Combination Sum

class Solution {
public:
    vector<vector<int> > ans;
    
    int targetG, len;
    
    vector<int> candidatesG;
    
    void search(int start, int sum, vector<int>& tmp)
    {
        if (sum == targetG)
        {
            ans.push_back(tmp);
            return;
        }
        
        if (start>=len || sum>targetG)
            return;
        
        for (int i=0; i*candidatesG[start]+sum<=targetG; ++i)
        {
            vector<int> tmpV(i, candidatesG[start]);
            tmpV.insert(tmpV.begin(), tmp.begin(), tmp.end());
            search(start+1, sum+i*candidatesG[start], tmpV);
        }
    }

    vector<vector<int> > combinationSum(vector<int> &candidates, int target) {
        // Start typing your C/C++ solution below
        // DO NOT write int main() function
        ans.clear();
        
        targetG = target;
        len = candidates.size();
        
        sort(candidates.begin(), candidates.end());
        candidatesG = candidates;
        vector<int> tmp;
        
        search(0, 0, tmp);
        
        return ans;
    }
};