编写一个求n!的递归调用函数，求SUM=4! +10! +13!

private function fn(n as integer)as double
if n=1 then
fn=1
exit function
end if
n=n*fn(n-1)
end function

private sub command1_click()
print "SUM=" & (fn(4) + fn(10) + fn(13))
end sub

#include <stdio.h>
#include <string.h>
int fun(int n)
{
if(n==1)return 1;
else
return n*fun(n-1);}
int main()
{int sum=0;
sum=fun(4)+fun(10)+fun(13);
printf("%d",sum);
return 0;
getch();}