要求用c语言 怎么写😭

Question

Answer 1

以下程序参考：

#include <stdio.h>
double fac(int n)
{
  int i;
  double f = 1;
  for (i = 2; i <= n; i++)
    f *= i;
  return f;
}
int main(void)
{
  int m, n;
  double r;
  scanf("%d%d", &m, &n);
  r = fac(n) / (fac(m) * fac(n - m));
  printf("result = %.f\n", r);
  return 0;
}