万年历

</pre><pre class="cpp" name="code">#include<iostream>using namespace std;class Time{public:Time(int hour);Time(const Time& t);Time& operator=(const Time& t);private:int _hour;};class Date{public:Date (int year = 1900, int month = 1, int day = 1):_year(year),_month(month),_day(day){// 检查如果输入参数是非法时间，则初始化为1900-1-1if (CheckIsInvaildDate()){year = 1900;month = 1;day = 1;}}Date (const Date& d):_year(d._year),_month(d._month),_day(d._day){}Date& operator= (const Date& d){if (this != &d){this->_year = d._year;this->_month = d._month;this->_day = d._day;}return *this;}// 检查时间是否有效bool CheckIsInvaildDate (){if (_year < 1|| (_month < 1 || _month > 12)|| (_day < 1  || _day > DateOfMonth(_year, _month))){  return true;}return false;}void Display (){cout<<_year<<"-"<<_month<<"-"<<_day<<endl<<endl;}public:// 若日期非法static int DateOfMonth (int year, int month){if (year < 1 || month < 1 || month > 12)return 0;static int monthDays[13] = {0，31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};// 瑞年的2月是29天monthDays[2] += IsLeapYear(year);return monthDays[month];}// 判断是否为瑞年。static bool IsLeapYear (int year){// 请思考为什么瑞年是这样计算，而不直接是year % 4 == 0就是闰年？// 四年一闰，百年不闰，四百年才闰if ((year % 4 == 0 && year % 100 != 0)|| year % 400 == 0){return true;}return false;}public:bool operator == (const Date& d){return _year == d._year&& _month == d._month&& _day == d._day;}bool operator != (const Date& d){return !(*this == d);}bool operator > (const Date& d){if(_year > d._year)return true;if (_year == d._year){if (_month > d._month){return true;}if (_month == d._month){if (_day > d._day){return true;}}}return false;}bool operator >= (const Date& d){return *this > d || *this == d;}bool operator < (const Date& d){return !(*this >= d);}bool operator <= (const Date& d){return !(*this > d);}// 将日期转换为正确的日期void _ToCrrectDate(){while(_day <= 0){_day += DateOfMonth (_year, _month);if (_month == 1){_year--;_month = 12;}else{--_month;}}while (_day > DateOfMonth(_year, _month)){_day -= DateOfMonth (_year, _month);if (_month == 12){++_year;_month = 1;}else{++_month;}}}// 计算一个日期加减一个天数以后的日期。Date operator + (int day){Date d(*this);if (day<0){day = 0 - day;return *this - day;}d._day += day;while (d._day>DateOfMonth(d._year, d._month)){d._day -= DateOfMonth(d._year, d._month);if (d._month < 12){d._month++;}if (d._month>12){d._year++;d._month = 1;}}return d;}Date operator-(int day){if (day < 0){day = 0 - day;return *this + day;}Date d(*this);d._day -= day;while (d._day <= 0){if (_month == 1){d._year--;d._month = 12;}if (_month>1){d._month--;}d._day += DateOfMonth(d._year, d._month);}return d;}Date& operator-=(int day){this->_day -= day;this->_ToCrrectDate();return *this;}Date& operator+=(int day){this->_day += day;this->_ToCrrectDate();return *this;} // 前置++const Date& operator++(){*this += 1;return *this;}// 后置++Date operator++(int){Date tmp(*this);*this += 1;return tmp;}// 前置--const Date& operator--(){*this -= 1;return *this;} // 后置--Date operator--(int){Date tmp(*this);*this -= 1;return tmp;}// 两个日期相加没有意义// 计算两个日期相减以后的差的天数int operator-(const Date& d){int flag = 1;Date x1 = *this, x2 = d;if (x1 < x2){flag = -1;x1 = d;x2 = *this;}int gapDays = 0;while (x1 != x2){++x2;gapDays++;}return gapDays*flag;}friend istream& operator>>(istream& in, Date& d);friend ostream& operator<<(ostream& out, Date& d);private:int _year;int _month;int _day;};istream& operator>>(istream& in, Date& d){cout<<"请依次输入日期的年-月-日"<<endl;in>>d._year;in>>d._month;in>>d._day;return in;}ostream& operator<<(ostream& out, Date& d){out<<d._year<<"-";out<<d._month<<"-";out<<d._day;return out;}void PromptInfo(){ system("cls");cout<<"==============日期计算器================"<<endl;cout<<"1.推后几天的日期"<<endl;cout<<"2.计算日期差"<<endl;cout<<"0.退出"<<endl;cout<<"========================================"<<endl;}int main(){Date d1, d2;    while(1){PromptInfo();int in=0, days=0;cin>>in;switch(in){case 0:cout<<"Exit"<<endl;return 0;case 1:cin>>d1;if (d1.CheckIsInvaildDate()){cout<<"输入日期非法！"<<endl;break;}cout<<"请出入计算推后的天数"<<endl;cin>>days;d1+=days;cout<<d1<<endl;system("pause");break;case 2:cin>>d1;if (d1.CheckIsInvaildDate()){cout<<"输入日期非法！"<<endl;break;}cin>>d2;if (d2.CheckIsInvaildDate()){cout<<"输入日期非法！"<<endl;break;}days = d1 - d2;cout<<"相差的天数:"<<days<<endl;system("pause");break;default:cout<<"选项错误，请重新选择"<<endl;break;}}system("pause");return 0;}