public IEnumerable <Cycle> GetCycles(bool simplifyToSmallest = false)
{
if (Vertices.Count < 3)
{
return(new List <Cycle>());
}
var result = new List <Cycle>();
var used = new List <Vertex>();
var parent = new Dictionary <Vertex, Vertex>();
var todo = new Stack <Vertex>();
todo.Push(Vertices[0]);
parent.Add(Vertices[0], Vertices[0]);
while (todo.Count > 0)
{
var cur = todo.Pop();
used.Add(cur);
foreach (var neighbour in cur.Edges.Select(edge => edge.GetOtherVertex(cur))
.Where(neighbour => parent[cur] != neighbour))
{
if (used.Contains(neighbour))
{
var cycle = new Cycle(this, parent[cur]);
cycle.AddEdge(parent[cur].GetEdgeTo(cur));
cycle.AddEdge(cur.GetEdgeTo(neighbour));
var v = neighbour;
while (v != parent[cur])
{
var e = v.GetEdgeTo(parent[v]);
cycle.AddEdge(e);
v = parent[v];
}
result.Add(cycle);
}
else if (!parent.ContainsKey(neighbour))
{
parent.Add(neighbour, cur);
todo.Push(neighbour);
}
}
}
if (simplifyToSmallest && result.Count > 0)
{
return(SmallestBase(result));
}
return(result);
}
