Astro 503, Spring 2006
Homework #8
Due THURSDAY, Mar 16

1. Write an implementation of the set template (and its iterator) using a binary tree.
Then write a driver program to test its methods by inserting a bunch
of objects and printing them out in order.
Here's what the interface to your stripped-down set class should look
like:

template<class T, class Pred>
class setIterator {
private:
  setIterator(...your arguments here);
public:
  setIterator(const setIterator& rhs);
  ~setIterator();
  setIterator& operator=(const setIterator& rhs);
  bool operator==(const setIterator& rhs);
  bool operator!=(const setIterator& rhs);
  setIterator& operator++();
  setIterator& operator--();
  T& operator*();	//dereference
  template<class U, class P>
  friend
  class set<U,P>;
};

template<class T, class Pred>
class set {
public:
  template<class U, class P>
  friend
  class setIterator<U,P>;
  typedef setIterator<T,Pred> iterator;  
  void insert(iterator& i, T& val);
  iterator erase(iterator& i);	//return iterator to element past
                                               //  erased one
  iterator begin() const;
  iterator end() const;
  bool empty() const;
  int size() const;
};

2. Alter the topTwelveWords.cpp program so that it will print out all
   the words that have the same frequency as the 12th as well as the
   top 12.

   Then write another program (or add to this one) that will print out
   the median word when they're placed in dictionary-style
   alphabetical order.

   Run on 
   ...the Gettysburg address
   ...the 2006 State of the Union address
   (will need to make perhaps your own classes to put into containers,
   and likely some predicate functions for them.)

3. Have a fully defined interface for your part of the Ephemeris Project.