exercise: queue_lunch linked lists

subjects/brackets/README.md

@@ -13,7 +13,6 @@ If there is no argument, the program must print nothing.
 ### Usage
 
 ```console
-student@ubuntu:~/[[ROOT]]/brackets$ go build
 student@ubuntu:~/[[ROOT]]/brackets$ ./brackets '(johndoe)' | cat -e
 OK$
 student@ubuntu:~/[[ROOT]]/brackets$ ./brackets '([)]' | cat -e

subjects/queue_lunch/README.md

@@ -0,0 +1,88 @@
+## lunch_queue
+
+### Instructions
+
+You will have to create an API to organize a queue of people.
+
+Using the given code create the following functions:
+
+- `new` that will initialize the `Queue`.
+- `add` that receives the person's information, so it can be added to the `Queue`
+- `invert_queue` that invert the queue of persons
+- `rm`, that will remove the person that finished ordering their food.
+  The method for organizing the manipulation of a data structure should be a
+  FIFO (first in first out) process. This function should return a tuple wrapped in an `Option`
+  with the information of that person
+- `search`, that return a tuple with the information of a given person `id`.
+
+You must also create a type called `Link` this will be the connection of the structures `Queue` and `Person`.
+Do not forget that this will be a recursion type and it must point to `None` if there is no persons.
+
+### Expected Function
+
+```rust
+pub struct Queue {
+    pub node: Link,
+}
+
+pub type Link =
+
+pub struct Person {
+    pub id: i32,
+    pub name: String,
+}
+
+impl Queue {
+    pub fn new() -> Queue {}
+    pub fn add(&mut self, t: String, name: String) {}
+    pub fn invert_queue(&mut self) {}
+    pub fn rm(&mut self) -> Option<String> {}
+    pub fn search(&self) -> Option<(String, String)> {}
+
+}
+```
+
+### Usage
+
+Here is a program to test your function
+
+```rust
+fn main() {
+    let mut list = Queue::new();
+    list.add(String::from("Marie"), 20);
+    list.add(String::from("Monica"), 15);
+    list.add(String::from("Ana"), 5);
+    list.add(String::from("Alice"), 35);
+    println!("{:?}", list);
+
+    println!("{:?}", list.search("Marie"));
+    println!("{:?}", list.search("Alice"));
+    println!("{:?}", list.search("someone"));
+
+    println!("removed {:?}", list.rm());
+    println!("list {:?}", list);
+    println!("invert {:?}", list.invert_queue());
+}
+```
+
+And its output:
+
+```console
+student@ubuntu:~/[[ROOT]]/test$ cargo run
+Queue { node: Some(Person { name: "Alice", discount: 35, next_person: Some(Person { name: "Ana", discount: 5, next_person: Some(Person { name: "Monica", discount: 15, next_person: Some(Person { name: "Marie", discount: 20, next_person: None }) }) }) }) }
+Some(("Marie", 20))
+Some(("Alice", 35))
+None
+removed Some(("Marie", 20))
+removed Some(("Monica", 15))
+list Queue { node: Some(Person { name: "Alice", discount: 35, next_person: Some(Person { name: "Ana", discount: 5, next_person: None }) }) }
+inverted list Queue { node: Some(Person { name: "Ana", discount: 5, next_person: Some(Person { name: "Alice", discount: 35, next_person: None }) }) }
+student@ubuntu:~/[[ROOT]]/test$
+```
+
+### Notions
+
+- https://doc.rust-lang.org/rust-by-example/custom_types/enum.html
+- https://doc.rust-lang.org/book/ch15-01-box.html
+- https://doc.rust-lang.org/std/option/
+- https://doc.rust-lang.org/book/ch15-01-box.html