输出一个字符串所有排列。注意有重复字符

C# code as below:

递归写的，因为产生了老多string，效率很慢,除去了重复的字符串
public static List<string> OutPutString(string str)

{

List<string> list = new List<string>();

if (str.Length == 1)

{

list.Add(str);

return list;

}

char[] myCharArray = str.ToCharArray();

for (int i = 0; i < str.Length; i++)

{

string str1 = myCharArray[i].ToString();

//Use OutPutString(), remove myCharArray[i] fromstring

foreach (string str2 in OutPutString(str.Remove(i,1)))

{

//Remove duplicated string

if (!list.Contains(str1 + str2))

{

list.Add(str1 + str2);

}

}

}

return list;

}