// Source : https://leetcode.com/problems/longest-palindrome/ // Author : Hao Chen // Date : 2016-11-13 /*************************************************************************************** * * Given a string which consists of lowercase or uppercase letters, find the length of * the longest palindromes that can be built with those letters. * * This is case sensitive, for example "Aa" is not considered a palindrome here. * * Note: * Assume the length of given string will not exceed 1,010. * * Example: * * Input: * "abccccdd" * * Output: * 7 * * Explanation: * One longest palindrome that can be built is "dccaccd", whose length is 7. ***************************************************************************************/ class Solution { public: int longestPalindrome(string s) { int hashtable[128]; memset(hashtable, 0, sizeof(hashtable)); for(char ch : s) { hashtable[ch]++; } int result = 0; bool hasOdd = false; for (int n : hashtable) { if ( n%2 == 0 ) { result += n; } else { result += n -1; hasOdd = true; } } return hasOdd ? result + 1 : result; } };