title: How to calculate execution time in milliseconds
body: <p>I'm pretty new to C++, I need to print the execution time of my program in milliseconds with 4 digits (X.XXX) - I tried to use </p>
  
  <pre><code>double start_s=clock();
  // my program here
  double stop_s=clock();
  cout &lt;&lt; "time: " &lt;&lt; (stop_s) &lt;&lt; endl;
  </code></pre>
  
  <p>I got 0.
  What am I doing wrong?
  Btw I am using (and have to use, college project) VS2010, so chrono is not an option.</p>