题目：

题解：

class Solution {public int longestPalindrome(String s) {int[] count = new int[128];int length = s.length();for (int i = 0; i < length; ++i) {char c = s.charAt(i);count[c]++;}int ans = 0;for (int v: count) {ans += v / 2 * 2;if (v % 2 == 1 && ans % 2 == 0) {ans++;}}return ans;}
}