#include <iostream>
using namespace std;

// Function to partition the array and return the pivot index.
int partition(int arr[], int low, int high) {
    int pivot = arr[high];
    int swapIndex = low-1;
    for(int currentIndex = low ; currentIndex<high; currentIndex++){
        if(arr[currentIndex] <= pivot){
            swapIndex++;
            std::swap(arr[swapIndex] ,arr[currentIndex]);
        }
    }
    std::swap(arr[swapIndex+1] ,arr[high]);
    return swapIndex+1;
}

void displayArray(int arr[], int n) {
    for (int i = 0; i < n; i++) {
        cout << arr[i] << " ";
    }
    cout << endl;
}
// Function to recursively sort the array using Quick Sort.
void quickSort(int arr[], int low, int high) {
    if(low<high){
        int pivotIndex = partition(arr,low,high);
        quickSort(arr,low,pivotIndex-1);
        quickSort(arr,pivotIndex+1,high);
    }
}

// Function to initiate the Quick Sort process.
void processQuickSort(int arr[], int n) {
    if(n>1){
        quickSort(arr,0,n-1);
    }
}


// Function to dynamically allocate an array and fill it with random values.
void fillDynamicArrayWithRandomValues(int** arr, int* n) {
    cout << "Enter the size of the array: ";
    cin >> *n;
    *arr = new int[*n];
    srand(time(0)); // Seed for random number generation
    for (int i = 0; i < *n; i++) {
        (*arr)[i] = rand() % 1000; // Fill with random numbers between 0 and 999
    }
}

int main() {
    int* arr;
    int n;
    fillDynamicArrayWithRandomValues(&arr, &n);
    cout << "Unsorted array: ";
    displayArray(arr, n);
    processQuickSort(arr, n);
    cout << "Sorted array: ";
    displayArray(arr, n);
    delete[] arr; // Deallocate dynamically allocated memory
    return 0;
}