@[清辉暮翊晨](/space/show?uid=142056) 最外面加个判断
```cpp
if(o<=m)
{
cout << 0 << endl ;
return 0 ;
}
```
by foxdemon @ 2019-06-02 18:37:53
@[清辉暮翊晨](/space/show?uid=142056)
[加上判断之后的记录](https://www.luogu.org/recordnew/show/19579669)
by foxdemon @ 2019-06-02 18:38:46
感谢大佬
by 清辉暮翊晨 @ 2019-06-03 21:07:49