#ifndef SET_H
#define SET_H

#include <bool.h>

class Set {

    // Returns a set which is the union of s1 and s2

    friend Set Union (const Set& s1, const Set& s2);

    // Returns a set which is the intersection of s1 and s2

    friend Set Intersection (const Set& s1, const Set& s2);

    // Returns a set which is the difference s1 - s2

    friend Set Difference (const Set& s1, const Set& s2);

private:

    //  The design of the private section is left to you.
    //  Declare private data and function members here.
    //  Do NOT change any of the declarations in the public
    //    section or the friend functions above.

public:

    //  Constructs an empty set

    Set ();

    //  Construct a set with a single element which is 
    //    the value n

    Set (int n);

    //  Construct a set whose elements are the integers
    //    between begin and end, inclusive
    //  
    //  Pre-condition:  begin <= end

    Set (int begin, int end);

    //  Construct a set whose elements are specified in
    //    an integer array pointed to by the first argument.
    //    The second argument specifies the size of the array.
    //  If the array has any duplicate elements, they are ignored.
    //
    //  Pre-condition:  numElems >= 1

    Set (int* iarray, int numElems);


    //  Copy constructor

    Set (const Set& s);
    
    //  Destructor

    ~Set ();
    
    //  Displays the elements of the set in ascending order.
    //  The elements are displayed as a comma-separated list
    //     enclosed in curly braces.  For example:
    //
    //        { 1, 4, 5, 11, 13, 19 }
    //
    //  If the set is empty, this function simply prints the
    //    word "Empty".

    void Display () const;

    //  Tests for membership in the set.
    //  Returns true if and only if n is a member of the set.

    bool IsMember (int n) const;

    //  Returns the cardinality of the set

    int Cardinality () const;


    //  Overloaded assignment operator

    Set& operator = (const Set& s);


    //  Overloaded equality operator

    bool operator == (const Set& s) const;

    //  Returns true if and only if the set is a subset of s

    bool IsSubsetOf (const Set& s) const;

    //  Returns true if and only if the set is a proper subset of s

    bool IsProperSubsetOf (const Set& s) const;
};

#endif