title: Finding a number that is sum of two other numbers in a sorted array
body: <p>As it said in the topic, I have to check if there is a number that is the sum of two other numbers in a sorted array.</p>
  
  <p>In first part of the question (for a unsorted array) I wrote a solution, just doing 3 loops and checking all the combinations.</p>
  
  <p>Now, I can't understand how to build the most efficient algorithm to do the same, but with a sorted array.</p>
  
  <p>Numbers are of type <code>int</code> (negative or positive) and any number can appear more then once. </p>
  
  <p>Can somebody give a clue about that logic problem ?</p>