LeetCode 409 LintCode 627 – Python 3 (Week 10 – 07)

class Solution:
    def longestPalindrome(self, s: str) -> int:
   
        if s is None:
            return 0
        ans = 0
        di = collections.Counter(s)
        center = False
        
        for st in di.keys():
            if di[st] % 2 == 0:
                ans += di[st]
            else:
                center = True
                ans += di[st] // 2 * 2
        if center:
            ans += 1
            
        return ans

 class Solution:
    """
    @param s: a string which consists of lowercase or uppercase letters
    @return: the length of the longest palindromes that can be built
    """
    def longestPalindrome(self, s):
        # write your code here
        if s is None:
            return 0

        hashTable = set()
        ans = 0
        for ch in s:
            if ch in hashTable:
                hashTable.remove(ch)
                ans += 2
            else:
                hashTable.add(ch)
                    
        if hashTable:
            ans += 1
       
        return ans