notes.scala

import scala.annotation.tailrec

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

    loop(1, n)
}

def fact(n: Int): Int = {
    if (n == 0) 1
    else n * fact(n - 1)
}