queue

#include <stdio.h>
#include <string.h>
#define Q_size 5

typedef struct{
    int data[Q_size+1];
    int head, tail;
}queue;

//enqueue
void enqueue(queue *q, int item)
{
    if((q->tail+1)%(Q_size+1) == q->head){
        printf("Queue is full\n");
        return;
    }
    q->data[q->tail] = item;
    q->tail = (q->tail+1)%(Q_size+1);
}

//dequeue
int dequeue(queue *q)
{
    int item;
    if(q->tail == q->head){
        printf("Queue is empty\n");
        return -1;
    }
    item = q->data[q->head];
    q->head = (q->head+1) % (Q_size+1);
    return item;
}
int main()
{
    queue my_q;
    int item;
    my_q.head = 0;
    my_q.tail = 0;

    //First enqueue 3 numbers
    enqueue(&my_q, 1);
    printf("Tail = %d\n", my_q.tail);
    enqueue(&my_q, 2);
    printf("Tail = %d\n", my_q.tail);
    enqueue(&my_q, 3);
    printf("Tail = %d\n", my_q.tail);
    //dequeue 2 numbers
    printf("Beginning head = %d\n", my_q.head);
    item = dequeue(&my_q);
    printf("item = %d, head=%d\n", item, my_q.head);
    item = dequeue(&my_q);
    printf("item = %d, head=%d\n", item, my_q.head);
    // enqueue 3 numbers
    enqueue(&my_q, 4);
    printf("Tail = %d\n", my_q.tail);
    enqueue(&my_q, 5);
    printf("Tail = %d\n", my_q.tail);
    enqueue(&my_q, 6);
    printf("Tail = %d\n", my_q.tail);

    //dequeue 4 numbers
    printf("Beginning head = %d\n", my_q.head);
    /*item = dequeue(&my_q);
    printf("item = %d, head=%d\n", item, my_q.head);
    item = dequeue(&my_q);
    printf("item = %d, head=%d\n", item, my_q.head);*/
    item = dequeue(&my_q);
    printf("item = %d, head=%d\n", item, my_q.head);
    item = dequeue(&my_q);
    printf("item = %d, head=%d\n", item, my_q.head);
    item = dequeue(&my_q);
    printf("item = %d, head=%d\n", item, my_q.head);
    item = dequeue(&my_q);
    printf("item = %d, head=%d\n", item, my_q.head);
    //if we dequeue here queue will be empty
    // enqueue 2 number
    enqueue(&my_q, 4);
    printf("Tail = %d\n", my_q.tail);
    enqueue(&my_q, 5);
    printf("Tail = %d\n", my_q.tail);
    //dequeue 2 number
    printf("Beginning head = %d\n", my_q.head);
    item = dequeue(&my_q);
    printf("item = %d, head=%d\n", item, my_q.head);
    item = dequeue(&my_q);
    printf("item = %d, head=%d\n", item, my_q.head);
    //queue is empty
    item = dequeue(&my_q);
    printf("item = %d, head=%d\n", item, my_q.head);
    //now if we want to enqueue again 2 number
    enqueue(&my_q, 4);
    printf("Tail = %d\n", my_q.tail);
    enqueue(&my_q, 5);
    printf("Tail = %d\n", my_q.tail);
    //dequeue 2 number
    printf("Beginning head = %d\n", my_q.head);
    item = dequeue(&my_q);
    printf("item = %d, head=%d\n", item, my_q.head);
    item = dequeue(&my_q);
    printf("item = %d, head=%d\n", item, my_q.head);
    item = dequeue(&my_q);
    printf("item = %d, head=%d\n", item, my_q.head);
    return 0;
}