title: doubly linked list implementation
body: <p>Which one would be more efficient?</p>
  
  <p>I want to keep a list of items but, it's required of me to sort list</p>
  
  <ul>
  <li>by id,</li>
  <li>by name</li>
  <li>by course credits</li>
  <li>by the user</li>
  </ul>
  
  <p>Would it be best to add items in list by id and then sort by the others or just add items without order and sort in the order needed when ever needed by the user?</p>