用java打印螺旋矩阵

Question

我正在尝试使用接受整数的方法来打印螺旋矩阵。然而，我在纸上的代码工作正常，但是当我运行时，我得到不同的数字来代替我想要的数字。

public class ConstructSpiral{
    public static void main(String[] args) {

        constructSpiral(3);
    }

    public static int[][] constructSpiral(int n) {
        
        int[][] matrix = new  int[n][n];
        int sum = 0;
        int i = matrix.length - 1;
        int j = matrix[i].length - 1;
        
        for(j = matrix[i].length - 1; j >= 0; j--)
        {
            sum += sum + 1;
            matrix[i][j] = sum;
        }
        
        j = 0;
        for(i = (matrix.length - 1) - 1; i >= 0; i--) {
            sum += sum + 1;
            matrix[i][j] = sum;
        }

        i = 0;
        for(j = 1;  j < matrix.length; j++)
        {
            sum += sum + 1;
            matrix[i][j] = sum;
        }

        i = 1;
        for(j = 2; j <= i; j--){
            sum += sum + 1;
            matrix[i][j] = sum;
        }

        for(i = matrix.length - 1; i >= 0; i--) {
            for(j = matrix[i].length - 1; j >= 0; j--) 
            {
                System.out.print(matrix[i][j] + ", ");
            }
            System.out.println();
        }

        return matrix;

    }
}

实际上，它应该打印类似

5 6 7
4 9 8
3 2 1

In help 的内容，我们将不胜感激。

Answer 1

我认为您走在正确的轨道上，您可能只想多利用 constructSpiral 方法的 n 参数，并将打印逻辑移至不同的方法中：

import java.util.Scanner;

public class ConstructSpiral {

    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        System.out.print("Enter value of n: ");
        int n = scanner.nextInt();
        int[][] spiral = constructSpiral(n);
        printSquareMatrix(spiral, n);
    }

    public static int[][] constructSpiral(int n) {
        int[][] matrix = new int[n][n];
        int sum = 1;
        int r1 = 0, c1 = 0, r2 = n - 1, c2 = n - 1;
        int i = 0, j = 0;
        while (sum <= n * n) {
            for (j = c2; j >= c1; j--)
                matrix[r2][j] = sum++;
            r2--;
            for (i = r2; i >= r1; i--)
                matrix[i][c1] = sum++;
            c1++;
            for (j = c1; j <= c2; j++)
                matrix[r1][j] = sum++;
            r1++;
            for (i = r1; i <= r2; i++)
                matrix[i][c2] = sum++;
            c2--;
        }
        return matrix;
    }

    public static void printSquareMatrix(int[][] matrix, int n) {
        int padLength = String.valueOf(n * n).length() + 1;
        for (int i = 0; i < n; i++) {
            for (int j = 0; j < n; j++) {
                System.out.printf("%1$-" + padLength + "s", matrix[i][j]);
            }
            System.out.println();
        }
    }

}

用法示例 1：

Enter value of n: 3
5 6 7 
4 9 8 
3 2 1 

用法示例 2：

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

用法示例 3：

Enter value of n: 10
19  20  21  22  23  24  25  26  27  28  
18  51  52  53  54  55  56  57  58  29  
17  50  75  76  77  78  79  80  59  30  
16  49  74  91  92  93  94  81  60  31  
15  48  73  90  99  100 95  82  61  32  
14  47  72  89  98  97  96  83  62  33  
13  46  71  88  87  86  85  84  63  34  
12  45  70  69  68  67  66  65  64  35  
11  44  43  42  41  40  39  38  37  36  
10  9   8   7   6   5   4   3   2   1