Minimum CompSci Knowledge Needed for Writing Desktop Apps

Question

Having been a hobbyist programmer for 3 years (mainly Python and C) and never having written an application longer than 500 lines of code, I find myself faced with two choices :

(1) Learn the essentials of data structures and algorithm design so I can become a l33t computer scientist.

(2) Learn Qt, which would help me build projects I have been itching to build for a long time.

For learning (1), everyone seems to recommend reading CLRS. Unfortunately, reading CLRS would take me at least an year of study (or more, I'm not Peter Krumins). I also understand that to accomplish any moderately complex task using (2), I will need to understand at least the fundamentals of (1), which brings me to my question : assuming I use C++ as the programming language of choice, which parts of CLRS would give me sufficient knowledge of algorithms and data structures to work on large projects using (2)?

In other words, I need a list of theoretical CompSci topics absolutely essential for everyday application programming tasks. Also, I want to use CLRS as a handy reference, so I don't want to skip any material critical to understanding the later sections of the book.

Don't get me wrong here. Discrete math and the theoretical underpinnings of CompSci have been on my "TODO: URGENT" list for about 6 months now, but I just don't have enough time owing to college work. After a long time, I have 15 days off to do whatever the hell I like, and I want to spend these 15 days building applications I really want to build rather than sitting at my desk, pen and paper in hand, trying to write down the solution to a textbook problem.

(BTW, a less-math-more-code resource on algorithms will be highly appreciated. I'm just out of high school and my math is not at the level it should be.)

Thanks :)

Answer 1

For a less-math, more code resource on algorithms than CLRS, check out Algorithms in a Nutshell. If you're going to be writing desktop applications, I don't consider CLRS to be required reading. If you're using C++ I think Sedgewick is a more appropriate choice.

Answer 2

Try some online comp sci courses. Berkeley has some, as does MIT. Software engineering radio is a great podcast also.

See these questions as well:

http://stackoverflow.com/questions/370976/electronic-computer-science-resources#371557 http://stackoverflow.com/questions/360542/plumber-programmers-vs-computer-scientists#360554

Answer 3

This could be considered heresy, but the vast majority of application code does not require much understanding of algorithms and data structures. Most languages provide libraries which contain collection classes, searching and sorting algorithms, etc. You generally don't need to understand the theory behind how these work, just use them!

However, if you've never written anything longer than 500 lines, then there are a lot of things you DO need to learn, such as how to write your application's code so that it's flexible, maintainable, etc.

Answer 4

Heed the wisdom of Don and just do it. Can you define the features that you want your application to have? Can you break those features down into smaller tasks? Can you organize the code produced by those tasks into a coherent structure?

Of course you can. Identify any 'risky' areas (areas that you do not understand, e.g. something that requires more math than you know, or special algorithms you would have to research) and either find another solution, prototype a solution, or come back to SO and ask specific questions.

Answer 5

Moving from 500 loc to a real (eve if small) application it's not that easy. As Don was pointing out, you'll need to learn a lot of things about code (flexibility, reuse, etc), you need to learn some very basic of configuration management as well (visual source safe, svn?)

But the main issue is that you need a way to don't be overwhelmed by your functiononalities/code pair. That it's not easy. What I can suggest you is to put in place something to 'automatically' test your code (even in a very basic way) via some regression tests. Otherwise it's going to be hard.

As you can see I think it's no related at all to data structure, algorithms or whatever.

Good luck and let us know

Answer 6

I must say that sitting down with a dry old textbook and reading it through is not the way to learn how to do anything effectively, even if you are making notes. Doing it is the best way to learn, using the textbooks as a reference. Indeed, using sites like this as a reference.

As for data structures - learn which one is good for whatever situation you envision: Sets (sorted and unsorted), Lists (ArrayList, LinkedList), Maps (HashMap, TreeMap). Complexity of doing basic operations - adding, removing, searching, sorting, etc. That will help you to select an appropriate library data structure to use in your application.

And also make sure you're reasonably warm with MVC - i.e., ensure your model is separate from your view (the QT front-end) as best as possible. Best would be to have the model and algorithms working on their own, and then put the GUI on top. Or a unit test on top. Etc...

Good luck!

Answer 7

It's like saying you want to move to France, so should you learn french from a book, and what are the essential words - or should you just go to France and find out which words you need to know from experience and from copying the locals.

Writing code is part of learning computer science. I was writing code long before I'd even heard of the term, and lots of people were writing code before the term was invented.

Besides, you say you're itching to write certain applications. That can't be taught, so just go ahead and do it. Some things you only learn by doing.

(The theoretical foundations will just give you a deeper understanding of what you wind up doing anyway, which will mainly be copying other people's approaches. The only caveat is that in some cases the theoretical stuff will tell you what's futile to attempt - e.g. if one of your itches is to solve an NP complete problem, you probably won't succeed :-)

Answer 8

I would say the practical aspects of coding are more important. In particular, source control is vital if you don't use that already. I like bzr as an easy to set up and use system, though GUI support isn't as mature as it could be.

I'd then move on to one or both of the classics about the craft of coding, namely

• The Pragmatic Programmer
• Code Complete 2

You could also check out the list of recommended books on Stack Overflow.