permutation in c#

Question

Is it possible to generate all permutations of a collection in c#?

char[] inputSet = { \'A\',\'B\',\'C\' };
Permutations permutations = new Permu         


        

Answer 1

A simple implementation using recursion

    static void Main(string[] args)
    {
        char[] inputSet = { 'A', 'B', 'C' };
        var permutations = GetPermutations(new string(inputSet));
        foreach (var p in permutations)
        {
            Console.WriteLine(String.Format("{{{0} {1} {2}}}", p[0], p[1], p[2]));
        }
    }

    public static List GetPermutations(string str)
    {
        List result = new List();

        if (str == null)
            return null;

        if (str.Length == 0)
        {
            result.Add("");
            return result;
        }

        char c = str.ElementAt(0);
        var perms = GetPermutations(str.Substring(1));

        foreach (var word in perms)
        {
            for (int i = 0; i <= word.Length; i++)
            {
                result.Add(word.Substring(0, i) + c + word.Substring(i));
            }
        }

        return result;
    }