you have been given tree, find a shortest path to travel from 1 to N, such that you visits some given set of nodes in your path from 1 to N. you are allowed to visit same node multiple times.

eg — N = 5

      1  
    /  \ 
  2     3
      /   \ 
    4      5

node_to_visit_in_path = { 2 ,4 } CONSTRAINTS — N UPTO ( 2 * 1e5 ) size of node_to_visit_in_path : upto N-1

solution — 6 ( 1 -> 2 -> 1 -> 3 -> 4 -> 3 -> 5)

is this a famous kind of problem ?, i think similar problem i have see somewhere.