private ISearch <EightPuzzleState> CreateSearch(Board initialBoard, Algorithm algorithm, HeuristicFunction heuristicFunction)
{
if (algorithm == Algorithm.AStar || algorithm == Algorithm.RecursiveBestFirstSearch)
{
IHeuristicFunction <EightPuzzleState> h;
var goalBoard = Board.CreateGoalBoard(initialBoard.RowCount, initialBoard.ColumnCount);
switch (heuristicFunction)
{
case HeuristicFunction.NoHeuristic:
h = new NoHeuristicFunction <EightPuzzleState>();
break;
case HeuristicFunction.ManhattanDistance:
h = new ManhattanHeuristicFunction(goalBoard);
break;
case HeuristicFunction.NilssonHeuristic:
h = new NilssonHeuristicFunction(goalBoard);
break;
case HeuristicFunction.RowColumnHeuristic:
h = new RowColumnHeuristicFunction(goalBoard);
break;
default:
throw new ArgumentOutOfRangeException(nameof(heuristicFunction), heuristicFunction, null);
}
switch (algorithm)
{
case Algorithm.AStar:
return(new AStarSearch <EightPuzzleState>(h));
case Algorithm.RecursiveBestFirstSearch:
return(new RecursiveBestFirstSearch <EightPuzzleState>(h));
default:
throw new ArgumentOutOfRangeException(nameof(algorithm), algorithm, null);
}
}
switch (algorithm)
{
case Algorithm.IterativeDeepeningSearch:
return(new IterativeDeepeningSearch <EightPuzzleState>());
default:
throw new ArgumentOutOfRangeException(nameof(algorithm), algorithm, null);
}
}
public void ShouldFindOptimal(Board board, int optimalSolution)
{
Assert.True(board.IsSolvable());
var problem = new EightPuzzleProblem(board);
var h = new ManhattanHeuristicFunction(Board.CreateGoalBoard(board.RowCount, board.ColumnCount));
var algorithms = new ISearch <EightPuzzleState>[]
{
new AStarSearch <EightPuzzleState>(h),
new RecursiveBestFirstSearch <EightPuzzleState>(h),
};
foreach (var algorithm in algorithms)
{
var result = algorithm.Search(problem).ToList();
Assert.NotEmpty(result);
Assert.Equal(optimalSolution, result.Count - 1);
}
}
public void ManhattanHeuristicFunctionTest( Board board, int expectedResult )
{
var h = new ManhattanHeuristicFunction( Board.CreateGoalBoard( board.RowCount, board.ColumnCount ) );
Assert.Equal( expectedResult, h.Calculate( new EightPuzzleState( board ) ) );
}
