// 1. remove first char
// 2. find permutations of the rest of chars
// 3. Attach the first char to each of those permutations.
// 3.1 for each permutation, move firstChar in all indexes to produce even more permutations.
// 4. Return list of possible permutations.
public string[] FindPermutations(string word)
{
if (word.Length == 2)
{
char[] _c = word.ToCharArray();
string s
= new string(new char[] { _c
[1], _c
[0] }); {
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();
}
//csharp/6443