title: Search An ArrayList of ArrayLists
body: <p>What is the most efficient way to search for a single element in an <code>ArrayList</code> of <code>ArrayLists</code>? Given the following:</p>
  
  <pre><code>ArrayList&lt;ArrayList&lt;Integer&gt;&gt; intList = new ArrayList&lt;ArrayList&lt;Integer&gt;&gt;();
  ArrayList&lt;Integer&gt; a = new ArrayList&lt;&gt;();
  a.add(1);
  a.add(2);
  ArrayList&lt;Integer&gt; b = new ArrayList&lt;&gt;();
  b.add(3);
  b.add(4);
  intList.add(a);
  intList.add(b);
  </code></pre>
  
  <p>How would I search to see if the <code>ArrayList</code> <code>intList</code> contains a specific <code>Integer</code>, like <code>3</code>?</p>