leetcode 每日一题 47. 全排列 II

class Solution:
    def permuteUnique(self, nums: List[int]) -> List[List[int]]:
        def pathProcess(first,usedList:List[int]):
            if  first==n:
                res.append(nums[:])
            for i in range(first,n):
                if  i != first and nums[i] in usedList:
                    continue 
                nums[first],nums[i] = nums[i],nums[first]
                pathProcess(first+1,[])
                nums[first],nums[i] = nums[i],nums[first]
                usedList.append(nums[i])
        n = len(nums)
        res = []
        pathProcess(0,[])
        return res