From eea0a2957e266eeaf9129e9f1ea3275d6af686ea Mon Sep 17 00:00:00 2001
From: tab <dearhange@126.com>
Date: Thu, 14 May 2020 23:34:23 +0800
Subject: [PATCH] things going to be harder and harder
---
exercises/standard_library_types/arc1.rs | 5 ++---
exercises/standard_library_types/iterators2.rs | 8 +++-----
exercises/standard_library_types/iterators3.rs | 14 +++++++++++++-
3 files changed, 18 insertions(+), 9 deletions(-)
diff --git a/exercises/standard_library_types/arc1.rs b/exercises/standard_library_types/arc1.rs
index 9784e84..f5e99bf 100644
--- a/exercises/standard_library_types/arc1.rs
+++ b/exercises/standard_library_types/arc1.rs
@@ -4,17 +4,16 @@
// somewhere. Try not to create any copies of the `numbers` Vec!
// Execute `rustlings hint arc1` for hints :)
-// I AM NOT DONE
-
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 = shared_numbers.clone();
joinhandles.push(thread::spawn(move || {
let mut i = offset;
let mut sum = 0;
diff --git a/exercises/standard_library_types/iterators2.rs b/exercises/standard_library_types/iterators2.rs
index 837725f..8ebf15f 100644
--- a/exercises/standard_library_types/iterators2.rs
+++ b/exercises/standard_library_types/iterators2.rs
@@ -7,13 +7,11 @@
// Try to ensure it returns a single string.
// As always, there are hints if you execute `rustlings hint iterators2`!
-// I AM NOT DONE
-
pub fn capitalize_first(input: &str) -> String {
let mut c = input.chars();
match c.next() {
None => String::new(),
- Some(first) => first.collect::<String>() + c.as_str(),
+ Some(first) => first.to_uppercase().collect::<String>() + c.as_str(),
}
}
@@ -37,14 +35,14 @@ mod tests {
#[test]
fn test_iterate_string_vec() {
let words = vec!["hello", "world"];
- let capitalized_words: Vec<String> = // TODO
+ let capitalized_words: Vec<String> = words.iter().map(|x| capitalize_first(x)).collect();
assert_eq!(capitalized_words, ["Hello", "World"]);
}
#[test]
fn test_iterate_into_string() {
let words = vec!["hello", " ", "world"];
- let capitalized_words = // TODO
+ let capitalized_words: String = words.iter().map(|x| capitalize_first(x)).collect();
assert_eq!(capitalized_words, "Hello World");
}
}
diff --git a/exercises/standard_library_types/iterators3.rs b/exercises/standard_library_types/iterators3.rs
index 353cea6..4bed64f 100644
--- a/exercises/standard_library_types/iterators3.rs
+++ b/exercises/standard_library_types/iterators3.rs
@@ -24,7 +24,19 @@ pub struct NotDivisibleError {
// This function should calculate `a` divided by `b` if `a` is
// evenly divisible by b.
// Otherwise, it should return a suitable error.
-pub fn divide(a: i32, b: i32) -> Result<i32, DivisionError> {}
+pub fn divide(a: i32, b: i32) -> Result<i32, DivisionError> {
+ match (a, b) {
+ (a, 0) => Err(DivisionError::DivideByZero),
+ (0, b) => Ok(0),
+ _ => match a % b {
+ 0 => Ok(a / b),
+ _ => Err(DivisionError::NotDivisible(NotDivisibleError {
+ dividend: a,
+ divisor: b,
+ })),
+ },
+ }
+}
#[cfg(test)]
mod tests {