> Going from "what to program" to "what code to write" is what programming is about.

Once your requirements are established there isn't any thing left to choose from, other than maybe whether to use a while loop instead of a for loop — stuff that makes absolutely no difference. The structure of your code, the algorithms you choose, etc. are all dictated by the requirements. So what lies in this nebulous in-between state and what makes it so hard? Is it choosing between for and while what you think is hard?