Advent of Code 07 part 1.scala

import java.io.FileInputStream
import scala.io.StdIn

@main def solve7() =
  def solve(colorLinks: Map[String, Vector[String]], firstBag: String): Int = {
    def findBags(bag: String): Set[String] = {
      val nexts = colorLinks.getOrElse(bag, Vector())
      nexts.flatMap(findBags).toSet ++ nexts.toSet
    }
    findBags(firstBag).size
  }

  val in = new FileInputStream("example7-1.in")
  System.setIn(in)

  val inputs = Iterator.continually(StdIn.readLine()).takeWhile(_ != null).toVector
  val colorLinks = inputs.foldLeft(Map[String, Vector[String]]()) { (acc, line) =>
    val Array(parent, children) = line.trim.init.replace("bags", "bag").split("contain")
    children.split(",").foldLeft(acc) { (subAcc, bag) =>
      val child: String = bag.filter(!_.isDigit).trim
      subAcc.updated(child, subAcc.getOrElse(child, Vector()) :+ parent.trim)
    }
  }
  println(solve(colorLinks, "shiny gold bag"))
  

Advent of Code 07 part 2.scala

import java.io.FileInputStream
import scala.io.StdIn

@main def solve7() =
  def solve(colorLinks: Map[String, Vector[(Int, String)]], firstBag: String): Int = {
    def childBagCount(bag: String): Int = {
      val nexts = colorLinks.getOrElse(bag, Vector())
      nexts.map { x => x._1 * (1 + childBagCount(x._2)) }.sum
    }
    childBagCount(firstBag)
  }

  val in = new FileInputStream("example7-1.in")
  System.setIn(in)

  val inputs = Iterator.continually(StdIn.readLine()).takeWhile(_ != null).toVector
  val colorLinks = inputs.foldLeft(Map[String, Vector[(Int, String)]]()) { (acc, line) =>
    val Array(parent, children) = line.trim.init.replace("bags", "bag").split("contain")
    children.split(",").foldLeft(acc) { (subAcc, bag) =>
      val child: String = bag.filter(!_.isDigit)
      val count = ("0" + bag.filter(_.isDigit)).toInt
      subAcc.updated(parent.trim, subAcc.getOrElse(parent.trim, Vector()) :+ (count, child.trim))
    }
  }
  println(solve(colorLinks, "shiny gold bag"))