【C++】实现万年历

1.此万年历功能

1>日期加减天数

2>日期与日期之间的差值

3>输入年月显示当月日历

2.代码实现

#include
#include
using namespace std;

class Date
{
public:
	Date(int year = 1990, int month = 1, int day = 1)  //构造函数
		:_year(year), _month(month), _day(day)
	{
		if (JudgeRightDate())     //判断传入的值是否是合法的，不合法则置成1990年1月1日
		{
			_year = 1990;
			_month = 1;
			_day = 1;
		}
	}

	bool JudgeRightDate()   //判断值是否合法函数
	{
		if (_year < 1 || ((_month< 1)||_month>12) ||
			(_day<1)||_day>GetMonthDay(_year,_month))
		{
			return true;
		}
		else
		{
			return false;
		}
	}

	int JudgeYear(int year)   //判断是否是闰年的函数
	{
		if (((year % 4 == 0) && (year % 100 != 0)) || (year % 400 == 0))
		{
			return 1;
		}
		else
			return 0;
	}

	int GetMonthDay(int year, int month)  //通过年和月得到对应的天数
	{
		int arr[13] = { 0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 };
		int days = arr[month];
		if (month == 2)
		{
			days += JudgeYear(year);   //如果是闰年的二月则天数加1
		}
		return days;
	}

	
	Date operator +(int days)    //日期加天数函数，重载“+”实现
	{
		_day += days;            //先将天数全部加到所给日期的“天”上
		GetRightDate(_year, _month, _day);  //再通过计算得到正确的日期。
		return *this;
	}

	void GetRightDate(int &year, int &month, int &day)   //计算出正确的日期
	{
		if (day <= 0)
		{
			while (day <= 0)
			{
				month--;
				day += GetMonthDay(year, month);
				if (month < 1)
				{
					year--;
					month = 13;
				}
			}
		}
		else
		{
			while (day>GetMonthDay(year, month))
			{
				day -= GetMonthDay(year, month);
				month++;
				if (month > 12)
				{
					year++;
					month = 1;
				}
			}
		}
	}

	Date operator -(int days)   //重载“-”实现日期减天数
	{
		_day -= days;
		GetRightDate(_year, _month, _day);
		return *this;
	}

	bool operator >(const Date &d)   //判断两个日期的大小
	{
		if (_year > d._year)
		{
			return true;
		}
		else if (_year == d._year)
		{
			if (_month > d._month)
			{
				return true;
			}
			else if (_month==d._month)
			{
				if (_day > d._day)
				{
					return true;
				}
			}
		}
		return false;
	}

	bool operator ==(const Date &d)   //判断两个日期是否相等
	{
		if (_year == d._year && _month == d._month && _day == d._day)
		{
			return true;
		}
		else
			return false;
	}

	int operator -( Date &d)  //计算日期差函数，重载“-”实现
	{
		int count = 0;
		Date tmp(*this);
		if (*this > d)
		{
			tmp = d;
			d = *this;
			*this = tmp;
		}
		while (!(*this==d))
		{
			count++;
			*this =*this+1;
		}
		return count;
	}


	void print()       //打印函数
	{
		cout << _year << "-" << _month << "-" << _day;
	}


	int week()   //求出日期对应的星期函数
	{
		int w = 0;
		int y = _year;
		int m = _month;
		if (m == 1 || m == 2)
		{
			m = _month + 12;
			y = _year - 1;
		}
		w = _day + 2 * m + 3 * (m + 1) / 5 + y + y / 4 - y / 100 + y / 400;
		w = w % 7 + 1;
		return w;
	}

	void print_week()
	{
		cout << "星期日 星期一 星期二 星期三 星期四 星期五 星期六" << endl;
	}

	void print_day()  //根据日期和星期，正确的输出日历
	{
		int line = 1;
		int days = GetMonthDay(_year,_day);
		int w = week();
		if (w != 7)
		{
			for (int blank = w - 1; blank; --blank, ++line)
			{
				cout << setw(7) << "";
			}
		}
		for (int d = 1; d <= days; ++d, ++line)
		{
			cout << setw(7) << d;
			if (line % 7 == 0)
			{
				cout << endl;
			}
		}
		cout << endl;
	}

private:
	int _year;
	int _month;
	int _day;
};
void menu()
{
	cout << setw(40) <<"万年历"<< endl;
	cout << "1.日期加减天数" << endl;
	cout << "2.日期减日期" << endl;
	cout << "3.输入年月显示当月日历" << endl;
}
void choice()
{
	int num = 0;
	int year, month, day, days;
	char ch = '+';
	cin >> num;
	if (num == 1)
	{
		cout << "请输入日期：" << endl;
		cin >> year >> month >> day;
		cout << "请输入天数:" << endl;
		cin >> days;
		cout << "请输入'+'或者'-':" << endl;
		cin >> ch;
		Date d1(year, month, day);
		Date d2;
		if (ch == '+')
		{
			d2 = d1 + days;
		}
		else if (ch == '-')
		{
			d2 = d1 - days;
		}
		else
		{
			cout << "无效的输入!" << endl;
		}
		cout << "计算后的日期为：";
		d2.print();
		cout << endl;
	}
	else if (num==2)
	{
		cout << "请输入日期：" << endl;
		cin >> year >> month >> day;
		Date d3(year, month, day);
		cout << "请输入日期：" << endl;
		cin >> year >> month >> day;
		Date d4(year, month, day);
		int ret = d3 - d4;
		cout << "期间相差：" << ret << endl;
	}
	else if (num == 3)
	{
		cout << "请输入年月:" << endl;
		cin >> year >> month;
		Date d5(year, month);
		d5.print_week();
		d5.print_day();
	}
}
int main()
{
	menu();
	choice();
	system("pause");
	return 0;
}