#include <iostream>
    
    using namespace std;
    
    // Definition for Class SL
    class SL {
    private: // Each object contains two values
        int *ptr;  // Pointer to int
        int val;   // Just an int
    public: // Member functions
        SL();
        ~SL();
        void Readin();
        void Printout();
        void Erase();
    };
    
    // Constructor for Class SL
    SL::SL()
    {ptr = 0;
     cout << "allocated SL " << this << endl;
    }
    
    SL::~SL()
    {cout << "deallocated SL " << this << endl;
     this->Erase();}
    
    void SL::Printout() // Printing out the contents of a SL
    {
       if (ptr == 0)
          {cout << "data " << " 0 value none int " << val << endl; return;}
       cout << "data " << ptr << " value " << *ptr << " int " << val << endl;
       return;
    }
    
    void SL::Readin()  // Reading in the contents of a SL
    { cout << "Input one value" << endl;
      ptr = new int;
      cin >> *ptr >> val;
    }
    
    void SL::Erase() {
       delete(ptr);
       ptr=0;
    }
    #include "listNode.h"
    
    int main()
    {
      cout << endl;
    
      SL* l;     //   A08
      l = new SL;
      l->Readin();
      cout << "SL* l" << " Located at " << l << endl;
      l->Printout();
      cout << endl;
          //  A08     A18    4    3
    
      SL* m;     //   A28
      m = new SL;
      m->Readin();
      cout << "SL* m"  << " Located at " << m<< endl;
      m->Printout();
      cout << endl;
          //  A28     A38     2    1
    
      SL* o= new SL(*m);  //  A48
    //  Terrible copy because CC is the default one
    //  and it does not copy dynamically allocated memory
      cout << "SL* o"  << " Located at " << o<< endl;
      o->Printout();
      cout << endl;
          //  A48     A38     2     1
    
      l->Erase();
      m->Erase();
    
    // One should not use the o list after this point
    
      cout << "SL* l"  << " Located at " << l<< endl;
      l->Printout();
          //  A08     A0    --    3
      cout << "SL* m"  << " Located at " << m<< endl;
      m->Printout();
          //  A28     A0    --    1
      cout << "SL* o"  << " Located at " << o<< endl;
      o->Printout();
          //  A48     A38     ...3648     1
      delete l;
      delete m;
      delete o;
      cout << endl;
    
      return 0;
    }