题解 | #空心正方形图案#

#include <stdio.h>

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


}