题解 | #空心正方形图案#

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