第12周 项目二

/*
*Copyright (c)2016,烟台大学计算机与控制工程学院
*All rights reserved.
*文件名称：main.cpp
*作    者：肖雪
*完成日期：2016年5月31日
*版 本 号：v1.0
*问题描述:实现Time类中的运算符重载

*/

#include <iostream>
using namespace std;
class CTime
{
private:
unsigned short int hour;
unsigned short int minute;
unsigned short int second;
public:
CTime(int h=0,int m=0,int s=0);
void setTime(int h,int m,int s);

friend istream &operator>>(istream &in,CTime &t);
friend ostream &operator<<(ostream &out,CTime t);

bool operator > (CTime &t);
bool operator < (CTime &t);
bool operator >= (CTime &t);
bool operator <= (CTime &t);
bool operator == (CTime &t);
bool operator != (CTime &t);

CTime operator+(CTime &c);
CTime operator-(CTime &c);
CTime operator+(int s);
CTime operator-(int s);

CTime operator++(int);
CTime &operator++();
CTime operator--(int);
CTime &operator--();

CTime &operator+=(CTime &c);
CTime &operator-=(CTime &c);
CTime &operator+=(int s);
CTime &operator-=(int s);
};

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;
}

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;
}

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 (*this<t || *this>t) return false;
return true;
}

bool CTime::operator != (CTime &t)
{
if (*this==t) return false;
return true;
}

bool CTime::operator >= (CTime &t)
{
if (*this<t) return false;
return true;
}

bool CTime::operator <= (CTime &t)
{
if (*this>t) return false;
return true;
}

CTime CTime::operator + (CTime &t)
{

int h,m,s;
s=second+t.second;
m=minute+t.minute;
h=hour+t.hour;
if (s>59)
{
s-=60;
m++;
}
if (m>59)
{
m-=60;
h++;
}
while (h>23) h-=24;
CTime t0(h,m,s);
return t0;
}

CTime CTime::operator+(int s)
{
int ss=s%60;
int mm=(s/60)%60;
int hh=s/3600;
CTime t0(hh,mm,ss);
return *this+t0;
}

CTime CTime::operator - (CTime &t)
{
int h,m,s;
s=second-t.second;
m=minute-t.minute;
h=hour-t.hour;
if (s<0)
{
s+=60;
m--;
}
if (m<0)
{
m+=60;
h--;
}
while (h<0) h+=24;
CTime t0(h,m,s);
return t0;
}

CTime CTime::operator-(int s)
{
int ss=s%60;
int mm=(s/60)%60;
int hh=s/3600;
CTime t0(hh,mm,ss);
return *this-t0;
}

CTime CTime::operator++(int)
{
CTime t=*this;
*this=*this+1;
return t;
}

CTime &CTime::operator++()
{
*this=*this+1;
return *this;
}

CTime CTime::operator--(int)
{
CTime t=*this;
*this=*this-1;
return t;
}

CTime &CTime::operator--()
{
*this=*this-1;
return *this;
}

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;
}

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;
}

学习心得：重载运算符"+"和"-"实现时间推后和提前若干分钟；

                 重载运算符"++"和"--"实现当前时间推后和提前1小时；

                 重载运算符">"、"<"、"=="来判断两个时间之间大于、小于、等于以及不等于的关系。

                 运算符重载不能改变运算符的逻辑特性