java 单向链表

精选转载

ybxywz 2013-11-04 10:12:21

文章标签 Object null return public 文章分类 Java 后端开发

/**
 * 链表结点类
 */
class Node{
 private Object data;  //链表结点的数据域
 private Node next;   //链表结点的指针域，指向直接后继结点

 public Node(){
  data = null;
  next = null;
 }

 public Node(Object data, Node next){
  this.data = data;
  this.next = next;
 }

 public Object getData(){
  return this.data;
 }

 public void setData(Object data){
  this.data = data;
 }

 public Node getNext(){
  return this.next;
 }

 public void setNext(Node next){
  this.next = next;
 }
}

/**
 * 链表类
 */
class LinkList{
 private Node head = null; //头结点指针
 private int size = 0;

 public LinkList(){
  head = new Node();
  size = 0;
 }

 //在i位置插入元素elem
 public boolean addAt(int i, Object elem) {
  if(i < 0 || i > size){
   return false;
  }

  Node pre,curr;
  int pos;
  for(pre=head; i>0 && pre.getNext()!=null; i--,pre=pre.getNext());
  curr = new Node(elem, pre.getNext());
  pre.setNext(curr);
  size++;
  return true;
 }

 //删除i位置的元素
 public boolean removeAt(int i) {
  if(i < 0 || i >= size){
   return false;
  }

  Node pre,curr;
  for(pre=head; i>0 && pre.getNext()!=null; i--,pre=pre.getNext());  
  curr = pre.getNext();
  pre.setNext(curr.getNext());
  size--;
  return true;
 }

 //根据值value查询结点是否存在，若存在返回位置，否则返回-1
 public int findByValue(Object value){
  Node curr;
  int pos;
  for(pos=0,curr=head.getNext(); curr!=null; pos++,curr=curr.getNext()){
   if(curr.getData().toString().equals(value.toString())){
    break;
   }
  }

  if(curr==null){
   return -1;
  }
  return pos;
  //return (curr!=null ? pos : -1);
 }

 public int getSize(){
  return size;
 }

 public boolean isEmpty(){
  return (size==0);
 }

 public void listAll(){
  for(Node curr=head.getNext(); curr!=null; curr=curr.getNext()){
   System.out.print(curr.getData() + "\t");
  }
  System.out.println();
 }
}