QUICK SORT IN JAVA

import java.io.*;

class Main

{

     public static void main(String[]args) throws IOException

     {

           BufferedReader br=new BufferedReader(new InputStreamReader(System.in));

          

           System.out.print("Enter the number of elements that you want to sort : ");

           int n=Integer.parseInt(br.readLine());

           int arr[]=new int[n];

           System.out.println("Enter the data of the array : ");

           for(int i=0;i<n;i++)

           {

                System.out.print("Enter the data item # "+(i+1)+" : ");

                arr[i]=Integer.parseInt(br.readLine());

           }

           quickSort(arr,0,arr.length-1);

           for(int i=0;i<n;i++)

                System.out.print(arr[i]+" , ");

     }

     public static void quickSort(int []arr,int p,int r)

     {

           if(p<r)

           {

                int q=partition(arr,p,r);

                quickSort(arr,p,q-1);

                quickSort(arr,q+1,r);

           }

     }

     public static int partition(int []arr,int p,int r)

     {

           int x=arr[r];

           int i=p-1;

           for(int j=p;j<r;j++)

           {

                if(arr[j]<x)

                {

                     i++;

                     int tmp=arr[j];

                     arr[j]=arr[i];

                     arr[i]=tmp;

                }

           }

           int tmp=arr[i+1];

           arr[i+1]=arr[r];

           arr[r]=tmp;

           return (i+1);

     }

}