链栈（c++实现）

代码如下：

#include <iostream>

using namespace std;

struct stackNode   //栈节点
{
    int value;
    stackNode* next;

    stackNode()  //无参构造
    {
        this->value = 0;
        this->next = NULL;
    }

    stackNode(int data) //有参构造
    {
        this->value = data;
        this->next = NULL;
    }

    

    void changeValue(int data)  //改数值
    {
        this->value = data;
        this->next = NULL;
    }
};


class NewStack
{
public:
    NewStack();
    ~NewStack() {}
    bool isEmpty();  //判断是否为空
    void push(int data);  //压栈
    void pop();  //弹栈
    int getTop();  //返回栈顶元素
    int getNum();  //栈元素数量
    void clean();  //清空栈
private:
    stackNode* top = new stackNode();
    stackNode* current;
    int nodeNum;
    void clean(stackNode *p);
};

NewStack::NewStack()
{
    top->next = NULL;
    current = top->next;
    nodeNum = 0;
}

bool NewStack::isEmpty()
{
    if(top->next == NULL)
        return true;
    return false;
}

int NewStack::getNum()
{
    return nodeNum;
}

int NewStack::getTop()
{
    return current->value;
}

void NewStack::push(int data)
{
    stackNode *newNode = new stackNode(data);
    top->next = newNode;
    newNode->next = current;
    current = newNode;
    ++ nodeNum;
}

void NewStack::pop()
{
    if(top->next == NULL)
        return ;
    stackNode *p = current;
    current = current->next;
    top->next = current;
    delete[] p;
    -- nodeNum;
}

void NewStack::clean(stackNode *p) //递归实现
{
    if(p->next != NULL)
        clean(p->next);
    delete[] p;
}

void NewStack::clean()
{
    if(top->next == NULL)
        return ;
    clean(current);
    top->next = NULL;
    nodeNum = 0；
}
    
int main()
{
    //test

    NewStack s;
    for(int i = 0; i < 10; ++i)
    {
        s.push(i);
    }

    cout << "The num of the stack is" << s.getNum() << endl;
    cout << "The top of the stack is" << s.getTop() << endl;
    cout << endl;

    for(int i = 0;i < 5; ++i)
    {
        s.pop();
        cout << "The num of the stack is" << s.getNum() << endl;
        cout << "The top of the stack is" << s.getTop() << endl;
        cout << endl;
    }

    s.clean();

    if(s.isEmpty() == true)
        cout << "The stack is empty" << endl;
    else
        cout << "The stack is not empty" << endl;
    

    return 0;
}