Romans

/*
 * The MIT License (MIT)
 *
 * Copyright (c) 2015 Víctor Matía Rodríguez <[email protected]>
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */

/*
 * Main.cpp
 *
 *  Created on: 25 de jun. de 2015
 *      Author: Víctor Matía Rodríguez
 */

#include <cstdlib>
#include <iostream>
#include <limits>
#include <string>

std::string
toRoman (int value)
{
  struct romandata_t
  {
    int value;
    char const* numeral;
  };
  struct romandata_t const romandata[] =
    { 1000, "M", 900, "CM", 500, "D", 400, "CD", 100, "C", 90, "XC", 50, "L",
    40, "XL", 10, "X", 9, "IX", 5, "V", 4, "IV", 1, "I", 0, nullptr };

  std::string result;

  for (romandata_t const* current = romandata; current->value > 0; ++current)
    while (value >= current->value)
      {
    result += current->numeral;
    value -= current->value;
      }

  return result;
}

int
main (int argc, char *argv[])
{
  int number;

  if (argc > 1)
    {
      number = atoi (argv[1]);
      std::cout << "Received number: " << number << std::endl;

      if (number <= 0 || number >= 4000)
    {
      std::cout << "Please, enter a valid integer in the range [1, 3999]: ";
      std::cin >> number;

      while (std::cin.fail () || number <= 0 || number >= 4000)
        {
          std::cout
          << "Please, enter a valid integer in the range [1, 3999]: ";
          std::cin.clear ();
          std::cin.ignore (std::numeric_limits<std::streamsize>::max (),
                   '\n');
          std::cin >> number;
        }
    }
    }
  else
    {
      std::cout << "Please, enter a number: ";
      std::cin >> number;

      while (std::cin.fail () || number <= 0 || number >= 4000)
    {
      std::cout << "Please, enter a valid integer in the range [1, 3999]: ";
      std::cin.clear ();
      std::cin.ignore (std::numeric_limits<std::streamsize>::max (), '\n');
      std::cin >> number;
    }
    }

  std::cout << "Your number is written as '" << toRoman (number)
      << "' in Roman numbers." << std::endl;

  return 0;
}