matrix.scala

final case class Matrix(s: String) {

  private val matrix = fromString3(s)

  def row(r: Int): Vector[Int] = {
    matrix(r)
  }

  def column(c: Int): Vector[Int] = {
    matrix.map(_(c))
  }

  private def fromString(s: String): Vector[Vector[Int]] = {
    val rowStrings = s.split("\n")
    rowStrings.map { rowString =>
      val numStrings = rowString.split(" ")
      numStrings.map(_.toInt).toVector
    }.toVector
  }

  private def fromString2(s: String): Vector[Vector[Int]] = {
    for {
      rowString <- s.split("\n").toVector
      numStrings = rowString.split(" ").toVector
      numVector = numStrings.map(_.toInt)
    } yield numVector
  }

  private def fromString3(s: String): Vector[Vector[Int]] = {
    splitWith("\n", splitWith(" ", _.toInt))(s)
  }

  private def splitWith[T](splitter: String, fn: String => T)(
      s: String): Vector[T] = {
    s.split(splitter)
      .toVector
      .map(fn)
  }
}