leetcode

0 class Solution {

1 public:

2 int longestPalindrome(vector<string> &words) {

3 unordered_map<string, int> um;

4 for (string &w : words)

5 um[w]++;

6

7 bool odd = false;

8 int res = 0;

9 for (const auto &[s, count] : um) {

10 if (!count) continue;

11

12 if (s[0] == s[1]) {

13 if (count % 2 == 0) {

14 res += count;

15 } else {

16 res += count - 1;

17 odd = true;

18 }

19 } else if (s[0] < s[1] && um.count({s[1], s[0]})) {

20 res += min(count, um[{s[1], s[0]}]) * 2;

21 }

22 }

23 if (odd) res++;

24 return res * 2;

25 }

26 };