title: Confused about BinarySearch after Reverse
body: <p>I want to find an element index in a descending order list, but BinarySearch returns a negative number. Why is it so? Here is my code snippet:</p>
  
  <pre><code>List&lt;int&gt; list = new List&lt;int&gt;();
  list.Add(4);
  list.Add(1);
  list.Add(5);
  list.Add(2);
  list.Add(3);
  list.Sort();
  list.Reverse();
  var elementIndex = list.BinarySearch(5);
  </code></pre>