
public static int MoveQuality(this TicTacToePosition position, int index)
{
var actual = MoveExpectation(position, index);
if (actual == GameOutcome.Illegal)
{
return(0);
}
var best = ExpectedWinner(position);
if (best == actual)
{
return(1);
}
else
{
return(-1);
}
}
private static void CoreUpdate()
{
s_Outcomes = TicTacToePosition
.AllLegalPositions()
.ToDictionary(p => p, p => GameOutcome.None);
var data = s_Outcomes
.Keys
.OrderByDescending(key => key.MarkCount);
foreach (var position in data)
{
if (position.Outcome != GameOutcome.None)
{
s_Outcomes[position] = position.Outcome;
continue;
}
var onMove = position.WhoIsOnMove;
GameOutcome bestOutcome = onMove == Mark.Cross
? GameOutcome.SecondWin
: GameOutcome.FirstWin;
foreach (var next in position.AvailablePositions())
{
GameOutcome outcome = s_Outcomes[next];
bestOutcome = onMove == Mark.Cross
? bestOutcome.BestForFirst(outcome)
: bestOutcome.BestForSecond(outcome);
}
s_Outcomes[position] = bestOutcome;
}
}
public void Expectations()
{
TicTacToePosition board = TicTacToePosition.Build("a1", "a2", "a3", "b3");
Assert.IsTrue(board.ExpectedWinner() == GameOutcome.FirstWin, board.DrawPosition());
}
/// <summary>
/// Best Moves (all winning moves or, if the position drawish, all draw moves)
/// </summary>
public static IEnumerable <(int line, int column, int index, string cell)> BestMoves(this TicTacToePosition position)
{
if (position is null)
{
yield break;
}
foreach (var move in position.AvailableMoves())
{
if (MoveQuality(position, move.index) == 1)
{
yield return(move);
}
}
}