第九周项目2-Time类中的运算符重载（续）

在Time类中的运算符重载基础上

（1）定义对时间对象的自增和自减一目运算符

（2）定义Time类中的<<和>>运算符重载，实现时间的输入输出，改造原程序中对运算结果显示方式，使程序读起来更自然。

/*
* Copyright (c) 2015,烟台大学计算机学院
* All right reserved.
* 作者：邵帅
* 文件：Demo.cpp
* 完成时间：2015年05月14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);
    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19:41:15
    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
    friend istream &operator>>(istream &in,CTime &t);
    friend ostream &operator<<(ostream &out,CTime t);
    //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
};
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;
}
// 重载输入运算符>>
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;
}

// 重载输出运算符<<
ostream &operator<<(ostream &out,CTime t)
{
    out<<t.hour<<':'<<t.minute<<':'<<t.second;
    return out;
}
bool CTime::operator > (CTime &t)
{
    int s1,s2;
    s1=hour*3600+minute*60+second;
    s2=t.hour*3600+t.minute*60+t.second;
    if (s1>s2) return true;
    else
        return false;
}
bool CTime::operator < (CTime &t)
{
    int s1,s2;
    s1=hour*3600+minute*60+second;
    s2=t.hour*3600+t.minute*60+t.second;
    if (s1<s2) return true;
    else
        return false;
}
bool CTime::operator >= (CTime &t)
{
    if (*this > t) return true;
    return false;

}
bool CTime::operator <= (CTime &t)
{
    if (*this > t) return false;
    return true;
}
bool CTime::operator == (CTime &t)
{
    int s1,s2;
    s1=hour*3600+minute*60+second;
    s2=t.hour*3600+t.minute*60+t.second;
    if (s1==s2) return true;
    else
        return false;
}
bool CTime::operator != (CTime &t)
{
    int s1,s2;
    s1=hour*3600+minute*60+second;
    s2=t.hour*3600+t.minute*60+t.second;
    if (s1!=s2) return true;
    else
        return false;
}
CTime CTime::operator+(CTime &t)
{
    int s;
    s=t.hour*3600+t.minute*60+t.second;
    while (s--)
    {
        second++;
        if (second>60)
        {
            minute++;
            second=1;
        }
        if (minute>60)
        {
            hour++;
            minute=1;
        }
    }
    CTime a(hour,minute,second);
    return a;
}
CTime CTime::operator-(CTime &t)
{
    int s;
    s=t.hour*3600+t.minute*60+t.second;
    while (s--)
    {
        second--;
        if (second<0)
        {
            minute--;
            second=60;
        }
        if (minute<0)
        {
            hour--;
            minute=60;
        }
    }
    CTime a(hour,minute,second);
    return a;
}
CTime CTime::operator+(int s)
{
    while (s--)
    {
        second++;
        if (second>60)
        {
            minute++;
            second=1;
        }
        if (minute>60)
        {
            hour++;
            minute=1;
        }
    }
    CTime a(hour,minute,second);
    return a;
}
CTime CTime::operator-(int s)
{
    while (s--)
    {
        second--;
        if (second<0)
        {
            minute--;
            second=60;
        }
        if (minute<0)
        {
            hour--;
            minute=60;
        }
    }
    CTime a(hour,minute,second);
    return a;
}
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)//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;
}

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;
}

运行结果：

@ Mayuko