LeetCode OJ : 5 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, and there exists one unique longest palindromic substring.

求字符串中的最长回文字符串；
我的思路比较简单，但是实现起来代码看着好乱。。。从第一个字符开始遍历，直到最后一个字符，对每一个在index位置的字符进行判断；
如果最长回文字符串是奇数，则判断--index和++index是否相等；
如果最长回文字符串是偶数，则判断index和++index是否相等；

class Solution {public:    string longestPalindrome(string s) {        int maxlen = 0, index = 0, length;                if (s.size() < 3){            return s;        }        for (int i = 0; i < s.size()-1; ++i){            length = findPalindrome(s, i);            if (maxlen < length){                maxlen = length;                index = i;            }        }                if (maxlen % 2 == 0)            index = index - maxlen/2 + 1;        else            index = index - maxlen/2;        string longestSubString(s, index, maxlen);        return longestSubString;    }    int findPalindrome(string &s, int index){        int l_index = index-1, r_index = index+1;        int length1 = 1, length2 = 0;                /*针对abvba这种奇数的情况*/        while((s[l_index--] == s[r_index++]) && (r_index <= s.size())){            length1 += 2;        }                /*针对abba这种偶数的情况*/        l_index = index;        r_index = index+1;        while((s[l_index--] == s[r_index++]) && (r_index <= s.size())){            length2 += 2;        }                return (length1 > length2) ?  length1 : length2;    }};

虽然代码看着恶习，但是运行效率还阔以，Runtime: 72 ms；我再找找其它的方法；