官方链接
https://leetcode-cn.com/problems/permutations-ii
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] ]
视频资源
解法一
class Solution:
def permuteUnique(self, nums: List[int]) -> List[List[int]]:
self.res = []
self.used = [False] * len(nums)
self.dfs(sorted(nums), [])
return self.res
def dfs(self, nums, temp):
if len(nums) == len(temp):
self.res.append(temp[:])
for i in range(len(nums)):
if self.used[i]: continue
if i > 0 and nums[i] == nums[i-1] and self.used[i-1]: continue
self.used[i] = True
temp.append(nums[i])
self.dfs(nums, temp)
self.used[i] = False
temp.pop()