I had about the same LoC for my ruby solution. Time was way longer because I had to read at least three wikipedia articles on various aspects of modulo arithmet

I had about the same LoC for my ruby solution. Time was way longer because I had to read at least three wikipedia articles on various aspects of modulo arithmetic after I was so ashamed of my brute force solutions. Wonder if anyone tried frequency analysis since that should work well on an affine transform...