<p>Given an integer array nums, return all the triplets <code>[nums[i], nums[j], nums[k]]</code> such that <code>i != j</code>, <code>i != k</code>, and <code>j != k</code>, and <code>nums[i] + nums[j] + nums[k] == 0</code>.</p>

<p>Notice that the solution set must not contain duplicate triplets.</p>

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

<pre>
<strong>Input:</strong> nums = [-1,0,1,2,-1,-4]
<strong>Output:</strong> [[-1,-1,2],[-1,0,1]]
<strong>Explanation:</strong> 
nums[0] + nums[1] + nums[2] = (-1) + 0 + 1 = 0.
nums[1] + nums[2] + nums[4] = 0 + 1 + (-1) = 0.
nums[0] + nums[3] + nums[4] = (-1) + 2 + (-1) = 0.
The distinct triplets are [-1,0,1] and [-1,-1,2].
Notice that the order of the output and the order of the triplets does not matter.
</pre>

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

<pre>
<strong>Input:</strong> nums = [0,1,1]
<strong>Output:</strong> []
<strong>Explanation:</strong> The only possible triplet does not sum up to 0.
</pre>

<p><strong class="example">Example 3:</strong></p>

<pre>
<strong>Input:</strong> nums = [0,0,0]
<strong>Output:</strong> [[0,0,0]]
<strong>Explanation:</strong> The only possible triplet sums up to 0.
</pre>

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

<ul>
	<li><code>3 &lt;= nums.length &lt;= 3000</code></li>
	<li><code>-10<sup>5</sup> &lt;= nums[i] &lt;= 10<sup>5</sup></code></li>
</ul>

class Solution {
public:
    vector<vector<int>> threeSum(vector<int>& nums) {
        set<vector<int>> result;

        sort(nums.begin(), nums.end());

        int sum = 0;

        for(int i : nums){
            if(i != 0){
                sum = 1;
                break;
            }
        }

        if(sum == 0){
            return vector<vector<int>> {{0, 0, 0}};
        }

        for(int i = 0; i  < nums.size()-2; i++){
            int target = -nums[i];
            int low = i+1;
            int high = nums.size()-1;
            while(high > low){
                if(nums[high] + nums[low] > target){
                    high--;
                }
                else if(nums[high] + nums[low] < target){
                    low++;
                }
                else{
                    vector<int> temp = {nums[i], nums[low], nums[high]};
                    sort(temp.begin(), temp.end());
                    result.emplace(temp);
                    low++;
                    high--;
                }
            }

        }
        vector<vector<int>> ans;

        for(auto i : result){
            ans.emplace_back(i);
        }

        return ans;

    }
};
312108