title: find shortest path in a graph that compulsorily visits certain Edges while others are not compulsory to visit
body: <p>I have an undirected graph with about 1000 nodes and 2000 edges, a start node and an end node. I have to traverse from the start node to the end node passing through all the compulsory edges(which are about 10) while its not necessary to traverse through all the vertices or nodes. Is there an easy solution to this like some minor changes in the existing graph traversing algorithms? How do I do it? </p>
  
  <p>Thanks for help.:)</p>
  
  <p>This question is different from <a href="https://stackoverflow.com/questions/222413/find-the-shortest-path-in-a-graph-which-visits-certain-nodes">Find the shortest path in a graph which visits certain nodes</a> as my question is regarding compulsory edges not vertices.</p>
  
  <p>EDIT: The compulsory edges can be traversed in any order.</p>