romanos.cpp

#include <map>
#include <string>
#include <iostream>
#include "romanos.hpp"
using namespace std;


string decimal_para_romanos(int num) {
    string str2;
    int romans[] = {1, 4, 5, 9, 10, 40, 50, 90, 100, 400, 500, 900, 1000};
    string symbol[] = {"I","IV","V","IX","X","XL","L","XC","C","CD","D","CM","M"};
    int i = 12;    
    while (num > 0) {
      int div = num/romans[i];
      num = num%romans[i];
      while(div--) str2 += symbol[i];
      i--;
    }
    return str2;
}


int romanos_para_decimal(string str) {
  int tam = str.size();
  map <char, int> M; 
  M.insert(pair<char, int> ('I', 1));
  M.insert(pair<char, int> ('V', 5));
  M.insert(pair<char, int> ('X', 10));
  M.insert(pair<char, int> ('L', 50));
  M.insert(pair<char, int> ('C', 100));
  M.insert(pair<char, int> ('D', 500));
  M.insert(pair<char, int> ('M', 1000));
  if(str.size() > 30) return -1;
  int res = 0;
  for (int i = 0; i < tam; i++) {
    if(M[str[i]] < M[str[i+1]]) res -= M[str[i]];
    else res += M[str[i]];
  }
    return res;
}

int validate_convert(string str) {
  int guess = romanos_para_decimal(str);
  if(str == decimal_para_romanos(guess) && guess <= 3000) return guess;
  else return -1;
}