C# Permutation of an array of arraylists?

Question

I have an ArrayList[] myList and I am trying to create a list of all the permutations of the values in the arrays.

EXAMPLE: (all values are strings)

Answer 1

This will work no matter how many arrays you add to your myList:

        static void Main(string[] args)
        {
            string[][] myList = new string[3][];
            myList[0] = new string[] { "1", "5", "3", "9" };
            myList[1] = new string[] { "2", "3" };
            myList[2] = new string[] { "93" };

            List permutations = new List(myList[0]);

            for (int i = 1; i < myList.Length; ++i)
            {
                permutations = RecursiveAppend(permutations, myList[i]);
            }

            //at this point the permutations variable contains all permutations

        }

        static List RecursiveAppend(List priorPermutations, string[] additions)
        {
            List newPermutationsResult = new List();
            foreach (string priorPermutation in priorPermutations)
            {
                foreach (string addition in additions)
                {
                    newPermutationsResult.Add(priorPermutation + ":" + addition);
                }
            }
            return newPermutationsResult;
        }

Note that it's not really recursive. Probably a misleading function name.

Here is a version that adheres to your new requirements. Note the section where I output to console, this is where you can do your own formatting:

static void Main(string[] args)
        {
            string[][] myList = new string[3][];
            myList[0] = new string[] { "1", "5", "3", "9" };
            myList[1] = new string[] { "2", "3" };
            myList[2] = new string[] { "93" };

            List> permutations = new List>();

            foreach (string init in myList[0])
            {
                List temp = new List();
                temp.Add(init);
                permutations.Add(temp);
            }

            for (int i = 1; i < myList.Length; ++i)
            {
                permutations = RecursiveAppend(permutations, myList[i]);
            }

            //at this point the permutations variable contains all permutations

            foreach (List list in permutations)
            {
                foreach (string item in list)
                {
                    Console.Write(item + ":");
                }
                Console.WriteLine();
            }

        }

        static List> RecursiveAppend(List> priorPermutations, string[] additions)
        {
            List> newPermutationsResult = new List>();
            foreach (List priorPermutation in priorPermutations)
            {
                foreach (string addition in additions)
                {
                    List priorWithAddition = new List(priorPermutation);
                    priorWithAddition.Add(addition);
                    newPermutationsResult.Add(priorWithAddition);
                }
            }
            return newPermutationsResult;
        }