时间类

#include <iostream>
using namespace std;
class Time
{
    public :
     void set_time();
     void show_time();
     inline void add_a_sec();
     inline void add_a_minute();
     inline void add_a_hour();
     void add_seconds(int);
     void add_minutes(int);
     void add_hours(int);
     private:
     bool is_time(int,int,int);
     int hour;
     int minute;
     int sec;
};
void Time::set_time()
{
    char c1,c2;
    cout<<"请输入一个时间："<<endl;
    cin>>hour>>c1>>minute>>c2>>sec;
    if(c1!=':'||c2!=':')
    {
        cout<<"格式不正确！请重新输入！"<<endl;}
        else if(!is_time(hour,minute,sec))
       {
           cout<<"时间非法！请重新输入！";
       }

}
void Time::show_time()
{
    cout<<hour<<":"<<minute<<":"<<sec<<endl;
}
bool Time::is_time(int h,int m,int s)
{
    if(hour<0||hour>24||minute<0||minute>60||sec<0||sec>60)
    return false;
    return true;
}
inline void Time::add_a_sec()
{
    ++sec;
    if(sec>59)
    {
        sec=0;
        add_a_minute();
    }
}
inline void Time::add_a_minute()
{
    ++minute;
    if(minute>59)
    {
        minute=0;
        add_a_hour();
    }
}
inline void Time::add_a_hour()
{
    ++hour;
    if(hour>23)
    {
        hour=0;
    }
}
void Time::add_seconds(int n)
{
    sec+=n;
    if(sec>59)
    {
        minute+=sec/60;
        sec%=60;
    }
}
void Time::add_minutes(int n)
{
    minute+=n;
    if(minute>59)
    {
        hour+=minute/60;
        minute%=60;
    }
}
void Time::add_hours(int n)
{
    hour+=n;
    if(hour>23)
    hour%=24;
}
int main()
{
    Time t1;
    Time &t2=t1;
    t1.set_time();
    cout<<"现在的时间是：";
    t2.show_time();
    t1.add_a_sec();
    cout<<"增加1秒钟后：";
    t1.show_time();
    t1.add_a_minute();
    cout<<"增加1分钟后：";
    t1.show_time();
    t1.add_a_hour();
    cout<<"增加一小时后：";
    t1.show_time();
    t1.add_seconds(40);
    cout<<"增加40秒后：";
    t1.show_time();
    t1.add_minutes(5);
    cout<<"增加5分钟后：";
    t1.show_time();
    t1.add_hours(1);
    cout<<"增加1小时后：";
    t1.show_time();
        return 0;
}