409. Longest Palindrome

摘要： Given a string which consists of lowercase or uppercase letters, find the length of the longest palindromes that can be built with those letters...

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.

難度：easy

題目：給定包含大小寫字元組成的字串，找出用這些字串所能夠成的最長迴文串。

思路：字元統計

Runtime: 5 ms, faster than 90.61% of Java online submissions for Longest Palindrome.

Memory Usage: 34.7 MB, less than 100.00% of Java online submissions for Longest Palindrome.

class Solution {
public int longestPalindrome(String s) {
int[] table = new int[255];
for (char c: s.toCharArray()) {
table[c]++;
}
int length = 0, odd = 0;
for (int i = 0; i < 255; i++) {
if (table[i] % 2 > 0) {
odd = 1;
}

length += table[i] - table[i] % 2;
}

return length + odd;
}
}