Java实现单链表

Posted 2020-10-07

  1 package Eric.ADT;
  2 
  3 import java.util.Scanner;
  4 
  5 import org.junit.Test;
  6 
  7 /**
  8  * <p>
  9  * Title:MyLinkedList
 10  * </p>
 11  * <p>
 12  * Description:用java实现单链表的基本操作
 13  * </p>
 14  * <p>
 15  * Location:Frostburg
 16  * </p>
 17  * 
 18  * @author: Eric.Chen
 19  * @date:2017年9月20日下午8:51:25
 20  */
 21 public class MyLinkedList {
 22     class Node {// 节点
 23         public Object value = null;// 节点的数据域
 24         public Node next = null;// 节点的指针域
 25     }
 26 
 27     private Node header = null;// 头结点
 28 
 29     void initList()// 初始化链表
 30     {
 31         header = new Node();
 32         header.value = null;
 33         header.next = null;
 34     }
 35 
 36     // 插入链表
 37     void tailInsertList(Object element) {// 尾插法
 38         Node e = new Node();// 创建一个新节点
 39         e.value = element;
 40         if (header.next == null)// 说明这是第一次插入数据
 41         {
 42             header.next = e;
 43         } else// 说明这不是第一次插入数据
 44 
 45         {
 46             Node temp = header;
 47             while (temp.next != null) {
 48                 temp = temp.next;
 49             }
 50             temp.next = e;
 51         }
 52 
 53     }
 54 
 55     void headInsertList(Object element)// 用头插法将元素放到链表中
 56     {
 57         Node e = new Node();
 58         e.value = element;
 59         if (header.next == null) {
 60             header.next = e;
 61         } else {
 62             e.next = header.next;
 63             header.next = e;
 64 
 65         }
 66     }
 67 
 68     // 将element元素从链表中删除
 69     void deleteList(Object element) {
 70         Node temp = header;
 71         while (temp.next != null) {
 72             if (temp.next.value.equals(element))// 找到要删除的值
 73             {
 74                 temp.next = temp.next.next;// 移动指针指向
 75             } else {
 76                 temp = temp.next;// 继续往下搜索
 77             }
 78         }
 79 
 80     }
 81 
 82     int size() {// 链表长度
 83         int i = 0;
 84         if (header.next == null)
 85             return 0;
 86         else {
 87             Node temp = header;
 88             while (temp.next != null) {
 89                 temp = temp.next;
 90                 i++;
 91             }
 92         }
 93         return i;
 94 
 95     }
 96 
 97     void printAllValues() {// 打印链表中所有数据
 98         Node temp = header;
 99         System.out.println("输出链表所有数据:");
100         while (temp.next != null) {
101             System.out.print(temp.next.value + " ");
102             temp = temp.next;
103         }
104     }
105 
106     public Object getElement(int i)// 获取指定位置上的元素
107     {
108         if (i <= 0 || i > size()) {
109             return null;
110         }
111 
112         Node temp = header;
113         int count = 1;
114         Object index = null;
115         while (temp.next != null) {
116             if (count == i) {
117                 index = temp.next.value;
118             }
119             temp = temp.next;
120             count++;
121         }
122 
123         return index;
124     }
125 
126     public boolean isContain(Object Ele)// 判断链表中是否含有指定元素
127     {
128         Node temp = header;
129         int count = 1;
130         int index = -1;
131         while (temp.next != null) {
132             if (temp.next.value == Ele) {
133                 index = count;
134             }
135             temp = temp.next;
136             count++;
137         }
138         if (index == -1)
139             return false;
140         else
141             return true;
142     }
143 
144     public int getIndex(Object Ele) {// 获取指定元素的位置
145         Node temp = header;
146         int count = 1;
147         int index = 0;
148         while (temp.next != null) {
149             if (temp.next.value == Ele) {
150                 index = count;
151             }
152             temp = temp.next;
153             count++;
154         }
155         return index;
156     }
157 //测试代码
158     public static void main(String[] args) {
159         MyLinkedList list = new MyLinkedList();
160         Scanner sc = new Scanner(System.in);
161         list.initList();
162         for (int i = 0; i < 10; i++) {
163             list.tailInsertList(i);
164         }
165         list.printAllValues();
166         System.out.println();
167         int size = list.size();
168         System.out.println("链表的长度为:" + size);
169         list.headInsertList(99);
170         list.printAllValues();
171         System.out.println();
172         int size2 = list.size();
173         System.out.println("链表的长度为:" + size2);
174         /*
175          * System.out.println("请输入要查询的元素的位置:"); int index1 = sc.nextInt();
176          * Object ele = list.getElement(index1); System.out.println("链表中第" +
177          * index1 + "个元素是:" + ele); System.out.println("请输入要查询的元素:"); Object
178          * value = sc.nextInt(); int index2 = list.getIndex(value);
179          * System.out.println("元素" + value + "的位置是:" + index2);
180          * System.out.println("请输入你要检验是否存在与链表中的元素:"); Object checkedElem =
181          * sc.nextInt(); boolean ifcontain = list.isContain(checkedElem); if
182          * (ifcontain) { System.out.println("该链表中有此元素！"); } else {
183          * System.out.println("该链表中没有此元素！"); }
184          */
185     }
186 }