Finish 2024 day 23 both parts

2024/kotlin/src/main/kotlin/Main.kt

@@ -22,6 +22,7 @@ import com.tymscar.day19.solve as day19
 import com.tymscar.day20.solve as day20
 import com.tymscar.day21.solve as day21
 import com.tymscar.day22.solve as day22
+import com.tymscar.day23.solve as day23
 
 fun main() {
     day01()
@@ -46,4 +47,5 @@ fun main() {
     day20()
     day21()
     day22()
+    day23()
 }

2024/kotlin/src/main/kotlin/com/tymscar/day23/part1/part1.kt

@@ -1,5 +1,38 @@
 package com.tymscar.day23.part1
 
+
+private fun getAllConnected(from: String, map: Map<String, List<String>>, groupCount: Int): List<String> {
+    var groups = listOf(listOf(from))
+
+    while (groups.first().count() < groupCount) {
+        groups = groups.flatMap { group ->
+            map[group.last()]!!
+                .filter { !group.contains(it) }
+                .map { group + it }
+        }
+    }
+
+    return groups
+        .filter { group ->
+            group.all { computer ->
+                group.all { peer ->
+                    map[computer]!!.contains(peer) || computer == peer
+                }
+            }
+        }.map { it.sorted().joinToString(",") }
+}
+
 fun solve(input: String): String {
-    return input
+    val map = input
+        .lines()
+        .flatMap {
+            val (from, towards) = it.split("-")
+            listOf(from to towards, towards to from)
+        }.groupBy({ it.first }, { it.second })
+
+    return map.keys.filter { it[0] == 't' }
+        .flatMap { getAllConnected(it, map, 3) }
+        .toSet()
+        .count()
+        .toString()
 }

2024/kotlin/src/main/kotlin/com/tymscar/day23/part2/part2.kt

@@ -1,5 +1,39 @@
 package com.tymscar.day23.part2
 
+
+fun getAllCliques(
+    graph: Map<String, List<String>>,
+    currentClique: Set<String>,
+    remainingNodes: MutableSet<String>,
+    visitedNodes: MutableSet<String>
+): List<Set<String>> {
+    if (remainingNodes.isEmpty() && visitedNodes.isEmpty()) return listOf(currentClique)
+    val results = mutableListOf<Set<String>>()
+
+    remainingNodes.toList().forEach { v ->
+        val neighbours = graph[v]?.toSet() ?: emptySet()
+        results.addAll(getAllCliques(
+            graph,
+            currentClique + v,
+            remainingNodes.intersect(neighbours).toMutableSet(),
+            visitedNodes.intersect(neighbours).toMutableSet()
+        ))
+        remainingNodes.remove(v)
+        visitedNodes.add(v)
+    }
+    return results
+}
+
 fun solve(input: String): String {
-    return input
+    val map = input
+        .lines()
+        .flatMap {
+            val (from, towards) = it.split("-")
+            listOf(from to towards, towards to from)
+        }.groupBy ({ it.first }, { it.second })
+
+    return getAllCliques(map, emptySet(), map.keys as MutableSet<String>, mutableSetOf())
+        .maxBy { it.count() }
+        .sorted()
+        .joinToString(",")
 }