C++ 中的 12 小时和 24 小时制，当我运行程序并输入我的决定时，它只是重复菜单，有什么建议吗？[关闭]

问：

这是我的 12 小时制和 24 小时制代码。这些时钟不必是实时的，也不必滴答作响，我需要它们来打印随机时间，并能够与可能想要增加一小时、一分钟或一秒的用户进行交互。 选项 1 应显示 12 小时制 选项 2 应显示 24 小时格式 选项 3 应该允许用户添加一个小时 选项 4 应允许用户添加一分钟 选项 5 应该让使用添加第二个

#include <iostream>
#include <string>

using namespace std;
// Functions to convert a number to a two-digit string 
string twoDigitString(unsigned int n) {
    if (n < 10) {
        return "0" + to_string(n);
    }
    else {
        return to_string(n);
    }
}

string nCharString(size_t n, char c) {
    if (n >= 0) {
        string result;
        for (size_t i = 0; i < n; ++i) {
            result += c;
        }
        return result;
    }
    else {
        return "";
    }
}
// Function to display time in a 12 hour format 
string formatTime12(unsigned int h, unsigned int m, unsigned int s) {
    string period = "AM"; // default period 

    if (h == 0) {
        h = 12;
    }

    else if (h >= 12) {
        period = "PM";

        if (h > 12) {
            h -= 12;
        }
    }

    string formattedTime = twoDigitString(h) + ":" + twoDigitString(m) + ":" + twoDigitString(s) + " " + period;
    
    return formattedTime;
}

// Function to display time in a 24 hour format 
string formatTime24(unsigned int h, unsigned int m, unsigned int s){ 
    string period = "AM";

    if (h == 0) {
        h = 24;
    }

    else if (h >= 12) {
        period = "PM";

    }
    string formattedTime = twoDigitString(h) + ":" + twoDigitString(m) + ":" + twoDigitString(s) + " " + period;

    return formattedTime;
}

int main() {
    unsigned int hours = 12;
    unsigned int minutes = 0;
    unsigned int seconds = 0;

    int choice;

    do {
        //display menu for time format 
        cout << "1. 12- hour format" << endl;
        cout << "2. 24- hour format" << endl;
        cout << "3. Add Hour" << endl;
        cout << "4. Add Minute" << endl;
        cout << "5. Add second" << endl;
        cout << "6. Exit" << endl;

        cin >> choice;

        switch (choice) {
        case 1:
            cout << "12- hour format" << formatTime12(hours, minutes, seconds) << endl;
            break;
        case 2:
            cout << "24- hour format" << formatTime24(hours, minutes, seconds) << endl;
            break;
        case 3:
            hours = (hours + 1) % 24;
            break;
        case 4:
            minutes = (minutes + 1) % 60;
            break;
        case 5:
            seconds = (seconds + 1) % 60;
            break;
        case 6:
            cout << "Exiting" << endl;
            break;

        default:
            cout << "Invaild input, please try again." << endl;

        }
    } while (choice != 0);
    

    return 0;
}

起初，我没有使用 while 循环，当我运行代码时，它会提示菜单，但当我做出选择时，它想退出。然后我添加了 while 循环，现在当我做出决定时，它只是重复菜单，如下所示。当我选择选项 6 退出时，菜单不会退出。

1. 12- hour format
2. 24- hour format
3. Add Hour
4. Add Minute
5. Add second
6. Exit
1
12- hour format12:00:00 PM
1. 12- hour format
2. 24- hour format
3. Add Hour
4. Add Minute
5. Add second
6. Exit
3
1. 12- hour format
2. 24- hour format
3. Add Hour
4. Add Minute
5. Add second
6. Exit
2
24- hour format13:00:00 PM
1. 12- hour format
2. 24- hour format
3. Add Hour
4. Add Minute
5. Add second
6. Exit
6
Exiting
1. 12- hour format
2. 24- hour format
3. Add Hour
4. Add Minute
5. Add second
6. Exit