From d6490f118b9b0e7a09c244cda49efa41d44b7f40 Mon Sep 17 00:00:00 2001
From: seth <yesifan66@gmail.com>
Date: Fri, 25 Jun 2021 10:37:53 +0800
Subject: [PATCH] complete: iterators
---
exercises/standard_library_types/arc1.rs | 6 ++---
exercises/standard_library_types/box1.rs | 10 ++++----
.../standard_library_types/iterators1.rs | 10 ++++----
.../standard_library_types/iterators2.rs | 13 +++++------
.../standard_library_types/iterators3.rs | 23 +++++++++++++++----
.../standard_library_types/iterators4.rs | 5 ++--
.../standard_library_types/iterators5.rs | 7 ++++--
7 files changed, 44 insertions(+), 30 deletions(-)
diff --git a/exercises/standard_library_types/arc1.rs b/exercises/standard_library_types/arc1.rs
index d167380..0965dd3 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` 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);
let mut joinhandles = Vec::new();
for offset in 0..8 {
- let child_numbers = // TODO
+ let child_numbers = Arc::clone(&shared_numbers);
joinhandles.push(thread::spawn(move || {
let mut i = offset;
let mut sum = 0;
diff --git a/exercises/standard_library_types/box1.rs b/exercises/standard_library_types/box1.rs
index f312f3d..23f4a03 100644
--- a/exercises/standard_library_types/box1.rs
+++ b/exercises/standard_library_types/box1.rs
@@ -16,11 +16,11 @@
//
// Execute `rustlings hint box1` for hints :)
-// I AM NOT DONE
+use crate::List::{Cons, Nil};
#[derive(PartialEq, Debug)]
pub enum List {
- Cons(i32, List),
+ Cons(i32, Box<List>),
Nil,
}
@@ -33,11 +33,13 @@ fn main() {
}
pub fn create_empty_list() -> List {
- unimplemented!()
+ Nil
}
pub fn create_non_empty_list() -> List {
- unimplemented!()
+ Cons(1, Box::new(
+ Cons(2, Box::new(Nil))
+ ))
}
#[cfg(test)]
diff --git a/exercises/standard_library_types/iterators1.rs b/exercises/standard_library_types/iterators1.rs
index 4606ad3..4254009 100644
--- a/exercises/standard_library_types/iterators1.rs
+++ b/exercises/standard_library_types/iterators1.rs
@@ -8,17 +8,15 @@
//
// 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 2.1
+ assert_eq!(my_iterable_fav_fruits.next(), Some(&"peach")); // TODO: Step 2.1
assert_eq!(my_iterable_fav_fruits.next(), Some(&"raspberry"));
- assert_eq!(my_iterable_fav_fruits.next(), ???); // TODO: Step 3
+ assert_eq!(my_iterable_fav_fruits.next(), None); // TODO: Step 3
}
diff --git a/exercises/standard_library_types/iterators2.rs b/exercises/standard_library_types/iterators2.rs
index 87b4eaa..50d62d2 100644
--- a/exercises/standard_library_types/iterators2.rs
+++ b/exercises/standard_library_types/iterators2.rs
@@ -3,16 +3,15 @@
// 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.
// "hello" -> "Hello"
pub fn capitalize_first(input: &str) -> String {
let mut c = input.chars();
- match c.next() {
- None => String::new(),
- Some(first) => ???,
+ if let Some(first) = c.next() {
+ first.to_uppercase().to_string() + c.as_str()
+ }else{
+ String::new()
}
}
@@ -21,7 +20,7 @@ pub fn capitalize_first(input: &str) -> String {
// Return a vector of strings.
// ["hello", "world"] -> ["Hello", "World"]
pub fn capitalize_words_vector(words: &[&str]) -> Vec<String> {
- vec![]
+ words.iter().map(|str| capitalize_first(str)).collect()
}
// Step 3.
@@ -29,7 +28,7 @@ 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()
+ words.iter().map(|str| capitalize_first(str)).collect()
}
#[cfg(test)]
diff --git a/exercises/standard_library_types/iterators3.rs b/exercises/standard_library_types/iterators3.rs
index 8c66c05..beec7eb 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` to get some hints!
-// I AM NOT DONE
-
#[derive(Debug, PartialEq, Eq)]
pub enum DivisionError {
NotDivisible(NotDivisibleError),
@@ -22,20 +20,35 @@ 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 {
+ let s = a / b;
+ if s*b == a {
+ Ok(s)
+ }else{
+ Err(DivisionError::NotDivisible(NotDivisibleError {
+ dividend: a,
+ divisor: 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));
+ 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<Result<i32, DivisionError>> {
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 8886283..3ba784b 100644
--- a/exercises/standard_library_types/iterators4.rs
+++ b/exercises/standard_library_types/iterators4.rs
@@ -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 +10,9 @@ pub fn factorial(num: u64) -> u64 {
// For an extra challenge, don't use:
// - recursion
// Execute `rustlings hint iterators4` for hints.
+ (1..num+1).fold(1, |acc, x| {
+ acc*x
+ })
}
#[cfg(test)]
diff --git a/exercises/standard_library_types/iterators5.rs b/exercises/standard_library_types/iterators5.rs
index d8d4453..7bfb341 100644
--- a/exercises/standard_library_types/iterators5.rs
+++ b/exercises/standard_library_types/iterators5.rs
@@ -11,8 +11,6 @@
//
// Make the code compile and the tests pass.
-// I AM NOT DONE
-
use std::collections::HashMap;
#[derive(PartialEq, Eq)]
@@ -35,6 +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(|&val| val == &value).count()
}
fn count_collection_for(collection: &[HashMap<String, Progress>], value: Progress) -> usize {
@@ -53,6 +52,10 @@ 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().fold(0, |acc, x| {
+ acc + x.values().filter(|&val| val == &value).count()
+ })
}
#[cfg(test)]