-
Notifications
You must be signed in to change notification settings - Fork 3
/
Day11.scala
42 lines (35 loc) · 1.72 KB
/
Day11.scala
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
package AdventOfCode2018
object Day11:
case class Point(x: Int, y: Int):
def delta(dx: Int, dy: Int): Point = Point(x + dx, y + dy)
def fuelCells(serialNumber: Int): Map[Point, Int] =
val points = for x <- 1 to 300; y <- 1 to 300 yield
val powerLevel = (((x + 10) * y + serialNumber) * (x + 10) / 100) % 10 - 5
Point(x, y) -> powerLevel
points.toMap
def summedAreaTable(fuelCells: Map[Point, Int]): Map[Point, Int] =
val points = for x <- 1 to 300; y <- 1 to 300 yield Point(x, y)
points.foldLeft(Map.empty[Point, Int].withDefaultValue(0)) { (sat, point) =>
val area = fuelCells(point) + sat(point.delta(-1, 0)) + sat(point.delta(0, -1)) - sat(point.delta(-1, -1))
sat.updated(point, area)
}
def powerGrid(sat: Map[Point, Int], size: Int): Seq[(Int, Point, Int)] =
val points = for x <- size to 300; y <- size to 300 yield Point(x, y)
points.map { point =>
val area = sat(point) - sat(point.delta(-size, 0)) - sat(point.delta(0, -size)) + sat(point.delta(-size, -size))
(size, point, area)
}
def part1(serialNumber: Int): String =
val sat = summedAreaTable(fuelCells(serialNumber))
val candidates = powerGrid(sat, 3)
val (size, point, area) = candidates.maxBy(_._3)
Seq(point.x - size + 1, point.y - size + 1).mkString(",")
def part2(serialNumber: Int): String =
val sat = summedAreaTable(fuelCells(serialNumber))
val candidates = for size <- 1 to 300 yield powerGrid(sat, size)
val (size, point, area) = candidates.flatten.maxBy(_._3)
Seq(point.x - size + 1, point.y - size + 1, size).mkString(",")
def main(args: Array[String]): Unit =
val serialNumber = 9005
println(part1(serialNumber))
println(part2(serialNumber))