package com.liam.learn.code2017;
public class LinkedList implements List {
private int size;
private Node head;
private Node tail;
public void add(Object o){
Node node = new Node(o, null);
if(head == null){
head = node;
tail = node;
}else{
tail.setNext(node);
tail = node;
}
size++;
}
public void add(int index , Object o){
if (index < 0 || index >= size){
throw new IllegalArgumentException("链表越界");
}
if (index == 0){
addFirst(o);
}else if(index == size-1){
addLast(o);
}else{
Node indexNode = getNode(index);
Node newNode = new Node(o, indexNode);
Node previousNode = getNode(index-1);
previousNode.setNext(newNode);
}
size++;
}
public Object get(int index){
Node node = getNode(index);
return node.getData();
}
private Node getNode(int index){
if (index < 0 || index >= size){
throw new IllegalArgumentException("链表越界");
}
if(index == 0){
return head;
}
if(index == size-1){
return tail;
}
Node temp = head;
for(int i=0; i<index; i++){
temp = temp.next;
}
return temp;
}
public Object remove(int index){
if (index < 0 || index >= size){
throw new IllegalArgumentException("链表越界");
}
if (index == 0){
return removeFirst();
}else if(index == size-1){
return removeLast();
}else{
Node previousNode = getNode(index-1);
Node nextNode = getNode(index+1);
previousNode.setNext(nextNode);
size--;
}
return get(index);
}
public int size(){
return size;
}
public void addFirst(Object o){
Node node = new Node(o, null);
if(head == null){
head = node;
tail = node;
}else{
node.setNext(head);
head = node;
}
size++;
}
public void addLast(Object o){
Node node = new Node(o, null);
if(head == null){
head = node;
tail = node;
}else{
tail.setNext(node);
tail = node;
}
size++;
}
public Object removeFirst(){
if (head == null){
throw new RuntimeException("链表为空");
}
if (size ==1){
Object ret = head.getData();
head = null;
tail = null;
return ret;
}
Object headData = head.getData();
head = getNode(1);
size--;
return headData;
}
public Object removeLast(){
if (head == null){
throw new RuntimeException("链表为空");
}
Object tailData = tail.getData();
tail = getNode(size-2);
size--;
return tailData;
}
public Iterator iterator(){
return null;
}
private static class Node{
private Object data;
private Node next;
public Node(Object data, Node next) {
this.data = data;
this.next = next;
}
public Object getData() {
return data;
}
public void setData(Object data) {
this.data = data;
}
public Node getNext() {
return next;
}
public void setNext(Node next) {
this.next = next;
}
}
/**
* 把该链表逆置
* 例如链表为 3->7->10 , 逆置后变为 10->7->3
*/
public void reverse(){
if(size == 0 || size ==1){
return;
}
/*LinkedList linkedList = new LinkedList();
for(int i=size-1; i>=0; i--){
linkedList.add(getNode(i));
}*/
Node temp = head;
head = tail;
tail = temp;
for(int i=size-2; i>=1; i--){
getNode(i+1).setNext(getNode(i));
}
getNode(1).setNext(tail);
}
/**
* 删除一个单链表的前半部分
* 例如：list = 2->5->7->8 , 删除以后的值为 7->8
* 如果list = 2->5->7->8->10 ,删除以后的值为7,8,10
*/
public void removeFirstHalf(){
int pre = size/2;
for (int i=0; i<pre; i++){
remove(i);
}
}
/**
* 从第i个元素开始， 删除length 个元素 ， 注意i从0开始
* @param i
* @param length
*/
public void remove(int i, int length){
for (int x=i; x<i+length; i++){
remove(i);
}
}
/**
* 假定当前链表和list均包含已升序排列的整数
* 从当前链表中取出那些list所指定的元素
* 例如当前链表 = 11->101->201->301->401->501->601->701
* listB = 1->3->4->6
* 返回的结果应该是[101,301,401,601]
* @param list
*/
public static int[] getElements(LinkedList list){
return null;
}
/**
* 已知链表中的元素以值递增有序排列，并以单链表作存储结构。
* 从当前链表中中删除在list中出现的元素
* @param list
*/
public void subtract(LinkedList list){
}
/**
* 已知当前链表中的元素以值递增有序排列，并以单链表作存储结构。
* 删除表中所有值相同的多余元素（使得操作后的线性表中所有元素的值均不相同）
*/
public void removeDuplicateValues(){
}
/**
* 已知链表中的元素以值递增有序排列，并以单链表作存储结构。
* 试写一高效的算法，删除表中所有值大于min且小于max的元素（若表中存在这样的元素）
* @param min
* @param max
*/
public void removeRange(int min, int max){
}
/**
* 假设当前链表和参数list指定的链表均以元素依值递增有序排列（同一表中的元素值各不相同）
* 现要求生成新链表C，其元素为当前链表和list中元素的交集，且表C中的元素有依值递增有序排列
* @param list
*/
public LinkedList intersection( LinkedList list){
return null;
}
}