Java单链表的实现代码

 public class Node { protected Node next; //指针域 public int data;//数据域 public Node( int data) { this. data = data; } //显示此节点 public void display() { System. out.print( data + " "); } }

 public class LinkList { public Node first; // 定义一个头结点 private int pos = 0;// 节点的位置 public LinkList() { this.first = null; } // 插入一个头节点 public void addFirstNode(int data) { Node node = new Node(data); node.next = first; first = node; } // 删除一个头结点,并返回头结点 public Node deleteFirstNode() { Node tempNode = first; first = tempNode.next; return tempNode; } // 在任意位置插入节点 在index的后面插入 public void add(int index, int data) { Node node = new Node(data); Node current = first; Node previous = first; while (pos != index) { previous = current; current = current.next; pos++; } node.next = current; previous.next = node; pos = 0; } // 删除任意位置的节点 public Node deleteByPos(int index) { Node current = first; Node previous = first; while (pos != index) { pos++; previous = current; current = current.next; } if (current == first) { first = first.next; } else { pos = 0; previous.next = current.next; } return current; } // 根据节点的data删除节点(仅仅删除第一个) public Node deleteByData(int data) { Node current = first; Node previous = first; // 记住上一个节点 while (current.data != data) { if (current.next == null) { return null; } previous = current; current = current.next; } if (current == first) { first = first.next; } else { previous.next = current.next; } return current; } // 显示出所有的节点信息 public void displayAllNodes() { Node current = first; while (current != null) { current.display(); current = current.next; } System.out.println(); } // 根据位置查找节点信息 public Node findByPos(int index) { Node current = first; if (pos != index) { current = current.next; pos++; } return current; } // 根据数据查找节点信息 public Node findByData(int data) { Node current = first; while (current.data != data) { if (current.next == null) return null; current = current.next; } return current; } }

 public class TestLinkList { public static void main(String[] args) { LinkList linkList = new LinkList(); linkList.addFirstNode(20); linkList.addFirstNode(21); linkList.addFirstNode(19); //print19,21,20 linkList.add(1, 22); //print19,22,21,20 linkList.add(2, 23); //print19,22,23,21,20 linkList.add(3, 99); //print19,22,23,99,21,20 //调用此方法会print 19,22,23,99,21,20 linkList.displayAllNodes(); } }