开头来一行
```cpp
#pragma GCC optimize(“Ofast”)
```
~~洛谷大概不能用?~~
by ywr8 @ 2021-10-16 18:31:21
@[ywr8](/user/70573) 以前能用,但是现在不能了(会CE)
by Z_301 @ 2021-10-16 18:41:32
好的
by xfzf_shentao @ 2021-10-16 18:51:41