Circular Doubly Linked List in DSA using C++ Part – 2

Program 1

// Circular double linked list code
#include<iostream>
#include<stdio.h>
#define clrscr() system("cls")
using namespace std;
class node
{
    public:
     node *ladd;
     int data;
     node *radd;
};
int count=0;
node *start=NULL,*new1,*temp,*prv,*nxt;
void create();
void display();
void insertfirst();
void insertmid();
void insertlast();
void delfirst();
void delmid();
void dellast();
int main()
{
     int choice;
     clrscr();
    do
   { 
    cout<<"\n--------------------Circular Double Linked List------------------";
    cout<<"\n1.Create";
    cout<<"\n2.Display";
    cout<<"\n3.Insert First";
    cout<<"\n4.Insert Middle";
    cout<<"\n5.Insert Last";
    cout<<"\n6.Delete First";
    cout<<"\n7.Delete Middle";
    cout<<"\n8.Delete Last";
    cout<<"\n9.Exit";
    cout<<"\n-------------------------------------------------------------------";
    cout<<"\n Enter your choice";
    cin>>choice;
  switch(choice)   
  {
     case 1:create();break;
     case 2:display();break;
     case 3:insertfirst();break;
     case 4:insertmid();break;
     case 5:insertlast();break;
     case 6:delfirst();break;
     case 7:delmid();break;
     case 8:dellast();break;
     case 9:break;
     default:cout<<"Invalid choice";
  }
   }while(choice!=9);
}
void create()
{
     int n;
     char ch;
     cout<<"Enter an element";
     cin>>n;
     start=new node;
     temp=start;
     start->data=n;
     start->ladd=temp;
     start->radd=temp;
     count++;
     cout<<"want to continue";
     cin>>ch;
     while(ch=='y'|| ch=='Y')
     {
        cout<<"Enter an element";
        cin>>n;
        new1=new node;
        new1->data=n;
        new1->ladd=temp;
        temp->radd=new1;
        start->ladd=new1;
        new1->radd=start;
        temp=temp->radd;
        count++;
        cout<<"want to continue";
        cin>>ch;

     }
}
void display()
{
//     temp=start;
//     cout<<"\nFirst Node: "<<temp->data;
//     temp=temp->ladd;
//   cout<<"\nLast Node: "<<temp->data;
//    temp=temp->radd;
//  cout<<"\nFirst Node: "<<temp->data;

    if(start==NULL)
    cout<<"\nList not found";
    else
  {  
    temp=start;
    do
    {
        cout<<temp->data<<"  ";
        temp=temp->radd;

    } while (temp!=start);
    cout<<"\n Total Node is List: "<<count;
  }   
}
void insertfirst()
{
      int n;
    if(start==NULL)
     cout<<"\n List not found....";
     else
     {
          cout<<"\n Enter an element for insert";
          cin>>n;
          temp=start->ladd;
          new1=new node;
          new1->data=n;
          new1->radd=start;
          start->ladd=new1;
          start=new1;
          start->ladd=temp;
          temp->radd=start;
          count++;

     }
}
void insertmid()
{

      int n,pos,i=1;
      if(start==NULL)
         cout<<"\n List not found";
     else
    {     
      cout<<"\nEnter position for insert";
      cin>>pos;
      if(pos>count)
        cout<<"\n Invalid position";
     else
     {
             cout<<"\nEnter an element for insert";
             cin>>n;
             new1=new node;
             new1->data=n;
             nxt=start;
             while(i<pos)
             {
                 prv=nxt;
                 nxt=nxt->radd;
                 i++;
             }
             prv->radd=new1;
             new1->ladd=prv;
             new1->radd=nxt;
             nxt->ladd=prv;
             count++;
     }
   }
}
void insertlast()
{
      int n;
    if(start==NULL)
     cout<<"\n List not found....";
     else
     {
          cout<<"\n Enter an element for insert";
          cin>>n;
          new1=new node;
          new1->data=n;
          temp=start->ladd;
          temp->radd=new1;
          new1->ladd=temp;
          start->ladd=new1;
          new1->radd=start;
          count++;
     }    


}
void delfirst()
{
     if(start==NULL)
     cout<<"\n List not found....";
    else
    {
        nxt=start->ladd;
        temp=start;
        start=start->radd;
        nxt->radd=start;
        start->ladd=nxt;
        cout<<"Delete node: "<<temp->data;
        delete temp;
        count--;
    }

}
void delmid()
{
     int pos,i;
    if(start==NULL)
      cout<<"\n List not found.....";
    else
    {
        cout<<"\nEnter position for delete";
        cin>>pos;
        if(pos>count)
            cout<<"\n Invalid position";
        else
        {
             i=1;
             temp=start;
             while(i<pos)
             {
                 temp=temp->radd;
                 i++;
             }
             prv=temp->ladd;
             nxt=temp->radd;
             prv->radd=nxt;
             nxt->ladd=prv;
             cout<<"\n Deleted node: "<<temp->data;
             delete temp;
             count--;
        }    
        
    }  
}
void dellast()
{
   if(start==NULL)
       cout<<"\n List not found...";
    else
    {
        temp=start->ladd;
        prv=temp->ladd;
        start->ladd=prv;
        prv->radd=start;
        cout<<"\n Deleted node : "<<temp->data;
        delete temp;
        count--;

    }   
}