🎉 complete quiz3

This commit is contained in:
laazy 2024-03-23 01:16:48 +08:00
parent 7bd260da33
commit df1f61200c
18 changed files with 58 additions and 49 deletions

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@ -3,7 +3,7 @@
// Execute `rustlings hint options1` or use the `hint` watch subcommand for a // Execute `rustlings hint options1` or use the `hint` watch subcommand for a
// hint. // hint.
// I AM NOT DONE use core::time;
// This function returns how much icecream there is left in the fridge. // This function returns how much icecream there is left in the fridge.
// If it's before 10PM, there's 5 pieces left. At 10PM, someone eats them // If it's before 10PM, there's 5 pieces left. At 10PM, someone eats them
@ -12,8 +12,11 @@ fn maybe_icecream(time_of_day: u16) -> Option<u16> {
// We use the 24-hour system here, so 10PM is a value of 22 and 12AM is a // We use the 24-hour system here, so 10PM is a value of 22 and 12AM is a
// value of 0 The Option output should gracefully handle cases where // value of 0 The Option output should gracefully handle cases where
// time_of_day > 23. // time_of_day > 23.
// TODO: Complete the function body - remember to return an Option! match time_of_day {
??? 0..=21 => Some(5),
22..=24 => Some(0),
_ => None,
}
} }
#[cfg(test)] #[cfg(test)]
@ -34,6 +37,6 @@ mod tests {
// TODO: Fix this test. How do you get at the value contained in the // TODO: Fix this test. How do you get at the value contained in the
// Option? // Option?
let icecreams = maybe_icecream(12); let icecreams = maybe_icecream(12);
assert_eq!(icecreams, 5); assert_eq!(icecreams.unwrap(), 5);
} }
} }

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@ -3,7 +3,6 @@
// Execute `rustlings hint options2` or use the `hint` watch subcommand for a // Execute `rustlings hint options2` or use the `hint` watch subcommand for a
// hint. // hint.
// I AM NOT DONE
#[cfg(test)] #[cfg(test)]
mod tests { mod tests {
@ -12,8 +11,7 @@ mod tests {
let target = "rustlings"; let target = "rustlings";
let optional_target = Some(target); let optional_target = Some(target);
// TODO: Make this an if let statement whose value is "Some" type if let Some(word) = optional_target {
word = optional_target {
assert_eq!(word, target); assert_eq!(word, target);
} }
} }
@ -32,7 +30,7 @@ mod tests {
// TODO: make this a while let statement - remember that vector.pop also // 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 // adds another layer of Option<T>. You can stack `Option<T>`s into
// while let and if let. // while let and if let.
integer = optional_integers.pop() { while let Some(integer) = optional_integers.pop().flatten() {
assert_eq!(integer, cursor); assert_eq!(integer, cursor);
cursor -= 1; cursor -= 1;
} }

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@ -3,7 +3,6 @@
// Execute `rustlings hint options3` or use the `hint` watch subcommand for a // Execute `rustlings hint options3` or use the `hint` watch subcommand for a
// hint. // hint.
// I AM NOT DONE
struct Point { struct Point {
x: i32, x: i32,
@ -14,7 +13,7 @@ fn main() {
let y: Option<Point> = Some(Point { x: 100, y: 200 }); let y: Option<Point> = Some(Point { x: 100, y: 200 });
match y { match y {
Some(p) => println!("Co-ordinates are {},{} ", p.x, p.y), Some(ref p) => println!("Co-ordinates are {},{} ", p.x, p.y),
_ => panic!("no match!"), _ => panic!("no match!"),
} }
y; // Fix without deleting this line. y; // Fix without deleting this line.

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@ -9,14 +9,13 @@
// Execute `rustlings hint errors1` or use the `hint` watch subcommand for a // Execute `rustlings hint errors1` or use the `hint` watch subcommand for a
// hint. // hint.
// 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.is_empty() { if name.is_empty() {
// Empty names aren't allowed. // Empty names aren't allowed.
None Err("`name` was empty; it must be nonempty.".into())
} else { } else {
Some(format!("Hi! My name is {}", name)) Ok(format!("Hi! My name is {}", name))
} }
} }

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@ -19,16 +19,19 @@
// Execute `rustlings hint errors2` or use the `hint` watch subcommand for a // Execute `rustlings hint errors2` or use the `hint` watch subcommand for a
// hint. // hint.
// I AM NOT DONE
use std::num::ParseIntError; use std::num::ParseIntError;
pub fn total_cost(item_quantity: &str) -> Result<i32, ParseIntError> { pub fn total_cost(item_quantity: &str) -> Result<i32, ParseIntError> {
let processing_fee = 1; let processing_fee = 1;
let cost_per_item = 5; let cost_per_item = 5;
let qty = item_quantity.parse::<i32>(); let qty = item_quantity.parse::<i32>()?;
Ok(qty * cost_per_item + processing_fee) Ok(qty * cost_per_item + processing_fee)
// match item_quantity.parse::<i32>(){
// Ok(qty) => Ok(qty * cost_per_item + processing_fee),
// Err(e) => Err(e)
// }
} }
#[cfg(test)] #[cfg(test)]

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@ -7,7 +7,6 @@
// Execute `rustlings hint errors3` or use the `hint` watch subcommand for a // Execute `rustlings hint errors3` or use the `hint` watch subcommand for a
// hint. // hint.
// I AM NOT DONE
use std::num::ParseIntError; use std::num::ParseIntError;
@ -15,7 +14,7 @@ fn main() {
let mut tokens = 100; let mut tokens = 100;
let pretend_user_input = "8"; let pretend_user_input = "8";
let cost = total_cost(pretend_user_input)?; let cost = total_cost(pretend_user_input).unwrap();
if cost > tokens { if cost > tokens {
println!("You can't afford that many!"); println!("You can't afford that many!");

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@ -3,8 +3,6 @@
// Execute `rustlings hint errors4` or use the `hint` watch subcommand for a // Execute `rustlings hint errors4` or use the `hint` watch subcommand for a
// hint. // hint.
// I AM NOT DONE
#[derive(PartialEq, Debug)] #[derive(PartialEq, Debug)]
struct PositiveNonzeroInteger(u64); struct PositiveNonzeroInteger(u64);
@ -17,7 +15,11 @@ enum CreationError {
impl PositiveNonzeroInteger { impl PositiveNonzeroInteger {
fn new(value: i64) -> Result<PositiveNonzeroInteger, CreationError> { fn new(value: i64) -> Result<PositiveNonzeroInteger, CreationError> {
// Hmm... Why is this always returning an Ok value? // Hmm... Why is this always returning an Ok value?
Ok(PositiveNonzeroInteger(value as u64)) match value {
v if v <0 => Err(CreationError::Negative),
0 => Err(CreationError::Zero),
v => Ok(PositiveNonzeroInteger(value as u64))
}
} }
} }

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@ -22,14 +22,13 @@
// Execute `rustlings hint errors5` or use the `hint` watch subcommand for a // Execute `rustlings hint errors5` or use the `hint` watch subcommand for a
// hint. // hint.
// I AM NOT DONE
use std::error; use std::error;
use std::fmt; use std::fmt;
use std::num::ParseIntError; use std::num::ParseIntError;
// TODO: update the return type of `main()` to make this compile. // TODO: update the return type of `main()` to make this compile.
fn main() -> Result<(), Box<dyn ???>> { fn main() -> Result<(), Box<dyn error::Error>> {
let pretend_user_input = "42"; let pretend_user_input = "42";
let x: i64 = pretend_user_input.parse()?; let x: i64 = pretend_user_input.parse()?;
println!("output={:?}", PositiveNonzeroInteger::new(x)?); println!("output={:?}", PositiveNonzeroInteger::new(x)?);

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@ -9,8 +9,6 @@
// Execute `rustlings hint errors6` or use the `hint` watch subcommand for a // Execute `rustlings hint errors6` or use the `hint` watch subcommand for a
// hint. // hint.
// I AM NOT DONE
use std::num::ParseIntError; use std::num::ParseIntError;
// This is a custom error type that we will be using in `parse_pos_nonzero()`. // This is a custom error type that we will be using in `parse_pos_nonzero()`.
@ -25,13 +23,15 @@ impl ParsePosNonzeroError {
ParsePosNonzeroError::Creation(err) ParsePosNonzeroError::Creation(err)
} }
// TODO: add another error conversion function here. // TODO: add another error conversion function here.
// fn from_parseint... fn from_parseint(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 // TODO: change this to return an appropriate error instead of panicking
// when `parse()` returns an error. // when `parse()` returns an error.
let x: i64 = s.parse().unwrap(); let x: i64 = s.parse().map_err(ParsePosNonzeroError::from_parseint)?;
PositiveNonzeroInteger::new(x).map_err(ParsePosNonzeroError::from_creation) PositiveNonzeroInteger::new(x).map_err(ParsePosNonzeroError::from_creation)
} }

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@ -6,9 +6,8 @@
// Execute `rustlings hint generics1` or use the `hint` watch subcommand for a // Execute `rustlings hint generics1` or use the `hint` watch subcommand for a
// hint. // hint.
// I AM NOT DONE
fn main() { fn main() {
let mut shopping_list: Vec<?> = Vec::new(); let mut shopping_list: Vec<&str> = Vec::new();
shopping_list.push("milk"); shopping_list.push("milk");
} }

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@ -6,14 +6,13 @@
// Execute `rustlings hint generics2` or use the `hint` watch subcommand for a // Execute `rustlings hint generics2` or use the `hint` watch subcommand for a
// hint. // hint.
// I AM NOT DONE
struct Wrapper { struct Wrapper<T> {
value: u32, value: T,
} }
impl Wrapper { impl<T> Wrapper<T> {
pub fn new(value: u32) -> Self { pub fn new(value: T) -> Self {
Wrapper { value } Wrapper { value }
} }
} }

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@ -7,14 +7,15 @@
// Execute `rustlings hint traits1` or use the `hint` watch subcommand for a // Execute `rustlings hint traits1` or use the `hint` watch subcommand for a
// hint. // hint.
// I AM NOT DONE
trait AppendBar { trait AppendBar {
fn append_bar(self) -> Self; fn append_bar(self) -> Self;
} }
impl AppendBar for String { impl AppendBar for String {
// TODO: Implement `AppendBar` for type `String`. // TODO: Implement `AppendBar` for type `String`.
fn append_bar(self) -> Self {
self + "Bar"
}
} }
fn main() { fn main() {

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@ -8,13 +8,18 @@
// //
// Execute `rustlings hint traits2` or use the `hint` watch subcommand for a hint. // Execute `rustlings hint traits2` or use the `hint` watch subcommand for a hint.
// I AM NOT DONE
trait AppendBar { trait AppendBar {
fn append_bar(self) -> Self; fn append_bar(self) -> Self;
} }
// TODO: Implement trait `AppendBar` for a vector of strings. // TODO: Implement trait `AppendBar` for a vector of strings.
impl AppendBar for Vec<String> {
fn append_bar(mut self) -> Self {
self.push("Bar".to_string());
self
}
}
#[cfg(test)] #[cfg(test)]
mod tests { mod tests {

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@ -8,10 +8,11 @@
// Execute `rustlings hint traits3` or use the `hint` watch subcommand for a // Execute `rustlings hint traits3` or use the `hint` watch subcommand for a
// hint. // hint.
// I AM NOT DONE
pub trait Licensed { pub trait Licensed {
fn licensing_info(&self) -> String; fn licensing_info(&self) -> String{
"Some information".to_string()
}
} }
struct SomeSoftware { struct SomeSoftware {

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@ -7,7 +7,6 @@
// Execute `rustlings hint traits4` or use the `hint` watch subcommand for a // Execute `rustlings hint traits4` or use the `hint` watch subcommand for a
// hint. // hint.
// I AM NOT DONE
pub trait Licensed { pub trait Licensed {
fn licensing_info(&self) -> String { fn licensing_info(&self) -> String {
@ -23,7 +22,7 @@ impl Licensed for SomeSoftware {}
impl Licensed for OtherSoftware {} impl Licensed for OtherSoftware {}
// YOU MAY ONLY CHANGE THE NEXT LINE // YOU MAY ONLY CHANGE THE NEXT LINE
fn compare_license_types(software: ??, software_two: ??) -> bool { fn compare_license_types(software: impl Licensed, software_two: impl Licensed) -> bool {
software.licensing_info() == software_two.licensing_info() software.licensing_info() == software_two.licensing_info()
} }

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@ -7,7 +7,6 @@
// Execute `rustlings hint traits5` or use the `hint` watch subcommand for a // Execute `rustlings hint traits5` or use the `hint` watch subcommand for a
// hint. // hint.
// I AM NOT DONE
pub trait SomeTrait { pub trait SomeTrait {
fn some_function(&self) -> bool { fn some_function(&self) -> bool {
@ -30,7 +29,7 @@ impl SomeTrait for OtherStruct {}
impl OtherTrait for OtherStruct {} impl OtherTrait for OtherStruct {}
// YOU MAY ONLY CHANGE THE NEXT LINE // YOU MAY ONLY CHANGE THE NEXT LINE
fn some_func(item: ??) -> bool { fn some_func(item: impl SomeTrait + OtherTrait) -> bool {
item.some_function() && item.other_function() item.some_function() && item.other_function()
} }

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@ -16,16 +16,20 @@
// //
// Execute `rustlings hint quiz3` or use the `hint` watch subcommand for a hint. // Execute `rustlings hint quiz3` or use the `hint` watch subcommand for a hint.
// I AM NOT DONE
pub struct ReportCard { use std::fmt::Display;
pub grade: f32,
pub struct ReportCard<T> {
pub grade: T,
pub student_name: String, pub student_name: String,
pub student_age: u8, pub student_age: u8,
} }
impl ReportCard { impl<T> ReportCard<T> {
pub fn print(&self) -> String { pub fn print(&self) -> String
where
T: Display,
{
format!("{} ({}) - achieved a grade of {}", format!("{} ({}) - achieved a grade of {}",
&self.student_name, &self.student_age, &self.grade) &self.student_name, &self.student_age, &self.grade)
} }
@ -52,7 +56,7 @@ mod tests {
fn generate_alphabetic_report_card() { fn generate_alphabetic_report_card() {
// TODO: Make sure to change the grade here after you finish the exercise. // TODO: Make sure to change the grade here after you finish the exercise.
let report_card = ReportCard { let report_card = ReportCard {
grade: 2.1, grade: "A+",
student_name: "Gary Plotter".to_string(), student_name: "Gary Plotter".to_string(),
student_age: 11, student_age: 11,
}; };