Super easy to understand solution -->>  Beats 100.00%
IntuitionApproachComplexity

Time complexity:
O(n)


Space complexity:
O(1)

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

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

# Complexity
- Time complexity:
O(n)

- Space complexity:
O(1)

# Code
```java []
class Solution {
    public boolean isFascinating(int n) {

        int[] count = new int[10];
        for (int i = 1; i < 4; i++)
            fascinating(n * i, count);

        if (count[0] != 0) return false;
        for (int i = 1; i < count.length; i++)
            if (count[i] != 1) return false;
        
        return true;
    }

    private static void fascinating(int n, int[] count) {

        while (n > 0) {
            count[n % 10]++;
            n /= 10;
        }
    }
}
```
['Java']