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class Solution {
public:
//approach ->picking up the first element and using two pointers in consective elements
//tc->o(n2)
//sc-o(1)
    vector<vector<int>> threeSum(vector<int>& nums)
    {
        sort(nums.begin(),nums.end());
        int e=nums.size()-1;
        vector<vector<int>>ans;
        for(int i=0;i<nums.size();i++)
        {
            if(i!=0&&i<nums.size()&&nums[i]==nums[i-1])
            {
               continue;
            }
            //  while(i!=0&&i<nums.size()&&nums[i]==nums[i-1])
            // {
            //    i++;
            // }
            int target=-nums[i];
            int j=i+1;
            int e=nums.size()-1;
            while(j<e)
            {
               long long int s=nums[j]+nums[e];
                if(s==target)
                {
                    ans.push_back({nums[i],nums[j],nums[e]});
                    j++;
                    while(j<e&&nums[j]==nums[j-1])
                    j++;
                    e--;
                    while(j<e&&nums[e]==nums[e+1])
                    e--;
                }
                else if(s>target)
                e--;
                else
                j++;
            }
        }
        return ans;
    }
};