I just wanted to say I've added a Scala implementation of the counting change exercise as I wanted to see the growth in procudural steps myself.
I put a simple counter in the CC method to count how many times that got called, then ran it a few times doubling the amount to computer in question (i.e. the first time I passed in 1, then 2, then 4 to see how many combinations were required).
If I got this right, it produces what I think is an exponential graph shape - but my maths is pretty shaky to say the least so terminology may be wrong