[Python3] Solution with explanation
We have to check if a resulting string contains unique digits except for zero.
The first condition cuts off cases when there are more digits than needed:
For ex
We have to check if a resulting string contains unique digits except for zero. 
The first condition cuts off cases when there are more digits than needed: 
For example, n = 334, then we have '3346681002'. Length of this string is 10, but we should have a maximum of 9 digits.
The second one is obvious, so as not to get zero when multiplied by 2.

```python []
class Solution:
    def isFascinating(self, n: int) -> bool:
        if n > 333:
            return False
        
        if n % 10 == 5 or n % 10 == 0:
            return False
        
        num = str(n) + str(2 * n) + str(3 * n)
        
        return len(set(num)) == len(num) and '0' not in num
```
['Python', 'Python3']