title: Number of shortest paths between two coordinate points in a graph with constraints
body: <p>I have been given few coordinate points :</p>
  
  <ol>
  <li><p>source <code>(0,0)</code></p></li>
  <li><p>destination <code>(m,n)</code></p></li>
  <li><p>a set of coordinate points <code>S = {(x,y)</code> such that <code>0 &lt; x &lt; m</code> and <code>0 &lt; y &lt; n}</code></p></li>
  </ol>
  
  <p>Objective is to find out the number of shortest paths between <code>(0,0)</code> and <code>(m,n)</code> such that any point in the set <code>S</code> is never encountered in these paths. How do i find it?</p>