package xyy.baselinked;
/**
* Created by 14258 on 2017/3/14.
*/
public class LinkedList implements List {
private Node head;
private int size;
@Override
public void add(Object o) {
addLast(o);
}
@Override
public void add(int index, Object o) {
if (index < 0 || index > size) {
throw new IndexOutOfBoundsException();
}
if (index == 0) {
addFirst(o);
return;
}
if (index == size) {
addLast(o);
return;
}
Node newNode = new Node(o);
Node node = head;
for (int i = 1; i < index; i++) {
node = node.next;
}
newNode.next = node.next;
node.next = newNode;
size++;
}
@Override
public Object remove(int index) {
if (index < 0 || index >= size) {
throw new IndexOutOfBoundsException();
}
if (index == 0) {
return removeFirst();
}
Node node = head;
Node pre = head;
for (int i = 1; i < index; i++) {
if (node.next != null) {
pre = node;
node = node.next;
}
}
Object obj = node.data;
if (head.next == null) {
head = null;
pre = null;
} else if (node.next == null) {
pre.next = null;
node = null;
} else {
pre.next = node.next;
node.next = null;
node = null;
}
size--;
return obj;
}
@Override
public int size() {
return size;
}
@Override
public Object get(int index) {
if (index < 0 || index >= size) {
throw new IndexOutOfBoundsException();
}
Node node = head;
for (int i = 0; i < index; i++) {
node = node.next;
}
Object data = node.data;
return data;
}
public void addFirst(Object o) {
Node newNode = new Node(o);
newNode.next = head;
head = newNode;
size++;
}
public void addLast(Object o) {
Node newNode = new Node(o);
if (head == null) {
head = newNode;
} else {
if (head.next == null) {
head.next = newNode;
} else {
Node node = head;
for (int i = 1; i < size; i++) {
node = node.next;
}
node.next = newNode;
}
}
}
public Object removeFirst() {
if (size <= 0) {
throw new IndexOutOfBoundsException();
}
Node node = head;
head = node.next;
node.next = null;
size--;
return node.data;
}
public Object removeLast() {
if (size <= 0) {
throw new IndexOutOfBoundsException();
}
Node node = head;
for (int i = 1; i < size; i++) {
node = node.next;
}
Object data = node.next.data;
node.next = null;
size--;
return data;
}
private class LinkedListIterator implements Iterator {
private Node node = head;
public boolean hasNext() {
return node != null;
}
public Object next() {
Object data = node.data;
node = node.next;
return data;
}
public void moveFirst() {
node = head;
}
}
public Iterator iterator() {
return new LinkedListIterator();
}
private static class Node {
Object data;
Node next;
public Node(Object data) {
this.data = data;
}
}
/**
* 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 node = head.next;
// Object[] arr = new Object[size];
// int i = size - 1;
// while (i >= 0) {
// arr[i--] = node.data;
// node = node.next;
// }
// node = head.next;
// for (int j = 0; j < size; j++) {
// node.data = arr[j];
// node = node.next;
// }
if (size <= 0) {
throw new IndexOutOfBoundsException("链表下表越界" + size);
}
Node node = head;
Node minNode = node;
int length = size;
for (int i = 0; i < length; i++) {
if (node.next != null) {
node = node.next;
addFirst(node.data);
}
}
minNode.next = null;
node = null;
size = length;
}
/**
* 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) {
throw new IndexOutOfBoundsException("链表下标越界" + size);
}
Node node = head;
Node pre = head;
int count = 0;
for (int i = 0; i < size / 2; i++) {
pre = node;
node = node.next;
count++;
}
head = node;
pre.next = null;
pre = null;
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) {
if (i < 0 || i >= size || length < 0 || length > size || (i + length > size)) {
throw new IndexOutOfBoundsException();
}
Node node = head;
Node pre = head;
Node iNode = head;
for (int j = 0; j < i + length; j++) {
if (node.next != null) {
pre = node;
if (j == (i - 1)) {
iNode = node;
}
node = node.next;
}
}
if (i == 0) {
head = node;
} else {
iNode.next = node;
}
pre.next = null;
pre = null;
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) {
if (list == null || list.size() == 0) {
throw new IndexOutOfBoundsException();
}
int[] arr = new int[list.size()];
for (int i = 1; i < list.size(); i++) {
int index = (Integer) list.get(i);
arr[i] = (Integer) get(index);
}
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) {
if (list == null || list.size() == 0) {
return;
}
for (int i = 0; i < list.size(); i++) {
int data = (Integer) list.get(i);
LinkedListIterator iterator = (LinkedListIterator) this.iterator();
int index = 0;
while (iterator.hasNext()) {
int obj = (Integer) iterator.next();
if (obj == data) {
remove(index);
iterator.moveFirst();
break;
}
index++;
}
}
}
/**
* 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 (head == null) {
return;
}
Node node = head;
Node pre = head;
while (node.next != null) {
node = node.next;
int value = (Integer) pre.data;
if ((Integer) node.data == value) {
//如果node 下一个是null.直接把node前一个pre的next指向空
if (node.next == null) {
pre.next = null;
size--;
break;
}
pre.next = node.next;
node = node.next;
size--;
}
pre = pre.next;
}
}
/**
* 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
*/
}