// Returns false if the switch is not possible

    bool exchangeEdges(unsigned int e1index, unsigned int e2index, bool switchType) {

        StoredEdge &se1 = edges[e1index];

        StoredEdge &se2 = edges[e2index];

        const Edge &e1 = se1.e;

        const Edge &e2 = se2.e;

        // The new edges configuration is one of these two

        // A) e1.u - e2.u and e1.v - e2.v

        // B) e1.u - e2.v and e2.u - e1.v

        // Note that to do (B) instead of (A), simply swap e2.u <-> e2.v

        // Now we can just consider switch type (A)

        if (switchType) {

            std::swap(se2.e.u, se2.e.v);

            std::swap(se2.u2vindex, se2.v2uindex);

        }

        // First check if the move is possible

        if (hasEdge({e1.u, e2.u}) || hasEdge({e1.v, e2.v}))

            return false; // conflicting edges

        // Clear old edges

        badj[e1.u][e1.v] = false;

        badj[e1.v][e1.u] = false;