练习：几何图形

我们将为三维几何图形创建几个实用函数，将点表示为 [f64;3]。函数签名由您自行确定。

1. // Calculate the magnitude of a vector by summing the squares of its coordinates
2. // and taking the square root. Use the `sqrt()` method to calculate the square
3. // root, like `v.sqrt()`.

5. fn magnitude(...) -> f64 {
6. todo!()
7. }

9. // Normalize a vector by calculating its magnitude and dividing all of its
10. // coordinates by that magnitude.

12. fn normalize(...) {
13. todo!()
14. }

16. // Use the following `main` to test your work.

18. fn main() {
19. println!("Magnitude of a unit vector: {}", magnitude(&[0.0, 1.0, 0.0]));

21. let mut v = [1.0, 2.0, 9.0];
22. println!("Magnitude of {v:?}: {}", magnitude(&v));
23. normalize(&mut v);
24. println!("Magnitude of {v:?} after normalization: {}", magnitude(&v));
25. }