Leetcode palindrome permutation

The original title link is here: https://leetcode.com/problems/palindrome-permutation/

Topic:

Given a string, determine if a permutation of the string could form a palindrome.

For example,
"code", False, "aab" True, "carerac" .

Exercises

See if you can pair it up.

Time Complexity:o (n). Space:o (n).

AC Java:

1  Public classSolution {2      Public BooleanCanpermutepalindrome (String s) {3         if(s = =NULL|| S.length () <= 1){4             return true;5         }6hashset<character> HS =NewHashset<character>();7          for(inti = 0; I<s.length (); i++){8             if(!Hs.contains (S.charat (i))) {9 Hs.add (S.charat (i));Ten}Else{ One Hs.remove (S.charat (i)); A             } -         } -         returnHs.size () = = 1 | | Hs.size () = = 0; the     } -}

can be used bitmap

1  Public classSolution {2      Public BooleanCanpermutepalindrome (String s) {3         if(s = =NULL|| S.length () <= 1){4             return true;5         }6         int[] Map =New int[256];7          for(inti = 0; I<s.length (); i++){8Map[s.charat (i)]++;9         }Ten         intCount = 0; One          for(inti = 0; i<256; i++){ A             if(count = = 0 && map[i]%2 = = 1) {//the first occurrence of frequency is an odd char -count++; -}Else if(Map[i]% 2 = = 1) {//the second occurrence of frequency is an odd char the                 return false; -             } -         } -         return true; +     } -}

Keep up with palindrome permutation ii.

Leetcode palindrome permutation