package com.ace.coding;
import java.lang.reflect.Array;
public class LinkedList implements List {
private Node head = null;
private int size = 0;
public void add(Object o){
Node newNode = new Node();
newNode.data = o;
if(head == null){
head = newNode;
} else {
Node pNode = head;
while(pNode.next != null){
pNode = pNode.next;
}
pNode.next = newNode;
}
size++;
}
public void add(int index , Object o){
checkLinkedListIndex(index);
Node newNode = new Node();
newNode.data = o;
Node pNode = getNode(index);
newNode.next = pNode.next;
pNode.next = newNode;
size++;
}
private Node getNode(int index){
Node pNode = head;
for(int i = 0; i < index; i++){
pNode = pNode.next;
}
return pNode;
}
public Object get(int index){
Node pNode = getNode(index);
return pNode.data;
}
public Object remove(int index){
checkLinkedListIndex(index);
if(index == 0){
return removeFirst();
}
Node pNode = head;
for(int i = 0; i < index - 1; i++){
pNode = pNode.next;
}
Node tempNode = getNode(index);
pNode.next = tempNode.next;
size--;
return tempNode.data;
}
public void addFirst(Object o){
Node newNode = new Node();
newNode.data = o;
newNode.next = head;
head = newNode;
size++;
}
public void addLast(Object o){
Node newNode = new Node();
newNode.data = o;
Node pNode = getNode(size() - 1);
pNode.next = newNode;
size++;
}
public Object removeFirst(){
Node pNode = head;
head = pNode.next;
size--;
return pNode.data;
}
public Object removeLast(){
Object obj = remove(size() - 1);
return obj;
}
public int size(){
return size;
}
private void checkLinkedListIndex(int index){
if(index < 0 || index >= size()){
throw new IndexOutOfBoundsException("The index " + index + " is invalid.");
}
}
public Iterator iterator(){
return null;
// return new ListIterator();
}
/*private class ListIterator implements Iterator{
private Node pNode = head;
@Override
public boolean hasNext() {
// TODO Auto-generated method stub
return pNode.next != null;
}
@Override
public Object next() {
// TODO Auto-generated method stub
Object obj = pNode.data;
pNode = pNode.next;
return obj;
}
}*/
private static class Node{
Object data;
Node 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(){
Node headNode = head;
Node newNode = null;
reverseNode(headNode, newNode);
}
private void reverseNode(Node headNode, Node newHead){
if(headNode != null){
return ;
}
Node next = headNode.next;
headNode.next = newHead;
if(next == null){
return ;
}
reverseNode(next, headNode);
}
private void checkLinkedListSize(){
if(this.size() <= 0){
throw new IndexOutOfBoundsException();
}
}
/**
* 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(){
//check empty
checkLinkedListSize();
int count = 1;
Node pNode = head;
for (int i = 0; i < size() / 2 - 1; i++) {
pNode = pNode.next;
count++;
}
head = pNode.next;
size = size() - count;
}
/**
* 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){
//check empty
// check i and length are validate
checkLinkedListSize();
checkLinkedListIndex(i);
checkLinkedListIndex(i+length);
if(i == 0){
Node pNode = getNode(length - 1);
head = pNode.next;
} else {
Node pNode = getNode(i - 1);
Node tempNode = getNode(i + length - 1);
pNode.next = tempNode.next;
}
size = size - 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 int[] getElements(LinkedList list){
int[] newArray = new int[list.size()];
ArrayList newArrayList = new ArrayList();
for(int i = 0; i < list.size(); i++){
newArray[i] = (int)this.get((int)list.get(i));
}
return newArray;
}
/**
* 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){
ArrayList arrayList = new ArrayList();
for(int i = 0; i < this.size(); i++){
for(int j = 0; j < list.size(); j++){
if(this.get(i) == list.get(j)){
arrayList.add(i);
break;
}
}
}
for(int k = 0; k < arrayList.size(); k++){
this.remove((int)arrayList.get(k) - k);
}
}
/**
* 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(){
ArrayList arrayList = new ArrayList();
for(int i = 0; i < this.size() - 1; i++){
if(this.get(i) == this.get(i+1)){
arrayList.add(i);
}
}
for(int k = 0; k < arrayList.size(); k++){
this.remove((int)arrayList.get(k) - k);
}
}
/**
* 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){
ArrayList newArrayList = new ArrayList();
int count = 0;
int start = 0;
int end = 0;
for (int i = 0; i < this.size(); i++) {
if(min >= (int)this.get(i)){
start = i+1;
}
if(max >= (int)this.get(i)){
end = i;
}
}
this.remove(start, end-start);
}
/**
* 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){
LinkedList newLinkedList = new LinkedList();
int l1 = 0;
int l2 = 0;
while(l1 < this.size() && l2 < list.size()){
if(this.get(l1) == list.get(l2)){
newLinkedList.add(this.get(l1));
l1 ++;
l2 ++;
} else if ((int)this.get(l1) > (int)list.get(l2)){
l1 ++;
} else {
l2 ++;
}
}
return newLinkedList;
}
private boolean contains(Object obj){
for(int i = 0; i < this.size(); i++){
if(this.get(i) == obj){
return true;
}
}
return false;
}
}