public static void P2()
{
var s = Utilities.GetLinesFromFile("Day10.txt").Select(x => x.Replace(",", "").ToArray()).ToArray();
var arr = new char[s.GetLength(0), s.GetLength(0)];
for (int i = 0; i < s.GetLength(0); i++)
{
for (int j = 0; j < s[0].GetLength(0); j++)
{
arr[i, j] = s[i][j];
}
}
int[] centerpoint = new int[] { 20, 23 };
arr[centerpoint[0], centerpoint[1]] = '*';
var angles = new Dictionary <float, List <Asteroid> >();
for (int i = 0; i < s.GetLength(0); i++)
{
for (int j = 0; j < s[0].GetLength(0); j++)
{
if (arr[i, j] == '#')
{
var angle = (float)(Math.Atan2((centerpoint[0] - i), (centerpoint[1] - j)) * (180 / (Math.PI)));
var x1 = (angle < 0 ? 360 : 0);
angle = angle + (angle < 0 ? 360 : 0);
angle = angle + (angle < 90 ? 360 : 0);
//Console.WriteLine($"x{j} y{i} angle: {angle}");
if (!angles.ContainsKey(angle))
{
angles[angle] = new List <Asteroid>();
}
angles[angle].Add(new Asteroid()
{
coords = $"x{j} y{i}", dist = Distance(centerpoint, new int[] { j, i }), x = j, y = i
});
}
}
}
var targets = angles.OrderBy(a => a.Key).ToList();
Asteroid lasthit = new Asteroid();
int countdown = 200;
int it = 0;
while (countdown > 0)
{
if (targets[it].Value.Count > 0)
{
var tdist = targets[it].Value.Min(x => x.dist);
var t = targets[it].Value.First(v => v.dist == tdist);
lasthit = t;
Console.WriteLine($"PEW! {t.coords}");
targets[it].Value.Remove(t);
countdown--;
}
it++;
if (it >= targets.Count())
{
it = 0;
}
}
Console.WriteLine($"Last ateroid hit: {lasthit.coords} answer is: {lasthit.answer}");
}
public static int Vaporize200Asteroids(string[] asteroidMap)
{
if (asteroidMap is null || asteroidMap.Length == 0)
{
throw new ArgumentException("map null or empty", nameof(asteroidMap));
}
var asteroids = new Dictionary <Point, Asteroid>();
var mapXMax = asteroidMap[0].Length - 1;
var mapYMax = asteroidMap.Length - 1;
for (int y1 = 0; y1 <= mapYMax; y1++)
{
for (int x1 = 0; x1 <= mapXMax; x1++)
{
if (asteroidMap[y1].Substring(x1, 1) == "#")
{
var asteroid = new Asteroid(x1, y1);
asteroids.Add(asteroid.Location, asteroid);
for (int y2 = 0; y2 <= mapYMax; y2++)
{
for (int x2 = 0; x2 <= mapXMax; x2++)
{
if (asteroidMap[y2].Substring(x2, 1) == "#" && !(x2 == x1 && y2 == y1))
{
var angle = (int)(((Math.Atan2((double)y2 - y1, (double)x2 - x1) * (180 / Math.PI) + 360) % 360) * 100); // multiplied by 100 so the precision is greater and I can still use array with int index
asteroid.AsteroidInView[angle] = true;
if (!(asteroid.AsteroidsInView.TryGetValue(angle, out var asteroidsInLine)))
{
asteroidsInLine = new List <Asteroid>();
asteroid.AsteroidsInView.Add(angle, asteroidsInLine);
}
asteroidsInLine.Add(new Asteroid(x2, y2, x1, y1));
}
}
}
}
}
}
var maxAsteroidsInView = int.MinValue;
Asteroid bestAsteroid = null;
foreach (var asteroid in asteroids)
{
var asteroidsSeen = asteroid.Value.AsteroidInView.Count(value => value);
if (asteroidsSeen > maxAsteroidsInView)
{
maxAsteroidsInView = asteroidsSeen;
bestAsteroid = asteroid.Value;
}
}
Asteroid target = null;
if (bestAsteroid != null)
{
var asteroidsVaporized = 0;
var angle = 36000 - (90 * 100); // zero is at X acsel. Se rewind 90 degrees (times 100 because the index)
while (asteroidsVaporized < 200)
{
if (bestAsteroid.AsteroidsInView.TryGetValue(angle, out var asteroidsInSight))
{
var minDistance = asteroidsInSight.Min(a => a.Vaporized ? double.MaxValue : a.Distance);
target = asteroidsInSight.Find(a => a.Distance == minDistance);
target.Vaporize();
asteroidsVaporized += 1;
}
angle += 1;
if (angle % 36000 == 0)
{
angle = 0;
}
}
}
return(target == null ? throw new Exception("something went wrong") : target.X * 100 + target.Y);
}
private static double Angle(Asteroid baseAsteroid, Asteroid asteroid)
{
return(Math.Atan2(asteroid.Y - baseAsteroid.Y, asteroid.X - baseAsteroid.X));
}
public AsteroidMap VisibilityMap(int stationRow, int stationCol)
{
// Create a map of what other asteroids are visible if i put a station on the inputted asteroid.
Asteroid station = new Asteroid(stationRow, stationCol, null);
AsteroidMap map = new AsteroidMap((string[])this.rows.Clone(), station);
station.map = map;
// If there is no asteroid in the inputted area, return null;
if (map.GetCell(stationRow, stationCol) != ASTEROID)
{
Console.WriteLine("ERROR! You asked for a visibility map for a location that has no asteroid.");
return(null);
}
// Logic:
// Look directly to the left of me, find the first asteroid, and consider everything else blocked.
// Look directly to the right of me, find the first asteroid, and consider everything else blocked.
// Look at the entire row above me. Find asteroids, and block everything behind it.
// And then move up a row.
// Look at the entire row below me. Find any asteroids, and block everything behind it.
for (int columnId = (stationCol - 1); columnId >= 0; columnId--)
{
int rowId = stationRow;
if (map.GetCell(rowId, columnId) == ASTEROID)
{
map.SetCellVisible(rowId, columnId, stationRow, stationCol);
// break;
}
}
for (int columnId = (stationCol + 1); columnId < this.mapWidth; columnId++)
{
int rowId = stationRow;
if (map.GetCell(rowId, columnId) == ASTEROID)
{
map.SetCellVisible(rowId, columnId, stationRow, stationCol);
//break;
}
}
for (int rowId = (stationRow - 1); rowId >= 0; rowId--)
{
for (int colId = 0; colId < this.mapWidth; colId++)
{
if (map.GetCell(rowId, colId) == ASTEROID)
{
map.SetCellVisible(rowId, colId, stationRow, stationCol);
//break;
}
}
}
for (int rowId = (stationRow + 1); rowId < this.mapHeight; rowId++)
{
for (int colId = 0; colId < this.mapWidth; colId++)
{
if (map.GetCell(rowId, colId) == ASTEROID)
{
map.SetCellVisible(rowId, colId, stationRow, stationCol);
//break;
}
}
}
return(map);
}
public int GetDistanceTo(Asteroid asteroid)
{
return(Math.Abs(asteroid.X - this.X) + Math.Abs(asteroid.Y - this.Y));
}