2D Prefix Sums

In the prefix sums category, I think it is useful to know about PIE (Principle of Inclusion and Exclusion). So, I was thinking that maybe you guys could make a section about PIE inside of the Prefix Sums nodule so that it is easier to understand the idea behind the 2D Prefix Sums category.

I think PIE is too complicated for silver… (Though, if the 2D prefix sum module is unclear, perhaps we should make better graphics to help people understand what’s being added and subtracted?)

It’s just that if I didn’t know what PIE was, then I wouldn’t understand why you would subtract values when filling in the prefix sum array. I think the graphics is a great idea though. I think with graphics, it would be much easier to understand why you subtract values.

TBH, I don’t think you have to teach people the basics of PIE just for them to be able to understand 2D prefix sums.