// LabContest #1
// Complete insert, show_perm, intersect of the Set class.
// - Set: a collection of distinct elements
// - Permutation: ordered arrangement of elts in which each elt appears
//   exactly once


/* A sample output
C:\>settst
Enter numbers for a set, a negative number when you are done: 3 5 7 -1
S1 = ( 3 5 7 )
    Permutations:
     - 357
     - 375
     - 537
     - 573
     - 735
     - 753
Enter numbers for a set, a negative number when you are done: 2 5 7 -1
S2 = ( 2 5 7 )
    Permutations:
     - 257
     - 275
     - 527
     - 572
     - 725
     - 752
S1 ^ S2 = ( 5 7 )
*/



#include <iostream.h>
#include <stdlib.h>  // Provides size_t
#include <assert.h>  // Provides assert

class Set
{   public:
        enum { CAPACITY = 3 }; // Or static const size_t CAPACITY = 3;
        typedef int Item;

        Set( ) { used = 0; }
        void insert(const Item& entry);
        size_t size( ) const { return used; }
        size_t occurrences(const Item& target) const;
        void show_perm() const;
        friend void operator >> (istream& ins, Set& b);
        friend void operator << (ostream& outs, Set& b);
        friend Set intersect(const Set& s1, Set& s2);
     private:
        Item data[CAPACITY];  // The array to store items
        size_t used;          // How much of array is used
};

size_t Set::occurrences(const Item& target) const
{
    size_t answer = 0;

    for (size_t i = 0; i < used; i++)
        if (target == data[i])
            answer++;
    return answer;
}


void Set::insert(const Item& entry)
{




}

void Set::show_perm() const  // binding time problem; should be recursive sol.
{





}

Set intersect(const Set& s1, Set& s2)
{




}

void operator >> (istream& ins, Set& b)
{
    Set::Item number;
    cout << "Enter numbers for a set, a negative number when you are done: ";
    ins >> number;
    while (number >= 0)
    {
        if (b.size( ) < b.CAPACITY)
            b.insert(number);
        else
            cout << "I have run out of room and can't add that number." << endl;
        cin >> number;
    }
}

void operator << (ostream& outs, Set& b)
{
    outs << "( ";
    for(int i = 0; i < b.used; i++)
       outs << b.data[i] << " ";
    outs << ")" << endl;
}

void main( )
{
    Set s1, s2;

    cin >> s1;
    cout << "S1 = " << s1;
    s1.show_perm();

    cin >> s2;
    cout << "S2 = " << s2;
    s2.show_perm();

    cout << "S1 ^ S2 = " << intersect(s1, s2);
}