forward-star@ruby。

かなり短い。

def parse_sgraph file
  sgraph ||= []
  nodes, arcs = 0, 0
  
  File.open(file).each do |line|
    case line
    when /^a +(d+) +(d+) +(d+)/
      sgraph[$1.to_i] ||= []
      sgraph[$1.to_i] << [$2.to_i, $3.to_i]
    when /^p +sp +(d+) +(d+)/
      nodes, arcs = $1.to_i, $2.to_i
    when /^[c,n]/ # comment. skip.
    else raise "Parse Error!!"
    end
  end
  
  return sgraph
end