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Use custom class for faster hashcode

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This commit is contained in:
Hubert Van De Walle 2020-12-24 16:11:12 +01:00
parent 5d73f12e43
commit e72f71c1bf
1 changed files with 9 additions and 17 deletions
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26
days/src/main/kotlin/Day24.kt
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@ -11,6 +11,10 @@ import org.eclipse.collections.api.factory.Bags
@Day(24)
class Day24(@Lines val input: Input<List<String>>) {
private data class HexPoint(val x: Int, val y: Int, val z: Int) {
fun translate(other: HexPoint) = HexPoint(this.x + other.x, this.y + other.y, this.z + other.z)
}
private enum class Direction(vararg coordinates: Int) {
E(1, -1, 0),
SE(0, -1, 1),
@ -19,7 +23,7 @@ class Day24(@Lines val input: Input<List<String>>) {
NW(0, 1, -1),
NE(1, 0, -1);
val coordinates = coordinates
val coordinates = HexPoint(coordinates[0], coordinates[1], coordinates[2])
}
private fun parseTile(line: String) = "e|se|sw|w|nw|ne".toRegex()
@ -29,30 +33,18 @@ class Day24(@Lines val input: Input<List<String>>) {
.toList()
private val tiles = input.value.map { parseTile(it) }.map {
it.map { it.coordinates }
.reduce { acc, ints -> intArrayOf(acc[0] + ints[0], acc[1] + ints[1], acc[2] + ints[2]) }
.toList()
it.map { it.coordinates }.reduce { acc, ints -> acc.translate(ints) }
}
fun part1() = Bags.immutable.ofAll(tiles).selectBlacks().size()
private fun Bag<List<Int>>.selectBlacks() = selectByOccurrences { it % 2 == 1 }
private fun Bag<HexPoint>.selectBlacks() = selectByOccurrences { it % 2 == 1 }
private fun List<Int>.adjacents(): List<List<Int>> {
val (x, y, z) = this
return listOf(
listOf(x + 1, y - 1, z),
listOf(x, y - 1, z + 1),
listOf(x - 1, y, z + 1),
listOf(x - 1, y + 1, z),
listOf(x, y + 1, z - 1),
listOf(x + 1, y, z - 1),
)
}
private fun HexPoint.adjacents() = Direction.values().map { this.translate(it.coordinates) }
// black -> odd
// white -> even || not in bag -> !in black
private fun day(bag: MutableBag<List<Int>>) {
private fun day(bag: MutableBag<HexPoint>) {
val blacks = bag.selectBlacks().toSet()
val all = (bag + bag.flatMap { it.adjacents() }).toSet()