2024 Day 2

src/main/kotlin/no/rodland/advent_2024/Day02.kt

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+package no.rodland.advent_2024
+
+import no.rodland.advent.Day
+
+// template generated: 02/12/2024
+// Fredrik Rødland 2024
+
+class Day02(val input: List<String>) : Day<Long, Long, List<List<Int>>> {
+
+    private val parsed = input.parse()
+
+    override fun partOne(): Long {
+
+
+        return parsed.count { it.isSafe() }.toLong()
+    }
+
+    override fun partTwo(): Long {
+        val expanded = parsed.expand()
+        return expanded.count { candidates ->
+            candidates.any { list -> list.isSafe() }
+        }.toLong()
+    }
+
+    override fun List<String>.parse(): List<List<Int>> {
+        return map { line ->
+            line.split(" ").map { it.toInt() }
+        }
+    }
+
+    private fun List<Int>.isSafe(): Boolean {
+        val inc = this[1] > this[0]
+        val diff = windowed(2).map {
+            if (inc) {
+                it.last() - it.first()
+            } else {
+                it.first() - it.last()
+            }
+        }
+        val all = diff.all { it in (1..3) }
+        return all
+    }
+
+    private fun List<List<Int>>.expand(): List<List<List<Int>>> {
+        return map { org ->
+            List(org.size) { index -> org.withoutItemAt(index) }
+        }
+    }
+
+    private fun List<Int>.withoutItemAt(index: Int) = filterIndexed { i, _ -> i != index }
+
+    override val day = "02".toInt()
+}
+
+
+

src/test/kotlin/no/rodland/advent_2024/Day02Test.kt

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+package no.rodland.advent_2024
+
+import no.rodland.advent.*
+import org.junit.jupiter.api.Nested
+import org.junit.jupiter.api.Test
+import readFile
+
+//
+//  run: download_aoc_input.sh to download input
+//
+
+@Suppress("ClassName")
+@DisableSlow
+internal class Day02Test {
+    private val data02 = "2024/input_02.txt".readFile()
+    private val test02 = "2024/input_02_test.txt".readFile()
+
+    private val resultTestOne = 2L
+    private val resultTestTwo = 4L
+    private val resultOne = 680L
+    private val resultTwo = 710L
+
+    val test = defaultTestSuiteParseOnInit(
+        Day02(data02),
+        Day02(test02),
+        resultTestOne,
+        resultOne,
+        resultTestTwo,
+        resultTwo,
+        { Day02(data02) },
+        { Day02(test02) },
+    )
+
+    @Nested
+    inner class Init {
+        @Test
+        fun `02,-,example,1`() {
+            report(AOCTest({ "123".toInt() }, Unit, 123, 5, "02".toInt(), Part.TWO, false, "example"))
+        }
+
+        @Test
+        fun `02,-,example,2`() {
+            report(test.initTest.copy())
+        }
+
+        @Test
+        fun `02,-,test,init`() {
+            report(test.initTest)
+        }
+
+        @Test
+        fun `02,-,live,init`() {
+            report(test.initLive)
+        }
+    }
+
+    @Nested
+    inner class `Part 1` {
+        @Test
+        fun `02,1,test`() {
+            report(test.testPart1)
+        }
+
+        @Test
+        fun `02,1,live,1`() {
+            report(test.livePart1)
+        }
+    }
+
+    @Nested
+    inner class `Part 2` {
+        @Test
+        fun `02,2,test`() {
+            report(test.testPart2)
+        }
+
+        @Test
+        fun `02,2,live,1`() {
+            report(test.livePart2)
+        }
+    }
+}

src/test/resources/2024/input_02_test.txt

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+7 6 4 2 1
+1 2 7 8 9
+9 7 6 2 1
+1 3 2 4 5
+8 6 4 4 1
+1 3 6 7 9