Longest Palindrome

Problem Statement:

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.



SOlution:
class Solution:
    def longestPalindrome(self, s: str) -> int:
        #### O(N),O(N)
        dict={}
        for i in s:
            if i not in dict:
                dict[i]=1
            else:
                dict[i]+=1
        cnt=0
        flag=False
        queue=[(i,j) for i,j in dict.items()]
        while queue:
            char,val=queue.pop(0)
            if val==1:
                flag=True
                continue
            if val%2==0:
                cnt+=val
            else:
                cnt+=val-1
                queue.append((char,1))
        if flag:
            return cnt+1
        else:
            return cnt