C#で全ての組み合わせを取得する方法

    public static class Combinations<T>
    {
        public static List<T[]> GetCombinations(List<T[]> sourceList)
        {
            List<T[]> resultList = new List<T[]>();
            Stack<T> stack = new Stack<T>();
            GetCombinationsCore(stack, resultList, sourceList);

            return resultList;
        }

        private static void GetCombinationsCore(Stack<T> stack, List<T[]> resultList, List<T[]> sourceList)
        {
            int dimension = stack.Count;
            if (sourceList.Count <= dimension)
            {
                T[] array = stack.ToArray();
                Array.Reverse(array);
                resultList.Add(array);
                return;
            }
            else
            {
                foreach (T item in sourceList[dimension])
                {
                    stack.Push(item);
                    GetCombinationsCore(stack, resultList, sourceList);
                    stack.Pop();
                }
            }
        }
    }

    static void Main(string[] args)
    {
        List<string[]> sourceList = new List<string[]>(3);
        sourceList.Add(new string[] { "a", "b" });
        sourceList.Add(new string[] { "c", "d", "e" });
        sourceList.Add(new string[] { "f", "g", "h", "i" });
        List<string[]> resultList = Combinations<string>.GetCombinations(sourceList);

        foreach (string[] item in resultList)
        {
            Console.WriteLine(string.Join(",", item));
        }
    }