Day 5

Author: Nxllpointer

build.gradle.kts

@@ -7,7 +7,7 @@ plugins {
 group = "de.nxll.aoc2022"
 version = "1.0"
 
-val currentDay = 4
+val currentDay = 5
 
 repositories {
  mavenCentral()

src/common/kotlin/Text.kt

@@ -0,0 +1,3 @@
+fun CharSequence.splitInTwo(delimiter: String): Pair<String, String> {
+ return this.split(delimiter, limit = 2).let { it.first() to it.last() }
+}

src/day_5/kotlin/Day5.kt

@@ -0,0 +1,70 @@
+// AOC Day 5
+
+typealias Container = Char
+typealias ContainerStack = ArrayDeque<Container>
+typealias StackNumber = Int
+
+data class MoveInstruction(val amount: Int, val from: Int, val to: Int)
+
+fun Map<StackNumber, ContainerStack>.deepCopy(): Map<StackNumber, ContainerStack> {
+ return toMap().mapValues { ArrayDeque(it.value) }
+}
+
+
+fun part1(stacks: Map<StackNumber, ContainerStack>, instructions: Collection<MoveInstruction>) {
+ instructions.forEach { (amount, from, to) ->
+ repeat(amount) {
+ stacks[from]!!.removeFirst().also { stacks[to]!!.addFirst(it) }
+ }
+ }
+
+ val topContainersText = stacks.toSortedMap().values.map { it.first() }.joinToString("")
+
+ println("Part 1: The top most containers form the text $topContainersText")
+}
+
+fun part2(stacks: Map<StackNumber, ContainerStack>, instructions: Collection<MoveInstruction>) {
+ instructions.forEach { (amount, from, to) ->
+ val transferStack = ContainerStack()
+ repeat(amount) {
+ stacks[from]!!.removeFirst().also { transferStack.addFirst(it) }
+ }
+ repeat(amount) {
+ transferStack.removeFirst().also { stacks[to]!!.addFirst(it) }
+ }
+ }
+
+ val topContainersText = stacks.toSortedMap().values.map { it.first() }.joinToString("")
+
+ println("Part 2: The top most containers form the text $topContainersText")
+}
+
+val INSTRUCTION_REGEX = Regex("\\d+")
+fun main() {
+ val (stacks, instructions) = getAOCInput { rawInput ->
+ val (sectionStacks, sectionInstructions) = rawInput.trim('\n').splitInTwo("\n\n").run {
+ first.split("\n") to second.split("\n")
+ }
+
+ val stacks = mutableMapOf<StackNumber, ContainerStack>()
+ sectionStacks.last().forEachIndexed { charIndex, char ->
+ if (char.isDigit()) {
+ val stack = ContainerStack().also { stacks[char.digitToInt()] = it }
+ for (layer in sectionStacks.dropLast(1).reversed()) {
+ val containerLabel = layer[charIndex]
+ if (containerLabel.isLetter()) stack.addFirst(layer[charIndex])
+ }
+ }
+ }
+
+ val instructions = sectionInstructions.map { rawInstruction ->
+ val instructionValues = INSTRUCTION_REGEX.findAll(rawInstruction).toList().map { it.value }.mapToInt()
+ MoveInstruction(instructionValues[0], instructionValues[1], instructionValues[2])
+ }
+
+ stacks to instructions
+ }
+
+ part1(stacks.deepCopy(), instructions)
+ part2(stacks.deepCopy(), instructions)
+}