编写一个程序：求1！+2！+3！+4!+···+20!

#include <stdio.h>
void main()
{int sum=0,a=1,i,b=1;
for (;a<=20;a++)
{for (i=1;i<=a;i++)
b*=i;
sum+=b;}
printf("sum=%d",sum);}

#include <vcl.h>
#pragma hdrstop
#include<iostream.h>
//---------------------------------------------------------------------------
using namespace std;
#pragma argsused
int main(int argc, char* argv[])
{
int i,n=20,sum=0,t=1;
for(i=1;i<=n;i++)
{
t*=i;
sum+=t;
}
cout<<"sum ="<<sum<<endl;
system("pause");
return 0;
}