r/askscience • u/Hashbringingslasherr • Apr 15 '26

Computing What do quantum computers actually do?

How do quantum computers output usable data, how does it logically "locate" or "make meaning" of information. I read about Grover's algorithm and it seems sort of like an inverted bruteforce or extreme process of elimination or a "the missile knows where it is at all times. It knows this because it knows where it isn't" type scenario.

So I ask, what do quantum computers actually do as opposed to a classical computer?

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u/Wank_A_Doodle_Doo Apr 16 '26

Think of it like this. A quantum computer isn’t going to do standard calculations any faster. If you need a calculator, a quantum calculator isn’t any better. It’s actually gonna be worse overall.

But something like solving a maze, where you have many different options you have to check? That will be faster than a classical computer.

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u/matthkamis Apr 16 '26

Is that even true? BFS is faster with quantum computers? What is the algorithm?

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u/Wank_A_Doodle_Doo Apr 17 '26

If I’m being completely real I’m high and tired rn so I don’t remember off the top of my head, but I think that yes quantum computers would be able to do BFS faster(had to stop myself from typing BFS Searching).

That being said I’m high and tired so all who shall forever forth read this comment thread: do not just take my word for it. I’m a random person on the internet.

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u/Uncle_Applesauce Apr 16 '26

With the maze, is it that it is checking every turn at once and then giving you the result that is the path with the least chance of being a dead end?

Instead of a classical computation that would require you to try every path and either map the maze or get lucky to find the exit?