求1+2!+3!+...+20!的值

//阶乘函数声明
int jiesheng(unsigned n);
main（）
{
int n,rnsum;
for (int i=1;i<=n;i++)
{
rnsum+=jiesheng(i);
}
}
//阶乘函数
int jiesheng(unsigned n)
{
int result=1;
for (int i=1;i<=n;i++)
{
result=result*i;
}
return result;
}

vb程序
dim i,j,sum1,sum2 as integer
sum1=1
for i =1 to 20
for j=1 to i
sum1=sum1*j
next j
sum2=sum2+sum1
next i

int N(int x)
{
if(x==0)
{
return 1;
}else{
return x*N(x-1)
}
}

int iRet=0;
for(int i=1;i<=n;i++)
{
iRet += N(i);
}

qbasic源程序
s=0
n=1
t=1
while i<=20
t=t*n
s=s+t
n=n+1
wend
print s
end

定义成整型？小心溢出哦！！