Input restricted Dequeue in One Way link list

Dequeue is basically queue .there is one difference b/w dequeue  & queue .

In queue insertion take place at end & deletion at beginning But in dequeue Insertion & deletion can take place at both end 

BUT here we wan't to create input restricted dequeue .
what it means : Dequeue with input restricted to only one end . at beginning or at end.
In this we make a dequeue with input restricted at end only.

     C program :

 //deQueue in one way list with input restricted only at end;  
 #include<stdio.h>  
 #include<stdlib.h>  
 #include<malloc.h>  
 struct node   
 {  
      int data;  
      struct node *link;  
 }*head,*tell; // creating to variable globly  
 typedef struct node node; // using typedef  
 /*........................main......................*/  
 main()  
 {  
      head=NULL; // initialy list is empty so head=tell=NULL  
      tell=NULL;  
      int i,a,n;  
      printf("inter elements :\n");  
      for(i=0;i<5;i++) // taking 5 element as input & create a deqeue  
      {  
           scanf("%d",&a);  
           create(a);  
      }  
      display();  
      printf("\n 1. insert a no");  
      printf("\n 2. delete a no at beg");  
      printf("\n 3. delete a no from end");  
      printf("\n any other to exit\n");  
      while(1) // documentation for operation on dequeue   
      {  
           printf("\n inter choice :");  
           scanf("%d",&n);  
           switch(n)  
           {  
                case 1:  
                     printf("\n inset volue:");  
                     scanf("%d",&a);  
                     create(a);  
                     display();  
                     break;  
                case 2:  
                     del_at_begg();  
                     display();  
                     break;  
                case 3:  
                     del_at_end();  
                     display();  
                     break;  
                default :  
                   exit(0);  
                   break;  
           }  
      }  
 }//end of main  
 /*..............funtion def..........................*/  
 create(int d) // insert data in dequeue at end  
 {  
      node *r;  
      r=(node*)malloc(sizeof(node)); //alocating space dynamicaly  
      if(head==NULL)  
      {  
           r->data=d;  
           head=r;  
           tell=r;  
           head->link=NULL;  
      }  
      else  
      {  
           r->data=d;  
           tell->link=r;  
           tell=tell->link;  
           tell->link=NULL;  
      }  
 }  
 display() // to dispaly data element of dequeue  
 {  
      node *temp;  
      if(head==NULL)  
      {  
           printf("\n queue is empty :\n");  
      }  
      else  
      {  
      temp=head;  
      printf("\n data element of list is ::");  
      while(temp!=NULL)  
      {  
           printf(" %d ",temp->data);  
           temp=temp->link;  
      }  
   }  
 }  
 del_at_begg() //delete at beg ; just point head to next node & free  
 {        // space of first node  
      node *r;  
      r=head;  
      head=head->link;  
      free(r);  
 }  
 del_at_end() // just point tell to node just before last  
 {      // & tell->link=NULL & free last node  
      node *temp;  
      temp=head;  
      if(head==tell) // if only one node in list   
      {  
           temp=head;  
           head=NULL;  
           tell=NULL;  
           free(temp);  
      }  
      else  
      {  
           while(temp->link != tell)  
           {  
                temp=temp->link;  
           }  
           tell=temp;  
           temp=temp->link;  
           tell->link=NULL;  
           free(temp);  
      }  
 }  

OUTPUT:-

Input restricted dequeue in one way link list