title: Binary search algorithm actual number of searches in average
body: <p>I know the time complexity of binary search algorithm is O(nlogn).</p>
  
  <p>But what is the average number of searches using binary search algorithm?</p>
  
  <p>I don't know whether which to use between the floor of nlogn or ceiling of nlogn.</p>
  
  <blockquote>
    <p>For a sorted array that contains 11 items, what is the average
    number of searches using a binary search algorithm? (Assume
    that all searches are successful in finding the item)</p>
  </blockquote>
  
  <p>How can I determine the average number of search with binary search algorithm?</p>
  
  <p>Thanks for your help in advance.</p>