随机快速排序问题

import java.util.Scanner;
import java.util.Random;
public class randomizedQuickSort {
     public static void main(String anr[]){
            int[] a=new int[7];
            a[6]=99999999;
       Scanner s = new Scanner(System.in);
       for(int i=1;i<6;i++)
       {
           System.out.println("请输入第"+i+"个数字");
           a[i]=s.nextInt();
       }
         int p = a[0],r = a[4];
        System.out.println("插入排序后的顺序为：");
        System.out.print(randomizedQuickSort(p,r));
        
        }
     
    private static void randomizedQuickSort(int p,int r)
    {
        if(p<r)
        {
            int q = randomizedPartition(p,r);
         randomizedQuickSort(p,q-1);
         randomizedQuickSort(q+1,r);
        }
    }
   
    private static int randomizedPartition(int p,int r)
    {
        int i = random(p,r);
        Math.swap(a,i,p);
        return partition(p,r);
    }
     
    private static int partition(int p,int r)
    {
        int i = p, j = r+1;
        Comparable x = a[p];
        while(true)
        {
            while(a[++i].compareTo(x)<0&&i<r);
            while(a[--j].compareTo(x)>0);
            if(i>=j)break;
            Math.swap(a,i,j);
        }
        a[p]=a[j];
        a[j]=x;
        return j;
    }
   
   
}