linked list

//linked list
#include<iostream>
using namespace std;
void first();
struct node* start;
struct node* ptr1;

struct node
{
int data;
node*next;
};
void create()
{

int value;
start=NULL;
ptr1=new node;

cout<<"enter to insert in 1st node\n";
cin>>value;
ptr1->data=value;
ptr1->next=NULL;
start=ptr1;

}
void show()
{
node* temp;
temp=start;
if(temp==NULL)
{
cout<<"empty";
}
       else
{
while(temp!=NULL)
{
cout<<temp->data<<"-->";
temp=temp->next;
}
cout<<"NULL";
}
}
/*void second_pos()
{

int val;
node *ptr2;
ptr2=new node;
cout<<"enter theitem to insert";
cin>>val;
     // node *temp;

ptr2->data=val;
ptr2->next=ptr1->next;
ptr1->next=ptr2;
 }*/
void del()
{


node *temp3;
node *temp4;
temp3=start;
temp4=temp3;
if(temp3==NULL)
{
cout<<"list is empty\n";
}
else
{
int val,ch;
cout<<"enter the pos of element to delete\n";
cin>>ch;
if(ch==1)
{
val=temp3->data;
   cout<<"deleted item\n"<<val;
   start=start->next;
}
else
     {
for(int i=1;i<ch;i++)
{
temp4=temp3;
temp3=temp3->next;

}
val=temp3->data;
cout<<" deleted element is"<<val;
temp4->next=temp3->next;
}
}
}
void between()
{
node *temp3,*ptr;
ptr=new node;
node *temp4;
temp3=start;
temp4=temp3;
if(temp3==NULL)
{
cout<<"list is empty\n";
}
else
{
int val,ch;
cout<<"enter the pos where element is to be inserted\n";
cin>>ch;
if(ch==1)
{
    // val=temp3->data;
  // cout<<"deleted item\n"<<val;
   //start=start->next;
   first();
}
else
     {
for(int i=1;i<ch;i++)
{
temp4=temp3;
temp3=temp3->next;

}
cout<<"enter the item to inserted\n";
cin>>ptr->data;
ptr->next=temp4->next;
temp4->next=ptr;
}
}
}
void first()
{
node *temp,*ptr3;
       // temp=start;
ptr3=new node;
cout<<"enter data\n";
cin>>ptr3->data;
ptr3->next=start;
start=ptr3;

}
void last()
{
node *temp,*temp2,*ptr3;
temp=start;
ptr3=new node;
cout<<"enter data\n";
cin>>ptr3->data;
if(temp==NULL)
{
cout<<"empty";
}
while(temp!=NULL)
{
temp2=temp;
temp=temp->next;
}
ptr3->next=temp->next;
temp2->next=ptr3;

}
void insert()
{

int pos;
cout<<"enter the position at which u want to insert\n";
cout<<"1  at first\n";
cout<<"2  at last\n";
cout<<"3  in between \n";
cin>>pos;
switch(pos)
{
case 1:first();
break;
case 2:last();
break;
case 4:between();
break;
default: cout<<"wrong choice";
break;
}
}



int main()
{
node s;
create();
int choice;
while(1)
{
cout<<"\t\t\t******MENU********";
cout<<"\n 1 insert\n 2 delete \n 3 DISPLAY\n 4 EXIT \n";
cin>>choice;
switch(choice)
{
case 1:insert();
break;
case 2:del();
break;
case 3:show();
break;
case 4: exit(0)  ;
break;
default: cout<<" wrong  choice\n:";
break;
}
}

return 0;    // getch();
}