C# advanced permutation scenario

Question

I am trying to figure how how to find all the combinations given the following information:

I start with a JSON dataset:

var choices = { 1: {\'Q\': 1         


        

Answer 1

It's a 10 digit base 4 number.

class Program
{
    static void Main(string[] args)
    {
        int baseN = 4;
        int maxDigits = 10;
        var max = Math.Pow(baseN, maxDigits);
        for (int i = 0; i < max; i++)
        { // each iteration of this loop is another unique permutation
            var digits = new int[maxDigits];
            int value = i;
            int place = digits.Length - 1;
            while (value > 0)
            {
                int thisdigit = value % baseN;
                value /= baseN;
                digits[place--] = thisdigit;
            }

            int choice = 0;
            foreach (var digit in digits)
            {
                choice ++;
                //Console.Write(digit);
                switch (digit)
                {
                    case 0: break; //choose Q from choice
                    case 1: break; //choose R from choice
                    case 2: break; //choose W from choice
                    case 3: break; //choose T from choice
                }
            }
            //Console.WriteLine();
            // add it to your list of all permutations here
        }
        Console.WriteLine("Done")
        Console.ReadLine();
    }
}