Added a Kotlin variation.

.gitignore

@@ -1,2 +1,2 @@
-# Project exclude paths
-/out/
+Rust/lab_1/target
+Rust/lab_2/target

Java/lab_1/lab_1.java

@@ -0,0 +1,31 @@
+import java.util.Scanner;
+
+public class lab_1 {
+    
+    public static int protectedInput(String variableToRead, Scanner input) {
+        do {
+            try {
+                System.out.printf("Enter %s: ", variableToRead);
+                return input.nextInt();
+            } catch (Exception e) {
+                System.out.printf("%s must be an integer.\n", variableToRead.toUpperCase());
+                input.nextLine();
+            }
+        } while (true);
+    }
+
+    public static void main(String[] args) {
+        Scanner input = new Scanner(System.in);
+
+        final int n = protectedInput("n", input);
+        final int m = protectedInput("m", input);
+        final int a = protectedInput("a", input);
+        final int b = protectedInput("b", input);
+
+        input.close();
+
+        final float s = ((float) (b + m) / 2) * (m - b + 1) * (n - a + 1);
+
+        System.out.println("S = " + s);
+    }
+}

Java/lab_1/lab_1.kt

@@ -0,0 +1,21 @@
+fun protectedInput(variableName: String): Int {
+    do {
+        try {
+            print("Enter $variableName: ")
+            return readln().toInt()
+        } catch (e: Exception) {
+            println("${variableName.uppercase()} must be an integer!")
+        }
+    } while (true)
+}
+
+fun main() {
+    val n: Int = protectedInput("n")
+    val m: Int = protectedInput("m")
+    val a: Int = protectedInput("a")
+    val b: Int = protectedInput("b")
+
+    val s: Float = (b + m).toFloat() / 2 * (m - b + 1) * (n - a + 1)
+
+    println("S = $s")
+}

Java/lab_2/lab_2.java

@@ -0,0 +1,106 @@
+import java.util.Scanner;
+
+public class lab_2 {
+
+    public static short protectedInput(String inputPrompt, String errorMessage, Scanner input) {
+        short read_variable;
+
+        do {
+            try {
+                System.out.println();
+                System.out.print(inputPrompt);
+
+                read_variable = input.nextShort();
+                break;
+            } catch (Exception e) {
+                System.out.println(errorMessage);
+                input.nextLine();
+            }
+        } while (true);
+
+        return read_variable;
+    }
+
+    public static String format(int number) {
+        int width = String.valueOf(number).length() + 1;
+        String format = "|%" + width + "d ";
+
+        return format;
+    }
+
+    public static double average(short[] row) {
+        short sum = 0;
+
+        for (short element : row) {
+            sum += element;
+        }
+
+        double result = sum / row.length;
+
+        return result;
+    }
+
+    public static void main(String[] args) {
+        short a, rows = 0, columns = 0;
+        String format;
+
+        Scanner input = new Scanner(System.in);
+
+        a = protectedInput("Input a constant to multipy a matrix by: ",
+                "A constant must be a short-data type integer, try again.", input);
+
+        System.out.println();
+        System.out.println("Input size of the matrix.");
+
+        do {
+            rows = protectedInput("Rows: ",
+                    "A number of rows must be a short-data type integer, try again.", input);
+        } while (rows <= 0);
+
+        do {
+            columns = protectedInput("Columns: ",
+                    "A number of columns must be a short-data type integer, try again.", input);
+        } while (columns <= 0);
+
+        input.close();
+
+        short[][] matrix_B = new short[rows][columns];
+
+        System.out.println();
+        System.out.println("Matrix B:");
+
+        format = format(rows * columns);
+
+        for (short i = 0; i < rows; i++) {
+            for (short j = 0; j < columns; j++) {
+                matrix_B[i][j] = (short) ((i + 1) * (j + 1));
+
+                System.out.printf(format, matrix_B[i][j]);
+            }
+
+            System.out.println("|");
+        }
+
+        System.out.println();
+        System.out.println("Matrix a×B:");
+
+        format = format(rows * columns * a);
+
+        for (short i = 0; i < matrix_B.length; i++) {
+            for (short j = 0; j < matrix_B[i].length; j++) {
+                matrix_B[i][j] *= (short) (a);
+
+                System.out.printf(format, matrix_B[i][j]);
+            }
+
+            System.out.println("|");
+        }
+
+        System.out.println();
+        System.out.println("Averages of each row:");
+
+        for (short[] row : matrix_B) {
+            System.out.println(average(row));
+        }
+    }
+}

Java/lab_3/lab_3.java

@@ -0,0 +1,58 @@
+package OOP.Java.lab_3;
+
+public class lab_3 {
+    static int maxStrLength;
+    static String result;
+    
+    public static void cSubUtil(StringBuilder stringbuilder, int leftBoundary, int rightBoundary) {
+        String string = stringbuilder.toString().toLowerCase().replaceAll("[^a-z]","");
+        // check if the indices lie in the range of string
+        // and also if it is palindrome
+        while (leftBoundary >= 0 && rightBoundary < string.length() && string.toLowerCase().charAt(leftBoundary) == string.toLowerCase().charAt(rightBoundary)) {
+            // expand the boundary
+            leftBoundary--;
+            rightBoundary++;
+        }
+        // if it's length is greater than maxLength update
+        // maxLength and res
+        if (rightBoundary - leftBoundary - 1 >= maxStrLength) {
+            result = string.substring(leftBoundary + 1, rightBoundary);
+            maxStrLength = rightBoundary - leftBoundary - 1;
+        }
+        return;
+    }
+
+    public static int longestPalSubstr(StringBuilder string)
+    {
+        result = "";
+        maxStrLength = 1;
+        // for every index in the string check palindromes
+        // starting from that index
+        for (int i = 0; i < string.length(); i++) {
+            // check for odd length palindromes
+            cSubUtil(string, i, i);
+            // check for even length palindromes
+            cSubUtil(string, i, i + 1);
+        }
+        System.out.println("Longest palindrome substring is: " + compareStrings(string));
+        return compareStrings(string).length();
+    }
+
+    public static String compareStrings(StringBuilder builder) {
+        for (int leftBoundary = 0; leftBoundary <= builder.length(); leftBoundary++) {
+            for (int rightBoundary = builder.length(); leftBoundary >= 0; rightBoundary--) {
+                if (result.equals(builder.substring(leftBoundary, rightBoundary).toString().toLowerCase().replaceAll("[^a-z]",""))) {
+                    return builder.substring(leftBoundary, rightBoundary).toString();
+                }
+            }
+        }
+        return "";
+    }
+
+    public static void main(String[] args) {
+        StringBuilder stringToDetect = new StringBuilder("Eva, can I see bees in a cave?");
+
+        System.out.println("Initial string: " + stringToDetect.toString());
+        System.out.println("Length is: " + longestPalSubstr(stringToDetect));
+    }
+}

Rust/lab_1/Cargo.lock

@@ -0,0 +1,16 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 3
+
+[[package]]
+name = "lab_1"
+version = "0.1.0"
+dependencies = [
+ "text_io",
+]
+
+[[package]]
+name = "text_io"
+version = "0.1.12"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d5f0c8eb2ad70c12a6a69508f499b3051c924f4b1cfeae85bfad96e6bc5bba46"

Rust/lab_1/Cargo.toml

@@ -0,0 +1,16 @@
+[package]
+name = "lab_1"
+version = "0.1.0"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[profile.release]
+opt-level = 'z'     # Optimize for size
+lto = true          # Enable link-time optimization
+codegen-units = 1   # Reduce number of codegen units to increase optimizations
+panic = 'abort'     # Abort on panic
+strip = true        # Strip symbols from binary*
+
+[dependencies]
+text_io = "0.1.12"

Rust/lab_1/src/main.rs

@@ -0,0 +1,22 @@
+fn protected_read(variable_name: &str) -> i32 {
+    use text_io::try_read;
+    loop {
+        print!("Enter {}: ", variable_name);
+        let read_result: Result<i32, _> = try_read!();
+        match read_result {
+            Ok(read_integer) => return read_integer,
+            Err(_e) => println!("{} must be an integer!", variable_name.to_uppercase()),
+        }
+    }
+}
+
+fn main() {
+    let n: i32 = protected_read("n");
+    let m: i32 = protected_read("m");
+    let a: i32 = protected_read("a");
+    let b: i32 = protected_read("b");
+
+    let s: f32 = ((b + m) as f32 / 2f32) * ((m - b + 1) * (n - a + 1)) as f32;
+
+    println!("S = {}", s);
+}

Rust/lab_2/Cargo.lock

@@ -0,0 +1,7 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 3
+
+[[package]]
+name = "lab_2"
+version = "0.1.0"

Rust/lab_2/Cargo.toml

@@ -0,0 +1,8 @@
+[package]
+name = "lab_2"
+version = "0.1.0"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]

Rust/lab_2/src/main.rs

@@ -0,0 +1,3 @@
+fn main() {
+    println!("Hello, world!");
+}