Linked List

#include <stdio.h>
#include <stdlib.h>
struct node 
{ 
  int data;
  struct node *next ;
  
}*head,*tail;
/* Code for insertion at the beginning*/
void insert_at_beg ()
{
  struct node *newnode ;
  newnode= (struct node*)malloc(sizeof(struct node));
  printf("Enter Data ");
  scanf("%d",&(*newnode).data);
  newnode->next=head;
  head=newnode;
  
}
/* Code for insertion at end*/
void insert_at_end()
{
  struct node *newnode ;
  newnode= (struct node*)malloc(sizeof(struct node));
  printf("Enter Data ");
  scanf("%d",&(*newnode).data);
  newnode->next=tail->next;
  tail->next=newnode;
  tail=newnode;
  
}

/* Code for insertion at ant specific position  */
void insert_at_pos()
{
  int pos;
  int count;
  printf("Enter the position");
  scanf("%d",&pos);
    int i=1;
    struct node *temp;
    temp=head;
    if (i<pos)
    {
      temp=temp->next;
    }
  struct node *newnode ;
  newnode= (struct node*)malloc(sizeof(struct node));
  printf("Enter Data ");
  scanf("%d",&(*newnode).data);
  newnode->next=temp->next;
  temp->next=newnode;
 
}



 /* Code for Displaying Elements*/
void display()
{
  tail= head;
 while(tail->next=head);
  {
    printf("%d",tail->data);
    printf("\n");
    tail=tail->next;
  }
  printf("%d",tail->data);
}
 
int main ()
{
  
 head=0;
 int dec =1;
 int count =0;
 while(dec)
 {
   /* Creating node*/
  struct node *newnode ;
  newnode= (struct node*)malloc(sizeof(struct node));
  printf("Enter Data ");
  scanf("%d",&(*newnode).data);
  newnode->next=0;
  count++;
  if(head==0)
   {
     head=newnode;
     tail=newnode;
   }
  else
   {
     tail->next=newnode;
     tail=newnode;
     
   } 
   printf("Do you want to continue(0,1)?");
   scanf("%d",&dec);
   newnode->next=head;
   
  }
  do
  {
   int choice;
   int flag =0;
  printf("Enter the Choice \n");
  printf("Enter 1 to insert at beginning \n");
  printf("Enter 2 to insert at end\n");
  printf("Enter 3 to insert at specific position\n");
  printf("Enter 4 to display element\n");
  scanf("%d",&choice);
  switch(choice)
  {
  case 1:insert_at_beg();
  break;
  case 2:insert_at_end();
  break;
  case 3: printf("Postion should be less than %d",count);
  printf("\n");
  insert_at_pos();
  break;
  case 4:display();
  break;
  default:
  flag=1;
  break;
  if (flag ==0)
  continue;
  if(flag==1)
  break;
  }
  }while(1);
 }