on line 29,
```cpp
if(siz[son[x]] < siz[to[i]]) son[i] = to[i];
```
改为
```cpp
if(siz[son[x]] < siz[to[i]]) son[x] = to[i];
```
by sansesantongshun @ 2024-01-19 13:21:20
@[sansesantongshun](/user/866613) thanks，wssb
by zhangxiao666 @ 2024-01-20 11:20:26