It asks for the shortest path, yet to get AC you must allow vertices on the graph to be repeated, isn't that contradicting the problem statement itself?
Consider this example :
2 AC B#
There is no shortest path as you would have to go through 'A' twice, yet the AC solution is 3.
I've the problem accepted, but I want to avoid this confusion in future, why are non distinct vertices allowed in the shortest path in this problem?