Clean up 2024 day 23

src/main/scala/eu/sim642/adventofcode2024/Day23.scala

@@ -7,9 +7,11 @@ object Day23 {
   type Computer = String
   type Edge = (Computer, Computer)
 
-  def find3Cliques(edges: Set[Edge]): Set[Set[Computer]] = {
-    val neighbors = (edges ++ edges.map(_.swap)).groupMap(_._1)(_._2)
+  def edges2neighbors(edges: Set[Edge]): Map[Computer, Set[Computer]] =
+    (edges ++ edges.map(_.swap)).groupMap(_._1)(_._2)
 
+  def find3Cliques(edges: Set[Edge]): Set[Set[Computer]] = {
+    val neighbors = edges2neighbors(edges)
     for {
       (from, to) <- edges
       third <- neighbors(from) & neighbors(to)
@@ -18,15 +20,11 @@ object Day23 {
 
   def count3CliquesT(edges: Set[Edge]): Int = find3Cliques(edges).count(_.exists(_.startsWith("t")))
 
-  def maximumClique(edges: Set[Edge]): Set[Computer] = {
-    val neighbors = (edges ++ edges.map(_.swap)).groupMap(_._1)(_._2)
-    BronKerbosch.maximumClique(neighbors)
-  }
+  def maximumClique(edges: Set[Edge]): Set[Computer] =
+    BronKerbosch.maximumClique(edges2neighbors(edges))
 
-  def lanPartyPassword(edges: Set[Edge]): String = {
-    val clique = maximumClique(edges)
-    clique.toSeq.sorted.mkString(",")
-  }
+  def lanPartyPassword(edges: Set[Edge]): String =
+    maximumClique(edges).toSeq.sorted.mkString(",")
 
   def parseEdge(s: String): Edge = s match {
     case s"$from-$to" => (from, to)