public Hint SingleHint(HintSelections hs)
{
Hint toDiscard = null;
Requirement c = EasiestRequirement;
if (c != null)
{
if (c.s == 0)
{
return(new ImpossibleHint(c));
}
if (c.s == 1 && hs.ForcedMoves)
{
return(new ForcedMoveHint(c, c.d.Candidate));
}
}
Candidate[] uc = UnselectedCandidates;
if (hs.ImmediateDiscardables)
{
foreach (Candidate k in uc)
{
int o;
CheckSelectCandidate(k, out c, out o);
if (o == 0)
{
toDiscard = new DiscardableHint(k, c, false);
}
}
}
foreach (Candidate k in uc)
{
int o, steps;
CheckSelectCandidateFollowingSingleOptions(k, out c, out o, out steps);
if (hs.EventualDiscardables && o == 0)
{
toDiscard = new DiscardableHint(k, c, steps > 1);
}
if (hs.EventualSolutions && o == 1)
{
return(new EventualSolutionHint(k));
}
if (hs.Selectables)
{
CheckDiscardCandidateFollowingSingleOptions(k, out c, out o);
if (o == 0)
{
return(new SelectableHint(k, c));
}
}
}
// It's preferable to use a hint that selects a candidate, because this satisfies requirements and moves towards a solution
return(toDiscard);
}
public override bool Equals(object obj)
{
if (!(obj is HintSelections))
{
return(false);
}
HintSelections hs = obj as HintSelections;
return(ForcedMoves == hs.ForcedMoves &&
ImmediateDiscardables == hs.ImmediateDiscardables &&
EventualDiscardables == hs.EventualDiscardables &&
Selectables == hs.Selectables &&
EventualSolutions == hs.EventualSolutions);
}
public IEnumerable <Hint> HintsToPaint(HintFlags ho, HintSelections hs, Func <Hint, bool> filter)
{
if (filter == null)
{
filter = (Hint h) => true;
}
bool first = true;
foreach (var hint in AllHints(hs).Where(filter))
{
if (hint.IsIn(hs))
{
yield return(hint);
if (first && (hint is ImpossibleHint || hint is ForcedMoveHint))
{
yield break; // Just paint one for that house
}
}
first = false;
}
}
public IEnumerable <Hint> AllHints(HintSelections hs)
{
foreach (var hint in ImpossibleHints)
{
yield return(hint);
}
if (hs == null || hs.ForcedMoves)
{
foreach (var hint in ForcedHints)
{
yield return(hint);
}
}
foreach (Candidate k in UnselectedCandidates)
{
Requirement c;
int o, steps;
CheckSelectCandidateFollowingSingleOptions(k, out c, out o, out steps);
bool eventual = steps > 1;
if (o == 0 && (hs == null || (eventual ? hs.EventualDiscardables : hs.ImmediateDiscardables)))
{
yield return(new DiscardableHint(k, c, eventual));
}
if (o == 1 && (hs == null || hs.EventualSolutions))
{
yield return(new EventualSolutionHint(k));
}
if (hs == null || hs.Selectables)
{
CheckDiscardCandidateFollowingSingleOptions(k, out c, out o);
if (o == 0)
{
yield return(new SelectableHint(k, c));
}
}
}
}
public abstract bool IsIn(HintSelections hs);
public override bool IsIn(HintSelections hs)
{
return(hs.EventualSolutions);
}
public override bool IsIn(HintSelections hs)
{
return(hs.Selectables);
}
public override bool IsIn(HintSelections hs)
{
return(eventual ? hs.EventualDiscardables : hs.ImmediateDiscardables);
}
public override bool IsIn(HintSelections hs)
{
return(hs.ForcedMoves);
}
public override bool IsIn(HintSelections hs)
{
return(true);
}
public bool IsLevel(Level level)
{
HintSelections hs = new HintSelections(level);
return(hs.Equals(this));
}
public HintOptions()
{
Flags = new HintFlags();
Show = new HintSelections(HintSelections.Level.Hard);
AutoSolve = new HintSelections(HintSelections.Level.Easy);
}