题解 | 空心正方形图案

#include <stdio.h>
int main()
{
	int n = 0;
	char a[20][20];
	while (scanf("%d", &n)!= EOF)
	{
		
		for (int i = 0; i < n; i++)
		{
			for (int j = 0; j < n; j++)
			{
				if (i == 0 || i == n - 1 || j == 0 || j == n - 1)
					a[i][j] = '*';
				else
					a[i][j] = ' ';
			}
		}
		for (int i = 0; i < n; i++)
		{
			for (int j = 0; j < n; j++)
			{
				printf("%c ",a[i][j]);
			}
			printf("\n");
		}
	}
	return 0;
}