Max Difference You Can Get From Changing an Integer

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18

class Solution:
    def maxDiff(self, num: int) -> int:
        a = b = str(num)

        for digit in a:
            if digit != "9":
                a = a.replace(digit, "9")
                break

        if b[0] != "1":
            b = b.replace(b[0], "1")
        else:
            for digit in b[1:]:
                if digit not in "01":
                    b = b.replace(digit, "0")
                    break

        return int(a) - int(b)