DiceCombinatory

N-DiceCombinatory.cs

static void Roll(string s = "", int depth = 1, int sides = 6)
{
    if (depth == 0)
        Console.WriteLine(s.Substring(1));
    else
        for (int i = 1; i <= sides; i++)
            Roll(s + "," + i, depth - 1);
}

static int[][] DiceCombinatoryEntry(int times, int diceSides = 6)
{
    var size = (int)Math.Pow(diceSides, times);

    var arrayList = new List<int[]>(size);
    var loopIndex = new int[times];

    DiceCombinatory(times, diceSides, arrayList, loopIndex);

    return arrayList.ToArray();
}

static void DiceCombinatory(int times, int diceSides, List<int[]> arrayList, int[] loopIndex)
{
    if (times == 0)
    {
        var len = loopIndex.Length;
        var arr = new int[len];
        for (int i = 0; i < len; i++) // Clone Array in Reverse
            arr[i] = loopIndex[len - i - 1];
        arrayList.Add(arr);
        //arrayList[index++] = arr;
        return;
    }
    for (int i = 1; i <= diceSides; i++)
    {
        loopIndex[times - 1] = i;
        DiceCombinatory(times - 1, diceSides, arrayList, loopIndex);
    }
}

static int CountSum(int[][] combinations, int value)
{
    int count = 0;
    foreach (var combination in combinations)
        if (combination.Sum() == value)
            count++;
    return count;
}

#region Main

const int SIDES = 6;
const int TIMES = 2;
var dice = DiceCombinatoryEntry(TIMES, SIDES);
var combinatory = dice.Length;

//Array.ForEach(dice, x => Console.Write(string.Join(",", x.Select(x => x.ToString())) + "\t"));
for (int i = 0; i < dice.Length; i++)
{
    Console.Write(string.Join(",", dice[i]) + "\t");
    if (i % SIDES == SIDES-1)
        Console.WriteLine();
}

var occurrences = CountSum(dice, 7);
var chance = occurrences / (double)combinatory;
Console.WriteLine($"{occurrences} / {combinatory} = {chance:0.##%}");

#endregion