Решение на упр.04 задача 2 от Илиян Гаврилов
Резултати
- 2 точки от тестове
- 0 бонус точки
- 2 точки общо
- 4 успешни тест(а)
- 0 неуспешни тест(а)
Код
// ------------------------------
// Declarations
// ------------------------------
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
enum CompareResult {
Less,
Equal,
Greater,
}
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
enum SortOrder {
Desc,
Asc,
}
#[derive(Clone)]
struct Book {
title: String,
author: String,
year: u32,
rating: f32,
}
// ------------------------------
// Traits & their implementations
// ------------------------------
trait Compare {
fn compare(&self, other: &Self) -> CompareResult;
}
impl Compare for Book {
fn compare(&self, other: &Self) -> CompareResult {
if self.year < other.year {
CompareResult::Less
} else if self.year > other.year {
CompareResult::Greater
} else {
CompareResult::Equal
}
}
}
trait Filter {
fn matches(&self, query: &str) -> bool;
}
impl Filter for Book {
fn matches(&self, query: &str) -> bool {
self.title.contains(query) || self.author.contains(query)
}
}
trait Aggregate {
type Output;
fn aggregate(items: &[Self]) -> Self::Output
where
Self: Sized;
}
impl Aggregate for Book {
type Output = f32;
fn aggregate(items: &[Self]) -> Self::Output {
if items.is_empty() {
0.0
} else {
let sum: f32 = items.iter().map(|b| b.rating).sum();
sum / items.len() as f32
}
}
}
// ------------------------------
// Functions
// ------------------------------
fn comparator<T: Compare>(a: &T, b: &T, order: SortOrder) -> bool {
match a.compare(b) {
CompareResult::Greater => order == SortOrder::Asc,
CompareResult::Less => order == SortOrder::Desc,
CompareResult::Equal => false,
}
}
fn process_items<T>(items: Vec<T>, query: &str, order: SortOrder) -> (Vec<T>, T::Output)
where T: Compare + Filter + Aggregate + Clone, {
// Filter
let mut filtered = Vec::new();
for item in items {
if item.matches(query) {
filtered.push(item);
}
}
// Sort
let n = filtered.len();
for i in 0..n {
let mut swapped = false;
for j in 0..n - i - 1 {
if comparator(&filtered[j], &filtered[j + 1], order) {
filtered.swap(j, j + 1);
swapped = true;
}
}
if !swapped {
break;
}
}
// Aggregate
let aggregate_result = T::aggregate(&filtered);
(filtered, aggregate_result)
}
fn main() {
let books = vec![
Book { title: "The Rust Book".into(), author: "Steve".into(), year: 2018, rating: 4.7 },
Book { title: "Rust Patterns".into(), author: "Anna".into(), year: 2020, rating: 4.9 },
Book { title: "C Programming".into(), author: "Dennis".into(), year: 1978, rating: 4.3 },
];
let (result, avg_rating) = process_items(books, "Rust", SortOrder::Asc);
println!("Filtered & sorted:");
for b in &result {
println!("{} by {} ({})", b.title, b.author, b.year);
}
println!("Average rating: {:.2}", avg_rating);
}
Лог от изпълнението
Updating crates.io index
Locking 17 packages to latest compatible versions
Compiling proc-macro2 v1.0.103
Compiling quote v1.0.41
Compiling unicode-ident v1.0.22
Compiling futures-core v0.3.31
Compiling futures-sink v0.3.31
Compiling futures-channel v0.3.31
Compiling pin-utils v0.1.0
Compiling memchr v2.7.6
Compiling syn v2.0.109
Compiling futures-task v0.3.31
Compiling pin-project-lite v0.2.16
Compiling slab v0.4.11
Compiling futures-io v0.3.31
Compiling solution v0.1.0 (/tmp/d20251106-1757769-1cplnaz/solution)
warning: enum `CompareResult` is never used
--> src/lib.rs:6:6
|
6 | enum CompareResult {
| ^^^^^^^^^^^^^
|
= note: `#[warn(dead_code)]` on by default
warning: enum `SortOrder` is never used
--> src/lib.rs:13:6
|
13 | enum SortOrder {
| ^^^^^^^^^
warning: struct `Book` is never constructed
--> src/lib.rs:19:8
|
19 | struct Book {
| ^^^^
warning: trait `Compare` is never used
--> src/lib.rs:30:7
|
30 | trait Compare {
| ^^^^^^^
warning: trait `Filter` is never used
--> src/lib.rs:46:7
|
46 | trait Filter {
| ^^^^^^
warning: trait `Aggregate` is never used
--> src/lib.rs:56:7
|
56 | trait Aggregate {
| ^^^^^^^^^
warning: function `comparator` is never used
--> src/lib.rs:79:4
|
79 | fn comparator<T: Compare>(a: &T, b: &T, order: SortOrder) -> bool {
| ^^^^^^^^^^
warning: function `process_items` is never used
--> src/lib.rs:87:4
|
87 | fn process_items<T>(items: Vec<T>, query: &str, order: SortOrder) -> (Vec<T>, T::Output)
| ^^^^^^^^^^^^^
warning: function `main` is never used
--> src/lib.rs:121:4
|
121 | fn main() {
| ^^^^
warning: `solution` (lib) generated 9 warnings
Compiling futures-macro v0.3.31
Compiling futures-util v0.3.31
Compiling futures-executor v0.3.31
Compiling futures v0.3.31
warning: function `main` is never used
--> tests/../src/lib.rs:121:4
|
121 | fn main() {
| ^^^^
|
= note: `#[warn(dead_code)]` on by default
warning: `solution` (test "solution_test") generated 1 warning
Finished `test` profile [unoptimized + debuginfo] target(s) in 10.72s
Running tests/solution_test.rs (target/debug/deps/solution_test-8c2c5f784503f204)
running 4 tests
test solution_test::test_aggregate ... ok
test solution_test::test_compare ... ok
test solution_test::test_matches ... ok
test solution_test::test_process ... ok
test result: ok. 4 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out; finished in 0.00s