private static void Visit(UndirectedGraph graph, IReporter reporter,
ISet <Vertex> candidates, ISet <Vertex> excluded, ImmutableArray <Vertex> cliqueInProgress)
{
Debug.Assert(candidates.All(v => graph.Degree(v) > 0));
Debug.Assert(excluded.All(v => graph.Degree(v) > 0));
Debug.Assert(!candidates.Overlaps(excluded));
Debug.Assert(candidates.Any());
while (candidates.Any())
{
var v = CollectionsUtil.PopArbitrary(candidates);
var neighbours = graph.Neighbours(v);
var neighbouringCandidates = CollectionsUtil.Intersection(candidates, neighbours);
if (neighbouringCandidates.Any())
{
var neighbouringExcluded = CollectionsUtil.Intersection(excluded, neighbours);
Visit(graph, reporter,
neighbouringCandidates, neighbouringExcluded,
CollectionsUtil.Append(cliqueInProgress, v));
}
else if (CollectionsUtil.AreDisjoint(excluded, neighbours))
{
reporter.Record(CollectionsUtil.Append(cliqueInProgress, v));
}
var added = excluded.Add(v);
Debug.Assert(added);
}
}
public void Append()
{
var empty = ImmutableArray.Create <uint>();
var one = CollectionsUtil.Append(empty, 11u);
var two = CollectionsUtil.Append(one, 22u);
Assert.That(empty.Length.Equals(0));
Assert.That(one.Length.Equals(1));
Assert.That(two.Length.Equals(2));
Assert.That(one[0].Equals(11u));
Assert.That(two[0].Equals(11u));
Assert.That(two[1].Equals(22u));
}
