AoC 2023 Day 1

Day1.scala

package net.tazato
import cats.effect.*

object Day1 extends IOApp.Simple {
  private def eat(s: String): String =  {
    s.replaceAll("one", "o1e")
      .replaceAll("two", "t2o")
      .replaceAll("three", "t3e")
      .replaceAll("four", "f4r")
      .replaceAll("five", "f5e")
      .replaceAll("six", "s6x")
      .replaceAll("seven", "s7n")
      .replaceAll("eight", "e8t")
      .replaceAll("nine", "n9e")
  }

  private def answer(s: List[String]): Int =
    s.map(s => eat(s).filter(_.isDigit))
      .map(s => s.take(1) ++ s.reverse.take(1))
      .flatMap(_.toIntOption)
      .sum

  private val input =
    """two1nine
      |eightwothree
      |abcone2threexyz
      |xtwone3four
      |4nineeightseven2
      |zoneight234
      |7pqrstsixteen"""
        .stripMargin
        .split('\n')
        .toList

  private val input2F = scala.io.Source.fromResource("day1.txt")
  private val input2 = try input2F.getLines().toList finally input2F.close()

  val run: IO[Unit] = for {
    _ <- IO.println(answer(input))
    _ <- IO.println(answer(input2))
  } yield ()
}