From 75373f98d02a62fb5d9c6576c812be4f56f24267 Mon Sep 17 00:00:00 2001 From: enforcer007 Date: Sun, 13 Nov 2022 14:51:37 +0530 Subject: [PATCH] iterators --- .../standard_library_types/iterators1.rs | 12 +++++------- .../standard_library_types/iterators2.rs | 8 +++----- .../standard_library_types/iterators3.rs | 19 ++++++++++++++----- .../standard_library_types/iterators4.rs | 6 ++++-- .../standard_library_types/iterators5.rs | 6 ++---- 5 files changed, 28 insertions(+), 23 deletions(-) diff --git a/exercises/standard_library_types/iterators1.rs b/exercises/standard_library_types/iterators1.rs index 0379c6bb..626a8524 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 () { +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 29c53afb..c1eb7fef 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().chain(c).collect(), } } @@ -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(|&x| capitalize_first(x)).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() + words.iter().map(|&x| capitalize_first(x)).collect() } #[cfg(test)] diff --git a/exercises/standard_library_types/iterators3.rs b/exercises/standard_library_types/iterators3.rs index c97a6258..e79fb7a5 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 +21,32 @@ 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 a02470ec..15661dba 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 +11,10 @@ pub fn factorial(num: u64) -> u64 { // For an extra challenge, don't use: // - recursion // Execute `rustlings hint iterators4` for hints. + if num == 0 { + return 1; + } + (1..=num).reduce(|accm, item| accm * item).unwrap() } #[cfg(test)] diff --git a/exercises/standard_library_types/iterators5.rs b/exercises/standard_library_types/iterators5.rs index 0593d123..686d628e 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(|&x| &value == x).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(|x| count_iterator(x, value)).sum() } #[cfg(test)]