SEND+MORE=MONEY in Ruby. ref: http://python.g.hatena.ne.jp/edvakf/20101225/1293305482

send-more-money.rb

#!/usr/bin/env ruby
# vim: set fileencoding=utf-8 :
$VERBOSE = true

require 'set'

def dig *args
  args.inject{|x, y| 10 * x + y}
end

digits09 = (0..9).to_set
digits19 = (1..9).to_set

puts digits19.inject([]){|res, s|
  s_ = [s]
  (digits09 - s_).each{|e|
    se = s_ + [e]
    (digits09 - se).each{|n|
      sen = se + [n]
      (digits09 - sen).each{|d|
        send = sen + [d]
        send_i = dig( s, e, n, d )
        (digits19 - send).each{|m|
          sendm = send + [m]
          (digits09 - sendm).each{|o|
            sendmo = sendm + [o]
            (digits09 - sendmo).each{|r|
              sendmor = sendmo + [r]
              more = dig( m, o, r, e )
              (digits09 - sendmor).each{|y|
                money = dig( m, o, n, e, y )
                res << "#{send_i} + #{more} = #{money}" if send_i + more == money
              }
            }
          }
        }
      }
    }
  }
  res
}