2023 - Day 21 - init

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

@@ -21,6 +21,24 @@ fun String.readFileAsString(): String {
     }
 }
 
+// https://kotlinlang.slack.com/archives/C87V9MQFK/p1703069274599999?thread_ts=1703048402.894019&cid=C87V9MQFK
+//fun chineseRemainder(values: List<Pair<Long, Long>>): Long {
+//    if (values.isEmpty()) {
+//        return 0L
+//    }
+//    var result = values[0].first
+//    var lcm = values[0].second
+//    for (i in 1 until values.size) {
+//        val (base, modulo) = values[i]
+//        val target = base % modulo
+//        while (result % modulo != target) {
+//            result += lcm
+//        }
+//        lcm = lcm(lcm, modulo)
+//    }
+//    return result
+//}
+
 fun lcm(n1: BigInteger, n2: BigInteger): BigInteger {
     // https://no.wikipedia.org/wiki/Minste_felles_multiplum
     // lcm = (n1 * n2) / gcd

src/main/kotlin/no/rodland/advent_2023/Day21.kt

@@ -0,0 +1,27 @@
+package no.rodland.advent_2023
+
+import no.rodland.advent.Day
+
+// template generated: 21/12/2023
+// Fredrik Rødland 2023
+
+class Day21(val input: List<String>) : Day<Long, Long, List<String>> {
+
+    private val parsed = input.parse()
+
+    override fun partOne(): Long {
+        return 2
+    }
+
+    override fun partTwo(): Long {
+        return 2
+    }
+
+    override fun List<String>.parse(): List<String> {
+        return map { line ->
+            line
+        }
+    }
+
+    override val day = "21".toInt()
+}

src/test/kotlin/no/rodland/advent_2023/Day21Test.kt

@@ -0,0 +1,82 @@
+package no.rodland.advent_2023
+
+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 Day21Test {
+    private val data21 = "2023/input_21.txt".readFile()
+    private val test21 = "2023/input_21_test.txt".readFile()
+
+    private val resultTestOne = 2L
+    private val resultTestTwo = 2L
+    private val resultOne = 2L
+    private val resultTwo = 2L
+
+    val test = defaultTestSuiteParseOnInit(
+        Day21(data21),
+        Day21(test21),
+        resultTestOne,
+        resultOne,
+        resultTestTwo,
+        resultTwo,
+        { Day21(data21) },
+        { Day21(test21) },
+    )
+
+    @Nested
+    inner class Init {
+        @Test
+        fun `21,-,example,1`() {
+            report(AOCTest({ "123".toInt() }, Unit, 123, 5, "21".toInt(), Part.TWO, false, "example"))
+        }
+
+        @Test
+        fun `21,-,example,2`() {
+            report(test.initTest.copy())
+        }
+
+        @Test
+        fun `21,-,test,init`() {
+            report(test.initTest)
+        }
+
+        @Test
+        fun `21,-,live,init`() {
+            report(test.initLive)
+        }
+    }
+
+    @Nested
+    inner class `Part 1` {
+        @Test
+        fun `21,1,test`() {
+            report(test.testPart1)
+        }
+
+        @Test
+        fun `21,1,live,1`() {
+            report(test.livePart1)
+        }
+    }
+
+    @Nested
+    inner class `Part 2` {
+        @Test
+        fun `21,2,test`() {
+            report(test.testPart2)
+        }
+
+        @Test
+        fun `21,2,live,1`() {
+            report(test.livePart2)
+        }
+    }
+}