The local commuter
railroad services a number of towns in Kiwiland. Because of monetary
concerns, all of the tracks are 'one-way.' That is, a route from Kaitaia
to Invercargill does not imply the existence of a route from Invercargill to
Kaitaia. In fact, even if both of these routes do happen to exist, they
are distinct and are not necessarily the same distance!
The purpose of this
problem is to help the railroad provide its customers with information about
the routes. In particular, you will compute the distance along a certain
route, the number of different routes between two towns, and the shortest route
between two towns.