recursion and inaccurate results

I just made a fraction simplifying program, and everything works except for one thing. When I run the program the first time, the answers are exact. But, when I recurse the main() function I get an answer that is close, but maybe off by a couple decimal places. This has happened to me with other programs before and I was just wondering what the cause of this was.

Code:

#include <iostream>
#include <vector>
using namespace std;
vector<int>toping;
vector<int>bottoming;

	
void process (int number, vector<int> &which)
{
	for (int index = 1; index <= number; ++index)
	{
		if (number%index == 0)
		{
			which.push_back(number/index);
		}					
	}
}

int compare (int top, int bottom)
{
	for (int index = 0; index < toping.size(); ++index)
	{
		for (int endex = 0; endex < bottoming.size(); ++endex)
		{
			if (toping[index] == bottoming[endex])
			{
				return bottoming[endex];
			}
		}
	}
	cout << "Error: Compare" << endl;
}

int main()
{
	int top = 0, bottom = 0, common = 0;
	int newtop = 0, newbottom = 0, flag = 0;
	char again;

	cout << "Numerator: ";
	cin >> top;
	if (top == 0)
	{
		return 0;
	}
	else if (top < 0)
	{
		top = top * -1;
	}

	cout << "Denominator: ";
	cin >> bottom;
	cout << endl;
	if (bottom == 0)
	{
		return 0;
	}
	else if (bottom < 0)
	{
		bottom = bottom * -1;
	}

	process(top, toping);
	process(bottom, bottoming);
	common = compare(top, bottom);
	newtop = top / common;
	newbottom = bottom / common;
	
	cout << '\t' << newtop << " / " << newbottom << endl << endl;
	if (common == 1)
	{
		cout << "Fraction is in lowest terms." << endl;
	}
	else if (common > 1)
	{
		cout << "The GCF is " << common << endl;
	}

	cin >> again;
	main(); // recurse main program
	return 0;
}

Nevermind, I solved my own problem. Haha, forgot to clear the vectors. Sorry...

You can't recurse main in C++. This is only allowable in C. You should use a loop:

Code:

do {
	int top = 0, bottom = 0, common = 0;
.
.
	cin >> again;
} while (again != 'n');

Good to know, thanks.