another variant
IntuitionApproachComplexity
Time complexity:

Space complexity:
Code
# Intuition
<!-- Describe your first thoughts on how to solve this problem. -->

# Approach
<!-- Describe your approach to solving the problem. -->

# Complexity
- Time complexity:
<!-- Add your time complexity here, e.g. $$O(n)$$ -->

- Space complexity:
<!-- Add your space complexity here, e.g. $$O(n)$$ -->

# Code
```golang []
func isFascinating(n int) bool {
    var digits[10] int
    str := strconv.Itoa(n) + strconv.Itoa(n * 2) + strconv.Itoa(n * 3)
    for _, el := range str {
        digits[el - '0']++
    }

    var one int
    for idx, el := range digits {
        one = el
        if one != 1 && idx != 0 || idx == 0 && one != 0 { return false }
    }
    return true
}
```
['Go']