90. Subsets II - LeetCode Solution

class Solution:
    def subsetsWithDup(self, nums: List[int]) -> List[List[int]]:
        ans = [[]]
        def trav(i, k):
            if i == len(nums):
                return
            
            for j in range(i, len(nums)):
                ans.append(sorted(k + [nums[j]]))
                trav(j+1, k+[nums[j]])
        
        trav(0, [])
        ans.sort()
        i = 0
        
        while i != len(ans)-1:
            if ans[i] == ans[i-1]:
                ans.pop(i)
                continue
            i+=1
  
        return ans