C# isPowerOf function

Question

I have the next function: ``` static bool isPowerOf(int num, int power) { double b = 1.0 / power; double a = Math.Pow(num, b); Console.WriteLine(a); return a == (int)a; } ``` I inserted the print function for analysis. If I call the function: ``` isPowerOf(25, 2) ``` It return true since `5^2` equals 25. But, if I call 16807, which is `7^5`, the next way: ``` isPowerOf(16807, 5) ``` In this case, it prints '7' but `a == (int)a` return false. Can you help? Thanks!

Accepted Answer

Try using a small epsilon for rounding errors:

```
return Math.Abs(a - (int)a) < 0.0001;
```

As harold suggested, it will be better to round in case `a` happens to be slightly smaller than the integer value, like 3.99999:

```
return Math.Abs(a - Math.Round(a)) < 0.0001;
```

C# isPowerOf function

Solution

Problem