题目：编写程序: 从键盘输入n,计算1!+2！+3！+4！+……+n!#include <iostream.h>
int main()
{
    int n,b,sum;
    b=1;
    sum=0;
    cout<<"n的阶乘是:";
    cin>>n;
    for(n=1; ;n++)
    {  
      n=b*n;
      sum=sum+n;
      break;
    }
      cout<<sum<<endl;
      system("pause");
}