Time类中的运算符重载

/* Copyright (c) 2016* All rights reserved 烟台大学计算机与控制工程学院
* 文件名称：3.cpp
* 作者：刘丽
* 完成日期：2016年 5 月 24日
* 版本号： v1.0
*/
#include <iostream>
using namespace std;
class CTime
{
private:
unsigned short int hour; // 时
unsigned short int minute; // 分
unsigned short int second; // 秒
public:
CTime(int h=0,int m=0,int s=0):hour(h),minute(m),second(s){};
void setTime(int h,int m,int s);

//输入输出运算的重载
friend istream &operator>>(istream &in,CTime &t);
friend ostream &operator<<(ostream &out,CTime t);
//比较运算符(二目)的重载
bool operator > (CTime &t);
bool operator < (CTime &t);
bool operator >= (CTime &t);
bool operator <= (CTime &t);
bool operator == (CTime &t);
bool operator != (CTime &t);
//二目运算符的重载
CTime operator+(CTime &c);//返回c所规定的时、分、秒后的时间，例t1(8,20,25),t2(11,20,50)，t1+t2为:41:15
CTime operator-(CTime &c);//对照+理解
CTime operator+(int s);//返回s秒后的时间
CTime operator-(int s);//返回s秒前的时间
//一目运算符的重载
CTime operator++(int);//后置++，下一秒
CTime &operator++();//前置++，下一秒
CTime operator--(int);//后置--，前一秒
CTime &operator--();//前置--，前一秒
//赋值运算符的重载
CTime &operator+=(CTime &c);
CTime &operator-=(CTime &c);
CTime &operator+=(int s);//返回s秒后的时间
CTime &operator-=(int s);//返回s秒前的时间
void display();
};
void CTime::setTime(int h,int m,int s)
{
hour=h;
minute=m;
second=s;
}
void CTime::display()
{
cout<<hour<<':'<<minute<<':'<<second<<endl;
}
//比较运算返回的是比较结果，是bool型的true或false
//可以直接使用已经重载了的运算实现新运算，例如果已经实现了 > ，则实现 <= 就可以很方便了……
bool CTime::operator > (CTime &t)
{
if(this->hour<=t.hour)
return false;
return true;
}
bool CTime::operator <= (CTime &t){return !(*this > t);}
bool CTime::operator < (CTime &t)
{
if(this->hour>=t.hour)
return false;
return true;
}
bool CTime::operator >= (CTime &t){return !(*this<t);}
bool CTime::operator == (CTime &t)
{
if(hour==t.hour&&minute==t.minute&&second==t.second)
return true;
return false;
}
bool CTime::operator != (CTime &t){return !(*this==t);}

//可以直接使用已经重载了的加减运算实现
//这种赋值, 例如 t1+=20，直接改变当前对象的值，所以在运算完成后，将*this作为返回值
CTime CTime:: operator+(CTime &t)
{
CTime c;
c.hour=this->hour+t.hour;
c.minute=this->minute+t.minute;
c.second=this->second+t.second;

if(c.second>=60)
{
c.second%=60;
c.minute=c.second/60;
}
if(c.minute>=60)
{
c.minute%=60;
c.hour=c.minute/60;
}
if(c.hour>=24)
c.hour%=24;
return c;
}
CTime CTime:: operator-(CTime &t)//对照+理解
{
CTime c;
int s;
s=(hour-t.hour)*360+(minute-t.minute)*60+second-t.second;
c.hour=s/360;
c.minute=s%360/60;
c.second=s%360%60;
return c;
}
CTime CTime::operator+(int s)//返回s秒后的时间
{
CTime c(*this);
c.second=second+s;
if(c.second>=60)
{

c.minute+=c.second/60;
c.second%=60;
}
if(c.minute>=60)
{

c.hour+=c.minute/60;
c.minute%=60;
}
if(c.hour>=24)
c.hour%=24;
return c;
}
CTime CTime::operator-(int s)//返回s秒前的时间
{
CTime c(*this);
int sum;
sum=c.hour*360+c.minute*60+c.second-s;
c.hour=s/360;
c.minute=s%360/60;
c.second=s%360%60;
return c;
}
CTime &CTime::operator+=(CTime &c)
{
*this=*this+c;
return *this;
}
CTime &CTime::operator-=(CTime &c)
{
*this=*this-c;
return *this;

}
CTime &CTime::operator+=(int s)//返回s秒后的时间
{
*this=*this+s;
return *this;
}
CTime &CTime::operator-=(int s)//返回s秒前的时间
{
*this=*this-s;
return *this;
}
CTime CTime::operator++(int)//后置++，下一秒
{
CTime t=*this;
*this=*this+1;
return t;
}
CTime &CTime::operator++()//前置++，下一秒
{
*this=*this+1;
return *this;
}
CTime CTime::operator--( int)//后置--，前一秒
{
CTime t=*this;
*this=*this-1;
return t;
}
CTime &CTime::operator--()//前置--，前一秒
{
*this=*this+1;
return *this;
}
istream &operator>>(istream &in,CTime &t)
{
char ch1,ch2;
while(1)
{
cout<<"请输入时间(hh:mm:ss) ";
cin>>t.hour>>ch1>>t.minute>>ch2>>t.second;
if (ch1==':' && ch2==':')
if (t.hour>-1 && t.hour<24 && t.minute>-1 && t.minute<60 && t.second>-1 && t.second<60) break;
cerr<<"时间格式不正确! 请重新输入\n";
}
return cin;
}

ostream &operator<<(ostream &out,CTime t)
{
out<<t.hour<<':'<<t.minute<<':'<<t.second;
return out;
}

int main()
{
CTime t1,t2,t;

cout<<"t1为：";
cin>>t1;
cout<<"t2为：";
cin>>t2;
cout<<"下面比较两个时间大小：\n";
if (t1>t2) cout<<"t1>t2"<<endl;
if (t1<t2) cout<<"t1<t2"<<endl;
if (t1==t2) cout<<"t1＝t2"<<endl;
if (t1!=t2) cout<<"t1≠t2"<<endl;
if (t1>=t2) cout<<"t1≥t2"<<endl;
if (t1<=t2) cout<<"t1≤t2"<<endl;
cout<<endl;
cout<<"t1= "<<t1<<endl;
cout<<"t2= "<<t2<<endl;

cout<<"t=t1++"<<endl;
t=t1++;
cout<<"t= "<<t<<" t1= "<<t1<<endl;

cout<<"t=++t1"<<endl;
t=++t1;
cout<<"t= "<<t<<" t1= "<<t1<<endl;

cout<<"t1+t2= "<<t1+t2<<endl;
cout<<"t1-t2= "<<t1-t2<<endl;
cout<<"t1+2000= "<<t1+2000<<endl;
cout<<"t1-5000= "<<t1-5000<<endl;
return 0;
}