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On November 04 2012 07:25 Lysenko wrote:Show nested quote +On November 04 2012 04:15 CecilSunkure wrote:On November 04 2012 02:09 Sawamura wrote:
now if could write some C++ program practice ^_^ hehehe thanks for the practice anyway 5/5 I could do that. I'm thinking of some object oriented C first though. You know, virtualizing some C++ features in C. I was on my way to a much longer post, but I don't want to get in the way of what you're doing here with a lot of negativity, so I'll just ask. Who learns C today, absent a specific need to write embedded code, modify a UNIX or Linux kernel, or write a driver? I'm speaking as someone who paid several years of bills as a C programmer, working on both embedded applications and desktop applications. This was, however, 17 years ago, before (as far as I have personally seen, which is why I'm asking) the entire world moved on to C++. ** I mean, I can see doing it out of nostalgia, or because I got a cheap deal on some single-chip-computer development board, but that's about it. Is this a topic of interest for typical, highly-motivated CS students these days? I'm not saying it's bad, I just don't get it.
You learn C to work with the crappy old codebase many companies still have. If you start a new project from scratch, you better have a damn good reason to use C. But if you work on something that uses old code, chances are it uses C.
That's no reason to start with C as your first language though.
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Hijacking this thread for a little bit:
When I'm done with High School I have a couple of months vacation and I'd like to teach myself how to program. Iit seems like a very useful skill and like something I would enjoy doing. With what language should I start? And I assume once you have learnt one, the others are easier to learn?
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On November 04 2012 18:06 Recognizable wrote:
Hijacking this thread for a little bit:
When I'm done with High School I have a couple of months vacation and I'd like to teach myself how to programme. Iit seems like a very useful skill and like something I would enjoy doing. With what language should I start? And I assume once you have learnt one, the others are easier to learn?
I've recently learnt programming myself, and I would recommend two things:
1. A steep learning curve, but learning it properly: starting with C then going to C++
2. An easy language that can be useful, and can certainly teach you how programming works: Python
You can learn the latter one on www.codecademy.org
It's easier to start with Python, but I think you learn it a lot better if you just start with C. (this is what professors at my university says, but our classes start with Python)
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You aren't doing yourself any favors by starting with C. You're most likely not even going to learn how to code properly in C.
Start with C# or Java but make sure you learn about reference types and value types.
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I say start with Python. As I mentioned above, the top tech schools are using it, a lot of the details resemble other more challenging languages, but you'll be building fun stuff a lot faster with it and it has significant value in the real world once you get out of school.
That said, if you're learning for yourself, do whatever sounds like fun!! Learn C, or hell, learn your favorite processor's assembler code. My own path went from Fortran to Applesoft Basic to Apple Pascal to 6502 assembler to Ada (which is what advanced CS students were learning at Harvey Mudd when I started in 1987) to Object Pascal to 68000 assembler to C to C++ to Perl to Objective C to Java to Python. Basically I just learned whatever was convenient and worked well on the platform I had available at any given time to let me do something fun.
It's worth trying out a range of languages, though. They differ in what they do well and it will make new languages easier to pick up. That said, Python is still an awesome place to start these days, it's pretty modern, works on just about any computer, and is very quick to get started with.
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If you want little programming exercises to learn a new language, I recommend using Project Euler (http://projecteuler.net/http://projecteuler.net/).
It's a set of problems that can be solved in any language you want, and once you solve each one you get access to a "forum" discussing the different solutions in different languages for that problem. Really cool.
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On November 04 2012 17:29 spinesheath wrote:Show nested quote +On November 04 2012 07:25 Lysenko wrote:On November 04 2012 04:15 CecilSunkure wrote:On November 04 2012 02:09 Sawamura wrote:
now if could write some C++ program practice ^_^ hehehe thanks for the practice anyway 5/5 I could do that. I'm thinking of some object oriented C first though. You know, virtualizing some C++ features in C. I was on my way to a much longer post, but I don't want to get in the way of what you're doing here with a lot of negativity, so I'll just ask. Who learns C today, absent a specific need to write embedded code, modify a UNIX or Linux kernel, or write a driver? I'm speaking as someone who paid several years of bills as a C programmer, working on both embedded applications and desktop applications. This was, however, 17 years ago, before (as far as I have personally seen, which is why I'm asking) the entire world moved on to C++. ** I mean, I can see doing it out of nostalgia, or because I got a cheap deal on some single-chip-computer development board, but that's about it. Is this a topic of interest for typical, highly-motivated CS students these days? I'm not saying it's bad, I just don't get it. You learn C to work with the crappy old codebase many companies still have. If you start a new project from scratch, you better have a damn good reason to use C. But if you work on something that uses old code, chances are it uses C. That's no reason to start with C as your first language though.
Sure, I agree, but the first language question is what I was getting at. 
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On November 04 2012 17:29 spinesheath wrote:Show nested quote +On November 04 2012 07:25 Lysenko wrote:On November 04 2012 04:15 CecilSunkure wrote:On November 04 2012 02:09 Sawamura wrote:
now if could write some C++ program practice ^_^ hehehe thanks for the practice anyway 5/5 I could do that. I'm thinking of some object oriented C first though. You know, virtualizing some C++ features in C. I was on my way to a much longer post, but I don't want to get in the way of what you're doing here with a lot of negativity, so I'll just ask. Who learns C today, absent a specific need to write embedded code, modify a UNIX or Linux kernel, or write a driver? I'm speaking as someone who paid several years of bills as a C programmer, working on both embedded applications and desktop applications. This was, however, 17 years ago, before (as far as I have personally seen, which is why I'm asking) the entire world moved on to C++. ** I mean, I can see doing it out of nostalgia, or because I got a cheap deal on some single-chip-computer development board, but that's about it. Is this a topic of interest for typical, highly-motivated CS students these days? I'm not saying it's bad, I just don't get it. You learn C to work with the crappy old codebase many companies still have. If you start a new project from scratch, you better have a damn good reason to use C. But if you work on something that uses old code, chances are it uses C. That's no reason to start with C as your first language though.
how about if I work on really low-footprint embedded applications where it's the only option, and also the only plausible option?
C is beautiful because it lets you in on what it's doing at a low level. It lets you abstract things *enough* to make good designs, but not so much that you trade all your performance for elegance.
I'm sure lots of companies are developing new code from scratch right now, because cheap mass-produced CPUs don't tend to run lisp interpreters and stuff. For many people in the 'modern' CS/programming world, C will be the "hardest" language they learn that anyone in industry cares about...that's a good reason to learn it if you want to work as a generalist. If you're more interested in pursuing your own projects, or doing something in academia, you can be much more selective about what you learn (i.e. stack-based, functional, etc.. language types).
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Hey, if you like C, it's cool, I'm not one to judge. But what about the children? What do you think all this glorification of C is going to lead them to? What's next, I'll tell you what's next, those kids are going to grow up thinking that C is OK, and that undermines the core of our society, which is getting things done.
Look at me, I started out with c because of peer pressure. Now I earned the right to say that really made me understand how things really work. Except it didn't. What it did do instead was making everything mind-numbingly tedious so that I never could actually do anything worthwhile - but I was too stubborn to drop it for a long while because after all that's the way real men write code. Don't be me, pick up the tool that you need for the job, and I guarantee you when you actually want to do something for which C is actually the best tool, it won't be any harder to learn. Plus at that point you might even not have given up already.
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On November 04 2012 21:27 Lysenko wrote:
I say start with Python. As I mentioned above, the top tech schools are using it, a lot of the details resemble other more challenging languages, but you'll be building fun stuff a lot faster with it and it has significant value in the real world once you get out of school.
That said, if you're learning for yourself, do whatever sounds like fun!! Learn C, or hell, learn your favorite processor's assembler code. My own path went from Fortran to Applesoft Basic to Apple Pascal to 6502 assembler to Ada (which is what advanced CS students were learning at Harvey Mudd when I started in 1987) to Object Pascal to 68000 assembler to C to C++ to Perl to Objective C to Java to Python. Basically I just learned whatever was convenient and worked well on the platform I had available at any given time to let me do something fun.
It's worth trying out a range of languages, though. They differ in what they do well and it will make new languages easier to pick up. That said, Python is still an awesome place to start these days, it's pretty modern, works on just about any computer, and is very quick to get started with.
I guess I'll start with Python and maybe Java(because I already spent an hour messing around with that). Why are there so many different programming languages anyway? I'm learning for myself, I don't plan on studying Computer Science, probably gonna study Physics. But I've always found it interesting for some reason so I'd like to give it a shot.
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On November 05 2012 03:00 Recognizable wrote:Show nested quote +On November 04 2012 21:27 Lysenko wrote:
I say start with Python. As I mentioned above, the top tech schools are using it, a lot of the details resemble other more challenging languages, but you'll be building fun stuff a lot faster with it and it has significant value in the real world once you get out of school.
That said, if you're learning for yourself, do whatever sounds like fun!! Learn C, or hell, learn your favorite processor's assembler code. My own path went from Fortran to Applesoft Basic to Apple Pascal to 6502 assembler to Ada (which is what advanced CS students were learning at Harvey Mudd when I started in 1987) to Object Pascal to 68000 assembler to C to C++ to Perl to Objective C to Java to Python. Basically I just learned whatever was convenient and worked well on the platform I had available at any given time to let me do something fun.
It's worth trying out a range of languages, though. They differ in what they do well and it will make new languages easier to pick up. That said, Python is still an awesome place to start these days, it's pretty modern, works on just about any computer, and is very quick to get started with. I guess I'll start with Python and maybe Java(because I already spent an hour messing around with that). Why are there so many different programming languages anyway? I'm learning for myself, I don't plan on studying Computer Science, probably gonna study Physics. But I've always found it interesting for some reason so I'd like to give it a shot.
A lot of it is due to history. The first languages were obviously very close to machine code, see Assembler. Then slowly people started to realize that they could introduce higher levels of abstraction (like C, C++, C#) to make programming easier, faster (as in the time spent on writing code), and less error prone. A lot of languages were developed to represent the increasing levels of abstraction as time went on and innovations in computer science came up. Computer science is still fairly young, there will still be lots of development which will lead to new languages which support concepts that would be hard to express in other languages (technically you can emulate the stuff in C++ or C# with C, but it's a LOT more work).
Then there are languages which were developed to make programming in a certain environment easy.
Lately we've seen a rise of functional programming languages which represent the logical/mathematical approaches more closely.
The upcoming languages will probably mostly try to deal with the increasing hardware parallelism, which isn't really handled natively in any of the current mainstream languages. Ideally the compiler would produce good parallel code without the programmer having to worry about it at all. Right now you always have to do some work to get your programs to run efficiently on multiple threads.
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I don't remember pointer intricacies D:
Props to those few of you that do this stuff in spare time.
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Personally I think C++ is way worse as a first language than C, but that's just me. I would go for Python, to start out and then move to Java or C and teach them about memory and pointers and all that good stuff. It's important to know for sure but when just starting out it only gets in the way. When starting out I think it's really important to be able to do interesting things quickly and easily.
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On November 05 2012 03:00 Recognizable wrote:Show nested quote +On November 04 2012 21:27 Lysenko wrote:
I say start with Python. As I mentioned above, the top tech schools are using it, a lot of the details resemble other more challenging languages, but you'll be building fun stuff a lot faster with it and it has significant value in the real world once you get out of school.
That said, if you're learning for yourself, do whatever sounds like fun!! Learn C, or hell, learn your favorite processor's assembler code. My own path went from Fortran to Applesoft Basic to Apple Pascal to 6502 assembler to Ada (which is what advanced CS students were learning at Harvey Mudd when I started in 1987) to Object Pascal to 68000 assembler to C to C++ to Perl to Objective C to Java to Python. Basically I just learned whatever was convenient and worked well on the platform I had available at any given time to let me do something fun.
It's worth trying out a range of languages, though. They differ in what they do well and it will make new languages easier to pick up. That said, Python is still an awesome place to start these days, it's pretty modern, works on just about any computer, and is very quick to get started with. I guess I'll start with Python and maybe Java(because I already spent an hour messing around with that). Why are there so many different programming languages anyway? I'm learning for myself, I don't plan on studying Computer Science, probably gonna study Physics. But I've always found it interesting for some reason so I'd like to give it a shot.
Go Python or Matlab imo. Both you might use for doing physics work anyway later. They both allow you to skip the intro to methods before learning variables, and both let you get stuff done quickly. I don't see a reason to learn Java if you're going to work on Python - just focus on that (if that's the one you like).
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On November 04 2012 18:06 Recognizable wrote:
Hijacking this thread for a little bit:
When I'm done with High School I have a couple of months vacation and I'd like to teach myself how to program. Iit seems like a very useful skill and like something I would enjoy doing. With what language should I start? And I assume once you have learnt one, the others are easier to learn?
I'm currently teaching myself Cplusplus (phone doesn't have plus sign lol). It's not that bad at least so far. Been only 4 days and in still at basics. I am learning from a set of tutorials by a guy named Bucky who's really good at explaining it. If you want a link or something let me know. I know everytime I have asked what language to start out with most say C#. I would recommend not C as it gives you bad habits. I know multiple books when I was younger always said not to start C as it gives really bad habits and forums. If you want links let me know!
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On November 04 2012 21:38 kirika80 wrote:If you want little programming exercises to learn a new language, I recommend using Project Euler ( http://projecteuler.net/http://projecteuler.net/). It's a set of problems that can be solved in any language you want, and once you solve each one you get access to a "forum" discussing the different solutions in different languages for that problem. Really cool.
I just solved the first 2 in R. The third one looks really hard. How do you find the biggest prime factor of a large number in under a minute?
http://projecteuler.net/problem=3
I hate you. Now I'm going to be thinking about it. I could do the problem with a list of prime factors going up to the square root of the number in question, but other than that I see no way of solving the problem in under a minute.
Finding prime numbers in and of itself is not easy to do. The only way I know how is to use sieve method. But that takes ungodly amounts of time.
For all I know the largest prime of 600851475143 is 775143. I could easily check if 775143 is a prime but even if it wasn't, I'd then have to check if 775141 was a prime. FUCK
I would not recommend learning a language with these exercises. They're meant for masochists, not for learning languages.
Is that how you do the question? With a list. Dumb question doesn't say what I can use. Actually, no, I can do it with sieve. nvm.
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On November 05 2012 13:09 obesechicken13 wrote:Show nested quote +On November 04 2012 21:38 kirika80 wrote:If you want little programming exercises to learn a new language, I recommend using Project Euler ( http://projecteuler.net/http://projecteuler.net/). It's a set of problems that can be solved in any language you want, and once you solve each one you get access to a "forum" discussing the different solutions in different languages for that problem. Really cool. I just solved the first 2 in R. The third one looks really hard. How do you find the biggest prime factor of a large number in under a minute? http://projecteuler.net/problem=3I hate you. Now I'm going to be thinking about it. I could do the problem with a list of prime factors going up to the square root of the number in question, but other than that I see no way of solving the problem in under a minute. Finding prime numbers in and of itself is not easy to do. The only way I know how is to use sieve method. But that takes ungodly amounts of time. For all I know the largest prime of 600851475143 is 775143. I could easily check if 775143 is a prime but even if it wasn't, I'd then have to check if 775141 was a prime. FUCK I would not recommend learning a language with these exercises. They're meant for masochists, not for learning languages. Is that how you do the question? With a list. Dumb question doesn't say what I can use.
Biggest prime factor is not difficult.
Do something like
for (int i = 2; i * i <= number; i++)
{
while (i%number == 0)
{
number = number / i;
}
}
printf("The greatest prime factor is %d\n", number);
I haven't tested this, but I've coded something similar recently. It can find the prime factors of 9,223,372,036,854,775,808 pretty fast [sub 5 seconds]
Two improvements that could be made:
1) Code a case to check if it is a prime number to begin with. If it isn't, then enter the loop
2) Code a case to check for divisibility of 2's, since all even divisors are divisible by two. Then you can modify the loop to start like: for (int i = 3; i < number * number; i = i + 2)
This makes it around twice as fast since you are only checking for positive odd real numbers, instead of all positive reals
Your output can be verified at wolfram alpha
http://www.wolframalpha.com/input/?i=prime factors of 600851475143
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1) Code a case to check if it is a prime number to begin with. If it isn't, then enter the loop
If I could do this I'd be a millionaire.
It can find the prime factors of 9,223,372,036,854,775,808 pretty fast [sub 5 seconds].
Lol. I don't know if you're trolling or if you misunderstand the problem. But That number above has only one prime factor: 2.
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On November 05 2012 13:25 obesechicken13 wrote:Show nested quote +1) Code a case to check if it is a prime number to begin with. If it isn't, then enter the loop If I could do this I'd be a millionaire
How about I make you a deal.
I'll teach you primality tests, and you split me half the million dollars
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On November 05 2012 13:25 obesechicken13 wrote:Show nested quote +1) Code a case to check if it is a prime number to begin with. If it isn't, then enter the loop If I could do this I'd be a millionaire. Show nested quote +It can find the prime factors of 9,223,372,036,854,775,808 pretty fast [sub 5 seconds]. Lol. I don't know if you're trolling or if you misunderstand the problem. But That number above has only one prime factor: 2.
I'm not trolling.
Since the algorithm divides, it will come up with the answer pretty fast. The factors are 2^63, and every pass will divide it by 2. Meaning the loop only needs to run 63 times.
The problem occurs when you have a huge jump, like the first prime factor is like 6,000,000,000+ or so.
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EPT
