Factorial Computation Program

Ok, so Im trying to write a program that computes factorials recursively.

Here is what Ive got (when I asked my teacher for help, he said my factorial.cpp has one key flaw but I cant find it)

Factorial.cpp

Code:

`int factorial(int N)`

{

//cout << "into factorial with " << N << endl;

if ( N < 1 )

return 1; // base case

//cout << " not a base case with N = " << N << endl;

int answer = factorial(N-1);

//cout << " returning " << answer << " as answer at N = " << N << endl;

return answer;

}

driveFactorial.cpp

Code:

#include <iostream>

#include <fstream>

using namespace std;

#include "factorial.cpp"

int main()

{

int FactForN = 1;

cout << "\n Factorial of what number? (negative to end) ";

while ( cin >> FactForN && FactForN > 0)

{

int answer = factorial(FactForN);

cout << "\n The factorial of " << FactForN << " is " << answer << endl;

cout << "\n Factorial of what number? (negative to end) ";

}

}

any help would be appreciated. Thanks!