change order of elements inside linked list
<p>I'm trying to use simple linked list:</p>

<pre><code>struct index
{
   struct index* next_element;
   int data;
   struct index* previous_element;
} 
</code></pre>

<p>What is the best way to change order of elements in terms of performance?
For example, i have 1 2 3 4 5 6 7 8 and i need  1 4 2 3 5 6 7 8.</p>
