This is a practice problem from a book, "Jumping into C++" by Alex Allain:
"Implement the source code that turns numbers into English text for numbers between -2 billion and 2 billion."
I want to know if the author is asking for a program that has the user input a number before having it turn it into text or if he just wants a program that lists every number from -2 billion to 2 billion in text fashion. To me, the problem sounds hard either way, but the former more so than the latter.
If you consider turning an arbitrary number into text as a function, then the only difference between your two interpretations is calling that function after prompting the user for a number, or calling that function inside a loop.
Frankly, the second interpretation doesn't make any sense. What are you going to do with 4 billion text strings? Display them on the console?