用C语言或者C++编程

用一重循环编程计算s=1！+2！+3！+4！+…+20!

供参考：

# include <stdio.h>
int main()
{
    int i, n;
    double s = 0, k = 1;
    scanf("%d", &n);
    for (i = 1; i <= n; i++)
    {
        k *= i;
        s += k;
    }
    printf("S=%f\n", s);
    return 0;
}