Hi All,

I have written reversible link list and pasting the code as below in c++. It works fine, please let me know if there are anything more that is required to make this more robust.
This is on a single link list.

#include "stdafx.h" 
#include <iostream>
using namespace std; 

      class revlinklist
      {

      private: 

            struct revnode
            {
                  char name[20];
                  int age;
                  float height;
                  revnode * link;


            };

            revnode * start;


      public:

            void addnode();
            void addatbeg();
            revlinklist();
            ~revlinklist();
            void revdisplay();
            void reverse();
            void count();


      };

      revlinklist::revlinklist()
      {

                  start= NULL;


      }

      void revlinklist::addnode()
      {

            

             start= new revnode;

            cout<<"Enter the name of the person"<<endl;
            cin>>start->name;
            cout<<"Enter the age of the person"<<endl;
            cin>>start->age;
            cout<<"Enter the height of the person"<<endl;
            cin>>start->height;

            start->link = NULL;


      }


      void revlinklist::addatbeg()
      {
                  revnode * temp;
                  temp = start;

                  start= new revnode;

                  cout<<"Enter the name of the person"<<endl;
                  cin>>start->name;
                  cout<<"Enter the age of the person"<<endl;
                  cin>>start->age;
                  cout<<"Enter the height of the person"<<endl;
                  cin>>start->height;

                  start->link = temp;

      }

      void revlinklist::count()
      {
                  
                  revnode *temp;                                  
                  temp = start;

                  int c=0;

                  while(temp != NULL)

                  {

                        temp = temp->link;

                        c++;

                  }

                  cout<<"\n";
                  cout<<"The total number of nodes are:"<<c;


      }

      void revlinklist::revdisplay()

      {
                  
                        revnode *temp;
                        temp=start;
                        while(temp != NULL)
                        {
                        cout<<"The name of the person"<<" : "<<temp->name;
                        cout<<"\n";
                        cout<<"The age of the person"<<" : "<<temp->age;
                        cout<<"\n";
                        cout<<"The height of the person"<<" : "<<temp->height;
                        cout<<"\n";
                        temp=temp->link;

                        }


      }

      void revlinklist::reverse()
      {

            revnode *q, *r, *s;

            q=start;

            r=NULL;

            while(q!=NULL)

            {
                  s=r;

                  r=q;

                  q=q->link;

                  r->link=s;
                  
            }

            
                  start = r;


      }
      revlinklist::~revlinklist()
      {
                  revnode *q;

                  while(start!=NULL)
                  {
                        q=start->link;

                        delete start;

                        start=q;
                  

                  }
                  

      }




      void main() 
{
            revlinklist l;
            int revopt =0; 
            
            do { 
            //disp_list(); 
            cout <<endl;
            cout<<"1-Add the node" << endl;
            cout<<"2-Add node at the beginning of the list" << endl;          
            cout<<"3-Number of nodes in the list" << endl;        
            cout<<"4-Display the list"<<endl; 
            cout<<"5-Reverse the list"<<endl;
            cout<<"Enter the option of your choice"<<endl; 
            cin>>revopt;
            switch(revopt) 
            {
            case 1: l.addnode(); break;   
            case 2: l.addatbeg(); break;
            case 3: l.count(); break;
            case 4: l.revdisplay();break;
            case 5: l.reverse();break;
            default: cout<<"Enter the correct option";break; 
            }
            
               } while(revopt !=0); 
}

The only potential issue I see is that if you call "addnode" twice. The method does not check to see if "start" is pointing at anything. If called a second time, you will lose the context to the node that was established in the first call.

You can really just do away with "addnode" and just use "addatbeg" to add nodes, even when the list is empty.

Thanks mike ... I was using it for testing purpose. Will remove it. Thanks again.

I would still keep this thread open for some more time to capture the comments of other members in the forum. This would help me improve a great deal in my programming skills.

I am learning datastructures in c++ and it is my only passtime for now.

Vilas