笔记/使用LinkedList实现Stack栈

class A{

private String b;

pubic String getB(){

return b;

}

public void setB(String b){

this.b=b;

}

public A(String b){

super();

this.b=b;

}

public String toString(){

return b;

}

interface  Stack{

public void push(A a);

public A pull();

public A peek();

}

public class MyStack implements Stack{

private LinkedList<A> ll=new LinkedList<A>();

public void push(A a){

if(a==null){

System.out.println("对象为空");

return;

}

ll.addLast(a);

}

public A pull(){

if(a.isEmpty()){

System.out.println("集合为空");

return null;

}else{

return ll.removeLast();

}

}

public A peek(){

if(ll.isEmpty()){

System.out.println("集合为空");

return null;

}else{

return ll.getLast();

}

}

public void display(){

for(Hero h:ll){

System.out.println(a);

}

}

public static void main(String[] args){

MyStack ms=new MyStack();

for(int i=0;i<5;i++){

ms.push(new A("A"+i));

}

ms.display();

ms.display();

ms.dispaly();

}

}