public void TrySelectAndDeselectPossibility_WithMultipleRequired_Works()
{
var puzzle = new Puzzle(4);
var matrix = ExactCoverGraph.Create(puzzle);
var possibilities = new FakePossibility[] {
new FakePossibility(),
new FakePossibility(),
};
var firstSelected = possibilities[0];
var secondSelected = possibilities[1];
var concreteObjective = Objective.CreateFullyConnected(matrix, possibilities, 2);
IObjective objective = concreteObjective;
Assert.True(objective.TrySelectPossibility(firstSelected.AttachedObjectives.First()));
Assert.NotEqual(NodeState.SELECTED, concreteObjective.State);
Assert.Equal(1, concreteObjective.CountUnknown);
Assert.Single(objective.GetUnknownDirectPossibilities(), secondSelected);
Assert.Contains(concreteObjective, matrix.GetUnsatisfiedRequiredObjectivesWithConcretePossibilities());
Assert.True(objective.TrySelectPossibility(secondSelected.AttachedObjectives.First()));
Assert.Equal(NodeState.SELECTED, concreteObjective.State);
Assert.Equal(0, concreteObjective.CountUnknown);
Assert.True(!matrix.GetUnsatisfiedRequiredObjectivesWithConcretePossibilities().Contains(concreteObjective) ||
matrix.GetUnsatisfiedRequiredObjectivesWithConcretePossibilities().Count() == 1);
objective.DeselectPossibility(secondSelected.AttachedObjectives.First());
Assert.NotEqual(NodeState.SELECTED, concreteObjective.State);
Assert.Equal(1, concreteObjective.CountUnknown);
Assert.Single(objective.GetUnknownDirectPossibilities(), secondSelected);
Assert.Contains(concreteObjective, matrix.GetUnsatisfiedRequiredObjectivesWithConcretePossibilities());
objective.DeselectPossibility(firstSelected.AttachedObjectives.First());
Assert.Equal(2, concreteObjective.CountUnknown);
}
public void TrySelectAndDeselectPossibility_Succeeds()
{
var fakePossibilities = new FakePossibility[] {
new FakePossibility(),
new FakePossibility(),
};
var childOptional = OptionalObjective.CreateWithPossibilities(
Possibilities.CreatePossibilities(new(), 2), 1);
var optional = OptionalObjective.CreateWithPossibilities(fakePossibilities, 2);
var linkToChildOptional = Link.CreateConnectedLink(childOptional, optional);
var parent = new FakeObjective(isRequired: true);
var linkToParent = Link.CreateConnectedLink(optional, parent);
IPossibility possibility = optional;
IObjective objective = optional;
Assert.True(objective.TrySelectPossibility(fakePossibilities[0].AttachedObjectives.First()));
Assert.Equal(NodeState.UNKNOWN, optional.State);
Assert.Equal(NodeState.UNKNOWN, childOptional.State);
Assert.All(((IObjective)childOptional).GetUnknownDirectPossibilities().Cast <Possibility>(),
p => Assert.Equal(NodeState.UNKNOWN, p.State));
Assert.Empty(fakePossibilities[0].DroppedFromObjectives);
Assert.Empty(fakePossibilities[1].DroppedFromObjectives);
Assert.Empty(parent.SelectedPossibilities);
Assert.True(objective.TrySelectPossibility(fakePossibilities[1].AttachedObjectives.First()));
Assert.Equal(NodeState.SELECTED, optional.State);
Assert.Equal(NodeState.UNKNOWN, childOptional.State);
Assert.All(((IObjective)childOptional).GetUnknownDirectPossibilities().Cast <Possibility>(),
p => Assert.Equal(NodeState.UNKNOWN, p.State));
Assert.Single(parent.SelectedPossibilities, linkToParent);
Assert.Empty(fakePossibilities[0].DroppedFromObjectives);
Assert.Empty(fakePossibilities[1].DroppedFromObjectives);
objective.DeselectPossibility(fakePossibilities[1].AttachedObjectives.First());
Assert.Equal(NodeState.UNKNOWN, optional.State);
Assert.Equal(NodeState.UNKNOWN, childOptional.State);
Assert.All(((IObjective)childOptional).GetUnknownDirectPossibilities().Cast <Possibility>(),
p => Assert.Equal(NodeState.UNKNOWN, p.State));
Assert.Empty(fakePossibilities[0].DroppedFromObjectives);
Assert.Empty(fakePossibilities[1].DroppedFromObjectives);
Assert.Empty(parent.SelectedPossibilities);
objective.DeselectPossibility(fakePossibilities[0].AttachedObjectives.First());
Assert.Equal(NodeState.UNKNOWN, optional.State);
Assert.Equal(NodeState.UNKNOWN, childOptional.State);
Assert.All(((IObjective)childOptional).GetUnknownDirectPossibilities().Cast <Possibility>(),
p => Assert.Equal(NodeState.UNKNOWN, p.State));
Assert.Empty(fakePossibilities[0].DroppedFromObjectives);
Assert.Empty(fakePossibilities[1].DroppedFromObjectives);
Assert.Empty(parent.SelectedPossibilities);
}
public void TrySelectPossibility_WhenRejectedByParent_LeavesUnchanged()
{
var fakePossibilities = new FakePossibility[] {
new FakePossibility(),
new FakePossibility(),
};
var childOptional = OptionalObjective.CreateWithPossibilities(
Possibilities.CreatePossibilities(new(), 2), 1);
var optional = OptionalObjective.CreateWithPossibilities(fakePossibilities, 1);
var linkToChildOptional = Link.CreateConnectedLink(childOptional, optional);
var parent = new FakeObjective(isRequired: true);
parent.CanSelectPossibilities = false;
var linkToParent = Link.CreateConnectedLink(optional, parent);
IPossibility possibility = optional;
IObjective objective = optional;
Assert.False(objective.TrySelectPossibility(fakePossibilities[0].AttachedObjectives.First()));
Assert.Equal(NodeState.UNKNOWN, optional.State);
Assert.Equal(NodeState.UNKNOWN, childOptional.State);
Assert.All(((IObjective)childOptional).GetUnknownDirectPossibilities().Cast <Possibility>(),
p => Assert.Equal(NodeState.UNKNOWN, p.State));
Assert.Empty(fakePossibilities[0].DroppedFromObjectives);
Assert.Empty(fakePossibilities[1].DroppedFromObjectives);
Assert.Empty(parent.SelectedPossibilities);
}
public void TrySelectPossibility_WithUndetachablePossibility_Fails()
{
var puzzle = new Puzzle(4);
var matrix = ExactCoverGraph.Create(puzzle);
var possibilities = new FakePossibility[] {
new FakePossibility(),
new FakePossibility(),
new FakePossibility(),
};
var toSelect = possibilities[0];
var undetachable = possibilities[2];
undetachable.CanBeDetached = false;
var concreteObjective = Objective.CreateFullyConnected(matrix, possibilities, 1);
IObjective objective = concreteObjective;
Assert.False(objective.TrySelectPossibility(toSelect.AttachedObjectives.First()));
Assert.Empty(possibilities[1].DroppedFromObjectives);
Assert.Empty(undetachable.DroppedFromObjectives);
Assert.Contains(objective, matrix.GetUnsatisfiedRequiredObjectivesWithConcretePossibilities());
Assert.Contains(toSelect, objective.GetUnknownDirectPossibilities());
Assert.Contains(possibilities[1], objective.GetUnknownDirectPossibilities());
Assert.Contains(undetachable, objective.GetUnknownDirectPossibilities());
}
public void TrySelectPossibility_CausesCascadingDrop_SelectsAndDeselectsCorrectly()
{
var puzzle = new Puzzle(4);
var matrix = ExactCoverGraph.Create(puzzle);
var fakePossibilities = new FakePossibility[] {
new FakePossibility(),
new FakePossibility(),
};
var optional = OptionalObjective.CreateWithPossibilities(fakePossibilities, 1);
var fakesOnParentToSelect = new FakePossibility[] {
new FakePossibility(),
new FakePossibility(),
};
var parentToSelect = OptionalObjective.CreateWithPossibilities(
fakesOnParentToSelect.Cast <IPossibility>().Prepend(optional).ToArray(), 2);
var fakeOnParentToDrop = new FakePossibility();
var parentToDrop = OptionalObjective.CreateWithPossibilities(
new IPossibility[] {
fakeOnParentToDrop,
optional,
}, 2);
var required = Objective.CreateFullyConnected(
matrix,
new IPossibility[] { parentToSelect, parentToDrop },
1);
IObjective objective = optional;
;
// Select one fake on parentToSelect so that selecting this optional will satisfy the
// objective.
Assert.True(((IObjective)parentToSelect).TrySelectPossibility(fakesOnParentToSelect[0].AttachedObjectives.First()));
Assert.True(objective.TrySelectPossibility(fakePossibilities[0].AttachedObjectives.First()));
Assert.Equal(NodeState.SELECTED, optional.State);
Assert.Equal(NodeState.SELECTED, parentToSelect.State);
Assert.Empty(fakesOnParentToSelect[1].DroppedFromObjectives);
Assert.Equal(NodeState.SELECTED, required.State);
Assert.Equal(NodeState.DROPPED, parentToDrop.State);
Assert.Empty(fakeOnParentToDrop.DroppedFromObjectives);
objective.DeselectPossibility(fakePossibilities[0].AttachedObjectives.First());
Assert.Equal(NodeState.UNKNOWN, optional.State);
Assert.Equal(NodeState.UNKNOWN, parentToSelect.State);
Assert.Empty(fakesOnParentToSelect[1].DroppedFromObjectives);
Assert.Equal(NodeState.UNKNOWN, required.State);
Assert.Equal(NodeState.UNKNOWN, parentToDrop.State);
Assert.Empty(fakeOnParentToDrop.DroppedFromObjectives);
// Select a possibility on parentToDrop first. This should result in no change overall.
Assert.True(((IObjective)parentToDrop).TrySelectPossibility(fakeOnParentToDrop.AttachedObjectives.First()));
// Selecting the objective would satisfy both optional parents, which violates the
// required objective.
Assert.False(objective.TrySelectPossibility(fakePossibilities[0].AttachedObjectives.First()));
// Deselect a possibility from parentToSelect so that we can now select parentToDrop.
((IObjective)parentToSelect).DeselectPossibility(fakesOnParentToSelect[0].AttachedObjectives.First());
Assert.True(objective.TrySelectPossibility(fakePossibilities[0].AttachedObjectives.First()));
Assert.Equal(NodeState.SELECTED, optional.State);
Assert.Equal(NodeState.DROPPED, parentToSelect.State);
Assert.Empty(fakesOnParentToSelect[1].DroppedFromObjectives);
Assert.Equal(NodeState.SELECTED, required.State);
Assert.Equal(NodeState.SELECTED, parentToDrop.State);
Assert.Empty(fakeOnParentToDrop.DroppedFromObjectives);
}
