{

vector<vector<int>> threeSum(vector<int>& nums) {

if(nums.size()<=2) return {};

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

vector<vector<int>>ans;

if(nums[nums.size()-1]<0) return {};

for(int i=0;i<nums.size()-2;i++){

if(nums[i]>0)break;

if(i>0 && nums[i]==nums[i-1]) continue;

int j=i+1,k=nums.size()-1;

while(k>j){

int s=nums[k]+nums[j];

if(nums[i]+s==0){

ans.push_back({nums[i],nums[j],nums[k]});

while(j<k && nums[j]==nums[j+1] ) j++;

while(j<k && nums[k]==nums[k-1] ) k--;

j++;

k--;

}

else if(nums[i]+s>0) k--;

else j++;

}

}

return ans;

}