高效率的全组合算法

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 + m_Data[i]);

                dic.Add(kv.Key + m_Data[i], i);

             }

      }

      if(dic.Count>0) GetString(dic);

}