QuickSortDemo.java

package shorting;

public class QuickSortDemo {
	 public void quicksort(int A[], int low, int high) {
	        if(low<high) {
	            int pi = partition(A,low,high);
	            quicksort(A,low,pi-1);
	            quicksort(A,pi+1,high);
	        }
	    }

	    public int partition(int A[], int low, int high) {
	        int pivot = A[low];
	        int i = low+1;
	        int j = high;
	        do {
	            while(i <= j && A[i] <= pivot)
	                i = i + 1;
	            while (i <= j && A[j] > pivot)
	                j = j - 1;
	            if (i <= j)
	                swap(A,i,j);
	        } while(i<j);
	        swap(A,low,j);
	        return j;
	    }

	    public void swap(int A[], int i, int j) {
	        int temp = A[i];
	        A[i] = A[j];
	        A[j] = temp;
	    }
	    public void display(int A[], int n) {
	        for(int i=0;i<n;i++)
	            System.out.print(A[i] + " ");
	        System.out.println();
	    }

	    public static void main(String args[]) {
	        QuickSortDemo s = new QuickSortDemo();
	        int A[] = {3, 5, 8, 9, 6, 2};
	        System.out.print("Original Array: ");
	        s.display(A, 6);
	        s.quicksort(A, 0, A.length-1);
	        System.out.print("Sorted Array: ");
	        s.display(A, 6);
	    }

}