private void InitializeBoardValues()
{
for (int i = 0; i < 81; i++)
{
cellData.Add(GridMath.AllPossibleValues());
}
}
public List <int> GetUnsolvedValues()
{
var result = GridMath.AllPossibleValues();
foreach (int index in Keys)
{
if (this[index].IsSolved())
{
result.Remove(this[index].First());
}
}
return(result);
}