<p>Given an array <code>nums</code> of <code>n</code> integers, return <em>an array of all the <strong>unique</strong> quadruplets</em> <code>[nums[a], nums[b], nums[c], nums[d]]</code> such that:</p>

<ul>
	<li><code>0 &lt;= a, b, c, d&nbsp;&lt; n</code></li>
	<li><code>a</code>, <code>b</code>, <code>c</code>, and <code>d</code> are <strong>distinct</strong>.</li>
	<li><code>nums[a] + nums[b] + nums[c] + nums[d] == target</code></li>
</ul>

<p>You may return the answer in <strong>any order</strong>.</p>

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

<pre>
<strong>Input:</strong> nums = [1,0,-1,0,-2,2], target = 0
<strong>Output:</strong> [[-2,-1,1,2],[-2,0,0,2],[-1,0,0,1]]
</pre>

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

<pre>
<strong>Input:</strong> nums = [2,2,2,2,2], target = 8
<strong>Output:</strong> [[2,2,2,2]]
</pre>

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

<ul>
	<li><code>1 &lt;= nums.length &lt;= 200</code></li>
	<li><code>-10<sup>9</sup> &lt;= nums[i] &lt;= 10<sup>9</sup></code></li>
	<li><code>-10<sup>9</sup> &lt;= target &lt;= 10<sup>9</sup></code></li>
</ul>

class Solution {
public:
    vector<vector<int>> fourSum(vector< int>& a, int target) {
    vector <vector <int>> vec;
    int y=0,y1=0,kol;
    
    sort(a.begin(),a.end());
    long int kk;
    if (a.size()>3)
    {
        while(y<a.size()-4)
    {
        kol=0;
        while(y1<a.size())
        {
            if (a[y]==a[y1] and kol==4)
            {
                a.erase(a.begin()+y1);
                y1--;
            }
            if (a[y]==a[y1] and kol<4)
            {
             kol++;   
            }

            y1++;
        }
        y++;
    }
    for (int i = 0; i < a.size()-3; i++)
    {
        for (int j = i + 1; j < a.size() - 2;j++)
        {
            for (int k = j + 1; k < a.size() - 1; k++)
            {
                for (int z = k + 1; z < a.size(); z++)
                {
                    kk=a[i];
                    kk+=a[j];
                    kk+=a[k];
                    kk+=a[z];

                    if (kk==target)
                    {
                        vector <int> cash;
                        cash.push_back(a[i]);
                        cash.push_back(a[j]);
                        cash.push_back(a[k]);
                        cash.push_back(a[z]);
                      
                        if(find(vec.begin(), vec.end(), cash) == vec.end()){
                            vec.push_back(cash);
                        }
                    }
                    
                }
            }
        }
    }

    
    return vec;
    }
    else
    {
      return vec;  
    }
    }
};
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