n = int(input().strip()) for i in range(n): row = [] for j in range(n): # 计算到四个边界的最小距离 distance_to_top = i distance_to_bottom = n - 1 - i distance_to_left = j distance_to_right = n - 1 - j # 取最小值并加1得到当前值 value = min(distance_to_top, distance_to_bottom, distance_to_left, distance_to_right) + 1 row.append(str(value)) # 输出当前行（空格分隔） print(" ".join(row))