MyklClason

# This is a very simple hash based graph utility class.
# By Mykl Clason
# https://gist.github.com/MyklClason/fe603a6005a1dedc6ec65fda7ff47f68
class Graph
  def self.undirected_graph_from_edges(edges)
    # Edges are (a,b) pairs with a => b and b => a relationships.
    edges.each_with_object(Hash.new { |h, k| h[k] = Set.new }) { |(k, v), h| h[k] << v }
  end
  
  def self.directed_graph_from_edges(edges)