#ifndef SETL_H
#define SETL_H

#include <string>
using namespace std;

class Set
{
  public:
    Set( );

    Set( const Set & rhs );
    ~Set( );
    const Set & operator= ( const Set & rhs );

    int size( ) const;
    bool isEmpty( ) const;
    void clear( );
    bool add( const string & x );
    bool remove( const string & x );
    bool contains( const string & x ) const;

  private:
    struct Node
    {
        string data;
        Node  *next;

        Node( const string & d = "", Node *n = NULL )
          : data( d ), next( n ) { }
    };

    Node *first;
    int   theSize;   // Needed so size() is efficient.
};

#endif