title: Design a datastructure to support stack operations and to find minimum
body: <p>Interview question: Design a data structure which has the following features</p>
  
  <ul>
  <li>push the data</li>
  <li>pops the last inserted data [LIFO]</li>
  <li>Gives the minimum</li>
  </ul>
  
  <p>All of the above operations should have a complexity of <code>O(1)</code></p>