Merge pull request #1084 from 01-edu/update-roman_numbers_iter-and-rpn-c-555

Update roman numbers iter and rpn c 555

subjects/roman_numbers_iter/README.md

@@ -2,50 +2,18 @@
 
 ### Instructions
 
-Implement the `IntoIterator` trait for the `RomanNumber` type to enable using a for loop notation. This implementation must allow taking ownership, borrowing and borrowing mutably.
-
-1. Taking ownership (this consumes the RomanNumber)
-
-```rust
-for digit in number {
-	...
-}
-```
-
-2. Borrowing immutably (this preserves the RomanNumber)
-
-```rust
-	for digit in &number {
-
-	}
-```
-
-3. Borrowing mutably (this allow you to modify the RomanNumber without having to return the ownership)
-
-```rust
-	for digit in &mut number {
-
-	}
-```
+Implement the `Iterator` trait for the `RomanNumber` type. You should use the code from the previous exercise roman_numbers.
 
 ### Notions
 
-- https://doc.rust-lang.org/std/iter/trait.IntoIterator.html
-- https://doc.rust-lang.org/std/iter/index.html
+- [Trait Iterator](https://doc.rust-lang.org/std/iter/trait.Iterator.html)
 
 ### Expected Functions
 
 ```rust
-use roman_numbers::{RomanDigit, RomanNumber};
+//...
 
-impl IntoIterator for &RomanNumber {
-}
-
-impl IntoIterator for &mut RomanNumber {
-}
-
-impl IntoIterator for RomanNumber {
-}
+impl Iterator for RomanNumber {}
 ```
 
 ### Usage
@@ -56,12 +24,10 @@ Here is a program to test your function.
 use roman_numbers::RomanNumber;
 
 fn main() {
-	let number = RomanNumber::from(15);
+	let mut number = RomanNumber::from(15);
 
-	for digit in &number {
-		println!("{:?}", digit);
-	}
 	println!("{:?}", number);
+	println!("{:?}", number.next());
 }
 ```
 
@@ -69,9 +35,7 @@ And its output
 
 ```console
 $ cargo run
-RomanNumber([X, X, X, I, I])
-RomanNumber([I, X])
-RomanNumber([X, L, V])
-RomanNumber([Nulla])
+RomanNumber([X, V])
+Some(RomanNumber([X, V, I]))
 $
 ```

subjects/rpn/README.md

@@ -2,17 +2,14 @@
 
 ### Instructions
 
-Write a **program** which takes a `string` which contains an equation written in `Reverse Polish Notation` (RPN) as its first argument,
-which evaluates the equation, and which prints the result on the standard output followed by a newline (`'\n'`).
+Write a **program** which takes a `string` that contains an equation written in `Reverse Polish Notation` (RPN) as an argument. The **program** must evaluate the equation, and then:
 
-`Reverse Polish Notation` is a mathematical notation in which every operator follows all of its operands. In RPN,
-every operator encountered evaluates the previous 2 operands, and the result of this operation then becomes the first of
-the two operands for the subsequent operator. Operands and operators must be spaced by at least one space.
+- If the `string` is not valid or if there is not exactly one argument, `Error` must be printed on the standard output followed by a newline.
+- If the `string` has extra spaces it is still considered valid.
 
-The following operators must be implemented : `+`, `-`, `*`, `/`, and `%`.
+`Reverse Polish Notation` is a mathematical notation in which every operator follows all of its operands. In RPN, every operator encountered evaluates the previous 2 operands, and the result of this operation then becomes the first of the two operands for the subsequent operator. Operands and operators must be spaced by at least one space.
 
-If the `string` is not valid or if there is not exactly one argument, `Error` must be printed on the standard output followed by a newline.
-If the `string` has extra spaces it is still considered valid.
+The following operators must be implemented : `+`, `-`, `*`, `/`, and `%`.
 
 All the given operands must fit in a `i64`.
 
@@ -55,7 +52,7 @@ For receiving arguments from the command line you should use something like:
 
 ### Usage
 
-````console
+```console
 $ cargo run "1 2 * 3 * 4 +"
 10
 $ cargo run "1 2 3 4 +"
@@ -67,4 +64,3 @@ $ cargo run "     1      3 * 2 -"
 $ cargo run "     1      3 * ksd 2 -"
 Error
 ```
-````