习题2-18
求组合数
include<stdio.h>
double fact( int n);
double fact(int n)
{ double z=1.0;
int i;
for(i=1;i<=n;i++)
z=z*i;
return(z);
}
int main()
{ int m,n;
double C;
printf("请输入两个整数m,n\n");
scanf("%d %d",&m,&n);
if(m<=n)
{
C=fact(n)/(fact(m)*fact(n-m));
printf(" result=%.0f\n",C);
}
else
printf("输入错误");
return 0;
}