Update Lab5.java

.gitignore

@@ -0,0 +1,2 @@
+# Project exclude paths
+/out/

.idea/.gitignore

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+# Default ignored files
+/shelf/
+/workspace.xml
+# Editor-based HTTP Client requests
+/httpRequests/
+# Datasource local storage ignored files
+/dataSources/
+/dataSources.local.xml

.idea/misc.xml

@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="ProjectRootManager" version="2" languageLevel="JDK_18" default="true" project-jdk-name="openjdk-18" project-jdk-type="JavaSDK">
+    <output url="file://$PROJECT_DIR$/out" />
+  </component>
+</project>

.idea/modules.xml

@@ -0,0 +1,8 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="ProjectModuleManager">
+    <modules>
+      <module fileurl="file://$PROJECT_DIR$/OOP_IO-2x_2023.iml" filepath="$PROJECT_DIR$/OOP_IO-2x_2023.iml" />
+    </modules>
+  </component>
+</project>

.idea/uiDesigner.xml

@@ -0,0 +1,124 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="Palette2">
+    <group name="Swing">
+      <item class="com.intellij.uiDesigner.HSpacer" tooltip-text="Horizontal Spacer" icon="/com/intellij/uiDesigner/icons/hspacer.svg" removable="false" auto-create-binding="false" can-attach-label="false">
+        <default-constraints vsize-policy="1" hsize-policy="6" anchor="0" fill="1" />
+      </item>
+      <item class="com.intellij.uiDesigner.VSpacer" tooltip-text="Vertical Spacer" icon="/com/intellij/uiDesigner/icons/vspacer.svg" removable="false" auto-create-binding="false" can-attach-label="false">
+        <default-constraints vsize-policy="6" hsize-policy="1" anchor="0" fill="2" />
+      </item>
+      <item class="javax.swing.JPanel" icon="/com/intellij/uiDesigner/icons/panel.svg" removable="false" auto-create-binding="false" can-attach-label="false">
+        <default-constraints vsize-policy="3" hsize-policy="3" anchor="0" fill="3" />
+      </item>
+      <item class="javax.swing.JScrollPane" icon="/com/intellij/uiDesigner/icons/scrollPane.svg" removable="false" auto-create-binding="false" can-attach-label="true">
+        <default-constraints vsize-policy="7" hsize-policy="7" anchor="0" fill="3" />
+      </item>
+      <item class="javax.swing.JButton" icon="/com/intellij/uiDesigner/icons/button.svg" removable="false" auto-create-binding="true" can-attach-label="false">
+        <default-constraints vsize-policy="0" hsize-policy="3" anchor="0" fill="1" />
+        <initial-values>
+          <property name="text" value="Button" />
+        </initial-values>
+      </item>
+      <item class="javax.swing.JRadioButton" icon="/com/intellij/uiDesigner/icons/radioButton.svg" removable="false" auto-create-binding="true" can-attach-label="false">
+        <default-constraints vsize-policy="0" hsize-policy="3" anchor="8" fill="0" />
+        <initial-values>
+          <property name="text" value="RadioButton" />
+        </initial-values>
+      </item>
+      <item class="javax.swing.JCheckBox" icon="/com/intellij/uiDesigner/icons/checkBox.svg" removable="false" auto-create-binding="true" can-attach-label="false">
+        <default-constraints vsize-policy="0" hsize-policy="3" anchor="8" fill="0" />
+        <initial-values>
+          <property name="text" value="CheckBox" />
+        </initial-values>
+      </item>
+      <item class="javax.swing.JLabel" icon="/com/intellij/uiDesigner/icons/label.svg" removable="false" auto-create-binding="false" can-attach-label="false">
+        <default-constraints vsize-policy="0" hsize-policy="0" anchor="8" fill="0" />
+        <initial-values>
+          <property name="text" value="Label" />
+        </initial-values>
+      </item>
+      <item class="javax.swing.JTextField" icon="/com/intellij/uiDesigner/icons/textField.svg" removable="false" auto-create-binding="true" can-attach-label="true">
+        <default-constraints vsize-policy="0" hsize-policy="6" anchor="8" fill="1">
+          <preferred-size width="150" height="-1" />
+        </default-constraints>
+      </item>
+      <item class="javax.swing.JPasswordField" icon="/com/intellij/uiDesigner/icons/passwordField.svg" removable="false" auto-create-binding="true" can-attach-label="true">
+        <default-constraints vsize-policy="0" hsize-policy="6" anchor="8" fill="1">
+          <preferred-size width="150" height="-1" />
+        </default-constraints>
+      </item>
+      <item class="javax.swing.JFormattedTextField" icon="/com/intellij/uiDesigner/icons/formattedTextField.svg" removable="false" auto-create-binding="true" can-attach-label="true">
+        <default-constraints vsize-policy="0" hsize-policy="6" anchor="8" fill="1">
+          <preferred-size width="150" height="-1" />
+        </default-constraints>
+      </item>
+      <item class="javax.swing.JTextArea" icon="/com/intellij/uiDesigner/icons/textArea.svg" removable="false" auto-create-binding="true" can-attach-label="true">
+        <default-constraints vsize-policy="6" hsize-policy="6" anchor="0" fill="3">
+          <preferred-size width="150" height="50" />
+        </default-constraints>
+      </item>
+      <item class="javax.swing.JTextPane" icon="/com/intellij/uiDesigner/icons/textPane.svg" removable="false" auto-create-binding="true" can-attach-label="true">
+        <default-constraints vsize-policy="6" hsize-policy="6" anchor="0" fill="3">
+          <preferred-size width="150" height="50" />
+        </default-constraints>
+      </item>
+      <item class="javax.swing.JEditorPane" icon="/com/intellij/uiDesigner/icons/editorPane.svg" removable="false" auto-create-binding="true" can-attach-label="true">
+        <default-constraints vsize-policy="6" hsize-policy="6" anchor="0" fill="3">
+          <preferred-size width="150" height="50" />
+        </default-constraints>
+      </item>
+      <item class="javax.swing.JComboBox" icon="/com/intellij/uiDesigner/icons/comboBox.svg" removable="false" auto-create-binding="true" can-attach-label="true">
+        <default-constraints vsize-policy="0" hsize-policy="2" anchor="8" fill="1" />
+      </item>
+      <item class="javax.swing.JTable" icon="/com/intellij/uiDesigner/icons/table.svg" removable="false" auto-create-binding="true" can-attach-label="false">
+        <default-constraints vsize-policy="6" hsize-policy="6" anchor="0" fill="3">
+          <preferred-size width="150" height="50" />
+        </default-constraints>
+      </item>
+      <item class="javax.swing.JList" icon="/com/intellij/uiDesigner/icons/list.svg" removable="false" auto-create-binding="true" can-attach-label="false">
+        <default-constraints vsize-policy="6" hsize-policy="2" anchor="0" fill="3">
+          <preferred-size width="150" height="50" />
+        </default-constraints>
+      </item>
+      <item class="javax.swing.JTree" icon="/com/intellij/uiDesigner/icons/tree.svg" removable="false" auto-create-binding="true" can-attach-label="false">
+        <default-constraints vsize-policy="6" hsize-policy="6" anchor="0" fill="3">
+          <preferred-size width="150" height="50" />
+        </default-constraints>
+      </item>
+      <item class="javax.swing.JTabbedPane" icon="/com/intellij/uiDesigner/icons/tabbedPane.svg" removable="false" auto-create-binding="true" can-attach-label="false">
+        <default-constraints vsize-policy="3" hsize-policy="3" anchor="0" fill="3">
+          <preferred-size width="200" height="200" />
+        </default-constraints>
+      </item>
+      <item class="javax.swing.JSplitPane" icon="/com/intellij/uiDesigner/icons/splitPane.svg" removable="false" auto-create-binding="false" can-attach-label="false">
+        <default-constraints vsize-policy="3" hsize-policy="3" anchor="0" fill="3">
+          <preferred-size width="200" height="200" />
+        </default-constraints>
+      </item>
+      <item class="javax.swing.JSpinner" icon="/com/intellij/uiDesigner/icons/spinner.svg" removable="false" auto-create-binding="true" can-attach-label="true">
+        <default-constraints vsize-policy="0" hsize-policy="6" anchor="8" fill="1" />
+      </item>
+      <item class="javax.swing.JSlider" icon="/com/intellij/uiDesigner/icons/slider.svg" removable="false" auto-create-binding="true" can-attach-label="false">
+        <default-constraints vsize-policy="0" hsize-policy="6" anchor="8" fill="1" />
+      </item>
+      <item class="javax.swing.JSeparator" icon="/com/intellij/uiDesigner/icons/separator.svg" removable="false" auto-create-binding="false" can-attach-label="false">
+        <default-constraints vsize-policy="6" hsize-policy="6" anchor="0" fill="3" />
+      </item>
+      <item class="javax.swing.JProgressBar" icon="/com/intellij/uiDesigner/icons/progressbar.svg" removable="false" auto-create-binding="true" can-attach-label="false">
+        <default-constraints vsize-policy="0" hsize-policy="6" anchor="0" fill="1" />
+      </item>
+      <item class="javax.swing.JToolBar" icon="/com/intellij/uiDesigner/icons/toolbar.svg" removable="false" auto-create-binding="false" can-attach-label="false">
+        <default-constraints vsize-policy="0" hsize-policy="6" anchor="0" fill="1">
+          <preferred-size width="-1" height="20" />
+        </default-constraints>
+      </item>
+      <item class="javax.swing.JToolBar$Separator" icon="/com/intellij/uiDesigner/icons/toolbarSeparator.svg" removable="false" auto-create-binding="false" can-attach-label="false">
+        <default-constraints vsize-policy="0" hsize-policy="0" anchor="0" fill="1" />
+      </item>
+      <item class="javax.swing.JScrollBar" icon="/com/intellij/uiDesigner/icons/scrollbar.svg" removable="false" auto-create-binding="true" can-attach-label="false">
+        <default-constraints vsize-policy="6" hsize-policy="0" anchor="0" fill="2" />
+      </item>
+    </group>
+  </component>
+</project>

.idea/vcs.xml

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+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="VcsDirectoryMappings">
+    <mapping directory="$PROJECT_DIR$" vcs="Git" />
+  </component>
+</project>

Lab2/Program.cs

@@ -1,32 +0,0 @@
-using System;
-
-public class Laba2
-{
-    
-
-    public static void Main(string[] args)
-    {
-        const int a = 2;
-        int[][] b = new[]
-        {
-            new int[] { 1, 2, 8 },
-            new int[] { 3, 4, 5 },
-            new int[] { 6, 7, 9 }
-        };
-        calculation(b, a);
-    }
-
-    private static int[][] calculation(int[][] b, int a)
-    {
-        int[][]c = new int[b.Length][b[0].Length]; //недопустимий специфікатор рангу: вимагається "," або "]";
-        for (int i = 0; i < b.Length; i++)
-        {
-            c[i] = new int[b[i].Length];
-            for (int j = 0; j < b[i].Length; j++)
-            {
-                c[i][j] = b[i][j] * a;
-            }
-        }
-        return c;
-    }
-}

Lab3/Lab3/Lab3/Program.cs

@@ -1,33 +0,0 @@
-using System;
-using System.Collections.Generic;
-
-class Lab3
-{
-    public static void Main(string[] args)
-    {
-        string text = "Вухатий великий синiй слон. Яблуко в саду. Зелене яблуко? Груша. Жовта слива висить у саду!";
-        Console.WriteLine(text );
-
-        // розділяємо текст на окремі речення
-        string[] textSplit = text.Split(new[] { '.', '?', '!' }, StringSplitOptions.RemoveEmptyEntries);
-
-        // обчислюємо кількість слів у кожному реченні та створюємо масив з кількістю слів у реченнях
-        int[] amountOfWords = new int[textSplit.Length];
-        for (int i = 0; i < textSplit.Length; i++)
-        {
-            string[] words = textSplit[i].Trim().Split(' ');
-            amountOfWords[i] = words.Length;
-        }
-
-        // створюємо Dictionary, де ключ - кількість слів у реченні, а значення - речення
-        Dictionary<int, string> sentenceDictionary = new Dictionary<int, string>();
-        for (int i = 0; i < textSplit.Length; i++)
-        {
-            sentenceDictionary.Add(amountOfWords[i], textSplit[i]);
-        }
-        var sortedDict = sentenceDictionary.OrderBy(x => x.Key).ToDictionary(x => x.Value, x => x.Key);
-
-
-        Console.WriteLine(String.Join(";", sortedDict.Keys));
-    }
-}

Lab4.java

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+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.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;
+    }
+}

OOP_IO-2x_2023.iml

@@ -0,0 +1,11 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<module type="JAVA_MODULE" version="4">
+  <component name="NewModuleRootManager" inherit-compiler-output="true">
+    <exclude-output />
+    <content url="file://$MODULE_DIR$">
+      <sourceFolder url="file://$MODULE_DIR$/src" isTestSource="false" />
+    </content>
+    <orderEntry type="inheritedJdk" />
+    <orderEntry type="sourceFolder" forTests="false" />
+  </component>
+</module>

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.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.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.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);
+    }
+}

src/Lab2.java

@@ -1,13 +1,36 @@
 public class Lab2 {
     public static void main(String[] args) {
-        int[] array = {1, 2, 3};
+        final int A = 2;
-        /*for (int i = 0; i < array.length; i++) {
+        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]);
@@ -22,5 +45,58 @@ public class Lab2 {
                 {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;
     }
 }