public void reorderList(ListNode head) {
		ListNode dummy = new ListNode(0);
		dummy.next = head;
		ListNode p = dummy;
		ListNode dummy1 = new ListNode(0);

		int l = 0;
		while(p.next != null){
			if(++l % 2 == 0){
				ListNode tmp = p.next;
				p.next = tmp.next;
				tmp.next = dummy1.next;
				dummy1.next = tmp;
			}else{
				p = p.next;
			}
		}

		p = dummy.next;
		while(dummy1.next  != null){
			ListNode tmp = dummy1.next;
			dummy1.next = tmp.next;
			tmp.next = p.next;
			p.next = tmp;
			p = tmp.next;
		}
	}