这个不太会，希望有人能教教我

有如下程序：#include <iostream.h>using namespace std;class Time{public: int hour; int minute; int sec;};int main( ){Time t1; cin>>t1.hour; cin>>t1.minute; cin>>t1.sec; cout<<t1.hour<<”:”<<t1.minute<<”:”<<t1.sec<<endl; return 0;}改写程序，要求：①将数据程序改为私有的；②将输入和输出的功能改为由成员函数实现；③在类体内定义成员函数。修改后的程序如下：

#include <iostream>

class Time {
   public:
    Time() = default;
    ~Time(){};
    void SetData();
    void PrintData();

   private:
    int hour;
    int minute;
    int sec;
};

void Time::SetData() {
    std::cin >> this->hour;
    std::cin >> this->minute;
    std::cin >> this->sec;
}

void Time::PrintData() {
    std::cout << this->hour << ":" << this->minute << ":" << this->sec
              << std::endl;
}

int main() {
    Time t1;
    t1.SetData();
    t1.PrintData();
    return 0;
}

也可以这样

#include <iostream>
using namespace std;
class Time{
    private:  // 从pubilc 改成 private
        int hour;
        int minute;
        int sec;
    
    public:
        //输出输入的成员函数 (需要用public) 
        void input(){
            cin>>hour;
            cin>>minute;
            cin>>sec;
        }
        void output(){
            cout<<hour<<":"<<minute<<":"<<sec<<endl;
        }
};
    
int main(){
    Time t1;
    t1.input();
    t1.output();
    return 0;
}