ほぼ日刊競プロ leetcode　1323. Maximum 69 Number

1323. Maximum 69 Number

You are given a positive integer num consisting only of digits 6 and 9.
Return the maximum number you can get by changing at most one digit (6 becomes 9, and 9 becomes 6).

考えたこと

与えられた整数の大きい位の数から１度だけ6を９に変換してあげれば良い．
なかったらそのままで

class Solution:
   def maximum69Number (self, num: int) -> int:
       temp = num
       x = [str(a) for a in str(num)]
       for i in range(len(x)):
           if x[i]=="6":
               x[i]="9"
               break
       return max(temp,int("".join(x)))