求一組9位數且不重複(19組成)，滿足前n位能被n整除，例如：取先二位能被2整除，取先三位能被3整除...取先九位能被9整除。

            Stopwatch l_cc_stopWatch = new Stopwatch();
            l_cc_stopWatch.Start();

            Random rad = new Random();
            while (true)
            {
                string ts = string.Empty;
                while (ts.Length < 9)
                {
                    string tmp = rad.Next(1, 10).ToString();
                    if (ts.IndexOf(tmp) < 0)
                    {
                        ts += tmp;  //得到9位不重複數
                    }
                }
                bool flag = false;
                for (int m = 2; m <= 9; m++)
                {
                    if (Int32.Parse(ts.Substring(0, m)) % m == 0)  //前n位能被n整除
                    {
                        flag = true;
                    }
                    else
                    {
                        flag = false;
                    }

                    if (flag == false)
                    {
                        break;
                    }
                }

                if (flag)
                {
                    Console.WriteLine(ts);
                    break;
                }
            }

            l_cc_stopWatch.Stop();
            Console.WriteLine("{0}:seconds", l_cc_stopWatch.Elapsed.TotalSeconds);