package com.java.gsl;
public class LinkedList implements List {
private Node head;
private int size = 0;
public void add(Object o){
}
public void add(int index , Object o){
if(index < 0 || index > size ){
return;
}
Node node = (Node) (index==size ? head : get(index));
Node prenode = node.pre;
// Node l = last;
// Node newNode = new Node(l, o, null);
// last = newNode;
// if (l == null)
// head = newNode;
// else
// l.next = newNode;
// size++;
}
public Object get(int index){
if (index < 0 || index >= size){
System.out.println("错误");
return null;
}
// 获取index处的节点。
// 若index < 双向链表长度的1/2,则从前先后查找;
// 否则，从后向前查找。
if (index < (size/2 )) {
for (int i = 0; i <= index; i++)
head = head.next;
} else {
for (int i = size; i > index; i--)
head = head.pre;
}
return head;
}
public Object remove(int index){
Node x = (Node) get(index);
Node next = x.next;
Node prev = x.pre;
if (prev == null) {
head = next;
} else {
prev.next = next;
x.pre = null;
}
if (next == null) {
x.last = prev;
} else {
next.pre = prev;
x.next = null;
}
size--;
return get(index);
}
public int size(){
return -1;
}
public void addFirst(Object o){
}
public void addLast(Object o){
}
public Object removeFirst(){
return null;
}
public Object removeLast(){
return null;
}
public Iterator iterator(){
return null;
}
private static class Node{
Object data;
Node next;
Node pre;
Node last;
}
}