<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:
    int solve(vector<int>& arr, int target, int last, int& num) {
        int l = last + 1, r = arr.size() - 1, found = -1;

        while (l <= r) {
            int mid = (l + r) / 2;

            if (arr[mid] == target) {
                num = arr[mid];
                found = 1;
                break;
            } else if (target < arr[mid]) {
                r = mid - 1;
            } else {
                l = mid + 1;
            }
        }
        return found;
    }

    bool repeat(vector<vector<int>>& arr, int a, int b, int c, int d) {
        for (int i = 0; i < arr.size(); i++) {
            vector<int> nums = arr[i];
            if (nums[0] == a && nums[1] == b && nums[2] == c && nums[3] == d) {
                return true;
            }
        }
        return false;
    }

    vector<vector<int>> fourSum(vector<int>& nums, int target) {
        int n = nums.size();
        vector<vector<int>> ans;
        sort(nums.begin(), nums.end());

        for (int i = 0; i < n; i++) {
            for (int j = i + 1; j < n; j++) {
                for (int k = j + 1; k < n; k++) {
                    long long sum = 0;
                    sum = sum + nums[i] + nums[j] + nums[k];
                    if (sum <= INT_MIN || sum >= INT_MAX) continue;

                    int res = target - sum, num = -1;
                    // cout<<res<<" --- "<<nums[i]<<" --- "<<nums[j]<<" --- "<<nums[k]<<" -- "<<res<<"\n";
                    int isFound = solve(nums, res, k, num);
                    if (isFound != -1 && !repeat(ans, nums[i], nums[j], nums[k], num)) {
                        vector<int> tp = {nums[i], nums[j], nums[k], num};
                        ans.push_back(tp);
                    }
                }
            }
        }

        return ans;
    }
};
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