Ordered List

#include<iostream.h>
#include<conio.h>

struct list
{
 int node;
 struct list *nxt;
};

class linked_list
{
 public:
  struct list *start;
  int nol;
   linked_list();
  ~linked_list();
  void insert_node();
  void delete_node();
  void display_list();
};

void linked_list :: linked_list()
{
  nol = 0;
  start = NULL;
}

void linked_list :: ~linked_list()
{
  nol = 0;
  struct list *nptr;
  nptr = start;
  start = NULL;
  delete nptr;
}

void linked_list :: insert_node()
{
 struct list *nptr;
 nptr = new list;
 cout<<"\n Enter the New Node to be Inserted : ";
 cin>>nptr->node;
 nptr->nxt = NULL;

 if(start == NULL)
  start = nptr;
 else
 {
  nptr->nxt = start;
  start = nptr;
 }
 nol += 1;
 cout<<"\n The Node has been Inserted into the List ";
 getch();
}


void linked_list :: delete_node()
{
 if(nol == 0)
  cout<<"\n WARNING !! No more Nodes in the List \n";
 else
 {
 struct list *loc,*locp,*nptr;
 int info;
 cout<<"\n Enter the Node to be Deleted : ";
 cin>>info;
 locp = NULL;
 loc = start;
 while(loc->node != info && loc != NULL)
 {
   locp = loc;
   loc = loc->nxt;
 }
 if(loc == NULL)
  cout<<"\n The Node is not present in the List ";
 else
 {
  nptr = new list;
  if(loc == start)
  {
   nptr = start;
   start = start->nxt;
  }
  else
  {
   nptr = loc;
   locp->nxt = loc->nxt;
  }
  nol -= 1;
  delete nptr;
  cout<<"\n The Node has been Deleted from the List ";
 }
 }
 getch();
}


void linked_list :: display_list()
{
 struct list *ptr;
 cout<<"\n The Linked List : \n\t";
 ptr = start;
 while(ptr != NULL)
 {
  cout<<ptr->node<<" -> ";
  ptr = ptr->nxt;
 }
 cout<<"NULL\n";
 cout<<"\n The Numer of Nodes in this List : "<<nol;
 getch();
}

class ord_linked_list : public linked_list
{
 public:
  ord_linked_list();
  ~ord_linked_list();
  void insert_node();
  void delete_node();
  void display_list();
};

void ord_linked_list :: ord_linked_list()
{
  linked_list::linked_list();
}

void ord_linked_list :: ~ord_linked_list()
{
  linked_list::~linked_list();
}

void ord_linked_list :: insert_node()
{
 struct list *nptr;
 nptr = new list;
 cout<<"\n Enter the New Node to be Inserted : ";
 cin>>nptr->node;
 nptr->nxt = NULL;

 if(start == NULL)
  start = nptr;
 else
 {
  struct list *loc,*locp;
  locp = NULL;
  loc = start;
  while(loc != NULL && loc->node <= nptr->node)
  {
   locp = loc;
   loc = loc->nxt;
  }
  if(loc == NULL)
   locp->nxt = nptr;
  else if(loc == start)
  {
   nptr->nxt = start;
   start = nptr;
  }
  else
  {
   locp->nxt = nptr;
   nptr->nxt = loc;
  }
 }
 nol += 1;
 cout<<"\n The Node has been Inserted into the List ";
 getch();
}


void ord_linked_list :: delete_node()
{
 linked_list::delete_node();
}


void ord_linked_list :: display_list()
{
 linked_list :: display_list();
}

void main()
{
 int cho;
 linked_list ll;
 linked_list();
 do
 {
 clrscr();
 cout<<"\n.. UNORDERED LINKED LIST MENU ..\n";
 cout<<"\n 1. Insert a node";
 cout<<"\n 2. Delete a node";
 cout<<"\n\n  Enter an option : ";
 cin>>cho;
 switch(cho)
 {
  case 1 :  ll.insert_node();
   break;
  case 2 :  ll.delete_node();
   break;
  default:  break;
 }
 ll.display_list();
 }while(cho == 1 || cho == 2);
 getch();


 clrscr();
 ord_linked_list oll;
 ord_linked_list();
 do
 {
 clrscr();
 cout<<"\n.. ORDERED LINKED LIST MENU ..\n";
 cout<<"\n 1. Insert a node";
 cout<<"\n 2. Delete a node";
 cout<<"\n\n  Enter an option : ";
 cin>>cho;
 switch(cho)
 {
  case 1 :  oll.insert_node();
   break;
  case 2 :  oll.delete_node();
   break;
  default:  break;
 }
 oll.display_list();
 }while(cho == 1 || cho == 2);
 getch();
}