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Thread Rules
1. This is not a "do my homework for me" thread. If you have specific questions, ask, but don't post an assignment or homework problem and expect an exact solution.
2. No recruiting for your cockamamie projects (you won't replace facebook with 3 dudes you found on the internet and $20)
3. If you can't articulate why a language is bad, don't start slinging shit about it. Just remember that nothing is worse than making CSS IE6 compatible.
4. Use [code] tags to format code blocks. |
On March 03 2011 01:15 FunkyLich wrote:
Okay, I am supposed to be making a linked list with java and I have a different problem than the person who brought up linked lists earlier. I understand the linked list concept very well. And I would love to be able to do it in C because I feel like pointers would make it easier. But I have to do it in Java.
This is the crux of my problem: I simply do not know how to iteratively create objects (see how this ties in with linked lists further down). According to my faulty understanding of objects, I need a variable for every object I make. Thus every time I make an object, I need to write a line like this.
CLASS object-variable = new CLASS();
If someone could be so kind to explain why this is unnecessary in java, and what is wrong with my understanding of objects that hinders me from seeing the light, that would be great. This is really all I'm asking, but if you want specifics keep reading.
In the way I have it set up, the linked list is (when instantiated) an object of objects. The objects that make the list are simple nodes with two data values (some integer and a reference value to the second node). The linked list class takes an array input and generates a linked list based on the size of the array. So with a length 100 array, the linked list class would need to instantiate 100 nodes. And I would need to do this iteratively of course (or recursively if you want). I just need a way to make these nodes without each of them needing its own variable.
Hopefully im understanding your problem right. So you have your class ListObject with a variable of the same type.
So what i would do for an array is simply write constructor which takes a ListObject and the integer and then you can simply do this
ListObject head = new ListObject(null,yourArray[0]);
for(int i = 1;i++,i<yourArray.size() ){
head = new ListObject(head,yourArray[i])
}
which is practically the same as in c++. What you are doing here, is putting a reference to a new ListObject into head, while putting the reference to the old object into the ListObject variable of this object.
Also in general you can use new even without a variable declaration.
For example calling a method that takes an Object you can just write, myMethod(new Object());
or you can even just use new by itself, for example if you have a class Calc, that calculates the squareroot of a number and then prints it a line like this is ok.
new Calc(x);
and it prints out result.
you can even call methods directly on these.
new Calc(x).showSteps();
Hope that helps in your understanding.
As an extra, there is a LinkedList already in Java, so you can look at its sourcecode for further understanding on other problems you might have.
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I believe it does. So I can create an object without assigning it a variable.
Many thanks for the prompt reply. I will try this out and report back if I run into another major snag.
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hey guys, ive been searching the internet on how to keep your C program running until the user terminates it.
The idea is that my program is showing some results/output until the user terminates it.
I tried opening time.h and use
while((start_time / CLOCKS_PER_SEC * 1000) != 15)
doesnt work =/
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Just keep a loop in your main that prevents the program from returning untill a condition is met
int main() {
not_done = 1;
while (not_done) {
.....
}
return 0;
}
Or poll for input or something. You are going to have to use some form of loop, just find a good loop condition and you are set.
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Okey guys, i have hit a wall here with my JavaScript code. I wanna force event bubbling on my site, in order to circumvent the onMouseDown() in favor for onClick() (button). I need some tips for an elegant solution please.
+ Show Spoiler +<body onMouseDown="updateMouse()"> <P ID = "p1">This is a paragraph obviously. </P> <input type="button" value="Start" onClick="startProcessing()"> <input type="button" value="End" onClick="showResult()"> </body>
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OKAY well I got 60/75 on the Junior Programs for the Canadian Computing Competition by Waterloo. Pretty good since I haven't done any programming in 8 or so months, and this was way more advanced than anything I've ever done. Couldn't for the life of me think of a solution to the last question though, worth the remaining 15 marks.
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And you're not going to tell us said question?
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On March 04 2011 14:20 Craton wrote:
And you're not going to tell us said question?
LOL well it had something to do with finding out the number of ways you can remove people in a friends list if you can't remove yourself, or people that your friends invited if the maximum list size is 6. I was hoping to look at the question again tomorrow and get back to you (guys). :3
From what I recall, you are given an integer, n, from 1-6 where the highest number is the user (deleter). Then you are given n-1 numbers telling you who invited who into the list.
So if you are given
3
3
3
Then there are three people, the user is the third, and friend one and friend two were both invited by the user (three). I'll try to find the whole question, but where would I start in solving that?
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On March 04 2011 14:26 Blisse wrote:Show nested quote +On March 04 2011 14:20 Craton wrote:
And you're not going to tell us said question? LOL well it had something to do with finding out the number of ways you can remove people in a friends list if you can't remove yourself, or people that your friends invited if the maximum list size is 6. I was hoping to look at the question again tomorrow and get back to you (guys). :3 From what I recall, you are given an integer, n, from 1-6 where the highest number is the user (deleter). Then you are given n-1 numbers telling you who invited who into the list. So if you are given 3 3 3 Then there are three people, the user is the third, and friend one and friend two were both invited by the user (three). I'll try to find the whole question, but where would I start in solving that?
Well, from what you told us:
If there are people on the list who you havent invited and arent friends of someone you invited you cannot remove those. They're therefor irrelevant.
I think you are able to remove people who were invited from your friends as soon as you remove the friend (or else the problem wouldnt make any sense. Just count the people you invited and it's basic combinatorics how many different ways are there to remove them).
So let's assume my thought is correct. Build a "tree" with yourself as the root. Then each chilldnode (of the root) is a person who you invited. Their children are the persons they invited.
Now count how many different ways you can find which visits all edges of the tree.
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Hi, does anyone know how to break a video into frames using java? I used MATLAB to write a little program for playing a video in reverse. I have relatively no knowledge of java, since MATLAB has the functions programmed in so I didn't need to learn any programming. I now need to convert it to java and I dont have a clue where to start. It would be great if anyone can point me in the right direction! thanks
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On March 10 2011 02:05 AoN.DimSum wrote:
Hi, does anyone know how to break a video into frames using java? I used MATLAB to write a little program for playing a video in reverse. I have relatively no knowledge of java, since MATLAB has the functions programmed in so I didn't need to learn any programming. I now need to convert it to java and I dont have a clue where to start. It would be great if anyone can point me in the right direction! thanks
It depends on the video format for how you would convert a frame's data into an image. I would try and find some open source video decoder that can support multiple video formats. Chances are it will convert the video's frames into a common renderable surface. Then you can choose to grab that data and convert it to the image format of your choice.
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On March 09 2011 00:35 Zocat wrote:Show nested quote +On March 04 2011 14:26 Blisse wrote:On March 04 2011 14:20 Craton wrote:
And you're not going to tell us said question? LOL well it had something to do with finding out the number of ways you can remove people in a friends list if you can't remove yourself, or people that your friends invited if the maximum list size is 6. I was hoping to look at the question again tomorrow and get back to you (guys). :3 From what I recall, you are given an integer, n, from 1-6 where the highest number is the user (deleter). Then you are given n-1 numbers telling you who invited who into the list. So if you are given 3 3 3 Then there are three people, the user is the third, and friend one and friend two were both invited by the user (three). I'll try to find the whole question, but where would I start in solving that? Well, from what you told us: If there are people on the list who you havent invited and arent friends of someone you invited you cannot remove those. They're therefor irrelevant. I think you are able to remove people who were invited from your friends as soon as you remove the friend (or else the problem wouldnt make any sense. Just count the people you invited and it's basic combinatorics how many different ways are there to remove them). So let's assume my thought is correct. Build a "tree" with yourself as the root. Then each chilldnode (of the root) is a person who you invited. Their children are the persons they invited. Now count how many different ways you can find which visits all edges of the tree.
Yes! That's the way I felt I should have went. Sadly, I have no idea how to build a tree. In any language other than written.  Also have to subtract something too I feel because some options don't work? Ugh. At least I knew something about tree diagrams... stupid site won't show this year's questions/answers (answers are in java/c, so no help for python). I'm happy because 60/75 last year was rank 35 of the competitors. Pretty good imo for a novice.
On the other side, the senior competitors, only two people got above 60, one was on the dot, another got 72... yikes! I'm glad I only did the junior one.
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Java question here:
For anyone familiar with the javax.sound packages, is it possible to capture internal audio data like from the Digital Audio (S/PDIF) device? I've found several examples of capturing audio data from a microphone, but can't find anything related to what I'm looking for, so I'm just wondering if it's possible with the javax.sound packages.
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C++ assistance:
If anybody would like to help me out on a programming assignment, I would greatly appreciate it. Im doing an intro to C++ course and I just cant get the grasp of this assignment.
The program:
Basically a conversion program that gets a metric input and converts it depending on what the user chooses. Its basically a couple of functions and switches. More details if anybody wishes to help me.
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On March 10 2011 03:01 Phunkapotamus wrote:Show nested quote +On March 10 2011 02:05 AoN.DimSum wrote:
Hi, does anyone know how to break a video into frames using java? I used MATLAB to write a little program for playing a video in reverse. I have relatively no knowledge of java, since MATLAB has the functions programmed in so I didn't need to learn any programming. I now need to convert it to java and I dont have a clue where to start. It would be great if anyone can point me in the right direction! thanks It depends on the video format for how you would convert a frame's data into an image. I would try and find some open source video decoder that can support multiple video formats. Chances are it will convert the video's frames into a common renderable surface. Then you can choose to grab that data and convert it to the image format of your choice.
thank you, I will play around with that.
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On March 16 2011 09:49 coZen wrote:
C++ assistance:
If anybody would like to help me out on a programming assignment, I would greatly appreciate it. Im doing an intro to C++ course and I just cant get the grasp of this assignment.
The program:
Basically a conversion program that gets a metric input and converts it depending on what the user chooses. Its basically a couple of functions and switches. More details if anybody wishes to help me.
What is the problem? An issue with the functions?
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On March 16 2011 09:49 coZen wrote:
C++ assistance:
If anybody would like to help me out on a programming assignment, I would greatly appreciate it. Im doing an intro to C++ course and I just cant get the grasp of this assignment.
The program:
Basically a conversion program that gets a metric input and converts it depending on what the user chooses. Its basically a couple of functions and switches. More details if anybody wishes to help me.
This should be pretty simple, just assign the user input for the value to a variable, then write a chain of if statements that check the value of the conversion field.
numericValue = userinputforvalue
conversionType = userinputforconversion
if inches then
output = numericValue * googledconvrate
else if pounds then
output = numericValue * google
else
etc. etc.
display output
Edit: not sure what you're struggling with, need more info tbh
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For anyone struggling with an intro class, I think it's mostly because they don't have a programmer's mindset yet. You have to be able to think about what the big problem is, splice it up into smaller portions, and then map out what basically needs to be done for each part. I personally like to use comments to organize what needs to happen at the different areas before I go hardcore into the coding. Like for this case, it seems like this is the basic problem:
//obtain user input
//obtain conversion type
//calculate conversion
//display result
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On March 16 2011 21:59 EscPlan9 wrote:
For anyone struggling with an intro class, I think it's mostly because they don't have a programmer's mindset yet. You have to be able to think about what the big problem is, splice it up into smaller portions, and then map out what basically needs to be done for each part. I personally like to use comments to organize what needs to happen at the different areas before I go hardcore into the coding. Like for this case, it seems like this is the basic problem:
//obtain user input
//obtain conversion type
//calculate conversion
//display result
I usually recommend to just think about "how would i do this manually?". Write all steps down on a paper and program one step after the other. If the step is too big to be written in 3 lines of code, think about how to do this one step manually and refine it until you can write a single step of it in 3 lines. Repeat until code is finished. After that, care about optimizing, structure or the other - for beginners not important - aspects.
It's a good starting point, though very tedious. I prefer my "read/hear the problem - have complete code written out in your mind before the problem description is complete" mindset, but that takes ages of practical experience.
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Any ASP.Net 4 users here?
I am building a web application where a user can search a database for a garbage item (which is associated with a ID) stored in a xls file. When they've selected one from a list, I access another list based on the ID of the item and display a description for which that ID belongs too, this description list is stored an a second sheet in the same xls file.
Problem I have is creating a database storing the data in the xls file and accessing it. I was told to either use SQL or Oracle, but I have never programmed on this platform or using any of those additional languages. Any help on where to get started would be greatly appreciated.
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EPT
