src/exercises/ex_j/Diner.java

@@ -1,33 +0,0 @@
-package exercises.ex_j;
-
-class Diner {
-    private String name;
-    private boolean isHungry;
-
-    public Diner(String name) {
-        this.name = name;
-        isHungry = true;
-    }
-
-    public String getName() {
-        return name;
-    }
-
-    public boolean isHungry() {
-        return isHungry;
-    }
-
-    public void eatWith(Spoon spoon, Diner spouse) {
-        while (isHungry) {
-            if (spoon.getOwner() == this) {
-                if (spouse.isHungry()) {
-                    System.out.println(getName() + ": You eat first my darling " + spouse.getName() + "!");
-                    spoon.setOwner(spouse);
-                } else {
-                    spoon.use();
-                    this.isHungry = false;
-                }
-            }
-        }
-    }
-}

src/exercises/ex_j/LivelockDinner.java

@@ -1,20 +0,0 @@
-package exercises.ex_j;
-
-public class LivelockDinner {
-    public static void main(String[] args) {
-        final Diner husband = new Diner("Bob");
-        final Diner wife = new Diner("Alice");
-        final Spoon spoon = new Spoon(husband);
-
-        new Thread(new Runnable() {
-            public void run() {
-                husband.eatWith(spoon, wife);
-            }
-        }).start();
-        new Thread(new Runnable() {
-            public void run() {
-                wife.eatWith(spoon, husband);
-            }
-        }).start();
-    }
-}

src/exercises/ex_j/Spoon.java

@@ -1,21 +0,0 @@
-package exercises.ex_j;
-
-class Spoon {
-    private Diner owner;
-
-    public synchronized Diner getOwner() {
-        return owner;
-    }
-
-    public Spoon(Diner d) {
-        owner = d;
-    }
-
-    public synchronized void setOwner(Diner d) {
-        owner = d;
-    }
-
-    public synchronized void use() {
-        System.out.printf("%s has eaten!", owner.getName());
-    }
-}

src/exercises/ex_k/Customer.java

@@ -1,31 +0,0 @@
-package exercises.ex_k;
-
-public class Customer implements Runnable {
-    private String name;
-    private PostOffice postOffice;
-
-    public Customer(String name, PostOffice postOffice) {
-        this.name = name;
-        this.postOffice = postOffice;
-    }
-
-    public String getName() {
-        return name;
-    }
-
-    @Override
-    public void run() {
-        Package pkg;
-        while (true) {
-            pkg = new Package(this);
-            System.out.println("Registering " + pkg + "...");
-            postOffice.registerPackage(pkg);
-            System.out.println("Registered " + pkg);
-            try {
-                Thread.sleep((long) (Math.random() * 2000 + 1000));
-            } catch (InterruptedException e) {
-                throw new RuntimeException(e);
-            }
-        }
-    }
-}

src/exercises/ex_k/Package.java

@@ -1,15 +0,0 @@
-package exercises.ex_k;
-
-public class Package {
-    private Customer sender;
-
-    public Package(Customer sender) {
-        this.sender = sender;
-    }
-    @Override
-    public String toString() {
-        return "Package{" +
-            "sender=" + sender.getName() +
-            '}';
-    }
-}

src/exercises/ex_k/PostOffice.java

@@ -1,38 +0,0 @@
-package exercises.ex_k;
-
-import java.util.LinkedList;
-import java.util.List;
-
-public class PostOffice {
-    public static final int CAPACITY = 5;
-    private List<Package> packages = new LinkedList<>();
-
-    public synchronized void registerPackage(Package pkg) {
-        while (packages.size() >= CAPACITY) {
-            try {
-                System.out.println("[PostOffice] Storage is full, waiting");
-                wait();
-            } catch (InterruptedException e) {
-                throw new RuntimeException(e);
-            }
-        }
-        packages.add(pkg);
-        System.out.println("[PostOffice] Storage: " + packages.size() + " / " + CAPACITY);
-        notifyAll();
-    }
-
-    public synchronized Package getNextPackage() {
-        while (packages.isEmpty()) {
-            try {
-                System.out.println("[PostOffice] Storage is empty, waiting");
-                wait();
-            } catch (InterruptedException e) {
-                throw new RuntimeException(e);
-            }
-        }
-        Package pkg = packages.removeFirst();
-        System.out.println("[PostOffice] Storage: " + packages.size() + " / " + CAPACITY);
-        notifyAll();
-        return pkg;
-    }
-}

src/exercises/ex_k/Postman.java

@@ -1,23 +0,0 @@
-package exercises.ex_k;
-
-public class Postman implements Runnable {
-    private PostOffice postOffice;
-
-    public Postman(PostOffice postOffice) {
-        this.postOffice = postOffice;
-    }
-
-    @Override
-    public void run() {
-        Package pkg;
-        while (true) {
-            pkg = postOffice.getNextPackage();
-            System.out.println("Delivering " + pkg);
-            try {
-                Thread.sleep(2000);
-            } catch (InterruptedException e) {
-                throw new RuntimeException(e);
-            }
-        }
-    }
-}

src/exercises/ex_k/TestingGuardedBlocks.java

@@ -1,10 +0,0 @@
-package exercises.ex_k;
-
-public class TestingGuardedBlocks {
-    public static void main(String[] args) {
-        PostOffice postOffice = new PostOffice();
-        (new Thread(new Postman(postOffice))).start();
-        (new Thread(new Customer("Mrs Darbellay", postOffice))).start();
-        (new Thread(new Customer("Mrs Müller", postOffice))).start();
-    }
-}

src/exercises/ex_n/News.java

@@ -1,21 +0,0 @@
-package exercises.ex_n;
-
-import java.time.LocalDateTime;
-
-public class News {
-    private String news;
-    private LocalDateTime date;
-
-    public News(String news) {
-        this.news = news;
-        this.date = LocalDateTime.now();
-    }
-
-    @Override
-    public String toString() {
-        return "News{" +
-        "news='" + news + '\'' +
-        ", date=" + date +
-        '}';
-    }
-}

src/exercises/ex_n/NewsFeed.java

@@ -1,37 +0,0 @@
-package exercises.ex_n;
-
-import java.util.Stack;
-import java.util.concurrent.locks.Lock;
-import java.util.concurrent.locks.ReadWriteLock;
-import java.util.concurrent.locks.ReentrantReadWriteLock;
-
-public class NewsFeed {
-    private final Stack<News> newsStack = new Stack<>();
-    private final ReadWriteLock lock = new ReentrantReadWriteLock();
-    private final Lock writeLock = lock.writeLock();
-    private final Lock readLock = lock.readLock();
-
-    public NewsFeed() {
-
-    }
-
-    public void put(News news) {
-        try {
-            writeLock.lock();
-            newsStack.push(news);
-        } finally {
-            writeLock.unlock();
-        }
-    }
-
-    public News read() {
-        News news;
-        try {
-            readLock.lock();
-            news = newsStack.peek();
-        } finally {
-            readLock.unlock();
-        }
-        return news;
-    }
-}

src/exercises/ex_n/TestingReentrantReadWriteLock_News.java

@@ -1,34 +0,0 @@
-package exercises.ex_n;
-
-public class TestingReentrantReadWriteLock_News {
-    public static void main(String[] args) {
-        NewsFeed newsFeed = new NewsFeed();
-        newsFeed.put(new News("START OF NEWS"));
-
-        // Create one writing thread
-        new Thread(new Runnable() {
-            @Override
-            public void run() {
-                for (int i=0;i<200;i++) {
-                    newsFeed.put(new News("News " + i));
-                }
-            }
-        }).start();
-
-        // Create several reading threads
-        for (int i=0; i<20;i++) {
-            new Thread((new Runnable() {
-                @Override
-                public void run() {
-                    for (int i=0;i<20;i++) {
-                        News news = newsFeed.read();
-                        if (news != null) {
-                            System.out.println("News read : "
-                            + newsFeed.read());
-                        }
-                    }
-                }
-            })).start();
-        }
-    }
-}

src/exercises/ex_o/LockedWithConditionsStack.java

@@ -1,51 +0,0 @@
-package exercises.ex_o;
-
-import java.util.Stack;
-import java.util.concurrent.locks.Condition;
-import java.util.concurrent.locks.ReentrantLock;
-
-public class LockedWithConditionsStack {
-    private final int capacity;
-    private final Stack<Integer> stack = new Stack<>();
-    private final ReentrantLock lock = new ReentrantLock();
-    private final Condition fullCondition = lock.newCondition();
-    private final Condition emptyCondition = lock.newCondition();
-
-    public LockedWithConditionsStack(int capacity) {
-        this.capacity = capacity;
-    }
-
-    public void pushToStack(int value) {
-        try {
-            lock.lock();
-            while (stack.size() == capacity) {
-                System.out.println("Stack is full, waiting until someone pops");
-                fullCondition.await();
-            }
-            stack.push(value);
-            emptyCondition.signalAll();
-        } catch (InterruptedException e) {
-            throw new RuntimeException(e);
-        } finally {
-            lock.unlock();
-        }
-    }
-
-    public int popFromStack() {
-        int value;
-        try {
-            lock.lock();
-            while (stack.isEmpty()) {
-                System.out.println("Stack is empty, waiting until someone pushes");
-                emptyCondition.await();
-            }
-            value = stack.pop();
-            fullCondition.signalAll();
-        } catch (InterruptedException e) {
-            throw new RuntimeException(e);
-        } finally {
-            lock.unlock();
-        }
-        return value;
-    }
-}

src/exercises/ex_o/NumberConsumer.java

@@ -1,16 +0,0 @@
-package exercises.ex_o;
-
-public class NumberConsumer implements Runnable {
-    private LockedWithConditionsStack stack;
-
-    public NumberConsumer(LockedWithConditionsStack stack) {
-        this.stack = stack;
-    }
-
-    @Override
-    public void run() {
-        while (true) {
-            System.out.println("Pop from stack: " + stack.popFromStack());
-        }
-    }
-}

src/exercises/ex_o/NumberProducer.java

@@ -1,17 +0,0 @@
-package exercises.ex_o;
-
-public class NumberProducer implements Runnable {
-    private LockedWithConditionsStack stack;
-    public NumberProducer(LockedWithConditionsStack stack) {
-        this.stack = stack;
-    }
-
-    @Override
-    public void run() {
-        for (int i = 0; i < 100; i++) {
-            System.out.println("Pushing to stack " + i + "...");
-            stack.pushToStack(i);
-            System.out.println("Pushed to stack " + i);
-        }
-    }
-}

src/exercises/ex_o/TestingReentrantLockWithConditions.java

@@ -1,9 +0,0 @@
-package exercises.ex_o;
-
-public class TestingReentrantLockWithConditions {
-    public static void main(String[] args) {
-        LockedWithConditionsStack stack = new LockedWithConditionsStack(5);
-        (new Thread(new NumberProducer(stack))).start();
-        (new Thread(new NumberConsumer(stack))).start();
-    }
-}

src/exercises/ex_p/Drum.java

@@ -1,13 +0,0 @@
-package exercises.ex_p;
-
-public class Drum {
-    private final String name;
-
-    public Drum(String name) {
-        this.name = name;
-    }
-
-    public void play() {
-        System.out.println("Playing " + name);
-    }
-}

src/exercises/ex_p/Partition.java

@@ -1,38 +0,0 @@
-package exercises.ex_p;
-
-import java.util.concurrent.Executors;
-import java.util.concurrent.ScheduledExecutorService;
-import java.util.concurrent.TimeUnit;
-
-public class Partition {
-    public static void main(String[] args) {
-        Drum bassDrum = new Drum("Bass Drum");
-        Drum floortom = new Drum("Floor Tom");
-        Drum snareDrum = new Drum("Snare Drum");
-        Drum rackTom = new Drum("Rack Tom");
-        Drum hiHat = new Drum("Hi-Hat");
-        Drum crashCymbal = new Drum("Crash Cymbal");
-        Drum rideCymbal = new Drum("Ride Cymbal");
-        Drum splashCymbal = new Drum("Splash Cymbal");
-        Drum chinaCymbal = new Drum("China Cymbal");
-        ScheduledExecutorService executor = Executors.newScheduledThreadPool(9);
-        int initialDelay = 1000;
-        int quaver = 500; // croche
-        int crotchet = 1000; // noire
-        int minim = 2000; // blanche
-        TimeUnit unit = TimeUnit.MILLISECONDS;
-
-        Drum[] drums = {
-            bassDrum, floortom, snareDrum,
-            rackTom, hiHat, crashCymbal,
-            rideCymbal, splashCymbal, chinaCymbal
-        };
-        int[] notes = {quaver, crotchet, minim};
-
-        for (int i=0; i < 9; i++) {
-            Drum drum = drums[i];
-            int rhythm = notes[(int) (Math.random() * 3)];
-            executor.scheduleAtFixedRate(drum::play, initialDelay, rhythm, unit);
-        }
-    }
-}

src/exercises/ex_p_bis/Ansi.java

@@ -1,13 +0,0 @@
-package exercises.ex_p_bis;
-
-public class Ansi {
-    public static final String RESET = "\u001B[0m";
-    public static final String BLACK = "\u001B[30m";
-    public static final String RED = "\u001B[31m";
-    public static final String GREEN = "\u001B[32m";
-    public static final String YELLOW = "\u001B[33m";
-    public static final String BLUE = "\u001B[34m";
-    public static final String PURPLE = "\u001B[35m";
-    public static final String CYAN = "\u001B[36m";
-    public static final String WHITE = "\u001B[37m";
-}

src/exercises/ex_p_bis/ChristmasTree.java

@@ -1,51 +0,0 @@
-package exercises.ex_p_bis;
-
-import java.util.HashMap;
-import java.util.Map;
-
-public class ChristmasTree {
-    private static final String[] lines = {
-        "     ★       ★     ★",
-        "       ★ ╱╲         ",
-        "  ★     ╱  ╲   ★    ",
-        "       ╱    ╲       ",
-        "   ★  ╱      ╲    ★ ",
-        "     ╱        ╲     ",
-        "    ╱─        ─╲    ",
-        "     ╱        ╲ ★   ",
-        " ★  ╱          ╲    ",
-        "   ╱────┐  ┌────╲   ",
-        "    ★   │  │     ★  ",
-    };
-    public static final int W = 20;
-    public static final int H = 11;
-    private final Map<Integer, Light> lights = new HashMap<>();
-
-    public void addLight(int x, int y, Light light) {
-        lights.put(x + y * W, light);
-        light.setTree(this);
-    }
-
-    public synchronized void show() {
-        String result = "";
-        for (int y=0; y < H; y++) {
-            String line = "";
-            for (int x=0; x < W; x++) {
-                String c = String.valueOf(lines[y].charAt(x));
-                if (c.equals("★")) {
-                    c = Ansi.YELLOW + c + Ansi.RESET;
-                }
-                Light light = lights.get(x + y * W);
-                if (light != null) {
-                    c = light.apply(c);
-                }
-                line += c;
-            }
-            if (y != 0) {
-                result += "\n";
-            }
-            result += line;
-        }
-        System.out.println(result);
-    }
-}

src/exercises/ex_p_bis/ChristmasTreeTester.java

@@ -1,32 +0,0 @@
-package exercises.ex_p_bis;
-
-import java.util.concurrent.Executors;
-import java.util.concurrent.ScheduledExecutorService;
-import java.util.concurrent.TimeUnit;
-
-public class ChristmasTreeTester {
-    public static void main(String[] args) {
-        ChristmasTree tree = new ChristmasTree();
-
-        Light light1 = new Light(Ansi.RED);
-        Light light2 = new Light(Ansi.RED);
-        Light light3 = new Light(Ansi.GREEN);
-        Light light4 = new Light(Ansi.GREEN);
-        Light light5 = new Light(Ansi.WHITE);
-        Light light6 = new Light(Ansi.WHITE);
-
-        tree.addLight(8, 3, light1);
-        tree.addLight(11, 5, light2);
-        tree.addLight(13, 6, light3);
-        tree.addLight(6, 7, light4);
-        tree.addLight(10, 2, light5);
-        tree.addLight(12, 8, light6);
-
-        ScheduledExecutorService executor = Executors.newScheduledThreadPool(5);
-        Light[] lights = {light1, light2, light3, light4, light5, light6};
-        for (int i = 0; i < 6; i++) {
-            Light light = lights[i];
-            executor.scheduleAtFixedRate(light::toggle, 0, (long) (1000 + Math.random() * 2000), TimeUnit.MILLISECONDS);
-        }
-    }
-}

src/exercises/ex_p_bis/Light.java

@@ -1,31 +0,0 @@
-package exercises.ex_p_bis;
-
-public class Light {
-    private boolean isOn = false;
-    private String prefix = "";
-    private static final String suffix = Ansi.RESET;
-    private ChristmasTree tree;
-
-    public Light(String prefix) {
-        this.prefix = prefix;
-    }
-
-    public void toggle() {
-        isOn = !isOn;
-        tree.show();
-    }
-
-    public void setTree(ChristmasTree tree) {
-        this.tree = tree;
-    }
-
-    public String apply(String c) {
-        if (isOn) {
-            return c;
-        }
-        if (c.equals(" ")) {
-            c = "⬤";
-        }
-        return prefix + c + suffix;
-    }
-}

src/exercises/ex_q1/Pizza.java

@@ -1,13 +0,0 @@
-package exercises.ex_q1;
-
-public class Pizza {
-    public void prepare() {
-        System.out.println("Preparing pizza.");
-    }
-    public void bake() {
-        System.out.println("Baking pizza.");
-    }
-    public void cut() {
-        System.out.println("Cutting pizza.");
-    }
-}

src/exercises/ex_q1/Pizzaiolo.java

@@ -1,34 +0,0 @@
-package exercises.ex_q1;
-
-import java.util.concurrent.Callable;
-
-public class Pizzaiolo implements Callable<Pizza> {
-    private final String name;
-
-    public Pizzaiolo(String name) {
-        this.name = name;
-    }
-
-    public void serve(Pizza pizza) {
-        System.out.println(name + "'s pizza is ready: pizza " + pizza.hashCode());
-    }
-
-    public Pizza makePizza() throws InterruptedException {
-        Pizza pizza = new Pizza();
-        pizza.prepare();
-        Thread.sleep(200);
-        pizza.bake();
-        Thread.sleep(300);
-        pizza.cut();
-        Thread.sleep(100);
-        return pizza;
-    }
-
-    @Override
-    public Pizza call() throws Exception {
-        System.out.println("Thread " + name + " started by the executor");
-        Pizza pizza = makePizza();
-        System.out.println("Thread " + name + " pizza finished");
-        return pizza;
-    }
-}

src/exercises/ex_q1/Pizzeria.java

@@ -1,26 +0,0 @@
-package exercises.ex_q1;
-
-import java.util.concurrent.ExecutionException;
-import java.util.concurrent.Executors;
-import java.util.concurrent.Future;
-import java.util.concurrent.ScheduledExecutorService;
-
-public class Pizzeria {
-    public static void main(String[] args) throws ExecutionException, InterruptedException {
-        ScheduledExecutorService executor = Executors.newSingleThreadScheduledExecutor();
-        Pizzaiolo marco = new Pizzaiolo("Marco");
-        Pizzaiolo antonio = new Pizzaiolo("Antonio");
-
-        Future<Pizza> future1 = executor.submit(marco);
-        Future<Pizza> future2 = executor.submit(antonio);
-        Future<Pizza> future3 = executor.submit(marco);
-        Future<Pizza> future4 = executor.submit(antonio);
-
-        marco.serve(future1.get());
-        antonio.serve(future2.get());
-        marco.serve(future3.get());
-        antonio.serve(future4.get());
-
-        executor.shutdown();
-    }
-}

src/exercises/ex_q2/CustomRecursiveAction.java

@@ -1,34 +0,0 @@
-package exercises.ex_q2;
-
-import java.util.concurrent.RecursiveAction;
-import java.util.logging.Logger;
-
-public class CustomRecursiveAction extends RecursiveAction {
-    private static final int threshold = 10;
-    private String song;
-
-    public CustomRecursiveAction(String song) {
-        this.song = song;
-    }
-
-    @Override
-    protected void compute() {
-        Logger logger = Logger.getAnonymousLogger();
-        if (song.length() <= threshold) {
-            logger.info("Splitting problem");
-            changeToUppercase();
-        } else {
-            logger.info("Problem is small enough");
-            int halfSize = song.length() / 2;
-            CustomRecursiveAction task1 = new CustomRecursiveAction(song.substring(0, halfSize));
-            CustomRecursiveAction task2 = new CustomRecursiveAction(song.substring(halfSize));
-            invokeAll(task1, task2);
-            song = task1.song + task2.song;
-            logger.info("Solution: " + song);
-        }
-    }
-
-    protected void changeToUppercase() {
-        song = song.toUpperCase();
-    }
-}

src/exercises/ex_q2/ForkJoinTest.java

@@ -1,28 +0,0 @@
-package exercises.ex_q2;
-
-import java.util.concurrent.ForkJoinPool;
-
-public class ForkJoinTest {
-    public static void main(String[] args) {
-        String song = "Georges Brassens (1964) - Les Copains d'abord"
-            + "Non, ce n'était pas le radeau"
-            + "De la Méduse, ce bateau"
-            + "Qu'on se le dise au fond des ports"
-            + "Dise au fond des ports"
-            + "Il naviguait en père peinard"
-            + "Sur la grand-mare des canards"
-            + "Et s'appelait les Copains d'abord"
-            + "Les Copains d'abord";
-        int processors = Runtime.getRuntime().availableProcessors();
-        System.out.println("Number of available processors: " + processors);
-        ForkJoinPool pool = new ForkJoinPool(processors);
-        long startTime = System.currentTimeMillis();
-        pool.invoke(new CustomRecursiveAction(song));
-        long endTime = System.currentTimeMillis();
-        System.out.println(
-            "Fork/Join tasks took "
-                + (endTime - startTime)
-                + " milliseconds."
-        );
-    }
-}

src/exercises/ex_q3/Book.java

@@ -1,8 +0,0 @@
-package exercises.ex_q3;
-
-public record Book(String ISBN, String title, String authorFirstName, String authorLastName, int year) implements Comparable<Book> {
-    @Override
-    public int compareTo(Book o) {
-        return title.compareTo(o.title);
-    }
-}

src/exercises/ex_q3/BookGenerator.java

@@ -1,67 +0,0 @@
-package exercises.ex_q3;
-
-import java.util.ArrayList;
-import java.util.Random;
-
-public class BookGenerator {
-    private static final String[] adjectives = {
-        "big", "red", "small", "weird", "amazing", "fantastic", "friendly", "curious", "frightening",
-    };
-    private static final String[] nouns = {
-        "apple", "car", "gingerbread man", "octopus", "planet", "volcano", "bottle", "adventure"
-    };
-    private static final String[] determinants = {"the", "a"};
-    private static final String vowels = "aeiou";
-
-    private static final String[] firstnames = {
-        "John", "Patrick", "Gérard", "Jean-Michel", "Ronswalle", "Guilherme", "Jean-Claude", "Perceval", "Hector", "Ferguson",
-        "Azénor", "Clémentine", "Ailizabette", "Bérangère", "Clothilde", "Mélissandre"
-    };
-
-    private static final String[] lastnames = {
-        "de Mont-Castel", "Smith", "Martin", "Ferguson", "Lassalle", "Berset", "Constantin"
-    };
-
-    private static final Random random = new Random();
-
-    private static String getRandom(String[] list) {
-        int i = random.nextInt(list.length);
-        return list[i];
-    }
-
-    public static Book generateRandomBook() {
-        String noun = getRandom(nouns);
-        String adj = getRandom(adjectives);
-        String det = getRandom(determinants);
-        if (det.equals("a") && vowels.contains(adj.substring(0, 1))) {
-            det += "n";
-        }
-        String title = det + " " + adj + " " + noun;
-        title = title.substring(0, 1).toUpperCase() + title.substring(1);
-
-        String isbn = "";
-        int checksum = 0;
-        for (int i = 0; i < 9; i++) {
-            int digit = random.nextInt(10);
-            isbn += String.valueOf(digit);
-            if (i % 4 == 0) {
-                isbn += "-";
-            }
-            checksum += (10 - i) * digit;
-        }
-        checksum = checksum % 11;
-        if (checksum != 0) {
-            checksum = 11 - checksum;
-        }
-        if (checksum == 10) {
-            isbn += "X";
-        } else {
-            isbn += String.valueOf(checksum);
-        }
-
-        String firstname = getRandom(firstnames);
-        String lastname = getRandom(lastnames);
-
-        return new Book(isbn, title, firstname, lastname, random.nextInt(1000, 2025));
-    }
-}

src/exercises/ex_q3/Library.java

@@ -1,20 +0,0 @@
-package exercises.ex_q3;
-
-import java.util.Arrays;
-
-public class Library {
-    private static final int SIZE = 100_000;
-    private static final Book[] books = new Book[SIZE];
-
-    public static void main(String[] args) {
-        for (int i = 0; i < SIZE; i++) {
-            Book book = BookGenerator.generateRandomBook();
-            books[i] = book;
-        }
-
-        Arrays.parallelSort(books);
-        for (int i = 0; i < Math.min(15, SIZE); i++) {
-            System.out.println(books[i]);
-        }
-    }
-}

src/exercises/ex_r/Customer.java

@@ -1,28 +0,0 @@
-package exercises.ex_r;
-
-public class Customer implements Runnable {
-    private String name;
-    private PostOffice office;
-
-    public Customer(String name, PostOffice office) {
-        this.name = name;
-        this.office = office;
-    }
-
-    public String getName() {
-        return name;
-    }
-
-    @Override
-    public void run() {
-        while (true) {
-            Package pkg = new Package(this);
-            office.registerPackage(pkg);
-            try {
-                Thread.sleep((long) (1000L + 5000L * Math.random()));
-            } catch (InterruptedException e) {
-                break;
-            }
-        }
-    }
-}

src/exercises/ex_r/Package.java

@@ -1,15 +0,0 @@
-package exercises.ex_r;
-
-public class Package {
-    private Customer sender;
-    public Package(Customer sender) {
-        this.sender = sender;
-    }
-
-    @Override
-    public String toString() {
-        return "Package{" +
-                   "sender=" + sender.getName() +
-               '}';
-    }
-}

src/exercises/ex_r/PostOffice.java

@@ -1,19 +0,0 @@
-package exercises.ex_r;
-
-import java.util.concurrent.BlockingQueue;
-import java.util.concurrent.LinkedBlockingQueue;
-
-public class PostOffice {
-    private BlockingQueue<Package> packages = new LinkedBlockingQueue<>();
-
-    public void registerPackage(Package pkg) {
-        packages.add(pkg);
-        System.out.println("Registered " + pkg + " (now " + packages.size() + ")");
-    }
-
-    public Package takePackage() throws InterruptedException {
-        Package pkg = packages.take();
-        System.out.println("Withdrawn " + pkg + " (now " + packages.size() + ")");
-        return pkg;
-    }
-}

src/exercises/ex_r/Postman.java

@@ -1,22 +0,0 @@
-package exercises.ex_r;
-
-public class Postman implements Runnable {
-    private PostOffice office;
-
-    public Postman(PostOffice office) {
-        this.office = office;
-    }
-
-    @Override
-    public void run() {
-        while (true) {
-            try {
-                Package pkg = office.takePackage();
-                Thread.sleep((long) (1000L + 2000L * Math.random()));
-                System.out.println("Delivered " + pkg);
-            } catch (InterruptedException e) {
-                break;
-            }
-        }
-    }
-}

src/exercises/ex_r/TestingBlockingQueue_PostOffice.java

@@ -1,10 +0,0 @@
-package exercises.ex_r;
-
-public class TestingBlockingQueue_PostOffice {
-    public static void main(String[] args) {
-        PostOffice postOffice = new PostOffice();
-        (new Thread(new Postman(postOffice))).start();
-        (new Thread(new Customer("Mrs Darbellay", postOffice))).start();
-        (new Thread(new Customer("Mrs Müller", postOffice))).start();
-    }
-}