Firstly, welcome to the forums.
While we are primarily here to help people with their Free Code Camp progress, we are open to people on other paths, too.
With your current questions, we don’t have enough context to know what you already know or don’t know, so it is impossible to guide you without just telling you the answer (which we won’t do).
It is pretty typical on here for people to share a codepen / repl.it / jsfiddle example of what they have tried so that anyone helping has more of an idea of what help is actually helpful.
Please provide some example of what you’ve tried and I’m sure you’ll get more help.
Happy coding 
Actually, I don’t know C++ right now… So, please help me with this question…
I don’t know C++, but in this forum if you need help you will need to provide what you have tried - then, someone that can help will point out what’s wrong and what you could do better, without giving you the answer
I can suggest a C++ tutorial
Anyone you know good at C++?
there are people that knows C++ that help in this forum, try yourself, show what you have tried, and someone will come along to help.
Although there are people here who can help you with your C++ code, we will not write it for you.