title: BST from two unsorted array
body: <p>This question was asked in one of the interview :
  Given two unsorted array, check if it will create the same bst.
  eg: 2, 1, 4, 0 and 2, 1, 0, 4 will both form same BST.</p>
  
  <pre><code>     2
      / \
     1   4
    /
   0
  </code></pre>
  
  <p>please suggest some good algo.</p>