Better late than never))

lesson_10/fuad.aliyev/src/HW10_task_with_recursion.java

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+//1) Напишите программу, которая выводит n-ый член последовательности Фибоначчи:
+//Последовательность Фибоначчи - первые 2 элемента равны 1, каждый следующий равен сумме двух предыдущих:
+//1 1 2 3 5 8 13 21 34 55 ...
+//Также определите сложность вашего решения
+//Задачу нужно решить с рекурсией и без ее использования
+
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStreamReader;
+
+public class HW10_task_with_recursion {
+
+    public static void main(String[] args) throws IOException {
+        BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(System.in));
+        int n = Integer.parseInt(bufferedReader.readLine());
+        showNthElementOfSequence(n, 1,0,1);
+    }
+
+    private static void showNthElementOfSequence(int n, int previousNumber, int beforePreviousNumber, int nthNumber) {
+        if(n > 1) {
+            nthNumber = previousNumber + beforePreviousNumber;
+            beforePreviousNumber = previousNumber;
+            previousNumber = nthNumber;
+            n--;
+            showNthElementOfSequence(n, previousNumber, beforePreviousNumber, nthNumber);
+        }
+        else
+            System.out.println(nthNumber);
+    }
+}

lesson_10/fuad.aliyev/src/HW10_task_without_recursion.java

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+//1) Напишите программу, которая выводит n-ый член последовательности Фибоначчи:
+//Последовательность Фибоначчи - первые 2 элемента равны 1, каждый следующий равен сумме двух предыдущих:
+//1 1 2 3 5 8 13 21 34 55 ...
+//Также определите сложность вашего решения
+//Задачу нужно решить с рекурсией и без ее использования
+
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStreamReader;
+
+public class HW10_task_without_recursion {
+
+    public static void main(String[] args) throws IOException {
+        BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(System.in));
+        int n = Integer.parseInt(bufferedReader.readLine());
+        System.out.println(showNthElementOfSequence(n));
+    }
+
+    private static int showNthElementOfSequence(int n) {
+        int previousElement = 1;
+        int beforePreviousElement = 0;
+        int nthElement = 1;
+        for(int i = 0; i < n - 1; i++) {
+            nthElement = previousElement + beforePreviousElement;
+            beforePreviousElement = previousElement;
+            previousElement = nthElement;
+        }
+        return nthElement;
+    }
+
+}

lesson_3/fuad.aliyev/src/MathCalc.java

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+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStreamReader;
+
+public class MathCalc {
+
+    public static void main(String[] args) throws IOException {
+        BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(System.in));
+        System.out.println("Input first operand:");
+        int firstOperand = Integer.parseInt(bufferedReader.readLine());
+        System.out.println("Input operation:");
+        String operation = bufferedReader.readLine();
+        System.out.println("Input second operand:");
+        int secondOperand = Integer.parseInt(bufferedReader.readLine());
+        System.out.print("Result: ");
+        if(operation.equals("+")) System.out.println(add(firstOperand, secondOperand));
+        else if(operation.equals("-")) System.out.println(subtract(firstOperand, secondOperand));
+        else if(operation.equals("*")) System.out.println(multiply(firstOperand, secondOperand));
+        else if(operation.equals("/")) System.out.println(divide(firstOperand,secondOperand));
+        else if(operation.equals("%")) System.out.println(modulo(firstOperand,secondOperand));
+        else if(operation.equals("abs")) {
+            System.out.print(absoluteValue(firstOperand) + " ");
+            System.out.println(absoluteValue(secondOperand));
+        }
+        else System.out.println("Our calc doesn't support this arithmetical operation");
+    }
+
+    private static int add(int firstOperand, int secondOperand) {
+        return firstOperand + secondOperand;
+    }
+
+    private static int subtract(int firstOperand, int secondOperand) {
+        return firstOperand - secondOperand;
+    }
+
+    private static int multiply(int firstOperand, int secondOperand) {
+        return firstOperand * secondOperand;
+    }
+
+    private static double divide(int firstOperand, int secondOperand) {
+        return firstOperand / secondOperand;
+    }
+
+    private static int modulo(int firstOperand, int secondOperand) {
+        return firstOperand % secondOperand;
+    }
+
+    private static int absoluteValue(int operand) {
+        return Math.abs(operand);
+    }
+}

lesson_3/fuad.aliyev/src/TipsCalc.java

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+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStreamReader;
+
+public class TipsCalc {
+
+    public static void main(String[] args) throws IOException {
+        BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(System.in));
+        System.out.println("Enter the sum:");
+        int sum = Integer.parseInt(bufferedReader.readLine());
+        System.out.println("Choose the service quality from the list: \n 1)terrible \n 2)poor \n 3)good \n 4)great \n 5)excellent ");
+        String serviceQuality = bufferedReader.readLine();
+        if(serviceQuality.equals("terrible") || serviceQuality.equals("1"))
+            System.out.println("Recommended tip: 0");
+        if(serviceQuality.equals("poor") || serviceQuality.equals("2"))
+            System.out.println("Recommended tip: " + 0.05 * sum);
+        if(serviceQuality.equals("good") || serviceQuality.equals("3"))
+            System.out.println("Recommended tip: " + 0.1 * sum);
+        if(serviceQuality.equals("great") || serviceQuality.equals("4"))
+            System.out.println("Recommended tip: " + 0.15 * sum);
+        if(serviceQuality.equals("excellent") || serviceQuality.equals("5"))
+            System.out.println("Recommended: tip " + 0.2 * sum);
+    }
+}

lesson_4/fuad.aliyev/src/HW4_eighth_task.java

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+//8) Найти все счастливые билеты от 100000 до 999999 :
+//билет счастливый если сумма первых трех цифр равна сумме трех последних
+
+public class HW4_eighth_task {
+
+    public static void main(String[] args) {
+        for(int i = 100000; i < 1000000; i++)
+            if(sumOfFirstThreeNumbers(i) == sumOfLastThreeNumbers(i))
+                System.out.println(i);
+    }
+
+    private static int sumOfFirstThreeNumbers(int number) {
+        number = number / 1000;
+        int sum = 0;
+        while(number != 0) {
+            sum = sum + (number % 10);
+            number /= 10;
+        }
+        return sum;
+    }
+
+    private static int sumOfLastThreeNumbers(int number) {
+        int sum = 0;
+        while(number > 1000) {
+            sum = sum + (number % 10);
+            number /= 10;
+        }
+        return sum;
+    }
+}

lesson_4/fuad.aliyev/src/HW4_eleventh_task.java

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+//11) Write  a program to repeatedly add all the digits until the result has only one digit of a given non-negative number:
+//The digital root of 555555 = 5 + 5 + 5 + 5 + 5 + 5 = 30 = 3 + 0 = 3
+
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStreamReader;
+
+public class Main {
+
+    public static void main(String[] args) throws IOException {
+        BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(System.in));
+        System.out.println("Enter number:");
+        int number = Integer.parseInt(bufferedReader.readLine());
+        convert(number);
+    }
+
+    private static void convert(int number) {
+        int sum = 0;
+        if(number > 9)
+            while(number != 0) {
+                sum += (number % 10);
+                number /= 10;
+                if(number == 0) {
+                    System.out.println(sum);
+                    convert(sum);
+                }
+            }
+    }
+}

lesson_4/fuad.aliyev/src/HW4_fifth_task.java

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+//5) Найти сумму первых n элементов массива
+
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStreamReader;
+
+public class HW4_fifth_task {
+
+    public static void main(String[] args) throws IOException {
+        int [] array = new int[10];
+        BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(System.in));
+        System.out.println("Enter n:");
+        int n = Integer.parseInt(bufferedReader.readLine());
+        if(n < array.length) {
+            System.out.println("Enter array of numbers:");
+            for(int i = 0; i < array.length; i++)
+                array[i] = Integer.parseInt(bufferedReader.readLine());
+            System.out.println(addNElementsOfArray(n, array));
+        }
+        else
+            System.out.println("Can't be done, because array is shorter than n");
+    }
+
+    private static int addNElementsOfArray(int n, int[] array) {
+        int sum = 0;
+        for(int i = 0; i < n; i++) {
+            sum += array[i];
+        }
+        return sum;
+    }
+}

lesson_4/fuad.aliyev/src/HW4_first_task.java

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+//1) Создайте программу, выводящую на экран все четырёхзначные числа последовательности 1000 1003 1006 1009 1012 1015 …
+
+public class HW4_first_task {
+
+    public static void main(String[] args) {
+        for(int i = 1000; i < 10000; i += 3)
+            System.out.println(i);
+    }
+}

lesson_4/fuad.aliyev/src/HW4_fourth_task.java

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+//4) Создайте программу, выводящую на экран первые 20 элементов последовательности 2 4 8 16 32 64 128 ….
+
+public class HW4_fourth_task {
+
+    public static void main(String[] args) {
+        int number = 2;
+        for(int i = 0; i < 20 ; i++) {
+            System.out.println(number);
+            number *= 2;
+        }
+    }
+}

lesson_4/fuad.aliyev/src/HW4_ninth_task.java

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+//9) Перевести число в двоичную систему счисления
+
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStreamReader;
+
+public class HW4_ninth_task {
+
+    public static void main(String[] args) throws IOException {
+        BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(System.in));
+        System.out.println("Enter decimal number:");
+        int number = Integer.parseInt(bufferedReader.readLine());
+        System.out.println("Number in binary format:");
+        System.out.println(convertDecimalToBinary(number));
+    }
+
+    private static int convertDecimalToBinary(int decimalNumber) {
+        String reversedBinaryNumber = "";
+        while(decimalNumber != 0) {
+            Integer buf = decimalNumber % 2;
+            reversedBinaryNumber += Integer.toString(buf);
+            decimalNumber /= 2;
+        }
+        int binaryNumber = Integer.parseInt(reverseString(reversedBinaryNumber));
+        return binaryNumber;
+    }
+
+    private static String reverseString(String string) {
+        String reversedString = "";
+        for(int i = string.length() - 1; i >= 0; i--) {
+            reversedString += string.charAt(i);
+        }
+        return reversedString;
+    }
+}

lesson_4/fuad.aliyev/src/HW4_second_task.java

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+//2) Создайте программу, выводящую на экран первые 55 элементов последовательности 1 3 5 7 9 11 13 15 17 …
+
+public class HW4_second_task {
+
+    public static void main(String[] args) {
+        int number = 1;
+        for(int i = 0; i < 55 ; i++) {
+            System.out.println(number);
+            number += 2;
+        }
+    }
+}

lesson_4/fuad.aliyev/src/HW4_seventh_task.java

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+//7) Найти сумму всех четных и сумму всех нечетных элементов массива
+
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStreamReader;
+
+public class HW4_seventh_task {
+
+    public static void main(String[] args) throws IOException {
+        BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(System.in));
+        int array[] = new int[5];
+        System.out.println("Enter array:");
+        for(int i = 0; i < array.length; i++)
+            array[i] = Integer.parseInt(bufferedReader.readLine());
+        System.out.println("Sum of odd numbers: " + sumOfOddNumbersInArray(array));
+        System.out.println("Sum of even numbers: " + sumOfEvenNumbersInArray(array));
+    }
+
+    private static int sumOfOddNumbersInArray(int array[]) {
+        int sum = 0;
+        for(int i = 0; i < array.length; i++)
+            if(array[i] % 2 != 0)
+                sum += array[i];
+        return sum;
+    }
+
+    private static int sumOfEvenNumbersInArray(int array[]) {
+        int sum = 0;
+        for(int i = 0; i < array.length ; i++)
+            if(array[i] % 2 == 0)
+             sum += array[i];
+        return sum;
+    }
+}

lesson_4/fuad.aliyev/src/HW4_sixth_task.java

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+//6) Найти минимальный и максимальный элемент массива
+
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStreamReader;
+
+public class HW4_sixth_task {
+
+    public static void main(String[] args) throws IOException {
+        BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(System.in));
+        System.out.println("Enter array:");
+        int array[] = new int[5];
+        for(int i = 0; i < array.length; i++)
+            array[i] = Integer.parseInt(bufferedReader.readLine());
+        System.out.println("Max number is " + maxNumberOfArray(array));
+        System.out.println("Min number is " + minNumberOfArray(array));
+    }
+
+    private static int maxNumberOfArray(int array[]) {
+        int max = array[0];
+        for(int i = 0; i < array.length; i++)
+            if(array[i] >= max)
+                max = array[i];
+        return max;
+    }
+
+    private static int minNumberOfArray(int array[]) {
+        int min = array[0];
+        for(int i = 0; i < array.length; i++)
+            if(array[i] <= min)
+                min = array[i];
+        return min;
+    }
+}