怎么用c语言输出一个空心正方形

#include <stdio.h>

int main() {int side;printf(“请输入正方形的边长：”);scanf(“%d”, &side);

for (int i = 1; i <= side; i++) {    for (int j = 1; j <= side; j++) {        if (i == 1 || i == side || j == 1 || j == side) {            printf("*");        } else {            printf(" ");        }    }    printf("\n");}return 0;

}