Main.scala

import scala.io.Source;

object Main {

  def main(args: Array[String]): Unit = {
    val nodes = for (line <- Source.fromFile("input.txt").getLines) yield parse(line)

    val navigationMap =  nodes.foldLeft(Map[String, Node]()) { (m, s) =>  m + (s.from -> s) }

    val part1 = navigationMap.keySet.filter(containsBag(navigationMap, _, "shiny gold")).size
    println("part1=" + part1)

    val part2 = coountBag(navigationMap, "shiny gold")
    println("part2=" + part2)
  }

  def containsBag(navigationMap: Map[String, Node], key:String, target: String): Boolean = {
    if (navigationMap.contains(key)) {
      if(navigationMap(key).to.contains(target)) true
      else navigationMap(key).to.keySet.exists(k => containsBag(navigationMap, k, target))
    } else {
      false
    }
  }

  def coountBag(navigationMap: Map[String, Node], key:String): Int = {

    if (navigationMap.contains(key)) {
      val childBags = navigationMap(key).to

      // toList 하지 않으면 set으로 변환되어 중복된 카운트 값이 있으면 누락됨
      childBags.keys.toList.map(k => childBags(k) + childBags(k) * coountBag(navigationMap,k)).sum

    } else 0
  }

  def parse(line: String) = {
    val toks = line.split("contain")
    val from = extractColor(toks(0))

    val toList = for {
      to <- toks(1).split(",");
      totoks = parseToToks(to);
      if !totoks(0).isEmpty();
    } yield (extractColor(totoks(1)), totoks(0).toInt)

    val toMap = toList.foldLeft(Map[String, Int]()) { (m, s) =>  m + (s(0) -> s(1)) }

    Node(from, toMap)
  }
}

def parseToToks(toks: String) =  {
  toks.trim().span(_.isDigit)
}

def extractColor(bags: String): String = {
  bags.split("bag")(0).trim
}

case class Node(from:String, to:Map[String, Int])