2024 Day 04 Part 1 & 2

src/main/kotlin/no/rodland/advent/Dir.kt

@@ -0,0 +1,12 @@
+package no.rodland.advent
+
+enum class Dir(val move: (input: Pos, howMuch: Int) -> Pos) {
+   N({ pos, howMuch -> pos.above(howMuch) }),
+   S({ pos, howMuch -> pos.below(howMuch) }),
+   W({ pos, howMuch -> pos.left(howMuch) }),
+   E({ pos, howMuch -> pos.right(howMuch) }),
+   NW({ pos, howMuch -> pos.nw(howMuch) }),
+   NE({ pos, howMuch -> pos.ne(howMuch) }),
+   SW({ pos, howMuch -> pos.sw(howMuch) }),
+   SE({ pos, howMuch -> pos.se(howMuch) }),
+}

src/main/kotlin/no/rodland/advent/SpacePos.kt

@@ -173,10 +173,10 @@ data class Pos(val x: Int, val y: Int) : SpacePos(), Comparable<Pos> {
     fun below(howMuch: Int = 1): Pos = Pos(x, y + howMuch)
     fun left(howMuch: Int = 1): Pos = Pos(x - howMuch, y)
     fun right(howMuch: Int = 1): Pos = Pos(x + howMuch, y)
-    private fun nw(): Pos = Pos(x - 1, y - 1)
-    fun ne(): Pos = Pos(x + 1, y - 1)
-    fun sw(): Pos = Pos(x - 1, y + 1)
-    fun se(): Pos = Pos(x + 1, y + 1)
+    fun nw(howMuch: Int = 1): Pos = Pos(x - howMuch, y - howMuch)
+    fun ne(howMuch: Int = 1): Pos = Pos(x + howMuch, y - howMuch)
+    fun sw(howMuch: Int = 1): Pos = Pos(x - howMuch, y + howMuch)
+    fun se(howMuch: Int = 1): Pos = Pos(x + howMuch, y + howMuch)
 
     private fun Any?.size(): Int {
         return when (this) {

src/main/kotlin/no/rodland/advent_2024/Day04.kt

@@ -0,0 +1,52 @@
+package no.rodland.advent_2024
+
+import no.rodland.advent.Day
+import no.rodland.advent.Dir
+import no.rodland.advent.Pos
+
+// template generated: 04/12/2024
+// Fredrik Rødland 2024
+typealias Grid = Array<CharArray>
+
+class Day04(val input: List<String>) : Day<Int, Int, Grid> {
+
+    private val parsed = input.parse()
+
+    override fun partOne(): Int {
+        return parsed.mapIndexed { y, row ->
+            row.mapIndexed { x, _ ->
+                val start = Pos(x, y)
+                val words = Dir.entries.map { d ->
+                    (0..3)
+                        .map { num -> d.move(start, num) }
+                        .filter { p -> p.isInGrid(parsed) }
+                        .map { p -> parsed[p.y][p.x] }
+                        .joinToString("")
+                }.count { it == "XMAS" }
+                words
+            }.sum()
+        }.sum()
+    }
+
+    override fun partTwo(): Int {
+        val intRange = 1..(parsed.size - 2) // assuming grid is square (which both example and input is), avoiding both a filter and many comparisons.
+        return intRange.sumOf { y ->
+            intRange.map { x ->
+                val start = Pos(x, y)
+                listOf(listOf(start.nw(), start, start.se()), listOf(start.sw(), start, start.ne()))
+                    .all { diagonal ->
+                        diagonal.map { p -> parsed[p.y][p.x] }.joinToString("").let { it == "MAS" || it == "SAM" }
+                    }
+            }.count { it }
+        }
+    }
+
+    override fun List<String>.parse(): Grid {
+        return indices.map { y -> indices.map { x -> this[y][x] }.toCharArray() }.toTypedArray()
+    }
+
+    override val day = "04".toInt()
+}
+
+
+

src/main/script/download_aoc_input.sh

@@ -26,3 +26,4 @@ tail -10 "$PUZZLE_FILE"
 echo
 echo "TEST-FILE: $PUZZLE_FILE_TEST"
 echo "FILE:      $PUZZLE_FILE"
+echo "NUM-LINES: " `wc -l $PUZZLE_FILE`

src/test/kotlin/no/rodland/advent_2024/Day04Test.kt

@@ -0,0 +1,84 @@
+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 Day04Test {
+    private val data04 = "2024/input_04.txt".readFile()
+    private val test04 = "2024/input_04_test.txt".readFile()
+
+    private val resultTestOne = 18
+    private val resultTestTwo = 9
+    private val resultOne = 2344
+    private val resultTwo = 1815
+
+    val test = defaultTestSuiteParseOnInit(
+        Day04(data04),
+        Day04(test04),
+        resultTestOne,
+        resultOne,
+        resultTestTwo,
+        resultTwo,
+        { Day04(data04) },
+        { Day04(test04) },
+        numTestPart1 = 1,
+        numTestPart2 = 1
+    )
+
+    @Nested
+    inner class Init {
+        @Test
+        fun `04,-,example,1`() {
+            report(AOCTest({ "123".toInt() }, Unit, 123, 5, "04".toInt(), Part.TWO, false, "example"))
+        }
+
+        @Test
+        fun `04,-,example,2`() {
+            report(test.initTest.copy())
+        }
+
+        @Test
+        fun `04,-,test,init`() {
+            report(test.initTest)
+        }
+
+        @Test
+        fun `04,-,live,init`() {
+            report(test.initLive)
+        }
+    }
+
+    @Nested
+    inner class `Part 1` {
+        @Test
+        fun `04,1,test`() {
+            report(test.testPart1)
+        }
+
+        @Test
+        fun `04,1,live,1`() {
+            report(test.livePart1)
+        }
+    }
+
+    @Nested
+    inner class `Part 2` {
+        @Test
+        fun `04,2,test`() {
+            report(test.testPart2)
+        }
+
+        @Test
+        fun `04,2,live,1`() {
+            report(test.livePart2)
+        }
+    }
+}

src/test/resources/2024/input_04_test.txt

@@ -0,0 +1,10 @@
+MMMSXXMASM
+MSAMXMSMSA
+AMXSXMAAMM
+MSAMASMSMX
+XMASAMXAMM
+XXAMMXXAMA
+SMSMSASXSS
+SAXAMASAAA
+MAMMMXMMMM
+MXMXAXMASX