这个可以精确e的1000次代码的算法是什么意思

int main()
{
    const int N = 1000;
    int a[N];
    int s = 1;
    for (int n = N; n >= 1; --n)
    {
        int r = s % n;
        s = s / n + 1;
        for (int i = 0; i < N; ++i)
        {
            r = r * 10 + a[i];
            a[i] = r / n;
            r %= n;
        }
        for (int i = N - 1; i > 0; --i)
        {
            a[i - 1] += a[i] / 10;
            a[i] %= 10;
        }
        s += a[0] / 10;
        a[0] %= 10;
    }
    printf("%d.", s);
    for (int i = 0; i < N; ++i)
        printf("%d", a[i]);
    printf("\n");

    return 0;

}

error reading the project file or the SLD configuration
各位大神 http://hub.qgis.org/projects/quantum-gis/wiki/QGIS_Server_Tutorial#QGIS-Server-configuration
我按照链接的步骤 安装了OsGeo4W-Installer 用Windows7 系统
appache 安装似乎不正确，因为链接不