数据结构(LinkedList的java实现)

 package day10;
import java.util.*;
public class MyLinkedList implements List
{
static class Node
{
public Object data;
public Node next;
public Node(Object data)
{
this.data=data;
}
}
private Node head;
public  MyLinkedList()
{
head=new Node(0);
}
public void add(int index, Object element)
{
if(index<(Integer)head.data)
{
Node current;
current=head;
for(int i=0;i<index;i++)
{
current=current.next;
}
Node p=new Node(element);
p.next=current.next;
current.next=p;   
head.data=(Integer)head.data+1;
}
else
{
System.out.println("ERROR!");
}
}
@Override
public boolean add(Object e)
{
Node current=head;
while(current.next!=null)
{
current=current.next;
}
Node p=new Node(e);
current.next=p;   
head.data=(Integer)head.data+1;
return true;
}
@Override
public boolean addAll(Collection c) {
// TODO Auto-generated method stub
return false;
}
@Override
public boolean addAll(int index, Collection c) {
// TODO Auto-generated method stub
return false;
}
@Override
public void clear()
{
head.next=null;
}
@Override
public boolean contains(Object o)
{
Node current=head;
while(current.next!=null)
{
current=current.next;
if(current.data.equals(o))
{
return true;
}
}
return false;
}
@Override
public boolean containsAll(Collection c)
{
// TODO Auto-generated method stub
return false;
}
@Override
public Object get(int index)
{
Node current;
current=head.next;
for(int i=0;i<index;i++)
{
current=current.next;
}
return current.data;
}
@Override
public int indexOf(Object o)
{
int i;
Node current=head;
for(i=0;i<(Integer)head.data;i++)
{
current=current.next;
if(current.data.equals(o))
{
break;
}
}
if(i<(Integer)head.data)
{
return i;
}
return -1;
}
@Override
public boolean isEmpty()
{
if(head.next!=null)
{
return true;
}
return false;
}
@Override
public Iterator iterator()
{
return new Iterator()
{
Nod