public class Solution {
    public boolean canPermutePalindrome(String s) {
        HashSet<Character> set = new HashSet<>();
        
        for(int i=0; i<s.length(); i++)
        {
            if(!set.contains(s.charAt(i)))
                set.add(s.charAt(i));
            else
                set.remove(s.charAt(i));
        }
        
        return set.size()==0 || set.size()==1;
        
    }
}