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Showing posts from June, 2023

### An Attempt to run Odd-Even Sorting in multi-threading

This is an attempt to run odd-even sorting from two threads without using locks. I have used a vector and split the vector logically in two halves if the size is beyond a value (Here as an example kept size 10, that means if the vector size is more than 10, then two threads will spawn and parallelize (on multi-core) sorting on the elements of the vector container. Finally, after sorting each half by two threads, another sorting will be arranged to make it finally sorted.  The Wiki contains the details about Odd-Even sorting. It's a comparison sorting. The below code snippet is a simple approach to odd-even sorting with multi-threading without having locks. No Extra space was allocated/used in this scenario.  void partBySort(std::vector<int>* vec, size_t begIndex, size_t endIndex) {     if (begIndex == endIndex) return;     bool isSorted = false;     while (!isSorted)     {         isSorted = true;         for (size_t i = begIndex; i <= endIndex - 1; i += 2)         {

### The Simplest sorting algorithm

The simplest sorting algorithm is not bubble sort or insertion sort but known as stupid sort aka gnome sort . The time complexity is like a bubble sort. However, the code base size is much smaller. Possibly it offers the smallest code base size in the domain of the sorting algorithm. The details can be found on Wikipedia . Here goes the code: void gnomeSort(std::vector<int>& data) {     int pos = 0;     while (pos < data.size())     {         if (pos == 0 or data[pos] >= data[pos - 1])             pos += 1;         else          {             std::swap(data[pos], data[pos - 1]);             pos -= 1;         }     } } int main() {        std::vector<int> v4 = { 10, 0, 2, 33, 5, 77, 8, 19, 1, 7 };       gnomeSort(v4);       for (auto i: v4)          std::cout << i << " "; } Happy sorting...

### Binomial coefficient using C++

We are aware of the Binomial coefficient, which is a mathematical term used to  represent the number of ways to select a certain number of items/objects from a larger set, without regard to their order. It's denoted by a symbol C(n, k)(n choose k or n over k). It gets computed by following formula:  C(n, k) = n! / (k! * (n - k)!)   The C++ implementation using the above formula is:  int factorial( int n) {     if (n <= 1 )         return 1 ;     else         return n * factorial(n - 1 ); } int binomialCoefficient( int n, int r) {     if (r > n)         return 0 ;     int numerator = factorial(n);     int denominator = factorial(r) * factorial(n - r);     int result = numerator / denominator;     return result; } int main() {      std::cout << "Value of C(" << 5 << ", " << 2 << ") is "          << binomialCoefficient( 5 , 2 ) << "\n" ; } So, the number of ways to choose two i

### IsDebuggerPresent API Vs Process Environment Block

Sometimes we've seen some application or process that can't be debugged using any debugger. As soon as we attach a debugger, either the application will terminate or pop up a message like a debugger attached with the process, so terminating the application. What so ever, in windows world, there is an API, which detects if the process is being debugged or not.  It's IsDebuggerPresent() Win32 API. You can refer to the  MSDN  link to get more details on it. So, I've written a test sample below: #include <Windows.h> int _tmain(int argc, _TCHAR* argv[]) {     if (IsDebuggerPresent() == TRUE)     {           MessageBox(NULL,            TEXT("Please close your debugging                 application and restart the program"),            TEXT("Debugger Found!"), 0);         ExitProcess(0);     }     MessageBox(NULL, TEXT("Hello World!"), TEXT("Bypassed"), 0);     ExitProcess(0);     return 0; } As usual, I did compile the code usin

### Periodically run a method without freezing UI.

This was one of the requirements to periodically check if the internet connection for a system is on / off. Based on the Internet Connectivity Status, it will do certain actions. How do I check the Internet Connection Status periodically and asynchronously?  To solve this programming puzzle (in C#.NET ), I have used System.Timers.Timer class. There was one more class available in the .NET framework, that was, System.Threading.Timer. I have chosen System.Timers.Timer class, because it is thread-safe but System.Threading.Timer class isn't out of the box. Step 1: Created an elapsed event handler for the timer class: <Code> // Create a timer with 10 seconds interval in the init method of the form application; m_Timer = new System.Timers.Timer(10 * 1000); /* It's going to fire the below-highlighted method every 10 seconds*/ m_Timer.Elapsed += checkInternetConnectionState ;  m_Timer.Enabled = true; </Code> Step 2: Created  checkInternetConnectionState  async method defin

### A concept to a product (Kimidori [ 黄緑]) - Part 3

The previous pos t explored the report part of the malicious link(s) with as many details as possible. So far the tool can be used any number of times to figure out whether a link is malicious or safe to use. Kimidori [ 黄緑] is not limited to only malicious link detection. This tool can be leveraged to detect the browsers installed on the system along with their executable as well as cookie path. So, far it can detect the following browsers if present / installed in the system.  1. Brave 2. Chrome 3. Edge 4. Firefox 5. Ice Dragon 6. Opera 7. SeaMonkey 8. Vivaldi 9. and WaterFox Support for other browsers will be given eventually.  Here is a glimpse of the page where it shows the browser details fetched by the tool: More browser support will be added soon along with cookie analysis for the user to let the user know what kind of cookies gets created by surfing the internet web pages by different browsers. This part will revisit soon. Along with browser-related stuff, this tool also digs