I'd fail an interview candidate that suggested adding 1 each time for subsequent prime testing
Congratulations! You must be that arrogant guy everybody hates interviewing with, the one with the superiority complex.
How about instead of just failing people over literally nothing (wasting everybody's time and money) - just ask the candidate whether they could somehow reduce the search space by utilizing the properties of a prime number?
-1 True
0 True
1 True
2 True
3 True
4 False-1, 0, and 1 are no good.
Two divisors for positive integer X: 1, X
I recently demonstrated GPT-4 via by having it explain phases of matter metaphorically with animals. Though impressive, it points to loose abstraction being more in range than firm abstraction. Let’s get that model a python interpreter and see how far we can take this party. Until then, I’m going to stick to explaining concepts.
————- included here for fun
Alright! Let's dive into the wild world of matter using some animal friends as examples:
1. *Solids* - Think of solids like a herd of elephants standing closely together. The elephants are packed in tight, barely moving, just maybe swaying a bit. They're sturdy and strong, just like solid things in our world. This is because the particles in a solid don't move around much; they just vibrate in place.
2. *Liquids* - Imagine a school of fish swimming in a pond. They're free to move around, weaving in and out, but they still stay pretty close to each other. They aren't packed as tightly as our elephant friends, but they aren't completely free either. This is like liquids: the particles are close, but they can move around and flow, just like water in a glass.
3. *Gases* - Now, picture a flock of birds soaring in the sky, free to fly in all directions. These birds aren't sticking close to one another; they're spread out, enjoying the vast space of the sky. In gases, the particles are like these birds, very spread out and moving all over the place.
4. *Plasma* - Think of plasma like dragons (I know they're mythical, but bear with me). These dragons breathe fire, and that fire is so hot and energetic that it can change the way things behave. Plasma is like that – it's gas that's become so hot that the particles are super energized and can even glow, like neon lights.
5. *Bose-Einstein Condensate (BEC)* - This one's a bit trickier, but imagine penguins in Antarctica. They huddle closely together to keep warm. BEC is like the coldest group of particles ever, where they start acting in strange, uniform ways, almost like one giant super-particle. It's like all the penguins moving together as one.
So, next time you think of matter, just remember our animal friends: the sturdy elephants, the flowing fish, the free-flying birds, the fiery dragons, and the huddled penguins!
Again, 1 fits, because it has two divisors: 1, and 1. You never said X != 1, nor does the definition upthread.
This isn't a silly gotcha, these things matter in math. For instance, when solving a quadratic equation, allowing for the solutions to be equal lets you avoid special-casing your understanding - instead of memorizing when the equation has zero, one or two solutions, you just learn it has two or zero (real) solutions, and the two solutions are allowed to be equal.
It's perfectly reasonable understanding. Inequality isn't a natural implicit assumption. E.g. if I say you have two variables:
int a;
int b;
An element to set relationship is that element A is or is not in set B. So, if the set of divisors only contains 1, there is only one divisor. If 1 and 1 made two divisors, 1 and 1 and 1 and… would make infinite divisors, rendering the concept of counting divisors (i.e., the cardinal number of the set of divisors) meaningless.
M is a divisor of N if it is a number that divides N without a remainder. While divisors can be negative, they are conventionally limited to non-negative integers in primality and factoring.
If you’d wanted to dig in on negative vs. positive divisors, that quickly provides an avenue for clearer formality, but piling on 1 and saying it’s not a silly gotcha is pretty fruitless. And please don’t bother to say “you didn’t say it has only two divisors”, as that would, again, be a silly argument.
So wind back and really formalize the definition if you want: A prime number is a natural number with only two divisors in the set of natural numbers, 1 and itself.
While set theory is axiomatic, it’s not practical for me (or anyone else) to explain conventional foundations to avoid someone feeling like they need to wiggle out of a prior bad argument.
Just say “ah, okay” or stop replying and move on. Feel free to read up in Wikipedia or any other texts (or ping me privately if you’d like to discuss further), but this thread isn’t looking like it’s going to meaningfully contribute to the broader discussion. Accordingly, I’ll leave it here unless something meaningful comes up.
My suggestion for your next interview: decide to hire them just based on their leetcode score, but invite to the interview just to flex that you're still better at puzzle solving :-D
Perfect
<pastes question and constraints from leetcode>
"solution begins with <insert default solution template from leetcode>".
Copy solution from gpt, paste in leetcode, run, submit.
"faster"
Repeat.
Repeat.
Next question.
it makes no sense that you're being crucified.
Or we have worked with junior developers who have really grown and flourished under our care, who would never have gotten that chance with such insane Draconian judgements.
It's such an obvious "GOTCHA!!" setting someone up for failure.
The way it's framed is very cringy because it signals that they don't care in their interviews about determining how objectively effective a software developer is.
If I have to write the loop above, I am assuming it is the Fizzbuzz equivalent of your company to show that I know how to write a while loop. I am not thinking about reducing the search space because I am writing the code semi-unconscious and frankly just want to get to the next question.
what does and container orchestration architect do ? Something like this cluster should use envoy and Prometheus. The new clusters rate isn’t usually high enough for the stack to change.
Real question I love these non conventional (swe, sre, pm, manager ) roles in tech
The problem a team that always seeks the optimal solution is that never they get shit done. And that’s rarely optimal in a business context. Your view does not strike me to be nearly as arrogant as it is short-sighted.
I think on a team of one I want the guy who gets it done without thinking. On a team of two I want a guy that’s somewhere in the middle. And on a team of three, that’s when I want my optimiser. Because in the time that guy number 3 has written let’s say 3 files of optimal code, guy number 10 files of not optimal code. And you rarely need guy number 3 to fix all ten, you just need him to fix the one or two files that actually matter.
Clients rarely ask “is this optimal?”. But they always ask “is this done?”.
All three developers have different approaches. All three are assets.
I think on some level then you’re making the same mistake that we could say the “just add one guy” made if your comment is honest- not factoring in (his) speed.
I think code readability, rather than code optimisation is far more important thing to get hung up on in an interview (and is, I must remind some of you, not to be confused with conciseness). And you can see this in the end result. But if you’re following along and the interviewee already knows you know what’s going on because of that, you can see it in smaller ways- it could be as simple as going back and changing a variable name such as open (maybe a function?) to isOpen (almost always a Boolean value).
I think most of us are in this position pretty often where we’re writing and figuring out something at the same time, maybe we just see if it works first and don’t give a name much thought or maybe we change the actual value or type of a variable in the process and the variable name becomes ambiguous. I’d look for small indicators that shoe me that this person is considering readability. But I still don’t necessarily expect it to be as readable as it would be in a more natural setting I mean I think 90% of these sorts of things start off with the person saying “I swear I can type” within the first five minutes of being watched- if they get flustered while being watched that it effects their typing, it certainly also effects their coding as well.
just not the super obvious one that demonstrates extremely basic understanding of what a prime number is
yes, we expect professional software developers to have basic maths skills
"what is a prime number" is taught to 7 year olds, it's not vector calculus
what else would you consider to be an unreasonable thing for an employer to require?
reading and writing skills of a typical 7 year old?
Second, basic math still that you never or rarely use or with very large time between usage might get rusty. You may understand the concept but not find the optimal solution. The way you are responding here shows quite a lot about how you are short sighted by instant-failing someone with a single question instead of trying to asses the whole person as much as you can. On you side, you are wasting opportunity to have a great person that could be a key player in your team by bringing other set of skill on the table.
it's part of the curriculum for children of this age where I grew up (I did check)
> The way you are responding here shows quite a lot about how you are short sighted by instant-failing someone with a single question instead of trying to asses the whole person as much as you can. On you side, you are wasting opportunity to have a great person that could be a key player in your team by bringing other set of skill on the table.
it may also be the case that I have more in depth knowledge about the roles that I've interviewed candidates for
most recently: hiring people to work for quants
not instantly knowing that even numbers (other than 2) are not prime is a very strong signal
A few do. And in 20 years you're reallyreally going to want to hire them.
Look, if you think this sort of thing allows you to identify great candidates, good for you. But in my experience, not only is this kind of practice stupid on its face, but it leads to engineering orgs packed with people who are good at memorizing trivia but terrible at solving real problems.
> yes, we expect professional software developers to have basic maths skills
Skill != knowledge. "What is a prime number" can be looked up and understood by any competent programmer in <5 minutes.
> "what is a prime number" is taught to 7 year olds, it's not vector calculus
Then it's reasonable to expect that an interviewee would be able to learn it as well, given the same resources. It does not however follow that an interviewee would inherently have that knowledge, just because 7 year olds are taught it.
Bottom line is, you're making too many assumptions about complete strangers.
Try actually measuring basic knowledge with competency at programming before thinking your opinion is better than measured data. Peer reviewed research finds similar results [1].
And yes, we tested all this carefully before enacting it. Interviews cost time and money, so giving 100% on every candidate despite quick signals is a waste of time and money that would be better spent on other candidates. If you want the best outcome then you allocate scarce resources based on expected returns, not on unfounded beliefs.
[1] https://helloworld.raspberrypi.org/articles/hw12-language-sk...
Common approach is to use square roots, this reduces the runtime. Recommend checking out project euler if you like solving hard math-code-o(n)-puzzles.
Yes it makes sense (in the GPT code) that you'd only go up to i * i ... although looking at pythonic while: statements is just gross to me in this context, it would feel a lot more readable to say, e.g. in PHP:
for ($i=2;$i<sqrt($n);) { $i+=($i==2 ? 1 : 2); //although the first one should just be outside the loop }
+1 is not a good idea since ~half of all numbers are effectively non-prime simply by being even numbers.
You can double the speed by using +2 without using any fancy tricks, just changing a single character.