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JPDev@programming.dev to Programmer Humor@programming.dev · 1 year ago

Returns a sorted list in O(1) time

programming.dev

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Returns a sorted list in O(1) time

programming.dev

JPDev@programming.dev to Programmer Humor@programming.dev · 1 year ago
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  • Rikudou_Sage@lemmings.world
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    1 year ago

    While this doesn’t work all the time, when it does, it’s really fast. Similar to the isPrime function, it’s correct most of the time and is much faster than alternative implementations:

    function isPrime(number) {
        return false;
    }
    
    • Dave.@aussie.zone
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      1 year ago

      What your code can do is run this first and if it returns false then do a quick double check using a traditional isPrime function. Really speeds things up!

      • Rikudou_Sage@lemmings.world
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        I mean, it has a 99.999%+ success rate on a large enough sample and I can live with that.

        • Dave.@aussie.zone
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          1 year ago

          Nah, you’ve always got to check the corner cases. It’s a variation on Murphy’s Law - you don’t encounter corner cases when you’re developing a program but corner cases are 99 percent of an everyday user’s interaction.

      • Doc Avid Mornington@midwest.social
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        1 year ago

        Good idea, but it would be much faster if you do the double-check on true instead.

        • xmunk@sh.itjust.works
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          1 year ago

          This is a power(ful) idea.

          Are my stats/programmers in the house?

      • fibojoly@sh.itjust.works
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        1 year ago

        Better. Return true if the number is in a stored list of known primes, otherwise return false right away. But then, start a separate thread with an actual verification algorithm. When the verification is done, if it was actually a prime number, you just crash the program with a WasActuallyPrime exception.

    • itslilith@lemmy.blahaj.zone
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      1 year ago

      asymptotically this is 100% correct!

      • mumblerfish@lemmy.world
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        1 year ago

        What would be the accuracy on something like a 64bit unsigned integer?

        • itslilith@lemmy.blahaj.zone
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          1 year ago

          WolframAlpha estimates PrimePi[2^64-1] to be about 4.15829E17, so about 97.7%

    • xmunk@sh.itjust.works
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      1 year ago

      deleted by creator

    • asudox@lemmy.world
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      1 year ago

      50/50 chance of being right in O(1) time

      • Rikudou_Sage@lemmings.world
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        1 year ago

        It’s right much more often than just 50/50.

      • andnekon@programming.dev
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        1 year ago

        50/50 would be for isOdd with the same implementation

      • Lmaydev@programming.dev
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        1 year ago

        Primes are not that common especially as numbers get bigger.

        It’ll be right the vast majority of times.

  • YaBoyMax@programming.dev
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    1 year ago

    Lossy sort

  • xmunk@sh.itjust.works
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    1 year ago

    Copilot is fucking killing it these days.

  • Jakylla@sh.itjust.works
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    1 year ago

    inplace sort be like:

    def sort(list: list):
        list.clear()
    
  • TheBananaKing@lemmy.world
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    1 year ago

    https://xkcd.com/221/

  • Trailblazing Braille Taser@lemmy.dbzer0.com
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    1 year ago

    Besides the obvious flaws… is that parameter a list named list, shadowing the list() constructor?

    • infinitepcg@lemmy.world
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      It works as long as you don’t call list() within that function.

    • Species5218@sh.itjust.works
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      That is a type hint

      • Trailblazing Braille Taser@lemmy.dbzer0.com
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        Well duh. I wonder what happens if you shadow the list constructor and try to use it as a type hint…

        def foo(list: list):
          def bar(thingies: list):
            pass
        
  • mcmodknower@programming.dev
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    you can even have a case where you return the first element of the list if the list is not empty, and it will still be O(1).

    • murtaza64@programming.dev
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      you can make it sort the first k elements and it will still be O(1). Set k high enough and it might even be useful

      • xmunk@sh.itjust.works
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        1 year ago

        I set k to 50,000,000,000… that’s more items than my shitty computer can fit in memory (including swsp) but I am now happy to celebrate my O(1) algorithm.

      • KubeRoot@discuss.tchncs.de
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        1 year ago

        By that logic, any sorting implementation is O(1), as the indexing variable/address type has limited size

  • SzethFriendOfNimi@lemmy.world
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    1 year ago

    Honey, wake up. The new Def Leppard Album just dropped

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