Java data structure

H!!
I am looking for a good on line tutorial about
Java Data structure. please help me.
peter

Hi again!
This is my first time that I want to learn
about : stack, list, linked list, queue, tree..
. whit Java.Stack, list, linked list, queue and trees are data structures which are the same independent of the programming language. They are more of a concept.
The best way to find more information is to google on the structure you want more information on. Here's an explanation on how a linked list works:
http://encyclopedia.lockergnome.com/s/b/Linked_list
/Kaj

Similar Messages

Java Data Structures Book

Hi all, I'm looking for a Data Structures and Algorithmitmics book in Java with the answers to many of the exercises.
Any idea?
Thanks

Hi all, I'm looking for a Data Structures and Algorithmitmics
book in Java with the answers to many of the exercises."Data Structures and Algorithmitmics book in Java " seems like a pretty generic name. Who is the author?
If the book is used for a university course, the publisher may only sell the answer book to authorized clients, e.g. the university bookstore. So you would have to ask them, but then they will ask if the request is on behalf of the professor. If you said you were a graduate student and a TA for the course, and on request from the professor you are asking to place an order, and to email/call you to pick it up for the professor then you might be able to get a copy. Or you could ask the professor for a letter and explain to him that you really need a copy of the answers. However, if the questions in the book are used as part of the grading questions, there is very little chance.
You could also try searching online, or ask the TA for help. In my experience, TAs have 1 or 2 hours a week where anyone can drop in and ask questions. Take advantage of that.
then you might be a

How do we do TypeMapping for Vector, Hashtable, or any java data structure in RPC?

I tried to implement a dynamic Client (RPC) however I got the following Error
when I ran the program.
Exception in thread "main" java.lang.ClassCastException
Here is my part of code
//create service
Service service = factory.createService( serviceName );
TypeMappingRegistry registry = service.getTypeMappingRegistry();
TypeMapping mapping = registry.getTypeMapping(
SOAPConstants.URI_NS_SOAP_ENCODING );
mapping.register( Vector.class,
          new QName( targetNamespace, "Vector" ),
          new language_builtins.util.VectorCodec(),                         new language_builtins.util.VectorCodec()
//create call
Call call = service.createCall();
//set port and operation name
call.setPortTypeName( portName );
call.setOperationName( operationName );
call.addParameter( "string",new QName( "http://www.w3.org/2001/XMLSchema","string"
ParameterMode.IN);
call.addParameter( "intVal",new QName( "http://www.w3.org/2001/XMLSchema","int"
ParameterMode.IN);
call.setReturnType( new QName( targetNamespace, "Vector" ) );
Vector v = (Vector) call.invoke(new Object[] {"Hi", new Integer(1) });
Any help on this will be greatly appreciated.
december

Hey December,
I looked at your WSDL, but it doesn't give any hint of what you are putting in
the LinkedList or Vector. All it says is that an "array of anything" (basically,
an array of java.lang.Object) is returned from the buy and sell web service operations.
Surely there is some complexType (i.e. TradeResults, TransactionResults, etc.)
that you want to return here. A java.util.LinkedList object is not a complexType.
It's a generic container object which is specific to the Java programming language.
Same with the java.util.Vector. Web services are programming language independent,
so a .NET client (written in C# or VB code) wouldn't really know how to deal with
a java.util.LinkedList, right? Web services do not transfer objects back and forth,
just XML. This means that the buy web service operation doesn't really return
a java.util.Vector over an HTTP connection. It returns an XML representation of
the "hierarchical state" associated with the complexTypes you put in the Vector,
inside the "service implementation" code on the server side.
What you want to do is use the WSDL "to describe" the data types your web services
accepts and returns. To do this, you'll need to define complexTypes to put in
the array of complex types that is returned. If you leave things as they are,
I don't think you'll ever be able to determine what's in "the Vector". Again,
this is because web services don't transfer objects back and forth, just the state
that is used to instanciate them :-)
HTH,
Mike Wooten
"december_i" <[email protected]> wrote:
>
>
>
Hi Michael Wooten,
When I printed out the Object class name, it returned this "[Ljava.lang.Object;"
So I tried this way again.
Object[] obj = (Object[])call.invoke(new Object[] {"Hi", new Integer(1)});
System.out.println("obj[0].getClass().getName()=" + obj[0].getClass().getName());
At this time, it printed this "java.lang.String".
I guess web services is not returning Vector.
I attached my WSDL file.
I really appreciated your help.
best wishes,
December
"Michael Wooten" <[email protected]> wrote:
If you are still getting a class cast exception, maybe it's becausethe
web service
isn't returning a Vector.
Change the following line in your client code:
Vector v = (Vector) call.invoke(new Object[] {"Hi", new Integer(1)});
to:
Object obj = call.invoke(new Object[] {"Hi", new Integer(1)});
System.out.println("obj.getClass().getName()=" + obj.getClass().getName());
That way you can see what the return type is :-)
You might want to post the WSDL and remote interface of the web service
you are
trying to call also.
Regards,
Mike Wooten
"december_i" <[email protected]> wrote:
Hi Mike Wooten,
Thanks for pointing out my mistake.
However I'm still getting same error. I know i'm gettting this error
because of
return type "Vector". But I don't know what I did wrong.
Does anybody have any sample example about TypeMapping for any datastructures?
Any help on this will be greatly appreciated.
December
"Michael Wooten" <[email protected]> wrote:
Hi December_i,
Your code is saying that the "Vector" type is in the target namespace
for your
web service. I don't think this is correct. Try this:
mapping.register(
java.util.Vector.class,
new QName("java:language_builtins.util", "Vector" ),
new language_builtins.util.VectorCodec(),
new language_builtins.util.VectorCodec()
call.setReturnType( new QName("java:language_builtins.util", "Vector"
HTH,
Mike Wooten
"december_i" <[email protected]> wrote:
I tried to implement a dynamic Client (RPC) however I got the following
Error
when I ran the program.
Exception in thread "main" java.lang.ClassCastException
Here is my part of code
//create service
Service service = factory.createService( serviceName );
TypeMappingRegistry registry = service.getTypeMappingRegistry();
TypeMapping mapping = registry.getTypeMapping(
SOAPConstants.URI_NS_SOAP_ENCODING
mapping.register( Vector.class,
          new QName( targetNamespace, "Vector" ),
          new language_builtins.util.VectorCodec(),                         new language_builtins.util.VectorCodec()
//create call
Call call = service.createCall();
//set port and operation name
call.setPortTypeName( portName );
call.setOperationName( operationName );
call.addParameter( "string",new QName( "http://www.w3.org/2001/XMLSchema","string"
ParameterMode.IN);
call.addParameter( "intVal",new QName( "http://www.w3.org/2001/XMLSchema","int"
ParameterMode.IN);
call.setReturnType( new QName( targetNamespace, "Vector" ) );
Vector v = (Vector) call.invoke(new Object[] {"Hi", new Integer(1)
Any help on this will be greatly appreciated.
december

Open ended data structure for retrieving SQL data

I have a flex project that reads data from a database and
sends it to my flex app to display in a chart. I need to do this in
Actionscript since I have to dynamically create different charts
based on the database definitions. Up til now, I have inserted the
data for each series into a separate
ArrayList(java)/ArrayCollection(flex) in this way:
BindingUtils.bindProperty(lineSeries, "dataProvider", series,
"pointList");
lineSeries.xField="point1";
lineSeries.yField="point2";
The series variable is a custom Actionscript/Java object
which contains an ArrayCollection called pointList. And the array
is made up of custom DataObjects with two fields, point1 &
point2.
But in the new paradigm, I'd basically like to create a big
array of arrays similar to a database table and then just point the
xField to one column, and the yField to another column. Anyway, it
seems like the problem is that my point1 and point2 in the current
implementation are variable names, but with this new dynamic
structure, I won't be able to create variables on the fly. So how
do I let flex know to look at column 3, for example for the yField?
The attached code is from the Flex documentation and is an example
of what I'd like to emulate (except I need to do it in
actionscript). I'd like to be able to select "month" or "amount",
etc. But coming from the Java side, there is no way for me to name
the array contained in each column.

I guess I wasn't clear enough. I am actually serializing a
java object and mapping it to an actionscript object via blazeDS. I
know about how the objects translate, for example for
ArrayCollections in flex, I use ArrayLists in java. The problem is
that I'm not sure how to get the associative aspects of the arrays
in flex into my java data structures in a way that will translate
to the way flex can define arrays, such as Month:"January".
It seems that in flex, you can create an Array and assign it
an element like {month:"January", amount:"450"} and it will create
an Object with variables for month and amount. But I don't know how
to do this on the fly in Java (or in Actionscript for that matter)
when I have no way of knowing beforehand how many variables my
object will need. Each series will need an x and y, though usually
the x will be dates which are the same for each series. So if I had
10 series sharing an axis, I'd need 11 variables in my object-
date, series1, series 2...series 10.

Data structures

what is the best data structure to use for keeping four different data
bases interconnected and updated about the changes in one another at all times while not using an existing java data structure but by implementing one by one's own?
thanx .

Data structure? Coherency Protocol!
What a question anyways? If you want to implement your own, the best thing to do is to get going ...

Is there a Java API for Tree data structure?

Hi,
I am wondering is there any Java API to work on Tree based data structure.
I could read in some forums / sites that teach me how to create tree based objects using collection.
But I wanted to know is there any core java API that can be used directly for tree based operations. (like binary tree or other type of trees)
Please comment on this doubt.

Headed using google and other stuff not found one.
Suggestion: Why not start building the one, its a good idea to do that, isn't it.

Data Structures and Algorithms in java book

Hi guys,
I want to know a good book which is good for Data Structures and Algorithms in java. I am good at Core java but a beginner for Data Structures in Java. I am a little poor in Data Structures concepts.
Following are the books I have found on the net. Could you help me the choose the best outta them.
1. Data Structures and Algorithms in Java - Mitchell Waite
2. Data Structures in Java - Sandra Anderson
3. Fundamentals of OOP and Data Structures in Java - Richard Weiner & Lewis J. Pinson
4. Object Oriented Data Structures Using Java - Nell Dale, Daniel T. Joyce, Chip Weems

lieni wrote:
I good data structures book doesn't have to be language-specific.Thx DrLazlo, my speachYes.
The OP wrote:
I have access to these books and dont know which one to start with.What I meant is that you shouldn't narrow your search to insist that the book you choose have "Java" in the title.

How to access data structures in C dll from java thru JNI?

We have been given API's( collection of C Functions) from some vendor.
SDK from vendor consist of:
Libpga.DLL, Libpga.h,Libpga.lib, Along with that sample program Receiver.h (i don't know its written in C or C++), I guess .C stnads for C files?
Considering that I don't know C or C++ (Except that I can understand what that program is doing) & i have experience in VB6 and Java, In order to build interface based on this API, I have two option left, Use these dll either from VB or Java.
As far as I know, calling this DLL in VB requires all the data structures & methods to be declared in VB, I guess which is not the case with Java (? I'm not sure)
I experiemnted calling these function from Java through JNI, and I successfully did by writting wrapper dll. My question is whether I have to declare all the constants & data structures defined in libpga.h file in java, in order to use them in my java program??
Any suggesstion would be greatly appreciated,
Vini

1. There are generators around that claim to generate suitable wrappers, given some dll input. I suggest you search google. Try JACE, jni, wrapper, generator, .... Also, serach back through this forum, where there have been suggestions made.
2. In general, you will need to supply wrappers, and if you want to use data from the "C side" in java, then you will need java objects that hold the data.

Trees Data Structures in Java

Hi all !
Currently I�m developing a Java software that requires a Tree data structure. Searching through Java API I�ve found classes like TreeMap and TreeSet, but although these classes seens to use tree structure behind what they really provide are linear data structure, not a tree data structure. My question is if there is a public and free Java tree data structure that permits to do activities such as:
- Search for a particular node (efficiently)
- Insert children to any node
- Maintain one Object in each node
Simple like this ! It must have something like this in Java, but I just can�t find it and I�m just too lazy to implement it :) ! Anyone can help me ?
Thanks in advance !

Mel,
I�ve seen javax.swing.tree.TreeModel and its seens more like an implementation of Control in swing MVC (Model Vision Control) swing paradigm for JTree. It has listeners generated for manipulation events for example. It uses javax.swing.tree.DefaultMutableTreeNode for its nodes, and maybe I could use this class for the nodes of my tree since it has many useful operations. However still I miss a node searching operation that this class doesn�t have.
Yes my problem is a simple Tree, but it is simple now and it might become much more complex, demanding more operations on the tree and specially efficient searching algorithms. Thats why I�m looking for a complete solution and I prefer something that is already done and well tested :) !
Thanks for your tip !

What Tree Data Structures does Java Include?

Hello,
I have been reading about several tree data structures like a binary search tree, self-balancing bst, minimum spanning tree, red-black tree, AVL tree, etc... Are there data structures in Java represent the various trees, or is implementation of the ds left to user?
Eric

"Java" can be termed the "Java Language". The language does not have trees.
In more general usage "Java" can refer to a standard, desktop, delivered VM which includes the standard Java API. The types that you are asking about would be found in the following package.
[http://java.sun.com/javase/6/docs/api/java/util/package-summary.html]
"Java" could also refer to any other commonly available implementations. In that case probably anything that can be implemented has been implemented somewhere. Googling works.

Difference speeds between Java�s data structures?

Hello,
I would appreciate to know, if there are any real efficiency differences between the data structures?
One of my programs using s Vector to store 50 thousand small class objects.
Adding to the vector seems quite slow, would anyone say the ArrayList/LinkedList is quicker. And the ArrayList/LinkedList are also quicker when looping through the objects again?
Cheers

ArrayList is basically the same as a Vector without the synchronization (and IIRC some slightly different default values). So if you don't need synchronization using an ArrayList is a sure, safe way to increase performance. Wether the gain is measurable depends on your problem. The question wether to use ArrayList or LinkedList depends mostly on how you access the values (do you need random access? do you just loop over them? do you need to insert values at the beginning or the middle?)

OC4J: marshalling does not recreate the same data structure onthe client

Hi guys,
I am trying to use OC4J as an EJB container and have come across the following problem, which looks like a bug.
I have a value object method that returns an instance of ArrayList with references to other value objects of the same class. The value objects have references to other value objects. When this structure is marshalled across the network, we expect it to be recreated as is but that does not happen and instead objects get duplicated.
Suppose we have 2 value objects: ValueObject1 and ValueObject2. ValueObject1 references ValueObject2 via its private field and the ValueObject2 references ValueObject1. Both value objects are returned by our method in an ArrayList structure. Here is how it will look like (number after @ represents an address in memory):
Object[0] = com.cramer.test.SomeVO@1
Object[0].getValueObject[0] = com.cramer.test.SomeVO@2
Object[1] = com.cramer.test.SomeVO@2
Object[1].getValueObject[0] = com.cramer.test.SomeVO@1
We would expect to see the same (except exact addresses) after marshalling. Here is what we get instead:
Object[0] = com.cramer.test.SomeVO@1
Object[0].getValueObject[0] = com.cramer.test.SomeVO@2
Object[1] = com.cramer.test.SomeVO@3
Object[1].getValueObject[0] = com.cramer.test.SomeVO@4
It can be seen that objects get unnecessarily duplicated â“ the instance of the ValueObject1 referenced by the ValueObject2 is not the same now as the instance that is referenced by the ArrayList instance.
This does not only break referential integrity, structure and consistency of the data but dramatically increases the amount of information sent across the network. The problem was discovered when we found that a relatively small but complicated structure that gets serialized into a 142kb file requires about 20Mb of network communication. All this extra info is duplicated object instances.
I have created a small test case to demonstrate the problem and let you reproduce it.
Here is RMITestBean.java:
package com.cramer.test;
import javax.ejb.EJBObject;
import java.util.*;
public interface RMITestBean extends EJBObject
public ArrayList getSomeData(int testSize) throws java.rmi.RemoteException;
public byte[] getSomeDataInBytes(int testSize) throws java.rmi.RemoteException;
Here is RMITestBeanBean.java:
package com.cramer.test;
import javax.ejb.SessionBean;
import javax.ejb.SessionContext;
import java.util.*;
public class RMITestBeanBean implements SessionBean
private SessionContext context;
SomeVO someVO;
public void ejbCreate()
someVO = new SomeVO(0);
public void ejbActivate()
public void ejbPassivate()
public void ejbRemove()
public void setSessionContext(SessionContext ctx)
this.context = ctx;
public byte[] getSomeDataInBytes(int testSize)
ArrayList someData = getSomeData(testSize);
try {
java.io.ByteArrayOutputStream byteOutputStream = new java.io.ByteArrayOutputStream();
java.io.ObjectOutputStream objectOutputStream = new java.io.ObjectOutputStream(byteOutputStream);
objectOutputStream.writeObject(someData);
objectOutputStream.flush();
System.out.println(" serialised output size: "+byteOutputStream.size());
byte[] bytes = byteOutputStream.toByteArray();
objectOutputStream.close();
byteOutputStream.close();
return bytes;
} catch (Exception e) {
System.out.println("Serialisation failed: "+e.getMessage());
return null;
public ArrayList getSomeData(int testSize)
// Create array of objects
ArrayList someData = new ArrayList();
for (int i=0; i<testSize; i++)
someData.add(new SomeVO(i));
// Interlink all the objects
for (int i=0; i<someData.size()-1; i++)
for (int j=i+1; j<someData.size(); j++)
((SomeVO)someData.get(i)).addValueObject((SomeVO)someData.get(j));
((SomeVO)someData.get(j)).addValueObject((SomeVO)someData.get(i));
// print out the data structure
System.out.println("Data:");
for (int i = 0; i<someData.size(); i++)
SomeVO tmp = (SomeVO)someData.get(i);
System.out.println("Object["+Integer.toString(i)+"] = "+tmp);
System.out.println("Object["+Integer.toString(i)+"]'s some number = "+tmp.getSomeNumber());
for (int j = 0; j<tmp.getValueObjectCount(); j++)
SomeVO tmp2 = tmp.getValueObject(j);
System.out.println(" getValueObject["+Integer.toString(j)+"] = "+tmp2);
System.out.println(" getValueObject["+Integer.toString(j)+"]'s some number = "+tmp2.getSomeNumber());
// Check the serialised size of the structure
try {
java.io.ByteArrayOutputStream byteOutputStream = new java.io.ByteArrayOutputStream();
java.io.ObjectOutputStream objectOutputStream = new java.io.ObjectOutputStream(byteOutputStream);
objectOutputStream.writeObject(someData);
objectOutputStream.flush();
System.out.println("Serialised output size: "+byteOutputStream.size());
objectOutputStream.close();
byteOutputStream.close();
} catch (Exception e) {
System.out.println("Serialisation failed: "+e.getMessage());
return someData;
Here is RMITestBeanHome:
package com.cramer.test;
import javax.ejb.EJBHome;
import java.rmi.RemoteException;
import javax.ejb.CreateException;
public interface RMITestBeanHome extends EJBHome
RMITestBean create() throws RemoteException, CreateException;
Here is ejb-jar.xml:
<?xml version = '1.0' encoding = 'windows-1252'?>
<!DOCTYPE ejb-jar PUBLIC "-//Sun Microsystems, Inc.//DTD Enterprise JavaBeans 2.0//EN" "http://java.sun.com/dtd/ejb-jar_2_0.dtd">
<ejb-jar>
<enterprise-beans>
<session>
<description>Session Bean ( Stateful )</description>
<display-name>RMITestBean</display-name>
<ejb-name>RMITestBean</ejb-name>
<home>com.cramer.test.RMITestBeanHome</home>
<remote>com.cramer.test.RMITestBean</remote>
<ejb-class>com.cramer.test.RMITestBeanBean</ejb-class>
<session-type>Stateful</session-type>
<transaction-type>Container</transaction-type>
</session>
</enterprise-beans>
</ejb-jar>
And finally the application that tests the bean:
package com.cramer.test;
import java.util.*;
import javax.rmi.*;
import javax.naming.*;
public class RMITestApplication
final static boolean HARDCODE_SERIALISATION = false;
final static int TEST_SIZE = 2;
public static void main(String[] args)
Hashtable props = new Hashtable();
props.put(Context.INITIAL_CONTEXT_FACTORY, "com.evermind.server.rmi.RMIInitialContextFactory");
props.put(Context.PROVIDER_URL, "ormi://lil8m:23792/alexei");
props.put(Context.SECURITY_PRINCIPAL, "admin");
props.put(Context.SECURITY_CREDENTIALS, "admin");
try {
// Get the JNDI initial context
InitialContext ctx = new InitialContext(props);
NamingEnumeration list = ctx.list("comp/env/ejb");
// Get a reference to the Home Object which we use to create the EJB Object
Object objJNDI = ctx.lookup("comp/env/ejb/RMITestBean");
// Now cast it to an InventoryHome object
RMITestBeanHome testBeanHome = (RMITestBeanHome)PortableRemoteObject.narrow(objJNDI,RMITestBeanHome.class);
// Create the Inventory remote interface
RMITestBean testBean = testBeanHome.create();
ArrayList someData = null;
if (!HARDCODE_SERIALISATION)
// ############################### Alternative 1 ##############################
// ## This relies on marshalling serialisation ##
someData = testBean.getSomeData(TEST_SIZE);
// ############################ End of Alternative 1 ##########################
} else
// ############################### Alternative 2 ##############################
// ## This gets a serialised byte stream and de-serialises it ##
byte[] bytes = testBean.getSomeDataInBytes(TEST_SIZE);
try {
java.io.ByteArrayInputStream byteInputStream = new java.io.ByteArrayInputStream(bytes);
java.io.ObjectInputStream objectInputStream = new java.io.ObjectInputStream(byteInputStream);
someData = (ArrayList)objectInputStream.readObject();
objectInputStream.close();
byteInputStream.close();
} catch (Exception e) {
System.out.println("Serialisation failed: "+e.getMessage());
// ############################ End of Alternative 2 ##########################
// Print out the data structure
System.out.println("Data:");
for (int i = 0; i<someData.size(); i++)
SomeVO tmp = (SomeVO)someData.get(i);
System.out.println("Object["+Integer.toString(i)+"] = "+tmp);
System.out.println("Object["+Integer.toString(i)+"]'s some number = "+tmp.getSomeNumber());
for (int j = 0; j<tmp.getValueObjectCount(); j++)
SomeVO tmp2 = tmp.getValueObject(j);
System.out.println(" getValueObject["+Integer.toString(j)+"] = "+tmp2);
System.out.println(" getValueObject["+Integer.toString(j)+"]'s some number = "+tmp2.getSomeNumber());
// Print out the size of the serialised structure
try {
java.io.ByteArrayOutputStream byteOutputStream = new java.io.ByteArrayOutputStream();
java.io.ObjectOutputStream objectOutputStream = new java.io.ObjectOutputStream(byteOutputStream);
objectOutputStream.writeObject(someData);
objectOutputStream.flush();
System.out.println("Serialised output size: "+byteOutputStream.size());
objectOutputStream.close();
byteOutputStream.close();
} catch (Exception e) {
System.out.println("Serialisation failed: "+e.getMessage());
catch(Exception ex){
ex.printStackTrace(System.out);
The parameters you might be interested in playing with are HARDCODE_SERIALISATION and TEST_SIZE defined at the beginning of RMITestApplication.java. The HARDCODE_SERIALISATION is a flag that specifies whether Java serialisation should be used to pass the data across or we should rely on OC4J marshalling. TEST_SIZE defines the size of the object graph and the ArrayList structure. The bigger this size is the more dramatic effect you get from data duplication.
The test case outputs the structure both on the server and on the client and prints out the size of the serialised structure. That gives us sufficient comparison, as both structure and its size should be the same on the client and on the server.
The test case also demonstrates that the problem is specific to OC4J. The standard Java serialisation does not suffer the same flaw. However using the standard serialisation the way I did in the test case code is generally unacceptable as it breaks the transparency benefit and complicates interfaces.
To run the test case:
1) Modify provider URL parameter value on line 15 of the RMITestApplication.java for your environment.
2) Deploy the bean to the server.
4) Run RMITestApplication on a client PC.
5) Compare the outputs on the server and on the client.
I hope someone can reproduce the problem and give their opinion, and possibly point to the solution if there is one at the moment.
Cheers,
Alexei

Hi,
Eugene, wrong end user recovery. Alexey is referring to client desktop end user recovery which is entirely different.
Alexy - As noted in the previous post:
http://social.technet.microsoft.com/Forums/en-US/bc67c597-4379-4a8d-a5e0-cd4b26c85d91/dpm-2012-still-requires-put-end-users-into-local-admin-groups-for-the-purpose-of-end-user-data?forum=dataprotectionmanager
Each recovery point has users permisions tied to it, so it's not possible to retroacively give the users permissions. Implement the below and going forward all users can restore their own files.
This is a hands off solution to allow all users that use a machine to be able to restore their own files.
1) Make these two cmd files and save them in c:\temp
2) Using windows scheduler – schedule addperms.cmd to run daily – any new users that log onto the machine will automatically be able to restore their own files.
<addperms.cmd>
Cmd.exe /v /c c:\temp\addreg.cmd
<addreg.cmd>
set users=
echo Windows Registry Editor Version 5.00>c:\temp\perms.reg
echo [HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Microsoft Data Protection Manager\Agent\ClientProtection]>>c:\temp\perms.reg
FOR /F "Tokens=*" %%n IN ('dir c:\users\*. /b') do set users=!users!%Userdomain%\\%%n,
echo "ClientOwners"=^"%users%%Userdomain%\\bogususer^">>c:\temp\perms.reg
REG IMPORT c:\temp\perms.reg
Del c:\temp\perms.reg
Please remember to click “Mark as Answer” on the post that helps you, and to click “Unmark as Answer” if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread. Regards, Mike J. [MSFT]
This posting is provided "AS IS" with no warranties, and confers no rights.

Dictionary Structure---data structure of Dictionary

I don't know how to build a data structure of dictionary...
somebody said it's was built by binary tree. but I don't know how.
somebody helps me????
thanks for reading my topic

A dictionary is not a tree/hierarchical structure. Have you ever opened a dictionary before?! If you have even once, you already know the structure of a dictionary. Now, how to build that in Java is another question. I'm not sure of your requirements but you could start by creating an object that represents a single term, it's definitions, usages, etc. Then you can create a List of them (and sort them alphabetically). Simple enough?

Efficient data structure to implement simple text editor?

I was given this problem in an interview:
What data structure would you use to implement a simple text editor that does these 4 functions:
a) goto(line number)
b) insert(char input,location)
c) delete(location)
d) printAll() //print entire file
Given that i'm such a newb, i was stumped. I came up with making a 2d array that would allow for o(1) time for goto, but o(n) for everything else (shifting everything in the array). there were other downfalls too dealing with space issues and such, but he wanted me to optimize this data structure. I then came up with a linked list of arrays, but that had similar problems.
But thinking about it further is driving me a little crazy so I'm wondering if you guys have any suggestions on how to answer this question...
one thing that came to mind after is to implement the data structure as a binary tree, where each node contains
class Node
char theChar
int position; // ie 0 = first character in the file, and 81 could be the first character in the 2nd line
node left,right,parent;
}so how it works is the cursor would know where the location was so i would know where to delete and insert within the tree.
insert {
     //search for location to insert after (log n)
       //create new character node and append to current node
     //increment position for all subsequent children
delete(x) {
     search for x position
     if found, remove node and decrement position value for all children
goto(line #) {
     return line # * 80 (or whatever max length for a single line)
}the major problem i see here is balancing the tree after every insert/delete
Thanks in advance.

One of many great things emacs has given us is the gap buffer:
http://en.wikipedia.org/wiki/Gap_buffer
To see a Java implementation of this you can look in the Java SDK source. The document model (I forget exactly what its called), used in Swing uses a gap buffer.

Data structure for simulation of message queue

Hello,
I have undertaken a project of simulating the point to point and publish/subscribe protocols of message queueing. This whole project would be done just in Java. There won't be any system level programming. Which data structure in Java would be the most efficient one for the message queue?

Hello,
I have undertaken a project of simulating the point to point and publish/subscribe protocols of message queueing. This whole project would be done just in Java. There won't be any system level programming. Which data structure in Java would be the most efficient one for the message queue?

Java data structure

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