public static void CheckCellForSingleOption(this Grid grid, int x, int y)
{
if (grid.GetCell(x, y).Solved)
{
return;
}
if (grid.GetCell(x, y).Options.Count == 1)
{
grid.SolveCell(x, y, grid.GetCell(x, y).Options[0]);
grid.UpdateNeighbours(x, y);
}
}
public static void SearchColumnForSingleCandidates(this Grid grid)
{
for (int col = 0; col < grid.GridSize; col++)
{
for (int value = 1; value <= grid.GridSize; value++)
{
// that value already exists in the col
if (Array.Exists(grid.GetColumn(col), element => element == value))
{
continue;
}
int result = grid.CheckColForValueInOptions(col, value);
if (result != -1)
{
grid.SolveCell(result, col, value);
grid.UpdateNeighbours(result, col);
}
}
}
}
// 3. Searching for Single Candidates: Square
// "is there a value in any square that is only possible in one location?"
public static void SearchSquareForSingleCandidates(this Grid grid)
{
for (int s = 0; s < grid.GridSize; s++)
{
for (int value = 1; value <= grid.GridSize; value++)
{
// that value already exists in the col
if (Array.Exists(grid.GetSquare(s), element => element == value))
{
continue;
}
Tuple <int, int> result = grid.CheckSquareForValueInOptions(s, value);
if (result.Item1 != -1 && result.Item2 != -1)
{
grid.SolveCell(result.Item1, result.Item2, value);
grid.UpdateNeighbours(result.Item1, result.Item2);
}
}
}
}
// TODO: rename - doesnt make sense. Should be single responsibility
public static void SearchRowForSingleCandidates(this Grid grid)
{
// 3. Searching for Single Candidates: ROW
// "is there a value in any row that is only possible in one location?"
for (int row = 0; row < grid.GridSize; row++)
{
for (int value = 1; value <= grid.GridSize; value++)
{
// that value already exists in the row
if (Array.Exists(grid.GetRow(row), element => element == value))
{
continue;
}
int result = grid.CheckRowForValueInOptions(row, value);
if (result != -1)
{
grid.SolveCell(row, result, value);
grid.UpdateNeighbours(row, result);
}
}
}
}