import scala.io.StdIn.readLine case class Node(c: Char, nbChild: Int, nbMetadata: Int, children: List[Node], metadata: List[Int]) { val metaSum: Int = metadata.sum } val it = readLine.split(" ").map(_.toInt).toList def readNode(c: Char, input: List[Int]): (Int, Node) = input match { case nbChild :: nbMeta :: t => val (read, children) = List.range(0, nbChild, 1).foldLeft((0, List.empty[Node])) { case (acc, id) => val (read, node) = readNode((c + id + 1).toChar, t.drop(acc._1)) (acc._1 + read, acc._2 ++ List(node)) } val metadata: List[Int] = input.drop(read + 2).take(nbMeta).toList (read + 2 + nbMeta, Node(c, nbChild, nbMeta, children, metadata)) case _ => (0, null) } val rootNode = readNode('A', it)._2 def sumMetadata(node: Node): Int = node match { case _ if node.nbChild > 0 => node.metadata.map { case m if m <= node.nbChild => sumMetadata(node.children(m - 1)) case _ => 0 }.sum case _ => node.metaSum } println(sumMetadata(rootNode))