int main()
{
    int i, n;
    queue q = q_new();

    for (i = 0; i < 100000000; i++) {
        n = rand();
        if (n > RAND_MAX / 2) {
        //  printf("+ %d\n", n);
            enqueue(q, n);
        } else {
            if (!dequeue(q, &n)) {
            //  printf("empty\n");
                continue;
            }
        //  printf("- %d\n", n);
        }
    }
    while (dequeue(q, &n));// printf("- %d\n", n);

    return 0;
}