My solution involves a bit of ruby-magic involving hashes. Unfortunately I couldn't come up with a better solution.
Trying recursive solutions meant large numbers couldn't be handled. At least this can handle relatively large numbers.
- Ruby 2.7.2
- Bundler
If you use Rbenv to manage your ruby installations, you can change the version used via the .ruby-version file
bundle exec rake
ruby app.rb will load a basic CLI that you can use to play around with my solution
Running this task will check for rubocop linter errors, as well as run all tests
lib/application uses a continuous loop to handle user input. Unfortunately it appears that these loops cannot
be reliably tested using Rspec, so this class remains untested. An alternative would be to force the user to load
a csv file instead of creating a CLI, but that would be a bad user experience.