2024 Day 01

src/main/kotlin/de/jball/aoc2024/day01/Day01.kt

@@ -0,0 +1,27 @@
+package de.jball.aoc2024.day01
+
+import de.jball.AdventOfCodeDay
+import kotlin.math.abs
+
+class Day01(test: Boolean = false): AdventOfCodeDay<Long>(test, 11, 31) {
+	private val regex = Regex("(\\d+)\\s+(\\d+)")
+	private val lists = input.map { line ->
+		val groups = regex.matchEntire(line)!!.groups
+		Pair(groups[1]!!.value.toLong(), groups[2]!!.value.toLong())
+	}.unzip()
+
+	override fun part1(): Long {
+		return lists.first.sorted().zip(lists.second.sorted()) { a, b -> abs(a-b) }.sum()
+	}
+
+	override fun part2(): Long {
+		val lookup = lists.second.groupingBy { it }.eachCount()
+		return lists.first.sumOf {
+			it * (lookup[it] ?: 0)
+		}
+	}
+}
+
+fun main() {
+	Day01().run()
+}

src/test/kotlin/de/jball/aoc2024/Tests2024.kt

@@ -0,0 +1,11 @@
+package de.jball.aoc2024
+
+import de.jball.aoc2024.day01.Day01
+import kotlin.test.Test
+
+class Tests2024 {
+	@Test
+	fun day01() {
+		Day01(true).run()
+	}
+}

src/test/resources/2024/Day01.txt

@@ -0,0 +1,6 @@
+3   4
+4   3
+2   5
+1   3
+3   9
+3   3