/** * QuickSort *  */public class QuickSort {	public static void sort(Comparable[] a, int lo, int hi) {		if(lo >= hi) {			return;		}		int mid = partition(a, lo, hi);		sort(a, lo, mid-1);		sort(a, mid+1, hi);	}		private static int partition(Comparable[] a, int lo, int hi) {		Comparable v = a[lo];		int i = lo;		int j = hi+1;				while(true) {			while(less(a[++i], v)) {				if(i == hi)					break;			}			while(less(v, a[--j])) {				if(j == lo) {					break;				}			}			if(i >= j) {				break;			}			exch(a, i, j);		}				exch(a, lo, j);				return j;	}		private static boolean less(Comparable v, Comparable w) {		return v.compareTo(w) < 0;	}		private static void exch(Comparable[] a, int i, int j) {		Comparable tmp = a[i];		a[i] = a[j];		a[j] = tmp;	}		public static void show(Comparable[] a) {		for(int i=0; i