public String intToRoman(int num) {

    Map<Integer, String> map = new LinkedHashMap<Integer, String>();
    map.put(1000, "M");
    map.put(900, "CM");
    map.put(500, "D");
    map.put(400, "CD");
    map.put(100, "C");
    map.put(90, "XC");
    map.put(50, "L");
    map.put(40, "XL");
    map.put(10, "X");
    map.put(9, "IX");
    map.put(5, "V");
    map.put(4, "IV");
    map.put(1, "I");

    StringBuilder sb = new StringBuilder();

    while (num > 0) {
      for (int base : map.keySet()) {
        if (num >= base) {
          num -= base;
          sb.append(map.get(base));
          break;
        }
      }
    }
    return sb.toString();
  }