// ListType.h

struct NodeType { // linked list node type
  int       info;
  NodeType *next; // points to next node
};

class ListType {
public:
  ListType();
  void append(int x);
  // appends x to list
  void print(); 
  // prints list items on screen
private:
  NodeType *head; // points to head of list
  NodeType *tail; // points to tail of list
};