1. /**
    2.  * @Description:反转单向链表和双向链表
    3.  * @Author: lizhouwei
    4.  * @CreateDate: 2018/4/6 11:07
    5.  */
    6. public class Chapter2_4 {
    7.     //反转单向链表
    8.     public Node reverse(Node head){
    9.         if(head ==null){
    10.             return null;
    11.         }
    12.          Node pre = null;
    13.         Node next=null;
    14.         while (head!=null){
    15.             next = head.next;
    16.             head.next = pre;
    17.             pre = head;
    18.             head = next;
    19.         }
    20.         return  pre;
    21.     }
    23.     //反转双向链表
    24.     public DoubleNode reverseDNode(DoubleNode head){
    25.         if(head ==null){
    26.             return null;
    27.         }
    28.         DoubleNode pre = null;
    29.         DoubleNode next=null;
    30.         while (head!=null){
    31.             next = head.next;
    32.             head.next = pre;
    33.             head.pre = next;
    34.             pre = head;
    35.             head = next;
    36.         }
    37.         return  pre;
    38.     }
    39.     public void printLink(Node head) {
    40.         System.out.println();
    41.         while (head != null) {
    42.             System.out.print(head.vlaue + " ");
    43.             head = head.next;
    44.         }
    45.     }
    47.     public void printDLink(DoubleNode head) {
    48.         System.out.println();
    49.         while (head != null) {
    50.             System.out.print(head.vlaue + " ");
    51.             head = head.next;
    52.         }
    53.     }
    55.     //测试
    56.     public static void main(String[] args) {
    57.         Chapter2_4 chapter = new Chapter2_4();
    58.         Link link1 = new Link();//单链表
    59.         Link link2 = new Link();//双链表
    61.         //构造链表
    62.         for (int i = 10; i > 0; i--) {
    63.             link1.add(i);
    64.             link2.addDoubleNode(i);
    65.         }
    66.         chapter.printLink(link1.head);
    67.         Node head = chapter.reverse(link1.head);
    68.         chapter.printLink(head);
    69.         chapter.printDLink(link2.dhead);
    70.         DoubleNode dhead = chapter.reverseDNode(link2.dhead);
    71.         chapter.printDLink(dhead);
    73.     }
    74. }