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