private bool IsPlanar(Graph g)
{
Counter++;
if (g.IsCompleteBipartite(3, 3) || g.IsComplete(5))
{
NonplanarSubgraph = g;
return false;
}
if (g.Size == 5)
return true;
foreach (var edge in g.GetAllEdges())
{
var h = g.Shrink(edge.U, edge.V);
var isPlanar = IsPlanar(h);
if (!isPlanar)
{
ExtendNonplanarSubgraph(g, edge);
return false;
}
}
return true;
}
