Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[Levi]

And you can't see other people's solutions for a problem there, until you answer it correctly.  The reduce(lcm, xrange(2, 21)) solution is just so much better than mine that I wish I'd thought of it.

I think its still in the spirit of things if you've already come up with your own solution.  As long as you understand why the other version works.

[Lightningfalcon]

Does anyone know any good guides for either Java, C++, or Robot C? 

[Skyrunner]

Java and C++ both have decent web tutorials and resources online...
Not sure about books, though. :3

On the topic of Euler: has anyone solved the last few pages? A single problem? xD I bet the forums over there are pretty quiet...

I think I'll try my hand at the easier ones, though it's hard to think of any method other than brute-force... for the first one, I have an idea that might be faster than brute-force.

[Aqizzar]

Almost nine months ago, I helped spawn this thread by fumbling around with C# on a whim.  I had gone to an incredibly depressing New Years party and decided I really needed a fucking hobby, and I fell in love with C# when I saw it.  Some stuff happened over the next couple weeks that convinced me to go to a job recruiter, and when they asked me about any skills or hobbies I mentioned that I was teaching myself computer programming.  They hooked me up with this schmuck who'd previously gone to them, and after a few weeks of interning with him, he hired me full time as the first employee of a new branch company.

The code that I had taken up as a hobby and really enjoyed suddenly became a forty hour a week chore.  It became physically impossible to even look at code when off the clock.  After six months, I think I've finally crossed over the hump, and my job coding has become routine enough that I have the willpower to work for myself at home.  And with an old friend of mine having a similar experience with 3D modeling, well lets just say the garage band is finally coming together.

In the meantime, I'm finally working on a roguelike again.  Big ideas are not a new thing, but the familiarity to see how all the parts are going to fit together sure is.  On that subject, what's the craziest sort of enumerated listing you've abused in your code?  I'm currently working with a Dictionary<string, Dictionary<string, Dictionary<int, int>>> and it's not putting up a fight yet.

[alway]

Java and C++ both have decent web tutorials and resources online...
Not sure about books, though. :3

All programming books are lacking 2 very important features:
1. google indexing
2. ctrl f

Stick to web resources; there are plenty. Even when doing pretty advanced stuff, there are almost always better or easier to use resources online; be they Rastertek for graphics programming tutorials or vterrain for procedural world generation. They often also have either full source or download links right on the page; whereas with a book you will often find dead web pages accompanying them.

[Willfor]

On that subject, what's the craziest sort of enumerated listing you've abused in your code?  I'm currently working with a Dictionary<string, Dictionary<string, Dictionary<int, int>>> and it's not putting up a fight yet.

The most abuse I've ever put it through is List<List<List<Tile>>> where "Tile" is pretty much what it looks like. I should try some whackier things though, it sounds fun...

[Aqizzar]

On that subject, what's the craziest sort of enumerated listing you've abused in your code?  I'm currently working with a Dictionary<string, Dictionary<string, Dictionary<int, int>>> and it's not putting up a fight yet.

The most abuse I've ever put it through is List<List<List<Tile>>> where "Tile" is pretty much what it looks like. I should try some whackier things though, it sounds fun...

That's kinda what I'm doing.  The triple dictionary was my original idea, I've scaled it back to a double dictionary in a containerizing object.  The idea with the Dictionary<string, Dictionary<string, Dictionary<int, int>>> was that the outermost dictionary would be the type of tile (door, horizontal wall, etc), the second dictionary was the style (room, cave, whatever), and the innermost was the important one, as the Key int would be the ASCII mapping code and the value would be the probability.  To generate a map, the correct type and style would be handed to a function that randomly picks a mapping code based on the probabilities.  The same thing would be done with colors.

I decided that instead of one whopping great static dictionary to contain all that crap, I'd make a VisualStyle container to cut out the middle dictionary, and keep tilesets and colors together.  I'm not totally pleased with any one design, just because there's so many arbitrary tasks in a videogame, but I think I'm reaching a good balance between explicit and flexible.

The text paging function I whipped up a couple weekends ago still impresses me, I'll have to find a place for it in a roguelike.  And man, the activity controller is going to be beautiful.

[Mego]

Does anyone know any good guides for either Java, C++, or Robot C?

I'm familiar with all 3. I taught myself C++ 3 years ago (and have been writing a tutorial here; see the OP), I learned Java last year and programmed competitively with it (Stargrasper has been writing a tutorial here; see the OP), and I was the lead programmer for Robotics at my high school last year. I used RobotC exclusively.

I consider this to be a good C++ tutorial. Also, this site has good reference material for C++. I'm not sure about a Java guide, as I learned it in a classroom setting, with a textbook. C++ and C are very similar, and C and RobotC are also very similar, so learning C++ should give you a good feel for RobotC. If you have any questions about any of those 3, feel free to ask here.

[Skyrunner]

I worked hard on my intelligent method for Euler Problem One, and it's slower than the brute force method of trial division. :<

I was bored, so I made this:

Spoiler: Graphs for problem solver counts per problem (click to show/hide)

The Euler problems are pretty close to logarithmic distribution, judging by the near linear log scale graph. I wonder why question 209 has a sudden spike in correct replies, along with question 205.

[Mego]

205 and 209 are fairly easily solved by brute-force, which is a rarity in the higher-numbered problems.

EDIT: That is, if you have the proper tools. I wrote Python code to brute force 205, only to discover that I have Python 2.6, and one of the functions I am trying to use (itertools.combinations_with_replacement) is only available in 2.7 and onwards. Compiling time!

[RulerOfNothing]

When you say you brute-forced 205, what exactly do you mean by that? Also Skyrunner, what exactly was your alternate method for problem 1?

[Valid_Dark]

I've done problems 1 - 15 of projecteuler,  but haven't done one in a while.

and, C++ question,
ok, so before now I've never done projects with multi file source code,  I'm sure my book covers it, but it's probably like 200+ pages later, so I was wondering if I could get a quick rundown on using them.

ok, so there are .h and .cpp files, yeah?
.h are for objects and .cpp are for object functons? and you just #include the files together?

[Nadaka]

A header file is for declaration of publicly accessible functions. It essentially provides the interface for your class so that you could distribute it as a binary object and people could still build code that references its methods.

[Mego]

I've done problems 1 - 15 of projecteuler,  but haven't done one in a while.

and, C++ question,
ok, so before now I've never done projects with multi file source code,  I'm sure my book covers it, but it's probably like 200+ pages later, so I was wondering if I could get a quick rundown on using them.

ok, so there are .h and .cpp files, yeah?
.h are for objects and .cpp are for object functons? and you just #include the files together?

Well, sort of. Typical project design puts class definitions (with function prototypes, not definitions) in header files, and then a source file #include's the header file and defines the member functions. Like so:

Spoiler: foo.h (click to show/hide)

Code: [Select]

#ifndef FOO_H_INCLUDED // Guard word, used to make sure that this code only gets included once in any compilation target, to prevent multiple definition errors
#define FOO_H_INCLUDED

#include <string>

using namespace std;

class Foo {
int a;
string s;

public:
Foo(int intParam, string strParam);
int getA();
string getS();
void setA(int newA);
void setS(string newS);
};

#endif


Spoiler: foo.cpp (click to show/hide)

Code: [Select]

#include "foo.h" // foo.h #include's <string>, so no need to #include it again

using namespace std;

Foo::Foo(int intParam, string strParam) {
a = intParam;
s = strParam;
}

int Foo::getA() {
return a;
}

string Foo::getS() {
return s;
}

void Foo::setA(int newA) {
a = newA;
}

void Foo::setS(string newS) {
s = newS;
}


That's not the only purpose of headers, though. I have been ninja'd by Nadaka. Headers are used to write code that will be used in multiple places, potentially across multiple files. They're like utilities that the source files can access to do what they need to do.

Spoiler: Secrets about headers (click to show/hide)

Headers are literally no different from source files to the compiler. You could use .cpp as the file extension for your headers and .h as the file extension for your source files. The compiler won't care, but your fellow programmers will. You can #include any source code file just as easily as a header.

Code: [Select]

#include "foo.cpp"

That is perfectly valid code. You will probably end up getting punched by a coworker for it, but it's still valid.

[Valid_Dark]

A header file is for declaration of publicly accessible functions. It essentially provides the interface for your class so that you could distribute it as a binary object and people could still build code that references its methods.

so, if the header file is ONLY for publicly accessible functions, I can't put private class variables in it?  :confused:



Ohh, thank you Mego