Given an integer, convert it to a roman numeral.
Roman numerals are formed by appending the conversions of decimal place values from highest to lowest. Subtractive cases: 4→IV, 9→IX, 40→XL, 90→XC, 400→CD, 900→CM.
Example 1:
Input: num = 3749 Output: "MMMDCCXLIX"
Example 2:
Input: num = 58 Output: "LVIII"
Constraints: 1 <= num <= 3999