mirror of
https://github.com/notohh/rustlings.git
synced 2024-11-21 21:42:23 -05:00
55 lines
1.4 KiB
Rust
55 lines
1.4 KiB
Rust
fn vec_loop(input: &[i32]) -> Vec<i32> {
|
|
let mut output = Vec::new();
|
|
|
|
for element in input {
|
|
output.push(2 * element);
|
|
}
|
|
|
|
output
|
|
}
|
|
|
|
fn vec_map_example(input: &[i32]) -> Vec<i32> {
|
|
// An example of collecting a vector after mapping.
|
|
// We map each element of the `input` slice to its value plus 1.
|
|
// If the input is `[1, 2, 3]`, the output is `[2, 3, 4]`.
|
|
input.iter().map(|element| element + 1).collect()
|
|
}
|
|
|
|
fn vec_map(input: &[i32]) -> Vec<i32> {
|
|
// We will dive deeper into iterators, but for now, this is all what you
|
|
// had to do!
|
|
// Advanced note: This method is more efficient because it automatically
|
|
// preallocates enough capacity. This can be done manually in `vec_loop`
|
|
// using `Vec::with_capacity(input.len())` instead of `Vec::new()`.
|
|
input.iter().map(|element| 2 * element).collect()
|
|
}
|
|
|
|
fn main() {
|
|
// You can optionally experiment here.
|
|
}
|
|
|
|
#[cfg(test)]
|
|
mod tests {
|
|
use super::*;
|
|
|
|
#[test]
|
|
fn test_vec_loop() {
|
|
let input = [2, 4, 6, 8, 10];
|
|
let ans = vec_loop(&input);
|
|
assert_eq!(ans, [4, 8, 12, 16, 20]);
|
|
}
|
|
|
|
#[test]
|
|
fn test_vec_map_example() {
|
|
let input = [1, 2, 3];
|
|
let ans = vec_map_example(&input);
|
|
assert_eq!(ans, [2, 3, 4]);
|
|
}
|
|
|
|
#[test]
|
|
fn test_vec_map() {
|
|
let input = [2, 4, 6, 8, 10];
|
|
let ans = vec_map(&input);
|
|
assert_eq!(ans, [4, 8, 12, 16, 20]);
|
|
}
|
|
}
|