Sparse is better than dense. clear solution for The Nearest Square Number by veky - python coding challenges

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Sparse is better than dense. solution in Clear category for The Nearest Square Number by veky

import bisect
squares = [x**2 for x in range(1001)]

def nearest_square(number):
    left = bisect.bisect_left(squares, number)
    right = bisect.bisect_right(squares, number) - 1
    return min(squares[left], squares[right], key=lambda sq: abs(number - sq))

March 22, 2018

Comments:

dig on Jan. 26, 2023, 9:22 p.m.
Wow! Is it better to use bisect more than import math and making square root?

veky on Jan. 27, 2023, 5:20 p.m.
As I said numerous times, "better" is always better with respect to some concrete situation. For example, as the numbers get very big, float math.sqrt gets less and less precise, until at some point it can't decide correctly which way the nearest integer lies. Of course, then the list in line 2 gets too big if it starts from 0, but you don't have to start from 0. On the other hand, this solution is exact. Of course, since this solution was published, math got an exact function isqrt, which can be used for fast and exact solution of this task. I leave it as a homework to you. :-)

dig on Jan. 29, 2023, 8:34 p.m.
wow! reeding your answer makes me think what a good level can someone get programming. Do you work in checkio? If not, I am wandering why you are not the kind of programmer who works a lot and woldn't have time to do these chellenges. I wish I have your level some day ;) thanks for ypur reply :-)

veky on Jan. 30, 2023, 5:48 a.m.
Hm. I think you don't really see how this works. <ol> <li>This is a social network. There are a lot of people with just a few followers, and there are a few of them with loads of followers, and of course everybody notices the second kind. (<a href="https://en.wikipedia.org/wiki/Friendship_paradox)">https://en.wikipedia.org/wiki/Friendship_paradox)</a> The high influencers usually don't work "in" Facebook/Instagram/whatever, mostly since they don't need to. They are much more effective, and can explore their techniques, without that baggage. Besides, with my attitude towards beginners, I'd probably get fired from CiO before long. :-D</li> <li>Programming is my hobby. You always have time for hobbies, even if you work a lot. (I don't, really, at least not in usual sense. As Philip Guo used to say, in academia you only have to work 20 hours a year. ;) As a proof, I coded the solution with sqrt too in the meantime.</li> </ol>

dig on Jan. 30, 2023, 11:05 a.m.
What a paradox ;) You are very right! I did not know about P. Guo, but seems interesting what he says! I guess you are good at programming for many reasons.One of them must be constancy, isn't it? Do you recommend to have a schedule? What do you think is the main key in this sence? I ask to you because I have you as a nice (meybe the best) reference.

veky on Jan. 30, 2023, 7:22 p.m.
Yeah, Guo is very interesting. Unfortunately, he almost disappeared from the Net a few years ago. Imagine you have a hobby, let's say guitar. And then someone comes to you and says "wow, you play so great! surely it's because of many reasons. Can you share them with me? Do you have a schedule? What is the main key?". And so on. If you're honest, you'll probably say "Dude, cool off. I just like the stuff. There is no rigid plan or anything, it's just that since I love it, I play it every time I have a bit of time to kill, and with years, I guess I have reached that 10 grand hours or however much is necessary to perfect a skill." Right? I could tell you, very precisely, how I organize my life, but I really doubt it would help you, since your life is not my life, and your brain is not my brain. It probably thrives on some other things I can't even imagine.

dig on Jan. 30, 2023, 9:13 p.m.
After reeding you, I guess the key is to enjoy it and, as a result (not as a target) you get a high level. Actually very interesting. I don't know how you organize your life but i'm very sure you are a healthy guy, not much stressed and taking care about yourself:) otherwise it is difficult to imagin someone very good at it without good habits!

veky on Jan. 31, 2023, 8:01 p.m.
Warning: this post might be TMI for some people. But it illustrates my point so perfectly, that I couldn't resist posting it. I have absolutely no problem sharing this, but if you're uncomfortable reading about someone's personal life (or if you idolize me thinking I'm not human but an automaton), please stop here. <hr /> <blockquote> i’m very sure you are a healthy guy, not much stressed and taking care about yourself:) </blockquote> See, that's precisely why I said that hobbies don't care: they are on a whole different level. Yes, now I'm in perfect health (as confirmed by my regular checkup), active in many sports (just today had two badminton sessions of over 1h each), no chronic problems at all (which is remarkable at age of 42), stress managed without issues (seeing a professional therapist), happily married, emotionally connected with wife and proud of my children, successful academic career (just got an invitation letter from a prestigious institution), and so on. But less than a year ago, I was very obese (more than 100kg), totally sedentary and inactive, no time nor energy for anything, spent all the time on Youtube and computer games, had two different addictions (one much more serious than Youtube and computer games, the other illegal), at the edge of getting fired, marriage in shambles (wife wouldn't look at me) and in serious depression (not clinical, because I couldn't even muster enough energy to get evaluated), and ill all the time. In almost all aspects, I'm a totally different person now. Yet when you look at my CiO contributions, they are pretty much consistent across. If anything, I spent more time here when I was sitting at my laptop the whole time. My brain simply likes Python, and the only difference is that last year, CiO was my escapism from reality, while this year it is just a controlled release valve. But even couch potatoes have hobbies. And Python is something you really don't need much energy for.

dig on Feb. 2, 2023, 10:23 a.m.
Wow, unbelievable! Actually very inspiring. I'm very happy about your big change. From the distance it seemed that there had a kind of guy like you (I mean, the new Veky) behind your responses. I looked a bit more about Guo! And he said the best way, by far, to learn programming is having a mentor. Did you have one? I wish I had one like you ;) Thanks for sharing your experience Veky :)

veky on Feb. 2, 2023, 12:04 p.m.
Most of my responses here are just routine: I learned a long time ago how to provoke the learning reflex in people, and that's what I love to do. Despite seeming tactless, it really works on majority of people. That's why I work in academia. But yeah, the teaching component of my life also didn't change much (I was on the edge of being fired because of my lacking scientific output; my student evaluations were good throughout). Students liked the old and new me pretty equally. My children too, no doubt because they also view me (in part) as a teacher. So, maybe my hobby is in fact teaching? It could be... I write most of my Python programs to showcase a concept, not primarily to solve a problem, as I'm sure you noticed. But still it shows my point: hobbies survive personal revolutions. I guess they really exist on a level beyond what you actually consciously think about your life. <hr /> No, I didn't have a mentor, probably because I despised authority when young. But I like reading a lot, and I have kinda eidetic memory, so that probably helped. For example, I can tell you (in broad strokes) all Guido's writings I've read, but it doesn't mean I agree with all (or even most) of them. So, is he my mentor? Semantics. :-) You can have me as a "mentor" (again, semantics), just read all of my posts here and you'll learn a lot. As said above, you don't need to agree with them for the process to work. [In fact, it works even better if you don't agree with carefully chosen ones.:]

dig on Feb. 2, 2023, 9:56 p.m.
You mean (when you say learning reflex) that being "provocative" is good for learning? It is very interesting what you said about hobbies. Actually not many people have healthy hobbies like you with Python. You are lucky in this sense. Most of hobbis are of the other kind...drinking beers with friends, whatch tv etc (at least here in spain). I can't say python is my hobby yet, brcause I'm not being too much consistent but I love it and I hope one day I could say it is!

veky on Feb. 3, 2023, 9:41 a.m.
<blockquote> You mean (when you say learning reflex) that being “provocative” is good for learning? </blockquote> Basically, yes. We [not all of us, but most of us] tend to remember more what we've learned in emotionally triggered situations. <blockquote> Most of hobbis are of the other kind…drinking beers with friends, whatch tv etc (at least here in spain). </blockquote> So, maybe I used a wrong word. English is not my native language. For what you enumerate, I'd use a word "leisure". It's not a matter of morally good/bad, but of something else. Let me try to explain. In my view, there is a strong divide between input and output activities. Let's call them I and O activity. Do you do it in order to produce something or in order to consume something? Of course, most activities are both, but still predominantly one or the other. And even if it is both equally, you still do it with the motivation to produce or to consume. Watching TV is pretty much all I. Watching Youtube less so, since you create playlists, write comments, and react in various ways, but still people usually do it with intention of I. Drinking beers with friends is interesting, because for some people, it is O (organizing, gossip, personal stories, jokes, seducing waitresses;), while for others, it is mostly I (these are ones that just go to a bar and sit looking at one point the whole time:). My strong belief is that I and O activities must be balanced in a fulfilling life. And it is orthogonal to work/personal_life balance, and to health/indulgement balance, and to physical/mental, chaotic/regular, and many others. Of course, for me CiO is O, and gives me a nice boost in "healthy" O (as opposed to many other social networks, which "normal" people use in order to establish their I/O balance).

dig on Feb. 6, 2023, 11:50 a.m.
That's very interesting (Input and Output activities). However, imagine paleolitics: it seems they only did outputs activities. The only input was eating and sleeping, so it seems it is far from this equilibrium. Don't you think? Actually, I have to say I thought about your theory these days and, for sure, is very realistic. Lot of people try to do a super schedule full of output activities the 1st of January and that's the reason why the 2nd week nobody follows it.

veky on Feb. 6, 2023, 11:55 a.m.
Second paragraph: spot on. :-) First paragraph: I don't think so. Few men were wise enough that they actually remembered interesting events from the past, and they were telling them to the new generations (O), which listened (I). Also, e.g. following somebody into the hunt is an I activity, despite there being nothing explicit to consume (yet:), because it involves being passive more than being creative.

dig on Feb. 6, 2023, 12:17 p.m.
you should publish an article about it (seems very interesting:) As a curiosity,do you program in your work? or nothing to do with it?

veky on Feb. 7, 2023, 11:45 a.m.
I don't think too many people would be interested in that. But you can write an article about it if you want. :-) Yes, I do program, but as I say, it's mostly as a teaching aid. I love showing people how beautiful mathematics can be, and if it requires programming, then I do it.

dig on Feb. 7, 2023, 1:18 p.m.
Are you mathematician? I'am ;) I love them! Do you do mathematics as a hobby like programing?

veky on Feb. 7, 2023, 1:35 p.m.
Yes, I work at university, teaching students various branches of mathematics. But it is also my hobby, in the sense that even if it wasn't my job, I would still do it.

dig on Feb. 7, 2023, 1:47 p.m.
I loved convergence of series and I hope one day I continue with this study... and more generic with real/complex analysis. I "envy" in the good sense the fact you work on what you would do in your free time!

veky on Feb. 7, 2023, 1:48 p.m.
I honestly couldn't have it any other way. My time is precious, why waste it doing what I don't like? :)

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