Circular linked list

#include<stdio.h>
#include<stdlib.h>
struct nod
{
   int data;
   struct nod *link;
};
typedef struct nod *node;;
node insert_front(node head,int data)
{
   node temp;
   temp=(node)malloc(sizeof(node));
   temp->data=data;
   temp->link=head->link;
   head->link=temp;
   return head;
}
node delete_rear(node head)
{
   node temp,prev;
   if(head->link==head)
   {
       printf("\n empty\n");
       return head;
   }
   prev=head;
   temp=head->link;
   while(temp->link!=head)
   {
       prev=temp;
      temp=temp->link;
   }
   prev->link=head;
   printf("\n the deleted node is %d",temp->data);
   free(temp);
   return head;
}
void display(node head)
{
   node temp;
   temp=head->link;
    printf("head->");
   while(temp!=head)
   {
       printf("%d\n       ",temp->data);
       temp=temp->link;
   }
}
main()
{
    int num,choice;
   node head;
   head=(node)malloc(sizeof(node));
   head->link=head;
   do
   {
       printf("\n MENU \n1.insert at front\n2.delete at rear\n3.display\n");
       scanf("%d",&choice);
       switch(choice)
       {
           case 1:
                printf("\n enter the element\n");
                scanf("%d",&num);
                head=insert_front(head,num);
                break;
            case 2:
                head=delete_rear(head);
                break;
            case 3:
                 display(head);
                 break;
       }
   }while(choice<4);
}