12.2 war falsch

Ich halte mich nicht genau an die Aufgabenstellung um nicht ganz so schlimme verbrechen zu begehen.
Alles was ich anderes gemacht habe ist als Verbesserungsvorschlag zu verstehen.

build.gradle

@@ -11,7 +11,7 @@ project.ext.junitVersion = '5.3.1'
 
 mainClassName = '_9._2.Lights'
 
-sourceCompatibility = 1.8
+sourceCompatibility = 12
 
 repositories {
     mavenCentral()

src/main/java/_10/_1/SearchThread.java

@@ -0,0 +1,59 @@
+package _10._1;
+
+public class SearchThread extends Thread {
+    private int[] array;
+    private int value;
+    private int from;
+    private int to;
+    private boolean found = false;
+
+    public SearchThread(int[] array, int value, int from, int to) {
+        this.array = array;
+        this.value = value;
+        this.from = from;
+        this.to = to;
+    }
+
+    public void run() {
+        for (int i = this.from; i < this.to; i++) {
+            if (this.array[i] == this.value) {
+                this.found = true;
+                System.out.println(this.getName() + ": found");
+                return;
+            }
+        }
+        System.out.println(this.getName() + ": not found");
+    }
+
+    public boolean getFound() {
+        return found;
+    }
+
+
+    public static void main(String[] args) {
+        int[] array = { 2, 7, 3, 9, 23 };
+        arraySearch(array,7);
+    }
+
+    private static void arraySearch(int[] array, int value) {
+        SearchThread thread1 = new SearchThread(array, value, 0, array.length/2);
+        SearchThread thread2 = new SearchThread(array, value, array.length/2, array.length);
+        thread1.setName("Thread 1");
+        thread2.setName("Thread 2");
+        thread1.start();
+        thread2.start();
+
+        try {
+            thread1.join();
+            thread2.join();
+            if (thread1.getFound() || thread2.getFound()) {
+                System.out.println("Found: true");
+            } else {
+                System.out.println("Found: false");
+            }
+        } catch (InterruptedException e) {
+            e.printStackTrace();
+        }
+    }
+
+}

src/main/java/_10/_2/QuickSortThreaded.java

@@ -0,0 +1,53 @@
+package _10._2;
+
+import provided._10._2.*;
+
+public class QuickSortThreaded extends QuickSort implements Runnable {
+	private int[] numbers;
+	private int leftIndex;
+	private int rightIndex;
+
+	public QuickSortThreaded() {
+	}
+
+	public QuickSortThreaded(int[] numbers, int leftIndex, int rightIndex) {
+		this.numbers = numbers;
+		this.leftIndex = leftIndex;
+		this.rightIndex = rightIndex;
+	}
+
+	@Override
+	public void run() {
+		quickSort(numbers, leftIndex, rightIndex);
+	}
+
+
+	/**
+	 * sortiert das uebergebene Array in aufsteigender Reihenfolge
+	 * gemaess dem QuickSort-Algorithmus (parallel!)
+	 */
+	public static void sort(int[] numbers) {
+		new QuickSortThreaded().quickSort(numbers, 0, numbers.length - 1);
+	}
+
+	/**
+	 * der Quicksort-Algorithmus wird auf dem Array zwischen den
+	 * angegebenen Indizes ausgefuehrt
+	 */
+	protected void quickSort(int[] numbers, int leftIndex, int rightIndex) {
+		if (leftIndex < rightIndex) {
+			int pivotIndex = divide(numbers, leftIndex, rightIndex);
+			Thread threadLeft = new Thread(new QuickSortThreaded(numbers, leftIndex, pivotIndex - 1));
+			Thread threadRight = new Thread(new QuickSortThreaded(numbers, pivotIndex + 1, rightIndex));
+			threadLeft.start();
+			threadRight.start();
+			try {
+				threadLeft.join(); // Wait for first thread.
+				threadRight.join();
+			} catch (InterruptedException e) {
+				e.printStackTrace();
+			}
+		}
+	}
+
+}

src/main/java/_10/_3/ImageFilterThreaded.java

@@ -0,0 +1,59 @@
+package _10._3;
+
+import java.awt.*;
+import provided._10._3.ImageFilter;
+
+public class ImageFilterThreaded extends ImageFilter {
+
+	class FilterThread implements Runnable {
+		private int x1;
+		private int x2;
+		private int y1;
+		private int y2;
+		private Color[][] result;
+		private float[][] filter;
+
+		private FilterThread(int x1, int x2, int y1, int y2, Color[][] result, float[][] filter) {
+			this.x1 = x1;
+			this.x2 = x2;
+			this.y1 = y1;
+			this.y2 = y2;
+			this.result = result;
+			this.filter = filter;
+		}
+
+		@Override
+		public void run() {
+			for (int x = x1; x < x2; x++) {
+				for (int y = y1; y < y2; y++) {
+					filterPixel(result, x, y, filter);
+				}
+			}
+		}
+	}
+
+	@Override
+	protected Color[][] filterMatrix(float[][] filter) {
+		Color[][] result = new Color[matrix.length][matrix[0].length];
+
+		Thread threadLB = new Thread(new FilterThread(0, matrix.length/2, matrix[0].length/2, matrix[0].length,result,filter));
+		Thread threadRB = new Thread(new FilterThread(matrix.length/2, matrix.length, matrix[0].length/2, matrix[0].length,result,filter));
+		Thread threadLT = new Thread(new FilterThread(0, matrix.length/2, 0, matrix[0].length/2,result,filter));
+		Thread threadRT = new Thread(new FilterThread(matrix.length/2, matrix.length, 0, matrix[0].length/2,result,filter));
+		threadLB.start();
+		threadRB.start();
+		threadLT.start();
+		threadRT.start();
+
+		try {
+			threadLB.join();
+			threadRB.join();
+			threadLT.join();
+			threadRT.join();
+		} catch (InterruptedException e) {
+			e.printStackTrace();
+		}
+		return result;
+	}
+
+}

src/main/java/_10/_4/NameOutput.java

@@ -0,0 +1,55 @@
+package _10._4;
+
+public class NameOutput extends Thread {
+    private NumberData currentNumber;
+    private int threadNumber;
+
+    public NameOutput(int threadNumber, NumberData currentNumber) {
+        this.threadNumber = threadNumber;
+        this.currentNumber = currentNumber;
+    }
+
+    @Override
+    public void run() {
+        while (true) {
+            synchronized (currentNumber) {
+                while (currentNumber.getNumber() != threadNumber) {
+                    try {
+                        currentNumber.wait();
+                    } catch (InterruptedException e) {
+                        e.printStackTrace();
+                    }
+                }
+                System.out.println(this.getName());
+                currentNumber.increaseNumber();
+            }
+        }
+    }
+
+    public static void main(String[] args) {
+        int numberOfThreads = 3;
+        NumberData currentNumber = new NumberData(numberOfThreads);
+        for (int i = 0; i < numberOfThreads; i++) {
+            Thread thread = new NameOutput(i, currentNumber);
+            thread.start();
+        }
+    }
+}
+
+class NumberData {
+    private int number = 0;
+    private int modulo;
+
+    public NumberData(int modulo) {
+        this.modulo = modulo;
+    }
+
+    public int getNumber() {
+            return number;
+    }
+
+    public void increaseNumber() {
+        this.number = (this.number + 1) % this.modulo;
+        notifyAll();
+    }
+}

src/main/java/_10/_4/alternative/NameOutput.java

@@ -0,0 +1,14 @@
+package _10._4.alternative;
+
+public abstract class NameOutput {
+
+	private NameOutput() {
+	}
+
+	public static void main(String[] args) {
+		final int n = 3;
+		for(int i = 0; i < n; i++) {
+			new NameOutputFairLock().start();
+		}
+	}
+}

src/main/java/_10/_4/alternative/NameOutputBusyWaiting.java

@@ -0,0 +1,31 @@
+package _10._4.alternative;
+
+// ordered by creation time, deadlocks if any thread in the chain is interrupted.
+public class NameOutputBusyWaiting extends Thread {
+
+	private static final Object LOCK = new Object();
+
+	private static int counter = 0;
+	private static int total = 0;
+
+	private final int number;
+
+	public NameOutputBusyWaiting() {
+		synchronized(LOCK) {
+			this.number = total;
+			total++;
+		}
+	}
+
+	@Override
+	public void run() {
+		while(!this.isInterrupted()) {
+			synchronized(LOCK) {
+				if(this.number == counter) {
+					System.out.println(this.getName());
+					counter = (counter + 1) % total;
+				}
+			}
+		}
+	}
+}

src/main/java/_10/_4/alternative/NameOutputFairLock.java

@@ -0,0 +1,22 @@
+package _10._4.alternative;
+
+import java.util.concurrent.locks.Lock;
+import java.util.concurrent.locks.ReentrantLock;
+
+// ordered by least recent access since creation
+public class NameOutputFairLock extends Thread {
+
+	private static final Lock LOCK = new ReentrantLock(true);
+
+	@Override
+	public void run() {
+		while(!this.isInterrupted()) {
+			LOCK.lock();
+			try {
+				System.out.println(this.getName());
+			} finally {
+				LOCK.unlock();
+			}
+		}
+	}
+}

src/main/java/_10/_4/alternative/NameOutputWaitNotify.java

@@ -0,0 +1,37 @@
+package _10._4.alternative;
+
+// ordered by creation time, deadlocks if any thread in the chain is interrupted.
+public class NameOutputWaitNotify extends Thread {
+
+	private static final Object LOCK = new Object();
+
+	private static int counter = 0;
+	private static int total = 0;
+
+	private final int number;
+
+	public NameOutputWaitNotify() {
+		synchronized(LOCK) {
+			this.number = total;
+			total++;
+		}
+	}
+
+	@Override
+	public void run() {
+		while(!this.isInterrupted()) {
+			synchronized(LOCK) {
+				while(this.number != counter) {
+					try {
+						LOCK.wait();
+					} catch(InterruptedException e) {
+						System.out.println(this.getName() + " was interrupted");
+					}
+				}
+				System.out.println(this.getName());
+				counter = (counter + 1) % total;
+				LOCK.notifyAll();
+			}
+		}
+	}
+}

src/main/java/_11/_1/InOut.java

@@ -0,0 +1,46 @@
+package _11._1;
+
+import provided.IO;
+import java.util.concurrent.Semaphore;
+
+class Output extends Thread {
+
+    public void run() {
+        try {
+            InOut.getSemaphore().acquire();
+            System.out.println(InOut.getValue() * InOut.getValue());
+        } catch (InterruptedException e) {
+
+        }
+    }
+}
+
+class Input extends Thread {
+
+    public void run() {
+        InOut.setValue(IO.readInt("Value: "));
+        InOut.getSemaphore().release();
+    }
+}
+
+public class InOut {
+
+    private static Semaphore semaphore = new Semaphore(0);
+    private static int value = 0;
+
+    public static Semaphore getSemaphore() { return semaphore; }
+
+    public static int getValue() {
+        return value;
+    }
+
+    public static void setValue(int value) {
+        InOut.value = value;
+    }
+
+    public static void main(String[] args) {
+        new Output().start();
+        new Input().start();
+    }
+
+}

src/main/java/_11/_2/Barriers.java

@@ -0,0 +1,101 @@
+package _11._2;
+
+public class Barriers {
+
+	private final static int NUMBER = 3;
+
+	public static void main(String[] args) {
+		Counter obj = new Counter(NUMBER);
+		NumberRunner[] runner = new NumberRunner[NUMBER];
+		for (int i = 0; i < NUMBER; i++) {
+			runner[i] = new NumberRunner(i, obj);
+		}
+		for (int i = 0; i < NUMBER; i++) {
+			runner[i].start();
+		}
+	}
+
+}
+
+class Counter {
+	private final int numb; // Anzahl Threads
+	private int numberIn = 0; // Anzahl der Threads an Sperre
+	private int numberOut; // Anzahl der laufenden Threads
+
+	public Counter(int number) {
+		this.numb = number;
+		this.numberOut = number;
+	}
+
+	public int getMax() { return this.numb; }
+
+	public int getIn() {
+		return this.numberIn;
+	}
+
+	public int getOut() { return this.numberOut; }
+
+	public void resetIn() { this.numberIn = 0; }
+
+	public void resetOut() { this.numberOut = 0; }
+
+	public void incrementIn() { this.numberIn++; }
+
+	public void incrementOut() { this.numberOut++; }
+
+}
+
+class NumberRunner extends Thread {
+
+	private int number;
+	private final Counter obj;
+
+	public NumberRunner(int n, Counter obj) {
+		this.number = n;
+		this.obj = obj;
+	}
+
+	@Override
+	public void run() {
+		for (int i = 0; i < 1000; i++) {
+
+			System.out.println("Thread " + number + ": " + i);
+
+			if (i%10 == 0 && i != 0) {
+				synchronized (obj) {
+					try {
+						// warte, falls andere Threads von vorheriger Sperre noch nicht wieder gestartet sind
+						while (obj.getOut() < obj.getMax()) {
+							obj.wait();
+						}
+
+						// Thread kommt an aktueller Sperre an
+						obj.incrementIn();
+
+						// letzter Thread, der ankommt, benachrichtigt alle, dass es weiter gehen kann
+						if (obj.getIn() >= obj.getMax()) {
+							obj.resetOut();
+							obj.notifyAll();
+						}
+
+						// Threads warten, bis alle angekommen sind
+						while (obj.getIn() < obj.getMax()) {
+							obj.wait();
+						}
+
+						// Thread startet wieder
+						obj.incrementOut();
+
+						// der letzte Thread, der startet, benachrichtigt alle, dass die naechste Sperre freigegeben ist
+						if (obj.getOut() == obj.getMax()) {
+							obj.resetIn();
+							obj.notifyAll();
+						}
+
+					} catch (InterruptedException e) {
+					}
+				}
+			}
+		}
+	}
+}

src/main/java/_11/_2/alternative/Barriers.java

@@ -0,0 +1,16 @@
+package _11._2.alternative;
+
+public class Barriers {
+
+	public static final int NUMBER_OF_RUNNERS = 3;
+
+	public static void main(String[] args) {
+		NumberRunner[] runners = new NumberRunner[NUMBER_OF_RUNNERS];
+		for(int i = 0; i < NUMBER_OF_RUNNERS; i++) {
+			runners[i] = new NumberRunner(i);
+		}
+		for(int i = 0; i < NUMBER_OF_RUNNERS; i++) {
+			runners[i].start();
+		}
+	}
+}

src/main/java/_11/_2/alternative/Checkpoint.java

@@ -0,0 +1,28 @@
+package _11._2.alternative;
+
+public class Checkpoint {
+
+	private final Object lock = new Object();
+	private int groupSize;
+	private int gathered = 0;
+
+	public Checkpoint(int groupSize) {
+		this.groupSize = groupSize;
+	}
+
+	/**
+	 * Blocks until called by {@link #groupSize} different Threads,
+	 * then wakes all of them up again.
+	 */
+	public void gather() throws InterruptedException {
+		synchronized(this.lock) {
+			if(++this.gathered != this.groupSize) {
+				this.lock.wait();
+			} else {
+				this.gathered = 0;
+				System.out.println("Group gathered");
+				this.lock.notifyAll();
+			}
+		}
+	}
+}

src/main/java/_11/_2/alternative/NumberRunner.java

@@ -0,0 +1,27 @@
+package _11._2.alternative;
+
+public class NumberRunner extends Thread {
+
+	private static final Checkpoint CHECKPOINT = new Checkpoint(Barriers.NUMBER_OF_RUNNERS);
+
+	private final int id;
+
+	public NumberRunner(int id) {
+		this.id = id;
+	}
+
+	@Override
+	public void run() {
+		for(int i = 0; i < 1000; i++) {
+			if(i % 10 == 0) {
+				try {
+					CHECKPOINT.gather();
+				} catch(InterruptedException e) {
+					throw new IllegalStateException("Group can never be complete again, because one of the members got lost", e);
+				}
+			}
+
+			System.out.println("Thread " + this.id + ": " + i);
+		}
+	}
+}

src/main/java/_11/_3/KnapsackDynamic.java

@@ -0,0 +1,35 @@
+package _11._3;
+
+import provided._11._3.Item;
+import provided._11._3.Knapsack;
+import provided._11._3.Selection;
+
+import java.util.*;
+
+public class KnapsackDynamic extends Knapsack {
+	
+	public KnapsackDynamic(int capacity, Collection<Item> candidates) {
+		super(capacity, candidates);
+	}
+
+	@Override
+	public Selection pack() {
+		return this.pack(new Selection(), new HashMap<>());
+	}
+
+	private Selection pack(Selection parent, Map<Integer, Selection> memory) {
+		return memory.computeIfAbsent(parent.getWeight(), weight -> {
+			final Collection<Selection> children = new ArrayList<>();
+			for(Item candidate : this.candidates) {
+				if(parent.getWeight() + candidate.getWeight() <= this.capacity) {
+					children.add(pack(new Selection(parent, candidate), memory));
+				}
+			}
+
+			return children.stream()
+					.max(Comparator.comparingDouble(Selection::getValue))
+					.orElse(parent);
+		});
+	}
+
+}

src/main/java/_11/_3/KnapsackGreedy.java

@@ -0,0 +1,43 @@
+package _11._3;
+
+import provided._11._3.Item;
+import provided._11._3.Knapsack;
+import provided._11._3.Selection;
+
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.Comparator;
+import java.util.List;
+
+public class KnapsackGreedy extends Knapsack {
+
+	private static final Comparator<Item> DESCENDING_ITEM_VALUE_COMPARATOR
+			= Comparator.comparing(Item::getValue).reversed();
+
+	public KnapsackGreedy(int capacity, Collection<Item> candidates) {
+		super(capacity, candidates);
+	}
+
+	@Override
+	public Selection pack() {
+		final List<Item> orderedCandidates = new ArrayList<>(this.candidates);
+		orderedCandidates.sort(DESCENDING_ITEM_VALUE_COMPARATOR);
+
+		/*
+		 * Fügt das wertvollste Item hinzu, solange es noch passt, geht
+		 * dann zum nächst wertvolleren Item über und wiederholt den Vorgang
+		 * so lange bis kein Item mehr passt.
+		 */
+		Selection selection = new Selection();
+		for(Item candidate : orderedCandidates) {
+			while(selection.getWeight() + candidate.getWeight() <= this.capacity) {
+				selection = new Selection(selection, candidate);
+				/*
+				 * Der Speicher leidet hier sehr,
+				 * weil Selection#add(Item) private ist.
+				 */
+			}
+		}
+		return selection;
+	}
+}

src/main/java/_11/_3/KnapsackRecursive.java

@@ -0,0 +1,35 @@
+package _11._3;
+
+import provided._11._3.Item;
+import provided._11._3.Knapsack;
+import provided._11._3.Selection;
+
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.Comparator;
+
+public class KnapsackRecursive extends Knapsack {
+
+	public KnapsackRecursive(int capacity, Collection<Item> candidates) {
+		super(capacity, candidates);
+	}
+
+	@Override
+	public Selection pack() {
+		return this.pack(new Selection());
+	}
+
+	private Selection pack(Selection parent) {
+		final Collection<Selection> children = new ArrayList<>();
+		for(Item candidate : this.candidates) {
+			if(parent.getWeight() + candidate.getWeight() <= this.capacity) {
+				children.add(pack(new Selection(parent, candidate)));
+			}
+		}
+
+		return children.stream()
+				.max(Comparator.comparingDouble(Selection::getValue))
+				.orElse(parent);
+	}
+
+}

src/main/java/_12/_1/FibonacciDynamic.java

@@ -0,0 +1,26 @@
+package _12._1;
+
+import provided._12._1.Fibonacci;
+import java.util.HashMap;
+import java.util.Map;
+
+public class FibonacciDynamic extends Fibonacci {
+    protected Map<Integer, Long> map = new HashMap<>();
+
+    public FibonacciDynamic() {
+        this.map.put(0, (long) 0);
+        this.map.put(1, (long) 1);
+    }
+
+    @Override
+    public long calculate(int n) {
+        if (this.map.containsKey(n)) {
+            return this.map.get(n);
+        } else {
+            long result = calculate(n-1) + calculate(n-2);
+            this.map.put(n, result);
+            return result;
+        }
+    }
+
+}

src/main/java/_12/_1/FibonacciDynamicParallel.java

@@ -0,0 +1,47 @@
+package _12._1;
+
+
+public class FibonacciDynamicParallel extends FibonacciDynamic {
+
+    @Override
+    public long calculate(int n) {
+        if (this.map.containsKey(n)) {
+            return this.map.get(n);
+        } else {
+            FibonacciThread thread1 = new FibonacciThread(n-1);
+            FibonacciThread thread2 = new FibonacciThread(n-2);
+            thread1.start();
+            thread2.start();
+
+            try {
+                thread1.join();
+                thread2.join();
+
+            } catch (InterruptedException e) {
+                e.printStackTrace();
+            }
+
+            long result = thread1.getResult() + thread2.getResult();
+            this.map.put(n, result);
+            return result;
+        }
+    }
+
+    class FibonacciThread extends Thread {
+        private int n;
+        private long result;
+
+        public FibonacciThread(int n) {
+            this.n = n;
+        }
+
+        @Override
+        public void run() {
+            result = calculate(n);
+        }
+
+        public long getResult() {
+            return result;
+        }
+    }
+}

src/main/java/_12/_1/FibonacciParallel.java

@@ -0,0 +1,50 @@
+package _12._1;
+
+import provided._12._1.Fibonacci;
+
+public class FibonacciParallel extends Fibonacci {
+
+    @Override
+    public long calculate(int n) {
+        if (n == 0) {
+            return 0;
+        } else if (n == 1) {
+            return 1;
+        } else {
+            FibonacciThread thread1 = new FibonacciThread(n-1);
+            FibonacciThread thread2 = new FibonacciThread(n-2);
+            thread1.start();
+            thread2.start();
+
+            try {
+                thread1.join();
+                thread2.join();
+
+            } catch (InterruptedException e) {
+                e.printStackTrace();
+            }
+            return thread1.getResult() + thread2.getResult();
+        }
+    }
+
+
+    class FibonacciThread extends Thread {
+        private int n;
+        private long result;
+
+        public FibonacciThread(int n) {
+            this.n = n;
+        }
+
+        @Override
+        public void run() {
+            result = calculate(n);
+        }
+
+        public long getResult() {
+            return result;
+        }
+    }
+}
+
+

src/main/java/_12/_1/FibonacciRecursive.java

@@ -0,0 +1,17 @@
+package _12._1;
+
+import provided._12._1.Fibonacci;
+
+public class FibonacciRecursive extends Fibonacci {
+
+    @Override
+    public long calculate(int n) {
+        if (n == 0) {
+            return 0;
+        } else if (n == 1) {
+            return 1;
+        } else {
+            return calculate(n-1) + calculate(n-2);
+        }
+    }
+}

src/main/java/_12/_1/lukas/FibonacciDoubling.java

@@ -0,0 +1,33 @@
+package _12._1.lukas;
+
+import provided._12._1.Fibonacci;
+
+/*
+ * F(2n) = F(n) * (2*F(n+1) - F(n)).
+ * F(2n+1) = F(n+1)^2 + F(n)^2.
+ *
+ * O(log(n))
+ */
+public class FibonacciDoubling extends Fibonacci {
+	@Override
+	public long calculate(int n) {
+		if(n < 0) {
+			throw new IllegalArgumentException("n must not be negative. Negafibonacci numbers are not supported.");
+		}
+		long a = 0L;
+		long b = 1L;
+		for(int bit = Integer.highestOneBit(n); bit != 0; bit >>>= 1) {
+			long aTemp = a * ((2 * b) - a);
+			long bTemp = a * a + b * b;
+			a = aTemp;
+			b = bTemp;
+
+			if((n & bit) != 0) {
+				long c = a + b;
+				a = b;
+				b = c;
+			}
+		}
+		return a;
+	}
+}

src/main/java/_12/_1/lukas/FibonacciDynamicIterative.java

@@ -0,0 +1,20 @@
+package _12._1.lukas;
+
+import provided._12._1.Fibonacci;
+
+// iterative, dynamic programing with minimal memory usage
+public class FibonacciDynamicIterative extends Fibonacci {
+	@Override
+	public long calculate(int n) {
+		if(n < 0) {
+			throw new IllegalArgumentException("n must not be negative. Negafibonacci numbers are not supported.");
+		}
+		long a = 0L, b = 1L, c;
+		for(int i = 0; i < n; i++) {
+			c = a + b;
+			a = b;
+			b = c;
+		}
+		return a;
+	}
+}

src/main/java/_12/_1/lukas/FibonacciDynamicRecursivePersistent.java

@@ -0,0 +1,31 @@
+package _12._1.lukas;
+
+import provided._12._1.Fibonacci;
+
+import java.util.HashMap;
+import java.util.Map;
+
+// uses recursion and dynamic programing with persistent memory
+public class FibonacciDynamicRecursivePersistent extends Fibonacci {
+	private final Map<Integer, Long> memory = new HashMap<>();
+
+	{
+		this.memory.put(0, 0L);
+		this.memory.put(1, 1L);
+	}
+
+
+	@Override
+	public long calculate(int n) {
+		if(n < 0) {
+			throw new IllegalArgumentException("n must not be negative. Negafibonacci numbers are not supported.");
+		}
+		if(this.memory.containsKey(n)) {
+			return this.memory.get(n);
+		}
+
+		long result = calculate(n - 1) + calculate(n - 2);
+		this.memory.put(n, result);
+		return result;
+	}
+}

src/main/java/_12/_1/lukas/FibonacciDynamicRecursivePersistentParallel.java

@@ -0,0 +1,46 @@
+package _12._1.lukas;
+
+import provided._12._1.Fibonacci;
+
+import java.util.HashMap;
+import java.util.Map;
+
+// eats up the heap
+public class FibonacciDynamicRecursivePersistentParallel extends Fibonacci {
+	private final Map<Integer, Long> memory = new HashMap<>();
+
+	{
+		this.memory.put(0, 0L);
+		this.memory.put(1, 1L);
+	}
+
+	@Override
+	public long calculate(int n) {
+		if(n < 0) {
+			throw new IllegalArgumentException("n must not be negative. Negafibonacci numbers are not supported.");
+		}
+		if(this.memory.containsKey(n)) {
+			return this.memory.get(n);
+		}
+
+		final long result;
+		{
+			final long[] parts = new long[2];
+			Thread big = new Thread(() -> parts[0] = calculate(n - 1));
+			Thread small = new Thread(() -> parts[1] = calculate(n - 2));
+			big.start();
+			small.start();
+
+			try {
+				big.join();
+				small.join();
+				result = parts[0] + parts[1];
+			} catch(InterruptedException e) {
+				throw new IllegalStateException(e);
+			}
+		}
+
+		this.memory.put(n, result);
+		return result;
+	}
+}

src/main/java/_12/_1/lukas/FibonacciRecursive.java

@@ -0,0 +1,16 @@
+package _12._1.lukas;
+
+import provided._12._1.Fibonacci;
+
+public class FibonacciRecursive extends Fibonacci {
+	@Override
+	public long calculate(int n) {
+		if(n < 0) {
+			throw new IllegalArgumentException("n must not be negative. Negafibonacci numbers are not supported.");
+		}
+		if(n == 0 || n == 1) {
+			return n;
+		}
+		return calculate(n - 1) + calculate(n - 2);
+	}
+}

src/main/java/_12/_1/lukas/FibonacciRecursiveParallel.java

@@ -0,0 +1,30 @@
+package _12._1.lukas;
+
+import provided._12._1.Fibonacci;
+
+// rest in peace ram
+public class FibonacciRecursiveParallel extends Fibonacci {
+	@Override
+	public long calculate(int n) {
+		if(n < 0) {
+			throw new IllegalArgumentException("n must not be negative. Negafibonacci numbers are not supported.");
+		}
+		if(n == 0 || n == 1) {
+			return n;
+		}
+
+		final long[] parts = new long[2];
+		Thread big = new Thread(() -> parts[0] = calculate(n - 1));
+		Thread small = new Thread(() -> parts[1] = calculate(n - 2));
+		big.start();
+		small.start();
+
+		try {
+			big.join();
+			small.join();
+			return parts[0] + parts[1];
+		} catch(InterruptedException e) {
+			throw new IllegalStateException(e);
+		}
+	}
+}

src/main/java/_12/_1/lukas/FibonacciTiming.java

@@ -0,0 +1,70 @@
+package _12._1.lukas;
+
+import provided._12._1.Fibonacci;
+
+public class FibonacciTiming {
+	private static final int[] NUMBERS = new int[]{ 3, 5, 8, 12, 9, 18, 15, 10, 7, 11, 20 };
+
+	private static final Fibonacci RECURSIVE = new FibonacciRecursive();
+	private static final Fibonacci PARALLEL_RECURSIVE = new FibonacciRecursiveParallel();
+	private static final Fibonacci DYNAMIC = new FibonacciDynamicRecursivePersistent();
+	private static final Fibonacci PARALLEL_DYNAMIC = new FibonacciDynamicRecursivePersistentParallel();
+	private static final Fibonacci ITERATIVE = new FibonacciDynamicIterative();
+
+	// can take a few minutes
+	public static void main(String[] args) {
+		System.out.println("# Sequential");
+		System.out.println("FibonacciRecursive (first): " + formatTime(
+				Timing.measureNanos(() -> generateHeat(RECURSIVE))
+		));
+		System.out.println("FibonacciDynamicRecursivePersistent (first): " + formatTime(
+				Timing.measureNanos(() -> generateHeat(DYNAMIC))
+		));
+		System.out.println("FibonacciDynamicIterative (first): " + formatTime(
+				Timing.measureNanos(() -> generateHeat(ITERATIVE))
+		));
+
+		System.out.println("FibonacciRecursive (1M iteration average): " + formatTime(
+				Timing.measureAverageNanos(1_000_000, () -> generateHeat(RECURSIVE))
+		));
+		System.out.println("FibonacciDynamicRecursivePersistent (1M iteration average): " + formatTime(
+				Timing.measureAverageNanos(1_000_000, () -> generateHeat(DYNAMIC))
+		));
+		System.out.println("FibonacciDynamicIterative (1M iteration average): " + formatTime(
+				Timing.measureAverageNanos(1_000_000, () -> generateHeat(ITERATIVE))
+		));
+
+		System.out.println("# Parallel");
+		System.out.println("FibonacciRecursiveParallel (first): " + formatTime(
+				Timing.measureNanos(() -> generateHeat(PARALLEL_RECURSIVE))
+		));
+		System.out.println("FibonacciDynamicRecursivePersistentParallel (first): " + formatTime(
+				Timing.measureNanos(() -> generateHeat(PARALLEL_DYNAMIC))
+		));
+		System.out.println("FibonacciRecursiveParallel (10 iteration average): " + formatTime(
+				Timing.measureAverageNanos(10, () -> generateHeat(PARALLEL_RECURSIVE))
+		));
+		System.out.println("FibonacciDynamicRecursivePersistentParallel (1M iteration average): " + formatTime(
+				Timing.measureAverageNanos(1_000_000, () -> generateHeat(PARALLEL_DYNAMIC))
+		));
+	}
+
+	private static void generateHeat(Fibonacci calculator) {
+		for(int n : NUMBERS) {
+			calculator.calculate(n);
+		}
+	}
+
+	private static String formatTime(double nanos) {
+		double digits = Math.log10(nanos);
+		if(digits > 9) {
+			return Math.round(nanos / 1e7) / 1e2 + " seconds";
+		} else if(digits > 6) {
+			return Math.round(nanos / 1e4) / 1e2 + " milliseconds";
+		} else if(digits > 3) {
+			return Math.round(nanos / 1e1) / 1e2 + " microseconds";
+		} else {
+			return Math.round(nanos) + " nanoseconds";
+		}
+	}
+}

src/main/java/_12/_1/lukas/Timing.java

@@ -0,0 +1,18 @@
+package _12._1.lukas;
+
+public class Timing {
+
+	public static long measureNanos(Runnable runnable) {
+		long start = System.nanoTime();
+		runnable.run();
+		return System.nanoTime() - start;
+	}
+
+	public static double measureAverageNanos(int iterations, Runnable runnable) {
+		long start = System.nanoTime();
+		for(int i = 0; i < iterations; i++) {
+			runnable.run();
+		}
+		return (System.nanoTime() - start) / (double) iterations;
+	}
+}

src/main/java/_8/Lecture.java

@@ -184,6 +184,18 @@ public class Lecture {
         Files.write(file, lines);
     }
 
+		/*
+		 * Bitte um Feedback, untere lösung (loadText2)
+		 * macht weniger Annahmen.
+		 *
+		 * Zeilenumbrüche zwischen name-value Paaren.
+		 * Whitespace weglassen macht probleme. Ist kompatibel mit
+		 * dem outout von saveText.
+		 * Nur eine Lecture pro Datei.
+		 *
+		 *
+		 *
+		 */
     public static Lecture loadText(String filename) throws IOException {
         Path file = Paths.get(filename);
         List<String> data = Files.readAllLines(file);

src/main/java/_8/io/SonReader.java

@@ -56,6 +56,7 @@ public class SonReader implements Closeable {
 		}
 	}
 
+	/* true untill the current inner most array or object is out of elements */
 	public boolean hasNext() throws IOException {
 		int c = this.nextNonWhitespace();
 		this.rememberChar(c);
@@ -93,6 +94,7 @@ public class SonReader implements Closeable {
 		return name.toString().trim();
 	}
 
+	/* put the reder in a state where it can accept a name */
 	private void prepareName() throws IOException {
 		SonState state = this.peekState();
 		if(state == NONEMPTY_OBJECT) { // not first in an object
@@ -104,6 +106,8 @@ public class SonReader implements Closeable {
 		this.replaceTopState(DANGLING_NAME);
 	}
 
+	/* put the reder in a state where it can accept a value
+	 */
 	private void prepareValue() throws IOException {
 		SonState state = this.peekState();
 		switch(state) {
@@ -136,6 +140,8 @@ public class SonReader implements Closeable {
 		return value.toString().trim();
 	}
 
+	/* should recursively skip a value */
+	//TODO funktioniert nicht so wie es soll
 	public void skipValue() throws IOException {
 		this.prepareValue();
 		int count = 0;

src/main/java/_9/_3/Observable.java

@@ -1,17 +1,19 @@
-package _9._3.observer;
+package _9._3;
+
+import provided._9.Observer;
 
 import java.util.ArrayList;
 import java.util.List;
 
-public abstract class Observable<Who extends Observable<Who, What>, What> {
+public abstract class Observable {
-    private List<Observer<Who, What>> observers = new ArrayList<>();
+    private List<Observer> observers = new ArrayList<>();
     private boolean changed = false;
 
-    public void addObserver(Observer<Who, What> o) {
+    public void addObserver(Observer o) {
         this.observers.add(o);
     }
 
-    public void removeObserver(Observer<Who, What> o) {
+    public void removeObserver(Observer o) {
         this.observers.remove(o);
     }
 
@@ -27,10 +29,10 @@ public abstract class Observable<Who extends Observable<Who, What>, What> {
         return changed;
     }
 
-    public void notifyObservers(What what) {
+    public void notifyObservers(ShipEvent what) {
         if (this.isChanged()) {
-            for (Observer<Who, What> observer : observers) {
+            for (Observer observer : observers) {
-                observer.update((Who) this, what);
+                observer.update(this, what);
             }
             this.clearChanged();
         }

src/main/java/_9/_3/Ship.java

@@ -1,8 +1,6 @@
 package _9._3;
 
-import _9._3.observer.Observable;
+public class Ship extends Observable {
-
-public class Ship extends Observable<Ship, ShipEvent> {
     private boolean sailsSet = false;
     private boolean cannonsLoaded = false;
     private int heading = 0;
@@ -15,10 +13,6 @@ public class Ship extends Observable<Ship, ShipEvent> {
         }
     }
 
-    public boolean isSailsSet() {
-        return this.sailsSet;
-    }
-
     public void strikeSails() {
         if (sailsSet) {
             sailsSet = false;
@@ -43,12 +37,12 @@ public class Ship extends Observable<Ship, ShipEvent> {
         }
     }
 
-    public boolean isCannonsLoaded() {
-        return this.cannonsLoaded;
-    }
-
     public void turnLeft() {
-        heading = (heading - 90) % 180;
+        if (heading - 90 < 0) {
+            heading = 360 + ((heading - 90) % 360);
+        } else {
+            heading = (heading - 90) % 360;
+        }
         this.setChanged();
         notifyObservers(ShipEvent.TURN_LEFT);
     }
@@ -58,8 +52,4 @@ public class Ship extends Observable<Ship, ShipEvent> {
         this.setChanged();
         notifyObservers(ShipEvent.TURN_RIGHT);
     }
-
-    public int getHeading() {
-        return this.heading;
-    }
 }

src/main/java/_9/_3/ShipEvent.java

@@ -1,6 +1,6 @@
 package _9._3;
 
-import java.util.concurrent.ThreadLocalRandom;
+import java.util.Random;
 
 public enum ShipEvent {
 	
@@ -13,6 +13,7 @@ public enum ShipEvent {
 	TURN_RIGHT;
 
 	public static ShipEvent getRandomShipEvent() {
-		return values()[ThreadLocalRandom.current().nextInt(values().length)];
+		Random random = new Random();
+		return values()[random.nextInt(values().length)];
 	}
 }

src/main/java/_9/_3/ShipLog.java

@@ -1,10 +1,11 @@
 package _9._3;
 
-import _9._3.observer.Observer;
+import provided._9.Observer;
 
-public class ShipLog implements Observer<Ship, ShipEvent> {
+public class ShipLog implements Observer {
+    private int heading = 0;
     @Override
-    public void update(Ship who, ShipEvent what) {
+    public void update(Observable who, ShipEvent what) {
         switch (what) {
             case SET_SAILS:
                 System.out.println("Sails set.");
@@ -19,10 +20,16 @@ public class ShipLog implements Observer<Ship, ShipEvent> {
                 System.out.println("Cannons fired.");
                 break;
             case TURN_LEFT:
-                System.out.println("Turned left. New heading " + who.getHeading() + " degrees.");
+                if (heading - 90 < 0) {
+                    heading = 360 + ((heading - 90) % 360);
+                } else {
+                    heading = (heading - 90) % 360;
+                }
+                System.out.println("Turned left. New heading " + heading + " degrees.");
                 break;
             case TURN_RIGHT:
-                System.out.println("Turned right. New heading " + who.getHeading() + " degrees.");
+                heading = (heading + 90) % 360;
+                System.out.println("Turned right. New heading " + heading + " degrees.");
                 break;
         }
     }

src/main/java/_9/_3/observer/Observer.java

@@ -1,5 +0,0 @@
-package _9._3.observer;
-
-public interface Observer<Who extends Observable<Who, What>, What> {
-	void update(Who who, What what);
-}

src/main/java/provided/_10/_2/QuickSort.java

@@ -0,0 +1,80 @@
+package provided._10._2;
+
+public class QuickSort {
+
+	/**
+	 * sortiert das uebergebene Array in aufsteigender Reihenfolge
+	 * gemaess dem QuickSort-Algorithmus
+	 */
+	public static void sort(int[] numbers) {
+		new QuickSort().quickSort(numbers, 0, numbers.length - 1);
+	}
+
+	/**
+	 * der Quicksort-Algorithmus wird auf dem Array zwischen den
+	 * angegebenen Indizes ausgefuehrt
+	 */
+	protected void quickSort(int[] numbers, int leftIndex, int rightIndex) {
+		if (leftIndex < rightIndex) {
+			int pivotIndex = divide(numbers, leftIndex, rightIndex);
+			quickSort(numbers, leftIndex, pivotIndex - 1);
+			quickSort(numbers, pivotIndex + 1, rightIndex);
+		}
+	}
+
+	/**
+	 * liefert den Index des Pivot-Elementes und ordnet das Array innerhalb
+	 * der angegebenen Indizes so um, dass alle Zahlen links vom Index
+	 * kleiner oder gleich und alle Zahlen rechts vom Index groesser
+	 * oder gleich dem Pivot-Element sind
+	 */
+	protected int divide(int[] numbers, int leftIndex, int rightIndex) {
+		int pivotIndex = choosePivotIndex(numbers, leftIndex, rightIndex);
+		int pivotValue = numbers[pivotIndex];
+		// das Pivot-Element kommt nach ganz rechts im Array
+		swap(numbers, pivotIndex, rightIndex);
+		int left = leftIndex - 1;
+		int right = rightIndex;
+		// ordne das Array so um, dass jeweils alle Elemente links vom
+		// Zeiger left kleiner und alle Elemente rechts vom Zeiger right
+		// groesser als das Pivot-Element sind
+		do {
+			left++;
+			while (left <= rightIndex && numbers[left] <= pivotValue)
+				left++;
+			right--;
+			while (right >= leftIndex && numbers[right] >= pivotValue)
+				right--;
+			if (left < right) {
+				swap(numbers, left, right);
+			}
+		} while (left < right);
+		// platziere das Pivot-Element an seine korrekte Position
+		if (left < rightIndex) {
+			swap(numbers, left, rightIndex);
+			return left;
+		} else {
+			return rightIndex;
+		}
+	}
+
+	/**
+	 * waehlt einen beliebigen Index zwischen den angegebenen Indizes
+	 */
+	protected int choosePivotIndex(int[] numbers, int leftIndex, int rightIndex) {
+		// in diesem Fall einfach der mittleren Index
+		return (leftIndex + rightIndex) / 2;
+	}
+
+	/**
+	 * tauscht die Elemente des Arrays an den angegebenen Indizes
+	 */
+	protected void swap(int[] numbers, int index1, int index2) {
+		if (index1 != index2) {
+			int tmp = numbers[index1];
+			numbers[index1] = numbers[index2];
+			numbers[index2] = tmp;
+		}
+	}
+	
+}

src/main/java/provided/_10/_2/QuickSortTest.java

@@ -0,0 +1,26 @@
+package provided._10._2;
+
+import _10._2.QuickSortThreaded;
+
+public class QuickSortTest {
+
+	public static void main(String[] args) {
+		int[] numbers = {2, 3, 9, 33, -2, 4, 55, 66, -234};
+		print(numbers);
+		QuickSort.sort(numbers);
+		print(numbers);
+		
+		int[] numbers2 = {2, 3, 9, 33, -2, 4, 55, 66, -234};
+		print(numbers2);
+		QuickSortThreaded.sort(numbers2);
+		print(numbers2);
+	}
+	
+	private static void print(int[] numbers) {
+		for (int number : numbers) {
+			System.out.print(number + " ");
+		}
+		System.out.println();
+	}
+
+}

src/main/java/provided/_10/_3/ImageFilter.java

@@ -0,0 +1,113 @@
+package provided._10._3;
+
+import javax.imageio.ImageIO;
+import java.awt.*;
+import java.awt.image.BufferedImage;
+import java.io.File;
+import java.io.IOException;
+
+public class ImageFilter {
+	
+	private static final int FILTER_SIZE = 3;
+	private static final int OFFSET = FILTER_SIZE / 2;
+
+	public static final float[][] FILTER_BLUR = new float[][] {
+		{ 0.111f, 0.111f, 0.111f },
+		{ 0.111f, 0.111f, 0.111f },
+		{ 0.111f, 0.111f, 0.111f }
+	};
+	public static final float[][] FILTER_SHARPEN = new float[][] {
+		{ 0.f, -1f, 0.f },
+		{ -1f, 5f, -1f },
+		{ 0.f, -1f, 0.f }
+	};
+	public static final float[][] FILTER_LINES = new float[][] {
+		{ -1f, -1f, -1f },
+		{ -1f, 8f, -1f },
+		{ -1f, -1f, -1f }
+	};
+	
+	protected Color[][] matrix = new Color[0][0];
+	
+	public void setImage(File input) throws IOException {
+		BufferedImage img = ImageIO.read(input);
+		getMatrix(img);
+	}
+	
+	public void applyFilter(float[][] filter, File output) throws IOException, InvalidFilterException {
+		if (filter == null || filter.length != FILTER_SIZE || filter[0].length != FILTER_SIZE) {
+			throw new InvalidFilterException();
+		}
+		Color[][] result = filterMatrix(filter);
+		BufferedImage img = new BufferedImage(result.length, result[0].length, BufferedImage.TYPE_INT_ARGB);
+		setMatrix(img, result);
+		ImageIO.write(img, "jpg", output);
+	}
+
+	protected Color[][] filterMatrix(float[][] filter) {
+		Color[][] result = new Color[matrix.length][matrix[0].length];
+		for (int x = 0; x < matrix.length; x++) {
+			for (int y = 0; y < matrix[x].length; y++) {
+				filterPixel(result, x, y, filter);
+			}
+		}
+		return result;
+	}
+
+	protected void filterPixel(Color[][] result, int x, int y, float[][] filter) {
+		Color[][] colors = getColorMatrix(x, y);
+		float red = 0;
+		float green = 0;
+		float blue = 0;
+		for (int i = 0; i < FILTER_SIZE; i++) {
+			for (int j = 0; j < FILTER_SIZE; j++) {
+				red += (float) colors[i][j].getRed() * filter[i][j];
+				green += (float) colors[i][j].getGreen() * filter[i][j];
+				blue += (float) colors[i][j].getBlue() * filter[i][j];
+			}
+		}
+		red = Math.min(red, 255);
+		red = Math.max(red, 0);
+		green = Math.min(green, 255);
+		green = Math.max(green, 0);
+		blue = Math.min(blue, 255);
+		blue = Math.max(blue, 0);
+		result[x][y] = new Color(Math.round(red), Math.round(green), Math.round(blue));
+	}
+
+	protected Color[][] getColorMatrix(int x, int y) {
+		Color[][] result = new Color[FILTER_SIZE][FILTER_SIZE];
+		for (int i = 0; i < FILTER_SIZE; i++) {
+			for (int j = 0; j < FILTER_SIZE; j++) {
+				result[i][j] = getColor(x + (i - OFFSET), y + (j - OFFSET));
+			}
+		}
+		return result;
+	}
+
+	protected Color getColor(int x, int y) {
+		x = Math.min(x, matrix.length - 1);
+		x = Math.max(x, 0);
+		y = Math.min(y, matrix[0].length - 1);
+		y = Math.max(y, 0);
+		return matrix[x][y];
+	}
+
+	private void setMatrix(BufferedImage img, Color[][] matrix) {
+		for (int x=0;x<matrix.length;x++) {
+			for (int y=0;y<matrix[x].length;y++) {
+				img.setRGB(x, y, matrix[x][y].getRGB());
+			}
+		}
+	}
+
+	private void getMatrix(BufferedImage img) {
+		matrix = new Color[img.getWidth()][img.getHeight()];
+		for (int x=0;x<img.getWidth();x++) {
+			for (int y=0;y<img.getHeight();y++) {
+				matrix[x][y] = new Color(img.getRGB(x, y));
+			}
+		}
+	}
+
+}

src/main/java/provided/_10/_3/ImageFilterTest.java

@@ -0,0 +1,51 @@
+package provided._10._3;
+
+import _10._3.ImageFilterThreaded;
+
+import java.io.File;
+import java.io.IOException;
+
+public class ImageFilterTest {
+	
+	private static final int REPETITIONS = 5;
+
+	public static void main(String[] args) {
+		ImageFilter filterSequential = new ImageFilter();
+		ImageFilter filterThreaded = new ImageFilterThreaded();
+		try {
+			filterSequential.setImage(new File("./university_of_oldenburg.jpg"));
+			filterThreaded.setImage(new File("./university_of_oldenburg.jpg"));
+		} catch (IOException e) {
+			e.printStackTrace();
+			return;
+		}
+		long start;
+		long stop;
+		long time;
+		start = System.nanoTime();
+		for (int i = 0; i < REPETITIONS; i++) {
+			runFilters(filterSequential);
+		}
+		stop = System.nanoTime();
+		time = (stop - start) / 1000000L;
+		System.out.println("Sequential runtime: " + time + " ms");
+		start = System.nanoTime();
+		for (int i = 0; i < REPETITIONS; i++) {
+			runFilters(filterThreaded);
+		}
+		stop = System.nanoTime();
+		time = (stop - start) / 1000000L;
+		System.out.println("Threaded runtime: " + time + " ms");
+	}
+	
+	private static void runFilters(ImageFilter filter) {
+		try {
+			filter.applyFilter(ImageFilter.FILTER_BLUR, new File("./university_of_oldenburg_blur.jpg"));
+			filter.applyFilter(ImageFilter.FILTER_SHARPEN, new File("./university_of_oldenburg_sharpen.jpg"));
+			filter.applyFilter(ImageFilter.FILTER_LINES, new File("./university_of_oldenburg_lines.jpg"));
+		} catch (IOException | InvalidFilterException e) {
+			e.printStackTrace();
+		}
+	}
+
+}

src/main/java/provided/_10/_3/InvalidFilterException.java

@@ -0,0 +1,7 @@
+package provided._10._3;
+
+public class InvalidFilterException extends Exception {
+
+	private static final long serialVersionUID = 1L;
+
+}

src/main/java/provided/_11/_3/Item.java

@@ -0,0 +1,76 @@
+package provided._11._3;
+
+public class Item {
+	
+	private String name;
+	private int value;
+	private int weight;
+	
+	public Item(String name, int value, int weight) {
+		super();
+		this.name = name;
+		this.value = value;
+		this.weight = weight;
+	}
+	
+	public String getName() {
+		return name;
+	}
+	
+	public void setName(String name) {
+		this.name = name;
+	}
+	
+	public int getValue() {
+		return value;
+	}
+	
+	public void setValue(int value) {
+		this.value = value;
+	}
+	
+	public int getWeight() {
+		return weight;
+	}
+	
+	public void setWeight(int weight) {
+		this.weight = weight;
+	}
+
+	@Override
+	public String toString() {
+		return name;
+	}
+
+	@Override
+	public int hashCode() {
+		final int prime = 31;
+		int result = 1;
+		result = prime * result + ((name == null) ? 0 : name.hashCode());
+		result = prime * result + value;
+		result = prime * result + weight;
+		return result;
+	}
+
+	@Override
+	public boolean equals(Object obj) {
+		if (this == obj)
+			return true;
+		if (obj == null)
+			return false;
+		if (getClass() != obj.getClass())
+			return false;
+		Item other = (Item) obj;
+		if (name == null) {
+			if (other.name != null)
+				return false;
+		} else if (!name.equals(other.name))
+			return false;
+		if (value != other.value)
+			return false;
+		if (weight != other.weight)
+			return false;
+		return true;
+	}
+
+}

src/main/java/provided/_11/_3/Knapsack.java

@@ -0,0 +1,67 @@
+package provided._11._3;
+
+import _11._3.KnapsackDynamic;
+import _11._3.KnapsackGreedy;
+import _11._3.KnapsackRecursive;
+
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.List;
+
+public abstract class Knapsack {
+	
+	protected List<Item> candidates = new ArrayList<>();
+	protected int capacity;
+
+	public Knapsack(int capacity, Collection<Item> candidates) {
+		super();
+		this.capacity = capacity;
+		this.candidates.addAll(candidates);
+	}
+
+	public int getCapacity() {
+		return capacity;
+	}
+
+	public void setCapacity(int capacity) {
+		this.capacity = capacity;
+	}
+
+	public List<Item> getCandidates() {
+		return candidates;
+	}
+	
+	public abstract Selection pack();
+	
+	private static final int REPETITIONS = 5;
+	private static final int CAPACITY = 49;
+
+	public static void main(String[] args) {
+		List<Item> items = new ArrayList<>();
+		items.add(new Item("Banknote", 100, 1));
+		items.add(new Item("Goldbar", 1000, 30));
+		items.add(new Item("Diamond", 750, 5));
+		test("Recursive", new KnapsackRecursive(CAPACITY, items));
+		test("Greedy", new KnapsackGreedy(CAPACITY, items));
+		test("Dynamic Programming", new KnapsackDynamic(CAPACITY, items));
+	}
+	
+	private static void test(String title, Knapsack knapsack) {
+		System.out.print(title);
+		Selection result = null;
+		long totalNs = 0;
+		for (int i = 0; i < REPETITIONS; i++) {
+			long start = System.nanoTime();
+			result = knapsack.pack();
+			long stop = System.nanoTime();
+			totalNs += stop - start;
+			System.out.print(".");
+		}
+		System.out.println("\n\t" + result);
+		totalNs /= REPETITIONS;
+		long totalMs = totalNs / 1000000L;
+		System.out.println("\tTime required: " + totalNs + " ns (~ " + totalMs + " ms)");
+		System.out.println();
+	}
+
+}

src/main/java/provided/_11/_3/Selection.java

@@ -0,0 +1,114 @@
+package provided._11._3;
+
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+public class Selection {
+	
+	private Map<Item, Integer> items = new HashMap<>();
+	private int value;
+	private int weight;
+	
+	public Selection() {
+		super();
+	}
+	
+	public Selection(Selection previous) {
+		super();
+		items.putAll(previous.items);
+		value = previous.value;
+		weight = previous.weight;
+	}
+	
+	public Selection(Selection previous, Item item) {
+		super();
+		items.putAll(previous.items);
+		value = previous.value;
+		weight = previous.weight;
+		add(item);
+	}
+	
+	private void add(Item item) {
+		items.put(item, getCount(item) + 1);
+		value += item.getValue();
+		weight += item.getWeight();
+	}
+	
+	public int getCount(Item item) {
+		Integer result = items.get(item);
+		if (result == null) {
+			result = 0;
+		}
+		return result;
+	}
+	
+	public Collection<Item> getItems() {
+		return items.keySet();
+	}
+	
+	public int getValue() {
+		return value;
+	}
+	
+	public void setValue(int value) {
+		this.value = value;
+	}
+	
+	public int getWeight() {
+		return weight;
+	}
+	
+	public void setWeight(int weight) {
+		this.weight = weight;
+	}
+
+	@Override
+	public String toString() {
+		StringBuilder b = new StringBuilder();
+		b.append("Value: ");
+		b.append(value);
+		b.append(", weight: ");
+		b.append(weight);
+		b.append(", items: ");
+		List<Item> list = new ArrayList<>(items.keySet());
+		list.sort((i1, i2) -> i1.getName().compareTo(i2.getName()));
+		for (int i = 0; i < list.size(); i++) {
+			b.append(items.get(list.get(i)));
+			b.append("x ");
+			b.append(list.get(i).getName());
+			if (i < list.size() - 1) {
+				b.append(", ");
+			}
+		}
+		return b.toString();
+	}
+
+	@Override
+	public int hashCode() {
+		final int prime = 31;
+		int result = 1;
+		result = prime * result + ((items == null) ? 0 : items.hashCode());
+		return result;
+	}
+
+	@Override
+	public boolean equals(Object obj) {
+		if (this == obj)
+			return true;
+		if (obj == null)
+			return false;
+		if (getClass() != obj.getClass())
+			return false;
+		Selection other = (Selection) obj;
+		if (items == null) {
+			if (other.items != null)
+				return false;
+		} else if (!items.equals(other.items))
+			return false;
+		return true;
+	}
+	
+}

src/main/java/provided/_12/_1/Fibonacci.java

@@ -0,0 +1,7 @@
+package provided._12._1;
+
+public abstract class Fibonacci {
+	
+	public abstract long calculate(int n);
+	
+}

src/main/java/provided/_9/Observer.java

@@ -0,0 +1,10 @@
+package provided._9;
+
+import _9._3.Observable;
+import _9._3.ShipEvent;
+
+public interface Observer {
+	
+	void update(Observable who, ShipEvent what);
+
+}

src/test/java/_12/_1/FibonacciTest.java

@@ -0,0 +1,81 @@
+package _12._1;
+
+import org.junit.jupiter.api.Test;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+
+class FibonacciTest {
+
+	private static final int[] NUMBERS = new int[] { 3, 5, 8, 12, 9, 18, 15, 10, 7, 11, 20 };
+	
+	@Test
+	void test() {
+
+		int count = 0;
+		long start;
+		long stop;
+		long time;
+		start = System.nanoTime();
+		FibonacciRecursive r = new FibonacciRecursive();
+		long[] rResult = new long[NUMBERS.length];
+		for (int i : NUMBERS) {
+			rResult[count] = r.calculate(i);
+			count++;
+		}
+		stop = System.nanoTime();
+		time = (stop - start) / 1000000L;
+		System.out.println("Rekursiv runtime: " + time + " ms");
+
+
+
+		count = 0;
+		start = System.nanoTime();
+		FibonacciParallel p = new FibonacciParallel();
+		long[] pResult = new long[NUMBERS.length];
+		for (int i : NUMBERS) {
+			pResult[count] = p.calculate(i);
+			count++;
+		}
+		stop = System.nanoTime();
+		time = (stop - start) / 1000000L;
+		System.out.println("Parallel runtime: " + time + " ms");
+
+
+		count = 0;
+		start = System.nanoTime();
+		FibonacciDynamic d = new FibonacciDynamic();
+		long[] dResult = new long[NUMBERS.length];
+		for (int i : NUMBERS) {
+			dResult[count] = d.calculate(i);
+			count++;
+		}
+		stop = System.nanoTime();
+		time = (stop - start) / 1000000L;
+		System.out.println("Dynamic runtime: " + time + " ms");
+
+
+		count = 0;
+		start = System.nanoTime();
+		FibonacciDynamicParallel dp = new FibonacciDynamicParallel();
+		long[] dpResult = new long[NUMBERS.length];
+		for (int i : NUMBERS) {
+			dpResult[count] = dp.calculate(i);
+			count++;
+		}
+		stop = System.nanoTime();
+		time = (stop - start) / 1000000L;
+		System.out.println("Dynamic Parallel runtime: " + time + " ms");
+
+
+
+		for (int i = 0; i < NUMBERS.length; i++) {
+			assertEquals(rResult[i], pResult[i]);
+			assertEquals(rResult[i], dResult[i]);
+			assertEquals(rResult[i], dpResult[i]);
+			assertEquals(pResult[i], dResult[i]);
+			assertEquals(pResult[i], dpResult[i]);
+			assertEquals(dResult[i], dpResult[i]);
+		}
+
+	}
+}

src/test/java/_12/_1/lukas/FibonacciTest.java

@@ -0,0 +1,59 @@
+package _12._1.lukas;
+
+import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.Test;
+import provided._12._1.Fibonacci;
+
+import java.util.Map;
+
+public class FibonacciTest {
+	private static final Map<Integer, Long> NUMBERS = Map.ofEntries(
+			Map.entry(3, 2L),
+			Map.entry(5, 5L),
+			Map.entry(8, 21L),
+			Map.entry(12, 144L),
+			Map.entry(9, 34L),
+			Map.entry(18, 2584L),
+			Map.entry(15, 610L),
+			Map.entry(10, 55L),
+			Map.entry(7, 13L),
+			Map.entry(11, 89L),
+			Map.entry(20, 6765L)
+	);
+
+	@Test
+	void recursive() {
+		Fibonacci calculator = new FibonacciRecursive();
+		NUMBERS.forEach((n, fn) -> Assertions.assertEquals(fn.longValue(), calculator.calculate(n)));
+	}
+
+	@Test
+	void recursiveParallel() {
+		Fibonacci calculator = new FibonacciRecursiveParallel();
+		NUMBERS.forEach((n, fn) -> Assertions.assertEquals(fn.longValue(), calculator.calculate(n)));
+	}
+
+	@Test
+	void dynamicRecursivePersistent() {
+		Fibonacci calculator = new FibonacciDynamicRecursivePersistent();
+		NUMBERS.forEach((n, fn) -> Assertions.assertEquals(fn.longValue(), calculator.calculate(n)));
+	}
+
+	@Test
+	void dynamicRecursivePersistentParallel() {
+		Fibonacci calculator = new FibonacciDynamicRecursivePersistentParallel();
+		NUMBERS.forEach((n, fn) -> Assertions.assertEquals(fn.longValue(), calculator.calculate(n)));
+	}
+
+	@Test
+	void dynamicIterative() {
+		Fibonacci calculator = new FibonacciDynamicIterative();
+		NUMBERS.forEach((n, fn) -> Assertions.assertEquals(fn.longValue(), calculator.calculate(n)));
+	}
+
+	@Test
+	void doubling() {
+		Fibonacci calculator = new FibonacciDoubling();
+		NUMBERS.forEach((n, fn) -> Assertions.assertEquals(fn.longValue(), calculator.calculate(n)));
+	}
+}