Longest Palindromic Substring

Given a string s, find the longest palindromic substring in s. You may assume that the maximum length of s is 1000.

Example:

Input: "babad"Output: "bab"Note: "aba" is also a valid answer.

Example:

Input: "cbbd"Output: "bb"

class Solution {public:    string longestPalindrome(string s) {        if (s.empty())        {            return "";        }        if (1 == s.size())        {            return s;        }        int maxLen = 0;        int len = s.size();        int table[len][len] = {0};                for (int i = 0; i < len; i++)        {            table[i][i] = 1;        }        string longstr = s.substr(0, 1);        maxLen = 1;        for (int i = 0; i < (len - 1); i++)        {            if (s[i] == s[i + 1])            {                table[i][i+1] = 1;                maxLen = 2;                longstr = s.substr(i, maxLen);                            }            else            {                table[i][i+1] = 0;            }        }                       for (int l = 3; l <= len; l++)       {           for (int i = 0; i <= (len - l); i++)           {               int j = i + l - 1;               if (s[i] == s[j])               {                   table[i][j] = table[i + 1][ j - 1];                   if (table[i][j] == 1 && l > maxLen)                    {                       maxLen = j + 1 - i;                       longstr = s.substr(i, maxLen);                                                                 }                                       }               else               {                   table[i][j] = 0;               }           }       }           return longstr;                    }};