week 11

After last week's lecture, I have gained a deeper understanding of recursion. In particular, we worked on the flatten recursion.

This excise is kind of straightforward. Here, (cons? L) produces true if L is a list, false then otherwise. So basically, you just need to substitute different number for L, and go through the conditions step by step.

Another tricky example,

however, I find that the number of the brackets inside the depth function determines the answer with other conditions being equal.

amazing recursion

Sierpinski's triangle

example of recursion

image-width of the circle : the original radius is doubled