#include #include #include using namespace std; string convertToDay(int nbD); int maxMonth(int month, int year) { int monthDays(0); if (month == 1 || month == 3 || month == 5 || month == 7 || month == 8 || month == 10 || month == 12) monthDays = 31; else if (month == 4 || month == 6 || month == 9 || month == 11) monthDays = 30; else if (month == 2 && ((year % 4 != 0) || (year % 100 == 0 && year % 400 != 0))) monthDays = 28; else monthDays = 29; return monthDays; } class Date { public: Date(string date); friend int dayNumber(Date u, Date p); bool inputFail(); private: int m_year; int m_month; int m_day; }; Date::Date(string date): m_year(0), m_month(0), m_day(0) { istringstream is; for (int i(0); i < date.size(); i++) { if (date[i] == ':') date[i] = ' '; } is.str(date); is >> m_day; is >> m_month; is >> m_year; } int dayNumber(Date u, Date p) { int d = p.m_day - 1; int days(1); int dayNb(3); int m(p.m_month), y(p.m_year); while (m != u.m_month || y != u.m_year || days != u.m_day) { days++; d++; if (days > maxMonth(m, y)) { m++; days = 1; } if (m > 12) { y++; m = 1; } } for (int i(0); i < d; i++) { dayNb++; if (dayNb > 6) dayNb = 0; } return dayNb; } bool Date::inputFail() { return m_year < 1970 || (m_month < 1 || m_month > 12) || (m_day < 1 || m_day > maxMonth(m_month, m_year)) || m_year==0 || m_day == 0 || m_month ==0; } int main() { const Date principalDate("01:01:1970"); string date; string day; cout << "NOTE: the date dd:mm:yyyy" << endl; cout << "enter the date: "; getline(cin, date); Date usrDate(date); if (usrDate.inputFail()) { cout << "oups! sorry, I can\'t do it" << endl; return 1; } day = convertToDay(dayNumber(usrDate, principalDate)); cout << day; return 0; } string convertToDay(int nbD) { string day; switch (nbD) { case 0: day = "monday"; break; case 1: day = "tuesday"; break; case 2: day = "wednesday"; break; case 3: day = "thursday"; break; case 4: day = "friday"; break; case 5: day = "saturday"; break; case 6: day = "sunday"; break; } return day; }

[Date] --> [day]