AdventOfCode 2018 Day 08

void Main()
{
    //Test values
    int r = 0;
    var test = "2 3 0 3 10 11 12 1 1 0 1 99 2 1 1 2";
    var testNode = new Node(Parse(test), ref r, 'A');


    //actual Test
    if(testNode.answerA != 138) throw new Exception("failed a");
    if(testNode.answerB != 066) throw new Exception("failed b");


    //get data
    var aoc = new AdventOfCode(2018, 8);

    //reset index
    r = 0;
    //create node
    var n = new Node(Parse(aoc.InputLines[0]), ref r, 'A');

    //submit answers
    aoc.SubmitAnswer(n.answerA, Part.A);
    aoc.SubmitAnswer(n.answerB, Part.B);

}


//convert input to int array
int[] Parse(string s) => s.Split(' ').Select(x => int.Parse(x)).ToArray();

class Node
{
    public Node[] childs;
    public int[] metaData;

    //get all metadata sum and of childeren
    public int answerA => metaData.Sum() + childs.Sum(x => x.answerA);

    public int answerB
    {
        get
        {
            //no children then metadata sum
            if(childs.Length == 0)
            {
                return metaData.Sum();
            }
            else
            {   //children use index -1 as source.
                int sum = 0;
                foreach (var index in metaData)
                {
                    if(index - 1< childs.Length)
                        sum += childs[index - 1].answerB;

                }
                return sum;
            }
        }
    }

    public Node(int[] input, ref int p, char Name)
    {
        //DETERMINE amounts
        this.childs = new Node[input[p++]];
        this.metaData = new int[input[p++]];

        //fill node
        for(int i = 0; i < childs.Length; i++)
            this.childs[i] = new Node(input, ref p, (char) (Name + 1 + i));

        //fill metadata
        for(int i = 0; i < metaData.Length; i++)
            this.metaData[i] = input[p++];

    }
}