public int Star2(Day10Input input)
{
var observatory = Star1(input);
var maxX = (int)observatory.Space.Max(c => c.Position.X);
var pt1 = observatory.Location;
var pt3 = new Point(pt1.X + maxX + 100, pt1.Y);
var positions = new List <SpaceUnitAngle>();
foreach (var spaceUnit in observatory.Space.GetFlat().Where(c => c.IsVisible))
{
var sup = spaceUnit.Position;
var pt2 = new Point(Math.Abs(sup.X), Math.Abs(sup.Y));
var angle = GetAngle(pt1, pt2, pt3);
var quad = -1;
if (sup.X >= pt1.X && sup.Y < pt1.Y)
{
quad = 0;
}
else if (sup.X > pt1.X && sup.Y >= pt1.Y)
{
quad = 1;
angle = -angle;
}
else if (sup.X <= pt1.X && sup.Y > pt1.Y)
{
quad = 2;
angle = -angle;
}
else if (sup.X <= pt1.X && sup.Y <= pt1.Y)
{
quad = 3;
}
else
{
throw new Exception("Missing param");
}
positions.Add(new SpaceUnitAngle
{
SpaceUnit = spaceUnit,
Angle = angle,
Quadrant = quad
});
}
positions = positions.OrderBy(c => c.Quadrant)
.ThenByDescending(c => c.Angle)
.ToList();
var p199 = positions[199];
return(p199.SpaceUnit.Position.X * 100 + p199.SpaceUnit.Position.Y);
}
public void SetUp()
{
_solver = new Day10Solver();
_input = new Day10Input();
}
public Observatory Star1(Day10Input input)
{
var observatories = new List <Observatory>();
for (var i = 0; i < input.Space.Rows; i++)
{
for (var j = 0; j < input.Space.Columns; j++)
{
var inputClone = (Day10Input)input.Clone();
var space = inputClone.Space;
var me = space[i, j];
if (!me.ContainsAsteroid)
{
continue;
}
var currentRange = 1;
while (true)
{
var region = space.GetRectFillInvalid(Region.FromCenter(i, j, currentRange, currentRange));
for (var i1 = 0; i1 < region.Rows; i1++)
{
for (var j1 = 0; j1 < region.Columns; j1++)
{
var objective = region[i1, j1];
if (objective.Position == new Point(-1, -1))
{
continue;
}
if (objective.Position.Y == i && objective.Position.X == j)
{
continue; // self
}
if (!objective.ContainsAsteroid)
{
continue;
}
var vector = new Point(objective.Position.X - me.Position.X, objective.Position.Y - me.Position.Y);
var lcm = LCM(vector.X, vector.Y);
if (lcm is {} lcmV)
{
vector = new Point(vector.X / lcmV, vector.Y / lcmV);
}
if (vector.X == 0)
{
vector.Y = vector.Y < 0 ? -1 : 1;
}
if (vector.Y == 0)
{
vector.X = vector.X < 0 ? -1 : 1;
}
var relPoint = objective.Position;
while (true)
{
relPoint = new Point(relPoint.X + vector.X, relPoint.Y + vector.Y);
if (relPoint.X < 0 || relPoint.X >= input.Space.Columns ||
relPoint.Y < 0 || relPoint.Y >= input.Space.Rows)
{
break;
}
space[relPoint.Y, relPoint.X].Shadowed = true;
}
}
}
currentRange += 2;
if (currentRange / 2 > input.Space.Rows && currentRange / 2 > input.Space.Columns)
{
break;
}
}
var observatory = new Observatory
{
Space = space,
Location = new Point(j, i),
TotalVisibleAsteroids = space.GetFlat().Count(c => c.IsVisible) - 1
};
observatories.Add(observatory);
}
}
return(observatories.OrderByDescending(c => c.TotalVisibleAsteroids).First());
}
