One of my very favorite basic ones: Point in polygon.

https://en.wikipedia.org/wiki/Point_in_polygon

I think direct democracy in the States would be fatal

He or she was probably referring to property tax. Illinois has one of the highest property tax rates in the US.

Shiffman's channel is great for new & experienced coders, but I will say it is especially good if you want to get a young kid interested in the field

He's an excellent teacher - you don't get bogged down in unnecessary complexity (he chooses simple libraries like three.js, or processing), but presents the inherent complexity of the problem.

Plus he makes it fun to watch with the enthusiastic style that's almost contagious.

IIRC, the maker has said HM was his inspiration. The expansions left him less than happy and he decided to do what he wanted himself.