My submission for Ruby Challenge #3: Short Circuit

rubylearning.com/blog/2009/10/30/rpcfn-short-circuit-3/

• 100% RSpec test coverage

• Works in both Ruby 1.8 and 1.9

I decided to play with a couple different concepts in this submission:

• Rather than using a known shortest path algorithm such as Dijkstra’s, I wanted to write my own from scratch with the goal of it being simple (even if it meant being computationally expensive).

• I wanted to make the algorithm recursive because I so rarely use recursion when building websites (my day job).

• I wanted to use Ruby’s infinity to represent the distance of an empty/dead-end path. It had a nice side effect of allowing me to remove all nil checks from the code.

require 'shortest_path'
include ShortestPath
shortest_path('A', 'B', [['A', 'B', 40], ['A', 'B', 50]]) => [['A', 'B', 40]]
unused_paths('A', 'B', [['A', 'B', 40], ['A', 'B', 50]]) => [['A', 'B', 50]]