//=================================================// File Name       :	LinkStack_demo//------------------------------------------------------------------------------// Author          :	Common//类名：Link_long//属性：//方法：class Link_long{			//链节点类	public long dData;	public Link_long next;				//链表中下一个节点的引用		public Link_long(long dData) {		super();		this.dData = dData;	}		public void displayLink(){			//显示当前节点的值		System.out.println("dData"+dData);	}	}//类名：LinkList_long//属性：//方法：class LinkList_long{	private Link_long first;			//只需要第一个节点，从第一个节点出发即可定位所有节点	public LinkList_long() {			//构造函数		this.first = null;	}		public boolean isEmpty(){		return (first == null);	}		public void insertFirst(long dd){		//插入元素是从链表的头开始插入		Link_long newLink = new Link_long(dd);		newLink.next = first;		first = newLink;	}		public long deleteFirst(){				//删除temp.dData		Link_long temp = first;					//暂存first		first = first.next;								//把next设为first		return temp.dData;						//返回原来的first	}		public void displayList(){		System.out.println("List(first-->last):");		Link_long current = first;			//用于不断改变位置实现遍历		while(current != null){			current.displayLink();			current = current.next;		}	}		public Link_long find(int key){					//查找指定的关键字		Link_long current = first;		while(current.dData != key){			if(current.next == null)				return null;			else				current = current.next;		}		return current;	}		public Link_long delete(int key){			//如果current的值匹配，则删除		Link_long current = first;						Link_long previous = first;		//没有匹配到值		while(current.dData != key){			if(current.next == null)				return null;			else{							//pre和cur向后移动				previous = current;				current = current.next;			}		}		//匹配到值		if(current == first)		//只有一个first，并匹配，则把first设成first.next			first = first.next;		else								//current的值匹配，则删除，并把cur的next赋给pre的next			previous.next = current.next;		return current;	}}//类名：LinkList_long//属性：//方法：class LinkStack{	//用链表实现栈，链表从First开始插入，新的元素将变成First，先删除后来元素		private LinkList_long theList;	public LinkStack() {		//构造函数		theList = new LinkList_long();	}		public void push(long j){		//入栈，即在链表的First插入元素		theList.insertFirst(j);	}		public long pop(){					//出栈，即删除链表的First元素		return theList.deleteFirst();	}		public boolean isEmpty(){	//判断栈是否为空，即判断链表是否为空		return (theList.isEmpty());	}		public void displayStack(){		System.out.println("Stack(top-->bottom):");		theList.displayList();	}	}//主类//Function        : 	LinkStack_demopublic class LinkStack_demo {	public static void main(String[] args) {		// TODO 自动生成的方法存根		LinkStack theStack = new LinkStack();		theStack.push(10);		theStack.push(20);		theStack.push(30);		theStack.displayStack();				theStack.pop();		theStack.pop();		theStack.displayStack();	}}