原理：
双端链表就是在上节链表的基础上加上了一个尾结点，据说是为了可以从尾部插入，可是我没用尾结点一样可以实现，顿时感觉双端链表很是鸡肋。
所以不多说代码奉上吧：
public class FirstLastLinklist {
private Node first;
private Node last; //尾结点
public FirstLastLinklist() {
// TODO Auto-generated constructor stub
first =null;
last = null;
}
public void insertFirst(int value) //头部插入
{
Node node = new Node(value);
if(IsEmpty())
{
first = node;
last =node ;
}
else
{
node.next = first;
first = node;
}
}
public void insertLast(int value) //从尾部插入结点
{
Node node = new Node(value);
if(IsEmpty())
{
first = node;
last =node;
}
else
{
last.next =node;
last = node;
}
}
public void deleteFirst() //删除头结点
{
Node tmp = first.next;
first= tmp;
if(first == null)
last =null;
}
public void find(int value) //查找数据
{
Node current = first;
while(current.data != value)
{
current =current.next;
}
current.display();
}
public void findDelete(int value) //查找数据并且删除
{
Node current = first;
Node pro = null;
if(first.data ==value)
{
first =first.next;
}
else
{
while(current.data != value)
{
pro =current;
current =current.next;
}
pro.next = current.next;
}
}
public boolean IsEmpty() //判断链表是否为空
{
return (first == null);
}
public void display() //显示全部结点
{
Node current = first;
while(current != null)
{
current.display();
current =current.next;
}
}
}