Solve 2025 day 10 part 2 naively

Author: sim642

src/main/scala/eu/sim642/adventofcode2025/Day10.scala

@@ -1,12 +1,12 @@
 package eu.sim642.adventofcode2025
 
-import eu.sim642.adventofcodelib.graph.{BFS, GraphSearch, TargetNode, UnitNeighbors}
+import eu.sim642.adventofcodelib.graph.{BFS, Dijkstra, GraphSearch, TargetNode, UnitNeighbors}
 
 object Day10 {
 
   type Lights = Vector[Boolean]
   type Buttons = Seq[Seq[Int]]
-  type Joltages = Seq[Int]
+  type Joltages = Vector[Int]
 
   case class Machine(lights: Lights, buttons: Buttons, joltages: Joltages)
 
@@ -25,11 +25,27 @@ object Day10 {
 
   def sumFewestPresses(machines: Seq[Machine]): Int = machines.map(fewestPresses).sum
 
+  // TODO: optimize
+  def fewestPresses2(machine: Machine): Int = {
+    val graphSearch = new GraphSearch[Joltages] with UnitNeighbors[Joltages] with TargetNode[Joltages] {
+      override val startNode: Joltages = machine.joltages.map(_ => 0)
+
+      override def unitNeighbors(joltages: Joltages): IterableOnce[Joltages] =
+        machine.buttons.map(_.foldLeft(joltages)((acc, i) => acc.updated(i, acc(i) + 1)))
+
+      override val targetNode: Joltages = machine.joltages
+    }
+
+    BFS.search(graphSearch).target.get._2
+  }
+
+  def sumFewestPresses2(machines: Seq[Machine]): Int = machines.map(fewestPresses2).sum
+
   def parseMachine(s: String): Machine = s match {
     case s"[$lightsStr] $buttonsStr {$joltagesStr}" =>
       val lights = lightsStr.map(_ == '#').toVector
       val buttons = buttonsStr.split(" ").map(_.tail.init.split(",").map(_.toInt).toSeq).toSeq
-      val joltages = joltagesStr.split(",").map(_.toInt).toSeq
+      val joltages = joltagesStr.split(",").map(_.toInt).toVector
       Machine(lights, buttons, joltages)
   }
 
@@ -39,5 +55,6 @@ object Day10 {
 
   def main(args: Array[String]): Unit = {
     println(sumFewestPresses(parseMachines(input)))
+    println(sumFewestPresses2(parseMachines(input)))
   }
 }

src/test/scala/eu/sim642/adventofcode2025/Day10Test.scala

@@ -17,4 +17,12 @@ class Day10Test extends AnyFunSuite {
   test("Part 1 input answer") {
     assert(sumFewestPresses(parseMachines(input)) == 449)
   }
+
+  test("Part 2 examples") {
+    assert(sumFewestPresses2(parseMachines(exampleInput)) == 33)
+  }
+
+  test("Part 2 input answer") {
+    //assert(sumFewestPresses2(parseMachines(input)) == 449)
+  }
 }