private IEnumerable <string> Crawl(BoogleCell currentCell, string path)
{
path = path + currentCell.Value;
if (!HasWordStartsWith(path))
{
yield break;
}
if (WordExists(path))
{
yield return(path);
}
if (currentCell.IsSameCell(_startCell))
{
yield break;
}
var cellsToMoveNext = CellsToMove(currentCell);
foreach (var cell in cellsToMoveNext)
{
var result = Crawl(cell, path);
foreach (var item in result)
{
yield return(item);
}
}
}
private IEnumerable <BoogleCell> CellsToMove(BoogleCell currentCell)
{
// left cell
if (!currentCell.IsLeftMost)
{
yield return(_cells[currentCell.Row, currentCell.Col - 1]);
}
// right cell
if (!currentCell.IsRightMost)
{
yield return(_cells[currentCell.Row, currentCell.Col + 1]);
}
// top cell
if (!currentCell.IsTopMost)
{
yield return(_cells[currentCell.Row - 1, currentCell.Col]);
}
// bottom cell
if (!currentCell.IsBottomMost)
{
yield return(_cells[currentCell.Row + 1, currentCell.Col]);
}
// topleft
if (!currentCell.IsTopMost && !currentCell.IsLeftMost)
{
yield return(_cells[currentCell.Row - 1, currentCell.Col - 1]);
}
// topright
if (!currentCell.IsTopMost && !currentCell.IsRightMost)
{
yield return(_cells[currentCell.Row - 1, currentCell.Col + 1]);
}
// bottomleft
if (!currentCell.IsBottomMost && !currentCell.IsLeftMost)
{
yield return(_cells[currentCell.Row + 1, currentCell.Col - 1]);
}
// bottomright
if (!currentCell.IsBottomMost && !currentCell.IsRightMost)
{
yield return(_cells[currentCell.Row + 1, currentCell.Col + 1]);
}
}
public BoogleBoardCrawler(BoogleCell[,] cells, BoogleCell startCell, string[] availableWords)
{
_cells = cells;
_startCell = startCell;
_availableWords = availableWords;
}