Creating file names automatically C++

Question

I\'m trying to write a program in C++, which creates some files (.txt) and writes down the result in them. The problem is that an amount of these files is not fixed at the begin

Answer 1

 for(int i=0; i!=n; ++i) {
     //create name
     std::string name="file_" + std::to_string(i) + ".txt"; // C++11 for std::to_string 
     //create file
     std::ofstream file(name);
     //if not C++11 then std::ostream file(name.c_str());
     //then do with file
 }