Update Lab5.java

Lab4.java

@@ -0,0 +1,68 @@
+import java.util.Scanner;
+import java.util.Arrays;
+import java.util.Comparator;
+
+public class Lab4 {
+
+    public static void main(String[] args) {
+        Students student1 = new Students("Максим", 22, "ФІОТ", 91, 8);
+        Students students2 = new Students("Ольга", 19, "ФЕА", 34, 4);
+        Students students3 = new Students("Владислав", 18, "ФММ", 55, 10);
+        Students students4 = new Students("Марія", 20, "ХТФ", 11, 6);
+        Students students5 = new Students("Петро", 23, "ФМФ", 78, 2);
+        Students[] students = {student1, students2, students3, students4, students5};
+        System.out.println("Список студентів: ");
+        System.out.println(String.format("%-9s | %-3s | %-9s | %-11s | %s", "Ім'я", "Вік", "Факультет", "Номер групи", "Рівень знань(від 0 до 10)"));
+        for (Students student : students) {
+            System.out.println(String.format("%-9s | %-3s | %-9s | %-11s | %s", student.getName(), student.getAge(), student.getNameOfFaculty(), student.getNumberOfGroup(), student.getLvlOfKnowledge()));
+        }
+        Scanner scan = new Scanner(System.in);
+        System.out.println("Введіть за чим сортувати: ");
+        System.out.println("1 - Зростання \n2 - Спадання:");
+        int incOrDec = scan.nextInt();
+        System.out.println("Введіть за чим хочете сортувати: ");
+        System.out.println("1 - Ім'я \n2 - Вік \n3 - Факультет\n4 - Група\n5 - Рівень знань: ");
+        int num = scan.nextInt();
+        if (incOrDec == 1) {
+            switch (num) {
+                case 1:
+                    Arrays.sort(students, Comparator.comparing(Students::getName));
+                    break;
+                case 2:
+                    Arrays.sort(students, Comparator.comparingInt(Students::getAge));
+                    break;
+                case 3:
+                    Arrays.sort(students, Comparator.comparing(Students::getNameOfFaculty));
+                    break;
+                case 4:
+                    Arrays.sort(students, Comparator.comparingInt(Students::getNumberOfGroup));
+                    break;
+                case 5:
+                    Arrays.sort(students, Comparator.comparingInt(Students::getLvlOfKnowledge));
+                    break;
+            }
+        } else {
+            switch (num) {
+                case 1:
+                    Arrays.sort(students, Comparator.comparing(Students::getName).reversed());
+                    break;
+                case 2:
+                    Arrays.sort(students, Comparator.comparingInt(Students::getAge).reversed());
+                    break;
+                case 3:
+                    Arrays.sort(students, Comparator.comparing(Students::getNameOfFaculty).reversed());
+                    break;
+                case 4:
+                    Arrays.sort(students, Comparator.comparingInt(Students::getNumberOfGroup).reversed());
+                    break;
+                case 5:
+                    Arrays.sort(students, Comparator.comparingInt(Students::getLvlOfKnowledge).reversed());
+                    break;
+            }
+        }
+        System.out.println(String.format("%-9s | %-3s | %-9s | %-11s | %s", "Ім'я", "Вік", "Факультет", "Номер групи", "Рівень знань(від 0 до 10)"));
+        for (Students student : students) {
+            System.out.println(String.format("%-9s | %-3s | %-9s | %-11s | %s", student.getName(), student.getAge(), student.getNameOfFaculty(), student.getNumberOfGroup(), student.getLvlOfKnowledge()));
+        }
+    }
+}

Lab5

@@ -1,184 +0,0 @@
-import java.util.ArrayList;
-import java.util.List;
-import java.util.Scanner;
-
-class Letter {
-    private char value;
-
-    public Letter(char value) {
-        this.value = value;
-    }
-
-    public char getValue() {
-        return value;
-    }
-}
-
-class Word {
-    private List<Letter> letters = new ArrayList<>();
-
-    public Word(String input) {
-        for (char c : input.toCharArray()) {
-            letters.add(new Letter(c));
-        }
-    }
-
-    public List<Letter> getLetters() {
-        return letters;
-    }
-
-    public String toString() {
-        StringBuilder sb = new StringBuilder();
-        for (Letter letter : letters) {
-            sb.append(letter.getValue());
-        }
-        return sb.toString();
-    }
-}
-
-class PunctuationMark {
-    private char value;
-
-    public PunctuationMark(char value) {
-        this.value = value;
-    }
-
-    public char getValue() {
-        return value;
-    }
-}
-
-class Sentence {
-    private List<Object> elements = new ArrayList<>();
-
-    public Sentence(String input) {
-        StringBuilder sb = new StringBuilder();
-        for (char c : input.toCharArray()) {
-            if (Character.isLetterOrDigit(c)) {
-                sb.append(c);
-            } else {
-                if (sb.length() > 0) {
-                    elements.add(new Word(sb.toString()));
-                    sb.setLength(0);
-                }
-                elements.add(new PunctuationMark(c));
-            }
-        }
-        if (sb.length() > 0) {
-            elements.add(new Word(sb.toString()));
-        }
-    }
-
-    public List<Object> getElements() {
-        return elements;
-    }
-
-    public String toString() {
-        StringBuilder sb = new StringBuilder();
-        for (Object element : elements) {
-            if (element instanceof Word) {
-                sb.append(((Word) element).toString());
-            } else {
-                sb.append(((PunctuationMark) element).getValue());
-            }
-        }
-        return sb.toString();
-    }
-}
-
-class Text {
-    private List<Sentence> sentences = new ArrayList<>();
-
-    public Text(String input) {
-        StringBuilder sb = new StringBuilder();
-        for (char c : input.toCharArray()) {
-            if (c == '.' || c == '?' || c == '!' || c == ',') {
-                sb.append(c);
-                sentences.add(new Sentence(sb.toString()));
-                sb.setLength(0);
-            } else {
-                sb.append(c);
-            }
-        }
-        if (sb.length() > 0) {
-            sentences.add(new Sentence(sb.toString()));
-        }
-    }
-
-    public List<Sentence> getSentences() {
-        return sentences;
-    }
-
-    public String toString() {
-        StringBuilder sb = new StringBuilder();
-        for (Sentence sentence : sentences) {
-            sb.append(sentence.toString());
-        }
-        return sb.toString();
-    }
-}
-
-public class Lab5 {
-    public static void main(String[] args) {
-        int C17 = 2430 % 17;
-        System.out.println("\n---------------------------------------------------------------------------------------------------------------------");
-        System.out.println("  C17 = " + C17 + ", So, the task is:  delete all previous occurrences of the last letter of each word of the specified text.");
-        System.out.println("---------------------------------------------------------------------------------------------------------------------");
-
-        Scanner scanner = new Scanner(System.in);
-        boolean isDone = false;
-        while (!isDone) {
-            System.out.print("\nEnter a string or type 'q' to quit: ");
-            String input = scanner.nextLine().trim();
-            if (input.equals("q")) {
-                System.out.print("\n The work is completed.");
-                isDone = true;
-            } else if (input.isEmpty()) {
-                System.out.println("Error: Input string is empty. Please enter a non-empty string.");
-            } else {
-                try {
-                    StringBuilder sb = new StringBuilder(input);
-                    String[] words = sb.toString().split("\\s+");
-                    for (int i = 0; i < words.length; i++) {
-                        String word = words[i];
-                        char lastChar = word.charAt(word.length() - 1);
-                        if (!Character.isLetterOrDigit(lastChar)) {
-                            int lastLetterIndex = -1;
-                            for (int j = word.length() - 2; j >= 0; j--) {
-                                if (Character.isLetter(word.charAt(j))) {
-                                    lastLetterIndex = j;
-                                    break;
-                                }
-                            }
-                            if (lastLetterIndex != -1) {
-                                char lastLetter = word.charAt(lastLetterIndex);
-                                String newWord = "";
-                                for (int j = 0; j < word.length() - 1; j++) {
-                                    if (!Character.isLetterOrDigit(word.charAt(j)) || word.charAt(j) != lastLetter) {
-                                        newWord += word.charAt(j);
-                                    }
-                                }
-                                newWord += lastChar;
-                                words[i] = newWord;
-                            }
-                        } else {
-                            char lastLetter = lastChar;
-                            String newWord = "";
-                            for (int j = 0; j < word.length() - 1; j++) {
-                                if (!Character.isLetterOrDigit(word.charAt(j)) || word.charAt(j) != lastLetter) {
-                                    newWord += word.charAt(j);
-                                }
-                            }
-                            newWord += lastLetter;
-                            words[i] = newWord;
-                        }
-                    }
-                    System.out.print("\n Final string: ");
-                    System.out.println(String.join(" ", words));
-                } catch (Exception e) {
-                    System.out.println("An error occurred: " + e.getMessage());
-                }
-            }
-        }
-    }
-}

Lab5.java

@@ -0,0 +1,107 @@
+public class Lab5 {
+    public static void main(String[] args) {
+        StringBuilder txt = new StringBuilder("соціальна мережа, яка є мережею мікроблогів. Дає змогу користувачам надсилати короткі текстові повідомлення (до 2802 символів, до 2017 року — до 140 символів), використовуючи SMS,");
+        System.out.println("Початковий текст:");
+        System.out.println(txt);
+        Text text = new Text(txt);
+        StringBuilder result = text.splitText();
+        System.out.println("Змінений текст:");
+        System.out.println(result);
+    }
+}
+
+class Text {
+    private final StringBuilder textString;
+    public Text(StringBuilder textString){
+        this.textString = textString;
+    }
+
+    public StringBuilder splitText() {
+        StringBuilder result = new StringBuilder();
+        String[] sentenceStrings = textString.toString().split("(?<=[?.!])\\s?");
+        for (String s : sentenceStrings) {
+            StringBuilder sb = new StringBuilder(s);
+            Sentence sentence = new Sentence(sb);
+            result.append(sentence.splitSentence());
+        }
+        return result;
+    }
+
+}
+
+class Sentence {
+    private final StringBuilder sentence;
+
+    public Sentence(StringBuilder sentence) {
+        this.sentence = sentence;
+
+    }
+
+    public StringBuilder splitSentence() {
+        StringBuilder returnSentence = new StringBuilder();
+        String text = sentence.toString();
+        String[] words = text.split(" ");
+        for (String w : words) {
+            StringBuilder wb = new StringBuilder(w);
+            Word word = new Word(wb);
+            returnSentence.append(word.splitWord()).append(" ");
+        }
+        return returnSentence;
+
+    }
+}
+
+class Word {
+    private final StringBuilder word;
+
+    public Word(StringBuilder word) {
+        this.word = word;
+    }
+
+    public StringBuilder splitWord() {
+        StringBuilder returnWord = new StringBuilder();
+        String wordstring = word.toString();
+        String[] letters = wordstring.split("");
+        String firstLetter = wordstring.substring(0, 1);
+        returnWord.append(firstLetter);
+        for (String l: letters){
+            StringBuilder lb = new StringBuilder(l);
+            Letter letter = new Letter(lb);
+            if (firstLetter.equals(letter.getLetter().toString())){
+                returnWord.append("");
+            }else{
+                if(l.equals("!") || l.equals("?") || l.equals(".") || l.equals(",") || l.equals(":") || l.equals(";")){
+                    Punctuation punctuation = new Punctuation(lb);
+                    returnWord.append(punctuation.getPunctuation());
+                }else{
+                    returnWord.append(letter.getLetter());
+                }
+            }
+        }
+        return returnWord;
+    }
+}
+
+class Letter {
+    private final StringBuilder letter;
+
+    public Letter(StringBuilder letter) {
+        this.letter = letter;
+    }
+
+    public StringBuilder getLetter() {
+        return letter;
+    }
+}
+
+class Punctuation {
+    private final StringBuilder punctuation;
+
+    public Punctuation(StringBuilder punctuation) {
+        this.punctuation = punctuation;
+    }
+
+    public StringBuilder getPunctuation() {
+        return punctuation;
+    }
+}

Lab6

@@ -1,225 +0,0 @@
-import java.util.ArrayList;
-import java.util.List;
-import java.util.Scanner;
-import java.util.Comparator;
-
-class ToyRoom {
-
-    public static void variant() {
-        int C13 = 2430 % 13;
-        System.out.println("\n            ---------------------------------------------------------------------------------------------------------------------");
-        System.out.println("                          C13 = " + C13 + ", So, the task is:  Prepare the toy room for children of different age groups.");
-        System.out.println("            ---------------------------------------------------------------------------------------------------------------------");
-    }
-
-    private List<Toy> toys;
-
-    public ToyRoom() {
-        this.toys = new ArrayList<>();
-    }
-
-    public void addToy(Toy toy) {
-        toys.add(toy);
-    }
-
-    public void displayToys() {
-        System.out.println(" -------------------------------------------------------");
-        System.out.printf(" | %-20s | %-10s | %-15s |\n", "Name", "Price ($)", "Age Group");
-        System.out.println(" |----------------------|------------|-----------------|");
-        for (Toy toy : toys) {
-            System.out.printf(" | %-20s | %-10.2f | %-15s |\n", toy.name, toy.price, toy.ageGroup);
-        }
-        System.out.println(" -------------------------------------------------------");
-    }
-
-    public void sortToys(boolean ascending) {
-        if (ascending) {
-            toys.sort(Comparator.comparingDouble(Toy::getPrice));
-        } else {
-            toys.sort(Comparator.comparingDouble(Toy::getPrice).reversed());
-        }
-    }
-
-    public List<Toy> findToysByPriceRange(double minPrice, double maxPrice) {
-        List<Toy> foundToys = new ArrayList<>();
-        for (Toy toy : toys) {
-            if (toy.getPrice() >= minPrice && toy.getPrice() <= maxPrice) {
-                foundToys.add(toy);
-            }
-        }
-        return foundToys;
-    }
-
-    public void findToysByName(String name) {
-        List<Toy> foundToys = new ArrayList<>();
-        for (Toy toy : toys) {
-            if (toy.name.toLowerCase().contains(name.toLowerCase())) {
-                foundToys.add(toy);
-            }
-        }
-
-        if (!foundToys.isEmpty()) {
-            System.out.println("\n Toys with matching name \"" + name + "\":");
-            System.out.println(" -------------------------------------------------------");
-            System.out.printf(" | %-20s | %-10s | %-15s |\n", "Name", "Price ($)", "Age Group");
-            System.out.println(" |----------------------|------------|-----------------|");
-            for (Toy toy : foundToys) {
-                System.out.printf(" | %-20s | %-10.2f | %-15s |\n", toy.name, toy.price, toy.ageGroup);
-            }
-            System.out.println(" -------------------------------------------------------");
-        } else {
-            System.out.println(" No toys found with a matching name.");
-        }
-    }
-}
-
-
-abstract class Toy {
-    protected String name;
-    protected double price;
-    protected String ageGroup;
-
-    public Toy(String name, double price, String ageGroup) {
-        this.name = name;
-        this.price = price;
-        this.ageGroup = ageGroup;
-
-    }
-
-    public double getPrice() {
-        return price;
-    }
-
-    @Override
-    public String toString() {
-        return name + " - $" + price + ageGroup;
-    }
-}
-
-class Car extends Toy {
-    public Car(String name, double price, String ageGroup) {
-        super(name, price, ageGroup);
-    }
-}
-
-class Doll extends Toy {
-    public Doll(String name, double price, String ageGroup) {
-        super(name, price, ageGroup);
-    }
-}
-
-class Ball extends Toy {
-    public Ball(String name, double price, String ageGroup) {
-        super(name, price, ageGroup);
-    }
-}
-
-class Cube extends Toy {
-    public Cube(String name, double price, String ageGroup) {
-        super(name, price, ageGroup);
-    }
-}
-
-public class Lab6 {
-    public static void main(String[] args) {
-        ToyRoom toyRoom = new ToyRoom();
-        ToyRoom.variant();
-
-        toyRoom.addToy(new Car("Small car 'Mcqueen'", 10.0, "1-3 years"));
-        toyRoom.addToy(new Car("Small Car 'Audi'", 12.0, "1-3 years"));
-        toyRoom.addToy(new Car("Medium Yellow Car", 15.0, "3-6 years"));
-        toyRoom.addToy(new Car("Medium Blue Car", 18.0, "3-6 years"));
-        toyRoom.addToy(new Car("Car on R/C", 30.0, "6-10 years"));
-        toyRoom.addToy(new Doll("Doll that can talk", 25.0, "1-3 years"));
-        toyRoom.addToy(new Doll("Doll 'Barbie'", 10.0, "3-6 years"));
-        toyRoom.addToy(new Doll("Bear Teddy", 14.5, "6-12 months"));
-        toyRoom.addToy(new Ball("Yellow Ball", 5.0, "6-12 months"));
-        toyRoom.addToy(new Ball("Big Blue Ball", 7.0, "1-3 years"));
-        toyRoom.addToy(new Ball("Football Ball", 12.5, "6-10 years"));
-        toyRoom.addToy(new Cube("Cubes with pictures", 6.5, "6-12 months"));
-        toyRoom.addToy(new Cube("Cubes with letters", 9.0, "3-6 years"));
-        toyRoom.addToy(new Cube("Rubik's Cube", 14.0, "6-10 years"));
-
-        boolean exit = false;
-        Scanner scanner = new Scanner(System.in);
-
-        while (!exit) {
-            System.out.println("\n Select an option:");
-            System.out.println("  1 - Display all toys;");
-            System.out.println("  2 - Find toy by price range;");
-            System.out.println("  3 - Sort toys by price;");
-            System.out.println("  4 - Find a toy by name;");
-            System.out.println("  Q - Quit;\n");
-
-            String option = scanner.nextLine();
-
-            switch (option.toLowerCase()) {
-                case "1":
-                    System.out.println(" Toys in the Toy Room:");
-                    toyRoom.displayToys();
-                    break;
-                case "2":
-                    System.out.print(" Enter the minimum price for the toy: ");
-                    double minPrice = scanner.nextDouble();
-                    scanner.nextLine();
-
-                    System.out.print(" Enter the maximum price for the toy: ");
-                    double maxPrice;
-                    do {
-                        maxPrice = scanner.nextDouble();
-                        scanner.nextLine();
-
-                        if (minPrice >= maxPrice) {
-                            System.out.println(" Error: The minimum price must be less than the maximum price. Please try again.");
-                            System.out.print(" Enter the maximum price for the toy: ");
-                        }
-                    } while (minPrice >= maxPrice);
-
-                    List<Toy> foundToys = toyRoom.findToysByPriceRange(minPrice, maxPrice);
-                    if (!foundToys.isEmpty()) {
-                        System.out.println("\n Found toys within the price range:");
-                        System.out.println(" -------------------------------------------------------");
-                        System.out.printf(" | %-20s | %-10s | %-15s |\n", "Name", "Price ($)", "Age Group");
-                        System.out.println(" |----------------------|------------|-----------------|");
-                        for (Toy toy : foundToys) {
-                            System.out.printf(" | %-20s | %-10.2f | %-15s |\n", toy.name, toy.price, toy.ageGroup);
-                        }
-                        System.out.println(" -------------------------------------------------------");
-                    } else {
-                        System.out.println("\n No toys found within the price range.");
-                    }
-                    break;
-
-                case "3":
-                    System.out.println(" Choose the sorting order:");
-                    System.out.println("  A - Ascending");
-                    System.out.println("  D - Descending");
-                    String sortOrder = scanner.nextLine();
-
-                    boolean ascending = true;
-                    if (sortOrder.equalsIgnoreCase("D")) {
-                        ascending = false;
-                    }
-
-                    toyRoom.sortToys(ascending);
-                    System.out.println("\n Toys in the Toy Room after sorting:");
-                    toyRoom.displayToys();
-                    break;
-
-                case "4":
-                    System.out.print(" Enter the toy name: ");
-                    String toyName = scanner.nextLine();
-
-                    toyRoom.findToysByName(toyName);
-                    break;
-
-                case "q":
-                    exit = true;
-                    System.out.println(" Program exited. Thank you!");
-                    break;
-                default:
-                    System.out.println(" Invalid option. Please try again.");
-            }
-        }
-    }
-}

Students.java

@@ -0,0 +1,30 @@
+public class Students {
+    private String name;
+    private int age;
+    private String nameOfFaculty;
+    private int numberOfGroup;
+    private int lvlOfKnowledge;
+
+    public Students(String name, int age, String nameOfFaculty, int numberOfGroup, int lvlOfKnowledge) {
+        this.name = name;
+        this.age = age;
+        this.nameOfFaculty = nameOfFaculty;
+        this.numberOfGroup = numberOfGroup;
+        this.lvlOfKnowledge = lvlOfKnowledge;
+    }
+    public String getName() {
+        return name;
+    }
+    public int getAge() {
+        return age;
+    }
+    public String getNameOfFaculty() {
+        return nameOfFaculty;
+    }
+    public int getNumberOfGroup() {
+        return numberOfGroup;
+    }
+    public int getLvlOfKnowledge() {
+        return lvlOfKnowledge;
+    }
+}

lab1 fedoniuk

@@ -1,96 +0,0 @@
-import java.util.Scanner;
-
-public class lab1 {
-    public static void main(String[] args) {
-        int C2, C3, C5;
-        var C7 = 0;
-
-        Scanner id = new Scanner(System.in);
-        System.out.print("Enter the student's ID number: ");
-        int idbook = id.nextInt();
-
-        C2 = idbook % 2;
-        C3 = idbook % 3;
-        C5 = idbook % 5;
-        C7 = idbook % 7;
-
-        String[] oper1 = {"+", "-"};
-        String[] oper2 = {"*", "/", "%", "+", "-"};
-        String[] oper3 = {"byte", "short", "int", "long", "char", "float", "double"};
-
-        int C = C3;
-
-        String O1 = oper1[C2];
-        String O2 = oper2[C5];
-        String O3 = oper3[C7];
-
-        System.out.println("C2 is: " + C2 + ", operation is: " + O1);
-        System.out.println("C3 = " + C);
-        System.out.println("C5 is: " + C5 + ", operation is: " + O2);
-        System.out.println("C7 is: " + C7 + ", Type of indexes i and j is: " + O3);
-
-        double i = 0;
-        double j = 0;
-        System.out.println("\nEnter a values for lower limits (i and j) in the "+ O3+" type: ");
-        switch (O3) {
-            case "byte" -> {
-                i = id.nextByte();
-                j = id.nextByte();
-            }
-            case "short" -> {
-                i = id.nextShort();
-                j = id.nextShort();
-            }
-            case "int" -> {
-                i = id.nextInt();
-                j = id.nextInt();
-            }
-            case "long" -> {
-                i = id.nextLong();
-                j = id.nextLong();
-            }
-            case "char" -> {
-                i = id.next().charAt(0);
-                j = id.next().charAt(0);
-            }
-            case "float" -> {
-                i = id.nextFloat();
-                j = id.nextFloat();
-            }
-            case "double" -> {
-                i = id.nextDouble();
-                j = id.nextDouble();
-            }
-        }
-
-        System.out.println("The value of the created variables is: " + i + " and " + j);
-        System.out.println("Enter values for top limits (n and m):");
-        int n, m;
-        n = id.nextInt();
-        m = id.nextInt();
-
-        double sum = 0, res = 0, res2 = 0;
-
-        if ((O1.equals("-") && i + n >= C && i <= C) || i > n || j > m || (C == 0 && i == 0)) {
-            System.out.println("Incorrect input, try another values");
-        } else {
-            for (double a = i; a <= n; a++) {
-                for (double b = j; b <= m; b++) {
-                    switch (O1) {
-                        case "+" -> res = a + C;
-                        case "-" -> res = a - C;
-                    }
-                    switch (O2) {
-                        case "+" -> res2 = a + b;
-                        case "-" -> res2 = a - b;
-                        case "*" -> res2 = a * b;
-                        case "/" -> res2 = a / b;
-                        case "%" -> res2 = a % b;
-                    }
-                    sum += res2 / res;
-                }
-            }
-            System.out.println("Sum is: " + sum);
-        }
-    }
-}

lab1.java

@@ -0,0 +1,29 @@
+import java.util.Scanner;
+
+public class lab1 {
+    public static void main(String[] args) {
+        float S = 0, i, j;
+        int C = 1;
+        Scanner scan = new Scanner(System.in);
+        System.out.println("Введіть значення a (a>1):");
+        int a = scan.nextInt();
+        System.out.println("Введіть значення b:");
+        int b = scan.nextInt();
+        System.out.println("Введіть значення n:");
+        int n = scan.nextInt();
+        System.out.println("Введіть значення m:");
+        int m = scan.nextInt();
+        for (i = a; i <= n; i++) {
+            if (i - C == 0) {
+                System.out.println("Ділення на 0");
+                return;
+            }
+            for (j = b; j <= m; j++) {
+                S += (i - j) / (i - C);
+
+            }
+        }
+        System.out.println(S);
+
+    }
+}

lab2

@@ -1,76 +0,0 @@
-import java.util.Scanner;
-import java.util.Random;
-
-public class Lab2 {
-    public static void main(String[] args) {
-        int C5, C11, C7;
-        int idbook = 2430;
-
-        C5 = idbook % 5;
-        C7 = idbook % 7;
-        C11 = idbook % 11;
-
-        System.out.println("C5 = " + C5 + " - Action between matrix is: C=a×B, a - const");
-        System.out.println("C7 = " + C7 + " - The matrix elements type is: byte");
-        System.out.println("C11 = " + C11 + " - The action with matrix C is: Find the matrix elements' average value");
-
-        Scanner sc = new Scanner(System.in);
-        System.out.print("\n Enter the number of rows: ");
-        int rows = sc.nextInt();
-        System.out.print(" Enter the number of columns: ");
-        int cols = sc.nextInt();
-        int min = 0;
-        int max = 0;
-        boolean valid = false;
-        while (!valid) {
-            System.out.print("\n Enter the minimum value of the matrix numbers (-128 to 127): ");
-            min = sc.nextInt();
-            System.out.print(" Enter the maximum value of the matrix numbers (-128 to 127): ");
-            max = sc.nextInt();
-            if (min >= -128 && max <= 127 && min < max) {
-                valid = true;
-            } else {
-                System.out.println("\nInvalid input. Please enter the values again.");
-            }
-        }
-        byte[][] matrix = new byte[rows][cols];
-        Random rand = new Random();
-        for (int i = 0; i < rows; i++) {
-            for (int j = 0; j < cols; j++) {
-                matrix[i][j] = (byte) (rand.nextInt(max - min + 1) + min);
-            }
-        }
-        System.out.println("\nThe matrix is:");
-        for (int i = 0; i < rows; i++) {
-            for (int j = 0; j < cols; j++) {
-                System.out.printf(" %-5d", matrix[i][j]);
-            }
-            System.out.println();
-        }
-
-        System.out.print("\nEnter the constant to multiply the matrix by: ");
-        int constant = sc.nextInt();
-        byte[][] multipliedMatrix = new byte[rows][cols];
-        System.out.println(" The matrix multiplied by " + constant + " is:");
-        for (int i = 0; i < rows; i++) {
-            for (int j = 0; j < cols; j++) {
-                multipliedMatrix[i][j] = (byte) (matrix[i][j] * constant);
-                System.out.printf(" %-5d", multipliedMatrix[i][j]);
-            }
-            System.out.println();
-        }
-
-        System.out.println("\n Press 'enter' to search for the average value of the matrix.");
-        sc.nextLine();
-        sc.nextLine();
-        int sum = 0;
-        for (int i = 0; i < rows; i++) {
-            for (int j = 0; j < cols; j++) {
-                sum += multipliedMatrix[i][j];
-            }
-        }
-        double average = (double) sum / (rows * cols);
-        System.out.println("The average value of the multiplied matrix is: " + average);
-    }
-}
-

lab2.java

@@ -0,0 +1,78 @@
+import java.util.Scanner;
+import java.util.Random;
+
+public class lab2 {
+    public static void main(String[] args) {
+        Scanner scan = new Scanner(System.in);
+
+        System.out.println("Введіть кількість рядків матриці А:");
+        int mA = scan.nextInt();
+        System.out.println("Введіть кількість стовпців матриці А:");
+        int nA = scan.nextInt();
+        System.out.println("Введіть кількість рядків матриці B:");
+        int mB = scan.nextInt();
+        if (nA != mB) {
+            System.out.println("Щоб помножити матриці, потрібно, щоб кількість стовпців матриці А == кількості рядків матриці B");
+            return;
+        }
+        System.out.println("Введіть кількість стовпців матриці B:");
+        int nB = scan.nextInt();
+        System.out.println("Границя значень у матрицях:");
+        int upperbound = scan.nextShort();
+        int[][] matrixA = new int[mA][nA];
+        int[][] matrixB = new int[mB][nB];
+        int[][] matrixC = new int[mA][nB];
+        generationMatrixes(matrixA, matrixB, upperbound);
+        printMatrixC(matrixA, matrixB, matrixC);
+        AverageValueofElementsofEachColumn(matrixC);
+    }
+
+    private static void AverageValueofElementsofEachColumn(int[][] matrixC) {
+        System.out.println("Середнє значення елементів кожного стовпчика матриці:");
+        System.out.print("||");
+        for (int i = 0; i < matrixC.length; i++) {
+            double sum = 0;
+            for (int j = 0; j < matrixC[i].length; j++) {
+                sum += matrixC[j][i];
+            }
+            System.out.printf(" %.2f ||", (sum) / matrixC.length);
+        }
+    }
+
+    private static void printMatrixC(int[][] matrixA, int[][] matrixB, int[][] matrixC) {
+        for (int i = 0; i < matrixC.length; i++) {
+            for (int j = 0; j < matrixC[i].length; j++) {
+                for (int k = 0; k < matrixA[j].length; k++) {
+                    matrixC[i][j] += matrixA[i][k] * matrixB[k][j];
+                }
+            }
+        }
+        System.out.println("Матриця С:");
+        for (int i = 0; i < matrixC.length; i++) {
+            for (int j = 0; j < matrixC[i].length; j++) {
+                System.out.printf("|%4d", matrixC[i][j]);
+            }
+            System.out.println("|");
+        }
+    }
+
+    private static void generationMatrixes(int[][] matrixA, int[][] matrixB, int upperbound) {
+        Random rand = new Random();
+        System.out.println("Матриця А:");
+        for (short i = 0; i < matrixA.length; i++) {
+            for (int j = 0; j < matrixA[i].length; j++) {
+                matrixA[i][j] = rand.nextInt(upperbound);
+                System.out.printf("|%4d", matrixA[i][j]);
+            }
+            System.out.println("|");
+        }
+        System.out.println("Матриця B:");
+        for (short i = 0; i < matrixB.length; i++) {
+            for (int j = 0; j < matrixB[i].length; j++) {
+                matrixB[i][j] = rand.nextInt(upperbound);
+                System.out.printf("|%4d", matrixB[i][j]);
+            }
+            System.out.println("|");
+        }
+    }
+}

lab3

@@ -1,63 +0,0 @@
-import java.util.Scanner;
-
-public class Lab5 {
-    public static void main(String[] args) {
-
-        int C17 = 2430 % 17;
-        System.out.println("\n---------------------------------------------------------------------------------------------------------------------");
-        System.out.println("  C17 = " + C17 + ", So, the task is:  delete all previous occurrences of the last letter of each word of the specified text");
-        System.out.println("---------------------------------------------------------------------------------------------------------------------");
-
-        Scanner scanner = new Scanner(System.in);
-        String input = null;
-        while (input == null || input.isEmpty()) {
-            System.out.print("\nEnter a string: ");
-            input = scanner.nextLine();
-        }
-        try {
-            StringBuilder sb = new StringBuilder(input);
-            String[] words = sb.toString().split("\\s+");
-            for (int i = 0; i < words.length; i++) {
-                String word = words[i];
-                char lastChar = word.charAt(word.length() - 1);
-                if (!Character.isLetterOrDigit(lastChar)) {
-                    // Last character is a punctuation mark
-                    int lastLetterIndex = -1;
-                    for (int j = word.length() - 2; j >= 0; j--) {
-                        if (Character.isLetter(word.charAt(j))) {
-                            lastLetterIndex = j;
-                            break;
-                        }
-                    }
-                    if (lastLetterIndex != -1) {
-                        char lastLetter = word.charAt(lastLetterIndex);
-                        String newWord = "";
-                        for (int j = 0; j < word.length() - 1; j++) {
-                            if (!Character.isLetterOrDigit(word.charAt(j)) || word.charAt(j) != lastLetter) {
-                                newWord += word.charAt(j);
-                            }
-                        }
-                        newWord += lastChar;
-                        words[i] = newWord;
-                    }
-                } else {
-                    // Last character is a letter or a digit
-                    char lastLetter = lastChar;
-                    String newWord = "";
-                    for (int j = 0; j < word.length() - 1; j++) {
-                        if (!Character.isLetterOrDigit(word.charAt(j)) || word.charAt(j) != lastLetter) {
-                            newWord += word.charAt(j);
-                        }
-                    }
-                    newWord += lastLetter;
-                    words[i] = newWord;
-                }
-            }
-            System.out.print("\nFinal string: ");
-            System.out.println(String.join(" ", words));
-        } catch (Exception e) {
-            System.out.println("An error occurred: " + e.getMessage());
-        }
-    }
-}
-

lab3.java

@@ -0,0 +1,21 @@
+public class lab3 {
+    public static void main(String[] args) {
+        StringBuilder txt = new StringBuilder("— соціальна мережа, яка є мережею мікроблогів, дає змогу користувачам надсилати короткі текстові повідомлення (до 2802 символів, до 2017 року — до 140 символів), використовуючи SMS,");
+        System.out.println(txt);
+        String[] words = txt.toString().split("\\s+");
+        StringBuilder result = new StringBuilder();
+        for (int i = 0; i < words.length; i++) {
+            StringBuilder word = new StringBuilder(words[i]);
+            StringBuilder firstLetter = new StringBuilder(word.substring(0, 1));
+            if (word.substring(1).contains(firstLetter.toString().toLowerCase()) || word.substring(1).contains(firstLetter)) {
+                String changedWord = firstLetter + word.substring(1).replaceAll(firstLetter.toString().toLowerCase(), "").replaceAll(firstLetter.toString(), "");
+                result.append(changedWord);
+                result.append(" ");
+            } else {
+                result.append(word);
+                result.append(" ");
+            }
+        }
+        System.out.println(result);
+    }
+}

lab4

@@ -1,115 +0,0 @@
-import java.util.Arrays;
-import java.util.Comparator;
-import java.util.Scanner;
-
-public class Lab4 {
-
-    public static class Student {
-        private int grBook;
-        private String name;
-        private int age;
-        private double gpa;
-        private String faculty;
-
-        public Student(int grBook, String name, int age, double gpa, String faculty) {
-            this.grBook = grBook;
-            this.name = name;
-            this.age = age;
-            this.gpa = gpa;
-            this.faculty = faculty;
-        }
-
-        public int getGrBook() {
-            return grBook;
-        }
-
-        public String getName() {
-            return name;
-        }
-
-        public int getAge() {
-            return age;
-        }
-
-        public double getGpa() {
-            return gpa;
-        }
-
-        public String getFaculty() {
-            return faculty;
-        }
-    }
-
-    public static void main(String[] args) {
-
-        int C11 = 2430 % 11;
-        System.out.println("\n  ----------------------------------------------------------------------------------------------------------");
-        System.out.println("          C11 = " + C11 + ", So, the task is:  Define the student class, which consists of at least 5 fields.");
-        System.out.println("  ----------------------------------------------------------------------------------------------------------");
-
-        Student[] students = {
-                new Student(1010, "Вікторія", 21, 84.6, "ФІОТ"),
-                new Student(2010, "Дарія", 20, 79.8, "РТФ"),
-                new Student(3010, "Анатолій", 19, 94.3, "ХТФ"),
-                new Student(4040, "Генадій", 22, 62.0, "ІХФ"),
-                new Student(5050, "Борис", 18, 89.1, "ФММ")
-        };
-
-        Scanner scanner = new Scanner(System.in);
-        boolean quit = false;
-        while (!quit) {
-
-            System.out.print("\nEnter the field to sort by (greed book, name, age, gpa, faculty) or enter 'quit' to exit: ");
-            String input = scanner.nextLine();
-
-            if (!input.equals("greed book") && !input.equals("name") && !input.equals("age") && !input.equals("gpa") && !input.equals("faculty") && !input.equals("quit")) {
-                System.out.println("Invalid field to sort by! Please enter 'grBook', 'name', 'age', 'gpa', or 'faculty'.");
-                continue;
-            }
-            if (input.equals("quit")) {
-                quit = true;
-                System.out.println("Thank you for using my program:)");
-                continue;
-            }
-
-            String field = input;
-            System.out.print("Enter the sort order (asc or desc): ");
-            String order = scanner.nextLine();
-
-            if (!order.equals("asc") && !order.equals("desc")) {
-                System.out.println("Invalid sort order! Please enter 'asc' or 'desc'.");
-                continue;
-            }
-
-            Comparator<Student> comparator = null;
-            switch (field) {
-                case "greed book":
-                    comparator = Comparator.comparingInt(Student::getGrBook);
-                    break;
-                case "name":
-                    comparator = Comparator.comparing(Student::getName);
-                    break;
-                case "age":
-                    comparator = Comparator.comparingInt(Student::getAge);
-                    break;
-                case "gpa":
-                    comparator = Comparator.comparingDouble(Student::getGpa);
-                    break;
-                case "faculty":
-                    comparator = Comparator.comparing(Student::getFaculty);
-                    break;
-            }
-            if (order.equals("desc")) {
-                comparator = comparator.reversed();
-            }
-            Arrays.sort(students, comparator);
-
-            System.out.println("\nSorted by " + field + " (in " + order + "ending order):");
-            System.out.println(String.format("%n%-15s | %-20s | %-4s | %-4s | %-10s", "Greed book", "Name", "Age", "GPA", " Faculty"));
-            System.out.println("----------------------------------------------------------------");
-            for (Student student : students) {
-                System.out.println(String.format("%-15d | %-20s | %-4d | %-3.1f | %-10s", student.getGrBook(), student.getName(), student.getAge(), student.getGpa(), student.getFaculty()));
-            }
-        }
-    }
-}

src/Lab1.java

@@ -0,0 +1,58 @@
+public class Lab1 {
+    public static void main(String[] args) {
+//        char c = 'a' + '1';
+        char c = 97;
+//        char c = '1';
+        System.out.println(c);
+        System.out.println((int) c);
+        c++;
+        System.out.println(c);
+        System.out.println((int) c);
+        System.out.println((double)'1'/'3');
+
+//        System.out.println( (double) 0 / 0 );
+//        System.out.println( Math.sqrt(-1) );
+        double s = 0;
+        /*for (int i = 1; i <= 3; i++) { // 1) <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20> i = 1, 2) <20><><EFBFBD><EFBFBD> <20> <= 3, 3) <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> 䳿 <20> <20><> <20><><EFBFBD><EFBFBD><EFBFBD>,
+            System.out.println(i);     // 4) <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20> <20><> 1, 5) <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><> <20><><EFBFBD><EFBFBD><EFBFBD> 2
+//            s = s + i;
+            s += i;
+        }*/
+        /*int[] array = new int[2];
+        for (int i = 0; i < array.length; i++) {
+
+        }*/
+        final int A = -3;
+        final int B = 0;
+        final int N = 2;
+        final int M = 2;
+
+        final int C = 1;
+//        boolean wasDivisionByZero = false;
+//        todo char
+//        todo[clear code] think about avoiding brackets
+        if ((A <= -C && -C <= N) || (B <= 0 && 0 <= M)) {
+            System.out.println("Division by zero!");
+            return;
+        }
+/*myLabel:*/for (int i = A; i <= N /*&& !wasDivisionByZero*/; i++) {
+            /*if (i + C == 0) { // todo optimize
+                System.out.println("Division by zero!");
+                wasDivisionByZero = true;
+                break; //todo flag vs return;
+            }*/
+            for (int j = B; j <= M; j++) {
+                /*if (j == 0) {
+                    System.out.println("Division by zero!");
+                    return;
+//                    wasDivisionByZero = true;
+//                    break myLabel;
+                }*/
+                s += (double) (i / j) / (i + C);
+            }
+        }
+//        if (!wasDivisionByZero) {
+            System.out.println("s = " + s);
+//        }
+    }
+}

src/Lab2.java

@@ -0,0 +1,102 @@
+public class Lab2 {
+    public static void main(String[] args) {
+        final int A = 2;
+        final int[][] MATRIX_B = {
+                {1, 202, 1, 1, 202, 3, 1, 202, 3,},
+                {1, 202, 1, 1, 202, 3, 1, 202, 3,},
+                {1, 1,   3, 1, 202, 3, 1, 202, 3,},
+//                {4, 5, 6,},
+        };
+
+        int[][] MATRIX_C = multiplication(A, MATRIX_B);
+
+        print(MATRIX_C);
+
+        System.out.println("Sum of smallest elements in every column: " + sumOfSmallestElementsInEveryColumn(MATRIX_C));
+
+        /*int[] array = {1, 2, 3};
+        int[] array2 = new int[3];
+        Object[] array3 = new String[3];
+        System.out.println(array3[0]); //nothing, trash from the memory, null || null
+        System.out.println(array2[0]); //nothing, trash from the memory, null || 0
+        System.out.println(array[0]); // || 1
+
+        int[][] matrix2 = new int[2][3];
+        matrix2[0] = new int[2];
+        matrix2[1] = new int[1];
+        for (int i = 0; i < array.length; i++) {
+            if (i % 2 == 0) {
+                System.out.println("!" + array[i]);
+            } else {
+                System.out.println("?" + array[i]);
+            }
+        }
+
+        for (int i = 0; i < array.length; i+=2) {
+            System.out.println("!" + array[i]);
+        }
+
+        for (int i = 1; i < array.length; i+=2) {
+            System.out.println("?" + array[i]);
+        }
+
+//        зубчасті матриці
+        int[][] matrix = {
+                {1, 2},
+                {3}
+        };
+
+//        C=a×B, a - const
+
+
+//        final int[][] MATRIX_C = int;
+
+
+        MATRIX_B[0][0] = 2;
+        MATRIX_B[0] = new int[]{1, 2};
+        System.out.println(MATRIX_B[0][0]);
+        MATRIX_B = new int[][]{
+                {1, 2},
+                {3}
+        };*/
+    }
+
+    private static int sumOfSmallestElementsInEveryColumn(final int[][] MATRIX_C) {
+//        todo check different length of rows
+//        todo try to change i and j
+//        todo check repetition of minimal elements
+        int sum = 0;
+        for (int i = 0; i < MATRIX_C[0].length; i++) {
+            int tmpSmallest = MATRIX_C[0][i];
+            for (int j = 1; j < MATRIX_C.length; j++) {
+                if (MATRIX_C[j][i] < tmpSmallest) {
+                    tmpSmallest = MATRIX_C[j][i];
+                }
+            }
+            sum += tmpSmallest;
+        }
+        return sum;
+    }
+
+    private static void print(final int[][] MATRIX_C) {
+        for (int i = 0; i < MATRIX_C.length; i++) {
+            for (int j = 0; j < MATRIX_C[i].length; j++) {
+//                System.out.print(MATRIX_C[i][j] + "\t");//printf("%4d",
+                System.out.printf("%4d ", MATRIX_C[i][j]);//printf("%4d",
+            }
+            System.out.println();
+        }
+    }
+
+    private static int[][] multiplication(int A, final int[][] MATRIX_B) {
+        final int[][] MATRIX_C = new int[MATRIX_B.length][/*MATRIX_B[0].length*/]; // todo !!!DANGER different lengths of rows
+//        final int[][] MATRIX_C = MATRIX_B;
+        for (int i = 0; i < MATRIX_B.length; i++) {
+            MATRIX_C[i] = new int[MATRIX_B[i].length];
+            for (int j = 0; j < MATRIX_B[i].length; j++) {
+                MATRIX_C[i][j] = MATRIX_B[i][j] * A;
+            }
+        }
+        return MATRIX_C;
+    }
+}

src/Main.java

@@ -1,8 +1,35 @@
 public class Main {
     public static void main(String[] args) {
-        System.out.println(args[1]);
+        System.out.println(args[2]);
         System.out.println("Hello world!");
 //        System.out.println(1);
+
+        int a = 1;
+        int b = 2;
+        int c = 1;
+        int d = 1;
+
+        System.out.println(2&1);
+        System.out.println(2|1);
+        int aa = 2;
+
+        /*if (aa) {
+
+        }*/
+
+//        System.out.println("a"&"b");
+        System.out.println('a'&'b');
+
+        if ((a > b) & MyBooleanMethod()) {
+            System.out.println("?????????????????????????");
+        }
+
+
+    }
+
+    static boolean MyBooleanMethod() {
+        System.out.println("!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!");
+        return true;
     }
 
     void myFunction() {

src/encapsulationInheritancePolymorphism/inheritance/ElectricEngine.java

@@ -2,4 +2,8 @@ package encapsulationInheritancePolymorphism.inheritance;
 
 public class ElectricEngine extends Engine {
     private String batteryType;
+
+    /*private class Engine {
+        private int power;
+    }*/
 }

src/encapsulationInheritancePolymorphism/inheritance/FuelEngine.java

@@ -0,0 +1,5 @@
+package encapsulationInheritancePolymorphism.inheritance;
+
+public class FuelEngine extends Engine {
+    private String fuelType;
+}

src/encapsulationInheritancePolymorphism/inheritance/Main.java

@@ -2,6 +2,7 @@ package encapsulationInheritancePolymorphism.inheritance;
 
 public class Main {
     public static void main(String[] args) {
-        ElectricEngine electricEngine = new ElectricEngine();
+        ElectricEngine electricEngine = new ElectricEngine(); // створення нового об'єкту (екземпляру) класу ElectricEngine
+        FuelEngine fuelEngine = new FuelEngine();
     }
 }

src/encapsulationInheritancePolymorphism/polymorphism/ElectricEngine.java

@@ -0,0 +1,14 @@
+package encapsulationInheritancePolymorphism.polymorphism;
+
+public class ElectricEngine extends Engine {
+    private String batteryType;
+
+    @Override
+    public int getPower() {
+        return 20;
+    }
+
+    /*private class Engine {
+        private int power;
+    }*/
+}

src/encapsulationInheritancePolymorphism/polymorphism/Engine.java

@@ -0,0 +1,9 @@
+package encapsulationInheritancePolymorphism.polymorphism;
+
+public class Engine {
+    private int power;
+
+    public int getPower() {
+        return power;
+    }
+}

src/encapsulationInheritancePolymorphism/polymorphism/FuelEngine.java

@@ -0,0 +1,10 @@
+package encapsulationInheritancePolymorphism.polymorphism;
+
+public class FuelEngine extends Engine {
+    private String fuelType;
+
+    @Override
+    public int getPower() {
+        return 50;
+    }
+}

src/encapsulationInheritancePolymorphism/polymorphism/Main.java

@@ -0,0 +1,38 @@
+package encapsulationInheritancePolymorphism.polymorphism;
+
+/*import encapsulationInheritancePolymorphism.inheritance.ElectricEngine;
+import encapsulationInheritancePolymorphism.inheritance.FuelEngine;*/
+
+public class Main {
+    public static void main(String[] args) {
+        /*encapsulationInheritancePolymorphism.inheritance.*/ElectricEngine electricEngine = new ElectricEngine(); // створення нового об'єкту (екземпляру) класу ElectricEngine
+        /*encapsulationInheritancePolymorphism.inheritance.*/FuelEngine fuelEngine = new FuelEngine();
+
+        Engine engine1 = fuelEngine;
+
+        Engine[] engines = {
+                electricEngine,
+                fuelEngine
+        };
+
+        for (Engine engine : engines) {
+            System.out.println(engine.getPower());
+        }
+
+        /*for (int i = 0; i < engines.length; i++) {
+            System.out.println(engines[i].getPower());
+        }*/
+
+//        +
+        int a = 1;
+        int b = 1;
+        int c = a + b;
+        System.out.println(c);
+
+
+        String sA = "1";
+        String sB = "1";
+        String sC = sA + sB;
+        System.out.println(sC);
+    }
+}

src/encapsulationInheritancePolymorphism/polymorphism/enhanced/ElectricEngine.java

@@ -0,0 +1,19 @@
+package encapsulationInheritancePolymorphism.polymorphism.enhanced;
+
+public class ElectricEngine extends Engine {
+    private String batteryType;
+    private int chargeLevel = 9;
+    private int criticalChargeLevel = 10;
+    private float coefficientCriticalPowerCut = 0.1f;
+
+    @Override
+    public int getPower() {
+        return chargeLevel > criticalChargeLevel
+                ? super.getPower()
+                : (int) (super.getPower() * coefficientCriticalPowerCut);
+    }
+
+    /*private class Engine {
+        private int power;
+    }*/
+}

src/encapsulationInheritancePolymorphism/polymorphism/enhanced/Engine.java

@@ -0,0 +1,9 @@
+package encapsulationInheritancePolymorphism.polymorphism.enhanced;
+
+public class Engine {
+    private int power = 100;
+
+    public int getPower() {
+        return power;
+    }
+}

src/encapsulationInheritancePolymorphism/polymorphism/enhanced/FuelEngine.java

@@ -0,0 +1,10 @@
+package encapsulationInheritancePolymorphism.polymorphism.enhanced;
+
+public class FuelEngine extends Engine {
+    private String fuelType;
+
+    /*public int getPower() {
+        return 50;
+    }*/
+
+}

src/encapsulationInheritancePolymorphism/polymorphism/enhanced/Main.java

@@ -0,0 +1,28 @@
+package encapsulationInheritancePolymorphism.polymorphism.enhanced;
+
+/*import encapsulationInheritancePolymorphism.inheritance.ElectricEngine;
+import encapsulationInheritancePolymorphism.inheritance.FuelEngine;*/
+
+public class Main {
+    public static void main(String[] args) {
+        /*encapsulationInheritancePolymorphism.inheritance.*/
+        ElectricEngine electricEngine = new ElectricEngine(); // створення нового об'єкту (екземпляру) класу ElectricEngine
+        /*encapsulationInheritancePolymorphism.inheritance.*/
+        FuelEngine fuelEngine = new FuelEngine();
+
+        Engine engine1 = fuelEngine;
+
+        Engine[] engines = {
+                electricEngine,
+                fuelEngine
+        };
+
+        for (Engine engine : engines) {
+            System.out.println(engine.getPower());
+        }
+
+        /*for (int i = 0; i < engines.length; i++) {
+            System.out.println(engines[i].getPower());
+        }*/
+    }
+}

src/encapsulationInheritancePolymorphism/polymorphism/overload/MyClassForOverloadExample.java

@@ -0,0 +1,17 @@
+package encapsulationInheritancePolymorphism.polymorphism.overload;
+
+public class MyClassForOverloadExample {
+    void myMethod(int a) {
+        System.out.println("Integer: " + a);
+    }
+
+    void myMethod(double a) {
+        System.out.println("Double: " + a);
+    }
+
+    public static void main(String[] args) {
+        MyClassForOverloadExample overload = new MyClassForOverloadExample();
+        overload.myMethod(1);
+        overload.myMethod(0.1);
+    }
+}