C++ File Organisation
Each class has their own ClassName.cpp and ClassName.h files. The .h files will hold all usages (#include statements) and declarations. The .cpp files will hold respective definitions.
.h style:
#ifndef PROJECTNAME_CLASSNAME_H
#define PROJECTNAME_CLASSNAME_H
#include <include>
class ClassName{
};
#endif // PROJECTNAME_CLASSNAME_H