• Rentlar@lemmy.ca
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    8 months ago

    They call me a StackOverflow expert:

    private bool isEven(int num) {
    if (num == 0) return true;
    if (num == 1) return false;
    if (num < 0) return isEven(-1 * num);
    return isEven(num - 2);
    }
    
    • Johanno@feddit.de
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      8 months ago

      StackoverflowException.

      What do I do now?

      Nvm. Got it.

        if(num % 2 == 0){
             int num1 = num/2
             int num2 = num/2
             return isEven(num1) && isEven(num2)   
        } 
      
      if(num % 3 == 0){
            int num1 = num/3
            int num2 = num/3
            int num3 = num/3
            return isEven(num1) && isEven(num2) && isEven(num3) 
      }
      

      Obviously we need to check each part of the division to make sure if they are even or not. /s

  • Skyline969@lemmy.ca
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    8 months ago

    Wow. Amateur hour over here. There’s a much easier way to write this.

    A case select:

    select(number){
        case 1:
            return false;
        case 2:
            return true;
    }
    

    And so on.

    • robotica@lemmy.world
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      8 months ago

      Don’t forget that you can have fall-through cases, so you can simplify it even further:

      switch (number) {
          case 1:
          case 3:
          case 5:
          case 7:
          case 9:
            ...
      
  • المنطقة عكف عفريت@lemmy.world
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    8 months ago

    I shit you not but one coworker I had dared call himself a data scientist and did something really similar to this but in Python and in production code. He should never have been hired. Coding in python was a requirement. I spent a good year sorting out through his spaghetti code and eventually rebuilt everything he had been working on because it was so bad that it only worked on his computer and he always pip freezes all requirements, and since he never used a virtual environment that meant we got a list of ALL packages he had installed on pip for a project. Out of those 100, only about 20 were relevant to the project.

      • herrvogel@lemmy.world
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        8 months ago

        Code reviews mean fuck all when the “senior” developer doing the review is someone who implements an entire API endpoint group in one single thousand-something lines magic function that is impossible to decipher for mere humans.

      • المنطقة عكف عفريت@lemmy.world
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        8 months ago

        A few members of my team were reviewing codes but lots of PRs could be merged without tests or checks passing and only about 2 people before I joined understood what cicd is, no one else believed in its importance. They thought doing otherwise would “slow down the work precess and waste time, we know what we’re doing anyway!”.

        I learned a lot from having to implement best practices and introduce tests in teams that don’t give a fuck or were never required to do it. I’m amazed at the industry standards and fully understand why job ads keep listing git as a requirement.

  • lobut@lemmy.ca
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    8 months ago

    Just do a while loop and subtract 2 if it’s positive or plus 2 is it’s negative until it reaches 1 or 0 and that’s how you know, easy! /s

  • enkers@sh.itjust.works
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    8 months ago

    This is your brain on python:

    def is_even (num):
         return num in [x*2 for x in range(sys.maxsize / 2)]
    
  • rollerbang@sopuli.xyz
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    8 months ago

    You have to make it easy on yourself and just use a switch with default true for evens, then gandle all the odd numbers in individual cases. There, cut your workload in half.

      • BeigeAgenda@lemmy.ca
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        8 months ago

        No its not the wrong solution! Premature optimization is a waste of time.

        Using if or case are not a solution because they are way too verbose and very easy to introduce an error.

        Modulo is a solution, and using bit-wise and is another faster solution.

        • droans@lemmy.world
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          8 months ago

          It’s only the wrong solution if you’re writing something where every operation needs to be accounted for. Modulo is a great, easy, readable method otherwise.

          Not too certain on C++, but I think this would be the cleanest implementation that still somewhat optimizes itself:

          private bool IsEven(int number){
              return !(number % 2)
          }
          
        • mryessir@lemmy.sdf.org
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          8 months ago

          You call it premature optimization. I call it obvious.

          You use a flat head as a Phillip’s.

          • Maalus@lemmy.world
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            8 months ago

            You can call it whatever you like, the fact of the matter remains - code readibility is more important than most optimizations you can ever hope to make.

            Bad programmers optimize everything and produce code that is not understandabe and 0.001% “faster”

            • spudwart@spudwart.com
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              8 months ago

              Optimization isn’t inherently better than Readable code.

              What’s most important is what matters to your project.

              If your project manages itself with limited resources, Optimization is better than Readable code, and it should be supplemented with comments.

              If your project has a wealth of resources, readable code is probably the better option.

              The “This is the ONLY WAY” mindset in coding is the only thing that I would argue is completely wrong. The “One-size fits all” mindset in development is short sighted, sure. but what makes it the worst, is when it becomes “One-Size fits all ONLY”.

              “One-size fits all” means the project runs well on everything. “Optimized for one” means the project runs exceptionally on one Architecture/OS.

              Basically, this situation is the highly unsatisfying “It’s your preference”.

              But given the context of Yandere Dev and the Target Audience of Yandere Simulator, his code is perfect. It’s code that runs terribly on everything and the project is for no one.

          • BeigeAgenda@lemmy.ca
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            8 months ago

            I call it making assumptions that may be incorrect, and do you know if the compiler will do the optimization anyway in this case?

            • mryessir@lemmy.sdf.org
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              8 months ago

              What statement do you flag as assumption? Yes, I do. The modulo operator is only a subset of bit masks. It is more explicit to write:

              if ( (variable &EVEN_MASK) == 0) …

              To act upon even numbers then:

              if ( (variable %2) == 0) …

              How would you name the 2 in the above statement for more expressive power?

              EVEN_MODULO_OP ? That may throw more people off imo.

              • Kogasa@programming.dev
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                8 months ago

                You shouldn’t rename 2 at all. “Even” has a commonly understood meaning that is instantly recognizable from (variable %2) == 0. The bitmask is an overgeneralization.

              • BeigeAgenda@lemmy.ca
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                8 months ago

                I give up, I was wrong to even think about the modulo operator, you are clearly the master programmer. 🥇

                This reminds me of a discussion about the ternary operator ? :, some people think its the one true way of writing code because its just so clear what it does. And I say please use it sparingly because if you start doing nested ternary operators its very hard to unpack what your code does, and I prefer readability over compact code, especially with today’s compilers.

      • TheManuz@lemmy.world
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        8 months ago

        Wrong means that it doesn’t produce the right output.

        How is the modulo operator the wrong solution?

        • mellejwz@lemmy.world
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          8 months ago

          Not neccessarily wrong, but you could also check the first bit. If it’s 1 the number is uneven, if it’s 0 the number is even. That seems to be more efficient.

          • dukk@programming.dev
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            8 months ago

            That’s what I was thinking too… Although, I wouldn’t be surprised if most languages convert modulo 2 to this automatically.

          • herrvogel@lemmy.world
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            8 months ago

            Modern compilers and interpreters are smart enough to figure out what you’re trying to do and automatically do that for you.

  • jsdz@lemmy.ml
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    8 months ago
    int is_even(int n)
    {
        int result = -1;
        char number[8]; //should be enough
        sprintf(number, "%d", n);
    
        // check the number
        // TODO: handle negative numbers
        for (char *p=number; *p; p++)
        {
            if (*p=='0' || *p=='2' || *p=='4' || *p=='6' || *p=='8')
                result = 1;
            else if (*p=='1' || *p=='3' || *p=='5' || *p=='7' || *p=='9')
                result = 0;
            else {
               fprintf(stderr, "Your number is wrong!\n");
               exit(1); 
            }
        }
        return result;
    }
    
  • affiliate@lemmy.world
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    8 months ago

    amateurs

    def is_even(n: int):
        if n ==0return True
        elif n < 0:
            return is_even(-n)
        else:
            return not is_even(n-1)
    
    • affiliate@lemmy.world
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      8 months ago

      here’s a constant time solution:

      def is_even(n: int):
          import math
          return sum(math.floor(abs(math.cos(math.pi/2 * n/i))) for i in range(1, 2 ** 63)) > 0
      
      spoiler

      i can’t imagine how long it’ll take to run, my computer took over 3 minutes to compute one value when the upper bound was replaced with 230. but hey, at least it’s O(1).

    • Karyoplasma@discuss.tchncs.de
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      8 months ago

      Don’t use recursion. Each call will need to allocate a new stack frame which leads to a slower runtime than an iterative approach in pretty much any language.