Search Results

Search found 36506 results on 1461 pages for 'unsigned long long int'.

Page 408/1461 | < Previous Page | 404 405 406 407 408 409 410 411 412 413 414 415  | Next Page >

  • How does the recursion here work?

    - by David
    code 1: public static int fibonacci (int n){ if (n == 0 || n == 1) { return 1; } else { return fibonacci (n-1) + fibonacci (n-2); } } how can you use fibonacci if you haven't gotten done explaining what it is yet? I've been able to understand using recursion in other cases like this: code two: class two { public static void two (int n) { if (n>0) { System.out.println (n) ; two (n-1) ; } else { return ; } } public static void main (String[] arg) { two (12) ; } } In the case of code 2 though n will eventualy reach a point at which it doesnt satisfy n0 and the method will stop calling itself recursivly. in the case of code 2 though i don't see how it would be able to get itself from 1 if n=1 was the starting point to 2 and 3 and 5 and so on. Also i don't see how the line `return fibonacci (n-1) + fibonacci (n-2) would work since fibbonacci n-2 has to contain in some sense fibonacci n-1 in order to wrok but it isn't there yet. I know my question is worded poorly but looking at this is making my mind explode. the book i'm looking at says it will work. how does it work? `

    Read the article

  • Hashtable comparator problem

    - by user288245
    Hi guys i've never written a comparator b4 and im having a real problem. I've created a hashtable. Hashtable <String, Objects> ht; Could someone show how you'd write a comparator for a Hashtable? the examples i've seen overide equals and everything but i simply dont have a clue. The code below is not mine but an example i found, the key thing in hashtables means i cant do it like this i guess. public class Comparator implements Comparable<Name> { private final String firstName, lastName; public void Name(String firstName, String lastName) { if (firstName == null || lastName == null) throw new NullPointerException(); this.firstName = firstName; this.lastName = lastName; } public String firstName() { return firstName; } public String lastName() { return lastName; } public boolean equals(Object o) { if (!(o instanceof Name)) return false; Name n = (Name)o; return n.firstName.equals(firstName) && n.lastName.equals(lastName); } public int hashCode() { return 31*firstName.hashCode() + lastName.hashCode(); } public String toString() { return firstName + " " + lastName; } public int compareTo(Name n) { int lastCmp = lastName.compareTo(n.lastName); return (lastCmp != 0 ? lastCmp : firstName.compareTo(n.firstName)); } }

    Read the article

  • WCF sending the same exception even if the service endpoint address is valid

    - by ALexr111
    Hi, I'm running into a really strange problem with WCF. I need to implement some recovery behavior for WCF service if not reachable endpoint IP address received or service can not bind. The flow is simple if the application fail on exception on service creation it terminate it and request from user another IP address and perform another attempt to create the service. (The code snippet below). If the address is not valid I get "A TCP error (10049: The requested address is not valid in its context) occurred while listening on IP Endpoint=.121.10.11.11" exception, but for any reason if I try the second attempt with valid address I've got the same exception with wrong IP address from previous attempt. Here is a code: ServiceHost service = null; try { Uri[] uris = { new Uri(Constants.PROTOCOL + "://" + address + ":" + port) }; service = new ServiceHost(typeof(IRemoteService), uris); NetTcpBinding tcpBinding = WcfTcpRemoteServicesManager.LessLimitedNewNetTcpBinding(int.MaxValue, int.MaxValue, int.MaxValue); ServiceEndpoint ep = service.AddServiceEndpoint(implementedContract.FullName, tcpBinding, serviceName); var throttle = service.Description.Behaviors.Find<ServiceThrottlingBehavior>(); if (throttle == null) { throttle = new ServiceThrottlingBehavior { MaxConcurrentCalls = Constants.MAX_CONCURRENT_CALLS, MaxConcurrentSessions = Constants.MAX_CONCURRENT_SESSIONS, MaxConcurrentInstances = Constants.MAX_CONCURRENT_INSTANCES }; service.Description.Behaviors.Add(throttle); } service.Open(); } catch (Exception e) { _debugLog.WriteLineMessage( "Failed to open or create service exception. Exception message:" + e.Message); if (service!=null) { try { service.Close(); } catch (Exception) { service.Abort(); service.Close(); throw e; } } } Thanks

    Read the article

  • Objective-C classes, pointers to primitive types, etc.

    - by Toby Wilson
    I'll cut a really long story short and give an example of my problem. Given a class that has a pointer to a primitive type as a property: @interface ClassOne : NSObject { int* aNumber } @property int* aNumber; The class is instantiated, and aNumber is allocated and assigned a value, accordingly: ClassOne* bob = [[ClassOne alloc] init]; bob.aNumber = malloc(sizeof(int)); *bob.aNumber = 5; It is then passed, by reference, to assign the aNumber value of a seperate instance of this type of class, accordingly: ClassOne* fred = [[ClassOne alloc] init]; fred.aNumber = bob.aNumber; Fred's aNumber pointer is then freed, reallocated, and assigned a new value, for example 7. Now, the problem I'm having; Since Fred has been assigned the same pointer that Bob had, I would expect that Bob's aNumber will now have a value of 7. It doesn't, because for some reason it's pointer was freed, but not reassigned (it is still pointing to the same address it was first allocated which is now freed). Fred's pointer, however, has the allocated value 7 in a different memory location. Why is it behaving like this? What am I minsunderstanding? How can I make it work like C++ does?

    Read the article

  • C++ behavior of for loops vs. while loops

    - by kjh
    As far as I understand, when you write a for-loop similar to this one for (int i = 0; i < SOME_NUM; i++) { if (true) do_something(); else do_something_else(); } The time complexity of this operation is mostly affected by the if (true) statement because the for-loop iterations don't actually involve any comparisons of i to SOME_NUM, the compiler will just essentially run the code inside the for-loop SOME_NUM times. Please correct me if I am wrong. However if this is correct, then how do the following nested for-loops behave? for (int i = 0; i < SOME_NUM; i++) { for (int j = 0; j < i; j++) { do_something(); } } The j in the inner for-loop is now upper bound by i, a value that changes every time the loop restarts. How will the compiler compile this? Do these nested for-loops essentially behave like a for-loop with while-loop inside of it? If you're writing an algorithm that uses nested for-loops where the inner counting variable depends on the outer counting variable should you be concerned about what this will do to the complexity of your algorithm?

    Read the article

  • Boost.Program_options fixed number of tokens

    - by kloffy
    Boost.Program_options provides a facility to pass multiple tokens via command line arguments as follows: std::vector<int> nums; po::options_description desc("Allowed options"); desc.add_options() ("help", "Produce help message.") ("nums", po::value< std::vector<int> >(&nums)->multitoken(), "Numbers.") ; po::variables_map vm; po::store(po::parse_command_line(argc, argv, desc), vm); po::notify(vm); However, what is the preferred way of accepting only a fixed number of arguments? The only solution I could come is to manually assign values: int nums[2]; po::options_description desc("Allowed options"); desc.add_options() ("help", "Produce help message.") ("nums", "Numbers.") ; po::variables_map vm; po::store(po::parse_command_line(argc, argv, desc), vm); if (vm.count("nums")) { // Assign nums } This feels a bit clumsy. Is there a better solution?

    Read the article

  • spring 3 AOP anotated advises

    - by Art79
    Trying to figure out how to Proxy my beans with AOP advices in annotated way. I have a simple class @Service public class RestSampleDao { @MonitorTimer public Collection<User> getUsers(){ .... return users; } } i have created custom annotation for monitoring execution time @Target({ ElementType.METHOD, ElementType.TYPE }) @Retention(RetentionPolicy.RUNTIME) public @interface MonitorTimer { } and advise to do some fake monitoring public class MonitorTimerAdvice implements MethodInterceptor { public Object invoke(MethodInvocation invocation) throws Throwable{ try { long start = System.currentTimeMillis(); Object retVal = invocation.proceed(); long end = System.currentTimeMillis(); long differenceMs = end - start; System.out.println("\ncall took " + differenceMs + " ms "); return retVal; } catch(Throwable t){ System.out.println("\nerror occured"); throw t; } } } now i can use it if i manually proxy the instance of dao like this AnnotationMatchingPointcut pc = new AnnotationMatchingPointcut(null, MonitorTimer.class); Advisor advisor = new DefaultPointcutAdvisor(pc, new MonitorTimerAdvice()); ProxyFactory pf = new ProxyFactory(); pf.setTarget( sampleDao ); pf.addAdvisor(advisor); RestSampleDao proxy = (RestSampleDao) pf.getProxy(); mv.addObject( proxy.getUsers() ); but how do i set it up in Spring so that my custom annotated methods would get proxied by this interceptor automatically? i would like to inject proxied samepleDao instead of real one. Can that be done without xml configurations? i think should be possible to just annotate methods i want to intercept and spring DI would proxy what is necessary. or do i have to use aspectj for that? would prefere simplest solution :- ) thanks a lot for help!

    Read the article

  • C# unaccurate timer?

    - by Ivan
    Hi there, I'm developing an application and I need to get the current date from a server (it differs from the machine's date). I receive the date from the server and with a simple Split I create a new DateTime: globalVars.fec = new DateTime(DateTime.Now.Year, DateTime.Now.Month, DateTime.Now.Day, int.Parse(infoHour[0]), int.Parse(infoHour[1]), int.Parse(infoHour[2])); globalVars is a class and fec is a public static variable so that I can access it anywhere in the application (bad coding I know...). Now I need to have a timer checking if that date is equal to some dates I have stored in a List and if it is equal I just call a function. List<DateTime> fechas = new List<DateTime>(); Before having to obtain the date from a server I was using computer's date, so to check if the dates matched I was using this: private void timerDatesMatch_Tick(object sender, EventArgs e) { DateTime tick = DateTime.Now; foreach (DateTime dt in fechas) { if (dt == tick) { //blahblah } } } Now I have the date from the server so DateTime.Now can't be used here. Instead I have created a new timer with Interval=1000 and on tick I'm adding 1 second to globalVars.fec using: globalVars.fec = globalVars.fec.AddSeconds(1); But the clock isn't accurate and every 30 mins the clock loses about 30 seconds. Is there another way of doing what I'm trying to do? I've thought about using threading.timer instead but I need to have access to other threads and non-static functions. Thanks in advance, Ivan

    Read the article

  • Javamail read multipart emails

    - by Hectai
    Hey! My code is below, and the problem is that some of the emails i get from my POP3 account cannot be read, but with a simple unix email client it can be. It would be very helpful if you can find me what the problem is, or give me some advices. ps.: yes, i have read the tutorials already. String[] messageText = new String[500]; Store store = session.getStore("pop3"); store.connect(host, username, password); Folder inbox = store.getFolder("INBOX"); inbox.open(Folder.READ_ONLY); Message[] messages = inbox.getMessages(); for(int i = 0; i < inbox.getMessageCount() ; i++) { Message m = messages[i]; Object o = m.getContent(); if (o instanceof String) messageText[i] = (String)o; else if(o instanceof Multipart) { Multipart mp = (Multipart)o; int count = mp.getCount(); for(int j = 0; j < count; j++) { BodyPart b = mp.getBodyPart(j); String disposition = b.getDisposition(); if (disposition != null && disposition.equals(BodyPart.ATTACHMENT))) { DataHandler handler = b.getDataHandler(); messageText[i] += "file name : " + handler.getName(); } else { messageText[i] += b.getContent(); } } } } store.close(); } catch(Exception ex) { notif("Failure - " + ex.getMessage()); }

    Read the article

  • why i add more insignificant code but cost less time

    - by user3714382
    i write a method and when i add some insignificant code it works faster, like these : array[1]=array[1]; array[0]=array[0]; array[3]=array[3]; array[2]=array[2]; i use double t=System.currentTimeMillis(); at first to record the time. then call the method and use System.out.println(System.currentTimeMillis()-t); in the end. when i delete the code (array[1]=array[1];...) the cost time is 1035.0 ms,but if i add these code, the cost time become 898.0ms. here is my method and my code. PS:this method is use for the game 2048, exp: {2,2,2,2} trans to {0,0,4,4} static void toRight2(int[] array){ if (array[2]==array[3] ) { array[3]=array[2]*2; if (array[0]==array[1]) { array[2]=array[1]*2; array[0]=0; array[1]=0; }else { array[2]=array[1]; array[1]=array[0]; array[0]=0; } } else{ if (array[0]==array[1]) { array[1]=array[1]*2; array[0]=0; array[3]=array[3]; array[2]=array[2]; }else { array[1]=array[1];//delete this cost more time array[0]=array[0];//delete this cost more time array[3]=array[3];//delete this cost more time array[2]=array[2];//delete this cost more time } } } public static void main(String[] args) { double t=System.currentTimeMillis(); int[] array={1,2,3,3}; for (int j = 2; j <400*1000000; j++) { toRight2(array); } System.out.println(System.currentTimeMillis()-t); }

    Read the article

  • C# Working with Locking and Threads

    - by aherrick
    Work on this small test application to learn threading/locking. I have the following code, I would think that the line should only write to console once. However it doesn't seem to be working as expected. Any thoughts on why? What I'm trying to do is add this Lot object to a List, then if any other threads try and hit that list, it would block. Am i completely misusing lock here? class Program { static void Main(string[] args) { int threadCount = 10; //spin up x number of test threads Thread[] threads = new Thread[threadCount]; Work w = new Work(); for (int i = 0; i < threadCount; i++) { threads[i] = new Thread(new ThreadStart(w.DoWork)); } for (int i = 0; i < threadCount; i++) { threads[i].Start(); } // don't let the console close Console.ReadLine(); } } public class Work { List<Lot> lots = new List<Lot>(); private static readonly object thisLock = new object(); public void DoWork() { Lot lot = new Lot() { LotID = 1, LotNumber = "100" }; LockLot(lot); } private void LockLot(Lot lot) { // i would think that "Lot has been added" should only print once? lock (thisLock) { if(!lots.Contains(lot)) { lots.Add(lot); Console.WriteLine("Lot has been added"); } } } }

    Read the article

  • flexible length struct array inside another struct using C

    - by renz
    Hi I am trying to use C to implement a simple struct: 2 boxes, each contains different number of particles; the exact number of particles are passed in main(). I wrote the following code: typedef struct Particle{ float x; float y; float vx; float vy; }Particle; typedef struct Box{ Particle p[]; }Box; void make_box(Box *box, int number_of_particles); int main(){ Box b1, b2; make_box(&b1, 5); //create a box containing 5 particles make_box(&b2, 10); //create a box containing 10 particles } I've tried to implement make_box with the following code void make_box(struct Box *box, int no_of_particles){ Particle po[no_of_particles]; po[0].x = 1; po[1].x = 2; //so on and so forth... box->p = po; } It's always giving me "invalid use of flexible array member". Greatly appreciated if someone can shed some light on this.

    Read the article

  • MATLAB Builder NE (.NET Assembly) Data type question

    - by Brett
    Hi coders, I am using MATLAB Builder NE (MATLAB's integrated .NET assmebly builder), but I am having an issue with data types. I have compiled a small, very simple, function in matlab and build it for .NET. I am able to call the namespace and even the function just fine. However, my function returns a value, and MATLAB defaults to returning it as an "object[]" data type. However, I know that the value is an integer, but I can't figure out how to cast it. My MATLAB function looks like this: function addValue = Myfunction(value1, value2) addValue=value1+value2; end Pretty simple right? And then in .NET I can call it as: xClass.addValue (1, 3, 4); where xClass is the name of the MATLAB built class but when I try: int x = xClass.addValue (1, 3, 4); C# errors out. Typical .NET casting (int) doesn't work. The compiler states it cannot convert object[] to int. Does anyone have experience with the .NET builder in MATLAB that can help me with this? It is really throwing me for a loop. I have scanned through most of the MATLAB BUILDER doc (484 pages!) with zero help. Thank you, Brett

    Read the article

  • AutoCompleteTextView displays 'android.database.sqlite.SQLiteCursor@'... after making selection

    - by user244190
    I am using the following code to set the adapter (SimpleCursorAdapter) for an AutoCompleteTextView mComment = (AutoCompleteTextView) findViewById(R.id.comment); Cursor cComments = myAdapter.getDistinctComments(); scaComments = new SimpleCursorAdapter(this,R.layout.auto_complete_item,cComments,new String[] {DBAdapter.KEY_LOG_COMMENT},new int[]{R.id.text1}); mComment.setAdapter(scaComments); auto_complete_item.xml <?xml version="1.0" encoding="utf-8"?> <TextView xmlns:android="http://schemas.android.com/apk/res/android" android:id="@+id/text1" android:layout_width="wrap_content" android:layout_height="wrap_content"/> and thi is the xml for the actual control <AutoCompleteTextView android:id="@+id/comment" android:hint="@string/COMMENT" android:layout_width="fill_parent" android:layout_height="wrap_content" android:textSize="18dp"/> The dropdown appears to work correctly, and shows a list of items. When I make a selection from the list I get a sqlite object ('android.database.sqlite.SQLiteCursor@'... ) in the textview. Anyone know what would cause this, or how to resolve this? thanks Ok I am able to hook into the OnItemClick event, but the TextView.setText() portion of the AutoCompleteTextView widget is updated after this point. The OnItemSelected() event never gets fired, and the onNothingSelected() event gets fired when the dropdown items are first displayed. mComment.setOnItemClickListener( new OnItemClickListener() { @Override public void onItemClick(AdapterView<?> arg0, View arg1, int arg2, long arg3) { // TODO Auto-generated method stub SimpleCursorAdapter sca = (SimpleCursorAdapter) arg0.getAdapter(); String str = getSpinnerSelectedValue(sca,arg2,"comment"); TextView txt = (TextView) arg1; txt.setText(str); Toast.makeText(ctx, "onItemClick", Toast.LENGTH_SHORT).show(); } }); mComment.setOnItemSelectedListener(new OnItemSelectedListener() { @Override public void onItemSelected(AdapterView<?> arg0, View arg1, int arg2, long arg3) { Toast.makeText(ctx, "onItemSelected", Toast.LENGTH_SHORT).show(); } @Override public void onNothingSelected(AdapterView<?> arg0) { // TODO Auto-generated method stub Toast.makeText(ctx, "onNothingSelected", Toast.LENGTH_SHORT).show(); } }); Anyone alse have any ideas on how to override the updating of the TextView? thanks patrick

    Read the article

  • Why is my Android app camera preview running out of memory on my AVD?

    - by Bryan
    I have yet to try this on an actual device, but expect similar results. Anyway, long story short, whenever I run my app on the emulator, it crashes due to an out of memory exception. My code really is essentially the same as the camera preview API demo from google, which runs perfectly fine. The only file in the app (that I created/use) is as below- package berbst.musicReader; import java.io.IOException; import android.app.Activity; import android.content.Context; import android.hardware.Camera; import android.os.Bundle; import android.view.SurfaceHolder; import android.view.SurfaceView; /********************************* * Music Reader v.0001 * Still VERY under construction. * @author Bryan * *********************************/ public class MusicReader extends Activity { private MainScreen main; @Override //Begin activity public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); main = new MainScreen(this); setContentView(main); } class MainScreen extends SurfaceView implements SurfaceHolder.Callback { SurfaceHolder sHolder; Camera cam; MainScreen(Context context) { super(context); //Set up SurfaceHolder sHolder = getHolder(); sHolder.addCallback(this); sHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS); } public void surfaceCreated(SurfaceHolder holder) { // Open the camera and start viewing cam = Camera.open(); try { cam.setPreviewDisplay(holder); } catch (IOException exception) { cam.release(); cam = null; } } public void surfaceDestroyed(SurfaceHolder holder) { // Kill all our crap with the surface cam.stopPreview(); cam.release(); cam = null; } public void surfaceChanged(SurfaceHolder holder, int format, int w, int h) { // Modify parameters to match size. Camera.Parameters params = cam.getParameters(); params.setPreviewSize(w, h); cam.setParameters(params); cam.startPreview(); } } }

    Read the article

  • ListField with image In Blackberry JDE

    - by Karthick
    I use the following code to retrieve image from the phone or SDCard and I use that image in to my ListField. It gives the output but it takes very Long time to produce the screen. How to solve this problem ?? Can any one help me?? Thanks in advance!!! String text = fileholder.getFileName(); try{ String path="file:///"+fileholder.getPath()+text; //path=”file:///SDCard/BlackBerry/pictures/image.bmp” InputStream inputStream = null; //Get File Connection FileConnection fileConnection = (FileConnection) Connector.open(path); inputStream = fileConnection.openInputStream(); ByteArrayOutputStream baos = new ByteArrayOutputStream(); int j = 0; while((j=inputStream.read()) != -1) { baos.write(j); } byte data[] = baos.toByteArray(); inputStream.close(); fileConnection.close(); //Encode and Resize image EncodedImage eImage = EncodedImage.createEncodedImage(data,0,data.length); int scaleFactorX = Fixed32.div(Fixed32.toFP(eImage.getWidth()), Fixed32.toFP(180)); int scaleFactorY = Fixed32.div(Fixed32.toFP(eImage.getHeight()), Fixed32.toFP(180)); eImage=eImage.scaleImage32(scaleFactorX, scaleFactorY); Bitmap bitmapImage = eImage.getBitmap(); graphics.drawBitmap(0, y+1, 40, 40,bitmapImage, 0, 0); graphics.drawText(text, 25, y,0,width); } catch(Exception e){}

    Read the article

  • Help with JPQL query

    - by Robert
    I have to query a Message that is in a provided list of Groups and has not been Deactivated by the current user. Here is some pseudo code to illustrate the properties and entities: class Message { private int messageId; private String messageText; } class Group { private String groupId; private int messageId; } class Deactivated { private String userId; private int messageId; } Here is an idea of what I need to query for, it's the last AND clause that I don't know how to do (I made up the compound NOT IN expression). Filtering the deactivated messages by userId can result in multiple messageIds, how can I check if that subset of rows does not contain the messageId? SELECT msg FROM Message msg, Group group, Deactivated unactive WHERE group.messageId = msg.messageId AND (group.groupId = 'groupA' OR group.groupId = 'groupB' OR ...) AND ('someUserId', msg.messageId) NOT IN (unactive.userId, unactive.messageId) I don't know the number of groupIds ahead of time -- I receive them as a Collection<String> so I'll need to traverse them and add them to the JPQL dynamically.

    Read the article

  • How to draw an overlay on a SurfaceView used by Camera on Android?

    - by Cristian Castiblanco
    I have a simple program that draws the preview of the Camera into a SurfaceView. What I'm trying to do is using the onPreviewFrame method, which is invoked each time a new frame is drawn into the SurfaceView, in order to execute the invalidate method which is supposed to invoke the onDraw method. In fact, the onDraw method is being invoked, but nothing there is being printed (I guess the camera preview is overwriting the text I'm trying to draw). This is a simplify version of the SurfaceView subclass I have: public class Superficie extends SurfaceView implements SurfaceHolder.Callback { SurfaceHolder mHolder; public Camera camera; Superficie(Context context) { super(context); mHolder = getHolder(); mHolder.addCallback(this); mHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS); } public void surfaceCreated(final SurfaceHolder holder) { camera = Camera.open(); try { camera.setPreviewDisplay(holder); camera.setPreviewCallback(new PreviewCallback() { public void onPreviewFrame(byte[] data, Camera arg1) { invalidar(); } }); } catch (IOException e) {} } public void invalidar(){ invalidate(); } public void surfaceChanged(SurfaceHolder holder, int format, int w, int h) { Camera.Parameters parameters = camera.getParameters(); parameters.setPreviewSize(w, h); camera.setParameters(parameters); camera.startPreview(); } @Override public void draw(Canvas canvas) { super.draw(canvas); // nothing gets drawn :( Paint p = new Paint(Color.RED); canvas.drawText("PREVIEW", canvas.getWidth() / 2, canvas.getHeight() / 2, p); } }

    Read the article

  • Typedef and Struct in C and H files

    - by Leif Andersen
    I've been using the following code to create various struct, but only give people outside of the C file a pointer to it. (Yes, I know that they could potentially mess around with it, so it's not entirely like the private keyword in Java, but that's okay with me). Anyway, I've been using the following code, and I looked at it today, and I'm really surprised that it's actually working, can anyone explain why this is? In my C file, I create my struct, but don't give it a tag in the typedef namespace: struct LABall { int x; int y; int radius; Vector velocity; }; And in the H file, I put this: typedef struct LABall* LABall; I am obviously using #import "LABall.h" in the c file, but I am NOT using #import "LABall.c" in the header file, as that would defeat the whole purpose of a separate header file. So, why am I able to create a pointer to the LABall* struct in the H file when I haven't actually included it? Does it have something to do with the struct namespace working accross files, even when one file is in no way linked to another? Thank you.

    Read the article

  • Ascii Bytes Array To Int32 or Double

    - by Michael Covelli
    I'm re-writing alibrary with a mandate to make it totally allocation free. The goal is to have 0 collections after the app's startup phase is done. Previously, there were a lot of calls like this: Int32 foo = Int32.Parse(ASCIIEncoding.ASCII.GetString(bytes, start, length)); Which I believe is allocating a string. I couldn't find a C# library function that would do the same thing automatically. I looked at the BitConverter class, but it looks like that is only if your Int32 is encoded with the actual bytes that represent it. Here, I have an array of bytes representing Ascii characters that represent an Int32. Here's what I did public static Int32 AsciiBytesToInt32(byte[] bytes, int start, int length) { Int32 Temp = 0; Int32 Result = 0; Int32 j = 1; for (int i = start + length - 1; i >= start; i--) { Temp = ((Int32)bytes[i]) - 48; if (Temp < 0 || Temp > 9) { throw new Exception("Bytes In AsciiBytesToInt32 Are Not An Int32"); } Result += Temp * j; j *= 10; } return Result; } Does anyone know of a C# library function that already does this in a more optimal way? Or an improvement to make the above run faster (its going to be called millions of times during the day probably). Thanks!

    Read the article

  • class array variable initialization error in java

    - by trinity
    Hello I am trying to write a java program that reads an input file consisting of URLs , extracts tokens from these , and accordingly insert into : class Tokens { String name ; int count ; } , where name is the name of every unique token , and count is the frequency of that token in the URLs file..I've written the following code : import java.io.*; import java.net.*; public class Main { static class Tokens { String name; int count; } public static void main(String[] args) { String url_str,host; String htokens[]; URL url; boolean found=false; Tokens t[]; int i,j,k; try { File f=new File("urlfile.txt"); FileReader fr=new FileReader(f); BufferedReader br=new BufferedReader(fr); while((url_str=br.readLine())!=null) { url=new URL(url_str); host=url.getHost(); htokens=host.split("\\.|\\-|\\_|\\~|[0-9]"); for(i=0;i<htokens.length;i++) { if(!htokens[i].isEmpty()) { for(j=0;j<t.length;j++) { if(htokens[i].equals(t[j].name)) { t[j].count++; found=true; } } if(!found) { k=t.length; t[k].name=htokens[i]; t[k].count=1; } } } System.out.println(t.length + "class tokens :"); for(i=0;i<t.length;i++) { System.out.println("name :"+t[i].name+" frequency :"+t[i].count); } } br.close(); fr.close(); } catch(Exception e) { System.out.println(e); } } } But when i run it , it says : variable t not initialized.. What should i do to set it right ?

    Read the article

  • Scalaz: request for use case

    - by oxbow_lakes
    This question isn't meant as flame-bait! As it might be apparent, I've been looking at Scalaz recently. I'm trying to understand why I need some of the functionality that the library provides. Here's something: import scalaz._ import Scalaz._ type NEL[A] = NonEmptyList[A] val NEL = NonEmptyList I put some println statements in my functions to see what was going on (aside: what would I have done if I was trying to avoid side effects like that?). My functions are: val f: NEL[Int] => String = (l: NEL[Int]) => {println("f: " + l); l.toString |+| "X" } val g: NEL[String] => BigInt = (l: NEL[String]) => {println("g: " + l); BigInt(l.map(_.length).sum) } Then I combine them via a cokleisli and pass in a NEL[Int] val k = cokleisli(f) =>= cokleisli(g) println("RES: " + k( NEL(1, 2, 3) )) What does this print? f: NonEmptyList(1, 2, 3) f: NonEmptyList(2, 3) f: NonEmptyList(3) g: NonEmptyList(NonEmptyList(1, 2, 3)X, NonEmptyList(2, 3)X, NonEmptyList(3)X) RES: 57 The RES value is the character count of the (String) elements in the final NEL. Two things occur to me: How could I have known that my NEL was going to be reduced in this manner from the method signatures involved? (I wasn't expecting the result at all) What is the point of this? Can a reasonably simple and easy-to-follow use case be distilled for me? This question is a thinly-veiled plea for some lovely person like retronym to explain how this powerful library actually works.

    Read the article

  • high performance hibernate insert

    - by luke
    I am working on a latency sensitive part of an application, basically i will receive a network event transform the data and then insert all the data into the DB. After profiling i see that basically all my time is spent trying to save the data. here is the code private void insertAllData(Collection<Data> dataItems) { long start_time = System.currentTimeMillis(); long save_time = 0; long commit_time = 0; Transaction tx = null; try { Session s = HibernateSessionFactory.getSession(); s.setCacheMode(CacheMode.IGNORE); s.setFlushMode(FlushMode.NEVER); tx = s.beginTransaction(); for(Data data : dataItems) { s.saveOrUpdate(data); } save_time = System.currentTimeMillis(); tx.commit(); s.flush(); s.clear(); } catch(HibernateException ex) { if(tx != null) tx.rollback(); } commit_time = System.currentTimeMillis(); System.out.println("Save: " + (save_time - start_time)); System.out.println("Commit: " + (commit_time - save_time)); System.out.println(); } The size of the collection is always less than 20. here is the timing data that i see: Save: 27 Commit: 9 Save: 27 Commit: 9 Save: 26 Commit: 9 Save: 36 Commit: 9 Save: 44 Commit: 0 This is confusing to me. I figure that the save should be quick and all the time should be spent on commit. but clearly I'm wrong. I have also tried removing the transaction (its not really necessary) but i saw worse times... I have set hibernate.jdbc.batch_size=20... i need this operation to be as fast as possible, ideally there would only be one roundtrip to the database. How can i do this?

    Read the article

  • Array of ArrayList Java

    - by David Bobo
    Hi, I am creating an PriorityQueue with multiple queues. I am using an Array to store the multiple ArrayLists that make up my different PriorityQueues. Here is what I have for my constructor so far: ArrayList<ProcessRecord> pq; ArrayList[] arrayQ; MultiList(){ arrayQ = new ArrayList[9]; pq = new ArrayList<ProcessRecord>(); } The problem comes when I am trying to get the size of the entire array, that is the sum of the sizes of each ArrayList in the array. public int getSize(){ int size = 0; for(int i = 1; i <=9; i++){ size = size + this.arrayQ[i].size(); } return size; } is not seeming to work. Am I declaring the Array of ArrayList correctly? I keep getting an error saying that this.arrayQ[i].size() is not a method. (the .size() being the problem) Thanks for any help! David

    Read the article

< Previous Page | 404 405 406 407 408 409 410 411 412 413 414 415  | Next Page >