从尾到头打印链表

public ArrayList<Integer> printListFromTailToHead(ListNode listNode) {
        ArrayList<Integer> list = new ArrayList<Integer>(0);
        while(listNode != null) {
            list.add(0,listNode.val);
            listNode = listNode.next;
        }
        return list;
    }

public ArrayList<Integer> printListFromTailToHead(ListNode listNode) {
        Stack<Integer> stack = new Stack<Integer>();
        ArrayList<Integer> list = new ArrayList<Integer>();
        while(listNode != null) {
            stack.push(listNode.val);
            listNode = listNode.next;
        }
        while(!stack.empty())
            list.add(stack.pop());
        return list;
}

public ArrayList<Integer> printListFromTailToHead(ListNode listNode) {
        if(listNode != null) {
            printListFromTailToHead(listNode.next);
            list.add(listNode.val);
        }
        return list;
}