81–90 of 149 posts
I don't know why he wants to waste so much space with twelve unsigned longs when he can do it in eight (one for each piece and two more masks for color).
A cell is either empty, or contains one of the 12 figures.
To store 13 values, you need 4 bits per cell i.e. 256 bits for the complete board. That’s 4 unsigned longs.
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Or maybe the OP understood that everyone who has ever implemented a chessboard are also building chess engines where memory efficiency and speed actually matter a lot. It's the interviewers who are ignorant here, they took a real problem and translated it badly into a toy problem. Then they failed to realize what they did.
GP is correct. The Quora answer has a false dilemma that you've just perpetuated here, viz. that an OO program cannot use a compact representation. But there are standard patterns for using a compact representation of data for domain-model objects. The article's author isn't just unaware of them, they've written a petulant, arrogant article demonstrating their own lack of experience and adaptability.
Is this for real? The solution he proposes is specific to Chess ! I mean, does this guy really think the company cares about efficiently representing chess game states?? Obviously, obviously, OBVIOUSLY, the Chess aspects of this question are irrelevant. What they are trying to find out if how well you will work on their actual codebase, which is presumably not comprised of global functions operating on bitfields
The guy is openly arguing with an interviewer after taking a question too literally. I suspect my interview impressions would've included "candidate may be on the spectrum". However, this entire thesis is founded on a false dilemma, because you can write an OO domain model with a compact representation.
That way you’ll end up with something that works much sooner, instead of getting caught up in designing layers of abstraction.
It seems nuts to me that anyone would expect the Queen class to extend Bishop just because they happen to move diagonally. A Queen "IS NOT A" Bishop. If anything, specify traits that define the movement of the pieces and have each piece extend that trait (with the Queen extending both CAN_MOVE_DIAGONALLY and CAN_MOVE_LATERALLY).
composition over inheritance https://en.wikipedia.org/wiki/Composition_over_inheritance
It's about defining what a class IS vs/ what a class HAS.
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OO is better because bundling data and code together is better, because code is data, and I have no idea what I'm babbling about. The real advantage of OOP, as used today in Java/C++, is instantiation . Instead of having procedures working on global variables, you have procedure working on local variables, including complex data structures. Instantiation took some time to get widespread adoption. Originally, even loc…
> Now however, instantiation is so pervasive (global variables are assumed evil by default), that we don't even call it OO any more. We just call it good practice. This is another one of my pet peeves... If it's global (a static resource), make it a global. Local variables for static resources make code so much less readable. The only argument against globals is testing, and that's only an argument because common OO…
No, the newer argument against globals is testing, but that's mostly a side effect of the older issue, that globals limit composability/reusability, which was the main objection to globals before TDD became a popular religion.
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Oh please. As if the interviewer's next question wouldn't be "make it faster/more efficient" anyway. The interviewer is the problem here because he wants to build a chess game in an extremely stupid way using OOP for no other reason than to use OOP. I'd say most applications of OOP fail in similar ways in real life, creating monsters of complexity where simplicity could have existed. The author should consider himsel…
The interviewer gave the OP a simple question that could be answered within a short time to gauge how well they understood OO design, and OP specifically implemented it in a way to frustrate them. So again, whose the idiot? If OP wanted to crush the question, they could quickly answer it by saying this is how you could implement using classes and inheritance, now let me explain why OO is a poor solution for this spec…
In my case, this is unlikely to yield an OOP solution. I'm even less likely to guess an OOP solution was even expected. And if I fail the interview because this particular company takes OOP for granted, I should fail the interview, and may even be glad I did.
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> Don’t all pieces have a location? Make a table containing locations for each piece. > Aren’t all pieces movable? Make a function ("procedure") that moves a piece (e.g. edits the location table). > Might we want to display pieces? Make a render function (e.g. gets a piece type and a position) > Do we want to journal them to files to save game state, or their moves to streams to play remotely? Write serialization and…
People who say this apparently have an inordinate love of switch statements.
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Because you can write an OO domain model using a bitboard representation. It's an opportunity to demonstrate advanced OO knowledge, which this Quora answer most definitely fails at.
I'm interested. Care to elaborate how this OO domain would look like?
There's simply no need for "instantiate all the things" approach assumed in the Quora answer. That is OO at its most naive.
OOP is messaging, encapsulation, and late binding. What you do inside the capsule is up to you; and at a higher level, how the behaviour emerges from a composition of objects is also up to you.
Is this for real? The solution he proposes is specific to Chess ! I mean, does this guy really think the company cares about efficiently representing chess game states?? Obviously, obviously, OBVIOUSLY, the Chess aspects of this question are irrelevant. What they are trying to find out if how well you will work on their actual codebase, which is presumably not comprised of global functions operating on bitfields
Yes, that is, it is precisely addressing the question asked, not some unstated drrff hidden intent.
If the tester wants to test ability to apply a particular paradigm, that paradigm should be part of the explicit question. If you want to use a chess representation as a vehicle for testing OOP skills, than specify that object orientation is a requirement in the question.
Otherwise, you should be judging the interviewee on how well they did on the challenge you actually posed. Otherwise, what you are really judging on is whether OOP is the tool the interviewee reaches for no matter whether it's really appropriate to the problem they are faced with.