simple c++ example

readme.txt

g++ * -o output
./output 4
24

factorial.cpp

#include "factorial.h"

int factorial(int x) {
	if (x==1) 
		return 1;
	else
		return x * factorial(x-1);
}

factorial.h

int factorial(int x);

main.cpp

#include "factorial.h"
#include <iostream>
#include <cstdlib>
using namespace std;

int main(int argc, char* argv[]) {
	int x = atoi(argv[1]);
	cout << "Invoking factorial on " << x << endl;
	int res = factorial(x);
	cout << "Result: " << res << endl;
	return 0;
}