123页30 题（第三章）

 

#include<stdio.h>
int main()
{
 double fun(double m,double n,double S1,double S2);
 double m,n,S1,S2;char ch;
 do
 {
     printf("请输入行号和列号：");
     scanf("%lf%lf",&m,&n);
     S1=m-1;
        S2=m-n;
     printf("第%.0lf行第%.0lf列的数是：%.0lf\n",m,n,fun(m,n,S1,S2));
  printf("是否继续？[y/n][y]");
  while((ch=getchar())!='\n');
 }while((ch=getchar())=='y'||ch=='\n');
 return 0;
}
double fun(double m,double n,double S1,double S2)
{
 double i;
 for(i=m-2;i>=1;i--)
  S1=S1*i;
 for(i=m-n-1;i>=1;i--)
  S2=S2*i;
 return S1/S2;
}