2024 day 1

2024/.gitignore

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+### IntelliJ IDEA ###
+out/
+!**/src/main/**/out/
+
+### Mac OS ###
+.DS_Store

2024/.idea/.gitignore

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+# Default ignored files
+/shelf/
+/workspace.xml

2024/.idea/codeStyles/Project.xml

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+<component name="ProjectCodeStyleConfiguration">
+  <code_scheme name="Project" version="173">
+    <JetCodeStyleSettings>
+      <option name="CODE_STYLE_DEFAULTS" value="KOTLIN_OFFICIAL" />
+    </JetCodeStyleSettings>
+    <codeStyleSettings language="kotlin">
+      <option name="CODE_STYLE_DEFAULTS" value="KOTLIN_OFFICIAL" />
+    </codeStyleSettings>
+  </code_scheme>
+</component>

2024/.idea/codeStyles/codeStyleConfig.xml

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+<component name="ProjectCodeStyleConfiguration">
+  <state>
+    <option name="USE_PER_PROJECT_SETTINGS" value="true" />
+  </state>
+</component>

2024/.idea/inspectionProfiles/Project_Default.xml

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+<component name="InspectionProjectProfileManager">
+  <profile version="1.0">
+    <option name="myName" value="Project Default" />
+    <inspection_tool class="ReplaceUntilWithRangeUntil" enabled="true" level="WEAK WARNING" enabled_by_default="true" />
+  </profile>
+</component>

2024/.idea/kotlinc.xml

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+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="Kotlin2JvmCompilerArguments">
+    <option name="jvmTarget" value="1.8" />
+  </component>
+  <component name="KotlinCommonCompilerArguments">
+    <option name="apiVersion" value="1.9" />
+    <option name="languageVersion" value="1.9" />
+  </component>
+</project>

2024/.idea/libraries/KotlinJavaRuntime.xml

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+<component name="libraryTable">
+  <library name="KotlinJavaRuntime" type="repository">
+    <properties maven-id="org.jetbrains.kotlin:kotlin-stdlib-jdk8:1.9.0" />
+    <CLASSES>
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlin/kotlin-stdlib-jdk8/1.9.0/kotlin-stdlib-jdk8-1.9.0.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlin/kotlin-stdlib/1.9.0/kotlin-stdlib-1.9.0.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlin/kotlin-stdlib-common/1.9.0/kotlin-stdlib-common-1.9.0.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/annotations/13.0/annotations-13.0.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlin/kotlin-stdlib-jdk7/1.9.0/kotlin-stdlib-jdk7-1.9.0.jar!/" />
+    </CLASSES>
+    <JAVADOC>
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlin/kotlin-stdlib-jdk8/1.9.0/kotlin-stdlib-jdk8-1.9.0-javadoc.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlin/kotlin-stdlib/1.9.0/kotlin-stdlib-1.9.0-javadoc.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlin/kotlin-stdlib-common/1.9.0/kotlin-stdlib-common-1.9.0-javadoc.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/annotations/13.0/annotations-13.0-javadoc.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlin/kotlin-stdlib-jdk7/1.9.0/kotlin-stdlib-jdk7-1.9.0-javadoc.jar!/" />
+    </JAVADOC>
+    <SOURCES>
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlin/kotlin-stdlib-jdk8/1.9.0/kotlin-stdlib-jdk8-1.9.0-sources.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlin/kotlin-stdlib/1.9.0/kotlin-stdlib-1.9.0-sources.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlin/kotlin-stdlib-common/1.9.0/kotlin-stdlib-common-1.9.0-sources.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/annotations/13.0/annotations-13.0-sources.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlin/kotlin-stdlib-jdk7/1.9.0/kotlin-stdlib-jdk7-1.9.0-sources.jar!/" />
+    </SOURCES>
+  </library>
+</component>

2024/.idea/misc.xml

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+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="ProjectRootManager" version="2" languageLevel="JDK_17" default="true" project-jdk-name="17" project-jdk-type="JavaSDK">
+    <output url="file://$PROJECT_DIR$/out" />
+  </component>
+</project>

2024/.idea/modules.xml

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+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="ProjectModuleManager">
+    <modules>
+      <module fileurl="file://$PROJECT_DIR$/AoC2024.iml" filepath="$PROJECT_DIR$/AoC2024.iml" />
+    </modules>
+  </component>
+</project>

2024/.idea/vcs.xml

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+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="VcsDirectoryMappings">
+    <mapping directory="" vcs="Git" />
+    <mapping directory="$PROJECT_DIR$" vcs="Git" />
+  </component>
+</project>

2024/AoC2024.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" />
+    </content>
+    <orderEntry type="inheritedJdk" />
+    <orderEntry type="sourceFolder" forTests="false" />
+    <orderEntry type="library" name="KotlinJavaRuntime" level="project" />
+  </component>
+</module>

2024/src/main/kotlin/day1.kt

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+import kotlin.math.abs
+
+fun main() {
+    val input = object {}.javaClass.getResourceAsStream("day1.txt")
+        ?.bufferedReader()
+        ?.lineSequence()
+        ?: error("Cannot read input")
+
+    val a = mutableListOf<Int>()
+    val b = mutableListOf<Int>()
+
+    val spaces = "\\s+".toRegex()
+
+    for (line in input) {
+        val parts = line.split(spaces, limit = 2)
+        val (first, second) = parts
+        a.add(first.toInt())
+        b.add(second.toInt())
+    }
+
+    assert(a.size == b.size)
+    a.sort()
+    b.sort()
+
+    var sum = 0
+    for (index in a.indices) {
+        sum += abs(a[index] - b[index])
+    }
+
+    println("Part 1: $sum")
+
+
+    sum = 0
+
+    for (value in a) {
+        sum += value * b.count { it == value }
+    }
+
+    println("Part 2: $sum")
+}