小算法：递归实现回文判断

static void Main(string[] args)

        {

            DateTime dt1 = DateTime.Now;



            string text = "abcdedcba";

            bool bYes = Recv(text);

            Console.Write("{0}：{1}回文！", text, bYes ? "是" : "不是");



            DateTime dt2 = DateTime.Now;

            Console.Write("耗时：{0}毫秒", (dt2 - dt1).TotalMilliseconds.ToString());

            Console.ReadLine();

        }



        private static bool Recv(string text)

        {

            string head = text.Substring(0, 1);

            string end = text.Substring(text.Length - 1, 1);

            if (head == end)

            {

                if (text.Length == 1)

                    return true;

                string t = text.Substring(1, text.Length - 2);

                return Recv(t);

            }

            return false;

        }