Lab 11: Fruitful Recursion

Worksheet Solutions

Create a new file called lab11.py and write all your code for today's lab in that file.

In a fruitful recursive function, which function frames contribute to the value returned by the original function frame?

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The answer here is "all of them." Although only the original function frame directly returns the result value, it will typically use information returned by other function frames to construct that value, so all of the function frames end up contributing to the eventual result somehow.
Why can't we use the early return pattern in a recursive function like we can if we're using a loop to repeat code?

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When we're writing code that uses a loop, as long as that code is inside of a function, a return statement will exit the entire function, thereby ending the loop. However, return only exits a single function call frame, and since recursion makes use of multiple function call frames to do its work, return will only exit one of them, effectively returning to an earlier "iteration" of the code (although of course it's a bit more complicated than that).