# Subsets II

## Problem statement:

Given an integer array `nums`

that may contain duplicates, return *all possible* *subsets* *(the power set)*.

The solution set **must not** contain duplicate subsets. Return the solution in **any order**.**Example 1:****Input:** nums = [1,2,2]**Output:** [[],[1],[1,2],[1,2,2],[2],[2,2]]**Example 2:****Input:** nums = [0]**Output:** [[],[0]]**Constraints:**

* `1 <= nums.length <= 10`

* `-10 <= nums[i] <= 10`

### Solution in C++

### Solution in Python

### Solution in Java

### Solution in Javascript

## Solution explanation

The algorithm first sorts the given array, and then it generates all possible subsets. For each subset, it checks if it already exists in the result set. If not, it adds the subset to the result set.

The algorithm uses a backtracking approach. It starts with an empty subset and iteratively adds elements from the input array to the subset. It keeps track of the starting index to avoid creating duplicate subsets.

In the C++ and Java implementations, a `set`

data structure is used to store unique subsets. In the Python implementation, Python's `set`

is used along with itertools' `combinations`

function to achieve the same result. In the JavaScript implementation, a `Set`

object is used, but as it doesn't handle array comparisons properly, each subset is converted into a JSON string to compare the string representation of subsets.

At the end, the function returns the result set, converted into the desired format (list of lists or vector of vectors).