diff -r 8686ae7174c3 -r 69b39df6ad4d pre_testing1/collatz.scala
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/pre_testing1/collatz.scala	Sat Oct 31 16:47:46 2020 +0000
@@ -0,0 +1,37 @@
+object CW6a {
+
+//(1) Complete the collatz function below. It should
+//    recursively calculate the number of steps needed 
+//    until the collatz series reaches the number 1.
+//    If needed, you can use an auxiliary function that
+//    performs the recursion. The function should expect
+//    arguments in the range of 1 to 1 Million.
+def stepsCounter(n: Long, s: Long) : Long = n match{
+    case 1 => s
+    case n if(n%2==0) => stepsCounter(n/2,s+1)
+    case _ => stepsCounter(3*n+1, s+1)
+}
+
+def collatz(n: Long) : Long = n match {
+    case n if(n>0) => stepsCounter(n,0)
+    case n if(n<=0) => stepsCounter(1,0)
+}
+
+
+
+//(2) Complete the collatz_max function below. It should
+//    calculate how many steps are needed for each number 
+//    from 1 up to a bound and then calculate the maximum number of
+//    steps and the corresponding number that needs that many 
+//    steps. Again, you should expect bounds in the range of 1
+//    up to 1 Million. The first component of the pair is
+//    the maximum number of steps and the second is the 
+//    corresponding number.
+
+def collatz_max(bnd: Long) : (Long, Long) =  {
+    val allCollatz = for(i<-1L until bnd) yield collatz(i)
+    val pair = (allCollatz.max, (allCollatz.indexOf(allCollatz.max) +1).toLong)
+    pair
+}
+
+}