Quick sort in cpp

#include <iostream>
using namespace std;

// Function to partition the array
int partition(int arr[], int low, int high) {
    // Select the pivot (using the last element in this case)
    int pivot = arr[high];
    
    // Index of the smaller element
    int i = low - 1;

    for (int j = low; j < high; j++) {
        // If the current element is smaller than or equal to the pivot
        if (arr[j] <= pivot) {
            i++;  // Increment the index of the smaller element
            swap(arr[i], arr[j]);  // Swap the smaller element with the current element
        }
    }

    // Place the pivot element in its correct position
    swap(arr[i + 1], arr[high]);
    
    return i + 1;  // Return the partitioning index
}

// Function to implement QuickSort
void quickSort(int arr[], int low, int high) {
    if (low < high) {
        // Partition the array around a pivot and get the partition index
        int pi = partition(arr, low, high);

        // Recursively sort the elements before and after partition
        quickSort(arr, low, pi - 1);
        quickSort(arr, pi + 1, high);
    }
}

// Function to print the array
void printArray(int arr[], int size) {
    for (int i = 0; i < size; i++) {
        cout << arr[i] << " ";
    }
    cout << endl;
}

int main() {
    int arr[] = {10, 80, 30, 90, 40, 50, 70};
    int n = sizeof(arr) / sizeof(arr[0]);

    cout << "Unsorted array: ";