Webastor - Programming Tips and Tricks

Hello, I have a small question to submit because I can not find the answer elsewhere, what does n - 1 do in c++? Please answer me quickly.

Hi, I would like to know if anyone knows though the correct x path is given, i couldn't automate the application with selenium web driver (php).how can i correct it? is there any solution? Thank you for answering the question quickly.