用Java实现螺旋方阵

螺旋方阵：是指呈螺旋状的矩阵。

具体实现如下：

public void screwMatrix() {

        System.out.print("请输入数字：");

        Scanner input = new Scanner(System.in);

        int number = input.nextInt();

        int[][] matrix = new int[number][number];

        int max = number * number;

        int row = 0, col = 0;

        int direction = 0;

        for (int j = 1; j <= max; j++) {

            matrix[row][col] = j;

            switch (direction) {

                case 0 :

                    if (col + 1 >= number || matrix[row][col + 1] > 0) {

                        direction += 1;

                        direction %= 4;

                        row += 1;

                    } else {

                        col = col + 1;

                    }

                    break;

                case 1 :

                    if (row + 1 >= number || matrix[row + 1][col] > 0) {

                        direction += 1;

                        direction %= 4;

                        col -= 1;

                    } else {

                        row = row + 1;

                    }

                    break;

                case 2 :

                    if (col - 1 < 0 || matrix[row][col - 1] > 0) {

                        direction += 1;

                        direction %= 4;

                        row = row - 1;

                    } else {

                        col = col - 1;

                    }

                    break;

                case 3 :

                    if (row - 1 < 0 || matrix[row - 1][col] > 0) {

                        direction += 1;

                        direction %= 4;

                        col += 1;

                    } else {

                        row = row - 1;

                    }

                    break;

                default :

                    System.out.println("ERROR");

                    System.exit(0);

            }

        }

        for (int j = 0; j < number; j++) {

            for (int k = 0; k < number; k++) {

                // 判断输出最大数的长度

                int size = ((number * number) + "").length();

                for (int i = 0; i <= (size - (matrix[j][k] + "").length() + 1); i++) {

                    System.out.print(" ");

                }

                System.out.print(matrix[j][k]);

            }

            System.out.println("");

        }

    }