day 1, day 2

Author: henckellbach

Advent22.iml

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+<?xml version="1.0" encoding="UTF-8"?>
+<module type="JAVA_MODULE" version="4">
+  <component name="NewModuleRootManager" inherit-compiler-output="true">
+    <exclude-output />
+    <content url="file://$MODULE_DIR$">
+      <sourceFolder url="file://$MODULE_DIR$/src/main/kotlin" isTestSource="false" />
+      <sourceFolder url="file://$MODULE_DIR$/src/main/resources" type="java-resource" />
+      <sourceFolder url="file://$MODULE_DIR$/src/test/kotlin" isTestSource="true" />
+      <sourceFolder url="file://$MODULE_DIR$/src/test/resources" type="java-test-resource" />
+    </content>
+    <orderEntry type="inheritedJdk" />
+    <orderEntry type="sourceFolder" forTests="false" />
+    <orderEntry type="library" name="KotlinJavaRuntime" level="project" />
+  </component>
+</module>

src/main/kotlin/Day01.kt

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+object Day01 {
+    private val input = Resource.parseAsString("1.txt")
+    private val totals = input.split("\n\n").map{
+        it.lines().sumOf { line -> line.toInt() }
+    }
+
+    fun solvePart1(): Int {
+        return totals.max()
+    }
+
+    fun solvePart2(): Int {
+        return totals.sortedDescending().slice(0..2).sum()
+    }
+}

src/main/kotlin/Day02.kt

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+object Day02 {
+    enum class Sign(val score: Int) {
+        ROCK(1), PAPER(2), SCISSORS(3)
+    }
+
+    private fun mapInputToSign(input: Char): Sign {
+        return when (input) {
+            'A', 'X' -> Sign.ROCK
+            'B', 'Y' -> Sign.PAPER
+            'C', 'Z' -> Sign.SCISSORS
+            else -> throw Error("Cannot convert to sign, wrong input.")
+        }
+    }
+
+    private val input = Resource.parseAsStringList("2.txt")
+
+    private fun getScore(playerSign: Sign, opponentSign: Sign): Int {
+        val stateScore = when (playerSign.score - opponentSign.score) {
+            -1, 2 -> 0
+            0 -> 3
+            1, -2 -> 6
+            else -> throw Error("Could not get score. Check your input.")
+        }
+
+        return stateScore + playerSign.score
+    }
+
+    fun solvePart1(): Int {
+        val games = input.map { it.split(" ").map { str -> mapInputToSign(str.first()) } }
+        val scores = games.map { getScore(it[0], it[1]) }
+
+        return scores.sum()
+    }
+
+    fun solvePart2(): Int {
+        val scores = input.map {
+            val (opponentChar, resultChar) = it.split(" ").map { str -> str.first() }
+            val opponentSign = mapInputToSign(opponentChar)
+            val playerSign = when (opponentSign to resultChar) {
+                Sign.SCISSORS to 'X', Sign.PAPER to 'Y', Sign.ROCK to 'Z' -> Sign.PAPER
+                Sign.PAPER to 'X', Sign.ROCK to 'Y', Sign.SCISSORS to 'Z' -> Sign.ROCK
+                Sign.ROCK to 'X', Sign.SCISSORS to 'Y', Sign.PAPER to 'Z' -> Sign.SCISSORS
+                else -> {
+                    throw Error("Could not convert result char to player sign. Check your input.")
+                }
+            }
+            getScore(playerSign, opponentSign)
+
+        }
+
+        return scores.sum()
+    }
+}

src/main/kotlin/Main.kt

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+fun main() {
+    val part1 = Day02.solvePart1()
+    println(part1)
+
+    val part2 = Day02.solvePart2()
+    println(part2)
+}

src/main/kotlin/Resource.kt

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+import java.io.File
+
+internal object Resource {
+    private fun getFile(filename: String): File {
+        return File("src/main/resources/$filename")
+    }
+
+    fun parseAsString(filename: String): String {
+        return getFile(filename).readText()
+    }
+
+    fun parseAsStringList(filename: String): List<String> {
+        return getFile(filename).readLines()
+    }
+
+    fun parseAsIntList(filename: String): List<Int?> {
+        return parseAsStringList(filename).map{ it.toInt() }
+    }
+}