Day 5

Author: Nxllpointer

build.gradle.kts

@@ -7,7 +7,7 @@ plugins {
 group = "de.nxll.aoc2022"
 version = "1.0"
 
-val currentDay = 5
+val currentDay = 6
 
 repositories {
  mavenCentral()

src/common/kotlin/Text.kt

@@ -1,3 +1,7 @@
 fun CharSequence.splitInTwo(delimiter: String): Pair<String, String> {
  return this.split(delimiter, limit = 2).let { it.first() to it.last() }
 }
+
+fun CharSequence.containsDuplicates(): Boolean {
+ return this.any { this.count(it::equals) > 1 }
+}

src/day_6/kotlin/Day6.kt

@@ -0,0 +1,32 @@
+// AOC Day 6
+
+fun findMarker(dataStream: String, markerSize: Int): Int? {
+ for (headPosition in markerSize until dataStream.length) {
+ /** [String.substring] start is inclusive, end exclusive */
+ val tailPositionIndex = headPosition - markerSize
+ if (!dataStream.substring(tailPositionIndex, headPosition).containsDuplicates()) {
+ return headPosition
+ }
+ }
+
+ return null
+}
+
+fun part1(dataStream: String) {
+ val firstPacketPosition = findMarker(dataStream, 4)!!
+
+ println("Part 1: The first packet starts at position $firstPacketPosition")
+}
+
+fun part2(dataStream: String) {
+ val firstMessagePacketPosition = findMarker(dataStream, 14)!!
+
+ println("Part 2: The first message packet starts at position $firstMessagePacketPosition")
+}
+
+fun main() {
+ val dataStream = getAOCInput { it.trim() }
+
+ part1(dataStream)
+ part2(dataStream)
+}