</strong>, not recursively.</li>
      <li>Add student test cases that confirm <code class="language-c++ highlighter-rouge"><span class="n">concatenate</span></code> does its job correctly. Be sure to consider the case when one or more of the lists is empty.</li>
    </ul>
  </li>
</ul>

<p>With your thoroughly-tested helper functions  <code class="language-c++ highlighter-rouge"><span class="n">partition</span></code> and <code class="language-c++ highlighter-rouge"><span class="n">concatenate</span></code