this post was submitted on 22 Jun 2024
403 points (97.4% liked)

Programmer Humor

19817 readers
555 users here now

Welcome to Programmer Humor!

This is a place where you can post jokes, memes, humor, etc. related to programming!

For sharing awful code theres also Programming Horror.

Rules

founded 2 years ago
MODERATORS
 
you are viewing a single comment's thread
view the rest of the comments
[โ€“] [email protected] 16 points 6 months ago (1 children)

A quadratic function is just one possible polynomial. They're also not really related to big-O complexity, where you mostly just care about what the highest exponent is: O(n^2) vs O(n^3).

For most short programs it's fairly easy to determine the complexity. Just count how many nested loops you have. If there's no loops, it's probably O(1) unless you're calling other functions that hide the complexity.

If there's one loop that runs N times, it's O(n), and if you have a nested loop, it's likely O(n^2).

You throw out any constant-time portion, so your function's actual runtime might be the polynomial: 5n^3 + 2n^2 + 6n + 20. But the big-O notation would simply be O(n^3) in that case.

I'm simplifying a little, but that's the overview. I think a lot of people just memorize that certain algorithms have a certain complexity, like binary search being O(log n) for example.

[โ€“] [email protected] 2 points 6 months ago

Spot on. Good explanation.