Permutation II.py

class Solution:
    def permuteUnique(self, nums: List[int]) -> List[List[int]]:
        res = []
        perm = []
        
        count = { n:0 for n in nums }
        
        for n in nums:
            count[n] += 1
            
        def dfs():
            if len(perm) == len(nums):
                res.append(perm.copy())   #we are making a copy as one variable and perm will be updated everytime
                return
            
            for n in count:
                
                if count[n] > 0:
                    perm.append(n)
                    count[n] -= 1
                    
                    dfs()
                    
                    count[n] += 1
                    perm.pop()
                    
        dfs()
        return res