Решение на упр.08 задача 1 от Ивайло Иванов
Резултати
- 4 точки от тестове
- 0 бонус точки
- 4 точки общо
- 2 успешни тест(а)
- 0 неуспешни тест(а)
Код
use std::rc::Rc;
use std::iter::Iterator;
struct List<T> {
head: Link<T>,
}
type Link<T> = Option<Rc<Node<T>>>;
struct Node<T> {
elem: T,
next: Link<T>,
}
struct Iter<'a, T> {
current: Option<&'a Rc<Node<T>>>,
}
impl<'a, T> Iterator for Iter<'a, T> {
type Item = &'a T;
fn next(&mut self) -> Option<Self::Item> {
self.current.map(|node| {
self.current = node.next.as_ref();
&node.elem
})
}
}
impl<T> List<T> {
// Създава празен списък
fn new() -> Self {
List { head: None }
}
// Връща първия елемент от списъка
fn head(&self) -> Option<&T> {
self.head.as_ref().map(|node| &node.elem)
}
// Връща опашката на списъка - т.е. списък съдържащ
// всички елементи освен първия.
// Опашката на празен списък е празен списък.
fn tail(&self) -> List<T> {
List {
head: self.head.as_ref().and_then(|node| node.next.clone())
}
}
// Добавя елемент към списъка.
// Връща нов списък с първи елемент е `value` и
// опашка стария списък.
fn prepend(&self, value: T) -> List<T> {
List {
head: Some(Rc::new(Node {
elem: value,
next: self.head.clone(),
})),
}
}
// Създава итератор по елементите на списъка.
// Итератора връща елементи от тип `&T`.
fn iter(&self) -> Iter<'_, T> {
Iter {
current: self.head.as_ref(),
}
}
fn drop_iteratively(mut self) {
let mut current = self.head.take();
while let Some(node) = current {
current = node.next.clone();
}
}
}
fn main() {
let mut list = List::new();
for i in 0..1_000_000 {
list = list.prepend(i);
}
//std::mem::drop(list); получава се overflow на стека заради голяма рекурсия
list.drop_iteratively();
}
Лог от изпълнението
Updating crates.io index
Locking 17 packages to latest compatible versions
Compiling proc-macro2 v1.0.103
Compiling unicode-ident v1.0.22
Compiling quote v1.0.42
Compiling futures-sink v0.3.31
Compiling futures-core v0.3.31
Compiling futures-channel v0.3.31
Compiling pin-project-lite v0.2.16
Compiling memchr v2.7.6
Compiling syn v2.0.111
Compiling futures-task v0.3.31
Compiling slab v0.4.11
Compiling pin-utils v0.1.0
Compiling futures-io v0.3.31
Compiling solution v0.1.0 (/tmp/d20251211-1757769-khgsss/solution)
warning: struct `List` is never constructed
--> src/lib.rs:4:8
|
4 | struct List<T> {
| ^^^^
|
= note: `#[warn(dead_code)]` on by default
warning: type alias `Link` is never used
--> src/lib.rs:8:6
|
8 | type Link<T> = Option<Rc<Node<T>>>;
| ^^^^
warning: struct `Node` is never constructed
--> src/lib.rs:10:8
|
10 | struct Node<T> {
| ^^^^
warning: struct `Iter` is never constructed
--> src/lib.rs:15:8
|
15 | struct Iter<'a, T> {
| ^^^^
warning: associated items `new`, `head`, `tail`, `prepend`, `iter`, and `drop_iteratively` are never used
--> src/lib.rs:33:8
|
30 | impl<T> List<T> {
| --------------- associated items in this implementation
...
33 | fn new() -> Self {
| ^^^
...
38 | fn head(&self) -> Option<&T> {
| ^^^^
...
45 | fn tail(&self) -> List<T> {
| ^^^^
...
54 | fn prepend(&self, value: T) -> List<T> {
| ^^^^^^^
...
65 | fn iter(&self) -> Iter<'_, T> {
| ^^^^
...
71 | fn drop_iteratively(mut self) {
| ^^^^^^^^^^^^^^^^
warning: function `main` is never used
--> src/lib.rs:80:4
|
80 | fn main() {
| ^^^^
warning: `solution` (lib) generated 6 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: method `drop_iteratively` is never used
--> tests/../src/lib.rs:71:8
|
30 | impl<T> List<T> {
| --------------- method in this implementation
...
71 | fn drop_iteratively(mut self) {
| ^^^^^^^^^^^^^^^^
|
= note: `#[warn(dead_code)]` on by default
warning: function `main` is never used
--> tests/../src/lib.rs:80:4
|
80 | fn main() {
| ^^^^
warning: `solution` (test "solution_test") generated 2 warnings
Finished `test` profile [unoptimized + debuginfo] target(s) in 8.26s
Running tests/solution_test.rs (target/debug/deps/solution_test-ee0783488e12dce9)
running 2 tests
test solution_test::test_iterator ... ok
test solution_test::test_list ... ok
test result: ok. 2 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out; finished in 0.00s