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 Degree()
{
var graph = new UndirectedGraph <char, EdgeData>();
graph.AddNodes('a', 'b', 'c', 'd', 'e');
graph.AddEdges(
('a', 'b', dummyEdgeData),
('a', 'c', dummyEdgeData),
('a', 'd', dummyEdgeData),
('b', 'c', dummyEdgeData),
('b', 'd', dummyEdgeData),
('c', 'd', dummyEdgeData),
('c', 'e', dummyEdgeData)
);
graph.Degree('a').Should().Be(3);
graph.Degree('b').Should().Be(3);
graph.Degree('c').Should().Be(4);
graph.Degree('d').Should().Be(3);
graph.Degree('e').Should().Be(1);
}