解决问题

This commit is contained in:
suxin2017 2022-04-24 09:37:34 +08:00
parent 9ec35d899c
commit e23a706713
79 changed files with 280 additions and 239 deletions

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@ -6,12 +6,11 @@
// check clippy's suggestions from the output to solve the exercise.
// Execute `rustlings hint clippy1` for hints :)
// I AM NOT DONE
use std::f32;
fn main() {
let pi = 3.14f32;
let pi = f32::consts::PI;
let radius = 5.00f32;
let area = pi * f32::powi(radius, 2);

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@ -1,12 +1,11 @@
// clippy2.rs
// Make me compile! Execute `rustlings hint clippy2` for hints :)
// I AM NOT DONE
fn main() {
let mut res = 42;
let option = Some(12);
for x in option {
if let Some(x) = option {
res += x;
}
println!("{}", res);

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@ -11,15 +11,18 @@
// Execute the command `rustlings hint hashmap1` if you need
// hints.
// I AM NOT DONE
use std::collections::HashMap;
fn fruit_basket() -> HashMap<String, u32> {
let mut basket = // TODO: declare your hash map here.
let mut basket = HashMap::new();// TODO: declare your hash map here.
// Two bananas are already given for you :)
basket.insert(String::from("banana"), 2);
basket.insert(String::from("apple"), 1);
basket.insert(String::from("oranage"), 0);
basket.insert(String::from("a"), 1);
basket.insert(String::from("b"), 1);
// TODO: Put more fruits in your basket here.

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@ -12,9 +12,7 @@
// Execute the command `rustlings hint hashmap2` if you need
// hints.
// I AM NOT DONE
use std::collections::HashMap;
use std::collections::HashMap;
#[derive(Hash, PartialEq, Eq)]
enum Fruit {
@ -38,6 +36,12 @@ fn fruit_basket(basket: &mut HashMap<Fruit, u32>) {
// TODO: Put new fruits if not already present. Note that you
// are not allowed to put any type of fruit that's already
// present!
match fruit {
Fruit::Apple | Fruit::Mango | Fruit::Lychee => (),
_ => {
basket.insert(fruit, 1);
}
}
}
}

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@ -4,11 +4,10 @@
// Make me compile and pass the test!
// Execute the command `rustlings hint vec1` if you need hints.
// I AM NOT DONE
fn array_and_vec() -> ([i32; 4], Vec<i32>) {
let a = [10, 20, 30, 40]; // a plain array
let v = // TODO: declare your vector here with the macro for vectors
let v = vec![10,20,30,40];// TODO: declare your vector here with the macro for vectors
(a, v)
}

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@ -7,12 +7,12 @@
// Execute the command `rustlings hint vec2` if you need
// hints.
// I AM NOT DONE
fn vec_loop(mut v: Vec<i32>) -> Vec<i32> {
for i in v.iter_mut() {
// TODO: Fill this up so that each element in the Vec `v` is
// multiplied by 2.
*i *= 2;
}
// At this point, `v` should be equal to [4, 8, 12, 16, 20].

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@ -37,6 +37,23 @@ impl Default for Person {
impl From<&str> for Person {
fn from(s: &str) -> Person {
let mut r = s.split(",");
let name = r.next();
let age = r.next();
let other = r.next();
if let (Some(name), Some(age), None) = (name, age, other) {
if name != "" && age != "" {
if let Ok(age) = age.parse() {
return Person {
name: name.to_string(),
age,
};
}
}
}
return Person::default();
}
}

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@ -5,11 +5,10 @@
// The goal is to make sure that the division does not fail to compile
// and returns the proper type.
// I AM NOT DONE
fn average(values: &[f64]) -> f64 {
let total = values.iter().sum::<f64>();
total / values.len()
total / values.len() as f64
}
fn main() {

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@ -1,11 +1,12 @@
// enums1.rs
// Make me compile! Execute `rustlings hint enums1` for hints!
// I AM NOT DONE
#[derive(Debug)]
enum Message {
// TODO: define a few types of messages as used below
Quit,
Echo,
Move,
ChangeColor, // TODO: define a few types of messages as used below
}
fn main() {

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@ -1,10 +1,13 @@
// enums2.rs
// Make me compile! Execute `rustlings hint enums2` for hints!
// I AM NOT DONE
#[derive(Debug)]
enum Message {
Move{x:i32,y:i32},
Echo(String),
ChangeColor(i32,i32,i32),
Quit
// TODO: define the different variants used below
}

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@ -1,10 +1,11 @@
// enums3.rs
// Address all the TODOs to make the tests pass!
// I AM NOT DONE
enum Message {
// TODO: implement the message variant types based on their usage below
ChangeColor((u8, u8, u8)),
Echo(String),
Move(Point),
Quit, // TODO: implement the message variant types based on their usage below
}
struct Point {
@ -36,6 +37,14 @@ impl State {
}
fn process(&mut self, message: Message) {
match message {
Message::ChangeColor(color) => self.color = color,
Message::Echo(mes) => println!("{mes}"),
Message::Move(point) => {
self.position = point;
}
Message::Quit => self.quit = true,
}
// TODO: create a match expression to process the different message variants
}
}

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@ -5,14 +5,12 @@
// construct to `Option` that can be used to express error conditions. Let's use it!
// Execute `rustlings hint errors1` for hints!
// I AM NOT DONE
pub fn generate_nametag_text(name: String) -> Option<String> {
pub fn generate_nametag_text(name: String) -> Result<String, String> {
if name.len() > 0 {
Some(format!("Hi! My name is {}", name))
Ok(format!("Hi! My name is {}", name))
} else {
// Empty names aren't allowed.
None
Err("`name` was empty; it must be nonempty.".to_string())
}
}

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@ -16,14 +16,13 @@
// There are at least two ways to implement this that are both correct-- but
// one is a lot shorter! Execute `rustlings hint errors2` for hints to both ways.
// I AM NOT DONE
use std::num::ParseIntError;
pub fn total_cost(item_quantity: &str) -> Result<i32, ParseIntError> {
let processing_fee = 1;
let cost_per_item = 5;
let qty = item_quantity.parse::<i32>();
let qty = item_quantity.parse::<i32>()?;
Ok(qty * cost_per_item + processing_fee)
}

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@ -4,15 +4,13 @@
// Why not? What should we do to fix it?
// Execute `rustlings hint errors3` for hints!
// I AM NOT DONE
use std::num::ParseIntError;
fn main() {
let mut tokens = 100;
let pretend_user_input = "8";
let cost = total_cost(pretend_user_input)?;
let cost = total_cost(pretend_user_input).unwrap();
if cost > tokens {
println!("You can't afford that many!");

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@ -1,8 +1,6 @@
// errors4.rs
// Make this test pass! Execute `rustlings hint errors4` for hints :)
// I AM NOT DONE
#[derive(PartialEq, Debug)]
struct PositiveNonzeroInteger(u64);
@ -14,7 +12,13 @@ enum CreationError {
impl PositiveNonzeroInteger {
fn new(value: i64) -> Result<PositiveNonzeroInteger, CreationError> {
Ok(PositiveNonzeroInteger(value as u64))
if value < 0{
Err(CreationError::Negative)
} else if value == 0 {
Err(CreationError::Zero)
} else {
Ok(PositiveNonzeroInteger(value as u64))
}
}
}

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@ -4,14 +4,12 @@
// It won't compile right now! Why?
// Execute `rustlings hint errors5` for hints!
// I AM NOT DONE
use std::error;
use std::fmt;
use std::num::ParseIntError;
// TODO: update the return type of `main()` to make this compile.
fn main() -> Result<(), ParseIntError> {
fn main() -> Result<(), Box<dyn error::Error>> {
let pretend_user_input = "42";
let x: i64 = pretend_user_input.parse()?;
println!("output={:?}", PositiveNonzeroInteger::new(x)?);

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@ -8,29 +8,30 @@
// Make these tests pass! Execute `rustlings hint errors6` for hints :)
// I AM NOT DONE
use std::num::ParseIntError;
// This is a custom error type that we will be using in `parse_pos_nonzero()`.
#[derive(PartialEq, Debug)]
enum ParsePosNonzeroError {
Creation(CreationError),
ParseInt(ParseIntError)
ParseInt(ParseIntError),
}
impl ParsePosNonzeroError {
// TODO: add another error conversion function here.
fn from_creation(err: CreationError) -> ParsePosNonzeroError {
ParsePosNonzeroError::Creation(err)
}
fn from_parse_int(err: ParseIntError) -> ParsePosNonzeroError {
ParsePosNonzeroError::ParseInt(err)
}
}
fn parse_pos_nonzero(s: &str)
-> Result<PositiveNonzeroInteger, ParsePosNonzeroError>
{
fn parse_pos_nonzero(s: &str) -> Result<PositiveNonzeroInteger, ParsePosNonzeroError> {
// TODO: change this to return an appropriate error instead of panicking
// when `parse()` returns an error.
let x: i64 = s.parse().unwrap();
PositiveNonzeroInteger::new(x)
.map_err(ParsePosNonzeroError::from_creation)
let x: i64 = s.parse().map_err(ParsePosNonzeroError::from_parse_int)?;
PositiveNonzeroInteger::new(x).map_err(ParsePosNonzeroError::from_creation)
}
// Don't change anything below this line.
@ -49,7 +50,7 @@ impl PositiveNonzeroInteger {
match value {
x if x < 0 => Err(CreationError::Negative),
x if x == 0 => Err(CreationError::Zero),
x => Ok(PositiveNonzeroInteger(x as u64))
x => Ok(PositiveNonzeroInteger(x as u64)),
}
}
}

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@ -1,8 +1,9 @@
// functions1.rs
// Make me compile! Execute `rustlings hint functions1` for hints :)
// I AM NOT DONE
fn main() {
call_me();
}
fn call_me() {}

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@ -1,13 +1,12 @@
// functions2.rs
// Make me compile! Execute `rustlings hint functions2` for hints :)
// I AM NOT DONE
fn main() {
call_me(3);
}
fn call_me(num:) {
fn call_me(num: i32) {
for i in 0..num {
println!("Ring! Call number {}", i + 1);
}

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@ -1,10 +1,9 @@
// functions3.rs
// Make me compile! Execute `rustlings hint functions3` for hints :)
// I AM NOT DONE
fn main() {
call_me();
call_me(10);
}
fn call_me(num: u32) {

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@ -4,14 +4,13 @@
// This store is having a sale where if the price is an even number, you get
// 10 Rustbucks off, but if it's an odd number, it's 3 Rustbucks off.
// I AM NOT DONE
fn main() {
let original_price = 51;
println!("Your sale price is {}", sale_price(original_price));
}
fn sale_price(price: i32) -> {
fn sale_price(price: i32) -> i32 {
if is_even(price) {
price - 10
} else {

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@ -1,7 +1,6 @@
// functions5.rs
// Make me compile! Execute `rustlings hint functions5` for hints :)
// I AM NOT DONE
fn main() {
let answer = square(3);
@ -9,5 +8,5 @@ fn main() {
}
fn square(num: i32) -> i32 {
num * num;
num * num
}

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@ -3,9 +3,8 @@
// Execute `rustlings hint generics1` for hints!
// I AM NOT DONE
fn main() {
let mut shopping_list: Vec<?> = Vec::new();
let mut shopping_list: Vec<&str> = Vec::new();
shopping_list.push("milk");
}

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@ -3,14 +3,12 @@
// Execute `rustlings hint generics2` for hints!
// I AM NOT DONE
struct Wrapper {
value: u32,
struct Wrapper<T> {
value: T,
}
impl Wrapper {
pub fn new(value: u32) -> Self {
impl<T> Wrapper<T> {
pub fn new(value: T) -> Self {
Wrapper { value }
}
}

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@ -10,18 +10,18 @@
// Execute 'rustlings hint generics3' for hints!
// I AM NOT DONE
pub struct ReportCard {
pub grade: f32,
pub struct ReportCard<T: std::fmt::Display> {
pub grade: T,
pub student_name: String,
pub student_age: u8,
}
impl ReportCard {
impl<T: std::fmt::Display> ReportCard<T> {
pub fn print(&self) -> String {
format!("{} ({}) - achieved a grade of {}",
&self.student_name, &self.student_age, &self.grade)
format!(
"{} ({}) - achieved a grade of {}",
&self.student_name, &self.student_age, &self.grade
)
}
}
@ -46,7 +46,7 @@ mod tests {
fn generate_alphabetic_report_card() {
// TODO: Make sure to change the grade here after you finish the exercise.
let report_card = ReportCard {
grade: 2.1,
grade: "A+",
student_name: "Gary Plotter".to_string(),
student_age: 11,
};

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@ -1,6 +1,5 @@
// if1.rs
// I AM NOT DONE
pub fn bigger(a: i32, b: i32) -> i32 {
// Complete this function to return the bigger number!
@ -8,6 +7,8 @@ pub fn bigger(a: i32, b: i32) -> i32 {
// - another function call
// - additional variables
// Execute `rustlings hint if1` for hints
if a > b {a} else {b}
}
// Don't mind this for now :)

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@ -4,13 +4,14 @@
// Step 2: Get the bar_for_fuzz and default_to_baz tests passing!
// Execute the command `rustlings hint if2` if you want a hint :)
// I AM NOT DONE
pub fn fizz_if_foo(fizzish: &str) -> &str {
if fizzish == "fizz" {
"foo"
} else if fizzish == "fuzz" {
"bar"
} else {
1
"baz"
}
}

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@ -5,8 +5,6 @@
// ready for the next exercise, remove the `I AM NOT DONE` comment below.
// Execute the command `rustlings hint intro1` for a hint.
// I AM NOT DONE
fn main() {
println!("Hello and");
println!(r#" welcome to... "#);

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@ -2,8 +2,6 @@
// Make the code print a greeting to the world.
// Execute `rustlings hint intro2` for a hint.
// I AM NOT DONE
fn main() {
println!("Hello {}!");
println!("a greeting to the world.");
}

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@ -1,7 +1,6 @@
// macros1.rs
// Make me compile! Execute `rustlings hint macros1` for hints :)
// I AM NOT DONE
macro_rules! my_macro {
() => {
@ -10,5 +9,5 @@ macro_rules! my_macro {
}
fn main() {
my_macro();
my_macro!();
}

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@ -1,14 +1,15 @@
// macros2.rs
// Make me compile! Execute `rustlings hint macros2` for hints :)
// I AM NOT DONE
fn main() {
my_macro!();
}
macro_rules! my_macro {
() => {
println!("Check out my macro!");
};
}
fn main() {
my_macro!();
}

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@ -2,10 +2,10 @@
// Make me compile, without taking the macro out of the module!
// Execute `rustlings hint macros3` for hints :)
// I AM NOT DONE
mod macros {
macro_rules! my_macro {
#[macro_export]
macro_rules! my_macro {
() => {
println!("Check out my macro!");
};

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@ -1,15 +1,13 @@
// macros4.rs
// Make me compile! Execute `rustlings hint macros4` for hints :)
// I AM NOT DONE
macro_rules! my_macro {
() => {
println!("Check out my macro!");
}
};
($val:expr) => {
println!("Look at this other macro: {}", $val);
}
};
}
fn main() {

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@ -1,7 +1,6 @@
// modules1.rs
// Make me compile! Execute `rustlings hint modules1` for hints :)
// I AM NOT DONE
mod sausage_factory {
// Don't let anybody outside of this module see this!
@ -9,7 +8,7 @@ mod sausage_factory {
String::from("Ginger")
}
fn make_sausage() {
pub fn make_sausage() {
get_secret_recipe();
println!("sausage!");
}

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@ -3,13 +3,12 @@
// 'use' and 'as' keywords. Fix these 'use' statements to make the code compile.
// Make me compile! Execute `rustlings hint modules2` for hints :)
// I AM NOT DONE
mod delicious_snacks {
// TODO: Fix these use statements
use self::fruits::PEAR as ???
use self::veggies::CUCUMBER as ???
pub use self::fruits::PEAR as fruit;
pub use self::veggies::CUCUMBER as veggie;
mod fruits {
pub const PEAR: &'static str = "Pear";

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@ -5,10 +5,9 @@
// from the std::time module. Bonus style points if you can do it with one line!
// Make me compile! Execute `rustlings hint modules3` for hints :)
// I AM NOT DONE
// TODO: Complete this use statement
use ???
use std::time::{SystemTime,UNIX_EPOCH};
fn main() {
match SystemTime::now().duration_since(UNIX_EPOCH) {

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@ -1,12 +1,11 @@
// move_semantics1.rs
// Make me compile! Execute `rustlings hint move_semantics1` for hints :)
// I AM NOT DONE
fn main() {
let vec0 = Vec::new();
let vec1 = fill_vec(vec0);
let mut vec1 = fill_vec(vec0);
println!("{} has length {} content `{:?}`", "vec1", vec1.len(), vec1);

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@ -2,12 +2,11 @@
// Make me compile without changing line 13 or moving line 10!
// Execute `rustlings hint move_semantics2` for hints :)
// I AM NOT DONE
fn main() {
let vec0 = Vec::new();
let mut vec1 = fill_vec(vec0);
let mut vec1 = fill_vec(&vec0);
// Do not change the following line!
println!("{} has length {} content `{:?}`", "vec0", vec0.len(), vec0);
@ -17,8 +16,8 @@ fn main() {
println!("{} has length {} content `{:?}`", "vec1", vec1.len(), vec1);
}
fn fill_vec(vec: Vec<i32>) -> Vec<i32> {
let mut vec = vec;
fn fill_vec(vec:& Vec<i32>) -> Vec<i32> {
let mut vec = vec.clone();
vec.push(22);
vec.push(44);

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@ -3,12 +3,11 @@
// (no lines with multiple semicolons necessary!)
// Execute `rustlings hint move_semantics3` for hints :)
// I AM NOT DONE
fn main() {
let vec0 = Vec::new();
let mut vec0 = Vec::new();
let mut vec1 = fill_vec(vec0);
let mut vec1 = fill_vec(&mut vec0);
println!("{} has length {} content `{:?}`", "vec1", vec1.len(), vec1);
@ -17,7 +16,7 @@ fn main() {
println!("{} has length {} content `{:?}`", "vec1", vec1.len(), vec1);
}
fn fill_vec(vec: Vec<i32>) -> Vec<i32> {
fn fill_vec(vec: &mut Vec<i32>) ->&mut Vec<i32> {
vec.push(22);
vec.push(44);
vec.push(66);

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@ -4,12 +4,8 @@
// freshly created vector from fill_vec to its caller.
// Execute `rustlings hint move_semantics4` for hints!
// I AM NOT DONE
fn main() {
let vec0 = Vec::new();
let mut vec1 = fill_vec(vec0);
let mut vec1 = fill_vec();
println!("{} has length {} content `{:?}`", "vec1", vec1.len(), vec1);
@ -20,7 +16,7 @@ fn main() {
// `fill_vec()` no longer takes `vec: Vec<i32>` as argument
fn fill_vec() -> Vec<i32> {
let mut vec = vec;
let mut vec = Vec::new();
vec.push(22);
vec.push(44);

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@ -3,13 +3,12 @@
// adding, changing or removing any of them.
// Execute `rustlings hint move_semantics5` for hints :)
// I AM NOT DONE
fn main() {
let mut x = 100;
let y = &mut x;
let z = &mut x;
*y += 100;
let z = &mut x;
*z += 1000;
assert_eq!(x, 1200);
}

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@ -2,24 +2,22 @@
// Make me compile! `rustlings hint move_semantics6` for hints
// You can't change anything except adding or removing references
// I AM NOT DONE
fn main() {
let data = "Rust is great!".to_string();
get_char(data);
get_char(&data);
string_uppercase(&data);
string_uppercase(data);
}
// Should not take ownership
fn get_char(data: String) -> char {
fn get_char(data: &String) -> char {
data.chars().last().unwrap()
}
// Should take ownership
fn string_uppercase(mut data: &String) {
data = &data.to_uppercase();
fn string_uppercase(mut data: String) {
data = data.to_uppercase();
println!("{}", data);
}

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@ -1,23 +1,19 @@
// option1.rs
// Make me compile! Execute `rustlings hint option1` for hints
// I AM NOT DONE
// you can modify anything EXCEPT for this function's signature
fn print_number(maybe_number: Option<u16>) {
println!("printing: {}", maybe_number.unwrap());
}
fn main() {
print_number(13);
print_number(99);
print_number(Some(13));
print_number(Some(99));
let mut numbers: [Option<u16>; 5];
let mut numbers: [Option<u16>; 5] = [None;5];
for iter in 0..5 {
let number_to_add: u16 = {
((iter * 1235) + 2) / (4 * 16)
};
let number_to_add: u16 = { ((iter * 1235) + 2) / (4 * 16) };
numbers[iter as usize] = number_to_add;
numbers[iter as usize] = Some(number_to_add);
}
}

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@ -1,12 +1,11 @@
// option2.rs
// Make me compile! Execute `rustlings hint option2` for hints
// I AM NOT DONE
fn main() {
let optional_word = Some(String::from("rustlings"));
// TODO: Make this an if let statement whose value is "Some" type
word = optional_word {
if let Some(word) = optional_word {
println!("The word is: {}", word);
} else {
println!("The optional word doesn't contain anything");
@ -19,7 +18,7 @@ fn main() {
// TODO: make this a while let statement - remember that vector.pop also adds another layer of Option<T>
// You can stack `Option<T>`'s into while let and if let
integer = optional_integers_vec.pop() {
if let Some(Some(integer)) = optional_integers_vec.pop() {
println!("current value: {}", integer);
}
}

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@ -1,7 +1,6 @@
// option3.rs
// Make me compile! Execute `rustlings hint option3` for hints
// I AM NOT DONE
struct Point {
x: i32,
@ -12,7 +11,7 @@ fn main() {
let y: Option<Point> = Some(Point { x: 100, y: 200 });
match y {
Some(p) => println!("Co-ordinates are {},{} ", p.x, p.y),
Some(ref p) => println!("Co-ordinates are {},{} ", p.x, p.y),
_ => println!("no match"),
}
y; // Fix without deleting this line.

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@ -2,7 +2,6 @@
// Fill in the rest of the line that has code missing!
// No hints, there's no tricks, just get used to typing these :)
// I AM NOT DONE
fn main() {
// Booleans (`bool`)
@ -12,7 +11,7 @@ fn main() {
println!("Good morning!");
}
let // Finish the rest of this line like the example! Or make it be false!
let is_evening = false; // Finish the rest of this line like the example! Or make it be false!
if is_evening {
println!("Good evening!");
}

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@ -2,7 +2,6 @@
// Fill in the rest of the line that has code missing!
// No hints, there's no tricks, just get used to typing these :)
// I AM NOT DONE
fn main() {
// Characters (`char`)
@ -16,7 +15,7 @@ fn main() {
println!("Neither alphabetic nor numeric!");
}
let // Finish this line like the example! What's your favorite character?
let your_character = 'f'; // Finish this line like the example! What's your favorite character?
// Try a letter, try a number, try a special character, try a character
// from a different language than your own, try an emoji!
if your_character.is_alphabetic() {

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@ -2,10 +2,9 @@
// Create an array with at least 100 elements in it where the ??? is.
// Execute `rustlings hint primitive_types3` for hints!
// I AM NOT DONE
fn main() {
let a = ???
let a = [0;100];
if a.len() >= 100 {
println!("Wow, that's a big array!");

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@ -2,13 +2,12 @@
// Get a slice out of Array a where the ??? is so that the test passes.
// Execute `rustlings hint primitive_types4` for hints!!
// I AM NOT DONE
#[test]
fn slice_out_of_array() {
let a = [1, 2, 3, 4, 5];
let nice_slice = ???
let nice_slice = &a[1..4];
assert_eq!([2, 3, 4], nice_slice)
}

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@ -2,11 +2,10 @@
// Destructure the `cat` tuple so that the println will work.
// Execute `rustlings hint primitive_types5` for hints!
// I AM NOT DONE
fn main() {
let cat = ("Furry McFurson", 3.5);
let /* your pattern here */ = cat;
let (name,age)/* your pattern here */ = cat;
println!("{} is {} years old.", name, age);
}

View File

@ -3,13 +3,12 @@
// You can put the expression for the second element where ??? is so that the test passes.
// Execute `rustlings hint primitive_types6` for hints!
// I AM NOT DONE
#[test]
fn indexing_tuple() {
let numbers = (1, 2, 3);
// Replace below ??? with the tuple indexing syntax.
let second = ???;
let second = numbers.1;
assert_eq!(2, second,
"This is not the 2nd number in the tuple!")

View File

@ -8,7 +8,6 @@
// more than 40 at once, each apple only costs 1! Write a function that calculates
// the price of an order of apples given the quantity bought. No hints this time!
// I AM NOT DONE
// Put your function here!
// fn calculate_apple_price {
@ -24,3 +23,11 @@ fn verify_test() {
assert_eq!(80, price2);
assert_eq!(65, price3);
}
fn calculate_apple_price(apple: i32)->i32{
if apple <= 40 {
apple * 2
} else {
apple * 1
}
}

View File

@ -7,7 +7,6 @@
// you think each value is. That is, add either `string_slice` or `string`
// before the parentheses on each line. If you're right, it will compile!
// I AM NOT DONE
fn string_slice(arg: &str) {
println!("{}", arg);
@ -17,14 +16,14 @@ fn string(arg: String) {
}
fn main() {
???("blue");
???("red".to_string());
???(String::from("hi"));
???("rust is fun!".to_owned());
???("nice weather".into());
???(format!("Interpolation {}", "Station"));
???(&String::from("abc")[0..1]);
???(" hello there ".trim());
???("Happy Monday!".to_string().replace("Mon", "Tues"));
???("mY sHiFt KeY iS sTiCkY".to_lowercase());
string_slice("blue");
string("red".to_string());
string(String::from("hi"));
string("rust is fun!".to_owned());
string("nice weather".into());
string(format!("Interpolation {}", "Station"));
string_slice(&String::from("abc")[0..1]);
string_slice(" hello there ".trim());
string("Happy Monday!".to_string().replace("Mon", "Tues"));
string("mY sHiFt KeY iS sTiCkY".to_lowercase());
}

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@ -7,7 +7,6 @@
// we expect to get when we call `times_two` with a negative number.
// No hints, you can do this :)
// I AM NOT DONE
pub fn times_two(num: i32) -> i32 {
num * 2
@ -19,12 +18,13 @@ mod tests {
#[test]
fn returns_twice_of_positive_numbers() {
assert_eq!(times_two(4), ???);
assert_eq!(times_two(4),8)
}
#[test]
fn returns_twice_of_negative_numbers() {
// TODO replace unimplemented!() with an assert for `times_two(-4)`
unimplemented!()
// unimplemented!()
assert_eq!(times_two(-4),-8)
}
}

View File

@ -5,7 +5,19 @@
// Write a macro that passes the quiz! No hints this time, you can do it!
// I AM NOT DONE
mod m {
#[macro_export]
macro_rules! my_macro {
($val:expr) => {
{
let mut s = String::from("Hello ");
s.push_str($val);
s
}
// format!("Hello {}",$val)
};
}
}
#[cfg(test)]
mod tests {
@ -13,6 +25,7 @@ mod tests {
#[test]
fn test_my_macro_world() {
my_macro!("world!");
assert_eq!(my_macro!("world!"), "Hello world!");
}

View File

@ -18,19 +18,17 @@
// where the second TODO comment is. Try not to create any copies of the `numbers` Vec!
// Execute `rustlings hint arc1` for hints :)
// 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);

View File

@ -16,11 +16,10 @@
//
// Execute `rustlings hint box1` for hints :)
// I AM NOT DONE
#[derive(PartialEq, Debug)]
pub enum List {
Cons(i32, List),
Cons(i32, Box<List>),
Nil,
}
@ -33,11 +32,13 @@ fn main() {
}
pub fn create_empty_list() -> List {
unimplemented!()
// unimplemented!()
List::Nil
}
pub fn create_non_empty_list() -> List {
unimplemented!()
// unimplemented!()
List::Cons(1,Box::new(List::Nil))
}
#[cfg(test)]

View File

@ -8,17 +8,16 @@
//
// Execute `rustlings hint iterators1` for hints :D
// 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
}

View File

@ -3,7 +3,6 @@
// can offer. Follow the steps to complete the exercise.
// As always, there are hints if you execute `rustlings hint iterators2`!
// I AM NOT DONE
// Step 1.
// Complete the `capitalize_first` function.
@ -12,7 +11,7 @@ pub fn capitalize_first(input: &str) -> String {
let mut c = input.chars();
match c.next() {
None => String::new(),
Some(first) => ???,
Some(first) => input.replace(first, &first.to_uppercase().to_string()),
}
}
@ -21,7 +20,11 @@ pub fn capitalize_first(input: &str) -> String {
// Return a vector of strings.
// ["hello", "world"] -> ["Hello", "World"]
pub fn capitalize_words_vector(words: &[&str]) -> Vec<String> {
vec![]
let mut result = vec![];
for word in words {
result.push(capitalize_first(word));
}
result
}
// Step 3.
@ -29,7 +32,7 @@ pub fn capitalize_words_vector(words: &[&str]) -> Vec<String> {
// 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)]

View File

@ -6,8 +6,6 @@
// list_of_results functions.
// Execute `rustlings hint iterators3` to get some hints!
// I AM NOT DONE
#[derive(Debug, PartialEq, Eq)]
pub enum DivisionError {
NotDivisible(NotDivisibleError),
@ -22,20 +20,36 @@ 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<i32, DivisionError> {}
pub fn divide(a: i32, b: i32) -> Result<i32, DivisionError> {
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<Vec<i32>, DivisionError> {
let numbers = vec![27, 297, 38502, 81];
let division_results = numbers.into_iter().map(|n| divide(n, 27));
let division_results = numbers
.into_iter()
.map(|n| divide(n, 27))
.collect::<Result<Vec<i32>, DivisionError>>();
division_results
}
// 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<Result<i32, DivisionError>> {
let numbers = vec![27, 297, 38502, 81];
let division_results = numbers.into_iter().map(|n| divide(n, 27));
let division_results = numbers.into_iter().map(|n| divide(n, 27)).collect();
division_results
}
#[cfg(test)]

View File

@ -1,7 +1,5 @@
// iterators4.rs
// I AM NOT DONE
pub fn factorial(num: u64) -> u64 {
// Complete this function to return the factorial of num
// Do not use:
@ -12,6 +10,13 @@ pub fn factorial(num: u64) -> u64 {
// For an extra challenge, don't use:
// - recursion
// Execute `rustlings hint iterators4` for hints.
// if num == 1 {
// 1
// }else {
// num * factorial(num - 1)
// }
(1..=num).fold(1, |acc, x| acc * x)
}
#[cfg(test)]
@ -29,6 +34,7 @@ mod tests {
#[test]
fn factorial_of_4() {
// 1 * 2 * 3 * 4
assert_eq!(24, factorial(4));
}
}

View File

@ -10,7 +10,6 @@
//
// Make the code compile and the tests pass.
// I AM NOT DONE
use std::collections::HashMap;
@ -34,6 +33,7 @@ fn count_for(map: &HashMap<String, Progress>, value: Progress) -> usize {
fn count_iterator(map: &HashMap<String, Progress>, value: Progress) -> usize {
// map is a hashmap with String keys and Progress values.
// map = { "variables1": Complete, "from_str": None, ... }
map.values().filter(|v|{if v == &&value {true} else {false}}).count()
}
fn count_collection_for(collection: &[HashMap<String, Progress>], value: Progress) -> usize {
@ -52,6 +52,7 @@ fn count_collection_iterator(collection: &[HashMap<String, Progress>], value: Pr
// collection is a slice of hashmaps.
// collection = [{ "variables1": Complete, "from_str": None, ... },
// { "variables2": Complete, ... }, ... ]
collection.iter().map(|hash|count_iterator(hash,value)).sum()
}
#[cfg(test)]

View File

@ -2,7 +2,6 @@
// Make me compile without changing the function signature!
// Execute `rustlings hint strings1` for hints ;)
// I AM NOT DONE
fn main() {
let answer = current_favorite_color();
@ -10,5 +9,5 @@ fn main() {
}
fn current_favorite_color() -> String {
"blue"
"blue".to_string()
}

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@ -2,11 +2,9 @@
// Make me compile without changing the function signature!
// Execute `rustlings hint strings2` for hints :)
// I AM NOT DONE
fn main() {
let word = String::from("green"); // Try not changing this line :)
if is_a_color_word(word) {
if is_a_color_word(&word) {
println!("That is a color word I know!");
} else {
println!("That is not a color word I know.");

View File

@ -1,13 +1,13 @@
// structs1.rs
// Address all the TODOs to make the tests pass!
// I AM NOT DONE
struct ColorClassicStruct {
struct ColorClassicStruct<'a> {
// TODO: Something goes here
name: &'a str,
hex: &'a str,
}
struct ColorTupleStruct(/* TODO: Something goes here */);
struct ColorTupleStruct<'a>(/* TODO: Something goes here */&'a str,&'a str);
#[derive(Debug)]
struct UnitStruct;
@ -19,7 +19,7 @@ mod tests {
#[test]
fn classic_c_structs() {
// TODO: Instantiate a classic c struct!
// let green =
let green = ColorClassicStruct {name:"green",hex:"#00FF00"};
assert_eq!(green.name, "green");
assert_eq!(green.hex, "#00FF00");
@ -28,7 +28,7 @@ mod tests {
#[test]
fn tuple_structs() {
// TODO: Instantiate a tuple struct!
// let green =
let green = ("green","#00FF00");
assert_eq!(green.0, "green");
assert_eq!(green.1, "#00FF00");
@ -37,7 +37,7 @@ mod tests {
#[test]
fn unit_structs() {
// TODO: Instantiate a unit struct!
// let unit_struct =
let unit_struct = UnitStruct;
let message = format!("{:?}s are fun!", unit_struct);
assert_eq!(message, "UnitStructs are fun!");

View File

@ -1,8 +1,6 @@
// structs2.rs
// Address all the TODOs to make the tests pass!
// I AM NOT DONE
#[derive(Debug)]
struct Order {
name: String,
@ -34,7 +32,15 @@ mod tests {
fn your_order() {
let order_template = create_order_template();
// TODO: Create your own order using the update syntax and template above!
// let your_order =
let your_order = Order {
name: String::from("Hacker in Rust"),
year: 2019,
made_by_email: true,
made_by_mobile: false,
made_by_phone: false,
item_number: 123,
count: 1,
};
assert_eq!(your_order.name, "Hacker in Rust");
assert_eq!(your_order.year, order_template.year);
assert_eq!(your_order.made_by_phone, order_template.made_by_phone);

View File

@ -4,7 +4,6 @@
// Make the code compile and the tests pass!
// If you have issues execute `rustlings hint structs3`
// I AM NOT DONE
#[derive(Debug)]
struct Package {
@ -17,6 +16,7 @@ impl Package {
fn new(sender_country: String, recipient_country: String, weight_in_grams: i32) -> Package {
if weight_in_grams <= 0 {
// panic statement goes here...
panic!("error");
} else {
Package {
sender_country,
@ -26,12 +26,14 @@ impl Package {
}
}
fn is_international(&self) -> ??? {
fn is_international(&self) -> bool {
// Something goes here...
self.sender_country == "Spain" && self.sender_country != "Canada"
}
fn get_fees(&self, cents_per_gram: i32) -> ??? {
fn get_fees(&self, cents_per_gram: i32) -> i32 {
// Something goes here...
self.weight_in_grams * cents_per_gram
}
}

View File

@ -6,12 +6,11 @@
// This test has a problem with it -- make the test compile! Make the test
// pass! Make the test fail! Execute `rustlings hint tests1` for hints :)
// I AM NOT DONE
#[cfg(test)]
mod tests {
#[test]
fn you_can_assert() {
assert!();
assert!(true);
}
}

View File

@ -2,12 +2,11 @@
// This test has a problem with it -- make the test compile! Make the test
// pass! Make the test fail! Execute `rustlings hint tests2` for hints :)
// I AM NOT DONE
#[cfg(test)]
mod tests {
#[test]
fn you_can_assert_eq() {
assert_eq!();
assert_eq!(1, 1);
}
}

View File

@ -4,7 +4,6 @@
// we expect to get when we call `is_even(5)`.
// Execute `rustlings hint tests3` for hints :)
// I AM NOT DONE
pub fn is_even(num: i32) -> bool {
num % 2 == 0
@ -16,11 +15,11 @@ mod tests {
#[test]
fn is_true_when_even() {
assert!();
assert!(is_even(2));
}
#[test]
fn is_false_when_odd() {
assert!();
assert!(!is_even(5));
}
}

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@ -6,9 +6,8 @@
// of "waiting..." and the program ends without timing out when running,
// you've got it :)
// I AM NOT DONE
use std::sync::Arc;
use std::sync::{Arc, Mutex};
use std::thread;
use std::time::Duration;
@ -17,15 +16,16 @@ struct JobStatus {
}
fn main() {
let status = Arc::new(JobStatus { jobs_completed: 0 });
let status = Arc::new(Mutex::new(JobStatus { jobs_completed: 0 }));
let status_shared = status.clone();
thread::spawn(move || {
for _ in 0..10 {
thread::sleep(Duration::from_millis(250));
status_shared.jobs_completed += 1;
let mut job = status_shared.lock().unwrap();
job.jobs_completed += 1;
}
});
while status.jobs_completed < 10 {
while status.lock().unwrap().jobs_completed < 10 {
println!("waiting... ");
thread::sleep(Duration::from_millis(500));
}

View File

@ -8,7 +8,6 @@
// which appends "Bar" to any object
// implementing this trait.
// I AM NOT DONE
trait AppendBar {
fn append_bar(self) -> Self;
@ -16,6 +15,12 @@ trait AppendBar {
impl AppendBar for String {
//Add your code here
fn append_bar(self)->Self{
// let mut s = self.clone();
// s.push_str("Bar");
// s
format!("{}{}",self,"Bar")
}
}
fn main() {

View File

@ -10,13 +10,17 @@
// No boiler plate code this time,
// you can do this!
// I AM NOT DONE
trait AppendBar {
fn append_bar(self) -> Self;
}
//TODO: Add your code here
impl AppendBar for Vec<String>{
fn append_bar(mut self) -> Self{
self.push("Bar".to_string());
self
}
}
#[cfg(test)]
mod tests {

View File

@ -2,9 +2,7 @@
// Make me compile!
// Execute the command `rustlings hint variables1` if you want a hint :)
// I AM NOT DONE
fn main() {
x = 5;
let x = 5;
println!("x has the value {}", x);
}

View File

@ -1,10 +1,9 @@
// variables2.rs
// Make me compile! Execute the command `rustlings hint variables2` if you want a hint :)
// I AM NOT DONE
fn main() {
let x;
let x = 10;
if x == 10 {
println!("Ten!");
} else {

View File

@ -1,10 +1,9 @@
// variables3.rs
// Make me compile! Execute the command `rustlings hint variables3` if you want a hint :)
// I AM NOT DONE
fn main() {
let x = 3;
let mut x = 3;
println!("Number {}", x);
x = 5; // don't change this line
println!("Number {}", x);

View File

@ -1,9 +1,8 @@
// variables4.rs
// Make me compile! Execute the command `rustlings hint variables4` if you want a hint :)
// I AM NOT DONE
fn main() {
let x: i32;
let x: i32 = 1;
println!("Number {}", x);
}

View File

@ -1,11 +1,10 @@
// variables5.rs
// Make me compile! Execute the command `rustlings hint variables5` if you want a hint :)
// I AM NOT DONE
fn main() {
let number = "T-H-R-E-E"; // don't change this line
println!("Spell a Number : {}", number);
number = 3;
let number = 3;
println!("Number plus two is : {}", number + 2);
}

View File

@ -1,9 +1,8 @@
// variables6.rs
// Make me compile! Execute the command `rustlings hint variables6` if you want a hint :)
// I AM NOT DONE
const NUMBER = 3;
const NUMBER:i32 = 3;
fn main() {
println!("Number {}", NUMBER);
}