Algorithm Design and Analysis

From the following list of bus rapid transit system(one way):

The problem:

Name	Route
Vacation	A->B->C->D
Work 1	E->B->F->G->H
Work 2	B->N->E
Work 3	H->D->N

• Task: Design an algorithm to read the bus rapid transit system routes list and print the number of tickets we need to purchase if we want to visit all places minimal twice. The complexity of the algorithm must be O(V+E). V is the number of places. E-> is the number of transits.
• PS: Use Tarjans or Kosarajus strongly connected component algorithm.