# https://leetcode.com/problems/maximum-difference-by-remapping-a-digit

from typing import List, Optional

class Solution:
    def minMaxDifference(self, num: int) -> int:
        n: List[str] = list(str(num))
        max_num: List[str] = []
        min_num: List[str] = []
        max_target: Optional[str] = None
        min_target: str = n[0]
        for i in range(len(n)):
            if n[i] == min_target:
                min_num.append('0')
            else:
                min_num.append(n[i])
            if max_target is None and n[i] != '9':
                max_target = n[i]
            if max_target == n[i]:
                max_num.append('9')
            else:
                max_num.append(n[i])
        return int(''.join(max_num)) - int(''.join(min_num))