下列程序输出结果为() import java.util.*; public class App12_9 { public static void main(String[] args) { HashSet
hs=new HashSet
(); for(String a:args) if(!hs.add(a)) System.out.println("元素"+a+"重复"); System.out.println("集合的容量为:"+hs.size()+",各元素为:"); Iterator it=hs.iterator(); while(it.hasNext()) System.out.print(it.next()+" "); } }