title: Finding a path with the biggest number of nodes in a directed graph
body: <p>What would be a good way to find in a directed graph a path which has the biggest number of nodes? </p>
  
  <p>I suppose I could traverse the graph in depth for each node and find out which path has the biggest number of nodes however I'm wondering if there are better approaches.</p>
  
  <p>Mention: the graph is guaranteed to have no cycles.</p>