用递归求阶乘

using System;
using System.Collections;
using System.Configuration;
using System.Data;
using System.Linq;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.HtmlControls;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Xml.Linq;

namespace DiGui
{
    public partial class _Default : System.Web.UI.Page
    {
        protected void Page_Load(object sender, EventArgs e)
        {
            Response.Write("3的阶乘为：" + DiGui(3).ToString());
        }

        private int DiGui(int n)
        {
            if (n == 0 || n == 1)
                return 1;
            else
                return n * DiGui(n - 1);
        }
    }
}