/*
* 程序的版权和版本声明部分:
* Copyright (c) 2013, 烟台大学计算机学院
* All rights reserved.
* 文件名称:test.cpp
* 作 者:周经纬
* 完成日期:2014年 4月 22日
* 版 本 号:v12.1
* 实现Time类中的运算符重载,
* 输入描述:无
* 问题描述:。
* 程序输出:
* 问题分析:略
* 算法设计:略
*/
#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);
void setTime(int h,int m,int s);
void display();
//二目的比较运算符重载
bool operator > (CTime &t);
bool operator < (CTime &t);
bool operator >= (CTime &t);
bool operator <= (CTime &t);
bool operator == (CTime &t);
bool operator != (CTime &t);
//二目的加减运算符的重载
//返回t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 &t);
CTime operator-(CTime &t);//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
//二目赋值运算符的重载
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
CTime operator ++(int);//后置++
CTime operator ++();//前置++
CTime operator --(int);//后置--
CTime operator --();//前置--
friend istream& operator>>(istream& input,CTime &s1);
friend ostream& operator<<(ostream& output,CTime &s1);
};
//下面实现所有的运算符重载代码。
CTime::CTime(int h,int m,int s)
{
hour=h;
minute=m;
second=s;
}
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 (hour > t.hour) return true;
if (hour< t.hour) return false;
if (minute > t.minute) return true;
if (minute < t.minute) return false;
if (second> t.second) return true;
return false;
}
bool CTime::operator < (CTime &t)
{
if (hour < t.hour) return true;
if (hour> t.hour) return false;
if (minute < t.minute) return true;
if (minute > t.minute) return false;
if (second< t.second) return true;
return false;
}
bool CTime::operator ==(CTime &t)
{
if (hour==t.hour) return true;
if (minute==t.minute) return true;
if (second==t.second) return true;
return false;
}
bool CTime::operator != (CTime &t)
{
if(*this==t)
return false;
return true;
}
//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 &c)
{
int h,m,s;
h=hour+c.hour;
m=minute+c.minute;
s=second+c.second;
if (s>59)
{
s-=60;
m++;
}
if (m>59)
{
m-=60;
h++;
}
if (h>23) h-=24;
CTime t3(h,m,s);
return t3;
}
CTime CTime::operator-(CTime &c)
{
int h,m,s;
h=hour-c.hour;
m=minute-c.minute;
s=second-c.second;
if (s<0)
{
s+=60;
m--;
}
if (m<0)
{
m+=60;
h--;
}
if (h<0) h+=24;
CTime t3(h,m,s);
return t3;
}
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)
{
*this=*this+s;
return *this;
}
CTime CTime::operator-=(int s)
{
*this=*this-s;
return *this;
}*/
CTime CTime::operator++(int)
{
CTime temp(*this);
second++;
if(second>59)
{
second-=60;
minute++;
}
if(minute>59)
{
minute-=60;
hour++;
}
if(hour>23)
{
hour-=24;
}
return temp;
}
CTime CTime::operator++()
{
++second;
if(second>59)
{
second-=60;
minute++;
}
if(minute>59)
{
minute-=60;
hour++;
}
if(hour>23)
{
hour-=24;
}
return *this;
}
CTime CTime::operator--(int)
{
CTime temp(*this);
second--;
if (second<0)
{
second+=60;
minute--;
}
if (minute<0)
{
minute+=60;
hour--;
}
if (hour<0) hour+=24;
return temp;
}
CTime CTime::operator--()
{
--second;
if (second<0)
{
second+=60;
minute--;
}
if (minute<0)
{
minute+=60;
hour--;
}
if (hour<0) hour+=24;
return *this;
}
istream & operator >>(istream &putin,CTime&c)
{
putin>>c.hour>>c.minute>>c.second;
return putin;
}
ostream & operator <<(ostream &output,CTime&c)
{
if(c.hour>=0||c.minute>=0||c.second>=0)
output<<c.hour<<":"<<c.minute<<":"<<c.second<<endl;
return output;
}
int main()
{
CTime t1(2,10,10),t2(3,9,11),t;
cout<<"t1:";
t1.display();
cout<<"t2:";
t2.display();
cout<<"时间大小的比较:"<<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<<"两时间的计算:"<<endl;
cout<<"t1+t2:"<<endl;
t=t1+t2;
t.display();
cout<<"t1-t2:"<<endl;
t=t1-t2;
t.display();
/*cout<<"减200秒后="<<endl;
t=t1-200;
t.display();
cout<<"加200秒后="<<endl;
t=t1+200;
t.display();*/
cout<<"t1+=t2:"<<endl;
t1+=t2;
t1.display();
cout<<"t1-=t2:"<<endl;
t1-=t2;
t1.display();
cout<<"++t1:"<<endl;
++t1;
t1.display();
cout<<"--t1:"<<endl;
--t1;
t1.display();
cout<<"t1++:"<<endl;
t1++;
t1.display();
cout<<"t1--:"<<endl;
t1--;
t1.display();
cout<<"--t:"<<endl;
t=--t;
cout<<t;
return 0;
}
//自行编制用于测试的main()函数,有些结果不必依赖display()函数,提倡用单步执行查看结果
其实就比上个多了个<<和>>的重载这一步,嘿嘿,就当混积分了吧;谁让老师项目二第二问就是这个呢,