static IEnumerable <Choosability.Graph> EnumerateWeightings(Choosability.Graph g)
{
var space = Not ? g.Vertices.Select(v => Enumerable.Range(0, Spread)).CartesianProduct() : g.Vertices.Select(v => Enumerable.Range(0, Spread).Reverse()).CartesianProduct();
foreach (var weighting in space)
{
var www = weighting.ToList();
if (www.Count(w => w > 0) > MaxHighs)
{
continue;
}
if (g.Vertices.Any(v => g.Degree(v) - www[v] <= 1))
{
continue;
}
if (LowMinDegree > 0)
{
var low = www.IndicesWhere(w => w == 0).ToList();
if (g.InducedSubgraph(low).MinDegree < LowMinDegree)
{
continue;
}
}
var gg = g.Clone();
gg.VertexWeight = www;
yield return(gg);
}
}
static void Main(string[] args)
{
var vertices = Enumerable.Range(1, N).Select(i => new Fraction()
{
Top = (int)f((uint)i), Bottom = (int)f((uint)i + 1)
}).ToList();
// var vertices = new FareySequence(N).ToList();
var adjacent = new bool[vertices.Count, vertices.Count];
for (int i = 0; i < vertices.Count; i++)
{
for (int j = 0; j < vertices.Count; j++)
{
adjacent[i, j] = adjacent[j, i] = Math.Abs(vertices[i].Top * vertices[j].Bottom - vertices[i].Bottom * vertices[j].Top) == 1.0;
}
}
//var g = new Choosability.Graph(adjacent);
//var R = g.Vertices;
//var G = g.Vertices.Except(g.Vertices).ToList();
List <int> R = null;
List <int> G = null;
var g = new Choosability.Graph(adjacent);
foreach (var red in g.EnumerateMaximalIndependentSets())
{
var bluegreen = g.Vertices.Except(red).ToList();
var h = g.InducedSubgraph(bluegreen);
if (!h.IsTwoColorableSlow())
{
continue;
}
R = red;
foreach (var green in g.EnumerateMaximalIndependentSets(bluegreen))
{
if (g.EdgesOn(bluegreen.Except(green).ToList()) <= 0)
{
G = green;
break;
}
}
if (G != null)
{
break;
}
}
var B = g.Vertices.Except(R).Except(G).ToList();
using (var sw = new StreamWriter("Ford" + N + ".tex"))
{
sw.WriteLine(@"\documentclass{standalone}");
sw.WriteLine(@"\usepackage{tikz}");
sw.WriteLine(@"\begin{document}");
sw.WriteLine(@"\begin{tikzpicture}");
var circles = string.Join(Environment.NewLine, Enumerable.Range(1, N).Select(i => new Fraction()
{
Top = (int)f((uint)i), Bottom = (int)f((uint)i + 1)
}).Select(f => new FordCircle(f)).Select((f, i) => string.Format(@"\fill[{3}] ({0},{1}) circle [radius={2}];", f.X, f.Y, f.R, Fill(f.F, i, R, G))));
sw.WriteLine(circles);
sw.WriteLine(@"\end{tikzpicture}");
sw.WriteLine(@"\end{document}");
//var k = g.CliqueNumberBronKerbosch();
//var gg = GraphIO.GraphFromEdgeWeightString(string.Join(" ", g.GetEdgeWeights()));
//var s = CompactSerializer.Serialize(gg);
}
}
