我的快速排序

    private void quickSort(int[] arr,int begin,int end)            
    {                                                              
      if(begin>=end)                                               
          return ;                                                 
                                                                   
      int low=begin;                                               
      int high=end;                                                
                                                                   
      int index=begin;                                             
      int temp=arr[begin];                                         
      boolean flag=false;//当flag的值为true向前,否则向后                     
      while(low!=high)                                             
      {                                                            
          if(flag)                                                 
          {                                                        
              for(;low<high;low++)                                 
              {                                                    
                  if(arr[low]>temp)                                
                  {                                                
                      arr[high]=arr[low];                          
                      high--;                                      
                      index=low;                                   
                      flag=false;                                  
                      break;                                       
                  }                                                
              }                                                    
          }                                                        
          else                                                     
          {                                                        
              for(;high>low;high--)                                
              {                                                    
                  if(arr[high]<temp)                               
                  {                                                
                      arr[low]=arr[high];                          
                      low++;                                       
                      index=high;                                  
                      flag=true;                                   
                      break;                                       
                  }                                                
              }                                                    
          }                                                        
      }                                                            
      arr[high]=temp;                                              
      if(high==low)                                                
      {                                                            
          quickSort(arr,begin,high-1);                             
          quickSort(arr,high+1,end);                               
      }                                                            
                                                                   
   }                                                               
    @Test                                                          
    public void testquicksort()                                    
    {                                                              
        int[] arr={49,38,65,97,76,13,27,49};                       
        quickSort(arr, 0, arr.length-1);                           
        for (int i = 0; i < arr.length; i++) {                     
            System.out.print(arr[i]+"  ");                         
                                                                   
        }                                                          
    }