反转单向链表

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;


/**
 * @描述： 反转单向链表
 * @思路： 涉及三个节点， preNode、currode、nextNode
 * 1.声明preNode nextNode；
 * 2.反转preNode、currNode顺序
 * 3.移动指针，更新preNode、currNode
 * @复杂度：时间O(N)
 * @链接：https://www.nowcoder.com/practice/b66a251dec8847f386bbe6cd96b7e9c8?tpId=101&tqId=33175&tPage=1&rp=1&ru=/ta/programmer-code-interview-guide&qru=/ta/programmer-code-interview-guide/question-ranking
 */



public class Main {

    public static void main(String[] args) throws IOException {
        BufferedReader input = new BufferedReader(new InputStreamReader(System.in));
        int n = Integer.parseInt(input.readLine());
        String[] strings1 = input.readLine().split(" ");
        Node head1 = Node.createNodeList(strings1);
        head1 = ReverseList.reverseList(head1);


        int m = Integer.parseInt(input.readLine());
        String[] strings2 = input.readLine().split(" ");
        DoubleNode head2 = DoubleNode.createNodeList(strings2);
        head2 = ReverseList.reverseDoubleList(head2);

        Node.printNodeList(head1);
        DoubleNode.printNodeList1(head2);

    }


}


class ReverseList {


    public static Node reverseList(Node head) {
        Node node = head;
        Node pre = null;  //初始化preNode
        Node next = null;
        while (node != null) {
            next = node.getNext(); //初始化nextNode

            //反转顺序
            node.setNext(pre);

            //移动
            pre = node; //pre 当前节点
            node = next;
        }
        return pre;
    }


    public static DoubleNode reverseDoubleList(DoubleNode head) {
        DoubleNode node = head;
        DoubleNode pre = null;  //初始化preDoubleNode
        DoubleNode next = null;
        while (node != null) {
            next = node.getNext(); //初始化nextDoubleNode
            //反转顺序
            node.setNext(pre);
            node.setLast(next);

            //移动
            pre = node; //pre 当前节点
            node = next;
        }
        return pre;
    }


}





class Node {

    private Node next;

    private int value;

    public Node(int value) {
        this.value = value;
    }

    public Node getNext() {
        return next;
    }

    public void setNext(Node next) {
        this.next = next;
    }

    public int getValue() {
        return value;
    }

    public void setValue(int value) {
        this.value = value;
    }


    public static Node createNodeList(Integer[] values) {
        Node head = new Node((values[0]));
        Node node = head;
        for (int i = 1; i < values.length; i++) {
            Node newNode = new Node(values[i]);
            node.next = newNode;
            node = newNode;
        }
        return head;
    }

    public static Node createNodeList(String[] values) {
        Node head = new Node(Integer.parseInt(values[0]));
        Node node = head;
        for (int i = 1; i < values.length; i++) {
            Node newNode = new Node(Integer.parseInt(values[i]));
            node.next = newNode;
            node = newNode;
        }
        return head;
    }


    public static void printNodeList(Node head) {
        StringBuilder sb = new StringBuilder();
        while (head != null) {
            sb.append(head.getValue()).append(" ");
            head = head.getNext();
        }
        System.out.println(sb.toString());
    }

}



class DoubleNode {

    private DoubleNode last;

    private DoubleNode next;

    private int value;

    public DoubleNode(int value) {
        this.value = value;
    }

    public int getValue() {
        return value;
    }

    public void setValue(int value) {
        this.value = value;
    }

    public DoubleNode getNext() {
        return next;
    }

    public void setNext(DoubleNode next) {
        this.next = next;
    }

    public DoubleNode getLast() {
        return last;
    }

    public void setLast(DoubleNode last) {
        this.last = last;
    }


    public static DoubleNode createNodeList(String[] values) {
        DoubleNode head = new DoubleNode(Integer.parseInt(values[0]));
        DoubleNode node = head;
        DoubleNode pre = null;
        for (int i = 1; i < values.length; i++) {
            DoubleNode newNode = new DoubleNode(Integer.parseInt(values[i]));
            node.next = newNode;
            node.last = pre;
            pre = node;
            node = newNode;
        }
        return head;
    }


    public static DoubleNode createNodeList(Integer[] values) {
        DoubleNode head = new DoubleNode((values[0]));
        DoubleNode node = head;
        DoubleNode pre = null;
        for (int i = 1; i < values.length; i++) {
            DoubleNode newNode = new DoubleNode(values[i]);
            node.next = newNode;
            node.last = pre;
            pre = node;
            node = newNode;
        }
        return head;
    }


    public static void printNodeList1(DoubleNode head) {
        StringBuilder sb = new StringBuilder();
        while (head != null) {
            sb.append(head.getValue()).append(" ");
            head = head.getNext();
        }
        System.out.println(sb.toString());
    }


    public static void printNodeList2(DoubleNode last) {
        StringBuilder sb = new StringBuilder();
        while (last != null) {
            sb.append(last.getValue()).append(" ");
            last = last.getLast();
        }
        System.out.println(sb.toString());
    }


}