public class Solution {        private int lo, maxLen;        public String LongestPalindrome(String s)        {            int len = s.Length;            if (len < 2)                return s;            for (int i = 0; i < len - 1; i++)            {                extendPalindrome(s, i, i);  //assume odd length, try to extend Palindrome as possible                extendPalindrome(s, i, i + 1); //assume even length.            }            return s.Substring(lo, maxLen);        }        private void extendPalindrome(String s, int j, int k)        {            while (j >= 0 && k < s.Length && s[j] == s[k])            {                j--;                k++;            }            if (maxLen < k - j - 1)            {                lo = j + 1;                maxLen = k - j - 1;            }        }}