Time类中的运算符重载

/*
* 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：任子仪
* 完成日期：2014年 4月 19日
* 版 本 号：v12.1
* 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
};
//下面实现所有的运算符重载代码。

//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
//下面实现所有的运算符重载代码。
//比较运算返回的是比较结果，是bool型的true或false
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;
}
CTime CTime::operator+(CTime &t)
{
    CTime t1(0,0,0);
    t1.second=t.second+second;
    while(t1.second>=60)
    {
        t1.minute++;
        t1.second-=60;
    }
    t1.minute=minute+t.minute;
    while(t1.minute>=60)
    {
        t1.hour++;
        t1.minute-=60;
    }
    t1.hour=hour+t.hour;
    while(t1.hour>=24)
    {
        t1.hour-=24;
    }
    return t1;
}
CTime CTime::operator-(CTime &t)
{
    CTime t1(0,0,0);
    t1.second=second-t.second;
    while(t1.second<0)
    {
        t1.minute--;
        t1.second+=60;
    }
    t1.minute=minute-t.minute;
    while(t1.minute<0)
    {
        t1.hour--;
        t1.minute+=60;
    }
    t1.hour=hour-t.hour;
    while(t1.hour<0)
    {
        t1.hour+=24;
    }
    return t1;
}
CTime CTime::operator+(int s)
{
    CTime t1=*this;
    t1.second=second+s;
    while(t1.second>=60)
    {
        t1.minute++;
        t1.second-=60;
    }
    while(t1.minute>=60)
    {
        t1.hour++;
        t1.minute-=60;
    }
    while(t1.hour>=24)
    {
        t1.hour-=24;
    }
    return t1;
}
CTime CTime::operator-(int s)
{
    CTime t1=*this;
    t1.second=second-s;
    while(t1.second<0)
    {
        t1.minute--;
        t1.second+=60;
    }
    while(t1.minute<0)
    {
        t1.hour--;
        t1.minute+=60;
    }
    while(t1.hour<0)
    {
        t1.hour+=24;
    }
    return t1;
}
// 判断时间t1<=t2
bool CTime::operator > (CTime &t)
{
    if (hour>t.hour||(hour==t.hour&&minute>t.minute)||(minute==t.minute&&second>t.second))
        return true;
    else
        return false;
}
bool CTime::operator<=(CTime &t)
{
    if(*this>t)
        return false;
    else
        return true;
}
bool CTime::operator<(CTime &t)
{
    if(hour<t.hour||(hour==t.hour&&minute<t.minute)||(minute==t.minute&&second<t.second))
        return true;
    else
        return false;
}
bool CTime::operator>= (CTime &t)
{
    if(*this<t)
        return false;
    else
        return true;
}

bool CTime::operator==(CTime &t)
{
    if (hour==t.hour&&minute==t.minute&&second==t.second)
        return true;
    else
        return false;
}
bool CTime::operator!=(CTime &t)
{
    if (*this==t)
        return false;
    else
        return true;
}

//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
int main()
{
    CTime t1(9,8,7),t2(8,7,6),t;
    int s=1;
    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;
    t=t1+t2;
    t.display();
    t=t1-t2;
    t.display();
    t=t1+s;
    t.display();
    t=t1-s;
    t.display();
    return 0;
}