![image](https://assets.leetcode.com/users/images/d3ad0ba4-47f2-4b6e-948a-e89b0ad33df7_1594904848.2841735.png)\n\nI have written a code to convert a roman numeral to an integer(problem #7: Roman to Integer) in python3, and each time I submit the code, I get a different runtime and memory usage, for the same code every time. Why is that?\n\n```\n    def romanToInt(s: str) -> int:\n        romanNums = {"I":1, "V":5, "X":10, "L":50, "C":100, "D":500, "M":1000}\n        number = 0\n        x = len(s) - 1\n        while x >= 0:\n            if romanNums[s[x]] > romanNums[s[x-1]] and x != 0:\n                number += romanNums[s[x]] - romanNums[s[x-1]]\n                x -= 2\n            else:\n                number += romanNums[s[x]]\n                x -= 1\n        return number\n```\n

\n\nI have written a code to convert a roman numeral to an integer(problem #7: Roman to Integer) in python3, and each time I submit the code, I get a different 