描述

给定一个可包含重复数字的序列，返回所有不重复的全排列。

示例:

输入: [1,1,2]
输出:
[
  [1,1,2],
  [1,2,1],
  [2,1,1]
]

Python

backtracking四连

class Solution:
    def permuteUnique(self, nums):
        res = []
        nums.sort()
        self.backtracking(nums,[],res)
        return res
    
    def backtracking(self,nums,member,res):
        if not nums:
            res.append(member)
        for i in range(len(nums)):
            if i>0 and nums[i]==nums[i-1]:continue
            self.backtracking(nums[:i]+nums[i+1:],member+[nums[i]],res)