高效率的全组合算法(按順序)

//來源:http://topic.csdn.net/u/20090217/21/f41ed9f6-f929-451c-a5c9-80d2e408422a.html#

C# code

 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);

}

运行结果：
A
B
C
D
E
AB
AC
AD
AE
BC
BD
BE
CD
CE
DE
ABC
ABD
ABE
ACD
ACE
ADE
BCD
BCE
BDE
CDE
ABCD
ABCE
ABDE
ACDE
BCDE
ABCDE