问题
I am tracking changes in a web-page using Ruby. After I removed all html tags and blank lines, I get an array of lines which needs to be checked for additions/removals assuming that there may be repetitions. Could you recommend a good gem if it has been done already?
I could make the array lines unique and then the problem is avoided. But what if I need to track the repeated lines as well with respect to their position in the text?
回答1:
Sounds like a textbook case of where you'd want to use the Diff algorithm.
There's a 'diff' gem, although to be fair I've never used it: http://rubygems.org/gems/diff
来源：https://stackoverflow.com/questions/4441458/compare-two-versions-of-a-text-file-and-find-additions-removals-with-ruby