update

Author: wauxing

exercises/iterators/iterators3.rs

@@ -9,7 +9,7 @@
 // Execute `rustlings hint iterators3` or use the `hint` watch subcommand for a
 // hint.
 
-// I AM NOT DONE
+
 
 #[derive(Debug, PartialEq, Eq)]
 pub enum DivisionError {
@@ -26,23 +26,31 @@ 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> {
-    todo!();
+    if b == 0 {
+        Err(DivisionError::DivideByZero)
+    } else if a % b == 0 {
+        Ok(a / b)
+    } 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));
+    Ok(division_results.map(|x| x.unwrap()).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)]

exercises/iterators/iterators4.rs

@@ -3,7 +3,6 @@
 // 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
@@ -15,6 +14,7 @@ pub fn factorial(num: u64) -> u64 {
     // For an extra challenge, don't use:
     // - recursion
     // Execute `rustlings hint iterators4` for hints.
+    (1..=num).fold(1,|acc,x| acc*x)
 }
 
 #[cfg(test)]

exercises/iterators/iterators5.rs

@@ -11,7 +11,7 @@
 // Execute `rustlings hint iterators5` or use the `hint` watch subcommand for a
 // hint.
 
-// I AM NOT DONE
+
 
 use std::collections::HashMap;
 
@@ -35,7 +35,8 @@ 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, ... }
-    todo!();
+    
+    map.iter().filter(|x| x.1==&value).count()
 }
 
 fn count_collection_for(collection: &[HashMap<String, Progress>], value: Progress) -> usize {
@@ -54,7 +55,7 @@ fn count_collection_iterator(collection: &[HashMap<String, Progress>], value: Pr
     // collection is a slice of hashmaps.
     // collection = [{ "variables1": Complete, "from_str": None, ... },
     //     { "variables2": Complete, ... }, ... ]
-    todo!();
+    collection.iter().flat_map(|map| map.values()).filter(|val| val==&&value).count()
 }
 
 #[cfg(test)]