Leetcode 40 Solution

class Solution {
    vector<int> cur;
    set<vector<int>> m_res;

public:
    void combinationSum(vector<int>& candidates, int target, int cur_sum, int from) {
        if (cur_sum > target)
            return;
        else if (cur_sum == target)
        {
            m_res.insert(cur);
            return;
        }
        
        for (int i = from; i < candidates.size(); i++)
        {
            int v = candidates[i];
            cur.push_back(v);
            
            int next = i + 1;
            combinationSum(candidates, target, cur_sum + v, i + 1);
            cur.pop_back();
        }
    }

    vector<vector<int>> combinationSum2(vector<int>& candidates, int target) {
        sort(candidates.begin(), candidates.end());
        combinationSum(candidates, target, 0, 0);
        
        vector<vector<int>> res;
        
        for (auto it = m_res.begin(); it != m_res.end(); it++)
            res.push_back(*it);
        return res;
    }
};