第二章 链表问题（反转双向链表）_I'm Salted Fish的博客

【题目】

实现反转双向链表的函数

    DoubleNode<Integer> reverseDoubleNode(DoubleNode<Integer> head) {
        if (head == null || head.next == null) {
            return head;
        }
        DoubleNode<Integer> next = null;
        DoubleNode<Integer> rev = null;
        while (head != null) {
            next = head.next;
            head.next = rev;
            head.last = next;
            rev = head;
            head = next;
        }
        return rev;
    }    DoubleNode<Integer> re