int main() { int n = 0; while (~scanf(" %d", &n)) { int i,j; for (i = 0; i <n; i++) { //行 for (j = 0; j < n; j++) { //列 if (j>0&&j<n-1&&i>0&&i<n-1) //确定空格范围 printf(" "); else printf("* "); } printf("\n"); } } return 0; }