static long Part1(List <Tile> allTiles)
{
int imageSize = (int)Math.Sqrt(allTiles.Count);
var visited = new bool[allTiles.Count];
var tiles = new TileContainer[imageSize, imageSize];
FindTileConfiguration(allTiles, visited, imageSize, 0, 0, tiles, 0);
return((long)tiles[0, 0].Tile.Id * (long)tiles[imageSize - 1, 0].Tile.Id * (long)tiles[0, imageSize - 1].Tile.Id * (long)tiles[imageSize - 1, imageSize - 1].Tile.Id);
}
static bool FindTileConfiguration(List <Tile> allTiles, bool[] visited, int imageSize, int currentY, int currentX, TileContainer[,] tiles, int count = 0, bool found = false)
{
if (found)
{
return(true);
}
if (count == imageSize * imageSize)
{
return(true);
}
for (int i = 0; i < allTiles.Count; i++)
{
if (!visited[allTiles[i].Index])
{
for (int c = 0; c < 8; c++)
{
bool[,] puzzle = GetConfiguration(allTiles[i], c);
if (IsConfigurationPossibleInPlace(tiles, currentX, currentY, puzzle.GetLength(0), puzzle))
{
tiles[currentY, currentX] = new TileContainer()
{
Tile = allTiles[i], ConfigurationNumber = c, CurrentConfiguration = puzzle
};
visited[i] = true;
if (currentX < imageSize - 1)
{
found = FindTileConfiguration(allTiles, visited, imageSize, currentY, currentX + 1, tiles, count + 1, found);
}
else
{
found = FindTileConfiguration(allTiles, visited, imageSize, currentY + 1, 0, tiles, count + 1, found);
}
visited[i] = false;
if (found)
{
return(found);
}
}
}
}
}
return(found);
}
static long Part2(List <Tile> allTiles)
{
int imageSize = (int)Math.Sqrt(allTiles.Count);
var visited = new bool[allTiles.Count];
var tiles = new TileContainer[imageSize, imageSize];
FindTileConfiguration(allTiles, visited, imageSize, 0, 0, tiles, 0);
var image = PrepareImage(tiles, imageSize);
var monster = LoadMonster();
var minRoughtness = int.MaxValue;
for (int c = 0; c < 8; c++)
{
var imageConf = GetConfiguration(image, c);
var roughtness = FindMonsters(imageConf, monster);
if (roughtness < minRoughtness)
{
minRoughtness = roughtness;
}
}
return(minRoughtness);
}