public override int SolvePart1()
{
var grid = new HexGrid2D(directionsList.Max(d => d.Directions.Count()) * 2);
foreach (var d in directionsList)
{
grid.FlipTileAt(d.Location);
}
return(grid.ValueCounters[TileColor.Black]);
}
public override int SolvePart2()
{
// Shamelessly copied the logic from D17
const int days = 100;
var defaultGrid = new HexGrid2D(directionsList.Max(d => d.Directions.Count()) * 2);
foreach (var d in directionsList)
{
defaultGrid.FlipTileAt(d.Location);
}
var grid = defaultGrid.ExpandForDays(days);
// There really could be many more improvements, just like in the solution for D17
// But I would rather bother with this while abstracting some of the expansion logic
for (int i = 1; i <= days; i++)
{
var tempGrid = new HexGrid2D(grid);
var currentOffset = grid.Center - defaultGrid.Center - new Location2D(i);
var currentSpace = defaultGrid.Dimensions + new Location2D(i * 2);
for (int x = 0; x < currentSpace.X; x++)
{
for (int y = 0; y < currentSpace.Y; y++)
{
var currentLocation = (x, y) + currentOffset;
var value = grid[currentLocation];
int adjacents = grid.GetAdjacentValues(currentLocation, TileColor.Black);
tempGrid[currentLocation] = (value, adjacents) switch
{
(TileColor.Black, 0 or > 2) => TileColor.White,
(TileColor.White, 2) => TileColor.Black,
_ => value
};
}
}
grid = tempGrid;
}
return(grid.ValueCounters[TileColor.Black]);
}
public HexGrid2D(HexGrid2D other, Location2D dimensions, Location2D offset)
: base(other, dimensions, offset)
{
}
public HexGrid2D(HexGrid2D other)
: base(other)
{
}