public List<List<Integer>> helper(List<List<Integer>> res, int[] c, int l, int h, int target, List<Integer> temp){
        if(target == 0){
            res.add(temp);
            System.out.println(temp);
            return res;
        }
        if(target < c[l]){
            return res;
        }
        for(int i = l; i <=h; i++){
            temp.add(c[i]);
            res = helper(res, c,i,h,target-c[i], temp);
            temp.remove(temp.size()-1);
        }
        return res;
    }

List<List<Integer>> res = new ArrayList<List<Integer>>();
List<Integer> temp = new ArrayList<Integer>();
res = helper(res,candidates, 0, candidates.length-1, target, temp);

[1, 1, 1, 1, 1, 1]
[1, 1, 1, 1, 2]
[1, 1, 1, 3]
[1, 1, 2, 2]
[1, 2, 3]
[2, 2, 2]
[3, 3]

res is [[],[],[],[],[],[],[]]

if(target == 0){
  ArrayList<Integer> copy = new ArrayList<>(temp);
  res.add(copy);
  return res;
}

public static List<List<Integer>> helper(List<List<Integer>> res, int[] c, int l, int h, int target, List<Integer> temp){
        if(target == 0){
            res.add(temp);
            System.out.println(temp);
            return res;
        }
        if(target < c[l]){
            return res;
        }
        for(int i = l; i <=h; i++){
            temp.add(c[i]);
            res = helper(res, c,i,h,target-c[i], new ArrayList<Integer>(temp));
            temp.remove(temp.size()-1);
        }
        return res;
    }