原本想算數學，後來發現 ，就直接照著直覺硬幹了。
from math import floor
class Solution:
def rotatedDigits(self, n: int) -> int:
result = 0
for num in range(1, n + 1):
# 'e' represent end of string
s = str(num) + "\0"
# If the number remain unchanged after switching
diff = False
for c in s:
if c in ["0", "1", "8"]:
continue
elif c in ["2", "5", "6", "9"]:
diff = True
continue
elif c == "\0" and diff:
result += 1
break
return result