練習用にmin実装

min.scala

// not tailrec... :(
def min(l: Seq[Int]): Int = l match {
  case h :: t if t.isEmpty => h
  case h :: t => min(t) match {
    case r if h < r => h
    case r => r
  }
}

// tailrec! :)
def min(l: Seq[Int]): Int = {
  @tailrec
  def min(l: Seq[Int], n: Int): Int = l match {
    case h :: t => min(t, if (n < h) n else h)
    case _ => n
  }
  min(l, l.head)
}

def min(l: Seq[Int]): Int = l.reduceLeft { (n, i) => if (n < i) n else i }

l.min