title: Time complexity and number of elements operated on
body: <p>Algorithm  A executes an operation of time complexity O(log n) on an array storing n elements. </p>
  
  <p>Algorithm B chooses log n elements from an array, and performs an O(n) calculation on each. </p>
  
  <p>Since d(n) = O(f(n)) and e(n) = O(g(n)), then d(n)*e(n) = O(f(n)*g(n)), does that mean that algorithms A and B both have a time complexity of O(n log n)?</p>