Advent of Code 06 part 1.scala

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

@main def solve6() =
  def solve(answers: Vector[String]): Int = {
    answers.flatMap(_.toSet).toSet.size
  }

  val in = new FileInputStream("example6-1.in")
  System.setIn(in)

  val inputs = Iterator.continually(StdIn.readLine()).takeWhile(_ != null).toVector
  val questions = inputs.foldLeft(Vector[Vector[String]](Vector())) { (acc, line) =>
    if line.trim.isEmpty then
      acc :+ Vector()
    else
      acc.init :+ (acc.last :+ line)
    }
  println(questions.map(solve).sum)
  

Advent of Code 06 part 2.scala

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

@main def solve6() =
  def solve(answers: Vector[String]): Int = {
    answers.map(_.toSet).reduce(_ intersect _).size
  }

  val in = new FileInputStream("example6-1.in")
  System.setIn(in)

  val inputs = Iterator.continually(StdIn.readLine()).takeWhile(_ != null).toVector
  val questions = inputs.foldLeft(Vector[Vector[String]](Vector())) { (acc, line) =>
    if line.trim.isEmpty then
      acc :+ Vector()
    else
      acc.init :+ (acc.last :+ line)
    }
  println(questions.map(solve).sum)