progs/collatz_sol.scala
author Christian Urban <christian.urban@kcl.ac.uk>
Wed, 12 Aug 2020 00:56:20 +0100
changeset 335 7e00d2b13b04
parent 140 ecec79b9ab25
permissions -rw-r--r--
updated

// Part 1 about the 3n+1 conjecture
//==================================

object CW6a {

def collatz(n: Long): Long =
  if (n == 1) 1 else
    if (n % 2 == 0) 1 + collatz(n / 2) else 
      1 + collatz(3 * n + 1)


def collatz_max(bnd: Long): (Long, Long) = {
  val all = for (i <- (1 to bnd.toInt).toList) yield collatz(i)
  val max = all.max
  (max, all.indexOf(max) + 1)
}


}