0409 Longest Palindrome

class Solution {
    func longestPalindrome(_ s: String) -> Int {
       var map = [Character: Int]()
       for (_, char) in s.enumerated() {
           if map.keys.contains(char) {
               map[char]! += 1
           } else {
               map[char] = 1
           }
       }

       var oddCountFound = false;
       var answer = 0;
       for (idx, (key, val)) in map.enumerated() {
           if val % 2 == 1 {
               oddCountFound = true;
               answer += val - 1
           } else {
               answer += val
           }
       }
       if oddCountFound {
           return answer + 1
       } else {
           return answer
       }
    }
}