Sortierte Listen auf Basis von verzeigerten Elementen III

CalendarMan.om

PROCEDURE InsertAppointment(VAR list: ListOfAppointments; appointment: Appointment); VAR ptr, prev, element: Element; BEGIN NEW(element); element.appointment := appointment; IF (list.first = NIL) OR (Op.Compare(appointment.time, list.first.appointment.time) < 0) THEN (* insert element at the beginning of the list *) element.next := list.first; list.first := element; ELSE prev := list.first; ptr := list.first.next; WHILE (ptr # NIL) & (Op.Compare(appointment.time, ptr.appointment.time) >= 0) DO prev := ptr; ptr := ptr.next; END; (* following holds now: (ptr = prev.next) & (appointment.time >= prev.appointment.time) & ((ptr = NIL) OR (appointment.time < ptr.appointment.time)) we insert element between prev and ptr: *) element.next := ptr; prev.next := element; END; INC(list.length); END InsertAppointment;