combination sum

class Solution {
public:
vector<vector<int>> combinationSum(vector<int>& candidates, int target) {
vector<vector<int>> path;
vector<int> p;
sort(candidates.begin(),candidates.end());
help(0,target,candidates,path,p);
return path;
}

void help(int index,int target,vector<int>& candidates,vector<vector<int>> &path,vector<int> &p){
int i;
for(i=index;i<candidates.size();i++){
if(target < candidates[i]) {
return;
}

p.push_back(candidates[i]);

if(target == candidates[i]) {
path.push_back(p);
p.pop_back();
return;
}
help(i,target-candidates[i],candidates,path,p);
p.pop_back();
}
return;

}
};