用java打印螺旋矩阵

Question

我想用一个整数的方法打印一个螺旋矩阵。然而，我在纸上的代码运行得很好，但是当我运行时，我会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;

    }
}

在现实中，它应该打印如下内容

5 6 7
4 9 8
3 2 1

如果您能帮忙，我们将不胜感激。

Answer 1

我认为你是在正确的轨道上，你可能只是想利用构造Spiral方法的n参数多一点，以及将打印逻辑移动到不同的方法中：

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 r1 = 0, c1 = 0, r2 = n - 1, c2 = n - 1, sum = 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 

示例用法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 

示例用法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