day3.scala

import scala.io.Source

def matchHalf(xs: String): String =
  val half = xs.take(xs.length / 2)
  val otherHalf = xs.takeRight(xs.length / 2)
  half.filter(otherHalf.contains)

def stringToPriority(s: String): Int =
  val c = s.charAt(0)
  c.isLower match
    case true => c - 'a' + 1
    case _ => c - 'A' + 27

def ans1(xs: List[String]): Int = xs.map(matchHalf andThen stringToPriority).sum

def matchBag(a: String, b: String): String = a.filter(b.contains)

def ans2(xs: List[String]): Int = 
  xs.grouped(3).map(bags => stringToPriority(matchBag(matchBag(bags(0), bags(1)), bags(2)))).sum

def solve =
  val input = Source.fromFile("day3.txt").getLines.toList
  println(ans1(input))
  println(ans2(input))