title: Finding unique numbers from sorted array in less than O(n)
body: <p>I had an interview and there was the following question:</p>
  
  <blockquote>
    <p>Find unique numbers from sorted array in less than O(n) time.</p>
  
  <pre><code>Ex: 1 1 1 5 5 5 9 10 10
  Output: 1 5 9 10
  </code></pre>
  </blockquote>
  
  <p>I gave the solution but that was of O(n).</p>
  
  <p><strong>Edit:</strong>  Sorted array size is approx 20 billion and unique numbers are approx 1000.</p>