Question

我应该创建一个矩阵并将其拆分为3个方法，其中第一个将读取矩阵，第二个将打印矩阵，第三个将交换对角线。读取矩阵有效但我试图将参数传递给其他方法，因此它们也可以工作，但是当我在主类中调用它们时，它不起作用。

    public static void readMatrix() {

    Random rand = new Random();
    Scanner in = new Scanner(System.in);
    System.out.println("Please insert how many rows and columns you want for matrix");
    int ColumnsAndRows = in.nextInt();

    int matrix[][] = new int[ColumnsAndRows][ColumnsAndRows];

    for (int row = 0; row < matrix.length; row++) {
        for (int column = 0; column < matrix[row].length; column++) {
            matrix[row][column] = rand.nextInt(ColumnsAndRows * ColumnsAndRows) + 1;

        }
    }

}

public int[][] printMatrix(int matrix[][]) {

    for (int row = 0; row < matrix.length; row++) {
        for (int column = 0; column < matrix[row].length; column++) {
            System.out.print(matrix[row][column] + " ");

        }
        System.out.println("");
    }
    return matrix;
}

public int[][] swapDiagonals(int ColumnsAndRows, int matrix[][]) {
    for (int i = 0; i < ColumnsAndRows; i++) {
    int temp = matrix[i][i];
    matrix[i][i] = matrix[i][ColumnsAndRows - i - 1];
    matrix[i][ColumnsAndRows - i - 1] = temp;
    }
    printMatrix(matrix);
    return matrix;

Answer 1

您可以使用int[][]存储从readMatrix返回的矩阵。
让printMatrix和swapDiagonals返回int[][]是多余的。
您可以让printMatrix和swapDiagonals成为静态，因此您可以使用main方法调用它们。

以下是一个示例：

public class Matrix {

    public static int[][] readMatrix() {

        Random rand = new Random();
        Scanner in = new Scanner(System.in);
        System.out.println("Please insert how many rows and columns you want for matrix");
        int ColumnsAndRows = in.nextInt();

        int matrix[][] = new int[ColumnsAndRows][ColumnsAndRows];

        for (int row = 0; row < matrix.length; row++) {
            for (int column = 0; column < matrix[row].length; column++) {
                matrix[row][column] = rand.nextInt(ColumnsAndRows * ColumnsAndRows) + 1;
            }
        }

        return matrix;
    }

    public static void printMatrix(int matrix[][]) {
        for (int row = 0; row < matrix.length; row++) {
            for (int column = 0; column < matrix[row].length; column++) {
                System.out.print(matrix[row][column] + " ");
            }
            System.out.println("");
        }
    }

    public static void swapDiagonals(int matrix[][]) {
        int ColumnsAndRows = matrix.length;
        for (int i = 0; i < ColumnsAndRows; i++) {
            int temp = matrix[i][i];
            matrix[i][i] = matrix[i][ColumnsAndRows - i - 1];
            matrix[i][ColumnsAndRows - i - 1] = temp;
        }
        printMatrix(matrix);
    }

    public static void main(String[] args) {
        int[][] matrix = readMatrix();
        printMatrix(matrix);
        System.out.println("swapDiagonals:");
        swapDiagonals(matrix);
    }
}

结果：

Please insert how many rows and columns you want for matrix
4
12 10 14 5 
14 8 9 13 
2 15 5 16 
11 9 8 10 
swapDiagonals:
5 10 14 12 
14 9 8 13 
2 5 15 16 
10 9 8 11

矩阵和交换对角线的单独方法

1 个答案: