Node节点:

/*

 * 链结点,相当于是车厢

 */

public class Node {

//数据域

public long data;

//指针域

public Node next;

public Node previous;

public Node(long value) {

this.data = value;

}

/**

* 显示方法

*/

public void display() {

System.out.print(data + " ");

}

}

双端链表:

/*

 * 双端链表

 */

public class FirstLastLinkList {

//头结点

private Node first;

//尾结点

private Node last;

public FirstLastLinkList() {

first = null;

last = null;

}

/**

* 插入一个结点,在头结点后进行插入

*/

public void insertFirst(long value) {

Node node = new Node(value);

if(isEmpty()) {

last = node;

}

node.next = first;

first = node;

}

/**

* 插入一个结点,从尾结点进行插入

*/

public void insertLast(long value) {

Node node = new Node(value);

if(isEmpty()) {

first = node;

} else {

last.next = node;

}

last = node;

}

/**

* 删除一个结点,在头结点后进行删除

*/

public Node deleteFirst() {

Node tmp = first;

if(first.next == null) {

last = null;

}

first = tmp.next;

return tmp;

}

/**

* 显示方法

*/

public void display() {

Node current = first;

while(current != null) {

current.display();

current = current.next;

}

System.out.println();

}

/**

* 查找方法

*/

public Node find(long value) {

Node current = first;

while(current.data != value) {

if(current.next == null) {

return null;

}

current = current.next;

}

return current;

}

/**

* 删除方法,根据数据域来进行删除

*/

public Node delete(long value) {

Node current = first;

Node previous = first;

while(current.data != value) {

if(current.next == null) {

return null;

}

previous = current;

current = current.next;

}

if(current == first) {

first = first.next;

} else {

previous.next = current.next;

}

return current;

}

/**

* 判断是否为空

*/

public boolean isEmpty() {

return (first == null);

}

}

测试:

public class TestFirstLastLinkList {

public static void main(String[] args) {

FirstLastLinkList fl = new FirstLastLinkList();

//fl.insertFirst(34);

//fl.insertFirst(56);

//fl.insertFirst(67);

//fl.display();

//

//fl.deleteFirst();

//fl.deleteFirst();

//fl.display();

fl.insertLast(56);

fl.insertLast(90);

fl.insertLast(12);


fl.display();

fl.deleteFirst();

fl.display();

}

}

双向链表:

/*

 * 双向链表

 */

public class DoubleLinkList {

//头结点

private Node first;

//尾结点

private Node last;

public DoubleLinkList() {

first = null;

last = null;

}

/**

* 插入一个结点,在头结点后进行插入

*/

public void insertFirst(long value) {

Node node = new Node(value);

if(isEmpty()) {

last = node;

} else {

first.previous = node;

}

node.next = first;

first = node;

}

/**

* 插入一个结点,从尾结点进行插入

*/

public void insertLast(long value) {

Node node = new Node(value);

if(isEmpty()) {

first = node;

} else {

last.next = node;

node.previous = last;

}

last = node;

}

/**

* 删除一个结点,在头结点后进行删除

*/

public Node deleteFirst() {

Node tmp = first;

if(first.next == null) {

last = null;

} else {

first.next.previous = null;

}

first = tmp.next;

return tmp;

}

/**

* 删除结点,从尾部进行删除

*/

public Node deleteLast() {

Node tmp = last;

if(first.next == null) {

first = null;

} else {

last.previous.next = null;

}

last = last.previous;

return last;

}

/**

* 显示方法

*/

public void display() {

Node current = first;

while(current != null) {

current.display();

current = current.next;

}

System.out.println();

}

/**

* 查找方法

*/

public Node find(long value) {

Node current = first;

while(current.data != value) {

if(current.next == null) {

return null;

}

current = current.next;

}

return current;

}

/**

* 删除方法,根据数据域来进行删除

*/

public Node delete(long value) {

Node current = first;

while(current.data != value) {

if(current.next == null) {

return null;

}

current = current.next;

}

if(current == first) {

first = first.next;

} else {

current.previous.next = current.next;

}

return current;

}

/**

* 判断是否为空

*/

public boolean isEmpty() {

return (first == null);

}

}

测试:

public class TestDoubleLinkList {

public static void main(String[] args) {

DoubleLinkList dl = new DoubleLinkList();

dl.insertLast(45);

dl.insertLast(56);

dl.insertLast(90);

dl.display();

while(!dl.isEmpty()) {

dl.deleteFirst();

dl.display();

}

}

}