All sorts of corrections.

.gitignore

@@ -0,0 +1,3 @@
+Java/Lab 1/Lab_1.class
+.gitignore
+Java/Lab 2/Lab_2.class

Java/Lab 1/Lab_1.java

@@ -1,63 +1,38 @@
 import java.util.Scanner;
 
 public class Lab_1 {
+
+    public static int protectedInput(String variable_to_read, Scanner input) {
+        int read_variable;
+        do {
+            try {
+                System.out.printf("Enter %s: ", variable_to_read);
+                read_variable = input.nextInt();
+                break;
+            } catch (Exception e) {
+                System.out.printf("%s must be an integer.\n", variable_to_read.toUpperCase());
+                input.nextLine();
+            }
+        } while (true);
+        return read_variable;
+    }
+
     public static void main(String[] args) {
         int n, m, a, b;
-        float s = 0;
 
         Scanner input = new Scanner(System.in);
-        
-        do {
-            try {
-                System.out.print("Enter n: ");
-                n = input.nextInt();
-                break;
-            } catch (Exception e) {
-                System.out.println("N must be an integer.");
-                input.nextLine();
-            }
-        } while (true);
 
-        do {
+        n = protectedInput("n", input);
-            try {
-                System.out.print("Enter m: ");
-                m = input.nextInt();
-                break;
-            } catch (Exception e) {
-                System.out.println("M must be an integer.");
-                input.nextLine();
-            }
-        } while (true);
 
-        do {
+        m = protectedInput("m", input);
-            try {
-                System.out.print("Enter a: ");
-                a = input.nextInt();
-                break;
-            } catch (Exception e) {
-                System.out.println("A must be an integer.");
-                input.nextLine();
-            }
-        } while (true);
 
-        do {
+        a = protectedInput("a", input);
-            try {
+
-                System.out.print("Enter b: ");
+        b = protectedInput("b", input);
-                b = input.nextInt();
-                break;
-            } catch (Exception e) {
-                System.out.println("B must be an integer.");
-                input.nextLine();
-            }
-        } while (true);
 
         input.close();
 
-        for (int i = a; i <= n; i++) {
+        float s = ((float)(b + m) / 2) * (m - b + 1) * (n - a + 1);
-            for (int j = b; j <= m; j++) {
-                s += j;
-            }
-        }
 
         System.out.println("S = " + s);
     }

Java/Lab 2/Lab_2.java

@@ -2,6 +2,25 @@ 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 ";
@@ -27,41 +46,20 @@ public class Lab_2 {
         
         Scanner input = new Scanner(System.in);
 
-        do {
+        a = protectedInput("Input a constant to multipy a matrix by: ", "A constant must be a short-data type integer, try again.", input);
-            try {
+        
-                System.out.println();
-                System.out.print("Input a constant to multipy a matrix by: ");
-
-                a = input.nextShort();
-                break;
-            } catch (Exception e) {
-                System.out.println("A constant must be a short-data type integer, try again.");
-                input.nextLine();
-            }
-        } while (true);
-
         System.out.println();
         System.out.println("Input size of the matrix.");
 
         do {
-            try {
+            rows = protectedInput("Rows: ", "A number of rows must be a short-data type integer, try again.", input);
-                System.out.print("Rows: ");
-                rows = input.nextShort();
-            } catch (Exception e) {
-                System.out.println("A number of rows must be a short-data type integer, try again.");
-                input.nextLine();
-            }
         } while (rows <= 0);
-
+        
         do {
-            try {
+            columns = protectedInput("Columns: ", "A number of columns must be a short-data type integer, try again.", input);
-                System.out.print("Columns: ");
-                columns = input.nextShort();
-            } catch (Exception e) {
-                System.out.println("A number of columns must be a short-data type integer, try again.");
-                input.nextLine();
-            }
         } while (columns <= 0);
+        
+        input.close();
 
         short[][] matrix_B = new short[rows][columns];
 
@@ -85,8 +83,8 @@ public class Lab_2 {
 
         format = format(rows * columns * a);
 
-        for (short i = 0; i < rows; i++) {
+        for (short i = 0; i < matrix_B.length; i++) {
-            for (short j = 0; j < columns; j++) {
+            for (short j = 0; j < matrix_B[i].length; j++) {
                 matrix_B[i][j] *= (short) (a);
 
                 System.out.printf(format, matrix_B[i][j]);
@@ -101,7 +99,5 @@ public class Lab_2 {
         for (short[] row : matrix_B) {
             System.out.println(average(row));
         }
-
-        input.close();
     }
 }

Rust/Lab 2/Lab_2.rs

@@ -0,0 +1,3 @@
+fn main() {
+    
+}