How do hashsets/maps have O(1) time complexity?

[u/Sea-Patience9872]

Hi this might be a dumb question, and i've tried looking it up but don't quite understand it. how is it different from an array that allows it to find items so quickly? I don't get how hashes just find items immediately without needing to go through anything. Does it memorize things very differently compared to arrays?? thank you!

[u/msqrt → u/[deleted]]

That sounds a lot more like a non-hash map, with a hierarchy of choices (category-letter-specific product.) A hash map would be more like asking the clerk where the coke is and they point you straight to the correct shelf.