Background

We just saw a lot of function invocations. Go ahead and look at the cost of function invocation. Every function invocation is costly for a program. In the example of recursive functions, we can use neater code, but it comes at a cost. Let’s take a look at it in greater detail.

Introduction to call stack

All programs maintain a “call stack” where every invocation of a function pushes them onto the stack and then removes them when the function returns. Every function invocation adds an ...