trival
class Solution {
public:
int longestPalindrome(string s) {
map<char,int> count;
for(int i=0;i<s.length();i++)
count[s[i]]++;
int lengthPal=0;
int oddFlag=0;
for(map<char,int>::iterator it=count.begin();it!=count.end();it++)
{
if(it->second%2==0)
lengthPal+=it->second;
else
{
if(oddFlag==0)
{
lengthPal+=it->second;
oddFlag=1;
}
else
lengthPal+=it->second-1;
}
}
return lengthPal;
}
};