quick_sort.cpp

#include <iostream>
using namespace std;

// Partition function
int partition(int arr[], int low, int high) {
    int pivot = arr[high];  // choose last element as pivot
    int i = low - 1;

    for(int j = low; j < high; j++) {
        if(arr[j] < pivot) {
            i++;
            swap(arr[i], arr[j]);
        }
    }

    swap(arr[i + 1], arr[high]);
    return i + 1;
}

// Quick Sort function
void quickSort(int arr[], int low, int high) {
    if(low < high) {
        int pi = partition(arr, low, high);

        quickSort(arr, low, pi - 1);
        quickSort(arr, pi + 1, high);
    }
}

int main() {
    int n;
    cout << "Enter number of elements: ";
    cin >> n;

    int* arr = new int[n];

    cout << "Enter elements:\n";
    for(int i = 0; i < n; i++)
        cin >> arr[i];

    quickSort(arr, 0, n - 1);

    cout << "Sorted array: ";
    for(int i = 0; i < n; i++)
        cout << arr[i] << " ";

    delete[] arr;
    return 0;
}