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" 题目含义：查找最长的回文子串

1 class Solution { 2    private int low, maxLen; 3  4     private void huiwen(String s, int i, int j) { 5         while (i >= 0 && j < s.length() && s.charAt(i) == s.charAt(j)) { 6             i--; 7             j++; 8         } 9         if (maxLen < j - i - 1) {10             low = i + 1;11             maxLen = j - i - 1;12         }13     }14     public String longestPalindrome(String s) {15         if (s.length() < 2) return s;16         for (int i = 0; i < s.length()-1; i++) {17             huiwen(s, i, i);18             huiwen(s, i, i + 1);19         }20         return s.substring(low, low+maxLen);  21     }22 }