/*链式栈
       用单链表实现的栈

*
*
*/

package com.tulun;

public class TestMl2 {

    public static void main(String[] args) {
        // TODO Auto-generated method stub
         LinkStack link=new LinkStack();
         for(int i=0;i<10;i++){
            link.insertHead(i);
         }
         link.show();
         link.pop();
         link.show();
         int a=link.getTop();
         System.out.println(a);
    }

}
class LinkStack{
    class Entry{
        int data;
        Entry next;
        public Entry(){
            this.data = -1;
            this.next = null;
        }
        public Entry(int data){
            this.data=data;
            this.next=null;
        }
    }
    private Entry head=null;
    public LinkStack(){
        this.head=new Entry();
    }
    //入栈     利用头插法方便一点
    public void insertHead(int val){
        Entry entry=new Entry(val);
        entry.next=head.next;
        head.next=entry;
    }
    //出栈  只需出头结点的后的第一个数据节点
    public void pop(){
        Entry cur=head.next;
        if(cur==null){
            return;
        }
        head.next=cur.next;
        cur=null;
        return;
    }
    //得到栈顶元素
    public int getTop(){
        return this.head.next.data;
    }
    public void show(){
        Entry cur=this.head.next;
        while(cur!=null){
            System.out.println(cur.data);
            cur=cur.next;
        }
        System.out.println();
    }
}