```cpp
void dfs(LL u,LL f){
d[u]=++d[f];
fa[u]=f;
siz[u]=1;
for(REG LL i=fir[u];i;i=las[i]){
if(t[i] == f)continue;
dfs(t[i],u);
siz[u]+=siz[t[i]];
if(siz[son[u]]<siz[t[i]])son[u]=t[i];
}
}
```
这一段里这个"d[u]=++d[f]"有点问题,应该改成d[u]=d[f]+1吧
by Sun_Email @ 2023-01-28 08:31:33