Merge pull request #91 from tlarsen0/feature/day08.2-2024-10-14

Feature/day08.2 2024 10 14

Author: tlarsen0

2023/day08_2/.idea/inspectionProfiles/Project_Default.xml

@@ -0,0 +1,15 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<module type="JAVA_MODULE" version="4">
+  <component name="NewModuleRootManager" inherit-compiler-output="true">
+    <exclude-output />
+    <content url="file://$MODULE_DIR$">
+      <sourceFolder url="file://$MODULE_DIR$/resources" type="java-resource" />
+      <sourceFolder url="file://$MODULE_DIR$/src" isTestSource="false" />
+      <sourceFolder url="file://$MODULE_DIR$/test" isTestSource="true" />
+      <sourceFolder url="file://$MODULE_DIR$/testResources" type="java-test-resource" />
+    </content>
+    <orderEntry type="inheritedJdk" />
+    <orderEntry type="sourceFolder" forTests="false" />
+    <orderEntry type="library" name="KotlinJavaRuntime" level="project" />
+  </component>
+</module>

2023/day08_2/.idea/kotlinc.xml

@@ -0,0 +1,94 @@
+import java.io.File
+import java.util.*
+import kotlin.collections.ArrayList
+
+fun main(args: Array<String>) {
+    println("AOC 2023, Day 8, Part 2 starting!!!!")
+
+    var firstLine = false
+    var directions = "None"
+    val allNodes = ArrayList<Node>()
+    File(args[0]).forEachLine {
+        if(!firstLine) {
+            directions = it
+            firstLine = true
+        } else if(it.isNotEmpty()) {
+            val nodeName = it.substring(0..2)
+            val connectionLeft = it.substring(7..9)
+            val connectionRight = it.substring(12..14)
+            allNodes.add(Node(nodeName, connectionLeft, connectionRight))
+        }
+    }
+
+    println("Total Nodes: ${allNodes.count()}")
+    val nodesEndWithA = findNodesEndsWithA(allNodes)
+    println("Finding nodes that end with A: $nodesEndWithA")
+    val nodesEndWithZ = findNodesEndsWithZ(allNodes)
+    println("Finding nodes that end with Z: $nodesEndWithZ")
+
+    val foundCount = Stack<Long>()
+    nodesEndWithA.forEach {
+        println("Starting search starting with $it")
+        foundCount.push(traverseNodeIterative(directions, allNodes, it))
+        println("found it! Path took ${foundCount.peek()} steps.")
+    }
+
+    println("Final path count results: $foundCount")
+
+    var stepsStack = foundCount.pop()
+    while(!foundCount.empty()) {
+        stepsStack = lcm(stepsStack, foundCount.pop())
+    }
+
+    println("Steps taken to traverse to all nodes end with Z: $stepsStack")
+
+    println("AOC 2023, Day 8, Part 2 completed!!!")
+}
+
+fun lcm(a: Long, b: Long): Long {
+    return (a / gcd(a, b)) * b
+}
+
+fun gcd(a: Long, b: Long): Long {
+    if (a == 0L) return b
+    return gcd(b % a, a)
+}
+
+
+fun findNodesEndsWithA(nodes: ArrayList<Node>):ArrayList<Node> {
+    val nodesEndsWithA = ArrayList<Node>()
+    nodes.filter { it.nodeName.last() == 'A' }.toCollection(nodesEndsWithA)
+    return nodesEndsWithA
+}
+
+fun findNodesEndsWithZ(nodes: ArrayList<Node>):ArrayList<Node> {
+    val nodesEndsWithZ = ArrayList<Node>()
+    nodes.filter { it.nodeName.last() == 'Z' }.toCollection(nodesEndsWithZ)
+    return nodesEndsWithZ
+}
+
+fun traverseNodeIterative(directions: String, nodes: ArrayList<Node>, startNode: Node): Long {
+    var totalSteps = 0L
+    var nextStep = 0
+    var currentNode = Node(startNode.nodeName, startNode.connectionLeft, startNode.connectionRight)
+    var nextNode:Node
+    while(currentNode.nodeName.last() != 'Z') {
+        val leftOrRight = directions[nextStep]
+        nextNode = if(leftOrRight.compareTo('L') == 0) {
+            nodes.find { it.nodeName == currentNode.connectionLeft }!!
+        } else {
+            nodes.find { it.nodeName == currentNode.connectionRight }!!
+        }
+        currentNode = nextNode
+
+        nextStep++
+        totalSteps++
+        if(nextStep >= directions.length) {
+            nextStep = 0
+        }
+    }
+
+    return totalSteps
+}
+
+data class Node (val nodeName:String, val connectionLeft:String, val connectionRight:String)