#define Day20
#if Day20
using AoC2021;

var lines = File.ReadAllLines("day20/input");
var translate = lines[0].Select(c => c == '#' ? "1" : "0").ToList();

int steps = 50;
int size = lines.Length - 2;
string[,] image = new string[size + 4,size + 4];

lines.Skip(2).ForEachIndex((l, row) => 
    l.ForEachIndex((c, col) => image[row + 2, col + 2] = c == '#' ? "1" : "0"));

string infinite = "0";
SetBorder(image, infinite);
// Print(image);

while (steps > 0) {
    size = image.GetLength(0);
    string[,] nextImage = new string[size + 2,size + 2];
    for (int row = 1; row < size-1; row++) {
        for (int col = 1; col < size-1; col++) {
            nextImage[row + 1, col + 1] = GetNewPoint(row, col, image);
        }
    }

    infinite = NextInfinite(infinite);
    SetBorder(nextImage, infinite);

    image = nextImage;
    // Print(image);
    // Console.WriteLine();
    steps--;
}

int count = 0;
for (int row = 0; row < image.GetLength(0); row++) {
    for (int col = 0; col < image.GetLength(1); col++) {
        if (image[row, col] == "1") {
            count++;
        }
    }
}

Console.WriteLine(count);

void Print(string[,] image) {
    for (int row = 0; row < image.GetLength(0); row++) {
        for (int col = 0; col < image.GetLength(1); col++) {
            Console.Write(image[row, col] == "1" ? '#' : '.');
        }

        Console.WriteLine();
    }
}

string GetNewPoint(int row, int col, string[,] imageToRead) {
    var binary = imageToRead[row - 1, col - 1] + imageToRead[row - 1, col] + imageToRead[row - 1, col + 1]
                 + imageToRead[row, col - 1] + imageToRead[row, col] + imageToRead[row, col + 1]
                 + imageToRead[row + 1, col - 1] + imageToRead[row + 1, col] + imageToRead[row + 1, col + 1];
    return translate[Convert.ToInt32(binary, 2)];
}

string NextInfinite(string infinite) {
    var infinitePos = Convert.ToInt32(String.Join("",Enumerable.Repeat(infinite, 9)), 2);
    return translate[infinitePos];
}

void SetBorder(string[,] image, string value) {
    int last = image.GetLength(0) - 1;
    Enumerable.Range(0, image.GetLength(0)).ForEachAsList(i => {
        image[0, i] = value;
        image[1, i] = value;
        image[i, 0] = value;
        image[i, 1] = value;
        image[last, i] = value;
        image[last-1, i] = value;
        image[i, last] = value;
        image[i, last-1] = value;
    });
}
#endif