java语言实现ArrayList，LinkedList，Heap，Stack

package com.coding.basic;

public interface List {
public void add(Object o);
public void add(int index, Object o);
public Object get(int index);
public Object remove(int index);
public int size();
}

package com.coding.basic;

import java.util.Arrays;

/**
* @autor zhougd 20170306
* 数组实现ArrayList
*/
public class ArrayList implements List {

private int size = 0;

private Object[] elementData;

//扩容默认值
private static final int INCREAMENT_CAP = 10;

//含参数的构造函数
public ArrayList(int size, Object[] elementData) {
this.size = size;
this.elementData = elementData;
}

//默认100容量的构造函数
public ArrayList() {
this.size = 0;
this.elementData = new Object[100];
}

@Override
public void add(Object o) {
//判断超过容量自动扩容
if (this.size + 1 > this.elementData.length) {
increase();
}
this.elementData[size++] = o;
}

@Override
public void add(int index, Object o) {
if (index < 0 || index > this.size) {
throw new IndexOutOfBoundsException("Index out of bound!");
}
//判断超过容量自动扩容
if (this.size + 1 > this.elementData.length) {
increase();
}
this.size++;
//index后面数组后移一位
for (int cur = this.size; cur > index; cur--) {
this.elementData[cur] = this.elementData[cur - 1];
}

this.elementData[index] = o;

}

public Object get(int index) {
if (index < 0 || index > this.size) {
throw new IndexOutOfBoundsException("Index out of bound!");
}
return this.elementData[index];
}

public Object remove(int index) {
Object o = this.get(index);
this.size--;
//index后面的数向前移动一位
for (int cur = index + 1; cur < this.size; cur++) {
this.elementData[cur] = this.elementData[cur + 1];
}
return o;
}

public int size() {
return this.size;
}

107bf
public Iterator iterator() {
return new ArrayListIterator();
}

@Override
public String toString() {
String arrayStr = "ArrayList{ size = " + this.size() + " , ";

arrayStr += "elementData=[";
for(int i = 0 ;i<this.size();i++){
arrayStr +=
i == this.size()-1 ?
elementData[i]+"]":elementData[i]+","  ;
}
arrayStr+= " }";
return arrayStr;

}

private void increase() {
this.elementData = Arrays.copyOf(this.elementData, this.elementData.length + INCREAMENT_CAP);
}

private class ArrayListIterator implements Iterator {

private int currentIndex = 0;
private int count = size();

@Override
public boolean hasNext() {
return currentIndex < count-1;
}

@Override
public Object next() {
currentIndex++;
return get(currentIndex);
}
}
}

package com.coding.basic;

import java.util.NoSuchElementException;

/**
* @author zhougd 20170306
* 单向链表实现LinkedList
*/

public class LinkedList implements List {
java.util.LinkedList a;
/**
* 第一个元素
*/
private Node head;

/**
* 最后一个元素
*/
private Node tail;

/**
* 元素容量
*/
private int size = 0;

public void add(Object o){
Node node = new Node(o);
//判断是否链表为空
if(this.size() == 0){
this.addFirst(node);
}else{
this.addLast(node);
}

}
public void add(int index , Object o){
checkIndex(index);

Node oldNode= this.getNode(index);
Object oldObject = oldNode.getData();
Node next = oldNode.getNext();

//将原位置修改为新元素
oldNode.setData(o);
//设置下一个元素
oldNode.setNext(new Node(oldObject));
//设置下一个元素的下一个元素
oldNode.getNext().setNext(next);

size ++;
}

public Object get(int index){
checkIndex(index);
return this.getNode(index).getData();
}

public Object remove(int index){
checkIndex(index);
//获取到当前元素和下一个元素
//把当前元素的值设置成下一个元素的值，删除掉下一个元素，这样的话，不必管上一个元素是什么，是不是第一个元素
Node node = this.getNode(index);
Object data = node.getData();
Node nextNode = this.getNode(index + 1);
node.setData(nextNode.getData());
node.setNext(nextNode.getNext());

return data;
}

public int size(){
return this.size();
}

public void addFirst(Object o){
Node node = new Node(o);
//原头变为第二
Node temp = this.head;
this.head = node;
node.next = temp;
size++;
}
public void addLast(Object o){
Node node = new Node(o);
Node t = this.tail;
if(t == null){
this.head = node;
}else{
this.tail.next = node;
this.tail = node;
}
size++;
}
public Object removeFirst(){
Node head = this.head;
if(head == null){
throw new NoSuchElementException("No such element !");
}
this.head = this.head.getNext();
size--;
return head ;
}

public Object removeLast(){
Node node ;
if(this.tail == null){
throw new NoSuchElementException("No such element !");
}
node = this.tail;
if(this.head ==this.tail){
node = this.head;
this.head = null;
this.size = 0;
}else{
//获取尾元素的上一个元素
this.tail = this.getNode(this.size-2);
this.tail.setNext(null);
this.size--;
}

return node;
}

public Iterator iterator(){
return new LinkedListIterator();
}

private void checkIndex(int index){
if(index < 0 || index >size()){
throw new IndexOutOfBoundsException("Index out of bound !");
}
}

private Node getNode(int index ){

Node node = this.head;
for(int i = 0 ;i<size();i++){
node = node.next;
}
return node;
}

private class LinkedListIterator implements Iterator{

private int currentIndex = 0;
private int count = size();

@Override
public boolean hasNext() {
return currentIndex < count-1;
}

@Override
public Object next() {
currentIndex++;
return get(currentIndex);
}
}

private static class Node{
Object data;
Node next;

public Node(Object data) {
this.data = data;
}

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;
}
}
}

package com.coding.basic;

/**
* author by zhougd 20170306
* 链表实现队列
*/
public class Queue {
private java.util.Queue a;;
/**
* 队列体，初始100个元素
*/
private List queue = new LinkedList();

public Queue(){}

/**
* 入队
* @param o
*/
public void enQueue(Object o){
queue.add(o);
}

/**
* 出队
* @return
*/
public Object deQueue(){
return queue.remove(0);
}

/**
* 队列是否为空
* @return
*/
public boolean isEmpty(){
return queue == null || queue.size() <= 0;
}

/**
* 获取队列大小
* @return
*/
public int size(){
return queue.size();
}
}

package com.coding.basic;

/**
* author zhougd 20170306
*
*/
public class Stack {
private List elementData = new ArrayList();

public Stack() {
}

/**
* 入栈
* @param o
*/
public void push(Object o){
elementData.add(o);
}

/**
* 出栈
* @return
*/
public Object pop(){
if(this.isEmpty()){
throw new IndexOutOfBoundsException("stack is empty!");
}
Object element = elementData.get(size()-1);
elementData.remove(size()-1);
return element;
}

/**
* 查看栈顶元素
* @return Object
*/
public Object peek(){
if(this.isEmpty()){
throw new IndexOutOfBoundsException("stack is empty!");
}
Object element = elementData.get(size()-1);
return element;
}

/**
* 查看栈是否为空
* @return boolean
*/
public boolean isEmpty(){

return elementData == null || elementData.size()<=0;

}

/**
* 获取栈大小
* @return
*/
public int size(){
return elementData.size();
}
}