Permutations II · Interview Problem

Leetcode

permutations-ii

Medium

Backtracking

Arrays

Permutations II

Generate all unique permutations of a list of numbers that might contain duplicates.

Acceptance 67%

Problem Statement

Core description from the backend problem record.

Given a collection of numbers, nums, that might contain duplicates, return all possible unique permutations in any order.

The input is a list of integers nums, which may contain duplicate elements.

Return a list of lists, where each inner list is a unique permutation of the input list.

1 <= nums.length <= 8 -10 <= nums[i] <= 10

Examples

Sample cases returned by the problem API.

Example 1

Input

[1,1,2]

Output

[[1,1,2],[1,2,1],[2,1,1]]

Explanation

All unique permutations of [1,1,2] are returned without duplicates.

Loading Preptin