[C++] Simple Solution
Code

# Code
```cpp []
class Solution {
public:
    vector<int> v;
    void helper(int n) {
        while(n > 0) {
            v[n%10]++;
            n/=10;
        }
    }
    bool isFascinating(int n) {
        v.resize(10, 0);
        int n2 = n*2;
        int n3 = n*3;
        helper(n);
        helper(n2);
        helper(n3);
        
        if(v[0] > 0) return false;
        for(int i=1; i<10; i++) {
            if(v[i] != 1) return false;
        }
        return true;
    }
};
```
['C++']