281. Zigzag Iterator

/*
 * 281. Zigzag Iterator
 * 2016-6-27 by Mingyang
 * 这里就利用了list里面的Iterator的性质，不断地交替取出Iterator，并且取下一个值
 */
 class ZigzagIterator {
     LinkedList<Iterator> list;
        public ZigzagIterator(List<Integer> v1, List<Integer> v2) {
            list = new LinkedList<Iterator>();
            if(!v1.isEmpty()) list.add(v1.iterator());
            if(!v2.isEmpty()) list.add(v2.iterator());
        }
        public int next() {
            Iterator poll = list.remove();
            int result = (Integer)poll.next();
            if(poll.hasNext()) list.add(poll);
            return result;
        }
        public boolean hasNext() {
            return !list.isEmpty();
        }
    }