数组

数组的代码

public class Myarr<T> {private int capacity=0;private int size=0;private T[]arr;//如果是空的则强制将容量扩充为10public Myarr(int capacity) {if (this.size == 0) {this.capacity = 10;this.arr=(T[]) new Object[this.capacity];}}//按顺序添加数据public void add(T value){if(this.size>=capacity){T[]arr1=Arrays.copyOf(arr,2*this.capacity);this.arr=arr1;this.capacity=this.capacity*2;}arr[this.size++]=value;}//按下标删除数据public void delete(int index){if(index>=this.size||index<0){System.out.println("输入有误");return;}if((this.size<=capacity/4)&&(capacity/4>0)){T []arr1=Arrays.copyOf(arr,this.capacity/4);this.arr=arr1;this.capacity=this.capacity/4;}for(int i=index+1;i<this.size;i++){arr[i-1]=arr[i];}this.size--;}//查找指定下标的数据public void search(int index){if(index>=this.size||index<0){System.out.println("输入有误");return;}System.out.println(index+"处的值为:"+arr[index]);}//修改指定下标的值public void modify(int index,T value){if(index>=this.size||index<0){System.out.println("输入有误");return;}arr[index]=value;}//将数组转为字符串输出@Overridepublic String toString() {StringBuffer stringBuffer=new StringBuffer();stringBuffer.append('[');for(int i=0;i<this.size;i++){stringBuffer.append(arr[i]);if(i!=this.size-1){stringBuffer.append(",");}}stringBuffer.append("]");return stringBuffer.toString();}//向数组指定位置添加数值public void aimedAdd(int index,T value){if(index<0||index>this.capacity){throw new IllegalArgumentException("索引越界！");}if(this.size>=capacity){T []arr1=Arrays.copyOf(arr,2*this.capacity);this.arr=arr1;this.capacity=this.capacity*2;}//当添加的数值大于数组实际长度时将进行扩容this.size++;for(int i=this.size;i>index;i--){arr[i]=arr[i-1];}arr[index]=value;}//获取数组长度public int getsize(){return this.size;}//获取数组容积public int getCapacity(){return this.capacity;}public T remove(){if((this.size<=capacity/4)&&(capacity/4>0)){T []arr1=Arrays.copyOf(arr,this.capacity/4);this.arr=arr1;this.capacity=this.capacity/4;}//当数组实际使用长度小于容积的四分之一时将对容积进行缩容arr[size]=null;this.size--;return arr[size];}public T gethead(){return arr[size-1];}
}

链表

链表的代码

public class MyLinkList<T> {class Node<T>{//使用内部类创建节点T data;//节点本身的数据Node next;//指向下一个节点public Node(T data,Node node){//内部类的构造this.data=data;this.next=node.next;}public Node(T data){this.data=data;this.next=null;}}//链表相关的属性和方法private Node head;//链表的头结点private int size;public MyLinkList(){this.head=new Node(null);this.size=0;}//判断链表是否为空public boolean isEmpty(){return this.size==0;}//头部插入元素public void addHead(T data){//1.创建结点Node node=new Node(data);node.next=node;//2.挂接node.next=this.head;this.head=node;//3.更新sizethis.size++;}public void addTail(T data){Node node=new Node(data);Node curnode=this.head;if(this.head==null){this.head=node;}else {while (curnode.next!=null){curnode=curnode.next;}curnode.next=node;}this.size++;}//获取链表大小public int getsize(){return this.size;}// 重写toString 打印链表中的数据@Overridepublic String toString(){//从头结点开始向后遍历Node curnode=this.head;StringBuffer stringBuffer=new StringBuffer();while(curnode!=null){stringBuffer.append(curnode.data+"--->");curnode=curnode.next;}stringBuffer.append("null");return stringBuffer.toString();}//根据索引获得链表的值public T getByIndex(int index){//1.判断索引是否有效if(index<0||index>this.size){throw new IllegalArgumentException("索引无效");}Node<T> curNode=this.head.next;int i=0;while(i<index){curNode=curNode.next;i++;}return curNode.data;}//从链表头部删除元素public T deleteHead(){if(this.isEmpty()){return null;}Node<T> delNode=this.head.next;this.head.next=delNode.next;delNode.next=null;this.size--;return delNode.data;}//从链表尾部删除元素public T deletetail(){if (this.isEmpty()){return null;}Node<T> pre=this.head;while(pre.next.next!=null){pre=pre.next;}this.size--;Node<T> delNode=pre.next;pre.next=delNode.next;delNode.next=null;return delNode.data;}//在链表任意位置删除public T deleteByIndex(int index){int count=1;if(index<0||index>this.size){return null;}Node<T> pre=this.head;while(pre.next!=null) {pre = pre.next;count++;if (count == index) {break;}}Node<T> delNode=pre.next;pre.next=delNode.next;delNode.next=null;return delNode.data;}//根据值在链表中删除元素public int removeByValue(T value){int count=0;//定义前驱结点Node<T> pre=this.head;while(pre.next!=null){Node<T> curNode=pre.next;if(curNode.data.equals(value)){pre.next=pre.next.next;curNode.data=null;this.size--;count++;}else{pre=pre.next;}}return count;}
}

栈

• 线性结构

• 数据只能从栈顶进，栈顶出

  图示

基于数组实现的栈

数组的代码：

public class Myarr<T> {private int capacity=0;private int size=0;private T[]arr;//如果是空的则强制将容量扩充为10public Myarr(int capacity) {if (this.size == 0) {this.capacity = 10;this.arr=(T[]) new Object[this.capacity];}}//按顺序添加数据public void add(T value){if(this.size>=capacity){T[]arr1=Arrays.copyOf(arr,2*this.capacity);this.arr=arr1;this.capacity=this.capacity*2;}arr[this.size++]=value;}//按下标删除数据public void delete(int index){if(index>=this.size||index<0){System.out.println("输入有误");return;}if((this.size<=capacity/4)&&(capacity/4>0)){T []arr1=Arrays.copyOf(arr,this.capacity/4);this.arr=arr1;this.capacity=this.capacity/4;}for(int i=index+1;i<this.size;i++){arr[i-1]=arr[i];}this.size--;}//查找指定下标的数据public void search(int index){if(index>=this.size||index<0){System.out.println("输入有误");return;}System.out.println(index+"处的值为:"+arr[index]);}//修改指定下标的值public void modify(int index,T value){if(index>=this.size||index<0){System.out.println("输入有误");return;}arr[index]=value;}//将数组转为字符串输出@Overridepublic String toString() {StringBuffer stringBuffer=new StringBuffer();stringBuffer.append('[');for(int i=0;i<this.size;i++){stringBuffer.append(arr[i]);if(i!=this.size-1){stringBuffer.append(",");}}stringBuffer.append("]");return stringBuffer.toString();}//向数组指定位置添加数值public void aimedAdd(int index,T value){if(index<0||index>this.capacity){throw new IllegalArgumentException("索引越界！");}if(this.size>=capacity){T []arr1=Arrays.copyOf(arr,2*this.capacity);this.arr=arr1;this.capacity=this.capacity*2;}this.size++;for(int i=this.size;i>index;i--){arr[i]=arr[i-1];}arr[index]=value;}//获取数组长度public int getsize(){return this.size;}//获取数组容积public int getCapacity(){return this.capacity;}public T remove(){if((this.size<=capacity/4)&&(capacity/4>0)){T []arr1=Arrays.copyOf(arr,this.capacity/4);this.arr=arr1;this.capacity=this.capacity/4;}arr[size]=null;this.size--;return arr[size];}public T gethead(){return arr[size-1];}
}

数组实现的栈的代码：

public class ArrStack<T> implements Mystack<T>{private Myarr<T> data;public ArrStack(Myarr data) {this.data = data;}@Overridepublic void push(T value) {this.data.add(value);}@Overridepublic T pop() {return this.data.remove();}@Overridepublic T peek() {return this.data.gethead();}@Overridepublic boolean IsEmpty() {if(this.data.getsize()==0){return true;}else{return false;}}
}

基于链表实现的栈

链表的代码

public class MyLinkList<T> {class Node<T>{//使用内部类创建节点T data;//节点本身的数据Node next;//指向下一个节点public Node(T data,Node node){//内部类的构造this.data=data;this.next=node.next;}public Node(T data){this.data=data;this.next=null;}}//链表相关的属性和方法private Node head;//链表的头结点private int size;public MyLinkList(){this.head=new Node(null);this.size=0;}//判断链表是否为空public boolean isEmpty(){return this.size==0;}//头部插入元素public void addHead(T data){//1.创建结点Node node=new Node(data);node.next=node;//2.挂接node.next=this.head;this.head=node;//3.更新sizethis.size++;}public void addTail(T data){Node node=new Node(data);Node curnode=this.head;if(this.head==null){this.head=node;}else {while (curnode.next!=null){curnode=curnode.next;}curnode.next=node;}this.size++;}//获取链表大小public int getsize(){return this.size;}// 重写toString 打印链表中的数据@Overridepublic String toString(){//从头结点开始向后遍历Node curnode=this.head;StringBuffer stringBuffer=new StringBuffer();while(curnode!=null){stringBuffer.append(curnode.data+"--->");curnode=curnode.next;}stringBuffer.append("null");return stringBuffer.toString();}//根据索引获得链表的值public T getByIndex(int index){//1.判断索引是否有效if(index<0||index>this.size){throw new IllegalArgumentException("索引无效");}Node<T> curNode=this.head.next;int i=0;while(i<index){curNode=curNode.next;i++;}return curNode.data;}//从链表头部删除元素public T deleteHead(){if(this.isEmpty()){return null;}Node<T> delNode=this.head.next;this.head.next=delNode.next;delNode.next=null;this.size--;return delNode.data;}//从链表尾部删除元素public T deletetail(){if (this.isEmpty()){return null;}Node<T> pre=this.head;while(pre.next.next!=null){pre=pre.next;}this.size--;Node<T> delNode=pre.next;pre.next=delNode.next;delNode.next=null;return delNode.data;}//在链表任意位置删除public T deleteByIndex(int index){int count=1;if(index<0||index>this.size){return null;}Node<T> pre=this.head;while(pre.next!=null) {pre = pre.next;count++;if (count == index) {break;}}Node<T> delNode=pre.next;pre.next=delNode.next;delNode.next=null;return delNode.data;}//根据值在链表中删除元素public int removeByValue(T value){int count=0;//定义前驱结点Node<T> pre=this.head;while(pre.next!=null){Node<T> curNode=pre.next;if(curNode.data.equals(value)){pre.next=pre.next.next;curNode.data=null;this.size--;count++;}else{pre=pre.next;}}return count;}
}

链表实现的栈的代码

public class LinkedStack<T> implements Mystack{private MyLinkList<T> data;public LinkedStack(){this.data=new MyLinkList<>();}@Overridepublic void push(Object value) {this.data.addTail((T) value);}@Overridepublic T pop() {return this.data.deleteHead();}@Overridepublic Object peek() {return this.data.getByIndex(data.getsize());}@Overridepublic boolean IsEmpty() {return this.data.isEmpty();}
}

栈的接口

public interface Mystack <T>{void push(T value);T pop();T peek();boolean IsEmpty();}