1.7 꼬리 재귀

tail recursion: If a function calls itself as its last action, the function's stack frame can be reused.

 

Exercise

factorial() 을 꼬리재귀 버전으로 구현하라.

import scala.annotation.tailrec

def factorial(n: Long): Long = {
  @tailrec
  def fact(n: Long, acc: Long): Long = if (n == 0) acc else fact(n - 1, n * acc)

  fact(n, 1)
}

@main def Main(): Unit = {
  val r = factorial(10)
  println(r)
}