leetcode216

public class Solution {
    public IList<IList<int>> CombinationSum3(int k, int n)
        {
            int[] num = { , , , , , , , ,  };
            var result = new List<IList<int>>();
            helper(result, new List<int>(), num, k, n, );
            return result;
        }

        public void helper(List<IList<int>> result, List<int> list, int[] num, int k, int target, int start)
        {
            if (k ==  && target == )
            {
                result.Add(new List<int>(list));
            }
            else
            {
                for (int i = start; i < num.Length && target >  && k > ; i++)
                {
                    list.Add(num[i]);
                    helper(result, list, num, k - , target - num[i], i + );
                    list.RemoveAt(list.Count - );
                }
            }
        }
}

https://leetcode.com/problems/combination-sum-iii/#/description