黑马程序员-.NET-C#查找字符串的所有排列组合

C#查找字符串的所有排列组合问题

<pre name="code" class="csharp">static string[] FindPermutations(string word)
{
if (word.Length == 2)
{
char[] _c = word.ToCharArray();
string s = new string(new char[] { _c[1], _c[0] });
return new string[]{word,s};
}

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

string[] _subsetPermutations = FindPermutations(word.Substring(1));
char _firstChar = word[0];
foreach (string s in _subsetPermutations)
{
string _temp = _firstChar.ToString() + s;
_result.Add(_temp);
char[] _chars = _temp.ToCharArray();
for (int i = 0; i < _temp.Length - 1; i++)
{
char t = _chars[i];
_chars[i] = _chars[i + 1];
_chars[i + 1] = t;
string s2 = new string(_chars);
_result.Add(s2);
}
}
return _result.ToArray();
}