1 public class Solution { 2     /** 3      * @param s input string 4      * @return the longest palindromic substring 5      */ 6     public static String longestPalindrome(String s) { 7         if (s == null || s.isEmpty()){ 8             return null; 9         }10         int left = 0;11         int right = 0;12         int len = s.length();13         int longest = 0;14         for (int i = 0; i < len; i++){15             for (int j = i + 1; j <= len; j++){16                 String cub = s.substring(i, j);17                 if (isPalindroma(cub) && cub.length() > longest){18                     longest = cub.length();19                     left = i;20                     right = j;21                 }22             }23         }24         String result = s.substring(left, right);25         return  result;26 27     }28     public static boolean isPalindroma(String s){29         if (s == null || s.isEmpty()){30             return false;31         }32         int len = s.length() - 1;33         for (int i = 0; i <= len; i++){34             if (s.charAt(i) != s.charAt(len - i)){35                 return false;36             }37         }38         return true;39     }40 }