title: Finding the minimum and maximm element from one of many arrays
body: <p>I received a question during an Amazon interview and would like assistance with solving it.</p>
  <p>Given N arrays of size K each, each of these K elements in the N arrays are sorted, and each of these N*K elements are unique. Choose a single element from each of the N arrays, from the chosen subset of N elements. Subtract the minimum and maximum element. This difference should be the least possible minimum.</p>
  <p>Sample:</p>
  <pre><code>N=3, K=3
  
  N=1 : 6, 16, 67
  N=2 : 11,17,68
  N=3 : 10, 15, 100
  </code></pre>
  <p>here if 16, 17, 15 are chosen, we get the minimum difference as
  17-15=2.</p>