bench/shootout/ackermann.ruby

   1 #!/usr/bin/ruby
   2 # -*- mode: ruby -*-
   3 # $Id: ackermann.ruby,v 1.2 2005-06-10 00:57:22 igouy-guest Exp $
   4 # http://www.bagley.org/~doug/shootout/
   5
   6 def ack(m, n)
   7     if m == 0 then
   8         n + 1
   9     elsif n == 0 then
  10         ack(m - 1, 1)
  11     else
  12         ack(m - 1, ack(m, n - 1))
  13     end
  14 end
  15
  16 NUM = Integer(ARGV.shift || 1)
  17 print "Ack(3,", NUM, "): ", ack(3, NUM), "\n"