package com.coding.basic.linklist;
import java.util.NoSuchElementException;
import com.coding.basic.Iterator;
import com.coding.basic.List;
public class LinkedList implements List {
private Node head;
private int size;
public void add(Object o) {
Node newNode = new Node(o, null);
if (head == null) {
head = newNode;
} else {
Node tmp = head;
while (tmp.next != null) {
tmp = tmp.next;
}
tmp.next = newNode;
}
size++;
}
public void add(int index, Object o) {
checkMinBound(index);
checkMaxBound(index, size);
Node newNode = new Node(o, null);
if (index == 0) {
newNode.next = head;
head = newNode;
} else {
int pos = 1;
Node tmp = head;
while (pos != index) {
tmp = tmp.next;
pos++;
}
newNode.next = tmp.next;
tmp.next = newNode;
}
size++;
}
private void checkMinBound(int index) {
if (index < 0) {
throw new IllegalArgumentException();
}
}
private void checkMaxBound(int index, int max) {
if (index > max) {
throw new IndexOutOfBoundsException();
}
}
public Object get(int index) {
checkMinBound(index);
checkMaxBound(index, size - 1);
Node cur = head;
if (index != 0) {
int pos = 0;
do {
cur = cur.next;
pos++;
} while (pos != index);
}
return cur.data;
}
public Object remove(int index) {
checkMinBound(index);
checkMaxBound(index, size - 1);
Node cur = head;
if (index == 0) {
head = cur.next;
} else {
int pos = 1;
Node prev = cur;
while (pos != index) {
prev = prev.next;
pos++;
}
cur = prev.next;
prev.next = cur.next;
}
size--;
return cur.data;
}
public int size() {
return size;
}
public void addFirst(Object o) {
Node newNode = new Node(o, null);
newNode.next = head;
head = newNode;
size++;
}
public void addLast(Object o) {
Node newNode = new Node(o, null);
if (head == null) {
head = newNode;
} else {
Node tmp = head;
while (tmp.next != null) {
tmp = tmp.next;
}
tmp.next = newNode;
}
size++;
}
public Object removeFirst() {
if (head == null) {
throw new NoSuchElementException();
}
Node ret = head;
head = head.next;
size--;
return ret.data;
}
public Object removeLast() {
if (head == null) {
throw new NoSuchElementException();
}
Node ret;
if (head.next == null) {
ret = head;
head = null;
} else {
Node prev = head;
ret = head.next;
while (ret.next != null) {
prev = ret;
ret = ret.next;
}
prev.next = null;
}
size--;
return ret.data;
}
public Iterator iterator() {
return null;
}
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() {
if(size == 0 || size == 1){
return ;
}
Node node = head;
Node nextNode = head.next;
Node tmp;
node.next = null;
do{
tmp = nextNode.next;
nextNode.next = node;
node = nextNode;
nextNode = tmp;
}while(nextNode != null);
head = node;
}
/**
* 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() {
if(size == 0 || size == 1){
return ;
}
int num = size / 2;
size -= num;
Node node = head;
while(num > 0){
node = node.next;
num--;
}
head = node;
}
/**
* 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) {
checkMinBound(i);
checkMaxBound(i + length, size);
Node prev = null;
Node node = head;
int index = 0;
while(index < i){
prev = node;
node = node.next;
index++;
}
Node nextNode = node.next;
while(index < (i + length - 1)){
nextNode = nextNode.next;
index++;
}
size -= length;
if(i == 0){
head = nextNode;
}else{
prev.next = nextNode;
head = prev;
}
}
/**
* 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[] ret = new int[list.size()];
if(ret.length == 0){
return ret;
}
int index;
int j = 0;
Node node = head;
for(int i=0;i<list.size();i++){
index = (int)list.get(i);
while(j < index){
node = node.next;
if(node == null){
throw new IndexOutOfBoundsException();
}
j++;
}
ret[i] = (int)node.data;
}
return ret;
}
/**
* 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) {
if(size == 0){
return ;
}
Node prev = null;
Node node = head;
int data;
for(int i=0;i<list.size();i++){
data = (int)list.get(i);
do{
if(data == (int)node.data){
if(prev == null){
head = node.next;
}else{
prev.next = node.next;
}
size--;
node = node.next;
break;
}
prev = node;
}while((node = node.next) != null);
}
}
/**
* 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() {
if(size == 0 || size == 1){
return ;
}
Node node = head;
Node next = node.next;
do{
if((int)node.data == (int)next.data){
node.next = next.next;
size--;
}else{
node = node.next;
}
next = next.next;
}while(next != 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。
* 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) {
Node prev = null;
Node node = head;
boolean foundMin = false;
do{
if(!foundMin && (int)node.data > min){
foundMin = true;
}
if(foundMin && (int)node.data > max){
break;
}
if(foundMin == false){
prev = node;
}else{
size -= 1;
}
node = node.next;
}while(node != null);
if(prev == null){
head = node;
}else{
prev.next = node;
}
}
/**
* 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 ret = new LinkedList();
Node node = head;
int nodeValue;
int elementValue;
for(int i=0;i<list.size();i++){
nodeValue = (int)node.data;
elementValue = (int)list.get(i);
if(nodeValue == elementValue){
ret.add(nodeValue);
}else if(nodeValue < elementValue){
node = node.next;
while(node != null){
nodeValue = (int)node.data;
if(nodeValue == elementValue){
ret.add(nodeValue);
node = node.next;
break;
}else if(nodeValue > elementValue){
break;
}
node = node.next;
}
}
}
return ret;
}
public String toString(){
Node node = head;
StringBuilder sb = new StringBuilder();
if(node == null){
return "";
}else{
sb.append(head.data);
while((node = node.next) != null){
sb.append(",").append(node.data);
}
return sb.toString();
}
}
}