void UpdateUnusableNumbersForCageNeighbours(Cage cage)
{
if (cage.SpansSingleRow || cage.SpansSingleColumn)
{
if (cage.SpansSingleRow)
AddUnusableNumbersToCells(_kenKenGrid.Row(cage.Cells.First().Row).Where(cell => !cage.Cells.Contains(cell)),
cage.CommonValuesInCellPossibilities);
if (cage.SpansSingleColumn)
AddUnusableNumbersToCells(_kenKenGrid.Column(cage.Cells.First().Column).Where(cell => !cage.Cells.Contains(cell)),
cage.CommonValuesInCellPossibilities);
}
else
{
// => Cage spans multiple rows or columns
// => Deleting invalid numbers from multicage cell neighbours is handled as a different
// step because it is too complex as a side-effect of another step
}
}
void MarkCageAsPartiallSolved(Cage cage, IEnumerable<Possibility> possibilities)
{
if (possibilities.Count() < 1)
throw new ArgumentException("List of possibilities cannot be empty");
cage.AddPossibilities(possibilities);
UpdateUnusableNumbersForCageNeighbours(cage);
}
List<Permutation> FindValidPermutationsForPossibility(Cage cage, Possibility possibility)
{
List<Permutation> validPerms = new List<Permutation>();
List<Permutation> perms = Helper.GetUniquePermutation(possibility.ToList<int>());
foreach (var permutation in perms)
{
Cage copyCage = cage.DeepCopy();
bool isPermutationValid = true;
for (int i = 0; i < copyCage.Cells.Count; i++)
{
if (!copyCage.Cells[i].IsValueFeasible(permutation[i]))
{
isPermutationValid = false;
break;
}
else
{
MarkCellAsSolved(copyCage.Cells[i], permutation[i], copyCage.Cells);
}
}
if (isPermutationValid)
validPerms.Add(permutation);
}
return validPerms;
}
List<Permutation> FindValidPermutationsForCagePossibilities(Cage cage)
{
List<Permutation> validPerms = new List<Permutation>();
cage.Possibilities.ForEach(possibility =>
validPerms.AddRange(FindValidPermutationsForPossibility(cage, possibility)));
return validPerms;
}
List<Possibility> EliminateAlreadyUsedNumbersFromPossibilities(IEnumerable<Possibility> possibilities, Cage cage)
{
List<int> unusableNumbers = cage.CommonUnusableNumbersInCells;
List<Possibility> filteredPossibilities = possibilities.Where(possibility => !possibility.ContainsAny(unusableNumbers)).ToList();
List<Possibility> invalidPossibilities = possibilities.Where(possibility => possibility.ContainsAny(unusableNumbers)).ToList();
if (invalidPossibilities.Count > 0)
{
Step localStepAction = new Step();
localStepAction.InvalidPossibilities = invalidPossibilities;
_log.LogStep("DiscardPossibilities", localStepAction);
}
filteredPossibilities = filteredPossibilities.FindAll(possibility =>
{
Cell found = cage.Cells.FirstOrDefault(cell => possibility.ContainsOnly(cell.UnusableNumbers));
if (found != null)
{
Step localStepAction = new Step();
localStepAction.FoundCell = found;
localStepAction.InvalidPossibilities = new List<Possibility>() { possibility };
_log.LogStep("DiscardPossibilityForCell", localStepAction);
return false;
}
else
{
return true;
}
});
return filteredPossibilities;
}
void DeleteCagePossibilities(Cage cage, List<Possibility> invalidPossibilities)
{
cage.DeletePossibilities(invalidPossibilities);
UpdateUnusableNumbersForCageNeighbours(cage);
}