private bool TryFind(List <Tile> tiles, out int index)
{
BlankTileIndexFinder blankTileIndexFinder = new BlankTileIndexFinder();
bool found = blankTileIndexFinder.TryFind(tiles, out index);
return(found);
}
public virtual Board Build(int size)
{
if (size < 1)
{
throw new ArgumentException($"Board size must be bigger then 0, got {size}");
}
List <Tile> tiles = GetLegalBoardTiles(size);
int blankIndex = blankTileIndexFinder.TryFind(tiles, out int index) ? index: throw new Exception("Illegal number of tiles!");
int numberOfMisplacedTiles = misplacedTilesCounter.Count(tiles);
Board board = new Board
{
Tiles = tiles,
BlankIndex = blankIndex,
Size = size,
TotalMisplacedTiles = numberOfMisplacedTiles,
IsSolved = numberOfMisplacedTiles == 0
};
return(board);
}
public virtual bool Validate(List <Tile> tiles, int size)
{
bool isValid = blankTileIndexFinder.TryFind(tiles, out int blankIndex);
if (isValid)
{
int numberOfInversions = inversionsCounter.Count(tiles);
bool isNumberOfInversionsEven = numberOfInversions % 2 == 0;
bool isSizeEven = size % 2 == 0;
if (isSizeEven)
{
int blankIndexRow = blankIndex / size;
bool isBlankOnAnEvenRow = blankIndexRow % 2 == 0;
isValid = isBlankOnAnEvenRow ^ isNumberOfInversionsEven;
}
else
{
isValid = isNumberOfInversionsEven;
}
}
return(isValid);
}