public class Node<T>{
      public  T data;
     public Node next;
}
public  class Stack<T>{
     private static Node bottom;
     private static Node top;
     private static Integer size;
     
     public void initStack(){
          bottom=top =new Node();
          top.next=bottom;
          size=0;
     }
     public static boolean isEmpty(){
            if(top.next == bottom){
                  return true;
            }
            return false;
     }
     public void pushStack(T element){
            Node temp=new Node();
           temp.data=element;
           if(top.next == bottom){
                  temp.next=bottom;
                  top.next=temp;
           }else{
                 temp.next=top.next;
                 top.next=temp;
             }
             size++;
     }
      public void popStack(){
             if(isEmpty()){
                    System.out.println("栈中没有元素！");
              }else{
                   System.out.println("出栈操作："+top.next.data+" ");
                   top.next=top.next.next;
             }
             size--;
       }
       public int sizeStack(){
             return size;
         }
      public static void getTop(){
            System.out.println("顶部值："+top.next.data);
      }
      public static void printStack() {
        Node temp = top;
        if (isEmpty()) {
            System.out.println("栈中没有元素！");
        } else {
            for (int i = 0; i < size; i++) {
                System.out.print(temp.next.data + " ");
                temp = temp.next;
            }
        }
        System.out.println();

    }