题目链接

https://leetcode-cn.com/problems/permutations-ii/

方法1 回溯

class Solution:
    def permuteUnique(self, nums: List[int]) -> List[List[int]]:

        o=[]


        def huisu(dangqianzhuangtai,kexuanzhuangtai):
            if not kexuanzhuangtai and dangqianzhuangtai not in o:
                o.append(dangqianzhuangtai)
            if not kexuanzhuangtai:
                return 
            # kexuanzhuangtai=kexuanzhuangtai
            for i in kexuanzhuangtai:
                t=dangqianzhuangtai[:]
                t.append(i)
                kz=kexuanzhuangtai[:]
                kz.remove(i)
                huisu(t,kz)


        huisu([],nums)

        return o