add Exercise 1 and 2

01/Drei.java

@@ -0,0 +1,28 @@
+import java.util.ArrayList;
+import java.util.List;
+
+public class Drei {
+
+    public int getTipPercentage(List<String> names) {
+        if (names.size() <= 2) {
+            return 0;
+        } else if (names.size() <= 4) {
+            return 10;
+        } else {
+            return 20;
+        }
+    }
+
+    public static void main(String[] args) {
+        Drei tipCalculator = new Drei();
+        List<String> names = new ArrayList<>();
+        names.add("test");
+        names.add("test2");
+        names.add("test3");
+        names.add("test4");
+        names.add("test5");
+
+        System.out.println(tipCalculator.getTipPercentage(names));
+    }
+
+}

01/ShoppingCart.java

@@ -1,10 +0,0 @@
-import java.util.ArrayList;
-import java.util.List;
-
-public class ShoppingCart {
-
-    private List<String> items = new ArrayList<String>();
-    private boolean bookAdded;
-
-    public static void main(String[] args) {}
-}

01/ShoppingCartFunctional.java

@@ -0,0 +1,25 @@
+import java.util.Arrays;
+import java.util.List;
+
+public class ShoppingCartFunctional {
+
+    /**
+     * Pure function that calculates the discount percentage based on the cart content.
+     * @param cart The list of items in the shopping cart.
+     * @return 5 if a book is present, 0 otherwise.
+     */
+    public static double getDiscountPercentage(List<String> cart) {
+        return cart.stream()
+                .anyMatch(item -> item.toLowerCase().contains("book"))
+                ? 5
+                        : 0;
+    }
+
+    public static void main(String[] args) {
+        List<String> cartWithBook = Arrays.asList("Apple", "Java Book");
+        List<String> cartWithoutBook = Arrays.asList("Apple", "Orange");
+
+        System.out.println("Discount with book: " + getDiscountPercentage(cartWithBook));
+        System.out.println("Discount without book: " + getDiscountPercentage(cartWithoutBook));
+    }
+}

01/ShoppingCartImperative.java

@@ -0,0 +1,48 @@
+import java.util.ArrayList;
+import java.util.List;
+
+public class ShoppingCartImperative {
+    private List<String> items = new ArrayList<>();
+    private boolean bookAdded = false;
+
+    public void addItem(String item) {
+        items.add(item);
+        if (item.toLowerCase().contains("book")) {
+            bookAdded = true;
+        } else {
+            bookAdded = false;
+        }
+    }
+
+    public void removeItem(String item) {
+        items.remove(item);
+        for (String remainingItem : items) {
+            if (remainingItem.toLowerCase().contains("book")) {
+                bookAdded = true;
+                return;
+            } else {
+                bookAdded = false;
+            }
+        }
+    }
+
+    public List<String> getItems() {
+        return new ArrayList<>(items);
+    }
+
+    public double getDiscount() {
+        return bookAdded ? 5 : 0;
+    }
+
+    public static void main(String[] args) {
+        ShoppingCartImperative cart = new ShoppingCartImperative();
+        cart.addItem("Apple");
+        cart.addItem("Java Book");
+        System.out.println("Items: " + cart.getItems());
+        System.out.println("Discount: " + cart.getDiscount());
+
+        cart.removeItem("Java Book");
+        System.out.println("Items after removal: " + cart.getItems());
+        System.out.println("Discount after removal: " + cart.getDiscount());
+    }
+}

02/WeDontLikeCharA.swift

@@ -0,0 +1,16 @@
+struct ScoreWord {
+    let word: String
+    
+    var score: Int {
+        return word.lowercased().filter { $0 != "a" }.count
+    }
+}
+
+let inputs: [String] = ["Apple", "Banana", "Cherry", "Date"]
+
+let scoredWords = inputs.map(ScoreWord.init)
+let sortedWords = scoredWords.sorted { $0.score > $1.score }
+
+for entry in sortedWords {
+    print("\(entry.word): \(entry.score) points")
+}