MBTA practice

To start

Fork, clone, branch (practice) and npm install

Objectives

Practice with classes, methods, and collections.
You may submit a pull request for this practice, but it is not required.

Activity

Create a class in lib/practice.rb with a method stops_between_stations to calculate the number of stops between stations on the "MBTA". Write additional classes and or methods as needed.
The method takes the line and stop name that a rider is getting on at and the line and stop name that a rider is getting off at and returns the total number of stops for the trip.
When MBTA::Subway::System.new is called, its initialize method should store all the information needed by stops_between_stations.

There are 3 subway lines:

The Red line has the following stops: South Station, Park Street, Kendall, Central, Harvard, Porter, Davis, Alewife
The Green line has the following stops: Government Center, Park Street, Boylston, Arlington, Copley, Hynes, Kenmore
The Orange line has the following stops: North Station, Haymarket, Park Street, State, Downtown Crossing, Chinatown, Back Bay, Forest Hills
All 3 subway lines intersect at Park Street, but there are no other intersection points. Some of this MBTA is fictionalized.

Checking your solution

Run rake test.

Hints

Assume good input. Your function need not check the validity of the line or stop name.
Consider diagramming the lines by sketching out the subway lines and their stops and intersection.
The key to the practice is to find the intersection of the lines at Park Street.
Solve an easier problem first.

Bonus

Think about adding Haymarket before Government Center on the Green line then try to find a solution when there are multiple intersections. Is there a way to decide if a particular solution is "correct"?

This bonus is completely optional and does not have tests, yet.

lcurran/ruby-objects-practice