设计一个多功能的MyTime类 代码参考

 #include <iostream>
 #include <cstdio>

 using namespace std;

 class MyTime
 {
     private:
         int hour;
         int minute;
         int second;
     public:
         MyTime(){hour=;minute=;second=;}
         MyTime(int,int,int);
         void Register(int,int,int);
         void Show_12();
         void Show_24();
         void Sub(int,int,int);
         void Add(int,int,int);
 };

 MyTime::MyTime(int a, int b, int c)
 {
     hour=a;
     minute=b;
     second=c;
 }

 void MyTime::Show_12()
 {
     if(hour>)
     {
         printf("%02d:%02d:%02d PM\n",hour-,minute,second);
     }
     else
     {
         printf("%02d:%02d:%02d AM\n",hour,minute,second);
     }
     return;
 }

 void MyTime::Show_24()
 {
     printf("%02d:%02d:%02d\n",hour,minute,second);
     return;
 }

 void MyTime::Sub(int a, int b, int c)
 {
     hour-=a;
     minute-=b;
     second-=c;
     while(second<)
     {
         second+=;
         minute-=;
     }
     while(minute<)
     {
         minute+=;
         hour-=;
     }
     while(hour<)
     {
         hour+=;
     }
     return;
 }

 void MyTime::Add(int a, int b, int c)
 {
     hour+=a;
     minute+=b;
     second+=c;
     while(second>)
     {
         second-=;
         minute+=;
     }
     while(minute>)
     {
         minute-=;
         hour+=;
     }
     while(hour>)
     {
         hour-=;
     }
     return;
 }

 void MyTime::Register(int a,int b, int c)
 {
     hour=a;
     minute=b;
     second=c;
     return;
 }

 int main()
 {
     MyTime one,two(,,);
     int a,b,c,x,y,z;
     cin>>a>>b>>c>>x>>y>>z;
     one.Show_12();
     one.Show_24();
     two.Show_12();
     two.Show_24();
     one.Register(a,b,c);
     one.Add(x,y,z);
     two.Sub(x,y,z);
     one.Show_12();
     one.Show_24();
     two.Show_12();
     two.Show_24();
     return ;
 }