Day02

Author: ath0s

src/main/kotlin/Day02.kt

@@ -0,0 +1,41 @@
+import kotlin.io.path.readText
+
+class Day02 : Day {
+    private val twiceRepeatPattern = Regex("""^(.*)\1$""")
+    private val atLeastTwiceRepeatPattern = Regex("""^(.*)(\1)+$""")
+
+    override fun partOne(filename: String, verbose: Boolean): Long =
+        twiceRepeatPattern.sumDuplicates(filename, verbose)
+
+    override fun partTwo(filename: String, verbose: Boolean) =
+        atLeastTwiceRepeatPattern.sumDuplicates(filename, verbose)
+
+    private fun Regex.sumDuplicates(filename: String, verbose: Boolean): Long {
+        val ranges = filename.asPath().readText().split(',').map {
+            val (start, end) = it.split('-')
+            (start.toLong()..end.toLong())
+        }
+        if (verbose) {
+            ranges.forEach { range ->
+                println("${range.first}-${range.last}")
+            }
+        }
+        val duplicates = ranges.flatMap { range ->
+            range.mapNotNull { number ->
+                number.takeIf { it.toString().matches(this) }
+            }
+        }
+        if (verbose) {
+            duplicates.forEach {
+                println("duplicate=$it")
+            }
+        }
+
+        return duplicates.sum()
+    }
+
+    companion object : Day.Main("Day02.txt") {
+        @JvmStatic
+        fun main(args: Array<String>) = main()
+    }
+}

src/main/resources/Day02.txt

@@ -0,0 +1 @@
+385350926-385403705,48047-60838,6328350434-6328506208,638913-698668,850292-870981,656-1074,742552-796850,4457-6851,138-206,4644076-4851885,3298025-3353031,8594410816-8594543341,396-498,1558-2274,888446-916096,12101205-12154422,2323146444-2323289192,37-57,101-137,46550018-46679958,79-96,317592-341913,495310-629360,33246-46690,14711-22848,1-17,2850-4167,3723700171-3723785996,190169-242137,272559-298768,275-365,7697-11193,61-78,75373-110112,425397-451337,9796507-9899607,991845-1013464,77531934-77616074

src/test/kotlin/Day02Test.kt

@@ -0,0 +1,4 @@
+class Day02Test : DayTest<Day02>("Day02_test.txt") {
+    override val partOneExpected = 1227775554L
+    override val partTwoExpected = 4174379265L
+}

src/test/resources/Day02_test.txt

@@ -0,0 +1 @@
+11-22,95-115,998-1012,1188511880-1188511890,222220-222224,1698522-1698528,446443-446449,38593856-38593862,565653-565659,824824821-824824827,2121212118-2121212124