why this code not working, it always show duplicates how to avoid it

Question

class Solution {
public:
vector<vector<int>> threeSum(vector<int>& nums) {
vector<vector<int>> ans;
vector<int>temp;
sort(nums.begin(), nums.end());
int n= nums.size();
for(int i= 0;i<n-2;i++) {
for(int j= i+1;j<n-1;j++) {
for(int k= j+1;k<n;k++) {
temp.clear();
if(nums[i] + nums[j] + nums[k]==0) {
temp.push_back(nums[i]);
temp.push_back(nums[j]);
temp.push_back(nums[k]);
}
if(temp.size()!= 0) {
ans.push_back(temp);
}
}
}
}
return ans;
}
};

Answer 1

I don't know much c++ however if you don't want duplicates I would recommend using a set.