Fields of a struct gets corrupted while in an ADT module

See also questions close to this topic

• Find element in a n-Ary tree

  Given the following structure

  struct nNode {
     int val;
     struct nNode parent;
     struct nNode children;
     struct nNode next;
     struct nNode prev;
  
  };
  

  Where the children points to first child and to traverse to the other childs we need to follow node->children->next ...

  I'm trying to return a pointer to the element that contains some val using the function

  struct nNode* nNode_find(struct nNode *node, int val)
  {
    // We found the node return the pointer
    if(node->val == val) return node;
    // We didn't found let's check the children
    struct nNode *child = node->children;
    while(child) {
      nNode_find(child, val);
      child = child->children;
      // We didn't found on child, lets check his brothers
      struct nNode *sibling = child->next;
      while(sibling) {
        nNode_find(sibling, val);
        sibling = sibling->next;
      }
    }
    // We didn't found the element return NULL
    return NULL;
  }
  

  Given a tree calle TREE like:

    /*                      1
     *            /---------|--------\
     *          2           3         4
     *        /   \                 /
     *      5       6              7
     */
  

  A command like

  struct nNode *ptr = nNode_find(TREE, 3);
  

  should return a pointer to root->children->next , but with actual nNode_find is returning NULL.
• Recursive copy function to copy data from socket to a file. What's wrong?

  My recursive copy function works on files, but not on socket to file. I believe it's because the files are "buffered" input/output. Sockets are not buffered right? So how would I make my copier work for both buffered/not buffered input output?

  Here is my copier function.

  /* file_download() - function to download a file.
   */
  size_t file_download(int sockfd, FILE *fout) {
      char data[CHUNK_SIZE];
      int bytesRead, bytesWritten;
      static size_t total_bytes = 0;
  
      bytesRead = read(sockfd, data, sizeof(data));
      if(bytesRead > 0)
          bytesWritten = fwrite(data, 1, bytesRead, fout); /* Fixed this line */
      if(bytesWritten == bytesRead)
          return total_bytes;
      else
          total_bytes += bytesWritten;
      file_download(sockfd, fout);
  }
  

  What it does is only copies one byte of data when not buffered. But, it copies the whole thing when it is buffered input/output. Any help in resolving this issue will be greatly appreciated. Thanks in advance.
• Why the child process is not executed?

  I have the following piece of code:

  int main() {
     int n = 1;
     if(fork() == 0) {
        printf("child");
        n = n + 1;
        exit(0);
     }
     n = n + 2;
     printf("%d: %d\n", getpid(), n);
     wait(0);
     return 0;
  }
  

  The problem is that I don't understand why the child process is not executing.

  The child process is executing only if i set sleep(1) in the parent process

  Thanks in advance.
• Find the number of ways to partition the array

  I want number of ways to divide an array of possitive integers such that maximum value of left part of array is greater than or equal to the maximum value of right part of the array.

  For example, 6 4 1 2 1 can be divide into:

  [[6,4,1,2,1]] [[6][4,1,2,1]] [[6,4][1,2,1]] [[6,4,1][2,1]] [[6,4,1,2][1]] [[6][4,1][2,1]] [[6][4][1,2,1]] [[6][4][1,2][1]] [[6][4,1,2][1]] [[6,4,1][2][1]] [[6][4,1][2][1]] [[6,4][1,2][1]]
  

  which are total 12 ways of partitioning.

  I tried a recursive approach but it fails beacause of termination due to exceed of time limit. Also this approach is not giving correct output always.

  In this another approach, I took the array ,sort it in decreasing order and then for each element I checked weather it lies on right of the original array, and if does then added it's partitions to it's previous numbers too.

  I want an approach to solve this, any implementation or pseudocode or just an idea to do this would be appreciable.
• Recommend a stretegy for handing dynamic questions/answers in ASP.NET / SQL

  I am looking to launch a candidate profile website programmed in C# / ASP.NET with an MSSQL backend. The purpose of the website will be to allow IT professionals (IT support, network, software development, security, management and project management professionals) to create a searchable online profile that does not rely on keyword searches gathered from reading in resumes. This website will be different to traditional sites websites because it will concentrate on capturing and measuring some fine grained details about a candidates actual talent and capability. I want recruiters to be able to visit the site and search using precise/defined fields as opposed to throwing in a bunch of keywords and expecting decent results.

  One of the things I would like to do is make subsequent questions dynamic. I.e, if the candidate answers the question “Which sector of IT do your work in?” with “Software Developer”, then the remaining questions the website will ask will be related to software development. Example, "Can you code in C#?". If the answer is "Yes", then a further question of "Has software you developed been marketed?" might be asked. If ofcourse, the answer to "Can you code in C#?" was a no, then I won't need to capture an answer for the next question.

  If they said they were working in “IT Support”, then we would ask them a different set of questions. I want the tables to easily handle the capturing of these dynamic answers and also to be able to handle answers to any future additional questions we put up on the site. I know this is a major database design consideration I need to think about.

  I'm a jack of all trades in IT, and understandably master of none. Have architected/supported MS IT infrastructures for 15 years and produced dozens of lightweight but useful .NET apps. I also have an intemediate understanding of SQL (and DB concepts). This would be my first project with ASP and a serious backend DB.

  I am looking for some suggestions on how to go about designing and handling my questions/answers within ASP.NET and SQL. Thanks
• how to store content that is displayed dynamically

  I was wondering what is the proper way of store in html content that is displayed dynamically.

  My case is that depending on what is clicked some sort of text is displayed in another part of a website. My first idea was to create a variable in js/jquery script to store this content so the script can access it whenever it is necessary.

  this is an example:

  var someContent=" Content to be displayed when something is clicked";
  var a=$('#myid');
  
  a.click(function(){
      $('#myOtherId').text(someContent);      
      });
  

  But after a while it came to my mind that the content should be stored in the html with a display value set to 'none' and js script should simple toggle its visibility depending wether it has been clicked or not.

  Storing the content in js script seems much easier - but something tells me that there is better way to do it...
• std::map is not inserting struct elements

  I have a struct Point

  struct Point
  {
      int x;
      int y;
      bool operator == (const Point& point) const {
          return this->x != point.x ? false : (this->y != point.y ? false : true);
      }
  
      bool operator < (const Point& point) const {
          return this->x < point.x && this->y < point.y;
      }
  };
  

  I also have a DraughtType enum

  enum class DraughtType {
      NORMAL, QUEEN
  };
  

  And I have a std::map < Point,DraughtType >. When I insert elements into std::map, only 3 values are inserted.

  This is the code for inserting white draughts

  void Board::initializeWhiteDraughts()
  {
      for (auto i = 0; i < 3; ++i) {
          int x = i;
          for (auto j = i % 2 == 0 ? 0 : 1 ; j < COLUMNS; j+=2) {
              Point point;
              point.x = x;
              point.y = j;
              whiteDraughts[point] = DraughtType::NORMAL;
          }
      }
  }
  

  But the output is the following:

  0 0
  1 1
  2 2
  

  It's clearly missing a lot of draughts.

  What's wrong with my code? I've tried to change the operator comparison, but it didn't work.
• Writing and Reading a structure from a binary file C

  I am simply trying to get user input, store it in a struct, write it to a binary file, and then read it again. It is for the start of a contact book type program. When I try to retrieve the data for a single struct, it does not read into my readStruct and I get a seg fault at the marked comment in the code.

  Also, please mind the messy use of dynamic strings and user input. I was just playing around and learning from it.

  Thanks.

  Heres the code:

  int main(void) {
  
    struct contactStruct {
      int phoneNumber;
      char * firstName;
      char * lastName;
      char * companyName;
    };
    struct contactStruct contact;
    struct contactStruct read;
  
    //Variable Declaration
    int j = 1;
    char tempInput[100] = "-";
    char * menuInput;
    char * searchInput;
    bool menuLoop = false;
    FILE * filePointer;
  
    filePointer = fopen("contactList.db", "r+");
    if (filePointer == NULL) {
      filePointer = fopen("contactList.db", "w+");
    }
  
    printf("Welcome to the Contact Book Program\n");
    printf("This program will let you store and access all of your contacts!\n");
    do {
      menuLoop = false;
      printf("Would you like to: 'ADD', 'EDIT', 'VIEW', or 'REMOVE' a contact? - ");
      fgets(tempInput, sizeof(tempInput), stdin);
      for (int i = 0; i < strlen(tempInput); i++) {
        tempInput[i] = tolower(tempInput[i]);
      }
      menuInput = malloc(sizeof(char) * strlen(tempInput) + 1);
      strcpy(menuInput, tempInput);
  
      if (strcmp(menuInput, "add\n") == 0) {
        printf("Phone Number: ");
        fgets(tempInput, sizeof(tempInput), stdin);
        contact.phoneNumber = atoi(tempInput);
  
        printf("First Name: ");
        fgets(tempInput, sizeof(tempInput), stdin);
        contact.firstName = malloc(sizeof(char) * strlen(tempInput) + 1);
        strcpy(contact.firstName, tempInput);
  
        printf("Last Name: ");
        fgets(tempInput, sizeof(tempInput), stdin);
        contact.lastName = malloc(sizeof(char) * strlen(tempInput) + 1);
        strcpy(contact.lastName, tempInput);
  
        printf("Company Name: ");
        fgets(tempInput, sizeof(tempInput), stdin);
        contact.companyName = malloc(sizeof(char) * strlen(tempInput) + 1);
        strcpy(contact.companyName, tempInput);
  
        fwrite( & contact, sizeof(struct contactStruct), 1, filePointer);
  
      } else if (strcmp(menuInput, "view\n") == 0) {
        printf("Who are you searching for? (First Name): ");
        scanf("%s", tempInput);
        searchInput = malloc(sizeof(char) * strlen(tempInput) + 1);
        strcpy(searchInput, tempInput); // Get name being searched for
  
        fread( & read, sizeof(struct contactStruct), 1, filePointer);
  
        printf("DEBUG - File Pos: %ld Size of Struct: %lu\n", ftell(filePointer), sizeof(struct contactStruct));
        printf("Input: %s Searching: %s\n", searchInput, read.firstName); //Seg Fault Happens Here
  
        if (strcmp(searchInput, read.firstName) == 0) {
          printf("Here is the contact information given:\n\n");
          printf("%d %s %s %s \n", read.phoneNumber, read.firstName, read.lastName, read.companyName);
        } else {
          printf("Did not find\n");
        }
      } else {
        printf("Invalid Option, Try Again.\n");
        menuLoop = true;
      }
    }
    while (menuLoop == true);
    free(menuInput);
    free(searchInput);
    fclose(filePointer);
  
    return 0;
  }
  
• Work with a matlab struct in c++ (return value of a matlab function call) (library generated by matlab compiler)

  Hi I have a fairly simple matlab function. E.g.:

  function [MYSTRUCT] = myfunc()
    MYSTRUCT.prop1 = 'test';
    MYSTRUCT.prop2 = 'foo';
    MYSTRUCT.prop3 = 42;
  end
  

  I compiled with the matlab compiler sdk a c++ library and added this properly to an c++ program using visual studio (all good so far).

  But how do I work with the struct in c++ ? My c++ code looks like this:

  //initialize matlab runtime
  //initialize my function
  
  mwArray out;
  myfunc(1, out);
  

  the function is called properly (e.g. if I add a imshowpair to the matlab function its displayed properly. so all good here)

  the return value of the function thats called by c++ (myfunc()) is of the type mwArray and therefore I cannot access the "property" values (in this case "test", "foo" and '42')

  How do I access them?

  (I thought about an "getter" matlab function maybe, where I can pass over the return value (variable out) to get the values. Is this possible / a good idea?)
• Explanation for output of given code

  #include <stdio.h>
  
  int sum(int a, int b, int c) {
      return a + b + c / 2;
  }
  
  void main() {
      int (*function_pointer)(int, int, int);     // how this will be interpreted
      function_pointer = sum;
      printf("%d", function_pointer(2, 3, 4));
      return ;
  }
  

  When i ran on ide it gave output 7, i dont understand how?
• How to distinguish between pointers to overloaded functions?

  I have a class

  struct MyClass
  {
      ...
      bool (* IsValid)(MyClass * self, int type);
      bool (* IsValid)(MyClass * self, char * str);
  };
  

  relevant functions

  bool IsValidMyClass(BitMask * self, int mask)
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      ...
  }
  bool IsValidMyClass(BitMask * self, char * str)
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  and a CTOR-like function

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  And here I got in confuse - how to say to compiler to do a correct assignment?
• How to implement a cQueue as a priority Queue in Omnet++?

  I want to use the Omnet++ based container cQueue as a priority Queue.
  As it is explained in the API reference and in the manual - I need to define it
  as follows:
  cQueue queue("Name of queue", someCompareFunc)

  When someCompareFunc is of type CompareFunc which is defined by omnet as:
  typedef int (*CompareFunc)(cObject *a, cObject *b);

  So, I wanted to implement this comparative function, but didn't manage to write something that will compile.
  I admit I didn't work with function pointers for some time now, but after a small research, I think I do understand and did write some test codes with eclipse IDE (c++).

  I'm trying to write the code at a simpleModule file.cc.
  So for every function I declare at the header file in the "regular way", in the .cc file I need to add the module name with "::" before the function's name.
  So in my header file I declared:
  int compareByNodes (cObject *a, cObject *b);

  And in the .cc file:

  int JobScheduler::compareByNodes (cObject *a, cObject *b){
         return 1;
      };
  

  My first try to define the cQueue was:

  cQueue queue("job_Buffer",&compareByNodes);
  

  But I received a compilation error of: 'compareByNodes' was not declared in this scope.
  So I figured it must have something to do with the 'JobScheduler::' that is missing.
  The second try was:

  CompareFunc tmp = (CompareFunc)&JobScheduler::compareByNodes;
  cQueue queue("job_Buffer",tmp);
  

  This time my errors were:
  "Multiple markers at this line
  - within this context
  - converting from ‘int (JobScheduler::)(omnetpp::cObject, omnetpp::cObject*)’ to ‘omnetpp::CompareFunc {aka int () (omnetpp::cObject, omnetpp::cObject*)}’ [-Wpmf-conversions]"

  Adding parenthesis after the 'ampersand' didn't help either.

  It would really help if I could use this method of Omnet and I guess I'm missing something since it's a well defined "feature" of the software.
  I also tried to google these subjects, searched in the google groups section, and didn't find any answers.
  Would appreciate any help
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  I am creating a client server application whit Java Sockets and am getting the SocketException: socket closed error when server send theLogin response to the client

  If someone can help me can download the code here: https://drive.google.com/drive/folders/0B_4RYSUcAbKlfjNNNDU4TzBPajVtZ3h0ODQwX25Rb08za3hKSUNIZ2xoQTVBMkZHdi0yZ1U?usp=sharing
• Installing an Android app : ADT vs Terminal

  When an app is launched via ADT the avg. execution of a specific code took ~150ms (note the debugger is not attached) When the same app is installed via adb and installed manually clicking on the icon the avg. time took to execute the same piece of code took ~58ms

  So the difference in time is ~100ms - and there is no difference in code base except the way app is installed and launched.

  Questions : What is the additional processing the app is doing when launched via ADT launcher? Did anyone came across this kind of scenario? What are the best/recommended ways/tools to measure/instrument execution times.

  Thanks!
• C++ ADT Set implementation on HashTable (resolving colisions with independent lists)

  As the title says I am trying to implement Set ADT on a Hashtable with independent lists. The thing is I don't know where I'm wrong.

  The code I am about to post is taken from a bigger project and I took just the esential parts of it to show you.

  SetADT.h:

      #pragma once
  #pragma once
  #include <stdio.h>
  
  #define CAPACITY 10
  
  using namespace std;
  
  template <typename TElement>
  class IteratorSet;
  
  
  
  
  
  
  template<typename TElement>
  class Set {
  
      class Nod {
      public:
          TElement element;
          Nod* next;
  
      };
  
  public:
  
      Set();
  
  
      void add(TElement element);
  
  
      int size();
  
  
      void sterge(TElement element);
  
  
      bool cauta(TElement element); 
  
  
      friend class IteratorSet<TElement>;
      IteratorSet<TElement> iterator() { return IteratorSet<TElement>(this); }
  
  private:
  
      int dimensiune;
  
  
      typename Set<TElement>::Nod* prim;
  
  
      int max;
  
  
      Nod** table;
  
  
      int hashFunction(TElement element) { return element.hashCode() % max; }
  
  
      Nod* set;
  };
  
  template<typename TElement>
  Set<TElement>::Set()
  
  {
      max = CAPACITATE;
      table = new Nod*[max];
      for (int i = 0; i < max; i++)
          table[i] = NULL;
  }
  
  template <typename TElement>
  void Set<TElement>::add(TElement element)
  
  {
      int pozitie = hashFunction(element);
      Nod* curent = table[pozitie];
      while (curent != NULL && !(element == curent->element))
          curent = curent->next;
      if (curent != NULL)
          return;
      else
      {
          Nod* n = new Nod;
          n->element = element;
          n->next = table[pozitie];
          table[pozitie] = n;
      }
      dimensiune++;
  }
  
  template <typename TElement>
  int Set<TElement>::size()
  
  {
      return dimensiune;
  }
  
  template <typename TElement>
  void Set<TElement>::sterge(TElement element)
  
  {
      int pozitie = hashFunction(element);
      Nod* curent = table[pozitie];
  
  
      if (table[pozitie] == NULL)
          return;
  
  
      if (table[pozitie]->element == element)
      {
          Nod* deSters = table[pozitie];
          table[pozitie] = table[pozitie]->next;
          delete deSters;
          dimensiune--;
          return;
      }
  
  
      Nod* elem = table[pozitie];
      while (elem->next != NULL && (elem->next->element) == element)
          elem = elem->next;
  
  
  
      if (elem->next != NULL)
      {
          Nod* deSters = elem->next;
          elem->next = elem->next->next;
          delete deSters;
          dimensiune--;
      }
  
  }
  
  template <typename TElement>
  bool Set<TElement>::cauta(TElement element)
  
  {
      int pozitie = hashFunction(element);
      Nod* curent = table[pozitie];
      while (curent != NULL && !(element == curent->element))
          curent = curent->next;
      if (curent != NULL)
      {
          return true;
      }
      return false;
  }
  
  
  
  
  
  
  
  template<typename TElement>
  class IteratorSet {
  public:
      IteratorSet(Set<TElement>* m);
      void next();
      bool valid();
      TElement element();
  private:
      Set<TElement>* Set;
      typename Set<TElement>::Nod* crt;
  };
  
  template<typename TElement>
  IteratorSet<TElement>::IteratorSet(Set<TElement>* mul) {
      Set = mul;
      crt = mul->prim;
  }
  
  template<typename TElement>
  bool IteratorSet<TElement>::valid() {
      return crt != NULL;
  }
  
  template<typename TElement>
  TElement IteratorSet<TElement>::element() {
      return crt->element;
  }
  
  template<typename TElement>
  void IteratorSet<TElement>::next() {
      crt = crt->next;
  }
  

  ======================================================= domain.h (names of Pizzas)

  #include <string>
  using namespace std;
  
  class Pizza {
  public:
      Pizza(string namePizza) : namePizza(namePizza) {}
      Pizza() : namePizza("") {}
  
      string getName() const {
          return namePizza;
      }
      int hashCode()
      {
          int sum = 0;
          for (unsigned i = 0; i < str.length(); i++)
              sum += str[i];
          return sum;
      }
      bool operator == (Pizza& other) {
          return namePizza == other.getName();
      }
  
  private:
      string namePizza;
      string str;
  };
  

  ==================================================== main.cpp:

  #include "SetADT.h"
  #include <string>
  #include <iostream>
  #include "domain.h"
  
  void show(Set<Pizza>* set) {
      IteratorSet<string> it = set->iterator();
      while (it.valid()) {
          cout << "\t" << it.element().getName() << endl;
          it.next();
      }
  }
  
  
  
  int main()
  {
      Set<Pizza> set;
  
      Pizza pizza1{ "diavola" };
      Pizza pizza2{ "prosciuto" };
  
      set.add(pizza1);
      set.add(pizza2);
  
      show(set);
  
      return 0;
  }
  

  When I try to print the objects added to the Set it pops and error and the program stops.

  I don't know anywhere else to look to find the problem.

  Anyway, if the code sample isn't enough, here the complete project ( has parts of romanian in it )

  http://www20.zippyshare.com/v/qKpEcZhr/file.html