Database Develop

Algorithm help

i need to make an algorithm, but i'm not really sure is it correct.
here is what i've got to do:
make an algorith, when enter a 5 digit number, it must check if it is divisible with the sum of it's digits
for example:
enter 38495, check is 38495 divisible with 3+8+4+9+5
please help me

As I hate to do homework for the others, I'm going to suggest you a tutorial to learn.
Good learning

As nathanpc said, we're not going to do your homework for you.
We might help with some pointers if you at least posted your attempts.

Thanks for the support MusikMonk

thx for your replies, but i still have no clue how to solve this

Ahhhh...
First of all, go at Google and learn more of algorithms, then get here

all im going to say is remember we are a community and we share a develop information together
if this guy had asked how to flash i can understand the need to come here and remind the OP of the rules that we research here not jump head first
however this is the off topic forum and we should encourage here, if you really hate doing other peoples homework don't respond, or do i have to put up my how not to ***** at people tutorial
either help or ignore

Here are some tutorials for you learn
Algorithms by S. Dasgupta, C.H. Papadimitriou and U.V. Vazirani
A fast learning algorithm for deep belief nets
Any questions just ask here
Enjoy your learning

Android Development

I'm posting this in the Development section because that is what I am trying to learn about. Please move me if I am mis-posting this.
I'm greatly interested in the the Roms people are making and everything that is being done on these forums. If someone wanted to start to learn about these things, developing and such, where should they start? Do I need to learn Java? Are there certain books I should be reading?
I can flash my phone like its my day job now, and I haven't come across any major problems I couldn't solve by reading, but I have no idea where to start to be able to develop things myself. If any developers here could maybe throw out a few tips on how to get started, what someone should focus on learning, etc., it would be greatly appreciated! I have plenty of time and a great desire to learn so I'm not intimidated by having to do the work, I just have to have some things to focus on. Thank you in advance for any help/advice you can give me!

I always wanted to know how make roms also I was looking around the internet but couldn't find anything that will describe it step by step word for word.
Maccie

It will be a huge writeup.But im sure someone will do it. I am still learning myself. There are some good topics around but different from what we have now

topshelf95 said:
I'm posting this in the Development section because that is what I am trying to learn about. Please move me if I am mis-posting this.
I'm greatly interested in the the Roms people are making and everything that is being done on these forums. If someone wanted to start to learn about these things, developing and such, where should they start? Do I need to learn Java? Are there certain books I should be reading?
I can flash my phone like its my day job now, and I haven't come across any major problems I couldn't solve by reading, but I have no idea where to start to be able to develop things myself. If any developers here could maybe throw out a few tips on how to get started, what someone should focus on learning, etc., it would be greatly appreciated! I have plenty of time and a great desire to learn so I'm not intimidated by having to do the work, I just have to have some things to focus on. Thank you in advance for any help/advice you can give me!
Click to expand...
Click to collapse
There are a number of aspects to android development you have to learn to know how to build a full ROM from scratch. C is of course required for kernel building, and apps are built from java in the dalvik-vm, but can be built against sun java.
of course, to get started, you would need the android sdk available here: http://developer.android.com/sdk/index.html
then there's the cloning of the android git:
http://android.git.kernel.org/
and, specifically for the captivate, there's the captivate source code:
http://opensource.samsung.com/
then there's pulling off the vendor proprietary libs from your phone (which is a ***** and I believe you can grab them from wes's github, though I can't speak for their accuracy) here:
http://github.com/wesgarner/proprietary_vendor_samsung
building the entire android OS from source is a challenge, especially compensating for some changes Samsung has introduced. this is what a real ROM is. now if you're talking about "ROM"s like Cognition and Shep's and even Eugene's Hybrid/Frankin-Twiz... they aren't comparable. Not to belittle any of their efforts, but this is simple "drag and drop" from stuff built by Samsung. While they're very useful tools, there is little actual development going on in them. There are improvements and tweaks, for sure... but it isn't a *true* ROM. All these releases by DesignGears, Eugene, and Shep are good and effective, but it'd be a shame if they weren't because they are just files thrown together from Samsung's already compiled ROM(s). Even the AOSP Beta 3 (which I have a qualm with the name, because it isn't actually AOSP, it's files pulled from an already built AOSP tossed onto Samsung's ROM again) is just modifying binaries (decompile, edit, recompile).
for those, it's as simple as extracting the zip, replacing the files you want, and rezip it. modifying the update-script inside meta-inf if there's something you want to add.

Awesome post Kaik, thanks, I was wondering some of those too.

Thx that explained a bunch
Maccie

Thank you for taking the time to post that Kaik! It's nice to have a place to start! Anyone else have any tips or things they think might be good to check out?

last, but certainly not least and I can't believe I forgot this, is Unhelpful's toolchain to compile against:
http://forum.xda-developers.com/showthread.php?t=761923
he did a lot of testing with various combinations, and this was the best he found to reduce wakeup lag and other issues

Wow. Kaik. That was the most awesome response to that question I have ever seen. Most people just point to developer.android.com and say go learn to program and come back in 5 years.
Thank you for this very useful information. Your the man now dog.

johnyhoffman said:
Most people just point to developer.android.com and say go learn to program and come back in 5 years.
Click to expand...
Click to collapse
Devs are not being mean or pissy, they are being honest and realistic. If development was just "point and click" XDA would not even be here. Give the devs/veterans a break and take it upon yourself to learn the basics and do some searches, if you are that interested.
I would love to just start making my own Android OS just the way I like too but to do that will require much more reading and learning, trying and failing.
You will probably not find "the answer" you are looking for but if you search, read and most importantly, respect the time, energy and anguish people have put into this site you will find the means to get where you want.
Otherwise you can expect... "Let me just glance and peek to see how to do this. Damn what the hell does that mean? Oh well here is a modded ROM. I'll try that. Jeez, that sucks. How do I make my own? Let me just glance and peek to see how to do this. Damn what the hell does that mean? Oh well ..." It is an endless cycle.
I'm not saying this to belittle anyone. Most have been there, including myself. I say this as a vote of confidence to all.
Hang in there, do the work, break some phones, read some books. Really! You have to!

koe1974 said:
Devs are not being mean or pissy, they are being honest and realistic. If development was just "point and click" XDA would not even be here. Give the devs/veterans a break and take it upon yourself to learn the basics and do some searches, if you are that interested.
I would love to just start making my own Android OS just the way I like too but to do that will require much more reading and learning, trying and failing.
You will probably not find "the answer" you are looking for but if you search, read and most importantly, respect the time, energy and anguish people have put into this site you will find the means to get where you want.
Otherwise you can expect... "Let me just glance and peek to see how to do this. Damn what the hell does that mean? Oh well here is a modded ROM. I'll try that. Jeez, that sucks. How do I make my own? Let me just glance and peek to see how to do this. Damn what the hell does that mean? Oh well ..." It is an endless cycle.
I'm not saying this to belittle anyone. Most have been there, including myself. I say this as a vote of confidence to all.
Hang in there, do the work, break some phones, read some books. Really! You have to!
Click to expand...
Click to collapse
this times one thousand. I linked you guys to some very useful sites when it comes to actually putting android together... but understanding how it all works, actually getting a successful build, fixing bugs, etc... I can't even begin to pretend to be able to help with that. if you have little to no experience in C and Java, these things will basically be useless to you. dev's aren't being mean when they brush you off like that, but usually if you can't figure out how to google what to do with the code, they don't have high hopes for what you'll be able to do with it once you find the code.
the idea isn't to be like "f*** off" when they say that, it's more of a "we'll help you when you learn, but you're the one who needs to take the first steps and you need to take the responsibility of learning on yourself."

I was actually referring to the fact that someone like me, a hobbyist programmer for about 10 years now, can make sense of his reply and use it to go forth and actually do something. Most of the guides you find on here that are supposedly pointed at noobs, do not layout things as easily as his post did.
Wasn't criticizing anyone, but I have seen less patience nowadays for any posts such as these.
Was just saying it was a gem of a post for me personally. Maybe it doesn't help the ultra noobs and the more experienced people see it as useless, but for someone with little time right now, it was a perfect post for me.

[Q] I want to become a dev.

I'm a creeper on the forums and i look up to you people...and Recently i saw a story on how the number1 iphone app was created by a fourteen year old.
It got me thinking.. and i really want to try this but i have absolutely zero coding experience..
I know it sounds noobish to say but all the devs on this forum had to start somewhere.. they didnt just magically get their talents.
What i'm asking for are tutorials, references, guides, even books, on how to develop android applications from scratch.
Please dont overlook me.. i just want to learn.
I have the android sdk and eclipse set up and linked together.
I even have app inventer.
Any help is appreciated

I'd recommend starting with the tutorials on the Android Developers website http://developer.android.com/resources/index.html. In the left column there are 6 tutorials that are quite good. I'd reccomend doing Hello World, Hello Views, Notepad Tutorial, and save the others for later. After that, your best bet would be to get an idea in your head and go for it. If you have questions the best place to ask is on IRC in #android-dev. Outside of that, google is your best friend. Just search for what you want to do.
Hope this helps!

Tutorials are usually a good way to learn what you can start doing.
After you get some basics and know how to search for certain functions/commands, then you can start thinking about what type of app you want.
A lot of books (I just glanced over them at the bookstore) suggested thinking of what you want the app to do and then designing the general User Interface on paper. And after the UI is in your mind, you can start programming.

thanks to both of you for the help really appreciate it.. people seem to ignore the noobs but anybody can learn.
ill put my ideas on paper first.
And ChainsDD what is the IRC in #android dev?

IRC is internet relay chat. To quote Wikipedia:
Wikipedia said:
Internet Relay Chat (IRC) is a popular[citation needed] form of real-time Internet text messaging (chat) or synchronous conferencing.[1] It is mainly designed for group communication in discussion forums, called channels,[2] but also allows one-to-one communication via private message[3] as well as chat and data transfer (including file sharing).[4]
Click to expand...
Click to collapse
There are many clients out there to connect to it, but I believe that XChat is cross-platform and quite good. Here's the website for it. The quick start guide on that page will get you online, but choose freenode as your network, as that's where #android-dev is. There's also #android for general android discussions, and #android-root for root discussions.

I would recommend you to start with the basics. With that I mean Java applications for the command window. It's easy to set up and use to learn basic stuff like data types, operators and class structures. Search for "basic java programming" or likewise and you will find a lot of good (and bad) tutorials.
For example: Java tutorial for beginners - Introduction
When you have learned to write a simple program in Java use the Android tutorials to learn how to use Google's Java libraries. The three tutorials ChainsDD mentioned are a good start.
people seem to ignore the noobs
Click to expand...
Click to collapse
Not all of us

Real Dev's code in Python (j/k)
But they all stated good things - pretty much pick a programming language and start from there. If it's Android development it is going to be Java (ugh).
If your serious about wanting to develop? I would recommend C++ as the language to get involved with. From there it is easy to branch off to other languages.
There is a TON of free material on the internet (that isn't pirated even) to help you get started. Compilers, code samples, documentation.. there is virtually no limit to the amount of data that is out there.
The trick is... A) to figure out what you want to do and B) remained focus on your goals and keep working at it. Coding is NOT easy (I can't code my way out of a wet paperbag - but I understand it) but can be very rewarding both personally and financially
So good luck!

avgjoegeek said:
but can be very rewarding both personally and financially
Click to expand...
Click to collapse
Nah, I code for years and didn't get any of those rewards.. just lame jobs and no life!

Need to learn the android development... From basics....

Hi,
First of all thank you so much for starting a forum for learning the Android Development.
I am very much interested in learning android, and i have gone through the official android developers site, and downloaded the SDK.
But i am stuck there, coz i am very new to the Linux/Unix part. I would like to learn more about that, but i do not want to learn programming unless it's necessary. I know it will take a long long time to learn that. So can anyone help me with the app development or fixing/understanding ROM/Kernels.
Sorry if i am being too much jumpy in the starting itself, It's because i do not know where/how to start.
Thanks,
Les

lesfauves said:
Hi,
First of all thank you so much for starting a forum for learning the Android Development.
I am very much interested in learning android, and i have gone through the official android developers site, and downloaded the SDK.
But i am stuck there, coz i am very new to the Linux/Unix part. I would like to learn more about that, but i do not want to learn programming unless it's necessary. I know it will take a long long time to learn that. So can anyone help me with the app development or fixing/understanding ROM/Kernels.
Sorry if i am being too much jumpy in the starting itself, It's because i do not know where/how to start.
Thanks,
Les
Click to expand...
Click to collapse
Unfortunately without learning programming, you will find it difficult to do any app development and kernel understanding or fixing.
Programming is key to both of these. So although you don't want to, have a look at some of the resources out there on how to learn to program.
Apps are written in java, kernel code is mostly C.
Maybe this helps? I think failing to start by learning to program will just leave you disappointed.

If it's okay, I'd like to suggest something.
@lesfauves
For kernel development, you really need to learn C, C+, C++ etc. C is the most important language here. However if you're gonna build vanilla kernels (with no modifications whatsoever), a simple guide should do it. Modifying source code requires knowledge of C (and maybe some other languages) as pulser_g2 has said.
For app development, you need to know the basics of Java. It's a must. Otherwise you'll end up getting nowhere.
For ROMs, you need to have a good understanding of both Java and C (and some other languages).
You can learn these online. I'm learning C myself. It's really easy.
Hope I helped.
sgt. meow

I too want to learn android development, just dont know where to start. Been waiting for xda university to open up for this very purpose. now I went through the site and still have a couple questions. I see that learning C is fundamental, where would you guys suggest would be the best place to learn? i was hoping for something like codeacademy, they dont have C though. Also, which distribution of linux would you guys suggest to install?

If you just want to dive in, and have fun creating small Android apps, learning Android concepts as you go, I highly recommend MIT App Inventor (AI): http://appinventor.mit.edu/ . It used to be Google AI but Google wanted to focus on other things.
I have decades of experience in Unix & Linux low level mostly C software development, but was new to Android & Java in Feb. 2011. App Inventor was a great intro to Android concepts, but it seems almost impossible to make commercial quality apps of any size with it.
So after a few months I dove into Java with the Android SDK & the concepts I learned with AI transferred well.
If you want to run Linux on your PC, which is a great way to learn Linux in general, Ubuntu remains quite popular, but a lot of us techy types have moved to Mint. I'm still on Ubuntu but will likely try Mint at some point.
The original and seminal book on C language is this: http://en.wikipedia.org/wiki/The_C_Programming_Language . It was a great intro for me back in the 1980's. But many C++ people will tell you learning C first may mess you up for C++. I never really caught on to C++ and don't care now as Java is IMO better.
This is the seminal book for C++: http://en.wikipedia.org/wiki/The_C++_Programming_Language
In general I think C is better for kernel and low level Android NDK stuff; C is the language of the kernel. For higher level Java of course, using Eclipse as an IDE since it still is the most widely used IDE I think.

Any good sites or tutorials for learning Linux????????????/

l0lh4rd said:
Any good sites or tutorials for learning Linux????????????/
Click to expand...
Click to collapse
http://www.ee.surrey.ac.uk/Teaching/Unix/

sgt. meow said:
If it's okay, I'd like to suggest something.
@lesfauves
For kernel development, you really need to learn C, C+, C++ etc. C is the most important language here. However if you're gonna build vanilla kernels (with no modifications whatsoever), a simple guide should do it. Modifying source code requires knowledge of C (and maybe some other languages) as pulser_g2 has said.
For app development, you need to know the basics of Java. It's a must. Otherwise you'll end up getting nowhere.
For ROMs, you need to have a good understanding of both Java and C (and some other languages).
You can learn these online. I'm learning C myself. It's really easy.
Hope I helped.
sgt. meow
Click to expand...
Click to collapse
I wanted to to help my phone community and my self of course...from where you can learn c online??i know my way with pc i make some roms from my community but i need to start learning to compile from source!!! share your links if you can thanks!!

Lynda.com
pikachukaki said:
I wanted to to help my phone community and my self of course...from where you can learn c online??i know my way with pc i make some roms from my community but i need to start learning to compile from source!!! share your links if you can thanks!!
Click to expand...
Click to collapse
A great site that I use to learn with for web design and development is Lynda.com which has a good amount of C tutorials and learning. It isn't free but a subscription is worth the site. There is a huge amount of information, tutorials, and learning that can be done there.

Go look at my post in this forum section.! May help you
Sent from my PG86100 using xda app-developers app

Thats great but remember that i study pc hardware and i dont have none of programming knowlage at all!!!i once try to learn basic but i get bored cause i dont needed then

pikachukaki said:
Thats great but remember that i study pc hardware and i dont have none of programming knowlage at all!!!i once try to learn basic but i get bored cause i dont needed then
Click to expand...
Click to collapse
Aaaaaah gotcha
Sent from my PG86100 using xda app-developers app

Search for newboston.org in Google it has tutorial + forums for every language + android app development too must see website for me! Enjoy development
Sent from my GT-S5360 using xda premium

Ok lets say i want to learn how to make a device tree for my device cause noone make it...then compile aosp or cm and make it a usable rom for a device...to go to a bookstore to buy a book in my language to remove the possibility of wrong learning...what book to buy??java, c , c++??

This is a great idea, and as i have just started learning C at university (And Java next year woo!) i will be visiting this alot for reference and tutorials. I still find C hard to get grips with but i do have a basic understanding of it. I also like messing around with kernel's and stuff on android and really want to make my own ROM or kernel soon!
So thanks XDA and everyone involved in this !

pikachukaki said:
Ok lets say i want to learn how to make a device tree for my device cause noone make it...then compile aosp or cm and make it a usable rom for a device...to go to a bookstore to buy a book in my language to remove the possibility of wrong learning...what book to buy??java, c , c++??
Click to expand...
Click to collapse
If you want to learn how to make a device tree check outthis guide, then when your ready to try compiling AOSP and Cyanogenmod check out this guide. If you want to learn to compile ROM's and then I would recommend a book on Linux and C for programming kernels such as C All-in-One Desk Reference. On the other hand if you want to program applications a good Java book is important and I would recommend Head First Java. Hope this clears things up, let me know if you still have questions.

shimp208 said:
If you want to learn how to make a device tree check outthis guide, then when your ready to try compiling AOSP and Cyanogenmod check out this guide. If you want to learn to compile ROM's and then I would recommend a book on Linux and C for programming kernels such as C All-in-One Desk Reference. On the other hand if you want to program applications a good Java book is important and I would recommend Head First Java. Hope this clears things up, let me know if you still have questions.
Click to expand...
Click to collapse
My point is basically to learn how to create the device tree and then compile any rom i can and hope that i can use fixes from others and hints from others...im not really interesting of making an application!!

can read my guide here

mithun46 said:
can read my guide here
Click to expand...
Click to collapse
Please stop spamming your link across each thread. And tone down the MASSIVE text in the thread - it just looks unprofessional.

so, where do I start? C or C++?
Sent from my R800i

need help in android studio software.

There will be 3 pages in the android studio software. The first two pages will contain the name of 3 anime series each with little tumbnails with them and a button below to go to the next page. The 3rd page will contain a shot video of 10 second or a gif. To run these content what codes are needed?

sakib021 said:
There will be 3 pages in the android studio software. The first two pages will contain the name of 3 anime series each with little tumbnails with them and a button below to go to the next page. The 3rd page will contain a shot video of 10 second or a gif. To run these content what codes are needed?
Click to expand...
Click to collapse
Your question is not specific, it's hard to understand what you really want to know. If you don't have programming experience and want this job to be done by someone else, I can make this app for you. All graphic assets must be provided by you.

Unity Dev said:
Your question is not specific, it's hard to understand what you really want to know. If you don't have programming experience and want this job to be done by someone else, I can make this app for you. All graphic assets must be provided by you.
Click to expand...
Click to collapse
okay. it would be very helpful. actually i have an assignment and i know literally nothing about programming.

I think you'r not explaining in the right way but i can help you to solve your problem. i have 8 years experience in software development and i develop so many software for multilevel and small level industry. You can contact me. gadget bytes. in.

Hello I need some advice or help on android studio plug in. I actually received an e mail I will just Copy it here :
EMAIL :
Dear Android developer,
We invite you to participate in a research study being conducted at Saarland University in Germany. We found your email address as a professional developer on Google Play.
We have developed FixDroid, an Android Studio plugin to help you learn about different aspects of software security. We're excited to be able to share this with you!
FixDroid helps you to learn more about secure coding. As you write code it finds insecure practices and warns you about them. In some cases it will offer you more secure alternatives as a QuickFix.
FixDroid is, and will remain, free to use and we're delighted if you can use it. In return we'll collect anonymous information about your use of it - but never any of your code or anything to identify you or the code. Please visit https://userstudies.cs.uni-saarland.de/fixdroid/installFixDroid.html to get access to the plugin.
While you try it out, if you've time, please could you possibly participate in a brief scientific study to help us improve FixDroid for you and other users?
Visit https://userstudies.cs.uni-saarland.de/fixdroid/70333f6d4789/468180b5cdf9 for more information or simply reply to this email. We'll be glad to answer any questions. If you don't want to receive emails from us, please visit https://userstudies.cs.uni-saarland.de/fixdroidstudy-bl/new/70333f6d4789/468180b5cdf9 and we will never contact you again.
Our research relies on the generous help of interested developers, so thank you for your help and feedback!
----
END
Now has any one else got this? Is this really helpful? I am asking here because I never heard of fixdroid. I know it is an html plug in and if it really is what it is maybe it will help others. I am just a junior developer so any help from a developer is appreciated tnx.

Help needed please!!
Hello. I'm new in developing apps and trying to learn on Android Studio. I'm creating a app for calculate the percent. The code is done and the interface, but when I run the app in the emulator all the buttons and the layouts appear on the top left of the screen one over the other. I don't know what i'm doing wrong. Thanks for your help.

omaritoml said:
Hello. I'm new in developing apps and trying to learn on Android Studio. I'm creating a app for calculate the percent. The code is done and the interface, but when I run the app in the emulator all the buttons and the layouts appear on the top left of the screen one over the other. I don't know what i'm doing wrong. Thanks for your help.
Click to expand...
Click to collapse
Please post your layout's xml file. Maybe you are using ConstraintLayout as a parent view instead of LinearLayour?