Java_Exceptions

import java.util.InputMismatchException;
import java.util.Scanner;
public class Java_Exceptions {
    public static void  main(String[] args){
        //  TODO: example_1
        Scanner scanner = new Scanner(System.in);
        try {
            System.out.print("Enter the first number: ");
            double number1 = scanner.nextDouble();
            System.out.print("Enter the second number: ");
            double number2 = scanner.nextDouble();
            div(number1, number2);
            mul(number1, number2);
        } catch (InputMismatchException e) {
            System.err.println("Error: " + e.getMessage());
        } finally {
            scanner.close();
        }
        //  TODO: example_2
        try {
            int[][] matrix = {{1, 2, 3}, {4, 5, 6}, {7, 8, 9}};
            System.out.println("Original Matrix:");
            displayMatrix(matrix);
            transposeInPlace(matrix);
            System.out.println("In-Place Transposed Matrix:");
            displayMatrix(matrix);
        } catch (IllegalArgumentException e) {
            System.err.println("Error: " + e.getMessage());
        }
        //  TODO: example_3
        try {
            char[] characters = {'a', 'b', 'c', 'd', 'e'};
            reverseArray(characters);
            System.out.println("Reversed Array:");
            for (char ch : characters) {
                System.out.print(ch + " ");
            }
        } catch (IllegalArgumentException e) {
            System.err.println("Error: " + e.getMessage());
        }
        //  TODO: example_4
        try {
            printPattern("triangle", 5);
            printPattern("inverted_triangle", 5);
            printPattern("pyramid", 5);
            // Uncomment the line below to test an invalid pattern type
            // printPattern("invalid_pattern", 5);
        } catch (IllegalArgumentException e) {
            System.err.println("IllegalArgumentException: " + e.getMessage());
        }
    }// end of main method

    //  TODO: example_1
    public static void div(double number1, double number2) {
        try {
            double result = number1 / number2;
            System.out.println("Result of division: " + result);
        } catch (ArithmeticException e) {
            System.err.println("Error during division: " + e.getMessage());
        }
    }
    public static void mul(double number1, double number2) {
        try {
            double result = number1 * number2;
            System.out.println("Result of multiplication: " + result);
        } catch (Exception e) {
            System.err.println("Error during multiplication: " + e.getMessage());
        }
    }
    //  TODO: example_2
    //  Transposing a 2D Array Without Creating a New Array using method
    public static void transposeInPlace(int[][] matrix) {
        if (matrix == null || matrix.length == 0 || matrix[0].length == 0) {
            throw new IllegalArgumentException("Matrix must be non-null and non-empty.");
        }
        for (int i = 0; i < matrix.length; i++) {
            for (int j = i + 1; j < matrix[i].length; j++) {
                int temp = matrix[i][j];
                matrix[i][j] = matrix[j][i];
                matrix[j][i] = temp;
            }
        }
    }
    public static void displayMatrix(int[][] matrix) {
        for (int i = 0; i < matrix.length; i++) {
            for (int j = 0; j < matrix[i].length; j++) {
                System.out.print(matrix[i][j] + " ");
            }
            System.out.println();
        }
    }
    //  TODO: example_3
    //  Reversing an Array
    public static void reverseArray(char[] array) {
        if (array == null || array.length == 0) {
            throw new IllegalArgumentException("Array must be non-null and non-empty.");
        }
        int start = 0;
        int end = array.length - 1;
        while (start < end) {
            // Swap elements at start and end indices
            char temp = array[start];
            array[start] = array[end];
            array[end] = temp;
            // Move indices towards the center
            start++;
            end--;
        }
    }
    //  TODO: example_4
    //  print patterns
    private static void printPattern(String patternType, int size) {
        if (size <= 0) {
            throw new IllegalArgumentException("Size must be a positive integer.");
        }
        switch (patternType.toLowerCase()) {
            case "triangle":
                printRightAngledTriangle(size);
                break;
            case "inverted_triangle":
                printInvertedRightAngledTriangle(size);
                break;
            case "pyramid":
                printPyramid(size);
                break;
            default:
                throw new IllegalArgumentException("Invalid pattern type: " + patternType);
        }
    }
    private static void printRightAngledTriangle(int size) {
        for (int i = 1; i <= size; i++) {
            for (int j = 1; j <= i; j++) {
                System.out.print("* ");
            }
            System.out.println();
        }
        System.out.println();
    }
    private static void printInvertedRightAngledTriangle(int size) {
        for (int i = size; i >= 1; i--) {
            for (int j = 1; j <= i; j++) {
                System.out.print("* ");
            }
            System.out.println();
        }
        System.out.println();
    }
    private static void printPyramid(int size) {
        for (int i = 1; i <= size; i++) {
            for (int j = 1; j <= size - i; j++) {
                System.out.print("  ");
            }
            for (int k = 1; k <= 2 * i - 1; k++) {
                System.out.print("* ");
            }
            System.out.println();
        }
        System.out.println();
    }
}