All Unique Permutations of a String

Problem Given a string s that may contain duplicate characters, return all unique permutations.

Input / Output

• Input: string s.
• Output: a list of all distinct permutations of s.

Constraints

• 1 ≤ |s| ≤ 8.
• Characters are uppercase English letters.

Example

• s="ABA" → ["AAB","ABA","BAA"]