gistfile1.rb

# Jumps to Jita!

jumps = {}

puts "processing database..."
File.open('jumps.dump','r') do |f|
  until f.eof?
    line = f.readline.strip
    if line == "/*!40000 ALTER TABLE `mapSolarSystemJumps` DISABLE KEYS */;"
      until ((line=f.readline.strip).size<20)
        data = line.split(',')
        (jumps[data[2].to_i] ||= []) << data[3].to_i
      end
    end
  end
end

puts jumps.size

puts "calculating optimal routes..."

JITA = 30000142

paths = {}
paths[JITA] = 0

400000.times do |ii|
  pd1 = paths.dup
  jumps.keys.each do |src|
    pd2 = paths.dup
    pd2.each do |dest,dist|
      # dest has found its shortest path to Jita, src has not, or this one is shorter.
      if jumps[src].include?(dest) && (!paths[src] || dist+1 < paths[src])
        paths[src] = dist+1 # we can get to jita by jumping through this system.
      end 
    end
  end
  break if paths == pd1
  puts "iteration #{ii} complete"
end

File.open('paths.marshal','w'){|f|f.puts Marshal.dump(paths)}