circular queue ONLY

#include<stdio.h>
#include<stdlib.h>


#define MAX 5
struct QUEUE
{
    int data[MAX];
    int front, rear;
    int count;
}q;

int f=1;

void print()
{
    int i,j;
    if(q.count==0)
    {
        printf("queue is empty\n");
    }
    else
    {

    if(f!=0)
        q.front=(q.front+1)%MAX;
    printf("elements of the queue are: ");
    i=(q.front);
    j=q.count;
    while(j!=0)
    {
        printf("%d ",q.data[i]);
        i=((i++)%MAX);
        j--;
    }
    if(f!=0)
        q.front=(MAX-1);
    }
}


int main()
{


    int ch,s=1;
    q.front=MAX-1;
    q.rear=MAX-1;
    q.count=0;

    do
    {
        printf("\n\n1.insert\t2.delete\t3.display\t4.exit\n enter ch: ");
        scanf("%d",&ch);

        switch(ch)
        {
        case 1:
            q.rear=((q.rear+1)%(MAX));
            if((q.rear==q.front)&&(q.count==MAX)&&(s==0))
            {
                printf("the queue is full\n");
                q.rear--;
                break;
            }

            printf("enter data \n");
            scanf("%d",&q.data[q.rear]);
            q.count++;
            if(q.rear==q.front)
            {
                q.rear--;
                s=0;
            }
            print();
            break;







        case 2:
                if(q.count==0)
                {
                    printf("nothing to delete\n");
                    break;
                }
                if(f!=0)
                    q.front=(q.front+1)%MAX;

                s=1;
                printf("%d deleted\n",q.data[q.front]);
                f=0;
                q.count--;
                q.front=((q.front+1)%(MAX));
                print();
                break;


        case 3:
            print();
            break;
        case 4:
            break;
        }
    }while(ch!=4);

return 0;
}









OUTPUT:

1.insert        2.delete        3.display       4.exit
 enter ch: 1
enter data
2
elements of the queue are: 2

1.insert        2.delete        3.display       4.exit
 enter ch: 1
enter data
3
elements of the queue are: 2 3

1.insert        2.delete        3.display       4.exit
 enter ch: 1
enter data
4
elements of the queue are: 2 3 4

1.insert        2.delete        3.display       4.exit
 enter ch: 1
enter data
5
elements of the queue are: 2 3 4 5

1.insert        2.delete        3.display       4.exit
 enter ch: 1
enter data
6
elements of the queue are: 2 3 4 5 6

1.insert        2.delete        3.display       4.exit
 enter ch: 1
the queue is full


1.insert        2.delete        3.display       4.exit
 enter ch: 2
2 deleted
elements of the queue are: 3 4 5 6

1.insert        2.delete        3.display       4.exit
 enter ch: 3
elements of the queue are: 3 4 5 6

1.insert        2.delete        3.display       4.exit
 enter ch: 2
3 deleted
elements of the queue are: 4 5 6

1.insert        2.delete        3.display       4.exit
 enter ch: 2
4 deleted
elements of the queue are: 5 6

1.insert        2.delete        3.display       4.exit
 enter ch: 2
5 deleted
elements of the queue are: 6

1.insert        2.delete        3.display       4.exit
 enter ch: 2
6 deleted
queue is empty


1.insert        2.delete        3.display       4.exit
 enter ch: 2
nothing to delete


1.insert        2.delete        3.display       4.exit
 enter ch: 4
Press any key to continue