Solved day08 part 2, but calculation is more than 1h

Author: Gentleman1983

build.gradle

@@ -4,7 +4,7 @@ plugins {
 
 // project meta data
 group 'de.havox_design.aoc2023'
-version '0.7.3'
+version '0.7.4'
 
 // Switch to gradle "all" distribution.
 wrapper {

day08/src/main/kotlin/de/havox_design/aoc2023/day08/Day08.kt

@@ -33,8 +33,29 @@ class Day08(private var filename: String) {
         return steps
     }
 
-    fun solvePart2(): Long =
-        6L
+    fun solvePart2(): Long {
+        convertInput()
+        val startNodeSuffix = "A"
+        val endNodeSuffix = "Z"
+
+        var steps = 0L
+        var currentNodes = NODES.filter { node -> node.name.endsWith(startNodeSuffix) }
+        val endNodes = NODES.filter { node -> node.name.endsWith(endNodeSuffix) }
+        var instructionIndex = 0
+
+        while(!endNodes.containsAll(currentNodes)) {
+            val currentInstruction = INSTRUCTIONS[instructionIndex]
+            instructionIndex++
+            instructionIndex %= INSTRUCTIONS.size
+            currentNodes = currentNodes
+                .parallelStream()
+                .map{node -> node.getNode(currentInstruction)}
+                .toList()
+            steps++
+        }
+
+        return steps
+    }
 
     private fun convertInput() {
         val input = getResourceAsText(filename)

day08/src/main/kotlin/de/havox_design/aoc2023/day08/Node.kt

@@ -1,6 +1,6 @@
 package de.havox_design.aoc2023.day08
 
-data class Node(val name: String, var left: Node?, var right: Node?) {
+data class Node(val name: String, var left: Node?, var right: Node?): Comparable<Node> {
     fun setNode(direction: Direction, node: Node) {
         when(direction) {
             Direction.LEFT -> left = node
@@ -18,4 +18,20 @@ data class Node(val name: String, var left: Node?, var right: Node?) {
             Direction.LEFT -> left!!
             Direction.RIGHT -> right!!
         }
+
+    override fun compareTo(other: Node): Int =
+        name.compareTo(other.name)
+
+    override fun equals(other: Any?): Boolean {
+        if (this === other) return true
+        if (javaClass != other?.javaClass) return false
+
+        other as Node
+
+        return name == other.name
+    }
+
+    override fun hashCode(): Int {
+        return name.hashCode()
+    }
 }