1013: 链式栈

题目描述

已知链栈类的定义、构造函数及main函数如下，请完成其余的成员函数实现。
template
class LinkStack
{
public:
LinkStack( ); //构造函数，置空链栈
~LinkStack( ); //析构函数，释放链栈中各结点的存储空间
void Push(T x); //将元素x入栈
T Pop( ); //将栈顶元素出栈
T GetTop( ); //取栈顶元素（并不删除）
bool Empty( ); //判断链栈是否为空栈
private:
Node top; //栈顶指针即链栈的头指针
};

/
前置条件：栈不存在
输 入：无
功 能：栈的初始化
输 出：无
后置条件：构造一个空栈
/

template
LinkStack::LinkStack( )
{
top=NULL;
}
int main()
{
LinkStack s;
char ch;
while(1)
{
cin>>ch;
if(ch==’#’) break;
s.Push(ch);
}
cout<<”Gettop:”< while(!s.Empty())
{
cout< }
cout< try{
cout<<”Gettop:”< }
catch(const char *ms){
cout<<”Gettop:”< }
return 0;
}

输入

输出

样例输入

asdfgh#

样例输出

Gettop:h
h g f d s a
Gettop:Downflow

提示

来源

提交

import java.util.Scanner;
class Node {
    public Object data;
    public Node next;
    public Node() {
        this(null,null);
    }
    public Node(Object data) {
        this(data,null);
    }
    public Node(Object data, Node next) {
        this.data = data;
        this.next = next;
    }
}
class LinkStack{
    Node top;
    public LinkStack() {
        top = null;
    }
    public void push(Object x){
        top = new Node(x,top);
    }
    public Object pop() throws Exception {
        if(isEmpty()){
            throw new Exception("Downflow");
        }else {
            Node p = top;
            top = top.next;
            return p.data;
        }
    }
    public Object getTop() throws Exception {
        if(isEmpty()){
            throw new Exception("Downflow");
        }else {
            return top.data;
        }
    }
    public boolean isEmpty(){
        return top==null;
    }
}
public class Main {
    public static void main(String[] args) {
        LinkStack l = new LinkStack();
        Scanner sc = new Scanner(System.in);
        String s = sc.next();
        for (int i = 0; i < s.length(); i++) {
            if(s.charAt(i) == '#')break;
            l.push(s.charAt(i));
        }
        try{
            System.out.println("Gettop:"+l.getTop());
        } catch (Exception e) {
            System.out.println("Gettop:"+e.getMessage());
        }
        while (!l.isEmpty()){
            try {
                System.out.print(l.pop() + " ");
            } catch (Exception e) {
                System.out.println("Pop:"+e.getMessage());
            }
        }
        System.out.println();
        try{
            System.out.println("Gettop:"+l.getTop());
        } catch (Exception e) {
            System.out.println("Gettop:"+e.getMessage());
        }
    }
}