QSort.java

public class QuickSort
{   public static void main(String args[])
    {   int a[]={5,7,4,3,6,8,9,1,2,0};
        QuickSort obj=new QuickSort();
        for(int i=0; i<a.length; i++) System.out.print(a[i]+" "); System.out.println();
        obj.quickSort(a,0,a.length-1);
        for(int i=0; i<a.length; i++) System.out.print(a[i]+" "); System.out.println();
    }
    void quickSort(int array[], int start, int end)
    {   int i = start;                          
        int k = end;                         
        if (end - start >= 1)
        {   int pivot = array[start];       
            while (k > i)
            {   while (array[i] <= pivot && i <= end && k > i) i++;      
                while (array[k] > pivot && k >= start && k >= i) k--;                                        
                if (k > i) swap(array, i, k);    
           } 
           swap(array, start, k);  
           quickSort(array, start, k - 1); // quicksort the left partition
           quickSort(array, k + 1, end);   // quicksort the right partition
        }
    }//quickSort()
    void swap(int array[], int index1, int index2) 
    {   int temp = array[index1];           
        array[index1] = array[index2];      
        array[index2] = temp;        
    }//swap()
}//class