05. Matrix shuffling

package MultidimensionalArrays_02;

import java.util.Scanner;

public class ShufflingMatrix_05 {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        String dimensions = scanner.nextLine(); //"3 4" -> split(" ") ->["3", "4"]
        int rows = Integer.parseInt(dimensions.split(" ")[0]);
        int cols = Integer.parseInt(dimensions.split(" ")[1]);

        String[][] matrix = new String[rows][cols];
        fillMatrix(matrix, scanner);

        String command = scanner.nextLine();
        while (!command.equals("END")) {
            //валидираме командата
            //невалидна
            if (!validateCommand(command, rows, cols)) {
                System.out.println("Invalid input!");
            }
            //валидна
            else {
                //"swap 0 0 1 1"
                String [] commandParts = command.split("\\s+");
                int row1 = Integer.parseInt(commandParts[1]);
                int col1 = Integer.parseInt(commandParts[2]);
                int row2 = Integer.parseInt(commandParts[3]);
                int col2 = Integer.parseInt(commandParts[4]);

                String firstElement = matrix[row1][col1];
                String secondElement = matrix[row2][col2];

                matrix[row1][col1] = secondElement;
                matrix[row2][col2] = firstElement;

                printMatrix(matrix, rows, cols);
            }


            command = scanner.nextLine();
        }
    }

    private static void printMatrix(String[][] matrix, int rows, int cols) {
        for (int row = 0; row < rows; row++) {
            for (int col = 0; col < cols; col++) {
                System.out.print(matrix[row][col] + " ");
            }
            System.out.println();
        }
    }

    private static void fillMatrix(String[][] matrix, Scanner scanner) {
        for (int row = 0; row < matrix.length; row++) {
            matrix[row] = scanner.nextLine().split("\\s+");
            //"1 2 3".split(" ") -> ["1", "2, "3"]
        }
    }

    private static boolean validateCommand(String command, int rows, int cols) {
        //true -> ако командата е валидна
        //false -> ако командата е невалидна
        //command = "swap row1 col1 row2 col2"
        String [] commandParts = command.split("\\s+");
        //"swap 1 2 3 4".split -> ["swap", "1", "2", "3", "4"]

        //1. определен брой части -> 5
        if (commandParts.length != 5) {
            return false;
        }

        //2. започва със swap
        if (!commandParts[0].equals("swap")) {
            return false;
        }

        //3. дали редовете и колоните са валидни
        int row1 = Integer.parseInt(commandParts[1]); // >= 0 && < бр. редовете
        int col1 = Integer.parseInt(commandParts[2]); // >= 0 && < бр. колони
        int row2 = Integer.parseInt(commandParts[3]); // >= 0 && < бр. редовете
        int col2 = Integer.parseInt(commandParts[4]); // >= 0 && < бр. колони

        if (row1 < 0 || row1 >= rows || row2 < 0 || row2 >= rows || col1 < 0 || col1 >= cols || col2 < 0 || col2 >= cols) {
            return false;
        }

        return true;


    }
}