#include #include #include using namespace std; class Roman { public : Roman(); void transform(int n); friend ostream &operator<<(ostream &stream, Roman const& roman); private : string m_romanForm; map m_basic; }; Roman::Roman() { m_basic[1] = "I"; m_basic[5] = "V"; m_basic[10] = "X"; m_basic[50] = "L"; m_basic[100] = "C"; m_basic[500] = "D"; m_basic[1000] = "M"; } void Roman::transform(int n) { if (n >= 1 && n <= 3) { for (int i(0); i < n; i++) m_romanForm += m_basic[1]; } if (n == 4) m_romanForm += "IV"; if (n >= 5 && n < 9) { m_romanForm += m_basic[5]; transform(n - 5); } if (n == 9) m_romanForm += "IX"; if (n >= 10 && n <= 39) { for (int i(0); i < n / 10; i++) m_romanForm += m_basic[10]; transform(n % 10); } if (n >= 40 && n <= 49) { m_romanForm += m_basic[10]; m_romanForm += m_basic[50]; transform(n - 40); } if (n >= 50 && n <= 89) { m_romanForm += m_basic[50]; transform (n - 50); } if (n >= 90 && n <= 99) { m_romanForm += m_basic[10]; m_romanForm += m_basic[100]; transform(n % 10); } if (n >= 100 && n <= 399) { m_romanForm += m_basic[100]; transform(n - 100); } if (n >= 400 && n <= 499) { m_romanForm += m_basic[100]; m_romanForm += m_basic[500]; transform(n - 400); } if (n >= 500 && n <= 899) { m_romanForm += m_basic[500]; transform(n - 500); } if (n >= 900 && n <= 999) { m_romanForm += m_basic[100]; m_romanForm += m_basic[1000]; transform(n % 100); } if (n >= 1000 && n <= 1999) { m_romanForm += m_basic[1000]; transform(n - 1000); } } ostream& operator<<(ostream &stream, Roman const& roman) { stream << roman.m_romanForm; return stream; } int main() { Roman roman; int n(0); string errorMessage; cout << "give a number between (0 and 2000) : "; cin >> n; if (n > 0 && n < 2000) { roman.transform(n); cout << "the roman form of " << n << " is: " << roman << endl; } else { errorMessage += "you entered "; if (n < 0) errorMessage += "a negative number"; else if (n >= 2000) errorMessage += "a number greater than 1999"; else if (n == 0) errorMessage += "a null number"; errorMessage += " ! Try Again!!"; cerr << errorMessage << endl; } return 0; }