package com.coding.weak1;
public class LinkedList implements List {
private Node head;
private int size;
public void add(Object o){
addLast(o);
}
public void add(int index , Object o){
if (index < 0 || index > size){
throw new IndexOutOfBoundsException("index: "+index);
}
if (index == size){
addLast(o);
}else if(index == 0) {
addFirst(o);
}else {
Node preNode = node(index - 1);
Node indexNode = node(index);
preNode.next = new Node(o, indexNode);
size++;
}
}
public Object get(int index){
Node node = node(index);
return node.data;
}
private Node node(int index){
if(index < 0 || index >= size){
throw new IndexOutOfBoundsException("index: "+index + ",size: "+size);
}
Node node = head;
for (int i = 0; i < size; i++ ){
if(i == index){
return node;
}
node = node.next;
}
return null;
}
public Object remove(int index){
if(index < 0 || index >= size){
throw new IndexOutOfBoundsException("index: "+index + ",size: "+size);
}
if(index == 0){
return removeFirst();
}else if(index == size-1){
return removeLast();
}
Node indexNode = node(index);
Node prev = node(index - 1);
Node next = node(index + 1);
prev.next = next;
size--;
return indexNode.data;
}
public int size(){
return size;
}
public void addFirst(Object o){
if (head == null)
head = new Node(o, null);
else {
Node node = new Node(o, head);
head = node;
}
size++;
}
public void addLast(Object o){
if(head == null){
head = new Node(o, null);
}else {
Node node = head;
for(int i = 0; i < size-1; i++){
node = node.next;
}
node.next = new Node(o, null);
}
size++;
}
public Object removeFirst(){
if(head == null)
return null;
Node oldFirst = head;
head = oldFirst.next;
size--;
return oldFirst;
}
public Object removeLast(){
if(head == null)
return null;
Node oldLast = node(size - 1);
Node preLast;
if (size - 2 >= 0){
preLast = node(size - 2);
preLast.next = null;
} else {
head = null;
}
size--;
return oldLast;
}
public Iterator iterator(){
return new LinkedListIter();
}
private class LinkedListIter implements Iterator{
private int cursor;
@Override
public boolean hasNext() {
return cursor++ < size;
}
@Override
public Object next() {
int index = cursor;
if(index > size)
throw new IndexOutOfBoundsException();
Node node = node(index);
cursor++;
return node.data;
}
}
private static class Node{
Object data;
Node next;
public Node(Object data, Node next) {
this.data = data;
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(){
}
/**
* 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(){
}
/**
* 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){
}
/**
* 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;
}
}