Advent 2017-02

advent02.sc

// -*- mode: scala -*-

import scala.io.Source

def input(fname: String): List[List[Int]] = input(Source.fromFile(fname))

def input(in: Source): List[List[Int]] = in.getLines.toList.map(_.split("[\t ]+").toList.map(_.toInt))

def calc(data: List[List[Int]]) =
  data.map(row => {
    val s = row.sorted
    s.last - s.head
  }).sum

def findCombs[A](l: List[A]): List[(A, A)] = {
  for(a <- l; lA <- l if lA != a) yield (a, lA)
}

def find(l: List[Int]) = findCombs(l).collectFirst {
  case (a, b) if a % b == 0 => a / b
}

def calc2(data: List[List[Int]]) =
  data.map(row => find(row).get).sum

@main
def go() = {
  val data = input("input02.txt")
  println(s"1: ${calc(data)}")
  println(s"2: ${calc2(data)}")
}