NCR

This algorithm finds all the possible combination of the value n and r.

									/*****Please include following header files*****/
// cstdint
/***********************************************/

int64_t Factorial(int number) {
	if (number < 0)
		return -1; //Error

	int64_t result = 1;

	for (int i = 1; i <= number; ++i)
		result *= i;

	return result;
}

int64_t NCR(int n, int r) {
	return Factorial(n) / (Factorial(r) * Factorial(n - r));
}

Example

									int64_t ncr = NCR(5, 2);

Output