public async Task <GameSolution> SolveGameAsync(GameState initialGameState, CancellationToken cancellationToken = default(CancellationToken))
{
return(await Task.Run(() =>
{
HashSet <GameState> gameStates = new HashSet <GameState>();
Queue <GameState> gameStatesToProcess = new Queue <GameState>();
IWordStateMachine wordStateMachine = this.wordStateMachineFactory.GetWordStateMachine();
gameStates.Add(initialGameState);
gameStatesToProcess.Enqueue(initialGameState);
while (gameStatesToProcess.Count != 0)
{
cancellationToken.ThrowIfCancellationRequested();
var currentGameState = gameStatesToProcess.Dequeue();
foreach (var newGameState in CreateGameStates(currentGameState, wordStateMachine))
{
if (gameStates.Add(newGameState))
{
gameStatesToProcess.Enqueue(newGameState);
}
}
}
return new GameSolution(gameStates.Where(gameState => IsGameStateFinal(gameState)));
}));
}
private IEnumerable <GameState> CreateGameStates(GameState gameState, IWordStateMachine wordStateMachine)
{
for (int index = 0; index < gameState.OccupationField.Length; index++)
{
GamePoint startGamePoint = new GamePoint(gameState.GameInformation, index);
wordStateMachine.Reset();
if (wordStateMachine.CanNavigateForward(startGamePoint.ToChar()) && !gameState.OccupationField[startGamePoint.Index])
{
TemporaryGameState temporaryGameState = new TemporaryGameState(gameState, startGamePoint, wordStateMachine);
foreach (var newGameState in CreateGameStates(temporaryGameState))
{
yield return(newGameState);
}
}
}
}
public TemporaryGameState(GameState initialGameState, GamePoint initialPoint, IWordStateMachine wordStateMachine)
{
this.wordStateMachine = wordStateMachine;
this.wordStateMachine.Reset();
this.wordStateMachine.NavigateForward(initialPoint.ToChar());
this.gamePoints = new Stack <GamePoint>();
this.gamePoints.Push(initialPoint);
this.GameInformation = initialGameState.GameInformation;
this.GameState = initialGameState;
this.InitialPoint = initialPoint;
this.currentPoint = initialPoint;
this.occupationField = new BitArray(initialGameState.OccupationField)
{
[currentPoint.Index] = true
};
}
