打印回形数组

题目：输入一个整数N，打印出从1~N*N的N*N矩阵。 

比如N = 3，构成矩阵： 

1,2,3,

8,9,4,

7,6,5,

比如N = 4，构成矩阵： 

 1, 2, 3, 4,

12,13,14, 5,

11,16,15, 6,

10, 9, 8, 7,

public enum DirectionEnum{
    RIGHT(1,"向右"),
    DOWN(2,"向下"),
    LEFT(3,"向左"),
    UP(0,"向上");

    public int getCode() {
        return code;
    }

    public void setCode(int code) {
        this.code = code;
    }

    public String getDescription() {
        return description;
    }

    public void setDescription(String description) {
        this.description = description;
    }

    DirectionEnum(int code, String description) {
        this.code = code;
        this.description = description;
    }

    private int code;

    private String description;

    public static DirectionEnum getDirectionByCode(int code){
        for (DirectionEnum directionEnum : DirectionEnum.values()) {
            if (directionEnum.getCode() == code) {
                return directionEnum;
            }
        }
        return null;
    }
}
           

public class TestBackFormArray {

    public static void main(String args[]) {
        TestBackFormArray test = new TestBackFormArray();
        test.dotest();
    }


    public void dotest() {
        int n = 5;
        int maxNumLength = String.valueOf(n * n).length();
        int[][] result = algorithm(n);
        //格式化打印输出
        for (int i = 0; i < result.length; i++) {
            for (int j = 0; j < result[i].length; j++) {
                System.out.print(String.format("%" + maxNumLength + "d", result[i][j]) + ",");
            }
            System.out.println();
        }
    }


    private int[][] algorithm(int n) {
        int length = n * n;
        int[][] result = new int[n][n];
        int direction = 1;
        int i = 0, j = 0;
        for (int k = 1; k <= length; k++) {
            result[i][j] = k;
            DirectionEnum directionEnum = DirectionEnum.getDirectionByCode(direction % 4);
            switch (directionEnum) {
                case RIGHT: {
                    if (j == n - 1 || result[i][j + 1] != 0) {
                        i++;
                        direction++;//改变方向
                    } else {
                        j++;
                    }
                }
                break;
                case DOWN: {
                    if (i == n - 1 || result[i + 1][j] != 0) {
                        j--;
                        direction++;//改变方向
                    } else {
                        i++;
                    }
                }
                break;
                case LEFT: {
                    if (j == 0 || result[i][j - 1] != 0) {
                        i--;
                        direction++;//改变方向
                    } else {
                        j--;
                    }
                }
                break;
                case UP: {
                    if (i == 0 || result[i - 1][j] != 0) {
                        j++;
                        direction++;//改变方向
                    } else {
                        i--;
                    }
                }
                break;
                default:
            }
        }
        return result;
    }

}
           

结果：

1, 2, 3, 4, 5,
16,17,18,19, 6,
15,24,25,20, 7,
14,23,22,21, 8,
13,12,11,10, 9,