C#组合算法

  static string[] m_Data = { "A", "B", "C", "D", "E" };
        static void Main(string[] args)
        {
            Dictionary<string, int> dic = new Dictionary<string, int>();
            for (int i = 0; i < m_Data.Length; i++)
            {
                Console.WriteLine(m_Data[i]);//如果不需要打印单元素的组合，将此句注释掉
                dic.Add(m_Data[i], i);
            }
            GetString(dic);
            Console.ReadLine();
        }
        static void GetString(Dictionary<string, int> dd)
        {
            Dictionary<string, int> dic = new Dictionary<string, int>();
            foreach (KeyValuePair<string, int> kv in dd)
            {
                for (int i = kv.Value + 1; i < m_Data.Length; i++)
                {
                    //Console.WriteLine(kv.Key + " " + kv.Value + " " + i);
                    Console.WriteLine(kv.Key + m_Data[i]);
                    dic.Add(kv.Key + m_Data[i], i);
                }
            }
            //Console.WriteLine(dic.Count);
            if (dic.Count > 0) GetString(dic);
        }