Comment by baobabKoodaa

> No need to get condescending.

I apologize.

> Ok, but no, I did not mean to imply that. What I mean is that most programs are either straightforward linear scans over whole arrays, or working on data that was specifically requested by some index requested by a separate entity. Using a hashmap to lookup items faster is almost at the ceiling of complexity of most real-world programs.

Ok, now I see what you mean. I mean, I disagree with you, but I understand your point now.

> And really, that's sufficient to do most things at max speed. "Algorithms" (meaning stuff like interval trees, Fenwick trees, LCA computation, square root decomposition...) is irrelevant academic exercise for the vast majority of applications (including kernels and games).

Yes, all of the examples you provided are irrelevant for your average project. I don't mean that your average project would run into a need to optimize range queries with Fenwick trees. I mean your average project will run into situations where someone needs to write a simple O(n) list traversal, and they somehow manage to write it as O(n^2) because they have no understanding or interest towards algorithms. If the organization has staffed at least some people who care and have algorithm skills, they will spot these "low hanging fruit inefficiencies" and fix them.