C语言：排列组合

#include<stdio.h>
int main()
{
	int m, n = 0;
	scanf_s("%d%d", &n, &m);
	int a = 1;
	int b = 1;
	int c = 1;
	int i = 0;
	for (i = n;i >= n - m + 1;i--)
		a *= i;
	for (i = 1;i <= m;i++)
		b *= i;
	c = a / b;
	printf("C(%d,%d)=%d\n", n, m, c);
	printf("A(%d,%d)=%d\n", n, m, a);
	return 0;
}