diff -r 5bbbe737184e -r f8883f8a14ad solutions1/collatz.scala --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/solutions1/collatz.scala Sat Nov 17 13:35:08 2018 +0000 @@ -0,0 +1,29 @@ +// Part 1 about the 3n+1 conjecture +//================================== + + +object CW6a { // for purposes of generating a jar + +def collatz(n: Long): Long = + if (n == 1) 0 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 <- (1L to bnd)) yield (collatz(i), i) + all.maxBy(_._1) +} + + +/* some test cases +val bnds = List(10, 100, 1000, 10000, 100000, 1000000) + +for (bnd <- bnds) { + val (steps, max) = collatz_max(bnd) + println(s"In the range of 1 - ${bnd} the number ${max} needs the maximum steps of ${steps}") +} + +*/ + +}