Convert Between Integer and Roman (Two-Way)

Given an integer num (1 ≤ num ≤ 3999), convert it to a Roman numeral string. Also given a valid Roman numeral string s (representing the same range), convert it to an integer. Implement two functions: intToRoman(num) -> string romanToInt(s) -> int Requirements: Use standard Roman numeral rules (including subtractive forms like IV, IX, XL, XC, CD, CM). The input to romanToInt is guaranteed to be a valid Roman numeral. Constraints: num is in 1..3999 s.length ≤ 15 Provide test cases that validate correctness (cover: min, max, multiple subtractive forms, additive-only cases). Example Input intToRoman 1 Output I