gistfile1.rb

# BFS

def bfs(source, target)
  q = []
  visited = {}
  
  q << source
  while !q.empty?
    current = q.shift
    visited[current] = true
    
    return if (current == target) # done
    
    current.neighbors.each do |neighbor|
      q << neighbor if !visited[neighbor] 
    end
  end
  
  # no solution
end