Merge remote-tracking branch 'origin/master'

This reverts commit 29e63163a4.

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) ��������� � i = 1, 2) ���� � <= 3, 3) �������� 䳿 � �� �����,
+            System.out.println(i);     // 4) �������������� � �� 1, 5) ����������� �� ����� 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 +1,140 @@
+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, 4},
+                {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));
+        try {
+            System.out.println("Sum of smallest elements in every column: " + sumOfSmallestElementsInEveryColumnRenew(MATRIX_C));
+            System.out.println("???...");
+        } catch (Exception e) {
+            System.err.println(e.getMessage());
+        }
+
+        System.out.println("I'm still working...");
+
+        /*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 int sumOfSmallestElementsInEveryColumnRenew(final int[][] MATRIX_C) throws Exception {
+//        todo check different length of rows
+        for (int i = 1; i < MATRIX_C.length; i++) {
+            if (MATRIX_C[i].length != MATRIX_C[0].length) {
+                throw new /*Runtime*/Exception("There are different lengths of matrix rows.");
+//                System.err.println("There are different lengths of matrix rows.");
+//                System.exit(0);
+            }
+        }
+        int sum = 0;
+        for (int j = 0; j < MATRIX_C[0].length; j++) {
+            int tmpSmallest = MATRIX_C[0][j];
+            boolean valueRepeats = false;
+            for (int i = 1; i < MATRIX_C.length; i++) {
+                if (MATRIX_C[i][j] < tmpSmallest) {
+                    tmpSmallest = MATRIX_C[i][j];
+                    valueRepeats = false;
+                } else if (MATRIX_C[i][j] == tmpSmallest) {
+                    valueRepeats = true;
+                }
+            }
+            sum += tmpSmallest;
+
+            if (!valueRepeats) {
+                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/Lab3.java

@@ -0,0 +1,73 @@
+public class Lab3 {
+    private static final int REPETITION_NUMBER = 10;
+    public static void main(String[] args) {
+        StringBuilder result = new StringBuilder();
+        for (int i = 0; i < REPETITION_NUMBER; i++) {
+//            result += Integer.toString(i);
+//            result += String.valueOf(i);
+            result.append(i);
+        }
+
+
+
+        /*float f = 1.1f;
+        double d = 2.2;
+//        f = (float) (f + d);
+        f += d;*/
+
+        String s = "ASD";
+
+        StringBuilder stringBuilder = new StringBuilder("ASD");
+        StringBuffer stringBuffer = new StringBuffer("ASD");
+
+        stringBuilder.append("A");
+        System.out.println(s.length());
+        System.out.println(stringBuilder.length());
+        System.out.println(stringBuffer.length());
+
+        System.out.println(s.endsWith("D"));
+//        System.out.println(stringBuilder.substring(stringBuilder.length() - 1).equals("A"));
+        System.out.println("A".equals(stringBuilder.substring(stringBuilder.length() - 1)));
+        System.out.println("A".equals(stringBuffer.substring(stringBuffer.length() - 1)));
+
+        String sNull = null;
+        System.out.println("A".equals(sNull));
+        System.out.println(sNull.equals("A"));
+
+        System.out.println(s.substring(2));
+        System.out.println(s.contains("AS"));
+
+        System.out.println(s.indexOf('a'));
+
+//        System.out.println(s.charAt(-1));
+
+        System.out.println("s.equalsIgnoreCase(\"AsD\") = " + s.equalsIgnoreCase("AsD"));
+
+        String s2 = s;
+        System.out.println("s2 = " + s2);
+        System.out.println(s == s2); // true?
+        System.out.println(s.equals(s2)); // true?
+        s += "B";
+        System.out.println(s);
+        System.out.println("s2 = " + s2);
+
+        System.out.println(s == s2); // false?
+        System.out.println(s.equals(s2)); // false?
+
+        String s3 = new String("ASD");
+        System.out.println(s3 == s2); // true? (false)
+        System.out.println(s3.equals(s2)); // false? (true)
+
+//      String Pool
+        String s4 = "ASD";
+//        String s5 = new String("ASD");
+        String s5 = "AS";
+        s5 += "D";
+        System.out.println(s4 == s5); // true? (SP)
+        System.out.println(s4.equals(s5)); // (true)
+
+
+
+        System.out.println("Done!");
+    }
+}

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

@@ -0,0 +1,9 @@
+package encapsulationInheritancePolymorphism.inheritance;
+
+public class ElectricEngine extends Engine {
+    private String batteryType;
+
+    /*private class Engine {
+        private int power;
+    }*/
+}

src/encapsulationInheritancePolymorphism/inheritance/Engine.java

@@ -0,0 +1,5 @@
+package encapsulationInheritancePolymorphism.inheritance;
+
+public 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

@@ -0,0 +1,8 @@
+package encapsulationInheritancePolymorphism.inheritance;
+
+public class Main {
+    public static void main(String[] args) {
+        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);
+    }
+}

src/lab4/Main.java

@@ -0,0 +1,7 @@
+package lab4;
+
+public class Main {
+    public static void main(String[] args) {
+        //todo equals+hashcode
+    }
+}

src/test/Test.java

@@ -0,0 +1,13 @@
+package test;
+
+public class Test {
+    public static void main(String[] args) {
+
+    }
+    static int m(){
+        System.exit(0);
+//        return 1;
+        System.out.println(123);
+        return 1;
+    }
+}

src/test/one/A.java

@@ -0,0 +1,7 @@
+package test.one;
+
+public class A implements MyMethodInterface {
+    public void myMethod() {
+
+    }
+}

src/test/one/B.java

@@ -0,0 +1,7 @@
+package test.one;
+
+public class B implements MyMethodInterface {
+    public void myMethod() {
+
+    }
+}

src/test/one/Main.java

@@ -0,0 +1,13 @@
+package test.one;
+
+public class Main {
+    public static void main(String[] args) {
+        Object[] objects = {
+                new A(),
+                new B(),
+        };
+        for (Object object : objects) {
+            ((MyMethodInterface)object).myMethod();
+        }
+    }
+}

src/test/one/MyMethodInterface.java

@@ -0,0 +1,5 @@
+package test.one;
+
+public interface MyMethodInterface {
+    void myMethod();
+}