title: Finding a loopless path passing through a series of nodes?
body: <p>Given a directed graph, which has n points, there are k "must pass" points, where k &lt; n-2.</p>
  
  <p>How do I find a path from a start node to an end node that passes through all the "must pass" points without revisiting any nodes? Maybe this is a NP-complete problem... seems like TSP is very similar to this problem.</p>