title: Enqueue/ Dequeue OR offer/ poll
body: <p>This seems like a very basic question, but I've been stuck for hours.</p>
  
  <p>When do we use methods enqueue/ dequeue &amp; when do we use offer/ poll?!</p>
  
  <p>I want to create a PQ of integers with the <code>void enqueue(int x, int p)</code> and <code>int dequeue()</code> methods, how do I declare such a queue?</p>
  
  <p>Thanks.</p>