一.代码部分

1.定义接口

public interface Stack
     
       {    int getSize();    boolean isEmpty();    void push(E e);    E pop();    E peek();}
     

2.基于数组实现：

public class ArrayStack
     
       implements Stack
      
        {    ArrayList
       
         arrayList;    public ArrayStack(int capacity){        arrayList = new ArrayList(capacity);    }    public ArrayStack(){        arrayList = new ArrayList
        
         ();    }    @Override    public int getSize() {        return arrayList.getSize();    }    @Override    public boolean isEmpty() {        return arrayList.isEmpty();    }    @Override    public void push(E e) {        arrayList.addLast(e);    }    @Override    public E pop() {        return arrayList.removeLast();    }    @Override    public E peek() {        return arrayList.get(getSize()-1);    }    public int getCapacity(){        return arrayList.getCapacity();    }    @Override    public String toString() {        StringBuilder res = new StringBuilder();        res.append("Stack:");        res.append("[");        for (int i = 0; i < arrayList.getSize(); i++) {            res.append(arrayList.get(i));            if(i != arrayList.getSize()-1){                res.append(",");            }        }        res.append("] top");        return res.toString();    }}
        
       
      
     

 3.基于链表实现：

public class LinkedListStack
     
       implements Stack
      
        {    private LinkedListPlus
       
         list;    public LinkedListStack(){        list = new LinkedListPlus<>();    }    @Override    public int getSize() {        return list.getSize();    }    @Override    public boolean isEmpty() {        return list.isEmpty();    }    @Override    public void push(E e) {        list.addFirst(e);    }    @Override    public E pop() {        return list.removeFirst();    }    @Override    public E peek() {        return list.getFirst();    } 　　@Override 　　public String toString() {
           　　StringBuilder res = new StringBuilder(); 　　res.append("stack:top"); 　　res.append(list); 　　return res.toString(); 　　}}