OP solved it, closing

Your tons of code make me laugh. +1 Clever for making my day, big brain :)

I was talking about .capacity, not the other one.

Function .rfind reads the "str" string and returns position of "ending" string from 0 to (.size - 1) or returns -1 if nothing is found. It's very useful to check where should be "ending" and form right condition.

but I want complete this code by this method

Why? There is really no reason to do that. I've never seen that method ever used in any kata, for obvious reasons (if you read its documentation). It probably has its uses elsewhere.

Ty. I know that there are other methods, but I want complete this code by this method. I used size and length too, but it was completely usefull.

No need to repeat the same question. Capacity might not work as you expect (for example it returns 15 for "abc"). There are other better methods for that purpose.

As I know, length is for string, but is a vector, that means dinamic array of strings. I used names.size()