47-PermutationsII

Permutations II

Problem can be found in here!

Solution: Backtracking

def permuteUnique(nums: List[int]) -> List[List[int]]:
    def helper(tempt: List[int], counter: Counter):
        if len(tempt) == len(nums):
            result.append(tempt[:])
            return

        for key, value in counter.items():
            if value > 0:
                tempt.append(key)
                counter[key] -= 1
                helper(tempt, counter)
                tempt.pop()
                counter[key] += 1

    result = []
    helper([], Counter(nums))
    return result