rust BMI
fn bmi(weight: u32, height: f32) -> &'static str {
let index = weight as f32 / height.powi(2);
match index {
index if index <= 18.5 => "Underweight",
index if index <= 25.0 => "Normal",
index if index <= 30.0 => "Overweight",
_ => "Obese"
}
}