detectedgecycles

    list<Edge*>CheckList checklist;

    class Node
    {
        //location data
    }

    class Edge
    {
    public:
        Node* m_nA;
        Node* m_nB;
        Edge* m_eB;
        bool m_IsTraced;
    bool m_IsAdded;
    }

    void AddEdge(Edge* edge, CheckList& checklist)
    {
        for (int i = 0; i < checklist.count(); i++)
        {
            if (checklist.getat(i)->m_nB == edge->m_nA)
            {
                checklist.getat(i)->m_eB = edge;
            }
        }
    }

    void Build()
    {
        for(int i = 0; i < list.count(); i++)
        {
            AddEdge(new Edge(list.getat[i].x1, list.getat[i].y1), CheckList& checklist);
        }
    }

    bool DetectTrace(Edge* edge)
    {
        if (edge->m_IsTraced)
        {
            edge->m_IsTraced = false;
            return false;
        }
        edge->m_IsTraced = true;
        bool returnvalue = DetectTrace(edge->m_eB);
        edge->m_IsTraced = false;
        return returnvalue;
    }

    void Clean()
    {
        for (int i = 0; i < checklist.count(); i++)
        {
            Edge* test = checklist.getat(i);
            if (!(test->m_isAdded)) checklist.removeat(i);
            for (int j = 0; j < checklist.count(); j++)
            {
                if (checklist.getat(j)->m_eB == test) checklist.getat(j)->m_eB = null;
            }
        }
    }

    void Detect()
    {
        for(int i = 0; i < checklist.count(); i++)
        {
        checklist.getat(i)->m_IsAdded = true;
            if (!DetectTrace(checklist.getat(i))) checklist.getat(i)->m_IsAdded = false;
        }
    }

    int main()
    {
        Build();
        Detect();
        Clean();
        // use checklist as final collection.
    }