Given a string, determine if a permutation of the string could form a palindrome.
For example,
"code" -> False, "aab" -> True, "carerac" -> True.
Solution：hashmap(bucket)count or hashset
Time Complexity: O(N) Space Complexity: O(N)
Solution Code：
class Solution {
public boolean canPermutePalindrome(String s) {
Set<Character> set=new HashSet<Character>();
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;
}
}
