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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

#41

Post by henrik_w »

modernerd wrote: post #19

"If you can't answer the majority of the questions on these four papers, and you're working or intend to work as a software developer, you should ask yourself why — most likely you're either you're missing something you really should know, or you're lucky enough to be working within a narrow area where your deficit doesn't matter." [1] I'm a self-taught front end web developer who didn't have a traditional computer s…

Coursera has several algorithm classes. I took Design and Analysis of Algorithms I (https://www.coursera.org/course/algo) from Stanford last spring. I thought it was really good, reviewed it here: http://henrikwarne.com/2012/05/08/coursera-algorithms-course.... There is also another algorithm course from Princeton on Coursera.

Class central (http://www.class-central.com/) is a good resource for seeing what is about to start.

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

#42

Post by hermannj314 »

I have no educational training in computer science, but I work as a software developer. I could not answer any of those questions, literally 0 out of 5.

1. Is O(2^n) equal to O(3^n)? Why? I have absolutely no idea what that means.

But I did have to answer this question: why does the application crash? "Oh...that's because the developer that was pontificating yesterday about how heap operations behave asymptotically forgot to check if the database connection was open before he called the Save method. Apparently, such arcane trivia is beneath him. I can fix it."

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

#43

Post by [deleted] »

plinkplonk wrote: post #14

This is the interesting bit "on each paper, at least four of the five questions relates directly to material I have needed to know during my time working on Tarsnap, " Most software jobs are far more distant from CS that Colin's. And more power to him for working fulltime on something that leverages his knowledge. (spoken as someone who spent a decade doing glue-random-apis-together-and-bill -by-the-hour enterprise s…

[deleted]

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

#44

Post by Altaco »

hermannj314 wrote: post #42

I have no educational training in computer science, but I work as a software developer. I could not answer any of those questions, literally 0 out of 5. 1. Is O(2^n) equal to O(3^n)? Why? I have absolutely no idea what that means. But I did have to answer this question: why does the application crash? "Oh...that's because the developer that was pontificating yesterday about how heap operations behave asymptotically f…

Meanwhile, you discover a long time down the road that the algorithm you thought was fine is actually incredibly slow when scaled to large inputs because you didn't have a good understanding of runtime analysis.

Or maybe, as you say, understanding more things makes you worse at coding. Who knows.

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

#45

Post by crntaylor »

quilby wrote: post #11

These questions are way too basic- the first 4 can be answered directly from the definition of each term, and there is no thinking involved. The 5th question can be answered with knowledge from 1 lesson in graph theory.

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 tentative position is that these questions are easy if you've covered the relevant material before, and very hard to impossible if not.

Disclaimer 1: my degree was mathematics, not computer science, and I don't work as a software developer (though I do write code every day).

Disclaimer 2: one of the questions I "knew" the answer to, I got wrong!

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

#47

Post by henrik_w »

I love clever algorithms, and really enjoyed algorithm and data structure classes at university. However, despite having worked for over 20 years as a programmer in several software-intense companies (big and small) in the telecommunications and VoIP field, I have almost never had a need to know the answers to these questions.

In fact, it was the second biggest surprise for me when starting out as a programmer after university. I wrote this up in "Top 5 Surprises When Starting Out as a Software Developer" http://henrikwarne.com/2012/08/22/top-5-surprises-when-start...

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

#48

Post by alexkus »

ataggart wrote: post #40
alexkus wrote: post #24

Earlier quoted context omitted.

I use these kind of questions in interviews. You either know the answers or you don't. There's no looking at your 'phone in an interview (at least not one with me being the interviewer).

Fair enough. I take a different approach in my interviews: try to gauge how useful the person will be to the team. We have internet access, and a library with CLRS if someone needs to implement a bipartite graph test. It matters more to me that they'd know why they'd need one.

We use those kinds of approaches too. I never said the interview consists solely of closed book tests, they're just one thing I find useful to help gauge the suitability of an interviewee.

[EDIT] The thing I'm most looking out for is how a candidate answers when they don't know the right answer.

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

#49

Post by cperciva »

crntaylor wrote: post #45
quilby wrote: post #11

These questions are way too basic- the first 4 can be answered directly from the definition of each term, and there is no thinking involved. The 5th question can be answered with knowledge from 1 lesson in graph theory.

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.

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

#50

Post by jrabone »

hermannj314 wrote: post #42

I have no educational training in computer science, but I work as a software developer. I could not answer any of those questions, literally 0 out of 5. 1. Is O(2^n) equal to O(3^n)? Why? I have absolutely no idea what that means. But I did have to answer this question: why does the application crash? "Oh...that's because the developer that was pontificating yesterday about how heap operations behave asymptotically f…

Some things you can look up quickly. Being functionally innumerate is not something you can fix with Google.

The tedious details of whatever god-forsaken CRUD framework is flavour-of-the-week with the cool kids probably WERE beneath him.

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