A Common-Sense Guide to Data Structures and Algorithms in JavaScript, Volume 1

Top-Down Recursion: A New Way of Thinking

This brings us to the central point of this chapter: recursion shines when implementing a top-down approach because going top-down offers a new mental strategy for tackling a problem. That is, a recursive top-down approach allows one to think about a problem in a completely different way.

Specifically, when we go top-down, we get to mentally “kick the problem down the road.” We can free our mind from some of the nitty-gritty details we normally have to think about when going bottom-up.

To see what I mean, let’s take another look at the key line from our top-down factorial implementation:

return number * factorial(number - 1);

This line of code makes its calculation based on factorial(number - 1). When ...