jlhonora

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

/**
* Solution for "Coding for Interviews" challenge 20.
  Consists of creating a queue using two stacks.
  I declare the first stack as "downwards" and the
  second one as "upwards". If we need to enqueue we just
  add to the "downwards" stack. If we need to dequeue then