时间累，

#include <iostream>
using namespace std;
class Time
{
public:
	void set_time( );   
	void show_time( ); 
	inline void add_a_sec();//增加一秒钟
	inline void add_a_minute();//增加一分钟
	inline void add_an_hour();//增加一小时、
	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<<"请输入时间(格式hh:mm:ss)";
	while(1)
	{	
		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"<<endl;
        else 
			break;
	}
}
void Time::show_time( )      
{	
	cout<<hour<<":"<<minute<<":"<<sec<<endl;
}
bool Time::is_time(int h,int m, int s)
{	
	if (h<0 ||h>24 || m<0 ||m>60 || s<0 ||s>60)
		return false;
    return true;
}
inline void Time::add_a_sec()
{
	sec+=1;
	if(sec>59)
	{
	   sec-=60;
	   add_a_minute();
    }
}
inline void Time::add_a_minute()
{
	minute+=1;
	if(minute>59)
	{
		minute-=60;
	    add_an_hour();
	}
}
inline void Time::add_an_hour()
{
	hour+=1;
	if(hour>23)
		hour=0;
}
void Time::add_seconds(int n)
{
     sec+=n;
	 if(sec>59)
	 {
		 add_minutes(sec/60);
		 sec%=60;
	 }
}
void Time::add_minutes(int n)
{
	minute+=n;
	if(minute>59)
	{
		add_hours(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<<"您输入的时间是："<<endl;
    t2.show_time( );

	cout<<"增加一秒后的时间是:"<<endl;
	t1.add_a_sec();
	t1.show_time();

	cout<<"增加一分钟后的时间是:"<<endl;
	t1.add_a_minute();
	t1.show_time();

	cout<<"增加一小时后的时间是:"<<endl;
	t1.add_an_hour();
	t1.show_time();

	cout<<"增加78秒后的时间是:"<<endl;
	t1.add_seconds(78);
	t1.show_time();
	cout<<"增加23分钟后的时间是:"<<endl;
	t1.add_minutes(23);
	t1.show_time();

	cout<<"增加25小时后的时间是:"<<endl;
	t1.add_hours(25);
	t1.show_time();
    return 0;
}