Chapter 1: simplify the same code decimal sum s (D, n)

int main()
{
    
	int d, n;
	double s;
	printf("  please enter an integer d, n");
	scanf("%d,%d", &d, &n);
	s = (n - 0.111111111) * d / 9;
	printf(" s(%d, %d) = %.8f\n", d, n, s);
	return 0;
	
}

The results verify that ：