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The software development final exam: Algorithms and Data Structures

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Re: The software development final exam: Algorithms and Data Structures

#181

Post by randomdata »

jemfinch wrote: post #147

I'm seeing a lot of apologists for mediocrity here. They seem to be drawn out by articles like this one as well as articles about interviewing. Despite the sentiment here, Colin is right: this is knowledge that developers ought to have. Not because they need it to do their day job, but because they can't avoid learning these topics if they truly love the field. Sure, you can earn a pretty decent paycheck hacking web…

As a mediocre programmer, I probably could have answered the questions at some point in time, but since they are not applicable to my day-to-day life, much of the information has faded away. This has prompted me to refresh my memory, but it is too late for this quiz, as per the requirements.

Assuming you've been in the business for a long time, and not just fresh CS graduate or something, what have you done to stay intimately familiar with the concepts that you do not utilize in any regular capacity?

Re: The software development final exam: Algorithms and Data Structures

#182

Post by cunac »

panda_person wrote: post #117
clinth wrote: post #102

Earlier quoted context omitted.

I see that you're the author. Thanks for replying! > Sure, there's plenty of software development which doesn't involve fancy algorithms or data structures... avoiding computer architecture, operating systems, mathematics, networking, databases, and distributed systems as well is a bit harder. This is at odds with the statement in your article that jumped out at me: "If you can't answer the majority of the questions…

Yeah, but they are really important to know for interviews. Which of course may or may not have anything to do with the actual life of a developer, but that's life.

whenever prospective employer has this type of CS trivia questions I lose interest to work in that environment regardless if I know or don't know answers. It shows lack of maturity and experience to understand what are actually characteristics to look for to determine good developer. This type of questions might be useful for non experienced candidates but it is fairly counterproductive for experienced candidates

Re: The software development final exam: Algorithms and Data Structures

#183

Post by cunac »

cperciva wrote: post #49
crntaylor wrote: post #45

Earlier quoted context omitted.

The first two questions I knew the answer immediately because I've read about asymptotics and runtime analysis. Questions 3 and 4 I simply don't have the background (I've never heard of a B-tree, and I've heard of heap sort but I don't know the algorithm). Question 5 I'd not seen before, but an algorithm was quite obvious because I've taken a course on graph theory (of course, my answer could easily be wrong). My ten…

So, my tentative positions is that these questions are easy if you've covered the relevant material before, and very hard to impossible if not. There's a lot of people who are very confidently giving wrong answers to questions, which weighs against that position.

which is exactly the point why this type of question is useless I will always reference other sources (google,book,peer) if I am not sure and I am not sure for anything that I am not using frequently Real test is how many people will get it wrong using all resources usually available in working environment

Re: The software development final exam: Algorithms and Data Structures

#184

Post by notJim »

biafra wrote: post #106
damian2000 wrote: post #100

Earlier quoted context omitted.

Highly recommend this free online course given by Robert Sedgewick from Princeton. https://class.coursera.org/algs4partI-2012-001/lecture/index He covers all the questions in this, except the last one regarding graphs.

How do I access this course? The website says: "Enrollment is Closed"

Try this link: https://www.coursera.org/course/algs4partI, if that doesn't work, just log in to coursera, then find Courses, then look for Sedgwick.

Re: The software development final exam: Algorithms and Data Structures

#185

Post by kamaal »

jrabone wrote: post #161
mechanical_fish wrote: post #126

If you can't answer the majority of the questions...you're lucky enough to be working within a narrow area where your deficit doesn't matter. Where by "narrow" one presumably means "narrow in theoretical scope, but extremely large in terms of number of people, number of customers, number of paid hours spent working on things, and amount of impact on the world". Most of the web was built by people who don't know what…

Most of the web was built by people who don't know what B-trees are. By number of sites, perhaps. By revenue, I don't think so. The big names that dominated what the web is to most people certainly do know this stuff, at least insofar as the practical implications, and they try not to hire people that don't for development roles. That isn't to say that they don't also just use Postgres (or Berkeley DB, or whatever) i…

>>By number of sites, perhaps. By revenue, I don't think so.

>>Software Fitter would be a much better description for the skilled assembly role that a lot of modern software boils down to. CRUD Technician is going to to need some PR work though!

I don't know why intelligent people with a little knowledge automatically think they are going to be rich. This causes a lot of heart burn and pain to people in later parts of their lives when they figure out things don't work that way in the real world.

Regardless of whatever you may think about them. You may even think them undeserving of all the money they earn, you may think they are stupid. The fact is abstraction enables people to work with a lot of things without knowing much about them in detail. In fact abstractions are invented for that very purpose. So that a million people shouldn't waste their time, energy and effort to relearn things, when all their resources can be better utilized to know just the abstract details and build things on top of it. This enables people to build things quickly on what is already available.

Revenues, money et al are dictated by what the world considers valuable at any time. You might know 1000 algorithms from the book, you might have studied every other data structure that's out there. But if knowing how to write a SQL query is what is valuable in the economy right now, guys doing that are likely to be paid more than you.

This isn't surprising at all. As developers we enjoy a unique position in the market. As for the money we get, compare this with any other industry, our peers working there get paid well less. How is is possible that people who work at the same level of difficult as we do get paid less than us? Because- merely knowing things and difficulty of tasks doesn't qualify for a better compensation.

Re: The software development final exam: Algorithms and Data Structures

#186

Post by kamaal »

lifeformed wrote: post #164
amix wrote: post #7

While I can answer some of these questions (and could answer them all a few years ago while attending university) this kind of knowledge is simply not something that I use on a daily basis. I also doubt that many others developers use it unless they have very specialized jobs. These kind of questions should not be the only basis of the software development final exam. In software development problem solving, communic…

I don't know these answers off the top of my head, but if I needed to know them in the real world, I could easily find them out in a couple of seconds or minutes with Google and Wikipedia. The difference between me and someone who is unfamiliar with computer science (but is still good with Google) is that I can read the answers and their corresponding articles and understand what they mean, as opposed to the other pe…

Actually a few years into the industry, I would doubt any body who claims to know these things straight out of this heart(Unless that is his day job).

Seriously do people remember all this math all the years they are building software? Unless you spend a great deal of time revisiting these concepts every other month, there is no way this is all going to be in your head. And if you actually are spending that amount of time learning this kind of math, I would wonder what kind of a programmer you are. A programmer is supposed to build things in this time, gaining mountains of factual knowledge which doesn't have much value in the real world is not very good use of time.

By the way this algo/DS love looks very similar to tool religion. People focus too much on tools used to solve problem, while they should actually be focused on problems.

Re: The software development final exam: Algorithms and Data Structures

#187

Post by Zarel »

DanWaterworth wrote: post #103
buro9 wrote: post #101

Earlier quoted context omitted.

Whilst I agree with you on being self-taught and knowing those answers I will say that I finally went and got an MSc in Computer Science after 12 years working professionally as a developer and being self-taught. Part of the reason was to find out what I didn't know. What I didn't know was basically some parts of set theory and quite a chunk of automata theory. I did find cperciva's questions to be trivial, but I wou…

I agree, you'll only know the answer if you've taken the time to learn about the specific concepts being tested. I suppose what I'm surprised about is that a large number of developers haven't taken the time to learn (or have since forgotten) the theory around these particular concepts.

I aced an Advanced Algorithms course at a major public university last semester, and I don't recall learning about B-trees. I mean, I usually have pretty good retention of things I learn, and the rest of the "test" was easy enough, and I'd expect to at least think "that sounds familiar" about anything that's come up in a class, but even after I looked up B-trees, I grasped the concept fairly quickly, but it didn't seem like anything I'd learned before.

I wonder if I legitimately just forgot about B-trees, or if my algorithms courses just didn't cover them.

Re: The software development final exam: Algorithms and Data Structures

#188

Post by kamaal »

cunac wrote: post #182
panda_person wrote: post #117

Earlier quoted context omitted.

Yeah, but they are really important to know for interviews. Which of course may or may not have anything to do with the actual life of a developer, but that's life.

whenever prospective employer has this type of CS trivia questions I lose interest to work in that environment regardless if I know or don't know answers. It shows lack of maturity and experience to understand what are actually characteristics to look for to determine good developer. This type of questions might be useful for non experienced candidates but it is fairly counterproductive for experienced candidates

Last year I interviewed a BigCorp which was all about these interviews. The first guy clearly told me that the project was sort of stuck and they needed to sprint to make it happen.

The interview was 99% math. The people who asked me question looked all smart alecs and their questions all seemed to indicate that they wanted to show me how intelligent they are, and how stupid I am.

By the end of the interview it was clear to me why they were stuck. Those people had absolutely no interest in building things. It was all about individual One-upmanship, and showing their little math and puzzle tricks they would have gathered by combined reading on the internet over the years.

Re: The software development final exam: Algorithms and Data Structures

#189

Post by kamaal »

jemfinch wrote: post #147

I'm seeing a lot of apologists for mediocrity here. They seem to be drawn out by articles like this one as well as articles about interviewing. Despite the sentiment here, Colin is right: this is knowledge that developers ought to have. Not because they need it to do their day job, but because they can't avoid learning these topics if they truly love the field. Sure, you can earn a pretty decent paycheck hacking web…

I would say that a good developer must work 19 hours a day, have at least 20 projects on github and must be able to burn through tough deadlines every day.

I would say any developer worth his salt ought to have(as you would say it) all this skills.

Re: The software development final exam: Algorithms and Data Structures

#190

Post by nitrogen »

SCdF wrote: post #171

I'm not going to put judgement on this statement, but here is (what I'm fairly sure is) the truth: most people developing software (we're talking, not in silicon valley, or in the united states, but globally) need exactly none of this. My current day job is working for the company that maintains and manages NZ's Company registry, as well as a dozen or so other registries over varying subjects. My previous day jobs we…

The tricky thing about problems best solved by applying CS concepts is that they're never worded that way. By way of analogy, when I was in junior high or early high school (before I'd taken calculus, at any rate), I participated in a math contest. After the test I remarked, "That test didn't really have any calculus in it!" Only later, when I actually learned calculus, did I realize the calculus problems were never, "Apply the derivative and integral to this set of functions," but "These two quantities and their slopes are related to a third quantity by these rules. Write an equation for the third quantity."

Graph theory has also proven useful. I created a simple topological sort to ensure that objects in my dataflow-based visual programming system targeted at home automation are run in the correct order.

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