Circular Queue using linked list

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#include<conio.h>
#include<stdlib.h>
#include<stdio.h>
struct node
{
    int data;
    struct node *next;
};
struct node *newnode, *temp;
void enqueue(struct node **f, struct node **r)
{
    int data,choice=1;
    while(choice==1)
    {
    newnode=(struct node*)malloc(sizeof(struct node));
    printf("Enter the data: ");
    scanf("%d",&newnode->data);
    newnode->next=0;
    if(*f==0 && *r==0)
    {
        *f = newnode;
        *r = newnode;
        (*r)->next=*f;
        // or (*r)->next=*r; that's same thing bcz there is only one node.
    }
    else
    {
        newnode->next=(*r)->next;
        (*r)->next=newnode;
        (*r)=newnode;
    }
    printf("want another element to be inserted(0,1): ");
    scanf("%d",&choice);
    }
}
void dequeue(struct node **f, struct node **r)
{
int choice=1;
while(choice==1)
  {
    if(*f==0 && *r==0)
        {printf("Queue is Empty\n");break;}
    else if(*f==*r)
    {
        printf("Deleted element is: %d",(*f)->data);
        temp=*f;
        free(temp);
        *f=0;
        *r=0;
    }
    else
    {
         printf("Deleted element is: %d",(*f)->data);
         temp=*f;
         *f=(*f)->next;
         (*r)->next=*f; //You have to modify the link part of last node also;
         free(temp);
    }
    printf("\nWant another element to be deleted(0,1): ");
    scanf("%d",&choice);
  }
}
void display(struct node *f, struct node *r)
{
    temp=f;
    if(f==0 && r==0)
        printf("Queue is empty\n");
    else
    {
        printf("Queue is:\n");
        while(temp->next!=f)
        {
            printf("%d\n",temp->data);
            temp=temp->next;
        } // Loop will break before printing the last element because the last node will store the same value of front; //check the condition of loop;
        printf("%d\n",temp->data);
    }
}
void peek(struct node *f, struct node *r)
{
if(f==0 && r==0)
    printf("Queue is empty\n");
else
    printf("The element at the top of Queue is: %d\n", f->data);
}
int main()
{
    int ch,choice=1;
    struct node *frnt, *rear;
    frnt=0;rear=0;
    while(choice==1){
    printf("\nEnter 1. to enqueue(insert in queue) \n");
    printf("Enter 2. to dequeue (to delete from queue)\n");
    printf("Enter 3. to display \n");
    printf("Enter 4. to peek (to show the element at front) \n choice: ");
    scanf("%d",&ch);
    if(ch==1)
        enqueue(&frnt, &rear);
    else if(ch==2)
        dequeue(&frnt, &rear);
    else if(ch==3)
        display(frnt, rear);
    else if(ch==4)
        peek(frnt, rear);
    else
        printf("invalid choice:");
    printf("\nDo you want to continue(0,1): ");
    scanf("%d",&choice);
    }
}

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