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  • How to handle duplicate values in d3.js

    - by Mario
    First I'm a d3.js noob :) How you can see from the title I've got a problem with duplicated data and aggregate the values is no option, because the name represent different bus stops. In this example maybe the stops are on the fron side and the back side of a building. And of course I like to show the names on the x-axis. If i created an example and the result is a bloody mess, see jsFiddel. x = index name = bus stop name n = value I've got a json e.g.: [{ "x": 0, "name": "Corniche St / Abu Dhabi Police GHQ", "n": 113 }, { "x": 1, "name": "Corniche St / Nation Towers", "n": 116 }, { "x": 2, "name": "Zayed 1st St / Al Khalidiya Public Garden", "n": 146 }, ... { "x": 49, "name": "Hamdan St / Tariq Bin Zeyad Mosque", "n": 55 }] The problem: It is possible that the name could appear more then once e.g. { "x": 1, "name": "Corniche St / Nation Towers", "n": 116 } and { "x": 4, "name": "Corniche St / Nation Towers", "n": 105 } I like to know is there a way to tell d3.js not to use distinct names and instead just show all names in sequence with their values. Any ideas or suggestions are very welcome :) If you need more information let me know. Thanks in advanced Mario

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  • PHP: json_decode dumping NULL, BOM not found

    - by SerEnder
    I've been trying to find out why this 'json_encode'd string isn't parsing out correctly, and came across previously answered questions that had the UTF BOM sequence that was throwing the error, but didn't help me here. Here's the code that isn't currently working: //Decode the notes attached to the sig $aNotes = json_decode($rule->getNotes(),true); $bom = pack("CCC",0xef,0xbb,0xbf); if(0 == strncmp($rule->getNotes(),$bom,3)) { print('BOM detected - json encoding in UTF-8<br/>'); } else { print('BOM NOT detected - json encoding correctly<br/>'); } print('rule->getNotes:<br/>' . $rule->getNotes() .'<br/>'); var_dump($aNotes); Which generates this result: BOM NOT detected - json encoding correctly rule->getNotes: [{"lDate":"Unknown","sAuthor":"Unknown","sNote":"This is a general purpose Russian spam rule that matches anything starting with 2, 3 or 4 hex digits followed by a domain name ending with .ru -RSK 2010-05-10"},{"lDate":"1295031463082","sAuthor":"Drew Thorstenson","sNote":"this is Ryan's ru rule"}] NULL I've run it through JSON Lint, which said it was valid, and An Online JSON Parser which parsed it correctly too. Any insight would be greatly appreciated.

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  • Cross-platform iteration of Unicode string

    - by kizzx2
    I want to iterate each character of a Unicode string, treating each surrogate pair and combining character sequence as a single unit (one grapheme). Example The text "??????" is comprised of the code points: U+0928, U+092E, U+0938, U+094D, U+0924, U+0947, of which, U+0938 and U+0947 are combining marks. static void Main(string[] args) { const string s = "??????"; Console.WriteLine(s.Length); // Ouptuts "6" var l = 0; var e = System.Globalization.StringInfo.GetTextElementEnumerator(s); while(e.MoveNext()) l++; Console.WriteLine(l); // Outputs "4" } So there we have it in .NET. We also have Win32's CharNextW() #include <Windows.h> #include <iostream> #include <string> int main() { const wchar_t * s = L"??????"; std::cout << std::wstring(s).length() << std::endl; // Gives "6" int l = 0; while(CharNextW(s) != s) { s = CharNextW(s); ++l; } std::cout << l << std::endl; // Gives "4" return 0; } Question Both ways I know of are specific to Microsoft. Are there portable ways to do it? I heard about ICU but I couldn't find something related quickly (UnicodeString(s).length() still gives 6). Would be an acceptable answer to point to the related function/module in ICU. C++ doesn't have a notion of Unicode, so a lightweight cross-platform library for dealing with these issues would make an acceptable answer.

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  • Deploy and Run application at beginning of WIX Install

    - by Doctor Fro
    I'm trying to deploy and run an application (C# console app) at the beginning of the MSI install with WIX but having some difficulty. The application needs to run before any of the webserver actions happen but after the files have been copied from the MSI to the target location. I can get the app to run but only if I have actually copied the application in the directory before I run the MSI. If I don't do that, I get an error relating to the app not existing in the MSI logs. So basically I think it has to do with the launch sequence I am using I need to ensure that the app exists before it is run. Wondering if one of you good folks could help me out. The requirement is that the application must run as the first thing the WIX MSI does, (well actually before any of the webservice parts happen). The relevant bits of the Wix are as follows. <CustomAction Id='LaunchUpdaterRunFirst' FileKey='serverUpdaterRunFirstExe' ExeCommand='' Return='ignore' /> ... <InstallExecuteSequence> <Custom Action='CA_BlockOlderVersionInstall' After='FindRelatedProducts'>NEWERVERSIONDETECTED</Custom> <RemoveExistingProducts After="InstallInitialize" /> <Custom Action='LaunchUpdaterRunFirst' After='InstallInitialize' /> <Custom Action='LaunchInstaller' After='InstallFinalize'><![CDATA[ REMOVE <> "ALL" and UILevel <> 2]]></Custom> </InstallExecuteSequence> ... <Component Id="ServerInstaller" DiskId="1" Guid="9662EC72-1774-4d22-9F41-AD98A5DCD729"> <File Id="serverUpdaterRunFirstExe" Name="MyCompany.Server.Updater.RunFirst.exe" Source="$(var.SOURCEPATH)\MyCompany.Server.Updater.RunFirst.exe" /> <File Id="serverUpdaterRunFirstExeConfig" Name="MyCompany.Server.Updater.RunFirst.exe.config" Source="$(var.SOURCEPATH)\MyCompany.Server.Updater.RunFirst.exe.config" /> Any help or references greatly appreciated.

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  • Sharing a COM port over TCP

    - by guinness
    What would be a simple design pattern for sharing a COM port over TCP to multiple clients? For example, a local GPS device that could transmit co-ordinates to remote hosts in realtime. So I need a program that would open the serial port and accept multiple TCP connections like: class Program { public static void Main(string[] args) { SerialPort sp = new SerialPort("COM4", 19200, Parity.None, 8, StopBits.One); Socket srv = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp); srv.Bind(new IPEndPoint(IPAddress.Any, 8000)); srv.Listen(20); while (true) { Socket soc = srv.Accept(); new Connection(soc); } } } I would then need a class to handle the communication between connected clients, allowing them all to see the data and keeping it synchronized so client commands are received in sequence: class Connection { static object lck = new object(); static List<Connection> cons = new List<Connection>(); public Socket socket; public StreamReader reader; public StreamWriter writer; public Connection(Socket soc) { this.socket = soc; this.reader = new StreamReader(new NetworkStream(soc, false)); this.writer = new StreamWriter(new NetworkStream(soc, true)); new Thread(ClientLoop).Start(); } void ClientLoop() { lock (lck) { connections.Add(this); } while (true) { lock (lck) { string line = reader.ReadLine(); if (String.IsNullOrEmpty(line)) break; foreach (Connection con in cons) con.writer.WriteLine(line); } } lock (lck) { cons.Remove(this); socket.Close(); } } } The problem I'm struggling to resolve is how to facilitate communication between the SerialPort instance and the threads. I'm not certain that the above code is the best way forward, so does anybody have another solution (the simpler the better)?

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  • How to associate application with existing file types using WiX installer?

    - by Marek
    related to this: http://stackoverflow.com/questions/138550/how-to-register-file-types-extensions-with-a-wix-installer but not a duplicate. I need to handle existing file types (.jpg files). I do not want to be the default handler for .jpg, I would just like to extend the "Open with" menu with a link to my app. I see HKCR\.jpg\OpenWithList\ and HKCR\.jpg\OpenWithProgIds\ in the registry but I am not sure whether to write to these and how to do it correctly with WiX. Should I use something like this? <ProgId Id='??what here?' Description='Jpeg handled by my App'> <Extension Id='jpg' ContentType='image/jpeg'> <Verb Id='openwithmyapp' Sequence='10' Command='OpenWithMyApp' Target='[!FileId]' Argument='"%1"' /> </Extension> </ProgId> There are many ways how to fail here (like Photo Mechanics did, the HKCR for image file types is a real mess after I have installed this software) How to do this correctly with WiX?

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  • algorithm to generate maximum number of character 'A' using keystrokes 'A', CTRL + 'A', CTRL + 'C' and CTRL + 'V'

    - by munda
    This is an interview question from google. I am not able to solve it by myself. Can somebody throw some light? The question goes like this. Write a program to print the sequence of keystrokes such that it generates the maximum number of character 'A's. You are allowed to use only 4 keys: 'A', CTRL + 'A', CTRL + 'C' and CTRL + 'V'. Only N keystrokes are allowed. All CTRL+ characters are considered as one keystroke, so CTRL+A is one keystroke. e.g.: A, ctrl+A, ctrl+C, ctrl+V generates two As in 4 keystrokes. Edit: CTRL + A is Select All CTRL + C is copy CTRL + V is paste I did some mathematics. For any N, using x numbers of A's , one CTRL+A, one CTRL+C and y CTRL+V, we can generate max ((N-1)/2)^2 numbers of A's. But for some N M, it is better to use as many ^A, ^C and ^V as it doubles the number of As. Edit 2: ^A, ^V and ^C will not overwrite on the existing selection but it will append the copied selection to selected one.

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  • Java: design for using many executors services and only few threads

    - by Guillaume
    I need to run in parallel multiple threads to perform some tests. My 'test engine' will have n tests to perform, each one doing k sub-tests. Each test result is stored for a later usage. So I have n*k processes that can be ran concurrently. I'm trying to figure how to use the java concurrent tools efficiently. Right now I have an executor service at test level and n executor service at sub test level. I create my list of Callables for the test level. Each test callable will then create another list of callables for the subtest level. When invoked a test callable will subsequently invoke all subtest callables test 1 subtest a1 subtest ...1 subtest k1 test n subtest a2 subtest ...2 subtest k2 call sequence: test manager create test 1 callable test1 callable create subtest a1 to k1 testn callable create subtest an to kn test manager invoke all test callables test1 callable invoke all subtest a1 to k1 testn callable invoke all subtest an to kn This is working fine, but I have a lot of new treads that are created. I can not share executor service since I need to call 'shutdown' on the executors. My idea to fix this problem is to provide the same fixed size thread pool to each executor service. Do you think it is a good design ? Do I miss something more appropriate/simple for doing this ?

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  • Where does "new" fit in the flex creation cycle?

    - by deux11
    In the following code, the call to myChild.bar() results in an exception because myChild is null. myParent is a valid object. What I don't understand is why myChild has not been created yet. I have read the following document related to object creation sequence, but I am unsure how "new" is related: http://livedocs.adobe.com/flex/3/html/help.html?content=layoutperformance_03.html Any help is appreciated! // Main.mxml <mx:Application xmlns:mx="http://www.adobe.com/2006/mxml" creationComplete="created()"> <mx:Script> <![CDATA[ public var myParent:Parent = new Parent(); public function created():void { myParent.foo(); } ]]> </mx:Script> </mx:Application> // Parent.mxml <mx:Canvas xmlns:mx="http://www.adobe.com/2006/mxml" xmlns="*"> <mx:Script> <![CDATA[ public function foo():void { myChild.bar(); } ]]> </mx:Script> <Child id="myChild"/> </mx:Canvas> // Child.mxml <mx:Canvas xmlns:mx="http://www.adobe.com/2006/mxml"> <mx:Script> <![CDATA[ public function bar():void { trace("Hello World"); } ]]> </mx:Script> </mx:Canvas>

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  • Problem logging in and changing permissions in Facebook

    - by kujawk
    Hi everybody, I've got a piece of code that logs into Facebook, gets a session, sets status_update and offline_access permission if they are not set, and gets a new session with the newly set permissions. This code used to work fine but now I'm getting error 100 "One of the parameters specified was missing or invalid" as a response to the second call to get session and I can't figure out why. Here's the sequence in detail: CREATE TOKEN restserver.php?method=auth.createToken&api_key=[our key]&v=1.0&format=JSON&sig=[sig created with our secret] response: new token LOGIN m.facebook.com/login.php?api_key=[our key]&v=1.0&auth_token=[token created above] login screen loads and user successfully logs in with their username/password. GET SESSION restserver.php?method=auth.getSession&api_key=[our key]&v=1.0&format=JSON&auth_token=token created above&sig=[sig created with our secret] response: session key with expiration date and a secret CHECK/AUTHORIZE PERMISSIONS restserver.php?method=users.hasAppPermission&api_key=[our key]&v=1.0&format=JSON&ext_perm=status_update&call_id=[proper id]&session_key=[key returned above]&sig=[sig created with secret returned for get session] response: 0 m.facebook.com/authorize.php?api_key=[our key]&v=1.0&ext_perm=status_update authorization screen loads and user authorizes Same steps for status_update CREATE NEW TOKEN Same steps as done to create the first token LOGIN m.facebook.com/login.php?api_key=[our key]&v=1.0&auth_token=[new token] user is already logged in, redirected to their homepage GET NEW SESSION restserver.php?method=auth.getSession&api_key=[our key]&format=JSON&auth_token=[new token]&sig=[sig created with our secret] response: error 100 - missing or invalid parameter. Of course it doesn't tell me which one. Anybody have any ideas what I'm doing wrong here? I tried skipping the second login and going right to creating the new session and that didn't work. The only thing that seems to work is logging out the user after they've authorized the permissions and having them log back in again. I'd like to avoid this if possible. Can you have two outstanding sessions at one time? This code used to work but I'm thinking maybe something changed on Facebook's end that I'm not aware of. Thanks, kris

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  • OpenGL circle rotation

    - by user350632
    I'm using following code to draw my circles: double theta = 2 * 3.1415926 / num_segments; double c = Math.Cos(theta);//precalculate the sine and cosine double s = Math.Sin(theta); double t; double x = r;//we start at angle = 0 double y = 0; GL.glBegin(GL.GL_LINE_LOOP); for(int ii = 0; ii < num_segments; ii++) { float first = (float)(x * scaleX + cx) / xyFactor; float second = (float)(y * scaleY + cy) / xyFactor; GL.glVertex2f(first, second); // output Vertex //apply the rotation matrix t = x; x = c * x - s * y; y = s * t + c * y; } GL.glEnd(); The problem is that when scaleX is different from scaleY then circles are transformed in the right way except for the rotation. In my code sequence looks like this: circle.Scale(tmp_p.scaleX, tmp_p.scaleY); circle.Rotate(tmp_p.rotateAngle); My question is what other calculations should i perform for circle to rotate properly when scaleX and scaleY are not equal?

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  • How can I exclude words with apostrophes when reading into a table of strings?

    - by rearden
    ifstream fin; string temp; fin.open("engldict.txt"); if(fin.is_open()) { bool apos = false; while(!fin.eof()) { getline(fin, temp, '\n'); if(temp.length() > 2 && temp.length() < 7) { for(unsigned int i = 0; i < temp.length(); i++) { if(temp.c_str()[i] == '\'') apos = true; } if(!apos) dictionary.insert(temp); } } } This code gives me a runtime error: Unhandled exception at 0x00A50606 in Word Jumble.exe: 0xC0000005: Access violation reading location 0x00000014. and throws me a break point at: size_type size() const _NOEXCEPT { // return length of sequence return (this->_Mysize); } within the xstring header. This exception is thrown no matter what character I use, so long as it is present within the words I am reading in. I am aware that it is probably a super simple fix, but I just really need another set of eyes to see it. Thanks in advance.

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  • In-order tree traversal

    - by Chris S
    I have the following text from an academic course I took a while ago about in-order traversal (they also call it pancaking) of a binary tree (not BST): In-order tree traversal Draw a line around the outside of the tree. Start to the left of the root, and go around the outside of the tree, to end up to the right of the root. Stay as close to the tree as possible, but do not cross the tree. (Think of the tree — its branches and nodes — as a solid barrier.) The order of the nodes is the order in which this line passes underneath them. If you are unsure as to when you go “underneath” a node, remember that a node “to the left” always comes first. Here's the example used (slightly different tree from below) However when I do a search on google, I get a conflicting definition. For example the wikipedia example: Inorder traversal sequence: A, B, C, D, E, F, G, H, I (leftchild,rootnode,right node) But according to (my understanding of) definition #1, this should be A, B, D, C, E, F, G, I, H Can anyone clarify which definition is correct? They might be both describing different traversal methods, but happen to be using the same name. I'm having trouble believing the peer-reviewed academic text is wrong, but can't be certain.

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  • Simplest way to mix sequences of types with iostreams?

    - by Kylotan
    I have a function void write<typename T>(const T&) which is implemented in terms of writing the T object to an ostream, and a matching function T read<typename T>() that reads a T from an istream. I am basically using iostreams as a plain text serialisation format, which obviously works fine for most built-in types, although I'm not sure how to effectively handle std::strings just yet. I'd like to be able to write out a sequence of objects too, eg void write<typename T>(const std::vector<T>&) or an iterator based equivalent (although in practice, it would always be used with a vector). However, while writing an overload that iterates over the elements and writes them out is easy enough to do, this doesn't add enough information to allow the matching read operation to know how each element is delimited, which is essentially the same problem that I have with a single std::string. Is there a single approach that can work for all basic types and std::string? Or perhaps I can get away with 2 overloads, one for numerical types, and one for strings? (Either using different delimiters or the string using a delimiter escaping mechanism, perhaps.)

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  • Compound Primary Key in Hibernate using Annotations

    - by Rich
    Hi, I have a table which uses two columns to represent its primary key, a transaction id and then the sequence number. I tried what was recommended http://docs.jboss.org/hibernate/stable/annotations/reference/en/html_single/#entity-mapping in section 2.2.3.2.2, but when I used the Hibernate session to commit this Entity object, it leaves out the TXN_ID field in the insert statement and only includes the BA_SEQ field! What's going wrong? Here's the related code excerpt: @Id @Column(name="TXN_ID") private long txn_id; public long getTxnId(){return txn_id;} public void setTxnId(long t){this.txn_id=t;} @Id @Column(name="BA_SEQ") private int seq; public int getSeq(){return seq;} public void setSeq(int s){this.seq=s;} And here are some log statements to show what exactly happens to fail: In createKeepTxnId of DAO base class: about to commit Transaction :: txn_id->90625 seq->0 ...<Snip>... Hibernate: insert into TBL (BA_ACCT_TXN_ID, BA_AUTH_SRVC_TXN_ID, BILL_SRVC_ID, BA_BILL_SRVC_TXN_ID, BA_CAUSE_TXN_ID, BA_CHANNEL, CUSTOMER_ID, BA_MERCHANT_FREETEXT, MERCHANT_ID, MERCHANT_PARENT_ID, MERCHANT_ROOT_ID, BA_MERCHANT_TXN_ID, BA_PRICE, BA_PRICE_CRNCY, BA_PROP_REQS, BA_PROP_VALS, BA_REFERENCE, RESERVED_1, RESERVED_2, RESERVED_3, SRVC_PROD_ID, BA_STATUS, BA_TAX_NAME, BA_TAX_RATE, BA_TIMESTAMP, BA_SEQ) values (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?) [WARN] util.JDBCExceptionReporter SQL Error: 1400, SQLState: 23000 [ERROR] util.JDBCExceptionReporter ORA-01400: cannot insert NULL into ("SCHEMA"."TBL"."TXN_ID") The important thing to note is I print out the entity object which has a txn_id set, and then the following insert into statement does not include TXN_ID in the listing and thus the NOT NULL table constraint rejects the query.

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  • Specifying character

    - by danutenshu
    So below I have a code in C++ that is supposed to invert the arguments in a vector, but not the sequence. I have listed my problems as sidenotes in the code below. The invert function is supposed to invert each argument, and then the main function just outputs the inverted words in same order For instance, program("one two three four")=ruof eerth owt eno #include <iostream> #include <string> using namespace std; int invert(string normal) { string inverted; for (int num=normal.size()-1; num>=0; num--) { inverted.append(normal[num]); //I don't know how to get each character //I need another command for append } return **inverted**; <---- } int main(int argc, char* argv[]) { string text; for (int a=1; a<argc; a++) { text.append(invert(argv[a])); //Can't run the invert function text.append(" "); } cout << text << endl; return 0; }

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  • An algo for generating code callgraphs

    - by Shrey
    I am working on a project which requires generating some metrices of a code (it can be C/C++/Java/Python). One of the metrices can be that I create a callgraph after parsing the code entered (the programs are expected to be small - probably under 1000L). As of now, I am looking for a way to create a program (it can be C/Python) which can take as input a file (C/C++/Python/Java) and then create a textual output containing approximate calling sequence as well as tokens in the code file. As of now, I have looked at some other tools which do the same thing - like splint, pylint, codeviz etc. So, I have two ways of solving my problem: Read and understand the algorithm these tools use (tokenization-graph generation etc) Or, have a basic algo (something like very high level steps) and then sit down to create each of them as I want them to be. I know, re-inventing the wheel is not a good idea, but, I would still like to give option (2) a shot. Only issue is, currently I am a blank. My question: Does any one have any knowhow about how to create code graphs? Any hints as to what I should do? Any top levels steps which I can follow? Thanks a lot.

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  • Create Session Variable from different datasources?

    - by Szafranamn
    Currently I am developing a dynamic website using Dreamweaver cs5 with ColdFusion 9 and using Access to create my databases along with QuickBooks and QODBC to create database. I have established a login session variable stemming from the login page. This session variable is being drawn from one Datasource "Access" Table "Logininfo" Field "FullName" but I wanted to create another session variable either at this point or further into the member's page to use in a query sequence. This session variable would stem from another Datasoucre "QBs" Table "Invoice" Field "CustomerRefFullName" which is generated through Quickbooks and QODBC. I am not sure if this is possible but if it is how do I do it. I want to do this so I can query the Invoice database to upload the customer's Invoices unique to them onto their page. So it would have to be related to their login credentials. If there is another better route to take I would greatly appreciate the advice. Below is the login code if there is additional information needed let me know. This is my current thinking/plan to do what I wish to intend hence the need to create the session variable: I have another Datasource "QBs" with a Table "Invoice" when I create another webpage for the customer to see their invoice I need to create a recordset that accesses that Table. In order to do so I think the best way would some home convert the session.FullName (which came from Access Datasource, Logininfor Table) into a session.CustomerRefFullName (which would have to come from (Datasource: QBs Table: Invoice Field: CustomerRefFullName) that way I could set the query WHERE CustomerRefFullName and have each logged in user see their specific Invoices. So is there a way to turn the session variable off one datasource/table into a different sessionvariable off a new datasource/table even if it is unique just to that page??? <cfif IsDefined("FORM.username")> SELECT FullName, Username,Password,AccessLevels FROM Logininfo WHERE Username= AND Password=

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  • algorithm - How to sort a 0/1 array with 2n/3 comparisons?

    - by Jackson Tale
    In Algorithm Design Manual, there is such an excise 4-26 Consider the problem of sorting a sequence of n 0’s and 1’s using comparisons. For each comparison of two values x and y, the algorithm learns which of x < y, x = y, or x y holds. (a) Give an algorithm to sort in n - 1 comparisons in the worst case. Show that your algorithm is optimal. (b) Give an algorithm to sort in 2n/3 comparisons in the average case (assuming each of the n inputs is 0 or 1 with equal probability). Show that your algorithm is optimal. For (a), I think it is fairly easy. I can choose a[n-1] as pivot, then do something like in quicksort partition, scan 0 to n - 2, find the middle point where left side is all 0 and right side is all 1, this take n - 1 comparisons. But for (b), I can't get a clue. It says "each of the n inputs is 0 or 1 with equal probability", so I guess I can assume the numbers of 0 and 1 equal? But how can I get a result which is related to 1/3? divide the whole array into 3 groups? Thanks

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  • ZeroMQ REQ/REP on ipc:// and concurrency

    - by Metiu
    I implemented a JSON-RPC server using a REQ/REP 0MQ ipc:// socket and I'm experiencing strange behavior which I suspect is due to the fact that the ipc:// underlying unix socket is not a real socket, but rather a single pipe. From the documentation, one has to enforce strict zmq_send()/zmq_recv() alternation, otherwise the out-of-order zmq_send() will return an error. However, I expected the enforcement to be per-client, not per-socket. Of course with a Unix socket there is just one pipeline from multiple clients to the server, so the server won't know who it is talking with. Two clients could zmq_send() simultaneously and the server would see this as an alternation violation. The sequence could be: ClientA: zmq_send() ClientB: zmq_send() : will it block until the other send/receive completes? will it return -1? (I suspect it will with ipc:// due to inherent low-level problems, but with TCP it could distinguish the two clients) ClientA: zmq_recv() ClientB: zmq_recv() so what about tcp:// sockets? Will it work concurrently? Should I use some other locking mechanism to work around this?

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  • Cross-platform general purpose C++ RPC library

    - by iUm
    Here's the task: Imagine, we have an applications and a plug-in for it (dynamic library). Interface between the application and the plug-in is completely defined. Now I need to run the application and the plug-in on different computers. I wrote a stub for the plug-in on a computer where the real applications is running. And the application loads it and calls its functions like if it were a native plug-in. On the other computer there's a stub instead of the real application, which loads the native plug-in. Now I need to organize RPCs between my stubs over the network, regardless the very transport. Usually, it's not difficult. But there're some restrictions: Application-plug-in interaction can be reenterable (e.g. application calls f1() from plug-in, in f1() plug-in calls g1() from application, in g1() application calls f2() from plug-in and so on...) Any such reenteration should be executed exactly by the same thread, which started the sequence Where can I find a cross-platform C++ RPC library with such features?

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  • Searching in graphs trees with Depth/Breadth first/A* algorithms

    - by devoured elysium
    I have a couple of questions about searching in graphs/trees: Let's assume I have an empty chess board and I want to move a pawn around from point A to B. A. When using depth first search or breadth first search must we use open and closed lists ? This is, a list that has all the elements to check, and other with all other elements that were already checked? Is it even possible to do it without having those lists? What about A*, does it need it? B. When using lists, after having found a solution, how can you get the sequence of states from A to B? I assume when you have items in the open and closed list, instead of just having the (x, y) states, you have an "extended state" formed with (x, y, parent_of_this_node) ? C. State A has 4 possible moves (right, left, up, down). If I do as first move left, should I let it in the next state come back to the original state? This, is, do the "right" move? If not, must I transverse the search tree every time to check which states I've been to? D. When I see a state in the tree where I've already been, should I just ignore it, as I know it's a dead end? I guess to do this I'd have to always keep the list of visited states, right? E. Is there any difference between search trees and graphs? Are they just different ways to look at the same thing?

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  • PDFParsing & extracting the images only in iPhone application.

    - by sagar
    Hello - Every one. ** : My Query : ** I want to extract only images from entire pdf document. ( Using Objective C - for iPhone Application ) : My Efforts : I have gone through this link which has details regarding different operators of PDF Document. ( http://mail-archives.apache.org/mod_mbox/pdfbox-commits/200912.mbox/%[email protected]%3E ) I also studied this document - ( http://developer.apple.com/mac/library/documentation/GraphicsImaging/Conceptual/drawingwithquartz2d/dq_pdf_scan/dq_pdf_scan.html#//apple_ref/doc/uid/TP30001066-CH220-TPXREF101 ) I also have gone through entire document of PDFReference.pdf ( From original Adobe Site ) PDFReference.pdf (Adobe Document - says that - for image there are following operators ) q Q BI EI I have placed following table get the image myTable = CGPDFOperatorTableCreate(); CGPDFOperatorTableSetCallback(myTable, "q", arrayCallback2); CGPDFOperatorTableSetCallback(myTable, "TJ", arrayCallback); CGPDFOperatorTableSetCallback(myTable, "Tj", stringCallback); I have following arrayCallback2 method for getting image void arrayCallback2(CGPDFScannerRef inScanner, void *userInfo) { // how to extract image from this code // means I have tried too many different ways. following is incorrect way & not giving image // CGPDFStreamRef stream; // represents a sequence of bytes // if (CGPDFDictionaryGetStream (d, "BI", &stream)){ // CGPDFDataFormat t=CGPDFDataFormatJPEG2000; // CFDataRef data = CGPDFStreamCopyData (stream, &t); // } } above arrayCallback2 method is called for operator "q", But I don't know How to extract the image from it. In short. What should be the solution for extracting the images from the pdf documents? Thanks in advance for your kind help. Sagar kothari.

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  • Restoring dev db from production: Running a set of SQL scripts based on a list stored in a table?

    - by mattley
    I need to restore a backup from a production database and then automatically reapply SQL scripts (e.g. ALTER TABLE, INSERT, etc) to bring that db schema back to what was under development. There will be lots of scripts, from a handful of different developers. They won't all be in the same directory. My current plan is to list the scripts with the full filesystem path in table in a psuedo-system database. Then create a stored procedure in this database which will first run RESTORE DATABASE and then run a cursor over the list of scripts, creating a command string for SQLCMD for each script, and then executing that SQLCMD string for each script using xp_cmdshell. The sequence of cursor-sqlstring-xp_cmdshell-sqlcmd feels clumsy to me. Also, it requires turning on xp_cmdshell. I can't be the only one who has done something like this. Is there a cleaner way to run a set of scripts that are scattered around the filesystem on the server? Especially, a way that doesn't require xp_cmdshell?

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  • why does setting stderr=subprocess.STDOUT fix a subprocess.check_output call?

    - by ShankarG
    I have a python script running on a small server that is called in three different ways - from within another python script, by cron, or by gammu-smsd (an SMS daemon with the wonderful mobile utility [gammu]). The script is for maintenance and contained the following kludge to measure used space on the system (presumably this is possible from within Python, but this was quick and dirty): reportdict['Used Space'] = subprocess.check_output(["df / | tail -1 | awk '{ print $5; }'"], shell=True)[0:-1] Oddly enough this line would only fail when the script was called by a shell script running from gammu-smsd. The line would fail with a CalledProcessError exception saying "returned exit status 2", even though the output attribute of the CalledProcessError object contained the correct output. The only command in the sequence of shell commands that would give such an error status would be awk, with status 2 indicating a fatal error. If the python script with this line was called by cron, by another python script, or from the command line, this line would work fine. I broke my head trying to fix the environment for the script, thinking this must be the problem. Finally though I put in stderr=subprocess.STDOUT, like so: reportdict['Used Space'] = subprocess.check_output(["df / | tail -1 | awk '{ print $5; }'"], stderr=subprocess.STDOUT, shell=True)[0:-1] This was a debug measure to help me figure out if some output was coming on stderr. But after this the script started working, even when called from gammu-smsd! Why might this be the case? I ask for future reference when using subprocess...

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