Working on AList project.

Author: Clément

source/order

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 ./projects/species.md
 ./projects/file_displayer.md
 ./projects/texfilehelper.md
+./projects/alist.md

source/projects/alist.md

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+# AList
+
+## Description
+
+### Purpose
+
+This project is designed to teach you how to implement lists using a more familiar datastructure, arrays.
+It requires to understand abstract data types, array manipulations and interfaces (as a bonus).
+
+### Challenge
+
+#### In short
+
+Our goal is to provide an implementation of the list abstract data type using arrays.
+Our implementation should be "from an external point of view" exactly like lists, with features similar to the C# implementation of lists.
+
+#### In more details
+
+We want to implement (a simplified version of) the [list abstract data type](https://princomp.github.io/lectures/data/lists#abstract-data-type). A list should be 
+
+- a finite collection of elements,
+- in a particular order,
+- capable of containing the same element multiple times.
+
+and we should have operations to… 
+
+- … create an empty list,
+- … test for emptiness,
+- … obtain the number of elements in the list,
+- … add an element at "the beginning" of the list ("to the left"),
+- … remove the first element with a particular value if it exists,
+- … empty the list.
+
+**The main challenge of this project is to implement those features using only an array as an attribute.**
+Your class should begin as follows:
+
+```
+using System;
+
+public class AList<T>
+{
+
+  private T[] alist;
+  …
+}
+```
+
+with the array `alist` being used to store the elements of the list. **Pay attention to details**:
+
+- make sure that the class always returns the right value for the number of elements in the list,
+- make sure your methods correctly insert and remove values without losing any information,
+- write good test cases in your `main` method,
+- **do not load any additional libraries**, in particular, **do not use C# native lists or LINQ**.
+
+
+### Bonuses
+
+Bonus points will be given if:
+
+- (easy) You provide at least one additional methods among the following:
+    - A relevant `ToString`,
+    - A method to insert a value "at the end" ("to the right") of the list,
+    - A method to insert a value at a given index.
+- (medium) Your `main` method is particularly well thought, and showcase many test cases. **A proper `main` method will help you in debugging your code.**
+- (hard) Make your class realizes the `ICollection<T>` interface: 
+
+    - You are then allowed to load the additional two libraries:
+    
+        ```
+        using System.Collections;
+        using System.Collections.Generic;
+        ```
+    - You will need to add a second attribute to your class,
+    - Add all the required methods, in particular write a meaningful `CopyTo` method.
+
+### Submission
+
+Please, follow our [guideline on project submission](./projects/submission).
+In particular, make sure you write your name and the date in a delimited comment at the beginning of your file.