re = /1(?!.*[23456789])|2(?!.*[3456789])|3(?!.*[456789])|4(?!.*[56789])|5(?!.*[6789])|6(?!.*[789])|7(?!.*[89])|8(?!.*[9])|9(?!.*[9])/m
str = '26418917853216548456418745445321'
# Print the match result
str.scan(re) do |match|
puts match.to_s
end
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for Ruby, please visit: http://ruby-doc.org/core-2.2.0/Regexp.html