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

This is my solution which it is easy for me to understand

class ClassicPermutationProblem
{
    ClassicPermutationProblem() { }

    private static void PopulatePosition(List> finalList, List list, List temp, int position)
    {
         foreach (T element in list)
         {
             List currentTemp = temp.ToList();
             if (!currentTemp.Contains(element))
                currentTemp.Add(element);
             else
                continue;

             if (position == list.Count)
                finalList.Add(currentTemp);
             else
                PopulatePosition(finalList, list, currentTemp, position + 1);
        }
    }

    public static List> GetPermutations(List list)
    {
        List> results = new List>();
        PopulatePosition(results, list, new List(), 1);
        return results;
     }
}

static void Main(string[] args)
{
    List> results = ClassicPermutationProblem.GetPermutations(new List() { 1, 2, 3 });
}