<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 helper(vector<int>& nums,vector<vector<int>>&ans,int i,vector<int> v){
        if(i==nums.size()){
            ans.push_back(v);
            return;
        }
        // if(i==0){
        // helper(nums,ans,i+1,v);
        // v.push_back(nums[i]);
        // helper(nums,ans,i+1,v);
        // }
        if(i>0&&nums[i-1]==nums[i]&&v.size()>0&&v.back()==nums[i]){
            v.push_back(nums[i]);
            helper(nums,ans,i+1,v);
        }
        else{
          helper(nums,ans,i+1,v);
          v.push_back(nums[i]);
          helper(nums,ans,i+1,v);
        }
    }
    vector<vector<int>> subsetsWithDup(vector<int>& nums) {
        sort(nums.begin(),nums.end());
        vector<vector<int>> ans;
        helper(nums,ans,0,{});
        return ans;
    }
};
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