QuickSortP1.java

import java.util.*;

public class QuickSortP1 
{
    static void partition(int[] ar) 
    {
        int temp=0;
        int pivot=ar[0];
        int pIndex=ar.length-1;
        for(int i=ar.length-1;i>=1;i--)
        {
            if(ar[i]>=pivot)
            {
                temp=ar[i];
                ar[i]=ar[pIndex];
                ar[pIndex]=temp;
                pIndex-=1;
            }
        }
        temp=ar[pIndex];
        ar[pIndex]=ar[0];
        ar[0]=temp;
        printArray(ar); 
    }    
    
    static void printArray(int[] ar)
    {
         for(int n: ar)
         {
            System.out.print(n+" ");
         }
         System.out.println("");
    }
       
    public static void main(String[] args) 
    {
        Scanner in = new Scanner(System.in);
        int n = in.nextInt();
        int[] ar = new int[n];
        for(int i=0;i<n;i++)
        {
            ar[i]=in.nextInt(); 
        }
            partition(ar);
    }    
}