<p>Given a collection of numbers, <code>nums</code>,&nbsp;that might contain duplicates, return <em>all possible unique permutations <strong>in any order</strong>.</em></p>

<p>&nbsp;</p>
<p><strong class="example">Example 1:</strong></p>

<pre>
<strong>Input:</strong> nums = [1,1,2]
<strong>Output:</strong>
[[1,1,2],
 [1,2,1],
 [2,1,1]]
</pre>

<p><strong class="example">Example 2:</strong></p>

<pre>
<strong>Input:</strong> nums = [1,2,3]
<strong>Output:</strong> [[1,2,3],[1,3,2],[2,1,3],[2,3,1],[3,1,2],[3,2,1]]
</pre>

<p>&nbsp;</p>
<p><strong>Constraints:</strong></p>

<ul>
	<li><code>1 &lt;= nums.length &lt;= 8</code></li>
	<li><code>-10 &lt;= nums[i] &lt;= 10</code></li>
</ul>

class Solution {
public:
void Unique(vector<int>& nums,  vector<int>&v, set<vector<int>>&ans) {

                if(nums.size()==0)
                {
                    if(ans.find(v)==ans.end())
                    {
                        ans.insert(v);

                    }
                    return ;
                }

                for(int i =0;i<nums.size();i++)
                {
                    int curr = nums[i];

                    vector<int>remain;
                    // vector<int>v;
                    remain.insert(remain.end(), nums.begin(),nums.begin()+i);
                    remain.insert(remain.end(), nums.begin()+i+1,nums.end());
                    v.push_back(curr);
                    Unique(remain,v,ans);

                     v.pop_back();
                }
    }
    vector<vector<int>> permuteUnique(vector<int>& nums) {
        vector<int>v;
        set<vector<int>>s;
        vector<vector<int>>ans2;
        Unique(nums,v,s);
        for(auto i:s){

            ans2.push_back(i);
        }
        return ans2;
    }
};
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