1.定义Node节点类
/* * 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(long value) { this.data = value; } /** * 显示方法 */ public void display() { System.out.print(data + " "); } }
2.定义双端链表类FirstLastLinkList
/* * 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); } }