// Singly-linked list node
template <class Elem> class PolyLinkT {
public:
  Elem element;           // Value for this node
  PolyLinkT *next;        // Pointer to next node in list
  PolyLinkT(const Elem& elemval, PolyLinkT* nextval =NULL)
    { element = elemval;  next = nextval; }
  PolyLinkT(PolyLinkT* nextval =NULL) { next = nextval; }
};