title: Find out how many binary digits a particular integer has
body: <blockquote>
    <p><strong>Possible Duplicate:</strong><br>
    <a href="https://stackoverflow.com/questions/3272424/compute-fast-log-base-2-ceiling">Compute fast log base 2 ceiling</a>  </p>
  </blockquote>
  
  
  
  <p>What is the fastest possible way to find out how many binary digits a particular integer has when it is converted from decimal to binary in C/C++? </p>
  
  <p>Ex. 47<sub>(10)</sub> = 101111<sub>(2)</sub></p>
  
  <p>So 47 has 6 digits represented in binary.</p>