//4. 写一函数fac(n) 求n!。在主函数中输入a，b两个整数，输出求a!+b!的值。
include <stdio.h>int digui (int a)
{
int b;
if (a<0)
{
printf("输出错误\n",a);
return 0;
}
else if ((a==0 )|| (a==1))
{
return 1;
}
else
{
b =digui(a-1)*a;
}
return b;
}
int main ()
{
int a,b;
scanf("%d%d",&a,&b);
printf ("%d的递归为%d\n",a,digui(a));
printf ("%d的递归为%d\n",b,digui(b));
return 0;
}