From 8da8070961f1c9925d6510db833eb9dea9dcf146 Mon Sep 17 00:00:00 2001 From: Jake Walker Date: Fri, 14 Oct 2022 18:14:56 +0100 Subject: [PATCH] Solutions 3 --- exercises/lifetimes/lifetimes1.rs | 4 +--- exercises/lifetimes/lifetimes2.rs | 4 +--- exercises/lifetimes/lifetimes3.rs | 8 +++----- exercises/standard_library_types/arc1.rs | 6 ++---- exercises/standard_library_types/box1.rs | 8 +++----- exercises/standard_library_types/cow1.rs | 5 +---- exercises/standard_library_types/iterators1.rs | 10 ++++------ exercises/standard_library_types/iterators2.rs | 8 +++----- exercises/standard_library_types/iterators3.rs | 16 +++++++++++----- exercises/standard_library_types/iterators4.rs | 3 +-- exercises/standard_library_types/iterators5.rs | 6 ++---- exercises/standard_library_types/rc1.rs | 13 ++++++------- exercises/tests/tests1.rs | 4 +--- exercises/tests/tests2.rs | 4 +--- exercises/tests/tests3.rs | 6 ++---- 15 files changed, 42 insertions(+), 63 deletions(-) diff --git a/exercises/lifetimes/lifetimes1.rs b/exercises/lifetimes/lifetimes1.rs index 0236470..a12d3f5 100644 --- a/exercises/lifetimes/lifetimes1.rs +++ b/exercises/lifetimes/lifetimes1.rs @@ -7,9 +7,7 @@ // // Execute `rustlings hint lifetimes1` or use the `hint` watch subcommand for a hint. -// I AM NOT DONE - -fn longest(x: &str, y: &str) -> &str { +fn longest<'a>(x: &'a str, y: &'a str) -> &'a str { if x.len() > y.len() { x } else { diff --git a/exercises/lifetimes/lifetimes2.rs b/exercises/lifetimes/lifetimes2.rs index b48feab..77d350e 100644 --- a/exercises/lifetimes/lifetimes2.rs +++ b/exercises/lifetimes/lifetimes2.rs @@ -6,8 +6,6 @@ // // Execute `rustlings hint lifetimes2` or use the `hint` watch subcommand for a hint. -// I AM NOT DONE - fn longest<'a>(x: &'a str, y: &'a str) -> &'a str { if x.len() > y.len() { x @@ -18,9 +16,9 @@ fn longest<'a>(x: &'a str, y: &'a str) -> &'a str { fn main() { let string1 = String::from("long string is long"); + let string2 = String::from("xyz"); let result; { - let string2 = String::from("xyz"); result = longest(string1.as_str(), string2.as_str()); } println!("The longest string is '{}'", result); diff --git a/exercises/lifetimes/lifetimes3.rs b/exercises/lifetimes/lifetimes3.rs index ea48370..c0818f0 100644 --- a/exercises/lifetimes/lifetimes3.rs +++ b/exercises/lifetimes/lifetimes3.rs @@ -4,11 +4,9 @@ // // Execute `rustlings hint lifetimes3` or use the `hint` watch subcommand for a hint. -// I AM NOT DONE - -struct Book { - author: &str, - title: &str, +struct Book<'a> { + author: &'a str, + title: &'a str, } fn main() { diff --git a/exercises/standard_library_types/arc1.rs b/exercises/standard_library_types/arc1.rs index 93a2703..c065d49 100644 --- a/exercises/standard_library_types/arc1.rs +++ b/exercises/standard_library_types/arc1.rs @@ -18,19 +18,17 @@ // where the second TODO comment is. Try not to create any copies of the `numbers` Vec! // Execute `rustlings hint arc1` or use the `hint` watch subcommand for a hint. -// I AM NOT DONE - #![forbid(unused_imports)] // Do not change this, (or the next) line. use std::sync::Arc; use std::thread; fn main() { let numbers: Vec<_> = (0..100u32).collect(); - let shared_numbers = // TODO + let shared_numbers = Arc::new(numbers); // TODO let mut joinhandles = Vec::new(); for offset in 0..8 { - let child_numbers = // TODO + let child_numbers = Arc::clone(&shared_numbers); // TODO joinhandles.push(thread::spawn(move || { let sum: u32 = child_numbers.iter().filter(|n| *n % 8 == offset).sum(); println!("Sum of offset {} is {}", offset, sum); diff --git a/exercises/standard_library_types/box1.rs b/exercises/standard_library_types/box1.rs index 66cf00f..2b1197d 100644 --- a/exercises/standard_library_types/box1.rs +++ b/exercises/standard_library_types/box1.rs @@ -16,11 +16,9 @@ // // Execute `rustlings hint box1` or use the `hint` watch subcommand for a hint. -// I AM NOT DONE - #[derive(PartialEq, Debug)] pub enum List { - Cons(i32, List), + Cons(i32, Box), Nil, } @@ -33,11 +31,11 @@ fn main() { } pub fn create_empty_list() -> List { - todo!() + List::Nil } pub fn create_non_empty_list() -> List { - todo!() + List::Cons(12, Box::new(List::Cons(52, Box::new(List::Nil)))) } #[cfg(test)] diff --git a/exercises/standard_library_types/cow1.rs b/exercises/standard_library_types/cow1.rs index 5fba251..52b961e 100644 --- a/exercises/standard_library_types/cow1.rs +++ b/exercises/standard_library_types/cow1.rs @@ -5,8 +5,6 @@ // It can enclose and provide immutable access to borrowed data, and clone the data lazily when mutation or ownership is required. // The type is designed to work with general borrowed data via the Borrow trait. -// I AM NOT DONE - use std::borrow::Cow; fn abs_all<'a, 'b>(input: &'a mut Cow<'b, [i32]>) -> &'a mut Cow<'b, [i32]> { @@ -41,8 +39,7 @@ fn main() { let slice = vec![-1, 0, 1]; let mut input = Cow::from(slice); match abs_all(&mut input) { - // TODO - Cow::Borrowed(_) => println!("I own this slice!"), + Cow::Owned(_) => println!("I own this slice!"), _ => panic!("expected borrowed value"), } } diff --git a/exercises/standard_library_types/iterators1.rs b/exercises/standard_library_types/iterators1.rs index 0379c6b..544dc67 100644 --- a/exercises/standard_library_types/iterators1.rs +++ b/exercises/standard_library_types/iterators1.rs @@ -8,17 +8,15 @@ // // Execute `rustlings hint iterators1` or use the `hint` watch subcommand for a hint. -// I AM NOT DONE - fn main () { let my_fav_fruits = vec!["banana", "custard apple", "avocado", "peach", "raspberry"]; - let mut my_iterable_fav_fruits = ???; // TODO: Step 1 + let mut my_iterable_fav_fruits = my_fav_fruits.iter(); // TODO: Step 1 assert_eq!(my_iterable_fav_fruits.next(), Some(&"banana")); - assert_eq!(my_iterable_fav_fruits.next(), ???); // TODO: Step 2 + assert_eq!(my_iterable_fav_fruits.next(), Some(&"custard apple")); // TODO: Step 2 assert_eq!(my_iterable_fav_fruits.next(), Some(&"avocado")); - assert_eq!(my_iterable_fav_fruits.next(), ???); // TODO: Step 3 + assert_eq!(my_iterable_fav_fruits.next(), Some(&"peach")); // TODO: Step 3 assert_eq!(my_iterable_fav_fruits.next(), Some(&"raspberry")); - assert_eq!(my_iterable_fav_fruits.next(), ???); // TODO: Step 4 + assert_eq!(my_iterable_fav_fruits.next(), None); // TODO: Step 4 } diff --git a/exercises/standard_library_types/iterators2.rs b/exercises/standard_library_types/iterators2.rs index 29c53af..33fbd9f 100644 --- a/exercises/standard_library_types/iterators2.rs +++ b/exercises/standard_library_types/iterators2.rs @@ -3,8 +3,6 @@ // can offer. Follow the steps to complete the exercise. // Execute `rustlings hint iterators2` or use the `hint` watch subcommand for a hint. -// I AM NOT DONE - // Step 1. // Complete the `capitalize_first` function. // "hello" -> "Hello" @@ -12,7 +10,7 @@ pub fn capitalize_first(input: &str) -> String { let mut c = input.chars(); match c.next() { None => String::new(), - Some(first) => ???, + Some(first) => first.to_uppercase().to_string() + c.as_str(), } } @@ -21,7 +19,7 @@ pub fn capitalize_first(input: &str) -> String { // Return a vector of strings. // ["hello", "world"] -> ["Hello", "World"] pub fn capitalize_words_vector(words: &[&str]) -> Vec { - vec![] + words.iter().map(|word| capitalize_first(word)).collect() } // Step 3. @@ -29,7 +27,7 @@ pub fn capitalize_words_vector(words: &[&str]) -> Vec { // Return a single string. // ["hello", " ", "world"] -> "Hello World" pub fn capitalize_words_string(words: &[&str]) -> String { - String::new() + capitalize_words_vector(words).join("") } #[cfg(test)] diff --git a/exercises/standard_library_types/iterators3.rs b/exercises/standard_library_types/iterators3.rs index c97a625..1f4c381 100644 --- a/exercises/standard_library_types/iterators3.rs +++ b/exercises/standard_library_types/iterators3.rs @@ -6,8 +6,6 @@ // list_of_results functions. // Execute `rustlings hint iterators3` or use the `hint` watch subcommand for a hint. -// I AM NOT DONE - #[derive(Debug, PartialEq, Eq)] pub enum DivisionError { NotDivisible(NotDivisibleError), @@ -23,21 +21,29 @@ pub struct NotDivisibleError { // Calculate `a` divided by `b` if `a` is evenly divisible by `b`. // Otherwise, return a suitable error. pub fn divide(a: i32, b: i32) -> Result { - todo!(); + if (b == 0) { + Err(DivisionError::DivideByZero) + } else if (a % b != 0) { + Err(DivisionError::NotDivisible(NotDivisibleError { dividend: a, divisor: b })) + } else { + Ok(a / b) + } } // Complete the function and return a value of the correct type so the test passes. // Desired output: Ok([1, 11, 1426, 3]) -fn result_with_list() -> () { +fn result_with_list() -> Result, DivisionError> { let numbers = vec![27, 297, 38502, 81]; let division_results = numbers.into_iter().map(|n| divide(n, 27)); + division_results.collect() } // Complete the function and return a value of the correct type so the test passes. // Desired output: [Ok(1), Ok(11), Ok(1426), Ok(3)] -fn list_of_results() -> () { +fn list_of_results() -> Vec> { let numbers = vec![27, 297, 38502, 81]; let division_results = numbers.into_iter().map(|n| divide(n, 27)); + division_results.collect() } #[cfg(test)] diff --git a/exercises/standard_library_types/iterators4.rs b/exercises/standard_library_types/iterators4.rs index a02470e..b462ae3 100644 --- a/exercises/standard_library_types/iterators4.rs +++ b/exercises/standard_library_types/iterators4.rs @@ -1,8 +1,6 @@ // iterators4.rs // Execute `rustlings hint iterators4` or use the `hint` watch subcommand for a hint. -// I AM NOT DONE - pub fn factorial(num: u64) -> u64 { // Complete this function to return the factorial of num // Do not use: @@ -13,6 +11,7 @@ pub fn factorial(num: u64) -> u64 { // For an extra challenge, don't use: // - recursion // Execute `rustlings hint iterators4` for hints. + (1..=num).product() } #[cfg(test)] diff --git a/exercises/standard_library_types/iterators5.rs b/exercises/standard_library_types/iterators5.rs index 0593d12..d528964 100644 --- a/exercises/standard_library_types/iterators5.rs +++ b/exercises/standard_library_types/iterators5.rs @@ -10,8 +10,6 @@ // // Make the code compile and the tests pass. -// I AM NOT DONE - use std::collections::HashMap; #[derive(Clone, Copy, PartialEq, Eq)] @@ -34,7 +32,7 @@ fn count_for(map: &HashMap, value: Progress) -> usize { fn count_iterator(map: &HashMap, value: Progress) -> usize { // map is a hashmap with String keys and Progress values. // map = { "variables1": Complete, "from_str": None, ... } - todo!(); + map.values().filter(|p| **p == value).count() } fn count_collection_for(collection: &[HashMap], value: Progress) -> usize { @@ -53,7 +51,7 @@ fn count_collection_iterator(collection: &[HashMap], value: Pr // collection is a slice of hashmaps. // collection = [{ "variables1": Complete, "from_str": None, ... }, // { "variables2": Complete, ... }, ... ] - todo!(); + collection.iter().map(|map| count_iterator(map, value)).sum() } #[cfg(test)] diff --git a/exercises/standard_library_types/rc1.rs b/exercises/standard_library_types/rc1.rs index 9b907fd..fce56ed 100644 --- a/exercises/standard_library_types/rc1.rs +++ b/exercises/standard_library_types/rc1.rs @@ -5,7 +5,6 @@ // Make this code compile by using the proper Rc primitives to express that the sun has multiple owners. -// I AM NOT DONE use std::rc::Rc; #[derive(Debug)] @@ -54,17 +53,17 @@ fn main() { jupiter.details(); // TODO - let saturn = Planet::Saturn(Rc::new(Sun {})); + let saturn = Planet::Saturn(Rc::clone(&sun)); println!("reference count = {}", Rc::strong_count(&sun)); // 7 references saturn.details(); // TODO - let uranus = Planet::Uranus(Rc::new(Sun {})); + let uranus = Planet::Uranus(Rc::clone(&sun)); println!("reference count = {}", Rc::strong_count(&sun)); // 8 references uranus.details(); // TODO - let neptune = Planet::Neptune(Rc::new(Sun {})); + let neptune = Planet::Neptune(Rc::clone(&sun)); println!("reference count = {}", Rc::strong_count(&sun)); // 9 references neptune.details(); @@ -85,13 +84,13 @@ fn main() { drop(mars); println!("reference count = {}", Rc::strong_count(&sun)); // 4 references - // TODO + drop(earth); println!("reference count = {}", Rc::strong_count(&sun)); // 3 references - // TODO + drop(venus); println!("reference count = {}", Rc::strong_count(&sun)); // 2 references - // TODO + drop(mercury); println!("reference count = {}", Rc::strong_count(&sun)); // 1 reference assert_eq!(Rc::strong_count(&sun), 1); diff --git a/exercises/tests/tests1.rs b/exercises/tests/tests1.rs index 8b6ea37..479f182 100644 --- a/exercises/tests/tests1.rs +++ b/exercises/tests/tests1.rs @@ -7,12 +7,10 @@ // pass! Make the test fail! // Execute `rustlings hint tests1` or use the `hint` watch subcommand for a hint. -// I AM NOT DONE - #[cfg(test)] mod tests { #[test] fn you_can_assert() { - assert!(); + assert!(true); } } diff --git a/exercises/tests/tests2.rs b/exercises/tests/tests2.rs index a5ac15b..abb2ec6 100644 --- a/exercises/tests/tests2.rs +++ b/exercises/tests/tests2.rs @@ -3,12 +3,10 @@ // pass! Make the test fail! // Execute `rustlings hint tests2` or use the `hint` watch subcommand for a hint. -// I AM NOT DONE - #[cfg(test)] mod tests { #[test] fn you_can_assert_eq() { - assert_eq!(); + assert_eq!("Hi Mom!", "Hi Mom!"); } } diff --git a/exercises/tests/tests3.rs b/exercises/tests/tests3.rs index 196a81a..8243035 100644 --- a/exercises/tests/tests3.rs +++ b/exercises/tests/tests3.rs @@ -4,8 +4,6 @@ // we expect to get when we call `is_even(5)`. // Execute `rustlings hint tests3` or use the `hint` watch subcommand for a hint. -// I AM NOT DONE - pub fn is_even(num: i32) -> bool { num % 2 == 0 } @@ -16,11 +14,11 @@ mod tests { #[test] fn is_true_when_even() { - assert!(); + assert!(is_even(4)); } #[test] fn is_false_when_odd() { - assert!(); + assert!(!is_even(5)); } }