給出一個包含大小寫字母的字串。求出由這些字母構成的最長的迴文串的長度是多少。資料是大小寫敏感的，也就是說，"Aa" 並不會被認為是一個迴文串。 注意事項假設字串的長度不會超過 1010。您在真實的面試中是否遇到過這個題？ Yes樣例給出 s = "abccccdd" 返回 7一種可以構建出來的最長迴文串方案是 "dccaccd"。class Solution {public: /** * @param s a string which consists of lowercase or uppercase letters * @return the length of the longest palindromes that can be built */ int longestPalindrome(string& s) { // Write your code heretypedef struct _mapval{bool isEven;int count; //字元數量}mapval;if(s.size() <= 0 ) return 0; mapphone2intmap;char *phones = new char [s.size()+1];memset(phones, 0, s.size()+1);strcpy(phones, s.c_str());char *tmpphone = phones;while(*tmpphone != '\0'){map::iterator it = phone2intmap.find(*tmpphone);if(it != phone2intmap.end()){it->second.isEven = (it->second.isEven == true)?false:true;it->second.count += 1;phone2intmap[it->first] = it->second;}else{mapval curval;curval.isEven = false;curval.count = 1;phone2intmap.insert(make_pair(*tmpphone, curval));}tmpphone++;}delete []phones;int sumEvenNum = 0;int sumOddNum = 0;int oddMaxLen = 0;bool flag = false;map::iterator it = phone2intmap.begin();while(it != phone2intmap.end()){if(it->second.isEven) sumEvenNum += it->second.count;else{flag = true;if(it->second.count > 2) sumOddNum += it->second.count - 1; }phone2intmap.erase(it++);}sumOddNum += (true == flag) ? 1 : 0;return (sumEvenNum + sumOddNum); }};