public IList <Edge> GetEdges(LocalArrangement localArrangement, int u)
{
if (localArrangement == null)
{
return(g.GetEdges(u));
}
var vs = localArrangement.ToArray();
var edges = new List <Edge>(vs.Length);
foreach (int v in vs)
{
edges.Add(g.CreateEdge(u, v));
}
return(edges);
}
/// <summary>
/// Create the current local arrangement for vertex 'u' - if the arrangment
/// already exists then that arrangement is used.
/// </summary>
/// <param name="u">vertex to get the arrangement around</param>
/// <returns>current local arrangement</returns>
private LocalArrangement CreateArrangement(int u)
{
if (!arrangement.TryGetValue(u, out LocalArrangement la))
{
la = new LocalArrangement();
int d = g.Degree(u);
for (int j = 0; j < d; ++j)
{
Edge e = g.EdgeAt(u, j);
la.Add(e.Other(u));
}
arrangement[u] = la;
}
return(la);
}
