fp in scala part 1

fp_scala_p1.scala

def fib(n: Int): Int = {
  @annotation.tailrec
  def loop(n: Int, prev: Int, cur: Int): Int =
    if (n == 0) prev
    else loop(n - 1, cur, prev + cur)
  loop(n, 0, 1)
}


fib(6)


def isSorted[A](as: Array[A], ordered: (A,A) => Boolean): Boolean = {
  def loop(index: Int): Boolean =
    if (as.length == index + 1) true
    else if (!ordered(as(index + 1), as(index))) false
    else loop(index + 1)

  loop(0)
}

isSorted(Array(1,3,4, 12, 5), (x: Int, y: Int) => x > y)