Listing all permutations of a string/integer

Question

A common task in programming interviews (not from my experience of interviews though) is to take a string or an integer and list every possible permutation.

Is there

Answer 1

class Program
{
    public static void Main(string[] args)
    {
        Permutation("abc");
    }

    static void Permutation(string rest, string prefix = "")
    {
        if (string.IsNullOrEmpty(rest)) Console.WriteLine(prefix);

        // Each letter has a chance to be permutated
        for (int i = 0; i < rest.Length; i++)
        {                
            Permutation(rest.Remove(i, 1), prefix + rest[i]);
        }
    }
}