ate: 03/31/2005
title: spqr - convert from roman numerals
author: Ralf Elfinger
email: ralf at ixos dot de
comments: inspired by ruby quiz #22, but this rather robust ... will not decode badformed romans as IIII, IVI, XVIIII, IL, XIXX. Now plays by rules #1 and #4 :)
code:
def spqr r
	r="/#{r.upcase}"; %w(M CDM XLC IVX).each{|d|
		r.sub!(/\/[#{d}]*/){|s|s=s.tr(d,'047').sub('04','3'); break unless 
		s.sub!(/^\/((3)|0(7)|(4)0?0?0?|(0)0?0?)$|^\/$/){|t|
		$+?($+[0]+$1.size).chr: '0'}
	s+'/'}}; r.sub(/^\d+\/.+$/,'0').to_i
end

if ARGV.empty?
	puts "Usage: ruby #$0 <your favourite ROMAN numbers up to MMMCMXCIX here>"
else	
	ARGV.each {|r| puts "%16s := %s"%[r.upcase,spqr(r)]}
end