《第八周实验报告任务2》

/* (程序头部注释开始)
* 程序的版权和版本声明部分
* Copyright (c) 2011, 烟台大学计算机学院学生
* All rights reserved.
* 文件名称：     Time类中的重载运算
* 作    者：       刘江波
* 完成日期：    2012     年   04    月    07    日
* 版本号：     v.04072
* 对任务及求解方法的描述部分
* 问题描述：实现Time类中的运算符重载
* 程序头部的注释结束
*/
#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);
	void display();
	//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
};
//下面实现所有的运算符重载代码。
//为简化编程，请注意通过调用已有函数，利用好各函数之间的关系

void CTime::setTime(int h, int m, int s)
{
	hour = h;

	minute = m;

	second = s;
}

void CTime::display()
{
	cout << hour << ":" << minute << ":"  << second << endl;
}

bool CTime::operator > (CTime &t)//转换为秒，在进行比较。
{
	if(hour * 3600 + minute * 60 + second > t.hour * 3600 + t.minute * 60 + t.second)
	{
		return true;
	}
	else
	{
		return false;
	}
}

bool CTime::operator < (CTime &t)
{
	if(hour * 3600 + minute * 60 + second < t.hour * 3600 + t.minute * 60 + t.second)
	{
		return true;
	}
	else
	{
		return false;
	}
}

bool CTime::operator >= (CTime &t)
{
	if(hour * 3600 + minute * 60 + second >= t.hour * 3600 + t.minute * 60 + t.second)
	{
		return true;
	}
	else
	{
		return false;
	}
}
bool CTime::operator <= (CTime &t)
{
	if(hour * 3600 + minute * 60 + second <= t.hour * 3600 + t.minute * 60 + t.second)
	{
		return true;
	}
	else
	{
		return false;
	}
}
bool CTime::operator == (CTime &t)//小时，分钟，秒数都相同
{
	if(hour == t.hour && minute == t.minute && second == t.second)
	{
		return true;
	}
	else
	{
		return false;
	}
}
bool CTime::operator != (CTime &t)//小时，分钟，秒数有一个不同即可
{
	if(hour != t.hour || minute != t.minute || second != t.second)
	{
		return true;
	}

	else
	{
		return false;
	}
}

CTime CTime::operator + (CTime &c)
{
	CTime c2;
	int time;
	//现将两个时间转化为秒，再依次求出小时，分，秒即可。
	time = (hour * 3600 + minute * 60 + second) + (c.hour * 3600 + c.minute * 60 + c.second);

	c2.hour = time / 3600;

	time = time % 3600;

	c2.minute = time / 60;

	time = time % 60;

	c2.second = time;

	return c2;
}
CTime CTime::operator - (CTime &c)
{
	CTime c2;
	int time;
	//现将两个时间转化为秒，再依次求出小时，分，秒即可。
	time = (hour * 3600 + minute * 60 + second) - (c.hour * 3600 + c.minute * 60 + c.second);

	c2.hour = time / 3600;

	time = time % 3600;

	c2.minute = time / 60;

	time = time % 60;

	c2.second = time;

	return c2;
}

CTime CTime::operator + (int s)
{
	int time;

	time = hour * 3600 + minute * 60 + second + s;

	hour = time / 3600;

	time = time % 3600;

	minute = time / 60;

	time = time % 60;

	second = time;  

	return (*this);
}  

CTime CTime::operator - (int s)
{
	int time;

	time = hour * 3600 + minute * 60 + second;

	time = time - s;

	hour = time / 3600;

	time = time % 3600;

	minute = time / 60;

	time = time % 60;

	second = time;

	return (*this);
}

CTime CTime::operator ++ (int) //后置
{
	CTime temp = (*this);

	int time;

	time = hour * 3600 + minute * 60 + second + 1;

	hour = time / 3600;

	time = time % 3600;

	minute = time / 60;

	time = time % 60;

	second = time;

	return temp;//返回自加前的对象
}

CTime CTime::operator ++ ()//前置
{
	int time;

	time = hour * 3600 + minute * 60 + second +1;

	hour = time / 3600;

	time = time % 3600;

	minute = time / 60;

	time = time % 60;

	second = time;

	return (*this);//返回自加后的当前对象
}
CTime CTime::operator -- (int)//后置
{
	CTime temp = (*this);

	int time;

	time = hour * 3600 + minute * 60 + second - 1;

	hour = time / 3600;

	time = time % 3600;

	minute = time / 60;

	time = time % 60;

	second = time;

	return temp;//返回自减前的对象
}
CTime CTime::operator -- ()//前置
{
	int time;

	time = hour * 3600 + minute * 60 + second - 1;

	hour = time / 3600;

	time = time % 3600;

	minute = time / 60;

	time = time % 60;

	second = time;

	return (*this);//返回自减后的当前对象
}

CTime CTime::operator += (CTime &c)
{
	CTime c2;
	
	c2 = (*this) + c;//调用重载运算符，第一个+号

	return c2;
}
CTime CTime::operator -= (CTime &c)
{
	CTime c2;
	
	c2 = (*this) - c;//调用重载运算符，第一个-号

	return c2;
}
CTime CTime::operator += (int s)
{
	CTime c2;

	c2 = (*this) + s;//调用重载运算符，第2个+号

	return c2;
}
CTime CTime::operator -= (int s)
{
	CTime c2;

	c2 = (*this) - s;//调用重载运算符，第2个-号

	return c2;
}

void main()
{
	CTime t1(8,20,25), t2(11,20,50), t;

	cout << "t1为：";

	t1.display();

	cout << "t2为：";

	t2.display();

	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;

	cout << "t1 + t2 =";

	t.display();

	t = t2 - t1;

	cout << "t2 - t1 =";

	t.display();

	t = t1;

	t = t + 40;

	cout << "t1 + 40s =";

	t.display();

	t = t2;

	t = t - 10;

	cout << "t2 - 10s =";

	t.display();

	t = t1++;

	cout << "t1++ =";

	t.display();

	t = --t2;

	cout << "--t2 =";

	t.display();

	t = t1;

	t += t2;

	cout << "t1 += t2 , t1 = ";

	t.display();

	t = t2;

	t -= 5;

	cout << "t2 -= 5, t2 = ";

	t.display();

	system("pause");
}
知识点总结：
在自增运算符重载中，增加一个int型形参，就是后置自增运算符函数。
《第八周实验报告任务2》

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