链表逆序

ArrayList<Integer> list = new ArrayList<>();
        if(head == null ){
            return new int[0];
        }
        if(head.next == null){
            return new int[]{head.val};
        }
        ListNode cur = head.next;
        head.next = null;
        while(cur != null){
            ListNode curNext = cur.next;
            cur.next = head;
            head = cur;
            cur = curNext;
        }
        cur = head;
        while(cur != null){
            list.add(cur.val);
            cur = cur.next;
        }
        int[] ret = new int[list.size()];
        for(int i = 0;i< ret.length;i++){
            ret[i] = list.get(i);
        }
        return ret;