题目
Given a collection of numbers, nums
, that might contain duplicates, return all possible unique permutations in any order.
Example 1:
Input: nums = [1,1,2]
Output:
[[1,1,2],
[1,2,1],
[2,1,1]]
Example 2:
Input: nums = [1,2,3]
Output: [[1,2,3],[1,3,2],[2,1,3],[2,3,1],[3,1,2],[3,2,1]]
Constraints:
1 <= nums.length <= 8
-10 <= nums[i] <= 10
思路
全排列,注意去重的方法是每次插入序列的元素时,只遍历到重复值出现前即可。
代码
python版本:
class Solution:
def permuteUnique(self, nums: List[int]) -> List[List[int]]:
res = [[]]
for n in range(len(nums)):
res = [r[:i]+[nums[n]]+r[i:] for r in res for i in range((r+[n]).index(n)+1)]
return res