手写单向链表和反转

单向链表
添加元素和反转

import lombok.Data;

@Data
public class Link {
    // 有了这个东西其他就好操作了
    private Node pre = new Node<>(null);
    private Node tail;

    public Node getHead() {
        return pre.getNext();
    }

    public void append(T data) {
        if (tail == null) {
            tail = new Node<>(data);
            pre.setNext(tail);
        } else {
            tail.setNext(new Node<>(data));
            tail = tail.getNext();
        }
    }

    public void revert() {
        Node p = pre.next;
        Node q = p.next;
        p.next = null;
        while (q != null) {
            Node node = q.next;
            q.next = p;
            p = q;
            q = node;
        }
        pre.next = p;
    }

    @Data
    public static class Node {
        public Node(T data) {
            this.data = data;
        }

        private T data;
        private Node next;
    }

    public static void main(String[] args) {
        final Link link = new Link<>();
        for (int i = 0; i < 5; i++) {
            link.append((char) (i + 'a'));
        }

        Node node = link.getHead();
        while (node != null) {
            System.out.println(node.getData());
            node = node.getNext();
        }

        System.out.println("----------");
        link.revert();
        node = link.getHead();

        while (node != null) {
            System.out.println(node.getData());
            node = node.getNext();
        }
    }
}