<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:
    vector<vector<int>> result;
    vector<int> temp;
    int N;
    void solve(unordered_map<int,int> mp){
        if(temp.size() >= N){
            result.push_back(temp);
            return;
        }
        
        for(auto &[num, count] : mp){
            if(count == 0) continue;
            temp.push_back(num);
            mp[num]--;
            solve(mp);
            temp.pop_back();
            mp[num]++;
        }
    }

    vector<vector<int>> permuteUnique(vector<int>& nums) {
        N = nums.size();
        unordered_map<int,int> mp;
        unordered_set<int> st;

        for(int &num : nums)
            mp[num]++;
        
        solve(mp);

        return result;
    }
};
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