Depends on the programming language you are using. Some programming languages require some type conversion and work with arrays, but others it might be super easy.

I wouldn't worry about it.

Sounds like you pre-assigned the minimum variable to 0.

But, can't say for sure without knowing which programming language you are using and maybe seeing your current code.

Isn't it 8 kyu? It is so damn easy to solve

4^1.5 is sqrt(4)^3 (that is 8), like 4^(3/2) or 4^0.5x3 or (4^0.5)^3
because 1.5 is 3/2, we root by num below and powering to an above num :3