### 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)
{
if (vec->operator[](i) > vec->operator[](i + 1))
{
std::swap(vec->operator[](i), vec->operator[](i + 1));
isSorted = false;
}
}

for (size_t i = begIndex + 1; i <= endIndex - 1; i += 2)
{
if (vec->operator[](i) > vec->operator[](i + 1))
{
std::swap(vec->operator[](i), vec->operator[](i + 1));
isSorted = false;
}
}
}
}

int main()
{
std::vector<int> vec = { 22, 0, 1, 7, 8, 23, 10, 9, 3, 11, 80, 12, 6, 13, 4, 21, 16, 18 };
//if (vec.size() <= 1) return 0;

if (vec.size() <= 10) {
partBySort(&vec, 0, vec.size() > 0 ? vec.size() - 1 : 0);
}
else {
// Creating two threads just for the demo...
size_t midIndex = (vec.size() - 1) / 2;

// Final sort on the full array
partBySort(&vec, 0, vec.size() - 1);
}

for (const auto& i : vec)
std::cout << i << " ";

std::cout << std::endl;
}

### Reversing char array without splitting the array to tokens

I was reading about strdup, a C++ function and suddenly an idea came to my mind if this can be leveraged to aid in reversing a character array without splitting the array into words and reconstructing it again by placing spaces and removing trailing spaces. Again, I wanted an array to be passed as a function argument and an array size to be passed implicitly with the array to the function. Assumed, a well-formed char array has been passed into the function. No malformed array checking is done inside the function. So, the function signature and definition are like below: Below is the call from the client code to reverse the array without splitting tokens and reconstructing it. Finally, copy the reversed array to the destination.  For GNU C++, we should use strdup instead _strdup . On run, we get the following output: Demo code

### A simple approach to generate Fibonacci series via multi-threading

T his is a very simple approach taken to generate the Fibonacci series through multithreading. Here instead of a function, used a function object. The code is very simple and self-explanatory.  #include <iostream> #include <mutex> #include <thread> class Fib { public:     Fib() : _num0(1), _num1(1) {}     unsigned long operator()(); private:     unsigned long _num0, _num1;     std::mutex mu; }; unsigned long Fib::operator()() {     mu.lock(); // critical section, exclusive access to the below code by locking the mutex     unsigned long  temp = _num0;     _num0 = _num1;     _num1 = temp + _num0;     mu.unlock();     return temp; } int main() {     Fib f;          int i = 0;     unsigned long res = 0, res2= 0, res3 = 0;     std::cout << "Fibonacci series: ";     while (i <= 15) {         std::thread t1([&] { res = f(); }); // Capturing result to respective variable via lambda         std::thread t2([&] { res2 = f(); });         std::thread t3(

### Close a Window Application from another application.

This is just a demo application code to show how the WM_CLOSE message can be sent to the target process which has a titled window to close the application. To achieve this, either we can use SendMessage or PostMessage APIs to send required Windows messages to the target application. Though both the APIs are dispatching WM_XXXXX message to target application two APIs has some differences, these are as below: 1. SendMessage () call is a blocking call but PostMessage is a non-blocking call(Asynchronous) 2. SendMessage() APIs return type is LRESULT (LONG_PTR) but PostMessage() APIs return type is BOOL(typedef int). In Short, SendMessage () APIs return type depends on what message has been sent to the Windowed target process. For the other one, it's always a non-zero value, which indicates the message has been successfully placed on the target process message queue. Now let's see how can I close a target windowed application "Solitaire & Casual Games" from my custom-