package com.sort;

import java.util.Random;

public class RandomQuickSort {
  private static int partition(int []data ,int p,int r){
    int random=new Random().nextInt(r-p)+p;
    int tmpR=data[random];
    data[random]=data[r];
    data[r]=tmpR;
    
    int x=data[r];
    int i=p-1;
    for(int j=p;j<=r-1;j++){
      if(data[j]<=x){
        i=i+1;
        int tmp=data[i];
        data[i]=data[j];
        data[j]=tmp;
      }
    }
    int tmp=data[i+1];
    data[i+1]=data[r];
    data[r]=tmp;
    return i+1;
  }
  
  public static void quickSort(int[]data,int p,int r){
    if(p<r){
      int q=partition(data,p,r);
      quickSort(data,p,q-1);
      quickSort(data,q+1,r);
    }
  }
  public static void main(String[] args) {
    int[] data=new int[]{1,3,7,9,11,12,5,4};
    for(int i=0;i<data.length;i++){
      System.out.print(data[i]+" ");
    }
    System.out.println();
    quickSort(data,0,data.length-1);
    for(int i=0;i<data.length;i++){
      System.out.print(data[i]+" ");
    }
    System.out.println();
  }

}