lec3_LongestPalandroone.cpp

https://leetcode.com/problems/longest-palindrome/description/
class Solution {
public:
    int longestPalindrome(string s) {

        vector<int> lower(26 , 0);
        vector<int>upper(26 , 0 );

        for( int i = 0  ; i<s.size();i++)
        {
            if(s[i]>='a')
            {
                lower[ s[i] - 'a']++;

            }
            else
            {
                upper[s[i]-'A']++;
            }
        }

        int count = 0 ;
        bool odd = 0 ;

        for(int i = 0 ; i<26 ; i++)
        {
            if(lower[i] %2 ==0)
            {
                count+= lower[i];

            }
            else
            {
                odd = 1; 
                count += lower[i]-1;
            }

            if(upper[i]%2==0)
            {
                count+=upper[i];
            }
            else
            {
                count+=upper[i]-1;
                odd =1 ;
            }

        }

        return odd +count;
        
    }
};