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;
        }