栈的链表实现, 底层使用链表

package suanfa;

public class MylinkStack<T>  implements Mystack<T> {

    private Node1 top=null;
    int size=0;
    
    
    
    
    @Override
    public boolean isempty() {
        // TODO Auto-generated method stub
        return size==0;
    }

    @Override
    public void clear() {
        // TODO Auto-generated method stub
        top=null;
        size=0;
    }

    @Override
    public int length() {
        // TODO Auto-generated method stub
        return size;
    }

    @Override
    public boolean push(T data) {
        // TODO Auto-generated method stub
        Node1 newnode=new Node1();
        newnode.data=data;
        newnode.prev=top;
        top=newnode;
        size++;
        
        return true;
    }

    @Override
    public T pop() {
        // TODO Auto-generated method stub
        if(top==null){
            
            return null;
        }
        
        Node1 node=top;
        top=top.prev;
        size--;
        return (T)node.data;
        
    }

    public class Node1{
        
        Node1 prev;
        T data;
        
    }
}