Answer of 13th question of Leetcode which is Roman to Integer. Link is https://leetcode.com/problems/roman-to-integer/ Example 1: Input: s = "III" Output: 3 Explanation: III = 3.
Example 2: Input: s = "LVIII" Output: 58 Explanation: L = 50, V= 5, III = 3.
Example 3: Input: s = "MCMXCIV" Output: 1994 Explanation: M = 1000, CM = 900, XC = 90 and IV = 4.
Constraints: 1 <= s.length <= 15 s contains only the characters ('I', 'V', 'X', 'L', 'C', 'D', 'M').