// https://www.geeksforgeeks.org/euclidean-algorithms-basic-and-extended/
// PGCD de deux nombres entiers
#include <iostream>
using namespace std;

// Function to return gcd of a and b
int gcd(const int a, const int b)
{
	if(a == 0)
		return b;

	return gcd(b % a, a); // appel récursif
} // gcd()

int main()
{
	int a = 10, b = 15;
	cout << "GCD(" << a << ", " << b << ") = " << gcd(a, b) << '\n';

	a = 35, b = 10;
	cout << "GCD(" << a << ", " << b << ") = " << gcd(a, b) << '\n';

	a = 31, b = 2;
	cout << "GCD(" << a << ", " << b << ") = " << gcd(a, b) << '\n';

	return 0;
} // main()