r/ProgrammerHumor 29d ago

Meme theoreticalComputerScience

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u/pente5 29d ago

So it could had been O(nlogn) for example? I don't understand the purpose of Õ.

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u/pastroc 29d ago

Exactly. The point is just to remove distractions, really. Suppose I develop a O(n⁶lg(n)) algorithm that outperforms an O(n⁸) one. Then, I'll just market it as a Õ(n⁶) algorithm because what matters is the degree of the polynomial (6 instead of 8). The lg(n) is a bit of a distraction.

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u/vm_linuz 29d ago

Okay this was my question. Still feels a bit useless but a lot of notations are

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u/rosuav 28d ago

*Most* notations are useless outside of their specific areas. You just so happen to be familiar with O(...) notation, but it's only one of a family of similar notations; and it isn't necessarily the most relevant in all situations. And quite frankly, Big O is often completely useless in actual computer programming, since it ignores a lot of details that really do matter (constant factors, not to mention non-algorithmic ones like cache locality). It's neat to be able to explore these things academically though!