LeetCode409 Longest Palindrome

public int longestPalindrome(String s) {
        if (s.length() == 0) return 0;
        if (s.length() == 1) return 1;
        int[] recordLow = new int[26];
        int[] recordUp = new int[26];
        int count = 0;
        boolean extra = false;
        for (int i = 0; i < s.length(); i++) {
            char c = s.charAt(i);
            if (c - 'a' >= 0) recordLow[c - 'a']++;
            else recordUp[c - 'A']++;
        }

        for (int i = 0; i < 26; i++) {

            if (recordLow[i] % 2 == 0)
                count += recordLow[i] / 2;
            else {
                count += (recordLow[i] - 1) / 2;
                extra = true;
            }

            if (recordUp[i] % 2 == 0)
                count += recordUp[i] / 2;
            else {
                count += (recordUp[i] - 1) / 2;
                extra = true;
            }
        }

        if (extra) return count * 2 + 1;
        else return count * 2;
    }