86 lines
2.6 KiB
Kotlin
86 lines
2.6 KiB
Kotlin
package aoc.thirteen
|
|
|
|
import aoc.thirteen.Field
|
|
import aoc.thirteen.Turn
|
|
import aoc.thirteen.Train
|
|
import java.io.File
|
|
import java.io.InputStream
|
|
|
|
class Main() {
|
|
|
|
companion object {
|
|
public var field: MutableList<MutableList<Field>> = mutableListOf<MutableList<Field>>()
|
|
var noCrash = true
|
|
|
|
fun parseField(c: Char): Field {
|
|
return when (c) {
|
|
'|', 'v', '^' -> Field.VERTICAL
|
|
'-', '>', '<' -> Field.HORIZONTAL
|
|
'/' -> Field.TOP_LEFT
|
|
'\\' -> Field.TOP_RIGHT
|
|
'+' -> Field.INTERSECTION
|
|
' ' -> Field.EMPTY
|
|
else -> throw IllegalArgumentException("can’t parse field " + c)
|
|
}
|
|
}
|
|
|
|
fun parseTrain(c: Char, x: Int, y: Int): Train {
|
|
val dir = when (c) {
|
|
'^' -> 0
|
|
'>' -> 1
|
|
'v' -> 2
|
|
'<' -> 3
|
|
else -> throw IllegalArgumentException("this shouldn’t happen rooDerp")
|
|
}
|
|
return Train(dir, x, y)
|
|
}
|
|
|
|
fun moveTrain(t: Train): Train {
|
|
when (t.direction) {
|
|
0 -> t.y += 1
|
|
1 -> t.x += 1
|
|
2 -> t.y -= 1
|
|
3 -> t.x -= 1
|
|
else -> throw IllegalArgumentException("this shouldn’t happen either selphyDerp")
|
|
}
|
|
val current = field[t.x][t.y]
|
|
when (current) {
|
|
Field.VERTICAL, Field.HORIZONTAL -> {}
|
|
Field.TOP_LEFT -> t.direction = t.direction xor 1
|
|
Field.TOP_RIGHT -> t.direction = t.direction xor 3
|
|
Field.INTERSECTION -> t.crossIntersection()
|
|
Field.EMPTY -> IllegalStateException("I shouldn’t be here")
|
|
}
|
|
return t
|
|
}
|
|
|
|
@JvmStatic
|
|
fun main(args: Array<String>) {
|
|
val inputStream = File("input").inputStream()
|
|
val inputLines = inputStream.bufferedReader().use { it.readText() }.split("\n")
|
|
val TRAINS = charArrayOf('<', '>', '^', 'v')
|
|
|
|
var trains = mutableListOf<Train>()
|
|
|
|
for ((x, line) in inputLines.withIndex()) {
|
|
var fields = mutableListOf<Field>()
|
|
for ((y, char) in line.toCharArray().withIndex()) {
|
|
if (char in TRAINS) {
|
|
trains.add(parseTrain(char, x, y))
|
|
}
|
|
fields.add(parseField(char))
|
|
}
|
|
field.add(fields)
|
|
}
|
|
var positions = HashSet<Pair<Int, Int>>(trains.size)
|
|
positions.addAll(trains.map{ t -> Pair(t.x, t.y) })
|
|
while (positions.size == trains.size) {
|
|
trains.forEach{ t -> moveTrain(t) }
|
|
positions.clear()
|
|
positions.addAll(trains.map{ t -> Pair(t.x, t.y) })
|
|
}
|
|
println(trains)
|
|
}
|
|
}
|
|
}
|