<p>Given an integer array <code>nums</code> that may contain duplicates, return <em>all possible</em> <span data-keyword="subset"><em>subsets</em></span><em> (the power set)</em>.</p>

<p>The solution set <strong>must not</strong> contain duplicate subsets. Return the solution in <strong>any order</strong>.</p>

<p>&nbsp;</p>
<p><strong class="example">Example 1:</strong></p>
<pre><strong>Input:</strong> nums = [1,2,2]
<strong>Output:</strong> [[],[1],[1,2],[1,2,2],[2],[2,2]]
</pre><p><strong class="example">Example 2:</strong></p>
<pre><strong>Input:</strong> nums = [0]
<strong>Output:</strong> [[],[0]]
</pre>
<p>&nbsp;</p>
<p><strong>Constraints:</strong></p>

<ul>
	<li><code>1 &lt;= nums.length &lt;= 10</code></li>
	<li><code>-10 &lt;= nums[i] &lt;= 10</code></li>
</ul>

class Solution {
public:

    void powerSet(vector<int>&nums,vector<vector<int>>&ans, vector<int>&aux, int i){
        if(i>=nums.size()){
            ans.push_back(aux);
            return;
        }

        aux.push_back(nums[i]);
        powerSet(nums,ans,aux,i+1);

        aux.pop_back();
        powerSet(nums,ans,aux,i+1);
    }

    vector<vector<int>> subsetsWithDup(vector<int>& nums) {
        sort(nums.begin(),nums.end());
        vector<vector<int>> ans;
        vector<int> aux;
        set<vector<int>> st;
        powerSet(nums,ans,aux,0);

        for(auto e:ans){
            st.insert(e);
        }
        ans.clear();
        for(auto it:st){
            ans.push_back(it);
        }

        return ans;
    }
};
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