Quick sorting program

Worse case performance: O(n^2)
Best case performance: O(nlogn)
Average performance: O(nlogn)


#include <iostream>
void quicksort(int arr[],int low,int high);
int partition(int arr[],int low,int high);
using namespace std;
/***********************************/
int partition(int arr[],int low,int high)
{
    int pivot,i;
    pivot=arr[high];
    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);
}
/*********************************/
void quicksort(int arr[],int low, int high)
{
    if(low<high)
    {
    int pivot;
    pivot=partition(arr,low,high);

    quicksort(arr,low,pivot-1);
    quicksort(arr,pivot+1,high);
    }
}
/*********************************/
int main()
{
    int arr[5]={5,4,3,2,1};
    int n=5;
    cout << "Before sorting values is: ";
    for(int i=0;i<n;i++)
    {
    cout<<arr[i]<<" ";
    }
    quicksort(arr,0,n-1);
    cout<<"\n After sorting: ";
    for(int i=0;i<n;i++)
    {
    cout<<arr[i]<<" ";
    }
    cout<<endl;
    return 0;
}