I program on C++. This language lets to create projects that consist of several files. For example, I can create separate files with my own functions(in the project) and then use them in function main. But when I submit my solution there are only 2 options: print source code, or give source file(only one file). And how can I submit my solution if it consists of several files?

Make one file and submit it

I wanted to know if there is any way to submit several files?

No way