What is this repository ?

This repository contains exercises given in the algorithmic course to students in Computer Science at Université Catholique de Louvain. The content of the exercises are based on the book Algorithm 4th Edition, by Robert Sedgewick and Kevin Wayne. The exercises are meant to be easily exportable so you can reuse them in other courses.

Structure of the repository

The repository is built as a java project (we use Maven to build the project). This means that

• For all the exercises, the solution is given in this repository.
• The solution can be removed by stripping the files using the in-file tags
• Running mvn test run all the tests for the exercises and ensure the exercise is doable by the students

The mains directories of the project:

• data/ contains data file for the parameterized tests
• libs/ contains some test libraries
• src/{main,test}/java contains, respectively, the exercises and the associated tests

The rest of the files are specific to us and how student submissions are handled (using INGInious)

How to create an exercise

An exercise is composed exclusively of the following files:

1. src/main/java/Exercise.java contains the statement with the functions, classes, etc. to fill by the students
2. src/test/java/ExerciseTest.java contains the unit test for the students to check their solution
3. An optional src/main/java/ExerciseGenerator.java data generator file for parameterized tests

Every additional class needed for the exercise must be an internal class in Exercise.java. This is an intended design, the cost of the overhead in the code is compensated by:

• It is easier for students to navigate in the exercise. Everything they need is in one file and they can concentrate on the algorithmic part.
• We give to students a Maven project in a zip file for each exercise. Identifying all file by the exercise name makes it easier to create such archive.
• It is easy to extract some exercise from the repository, only the three mentioned file needs to be copied in order to have the full exercise.

Example

Here is an example of exercise that would be located at src/main/java/Mean.java

/**
 * In this exercise we ask you to compute the mean of two numbers, `a` and `b`. You should return an
 * integer. This means that the mean of 2 and 5 is not 3.5 but 3
 */
public class Mean {
  
  /**
   * Returns the integer means of two numbers
   * @params a The first number in the mean
   * @params b The second number in the mean
   * @returns the mean of a and b
   */
  public static int mean(int a, int b) {
    // BEGIN STRIP
    return (a+b)/2;
    // END STRIP
    // TODO
    // STUDENT return 0;
  }
}

After processing it, the file given to the students (alongside a test file) is

/**
 * In this exercise we ask you to compute the mean of two numbers, `a` and `b`. You should return an
 * integer. This means that the mean of 2 and 5 is not 3.5 but 3
 */
public class Mean {
  
  /**
   * Returns the integer means of two numbers
   * @params a The first number in the mean
   * @params b The second number in the mean
   * @returns the mean of a and b
   */
  public static int mean(int a, int b) {
    // TODO
    return 0;
  }
}

• The statement is given as comments at the top of the class.
• The method(s) that the students should implement can be anything and they are free to add additional methods (in our case they submit the whole file for verification)
• The solution of the exercise is given but between tags to ensure that it is removed before giving the exercise to the students
• A tag STUDENT is used if a return line must be specified (the files given to the students MUST compile even without the solution)
• The associated tests are located at src/test/java/MeanTest.java. This is essential that only Test is added for the filename.

The goal is that an exercise is composed of

1. An exercise file in src/main/java
2. A test file in src/test/java
3. An optional instance generator named ExerciseGenerator.java

Contributing

1. If you spot a mistake in the tests, or the solutions of the exercises, do not hesitate to open a PR with the fix, or report it in an issue
2. f you have an idea for an exercise that is not yet implemented, feel free to open an issue to describe the exercise, or a PR with the code formatted as explained above