#include<stdio.h>

#define MAX 30

typedef int ElementType;

ElementType queue[MAX];
int queue_first = 0;
int queue_last = 0;

void enqueue(ElementType element) {
  queue[queue_last] = element;
  queue_last = (queue_last+1) % MAX;
}

ElementType dequeue() {
  ElementType tmpElement = queue[queue_first];
  queue_first = (queue_first+1) % MAX;
  return tmpElement;
}

int emptyQueue() {
  return queue_first == queue_last;
}

int main() {
  int i;
  for (i = 0; i < 10; ++i) 
    enqueue(i);
  
  while(!emptyQueue())
    printf("dequeued: %d\n",dequeue());
}