第三周项目三-时间类

#include <iostream>
using namespace std;
class Time
{
public:
void set_time( );
void show_time( );
void add_seconds(int);
void add_minutes(int);
void add_hours(int);
void add_a_sec( )//类内定义
{
int h,m,s;
h=hour,m=minute,s=sec;
s+=1;
if(s==60)
{
m+=1;
s=0;
}
if(m==60)
{
h+=1;
m=0;
}
cout<<h<<":"<<m<<":"<<s<<endl;
}
void add_a_minute()
{
int h,m,s;
h=hour,m=minute,s=sec;
m+=1;
if(m==60)
{
h+=1;
m=0;
}
if(h==24)
{
h=0;
}
cout<<h<<":"<<m<<":"<<s<<endl;
}
void add_an_hour()
{
int h,m,s;
h=hour,m=minute,s=sec;
h+=1;
if(h==24)
{
h=0;
}
cout<<h<<":"<<m<<":"<<s<<endl;
}

private:
bool is_time(int, int, int);   //这个成员函数设置为私有的，是合适的，请品味
int hour;
int minute;
int sec;
};
void Time:: add_seconds(int n)
{
int h,m,s;
h=hour,m=minute,s=sec;
s+=n;
while(s>=60)
{
m+=1;
s=s-60;
}
while(m>=60)
{
h+=1;
m=m-60;
}
while(h>=24)
{
h=h-24;
}
cout<<h<<":"<<m<<":"<<s<<endl;
}
void Time::add_minutes(int n)
{
int h,m,s;
h=hour,m=minute,s=sec;
m+=n;
while(m>=60)
{
h+=1;
m=m-60;
}
while(h>=24)
{
h=h-24;
}
cout<<h<<":"<<m<<":"<<s<<endl;
}
void Time::add_hours(int n)
{
int h,m,s;
h=hour,m=minute,s=sec;
h+=n;
while(h>=24)
{
h=h-24;
}
cout<<h<<":"<<m<<":"<<s<<endl;
}
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;
}
int main( )
{
int n;
Time t1;
t1.set_time( );
t1.show_time( );
t1.add_a_sec( );
t1.add_a_minute( );
t1.add_an_hour( );
cout<<"输入n的值：";
cin>>n;
t1.add_seconds(n);
t1.add_minutes(n);
t1.add_hours(n);
return 0;
}