C++ 万年历

显示公历的万年历，输入的年份在1800-2100年之间。功能要求如下：

（1）输入一个年份，输出是在屏幕上显示该年的日历。

（2）输入年、月，输出该月的日历。

（3）输入年月日，输出距今天还有多少天，星期几，是否是为公历节日。

部分算法

程序主要分为四个部分：菜单，年历，月历，具体某天的日历信息。

年历

void nianli()     //输出一整年的年历
{cout << "请输入年份：";runnian();system("cls");     cout << "Please input the year whose calendar you want to know:" << year << endl;cout << endl;char str[100] = "===========The Calendar of Year ";for (int m = 0; m < 32; m++) {cout << str[m];}cout << (year / 1000) % 10 << (year / 100) % 10 << (year / 10) % 10 << year % 10;for (int m = 41; m < 52; m++) {cout <<'=';}cout << endl << endl;s = (year - 1 + (year - 1) / 4 - (year - 1) / 100 + (year - 1) / 400 + 1) % 7;     //该年1月1日的星期数for (i = 1; i <= 12; i++){cout << "***********************************************"<<endl;cout << setw(2) << i << setw(4) << "SUN" << setw(6) << "MON" << setw(6) << "TUE" << setw(6) << "WED" << setw(6) << "THU" << setw(6) << "PRI" << setw(6) << "SAT" << endl;for (j = 0; j < s; j++){cout << setw(6) << " ";}for (t = 1; t <= months[i]; t++){cout << setw(6) << t;s = (s + 1) % 7;if (s % 7 == 0)     //当打印到星期六时，换行{cout << endl;}}cout << endl;}cout << "***********************************************" << endl;cout << endl;fflush(stdin);cout << "请按4返回主菜单:";cin >> c;system("cls");menu();
}

月历

void yueli()//输出一个月的月历
{int s = 0;cout << "请输入年份：";runnian();cout << "请输入月份：";cin >> month;system("cls");cout << "请输入年份：" << year << endl;cout << "请输入月份：" << month << endl;for (i = 1; i <= month - 1; i++){s = s + months[i];     //该年1月1日到所求日期前一天的天数}s = (year - 1 + (year - 1) / 4 - (year - 1) / 100 + (year - 1) / 400 + 1 + s) % 7;     //所求日期的星期数cout << "***********************************************" << endl;cout << setw(2) << i << setw(4) << "SUN" << setw(6) << "MON" << setw(6) << "TUE" << setw(6) << "WED" << setw(6) << "THU" << setw(6) << "PRI" << setw(6) << "SAT" << endl;for (j = 0; j < s; j++){cout << setw(6) << " ";}for (t = 1; t <= months[month]; t++){cout << setw(6) << t;s = (s + 1) % 7;if (s % 7 == 0){cout << endl;}}cout << endl;cout << "***********************************************" << endl;cout << "请按4返回主菜单:";cin >> c;system("cls");menu();
}

具体某一天

此处默认为2020.1.13，可自行输入。

void tianshu()   //计算天数,默认今天为2020.01.10
{int s = 0;cout << "请输入年份：";runnian();cout << "请输入月份：";cin >> month;cout << "请输入日期：";cin >> day;system("cls");cout << "请输入年份：" << year << endl;cout << "请输入月份：" << month << endl;cout << "请输入日期：" << day << endl;if (year < 2020) {if (month == 2) {sum += months[2] - day + 1;}for (int m = month + 1; m <= 12; m++) {if (m == 1 || m == 3 || m == 5 || m == 7 || m == 8 || m == 10 || m == 12) {sum += 31;}if (m == 3 || m == 4 || m == 6 || m == 9 || m == 10 || m == 11 || m == 1) {sum += 30;}if (m == 2);sum += months[2];}for (int m = year + 1; m < 2020; m++) {if ((m % 4 == 0 && m % 100 != 0) || (m % 400 == 0))     //闰年判断公式{months[2] = 29;}for (i = 1; i <= 12; i++){sum = sum + months[i];}}sum += 10;}if (year > 2020) {for (int m = year + 1; m < 2020; m++) {if ((m % 4 == 0 && m % 100 != 0) || (m % 400 == 0))     //闰年判断公式{months[2] = 29;}for (i = 1; i <= 12; i++){sum = sum + months[i];}}sum += 355;}if (year == 2020) {if (month == 1) {sum += fabs(day - 10);}if (month != 1) {for (int m = month + 1; m <= 12; m++) {sum += months[m];}sum += 21;}}for (i = 1; i <= month - 1; i++){s = s + months[i];}s = (year - 1 + (year - 1) / 4 - (year - 1) / 100 + (year - 1) / 400 + day + s) % 7;cout << "星期数:" << s << endl;cout << "距离2020.01.01 " << sum << " 天";cout << endl;if ((month == 2 && day == 14) || (month == 3 && day == 8) || (month == 1 && day == 1) || (month == 3 && day == 12) || ((month == 5 || month == 6 || month == 7 || month == 8 || month == 10) && day == 1) || (month == 9 && day == 10)) {cout << year << "." << month << "." << day << "是公历节日" << endl;}else {cout << year << "." << month << "."<< day << "不是公历节日" << endl;}cout << endl;cout << "请按4返回主界面:";cin >> c;system("cls");menu();
}

主函数

int main()//主函数
{setlocale(LC_ALL, "chs");//转中文menu();while (number != 0||(year >= 1800 && year <= 2100)){switch (number){case 1:{nianli();break;}case 2:{yueli();break;}case 3:{tianshu();break;}}months[2] = 28;  //把months[2]变为初值28}if (number == 0){system("pause");//退出}return 0;
}

运行截图

菜单：

年历（2020）：

月历：

具体某一天：