LeetCode - Combinations Sum II

class Solution {
public:
    vector<vector<int>> combinationSum2(vector<int>& candidates, int target) {
        sort(candidates.begin(), candidates.end());
        vector<vector<int>> res;
        vector<int> out;
        helper(candidates, 0, target, out, res);
        return vector<vector<int>>(res.begin(), res.end());
    }
    void helper(vector<int>& candidates, int pos, int target, vector<int>& out, vector<vector<int>>& res){
        if(target==0) res.push_back(out);
        else if(target<0) return;
        else{
            for(int i=pos; i<candidates.size();i++){
                if(i!=pos && candidates[i]==candidates[i-1] ) continue;
                // if (i > pos && candidates[i] == candidates[i - 1]) continue;
                out.push_back(candidates[i]);
                helper(candidates, i+1, target-candidates[i], out, res);
                out.pop_back();
            }
        }
    }
};