编辑代码

import java.util.Scanner;
public class Example1
{
    public static void main(String args[])
    {
        System.out.println("请输入中心数");
        Scanner reader=new Scanner(System.in);
        int n=reader.nextInt();
        int [][]a=new int[2*n][2*n];
        int layer;
        for(layer=1;layer<=n;layer++)
        {
            for(int j=layer;j<=n;j++)
            {
                int i=layer;
                a[i][j]=layer;
            }
            for(int i=layer;i<=n;i++)
            {
                int j=layer;
                a[i][j]=layer;
            }
        }
        for(layer=1;layer<n;layer++)
        {
            for(int i=1;i<=n;i++)
            a[i][2*n-layer]=a[i][layer];
        }
        for(layer=1;layer<n;layer++)
        {
            for(int j=1;j<=2*n-1;j++)
              a[2*n-layer][j]=a[layer][j];
        }
        for(int i=1;i<=2*n-1;i++)
        {
            for(int j=1;j<2*n-1;j++)
            {
                System.out.print(a[i][j]+"");
            }

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