What was the difference between yours and theirs?

That's the sort of question that google was designed for :P But for this kata you can use either sprintf or stringstream. (you'll have to figure out how)

Read how to use markdown formatting so some things don't dissapear from your code when pasted here. I don't know C++ myself very well, but I'd check two things if I were you:

• Can you assign like that to an empty vector?
• Check what you're doing inside your loop, signature has only 3 elements

Good luck with that.

You can't view solutions of katas more than one level above yours, so either debug your code step by step and figure it out yourself what's wrong with it, ask for help showing your code and marking your post as having spoiler content, or solve more katas until you reach 7kyu and then you can forfeit this one.

It means you passed some test, while others made your code crash.