c++ 用switch语句设计一个选择式菜单，编写链式栈进栈、出栈、显示栈中全部元素的程序，将一个正整数n转换成R进制，要求用顺序栈的来实现

以下是使用switch语句设计的选择式菜单的代码：

#include <iostream>
using namespace std;

int main() {
    int choice;

    cout << "请选择菜单项：" << endl;
    cout << "1. 新建" << endl;
    cout << "2. 打开" << endl;
    cout << "3. 保存" << endl;
    cout << "4. 另存为" << endl;
    cout << "5. 退出" << endl;

    cin >> choice;

    switch (choice) {
        case 1:
            cout << "新建文件" << endl;
            break;
        case 2:
            cout << "打开文件" << endl;
            break;
        case 3:
            cout << "保存文件" << endl;
            break;
        case 4:
            cout << "另存为文件" << endl;
            break;
        case 5:
            cout << "退出程序" << endl;
            break;
        default:
            cout << "无效选择" << endl;
            break;
    }

    return 0;
}

下面是链式栈的实现代码：

#include <iostream>
using namespace std;

struct Node {
    int data;
    Node* next;
};

class LinkedList {
private:
    Node* head;
public:
    LinkedList() {
        head = NULL;
    }

    void push(int value) {
        Node* newNode = new Node;
        newNode->data = value;
        newNode->next = head;
        head = newNode;
    }

    void pop() {
        if (head == NULL) {
            cout << "栈已空" << endl;
            return;
        }

        Node* temp = head;
        head = head->next;
        delete temp;
    }

    void display() {
        if (head == NULL) {
            cout << "栈已空" << endl;
            return;
        }

        Node* temp = head;

        while (temp != NULL) {
            cout << temp->data << " ";
            temp = temp->next;
        }

        cout << endl;
    }
};

int main() {
    LinkedList stack;

    stack.push(1);
    stack.push(2);
    stack.push(3);

    stack.display();

    stack.pop();
    stack.pop();

    stack.display();

    return 0;
}

下面是将一个正整数n转换成R进制的代码：

#include <iostream>
using namespace std;

int main() {
    int n, r;
    cout << "请输入一个正整数n和进制r：";
    cin >> n >> r;

    int stack[100];
    int top = -1;

    while (n != 0) {
        stack[++top] = n % r;
        n /= r;
    }

    while (top != -1) {
        cout << stack[top--];
    }

    cout << endl;

    return 0;
}