private:

vector<vector<int> > ret;

vector<int> a;

public:

void solve(int dep, int maxDep, int target, vector<int> &cand) {

if (target < 0) return;

if (dep == maxDep) {

if (target == 0) {

vector<int> res;

for (int i = 0; i < maxDep; i++)

for (int j = 0; j < a[i]; j++) res.push_back(cand[i]);

ret.push_back(res);

}

return;

}

for (int i = 0; i <= target / cand[dep]; i++) {

a[dep] = i;

solve(dep + 1, maxDep, target - cand[dep] * i, cand);

}

}

vector<vector<int> > combinationSum(vector<int> &candidates, int target) {

// Start typing your C/C++ solution below

// DO NOT write int main() function

sort(candidates.begin(), candidates.end());

a.resize(candidates.size());

ret.clear();

if (candidates.size() == 0) return ret;

solve(0, candidates.size(), target, candidates);

return ret;

}

/* code */

return 0;

}