Using Distinct, ... continued
	public:  // Creating a new poly  poly() { i=0; tag=I; }  poly(int ii) { i=ii; tag=I; }  poly(node<poly> * pp) { p=pp; tag=P; }  // Changing the value in a poly  void set(int ii) { i=ii; tag=I; }  void set(node<poly> * pp) { p=pp; tag=P; }  void print_preorder(void); }; template <class t> struct node {    t data;    node<t>* next; };