Quick sort DSA

#include <iostream>
using namespace std;

class quick{
    int arr[9] = {1,2,5,10,61,77,45,95,89};
public:

    void quicksort(int p, int q){
        int pivot;
        if(p < q){
            pivot = partition(p, q);
            quicksort(p, pivot-1);
            quicksort(pivot+1, q);
        }
    }

    void swap(int i, int j){
        cout << arr[i] << " " << arr[j] << endl;
        int temp = arr[i];
        arr[i] = arr[j];
        arr[j] = temp;
        cout << arr[i] << " " << arr[j] << endl;
    }

    int partition(int start, int last){
        int low = start;
        int high = last;
        float pivot = arr[low];
        do{
            do{
                low ++;
            }while(arr[low] <= pivot);
            do{
            high --;
            }while(arr[high] > pivot);
            if(low < high){
            swap(low, high);
            }
        }while(low < high);
        swap(start, high);
        return high;
    }

    void display(int n){
        cout << "Sorted:";
        for(int i = 0; i < n; i++){
            cout << " " << arr[i];
        }
    }

};

int main(){
    quick q;
    q.quicksort(0, 9);
    q.display(9);
//  q.quicksort(0,8);
//  q.swap(2,4);
    return 0;
}