//寻找一个单向链表的中项,如果存在两个则返回前一个,给出算法描述,并实现
package pra_bd;
import java.awt.DisplayMode;
import javax.naming.spi.DirStateFactory.Result;
import org.w3c.dom.Node;
public class LinkList {
//头结点
Link first;
//单链表构造函数
public LinkList(){
first = null;
}
//判断单链表是否为空
public boolean isEmpty(){
return (null==first);
}
//在单链表头插入新结点
public void insertFirst(Integer value, Integer integer){
Link newLink = new Link(value);
newLink.next = first;
first = newLink;
}
//删除单链表头
public Link deleteFirst(){
Link result = first;
first = first.next;
return result;
}
//显示链表
public void display(){
Link current = first;
while(null!=current){
current.display();
current = current.next;
}
System.out.println("");
}
//计算单链表长度
public int getLength(){
int result = 0;
Link current = first;
while(null!=current){
result++;
current = current.next;
}
System.out.println("长度: "+result);
return result;
}
private class Link{
long lvalue;
Link next;
//结点构造函数
public Link(long value){
lvalue = value;
next = null;
}
//显示结点
public void display(){
System.out.print(lvalue+" ");
}
public long length(){
return this.length( );
}
}
public static Link getMiddleNode(Link first) {
// TODO Auto-generated constructor stub
if (first==null||first.next==null ){
return first;
}
Link p=first;
Link q=first;
while(q.next!=null){
q=q.next;
p=p.next;
if(q.next!=null){
q=q.next;
}
System.out.println("fanhui"+p);
}
return p;
}
public long length(Link node){
if(node==null)
return 0;
else if(node.next==null)
return 1;
else
return 1+this.length(node.next);
}
public static void main(String[] args) {
// TODO Auto-generated method stub
//测试单链表
LinkList linklist = new LinkList();
int a [] = {100,200,300};
for(int i=0;i<a.length;i++){
linklist.insertFirst(a[i],new Integer(i+1));
}
// linklist.insertFirst(1);
// linklist.insertFirst(2);
// linklist.insertFirst(3);
// linklist.insertFirst(4);
// linklist.insertFirst(5);
// linklist.insertFirst(6);
linklist.display();
// linklist.deleteFirst();
// linklist.deleteFirst();
linklist.getLength();
Link.getMiddleNode();//就是这一行报错!!!!
}
}
最后getmiddlenode怎么调用啊,显示有问题,谢谢大家!